US3825994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of soldering circuit components to a substrate
Assignee: RCA Licensing Corp
•
Filing: 1972-11-15
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Granted: 1974-07-30
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Expires: 1992-11-15
Abstract
Abstract A method of batch soldering components of hybrid circuits to substrates comprising advancing the substrates having mounted thereon solder paste layers or preforms on which the components are resting in unsoldered state, along a path which leads through a wave of hot, dense liquid, such that the substrates float free on the liquid wave for a period long enough to melt the solder paste or preform, and then moving the substrates out of contact with the liquid wave to cool the assemblies which now have the components soldered down to them.
Inventors
- 👤 C Coleman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:44
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3494; B; B23; B23K; B23K1/00; B23K1/08; B23K1/085; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K2203/00; H05K2203/07; H05K2203/0756; H05K2203/0776; H05K2203/15; H05K2203/1581; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
116 words
A method of soldering a circuit component to a first surface of a heat-resistant substrate having two opposed surfaces, comprising providing a solid layer of solder between said component and said first surface of said substrate, floating said substrate with the surface of said substrate which is opposite said first surface, on a liquid which has a greater specific gravity than the combined specific gravity of said substrate and said components, for a predetermined period, said liquid being chemically inert and non-wetting to said substrate, and being maintained at a temperature above the melting point of said solder, to melt said solder, and then removing said substrate from contact with said liquid to re-solidify said solder.
Claim 2
Independent Claim
116 words
A method of soldering a circuit component to a first surface of a heat-resistant substrate having two opposed surfaces, comprising providing a solid layer of solder between said component and said first surface of said substrate, floating said substrate with the surface of said substrate which is opposite said first surface, on a liquid which has a greater specific gravity than the combined specific gravity of said substrate and said components, for a predetermined period, said liquid being chemically inert and non-wetting to said substrate, and being maintained at a temperature above the melting point of said solder, to melt said solder, and then removing said substrate from contact with said liquid to re-solidify said solder.
Claim 3
Dependent Claim
14 words
A method according to claim 1 in which said liquid is a solder composition.
Claim 4
Dependent Claim
19 words
A method according to claim 1 in which said liquid is maintained as a fountain and is continuously re-circulated.
Claim 5
Dependent Claim
13 words
A method according to claim 1 in which said substrate is a ceramic.
Claim 6
Dependent Claim
29 words
A method according to claim 1 in which said substrate is pre-heated to a temperature below the melting point of said solder before it is floated on said liquid.
Claim 7
Independent Claim
145 words
A method of soldering a circuit component to a first surface of a heat-resistant substrate having two opposed surfaces, comprising placing said component on said first surface of said substrate with a solid solder layer therebetween, moving said substrate and said component along a path at a certain level, bringing the surface of said substrate which is opposite said first surface, into contact with a wave of molten solder which has a greater specific gravity than the combined specific gravity of said substrate and component and which is at a temperature higher than the melting point of said solder layer, such that said substrate floats free as it moves across said solder wave and is heated to a temperature sufficient to melt the solder of said layer, and then removing said substrate from contact with said solder wave to resolidify the solder of said layer.
Claim 8
Independent Claim
145 words
A method of soldering a circuit component to a first surface of a heat-resistant substrate having two opposed surfaces, comprising placing said component on said first surface of said substrate with a solid solder layer therebetween, moving said substrate and said component along a path at a certain level, bringing the surface of said substrate which is opposite said first surface, into contact with a wave of molten solder which has a greater specific gravity than the combined specific gravity of said substrate and component and which is at a temperature higher than the melting point of said solder layer, such that said substrate floats free as it moves across said solder wave and is heated to a temperature sufficient to melt the solder of said layer, and then removing said substrate from contact with said solder wave to resolidify the solder of said 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) | 1977-07-29 | 1978-01-28 | 1978-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-29 | 1982-01-28 | 1982-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-29 | 1986-01-28 | 1986-07-30 | $7700.00 | Window Closed / Lapsed |