US5803343A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solder process for enhancing reliability of multilayer hybrid circuits
Assignee: HTC Corp
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Filing: 1995-10-30
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Granted: 1998-09-08
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Expires: 2015-10-30
Abstract
Abstract A thick film hybrid multilayer circuit characterized by circuit components that are electrically interconnected with a multilayer structure composed of multiple layers of conductors interlaid with layers of a dielectric material in order to achieve high component density. The circuit components of the hybrid circuit are bonded to the multilayer structure with a novel soldering technique employing multiple solder compositions, which reduces the occurrence of dielectric fatigue cracking from thermal cycling. As a result, the multilayer structure exhibits significantly enhanced thermal fatigue resistance.
Inventors
- 👤 Dwadasi Hare Rama Sarma
- 👤 Christine Ann Paszkiet
- 👤 James Catlin Orem
- 👤 Christopher Roderick Needes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:48
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/01; H10W70/05; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; H05K3/3485; H10W70/60; H10W70/62; H10W70/66; H10W72/00; H10W72/30; H05K1/00; H05K1/02; H05K1/09; H05K1/092; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/035; H05K2201/10; H05K2201/10613; H05K2201/10954; H05K2201/10992; H10W72/381; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49155
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
148 words
A method of forming a thick film hybrid multilayer circuit, the method comprising the steps of: providing a substrate having a surface; forming a thick film multilayer structure on said surface, said multilayer structure including a dielectric layer and a conductor layer supported on said dielectric layer; depositing a first solder layer on a portion of said conductor layer, said first solder layer being formed of a first solder material; depositing a second solder layer over said first solder layer, said second solder layer being formed of a second solder material having a higher tin content and a lower liquidus temperature than said first solder material, thereby to reduce diffusion of tin into said conductor layer, consequently reducing thermal stress in said dielectric layer and increasing its thermal-cycle life; and electrically and mechanically connecting a circuit component to said conductor layer with said first and second solder layers.
Claim 2
Independent Claim
148 words
A method of forming a thick film hybrid multilayer circuit, the method comprising the steps of: providing a substrate having a surface; forming a thick film multilayer structure on said surface, said multilayer structure including a dielectric layer and a conductor layer supported on said dielectric layer; depositing a first solder layer on a portion of said conductor layer, said first solder layer being formed of a first solder material; depositing a second solder layer over said first solder layer, said second solder layer being formed of a second solder material having a higher tin content and a lower liquidus temperature than said first solder material, thereby to reduce diffusion of tin into said conductor layer, consequently reducing thermal stress in said dielectric layer and increasing its thermal-cycle life; and electrically and mechanically connecting a circuit component to said conductor layer with said first and second solder layers.
Claim 3
Dependent Claim
19 words
A method as recited in claim 1 wherein said first and second solder materials are each tin-lead base alloys.
Claim 4
Dependent Claim
19 words
A method as recited in claim 1 wherein said first solder layer is thinner than said second solder layer.
Claim 5
Dependent Claim
41 words
A method as recited in claim 1 wherein said first solder layer is deposited to a thickness of about 5 to about 50 micrometers and said second solder layer is deposited to a thickness of about 50 to about 150 micrometers.
Claim 6
Dependent Claim
16 words
A method as recited in claim 1 wherein said connecting step comprises a reflow solder technique.
Claim 7
Dependent Claim
39 words
A method as recited in claim 5 wherein said connecting step comprises heating said second solder layer to a temperature above the liquidus temperature of said second solder layer but below the liquidus temperature of said first solder layer.
Claim 8
Dependent Claim
28 words
A method as recited in claim 1 wherein said second solder layer is deposited directly on said first solder layer, so as to form a two-layer solder joint.
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) | 2001-09-07 | 2002-03-09 | 2002-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-07 | 2006-03-09 | 2006-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-07 | 2010-03-09 | 2010-09-08 | $7700.00 | Window Closed / Lapsed |