Printed wiring board.

摘要

A printed wiring board includes an insulated base plate (1), a circuit pattern at least on one surface of the base plate (1), and solder resist film (6) containing silicon series and/or fluorine series resin and covering the base plate (1) except desired soldering area of the circuit pattern. Such solder resist film (6) has desired property to prevent bridging of solder across adjacent circuits. However, the solder repelling property apts to form dots on the solder resist film (6). Accordingly, at least one flux accumulating means is formed on said one surface of the base plate (1) to accumulate flux repelled by the solder resist film. The flux accumulating means may be recess and/or through hole means arranged on the surface of the solder resist film.