GB1274058A - Methods of manufacturing glass enclosed electrical devices - Google Patents

Abstract

1,274,058. Semi-conductor devices. M. STOLL. 24 Nov., 1969, No. 57368/69. Heading H1K. [Also in Division C1] Electrical devices, particularly semi-conductor devices, are positioned within an openended tubular glass casing, the open end heated to collapse the glass on to the lead-in wire of the device or a glass lead thereon to form an initial ring seal and then applying a fluid at a pressure greater than that used during the heating to squeeze the glass at the initial ring seal to form a strong seal at the casing end. As shown, a tubular casing 33 with open end 34 and enclosing the lower semi-conductor body 40 and lead wire 42 is positioned in a clamp 46, 54 and an upper lead wire 20 and contact 18 is held by a magnetic chuck 26 and pressed down in alignment with the body 40 by weights 32. The assembly is enclosed in a hermetically sealable chamber 15. A glass bead 22 on wire 20 is spaced from the contact 18. Heading of the open end 34 of casing 33 is effected by an electric element 58 until the glass softens and, as shown, collapses on to the glass lead 22. The pressure P 1 in the chamber 15 is then increased (P 2 , Fig. 3) so that the softened glass is pressed fully into contact with the glass bead to effect the seal. The clamp 46, 54 may be of metal to act as a heat sink to cool the main part of the casing 33 round the body 40. Sealing may be effected in any desired atmosphere such as nitrogen or other inert gases, air or other non-oxidizing atmosphere. Initial pressure may be atmospherio, elevated, reduced or a vacuum.