Multichip module having a stacked chip arrangement

• US 5,323,060 A
• Filed: 06/02/1993
• Issued: 06/21/1994
• Est. Priority Date: 06/02/1993
• Status: Expired due to Term

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Semiconductor, Inc. (Micron Technology, Inc.)
• Inventors: Fogal, Rich, Ball, Michael B.
• Primary Examiner(s): Jackson, Jerome
• Assistant Examiner(s): GUAY, JOHN FRANCIS
• Application Number:
  US08/071,580
• Time in Patent Office: 384 Days
• Field of Search: 257/685, 257/686, 257/700, 257/67, 257/83, 257/723, 257/724, 257/777, 257/782, 437/208
• US Class Current: 257/777
• CPC Class Codes: H01L 2224/05599 Material
• 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 2224/32014 the layer connector being smaller than the bonding area, e.g. bond pad
• CPC Class Codes: H01L 2224/32145 the bodies being stacked
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48095 Kinked
• CPC Class Codes: H01L 2224/4813 Connecting within a semiconductor or solid-state body, i.e. fly wire, bridge wire
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48175 the item being metallic
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2224/49433 outside the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/78 Apparatus for connecting with wire connectors
• CPC Class Codes: H01L 2224/8319 Arrangement of the layer connectors prior to mounting
• CPC Class Codes: H01L 2224/8385 using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 24/32 : of an individual layer connector
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/49 : of a plurality of wire connectors
• CPC Class Codes: H01L 24/73 : Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 24/85 : using a wire connector wire bonding in general B23K20/004
• CPC Class Codes: H01L 25/0652 : the devices being arranged next and on each other, i.e. mixed assemblies
• 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 2924/00012 : 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 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/0665 : Epoxy resin
• CPC Class Codes: H01L 2924/07802 : not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/19105 : in a side-by-side arrangement on a common die mounting substrate
• CPC Class Codes: H01L 2924/19107 : off-chip wires

Abstract

A multichip module includes: a) a multichip module substrate; b) a first chip, the first chip having opposed base and bonding faces, the base face being adhered to the multichip module substrate, the first chip bonding face including a central area and a plurality of bonding pads peripheral to the central area; c) a second chip, the second chip having opposed base and bonding faces, the second chip bonding face including a central area and a plurality of peripheral bonding pads; d) a first/second adhesive layer interposed between and connecting the first chip bonding face and the second chip base face, the first/second adhesive layer having a thickness and a perimeter, the perimeter being positioned within the central area inside of the peripheral bonding pads; e) a plurality of first loop bonding wires bonded to and between the respective first chip bonding pads and the multichip module substrate, the respective first bonding wires having outwardly projecting loops of a defined loop height, the thickness of the adhesive layer being greater than the loop height to displace the second chip base face in a non-contacting relationship above and with respect to the first wires; and f) a plurality of second loop bonding wires bonded to and between the respective second chip bonding pads and the multichip module substrate.

Claims

1. A multichip module comprising:

a multichip module substrate;

a first chip, the first chip having opposed base and bonding faces, the base face being adhered to the multichip module substrate, the first chip bonding face including a central area and a plurality of bonding pads laterally peripheral to the central area;

a second chip, the second chip having opposed base and bonding faces, the second chip bonding face including a central area and a plurality of peripheral bonding pads;

an adhesive layer interposed between and connecting the first chip bonding face and the second chip base face, the adhesive layer having a thickness and a lateral perimeter, the lateral perimeter being positioned entirely within the central area inside of the peripheral bonding pads;

a plurality of first loop bonding wires bonded to and between the respective first chip bonding pads and the multichip module substrate, the respective first loop bonding wires having outwardly projecting loops of a defined loop height, the loop height being defined by the distance between the first chip bonding face and the vertexes of the outwardly projecting loops of the first loop bonding wires, the thickness of the adhesive layer being greater than the loop height to displace the second chip base face in a non-contacting relationship above and with respect to the first wires; and

a plurality of second loop bonding wires bonded to and between the respective second chip bonding pads and the multichip module substrate.

2. The multichip module of claim 1 wherein the adhesive comprises a tape.

3. The multichip module of claim 1 wherein the adhesive comprises a tape coated with thermoplastic material.

4. The multichip module of claim 1 wherein the first chip, adhesive and second chip comprise a z-direction multichip stack, the multichip stack having a top-most chip, the top-most chip having a bonding face including a central area and a plurality of bonding pads laterally peripheral to the central area, the multichip module further comprising:

an overlying adhesive layer adhered to the top-most chip bonding face, the overlying adhesive layer having a lateral perimeter, the lateral perimeter being positioned entirely within the top chip central area inside of the peripheral top chip bonding pads.

5. The multichip module of claim 1 wherein the first chip, adhesive and second chip comprise a z-direction multichip stack, the multichip stack having a top-most chip, the top-most chip having a bonding face including a central area and a plurality of bonding pads laterally peripheral to the central area, the multichip module further comprising:

an overlying adhesive layer adhered to the top-most chip bonding face, the overlying adhesive layer having a lateral perimeter, the lateral perimeter being positioned entirely within the top chip central area inside of the peripheral top chip bonding pads; and

the adhesive and the overlying adhesive comprising a tape.