Abstract: Inspection of solder paste on a printed circuit board using a histogram of an image before printing (pre-application image) to normalize an image after printing of the printed circuit board (post-application image) is described. Existing lighting and optics used for alignment of the screen-printing stencil to the printed circuit board are used for the solder paste inspection.

Abstract: Inspection of solder paste on a printed circuit board using a before printing image (pre-image) to normalize an after printing image (post-image) of the printed circuit board. Existing lighting and optics used for alignment of the screen printing stencil to the printed circuit board are used for the solder paste inspection. A stencil in the screen printing process is also inspected using a before printing image (pre) to normalize an after printing image (post) of the stencil.

Abstract: The invention automatically inspects the bond of a wire to a contact pad on a semiconductor chip. The apparatus includes a movable platform for holding semiconductor chips situated in lead frames; a video camera for sensing images; illumination means for illuminating a chip in a lead frame; an image processor to digitize and analyze the images; a bonding mechanism; and a host controller electronically connected to bonding mechanism, movable platform, video camera, and image processor. Image processor locates a bond on a pad in a digitized image and provides a first nominal center of ball bond image. The invention aligns the center of a polar coordinate transform image having one or more segments with the nominal center of ball bond image and evaluates ball bond image using the polar coordinate transform image to create a polar projection histogram array and store it. An edge filter is applied to histogram array to detect peaks and store their number and values.

Abstract: This invention provides a method and apparatus for automatically locating the bond of a wire to a lead frame and semiconductor chip or similar device as an in-process operation to facilitate in-process inspection. The apparatus includes a wire bonding machine, or similar apparatus, having a movable platform such as an X-Y table for holding semiconductor chips situated in lead frames; a video camera or other optical sensing or imaging device for generating images, which camera is typically positioned over the target chip and lead frame to be bonded; illumination means for illuminating the chip in a lead frame; an image processor capable of digitizing and analyzing the optically sensed images; a bonding mechanism; and a host controller connected to the bonding mechanism, the movable platform, the camera and the image processor.

Abstract: A method and apparatus for locating and measuring capillary indentation marks on wire bonded leads by creating a normalized, one-dimensional circumferential projection of a candidate center location in an image of a capillary indentation mark and detecting signals in the one-dimensional circumferential projection that correspond to a predefined pattern. The one-dimensional circumferential projection can be generated and evaluated for a full or a sub-sampled set of candidate center locations according to a number of different methods.

Abstract: A machine vision system for identifying the locations of bonding pads on an integrated circuit mounted in a lead frame. The system involves locating the bonding pads by searching an image with suitably rotated corner templates. A set of possible candidate bonding pads is created from the location of corner templates found during the search. The set is then scored utilizing matching criteria. The best candidate is selected from the set based upon the candidates' scores. The location of the bonding pad is then generated from the best candidate's corner template locations. The invention can be beneficially applied to locate bonding pads during wire bonding, as well as other machine vision applications.

Abstract: A machine vision system for identifying the locations of bonding pads on an integrated circuit mounted in a lead frame. The system involves rotating the image of the die to produce an image of the die unrotated with respect to the lead frame (the "counter-rotated image"). The counter-rotated image is searched with corner templates of the bonding pad. A set of possible candidate bonding pads is created from the location of corner templates found during the search. The set is then scored utilizing matching criteria. The best candidate is selected from the set based upon the candidates' scores. The location of the bonding pad is then generated from the best candidate's corner template locations. The invention can be beneficially applied to locate bonding pads during wire bonding, as well as other machine vision applications.

Abstract: This invention provides a method and apparatus for automatically locating the bond of a wire to a lead frame and semiconductor chip or similar device as an in-process operation to facilitate in-process inspection. The apparatus includes a wire bonding machine, or similar apparatus, having a movable platform such as an X-Y table for holding semiconductor chips situated in lead frames; a video camera or other optical sensing or imaging device for generating images, which camera is typically positioned over the target chip and lead frame to be bonded; illumination means for illuminating the chip in a lead frame; an image processor capable of summing said absolute difference values, whereby each sum is stored as a difference metric, and digitizing and analyzing the optically sensed images; a bonding mechanism; and a host controller connected to the bonding mechanism, the movable platform, the camera and the image processor.

Abstract: The invention automatically inspects the bond of a wire to a contact pad on a semiconductor chip. The apparatus includes a movable platform for holding semiconductor chips situated in lead frames; a video camera for sensing images; illumination means for illuminating a chip in a lead frame; an image processor to digitize and analyze the images; a bonding mechanism; and a host controller electronically connected to bonding mechanism, movable platform, video camera, and image processor. Image processor locates a bond on a pad in a digitized image and provides a first nominal center of ball bond image. The invention aligns the center of a polar coordinate transform image having one or more segments with the nominal center of ball bond image and evaluates ball bond image using the polar coordinate transform image to create a polar projection histogram array and store it. An edge filter is applied to histogram array to detect peaks and store their number and values.

Abstract: Method and apparatus for automatically locating the center of a ball bond of a wire to a lead frame and semiconductor chip or similar device; analyzing the optically sensed images; a bonding mechanism; and a host controller connected to the bonding mechanism, the movable platform. The present invention constructs a synthetic flattened cone model using a center radius, and monotonically increasing slope values to generate a model having a variation in grey levels, and inner and outer radii that will encompass expected size variations in a ball bond; sets a threshold for acceptable normalized correlation search results; acquires a digitized image of the bond, including a nominal location for the bond; conducts a normalized correlation search of the digitized image at the bond location, using the flattened synthetic cone model; and indicates the presence and location of the expected circular object as the location having the largest coefficient which exceeds a threshold.

Abstract: This invention provides a method and apparatus for automatically locating the bond of a wire to a lead flame and semiconductor chip or similar device as an in-process operation to facilitate in-process inspection. The apparatus includes a wire bonding machine, or similar apparatus, having a movable platform such as an X-Y table for holding semiconductor chips situated in lead frames; a video camera or other optical sensing or imaging device for generating images, which camera is typically positioned over the target chip and lead flame to be bonded; illumination means for illuminating the chip in a lead flame; an image processor capable of digitizing and analyzing the optically sensed images; a bonding mechanism; and a host controller connected to the bonding mechanism, the movable platform, the camera and the image processor.