Apparatus and method for verifying the coplanarity of a ball grid array
First Claim
1. A method for verifying the coplanarity of a ball grid array having a plurality of solder balls on the underside of a semiconductor device package, comprising the steps of:
- positioning the semiconductor device with the ball grid array down on a flat transparent surface;
positioning a light source and an image capturer generally above the semiconductor device;
directing light from said light source through the flat transparent surface to the ball grid array;
directing the image of the ball grid array through the flat transparent surface to said image capturer;
focusing said image capturer on each of said plurality of solder balls and generating a focus data for each solder ball; and
determining the coplanarity of the ball grid array from said focus data.
1 Assignment
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Accused Products
Abstract
The apparatus (10) includes a flat transparent surface (30) and two angled mirrored surfaces (32, 34) which direct the light to the ball grid array (12) on the underside of the semiconductor device (14) positioned on the flat transparent surface (30) in a live bug mode. The mirrored surfaces (32, 34) also direct the image of the ball grid array (12) to an image capturer (18) such as a video camera. The focus information of each solder ball is used to determine the distance to the tips of each solder ball. The coplanarity of the ball grid array can then be determined and/or verified.
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Citations
13 Claims
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1. A method for verifying the coplanarity of a ball grid array having a plurality of solder balls on the underside of a semiconductor device package, comprising the steps of:
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positioning the semiconductor device with the ball grid array down on a flat transparent surface; positioning a light source and an image capturer generally above the semiconductor device; directing light from said light source through the flat transparent surface to the ball grid array; directing the image of the ball grid array through the flat transparent surface to said image capturer; focusing said image capturer on each of said plurality of solder balls and generating a focus data for each solder ball; and determining the coplanarity of the ball grid array from said focus data. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. Apparatus for verifying the coplanarity of a plurality of solder balls of a ball grid array located on an underside of a semiconductor device, comprising:
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an optical assembly having a flat transparent surface supporting said semiconductor device in a live bug mode; a light source illuminating said ball grid array; and an image capturer having a focus mechanism generating focus data for each of said plurality of solder balls. - View Dependent Claims (9, 10, 11, 12, 13)
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Specification