Patent US4862247A successfully refreshed from Google Patents.
US4862247A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Contact joint for semiconductor chip carriers
Assignee: Texas Instruments Inc
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Filing: 1989-01-26
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Granted: 1989-08-29
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Expires: 2009-01-26
Abstract
Abstract A chip carrier (34) having a peripheral edge (40), a bottom surface (42) and an inwardly directed arcuate connecting surface (44) is provided. The chip carrier (34) is connected to a printed wiring board (36) by solder (38). The solder (38) adheres to the metallized portion (46) on the chip carrier (34) and the metallized portion (48) on the printed wiring board (36). The connecting surface (44) allows stress to be more evenly distributed to reduce the occurrence of the cracks in the solder (38) which cause failure of the circuit.
Inventors
- 👤 Lesli Derryberry
- 👤 Tom Petrovich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:30
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/341; H05K3/3431; H05K3/3442; H10; H10W; H10W70/00; H10W70/60; H10W70/67; H10W70/68; H05K2201/00; H05K2201/09; H05K2201/09145; H05K2201/09154; H05K2201/10; H05K2201/10613; H05K2201/10621; H05K2201/10727; Y; Y02; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
96 words
An improved leadless chip carrier including a contact area for joining the chip carrier to conductive pad on a printed wiring board, the leadless chip carrier further including: a peripheral edge; a bottom surface; and a connecting surface including a metallized solder adhering portion flush with the face of the connecting surface, the connecting surface being directed inwardly toward the bottom surface from the peripheral edge to the bottom surface, in order to provide a contact area which allows for an improved distribution of stress in a joint between the chip carrier and the wiring board.
Claim 2
Dependent Claim
96 words
An improved leadless chip carrier including a contact area for joining the chip carrier to conductive pad on a printed wiring board, the leadless chip carrier further including: a peripheral edge; a bottom surface; and a connecting surface including a metallized solder adhering portion flush with the face of the connecting surface, the connecting surface being directed inwardly toward the bottom surface from the peripheral edge to the bottom surface, in order to provide a contact area which allows for an improved distribution of stress in a joint between the chip carrier and the wiring board.
Claim 3
Dependent Claim
15 words
The improved chip carrier of claim 1, wherein said connecting surface includes an arcuate surface.
Claim 4
Dependent Claim
15 words
The improved chip carrier of claim 1, wherein said connecting surface includes a beveled surface.
Claim 5
Dependent Claim
31 words
The improved chip carrier of claim 1, wherein said peripheral edge, said bottom surface and said connecting surface are metallized to match with the conductive pads on the printed wiring board.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-28 | 1993-02-27 | 1993-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-28 | 1997-02-27 | 1997-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-28 | 2001-02-27 | 2001-08-29 | $7700.00 | Window Closed / Lapsed |