Method for manufacturing shielded printed wiring board and shielded printed wiring board

A method of producing a shielded printed wiring board, the method comprising:

• a printed wiring board preparing step of preparing a printed wiring board including a base film, a printed circuit formed on the base film, and a coverlay covering the printed circuit;
• a first electromagnetic wave shielding film preparing step of preparing a first electromagnetic wave shielding film sequentially including a first protective film, a first insulating layer, and a first adhesive layer;
• a second electromagnetic wave shielding film preparing step of preparing a second electromagnetic wave shielding film sequentially including a second protective film, a second insulating layer, and a second adhesive layer;
• a first electromagnetic wave shielding film placing step of placing the first electromagnetic wave shielding film on the printed wiring board so that the first adhesive layer is in contact with one face of the printed wiring board, and part of the first adhesive layer protrudes from an end of the printed wiring board to form a first extending end portion;
• a second electromagnetic wave shielding film placing step of placing the second electromagnetic wave shielding film on the printed wiring board so that the second adhesive layer is in contact with the other face of the printed wiring board, and part of the second adhesive layer protrudes from an end of the printed wiring board to form a second extending end portion;
• a stacking step of stacking the first extending end portion on the second extending end portion so that a gap is created between the first extending end portion and the second extending end portion, whereby a first intermediate product is prepared;
• an initial pressing step of pressurizing and heating the first intermediate product to the extent that the first adhesive layer and the second adhesive layer are not completely cured and the gap remains present, whereby a second intermediate product is prepared;
• a protective film peeling step of peeling off the first protective film and the second protective film from the second intermediate product, whereby a third intermediate product with the gap still present is prepared;
• and
• a subsequent pressing step of pressurizing and heating the third intermediate product to cure the first adhesive layer and the second adhesive layer and to eliminate the gap, whereby the shielded printed wiring board is prepared.