Patent US4696776A successfully refreshed from Google Patents.
US4696776A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing polyurethane foams for low stress encapsulation
Assignee: Motorola Solutions Inc
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Filing: 1986-07-21
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Granted: 1987-09-29
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Expires: 2006-07-21
Abstract
Abstract A method for encapsulating electronic components in high acceleration and high thermal cycling environments. A liquid uncured thermal setting polyurethane formulation is mixed with a finely ground particulate foam which serves as a nucleating agent. The mixture is in accordance with the polyurethane formulation. The resultant foam contains open air pockets which allow it to be compressed and then re-expand.
Inventors
- 👤 James R. Hooker
- 👤 Robert M. Foss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:43
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/02; B29C44/12; B29C44/1266; B29C67/00; B29C67/20; B29C67/207; B29C70/00; B29C70/58; B29C70/66; B29K; B29K2075/00; B29K2105/00; B29K2105/06; B29K2105/16; B29K2105/165; B29L; B29L2031/00; B29L2031/30; B29L2031/3055; B29L2031/3061; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S264/07
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
120 words
A method of encapsulating electronic components and the like comprising the steps of: selecting an uncured liquid thermosetting polyurethane formulation; selecting one or more of the group consisting of elastomeric, rigid and semi-rigid finely ground particulate foams to act as a nucleating agent; adding said particulate foam by weight to said liquid polyurethane formulation; mixing said particulate foam and said liquid polyurethane formulation into a substantially homogeneous mixture; applying said homogeneous mixture of said particulate foam and said liquid polyurethane formulation to one of a form, casting, and the like containing electronic components to be encapsulated; and curing said homogeneous mixture encapsulating electronic components for a pre-determined period of time at a predetermined temperature relative to the polyurethane formulation used.
Claim 2
Independent Claim
120 words
A method of encapsulating electronic components and the like comprising the steps of: selecting an uncured liquid thermosetting polyurethane formulation; selecting one or more of the group consisting of elastomeric, rigid and semi-rigid finely ground particulate foams to act as a nucleating agent; adding said particulate foam by weight to said liquid polyurethane formulation; mixing said particulate foam and said liquid polyurethane formulation into a substantially homogeneous mixture; applying said homogeneous mixture of said particulate foam and said liquid polyurethane formulation to one of a form, casting, and the like containing electronic components to be encapsulated; and curing said homogeneous mixture encapsulating electronic components for a pre-determined period of time at a predetermined temperature relative to the polyurethane formulation used.
Claim 3
Dependent Claim
28 words
The method of claim 1 wherein the finely ground particulate foam contains at least one of closed air cells and reticulated foam structure which carries associated air bubbles.
Claim 4
Dependent Claim
31 words
The method of claim 1 wherein a controlled amount of at least one of air cells, air bubbles and individual microspheres of flexible material may be added to the homogeneous mixture.
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) | 1990-09-28 | 1991-03-30 | 1991-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-28 | 1995-03-30 | 1995-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-28 | 1999-03-30 | 1999-09-29 | $7700.00 | Window Closed / Lapsed |