| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a technique for manufacturing a multilayer printed wiring board by forming a metal foil with carbon dioxide gas laser directly and forming a via hole in an insulating layer immediately below, without forming a window in the metal foil (conductor layer), and without roughening the metal foil surface.SOLUTION: A method for forming a via hole 9 in a multilayer printed wiring board 20 including more than one conductor layers 1, 1' in which the conductor layers 1, 1' and an insulating layer 2 are laminated alternately comprises: a step of coating the conductor layer of the outermost surface with a pattern of a paste material 3 absorbing carbon dioxide gas laser light; and a step of forming a via hole by irradiating the paste material 3 with the carbon dioxide gas laser light, and removing the conductor layer 1 of the outermost surface and the insulating layer 2 on the underside thereof, so as to expose the conductor layer 1' on the underside of the insulating layer 2. A method of manufacturing a multilayer printed wiring board 20 using the method for forming a via hole is also provided.</p> |
