US3795047A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical interconnect structuring for laminate assemblies and fabricating methods therefor
Assignee: International Business Machines Corp
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Filing: 1972-06-15
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Granted: 1974-03-05
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Expires: 1992-06-15
Abstract
Abstract This is a structuring technique for fabricating a multilayer circuit assembly by laminating subassemblies and joining the conductive elements from one subassembly to another both electrically and mechanically by application of a metal powder epoxy (MPE) process at each joint interface. Adjacent conductive surfaces are interconnected by first applying a thin layer of Bstage epoxy to the circuit areas of one conductive surface. Uniformly spherical metal particulate powder is then sprinkled over the entire surface. After moderate heating the powder particulate will remain only on the epoxied areas. The other surface is uniformly covered with B-stage epoxy. The two surfaces so pretreated are then laminated together in an alignment fixture under both pressure and heat. The metal particles, which are spherical and equal sized, and harder than both of the conductive surfaces, are able to penetrate the epoxy layers and into contact with the metallic conductive surfaces during the heating and pressure process. The epoxy is cured with a resultant interconnection that is electrically good and mechanically strong.
Inventors
- 👤 F Lee
- 👤 C Watson
- 👤 O Abolafia
- 👤 J Lau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:00
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/46; H05K3/4611; H05K3/4614; H05K3/462; H05K1/00; H05K1/02; H05K1/0272; H05K2201/00; H05K2201/09; H05K2201/09209; H05K2201/095; H05K2201/09536; H05K2201/096; H05K2201/10; H05K2201/10227; H05K2201/10378; H05K2201/10613; H05K2201/10621; H05K2201/10666; H05K2201/20; H05K2201/2036; H05K3/30; H05K3/32; H05K3/321; H05K3/323; H05K3/4623; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49126; Y10T29/49147; Y10T29/49149
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
102 words
A method of electrically joining adjacent metallic elements comprising the steps: a. applying a thin and uniform coating of epoxy to one surface of a first metallic element, b. applying a metal powder particulate to the epoxy coating on the first metallic element, c. moderately heating the coated first metallic element to effect a partial cure of the epoxy, d. removing excessive metal powder particulate, e. applying a uniform layer of epoxy coating to the opposing metallic surface of a second metallic element, f. aligning the opposing metallic elements, and g. joining the opposing surfaces by an application of heat and pressure.
Claim 2
Independent Claim
102 words
A method of electrically joining adjacent metallic elements comprising the steps: a. applying a thin and uniform coating of epoxy to one surface of a first metallic element, b. applying a metal powder particulate to the epoxy coating on the first metallic element, c. moderately heating the coated first metallic element to effect a partial cure of the epoxy, d. removing excessive metal powder particulate, e. applying a uniform layer of epoxy coating to the opposing metallic surface of a second metallic element, f. aligning the opposing metallic elements, and g. joining the opposing surfaces by an application of heat and pressure.
Claim 3
Dependent Claim
31 words
A method of electrically joining adjacent metallic elements as described in claim 1 and further characterized by the step of permitting the joined elements to cool under an application of pressure.
Claim 4
Dependent Claim
30 words
A method of electrically joining adjacent metallic elements as defined in claim 1 wherein the metal powder partIculate applied to the first metallic element is uniformly spherical and equal sized.
Claim 5
Dependent Claim
33 words
A method of electrically joining adjacent metallic elements as defined in claim 1 wherein the partial curing of step (c) is effected at a temperature in a range of 180* to 250* F.
Claim 6
Dependent Claim
49 words
A method of electrically joining adjacent metallic elements as defined in claim 1 and wherein the joining effected in step (g) is by an application of heat in the range of 200* to 360* F. and a pressure in the range of 100 to 800 pounds per square inch.
Claim 7
Dependent Claim
32 words
A method of electrically joining adjacent metallic elements as defined in claim 1 wherein a multilayer assembly having a high aspect ratio can be fabricated through a stacking of metallic element subassemblies.
Claim 8
Independent Claim
97 words
A method of physically and electrically conductively joining juxtapositioned metallic elements attached to dielectric substrate members comprising: a. applying a thin and uniform layer of epoxy to one of the metallic surfaces attached to a dielectric substrate, b. applying a metal powder particulate to the epoxy layer, c. partially curing the epoxied layer, d. removing excessive metal powder particulate, e. applying a uniform layer of epoxy to the metallic surface of the opposing dielectric substrate, f. aligning and assembling the dielectric substrates in juxtaposition, and g. finally joining the assemblies by an application of heat and pressure.
Claim 9
Independent Claim
97 words
A method of physically and electrically conductively joining juxtapositioned metallic elements attached to dielectric substrate members comprising: a. applying a thin and uniform layer of epoxy to one of the metallic surfaces attached to a dielectric substrate, b. applying a metal powder particulate to the epoxy layer, c. partially curing the epoxied layer, d. removing excessive metal powder particulate, e. applying a uniform layer of epoxy to the metallic surface of the opposing dielectric substrate, f. aligning and assembling the dielectric substrates in juxtaposition, and g. finally joining the assemblies by an application of heat and pressure.
Claim 10
Dependent Claim
32 words
A method of physically and electrically conductively joining juxtapositioned metallic elements attached to dielectric substrate members as defined in claim 7 wherein the metal powder particulate is uniformly spherical and equal sized.
Claim 11
Dependent Claim
41 words
A method of physically and electrically conductively joining juxtapositioned metallic elements attached to dielectric substrate members as defined in claim 7 wherein the partial curing of step 3 is effected at a temperature in a range of 180* to 250* F.
Claim 12
Dependent Claim
59 words
A method of physically and electrically conductively joining juxtapositioned metallic elements attached to dielectric substrate members as defined in claim 7 wherein the final joining and assembly of step 7 is effected by an application of heat in the range of 200* to 360* F. and a pressure in the range of 100 to 800 pounds per square inch.
Claim 13
Dependent Claim
35 words
A method of physically and electrically conductively joining juxtapositioned metallic elements attached to dielectric substrate members as defined in claim 7 further characterized by permitting the assembly to cool while the joining pressure remains applied.
References Cited (Backward Citations)
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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) | 1977-03-04 | 1977-09-03 | 1978-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-04 | 1981-09-03 | 1982-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-04 | 1985-09-03 | 1986-03-05 | $7700.00 | Window Closed / Lapsed |