Low-cost semiconductor device package process

• US 4,908,086 A
• Filed: 06/24/1985
• Issued: 03/13/1990
• Est. Priority Date: 06/24/1985
• Status: Expired due to Term

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Goodrich, Gary B., Belani, Jadish G.
• Primary Examiner(s): Gallagher, John J.
• Application Number:
  US06/747,713
• Time in Patent Office: 1,723 Days
• Field of Search: 156/331.1, 156/331.5, 156/281, 524/104, 524/440, 29/588, 174/52 PE, 437/1, 437/218, 437/210
• US Class Current: 156/281
• CPC Class Codes: C08G 73/1067 Wholly aromatic polyimides, i.e. having both tetracarboxylic and diamino moieties aromatically bound
• CPC Class Codes: H01B 1/22 the conductive material comprising metals or alloys
• CPC Class Codes: H01L 2224/2919 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48472 the other connecting portion not on the bonding area also being a wedge bond, i.e. wedge-to-wedge
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/83191 wherein the layer connectors are disposed only on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/83805 involving forming a eutectic alloy at the bonding interface
• CPC Class Codes: H01L 2224/83855 Hardening the adhesive by curing, i.e. thermosetting
• CPC Class Codes: H01L 23/4828 Conductive organic material or pastes, e.g. conductive adhesives, inks
• CPC Class Codes: H01L 24/29 of an individual layer connector
• CPC Class Codes: H01L 24/32 of an individual layer connector
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/83 using a layer 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 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/0132 : Binary Alloys
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/07025 : Polyimide
• CPC Class Codes: H01L 2924/07802 : not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/12044 : OLED
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15153 : the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/15165 : Monolayer substrate
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap

Abstract

An adhesive composition for attaching semiconductor die to a substate of a semiconductor device package includes a crosslinkable resinous polyimide, and an aminosilane cross-linking agent. For applications where backside contact to the semiconductor die is desired, the composition also contains finely divided conductive metal, such as silver flakes. When used in a novel process in which the adhesive composition is placed on the semiconductor device substrate prior to gelling, outgassed, a semiconductor die is placed on the outgassed composition, and the composition cured, the resulting semiconductor device package meets military specifications with a substantial cost reduction.

Claims

1. A process for encapsulating a semiconductor die, which comprises:

adding an alkylaminotrialkoxysilane crosslinking agent to a crosslinkable resinous polyimide precursor which will cure to give a polyimide having a recurring unit of the formula;

##STR2## in which R₁ and R₂ are radicals of a tetravalent aromatic group and a divalent aromatic group, respectively, and n is a positive integer,

degassing the resulting composition,

applying the degassed composition to a substrate prior to gelling of the composition,

positioning the semiconductor die on the substrate,

curing the degassed composition to attach the semiconductor die to the substrate,

applying an enclosure over the semiconductor die on the substrate, and

hermetically sealing the attached semiconductor die by bonding the enclosure to the substrate over the semiconductor die through application of heat at a temperature of at least about 450°

C.

2. The process of claim 1 in which the degassing is carried out in a vacuum.

3. The process of claim 1 additionally comprising the step of adding a sufficient amount of a finely divided conductive metal to render the composition conductive in the cured state prior to degassing the composition.