Friday, May 25, 2018
Publication Date:09/1/2007
Archive >  September 2007 Issue >  Electronic Mfg. Products > 

Exerra Screen Printer Has Built-In Inspection
Screen printer with built-in inspection.
Alpharetta GA — The eP Series screen printers from Exerra, Inc. a member of the GRIP Technologies Group based in Israel, combine a mono-block casting and a two-stage, servo-driven granite table with a digital, servo-controlled drive system on every axis for very high speed and accuracy. The integral 2D&D Print Quality Inspection, a triple-section PC board transport system and programmable squeegee pressure control with continuous in-process monitoring enable assembler to manage every detail of the paste printing process.

The system's 2D&D print quality inspection is based on a proprietary image processing generator that enables 100 percent inspection of all assemblies without compromising throughput. A camera rapidly scans the PC board and acquires a set of color images at 10-micron resolution. The system compares the images to a reference image and manipulates them to determine acceptability. Using a color camera enables the system to analyze solder color differentiation. An intuitive interface lets users define areas of interest for close-up identification, and the screen displays each type of defect in a unique color to speed the identity of various types of products. For stencil inspection, the printers have an automated process to ensure stencil apertures are free of paste. Users can define selected areas, and they can set results to trigger automatic or manual stencil cleaning.

The printer uses the self-learning UniPlane Imaging System for accuracy of ±12µm at 6 Sigma by capturing the stencil and PC board in the printing position using a high-resolution color camera. Any shape on the stencil or PC board can be used as a fiducial, and any number of fiducials can be chosen to increase alignment accuracy.

With the triple-section conveyor transport, side sections can be used as buffers to reduce cycle time. The eP33 printer has a cycle time of less than 12 seconds, and the eP35 has a cycle time of less than 8 seconds, not including printing. Print speed is 1 to 200mm/second.

For more information, contact: Exerra, Inc., 5110 McGinnis Ferry Rd., Alpharetta, GA 30005 770-751-4533 E-mail: Web:

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