US4728195A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for imaging printed circuit board component leads
Assignee: Cognex Corp
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Filing: 1986-03-19
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Granted: 1988-03-01
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Expires: 2006-03-19
Abstract
Abstract The invention provides a novel system for imaging a component lead on an assembled printed circuit board. The system incorporates a light source for illuminating a substantial portion of a solder pad of the circuit board being inspected. A photoreceptor receives emissions reflected from the illuminated portion of said solder pad and generates an image representative thereof. This photoreceptor is arranged so that passage of a component lead through the component hole occludes or shadows a portion of the solder pad from which the photoreceptor would otherwise receive reflected emissions. The system has application in the testing of printed circuit boards prior to wave soldering.
Inventors
- 👤 William M. Silver
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:32
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/956; G01N21/95684; H; H05; H05K; H05K13/00; H05K13/08; H05K13/081; H05K13/0815
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
128 words
A method for generating a component pin signature for an assembled printed circuit board, the method comprising the steps of (A) simultaneously illuminating with a light source at least a substantial portion of a solder pad of the circuit board, said solder pad being associated with a component hole in the board and being arranged for electrical connection with a component lead passed through the component hole, (B) receiving with a photoreceptor emissions reflected from the illuminated portion of said solder pad, said photoreceptor being so arranged that passage of the component lead through the component hole occludes or shadows a portion of the solder pad from which the photoreceptor would otherwise receive reflected emissions, and (C) generating an imaging signal representative of emissions received at the photoreceptor.
Claim 2
Independent Claim
128 words
A method for generating a component pin signature for an assembled printed circuit board, the method comprising the steps of (A) simultaneously illuminating with a light source at least a substantial portion of a solder pad of the circuit board, said solder pad being associated with a component hole in the board and being arranged for electrical connection with a component lead passed through the component hole, (B) receiving with a photoreceptor emissions reflected from the illuminated portion of said solder pad, said photoreceptor being so arranged that passage of the component lead through the component hole occludes or shadows a portion of the solder pad from which the photoreceptor would otherwise receive reflected emissions, and (C) generating an imaging signal representative of emissions received at the photoreceptor.
Claim 3
Dependent Claim
76 words
A method according to claim 1, wherein step (A) includes the step of arranging the light source for providing emissions having designated angle of incidence to a reflecting surface of the solder pad, and step (B) includes the step of receiving emissions reflected from the solder pad at a designated angle of reflectance to the reflecting surface of the solder pad, the angle of incidence and the angle of reflectance being substantially equal and substantially non-zero.
Claim 4
Dependent Claim
84 words
A method according to claim 1, wherein step (A) includes the step of arranging the light source for providing emissions having a designated angle of incidence to a reflecting surface of the solder pad, and step (B) includes the step of receiving emissions reflected from the solder pad at a designated angle of reflectance to the reflecting surface of the solder pad, each of said designated angle of incidence and said designated angle of reflectance being in the range of 30 to 60 degrees.
Claim 5
Dependent Claim
81 words
A method according to claim 1, wherein step (A) includes the step of arranging the light source for providing emissions having a designated angle of incidence to a reflecting surface of the solder pad, and step (B) includes the step of receiving emissions reflected from the solder pad at a designated angle of reflectance to the reflecting surface of the solder pad, each of said designated angle of incidence and said designated angle of reflectance being substantially equal to 45 degrees.
Claim 6
Dependent Claim
31 words
A method according to claim 1, wherein step (A) includes the step of providing within the light source a diffuser element for diffusing emissions which are to illuminate the solder pad.
References Cited (Backward Citations)
US4240750A
Cited
JPH107202A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-01 | 1991-08-31 | 1992-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-01 | 1995-08-31 | 1996-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-01 | 1999-08-31 | 2000-03-01 | $7700.00 | Window Closed / Lapsed |