STEM FOR SEMICONDUCTOR DEVICE

PURPOSE:To enlarge the space of the surface of the circuit substrate mounting base in the stem by a method wherein bending parts are provided to leas terminals in a through hole, and the lead-out positions inside and outside the terminal are made eccentric, when the lead terminals are hermetically sealed via glass to the trhough hole provided in the metallic base. CONSTITUTION:When the through holes 13 for penetrating the lead terminals 15 are bored in the metallic base 12 constituting the stem 11 for the semiconductor, these holes are made eccentric, thus keeping the bottom area of an eccentric hole 13 larger than the surface area by a step part 9 in the hole 13. Next, a bent lead terminal 15 having the bending part 10 in the hole 13 is inserted therein, which is then hermetically sealed with the glass 4. At this time, the position of the terminal 15 projecting out of the lower surface of the base 12 is determined as the reference position; the position of the terminal 15 projecting out to the upper surface is put outside it, and thus the interval therebetween is increased. Tus, a wide space is obtained, and the mounting of the large area circuit substrate 17 for fixing a semiconductor element 6 thereon is enabled.