Method for Fabricating a Varistor Device and Varistor Device

Patent metadata

Field	Value
Publication number	US-2016307673-A1
Application number	US-201415102645-A
Country	US
Kind code	A1
Filing date	Nov 13, 2014
Priority date	Dec 24, 2013
Publication date	Oct 20, 2016
Grant date	—

Abstract

A method for fabricating a varistor device is presented. In an embodiment the method includes providing a base body for the varistor device, wherein the base body comprises a ceramic material, providing a basic material for a base metal electrode region on the base body, exposing the base body with the basic material to a temperature under a protective gas atmosphere such that the base metal electrode region is formed and firmly connected to the base body and completing the varistor device.

First claim

1 .- 13 . (canceled)

14 . A method for fabricating a varistor device, the method comprising:
providing a base body for the varistor device, wherein the base body comprises a ceramic material; providing a basic material for a base metal electrode region on the base body; exposing the base body with the basic material to a temperature under a protective gas atmosphere such that the base metal electrode region is formed and firmly connected to the base body; and completing the varistor device.

15 . The method according to claim 14 , wherein, before providing the basic material on the base body, providing the base body with a passivation.

16 . The method according to claim 15 , wherein the base body is provided with the passivation such that sides or surface regions of the base body remain free and the basic material can, later on, be provided or applied in the free or uncoated regions in order to provide one or more electrodes of the varistor device.

17 . The method according to claim 15 , wherein providing the base body with a passivation comprises providing the base body with a raw material, and, after the base body is provided with the raw material, curing the raw material at temperatures from 300° C. to 600° C. in order to form the passivation.

18 . The method according to claim 14 , wherein providing the base body with the basic material comprises screen printing the base body with the basic material.

19 . The method according to claim 14 , wherein exposing the base body to the temperature comprises exposing the base body to the temperature in a furnace with zones of different temperatures.

20 . The method according to claim 19 , wherein the base body is exposed for a duration between 5 min and 30 min in a zone with temperatures between 450° C. and 800° C. such that the base metal electrode region is formed and firmly connected to the base body.

21 . The method according to claim 14 , wherein, after exposing the base body to the temperature, providing the base body with solder contacts and/or solder straps.

22 . A varistor device comprising:
a ceramic base body; and an electrode comprising a base metal electrode region, wherein the base metal electrode region is directly connected to the ceramic base body.

23 . The varistor device according to claim 22 , wherein the base metal electrode region contains copper.

24 . The varistor device according to claim 22 , further comprising a passivation directly connected to the ceramic base body.

25 . The varistor device according to claim 24 , wherein the ceramic base body comprises two base metal electrode regions each connected to a main surface of the ceramic base body, wherein the passivation is only arranged at an edge surface of the ceramic base body, and wherein the edge surface connects the main surfaces of the ceramic base body.

26 . The varistor device according to claim 24 , wherein the passivation is a lead-free glass, a ceramic material and/or an inorganic material.

27 . The varistor device according to claim 22 , wherein the base metal electrode region is a layer with a thickness between 5 μm and 30 μm.

28 . A varistor device comprising:
a ceramic base body; an electrode comprising a base metal electrode region, wherein the base metal electrode region is directly connected to the ceramic base body; and a passivation directly connected to the ceramic base body, wherein the ceramic base body comprises two base metal electrode regions, each connected to a main surface of the ceramic base body, wherein the passivation is arranged only at an edge surface of the ceramic base body, and wherein the edge surface connects the main surfaces of the ceramic base body.

Assignees

• Epcos Ag

Inventors

• Sun Dennis
• Jing Jamie
• Li Qirong

Classifications

• H01C17/28

  adapted for applying terminals · CPC title

• H01C17/30

  adapted for baking · CPC title

• H01C1/142

  the terminals or tapping points being coated on the resistive element · CPC title

• H01C7/102 Primary

  Varistor boundary, e.g. surface layers (H01C7/12 takes precedence) · CPC title

• H01C1/144

  the terminals or tapping points being welded or soldered · CPC title