(19)

(11)

EP 0 250 541 A1

(12)

(43) Date of publication: 07.01.1988 Bulletin 1988/01 (21) Application number: 87900403.0 (22) Date of filing: 24.11.1986

(51) International Patent Classification (IPC):  H01L 23/ 48( . ) H01L 21/ 60( . ) H01L 23/ 492( . ) H01L 21/ 58( . ) H01L 23/ 485( . ) (86) International application number: PCT/US1986/002519 (87) International publication number: WO 1987/004010 (02.07.1987 Gazette 1987/14)

(84) Designated Contracting States: DE FR GB IT NL (30) Priority: 20.12.1985 US 19850811239 (71) Applicant: Hughes Aircraft Company Los Angeles California 90045-0066 (US)	(72) Inventor: PATRAW, Nils, E. Redondo Beach, CA 90277 (US) (74) Representative: KUHNEN, WACKER & PARTNER  Alois-Steinecker-Strasse 22 D-85354 Freising D-85354 Freising (DE)