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US 6,289,492 B1Granted
Methods and apparatuses for defining a region on an elongated object
AssigneeCognex Corporation
InventorsPaul Dutta-Choudhury, Len Picard, Yasunari Tosa
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AssigneeCognex Corporation
InventorsPaul Dutta-Choudhury, Len Picard, Yasunari Tosa
Estimating the term…
Methods and apparatuses are disclosed for defining a locus of viable points on an elongated object, such as a locus of viable bond points on a lead of a lead frame. The locus guides the bond point positioning of a wire bonder so that the number of unacceptable wire bonds is reduced. The locus is a region adapted to receive a bond, and is defined such that for any bond centered therein, the probability of forming an unacceptable bond is reduced by offsetting the locus from at least a portion of the lead edge(s) by a minimum-offset distance. The minimum-offset distance is based on various factor(s), such as user tolerance and bond width. Further, the definition of the locus is independent of lead shape, and consequently works with a variety of lead shapes. The locus can also have various shapes for a single lead, and the shapes can vary depending on the application. The method and apparatus herein disclosed describe a variety of methods to detect the leads and define the size, position, and shape of the locus during training. Preferably, the lead tip is also detected so that the locus can be defined based on an offset from the front of the lead. During operation, characteristics of the locus and/or the target bond point are used to relocate the lead and refine the target bond/point before bonding. Alternative embodiments disclosed include inspecting the leads.
A method for defining a region of viable bond points on first elongated objects, the method comprising:
An apparatus adapted to define one or more bond points on first elongated objects, the apparatus comprising:
A method for positioning a point on a first elongated object, the method comprising:
An apparatus defining regions on a plurality of first elongated objects, the apparatus comprising:
Dependencies are inferred from the claim text.