Patents by Inventor Walter E. Marrable, Jr.

Walter E. Marrable, Jr. has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Apparatus and method for verifying the coplanarity of a ball grid array
    Patent number: 5621530
    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.
    Type: Grant
    Filed: April 26, 1995
    Date of Patent: April 15, 1997
    Assignee: Texas Instruments Incorporated
    Inventor: Walter E. Marrable, Jr.