PURPOSE: To make a smaller-sized printed board and to increase its thermal resistant property, by forming a metal conductive layer having a specified circuit pattern and by connecting upper and lower circuits through via holes formed on an oxide insulating layer.
CONSTITUTION: SiO2 is formed as an insulating film on an Al plate having a good radiation of heat. Nextly, vacuum evaporation of Cu is conducted on the substrate. Then, this is etched to form a printed circuit. On it, vacuum evaporation of SiO2 is conducted and then this is etched to form an insulating layer and via holes. Further, on this, vacuum evaporation of Cu is conducted to fill in the via holes on the insulating layer, to form a conductive layer. After that, this is etched to form a second printed circuit. Then, this process is repeated. By this method, it is possible to increase the thermal resistance and strength of a printed board. An easy formation of compact and solid circuit is also available by this method.
YOSHIDA HIROSHI
HIGUCHI KAZUAKI
| JPS6281093A | 1987-04-14 | |||
| JPS5035666A | 1975-04-04 | |||
| JPS51124681A | 1976-10-30 | |||
| JPS59175794A | 1984-10-04 |