PURPOSE: To enable the formation of an earth circuit whose thickness is equivalent to that of a shielding layer by a method wherein a relief part whose diameter is larger than the outer diameter of a connection land is formed through a screen printing above the connection land between the shielding layer and a printed wiring circuit.
CONSTITUTION: A printed wiring circuit composed of required patterns is formed on both the sides of an insulating boards 1 through the intermediary of a through-hole 8. A sealing member 3a is formed in such a manner that paste formed of photocuring synthetic resin material is filled into conduction through-holes 7 of a printed wiring board 9 and set. An insulating layer 4 is formed through a screen printing or the like, an electromagnetic wave shielding layer 5 is deposited on the layer 4, and a solder resist layer 6 serving also as a protective layer of the electromagnetic wave shielding layer 5 is formed. A relief part 40 shaped like a saucer is formed above a connection land 20 between the shielding layer 5 of the printed wiring circuit and an earth circuit 5a as shown in a figure b. The earth circuit 5a of the connection land 20 is formed at a time which the formation of the shielding layer 5. The relief part 40 is formed in such a manner that the part 40 which has the same diameter as the connection land 20 is formed through a first screen printing and then successive screen printings are carried out in stages to make the diameter of the part 40 gradually larger than that of the land 20.
HARUYAMA SATORU
OKONOGI HIROTAKA
| JPS63283186A | 1988-11-21 |