US4831723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct bond circuit assembly with crimped lead frame
Assignee: TDY Industries LLC
•
Filing: 1988-04-12
•
Granted: 1989-05-23
•
Expires: 2008-04-12
Abstract
Abstract An electric circuit assembly (10) includes a ceramic substrate (14), a copper lead frame (20) having pad portions (22, 24, 26) directly bonded on the substrate, crimped portions (28, 30, 32) extending from the pad portions in a humped configuration above the substrate, and extension portions (34, 36, 38) extending from the crimped portions laterally beyond the substrate. The crimped portions prevent bonding of the extension portions to the substrate, to enable upward bending of the extension portions and crimped portions along bend lines (54) spaced laterally inwardly of the outer edge (18) of the substrate.
Inventors
- 👤 Lance R. Kaufman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:09
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/481; H05; H05K; H05K3/00; H05K3/40; H05K3/4092; H05K1/00; H05K1/02; H05K1/0271; H05K1/03; H05K1/0306; H05K3/10; H05K3/20; H05K3/202; H10W72/00; H10W72/90; H10W72/931; H10W72/932; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121; Y10T29/49124; Y10T29/49147; Y10T29/49149
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
174 words
A method of making an electric circuit assembly comprising: providing an electrically insulating thermally conductive non-metallic refractory substrate; providing a substantially flat electrically conductive metallic lead frame having a pad portion and an extension portion and a linking crimped portion therebetween having a humped configuration extending slightly above the plane of said pad portion and said extension portion; directly bonding said lead frame pad portion to said substrate by placing said lead frame pad portion in contact with said substrate such that said crimped portion is spaced above said substrate, and said extension portion extends laterally beyond the outer edge of said substrate, and the junction of said crimped portion and said extension portion is proximate the outer edge of said substrate, heating said lead frame and said substrate to a temperature below the melting point of said lead frame to form a eutectic with said lead frame which wets said lead frame and said substrate, and cooling said lead frame and said substrate, with said lead frame pad portion bonded to said substrate.
Claim 2
Independent Claim
174 words
A method of making an electric circuit assembly comprising: providing an electrically insulating thermally conductive non-metallic refractory substrate; providing a substantially flat electrically conductive metallic lead frame having a pad portion and an extension portion and a linking crimped portion therebetween having a humped configuration extending slightly above the plane of said pad portion and said extension portion; directly bonding said lead frame pad portion to said substrate by placing said lead frame pad portion in contact with said substrate such that said crimped portion is spaced above said substrate, and said extension portion extends laterally beyond the outer edge of said substrate, and the junction of said crimped portion and said extension portion is proximate the outer edge of said substrate, heating said lead frame and said substrate to a temperature below the melting point of said lead frame to form a eutectic with said lead frame which wets said lead frame and said substrate, and cooling said lead frame and said substrate, with said lead frame pad portion bonded to said substrate.
Claim 3
Dependent Claim
38 words
The invention according to claim 1 comprising bending said lead frame extension portion and crimped portion upwardly from said substrate at said pad portion along a bend line spaced laterally inwardly from said outer edge of said substrate.
Claim 4
Dependent Claim
52 words
The invention according to claim 2 wherein said junction of said crimped portion and said extension portion is subject to tack bonding with said substrate proximate said outer edge, which tack bond is readily broken, and comprising breaking said tack bond during said upward bending of said extension portion and crimped portion.
References Cited (Backward Citations)
US3744120A
Cited
US3766634A
Cited
US3854892A
Cited
US3993411A
Cited
US3911553A
Cited
US3958075A
Cited
US3994430A
Cited
US4129243A
Cited
US4156148A
Cited
US4394530A
Cited
US4196411A
Cited
US4218724A
Cited
US4250481A
Cited
US4266140A
Cited
US4215235A
Cited
US4445271A
Cited
US4449165A
Cited
US4488202A
Cited
US4498120A
Cited
US4574162A
Cited
US4449292A
Cited
US4500029A
Cited
US4546410A
Cited
US4554613A
Cited
US4546411A
Cited
US4577387A
Cited
US4630174A
Cited
US4700273A
Cited
US4713723A
Cited
US4724514A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-22 | 1992-11-21 | 1993-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-22 | 1996-11-21 | 1997-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-22 | 2000-11-21 | 2001-05-23 | $7700.00 | Window Closed / Lapsed |