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Method for improving attachment reliability of semiconductor chips and modules

  • US 6,251,766 B1
  • Filed: 09/02/1999
  • Issued: 06/26/2001
  • Est. Priority Date: 03/12/1997
  • Status: Expired due to Term
First Claim
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1. A process for forming an improved solder interconnection on a semiconductor device and supporting substrate comprising:

  • forming a raised solder wettable pad structure on said supporting substrate by depositing a first layer on said supporting substrate and depositing a second layer over said first layer, said first and second layers are substantially circular, each having a respective diameter, said diameter of said second layer is in the range of 30-70% of said diameter of said first layer, said first layer has a thickness at least 10% of said diameter of said first layer, said thickness of said first layer is in the range of 33-41 μ

    m (0.0013 to 0.0016 inches) and said second layer has a thickness in the range of 63-76 μ

    m (0.0025 to 0.0030 inches);

    said substrate is one of the group consisting of an organic chip carrier, a ceramic chip carrier, and an organic circuit board;

    depositing a layer of solder over the resultant pad structure;

    placing said semiconductor device, provided with a corresponding solder wettable pad, on said supporting substrate; and

    heating to join said pad on said semiconductor device to said pad structure on said substrate by reflowing said layer of solder.

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