| 摘要 |
PURPOSE: To control the thickness between insulating layers with high accuracy and thereby increase reliability by forming the resin insulating layer in a reversed pattern to an inner-layer circuit pattern and thereby flattening the surface of an inner-layer circuit board. CONSTITUTION: On both faces of an inner-layer circuit board 3, inner-layer circuits 5 are preliminarily formed. Then, resin insulating layers in a reversed pattern to that of the inner- layer circuits are formed by screen printing or another method on the entire surface of the inner-layer circuit board 3 except for a part where the inner-layer circuits 5 are formed. Between a plurality of the inner-layer circuit boards 3 on which the resin insulating layers 2 are formed or in the most outer layers, prepregs 4 are located. Then, copper foils 1 are stacked on both faces of the stacked body and then the stacked body is heated and pressed to be formed into an integral body. A multilayer printed wiring board is thus manufactured. By forming the resin insulating layers 2 in a reversed pattern to that of the inner-layer circuits on the entire surface of the inner-layer circuit board except for a part where inner- layer circuits are formed, the surface of the inner-layer circuit board 3 can be flattened. A resin component which constitutes the thickness of the insulating layer is not influenced by the inner-layer circuit density and is not limited by routing of inner-layer circuits. Therefore, an accuracy of the thickness between the insulating layers is increased and thereby the reliability can be increased, too. |
