Microvoid Impact and Solder Cracking

Assembled packages with microvoids that have resulted in solder cracking and limited attachment areas.
Photography courtesy of Intel Corporation.

Microvoids Impact Reliability

Intel has characterized the reliability impact of microvoids on Intel product as follows:

• Excessive microvoids reduce solder fatigue margin
  • Excessive microvoids degrade temperature cycle performance
  • Excessive microvoids cause cracks to initiate sooner and propagate faster.
  • The degree of the effect is based on microvoid density.
• Board level shock failures have been observed when severe microvoids were present
• Excessive microvoids have led to 100% solder joint crack

Definition Source: Intel Corporation

Solder Cracking

Planar microvoids differ in size and density from the more common process voids that are found in solder joints. Planar microvoids reduce the reliability by accelerating solder cracking during thermal cycling. Reliability is further impacted when dealing with advanced fine pitch technology, such a BGA applications.

To view or download the AlphaSTAR Microvoid Study, click here.