Method and apparatus for prevention of solder corrosion

• US 7,651,890 B2
• Filed: 09/15/2006
• Issued: 01/26/2010
• Est. Priority Date: 09/15/2006
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kostenko, William P., Singh, Prabjit, Torok, John G., Loparco, John J., Goth, Gary F.
• Primary Examiner(s): Louie; Wai-Sing
• Assistant Examiner(s): MONTALVO, EVA Y
• Application Number:
  US11/532,329
• Publication Number:
  US 20080067696A1
• Time in Patent Office: 1,229 Days
• Field of Search: 438/124, 438/127, 438/112, 438/122, 438/115, 257/682, 257/E23.137
• US Class Current: 438/115
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 23/26 including materials for absorbing or reacting with moisture or other undesired substances , e.g. getters
• CPC Class Codes: H01L 23/3672 Foil-like cooling fins or heat sinks being part of lead-frames H01L23/49568
• CPC Class Codes: H01L 25/0655 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00011 Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/1433 Application-specific integrated circuit [ASIC]
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA

Abstract

Disclosed a multi-chip module with solder corrosion prevention including one or more chips connected to a substrate by soldering, the substrate disposed on a printed circuit board. The multi-chip module also includes a quantity of molecular sieve desiccant, and a first cover to contain the one or more chips, the substrate, and the molecular sieve desiccant, the first cover having a seal to the printed circuit board.

Claims

1. A method of preventing corrosion of multi-chip module solder connections, comprising:

disposing a plurality of chips at a first side of a printed circuit board;

defining a cap comprising a heat sink;

disposing a molecular sieve in a cavity of the heat sink, the cavity defining a portion of the cap;

positioning the cap over the first side of the printed circuit board, thereby defining a first chamber in which the plurality of chips is frilly contained;

sealing the cap to the first side of the printed circuit board;

disposing a stiffener at a second side of the printed circuit board thereby defining a second chamber between the stiffener and the second side of the printed circuit board;

sealing the stiffener at the second side of the printed circuit board; and

adsorbing moisture within the first chamber and second chamber with the molecular sieve.

2. The method of claim 1, further comprising:

adsorbing carbon dioxide within the first chamber and the second chamber with the molecular sieve.