USH73H
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated circuit packages
Assignee: Nokia Bell Labs
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Filing: 1983-08-25
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Granted: 1986-06-03
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Expires: 2003-08-25
Abstract
Abstract A package for wire-bonded semiconductor integrated circuit chips is disclosed. The chip is covered by a protective layer of material such as room temperature vulcanizing silicone rubber. The thickness of the layer is such that it covers a portion of the arched wires, thereby concentrating the stresses away from the wire-ball bond interfaces. The chip is encapsulated in a plastic material while providing an air gap between the plastic and protective layer.
Inventors
- 👤 Kenneth K. Claasen
- 👤 Ronald N. Graver
- 👤 Frank P. Pelletier
- 👤 Kurt M. Striny
- 👤 Ronald J. Wozniak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:05
CPC Classifications
H; H10; H10W; H10W99/00; H10W74/00; H10W74/40; H10W74/47; H10W74/10; H10W74/111; H10W74/121; H10W72/00; H10W72/01; H10W72/015; H10W72/01515; H10W72/071; H10W72/075; H10W72/50; H10W72/531; H10W72/536; H10W72/5363; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
142 words
A semiconductor device comprising: a semiconductor chip electrically interconnected to metal leads by means of wires ball bonded to pads on a surface of the chip and extending from the pads to the leads, said wires including arched portions of a varying slope; a thick protective layer formed over and limited to said surface of the chip and including areas over the pads, said layer formed to a thickness which covers at least a part of the arched portions where the slope of the wires is reduced to less than 45° relative to the chip surface, but does not cover the entire length of the wires, said layer comprising a material having a large expansion coefficient and low shear modulus; and a plastic encapsulating material surrounding said chip, protective layer, a portion of said leads, and covering a portion of said wires.
Claim 2
Dependent Claim
142 words
A semiconductor device comprising: a semiconductor chip electrically interconnected to metal leads by means of wires ball bonded to pads on a surface of the chip and extending from the pads to the leads, said wires including arched portions of a varying slope; a thick protective layer formed over and limited to said surface of the chip and including areas over the pads, said layer formed to a thickness which covers at least a part of the arched portions where the slope of the wires is reduced to less than 45° relative to the chip surface, but does not cover the entire length of the wires, said layer comprising a material having a large expansion coefficient and low shear modulus; and a plastic encapsulating material surrounding said chip, protective layer, a portion of said leads, and covering a portion of said wires.
Claim 3
Dependent Claim
15 words
The device according to claim 1 wherein the protective layer is an RTV silicone rubber.
Claim 4
Dependent Claim
26 words
The device according to claim 1 wherein the thickness of the protective layer is within the range 6-15 mils in the areas over the chip pads.
Claim 5
Dependent Claim
35 words
The device according to claim 1 wherein an air gap is formed between the protective layer and plastic encapsulating material having a width in the range 1-5 mils in the areas over the chip pads.
Claim 6
Dependent Claim
35 words
The device according to claim 1 wherein the protective layer material has an expansion coefficient of greater than 200 ppm/°C. and a shear modulus of less than 100 psi at -40° C. to 150° C.
Claim 7
Dependent Claim
29 words
The device according to claim 1 wherein the plastic encapsulating material comprises a material having a coefficient of expansion less than 25 ppm/°C. at -40° C. to 125° C.
Claim 8
Dependent Claim
172 words
A semiconductor device comprising: a semiconductor chip electrically interconnected to metal leads by means of wires ball-bonded to pads on a surface of the chips and extending from the pads to the leads, said wires including arched portions; a layer of RTV silicone rubber formed over and limited to said surface of the chip and including areas over the chip pads, said RTV layer formed to a cured thickness within the range 6-15 mils in the areas over the chip pads so that the RTV layer covers only a portion of the wires, said RTV layer having an expansion coefficient of at least 200 ppm/°C. at -40° C. to 150° C. and a shear modulus of less than 100 psi from -40° C. to 150° C.; and a plastic encapsulating material surrounding said chip, RTV layer, a portion of said leads, and covering a portion of the wires, with a gap between the RTV layer and encapsulant within the range 1-5 mils at room temperature in the areas over the chip pads.
Claim 9
Dependent Claim
172 words
A semiconductor device comprising: a semiconductor chip electrically interconnected to metal leads by means of wires ball-bonded to pads on a surface of the chips and extending from the pads to the leads, said wires including arched portions; a layer of RTV silicone rubber formed over and limited to said surface of the chip and including areas over the chip pads, said RTV layer formed to a cured thickness within the range 6-15 mils in the areas over the chip pads so that the RTV layer covers only a portion of the wires, said RTV layer having an expansion coefficient of at least 200 ppm/°C. at -40° C. to 150° C. and a shear modulus of less than 100 psi from -40° C. to 150° C.; and a plastic encapsulating material surrounding said chip, RTV layer, a portion of said leads, and covering a portion of the wires, with a gap between the RTV layer and encapsulant within the range 1-5 mils at room temperature in the areas over the chip pads.
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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) | 1989-06-02 | 1989-12-02 | 1990-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-02 | 1993-12-02 | 1994-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-02 | 1997-12-02 | 1998-06-03 | $7700.00 | Window Closed / Lapsed |