US4234626A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Producing printed circuits by conjoining metal powder images
Assignee: EIDP Inc
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Filing: 1978-02-01
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Granted: 1980-11-18
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Expires: 1998-02-01
Abstract
Abstract By the process of this invention, printed circuits are prepared containing an electrically conductive wiring trace from materials having adherent and non-adherent surface areas, e.g., printed circuit substrates bearing an imaged photoadhesive layer. Onto the adherent surface areas of the material are applied ductile metal or alloy particles, and any excess particles are removed from the non-adherent areas. The metallized areas are conjoined, e.g., with silicon carbide brush or rounded metal rod. The conjoined areas can be electrolessly plated, electroplated or soldered. Multilayer printed circuits can also be prepared by repeating these steps with additional layers of photoadhesive material adhered to underlying printed circuits.
Inventors
- 👤 Robert W. Peiffer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:57
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/24; H05K3/245; H05K3/246; H05K3/10; H05K3/102; H05K3/18; H05K3/181; H05K3/182; H05K3/185; H05K3/26; H05K3/38; H05K3/381; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0347; H05K2203/00; H05K2203/02; H05K2203/0257; H05K2203/0271; H05K2203/04; H05K2203/044; H05K2203/05; H05K2203/0502; H05K2203/0525; H05K3/0011; H05K3/0017; H05K3/0023; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; H05K3/3468
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
81 words
In a process for producing a printed circuit containing an electrically conductive circuit trace from an electrically insulating material having adherent and non-adherent surface areas which comprises applying finely divided ductile metal or alloy particles to the surface areas; removing any excess metal or alloy particles from the non-adherent areas; the improvement comprising applying limited shear or pressure to the adherent ductile metal particles by which the particles are conjoined without damaging the metallized areas to form an electrically conductive circuit.
Claim 2
Dependent Claim
81 words
In a process for producing a printed circuit containing an electrically conductive circuit trace from an electrically insulating material having adherent and non-adherent surface areas which comprises applying finely divided ductile metal or alloy particles to the surface areas; removing any excess metal or alloy particles from the non-adherent areas; the improvement comprising applying limited shear or pressure to the adherent ductile metal particles by which the particles are conjoined without damaging the metallized areas to form an electrically conductive circuit.
Claim 3
Dependent Claim
20 words
A process according to claim 1 wherein the particulate metallized areas are hardened or cured prior to or during conjoining.
Claim 4
Dependent Claim
31 words
A process according to claim 2 wherein the particulate metallized areas are hardened or cured by heating, by exposing to actinic radiation or by treating with a hardening or curing reagent.
Claim 5
Dependent Claim
20 words
A process according to claim 1 wherein the particulate metallized areas are heated to less than 180° C. before conjoining.
Claim 6
Dependent Claim
26 words
A process according to claim 1 wherein the finely divided, ductile metal or alloy particles have an average diameter of about 1 to about 250 microns.
Claim 7
Dependent Claim
16 words
A process according to claim 1 wherein the metal particles are copper or a copper alloy.
Claim 8
Dependent Claim
30 words
A process according to claim 1 wherein the adherent and non-adherent surface areas are tacky and non-tacky surface areas, respectively, and are present in an imaged layer of photoadhesive composition.
Claim 9
Dependent Claim
25 words
A process according to claim 7 wherein the photoadhesive composition is a photohardenable composition taken from the group consisting of photopolymerizable, photocrosslinkable, and photodimerizable compositions.
Claim 10
Dependent Claim
15 words
A process according to claim 1 wherein the electrically conductive circuit trace is electrolessly plated.
Claim 11
Dependent Claim
14 words
A process according to claim 1 wherein the electrically conductive circuit trace is electroplated.
Claim 12
Dependent Claim
14 words
A process according to claim 1 wherein the electrically conductive circuit trace is soldered.
Claim 13
Dependent Claim
17 words
A process according to claim 1 wherein the metallized areas are conjoined with a silicon carbide brush.
Claim 14
Dependent Claim
17 words
A process according to claim 1 wherein the metallized areas are conjoined with a rounded metal rod.
Claim 15
Dependent Claim
87 words
A process according to claim 1 wherein a multilayer printed circuit element is prepared comprising (1) applying a photoadhesive layer to a previously prepared printed circuit board, (2) exposing the photoadhesive layer to actinic radiation through an appropriate phototool in register with the underlying printed circuit, (3) applying to the adherent image areas finely divided, ductile metal or alloy particles, (4) removing any excess metal or alloy particles from the non-adherent image areas, and (5) conjoining the particulate metallized surface areas to obtain a two-layer multilayer circuit.
Claim 16
Dependent Claim
64 words
A process according to claim 14 wherein multilayer printed circuit elements having three or more circuit layers are prepared by repeating at least once steps (1) through (5) for each additional circuit layer using the multilayer circuit previously prepared in each subsequent step (1) and using the appropriate phototool in register with at least one of the underlying printed circuits in each step (2).
Claim 17
Dependent Claim
70 words
A process according to claim 14 wherein holes are drilled or punched in desired junction areas of the conjoined electrically conductive, multilayer circuit printed circuit board; the holes are catalyzed with a colloidal suspension of stannous and palladium chlorides; the circuit board is cleaned to remove excess catalyst from the board side surfaces; and electroless metal plate is applied to obtain electrically conductive through holes interconnecting the multilayered printed circuit.
Claim 18
Dependent Claim
17 words
A process according to claim 1 wherein the conjoining is accomplished by burnishing the particulate metallized areas.
Claim 19
Dependent Claim
12 words
A process according to claim 17 wherein the burnished areas are soldered.
Claim 20
Dependent Claim
96 words
In a process for producing a printed circuit containing an electrically conductive circuit trace from a printed circuit substrate bearing a layer of a photohardened photoadhesive composition having adherent and non-adherent surface areas which comprise applying copper particles, 5 to 125 microns in average diameter, removing excess copper particles from the non-adherent areas, heating the particulate metallized areas; the improvement comprising by means of a silicon carbide brush applying limited shear or pressure to the adherent ductile metal particles by which the particles are conjoined without damaging the metallized areas to form an electrically conductive circuit.
Claim 21
Dependent Claim
96 words
In a process for producing a printed circuit containing an electrically conductive circuit trace from a printed circuit substrate bearing a layer of a photohardened photoadhesive composition having adherent and non-adherent surface areas which comprise applying copper particles, 5 to 125 microns in average diameter, removing excess copper particles from the non-adherent areas, heating the particulate metallized areas; the improvement comprising by means of a silicon carbide brush applying limited shear or pressure to the adherent ductile metal particles by which the particles are conjoined without damaging the metallized areas to form an electrically conductive circuit.
Claim 22
Dependent Claim
23 words
A process according to claim 19 wherein the particulate metallized areas are heated to less than 180° C. for less than 100 seconds.
Claim 23
Dependent Claim
37 words
A process according to claim 19 wherein the adherent areas containing copper particles are hardened by heating, by exposing to actinic radiation or by treating with a hardening or curing reagent either prior to or during conjoining.
Claim 24
Dependent Claim
20 words
A process according to claim 19 wherein the areas are hardened by exposing uniformly to actinic radiation prior to conjoining.
Claim 25
Dependent Claim
25 words
A process for making a multilayer printed circuit board according to claim 19 wherein the printed circuit substrate contains thereon a previously prepared printed circuit.
Claim 26
Dependent Claim
126 words
A process for forming an electrically conductive multilayer printed circuit from a printed circuit board having an electrically conductive circuit trace present on each side of its printed circuit substrate which comprises drilling holes through the circuit board; applying a photohardenable composition to the surface of the circuit board and hole walls; laminating a cover sheet to each side of the circuit board; exposing each side of the circuit board through an image-bearing transparency to actinic radiation for the photohardenable layer; removing the cover sheets sheets; applying ductile metal or alloy particles, 5 to 250 microns in average diameter, to the exposed surfaces and hole walls; heating the metallized printed circuit, and conjoining the metallized areas and holes to form said electrically conductive multilayer printed circuit.
Claim 27
Dependent Claim
126 words
A process for forming an electrically conductive multilayer printed circuit from a printed circuit board having an electrically conductive circuit trace present on each side of its printed circuit substrate which comprises drilling holes through the circuit board; applying a photohardenable composition to the surface of the circuit board and hole walls; laminating a cover sheet to each side of the circuit board; exposing each side of the circuit board through an image-bearing transparency to actinic radiation for the photohardenable layer; removing the cover sheets sheets; applying ductile metal or alloy particles, 5 to 250 microns in average diameter, to the exposed surfaces and hole walls; heating the metallized printed circuit, and conjoining the metallized areas and holes to form said electrically conductive multilayer printed circuit.
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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) | 1983-11-18 | 1984-05-19 | 1984-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-18 | 1988-05-19 | 1988-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-18 | 1992-05-19 | 1992-11-18 | $7700.00 | Window Closed / Lapsed |