Survivability of soldered leadless chip carriers after temperature cycling
Temperature cycling evaluations were conducted on leadless chip carriers (LCCs) soldered to thick film networks (TKNs). Various temperature ranges, rates of change, cycle times, number of cycles, and sizes of LCCs were used. The TKNs were attached to metal backing plates with 63Sn/37Pb solder preforms using an infrared vacuum soldering process. The LCCs were attached to Pt/Au TKNs with 63Sn/37Pb solder paste using a belt reflow process. Visual examination and cross-sectional analysis were used to evaluate the survivability. Results were also correlated with finite elemental analysis. Considering the initial results, possible solutions included changing the solder from 63Sn/37Pb to 50Pb/50In, deleting the metal backplate, changing the rate of change in the temperature cycle, and/or adding leads to the large LCCs. Because of a system requirement, the rate of change in the temperature cycle could not be changed. Since there was no long term reliability information on the Pt/Au TKN with 50Pb/50In solder, this option was also dropped. Additional evaluations showed little difference in the survivability of large LCC solder joints with or without the metal backing plate. The final results indicated that LCCs beyond a certain physical size required compliant leads to survive the temperature cycle requirements.
- Research Organization:
- Allied-Signal Aerospace Co., Kansas City, MO (United States). Kansas City Div.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-76DP00613
- OSTI ID:
- 10189880
- Report Number(s):
- KCP-613-5388; CONF-941199-3; ON: DE95001497; TRN: 94:010027
- Resource Relation:
- Conference: Joint American Ceramic Society (ACS) Electronics Division/ISHM Fall meeting,Boston, MA (United States),15-17 Nov 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
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