Patent ID: 6926789

Claim:
A method of producing a wiring board, comprising: forming a first rough surface having concavities therein on at least a portion of a transfer surface of a carrier base; forming a wiring transfer sheet by forming a wiring layer directly on the transfer surface of the carrier base without any intervening adhesive material so that the wiring layer directly contacts the transfer surface, the wiring layer being formed so that a portion of the wiring layer is located within the concavities of the first rough surface; transferring the wiring layer to a receiving surface of an electrically insulating substrate, said transferring comprising: superposing the wiring transfer sheet onto the receiving surface of the substrate; heating and pressurizing the wiring transfer sheet and the substrate so as to adhere the wiring layer of the wiring transfer sheet to the substrate, and so as to form a second rough surface on at least a portion of the receiving surface of the substrate, the second rough surface being complementary to the first rough surface; and removing the carrier base of the wiring transfer sheet.