| 摘要 |
PURPOSE:To improve drilling workability and reliability of soldered part of an electronic component to be mounted by composing the insulating layer of the circuit of an inner layer of thermosetting resin impregnated glass nonwoven fabric, and composing the insulating layer of the circuit of an outer layer of thermosetting resin impregnated glass woven fabric. CONSTITUTION:The insulating layer 2 of an inner layer circuit 1 is composed of thermosetting resin impregnated glass nonwoven fabric. The insulating layer 4 of an outer layer circuit 3 is composed of thermosetting resin impregnated glass woven fabric. Further, when the circuit of the inner layer is formed of many layers, an adhesive insulating layer 5 between inner layer circuit boards is composed of thermosetting resin impregnated glass nonwoven fabric. The layer 5 has a role of an adhesive layer when the inner layer circuit boards (a constitution in which the inner layer circuit 1 is integrated with the layer 2 of the inner layer circuit) are superposed to be integrated, and the layer 4 of the outer layer circuit has a role of an adhesive layer when the circuit 3 is integrated with the inner layer circuit board. Thus, drilling workability can be improved. The rigidity of the multilayer printed circuit board is reduced, and the reliability of a soldered junction of a cold heat cycle is proved. |
