Inspection of ball grid arrays (BGA) by using shadow images of the solder balls
First Claim
1. A system for inspecting a ball grid array on an integrated circuit for verifying if said array conforms to specific position parameters, the system comprising:
- a source of electromagnetic radiation projected at a predetermined angle onto a substrate of the integrated circuit on which substrate surface is said array;
an imaging device to obtain an image of shadows cast by balls of the ball grid array; and
an image analysis engine to analyze said image to obtain contour data of the shadows cast by the balls.
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Accused Products
Abstract
A method for measuring such parameters as height, position, shape, colinearity, and coplanarity of arrays of minute objects on the surface of integrated circuits, such as Ball Grid Arrays (BGA), all in one simple and straight forward procedure during the manufacturing process of integrated circuits. Shadows of the objects are created on the substrate through the use of x-rays or other light sources placed at predetermined distances and angles from the objects. An imaging device obtains images from the shadows cast onto the substrate and the images are then analyzed to determine if they meet predefined parameters. Multiple sources of illumination can be used to illuminate the array in order to create a more precise image for analysis and three dimensional images of the BGA can be created for analysis.
86 Citations
25 Claims
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1. A system for inspecting a ball grid array on an integrated circuit for verifying if said array conforms to specific position parameters, the system comprising:
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a source of electromagnetic radiation projected at a predetermined angle onto a substrate of the integrated circuit on which substrate surface is said array;
an imaging device to obtain an image of shadows cast by balls of the ball grid array; and
an image analysis engine to analyze said image to obtain contour data of the shadows cast by the balls. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for verifying that an array of minute objects on a workpiece conform to specific parameters, said method comprising:
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projecting electromagnetic radiation at a predetermined angle onto a substrate surface of the workpiece on which substrate surface are positioned an array of minute objects;
imaging the shadows cast by the minute objects as a result of being illuminated by the electromagnetic radiation;
analyzing the images so obtained to determine if the array of minute objects meet certain predefined parameters. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23)
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24. A system for verifying that an array of minute objects on a workpiece conform to specific parameters, the system comprising:
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a source of electromagnetic radiation projected at a predetermined angle onto a substrate of the work piece on which substrate surface are an array of minute objects, an imaging device to image the shadows cast by the minute objects, an image analysis engine to analyze the shadows cast to determine if the minute objects and substrate meet certain predefined parameters. - View Dependent Claims (25)
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Specification