US5659203A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reworkable polymer chip encapsulant
Assignee: GlobalFoundries Inc
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Filing: 1995-06-07
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Granted: 1997-08-19
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Expires: 2015-06-07
Abstract
Abstract A C4 or flip chip reworkable electronic device is provided comprising integrated circuit chip having conductive pads thereon which pads are electrically connected to corresponding pads on an interconnection substrate by solder connections, wherein the space between the chip and substrate is sealed using a specially defined thermoplastic resin such as polysulfone and polyetherimide.
Inventors
- 👤 Anson Jay Call
- 👤 Stephen Leslie Buchwalter
- 👤 Sushumna Iruvanti
- 👤 Stanley J. Jasne
- 👤 Frank L. Pompeo, Jr.
- 👤 Paul Anthony Zucco
- 👤 Wayne Martin Moreau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:07
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/01; H10W74/012; H10W74/10; H10W74/15; H10W74/40; H10W74/47; H10W74/473; H10W72/00; H10W72/01; H10W72/012; H10W72/01215; H10W72/071; H10W72/072; H10W72/20; H10W72/241; H10W72/851; H10W72/853; H10W72/856; H10W90/00; H10W90/701; H10W90/721; H10W90/724; H10W90/731; H10W90/734
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
84 words
A reworkable electronic device comprising an integrated circuit chip having pads thereon which is electrically connected to corresponding pads on a substrate by solder connections made by a solder reflow process which connections result in a space between the surface of the chip and surface of the substrate and the space is sealed with a thermoplastic polymer around the periphery of the chip, the thermoplastic polymer having a Tg greater than about 120° C. and which polymer does not degrade at solder reflow temperatures.
Claim 2
Dependent Claim
84 words
A reworkable electronic device comprising an integrated circuit chip having pads thereon which is electrically connected to corresponding pads on a substrate by solder connections made by a solder reflow process which connections result in a space between the surface of the chip and surface of the substrate and the space is sealed with a thermoplastic polymer around the periphery of the chip, the thermoplastic polymer having a Tg greater than about 120° C. and which polymer does not degrade at solder reflow temperatures.
Claim 3
Dependent Claim
20 words
The electronic device of claim 1 wherein the thermoplastic polymer encapsulates the first rows of solder connections around the chip.
Claim 4
Dependent Claim
15 words
The electronic device of claim 1 wherein substantially all of the solder connections are encapsulated.
Claim 5
Dependent Claim
24 words
The electronic device of claim 1 wherein the thermoplastic resin is selected from the group consisting of polysulfone, polyethersulfone, polyetherimide, polyarylate and polyimide siloxane.
Claim 6
Dependent Claim
14 words
The electronic device of claim 4 wherein the thermoplastic resin is polysulfone or polyetherimide.
Claim 7
Dependent Claim
13 words
The electronic device of claim 1 wherein the thermoplastic polymer contains a filler.
Claim 8
Dependent Claim
31 words
The electronic device of claim 6 wherein the filler is selected from the group consisting of silica, ceramic, glass/ceramic, barium titanate, alumina, Kevlar, boron, carbon and PBI fibers and mixtures thereof.
Claim 9
Dependent Claim
17 words
The electronic device of claim 1 wherein the integrated circuit chip and the substrate are both silicon.
Claim 10
Dependent Claim
15 words
The electronic device of claim 1 wherein the integrated circuit chip is a passive device.
Claim 11
Dependent Claim
24 words
The electronic device of claim 9 wherein the active device is a very large scale integration (VLSI) or ultra large scale integration (ULSI) chip.
Claim 12
Dependent Claim
17 words
The electronic device of claim 1 wherein the electronic device is electrically connected to another electronic device.
Claim 13
Dependent Claim
16 words
The reworkable electronic device of claim 1 wherein the integrated circuit chip is an active device.
Claim 14
Dependent Claim
25 words
The reworkable electronic device of claim 1 wherein the thermoplastic polymer is applied as a solid in the space and melted to form the seal.
Claim 15
Dependent Claim
34 words
The reworkable electronic device of claim 1 wherein the thermoplastic polymer is dissolved in a solvent and applied at the chip edges and heated to evaporate the solvent and the polymer seals the space.
Claim 16
Dependent Claim
22 words
The reworkable electronic device of claim 14 wherein the polymer is heated under vacuum so that the polymer flows under the chip.
Claim 17
Dependent Claim
46 words
The reworkable electronic device of claim 1 wherein the thermoplastic polymer is in the form of a preform which is applied to the chip and substrate assembly before solder joining and the joined assembly heated, if necessary, to melt the polymer and encapsulate the solder connections.
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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) | 2000-08-18 | 2001-02-17 | 2001-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-08-18 | 2005-02-17 | 2005-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-08-18 | 2009-02-17 | 2009-08-19 | $7700.00 | Window Closed / Lapsed |