Assessment of circuit board surface finishes for electronic assembly with lead-free solders
- Bell Labs., Princeton, NJ (United States). Lucent Technologies
- Ford Motor Co., Dearborn, MI (United States)
- Sandia National Labs., Albuquerque, NM (United States)
The suitability of various metallic printed wiring board surface finishes was assessed for new technology applications that incorporate assembly with Lead-free solders. The manufacture of a lead-free product necessitates elimination of lead (Pb) from the solder, the circuit board as well as the component lead termination. It is critical however for the selected interconnect Pb-free solder and the corresponding printed wiring board (PWB) and component lead finishes to be mutually compatible. Baseline compatibility of select Pb-free solders with Pb containing PWB surface finish and components was assessed. This was followed by examining the compatibility of the commercially available CASTIN{trademark} (SnAgCuSb) Pb-free solder with a series of PWB metallic finishes: Ni/Au, Ni/Pd, and Pd/Cu. The compatibility was assessed with respect to assembly performance, solder joint integrity and long term attachment reliability. Solder joint integrity and mechanical behavior of representative 50 mil pitch 20I/O SOICs was determined before and after thermal stress. Mechanical pull test studies demonstrated that the strength of SnAgCuSb solder interconnections is notably greater than that of SnPb interconnections.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 378903
- Report Number(s):
- SAND-96-2265C; CONF-9609212-4; ON: DE96014884; TRN: AHC29620%%117
- Resource Relation:
- Conference: Surface Mount International: advanced electronics manufacturing technologies, San Jose, CA (United States), 3-12 Sep 1996; Other Information: PBD: [1996]
- Country of Publication:
- United States
- Language:
- English
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