Method for imaging printed circuit board component leads
AssigneeCognex Corporation
InventorWilliam M. Silver
Life of this patent
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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.
Claims5
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.
Dependencies are inferred from the claim text.