Method for producing a metal-ceramic soldered connection

Patent metadata

Field	Value
Publication number	US-2016228966-A1
Application number	US-201415025339-A
Country	US
Kind code	A1
Filing date	Oct 6, 2014
Priority date	Oct 8, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

A method for producing a material-bonding metal-ceramic soldered connection of an uncoated ceramic body to a metal part uses a metallic solder and begins by choosing the metal part with a 50% fraction of an oxygen-affine element; choosing the ceramic body with at least 80% aluminum oxide, zirconium oxide, silicon oxide or an alloy thereof; choosing an inactive, eutectic or near-eutectic solder; and forming a structure with the ceramic body and the metal part with an intermediate space between the their opposing surfaces. The solder is introduced into the intermediate space or the vicinity thereof. The structure is heated in a vacuum at a soldering temperature (T) greater than the liquidus temperature (TL) of the solder for a soldering period. The connection is applied between a ceramic bushing and a high-temperature sensor.

First claim

1 . A method for producing a materially-bonded metal/ceramic solder connection of an uncoated ceramic body to a metal part with coefficients of thermal expansion of the ceramic body and the metal part, which are tuned to one another, while using a metallic solder, the method comprising the steps:
choosing the metal part having a proportion of 50% of an oxygen-affinitive element, choosing the ceramic body having at least 80% of which consists of aluminium oxide, zirconium oxide, silicon oxide or a mixture thereof; choosing a solder that is either an inactive solder, or a solder that is eutectic or a solder that is a near eutectic solder; formation of a structure with opposing surfaces of the ceramic body and the metal part, wherein the opposing surfaces thereof form an intermediate space with respect to one another, wherein the solder is brought into the vicinity of or into the intermediate space; putting the structure into an oven; application of a vacuum or an oxygen-free protective gas atmosphere around the structure with the solder; heating the oven to a solder temperature greater than the liquidus temperature (TL) of the solder; maintenance of the solder temperature in the oven for a solder duration until the solder, forming a mixed-phase region (M) together with a portion of dissolved metal part, completely fills and wets the intermediate space.

2 . The method according to claim 1 , wherein the oven is heated at most to a solder temperature of 60° C. above the liquidus temperature of the solder.

3 . The method according to claim 1 , wherein the metal part comprises titanium, hafnium or zirconium or an alloy of these elements as oxygen-affinitive element.

4 . The method according to claim 1 , wherein the solder duration is between five and ten minutes.

5 . The method according to claim 1 , wherein low-melting non-active solders with a liquidus temperature lower than or equal to 1000° C. are used.

6 . The method according to claim 5 , wherein a silver- or gold-based solder is used.

7 . The method according to claim 1 , wherein the solder is present in the form of wire solder, solder film or paste.

8 . The method according to claim wherein the intermediate space forms a capillary solder gap.

9 . The method according to claim 1 , wherein the metal part and the ceramic body are positioned in such a manner that the size of the intermediate space is not greater than 0.03 mm.

10 . The method according to claim 1 , wherein the ceramic body has a glass-phase portion of 0 to 6% by weight.

11 . A materially-bonded metal/ceramic solder connection with an intermediate space, which is filled at least to some extent by a solder, between a surface of an uncoated ceramic body, at least 80% of which consists of aluminium oxide, zirconium oxide, silicon oxide or a mixture thereof, and a surface of a metal part, wherein the metal part comprises a proportion of at least 50% of an oxygen-affinitive element, and in that at least 80% of the ceramic body consists of aluminium oxide, zirconium oxide, silicon oxide or a mixture thereof, and in that the solder is an eutectic or near eutectic, non-active solder, and wherein the intermediate space is completely filled by a composition, which forms a mixed phase region and is an alloy made up of a portion of dissolved metal part and the solder, wherein the transition from mixed-phase region to metal part is configured to be gradual.

12 . The connection according to claim 11 , wherein the intermediate space is configured as a capillary solder gap.

13 . The connection according to claim 12 , wherein the mixed-phase region has a thickness which corresponds to the capillary solder gap width of the capillary solder gap.

14 . The connection according to claim 11 , wherein the metal part comprises titanium, hafnium, zirconium or an alloy of these elements.

15 . The connection according to claim 11 , wherein the mixed-phase region is formed by a silver- or gold-based solder and the portion of dissolved metal part.

16 . The connection according to claim 11 , wherein during the soldering process, a thickness of the metal part of at least 3 μm normal to the surface of the metal part 2 , 3 , which faces the intermediate space or the capillary solder gap, is completely dissolved and fills the intermediate space together with the solder.

17 . The connection according to claim 11 , configured as a ceramic duct, which enables the electrically and/or thermally insulated passage of a conductor through a housing.

18 . The connection according to claim 17 , wherein the ceramic duct is disposed in a housing, wherein the ceramic duct encases a conductor connected to a measuring element.

19 . A high-temperature sensor comprising a ceramic duct according to claim 18 .

Assignees

• Kistler Holding Ag
• Kristler Holding AG

Inventors

• Mastrogiacomo Giovanni
• Märki Hans-Beat

Classifications

• B23K35/24

  Selection of soldering or welding materials proper (B23K35/34 takes precedence) · CPC title

• B23K1/0008 Primary

  specially adapted for particular articles or work · CPC title

• B23K35/3006

  Ag as the principal constituent · CPC title

• B23K1/008

  Soldering within a furnace (B23K1/012 takes precedence) · CPC title

• B23K2103/52

  Ceramics · CPC title