PRINTED WIRING BOARD AND MANUFACTURE THEREOF

PURPOSE:To prevent the occurrence of short-circuit defects due to solder balls and to improve solder finishing property at the same time, by providing projections, which are formed higher than foot patterns in the vicinities of said foot patterns, so as to prevent the expansion of the solder, which conencts the lead of each electronic part to each foot pattern. CONSTITUTION:Resist 13 is applied to a part, which requires insulation, on a board 11, on which a foot pattern 12 is formed. Two straight lines each having a specified width are printed in the vicinities of the exposed parts of the foot patterns 12. Thus projections 14 are formed on the resist 13 in the vicinities of the exposed parts. The projections 14 in the horizontal direction and in the vertical direction are mutually linked at corner parts. The distance, which is required for shortening the horizontal foot pattern 12a and the vertical foot pattern 12b, becomes substantially long. A solder ball is hard to be present between the foot patterns 12a and 12b. Therefore, short circuits between both parts can be prevented more effectively.