| 摘要 |
PURPOSE: To provide a method of forming a resin layer suitable for forming a resin insulating layer in a surface-layer printed wiring board (SLC). CONSTITUTION: An insulating board 2 on which a copper layer 1 is stuck is patterned, and a wiring layer containing a signal wiring conductor 3 is formed (a, b). A resin having photosensitivity and thermosetting properties is dissolved in a solvent, a wiring-layer forming surface is coated with the solvent, and a resin-insulating layer 4 is formed (c). The resin-insulating layer 4 is precured, the solvent contained in the resin-insulating layer 4 is evaporated, and the resin- insulating layer 4 is cured (d). When the resin-insulating layer 4 reaches a hardness resistant to mechanical grinding, the surface of the resin-insulating layer 4 is ground, and leveled (e). Exposure and development are conducted (f), and the resin-insulating layer 4 is cured (g), and leveled (h). Not more than 16 wt.% of solvent contained in the resin-insulating layer 4 at the time of precuring is used as the measure of hardness resistant to the mechanical grinding in the resin-insulating layer 4. |
