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Underfill Process Guideline for Pb-free Leadless Devices

Idea/Definition Information
Actual Project Stage: 
Idea and Definition
Project Category: 
Lead-Free
Project Leader Company: 
Philips
Background: 

High reliability industries require signifcant testing and rationale for adopting Pb-free processing due to mission criticality and field-life requirements.

Recent investigations have shown that Pb-free solder joints for BGA's and CSP are robust in standard thermal cycling fatigue life-testing, but insufficient testing has been conducted to understand field behavior.

Other work has shown that Pb-free alloys significantly reduce the mechanical shock endurance of Pb-free BGA and CSP assemblies.

Underfill is widely recommended to strengthen Pb-free solder jointsduring thermal cycling and in mechanical shock environments.

Problem: 

The method of selecting underfill materials for specific applications is not well understood. This drives issues of compromised reliability and unnecessary costs.

Previous work such as J-STD-030 addresses processing, testing and acceptance but not reliability and costs.

Approach: 

Discussion will be initiated with underfill suppliers on materials and tradeoffs.

The group will understand use environments for both HDPug users and others.

This project will enlist expertise in finite element modeling as well. Models can focus the material discussion towards the use environment.

We will leverage test vehicles and plans from previous Pb-free HDPUG studies. By adding underfill data, overall conclusions will be enriched.

Definition Stage Documents:

Click the link below to download the

Project Update Santa Clara, CA, February 2010 Member Meeting

HDP User Group Project Facilitator: 
Laurence Schultz
Key Participants: 

3M   
Agilent
Alcatel-Lucent                                       
Asymtek
Celestica
Cisco
Conpart 
DELO
Flextronics
Epotek
Freescale
Fujitsu
DfR
Electronic Materials, Inc
Epoxy Technology
Huawei
IBM
Indium
IST Group
Meadville Group
NAMICS
NSN
Philips
Sanmina SCI
Sumitomo Plastics
Sun
Sunstar Engineering
Venture