PURPOSE: To enable an oven to be lessened in electric power cost and shortened in time required for decrease or increase in temperature by a method wherein an insulated lead pin and a low melting point glass member are mounted on a stem base, and the stem is heated at a temperature of 450-600°C to seal up the through-hole of the stem board where the insulated lead is inserted with the low-melting glass member.
CONSTITUTION: A gold plating layer 14 is formed on a stem base 11 subjected to nickel electroplating and a nickel plating layer provided onto an insulated lead pin 12 and an earth lead pin 13. The stem base 11 is made to travel through a temperature zone of 450-600°C in a heating oven, whereby the insulated lead pin 12 provided in a through-hole is bonded to the stem base 11 through the intermediary of a soft lead glass layer 15 to seal up the through-hole. As mentioned above, glass sealing and brazing are carried out at the same time, so that the gold plating layer 14 is prevented from disappearing due to its thermal diffusion into a nickel plating layer and material, in result a stem excellent in connecting stability and solderability. By this setup, a sealing oven can be lessened in size and electric power cost and shortened in time required for an oven to decrease or increase in temperature.
KOMATSUBARA YUKIO
UEDA YUJI
YAMADA MASAHIRO
