Compressive pedestal for microminiature connections

• US 4,716,049 A
• Filed: 06/30/1986
• Issued: 12/29/1987
• Est. Priority Date: 12/20/1985
• Status: Expired due to Fees

• Current Assignee: Hughes Aircraft Company (Rtx Corporation)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Patraw, Nils E.
• Primary Examiner(s): Smith, John D.
• Assistant Examiner(s): Dang, Vi D.
• Application Number:
  US06/880,478
• Time in Patent Office: 547 Days
• Field of Search: 427/96, 427/82, 427/88, 427/259, 427/265, 427/266
• US Class Current: 216/18
• CPC Class Codes: H01L 21/4846 Leads on or in insulating or insulated substrates, e.g. metallisation H01L21/4821 takes precedence; metallisation of ceramics in general C04B41/51; printed circuits H05K3/00
• CPC Class Codes: H01L 2224/13111 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48 of an individual wire connector
• CPC Class Codes: H01L 2224/81801 Soldering or alloying
• CPC Class Codes: H01L 24/72 Detachable connecting means consisting of mechanical auxiliary parts connecting the device, e.g. pressure contacts using springs or clips
• CPC Class Codes: H01L 24/81 using a bump connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01032 Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01049 Indium [In]
• CPC Class Codes: H01L 2924/0105 Tin [Sn]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/014 Solder alloys
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/30105 : Capacitance
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H05K 3/325 : by abutting or pinching, i.e. without alloying process; mechanical auxiliary parts therefor adaptations of leads inserted in holes for press-fit connections H05K3/308
• CPC Class Codes: H05K 3/4007 : Surface contacts, e.g. bumps H05K3/4092 takes precedence; deposition of finish layers on pads H05K3/24; forming solder bumps H05K3/3457
• CPC Class Codes: H05K 3/4092 : Integral conductive tabs, i.e. conductive parts partly detached from the substrate

Abstract

Apparatus is disclosed for providing microelectronic, intra-chip and chip-to-chip interconnections in an ultra-dense integrated circuit configuration. Compressive pedestals 20 are used to form spring-loaded electrical and mechanical interconnections to conductive terminals on a chip interface mesa and chip assembly 28 in order to form a large multi-chip array 23 on an interconnection substrate 24. Methods are also disclosed for fabricating the compressive pedestals 20.

Claims

1. A method for making a resilient microelectronic connective member including the steps of:

providing a substrate for forming said resilient microelectronic connective member;

covering said substrate with a substrate mask having an aperture;

filling said aperture with a filling material which will form a positive meniscus at the top boundary of said substrate mask in order to form a rounded pillar on said substrate within said aperature;

dissolving said substrate mask with a dissolving substance that will remove said substrate mask from said substrate but that will leave said pillar intact on said substrate;

impressing a pedestal design mask over said pillar;

depositing a layer of metal over said pedestal design mask in order to form a resilient microelectronic connective member; and

dissolving said pillar with a dissolving substance that will remove said pillar but that will leave said resilient microelectronic connective member on said substrate.

2. A method for fabricating a compressive pedestal for microminiature connections including the steps of:

providing a multi-layer, dielectric substrate for forming said compressive pedestal for microminiature connection;

covering said substrate with a photoresist substrate mask having a cylindrical holes;

depositing potassium chloride in said hole in order to form a pillar having a generally rounded top portion of said substrate within said cylindrical hole;

dissolving said photoresist substrate mask with a dissolving substrate that will remove said photoresist substrate mask from said substrate but that will leave said pillar intact on said substrate;

impressing a pedestal design mask over said pillar;

depositing a layer of aluminum over said pedestal design mask in order to form a compressive pedestal for microminiature connection; and

dissolving said pillar with a dissolving substance that will remove said pillar but that will leave said compressive pedestal for microminiature connection on said substrate.