| 摘要 |
PURPOSE:To improve heat impact proof characteristic (cracking resistance) by insulating signal circuits mutually or insulating a signal circuit from a power supply circuit through an insulating layer and by constituting each insulating layer wherein resin of a large bending strength is immersed and cured. CONSTITUTION:Insulation is made between signal circuits 2 or between a signal circuit 2 and a power source circuit 1 by an insulating layer whose dielectric constant at one MHz is at most 4. Resin (which shows a value of the upper side of the line l1) whose bending strength after cured is larger than a value of a heat stress between a signal circuit conductor shown by a line l1 and the insulating layer, is immersed in the insulating layer of the signal circuit 2. In the insulating layer of the power source circuit 1, resin (which shows a value of the upper side of a line l2) whose bending strength after cured is larger than a value of a heat stress between the power source circuit conductor shown in the line l2 and the insulating layer is immersed. Cracks in each insulat ing layer can be thereby prevented. |
