Method of Bonding Two Substrates and Device Manufactured Thereby

Abstract

The invention relates to method for bonding at least two substrates, for example made from glass, silicon, ceramic, aluminum, or boron, by using an intermediate thin film metal layer for providing the bonding, said method comprising the following steps of: a) providing said two substrates; b) depositing said thin film metal layer on at least a part of a surface of a first substrate of the two substrates; c) bringing a surface of the second substrate into contact with said thin film metal layer on said surface of the first substrate such that a bonding between the second substrate and the thin film metal layer on the first substrate is provided; and d) at least locally strengthening the bonding between the second substrate and the thin film metal layer on the first substrate. The invention also relates to a device comprising two substrates, for example made from glass, silicon, ceramic, aluminum, or boron, and an intermediate thin film metal layer.

1 . A method for bonding at least two substrates, for example made from glass, silicon, ceramic, aluminum, or boron, characterized by using an intermediate thin film metal layer for providing the bonding, said method comprising the following steps of:
 a) providing said two substrates;   b) depositing said thin film metal layer on at least a part of a surface of a first substrate of the two substrates;   c) bringing a surface of the second substrate into contact with said thin film metal layer on said surface of the first substrate such that a bonding between the second substrate and the thin film metal layer on the first substrate is provided; and   d) at least locally strengthening the bonding between the second substrate and the thin film metal layer on the first substrate.   
     
     
         2 . The method according to  claim 1 , wherein said thin film metal layer comprises a metal chosen from the group comprising palladium, copper, tungsten, aluminum, cobalt, nickel, thalium, ruthenium, iron, molybdenum, stainless steel, chromium, tantalum, vanadium and titanium, and wherein said thin film metal layer comprises a metal oxide layer. 
     
     
         3 . The method according to  claim 1 , wherein said thin film metal layer comprises a metal chosen from the group comprising silver, platinum and gold. 
     
     
         4 . The method according to  claim 1 , wherein step d) is performed by urging the two substrates together. 
     
     
         5 . The method according to  claim 1 , wherein step (d) is performed by at least locally heating said thin film metal layer. 
     
     
         6 . The method according to  claim 5 , wherein said heating is performed by means of a laser and at least one of the substrates is transparent for said laser, an electric current, microwave radiation or ultrasonic energy. 
     
     
         7 . The method according to  claim 1 , wherein step (d) is performed by heating the two substrates and the intermediate thin film metal layer in an oven. 
     
     
         8 . The method according to  claim 1 , wherein step (d) is performed by applying an underpressure, for example a vacuum, to the two substrates and the intermediate thin film metal layer. 
     
     
         9 . The method according to  claim 1 , wherein:
 at least one of the two substrates provided in step (a) comprises a cavity;   step (b) is performed such that said thin film metal layer surrounds a portion of the surface of the first substrate;   step (c) is performed such that after step (c), said portion, said cavity, and the inner surface of the thin film metal layer directed to said portion, define an inner space between said two substrates, and   step (d) is performed such that a sealing of the inner space between said two substrates is provided.   
     
     
         10 . The method according to  claim 1 , wherein step (b) is performed such that it allows at least a part of said thin film metal layer to be used as an electrical connection and/or an optical element and/or a chemical element. 
     
     
         11 . The method according to  claim 10 , wherein step (b) is performed such that said part of said thin film metal layer that forms the electrical connection extends from the inside of the inner space to the outside of the inner space. 
     
     
         12 . The method according to  claim 5 , wherein said heating is performed by irradiating a predetermined pattern in the thin film metal layer by means of a laser, wherein at least one of the substrates is transparent for said laser, wherein said pattern defines an unirradiated second pattern that is electrically conductive. 
     
     
         13 . The method according to  claim 9 , wherein said irradiated pattern crosses through said surrounding thin film metal layer in order to break an electrical circuit of the thin film metal layer. 
     
     
         14 . The method according to  claim 12 , wherein said unirradiated second pattern extends from the inside of an inner space or the inner space to the outside of the inner space. 
     
     
         15 . The method according to  claim 1 , wherein said thin film metal layer is biocompatible. 
     
     
         16 . The method according to  claim 1 , comprising the steps, to be performed after step (b) and before step (c), of:
 e) depositing a resist on said thin film metal layer;   f) patterning said resist and said thin film metal layer on said part of the surface of the first substrate;   g) etching said first substrate comprising said thin film metal layer and said resist such that at least one microstructure is formed in said first substrate; and   h) removing said resist such that said thin film metal layer remains on said first substrate.   
     
     
         17 . The method according to  claim 16 , comprising the step, to be performed after step (g) and before step (h), of;
 i) etching parts of said thin film metal layer that overlap said microstructure to compensate for underetching.   
     
     
         18 . The method according to  claim 9 , wherein the sealing of the inner space between said two substrates is hermetic, and comprising the step of:
 j) arranging temperature-sensitive components in the inner space.   
     
     
         19 . A device comprising two substrates and an intermediate thin film metal layer, which device comprises an inner space between the two substrates, which inner space is surrounded by said intermediate thin film metal layer that hermetically seals the inner space, wherein the thin film metal layer is biocompatible, and wherein temperature-sensitive components are arranged in said inner space. 
     
     
         20 . The device according to  claim 19 , wherein the two substrates independently comprise a material selected from the group consisting of glass, silicon, ceramic, aluminum and boron, and combinations thereof.