| 摘要 |
PURPOSE:To maintain a secure insulation reliability for a long term by a method wherein an insulating layer between two or more conductor pattern layers is composed of an insulating film with a fixed thickness. CONSTITUTION:A circuit sheet composed of two or more conductor pattern layers 2 and 4 and an insulating film 1 provided between them is placed in a molding die. After the die is closed, melted molding resin is injected into the die to form a substrate 8 on the side of one conductor pattern layer 4. As both the conductor pattern layers 2 and 4 are formed on the surfaces of the insulating films 1, the conductor pattern layers 2 and 4 can be formed with a fixed accuracy, and the degrees of fineness and the resistance values of the respective conductor pattern layers can be easily maintained at the fixed values. With this constitution, a multilayer printed wiring board with an excellent reliability of insulation between the conductor pattern layers 2 and 4 can be obtained. |
