Platinum temperature sensor

Abstract

A Platinum temperature sensor comprises a ceramic substrate and a platinum thin-film resistor applied to said ceramic substrate, a ceramic cover layer and a connecting layer generated from a ceramic green layer by pressure and temperature treatment. The ceramic cover layer is connected with the ceramic substrate in such a way via the connecting layer that the platinum thin-film resistor is sealingly encapsulated with regard to the environment.

What is claimed is:  
     
         1 . Platinum temperature sensor comprising: 
 a ceramic substrate;    a platinum thin-film resistor applied to the ceramic substrate;    a ceramic cover layer; and    a connecting layer produced from a ceramic green sheet by pressure and temperature treatment, by means of which the ceramic cover layer is connected with the ceramic substrate in such a way that the platinum thin-film resistor is sealingly encapsulated with re-gard to the environment.    
     
     
         2 . Platinum temperature sensor according to  claim 1  wherein the connecting layer is formed as a continuous face on the ceramic substrate and the platinum thin-film resistor.  
     
     
         3 . Platinum temperature sensor according to  claim 1  wherein the connecting layer is applied in a boarder area surrounding the platinum thin-film resistor on the ceramic substrate.  
     
     
         4 . Platinum temperature sensor according to  claim 1  wherein the connecting layer is generated from an Al 2 0 3  green-layer.  
     
     
         5 . Platinum temperature sensor comprising: 
 a ceramic substrate;    a platinum thin-film resistor applied to the ceramic substrate;    a ceramic cover layer; and    a connecting layer made of a glaze that is applied to the ceramic substrate in a boarder area surrounding the platinum thin-film resistor by means of which the ceramic cover layer is connected with the ceramic substrate in such way that the platinum thin-film resistor is sealingly encapsulated with regard to the environment.    
     
     
         6  Platinum temperature sensor according to  claim 1  wherein the ceramic substrate is made of Al 2 0 3 .  
     
     
         7 . Platinum temperature sensor according to  claim 1  wherein the ceramic cover layer is made of Al 2 0 3 .  
     
     
         8 . Platinum temperature sensor according to  claim 1  wherein a sealing cover is applied to the outer peripheral edges of the layer structure consisting of ceramic substrate, connecting layer and ceramic cover layer.  
     
     
         9 . Platinum temperature sensor according to  claim 8  wherein the sealing layer is made of glass.  
     
     
         10 . Method for producing a platinum temperature sensor comprising the steps of: 
 a) providing a fired ceramic substrate with a platinum thin-film resistor applied to the main surface thereof;    b) applying a connecting layer made of a ceramic green layer to the main surface of the ceramic substrate; and    c) applying a fired ceramic cover layer to the connecting layer in such a way that the platinum thin-film resistor is sealingly encapsulated with regard to the environment by subjecting the ceramic green layer to a temperature treatment under application of pressure in such a way that the ceramic substrate and the ceramic cover layer will be connected.    
     
     
         11 . Method according to  claim 10  wherein the connecting layer is applied as a continuous face in step b).  
     
     
         12 . Method according to  claim 10  wherein the connecting layer is applied to the ceramic substrate in a border 
 area surrounding the platinum thin-film resistor in step b).  
 
     
     
         13 . Method according to  claim 10  wherein a sealing layer is applied to outer peripheral edges of the layer 
 structure consisting of ceramic substrate, connecting layer and ceramic cover layer.  
 
     
     
         14 . Platinum temperature sensor according to  claim 5  wherein the ceramic substrate is made of Al 2 0 3 .  
     
     
         15 . Platinum temperature sensor according to  claim 5  wherein the ceramic cover layer is made of Al 2 O 3 .  
     
     
         16 . Platinum temperature sensor according to  claim 5  wherein a sealing cover is applied to the outer peripheral edges of the layer structure consisting of ceramic substrate, connecting layer and ceramic cover layer.  
     
     
         17 . Platinum temperature sensor according to  claim 16  wherein the sealing layer is made of glass.