Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D48/00—Individual devices not covered by groups H10D1/00 - H10D44/00
  • H10D48/01—Manufacture or treatment
  • H10D48/04—Manufacture or treatment of devices having bodies comprising selenium or tellurium in uncombined form
  • H10D48/042—Preparation of foundation plates
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D48/00—Individual devices not covered by groups H10D1/00 - H10D44/00
  • H10D48/01—Manufacture or treatment
  • H10D48/04—Manufacture or treatment of devices having bodies comprising selenium or tellurium in uncombined form
  • H10D48/048—Treatment of the complete device, e.g. by electroforming to form a barrier
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S438/00—Semiconductor device manufacturing: process
  • Y10S438/964—Roughened surface

Definitions

• the support of aluminum, magnesium, alloys thereof or of an equivalent light metal is pickled before applying thereto the selenium in order to roughen the surface.
• the advantage obtained thereby is probably based upon the .fact that the Jet sand blast causes sharp tiny points to. lie-produced on the surface. ⁇ The selenium adheres insuifi ciently or not at all to these sharp'points. Consequently, the counter-electrode which is normally sprayed ontothe selenium coating easily comes into direct contact with these points of the light metal support,.thus causing short-circults. If it should not bepossible to eliminate these short-circuits during theforming process or similar processes of treatment. the element" is of no value.
• the pickling has furthermore the advantage that it is not so criticalras the treat- 80 ment by means of a sand Jet; however, the joint is above all more intimate and more durable than when roughening the surface by means ofga sand jet and consequently the seasoning effect of the rectifiers is decreased.
• a foreignclayenparticularly an oxide layer preventsundercircumstances the so formation of such anintermediate-layen so that the necessary adhesion is not broughtaboutj f
• a rectifier according to to*thc. invcntion1i8 manufactured. for instance in the. following manner.
• a support which may consist of c'ommercial aluminum is pickled in diluted hot'hy drochloric acid to which is added one gram of iron .per liter.
• the plate is then heat treated in a furnace at a temperature somewhat about 200 degree centi-q 10 grade for one or more.hours, care being taken to ensure a sufficient amount of air to be admitted.
• the selenium is converted into an electrically conductive state.
• the selenium coating is then subjected for a short time 16 to the action of sulphur vapors. -In this manner a discontinuous film of sulphur is produced on the selenium coating, on which film is sprayed a layer of a metal of low fusibility, for instance, an alloy of lead and bismuth or of cadmium and 90 bismuth.
• the rectifier element thus produced is then formed by the action of an electric current by applying in the inverse direction a direct voltage which increases with increasing resistance in the 25 inverse direction, for instance, from 5 to about '18 volts, the current flowing atthe beginning in the inverse direction thus decreasing under the 1 action of the voltage to a few milliamperes.
• V 1 The method of manufacturing a selenium rectifier which consists of melting a. selenium coating on a support of light metal, for instance, aluminum, magnesium or the 19.110575 thereof,

Landscapes

• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
• Electroplating Methods And Accessories (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7474837

Family Applications (1)

Country Status (5)

Cited By (3)

Family Cites Families (3)

• 1938
  • 1938-08-16 DE DES15120D patent/DE922896C/de not_active Expired
• 1939
  • 1939-08-07 CH CH214717D patent/CH214717A/de unknown
  • 1939-08-11 FR FR858998D patent/FR858998A/fr not_active Expired
  • 1939-08-12 US US289790A patent/US2221614A/en not_active Expired - Lifetime
  • 1939-08-12 BE BE435957D patent/BE435957A/xx unknown

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