The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 22, 1992
Filed:
May. 06, 1992
Christopher A Hicks, Austin, TX (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The method of the present invention permit the accurate sensing of the height of a solder nozzle above a circuit board during operation of the solder nozzle. A non-contact limit switch, which provides an indication of the presence of a planar surface at a preselected proximity, is mounted in a fixed relationship with a solder nozzle which is manipulatable by means of a robotic arm. A reference surface is provided which includes a proximity sensor, such as a through beam fiber optic switch. The proximity sensor is mounted a predetermined distance above the reference surface and is utilized to detect the solder nozzle as it is moved toward the reference surface. By noting the position coordinates of the robotic arm at which the proximity sensor indicates the presence of the solder nozzle at the predetermined distance above the reference surface, and the position of the robotic arm at which the non-contact limit switch closes in response to the proximity of the reference surface, it is possible to accurately calculate a calibration offset value which may be utilized in conjunction with the output of the non-contact limit switch to precisely position the solder nozzle at a desired distance above a circuit board. In one preferred embodiment of the present invention, the solder nozzle is repeatedly moved toward the reference surface during calibration to ensure that the calibration offset value obtained is statistically significant.