Patent US5026667A successfully refreshed from Google Patents.
US5026667A
Expired / Lapsed
US
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Producing integrated circuit chips with reduced stress effects
Assignee: Analog Devices Inc
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Filing: 1989-10-18
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Granted: 1991-06-25
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Expires: 2009-10-18
Abstract
Abstract Wire-bonded IC chips are coated with siloxane polyimide and cured to a hardened state. The coating is applied over portions of the circuitry which are stress-sensitive. The coating is spaced away from the wire-bond regions of the chip. Thereafter, the coated chip is plastic encapsulated in conventional fashion.
Inventors
- 👤 Carl M. Roberts, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:24
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/90; H10W74/00; H10W74/01; H10W74/10; H10W74/111; H10W74/121; H10W74/40; H10W74/47; H10W74/476; H10W72/50; H10W72/531; H10W72/536; H10W72/541; H10W72/5449; H10W72/59; H10W72/931; H10W72/932; H10W72/951; H10W72/952
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
97 words
In making plastic-encapsulated IC ships formed with an integrated circuit having stress-sensitive portions, the method of reducing stress-induced effects on the performance of the integrated circuit, comprising: forming the IC chip including wire-bond pads; applying over the stress-sensitive portions of the chip a coating of flowable insulating material while restricting the flow of the insulating material to provide an insulation free region around each of the wire-bond pads preventing contact between the insulation material and the pads; before or after said coating is applied, bonding wires to the bond pads; and encapsulating said coated chip in plastic.
Claim 2
Dependent Claim
97 words
In making plastic-encapsulated IC ships formed with an integrated circuit having stress-sensitive portions, the method of reducing stress-induced effects on the performance of the integrated circuit, comprising: forming the IC chip including wire-bond pads; applying over the stress-sensitive portions of the chip a coating of flowable insulating material while restricting the flow of the insulating material to provide an insulation free region around each of the wire-bond pads preventing contact between the insulation material and the pads; before or after said coating is applied, bonding wires to the bond pads; and encapsulating said coated chip in plastic.
Claim 3
Dependent Claim
20 words
The method of claim 1, wherein the wires are bonded to the bond pads prior to application of the coating.
Claim 4
Dependent Claim
17 words
The method of claim 2, including the steps of processing the coating to cause it to harden.
Claim 5
Dependent Claim
12 words
The method of claim 1, wherein the flowable material is a polyimide.
Claim 6
Dependent Claim
20 words
The method of claim 4, wherein the material is a polyimide which is cured in two steps at different temperatures.
Claim 7
Dependent Claim
14 words
The method of claim 1, wherein the flowable material is applied by a syringe.
Claim 8
Dependent Claim
102 words
In making plastic-encapsulated IC chips formed with an integrated circuit having stress-sensitive portions, the method of reducing stress-induced effects on the performance of the integrated circuit, comprising: forming the IC chip including wire-bond pads; bonding wires to the bond pads by forming ball bonds; then applying over the stress-sensitive portions of the chip a coating of flowable insulating material while allowing the insulating material to flow into contact with at least one of said pads; the thickness of said flowable material being controlled during application to be less than the height of the ball bond; and encapsulating said coated chip in plastic.
Claim 9
Dependent Claim
102 words
In making plastic-encapsulated IC chips formed with an integrated circuit having stress-sensitive portions, the method of reducing stress-induced effects on the performance of the integrated circuit, comprising: forming the IC chip including wire-bond pads; bonding wires to the bond pads by forming ball bonds; then applying over the stress-sensitive portions of the chip a coating of flowable insulating material while allowing the insulating material to flow into contact with at least one of said pads; the thickness of said flowable material being controlled during application to be less than the height of the ball bond; and encapsulating said coated chip in plastic.
Claim 10
Dependent Claim
24 words
The method of claim 7, wherein the thickness of said material is controlled to be less than one-half the height of the ball bond.
Claim 11
Dependent Claim
125 words
In making plastic-encapsulated IC chips formed with an integrated circuit having stress-sensitive portions, the method of reducing stress-induced effects on the performance of the integrated circuit, comprising: forming a wafer with a plurality of IC chips including wire bond pads; applying over the wafer a coating of flowable insulating material; removing the flowable material from regions of said chips around said bonding pads so as to provide marginal insulation-free regions around each bond pad to laterally separate the wire-bond pads from the insulating material to assure that wires thereafter bonded to each pad are spaced away and thereby isolated from said insulating material; splitting said wafer into separate chips; bonding wires to the bond pads of said chips; and encapsulating said coated chips in plastic.
Claim 12
Dependent Claim
125 words
In making plastic-encapsulated IC chips formed with an integrated circuit having stress-sensitive portions, the method of reducing stress-induced effects on the performance of the integrated circuit, comprising: forming a wafer with a plurality of IC chips including wire bond pads; applying over the wafer a coating of flowable insulating material; removing the flowable material from regions of said chips around said bonding pads so as to provide marginal insulation-free regions around each bond pad to laterally separate the wire-bond pads from the insulating material to assure that wires thereafter bonded to each pad are spaced away and thereby isolated from said insulating material; splitting said wafer into separate chips; bonding wires to the bond pads of said chips; and encapsulating said coated chips in plastic.
Claim 13
Dependent Claim
18 words
The method of claim 9, wherein the flowable insulating material is applied to the wafer by spin coating.
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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) | 1994-06-24 | 1994-12-24 | 1995-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-24 | 1998-12-24 | 1999-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-24 | 2002-12-24 | 2003-06-25 | $7700.00 | Window Closed / Lapsed |