Patent US5371328A successfully refreshed from Google Patents.
US5371328A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Component rework
Assignee: International Business Machines Corp
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Filing: 1993-08-20
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Granted: 1994-12-06
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Expires: 2013-08-20
Abstract
Abstract An easily reworkable circuit module is provided that allows unusable electronic components that have been encapsulated to be removed from a printed circuit board. A chip or MCM attached to a carrier using direct chip attach methods (DCA), such as C4 or SBC techniques that leave a space between the chip/MCM and carrier, due to the height of the solder balls, connection pads and the like. The present invention places a non-stick release coating on all surfaces intermediate of the chip and carrier. That is, the release coating of the present invention is placed by spraying, or the like between the chip and carrier to form a thin liquid film which inhibits the adhesion of a subsequently applied and cured rigid polymer encapsulant. Thus, when a chip or MCM tests as "bad", rework is a relatively simple matter. The solder connections between the chip and carrier of the module are reflowed and the chip is lifted off. The solder reflow temperature will be below the melting point of the encapsulant, and since the encapsulant did not stick to the chip or carrier, it can be merely wiped away with a dry cloth.
Inventors
- 👤 Barbara L. Gutierrez
- 👤 Cheng-Yuan Yu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:19
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/28; H05K3/288; H05K3/30; H05K3/32; H05K3/34; H05K3/341; H05K3/3431; H05K3/3436; H10; H10W; H10W74/00; H10W74/01; H10W74/012; H10W74/10; H10W74/15; H05K2201/00; H05K2201/10; H05K2201/10613; H05K2201/10954; H05K2201/10977; H05K2201/10992; H05K2203/00; H05K2203/04; H05K2203/041; H05K2203/17; H05K2203/176; H05K3/284; H10W72/00; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/07251; H10W72/20; H10W72/851; H10W72/853; H10W72/856; Y; Y02; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
51 words
An assembly including a carrier with least one electronic component affixed thereto, comprising: means for electrically connecting said component with said carrier; encapsulation means for supporting said electrical connection means; and means for preventing said encapsulation means from adhering to any of said carrier, said electrical connection means and said component.
Claim 2
Dependent Claim
51 words
An assembly including a carrier with least one electronic component affixed thereto, comprising: means for electrically connecting said component with said carrier; encapsulation means for supporting said electrical connection means; and means for preventing said encapsulation means from adhering to any of said carrier, said electrical connection means and said component.
Claim 3
Dependent Claim
19 words
An assembly according to claim 1 wherein said means for preventing are disposed intermediate said carrier and said component.
Claim 4
Dependent Claim
25 words
An assembly according to claim 2 wherein said encapsulation means are disposed intermediate said carrier and said component and contacts only said means for preventing.
Claim 5
Dependent Claim
20 words
An assembly according to claim 3 wherein said component is one of an integrated circuit device and a multichip module.
Claim 6
Dependent Claim
14 words
An assembly according to claim 4 wherein said carrier is a printed wire board.
Claim 7
Dependent Claim
16 words
An assembly according to claim 5 wherein said encapsulation means includes means for excluding environmental contaminants.
Claim 8
Dependent Claim
18 words
An assembly according to claim 5 wherein said means for preventing are comprised of a non-stick coating material.
Claim 9
Dependent Claim
20 words
An assembly according to claim 5 wherein said non-stick coating material is comprised of a silicone or perfluorinated liquid material.
Claim 10
Dependent Claim
17 words
An assembly according to claim 5 wherein said non-stick coating is comprised of a water soluble material.
Claim 11
Dependent Claim
16 words
An assembly according to claim 5 wherein said non-stick coating is comprised of a thermoplastic material.
Claim 12
Dependent Claim
26 words
An assembly according to claim 5 wherein said electrical connection means include solder balls disposed on said component, and electrical connection pads disposed on said carrier.
Claim 13
Dependent Claim
34 words
An assembly according to claim 1 wherein said means for preventing is disposed on a surface of said carrier, intermediate said component and said carrier and extending outwardly around the periphery of said component.
Claim 14
Dependent Claim
23 words
An assembly according to claim 12 wherein said encapsulation means is disposed to encompass said component and to contact said means for preventing.
Claim 15
Dependent Claim
21 words
An assembly according to claim 13 wherein said component is an integrated circuit device and said carrier is a flexible substrate.
Claim 16
Dependent Claim
15 words
An assembly according to claim 14 wherein said means for preventing is a non-stick material.
Claim 17
Dependent Claim
19 words
An assembly according to claim 15 wherein said non-stick material is comprised of a silicone or perfluorinated liquid material.
Claim 18
Dependent Claim
17 words
An assembly according to claim 16 wherein said non-stick material is comprised of a water soluble material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-12-05 | 1998-06-06 | 1998-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-05 | 2002-06-06 | 2002-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-05 | 2006-06-06 | 2006-12-06 | $7700.00 | Window Closed / Lapsed |