CH190817A - Process for the production of electrical resistors provided with connection contacts with a negative temperature coefficient from a sintered, semiconducting mixture containing excess silicon, and a resistor produced therefrom. - Google Patents

Process for the production of electrical resistors provided with connection contacts with a negative temperature coefficient from a sintered, semiconducting mixture containing excess silicon, and a resistor produced therefrom.

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Publication number
CH190817A
CH190817A CH190817DA CH190817A CH 190817 A CH190817 A CH 190817A CH 190817D A CH190817D A CH 190817DA CH 190817 A CH190817 A CH 190817A
Authority
CH
Switzerland
Prior art keywords
sintered
production
negative temperature
mixture containing
electrical resistors
Prior art date
Application number
Other languages
German (de)
Inventor
Gloeilampenfabrieken N Philips
Original Assignee
Philips Nv
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
Application filed by Philips Nv filed Critical Philips Nv
Publication of CH190817A publication Critical patent/CH190817A/en

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  • Apparatuses And Processes For Manufacturing Resistors (AREA)

Description

  

  verfahren zur Herstellung von mit     Anschlusskontakten        versehenen    elektrischen  Widerständen mit negativem Temperaturkoeffizienten aus einem gesinterten,  halbleitenden, Silizium im Überschuss enthaltenden Gemisch,  und     darnach    hergestellter Widerstand.    Es ist nicht leicht,     elektrische,    aus gesin  terten     Materialien    hergestellte Widerstände  mit gut haftenden, keinen unerwünschten  Übergangswiderstand gebenden Kontakten  zu versehen.

   Zu diesem Zweck sind verschie  dene Verfahren vorgeschlagen worden, beson  ders für elektrische Widerstände mit negati  vem     Temperaturkoeffizienten,    die aus nie  drigeren Oxyden des Chroms oder     des.    Urans  hergestellt sind. Dabei hat man darauf hin  gewiesen, dass das Zusammensintern von  Metall und Kohlenstoff wegen der Bildung  des     Karbids    zu einem ungewünschten Er  gebnis führt.  



  Gegenstand der Erfindung ist nun ein  Verfahren zur     Herstellung    von mit An  schlusskontakten versehenen elektrischen Wi  derständen mit     negativem    Temperaturkoeffi  zienten aus einem gesinterten halbleitenden  Gemisch, das Silizium im Überschuss ent-    hält. Dieses Verfahren ist gemäss     Erfindung          dadurch        gekennzeichnet,        ,dassi    für die     Bildung     der Kontakte bestimmte     Kohlenstoffkörper     während der     Sinterung        des    halbleitenden Ge  misches damit zu einem Ganzen zusammen  gesintert werden.  



  Die     Erfindung    ist nachstehend an     einem          Ausführungsbeispiel    näher erläutert.  



  50g     Ferrosilizium    mit hohem .Silizium-,       gehalt,    z.     B.   <B>98%,</B>     wird    in Pulverform ge  bracht, gesiebt und darauf mit 10 g Ton und  50 mg     Tragant,    gleichfalls in Pulverform,  mit Hinzufügung von 7     cm3    Wasser ge  mischt, bis     eine    homogene Paste erzielt wor  den ist, die in Form von Stäbchen 1 gepresst  wird;

   bei dieser     Behandlung    werden gleich  zeitig die     Graphitblöckchen    2     angepresst.     Darauf werden die so mit     G.raphitkontakten     2. versehenen Stäbchen 1 während einiger  Stunden in Luft getrocknet und darauf wäh-      send     annähernd    60 Minuten auf einer     '11com-          peratur    von<B>1300,'</B> C in einer reduzierenden  Gasatmosphäre erhitzt, wobei die für die  Bildung der Kontakte bestimmten Graphit  körper während ,der     Sinterung    des halbleiten  den Gemisches damit zu einem Ganzen zu  sammen gesintert werden.

   Die     Graphitkon-          takte    sind dann fest mit dem     siliziumhalti-          gen    Widerstandsmaterial verbunden und wei  sen keinen hinderlichen Übergangswiderstand  auf. Sie können weiter mit z. B. aus Nickel  bestehenden Stäbchen 3 für die Stromzufüh  rung versehen werden.  



  Zur     Erläuterung    diene noch,     dass.    mit  einem Überschuss an Silizium im Wider  standsmaterial erreicht wird, dass der Wider  standswert dieser z. B. für die Anwendung  als     Anlasswiderstand    für Motoren sehr ge  eigneten Widerstände bei Zimmertemperatur  gross, bei einer     Betriebstemperatur    z. B. von  <B>700'</B> C aber sehr klein ist,     sodass    ein nega-         tiver    Temperaturkoeffizient von hohem Wert  entsteht.



  Method for the production of electrical resistors provided with connection contacts with a negative temperature coefficient from a sintered, semiconducting mixture containing excess silicon, and a resistor produced therefrom. It is not easy to provide electrical resistors made from sintered materials with contacts that adhere well and that do not give undesired contact resistance.

   For this purpose, various methods have been proposed, especially for electrical resistors with negative temperature coefficients, which are made from never drigeren oxides of chromium or uranium. It has been pointed out that sintering the metal and carbon together leads to an undesirable result because of the formation of the carbide.



  The subject of the invention is a method for the production of electrical resistors provided with connection contacts with negative temperature coefficients from a sintered semiconducting mixture which contains silicon in excess. According to the invention, this method is characterized in that carbon bodies intended for the formation of the contacts are sintered together to form a whole during the sintering of the semiconducting mixture.



  The invention is explained in more detail below using an exemplary embodiment.



  50g ferrosilicon with a high silicon content, e.g. B. 98% is brought into powder form, sieved and then mixed with 10 g clay and 50 mg tragacanth, also in powder form, with the addition of 7 cm3 water until a homogeneous paste is obtained which is pressed in the form of rods 1;

   During this treatment, the graphite blocks 2 are pressed at the same time. The rods 1 thus provided with graphite contacts 2. are then dried in air for a few hours and then heated for approximately 60 minutes at a temperature of 1300 ° C. in a reducing gas atmosphere , the graphite body intended for the formation of the contacts during the sintering of the semiconducting the mixture thus being sintered to form a whole.

   The graphite contacts are then firmly connected to the silicon-containing resistance material and do not have any obstructive contact resistance. You can continue with z. B. made of nickel rods 3 for the Stromzufüh tion are provided.



  To explain it still serve that. With an excess of silicon in the resistance material is achieved that the resistance value of this z. B. for use as a starting resistor for motors very ge suitable resistances at room temperature large, at an operating temperature z. B. of <B> 700 '</B> C but is very small, so that a negative temperature coefficient of high value is created.

 

Claims (1)

PATENTANSPRüCHE I. Verfahren zur Herstellung von mit An schlusskontakten versehenen elektrischen Widerständen mit negativem Tempera turkoeffizienten aus einem gesinterten, halbleitenden Gemisch, das Silizium im Überschuss enthält, dadurch gekennzeich net, dass für die Bildung der Kontakte bestimmte Kohlenstoffkörper während der Sinterung des halbleitenden Ge misches damit zu einem Ganzen zusam mengesintert werden. II. Elektrischer Widerstand, hergestellt nach dem Verfahren gemäss Patentanspruch I. PATENT CLAIMS I. Process for the production of electrical resistors provided with connection contacts with negative temperature coefficients from a sintered, semiconducting mixture containing excess silicon, characterized in that certain carbon bodies are used to form the contacts during the sintering of the semiconducting mixture be sintered together to form a whole. II. Electrical resistance produced by the method according to claim I.
CH190817D 1935-08-17 1936-08-15 Process for the production of electrical resistors provided with connection contacts with a negative temperature coefficient from a sintered, semiconducting mixture containing excess silicon, and a resistor produced therefrom. CH190817A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE190817X 1935-08-17

Publications (1)

Publication Number Publication Date
CH190817A true CH190817A (en) 1937-05-15

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Family Applications (1)

Application Number Title Priority Date Filing Date
CH190817D CH190817A (en) 1935-08-17 1936-08-15 Process for the production of electrical resistors provided with connection contacts with a negative temperature coefficient from a sintered, semiconducting mixture containing excess silicon, and a resistor produced therefrom.

Country Status (1)

Country Link
CH (1) CH190817A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE890385C (en) * 1939-02-22 1953-09-17 Conradty Fa C Carbon lamella for collectors of electrical machines

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE890385C (en) * 1939-02-22 1953-09-17 Conradty Fa C Carbon lamella for collectors of electrical machines

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