US4842685A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming a cast membrane protected pressure sensor
Assignee: Motorola Solutions Inc
•
Filing: 1987-10-22
•
Granted: 1989-06-27
•
Expires: 2007-10-22
Abstract
Abstract A method for forming a solid state semiconductor pressure sensor in which the pressure sensor element is protected from the ambient whose pressure is being measured by a combination of a pressure transfer medium and a thin covering membrane. The method includes applying the thin covering membrane so as to substantially avoid entrapment of air or formation of voids in the pressure transfer medium which would degrade the performance of the sensor. The pressure transfer medium is a gel-like material such as a silastic. The membrane is chosen to be substantially impermeable to the ambients being measured and sufficiently flexible to avoid attenuation of the input pressure signal. The membrane is cast in place by applying a thin liquid coating or a heat deformable film over the pressure transfer medium and then coverting it into a thin solid membrane stuck to the pressure transfer medium and the pressure sensor body.
Inventors
- 👤 Victor J. Adams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:11
CPC Classifications
G; G01; G01L; G01L19/00; G01L19/14; G01L19/142; G01L19/143; G01L19/0061; G01L19/0084; G01L19/06; G01L19/0627; G01L19/0645; G01L19/147
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
95 words
A method for forming an environmentally protected pressure sensor, comprising: providing a body having an opening containing a cavity, wherein said cavity has a first surface for receiving a solid pressure sensor element and a second surface extending from said opening to said first surface; mounting said pressure sensor element on said first surface; partially filling said cavity around said pressure sensor element with a pressure transfer material in contact with said second surface and having an exposed surface; and casting a diaphragm means on said exposed surface and in contact with said second surface.
Claim 2
Independent Claim
95 words
A method for forming an environmentally protected pressure sensor, comprising: providing a body having an opening containing a cavity, wherein said cavity has a first surface for receiving a solid pressure sensor element and a second surface extending from said opening to said first surface; mounting said pressure sensor element on said first surface; partially filling said cavity around said pressure sensor element with a pressure transfer material in contact with said second surface and having an exposed surface; and casting a diaphragm means on said exposed surface and in contact with said second surface.
Claim 3
Dependent Claim
40 words
The method of claim 1 wherein said casting step comprises placing a membrane forming liquid material on said exposed surface, spreading it out to contact said second surface, and converting said liquid material at least partially to a solid material.
Claim 4
Dependent Claim
29 words
The method of claim 1 wherein said partially filling step comprises partially filling said cavity with a liquid material and then curing said liquid material to a gel-like state.
Claim 5
Dependent Claim
26 words
The method of claim 1 wherein said step of casting a diaphragm means comprises forming a polymeric material having a Shore A hardness less than 70.
Claim 6
Dependent Claim
13 words
The method of claim 1 wherein said diaphragm means is a fluorosilicone material.
Claim 7
Dependent Claim
14 words
The method of claim 1 wherein said pressure transfer material is a silastic material.
Claim 8
Independent Claim
109 words
A method for forming a sealed pressure sensor, comprising: providing a body for receiving a pressure sensor element on a first surface of said body; mounting said pressure sensor element on said first surface; placing a non-gaseous pressure transfer medium on said pressure sensor element and in contact with said body, wherein said pressure transfer medium has an exposed surface; coating said exposed surface with a membrane forming liquid material in contact with a portion of said body surrounding said exposed surface; and converting at least a portion of said liquid material to a solid material to form a membrane covering said exposed surface and sealing to said body.
Claim 9
Independent Claim
109 words
A method for forming a sealed pressure sensor, comprising: providing a body for receiving a pressure sensor element on a first surface of said body; mounting said pressure sensor element on said first surface; placing a non-gaseous pressure transfer medium on said pressure sensor element and in contact with said body, wherein said pressure transfer medium has an exposed surface; coating said exposed surface with a membrane forming liquid material in contact with a portion of said body surrounding said exposed surface; and converting at least a portion of said liquid material to a solid material to form a membrane covering said exposed surface and sealing to said body.
Claim 10
Independent Claim
108 words
A method for forming a sealed pressure sensor, comprising: providing a body for receiving a pressure sensor element on a first surface of said body; mounting said pressure sensor element on said first surface; placing a non-gaseous pressure transfer medium on said pressure sensor element and in contact with said body, wherein said pressure transfer medium has an exposed surface; loosely covering said exposed surface with a heat softenable membrane forming material in contact with said exposed surface and said body surrounding said exposed surface; and heating said membrane forming material to collapse it onto said exposed surface and stick it to said body surrounding said exposed surface.
Claim 11
Independent Claim
108 words
A method for forming a sealed pressure sensor, comprising: providing a body for receiving a pressure sensor element on a first surface of said body; mounting said pressure sensor element on said first surface; placing a non-gaseous pressure transfer medium on said pressure sensor element and in contact with said body, wherein said pressure transfer medium has an exposed surface; loosely covering said exposed surface with a heat softenable membrane forming material in contact with said exposed surface and said body surrounding said exposed surface; and heating said membrane forming material to collapse it onto said exposed surface and stick it to said body surrounding said exposed surface.
References Cited (Backward Citations)
US2569987A
Cited
US3566459A
Cited
US4274423A
Cited
JPS54153684A
Cited
US4241493A
Cited
JPS55122125A
Cited
US4644797A
Cited
US4655088A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-26 | 1992-12-26 | 1993-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-26 | 1996-12-26 | 1997-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-26 | 2000-12-26 | 2001-06-27 | $7700.00 | Window Closed / Lapsed |