Cognex Corporation

Len L Picard

Yasunari Tosa

Paul Dutta-Choudhury

John P Petry, Iii

Clifford T Fitzgerald

Ralph D Mayer

Neil S Levine

Frederic Barber

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.

Methods and apparatuses for defining a region on an elongated object

This invention provides an apparatus and method for locating a curvilinear symbol by generating a grey scale model of a segment of a curvilinear symbol and interpolating curvature at the segment's periphery; reflecting this segment around the axes of symmetry to generate a full size model; generating full resolution subfeature models; assigning coordinate axes weighting to each subfeature model x and y axis; defining tolerance thresholds for deviations from an idealized curvilinear symbol; searching a digitized image for shapes corresponding to the subfeature models; assigning weights to scores returned for positions found corresponding to the subfeature models; producing weighted positions combining both coordinate axis weighting and score weighting; computing a best fit for the image found; comparing the positions found to tolerance thresholds and discarding those positions outside the thresholds; substituting and weighting alternate positions found, if any, to compute the location of the curvilinear symbol from remaining positions within the threshold.

Circle location

A machine vision system for inspection of a mark (such as a multi-character mark) on an IC device as shown. The system provides search and defect analysis for the mark, individual characters of the mark, and the foreground and the background of the mark. The system provides for search and defect analysis reports thereof. It includes components for operator training search and defect analysis models for the whole mark, and for automatic training of such models for individual characters of the mark.

Mark quality inspection apparatus and method

A method and apparatus for locating curvilinear objects of variable scale in digitized images using feathered fiducials. The leathered fiducials are constructed by: defining a range of tolerated object size scale variations; generating an enlarged submodel within the range of tolerated scale variations and assigning background pixel values exterior to the enlarged submodel; generating a reduced size submodel within the range of tolerated scale variations and assigning foreground pixel values to the reduced size submodel; disposing the reduced size submodel within and tangent to the enlarged submodel at the application point; uniformly changing grey scale pixel values in a graduated manner from foreground to background between the reduced size submodel and the enlarged one. The curvilinear objects are then located by conducting searches using the constructed fiducials.

Locating curvilinear objects using feathered fiducials

A frontal illumination system includes a light source and a finite plurality of reflecting surfaces. The reflecting surfaces can be characterized as the inner surfaces of a set of conical frustums arranged to approximate the illumination coming from the inner surface of a hemisphere. The light source is located within or adjacent to at least one of the reflecting surfaces. It emits light that is reflected off opposing portions of at least one, and preferably all, of the surfaces. The system is capable of illuminating the object from a very large solid angle, even though it is disposed in a substantially short axial space.

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Wilmington, MA, United States of America

Len L Picard