An insulating board, having {TAIL ~ a plurality} of {HEAD ~ openings} at positions corresponding to the IC chip contact areas, is interposed between the IC chip and the multilayer circuit board 
An insulating board , having { TAIL ~ a plurality } of { HEAD ~ openings } at positions corresponding to the IC chip contact areas , is interposed between the IC chip and the multilayer circuit board
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH