Patent US5454904A successfully refreshed from Google Patents.
US5454904A
Expired / Lapsed
US
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Micromachining methods for making micromechanical moving structures including multiple contact switching system
Assignee: General Electric Co
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Filing: 1994-08-05
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Granted: 1995-10-03
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Expires: 2014-08-05
Abstract
Abstract Micromachining methods for fabricating micromechanical structures which include plunger elements free to reciprocate within cavities are fabricated using processing steps in common with those employed in high density interconnect (HDI) technology for multi-chip module packaging. A polymer, such as a polyimide, is utilized as a micromachinable material. In one embodiment, cavities are formed in the polymer material by laser ablation, employing a sacrificial layer as a mask. Electroplated copper may be employed as a sacrificial release layer. One particular structure is a micromechanical electric switch including an array of individual switch contacts actuatable in common.
Inventors
- 👤 Mario Ghezzo
- 👤 Richard J. Saia
- 👤 Bharat S. Bagepalli
- 👤 Imdad Imam
- 👤 Dennis L. Polla
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:37
CPC Classifications
H; H01; H01H; H01H50/00; H01H50/005; B; B29; B29C; B29C59/00; B29C59/16; B29C35/00; B29C35/02; B29C35/08; B29C35/0805; B29C2035/0838; H01H1/00; H01H1/06; H01H1/0036; H01H2001/0052; H01H2001/0057; H01H9/00; H01H9/30; H01H9/40; Y; Y10; Y10S; Y10S438/00; Y10S438/94
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
123 words
A micromachining method for fabricating a micromechanical structure which includes a plunger element free to reciprocate within a cavity, comprising the steps of: providing a base having a generally planar surface; applying a layer of polymer material on the base; forming a cavity in the polymer layer extending at least partially through the polymer layer; conformally depositing a lining sacrificial layer within the cavity and over the layer of polymer material; conformally forming an outer layer on the lining sacrificial layer, a portion of the outer layer within the cavity comprising the plunger element; and releasing the outer layer for axial movement within the cavity relative to the layer of polymer material by employing a selective etch to remove the lining sacrificial layer.
Claim 2
Dependent Claim
123 words
A micromachining method for fabricating a micromechanical structure which includes a plunger element free to reciprocate within a cavity, comprising the steps of: providing a base having a generally planar surface; applying a layer of polymer material on the base; forming a cavity in the polymer layer extending at least partially through the polymer layer; conformally depositing a lining sacrificial layer within the cavity and over the layer of polymer material; conformally forming an outer layer on the lining sacrificial layer, a portion of the outer layer within the cavity comprising the plunger element; and releasing the outer layer for axial movement within the cavity relative to the layer of polymer material by employing a selective etch to remove the lining sacrificial layer.
Claim 3
Dependent Claim
24 words
The method of claim 1, wherein the step of forming a well-like cavity includes forming the cavity to extend entirely through the polymer layer.
Claim 4
Dependent Claim
71 words
The method of claim 1, which further comprises, prior to the step of forming a cavity in the polymer layer, depositing an initial sacrificial layer onto the layer of polymer material to provide greater sacrificial layer thickness on the layer of polymer material compared to sacrificial layer thickness within the cavity; and wherein the step of forming a well-like cavity includes forming the cavity to extend through the initial sacrificial layer.
Claim 5
Dependent Claim
21 words
The method of claim 1, wherein the step of forming a cavity comprises laser-ablating a predetermined portion of said polymer layer.
Claim 6
Dependent Claim
43 words
The method of claim 1, wherein the step of forming a cavity comprises: providing a metal mask over the polymer layer, with an opening in the metal mask defining the cavity location; and ablating with a laser the polymer layer where not masked.
Claim 7
Dependent Claim
52 words
The method of claim 3, wherein: the initial sacrificial layer comprises a metal; and wherein the said step of forming a cavity comprises: forming an opening in the initial sacrificial layer defining the cavity location, and employing a laser to ablate the polymer layer where not masked by said initial sacrificial layer.
Claim 8
Dependent Claim
20 words
The method of claim 1, wherein the step of conformally depositing a lining sacrificial layer comprises depositing a metal layer.
Claim 9
Dependent Claim
19 words
The method of with claim 7, wherein the step of conformally depositing a lining sacrificial layer comprises copper electroplating.
Claim 10
Dependent Claim
27 words
The method of with claim 3, wherein the steps of depositing an initial sacrificial layer and depositing a lining sacrificial layer each comprise depositing a metal layer.
Claim 11
Dependent Claim
23 words
The method of claim 9, wherein the steps of depositing an initial sacrificial layer and depositing a lining sacrificial layer comprise copper electroplating.
Claim 12
Dependent Claim
174 words
A micromachining method for fabricating a micromechanical electric switch comprising the steps of: providing an electrically-insulative base having a generally planar surface; forming a patterned first conductive layer on the base, portions of the patterned first conductive layer comprising stationary switch contacts; applying a cavity-supporting polymer dielectric layer to the base and over the patterned first conductive layer thereon; exposing the stationary switch contacts by forming at least one cavity extending through the cavity-supporting polymer dielectric layer; conformally depositing a lining sacrificial layer within the at least one cavity and over the cavity-supporting polymer dielectric layer; conformally forming a second conductive layer over the lining sacrificial layer such that at least one portion of the second conductive layer within the at least one cavity can serve as at least one movable switch contact; and releasing the second conductive layer for axial movement of the at least one movable switch contact within the at least one cavity relative to the cavity-supporting polymer dielectric layer by employing a selective etch to remove the lining sacrificial layer.
Claim 13
Dependent Claim
174 words
A micromachining method for fabricating a micromechanical electric switch comprising the steps of: providing an electrically-insulative base having a generally planar surface; forming a patterned first conductive layer on the base, portions of the patterned first conductive layer comprising stationary switch contacts; applying a cavity-supporting polymer dielectric layer to the base and over the patterned first conductive layer thereon; exposing the stationary switch contacts by forming at least one cavity extending through the cavity-supporting polymer dielectric layer; conformally depositing a lining sacrificial layer within the at least one cavity and over the cavity-supporting polymer dielectric layer; conformally forming a second conductive layer over the lining sacrificial layer such that at least one portion of the second conductive layer within the at least one cavity can serve as at least one movable switch contact; and releasing the second conductive layer for axial movement of the at least one movable switch contact within the at least one cavity relative to the cavity-supporting polymer dielectric layer by employing a selective etch to remove the lining sacrificial layer.
Claim 14
Dependent Claim
83 words
The method of claim 11, which further comprises, prior to the step of exposing the stationary switch contacts, depositing an initial sacrificial layer over the cavity-supporting polymer dielectric layer to provide greater sacrificial layer thickness over the cavity-supporting polymer dielectric layer compared to sacrificial layer thickness within the at least one cavity; and wherein the step of exposing the stationary switch contacts includes forming a the cavity to extend through the initial sacrificial layer as well as through the cavity-supporting polymer dielectric layer.
Claim 15
Dependent Claim
23 words
The method of claim 11, wherein the step of exposing the stationary switch contacts comprises laser-ablating a predetermined portion of said polymer layer.
Claim 16
Dependent Claim
58 words
The method of claim 11, wherein the step of exposing the stationary switch contacts comprises: providing a metal mask over the cavity-supporting polymer dielectric layer, with at least one opening in the metal mask defining the location of the at least one cavity; and laser-ablating the cavity-supporting polymer dielectric layer at locations not masked by said metal mask.
Claim 17
Dependent Claim
68 words
The method of claim 12, wherein: the initial sacrificial layer comprises a metal; and wherein the step of exposing the stationary switch contacts comprises: employing the sacrificial layer as a mask layer by forming at least one opening in the initial sacrificial layer defining the location of the at least one cavity; and laser-ablating the cavity-supporting polymer dielectric layer at locations not masked by said initial sacrificial layer.
Claim 18
Dependent Claim
20 words
The method of claim 11, wherein the step of conformally depositing a lining sacrificial layer comprises depositing a metal layer.
Claim 19
Dependent Claim
18 words
The method of claim 16, wherein the step of conformally depositing a lining sacrificial layer comprises copper electroplating.
Claim 20
Dependent Claim
37 words
The method of claim 16, wherein the steps of forming first and second conductive layers each comprises forming the respective conductive layer of a metal resistant to the selective etch employed to remove the lining sacrificial layer.
Claim 21
Dependent Claim
24 words
The method of claim 17, wherein the steps of forming first and second conductive layers each comprises forming the respective conductive layers of gold.
Claim 22
Dependent Claim
29 words
The method of claim 12, wherein the step of depositing an initial sacrificial layer and the step of depositing a lining sacrificial layer each comprises depositing a metal layer.
Claim 23
Dependent Claim
27 words
The method of claim 20, wherein the step of depositing an initial sacrificial layer and the step of depositing a lining sacrificial layer each comprises copper electroplating.
Claim 24
Dependent Claim
36 words
The method of claim 20, wherein the steps of forming first and second conductive layers each comprises forming the respective conductive layer of a metal resistant to the selective etch employed to remove the sacrificial layers.
Claim 25
Dependent Claim
22 words
The method of claim 21, wherein the steps of forming first and second conductive layers each comprises forming a gold conductive layer.
Claim 26
Dependent Claim
57 words
The method of claim 11, wherein the step of exposing the stationary switch contacts comprises forming said at least one cavity at a location where two stationary switch contacts are exposed at the bottom of said at least one cavity such that the two stationary switch contacts can be electrically bridged by a single movable switch contact.
Claim 27
Dependent Claim
66 words
The method of claim 11, wherein the step of exposing the stationary switch contacts comprises forming said at least one cavity and a second cavity at respective locations where a single stationary contact is exposed at the bottom of each of said cavities, respectively, such that the two stationary contacts can be electrically connected through respective movable switch contacts comprising portions of the second conductive layer.
Claim 28
Dependent Claim
156 words
A micromachining method for fabricating a micromechanical electric switch comprising the steps of: providing an electrically-insulative base having a generally planar surface; forming a patterned first conductive layer on the base, portions of the patterned first conductive layer comprising stationary switch contacts; applying a cavity-supporting polymer dielectric layer to the base and over the patterned first conductive layer thereon; exposing the stationary switch contacts by forming a plurality of cavities extending through the cavity-supporting polymer dielectric layer; conformally depositing a lining sacrificial layer within said cavities and over the cavity-supporting polymer dielectric layer; conformally forming a second conductive layer over the lining sacrificial layer such that portions of the second conductive layer within said cavities will serve as movable switch contacts; and releasing the second conductive layer for axial movement of the movable switch contacts within said cavities relative to the cavity-supporting polymer dielectric layer by employing a selective etch to remove the lining sacrificial layer.
Claim 29
Dependent Claim
156 words
A micromachining method for fabricating a micromechanical electric switch comprising the steps of: providing an electrically-insulative base having a generally planar surface; forming a patterned first conductive layer on the base, portions of the patterned first conductive layer comprising stationary switch contacts; applying a cavity-supporting polymer dielectric layer to the base and over the patterned first conductive layer thereon; exposing the stationary switch contacts by forming a plurality of cavities extending through the cavity-supporting polymer dielectric layer; conformally depositing a lining sacrificial layer within said cavities and over the cavity-supporting polymer dielectric layer; conformally forming a second conductive layer over the lining sacrificial layer such that portions of the second conductive layer within said cavities will serve as movable switch contacts; and releasing the second conductive layer for axial movement of the movable switch contacts within said cavities relative to the cavity-supporting polymer dielectric layer by employing a selective etch to remove the lining sacrificial layer.
Claim 30
Dependent Claim
19 words
The method of claim 26, which further comprises the step of attaching an actuator to said second conductive layer.
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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) | 1998-10-02 | 1999-04-03 | 1999-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-02 | 2003-04-03 | 2003-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-02 | 2007-04-03 | 2007-10-03 | $7700.00 | Window Closed / Lapsed |