Apparatus and method for plating pin grid array packaging modules

• US 5,869,139 A
• Filed: 02/28/1997
• Issued: 02/09/1999
• Est. Priority Date: 02/28/1997
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: McLaughlin, Karen P., Vitek, Victor M., Di Santis, John, Palmatier, Phillip W., Findeis, Paul F., Biggs, Glen N.
• Primary Examiner(s): BELL, JANYCE A
• Application Number:
  US08/808,925
• Time in Patent Office: 711 Days
• Field of Search: 427/304, 427/305, 427/282, 427/443.2, 427/430.1, 118/406, 118/428, 118/503, 118/505, 118/50, 204/297 M, 204/224 R, 205/122, 205/125, 205/136
• US Class Current: 427/282
• CPC Class Codes: C25D 17/08 Supporting racks , i.e. not for suspending
• CPC Class Codes: C25D 5/028 one side electroplating, e.g. substrate conveyed in a bath with inhibited background plating
• CPC Class Codes: C25D 7/12 Semiconductors
• CPC Class Codes: H01L 21/6715 Apparatus for applying a liquid, a resin, an ink or the like H01L21/67126 takes precedence

Abstract

An apparatus and a method for its use for plating pin grid array packaging modules, with a fixture capable of simultaneously holding a plurality of said pin grid array modules such that three-dimensional bottom surface metallurgy (BSM) is sealingly protected during plating of top surface metallurgy (TSM).

Claims

1. An apparatus for plating pin grid array modules equipped with a pinned surface, comprising:

a fixture for holding a plurality of said pin grid modules at the same time, comprising;

a base plate having an upper portion including a planar top surface bounding a plurality of receptacles in said upper portion which open to said planar top surface, wherein each receptacle has sidewalls and a receptacle bottom defining an internal space capable of accommodating a pinned surface of a pin grid module, and each said receptacle includes a vacuum port through which a vacuum can be drawn and maintained between a bottom surface of a pin grid module and said base plate for releasably holding a pin grid module;

a gasket means having a top side and a bottom side wherein said bottom side is supported by said planar top surface of said base plate, and wherein said gasket means has a plurality of spaced openings centered with said receptacles in said upper portion of said base plate; and

a cover frame having a plurality of spaced openings centered with said gasket openings and said receptacles in said upper portion of said base plate, said cover frame having a cover frame bottom surface and top surface, wherein said cover frame bottom surface includes a protuberance capable of exerting clamping pressure on said top side of the gasket means.

2. The apparatus of claim 1, wherein said gasket means comprises a compressible elastomeric material.

3. The apparatus of claim 1, wherein said gasket means comprises neoprene.

4. The apparatus of claim 3, wherein said gasket means has a Durometer "A" hardness reading between about 30 to about 70.

5. The apparatus of claim 1, wherein said base plate comprises a dielectric material.

6. The apparatus of claim 1, wherein said cover frame comprises a dielectric material.

7. A method for simultaneously plating a plurality of pin grid array packaging modules equipped with a pinned surface, comprising the steps of:

(a) providing a fixture for holding a plurality of said pin grid modules at the same time, comprising;

a base plate having an upper portion including a planar top surface bounding a plurality of receptacles in said upper portion which open to said planar top surface, wherein each receptacle has sidewalls and a receptacle bottom defining an internal space capable of accommodating a pinned surface of a pin grid module, and each said receptacle includes a vacuum port through which a vacuum can be drawn and maintained between a bottom surface of a pin grid module and said base plate for releasably holding a pin grid module;

a gasket means having a top side and a bottom side wherein said bottom side is supported by said planar top surface of said base plate, and wherein said gasket means has a plurality of spaced openings centered with said receptacles in said upper portion of said base plate; and

a cover frame having a plurality of spaced openings, said cover frame having a cover frame bottom surface and top surface, wherein said cover frame bottom surface includes a protuberance;

(b) inserting said PGA packaging modules into said receptacles such that portions of said backside of the pin grid modules rest flush upon said top surface of said gasket means;

(c) mounting said cover frame onto said gasket such that said cover frame openings are centered with said gasket openings;

(d) fastening said cover frame to said base plate such that said protuberance on said frame bottom surface exerts clamping pressure on said top side of the gasket means;

(e) creating a vacuum in said receptacles; and

(f) immersing said fixture in a plating bath effective to metal plate a top surface metallurgy (TSM) of the PGA packaging modules while protecting said pinned surface from plating.

8. The method of claim 7, wherein said metal plating is gold.