Controlled thermal expansion composite and printed circuit board embodying same

• US 4,513,055 A
• Filed: 11/30/1981
• Issued: 04/23/1985
• Est. Priority Date: 11/30/1981
• Status: Expired due to Term

• Current Assignee: TRW Inc. (Northrop Grumman Corporation)
• Original Assignee: TRW Inc. (Northrop Grumman Corporation)
• Inventors: Leibowitz, Joseph D.
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/325,810
• Time in Patent Office: 1,240 Days
• Field of Search: 428/245, 428/251, 428/252, 428/259, 428/901, 428/258, 428/225, 428/257, 174/68.5
• US Class Current: 442/212
• CPC Class Codes: H05K 1/0366 reinforced, e.g. by fibres, fabrics H05K1/036 takes precedence
• CPC Class Codes: H05K 2201/0278 Polymeric fibers
• CPC Class Codes: H05K 2201/029 Woven fibrous reinforcement or textile
• CPC Class Codes: H05K 2201/068 wherein the coefficient of thermal expansion is important
• CPC Class Codes: Y10S 428/901 Printed circuit
• CPC Class Codes: Y10T 442/3252 Including synthetic polymeric strand material

Abstract

A composite characterized by a controlled coefficient of thermal expansion and comprising a thermal coefficient control fabric embedded in a resin matrix and composed of yarns with positive and negative coefficients of thermal expansion. A composite circuit board constructed of the composite and having a coefficient of thermal expansion matched to a particular integrated chip carrier material, such as aluminum oxide.

Claims

1. A composite comprising:

a resin matrix,

a woven thermal expansion coefficient control fabric embedded in said resin matrix including a first group of generally parallel first and second yarns and a second group of generally parallel first and second yarns extending transverse to the yarns of said first group,

said first yarns having a positive coefficient of thermal expansion, and

said second yarns having a negative coefficient of thermal expansion.

2. The composite of claim 1 wherein:

p1 said first yarns comprise glass fibers and said second yarns comprise aramid fibers.

3. A laminated composite comprising:

a plurality of layers each comprising a resin matrix and a woven thermal expansion coefficient contral fabric embedded in said resin matrix including a first group of generally parallel first and second yarns and a second group of generally parallel first and second yarns extending transverse to the yarns of said first group,

said first yarns having a positive coefficient of thermal expansion and

said second yarns having a negative coefficient of thermal expansion.

4. The composite of claim 3 wherein:

said first yarns comprise glass fibers and said second yarns comprise aramid fibers.