Electro-Chemical Migration Definition Stage Project Wallace Ables - Dell HDP User Group Member Meeting Host: IBM/DELL Austin, Texas Sept. 26, 2012 © HDP User Group International, Inc.

2 Problem Statement The current industry standard test protocols were originally developed to identify highly ionic contaminant levels (halides) after a cleaning process. These test protocols are not completely effective at identifying ECM exposures from no-clean flux residues. © HDP User Group International, Inc.

3 Background 1. Various forms of corrosion and Electro Chemical Migration failures on products that pass the current cleanliness and corrosion resistance test protocols have demonstrated that these test procedures are not effective. 2. The failure mechanism is the same regardless what segment of the electronics industry the PCBA is used. 3. The current testing does not take into consideration various acceleration factors associated with no clean flux and product design features. © HDP User Group International, Inc

4 No clean ECM corrosion failures Surface corrosion Solder mask Porosity Open trace / solder mask opening Surface corrosion Dendrite / short / open Dendrite / short © HDP User Group International, Inc.

5 Project Objectives Identify required enhancements to the current industry specifications, test methods, test boards and coupon design to increase detection of ECM and corrosion induced failures when no clean flux systems are used.  Cleanliness testing  Corrosion resistance testing  ECM testing  Maximum acceptable residue levels  Influence of PCB manufacturing  Influence of PCBA design © HDP User Group International, Inc.

Not in immediate scope 6 Some closely aligned aspects of this project will be put off until a follow-on project is underway. Therefore the following issues will not be in the scope of this project: 1.Conformal coating over no-clean fluxes. This may allow ECM under the conformal coating. 2.Solder mask test standards for ECM controls. © HDP User Group International, Inc

7 Project Goals 1.Develop a set of specifications and test methods (or enhancements to the current industry specifications) for cleanliness testing, corrosion resistance testing, and ECM testing to increase detection of corrosion when no clean flux systems are used. Primary areas of investigation: a.Characterize failures escaping current test methods b.Test flux residues: SMT, Wave Solder, Rework c.Test flux application methods: controls, acceptable application levels, measurement methods and test methods d.Enhance test board and test coupon designs e.Identify acceptable flux residue levels by product class level © HDP User Group International, Inc.

8 Project Goals 2.Identify the influence of PCB manufacturing and design properties on the development of ECM and corrosion failures. a.Exposed Cu from solder mask openings (pin holes, undercut, damage, etc.) b.Moisture and chemical absorption properties c.Minimum cure level d.Voltage bias on a trace e.Minimum spacing between positive and negative features to prevent ECM © HDP User Group International, Inc.

9 Proposed Execution Plan How the project will answer the Objective and Goals Compile list of current test methods / standards / test vehicles Compile list of failure modes from team members Correlate corrosion failures to gaps in current test methods Identify modifications required to current test methods Develop DOE’s to validate proposed changes Perform DOE’s. Collect and evaluate test data Draft proposed changes to test methods / standards / test vehicles Provided proposed changes and supporting data to test standard owners. Write final report

10 Current Project Execution Plan Project TaskTargetActual List current test methods / etc. List failure modes Correlate failures to gaps in test methods Identify modifications required to test methods Develop DOE’s to validate proposed changes Perform DOE’s. Collect and evaluate test data Draft proposed changes to test methods / etc. Provided proposed changes and supporting data to IPC, JEDIC, etc. Write final report © HDP User Group International, Inc.

Have started the list of specifications that maybe affected. Have started gathering defects. Started gathering existing possible Test Vehicles. Have met with IPC sub-committees on Coatings, Cleaning and Testing to discuss our activity. 11 Current Project Activities

Team Members –To Date Agilent Alcatel-Lucent Arlon ASE Cisco Cobar Ciena Dell Ericsson Flextronics Fujitsu IBM Intel Isola Multek Nihon-Superior Oracle Phillips Plexus Rockwell TTM Tech 12 © HDP User Group International, Inc.

Key issue to be addressed: Continue defining the scope of the project Continue to identify the areas of specifications effected Continue collecting Corrosion data and examples from team members 13