MODULE ASSEMBLY AND METHOD OF MAKING SAME

• US 3,590,328 A
• Filed: 10/29/1969
• Issued: 06/29/1971
• Est. Priority Date: 10/29/1969
• Status: Expired due to Term

• Current Assignee: Bert L. Frescura, Harry P. Vossen, Nicholas G. Spilling
• Original Assignee: Bert L. Frescura, Harry P. Vossen, Nicholas G. Spilling
• Inventors: Frescura, Bert L., Spilling, Nicholas G., Vossen, Harry P.
• Application Number:
  US04/872,204
• Time in Patent Office: 608 Days
• US Class Current: 361/708
• CPC Class Codes: H01L 25/13 the devices being of a type provided for in group H01L33/00
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A module assembly includes a sheetlike aluminum substrate, a plurality of semiconductor light emitting elements bonded to one edge of the substrate, and an integrated circuit and metal plane conductor pattern bonded to the lateral surface of the substrate. The conductor pattern and substrate are bonded together by a Teflon FEP coated polyimide film disposed between them. The conductor pattern electrically interconnects the light emitting elements and the integrated circuit and provides input terminals connectable to an external signal source. Selected areas of the module are encapsulated with a very thin layer of silicone compound which is secured to the substrate. The module components are fabricated by bonding and encapsulating steps which permit formation of a thin, mechanically sturdy and integral unit without causing thermal stress in the semiconductor components thereof.

Claims

1. A miniaturized module assembly comprising:

a thermally and electrically conductive plate member having lateral and edge surfaces;

an insulating film overlaying and bonded to a lateral surface of said plate member, said film being apertured to expose a portion of the lateral surface;

an integrated circuit chip bonded to said exposed portion of the lateral surface of said plate member in electrical and thermal contact therewith;

a display assembly including;

an electrically conductive elongated mounting strip;

a plurality of indicating elements attached in spaced-apart relation in a linear array on Said mounting strip;

said mounting strip and attached indicating elements being bonded onto an edge of said plate member;

a metal plane conductor pattern overlaying and bonded to said insulating film, said conductor pattern having a first array of contact points disposed along said edge of said plate member and connected to said plurality of indicating elements, a second array of contact points disposed about the periphery of said exposed portion of the lateral surface and connected to said integrated circuit chip, and a third array of contact points forming end terminals projecting from another edge of said plate member for coupling electrical input signals to said indicating elements and said integrated circuit chip; and

a plastic insulating material providing a thin encapsulating layer over selected areas of said plate member and said metal plane conductor pattern.

2. The module assembly of claim 1:

said plate member having a plurality of apertures therethrough communicating between said lateral surfaces;

said insulating film having apertures coinciding with said plurality of apertures in said plate member; and

said plastic encapsulating material being formed into said apertures to securely hold said thin encapsulating layer.

3. The module assembly of claim 2, wherein said plate member is formed from an aluminum sheet.

4. The module assembly of claim 2, said encapsulating material being formed to expose said first, second and third arrays of contact points, said indicating elements, and said integrated circuit chip.

5. The module assembly of claim 4, further including:

a cover plate overlaying said integrated circuit chip; and

an elongated translucent cap covering said linear array of indicating elements and said first array of contact points connectable to said indicating elements.

6. The module assembly of claim 1, wherein said insulating film is formed of a polyimide material coated on both sides with fluorinated ethylenepropylene.

7. In a method of making a module assembly the steps comprising:

forming a first sheet of metal into a substrate;

forming a second sheet of metal into a conductor pattern;

shaping an insulating film of polyimide material coated on both sides with a temperature sensitive bonding material to overlay a lateral surface of said substrate and to expose a portion of said lateral surface through at least one aperture in said film;

bonding said conductor pattern to said lateral surface of said substrate by placing therebetween said film of coated polyimide material, pressing said substrate and said conductor pattern together with a predetermined pressure, and applying heat at a predetermined temperature to soften said bonding material coatings;

encapsulating selected portions of the bonded substrate and conductor pattern by molding a layer of silicone compound thereon;

attaching a plurality of indicating elements in a linear array onto a metal mounting strip, and bonding said mounting strip onto said exposed edge of said sheet metal substrate; and

attaching an integrated circuit chip to a metal mounting pad and bonding said mounting pad to the exposed lateral surface portion of said substrate;

whereby thermal stress on the module components is minimized during fabrication of the module.

8. The method of claim 7, wherein said temperature sensitive bonding material coating on both sides of said polyimide material is fluorinated ethylenepropylene.

9. The method of claim 7, wherein the first bonding step includes pressing said substrate and said conductor pattern together with a pressure of 275 to 350 pounds per square inch and applying heat at a temperature of 290* to 320* C. for a time period not less than 5 minutes.

10. The method of claim 7, wherein after the steps of forming a substrate and shaping an insulating film there is further included the step of making a plurality of holes through said sUbstrate and said overlaying insulating film, and wherein the step of encapsulating includes molding said silicone compound into said holes to securely hold the encapsulating layer on said substrate and said conductor pattern.