Abstract: A semiconductor device (100) has a semiconductor chip (102) mounted on a tape carrier (104). Tape carrier (104) of thickness t has a plurality of via holes (118) of inner diameter Dv penetrating the tape carrier (104). Solder balls (114) having outer diameter Db are attached through the via holes (118) to serve as external connection terminals for the semiconductor chip (102). Specific dimensional relationships are established among thickness t of tape carrier (104), inner diameter Dv of via holes (118) and outer diameter Db of solder balls (114) in order to improve connection reliability by reducing poor connections of solder balls (114).

Abstract: A semiconductor device and its manufacturing method with which the connection reliability can be improved without complicating the manufacturing process. Semiconductor chip 102 is mounted on the principal surface of insulated substrate 104, and a conductive paste containing a heat-curing epoxy resin is supplied to via holes 116 from the back of insulated substrate 104. Then, solder balls 118 are transferred onto the conductive paste of insulated substrate 104, and reflow soldering is applied in order to bond solder balls 118 to insulated substrate 104. During the reflow soldering, the heat-curing epoxy resin forms resin parts 120 around solder balls 118.