Abstract: A centralized computer system in communication with a measurement system including a multi-point probe is programmed to analyze a plurality of conductor formations on a particular substrate, store information relating to an electrical characteristic of each conductor formation analyzed, and generate a report including information as to the variance in the electrical characteristic as a function of substrate position. To step through all of the conductor formations on a particular substrate, the computer may either be programmed to move a chuck holding the substrate under test relative to the points of the probe, or the system may include switching means disposed in an electrical path between the points of the probe and the resistance measurement system, enabling the computer to step through all of the conductor formations on a particular substrate by instructing the switching means to select points associated with only a single conductor formation for connection to the resistance measurement system.

Abstract: Multilayer printed wiring boards are conventionally laminated using epoxy adhesives. When the boards are drilled, a residual smear often remains within the drilled holes. This smear prevents proper through plating of the holes and the layers are left without some of the intended interconnections. In the past, the residual smear was removed by wet etching. A technique is described using plasma etching with the conductive surface layers of the drilled boards as the electrodes to generate the plasma. The plasma forms directly within the holes and effectively removes the smear. A dielectric material in contact or close proximity to the perimeter of each board provides uniformity of treatment over the panels.

Abstract: Multilayer printed wiring boards are conventionally laminated using epoxy adhesives. When the boards are drilled, a residual smear often remains within the drilled holes. This smear prevents proper through plating of the holes and the layers are left without some of the intended interconnections. In the past, the residual smear was removed by wet etching. A technique is described using plasma etching with the conductive surface layers of the drilled boards as the electrodes to generate the plasma. The plasma forms directly within the holes and effectively removes the smear. A dielectric material in contact or close proximity to the perimeter of each board provides uniformity of treatment over the panels.

Abstract: An underwater viewing device for use by a person standing in relatively shallow water and comprising a central transparent viewing window peripherally surrounded by a support structure which maintains the window parallel with and slightly beneath the surface of the water. A light affecting element is disposed within the structure adjacent the window. The support structure houses one or more storage compartments and a flotation ring which buoys and trims the viewing device while floating in the water. Fishnet covers enclose the compartments to prevent spillage of their contents. A light within the support structure permits night use.