US4793543A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solder joint
Assignee: STC PLC
•
Filing: 1987-08-28
•
Granted: 1988-12-27
•
Expires: 2007-08-28
Abstract
Abstract A power component such as a power transistor is mounted on an insulating substrate of, e.g., beryllia by using a thick film deposition technique. A first layer (2) is deposited and a second layer (3) is deposited over the first layer to produce a regular series of troughs and lands, in the preferred embodiment troughs and ridges, whereby voiding in the solder bond is minimized if not eliminated to thus maintain a good thermal conductivity between the component and the substrate.
Inventors
- 👤 Trevor C. Gainey
- 👤 Ian Hall
- 👤 Alan R. Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:58
CPC Classifications
H; H05; H05K; H05K1/00; H05K1/02; H05K1/11; H05K1/111; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/341; H10; H10W; H10W72/00; H10W72/30; H05K1/09; H05K1/092; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/035; H05K2201/0364; H05K2201/0373; H05K2201/10; H05K2201/10007; H05K2201/10166; H05K2201/10613; H05K2201/10954; H05K2201/10969; H05K3/22; H05K3/24; H05K3/245; H05K3/247; H05K3/248; H10W46/00; H10W46/101; H10W46/301; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/073; H10W72/07321; H10W72/07327; H10W72/07331; H10W72/07336; H10W72/07337; Y; Y02; Y02P; Y02P70/00; Y02P70/50; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49144
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
72 words
A method of mounting an electrical component on to a discrete area of an insulating substrate, comprising providing on said discrete area a first thick film conductive layer on the substrate and providing a second thick film conductive layer over the first layer, the second layer forming an evenly distributed series of troughs and lands, and securing the component on to the second layer by means of an adhesive such as solder.
Claim 2
Independent Claim
72 words
A method of mounting an electrical component on to a discrete area of an insulating substrate, comprising providing on said discrete area a first thick film conductive layer on the substrate and providing a second thick film conductive layer over the first layer, the second layer forming an evenly distributed series of troughs and lands, and securing the component on to the second layer by means of an adhesive such as solder.
Claim 3
Dependent Claim
22 words
A method as claimed in claim 1, wherein the ratio of troughs to lands is 30% or less of the discrete area.
Claim 4
Dependent Claim
21 words
A method as claimed in claim 1 wherein the troughs are in the form of elongate grooves separated by elongate ribs.
Claim 5
Dependent Claim
16 words
A method as claimed in claim 1 wherein the electrical component is a power MOS transistor.
Claim 6
Dependent Claim
33 words
A method as claimed in claim 1, wherein the first conductive layer is screen printed on to the substrate and the second conductive layer is screen printed on top of the first layer.
Claim 7
Dependent Claim
14 words
A method as claimed in claim 1 wherein the substrate is beryllia or alumina.
Claim 8
Dependent Claim
36 words
A method as claimed in claim 1 wherein the materials used for the 1st and 2nd layers are selected from the group consisting of copper, palladium, gold, silver, platinum gold, and palladium silver, in any combination.
Claim 9
Dependent Claim
56 words
An insulating substrate for mounting a heat-generating device, comprising a mounting pad in the form of a discrete area on which has been formed a first thick film layer and a second thick film layer on top of the first, the second layer being in the form of an evenly distributed series of troughs and lands.
Claim 10
Dependent Claim
56 words
An insulating substrate for mounting a heat-generating device, comprising a mounting pad in the form of a discrete area on which has been formed a first thick film layer and a second thick film layer on top of the first, the second layer being in the form of an evenly distributed series of troughs and lands.
Claim 11
Dependent Claim
35 words
An insulating substrate as claimed in claim 8, in combination with an electrical component which in use will generate heat, said component being soldered to said series of troughs and lands in said discrete area.
References Cited (Backward Citations)
GB1440545A
Cited
SU538834A1
Cited
US3934336A
Cited
US4413766A
Cited
US4409278A
Cited
US4540462A
Cited
SU1215908A1
Cited
US4650107A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-12-27 | 1992-06-27 | 1992-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-27 | 1996-06-27 | 1996-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-27 | 2000-06-27 | 2000-12-27 | $7700.00 | Window Closed / Lapsed |