US4411980A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of flexible circuits
Assignee: EIDP Inc
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Filing: 1981-09-21
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Granted: 1983-10-25
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Expires: 2001-09-21
Abstract
Abstract Process for the preparation of flexible circuits formed from flexible photohardenable elements having at least one organic elastomeric polymeric binder which comprises (a) exposing imagewise said element, (b) applying particulate conductive metal, e.g., nickel, copper, to the unexposed image areas, optionally (c) heating the metal bearing areas, then (d) removing excess metal particles, optionally (e) fixing the particulate metal to the layer by heating, exposing to UV light or mechanical embedding, and (f) plating electrolessly or soldering the metal containing areas. The process can be operated continuously to prepare single and double layer flexible printed circuits, membrane switches, etc.
Inventors
- 👤 Douglas M. Haney
- 👤 John W. Lott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:40
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/24; H05K3/245; H05K3/246; G; G03; G03F; G03F7/00; G03F7/26; G03F7/28; H05K3/10; H05K3/102; H05K1/00; H05K1/02; H05K1/03; H05K1/0393; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0347; H05K2201/09; H05K2201/09209; H05K2201/095; H05K2201/09509; H05K2203/00; H05K2203/04; H05K2203/044; H05K2203/05; H05K2203/0502; H05K2203/0505; H05K2203/0525; H05K2203/15; H05K2203/1545; H05K3/0011; H05K3/0017; H05K3/0023; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; H05K3/3468
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
214 words
A process for the preparation of flexible circuits formed from a flexible photohardenable element which comprises: (a) exposing imagewise to actinic radiation the flexible photohardenable element comprising, in order, (1) a flexible support, (2) a dry, tacky photohardenable layer comprising a photohardenable composition, including at least one organic elastomeric polymeric binder compound, and, optionally, (3) a removable cover sheet; (b) removing the cover sheet, if present, and applying particulate metal to the unexposed image areas of the photohardenable layer; optionally (c) heating the element to a temperature in the range of 25° C. to 80° C.; then (d) removing excess particulate metal; optionally, (e) fixing or binding the particulate metal to the photohardenable layer by heating, curing by exposing to actinic radiation, embedding mechanically, and combinations thereof; and (f) plating electrolessly or soldering the particulate metal bearing or metal containing areas thereby forming an electrically conductive flexible circuit, said electrically conductive flexible circuit when having a thickness of 0.001" can be repeatedly bent around a structure having a diameter of 0.600" without breaking, cracking or delaminating, said electrically conductive flexible circuit when having thicknesses different from 0.001" the diameter of said structure would be increased or decreased proportionally with the proviso that the minimum diameter of said structure would always be greater than 0.25".
Claim 2
Dependent Claim
214 words
A process for the preparation of flexible circuits formed from a flexible photohardenable element which comprises: (a) exposing imagewise to actinic radiation the flexible photohardenable element comprising, in order, (1) a flexible support, (2) a dry, tacky photohardenable layer comprising a photohardenable composition, including at least one organic elastomeric polymeric binder compound, and, optionally, (3) a removable cover sheet; (b) removing the cover sheet, if present, and applying particulate metal to the unexposed image areas of the photohardenable layer; optionally (c) heating the element to a temperature in the range of 25° C. to 80° C.; then (d) removing excess particulate metal; optionally, (e) fixing or binding the particulate metal to the photohardenable layer by heating, curing by exposing to actinic radiation, embedding mechanically, and combinations thereof; and (f) plating electrolessly or soldering the particulate metal bearing or metal containing areas thereby forming an electrically conductive flexible circuit, said electrically conductive flexible circuit when having a thickness of 0.001" can be repeatedly bent around a structure having a diameter of 0.600" without breaking, cracking or delaminating, said electrically conductive flexible circuit when having thicknesses different from 0.001" the diameter of said structure would be increased or decreased proportionally with the proviso that the minimum diameter of said structure would always be greater than 0.25".
Claim 3
Dependent Claim
50 words
A process according to claim 1 wherein the photohardenable layer comprises (i) an addition polymerizable ethylenically unsaturated compound having at least two terminal ethylenic groups, (ii) at least one organic elastomeric polymeric binder compound, and (iii) a free radical generating addition polymerization initiator or initiator system activatable by actinic radiation.
Claim 4
Dependent Claim
24 words
A process according to claim 1 or claim 2 wherein the binder is a combination of methylmethacrylate/styrene/acrylonitrile/butadiene interpolymer and a carboxylated acrylonitrile/butadiene rubber compound.
Claim 5
Dependent Claim
16 words
A process according to claim 1 or claim 2 wherein the binder is a methylmethacrylate/styrene/acrylonitrile/butadiene interpolymer.
Claim 6
Dependent Claim
17 words
A process according to claim 1 or claim 2 wherein the binder is a polymer of n-butylmethacrylate.
Claim 7
Dependent Claim
17 words
A process according to claim 1 or claim 2 wherein the binder is a polyether polyurethane polymer.
Claim 8
Dependent Claim
15 words
A process according to claim 1 wherein the steps of the process are performed continuously.
Claim 9
Dependent Claim
18 words
A process according to claim 1 wherein the flexible electrically conductive circuit is adhered to a backing sheet.
Claim 10
Dependent Claim
16 words
A process according to claim 8 wherein the backing sheet is a rigid substrate or surface.
Claim 11
Dependent Claim
12 words
A process according to claim 1 wherein the particulate metal is copper.
Claim 12
Dependent Claim
12 words
A process according to claim 1 wherein the particulate metal is nickel.
Claim 13
Dependent Claim
23 words
A process according to claim 1 wherein the particulate metal is applied to the unexposed areas by embedding the metal into the surface.
Claim 14
Dependent Claim
17 words
A process according to claim 1 wherein the excess particulate metal is removed by impingement with water.
Claim 15
Dependent Claim
16 words
A process according to claim 1 wherein the excess particulate metal is removed by air impingement.
Claim 16
Dependent Claim
45 words
A process according to claim 1 wherein the particulate metal is fixed or bound to the photohardened layer by heating in the temperature range of 80° to 150° C., for at least 10 seconds, the temperature being below the degradation temperature of the photohardened element.
Claim 17
Dependent Claim
15 words
A process according to claim 1 wherein the particulate metal bearing areas are plated electrolessly.
Claim 18
Dependent Claim
14 words
A process according to claim 1 wherein the particulate metal bearing areas are soldered.
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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) | 1986-10-24 | 1987-04-25 | 1987-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-24 | 1991-04-25 | 1991-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-24 | 1995-04-25 | 1995-10-25 | $7700.00 | Window Closed / Lapsed |