1. Jason Keeping, Celestica Dave Hillman Rockwell Collins ISCR 2016
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
Jason Keeping, Celestica
Dave Hillman Rockwell Collins
ISCR 2016

2. Agenda Background IPC Committee Task Plan Test Materials Test Vehicle
Metallographic Sectioning Plan
Conformal Coating Measurements
Results To Date
Looking At “Future”

3. Background
Photo Credits: Left – Rockwell Collins, Right – NASA Card Guide tin plated Beryllium

4. Background
Graphic Courtesy of CALCE Consortia

5. Background
Graphic Courtesy of CALCE Consortia

6. Background
Graphic Courtesy of CALCE Consortia

7. Background
Graphic Courtesy of CALCE Consortia

8. Background
Graphic Courtesy of PERM group

9. Background
Cell Source: S. Meschter, “ReMAP Materials Project M2: High Temperature High Humidity Corrosion and Tin Whisker Evaluation of Bi containing Leadfree Alloys, SMTA ICSR Conference, 2016.

10. Background
Cell Source: S. Meschter, “Strategic Environmental Research and Development Program (SERDP) Layered Nanoparticle
Enhanced Conformal Coating for Whisker Mitigation, SMTA ICSR Conference, 2016.

11. IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
IPC-JSTD-001E Subcommittee Task Team:
Conformal Coating Material & Application “State of the Industry” Assessment
The goal of the project is to document the current “State of the Industry” of conformal coating application on printed wiring assemblies.
The project will look at the major conformal coating types (i.e. AR, UR, ER, SR, XY) and method of application (i.e. spray, dip, brush).
The project will not evaluate individual companies or specific conformal coating products – plan is to do a “blind” task activity. Study will produce baseline data on what thickness/coverage the industry is/can achieve with conformal coating materials.

12. Conformal Coating Types: AR = acrylic UR = urethane ER = epoxy
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
Conformal Coating Types:
AR = acrylic
UR = urethane
ER = epoxy
SR = silicone
XY = paraxylylene
Application Method:
Machine or Manual
Spray
Dip
Brush
Other
Application Volunteers to collect and retain detailed documentation of application method –NO IP will be disclosed. Sufficient baseline application process details have been disclosed for every application method.
Test Vehicle

13. Task Group coating/application tasks complete:
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
Current Status:
Task Group coating/application tasks complete:
~12 volunteer conformal coating facilities utilized
~ 95 individual test vehicles processed
Application Method:
Manual Spray: AR = 1, UR = 2, SR=3
Automated Spray: AR = 2, UR = 9, ER = 2, SR = 3
Vapor Deposition: XY = 1
Dip Deposition: AR = 1
Manual Brush: AR = 1
Manual Syringe/Automated Spray: AR =1
Cure Method:
Heat “Thermal” UV
Air/Heat/Humidity/UV combinations
General:
3 Different Automated Spray Systems, Multiple Spray Angle/Pass Combinations

14. Processing: Photodocumentation
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
Processing: Photodocumentation

15. Will “cap coat” gold layer for metallographic section purposes
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
Coating Coverage and Thickness Assessment Method: Metallographic Cross-sectioning
Details:
Will gold sputter to define conformal coating outer edge before potting
Will “cap coat” gold layer for metallographic section purposes
Will cross-section from two angles
Straight On
Profile
Lots of Photographs with general assessment before cross-section (photos, flat thickness measurement)
Task Group Metallographic Process Document Available on IPC Kavi Site

16. 3 Test Vehicles/Data Set, 25 Sections/TV
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
3 Test Vehicles/Data Set, 25 Sections/TV
Gold Sputtering/Protective Cap Layer

17. IPC Conformal Coating Material & Application “State of the Industry” Assessment Project

18. IPC Conformal Coating Material & Application “State of the Industry” Assessment Project

19. Measurements: Maximum, Minimum, and Top of Component Examples
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
Measurements: Maximum, Minimum, and Top of Component Examples

20. Background: IPC Committee Test
Task Summary: 2,028 cross sections, 3 years, 5 co-ops, Conservatively $350K in labor expenditures

21. Where are we today – All Done!: Cure Method:
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
Where are we today – All Done!:
Cure Method:
Heat Cure: of 10 Sets Completed
UV Cure: 6 of 6 Sets Completed,
Air Cure: of 2 Sets Completed
Air/Heat Combo: 6 of 6 Sets Completed
Polymerized: 1 of 1 Set Completed
Air/Humidity Combo: 1 of 1 Set Completed 21

22. Example Application Details:
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
Example Application Details: SR
Manually Sprayed with Binks Model 2001 conventional gun at angle (approximately 45 degree) with applications at every 90 degrees (the boards are rotated to receive the angle spray from 4 sides to prevent shadowing). UR
Asymtek C740 equipment, SC300 atomizing head, 0.26 mm nozzle, 10 Degree flute, 10 psi fluid pressure, 30 psi atomizing pressure, 4 passes per path direction procedure. ER
Atomized Spray Coating, 10 passes each in X & Y axis, IR Profile followed by Batch Cure 45 min, mils.

23. Coating Type: Application: Cure Method: Air/Heat & Heat Cure 17 mils
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
Coating Type:
AR – Acrylic Only
Application:
M+A Spray, DIP, Brush
Cure Method:
Air/Heat & Heat Cure
17 mils
Notes:
1) Lines (Green to Red) Manual Brush & Dip similar nominal thickness, but DIP higher coverage with more variability
2) Line (Blue)
Has the lowest variation from the nominal thickness 23

24. Coating Type: Application: Auto & Man Spray Cure Method:
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
Coating Type:
UR – Urethane Only
Application:
Auto & Man Spray
Cure Method:
Heat, UV & Air/Heat
Notes:
1) There are 3 nominal thicknesses
2) Lines (Green to Black) Air/Heat tracks UV; but slightly thinner
3) Lines (Red to Blue)
Overall nominal thickness higher coverage higher 24

25. Coating Type: Application: Auto Spray Cure Method: 9.1 mils Heat
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
Coating Type:
UR – Urethane Only
Application:
Auto Spray
Cure Method:
Heat
9.1 mils
Notes:
1) There are 3 nominal thicknesses
2) The (Green to others) nominal thickness along with coverage between the other two
3) Lines (Red to Blue)
Nominal thickness is higher than the blue, but the coverage is lower 25

26. Coating Type: Application: Auto & Man Spray Cure Method:
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
Coating Type:
SR – Silicone Only
Application:
Auto & Man Spray
Cure Method:
Heat, Air & Air/Humidity
Notes:
1) The higher the nominal thickness; higher variation
2) Lines (Green to Purple) Auto-spray; air cure has higher variation then heat 26

27. How Does All of this Effort Pay-off?
IPC Conformal Coating Material & Application “State of the Industry” Assessment Project
How Does All of this Effort Pay-off?
Provides a measure of industry conformal coating process benchmark for both OEM and Customer
Provides both OEM and Customer a common dialogue starting point
Provides tin whisker research community a basis for conformal coating/whisker testing 27

28. Questions ??? 28