US2364642A - Method of making selenium elements - Google Patents

Method of making selenium elements Download PDF

Info

Publication number
US2364642A
US2364642A US485384A US48538443A US2364642A US 2364642 A US2364642 A US 2364642A US 485384 A US485384 A US 485384A US 48538443 A US48538443 A US 48538443A US 2364642 A US2364642 A US 2364642A
Authority
US
United States
Prior art keywords
selenium
temperature
base plate
layer
platen
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US485384A
Inventor
Arthur J Miller
Taylor Irving Richard
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STC PLC
Federal Telephone and Radio Corp
Original Assignee
Standard Telephone and Cables PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to NL136384D priority Critical patent/NL136384B/xx
Priority to BE459936D priority patent/BE459936A/xx
Priority to NL69281D priority patent/NL69281C/xx
Priority to BE461663D priority patent/BE461663A/xx
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to US485384A priority patent/US2364642A/en
Priority to US533426A priority patent/US2462906A/en
Priority to GB8159/44A priority patent/GB578208A/en
Application granted granted Critical
Publication of US2364642A publication Critical patent/US2364642A/en
Priority to GB8130/45A priority patent/GB596404A/en
Priority to CH247861D priority patent/CH247861A/en
Priority to FR940901D priority patent/FR940901A/en
Priority to FR915182D priority patent/FR915182A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/06—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials
    • H01L21/10—Preliminary treatment of the selenium or tellurium, its application to the foundation plate, or the subsequent treatment of the combination
    • H01L21/103—Conversion of the selenium or tellurium to the conductive state
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B15/00—Peroxides; Peroxyhydrates; Peroxyacids or salts thereof; Superoxides; Ozonides
    • C01B15/055—Peroxyhydrates; Peroxyacids or salts thereof
    • C01B15/12—Peroxyhydrates; Peroxyacids or salts thereof containing boron
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02518—Deposited layers
    • H01L21/02521—Materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02656—Special treatments
    • H01L21/02664—Aftertreatments
    • H01L21/02667—Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/06—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/06—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials
    • H01L21/08—Preparation of the foundation plate
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/06—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials
    • H01L21/10—Preliminary treatment of the selenium or tellurium, its application to the foundation plate, or the subsequent treatment of the combination
    • 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
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/922—Static electricity metal bleed-off metallic stock
    • Y10S428/9265—Special properties
    • Y10S428/929—Electrical contact feature
    • 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
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12528—Semiconductor component

Definitions

  • selenium elements such as rectlfiers can be made by sprinkling selenium powder on a base plate and compressing the powder against the plate, preferably at an elevated temperature. This causes the powder particles to compact and adhere to each other and to the base plate. Following this treatment the selenium-coated element may then be heat treated at a high temperature somewhat below the melting point of the selenium to complete the crystallization of the selenium in a well-known manner; after which the usual counterelectrode may be applied to the selenium surface and the element electro-formed in a usual manner.
  • the drawing comprises a perspective view of a disc with aligned compressing and heating members.
  • the drawing shows a base plate or disc I which is shown with a centrally located hole 2 such as is often used in practice.
  • the plate is covered with a layer of selenium powder 3 which may be provided by grinding selenium which has been melted and then solidifled.
  • the base plate may be of iron, steel. aluminum, or the like and may be roughened and nickel coated according to a common practice.
  • selenium covered plate is shown in position between the platens 4 and 5 of a press so that when the platens are brought together. the selenium powder layer 3 is compressed against the base plate I.
  • the pressure is not critical although it should be sui'flcient for a good adherence of the selenium to the carrier plate. A pressure of around 4000 pounds per square inch has been found suitable.
  • the lower platen is heated hotter than the upper platen.
  • a suitable temperature range for the lower platen may be, for example, from 110 C. to a temperature around the melting point of selenium which is around 217 C. and a suitable temperatur range fOr the upper platen may be from 20 C. to 110 C. for example.
  • the application of the elevated temperature during the compression to the selenium layer serves to soften the selenium causing the particles to adhere to each other as they are packed together, forming a solid layer of selenium adhering to the carrier plate.
  • the time required for the compression need not be long, for example, one or two minutes or perhaps a little longer.
  • the element may then be further heat treated without pressure according to a well-known process, for example by placing the selenium element in an oven at a temperature somewhat below the melting point of selenium, for example, around 200 C. for around a half hour or even longer. This produces a complete crystallization of selenium rendering it conductive and therefore useful as an electrical element.
  • the selenium surface may then be treated, if desired, by any of a number of well-known treatments for improving the blocking layer and the counterelectrode may then be applied.
  • the counterelectrode may, for example, be an alloy such as Woods metal which'may be melted and sprayed on. When cooled, it forms a closely adherent contact layer in intimate contact with the selenium surface. It is then the common practice to electro-form the element by passing a D. C. or a pulsating D. C. current in the direction opposite from that of normal current flow. This builds up the barrier layer and improves the rectifying and voltage resisting characteristic. 7
  • the method of making a selenium element which comprises compressing selenium powder against a base plate and maintaining the carrier plate temperature higher than the temperature of the selenium surfaceduring the compression.
  • a. selenium element which comprises compressing a-base plate having a layer of selenium powder between the platens Lora press. 'the s-preu platen adjacent the plate being at a'rnizherrtemperature :than the platen taining a. layer :of selenium ypowder between the platens -01 a press with "the platen adjacent the :powderratatempemtureinatherange-oi.about 20 C. 'to 110 -.'C., the temperature of the platen adjacent the-'plate'l being'in therang of about 110* C. to 217 C.
  • the method aselenium element which (comprises 'compressing'a :base plate and a layer-of selenium gpowder thereon between the platens of a. gpl'essxatha. pressure in the general order rof -'4;000 pounds Per square inch with the platen tadjacenirthe base .plate at a temperature in *thesrange 0! about I110 C. to 217 C. and the platen adiarzent the l-seleniumgpowder in the range 0f.20 C.'t0. 110 C.

Landscapes

  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Physics & Mathematics (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Powder Metallurgy (AREA)
  • Motor Or Generator Current Collectors (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)

Description

Dec. 12, 1944. A, J. MILLER ET AL METHOD OF MAKING SELENIUM ELEMENTS Filed May 1, 1943 ATTORNEY Patented Dec. 12, 1944 METHOD OFMAKING SELENIUM ELEMENTS Arthur, J. Miller, Newark, N. J and Irving Richard Taylor, Brooklyn, N. Y., assignors to Federal Telephone and Radio Corporation, New York, 1 acorporation of Delaware I Application May 1, 1943, Serial No. 485,384
4 Claims. (Cl. 175-366) This invention relat'e'sto selenium elements and has for its obaect'to improve the adherence of the selenium to its base plate and to improve the electrical characteristics of the elements.
It is known that selenium elements such as rectlfiers can be made by sprinkling selenium powder on a base plate and compressing the powder against the plate, preferably at an elevated temperature. This causes the powder particles to compact and adhere to each other and to the base plate. Following this treatment the selenium-coated element may then be heat treated at a high temperature somewhat below the melting point of the selenium to complete the crystallization of the selenium in a well-known manner; after which the usual counterelectrode may be applied to the selenium surface and the element electro-formed in a usual manner.
We have found that better adherence of the selenium layer to the base plate may be obtained by heating the selenium to a higher temperature than is desired for the best electrical properties of the element. The temperature during the compression which gives the best electrical rectitying properties is around 80 to 150 C, while the temperature giving best adherence to the base plate during the compression is higher and may well be near or even higher than the melting point of selenium which is around 217 C. In accordance with our invention we apply temperatures during the compression treatment which are different at the surface of the selenium layer than at the base plate, the base plate temperature being higher than the surface temperature. In this way a good adherence at the base plate may be obtained while providing a suitable treatment at the surface to give good electrical and rectifying properties.
The invention will be better understood from the following detailed description taken in conjunction with the drawing which comprises a perspective view of a disc with aligned compressing and heating members. The drawing shows a base plate or disc I which is shown with a centrally located hole 2 such as is often used in practice. The plate is covered with a layer of selenium powder 3 which may be provided by grinding selenium which has been melted and then solidifled. The base plate may be of iron, steel. aluminum, or the like and may be roughened and nickel coated according to a common practice. The
selenium covered plate is shown in position between the platens 4 and 5 of a press so that when the platens are brought together. the selenium powder layer 3 is compressed against the base plate I. The pressure is not critical although it should be sui'flcient for a good adherence of the selenium to the carrier plate. A pressure of around 4000 pounds per square inch has been found suitable.
Provision is made for heating the press platens, these being shown as the electrical heating element 6 associated with the lower platen 4 and electrical heating element 1 associated with the upper platen 5. The lower platen is heated hotter than the upper platen. A suitable temperature range for the lower platen may be, for example, from 110 C. to a temperature around the melting point of selenium which is around 217 C. and a suitable temperatur range fOr the upper platen may be from 20 C. to 110 C. for example. The application of the elevated temperature during the compression to the selenium layer serves to soften the selenium causing the particles to adhere to each other as they are packed together, forming a solid layer of selenium adhering to the carrier plate. The time required for the compression need not be long, for example, one or two minutes or perhaps a little longer.
After this compression treatment the element may then be further heat treated without pressure according to a well-known process, for example by placing the selenium element in an oven at a temperature somewhat below the melting point of selenium, for example, around 200 C. for around a half hour or even longer. This produces a complete crystallization of selenium rendering it conductive and therefore useful as an electrical element. The selenium surface may then be treated, if desired, by any of a number of well-known treatments for improving the blocking layer and the counterelectrode may then be applied. The counterelectrode may, for example, be an alloy such as Woods metal which'may be melted and sprayed on. When cooled, it forms a closely adherent contact layer in intimate contact with the selenium surface. It is then the common practice to electro-form the element by passing a D. C. or a pulsating D. C. current in the direction opposite from that of normal current flow. This builds up the barrier layer and improves the rectifying and voltage resisting characteristic. 7
By our step of heating the base plate to a higher temperature than the exposed surface of selenium, a good adherence of the selenium layer is had to its base plate so that the selenium cannot readily be knocked off. At the same time the best temperature for a good electrical quality of the blocking layer is had at the surface or the selenium, thereby resulting in th most eflective rectification ratio and voltage resisting properties. If it were attempted to heat the entire element at the temperature which is'best-for good adherence the electrical and rectifying properties would not be as good, and likewise if it wereaattempted to heat the entire element at the best temperature for good electrical and rectifying properties, the adherence would not be so'good. But by the use of the difierenttemperatures above and below the element the best temperatures for both purposes are had at the same time.
What is claimed is:
1. The method of making a selenium element which comprises compressing selenium powder against a base plate and maintaining the carrier plate temperature higher than the temperature of the selenium surfaceduring the compression.
2. The method of making a. selenium element which comprises compressing a-base plate having a layer of selenium powder between the platens Lora press. 'the s-preu platen adjacent the plate being at a'rnizherrtemperature :than the platen taining a. layer :of selenium ypowder between the platens -01 a press with "the platen adjacent the :powderratatempemtureinatherange-oi.about 20 C. 'to 110 -.'C., the temperature of the platen adjacent the-'plate'l being'in therang of about 110* C. to 217 C.
:4. The method aselenium element which (comprises 'compressing'a :base plate and a layer-of selenium gpowder thereon between the platens of a. gpl'essxatha. pressure in the general order rof -'4;000 pounds Per square inch with the platen tadjacenirthe base .plate at a temperature in *thesrange 0! about I110 C. to 217 C. and the platen adiarzent the l-seleniumgpowder in the range 0f.20 C.'t0. 110 C.
J. MILLER. 'R. TAYLOR.
US485384A 1943-05-01 1943-05-01 Method of making selenium elements Expired - Lifetime US2364642A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
NL136384D NL136384B (en) 1943-05-01
BE459936D BE459936A (en) 1943-05-01
NL69281D NL69281C (en) 1943-05-01
BE461663D BE461663A (en) 1943-05-01
US485384A US2364642A (en) 1943-05-01 1943-05-01 Method of making selenium elements
US533426A US2462906A (en) 1943-05-01 1944-04-29 Manufacture of metal contact rectifiers
GB8159/44A GB578208A (en) 1943-05-01 1944-05-01 Method of making selenium elements
GB8130/45A GB596404A (en) 1943-05-01 1945-03-30 Manufacture of metal contact rectifiers
CH247861D CH247861A (en) 1943-05-01 1945-04-28 Process for the production of dry rectifier disks and rectifier disks produced by this process.
FR940901D FR940901A (en) 1943-05-01 1945-07-31 Improvements in the manufacture of metal contact rectifiers
FR915182D FR915182A (en) 1943-05-01 1945-09-29 selenium rectifier elements and their manufacture

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US485384A US2364642A (en) 1943-05-01 1943-05-01 Method of making selenium elements
US533426A US2462906A (en) 1943-05-01 1944-04-29 Manufacture of metal contact rectifiers

Publications (1)

Publication Number Publication Date
US2364642A true US2364642A (en) 1944-12-12

Family

ID=27048329

Family Applications (2)

Application Number Title Priority Date Filing Date
US485384A Expired - Lifetime US2364642A (en) 1943-05-01 1943-05-01 Method of making selenium elements
US533426A Expired - Lifetime US2462906A (en) 1943-05-01 1944-04-29 Manufacture of metal contact rectifiers

Family Applications After (1)

Application Number Title Priority Date Filing Date
US533426A Expired - Lifetime US2462906A (en) 1943-05-01 1944-04-29 Manufacture of metal contact rectifiers

Country Status (6)

Country Link
US (2) US2364642A (en)
BE (2) BE459936A (en)
CH (1) CH247861A (en)
FR (2) FR940901A (en)
GB (2) GB578208A (en)
NL (2) NL69281C (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2575392A (en) * 1947-12-11 1951-11-20 Vickers Inc Method of annealing a selenium coating
US2599478A (en) * 1948-03-15 1952-06-03 Vickers Inc Apparatus for making devices which have selenium as constituent parts thereof
US2629039A (en) * 1950-06-07 1953-02-17 Weston Electrical Instr Corp Selenium cell and process for manufacturing the same
US2877284A (en) * 1950-05-23 1959-03-10 Rca Corp Photovoltaic apparatus
US4244722A (en) * 1977-12-09 1981-01-13 Noboru Tsuya Method for manufacturing thin and flexible ribbon of dielectric material having high dielectric constant
US4257830A (en) * 1977-12-30 1981-03-24 Noboru Tsuya Method of manufacturing a thin ribbon of magnetic material
US4265682A (en) * 1978-09-19 1981-05-05 Norboru Tsuya High silicon steel thin strips and a method for producing the same
US4525223A (en) * 1978-09-19 1985-06-25 Noboru Tsuya Method of manufacturing a thin ribbon wafer of semiconductor material

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL204119A (en) * 1939-01-22
DE925847C (en) * 1949-10-31 1955-03-31 Licentia Gmbh Method of manufacturing selenium rectifiers
US2644915A (en) * 1950-07-24 1953-07-07 Bell Telephone Labor Inc Selenium rectifier and method of its production
US2749489A (en) * 1950-12-04 1956-06-05 Int Standard Electric Corp Dry contact rectifiers
DE976655C (en) * 1951-11-24 1964-01-30 Francois Gans Process for the production of photoresist cells from powders of cadmium sulfide, cadmium selenide or cadmium telluride
US2795033A (en) * 1952-01-31 1957-06-11 Raytheon Mfg Co Molded cathodes
NL95545C (en) * 1952-04-19
NL178572B (en) * 1952-06-19 Vaw Ver Aluminium Werke Ag METHOD FOR THE FLUID-FREE SOLDERING OF ALUMINUM MATERIALS.
DE1027799B (en) * 1952-12-05 1958-04-10 Standard Elektrik Ag Heated pressing device for the production of selenium rectifiers and selenium photo elements
NL104654C (en) * 1952-12-31 1900-01-01
NL102345C (en) * 1954-06-16
BE539442A (en) * 1954-07-01
DE1153119B (en) * 1955-08-05 1963-08-22 Siemens Ag Method for manufacturing a semiconductor device
US2903666A (en) * 1955-08-23 1959-09-08 Speer Carbon Company Resistors with integral molded metal terminals
NL263391A (en) * 1960-06-21
US3148981A (en) * 1961-04-21 1964-09-15 Nat Beryllia Corp Metal-oxide gradient ceramic bodies
US3243862A (en) * 1961-10-24 1966-04-05 Westinghouse Electric Corp Method of making semiconductor devices
US3214651A (en) * 1961-10-27 1965-10-26 Westinghouse Electric Corp Semiconductor device base electrode assembly and process for producing the same
US3432365A (en) * 1963-02-07 1969-03-11 North American Rockwell Composite thermoelectric assembly having preformed intermediate layers of graded composition
DE3035563C2 (en) * 1980-09-20 1984-10-11 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Method for producing a polycrystalline silicon solar cell

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2342278A (en) * 1944-02-22 Manufacturing selenium cells
US1826955A (en) * 1927-03-30 1931-10-13 Ruben Rectifier Corp Electric current rectifier
US1678826A (en) * 1927-04-26 1928-07-31 Ruben Rectifier Corp Electric-current rectifier
US1896853A (en) * 1930-09-22 1933-02-07 Gen Electric Welding process
NL46218C (en) * 1936-06-20 1900-01-01
NL53994C (en) * 1937-06-25 1900-01-01
US2267954A (en) * 1939-05-17 1941-12-30 Bell Telephone Labor Inc Electrically conductive device
US2325071A (en) * 1940-11-30 1943-07-27 Indium Corp America Bearing and like article

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2575392A (en) * 1947-12-11 1951-11-20 Vickers Inc Method of annealing a selenium coating
US2599478A (en) * 1948-03-15 1952-06-03 Vickers Inc Apparatus for making devices which have selenium as constituent parts thereof
US2877284A (en) * 1950-05-23 1959-03-10 Rca Corp Photovoltaic apparatus
US2629039A (en) * 1950-06-07 1953-02-17 Weston Electrical Instr Corp Selenium cell and process for manufacturing the same
US4244722A (en) * 1977-12-09 1981-01-13 Noboru Tsuya Method for manufacturing thin and flexible ribbon of dielectric material having high dielectric constant
US4257830A (en) * 1977-12-30 1981-03-24 Noboru Tsuya Method of manufacturing a thin ribbon of magnetic material
US4265682A (en) * 1978-09-19 1981-05-05 Norboru Tsuya High silicon steel thin strips and a method for producing the same
US4525223A (en) * 1978-09-19 1985-06-25 Noboru Tsuya Method of manufacturing a thin ribbon wafer of semiconductor material

Also Published As

Publication number Publication date
FR940901A (en) 1948-12-28
GB578208A (en) 1946-06-19
BE461663A (en) 1900-01-01
FR915182A (en) 1946-10-29
GB596404A (en) 1948-01-02
NL69281C (en) 1900-01-01
BE459936A (en) 1900-01-01
NL136384B (en) 1900-01-01
CH247861A (en) 1947-03-31
US2462906A (en) 1949-03-01

Similar Documents

Publication Publication Date Title
US2364642A (en) Method of making selenium elements
GB752751A (en) Method of producing selenium rectifier plates
US2345122A (en) Dry rectifier
US2474038A (en) Composite metal
US2279187A (en) Alternating electric current rectifier of the selenium type
US2307474A (en) Manufacture of selenium rectifiers
US2124306A (en) Electrical device
US2166205A (en) Fixed capacitor
US2193610A (en) Selenium contact electrode
US3226804A (en) Method of soldering peltier devices
US3117367A (en) Method of manufactuirng a magnetic head having a glass spacer
US2488369A (en) Selenium rectifier
US2378438A (en) Method of making selenium elements
US2359377A (en) Method of making selenium elements
US2405192A (en) Resistor
US2413013A (en) Method of making selenium rectifiers
US2229807A (en) Method of manufacturing selenium rectifiers
US2274830A (en) Resistor and method of manufacturing the same
US2438923A (en) Method and means for making selenium elements
US2446467A (en) Dry plate rectifier
US2321523A (en) Method of reclaiming selenium elements
US2195725A (en) Method of manufacturing selenium rectifiers
US1936792A (en) Method of making copper oxide rectifiers for high voltage application
US2554979A (en) Element of asymmetric conductivity of selenium
US2168462A (en) Manufacture of alternating current rectifiers of the dry-contact type