Abstract: A method and apparatus which incorporate self learning techniques for the detection of solder defects and for statistical process control of solding operations on printed circuit board assemblies (PCBA) are disclosed. The invention includes learning techniques which are used during the inspection of cross-sectional X-ray images of solder joints. These learning techniques improve measurement accuracy by accounting for localized shading effects, which can occur when inspecting double-sided printed circuit board assemblies. Two specific examples are discussed. The first is a method for detection of solder short defects. The second method utilizes learning to improve the accuracy of statistical process control (SPC) measurements.

Abstract: A method and apparatus which incorporate self learning techniques for the detection of solder defects and for statistical process control of solding operations on printed circuit board assemblies (PCBA) are disclosed. The invention includes learning techniques which are used during the inspection of cross-sectional X-ray images of solder joints. These learning techniques improve measurement accuracy by accounting for localized shading effects, which can occur when inspecting double-sided printed circuit board assemblies. Two specific examples are discussed. The first is a method for detection of solder short defects. The second method utilizes learning to improve the accuracy of statistical process control (SPC) measurements.

Abstract: A method and apparatus for the detection of excess or insufficient solder conditions at electrical connections on printed circuit boards are disclosed. The invention analyzes a cross-sectional image of an electrical connection to obtain the average solder thickness of the connection. This average solder thickness is then compared to an upper threshold value to determine if the connection is an excess solder defect, and a lower threshold value to determine if the connection is an insufficient solder defect. In one embodiment, the present invention compensates for variations in image intensity due to the background by employing a first and second correction factor in the calibration technique. The first correction factor is the measured background gray scale value local to the connection, while the second correction factor is determined to have a substantially linear relationship to the background image intensity local to each solder connection.

Abstract: A tomographic inspection system which enables multiple locations within an object to be imaged without mechanical movement of the object. The object is interposed between a rotating X-ray source and a synchronized rotating detector. A focal plane within the object is imaged onto the detector so that a cross-sectional image of the object is produced. The X-ray source is produced by deflecting an electron beam onto a target anode. The target anode emits X-ray radiation where the electrons are incident upon the target. The electron beam is produced by an electron gun which includes X and Y deflection coils for deflecting the electron beam in the X and Y directions. Deflection voltage signals are applied to the X and Y deflection coils and cause the X-ray source to rotate in a circular trace path. An additional DC voltage applied to the X or Y deflection coil will cause the circular path traced by the X-ray source to shift in the X or Y direction by a distance proportional to the magnitude of the DC voltage.

Abstract: A high resolution laminography system for the inspection of integrated circuits wherein a beam of highly focused electrons is traced in a circular pattern on a flat target within a vacuum chamber. The target converts the electron beam into X-rays, so that a source of X-rays is produced which rotates in synchronization with a rotating detector assembly. An object is placed within the vacuum chamber, between the X-ray source and the detector so that an X-ray cross sectional image of a cutting plane of the object is produced. A computer and feedback system controls image acquisition and an automated positioning system. The computer system can also operate under program control to automatically analyze data, measure characteristics of the object under inspection, and make decisions regarding the acceptability of the object's quality.

Abstract: A tomographic inspection system wherein the electron beam of a microfocus X-ray tube is deflected in a circular scan pattern onto the tube anode in synchronization with a rotating detector that converts the X-ray shadowgraph into an optical image and derotates the image so as to be viewed and integrated in a stationary video camera. A computer system controls an automated positioning system that supports the item under inspection and moves successive areas of interest into view. In order to maintain high image quality, a computer system also controls the synchronization of the electron beam deflection and rotating optical system, making adjustments for inaccuracies of the mechanics of the system. The computer system can also operate under program control to automatically analyze data, measure characteristics of the item under inspection and make decisions regarding the acceptability of the item's quality.

Abstract: A tomographic inspection system wherein the electron beam of a microfocus X-ray tube is deflected in a circular scan pattern onto the tube anode in synchronization with a rotating detector that converts the X-ray shadowgraph into an optical image and derotates the image so as to be viewed and integrated in a stationary video camera. A computer system controls an automated positioning system that supports the item under inspection and moves successive areas of interest into view. In order to maintain high image quality, a computer system also controls the synchronization of the electron beam deflection and rotating optical system, making adjustments for inaccuracies of the mechanics of the system. The computer system can also operate under program control to automatically analyze data, measure characteristics of the item under inspection and make decisions regarding the acceptability of the item's quality.

Abstract: A tomographic inspection system wherein the electron beam of a microfocus X-ray tube is deflected in a circular scan pattern onto the tube anode in synchronization with a rotating detector that converts the X-ray shadowgraph into an optical image and derotates the image so as to be viewed and integrated in a stationary video camera. A computer system controls an automated positioning system that supports the item under inspection and moves successive areas of interest into view. In order to maintain high image quality, a computer system also controls the synchronization of the electron beam deflection and rotating optical system, making adjustments for inaccuracies of the mechanics of the system. The computer system can also operate under program control to automatically analyze data, measure characteristics of the item under inspection and make decisions regarding the acceptability of the item's quality.

Abstract: A roller assembly having longitudinal ribs which snap fit into shelf members of a support frame. In one embodiment the shelf members have upright T-shaped end members with lateral extending feet that engage the ribs. In another embodiment the shelf members have longitudinal feet that engage the ribs. Preferably, the edge forming the underside of the roller assembly are supported by base portions of the shelf member.

Abstract: A roller assembly for use in a package flow system. The roller assembly has a unitary rail frame assembly with pairs of opposed arcuate shaft sections spaced along the rail frame. The arcuate shaft sections of each pair are axially spaced from each other and extend integrally from the rail frame to provide integral bearing frame surfaces for supporting one of a plurality of rollers.