JPS6413788A - Printed board - Google Patents

Abstract

PURPOSE:To increase the quantity of heat dissipation of a printed board simply at low cost by forming a wiring pattern and a foot pattern, to which a heat-generating part is fixed, onto the main surface of an insulating plate, shaping a heat-dissipating pattern consisting of copper foil, etc., and having a constant area onto a rear oppositely faced to the main surface and connecting both patterns by a thermal conduction means. CONSTITUTION:A heat-dissipating pattern 4 is formed in a pattern composed of copper foil in size, in which the copper foil is not brought into contact with other patterns, on a rear oppositely faced to a foot pattern 2 shaped onto a main surface, the heat- dissipating pattern 4, a wiring pattern 3 on the main surface side and the foot pattern 2 are formed by photoetching an insulating plate 1, on both surfaces of which copper foil are stuck, and the heat generation of an electronic part is dissipated into air. A through-hole in predetermined size is shaped to the heat-dissipating pattern 4 from the foot pattern 2 as a through-hole 5, and the inwall of the lower hole of the through- hole is plated with copper and the patterns 4 and 2 are connected. The underside of a heat-generating part 6 is fastened to the foot pattern 2 formed to the main surface with solder 7, thus thermally conducting the heat of the heat-generating part 6 with the heat-dissipating pattern 4 through the through-hole 5 having high thermal conductivity.