base plate 30 through a solder 17 in the power semiconductor device 1 for protection of the semiconductor chip 20 silicone gel 24 the hatching thereof not shown for clarity is filled over the semiconductor chip 20 and the insulating substrate 15 the silicone gel 24 is then sealed by epoxy resin 25 deposited thereon lastly a cover 26 is formed on the epoxy resin 25 according to the power semiconductor device 1 of the present invention each of main terminals 11 has a terminal through hole 2 a extending in a vertical direction also the housing 10 and base plate 30 have a housing through hole 2 b and a base plate through hole 2 c respectively which are aligned with and formed coaxially with the terminal through hole 2 a extending in the vertical direction therefore the power semiconductor device 1 of the present invention as a whole has a through hole 2 defined by the terminal through hole 2 a of the main terminal 11 the housing through hole 2 b of the housing 10 and the base plate through hole 2 c of the base plate 30 next referring to fig2 and 3 a process for assembly of the power semiconductor device 1 so constructed to a peripheral device will be described hereinafter a plurality of bus bars 40 are provided each of which is an external conducting plate also referred to as u201c conducting member u201d each of the bus bars 40 also has a bus bar through hole 42 extending in the.