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
  • H10D48/043—Preliminary treatment of the selenium or tellurium, its application to foundation plates or the subsequent treatment of the combination
• • 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
  • H10D48/043—Preliminary treatment of the selenium or tellurium, its application to foundation plates or the subsequent treatment of the combination
  • H10D48/045—Treatment of the surface of the selenium or tellurium layer after having been made conductive
• • 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
  • H10D48/043—Preliminary treatment of the selenium or tellurium, its application to foundation plates or the subsequent treatment of the combination
  • H10D48/046—Provision of discrete insulating layers

Definitions

• the invention refers to a method of manufacturing rectifier elements, particularly those which can withstand a very high reverse voltage.
• the main object of the present invention to provide a method which will enable the rectifier element to withstand up to more than five times the normal reverse voltage.
• the object of the present invention is achieved by substituting the mentioned application of insulating lacquers or oxidizing agents to the metallic selenium surface by an electrolytic process to which the rectifier disc is subjected, after the selenium layer has been converted into its metallic state, in which process the rectifier disc is used as the cathode.
• the purpose of the electrolytic process is the application of a barrier layer comprising a metal organic polyselenide and, preferably, a cadmium organic'polyselenide or a tin organic polyselenide, respectively, depending on the use of cadmium or tin in the electrolyte or in the counterelectrode, or even in both.
• a barrier layer comprising a metal organic polyselenide and, preferably, a cadmium organic'polyselenide or a tin organic polyselenide, respectively, depending on the use of cadmium or tin in the electrolyte or in the counterelectrode, or even in both.
• any metal forming a basic plating solution can be used in the electrolytic process, the same metal which is to be plated being used as the anode.
• the applied current may vary from 2.5 ma. per em. up to 50 ma. per cm. of
• a cadmium, tin or any other metal as a lead anode capable of forming a basic plating solution is provided in the electrolytic process and a corresponding commercial cadmium plating solution (CdO-l-NaOI-I-l-NaCN) a commercial tin plating solution (NazSnOH-NaOH-l-NaCzHaOz) or any other basic plating solution which is,
• an alkaline hydroxide or an alkaline salt in addition to an organic agent is used as the electrolyte.
• a layer of cadmium, tin or other metal organic polyselenide which is a stable compound will be formed on the surface of the selenium layer. immediately in one-step upon application of the electrolytic process. 'I'hu's it can be seen that the layer of cadmium, tin or other metal organic polyselenide is here achieved as a result of the electrolytic process in one step even before providing the counter-electrode alloy, whereas according to the firstmentioned method two steps are necessary, namely the electrolytic process and the forming of the counter-electrode layer.
• the concentration of the electrolyte may be as low as necessary to merely maintain the conductivity of the solution. say about .001 normal, whereas the maximum'concentration to be used will be at the saturation point at room tempertration of the electrolyte, it can be seen that the grade of concentration of the electrolyte provides some means to control the results to be achieved.
• the electrolyte in the first as well as in the second modification of the method comprises in addition to the aqueous solution an organic agent.
• organic agents which are soluble in water can be used as addition to the electrolyte. Therefore, alcohols, aldehydes. ketones, acids, phenols, and the like can be used or also more than one of the mentioned products at the same time.
• the concentration of the organic agents will be at least and any higher concentration than the minimum value will yield high voltage rectifiers provided that the solution is still .electrically conductive at said particular concentration.
• Units subjected to the electrolytic process as given in Example 2 will withstand more than 100 volts A. C. in the reverse direction.
• the forward resistance will be relatively high and, therefore, it is not advisable to use such units for power rectification.
• these units may be used in such applications where high-D. C. voltages must be maintained while no current is drawn from the power supply, e. g. in maintaining electrostatic fields.
• Example 1 where hydroxide has been used as the electrolyte the organic agent was 10% by volume whereas the hydroxide solution was by volume.
• Example 2 where a salt solution is used as the electrolyte only 70% by volume of the salt is used, whereas the organic agent rises to 30% by volume.
• the organic. concentration is reduced to 5% instead of 0, or in Example 2 to 20% instead of 30, still higher than normal voltages can be recognized.
• the counter-electrode alloy will preferably always contain cadmium, though in the case of using a cadmium anode and a cadmium plating solution in the electrolytic process a counterelectrode alloy canbe used, which does not contain cadmium.
• the currents used in both mentioned modifications can vary from 2%.; ma. up to 50 ma. and the time within which the electrolytic process has to be performed is varied inversely as the current is used in attaining the same quality rectification and correspondingly the times varies from seconds down .to 7 seconds.
• the improvement that comprises, prior to application of the counter-electrode, making the selenium coated base plate the cathode during electrolysis of analkaiine aqueous electrolyte, the anode used in the electrolysis being ametal selected from the class consisting of tin andcadmium and the electrolyte comprising a solution for electroplating the metal of which the anode is formed and also including an organic substance selected from the class consisting of water soluble alcohols, water soluble aldehydes, water soluble ketones, water soluble organic acids, water soluble phenols.

Landscapes

• Electroplating And Plating Baths Therefor (AREA)
• Rectifiers (AREA)
• Electrodes For Compound Or Non-Metal Manufacture (AREA)
• Electroplating Methods And Accessories (AREA)

Priority Applications (12)

Applications Claiming Priority (2)

Publications (1)

Family

ID=27081729

Family Applications (2)

Family Applications After (1)

Country Status (6)

Families Citing this family (2)

Citations (8)

Family Cites Families (2)

• 0
  • BE BE476268D patent/BE476268A/xx unknown
  • BE BE467627D patent/BE467627A/xx unknown
  • BE BE474674D patent/BE474674A/xx unknown
• 1945
  • 1945-05-12 US US593542A patent/US2462917A/en not_active Expired - Lifetime
  • 1945-07-17 US US605617A patent/US2468131A/en not_active Expired - Lifetime
• 1946
  • 1946-04-18 GB GB12047/46A patent/GB610999A/en not_active Expired
  • 1946-10-10 FR FR934441D patent/FR934441A/fr not_active Expired
  • 1946-10-10 FR FR934443D patent/FR934443A/fr not_active Expired
  • 1946-12-23 CH CH268668D patent/CH268668A/fr unknown
• 1950
  • 1950-10-01 DE DEF4320A patent/DE846738C/de not_active Expired

Patent Citations (8)

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