Tin Whiskers | onsemi

Mitigation Strategies

Changing the lead plating material to 100% matte Sn (tin) from SnPb raises industry concerns about tin whisker growth. onsemi has implemented the following mitigation strategies to minimize the occurrence of tin whiskers.

Increased the plating thickness from 5 µm to 7.5 µm minimum; 10 µm nominal
Implemented a post - plate anneal of 150 ° C for 1 hour within 24 hours of plating
Implemented strict plating process controls

Whisker Testing

onsemi has conducted tin whisker testing following the guidelines of JEDEC standard JESD22A121. Testing has been conducted on packages utilizing Alloy 42 and Cu leadframe materials with matte tin lead finish. Three test conditions have been used to evaluate whisker growth: Temperature Cycling (-55/+85°C) Ambient Storage at 30°C/60%RH, and High Temperature/High Humidity Storage at 60°C/87%RH.

onsemi's internal whisker acceptance spec is 50µ maximum length. All whisker test results to date have passed this spec.

Baseline tin whisker test results available for onsemi assembly sites. Click on each report to download.

Application Note

Leshan

Alloy42 leadframe

Tin Whisker report for onsemi site in Leshan using matte tin plating over Alloy42 leadframe.

Seremban

Alloy42 leadframe

Tin Whisker report for onsemi site in Seremban using matte tin plating over Alloy42 leadframe

Seremban

Copper leadframe

Tin Whisker report for onsemi site in Seremban using matte tin plating over Copper leadframe.

Carmona

Copper leadframe

Tin Whisker report for onsemi site in Carmona using matte tin plating over Copper leadframe