| 摘要 |
PURPOSE:To obtain a printed wiring board having no short-circuit defect by using an inside layer material, in which the inside layer material is subjected to blackening treatment followed by flushing and being put in a drying process within a specific time for being dried. CONSTITUTION:An inside layer material, in which the inside layer material is subjected to blackening treatment followed by flushing and being put in a drying process within one minute so as to be dried, is used. An epoxy resin group, a phenol resin group, an unsaturated polyester resin group are used as resin to be used for an inside layer material, a prepreg, an outside layer material and, as occasion demands, talc, clay and silica are made to be contained. When a drying process exceeds one minute, foreign matters such as calcium copper oxide, sodium copper oxide and calcium copper hydroxide are generated so that it is important that the process starts within one minute. Further, it is desirable that hot wind not less than 120 deg.C is blown against overall the wetted inside layer material and early dried. Thereby, a short-circuit defect can be lowered. |
