Abstract: A guide for the grinding of a surface of an object having a region to be exposed, including at least two conductive leads and a conductive control track. Each conductive lead is associated with a different face of the object, and the control track interconnects the leads and extends across the surface to be ground which lies between the faces. At least a portion of the rear edge of the track is precisely located with respect to a predetermined grinding depth of the region so that a break in the track occurs with the grinding of the surface to that grinding depth.

Abstract: A grinding assembly for grinding an object such as a printed circuit board coupon at a predetermined angle and to a predetermined grinding depth, including a control board carrying a grinding guide having at least two conductive leads and a conductive control track interconnecting the conductive leads, and a shelf having an upper surface for supporting the object. The shelf is positioned relative to the control board to establish a grinding surface for the object biased at the predetermined angle. The shelf is further positioned to align the predetermined grinding depth of the object with a portion of the rear edge of the control track so that the track is ground through when the object is ground along the biased grinding surface to the predetermined grinding depth.

Abstract: A machine for grinding an object, such as a printed circuit board coupon, having a region to be exposed and having a novel control track that has at least a portion of the rear edge of the track precisely located with respect to a predetermined grinding depth for the region is provided according to this invention. The grinding machine includes means for engaging the object with an abrasive device and means, interconnected with the control track on the object, for disengaging the object and the abrasive device when a break in the track has been ground.

Abstract: A guide for the grinding of a surface of an object having a region to be examined is provided by this invention. The guide includes at least two conductive leads and a conductive control track interconnecting the conductive leads and extending across the surface to be ground. At least a portion of the rear edge of the track is precisely located with respect to a predetermined grinding depth of the region so that a break in the track occurs with the grinding of the surface to that grinding depth.