Photointerrupter Using Three-dimensional Molded Plastic Plated With Conductive Wiring

To achieve miniaturized, surface-mounting optoelectronic components, we have developed a technology of making threedimensional plastic-molded housings plated with wire-bondable metal electrodes. This technology has made it possible to manufacture leadless small components free from conventional problems, such as deformed leadframes and interfacial separation between molded plastic and leads, which would impair the reliability of the components. The fabrication process differs from the one using conventional leadframes in that multiple emitter and detector chips are mounted simultaneously on a three-dimensional framewiring substrate. Therefore, the fabrication process is extremely simple, with minimum fluctuation in the product Characteristics. By applying this technique to reflective type photointenupters, we have successfully reduced the mounting surface area to 65% of that by the conventional design, and achieved a higher light utilization efficiency.