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Design for the Environment Printed Wiring Board Project

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1 Design for the Environment Printed Wiring Board Project
Presentation of the Surface Finishes Cleaner Technologies Substitutes Assessment (CTSA) Results Presented in coordination with the Chicagoland Circuit Association Elk Grove, IL November 29, 2000

2 Acknowledgments This seminar presents the results of the Surface Finishes Cleaner Technologies Substitutes Assessment (CTSA), written by Jack Geibig, Mary Swanson, and Rupy Sawhney of the University of Tennessee’s Center for Clean Products and Clean Technologies. Valuable contributions to the project were provided by the project’s Core Group members not already mentioned above, including: Kathy Hart, EPA Project Lead and Core Group Co-Chair; Holly Evans and Christopher Rhodes, formerly of IPC-Association Connecting Electronics Industries, Core Group Co-Chairs; Dipti Singh, EPA Technical Lead and Technical Workgroup Co-Chair; John Sharp, Teradyne Inc., Technical Workgroup Co-Chair; Michael Kerr, BHE Environmental Inc., Communication Workgroup Co-Chair; Gary Roper, Substrate Technologies Inc.; Greg Pitts, Microelectronics and Computer Technology Corporation; and Ted Smith, Silicon Valley Toxics Coalition. We would like to acknowledge Ron Iman (505/ ) of Southwest Technology Consultants and Terry Munson of Contamination Studies Laboratory (CSL) for their work in planning and analyzing the results of the performance demonstration. Acknowledgment is also given to the suppliers of the technologies evaluated in the CTSA, including Alpha Metals; Dexter Electronic Materials; Electrochemicals, Inc.; Florida CirTech; MacDermid, Inc.; and Technic, Inc., who, in addition to supplying the various technologies, contributed significant technical input for the performance demonstration. Recognition is also given to ADI/Isola, who supplied the materials for the performance demonstration, to Network Circuits, for volunteering their services to build and test the boards, and to the sixteen test facilities. We would also like to express appreciation to Andrea Blaschka, Susan Dillman, Conrad Flessner, Franklyn Hall, Susan Krueger, Fred Metz, and Jerry Smrchek, as members of the EPA Risk Management Workgroup, who provided valuable expertise and input during the development of the CTSA. Many thanks also to the industry representatives and other interested parties who participated in the Technical Workgroup, for their voluntary commitments to this project.

3 Speaker Biographies Fern Abrams is the Director of Environmental Policy for IPC—Association Connecting Electronics Industries. Prior to joining IPC, she served as Manager of Environmental Affairs at the American Trucking Associations. She has additionally worked as an environmental consultant to a wide variety of industry and government clients, most recently while employed as a project manager with Ogden Environmental and Energy Sources. She earned a M.S. degree in Environmental Engineering from the Virginia Polytechnic Institute and a B.S. in Chemical Engineering from the University of Pennsylvania. Kathy Hart is with the Design for the Environment (DfE) Program in the U.S. Environmental Protection Agency’s Office of Pollution Prevention and Toxics, where she serves as Project Lead for the DfE Printed Wiring Board and Computer Display Projects. Prior to joining the DfE Program, she was a Senior Project Manager at Jellinek, Schwartz & Connolly, Inc. (JSC), an environmental policy consulting firm. Prior to joining JSC, Ms. Hart served as a Policy Analyst and Environmental Scientist with EPA’s Office of Toxic Substances and as an Environmental Scientist with the Environmental Impact Section of the Food and Drug Administration’s Center for Food Safety and Applied Nutrition. Ms. Hart earned a B.S. degree in Microbiology at the University of Michigan and holds a Masters degree in Zoology from Virginia Tech. Jack Geibig is a Senior Research Associate with the University of Tennessee Center for Clean Products and Clean Technologies, an interdisciplinary research center whose focus is to develop, evaluate, and promote cleaner products and technologies that will contribute to long-term sustainable development. At the Center he was a primary contributor in the EPA Design for the Environment (DfE) study of Making Holes Conductive technologies where he led all of the non-risk analyses. Currently, he is the Principal Investigator for the EPA DfE partnership with the electronics industry that is evaluating alternative PWB surface finishes. Prior to working at the Center, he worked over six years in the electronics industry, and has over three years experience managing a PWB manufacturing facility. Mr. Geibig holds a BS in chemical engineering.

4 Speaker Biographies Rupy Sawhney is an Assistant Professor of Industrial Engineering at the University of Tennessee, and the Director of the Lean Production Laboratory. His interest lies in the area of manufacturing systems analysis, with a focus on utilizing simulation modeling. Dr. Sawhney has applied this production knowledge to develop methodologies to access and evaluate the impact of pollution prevention initiatives on manufacturing systems. He has worked with Oak Ridge National Laboratory, Proctor and Gamble, Duracell, Saturn, Coca Cola, EPA, and other organizations. He has received a Lean Production System Industrial fellowship to assist Tennessee industries in improving their competitiveness. He teaches senior level and graduate level production control, experimental design, and simulation modeling courses. He is a member of Alpha Pi Mu, Tau Beta Pi, Institute of Industrial Engineers, and Society of Manufacturing Engineers. John Sharp is the Environmental and Safety Manager for the Connection Systems Division of Teradyne. He has also worked for Merix Corporation, CH2M Hill, Texas Eastman Chemical Co., and Conoco Chemicals, focusing on environmental and safety issues throughout his career. He has a Bachelor’s degree in Chemical Engineering, a Master’s degree in Oceanography, a Master’s degree in Environmental Engineering,and is a Professional Engineer in the fields of Chemical and Environmental Engineering. He is the Vice Chair of IPC’s Environmental, Health, and Safety Committee, and is the Technical Workgroup Co-Chair for the DfE Printed Wiring Board Surface Finishes Project. Terry Munson, President of CSL, has extensive electronics industry experience applying Ion Chromatography analytical techniques to a wide spectrum of manufacturing applications. This includes such areas as semiconductor manufacturing, bare board fabrication, low solids flux application techniques, and various electronic assembly processes. Terry currently chairs the IPC Ionic Cleanliness Task Group. He has served as session chair at technical seminars on contamination effects at industry shows.

5 Speaker Biographies Ted Smith is founder and Executive Director of the Toxics Coalition (SVTC), a non-profit grass roots organization consisting of environmental and Silicon Valley neighborhood groups, labor unions, public health leaders, people affected by toxic exposure, and others. The Toxics Coalition supports projects that encourage the development of a sustainable, non-polluting economy. SVTC has supported the development of local ordinances in Santa Clara County, including the Hazardous Materials Model Ordinance, the Toxic Gas Ordinance, and the county’s CFC Procurement Ordinance. Mr. Smith received his B.A. from Wesleyan University and his J.D. from Stanford University. He formerly taught Environmental Studies at San Jose State University and Labor Studies at San Jose City College. He is co-founder and Chair of the Campaign for Responsible Technology, a national network committed to working for the development of sustainable, non- polluting technologies. He is the author of numerous articles and other publications. Mary Swanson is a Research Scientist with the University of Tennessee’s Energy, Environment and Resources Center, and the Center for Clean Products and Clean Technologies. Her work involves evaluating the fate and effects of chemicals released to the environment, with special interest in the development and application of risk assessment and life-cycle impact assessment methodologies as tools for evaluating and developing cleaner products and technologies. Ms. Swanson has fourteen years of experience in environmental research and consulting, beginning with research at the University of Minnesota involving trace organic contaminants in rain and snow in the Great Lakes region. She worked for six years in environmental consulting as an Environmental Chemist and Environmental Engineer on hazardous waste site remedial investigations and feasibility studies, specializing in the areas of toxic contaminant fate and transport.

6 Design for the Environment Printed Wiring Board Project
Partnerships for a Cleaner Future

7 DfE Vision Business decision-makers integrate environmental concerns into cost and performance criteria Cost Performance Decision Environment

8 Project History Began working with the PWB industry in 1993
MCC study assessed the life cycle of a computer workstation Material and chemical use Hazardous waste Water use Energy use Conducted assessment of making holes conductive technologies as first project

9 Project Partners Partners for Change PWB Manufacturers and Suppliers
IPC EPA MCC Partners for Change Public Interest Groups University of Tennessee

10 DfE Workgroups Core Implementation Technical Communication Seminars
Occupational exposure Environmental releases Performance Cost Information products Implementation Seminars Implementation guides Web site Community outreach Communication P2 case studies Presentations Trade show booth Trade journals

11 Information Products Implementing Cleaner PWB Technologies: Surface Finishes PWB Cleaner Technologies Substitutes Assessment: Making Holes Conductive Implementing Cleaner Technologies in the PWB Industry: Making Holes Conductive PWB Pollution Prevention and Control: Analysis of Updated Survey Results PWB Industry and Use Cluster Profile Federal Environmental Regulations Affecting the Electronics Industry (1995) 9 Pollution Prevention Case Studies Project Fact Sheets and Journal Articles These reports can be ordered through EPA’s Pollution Prevention Information Clearinghouse, at 202/ , or viewed on the DfE website at

12 EPA Goals and Objectives
Effect change in PWB industry that results in pollution prevention Leverage industry resources Foster open and active participation in addressing environmental issues Demonstrate that pollution prevention makes economic sense

13 Design for the Environment Printed Wiring Board Project
Industry Perspectives

14 Industry Goals and Objectives
Identify and implement P2 technologies that perform competitively and are cost-effective Make informed decisions that include consideration of human health and environmental risk Develop useful information for PWB industry within a short time frame Help ensure credibility and validity of project data

15 Benefits to Industry Research conducted by neutral parties
Risk assessment expertise Full-time project leadership Change from confrontational to partnering relationship

16 Benefits to Industry Proactive management of environmental affairs and increased competitiveness: Reduce health and environmental risk Reduce material and compliance costs Reduce liabilities Leverages limited resources of small to medium-sized businesses

17 Advantages of DfE Approach
Cooperative approach to environmental problem-solving Focused project that produces useful data and facilitates pollution prevention EPA funding, which includes: Development and analysis of data Demonstration of alternative technologies Communication of cost-effective P2 information

18 Design for the Environment Printed Wiring Board Project
Community Perspectives

19 Community Goals and Objectives
Encourage the development of cleaner and safer technologies that provide better protection for workers and the community Develop a model for cleaner technology assessment, development, and implementation Learn more about the PWB industry and disseminate that information Help to equip community residents and workers to become more informed stakeholders so they can be more effective participants in joint projects Ensure that the DfE process is credible to communities and workers and that it is conducted in a comprehensive, fair, and equitable manner

20 Potential Benefits to the Community and Workers
The partnership and combined expertise between government, industry, academia, and NGOs can lead to an improved process, product, and data The results of the DfE process, if conducted properly and implemented successfully, can lead to improved public and occupational health The DfE process exposes all participants to each other’s interests, needs, and contrasts, and helps to overcome stereotypes

21 Potential Benefits to the Community and Workers
The DfE process can help support environmental advocates within the industry With the full support of all stakeholders, implementation can be more effective The DfE process recognizes that there are mutual benefits in the relationship between industry, government, universities, communities, and workers to encourage a sustainable economy and corporate accountability

22 Design for the Environment Printed Wiring Board Project
Introduction to PWB Manufacturing and CTSA Methodology

23 Informed decision by PWB Manufacturers
CTSA Process Use Cluster Profile Process identification Flow chart showing "steps" Description Phase Chemicals, materials, technologies Commonly accepted alternatives High environmental impact areas Use Cluster Risk and release Alternate chemicals, materials, and processes Selected step Scoring Cleaner Technologies Substitutes Assessment (CTSA) Cost and performance Environmental release Comparative risks Resource conservation Energy impacts Informed decision by PWB Manufacturers

24 Cluster Selection Evaluation showed essentially equal and medium risk
Making holes conductive was subject of first DfE/IPC project Surface finishing process selected Technology alternatives were available Timely

25 Electroless Nickel/Palladium/
Use Cluster Selected Surface Finishing Use Cluster Circuit Design/ Data Acquisition Inner Layer Image Transfer Laminate Inner Layers Drill Holes Clean Holes Make Holes Conductive Outer Layer Image Transfer Hot Air Solder Leveling OSP Immersion Silver Immersion Tin Surface Finish Electroless Nickel/ Immersion Gold Electroless Nickel/Palladium/ Immersion Gold Final Fabrication

26 CTSA Approach Industry and use cluster profiles
Pollution prevention survey Regulations affecting the electronics industry Workplace practices survey Performance demonstration Risk assessments Cost model and analysis Implementation guide Pollution prevention case studies

27 CTSA Methodology WP Survey P2 Survey Industry Profiles Regs Perf Demo
Risk Assessments

28 Surface Finish Mechanisms
Electroless- metal plating process driven by oxidation-reduction reaction without the use of an external power source auto-catalytic reaction multiple layers Immersion- metal plating driven by a chemical replacement reaction without the use of an external power source self-limiting reaction monomolecular layer Coating- application of a protective layer to the board by physical contact of the chemistry to the board coating can be thin or thick

29 HASL Profile Solder surface finish has been reliable standard for many years Selection of flux is critical to performance Lack of planarity and presence of lead has been driving development of alternatives Compatible with SMT and through-hole Operated in either conveyorized or non-conveyorized mode

30 Electroless Nickel/Immersion Gold Profile
Thin layer of gold prevents the highly active nickel layer from oxidizing, thus protecting the solderability of the finish Compatible with SMT, flip chip, and BGA technologies Aluminum wire-bondable Operated in either conveyorized or non-conveyorized mode

31 Electroless Nickel/Electroless Palladium/Immersion Gold Profile
Similar to Nickel/Gold, but with a palladium layer that lends added strength to the surface finish for component attachment Compatible with SMT, flip chip, and BGA technologies Both gold and aluminum wire-bondable Operated in either conveyorized or non-conveyorized mode

32 OSP Profile OSP applies a planar anti-oxidation coating to copper surface to preserve solderability benzotriazoles and imidazoles (thin) substituted benzimidazole (thick) Compatible with SMT, flip chip, and BGA technologies Operated in either conveyorized or non-conveyorized mode

33 Immersion Silver Profile
Organic inhibitor forms a hydrophobic layer on the silver surface, which protects solderability Compatible with SMT, flip chip, and BGA technologies Gold and aluminum wire-bondable Operated exclusively in horizontal, conveyorized mode

34 Immersion Tin Profile Immersion tin process utilizes a co-deposited organo-metallic compound prevents formation of a Sn-Cu intermetallic layer inhibits dendritic growth Compatible with SMT, flip chip, and BGA technologies Typically operated in horizontal, conveyorized equipment

35 Typical Facility Goal is to perform comparative, not absolute, evaluations Data aggregated across alternatives to determine basic parameters, for example: average throughput operating days per year Calculations were based on combination of average and high-end values from the Workplace Practices Survey

36 Typical Facility Characteristics
PWB operation occupies 45,400 square feet Facility manufactures 416,000 ssf of PWBs Surface finish processes operates in 3,670 square foot room operates 307 days per year temperature is 75º F (average) ventilation air flow rate of 4,650 cu.ft./min.

37 Typical Facility - Types of Employees in SF Area
Line operators Laboratory technicians Maintenance workers Supervisory personnel Wastewater treatment operators Others (e.g., quality inspectors process control specialist)

38 Typical Facility - SF Area Employee Data
Average employee duration in process area - 8 hour Employee work days per year - 250 Operation picked as first shift only Conveyorized process exposure is much lower than non-conveyorized

39 Surface Finish Automation
Process Configurations Evaluated in CTSA Surface Finish Process Non-Conveyorized Conveyorized HASL Nickel/Gold Nickel/Palladium/Gold OSP Silver Tin

40 Typical Processes for Alternatives - Examples
HASL Silver Nickel/Gold Cleaner Water Rinse x2 Flux HP Rinse Microetch Solder Air Knife Dryer Cleaner Water Rinse Microetch Predip Silver Dryer Cleaner Water Rinse Water Rinse Microetch Catalyst Water Rinse Water Rinse Acid Dip Nickel Water Rinse x2 Gold Water Rinse x2

41 Design for the Environment Printed Wiring Board Project
Cost Analysis of Surface Finish Technologies

42 Problem Framework B2 A2 B1 G2 BN A1 AN Sites G1 GN Database A B C D E
Model Facilities AC ANC DNC GC Generic Technologies $/ssf $/ssf $/ssf $/ssf

43 Project Tasks Develop costs for model facilities that utilize the generic technologies Develop cost estimates for the application of the surface finish for: 260,000 ssf of PWBs (avg. throughput for HASL processes) 60,000 ssf of PWBs (avg. throughput for non- HASL processes)

44 Cost Analysis Dimensions
Model Facilities AC ANC DNC GC $/260,000 ssf A1 A2 AN G1 G2 GN Actual Facilities

45 Cost Analysis Objectives
Fundamentally sound analysis of model facilities Flexible system to calculate actual facility cost Highlight environmental costs

46 Cost Analysis Goals Use the process to estimate comparative costs for model facilities Provide insight into costs for actual facilities activity-based costs sensitivity analysis

47 Hybrid Cost Formulation Framework
Surface Finish Processes Development of Cost Categories Development of Traditional Costs Formulation Development of the Bill of Activities (BOA) Development of Simulation Model Cost Analysis Sensitivity Analysis

48 Process Model Key Assumptions
Process operated at 6.8 hours per day Remaining 1.2 hours taken up by: routine maintenance start up and shut down procedures PWB panels are assumed to be available without delay when feeding surface finish process Simultaneous bath changeouts are considered to occur simultaneously with regard to downtime

49 Non-Conveyorized Process Key Assumptions
Production based on rate limiting step and overall cycle time One rack is allowed in a bath at one time A rack consists of 84.4 ssf of PWB Labor is calculated using 1.1 employees to reflect more labor intensive process Production system is cleared at the end of a shift or before a bath is replaced

50 Conveyorized Process Key Assumptions
Production based on average cycle time and conveyor speed A panel consumes 18 inches of the conveyor Process is operated by one line operator with regard to labor Production system is cleared at the end of a shift or before a bath is replaced

51 Cost Categories Cost Category Cost Components Capital Cost
Primary Equipment Installation Facility Material Cost Chemical(s) Utility Cost Water Electricity Gas Licensing/Permit Cost Wastewater Discharge Production Transportation of Material Labor for Normal Production Maintenance Cost Tank Cleanup Bath Setup Sampling and Testing Filter Replacement Total Cost

52 Simulation Model for the Conveyorized Immersion Tin Process

53 Simulation Output for Non-Conveyorized Nickel/Gold Process
Chemical Bath Frequency Average Time/ Total Time Replacement (min) (min) Cleaner 7 116 812 Microetch 9 116 1,044 Catalyst 6 116 696 Acid Dip 4 116 464 Electroless Nickel 40 116 4,640 Immersion Gold 6 116 696 Total 72 8,352

54 Surface Finish Process Operating Times
Data based on 260k ssf PWB production Surface Finish Simulation Simulation Operating Process Run Time Downtime Time (days) (days) (days) HASL [N] 43.7 5.7 38.0 HASL [C] 21.8 2.3 19.5 Nickel/Gold 212 18.8 193.4 Nickel/Palladium/Gold [N] 280 27.9 252.1 OSP [N] 35.2 6.2 29 OSP [C] 16.1 2.5 13.6 Silver [C] 64.2 3.4 60.8 Tin [N] 75.2 4.6 70.6 Tin [C] 107 2.5 104.5

55 BOA for Transportation of Chemicals
Activities Time (min) Resources Cost Transportation of chemicals to bath Labor Materials Forklift $/transport A. Paperwork and Maintenance $10.24/hr i. Request for Chemicals 2 $0.34 $0.10 $0.00 $0.44 ii. Updating Inventory Logs 1 $0.17 $0.05 $0.22 iii. Safety and environmental B. Move forklift to chemical storage area i. Move forklift to parking area $0.12 $0.46 ii. Prepare forklift to move chemicals 5 $0.85 $0.25 $0.30 $1.15 iii. Move to line container storage area iv. Prepare forklift to move line container 3 $0.51 $0.18 $0.69 v. Move forklift to chemical storage area

56 BOA for Transportation of Chemicals
Activities Time (min) Resources Cost Transportation of chemicals to bath Labor Materials Forklift $/transport C. Locate chemicals in storage area $10.24/hr i. Move forklift to appropriate area(s) 1 $0.17 $0.00 $0.06 $0.23 ii. Move chemical containers from storage to staging 2 $0.34 $0.00 $0.12 $0.46 iii. Move chemical containers from staging to storage 2 $0.34 $0.00 $0.12 $0.46 D. Preparation of chemicals for transfer i. Open chemical containers 1 $0.17 $0.05 $0.00 $0.22 ii. Utilize appropriate tools to appropriate containers 3 $0.51 $0.05 $0.00 $0.56 iii. Place appropriated chemicals in line container(s) 3 $0.51 $0.00 $0.00 $0.51 iv. Close chemical container(s) 1.5 $0.09 $0.00 $0.00 $0.09 v. Place line container(s) on forklift 1 $0.17 $0.00 $0.06 $0.23

57 BOA for Transportation of Chemicals
Activities Time (min) Resources Cost Transportation of chemicals to bath Labor Materials Forklift $/transport E. Transport chemicals to line i. Move forklift to line 2 $0.34 $0.00 $0.12 $0.46 ii. Unload line container(s) at line 1 $0.17 $0.06 $0.23

58 Cost Composition for Non-Conveyorized Nickel/Gold Process
Maintenance Cost to Produce 260,000 ssf Tank Cleanup Bath Setup Sampling Filter Replacement Number of tank cleanups Cost/tank setup annual number of samples utilization ratio cost per sample X X X Simulation Model (72) BOA ($67) Exposure Assessment (1260) Simulation Model (0.76) BOA ($3.70) X X X $4,824 $1,087 $3,530 $1,580

59 Cost Summary: Non-Conveyorized Nickel/Gold Process
Cost Category Cost Component Cost ($) Capital Costs Primary Equipment and Installation Facility $7,260 $2,930 Material Costs Chemical Products $108,600 Utility Costs Water Electricity Natural Gas $1,180 $2,360 $0 Wastewater Costs Wastewater Discharge $2,050 Production Costs Transportation of Materials Labor $668 $19,100 Maintenance Costs Tank Cleanup Bath Setup Sampling and Testing Filter Replacement $4,830 $1,090 $3,530 $1,580 Total Process Cost $156,000 Cost based on 260k ssf PWB production

60 Cost Comparison of PWB Surface Finish Processes
Total costs based on 260k ssf of PWB production Surface Finish Total Cost Cost Process ($) ($/ssf) HASL [N] $94,200 $0.36 HASL [C] $92,400 $0.35 Nickel/Gold [N] $156,000 $0.60 Nickel/Palladium/Gold [N] $399,000 $1.54 OSP [N] $28,700 $0.11 OSP [C] $26,300 $0.10 Silver [C] $73,800 $0.28 Tin [N] $46,900 $0.18 Tin [C] $64,700 $0.25

61 Cost Comparison of PWB Surface Finish Processes
Total costs based on 60k ssf of PWB production Surface Finish Total Cost Cost Process ($) ($/ssf) HASL [N] $20,000 $0.33 HASL [C] $19,800 $0.33 Nickel/Gold [N] $36,300 $0.61 Nickel/Palladium/Gold [N] $92,200 $1.54 OSP [N] $6,800 $0.11 OSP [C] $5,800 $0.10 Silver [C] $16,700 $0.28 Tin [N] $10,600 $0.18 Tin [C] $13,400 $0.22 Note: Costs are preliminary (not final)

62 Cost Comparison of PWB Surface Finish Processes
Total costs based on 260k ssf of PWB production Process 260K ($/ssf) +/- ($/ssf) % Change from baseline HASL [N] $0.36 * * HASL [C] $0.35 -$0.01 -3% Nickel/Gold [N] $0.60 +$0.24 +67% Nickel/Palladium/Gold [N] $1.54 +$1.18 +327% OSP [N] $0.11 -$0.25 -69% OSP [C] $0.10 -$0.26 -72% Silver [N] $0.28 -$0.08 -22% Tin [N] $0.18 -$0.18 -50% Tin [C] $0.25 -$0.11 -31%

63 Design for the Environment Printed Wiring Board Project
Comparative Risk of Surface Finish Technologies

64 Presentation Overview
Purpose of SF risk characterization Risk characterization methods Assumptions and Uncertainties Risk characterization results Process Safety Assessment

65 Purpose of SF Risk Characterization
Perform screening-level risk characterization to: compare risks of exposure to chemicals in baseline and alternative SF processes identify areas of potential concern for SF processes Present information about variability, uncertainty, and key assumptions

66 CTSA Risk Characterization Process
Workplace Practices Source Release Assessment Human Health Hazards Environmental Exposure Assessment Risk Characterization

67 Exposure Assessment Occupational exposure to:
line operators laboratory technicians others in process area Ambient population exposure to: humans living near a facility aquatic organisms Model facility approach 260,000 ssf production

68 Pathways for Worker Exposure
Release Medium Exposure Medium Exposure Route Chemical Source Evaporation Air Inhalation Aerosol generation Chemical Bath Dermal Contact Direct Contact Equipment Cleaning

69 Occupational Exposure Methodology
Air concentrations based on: supplier bath chemistry data workplace practices data (bath temperature, etc.) air emission models Dermal concentrations based on supplier bath chemistry data Exposure time based on Workplace Practices Survey data Exposure frequency based on Workplace Practices Survey data, supplier information, and modeled time to finish set amount of boards (260,000 ssf) Default assumptions for inhalation rate, body weight, exposure averaging times

70 Occupational Exposure: Non-Conveyorized Processes
Baths are not enclosed Inhalation exposure to vapors from all baths and to aerosols from air-sparged baths line operator is exposed 8 hours/day exposure to others is proportional to time spent in process area no vapor controls on baths Dermal exposure through line operation and bath maintenance, 8 hours/day

71 Occupational Exposure: Conveyorized Processes
Equipment is enclosed and typically vented to the outside Inhalation exposure to workers assumed negligible Dermal exposure through bath and filter replacement, bath sampling, and conveyor equipment cleaning Dermal exposure contact time varies by process and by bath

72 Population Exposure Inhalation exposure to humans living near a facility No air pollution controls assumed Outdoor air concentrations modeled using an EPA air dispersion model, and estimated air emission rates from process baths

73 Key Assumptions in the Exposure Assessment
Workers do not wear gloves; otherwise dermal exposure and risk would be negligible Non-conveyorized lines are fully manual Steady state air concentrations in process area Form/concentration of chemicals in bath are constant over time Air turnover rate = 1.56/hour (480 ft3/min. general ventilation rate, 18,200 ft3 room size)

74 Uncertainties in the Exposure Assessment
Similarity of model facility to any actual facility (variability among facilities) Chemical concentrations in baths variation among products variation with time Limitations of workplace practices data (variability in workplace practices) Uncertainties in models and assumptions (modeling estimates vs. monitoring data)

75 Exposure Risk Descriptors
High-end : Accounts for persons at the upper end of exposure distribution (capture variability) 90% of actual values would be less Central tendency: Average or median estimates of exposure values avoid estimates beyond true distribution What if : Based on hypothetical conditions or limited data where the distribution is unknown does not describe how likely estimated level of exposure might be

76 Descriptors for the SF Risk Characterization
Based on combination of average, high-end, and “what-if” values Aim was for overall high-end risk characterization Average: body weight, breathing rate, bath concentrations High-end: duration of worker activities What if: use of gloves, days/yr Result is “what if” risk characterization

77 Uncertainties in the Hazard Data
Effects of chemical mixtures Using short-term, high dose animal studies to predict effects in humans Lack of measured toxicity data for some chemicals Variability in characteristics of exposed population (some people are more sensitive than others)

78 Risk Characterization Overview
Cancer risks to humans Other chronic health risks (humans) Aquatic risks Results compared to levels of concern

79 Methods to Calculate Risk
Cancer risk expressed as probability result is upper bound lifetime excess cancer risk weight of evidence also considered Other chronic health risks expressed as ratio to reference value hazard quotient (better quality data), or margin of exposure qualitative (H, M, L) if no toxicity value was available

80 Carcinogenic WOE Classifications of SF Chemicals
Nickel/Gold Nickel/palladium/gold Urea Compound B Possible human carcinogen1 HASL Immersion Tin Lead Thiourea IARC Group B2 -possible human carcinogen EPA Group B2 -probable human carcinogen All processes Sulfuric acid IARC Group I -human carcinogen Inorganic metallic salt A Human carcinogen or probable human carcinogen1 Alternative Chemical Classification 1Specific classification not presented to protect confidential ingredient identity.

81 Cancer Risk Results Estimated for inhalation exposure to inorganic metallic salt A in the Nickel/gold process Occupational inhalation risks for line operators non-conveyorized: “high end” estimate ranges from near zero to 2 x (1 in 5 million) Estimated ambient population risks are low, with upper bound maximum of 1 in 50 billion

82 Chronic Health Risk Results
Low concerns for inhalation risks to nearby residents for all technologies Occupational inhalation risks assumed negligible for conveyorized processes concerns for some chemicals in four non-conveyorized processes Occupational dermal exposure risks concerns for some chemicals in five non-conveyorized and two conveyorized processes

83 SF Chemicals of Concern for Potential Inhalation Risks
Process (NC, 260,000 ssf) a Chemical HASL Nickel/Gold Nickel/Palladium/Gold OSP Immersion Tin Alkyldiol Ethylene Glycol Hydrochloric Acid Hydrogen Peroxide Nickel Sulfate Phosphoric Acid Propionic Acid a: Non-conveyorized Immersion Silver process not evaluated  Line operator risk results above concern levels (noncancer health effects)

84 SF Chemicals of Concern for Potential Dermal Risks
Process a (260,000 ssf) Immersion Tin (NC) Nickel/ gold/ (NC) Nickel/ Palladium/ gold (NC) HASL [NC] HASL [C] OSP [NC] OSP [C] Chemical Ammonia Compound A Ammonium chloride Ammonium hydroxide Copper ion   Copper salt C  Copper sulfate pentahydrate       Hydrogen peroxide Inorganic metallic salt B   Lead Nickel sulfate   Urea Compound C a: No risk results were above concern levels for the Immersion Silver (conveyorized) process  Line operator risk results above concern levels (noncancer health effects)  Line operator and laboratory technician risk results above concern levels (noncancer health effects) C = conveyorized (horizontal) process configuration NC = non-conveyorized (vertical) process configuration

85 Aquatic Risk Chemicals ranked for aquatic toxicity using established EPA criteria Concern concentration (CC) = acute or chronic toxicity value divided by uncertainty factor Inorganic metallic salt A, silver nitrate, and silver salt have lowest CC

86 Aquatic Hazard and Risk
CC compared to estimated surface water concentration (CSW ) Drag-out study used to estimate chemical loss through rinse water and surface water concentrations (assuming no treatment) Chemicals with CSW > CC evaluated further considering treatment efficiency Aquatic risk expressed as a ratio of estimated surface water concentration to CC

87 Drag-Out Study Develop a model that estimates the quantity and characteristics of drag-out Use the model to: identify critical factors influencing drag-out quantify chemical loss and subsequent mass loading of on-site treatment determine the effect of organic chemicals released through drag-out on surface waters Model was used to calculate a mass loading to the on-site treatment facility: inorganics assumed to be treated on-site to permit levels organics were considered treated in POTW

88 Aquatic Risk Non-metal Chemicals of Concern for
Estimated surface water concentration > Concern Concentration (CC) after POTW treatment

89 Comparing Risks to Concern Levels
E: Exposure estimate N or L: NOAEL or LOAEL SF: Cancer slope factor Csw: Surface water concentration RfD: Reference Dose CC: Aquatic concern concentration

90 Risk Comparison

91 Risk Conclusions Chemicals in seven process configurations may pose noncancer chronic health risks inhalation concerns: HASL, Nickel/gold, Nickel/palladium/gold and OSP (all non-conveyorized) dermal exposure concerns: HASL (NC & C), Nickel gold (NC), Nickel palladium gold (NC), OSP (NC & C), and Immersion tin (NC) Cancer risk in Nickel gold process due to confidential ingredient (inorganic metallic salt A) less than 1 x 10-6

92 Conclusions, continued
Overall, for health risks: risks are uncertain for lead in HASL (more monitoring data are needed) there are chemical risk results for human health above concern levels for all processes evaluated except Immersion silver and conveyorized immersion tin There are chemical risk results for aquatic life above concern levels for HASL, OSP, Immersion silver and Immersion tin

93 Process Safety Assessment
Used Material Safety Data Sheets for chemical products Process Safety Concerns general OSHA requirements equipment safeguards Chemical Safety Concerns flammable (F), combustible (C) explosive (E), fire hazard (FH), Corrosive (CO), oxidizer (O), reactive (R), or unstable (U) acute and chronic occupational health hazards other chemical hazards

94 Chemical Safety Concerns: Summary

95 Chemical Safety Concerns
Acute and chronic health hazards all alternatives listed both acute and chronic health hazards and sensitizers all listed irreversible eye damage Immersion silver and OSP were the only alternatives not containing a carcinogen Other Chemical Hazards most have chemical decomposition hazards chemical incompatibilities include acids, alkalis, oxidizers, metals, and reducing agents

96 Chemical Safety Concerns
Other Chemical Hazards, continued some have incompatibilities between chemical products used on the same process line HASL, OSP, Immersion Silver, and Immersion Tin contain chemical(s) that are considered flammable, explosive, or a fire hazard all alternatives contain corrosive chemicals Immersion Tin was the only alternative not to contain chemical(s) that were considered to be unstable, an oxidizer, or have a sudden release of pressure

97 Design for the Environment Printed Wiring Board Project
Resource Conservation and Energy Impacts

98 Objective Resource conservation Energy conservation
relative use of natural resources (water, chemicals, energy, etc.) during the surface finishing process (HASL vs. alternatives) Energy conservation relative rate of energy consumption during the application of the surface finish by HASL and the alternatives

99 Resource Conservation Data Types
Process specifications Physical process parameters Operating procedures

100 Water Consumption of Surface Finishing Processes
Rinse Water Water Surface Finish Process Rinse Consumed Consumption Stages (gal/260,000 ssf) (gal/ssf) HASL [N] 3+1 HP 3.22 x 10 5 5 1.24 HASL [C] 3+1 HP 2.58 x 10 5 5 0.99 Nickel/Gold [N] 8 5.37 x 10 5 5 2.06 Nickel/Palladium/Gold [N] 14 9.39 x 10 5 5 3.61 OSP [N] 3 2.01 x 10 5 5 0.77 OSP [C] 3 1.37 x 10 5 5 0.53 Silver [C] 3 1.37 x 10 5 5 0.53 Tin [N] 7 4.69 x 10 5 5 1.81 Tin [C] 5 2.29 x 10 5 5 0.88 N = Non-Conveyorized, C = Conveyorized, HP = High pressure rinse

101 Water Consumption of Surface Finish Technologies
Surface Finish Process Gal/ssf Change HASL [N] 1.24 --- HASL [C] 0.99 - 20% Nickel/Gold [N] 2.06 + 66% Nickel/Palladium/Gold [N] 3.61 + 191% OSP [N] 0.77 - 38% OSP [C] 0.53 - 57% Silver [C] 0.53 - 57% Tin [N] 1.81 + 46% Tin [C] 0.88 - 29% N = Non-Conveyorized, C = Conveyorized

102 Conclusions: Water Use
Several surface finish processes consumed less water than the baseline HASL process reduction primarily due to the reduced number of rinse stages conveyorized processes typically use less water than non-conveyorized Magnitude of savings is facility-dependent examples: efficiency of previous process, differences between alternatives, facility practices

103 Process Chemicals Quantitative analysis of process chemicals was not possible due to the variability of: process-specific factors (e.g., bath concentration, composition, operating parameters) facility-specific factors (e.g., operating practices, bath replacement frequency)

104 Wastewater Treatment Chemicals
Quantity of treatment chemicals consumed is dependent on: process-specific factors (e.g., type of process, water flow rate, volume of drag out) facility-specific factors (e.g., other mfg. processes, volume of wastewater, type of treatment system) Additional treatment steps or modifications may be desirable with certain finish processes (e.g., increased silver levels, thiourea, cyanide)

105 Energy Impacts Energy consumption during process operation
Energy production environmental impacts

106 Energy-Consuming Equipment
Type of Equipment Function Conveyor System Automate the movement of panels through the process. Panel Agitation Agitate apparatus used to gently rock panel racks back and Motor forth in the process baths. Not required for conveyorized processes. Fluid Pump Circulate bath fluid to facilitate uniform chemical contact with all surfaces of the PWB panels. Air Pump Compress air to be used by an air knife to blow residual bath chemisties or solder from the surface of the PWB. Air is also used to sparge select chemical baths in certain processes. Immersion Heater Raise and control temperature of a process bath to the optimal operating condition. Solder Pot Heats solder and maintains the molten solder at proper operating conditions. Gas Heater Heat PWB panels to promote drying of residual bath chemistries remaining on the panel surfaces.

107 Energy Usage Profiles Conv Agit. Air Fluid Bath Solder Gas Energy
Process Type Motor Pump Pump Heat Pot Dry Usage (BTU/hr) HASL [N] * 1 2 3 1 1 1 219,800 HASL [C] 1 * 2 4 1 1 1 260,400 Nickel/Gold [N] * 1 1 3 4 * * 88,700 Nickel/Palladium/ Gold [N] * 1 1 3 6 * * 116,700 OSP [N] * 1 2 3 2 * 1 165,500 OSP [C] 1 * 2 3 2 * 1 203,100 Silver [C] 1 * * 4 2 * 1 180,200 Tin [N] * 1 * 4 2 * 1 142,700 Tin [C] 1 * * 3 2 * 1 177,100

108 Nickel/Palladium/Gold [N]
Energy Consumption Process Total Energy Energy Usage Process Type Operating Time Consumed Rate (Hours) (BTU/260,000 ssf) (BTU/ssf) HASL [N] 258 5.67 x 10 7 7 218 HASL [C] 133 3.46 x 10 7 7 133 Nickel/Gold [N] 1310 1.16 x 10 8 8 447 Nickel/Palladium/Gold [N] 1710 2.00 x 10 8 8 768 OSP [N] 197 3.26x 10 7 7 125 OSP [C] 93 1.89 x 10 7 7 73 Silver [C] 414 7.46 x 10 7 7 287 Tin [N] 480 6.48 x 10 7 7 263 Tin [C] 710 1.36 x 10 8 8 522 N = Non-Conveyorized, C = Conveyorized

109 Comparison of Energy Consumption
Surface Finish Process BTU/ssf Change HASL [N] 218 --- HASL [C] 133 - 39% Nickel/Gold [N] 447 + 105% Nickel/Palladium/Gold [N] 768 + 252% OSP [N] 125 - 43% OSP [C] 73 - 66% Silver [C] 287 + 32% Tin [N] 263 + 21% Tin [C] 522 + 239% N = Non-Conveyorized, C = Conveyorized

110 Pollutants Produced Through Energy Production
Media of Release Environmental and Human Health Concerns Carbon dioxide Air Global warming Carbon monoxide Air Toxic organic, smog Dissolved solids Dissolved solids Water Air Odorant, smog Hydrocarbons Air Toxic inorganic, acid rain, corrosive, global warming, smog Nitrogen oxides Particulates Air Particulates Sulfur oxides Air Toxic inorganic, acid rain, corrosive Sulfuric acid Water Corrosive, dissolved solids

111 Conclusions: Energy Usage
HASL has the highest hourly energy consumption rate of all the finishing processes The overall production time is the critical factor which drives the overall energy consumed Energy consumption ranged by ~12X from the lowest to the highest energy consuming processes

112 Design for the Environment Printed Wiring Board Project
Performance Demonstration of Surface Finish Technologies

113 Division of Responsibilities
Southwest Technology Consultants - Albuquerque Analysis of test results and documentation Raytheon Company - McKinney, TX Environmental exposure and functional electrical testing of LRSTF PWA Contamination Studies Laboratory, Inc. - Kokomo, IN Failure Analysis

114 LRSTF Functional Printed Wiring Assembly
Features PTH and SMT components 23 electrical responses Circuitry High current low voltage (2) High voltage low current (2) High speed digital (2) High frequency LPF (6) High frequency TLC (5) Other networks (4) Stranded wire (2) ON HSD PTH PTH SW SMT PTH PTH SMT SMT SMT LRSTF PWA is a good discriminator -- unlike single function test vehicles HF Transmission lines HF Design Needs Updating

115 Overview of Manufacturing Parameters
164 Test Boards 16 Finishing sites 6 Surface finishes HASL  Immersion Ag OSP  Ni/Au Immersion Sn  Ni/Pd/Au 2 Fluxes Low-residue (LR) Water-soluble (WS) 23 Site / surface finish / flux combinations

116 Pre-test all 164 PWAs Phase 1 Phase 2 Environmental Test Conditions
3 Weeks of 85°C / 85% RH Phase 1 Thermal Shock Phase 2 Mechanical Shock

117 3 Weeks Exposure to 85°C / 85% RH
Pre-test prior to exposure Post-test after 3 weeks exposure 2 sets of chamber runs used

118 200 Cycles of Thermal Shock
-50°C to 125°C with 30 min dwell at each temp Instantaneous change in temperature Test after 200 cycles 2 sets of chamber runs used

119 Mechanical Shock Test Mount PWA in rectangular aluminum frame
Drop from 1 meter onto concrete as follows: 5 Times on each face (10 drops) 5 Times on each nonconnector edge (15 drops) Test after drops completed

120 CCAMTF JTP Acceptance Criteria
Test results for all 23 circuits were compared to acceptance criteria in the Joint Test Protocol for the LRSTF PWA These criteria require a comparison to Pre-test measurements for 17 of the 23 circuits These criteria were developed for programs currently being conducted by the Circuit Card Assembly and Materials Task Force (21 organizations, 35 individuals)

121 Overall Summary of Success Rates
Test Time Anomalies Success Rate Pre-test % Post 85/ % Post TS % Post MS % Total number of test measurements at each test time: 22* circuits x 164 PWAs = 3608 *HF TLC RNF gave a constant response throughout

122 General Linear Modeling of Test Results
All test results were subjected to general linear modeling (GLM) to determine the statistically significant experimental parameters The following GLM was used to analyze site and flux type: Y = 0 + 1D1 + 2D2 + 3D3 + 4D4 + 5D5 + 6D6 + 7D7 + 8D8 + 9D9 + 10D10 + 11D11 + 12D12 + 13D13 + 14D14 + 15D15 + 16D16 + 17D3D16 + 18D4D16 + 19D7D16 + 20D11D16 + 21D14D16 + 22D15D16 Main Effects 2-Factor Interactions

123 General Linear Modeling of Test Results
D1 = 0 if not Site 2 = 1 if Site 2 D2 = 0 if not Site 3 = 1 if Site 3    D15 = 0 if not Site 16 = 1 if Site 16 D16 = 0 if flux is not water soluble = 1 if flux is water soluble Base Case: all Di = 0 Site 1 with LR flux

124 General Linear Modeling of Test Results
The following GLM was used to analyze surface finish and flux: Y = 0 + 1D1 + 2D2 + 3D3 + 4D4 + 5D5 + 6D6

125 General Linear Modeling of Test Results
D1 = 0 if surface finish is not OSP = 1 if surface finish is OSP D2 = 0 if surface finish is not Immersion Sn = 1 if surface finish is Immersion Sn D3 = 0 if surface finish is not Immersion Ag = 1 if surface finish is Immersion Ag D4 = 0 if surface finish is not Ni/Au = 1 if surface finish is Ni/Au D5 = 0 if surface finish is not Ni/Au/Pd = 1 if surface finish is Ni/Au/Pd D6 = 0 if flux is not water soluble = 1 if flux is water soluble Base Case: all Di = 0 HASL with LR flux GLM Results Documented in Report

126 23 Surface Finish and Flux Combinations
SF Flux n (site) 1 HASL LR 8 (1) 2 HASL WS 8 (1) 3 HASL LR 8 (2) 4 HASL WS 8 (3) 5 OSP LR 4 (4) 6 OSP WS 8 (4) 7 OSP LR 8 (5) 8 OSP WS 8 (5) 9 OSP LR 8 (6) 10 Imm Sn LR 4 (7) 11 Imm Sn WS 8 (7) 12 Imm Sn LR 8 (8) 13 Imm Sn LR 8 (9) 14 Imm Sn WS 8 (10) SF Flux n (site) 15 Imm Ag LR 8 (11) 16 Imm Ag WS 4 (11) 17 Imm Ag WS 8 (12) 18 Ni/Au LR 4 (13) 19 Ni/Au WS 8 (13) 20 Ni/Au LR 8 (14) 21 Ni/Au WS 8 (15) 22 Ni/Pd/Au LR 8 (16) 23 Ni/Pd/Au WS 4 (16)

127 Multiple Comparisons of SF and Flux
The goal of this statistical analysis is to determine which sets of means for surface finish and flux combinations are significantly different from one another. (See Iman, 1994 for details) Note: statistical significance does not necessarily imply practical significance Multiple comparisons results are presented in graphical displays

128 Fisher’s Least Significant Difference
Two sets of means are declared significantly different from one another if their absolute difference exceeds Fisher’s least significance difference (LSD), which is defined as where  is the level of significance t is the /2 quantile from a Student’s t distribution with n-k d.f. MSE is the mean square error for the model nj and nj are the sample sizes for the means being compared

129 Illustration of a Boxplot
* X.50 X.25 X.75 Median Upper Quartile Lower Illustration with 5 data points Outlier

130 Boxplots of HCLVPTH by Site Flux
2 3 1 9 8 7 6 5 4 . S i t e F l u x H C L V P T P r e - T s t H C L V P T A S O I m n g N i / u d W x p l o t s f H C L V P T b y S i e u ( m a n r d c ) No Significant Differences

131 Boxplots of DPHCLVP by Site Flux
Note Use of Post 85/85 - Pre-test JTP No Significant Differences

132 Boxplots of DPHCLVP by Site Flux
Note Use of Post TS - Pre-test JTP No Significant Differences

133 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
Note Use of Post MS - Pre-test JTP No Significant Differences

134 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion 4A  X  6A Significant Differences - No Practical Differences

135 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion 4A  X  6A Significant Differences - No Practical Differences

136 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion 4A  X  6A Significant Differences - No Practical Differences

137 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion 4A  X  6A SMT Components Came Off the Board During MS

138 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 Significant Differences

139 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 Note: Improvement over Pre-test Significant Differences

140 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 NO Significant Differences

141 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 NO Significant Differences

142 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 Significant Differences

143 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 Note: Improvement over Pre-test NO Significant Differences

144 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 NO Significant Differences

145 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 NO Significant Differences

146 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 Significant Differences

147 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 Note: Improvement over Pre-test NO Significant Differences

148 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 NO Significant Differences

149 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 NO Significant Differences

150 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 Significant Differences

151 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 NO Significant Differences

152 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 NO Significant Differences

153 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
JTP Acceptance Criterion > 7.7 NO Significant Differences

154 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
Note:Initial measurement is low Significant Differences

155 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
Note Use of Post 85/85 - Pre-test JTP:  5dB Note: Initial low measurement causes subsequent difference to be high Significant Differences - No Practical Differences

156 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
Note Use of Post TS - Pre-test JTP:  5dB Significant Differences - No Practical Differences

157 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
Note Use of Post MS - Pre-test JTP:  5dB Significant Differences

158 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
Significant Differences

159 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
Note Use of Post 85/85 - Pre-test JTP:  5dB

160 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
Note Use of Post TS - Pre-test JTP:  5dB

161 Boxplots of Multiple Comparisons Results by Surface Finish and Flux Type
Note Use of Post MS - Pre-test JTP:  5dB

162 Circuits Meeting JTP Acceptance Criteria after Each Testing Sequence by Major Circuit Group
(17) (113) (527) Circuitry /85 Ther Shock Mech Shock HCLV (2) % % % HVLC (2) % % % HSD (2) % % % HF LPF (6) % % % HF TLC (5) % % % ON (4) % % % SW (2) % % % Totals % % % 92.9% SMT 100% SMT 72.5% SMT

163 Breakout of HF LPF Anomalies at Post Thermal Shock by Surface Finish
Surface Finish Anomalies None HASL OSP Immersion Sn Immersion Ag Ni/Au Ni/Au/Pd The hypothesis of the anomalies being uniformly distributed over the surface finishes is rejected using a chi-square test of independence. The p-value is (see Iman, 1994 for details). (6.8) (7.7) (4.3) (6.0) (2.6)

164 Root of HF LPF Anomalies
Open PTH - a break in the metallization within the hole across its length This is a PWB fabrication defect before the surface finish is applied - it not an assembly defect The via is plated with a very thin layer of electroless Cu to provide a “seed bed” for the primary plating Cu is then electroplated over the electroless Cu strike The final finish (Sn, Ag, etc.) is then applied Open PTH occurred in the small via holes in the HF sections - small vias are difficult to plate

165 Root of HF LPF Anomalies
Open PTH Defect was present at in-circuit and baseline testing Environmental exposure exaggerates this condition Could be related to the strength of the materials - Sn and Ag are relatively weak Need to subject to failure analysis

166 CSL Failure Analysis Summary
Observed levels of bromide and weak organic acids (WOA) on all 20 assemblies are typical and therefore not detrimental from an electrochemical standpoint Tested boards with known anomalies exhibit levels near or below CSL’s recommended guidelines, we can say with reasonable confidence that the anomalies are not the result of chloride, bromide, or WOA contamination From an overall contamination standpoint, the five non-HASL surface finishes tested in this analysis performed as well if not better against the HASL finish The few solder joint cracking failures were greater with the HASL finish, than with the alternative finishes. The opens occurred along the interface of the component leads on these older PTH technology boards.

167 Summary of Mechanical Shock Results
Tough Test! Changes Observed HCLV PTH is 0.2V higher HCLV SMT is 2.6V higher HVLC SMT - components came off board GW leakage 0.3 orders of magnitude lower - still quite high HSD circuits 0.15ns faster - good

168 Design for the Environment Printed Wiring Board Project
Summary of Project Results

169 Risk Conclusions Chemicals in seven process configurations may pose noncancer chronic health risks inhalation concerns: HASL, Nickel/gold, Nickel/palladium/gold and OSP (all non-conveyorized) dermal exposure concerns: HASL (NC & C), Nickel/gold (NC), Nickel/palladium/gold (NC), OSP (NC & C), and Immersion tin (NC) Cancer risk in Nickel gold process due to confidential ingredient (inorganic metallic salt A) less than 1 x 10-6

170 Risk Conclusions, continued
Overall, for for potential health risks risks are uncertain for lead in HASL there are chemical risk results for human health above concern levels for all processes evaluated except Immersion silver and conveyorized immersion tin There are chemical risk results for aquatic life above concern concentrations for HASL, OSP, Immersion silver and Immersion tin

171 Nickel/Palladium/Gold [N]
Cost Comparison of PWB Surface Finish Technologies Overall Cost comparison based on 260k ssf Process 60K ($/ssf) 260K +/- from Baseline HASL [N] $0.37 $0.36 * HASL [C] $0.35 -$0.01 - 3% Nickel/Gold [N] $0.62 $0.60 +$0.24 + 67% Nickel/Palladium/Gold [N] $1.54 +$1.18 + 327% OSP [N] $0.11 -$0.25 - 69% OSP [C] $0.10 -$0.26 - 72% Silver [N] $0.29 $0.28 -$0.08 - 22% Tin [N] $0.19 $0.18 -$0.18 - 50% Tin [C] $0.26 $0.25 -$0.11 -31% %Change

172 Surface Finish Process Nickel/Palladium/Gold [N]
Water Consumption of PWB Surface Finish Technologies Surface Finish Process Gal/ssf Change HASL [N] 1.24 --- HASL [C] 0.99 - 20% Nickel/Gold [N] 2.06 + 66% Nickel/Palladium/Gold [N] 3.61 + 191% OSP [N] 0.77 - 38% OSP [C] 0.53 - 57% Silver [C] 0.53 - 57% Tin [N] 1.81 + 46% Tin [C] 0.88 - 29% N = Non-Conveyorized, C = Conveyorized

173 Conclusions: Water Use
Several surface finish processes consumed less water than the baseline HASL process reduction primarily due to the reduced number of rinse stages conveyorized processes typically use less water than non-conveyorized Magnitude of savings is facility-dependent Examples: efficiency of previous process, differences between alternatives, facility practices

174 Surface Finish Process Nickel/Palladium/Gold [N]
Energy Consumption of PWB Surface Finish Technologies Surface Finish Process BTU/ssf Change HASL [N] 218 --- HASL [C] 133 - 39% Nickel/Gold [N] 447 + 105% Nickel/Palladium/Gold [N] 768 + 252% OSP [N] 125 - 43% OSP [C] 73 - 66% Silver [C] 287 + 32% Tin [N] 263 + 21% Tin [C] 522 + 239% N = Non-Conveyorized, C = Conveyorized

175 Conclusions: Energy Usage
HASL has the highest hourly energy consumption rate of all the finishing processes The overall production time is the critical factor, which drives the overall energy consumed Energy consumption ranged by ~12X from the lowest to the highest energy consuming processes

176 Comparison to HASL (NC) Nickel palladium gold (NC)
Summary of Risk, Resource Use and Cost Surface Finish Alternative Comparison to HASL (NC) Risk Water Energy Cost Overall Cancera NonCancerb Aquaticc HASL (C) = = = to  Nickel gold (NC)        to  Nickel palladium gold (NC) =            to   OSP (NC)      to OSP (C)          to Immersion Silver (C)        to   Immersion Tin (NC) =    to   Immersion Tin (C) =        to   a: Based on number of known or probable human carcinogens b: Based on number of chemicals with risk results above concern levels c: Based on number of chemicals with estimated surface water concentrations above concern concentrations =  10%  % better  % worse  % better  %+ worse

177 Design for the Environment Printed Wiring Board Project
Implementing Cleaner Technologies in the PWB Industry: Alternative Surface Finishes

178 Overview DfE PWB Project document, “Implementing Cleaner Technologies in the PWB Industry: Surface Finishes” Based on telephone interviews with PWB manufacturers who use the technologies and those who have used and discontinued, and vendors 8 PWB manufacturers, 9 assemblers, 6 vendors

179 ASF Technologies Immersion Silver Immersion Tin Enthone
Florida CirTech Inc.

180 ASF Technologies Organic Solderability Preservative (OSP)
MacDermid, Inc. Electrochemicals Electroless Nickel/Immersion Gold Technic, Inc Electroless Nickel/Electroless Palladium/ Immersion Gold

181 Operational Improvements
Improved coplanarity Reduced maintenance time Reduced costs Lower scrap rate Good press-fit for connections

182 Why Companies Switched
Customers’ specifications Anticipated competitive advantage Lead-free process Improved worker safety Appropriate for high-end PWBs

183 Comparisons to HASL Immersion Silver (2 PWB facilities interviewed)
Facility A uses Immersion silver on 5% of product, Facility B on 80% of product Reduced cycle time Improved process safety - lower temperatures, less noise Same scrap rate as HASL, but more attention is required for silver because of narrower process window Less maintenance time, but more lab analysis time Facility A gained a small contract as a result, but business has not increased greatly because of the new finish; Facility B has gained some new business Facility A required an XRF to measure silver thickness and auto-unloader for end of line Installation took 2 weeks, debugging 1 week

184 Comparisons to HASL Immersion silver - 1 assembly facility interviewed Facility C specifies Immersion silver because: Lead-Free Wire-Bondable, and works well with solders used Rework does not present any significant problems Simple process Low cost (only OSP is cheaper among ASFs) If a silver board is heated without solder, the silver tarnishes

185 Technology Implementation Suggestions
“Arrange and chair a meeting with the chemical supplier and equipment manufacturer to ensure that all specifications are clearly defined.” Facility B - Immersion silver “Manufacturers who are installing immersion silver should develop a relationship with the end users to determine the best specifications for the boards.” Facility A - Immersion silver

186 Comparisons to HASL Immersion tin - 3 PWB facilities interviewed
Facility F - 15% of product is Immersion tin Facility G - 5% of product is Immersion tin Facility E - 24% of product is Immersion tin All facilities installed their lines in > 1 week Cycle time and scrap similar to HASL Reduction in maintenance from HASL More lab analysis required than HASL Smaller process window than HASL, but better control within that window Improved safety, and reduced energy consumption

187 Comparisons to HASL Immersion tin - 3 Assembly facilities interviewed
Drivers for Immersion tin were: Flat, planar finish for fine-pitch SMT Lead-free finish Improvements in hole size tolerance Reduced costs Facility J has switched back to HASL, due to incomplete coverage of boards Facilities H and I are pleased and find that Immersion tin is closest to a drop-in replacement for HASL Does require good handling practices to minimize corrosion and ionic contamination

188 Technology Implementation Suggestions
“Make sure you have good quality control and testing procedures in place for this process and that you understand the thickness and coverage of the tin.” Assembler - Immersion Tin “By monitoring and controlling time, temperature, and concentrations, anyone can produce a reliably solderable immersion tin surface finish.” PWB Facility E - Immersion Tin “If you have to get the product wet for any reason prior to completion of any first time soldering operations, be sure not to leave it wet. Blow it off with compressed air to clear the water.” Assembler - Immersion Tin

189 Comparisons to HASL Organic Solderability Preservative (OSP) - 2 PWB facilities interviewed OSP installed at request of large customers about 6 years ago for both facilities Cycle time similar to HASL, maybe a little faster Scrap is less than HASL Less maintenance than HASL Tighter operating window, but better control of finish Improved process safety, less energy usage No effect on ability to recycle scrap boards

190 Comparisons to HASL Organic Solderability Preservative (OSP) - 2 assembly facilities interviewed No compatibility problems with components Facility N has found that OSP can break down on multiple passes; Facility L has found that DI water can remove OSP finish Requires more careful handling Use different machines to do HASL and OSP boards OSP required more heat and a more active flux than HASL

191 Technology Implementation Suggestions
“Don’t skimp on equipment. Some try to use old film developers, then have trouble with contamination. Most costs during operation are associated with drag-out, which is also equipment-dependent.” Electrochemicals - OSP “As long as the temperature is maintained properly, the same coating is obtained every time.” Facility L - OSP

192 Comparisons to HASL Electroless Nickel/Immersion Gold - 2 PWB facilities interviewed Facility M uses Ni/Au on 5% of production; installed a new line 4 years ago in order to reduce the usage of lead, and to retain business Facility O uses Ni/Au on 15 to 20% of production; would like to switch to more Ni/Au, but high cost keeps customers from allowing the switch; installed 2 years ago at request of 3 or 4 customers who desired better planarity and stability; converted unused electroless copper line; has led to a substantial increase in business Increased cycle time, higher scrap than HASL Less maintenance than HASL Increased lab analyses No noticeable improvement in process safety, similar energy usages

193 Comparisons to HASL Electroless Nickel/Immersion Gold - 2 assembly facilities interviewed Facility P’s customers like the flat finish and good press-fit connections;currently 40% of Facility P’s customers use Ni/Au, but that number is decreasing Facility D found that if the gold is too thin, nickel can oxidize leading to a finish to which solder will not bond; also, if the gold bath is not balanced properly, corrosion of nickel surface will cause a weak joint that is subject to fracturing Ni/Au boards are difficult to rework - hard to remove nickel layer without damaging board; also, after rework it is difficult to detect problems

194 Technology Implementation Suggestions
“Understand that no technology will be “plug and play.” There must be a commitment from all involved, from manager to equipment operator, to tackle the learning curve and work cooperatively with the supplier. If the new finish is being forced, the resulting resentment will cause the process to turn out poorly. If it is accepted with an open mind by all, then the facility will achieve the cost savings, better planarity, and other benefits that come with the technology.” Supplier - Electroless Ni/Immersion Au “… training someone who can troubleshoot the equipment and chemistry is a valuable component of the installation process.” Facility O - Electroless Ni/Immersion Au

195 Comparisons to HASL Electroless Nickel/Electroless Palladium/ Immersion Gold - No PWB facilities interviewed 5 installations of this process in US, and 10 worldwide Mainly being used on an experimental basis

196 Comparisons to HASL Electroless Nickel/Electroless Palladium/Immersion Gold - 2 Assembly facilities interviewed Facility Q uses this finish on <1% of production; Likes finish due to wire bondability and solderability Facility D uses this finish to reduce “black pad syndrome” that is encountered with nickel/gold Facility Q has found 2 problems - flux incompatibility and intermetallic embrittlement Facility D has not specified this finish due to volatile pricing of palladium

197 Summary of Lessons Learned
Thoroughly investigate an alternative surface finish before committing to it Work closely with the supplier and follow their recommendations Everyone, top to bottom in the organization, must commit to and participate in the implementation process Develop a relationship with the end user to ensure that the finish specifications are met Monitor process control closely Purchase your equipment from suppliers experienced with the particular surface finish and invest in the correct equipment

198 Design for the Environment Printed Wiring Board Project
Industry Representatives Panel Discussion

199 Design for the Environment Printed Wiring Board Project
Closure

200 Requests for Further Information/Publications
DfE PWB Project Web Site: Order DfE PWB publications through Pollution Prevention Information Clearinghouse phone: (202) fax: (202) on the internet:


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