Pick and place machine with component placement inspection

Abstract

Improved component placement inspection and verification is performed by a pick and place machine. Improvements include stereovision imaging of the intended placement location; enhanced illumination to facilitate the provision of relatively high-power illumination in the restricted space near the placement nozzle(s); optics to allow image acquisition device to view the placement location from an angle relative to a plane of the placement location, thereby reducing the possibility of such images being obstructed by the component; techniques for rapidly acquiring images with commercially available CCD arrays such that acquisition of before and after images does not substantially impact system throughput; and image processing techniques to provide component inspection and verification information.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional application of U.S. patent application Ser. No. 10 / 291,074, filed Nov. 8, 2002, which application claims priority to the following prior provisional applications: Ser. No. 60 / 338,233 filed Nov. 13, 2001 entitled INSPECTION METHODS FOR A PICK AND PLACE MACHINE; Ser. No. 60 / 356,801 filed Feb. 13, 2002 entitled PICK AND PLACE MACHINE WITH COMPONENT PLACEMENT INSPECTION; and Ser. No. 60 / 374,964 filed Apr. 22, 2002 entitled IMPROVED INSPECTION. Each and every provisional application listed above is incorporated by reference herein in its entirety.COPYRIGHT RESERVATION [0002] A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all c...

AI Technical Summary

Benefits of technology

[0011] Embodiments of the present invention improve upon component level inspection performed by pick and place machines. Such improvements include stereovision imaging of the intended placement location; enhanced illumination to facilitate the provision of relatively high-power illumination in the restricted space near the placement nozzle(s); optics to allow image acquisition device to view the placement location from an angle relative to a plane of the placement location, thereby reducing the possibility of such images being obstructed by the component; techniques for rapidly acquiring images with commercially available CCD arrays such that acquisitions of before and after images do not substantially impact system throughput; and image processing techniques to provide component inspection and verification information. These and other advantages of embodiments of the present invention will be apparent from the description below.

Problems solved by technology

Pick and place machine operation is challenging.

While such systems provide highly useful inspection, they do consume plant floor-space as well as programming time maintenance efforts and the like.

While the disclosure of Asai et al. marks one attempt to employ in-machine component level inspection, there remains much work to be done.

Thus, optics intended to image a plurality of placement events also move in x and / or y. Accordingly, the size and mass (inertial load) of the optical system itself can be prohibitive of on-head use in gantry-style machines.

For pick and place machines having heads that move in x and / or y, increased mass is an issue because of the increased inertia.

Given a certain motive power provided by the electromechanical system of the pick and place machine, increased mass causes decreased acceleration.

Size, that is volume and / or shape of the optical system attached to the moving head, can also be a problem for a number of reasons.

Another reason that the size and / or shape of the head can become a problem is that there are generally a relatively large number of cables, tubes, motors, and other structures mounted to the head.

Adding something that may conflict with assembly or maintenance of the machine is generally disfavored.

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