| 摘要 |
PURPOSE:To obtain the titled iron alloy capable of satisfying requirements for the improvement of reliability and having satisfactory solderability by specifying conditions during final heat treatment when an Fe-Ni-(Cr) alloy having a low coefft. of thermal expansion is manufactured. CONSTITUTION:An iron alloy consisting of 30-55wt% Ni and the balance Fe or further contg. 3-8wt% Cr, having a low coefft. of thermal expansion and useful as a lead material for a semiconductor device or a material for sealing glass is manufactured. At this time, the iron alloy is finally heat treated at such a high temp. as >=600 deg.C in a nonoxidizing atmosphere. The dew point of the atmospheric gas has been regulated to -20--50 deg.C. By the heat treatment, a thin surface oxide film having satisfactory solderability is formed and an iron alloy showing resistance to stress corrosion cracking is obtd. |
