METHOD AND APPARATUS FOR PREVENTION OF SOLDER CORROSION

• US 20080067696A1
• Filed: 09/15/2006
• Published: 03/20/2008
• Est. Priority Date: 09/15/2006
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Singh, Prabjit, Torok, John G., Loparco, John J., Goth, Gary F., Kostenko, William P.
• Granted Patent: US 7,651,890 B2
• Time in Patent Office: Days
• US Class Current: 257/777
• 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 multi-chip module with solder corrosion prevention comprising:

one or more chips connected to a substrate by soldering, the substrate disposed on a printed circuit board;

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.

2. The multi-chip module of claim 1 further comprising a second cover sealing a second side of the printed circuit board opposite a first side of the printed circuit board on which the substrate is disposed.

3. The multi-chip module of claim 1 wherein the first cover includes a seal for sealing to the printed circuit board.

4. The multi-chip module of claim 3 wherein the seal for sealing to the printed circuit board is formed of butyl rubber.

5. The multi-chip module of claim 1 wherein the multi-chip module connects to the printed circuit board by a land grid array.

6. The multi-chip module of claim 1 wherein the soldering is a controlled collapse chip connection.

14. The method of claim 1, further comprising:

adsorbing carbon dioxide within the chamber with the molecular sieve.

15. The method of claim 1, further comprising:

sealing a second side of a circuit board opposite a first side of the circuit board that is substantially within the chamber.

7. A multi-chip module with solder corrosion prevention comprising:

one or more chips connected to a substrate by soldering, the substrate disposed on a printed circuit board;

a first cover to contain the one or more chips and the substrate, the first cover having a seal to the printed circuit board;

a heat sink disposed on a second face of the first cover opposite a first face of the first cover nearest to the one or more chips, the heat sink having a cavity facing a through opening in the cover; and

a quantity of molecular sieve desiccant disposed in the cavity of the heat sink.

8. The multi-chip module of claim 7 further comprising a second cover sealing a second side of the printed circuit board opposite a first side of the printed circuit board on which the substrate is disposed.

9. The multi-chip module of claim 7 wherein the first cover includes a seal for sealing to the printed circuit board.

10. The multi-chip module of claim 9 wherein the seal for sealing to the printed circuit board is formed of butyl rubber.

11. The multi-chip module of claim 7 wherein the multi-chip module connects to the printed circuit board by a land grid array.

12. The multi-chip module of claim 7 wherein the soldering is a controlled collapse chip connection.

13. A method of preventing corrosion of chip solder connections, comprising:

sealing the chip in a chamber;

positioning a molecular sieve inside the chamber with the chip; and

adsorbing moisture within the chamber with the molecular sieve.