Method for bonding heat-conducting substrate and metal layer

Abstract

A method for bonding a heat-conducting substrate and a metal layer is provided. A heat-conducting substrate, a first metal layer and a preformed layer are provided. The preformed layer is between the heat-conducting substrate and the first metal layer. The preformed layer is a second metal layer or a metal oxide layer. A heating process is performed to the preformed layer in an oxygen-free atmosphere to convert the preformed layer to a bonding layer for bonding the heat-conducting substrate and the first metal layer. The temperature of the heating process is less than or equal to 300° C.

What is claimed is: 
     
         1 . A method for bonding a heat-conducting substrate and a metal layer, comprising:
 providing a heat-conducting substrate, a first metal layer and a preformed layer, wherein the preformed layer is located between the heat-conducting substrate and the first metal layer, and the preformed layer is a second metal layer; and   performing a heating process to the preformed layer in an oxygen-free atmosphere, to convert the preformed layer to a bonding layer to bond the heat-conducting substrate and the first metal layer, wherein the temperature of the heating process is less than or equal to 300° C.   
     
     
         2 . The method for bonding a heat-conducting substrate and a metal layer of  claim 1 , wherein after the preformed layer is formed on the heat-conducting layer or the first metal layer, the heat-conducting layer and the first metal layer are stacked to dispose the preformed layer between the heat-conducting layer and the first metal layer. 
     
     
         3 . The method for bonding a heat-conducting substrate and a metal layer of  claim 1 , wherein the second metal layer comprises a silver layer or a copper layer. 
     
     
         4 . The method for bonding a heat-conducting substrate and a metal layer of  claim 3 , wherein the formation of the second metal layer comprises electroplating. 
     
     
         5 . The method for bonding a heat-conducting substrate and a metal layer of  claim 1 , wherein the second metal layer is an adhesive layer containing a plurality of metal particles. 
     
     
         6 . The method for bonding a heat-conducting substrate and a metal layer of  claim 5 , wherein materials of the metal particles comprise silver, copper or a combination thereof. 
     
     
         7 . The method for bonding a heat-conducting substrate and a metal layer of  claim 5 , wherein a particle diameter of the metal particles is in the range between 5 nanometers and 50 nanometers. 
     
     
         8 . The method for bonding a heat-conducting substrate and a metal layer of  claim 5 , wherein the formation of the second metal layer comprises coating. 
     
     
         9 . The method for bonding a heat-conducting substrate and a metal layer of  claim 1 , wherein materials of the heat-conducting substrate comprise a metal or an alloy. 
     
     
         10 . The method for bonding a heat-conducting substrate and a metal layer of  claim 1 , wherein the heat-conducting substrate comprises a ceramic substrate having a metal surface, and the first metal layer is bonded to the metal surface via the bonding layer. 
     
     
         11 . The method for bonding a heat-conducting substrate and a metal layer of  claim 1 , wherein the oxygen-free atmosphere comprises an inert gas atmosphere or a reducing gas atmosphere. 
     
     
         12 . The method for bonding a heat-conducting substrate and a metal layer of  claim 11 , wherein the inert gas comprises nitrogen or argon. 
     
     
         13 . The method for bonding a heat-conducting substrate and a metal layer of  claim 11 , wherein the reducing gas comprises hydrogen or hydrogen-containing gas.