US5185498A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit assembly encapsulated with polybutadiene urethane
Assignee: Delphi Technologies Inc
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Filing: 1991-06-11
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Granted: 1993-02-09
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Expires: 2011-06-11
Abstract
Abstract An acceleration sensor is packaged in an open can and encapsulated in an elastomeric polybutadiene compound which maintains its mechanical properties over a range of -40° C. to 105° C. and transmits acceleration to the sensor with a unity transfer function. The encapsulation material comprises about 90 to 100 pbw of polyol and about 20 pbw of isocyanate, the polyol consisting of at least 70% of hydroxy-polybutadiene. For enhanced adhesion a foaming agent and/or an epoxy is added to the mixture.
Inventors
- 👤 Henry M. Sanftleben
- 👤 Ralph D. Hermansen
- 👤 Gary R. Shelton
- 👤 Petrina L. Schnabel
- 👤 Dennis T. Baird
- 👤 Douglas C. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:06
CPC Classifications
G; G01; G01P; G01P1/00; G01P1/02; G01P1/023; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
97 words
An electrical assembly subject to high thermal stresses comprising: electrical components; container means for containing the electrical components; and encapsulating means in the container means and surrounding the electrical components for environmentally protecting the components comprising polybutadiene urethane having a glass transition temperature below -10° C., and mechanical properties at 25° C. of a hardness of 15 to 90 shore A durometer, an elongation of 50 to 300%, and a tensile strength of 75 to 900 psi, and whereby the encapsulating means maintains its integrity under intense thermal cycling conditions to exclude foreign elements from the components.
Claim 2
Dependent Claim
97 words
An electrical assembly subject to high thermal stresses comprising: electrical components; container means for containing the electrical components; and encapsulating means in the container means and surrounding the electrical components for environmentally protecting the components comprising polybutadiene urethane having a glass transition temperature below -10° C., and mechanical properties at 25° C. of a hardness of 15 to 90 shore A durometer, an elongation of 50 to 300%, and a tensile strength of 75 to 900 psi, and whereby the encapsulating means maintains its integrity under intense thermal cycling conditions to exclude foreign elements from the components.
Claim 3
Dependent Claim
97 words
An electrical assembly subject to high thermal stresses comprising: electrical components; open container means for containing the electrical components; and polybutadiene urethane encapsulating material in the container means and bonded to the container means and to the electrical components for environmentally protecting the components, the material having a glass transition temperature below -40° C., and mechanical properties at 25° C. of 25 to 65 shore A durometer, 90 to 200% elongation, and 120 to 700 psi tensile strength, whereby the encapsulating material maintains its integrity under intense thermal cycling conditions to exclude foreign elements from the components.
Claim 4
Dependent Claim
97 words
An electrical assembly subject to high thermal stresses comprising: electrical components; open container means for containing the electrical components; and polybutadiene urethane encapsulating material in the container means and bonded to the container means and to the electrical components for environmentally protecting the components, the material having a glass transition temperature below -40° C., and mechanical properties at 25° C. of 25 to 65 shore A durometer, 90 to 200% elongation, and 120 to 700 psi tensile strength, whereby the encapsulating material maintains its integrity under intense thermal cycling conditions to exclude foreign elements from the components.
Claim 5
Dependent Claim
14 words
The invention as defined in claim 2 wherein the material contains substantially no fillers.
Claim 6
Dependent Claim
15 words
The invention as defined in claim 2 wherein the material contains less than 30% fillers.
References Cited (Backward Citations)
JPS56115308A
Cited
US4871477A
Cited
GB2168855A
Cited
JPS63130617A
Cited
US5079275A
Cited
JPH01215817A
Cited
US5079270A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-02-09 | 1996-08-10 | 1997-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-02-09 | 2000-08-10 | 2001-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-02-09 | 2004-08-10 | 2005-02-09 | $7700.00 | Window Closed / Lapsed |