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Credence Engineering Inc. |
LTCC and HTCC Process Equipment |
BLOCK CUTTING |
Our Cutter is fundamentally different from a typical capacitor cutter. A capacitor cutter utilize two (2) cameras to correct the rotational position of each cut so as to align the cut with the exposed metal on the edges of the laminated block. They can use this same method to cut LTCC packages by placing the cameras to look vertically down onto the part and make corrections based upon the position of special Fiducials on the top print. This means that as the parts within the block move during lamination (and they will move in relation to each other by as much as .1mm), capacitor cutters will rotate the block to compensate for the movement of the Fiducials so each cut hits the Fiducials. This approach causes trapezoidal parts! This method works on capacitors because capacitors are very small and a small rotational shift will not have a big effect on any given part. This is not the case with large parts. A small rotational movement of the cut to correct for lamination movement will, in effect, use up a large portion of the overall product size tolerance. You will find yourself constantly losing parts because they do not meet the overall part size specifications. The Credence C8 cutter utilizes a single camera and has an additional axis (X-Axis) so that we use the same camera to view some or all of the Fiducials. We do not make rotational corrections but X and Y Corrections to "Center" the parallel pair of cuts to "Best Fit" the Fiducials and we "Hold" the overall part size. We will read any number of the Fiducials within a row and then read any number of Fiducials within the opposite side of the parts. We then keep the overall size of the part fixed and shift the “pair” of cuts to "Best Fit" them to the parts within the block. This always produces square corners, parallel parts, and minimizes the amount of the product tolerance that we use in the cutting process. This method (proven by years of use at Medtronic) maximizes the yield for package-type products. |
Credence Engineering Incorporated, 237 W. La Vieve Ln., Tempe, Arizona, USA, Ph: USA-480-752-9776, E-Fax: USA-602-798-8277 |