Method for fabricating temperature sensitive and sputter target assemblies using reactive multilayer joining

Abstract

A method for joining component bodies of material over bonding regions of large dimensions by disposing a plurality of substantially contiguous sheets of reactive composite materials between the bodies and adjacent sheets of fusible material. The contiguous sheets of the reactive composite material are operatively connected by an ignitable bridging material so that an igniting reaction in one sheet will cause an igniting reaction in the other. An application of uniform pressure and an ignition of one or more of the contiguous sheets of reactive composite material causes an exothermic thermal reaction to propagate through the bonding region, fusing any adjacent sheets of fusible material and forming a bond between the component bodies.

1 . A method of forming a sputter target assembly, comprising the steps of:
 providing a backing plate having a top surface, and pre-wetting the top surface with a solder layer;   providing a sputter target having a bottom surface, and pre-wetting the bottom surface with a solder layer;   introducing a bonding foil, between the backing plate and the sputter target, wherein the bonding foil is an ignitable heterogeneous stratified structure for the propagation of an exothermic reaction;   pressing the backing plate and the sputter target together and igniting the bonding foil, therebetween to melt and bond the solder layer on the backing plate with the solder layer on the sputter target without affecting the microstructure or flatness of the sputter target in the formation of the sputter target assembly.   
   
   
       2 . The method of forming a sputter target assembly of  claim 1 , further comprising,
 aligning the target and backing plate in a press, prior to pressing and thereafter applying a load in excess of 50,000 lbs.   
   
   
       3 . The method of forming a sputter target assembly of  claim 1 , wherein the backing plate and the sputter target are made of different materials. 
   
   
       4 . The method of forming a sputter target assembly of  claim 1 , wherein the solder layers comprise tin in an amount of 63 weight percent and the balance is lead. 
   
   
       5 . The method of forming a sputter target assembly of  claim 1 , wherein the solder layers are of substantially the same thickness. 
   
   
       6 . The method of forming a sputter target assembly of  claim 1 , further comprising electrically igniting the foil to initiate the exothermic reaction. 
   
   
       7 . The method of forming a sputter target assembly of  claim 1 , wherein the thickness of the bonding foil falls within the range from about 0.002 to about 0.003 inches. 
   
   
       8 . The method of forming a sputter target assembly of  claim 1 , wherein the solder layers have a thickness falling within the range from about 0.005 to 0.010 inches. 
   
   
       9 . The method of forming a sputter target assembly of  claim 1 , wherein the pressure is applied via a hydraulic press, screw or manual press. 
   
   
       10 . The method of forming a sputter target assembly of  claim 1 , wherein the bonding foil is selected from among silicides, aluminides, borides, carbides, thermite reacting compounds, alloys, metallic glasses and composites. 
   
   
       11 . The method of forming a sputter target assembly of  claim 1 , the solder material is selected from among indium, tin-lead, or tin-silver. 
   
   
       12 . The method of forming a sputter target assembly of  claim 1 , wherein the sputter target is a substantially circular disc comprised of nickel or cobalt. 
   
   
       13 . A sputter target assembly comprising:
 a sputter target, a backing plate and a bonding foil, disposed between the backing plate and the sputter target, wherein the bonding foil is an ignitable heterogeneous stratified structure for the propagation of an exothermic reaction in order to bond the sputter target to the backing plate without affecting the microstructure or the flatness of the sputter target in the formation of the sputter target assembly.   
   
   
       14 . The sputter target assembly of  claim 13 , further comprising a first solder bond layer disposed between the backing plate and the bonding foil and a second solder bond layer between the target and the bonding foil. 
   
   
       15 . The sputter target assembly of  claim 14 , wherein the thickness of the bonding foil falls within the range from about 0.002 to about 0.003 inches. 
   
   
       16 . The sputter target assembly of  claim 15 , further comprising solder layers having a thickness that falls within the range from about 0.005 to 0.010 inches. 
   
   
       17 . The sputter target assembly of  claim 14 , wherein the bonding foil is selected from among silicides, aluminides, borides, carbides, thermite reacting compounds, alloys, metallic glasses and composites. 
   
   
       18 . The sputter target assembly of  claim 14 , wherein the sputter target is a substantially circular disc comprising nickel or cobalt. 
   
   
       19 . A method of forming a bonded plate assembly, comprising the steps of:
 providing a first plate having a top surface, and pre-wetting the top surface with a solder layer;   providing a second plate having a bottom surface, and pre-wetting the bottom surface with a solder layer;   introducing a bonding foil, between the first plate and the second wherein the bonding foil is an ignitable heterogeneous stratified structure for the propagation of an exothermic reaction;   pressing the first plate and the second plate together and igniting the bonding foil, therebetween to melt and bond the solder layer on the first plate with the solder layer on the second plate without affecting the microstructure or flatness of the second plate in the formation of the bonded plate assembly.   
   
   
       20 . The method of forming the bonded plate assembly of  claim 19 , further comprising,
 aligning the second plate and the first plate in a press, prior to pressing and thereafter applying a load in excess of at least 50,000 lbs.   
   
   
       21 . The method of forming the bonded plate assembly of  claim 19 , wherein the first plate and the second plate are made of different materials. 
   
   
       22 . The method of forming the bonded plate assembly of  claim 19 , wherein the solder layers are tin-lead solder. 
   
   
       23 . The method of forming the bonded plate assembly of  claim 19 , wherein the solder layers are of substantially the same thickness. 
   
   
       24 . The method of forming the bonded plate assembly of  claim 19 , further comprising electrically igniting the foil to initiate the exothermic reaction. 
   
   
       25 . The method of forming the bonded plate assembly of  claim 19 , wherein the thickness of the bonding foil falls within the range from about 0.002 to about 0.003 inches. 
   
   
       26 . The method of forming the bonded plate assembly of  claim 19 , wherein the solder layers have a thickness that falls within the range from about 0.005 to 0.010 inches. 
   
   
       27 . The method of forming the bonded plate assembly of  claim 19 , wherein the pressure is applied via a hydraulic press, screw or manual press. 
   
   
       28 . The method of forming the bonded plate assembly of  claim 19 , wherein the bonding foil is selected from among silicides, aluminides, borides, carbides, thermite reacting compounds, alloys, metallic glasses and composites. 
   
   
       29 . The method of forming the bonded plate assembly of  claim 19 , wherein the solder material is selected from among indium-tin, tin-lead, or tin-silver-copper. 
   
   
       30 . The method of forming the bonded assembly of  claim 19 , wherein the second plate is a substantially circular, disc-shaped nickel plate. 
   
   
       31 . A large area bonded plate assembly comprising:
 a first plate, a second plate and a bonding foil, disposed between the first plate and the second plate, wherein the bonding foil is an ignitable heterogeneous stratified structure for the propagation of an exothermic reaction in order to bond the first plate to the second plate without affecting the microstructure or the flatness of the second plate in the formation of the bonded plate assembly.   
   
   
       32 . The bonded plate assembly of  claim 31 , further comprising a first solder bond layer disposed between the first plate and the bonding foil and a second bond layer between the second plate and the bonding foil. 
   
   
       33 . The bonded plate assembly of  claim 31 , wherein the thickness of the bonding foil falls within the range from about 0.002 to about 0.003 inches. 
   
   
       34 . The bonded plate assembly of  claim 15 , further comprising solder layers having a thickness within the range from about 0.005 to 0.010 inches. 
   
   
       35 . The bonded plate assembly of  claim 31 , wherein the bonding foil is selected from among silicides, aluminides, borides, carbides, thermite reacting compounds, alloys, metallic glasses and composites. 
   
   
       36 . The bonded plate assembly of  claim 31 , wherein the second plate is a substantially circular, disc-shaped nickel plate.