Method for producing a double-sided wiring board
AssigneeInternational Business Machines Corporation
InventorsTakayuki Haze, Tsuneo Yabuuchi
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Abstract
The method for producing a printed wiring board comprising the steps of preparing a conductive substrate, forming an insulating layer on one surface of the said substrate, forming at least one via hole in the insulating layer, thermally curing the insulating layer, and reducing at least one oxidized layer formed on the other conductive surface of the substrate during the curing operation. Alternatively, the thermal cure may be accomplished in an atmosphere (e.g., reducing gas, inactive gas, or mixtures thereof) not conducive to oxide formation on metallized circuit surfaces.
Claims11
A method for producing a double-sided wiring board comprising the steps of:
- providing a conductive substrate having first and second opposed conductive surfaces;
- forming an insulating layer on said first conductive surface of said substrate;
- forming at least one via hole in said first insulating layer on said first conductive surface;
- thermally curing said first insulating layer in a reducing gas, inactive gas, or a mixture of these gases so as to prevent an oxidized layer from being formed on said second conductive layer of said substrate during said thermally curing step;
- forming a second insulating layer on said second conductive surface of said conductive substrate;
- forming at least one via hole in said second insulating layer;
- and
- forming conductive wiring on the surfaces of both said first and second insulating layers.
Dependencies are inferred from the claim text.