Multilayer printed wiring board

A multilayer printed wiring board comprising:

• a plurality of printed wiring boards each comprising a board and a plurality of conductor patterns provided onto said board;
• a plurality of through-hole pads each made of electric conductor material, provided onto said board so as to pass through said board, arranged at the same position on said board as those on other said boards, having the same height from a surface of said board as those of other said pads on said board, and having an end face at both ends of said pad having the same size respectively as those of other said pads on said board and on other said boards;
• a plurality of air gaps each provided between said printed wiring boards being adjacent to each other, for providing a designated space between surfaces of said conductor patterns provided respectively onto said printed wiring boards being adjacent to each other;
• a plurality of spacers each made of electric conductor material, provided onto said both end faces of each said through-hole pad, joined to another said spacer provided to opposite said through-hole pad, having a thickness being adequate for providing said air gap, and having an end face having size being smaller than a size of said end face of said through-hole pad for providing a drop part around a periphery of said spacer looking from a side surface of said through-hole pad;
• and
• solder which stays at each said drop part for joining said spacers and said through-hole pads, which are opposite to each other respectively, of said printed wiring boards being adjacent to each other.