Hewlett-packard Company

Agilent Technologies, Inc.

John M Heumann

Ed O Schlotzhauer

Bryan D Boswell

Kevin G Chandler

Barry A Alcorn

Ronald J Peiffer

David T Crook

David Lee Gines

John E McDermid

Ronald K Kerschner

Thomas F Uhling

Nicholas Tufillaro

James M Lindauer

David Reynolds

George L Booth

Jonathan Qiang Li

Gerald L Meyer

Tracy Kristine Ragland

Eduardo Acosta

Vance R Harwood

Colin Fox

Douglas R Manley

A system and method for performing auto-focusing operations for tomosynthetic reconstruction of images are provided. More specifically, embodiments of the present invention provide a system and method for efficiently computing the gradient of one or more depth layers of an object under inspection, wherein such gradients may be used in performing auto-focusing operations to determine a depth layer that includes an in-focus view of a feature that is of interest. In at least one embodiment, a method is provided that comprises capturing detector image data for an object under inspection, and using the detector image data for computing gradient information for at least one depth layer of the object under inspection without first tomosynthetically reconstructing a full image of the at least one depth layer.

System and method for performing auto-focused tomosynthesis

Techniques for detecting temporal process variation and for managing and predicting performance of automatic classifiers applied to such processes using performance estimates based on temporal ordering of the samples are presented.

Methods and apparatus for detecting temporal process variation and for managing and predicting performance of automatic classifiers

In one embodiment, a method for designing a radiographic imaging system includes 1) receiving a number of design constraints for the system, and then 2) in response to the constraints, generating a plurality of radiographic imaging system designs, each having a different number of radiographic sources, and each requiring a different number of nominal scan passes to image a specimen region of interest. Designs having a greater number of radiographic sources have sets of translated radiographic detection areas sharing at least some coincident, nominal scan passes as compared to radiographic imaging system designs having fewer radiographic sources. Each set of translated radiographic detection areas is associated with a radiographic source that is replicated and translated with respect to a radiographic source that forms part of a radiographic imaging system design having fewer radiographic sources. Related systems and apparatus are also disclosed.

Radiographic imaging systems and methods for designing same

A calibration technique is presented for calibrating non-reference indirect measurement systems with respect to a reference indirect measurement system. A reference map function filling procedure fits a reference map function based on known values of a parameter of interest associated with reference calibration samples and corresponding reference values associated with the reference calibration samples. A correction function fining procedure fits a correction function based on reference values for calibration samples measured on or simulated for the reference indirect measurement system and corresponding values measured on the non-reference indirect measurement system. During normal use, the non-reference indirect measurement system obtains measurements, corrects the measurements using the correction function, and estimates the parameter of interest of the object of interest using the reference map function based on the corrected measurements.

Method and apparatus for calibration of indirect measurement systems

A tomographic reconstruction method and system incorporating Bayesian estimation techniques to inspect and classify regions of imaged objects, especially objects of the type typically found in linear, areal, or 3-dimensional arrays. The method and system requires a highly constrained model M that incorporates prior information about the object or objects to be imaged, a set of prior probabilities P(M) of possible instances of the object; a forward map that calculates the probability density P(D|M), and a set of projections D of the object. Using Bayesian estimation, the posterior probability p(M|D) is calculated and an estimated model Mof the imaged object is generated. Classification of the imaged object into one of a plurality of classifications may be performed based on the estimated model M, the posterior probability p(M|D) or MAP function, or calculated expectation values of features of interest of the object.

Highly constrained tomography for automated inspection of area arrays

Disclosed are a method and apparatus for tomography of a curved surface in an object. One embodiment is a method that includes determining an expected distortion for each of a plurality of points in a projection of the curved surface, and correcting each of the plurality of points in the projection according to the expected distortion of that point by replacing pixel values in the uncorrected projection with corresponding interpolated pixel values at the expected positions.

Tomography of curved surfaces

A system and method of computed tomography is disclosed. The method includes acquiring at least one projection but less than all projections to be used in reconstruction of an unknown object and processing the at least one projection for reconstruction of the unknown object. After processing each projection is discarded. Projections are acquired until all projections have been processed. An estimate of the unknown object may be generated during the processing of each of the projections.

Computed tomography

A method for testing node interconnection on a circuit board. The method utilizes an automated test system having at least one test channel, wherein each test channel has a digital driver with a first input and a first output, and a digital receiver with a second output and a second input. The second input of the receiver is coupled to the first output of the driver and to a test probe. The test probe is configured to couple the driver and receiver to one of a plurality of nodes on a circuit board. During a node interconnection test, the driver of a first test channel applies a test signal to a selected node of the plurality of nodes. A predetermined amount of time after application of the test signal, the receiver of the first test channel reads a node voltage of the selected node. The node voltage is then compared to a predetermined threshold voltage of the receiver of the first test channel, and the result of the comparison is an indication as to whether the selected node is coupled to ground.

System and method for detecting shorts, opens and connected pins on a printed circuit board using automatic test equipment

An X-ray inspection system incorporates an improved technique for determining, in an X-ray image of a multilayered assembly, the gray level component of a first material in the presence of a second material. The total gray level of the image is dependent upon the physical characteristics of each material comprising the assembly. The present invention accurately determines the component of the total image gray level due to the first material. In the case of circuit board inspections using X-ray images of solder connections, a calibration procedure facilitates the direct conversion of the gray level component due to the solder connection to the thickness of the solder connection.

Enhanced thickness calibration and shading correction for automatic X-ray inspection

A method for testing node isolation on a circuit board. The method utilizes an automated test system having a plurality of test channels, wherein each test channel has a digital driver with a first input and a first output, and a digital receiver with a second output and a second input. The second input of the receiver is coupled to the first output of the driver, to a number of switches, and to a test probe. The test probe is configured to couple the driver and receiver to one of a plurality of nodes on a circuit board. The number of switches are configured to selectively couple the first output and second input to ground. During a node isolation test, each node of a test node group is coupled to one of the test channels. But for a selected node of the test node group, each node of the test node group is coupled to ground via the number of switches of the test channels coupled to the nodes. Thereafter, a test signal is applied to the selected node via the digital driver of a first test channel which is coupled to the selected node. It is then determined if the digital receiver of the first test channel indicates that the selected node is coupled to ground, and whether the selected node is isolated from the remaining nodes of the test node group. If the selected node is not isolated from the remaining nodes of the test node group, the nodes of the test node group are released from ground, a test signal is once again applied to the selected node, and a determination is made as to whether the selected node is grounded to thereby determine if the selected node is directly connected to ground. Finally, if the selected node is not directly connected to ground, varying subsets of the remaining nodes are coupled to ground, a test signal is once again applied to the selected node, and a determination is made as to whether the selected node is grounded to thereby determine which nodes of the test node group the selected node is isolated from.

A method for testing node interconnection on a circuit board. The method utilizes an automated test system having at least one test channel, wherein each test channel has a digital driver with a first input and a first output, and a digital receiver with a second output and a second input. The second input of the receiver is coupled to the first output of the driver and to a test probe. The test probe is configured to couple the driver and receiver to one of a plurality of nodes on a circuit board. During a node interconnection test, a first selected node is coupled to a first test channel, and it is determined whether the first selected node is connected to ground. If the first selected node is not connected to ground, a second selected node is connected to ground; a test signal is applied to the first selected node via the digital driver of the first test channel; and it is determined whether the first selected node is connected to the second selected node.

System and method for detecting shorts, opens and connected pins on a

A cone-beam tomographic system in which computation speed is improved by reducing the reconstructed images to thin planes. Reducing the images to thin planes reduces the number of picture elements to be computed, and reduces basis functions to a simple function of the angle of a ray relative to a plane. In a variation, computation speed is further improved by making pixel size inversely proportional to the distance of a plane from an emissions source. As a result of the variable pixel size, for each projection, a ray intersecting the center of a sensor element intersects the center of exactly one pixel in each object plane.

Computed tomography with iterative reconstruction of thin

An automatic circuit board tester for testing for shorts, opens, and interconnected pins or nodes on a circuit board. The tester first classifies the nodes as being in one of three categories based upon the design of the board and the intended interconnection of the nodes. The categories of nodes are: (1) connected to ground; (2) interconnected to all other nodes in the test group; or (3) isolated from all other nodes. The circuit board tester has a testhead containing a plurality of test channels, each configured to be coupled to a node on the circuit board. The testhead utilizes a digital signal from a digital driver to drive the node, at a predetermined voltage and a digital receiver to read the node voltage to determine if it is coupled to ground. Each test channel also includes a switch to connect the digital driver and receiver to the test node as well as a ground switch to selectively couple the node to ground. Various combinations of switch positions and testing sequences enables the circuit board tester to test all node connections and to ensure that the physical embodiment of the circuit board accurately reflects the circuit board design.

An automated analysis system that identifies detectability problems, diagnosability problems, and possible ways to change rank order of diagnoses in a diagnostic system and makes the problems and possible improvements visible to test programmers to aid in test improvement. Components that have no coverage and components that have inadequate coverage (according to a heuristic criteria) are identified as potential detectability problems. Components that are exercised by identical operations in all tests are identified as diagnosability problems. If an incorrect diagnosis is made, the automated analysis system identifies failing tests that have no coverage of any component in the true failure cause. In addition, if an incorrect diagnosis is made, the automated analysis system identifies ways of changing the rank order of diagnoses, including coverages that can be reduced and identification of operation violations that can be eliminated or deliberately added. If no historical data are available, a 'diagnosability index' may be computed by randomly sampling from the set of possible failure syndromes and observing the frequencies with which ties occur among the weights of the top-ranked candidate diagnoses. After historical data becomes available, a diagnosability index may be computed from the frequency with which two candidate diagnoses are assigned identical weights by the model-based diagnostic system over a set of representative failures.

Automated analysis of a model based diagnostic system

An automatic circuit board tester for testing for shorts, opens, and interconnected pins or nodes on a circuit board. The tester first classifies the nodes as being in one of three categories based upon the design of the board and the intended interconnection of the nodes. The categories of nodes are: (1) connected to ground; (2) interconnected to all other nodes in the test group; or (3) isolated from all other nodes. The circuit board tester has a testhead containing a plurality of test channels, each configured to be coupled to a node on the circuit board. The testhead utilizes a digital signal from a digital driver to drive the node at a predetermined voltage and a digital receiver to read the node voltage to determine if it is coupled to ground. Each test channel also includes a switch to connect the digital driver and receiver to the test node as well as a ground switch to selectively couple the node to ground. Various combinations of switch positions and testing sequences enables the circuit board tester to test all node connections and to ensure that the physical embodiment of the circuit board accurately reflects the circuit board design.

Growing community of inventors

Loveland, CO, United States of America

John M Heumann