| US 7,488,676 B2 | ||
| Manufacturing method of a multi-layered circuit board | ||
| Yasuhiko Kanaya, Ebina (Japan); Akira Irie, Ebina (Japan); Katsuhiro Nagasawa, Ebina (Japan); and Toru Yuki, Ebina (Japan) | ||
| Assigned to Hitachi Via Mechanics, Ltd., Kanagawa (Japan) | ||
| Filed on Dec. 09, 2005, as Appl. No. 11/297,358. | ||
| Claims priority of application No. 2004-359169 (JP), filed on Dec. 10, 2004. | ||
| Prior Publication US 2006/0127652 A1, Jun. 15, 2006 | ||
| Int. Cl. H01L 21/4763 (2006.01) | ||
| U.S. Cl. 438—618 [438/622] | 3 Claims |
| 1. A method of manufacturing a multi-layered circuit board formed by laminating and combining a plurality of substrates composed
of conductive layers and insulating layers through which a connecting hole, for inserting a power terminal of an electronic
part to be mounted on a surface of the multi-layered circuit board to connect with a first conductive layer, is to be formed,
said method comprising:
forming a detecting section having a detecting hole in a second conductive layer, the second conductive layer being positioned
toward a back face of the multi-layered circuit board with respect to the first conductive layer;
forming a through hole that penetrates from the surface of the multi-layered circuit board to the back face of the multi-layered
circuit board so as to contact with a surface conductive layer disposed on the surface of a surface substrate, which is one
of the plurality of substrates, positioned at the surface of the multi-layered circuit board and contact with the first conductive
layer, the first conductive layer being located between the surface of the multi-layered circuit board and the back face of
the multi-layered circuit board, and without contacting the detecting hole by having a diameter smaller than that of the detecting
hole;
plating an inner surface of the through hole;
drilling a hole with a tool having a diameter larger than the diameter of the detecting hole along the through hole from the
back side of the multi-layered circuit board while applying a predetermined voltage between the tool and the second conductive
layer having the detecting section and to a predetermined depth based on detection of the detecting hole, whereby the connecting
hole is formed by the through hole between the surface conductive layer and the first conductive layer where the plating is
left on an inner peripheral face of the through hole;
wherein the first conductive layer is on a surface side of a second substrate of the plurality of substrates adjacent to the
surface substrate and the second conductive layer is on a surface side of a third substrate adjacent to a back side of the
second substrate.
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