US3786172A
Expired / Lapsed
US
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Printed circuit board method and apparatus
Assignee: Accra Point Arrys Corp
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Filing: 1972-12-07
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Granted: 1974-01-15
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Expires: 1992-12-07
Abstract
Abstract A method for the low cost production of printed circuits with both soldered-in component leads and welded wire connections, which includes applying a sheet of highly weldable material such as stainless steel to an insulative board, plating a layer of highly solderable material such as copper over the stainless steel, applying a first resist pattern and then a first etchant such as ferric chloride that etches both copper and stainless steel to form a predetermined printed circuit pattern, and then applying a second resist pattern and a second etchant such as chromic acid which etches only the copper to leave exposed regions of the stainless steel. Components can be wave soldered in place, and the solder will not adhere to the stainless steel so that wires can later be welded to the exposed stainless steel weld regions. More uniform welding can be obtained by applying an underlayer of copper to the insulative substrate under the stainless steel layer, so that there is a low resistance path to all weld regions.
Inventors
- 👤 L Conley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:51
CPC Classifications
B; B23; B23K; B23K1/00; B23K1/20; H; H05; H05K; H05K1/00; H05K1/02; H05K1/09; H05K1/11; H05K1/111; H05K1/112; H05K1/114; H05K3/00; H05K3/02; H05K3/06; H05K3/067; H05K3/30; H05K3/32; H05K3/328; H05K3/34; H05K3/3452; H05K3/40; H05K3/42; H05K3/425; H05K3/427; B23K2101/00; B23K2101/36; B23K2101/40; B23K2101/42; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0338; H05K2201/0355; H05K2201/10; H05K2201/10227; H05K2201/10287; H05K2201/20; H05K2201/2081; H05K2203/00; H05K2203/03; H05K2203/0361; H05K2203/11; H05K2203/1184; H05K3/0011; H05K3/0017; H05K3/002; H05K3/3447; H05K3/3465; H05K3/3468
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
187 words
A circuit board comprising: A plate of electrically insulative material with a plurality of holes extending therethrough; a first layer of resistance weldable electrically conductive material disposed on said base; a second layer of solderable electrically conductive material disposed facewise over said first layer and with said layers in electrical contact along their facing surfaces to form a conductive sandwich, said solderable material also extending along the walls of said holes; said conductive sandwich forming a predetermined pattern on said base which includes solderable connector regions immediately around said holes; said first layer including regions integral with the solderable connector regions and extending therebeyond and devoid of said second layer to form weldable connector pad regions; a device with a plurality of electrical leads extending through different ones of said holes; a quantity of solder in each of said holes which contain said leads, said solder disposed about said leads and adhering to the walls of said hole and to regions of said second layer immediately surrounding said holes; and an electrically conductive wire extending between a plurality of said weldable connector pad regions and welded thereto.
Claim 2
Dependent Claim
187 words
A circuit board comprising: A plate of electrically insulative material with a plurality of holes extending therethrough; a first layer of resistance weldable electrically conductive material disposed on said base; a second layer of solderable electrically conductive material disposed facewise over said first layer and with said layers in electrical contact along their facing surfaces to form a conductive sandwich, said solderable material also extending along the walls of said holes; said conductive sandwich forming a predetermined pattern on said base which includes solderable connector regions immediately around said holes; said first layer including regions integral with the solderable connector regions and extending therebeyond and devoid of said second layer to form weldable connector pad regions; a device with a plurality of electrical leads extending through different ones of said holes; a quantity of solder in each of said holes which contain said leads, said solder disposed about said leads and adhering to the walls of said hole and to regions of said second layer immediately surrounding said holes; and an electrically conductive wire extending between a plurality of said weldable connector pad regions and welded thereto.
Claim 3
Dependent Claim
40 words
The circuit described in claim 1 including: an underlayer of highly conductive material lying under said first layer and electrically connected facewise thereto, said underlayer constructed of a material having a resistivity less than the resistivity of said first layer.
Claim 4
Dependent Claim
187 words
A circuit board comprising: a base of electrically insulative material; a first layer of resistance weldable electrically conductive material having a resistivity of more than 10 times the resistivity of copper disposed on said base; a second layer of solderable electrically conductive material having a resistivity less than one-tenth the resistivity of said weldable material and disposed facewise over said first layer and with said layers in electrical contact; said first and second layers forming a predetermined pattern on said base which includes solderable connector regions; said first layer including regions integral with the solderable connector regions and extending therebeyond and devoid of said second layer to form weldable connector pad regions; an underlayer of highly conductive material lying under said first layer and electrically connected facewise thereto, said underlayer constructed of a material having a resistivity less than one-tenth the resistivity of said first layer and having a thickness great enough so that more current flows through the underlayer than the first layer portions immediately thereover in welding; first wires soldered to the solderable connector regions; and second wires welded to the weldable connector pad regions.
Claim 5
Dependent Claim
187 words
A circuit board comprising: a base of electrically insulative material; a first layer of resistance weldable electrically conductive material having a resistivity of more than 10 times the resistivity of copper disposed on said base; a second layer of solderable electrically conductive material having a resistivity less than one-tenth the resistivity of said weldable material and disposed facewise over said first layer and with said layers in electrical contact; said first and second layers forming a predetermined pattern on said base which includes solderable connector regions; said first layer including regions integral with the solderable connector regions and extending therebeyond and devoid of said second layer to form weldable connector pad regions; an underlayer of highly conductive material lying under said first layer and electrically connected facewise thereto, said underlayer constructed of a material having a resistivity less than one-tenth the resistivity of said first layer and having a thickness great enough so that more current flows through the underlayer than the first layer portions immediately thereover in welding; first wires soldered to the solderable connector regions; and second wires welded to the weldable connector pad regions.
Claim 6
Dependent Claim
181 words
A circuit board comprising: a plate of electrically insulative material with a plurality of holes therein; a first layer of resistance weldable electrically conductive material disposed on said base; a second layer of solderable electrically conductive material disposed facewise over said first layer, at least in a region immediately about some of the holes, and with said layers in electrical contact along their facing surfaces to form a conductive sandwich; said conductive sandwich forming a predetermined pattern on said base which includes solderable connector regions immEdiately around at lease some of said holes; said first layer including regions integral with the solderable connector regions and extending therebeyond and devoid of said second layer to form weldable connector pad regions; a plurality of devices, each having at least one lead, and with the leads extending through different of said holes and held therein by solder disposed about the leads and in the holes and on regions of said second layer immediately surrounding the holes; and an electrically conductive wire extending between a plurality of said weldable connector pad regions and welded thereto.
Claim 7
Dependent Claim
181 words
A circuit board comprising: a plate of electrically insulative material with a plurality of holes therein; a first layer of resistance weldable electrically conductive material disposed on said base; a second layer of solderable electrically conductive material disposed facewise over said first layer, at least in a region immediately about some of the holes, and with said layers in electrical contact along their facing surfaces to form a conductive sandwich; said conductive sandwich forming a predetermined pattern on said base which includes solderable connector regions immEdiately around at lease some of said holes; said first layer including regions integral with the solderable connector regions and extending therebeyond and devoid of said second layer to form weldable connector pad regions; a plurality of devices, each having at least one lead, and with the leads extending through different of said holes and held therein by solder disposed about the leads and in the holes and on regions of said second layer immediately surrounding the holes; and an electrically conductive wire extending between a plurality of said weldable connector pad regions and welded thereto.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-14 | 1977-07-16 | 1978-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-14 | 1981-07-16 | 1982-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-14 | 1985-07-16 | 1986-01-15 | $7700.00 | Window Closed / Lapsed |