Using High Speed Shear and Cold Ball Pull to Characterize Lead Free Solder Alloys and Predict Board Level Drop Test Performance

2007 ◽  
Author(s):  
Michael E. Johnson ◽  
Henry Y. Lu ◽  
David Lawhead ◽  
Ted Tessier ◽  
Doug Scott ◽  
...  
Keyword(s):  
Test Performance ◽  
High Speed ◽  
Drop Test ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Free Solder ◽  
Board Level

Effect of Solder Composition and Substrate Surface Finish on Board Level Drop Test Reliability

2005 ◽  
Author(s):  
Don-Son Jiang ◽  
Joe Hung ◽  
Yu-Po Wang ◽  
C. S. Hsiao
Keyword(s):  
Solder Joint ◽  
Substrate Surface ◽  
Drop Impact ◽  
Drop Test ◽  
Test Reliability ◽  
Lead Free ◽  
Lead Free Solder ◽  
Snagcu Solder ◽  
Free Solder ◽  
Board Level

For handheld or portable telecommunication devices such as mobile phone, PDA, etc., board level joint reliability during drop impact is a great concern to simulate mishandling during usage. In general, solder composition and substrate surface finish would principally determine the solder joint reliability. Board level drop test reliability of two solder compositions (SnPb and lead free SnAgCu) and surface finishes (Ni/Au and OSP) were examined in this study. The result indicated SnAgCu lead free solder showed poorer reliability life than Sn-Pb solder during drop impact. The crack path in SnPb solder joint almost went through bulk solder near substrate side. However, another IMC/Ni interfacial failure mode near substrate side was found in SnAgCu solder to cause lower reliability. This difference could attribute to higher strength of SnAgCu solder and deformation with higher strain rate in drop test. Comparison between two surface finishes indicated Ni/Au is better than OSP in both SnPb and SnAgCu lead free solder joints. In SnAgCu lead free solder joint with OSP, there are thicker Cu6Sn5 IMC and many large Ag3Sn IMC plates in interface to degrade the interfacial bonding, so drop impact would easily cause the all cracks through IMC/Cu interface and then reduce the reliability.

Board Level Drop Tests Comparing Lead-Free and Eutectic Solder Interconnects on a BGA Package for Mobile ICT Applications

2004 ◽  
Author(s):  
Greg M. Heaslip ◽  
Jeff M. Punch ◽  
Bryan A. Rodgers ◽  
Claire Ryan
Keyword(s):  
High Speed ◽  
Printed Circuit Boards ◽  
Liquid Crystal Display ◽  
Failure Mechanisms ◽  
Lead Free ◽  
Lead Free Solder ◽  
Drop Tests ◽  
Free Solder ◽  
Board Level ◽  
The Impact

There is considerable reported evidence that a large percentage of failures which afflict portable electronic products are due to impact or shock during use. Failures of the external housing, internal electronic components, package-to-board interconnects, and liquid crystal display panels may occur as the result of accidental drops. Moreover, the introduction of lead-free solder to the electronics industry will bring additional design implications for future generations of mobile information and communication technology (ICT) applications. In this paper, drop tests performed on printed circuit boards (PCBs) populated with ball grid arrays (BGAs) are reported. During testing, measurements from strain gages were recorded using a high-speed data acquisition system. Electrical continuity through each package was monitored during the impact event in order to detect failure of package-to-board interconnects. Life distributions were established for both lead-free and eutectic solders for various drop heights. Microsections of the failed interconnects were obtained to determine the failure mechanisms for a range of drop heights. The life test data presented in this paper suggests that for board level drop testing different failure mechanisms can occur at different stress levels and that there is a considerable difference between lead-free solder characteristic life and tin-lead (SAC) solder characteristic life.

scholarly journals Electrochemical migration of lead-free solder alloys in Na2SO4 environment

2017 ◽  
Author(s):  
Balint Medgyes ◽  
Sandor Adam ◽  
Lajos Tar ◽  
Vadimas Verdingovas ◽  
Rajan Ambat ◽  
...  
Keyword(s):  
Lead Free ◽  
Electrochemical Migration ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Free Solder
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