Patent US4609586A successfully refreshed from Google Patents.
← Back to Patent Explorer
US4609586A Expired / Lapsed US ⏱️ 0.0 years remaining

Thermally conductive printed wiring board laminate

Assignee: Boeing Co
•
Filing: 1984-08-02
•
Granted: 1986-09-02
•
Expires: 2004-08-02
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A printed wiring board laminate is disclosed that is particularly suitable for use with leadless surface mounted devices such as ceramic chip carries. The laminate combines a low coefficient of thermal expansion in the X-Y direction with thermal conductivity. In one embodiment, the laminate comprises a support fabricated from graphite fiber reinforced metal adhesively secured to a printed wiring board fabricated from dielectric (e.g., glass) fiber reinforced resin. The support has an X-Y coefficient of thermal expansion less than about 4 ppm/°C., and the printed wiring board has a coefficient of thermal expansion greater than about 10 ppm/°C. In a second embodiment, the support comprises a core of graphite fiber reinforced metal or resin sandwiched between two metal sheets.

Inventors

  • 👤 Warren M. Jensen
  • 👤 William C. Wilkinson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 11:29
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/46; H05K3/4611; H05K3/4641; H05K1/00; H05K1/02; H05K1/03; H05K1/05; H05K1/056; H05K2201/00; H05K2201/03; H05K2201/032; H05K2201/0323; H05K3/0058; H05K3/38; H05K3/386; H05K3/40; H05K3/42; H05K3/429; H05K3/44; H05K3/445; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/12; Y10T428/12486; Y10T428/24; Y10T428/24802; Y10T428/24917; Y10T428/249921; Y10T428/249924; Y10T428/249927; Y10T428/30; Y10T428/31504; Y10T428/31511; Y10T428/31529

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 139 words
A printed wiring board laminate adapted for use with a ceramic chip carrier, the printed wiring board laminate comprising: an electrically conductive support comprising a metal matrix reinforced by graphite fiber, the support having a coefficient of thermal expansion parallel to the surface of the laminate of less than about 4 parts per million/°C.; and a printed wiring board comprising dielectric fiber reinforced resin, the printed wiring board being secured to the support by means of an adhesive and having a coefficient of thermal expansion greater than about 10 parts per million/°C.; whereby the apparent coefficient of thermal expansion of the laminate parallel to the surface of the laminate approximates the coefficient of thermal expansion of a ceramic chip carrier, and whereby heat generated by components mounted to the printed wiring board may be conducted away by the support.
Claim 2
Dependent Claim 139 words
A printed wiring board laminate adapted for use with a ceramic chip carrier, the printed wiring board laminate comprising: an electrically conductive support comprising a metal matrix reinforced by graphite fiber, the support having a coefficient of thermal expansion parallel to the surface of the laminate of less than about 4 parts per million/°C.; and a printed wiring board comprising dielectric fiber reinforced resin, the printed wiring board being secured to the support by means of an adhesive and having a coefficient of thermal expansion greater than about 10 parts per million/°C.; whereby the apparent coefficient of thermal expansion of the laminate parallel to the surface of the laminate approximates the coefficient of thermal expansion of a ceramic chip carrier, and whereby heat generated by components mounted to the printed wiring board may be conducted away by the support.
Claim 3
Dependent Claim 19 words
The laminate of claim 1, wherein the metal is selected from the group consisting of aluminum, magnesium and copper.
Claim 4
Dependent Claim 10 words
The laminate of claim 1, wherein the metal is aluminum.
Claim 5
Dependent Claim 15 words
The laminate of claim 1, wherein the support consists of 40%-60% by volume graphite fiber.
Claim 6
Dependent Claim 55 words
The laminate of claim 1, wherein the graphite fiber comprises a first set of graphite fibers extending in a first direction parallel to the surface of the laminate, and a second set of graphite fibers extending in a second direction parallel to the surface of the laminate and inclined with respect to the first direction.
Claim 7
Dependent Claim 148 words
A printed wiring board laminate adapted for use with a ceramic chip carrier, the printed wiring board laminate comprising: an electrically conductive support comprising a core positioned between two metal sheets, the core comprising a matrix reinforced by graphite fiber, the support having a coefficient of thermal expansion parallel to the surface of the laminate of less than about 4 parts per million/°C.; and a printed wiring board comprising dielectric fiber reinforced resin, the printed wiring board being secured to the support by means of an adhesive and having a coefficient of thermal expansion greater than about 10 parts per million/°C.; whereby the apparent coefficient of thermal expansion of the laminate parallel to the surface of the laminate approximates the coefficient of thermal expansion of a ceramic chip carrier, and whereby heat generated by components mounted to the printed wiring board may be conducted away by the support.
Claim 8
Dependent Claim 148 words
A printed wiring board laminate adapted for use with a ceramic chip carrier, the printed wiring board laminate comprising: an electrically conductive support comprising a core positioned between two metal sheets, the core comprising a matrix reinforced by graphite fiber, the support having a coefficient of thermal expansion parallel to the surface of the laminate of less than about 4 parts per million/°C.; and a printed wiring board comprising dielectric fiber reinforced resin, the printed wiring board being secured to the support by means of an adhesive and having a coefficient of thermal expansion greater than about 10 parts per million/°C.; whereby the apparent coefficient of thermal expansion of the laminate parallel to the surface of the laminate approximates the coefficient of thermal expansion of a ceramic chip carrier, and whereby heat generated by components mounted to the printed wiring board may be conducted away by the support.
Claim 9
Dependent Claim 11 words
The laminate of claim 6, wherein the matrix comprises a resin.
Claim 10
Dependent Claim 11 words
The laminate of claim 6, wherein the matrix comprises a metal.
Claim 11
Dependent Claim 12 words
The laminate of claim 6, wherein the metal sheets comprise copper sheets.
Claim 12
Dependent Claim 15 words
The laminate of claim 6, wherein the core consists of 40%-60% by volume graphite fiber.
Claim 13
Dependent Claim 55 words
The laminate of claim 6, wherein the graphite fiber comprises a first set of graphite fibers extending in a first direction parallel to the surface of the laminate, and a second set of graphite fibers extending in a second direction parallel to the surface of the laminate and inclined with respect to the first direction.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-09-01 1990-03-03 1990-09-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-09-01 1994-03-03 1994-09-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-09-01 1998-03-03 1998-09-02 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag