US4670298A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluorescent solder paste mixture
Assignee: Nortel Networks Ltd
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Filing: 1985-12-09
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Granted: 1987-06-02
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Expires: 2005-12-09
Abstract
Abstract A fluorescent solder paste mixture comprising a fluorescent pigment dispersed in a solder paste is disclosed. The solder paste comprises solder fragments dispersed in a solder flux. A method for making the solder paste mixture and a method for using the solder paste mixture to make a fluorescent solder joint between an electrical component and a circuit board are also disclosed. Use of the fluorescent solder paste mixture facilitates automatic and manual inspection of circuit boards during and after assembly.
Inventors
- 👤 James A. Lucas
- 👤 William P. Trumble
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:20
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/24; B23K35/26; B23K35/262; H; H05; H05K; H05K1/00; H05K1/02; H05K1/0266; H05K1/0269; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; H05K3/3485; H05K2203/00; H05K2203/16; H05K2203/161; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49144
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
49 words
A fluorescent solder paste mixture comprising a fluorescent pigment dispersed in a solder paste, the solder paste comprising solder fragments dispersed in a solder flux, wherein at least a portion of the fluorescent pigment disperses in the solder upon heating solder paste to the melting point of the solder.
Claim 2
Dependent Claim
49 words
A fluorescent solder paste mixture comprising a fluorescent pigment dispersed in a solder paste, the solder paste comprising solder fragments dispersed in a solder flux, wherein at least a portion of the fluorescent pigment disperses in the solder upon heating solder paste to the melting point of the solder.
Claim 3
Dependent Claim
57 words
A fluorescent solder paste mixture comprising a fluorescent pigment dispersed in a solder paste, the solder paste comprising solder fragments dispersed in a solder flux, wherein at least a portion of the fluorescent pigment disperses in the solder upon heating solder paste to the melting point of the solder, and wherein the fluorescent pigment is 4-methyl-7-diethylamino coumarin.
Claim 4
Dependent Claim
57 words
A fluorescent solder paste mixture comprising a fluorescent pigment dispersed in a solder paste, the solder paste comprising solder fragments dispersed in a solder flux, wherein at least a portion of the fluorescent pigment disperses in the solder upon heating solder paste to the melting point of the solder, and wherein the fluorescent pigment is 4-methyl-7-diethylamino coumarin.
Claim 5
Dependent Claim
24 words
The fluorescent solder paste mixture of claim 2 wherein the 4-methyl-7-diethylamino coumarin between about 0.005% and 0.2% by weight of the solder paste mixture.
Claim 6
Dependent Claim
22 words
The fluorescent solder paste mixture of claim 3 wherein the 4-methyl-7-diethylamino coumarin is approximately 0.05% by weight of the solder paste mixture.
Claim 7
Dependent Claim
20 words
The fluorescent solder paste mixture of claim 1 wherein the solder comprises approximately 43% tin, 43% lead and 14% bismuth.
Claim 8
Independent Claim
139 words
A method for making a fluorescent solder joint between an electrical component and a circuit board, the method comprising: (a) applying a solder paste mixture to a metallic solder pad on the circuit board, the solder paste mixture comprising a fluorescent pigment dispersed in a solder paste, the solder paste comprising solder fragments dispersed in a solder flux; (b) placing the electrical component on the circuit board such that electrical contact means on the electrical component contacts the solder paste mixture; (c) heating the solder paste mixture to fuse the solder; (d) allowing the solder to cool and solidify; and (e) washing the surface of the circuit board to remove the solder flux; wherein at least a portion of the fluorescent pigment disperses in the solder when upon heating the solder paste to the melting point of the solder.
Claim 9
Independent Claim
139 words
A method for making a fluorescent solder joint between an electrical component and a circuit board, the method comprising: (a) applying a solder paste mixture to a metallic solder pad on the circuit board, the solder paste mixture comprising a fluorescent pigment dispersed in a solder paste, the solder paste comprising solder fragments dispersed in a solder flux; (b) placing the electrical component on the circuit board such that electrical contact means on the electrical component contacts the solder paste mixture; (c) heating the solder paste mixture to fuse the solder; (d) allowing the solder to cool and solidify; and (e) washing the surface of the circuit board to remove the solder flux; wherein at least a portion of the fluorescent pigment disperses in the solder when upon heating the solder paste to the melting point of the solder.
Claim 10
Independent Claim
38 words
A method for making a fluorescent solder paste mixture comprising mechanically mixing a fluorescent pigment with a solder paste, the solder paste comprising solder fragments dispersed in a solder flux, and wherein the fluorescent pigment is 4-methyl-7-diethylamino coumarin.
Claim 11
Independent Claim
38 words
A method for making a fluorescent solder paste mixture comprising mechanically mixing a fluorescent pigment with a solder paste, the solder paste comprising solder fragments dispersed in a solder flux, and wherein the fluorescent pigment is 4-methyl-7-diethylamino coumarin.
Claim 12
Dependent Claim
12 words
The method of claim 6 wherein the fluorescent pigment is 4-methyl-7-diethylamino coumarin.
Claim 13
Dependent Claim
22 words
The method of claim 6 wherein the 4-methyl-7-diethylamino coumarin comprises between about 0.005% and 0.2% by weight of the solder paste mixture.
Claim 14
Dependent Claim
22 words
The method of claim 8 wherein the 4-methyl-7-diethylamino coumarin comprises between about 0.005% and 0.2% by weight of the solder paste mixture.
Claim 15
Dependent Claim
19 words
The method of claim 9 wherein the 4-methyl-7-diethylamino coumarin is approximately 0.05% by weight of the solder paste mixture.
Claim 16
Dependent Claim
19 words
The method of claim 10 wherein the 4-methyl-7-diethylamino coumarin is approximately 0.05% by weight of the solder paste mixture.
Claim 17
Independent Claim
42 words
A method for making a fluorescent solder paste mixture comprising mechanically mixing a fluorescent pigment with a solder paste, the solder paste comprising solder fragments dispersed in a solder flux, wherein the solder comprises approximately 43% tin, 43% lead and 14% bismuth.
Claim 18
Independent Claim
42 words
A method for making a fluorescent solder paste mixture comprising mechanically mixing a fluorescent pigment with a solder paste, the solder paste comprising solder fragments dispersed in a solder flux, wherein the solder comprises approximately 43% tin, 43% lead and 14% bismuth.
Claim 19
Dependent Claim
17 words
The method of claim 6 wherein the solder comprises approximately 43% tin, 43% lead and 14% bismuth.
References Cited (Backward Citations)
US3139360A
Cited
US3406285A
Cited
US3962116A
Cited
US4269870A
Cited
US4457861A
Cited
US4298407A
Cited
US4404237A
Cited
US4557767A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-01 | 1990-12-01 | 1991-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-01 | 1994-12-01 | 1995-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-01 | 1998-12-01 | 1999-06-02 | $7700.00 | Window Closed / Lapsed |