High temperature anodic bonding apparatus

Abstract

An anodic bonding apparatus includes: a first bonding plate mechanism operable to engage a first material sheet, and to provide at least one of controlled heating, voltage, and cooling thereto; a second bonding plate mechanism operable to engage a second material sheet, and to provide at least one of controlled heating, voltage, and cooling thereto; a pressure mechanism operatively coupled to the first and second bonding plate mechanisms and operable to urge the first and second bonding plate mechanisms toward one another to achieve controlled pressure of the first and second material sheets against one another along respective surfaces thereof; a control unit operable to produce control signals to the first and second bonding plate mechanisms and the pressure mechanism to provide heating, voltage, and pressure profiles sufficient to achieve anodic bonding between the first and second material sheets.

1 . An anodic bonding apparatus, comprising: 
 a first bonding plate mechanism operable to engage a first material sheet, and to provide at least one of controlled heating, voltage, and cooling thereto;    a second bonding plate mechanism operable to engage a second material sheet, and to provide at least one of controlled heating, voltage, and cooling thereto;    a pressure mechanism operatively coupled to the first and second bonding plate mechanisms and operable to urge the first and second bonding plate mechanisms toward one another to achieve controlled pressure of the first and second material sheets against one another along respective surfaces thereof;    a control unit operable to produce control signals to the first and second bonding plate mechanisms and the pressure mechanism to provide heating, voltage, and pressure profiles sufficient to achieve anodic bonding between the first and second material sheets.    
     
     
         2 . The anodic bonding apparatus of  claim 1 , wherein the first material sheet is at least one of a glass substrate and a glass ceramic substrate, and the second material sheet is a donor semiconductor wafer.  
     
     
         3 . The anodic bonding apparatus of  claim 1 , wherein the heating profile includes at least a peak temperature of at least one of the first and second material sheets of greater than about 600° C.  
     
     
         4 . The anodic bonding apparatus of  claim 1 , wherein the heating profile includes at least a peak temperature of at least one of the first and second material sheets of between about 600° C. and 1000° C.  
     
     
         5 . The anodic bonding apparatus of  claim 1 , wherein the heating profile includes at least a peak temperature of at least one of the first and second material sheets of greater than about 1000° C.  
     
     
         6 . The anodic bonding apparatus of  claim 1 , wherein the voltage profile includes at least a peak voltage of at least one of the first and second material sheets of between about 100 volts DC to about 2000 volts DC.  
     
     
         7 . The anodic bonding apparatus of  claim 6 , wherein at least one of: 
 the voltage profile includes at least a peak voltage difference of between about 1000 volts DC and about 2000 volts DC between the first material sheet and the second material sheet;    one of the first and second material sheets are at ground potential; and    the peak voltage difference is attained by applying a positive voltage potential to one of the first and second material sheets and a negative voltage potential to the other of the first and second material sheets.    
     
     
         8 . The anodic bonding apparatus of  claim 1 , wherein the pressure profile includes at least a peak pressure between the first and second material sheets of between about 1 pound per square inch (psi) and 100 psi.  
     
     
         9 . The anodic bonding apparatus of  claim 1 , wherein the pressure profile includes at least a peak pressure between the first and second material sheets of about 20 psi.  
     
     
         10 . The anodic bonding apparatus of  claim 1 , wherein the control unit is operable to produce control signals to at least one of the first and second bonding plate mechanisms to provide an active cooling profile to the first and second material sheets sufficient to facilitate separation of an exfoliation layer from one of the first and second material sheets that has been bonded to the other of the first and second material sheets.  
     
     
         11 . The anodic bonding apparatus of  claim 10 , wherein the cooling profile provides at least one of differing rates of cooling and differing levels of cooling to the first and second material sheets.  
     
     
         12 . An anodic bonding apparatus, comprising: 
 a first bonding plate mechanism operable to engage a first material sheet, and to provide at least one of controlled heating and voltage thereto;    a second bonding plate mechanism operable to engage a second material sheet, and to provide at least one of controlled heating and voltage thereto; and    a lift and press mechanism operatively coupled to the first bonding plate mechanism and operable to urge the first and second bonding plate mechanisms toward one another to achieve controlled pressure of the first and second material sheets against one another along respective surfaces thereof to assist in the anodic bonding of same.    
     
     
         13 . The anodic bonding apparatus of  claim 12 , wherein: 
 the first and second bonding plate mechanisms each include a bearing surfaces, each bearing surface defining a bearing plane for engaging a respective one of the first and second material sheets; and    the lift and press mechanism is operable to impart a controllable force on the first bonding plate mechanism, the controllable force being substantially perpendicular to the bearing plane thereof.    
     
     
         14 . The anodic bonding apparatus of  claim 13 , wherein the lift and press mechanism includes a bellows actuator operable to impart the controllable force in response to variations in fluid pressure provided to the actuator.  
     
     
         15 . The anodic bonding apparatus of  claim 14 , wherein the fluid is a gas.  
     
     
         16 . The anodic bonding apparatus of  claim 13 , wherein the lift and press mechanism is operable to provide: 
 a first actuator function imparting a coarse displacement of the first bonding plate mechanism to move the first bonding plate mechanism toward the second bonding plate mechanism; and    a second actuator function imparting the controllable force to the first bonding plate mechanism.    
     
     
         17 . The anodic bonding apparatus of  claim 16 , wherein the lift and press mechanism includes a piston-driven actuator operable to provide the first actuator function.  
     
     
         18 . The anodic bonding apparatus of  claim 16 , wherein the lift and press mechanism includes a bellows actuator operable to provide the second actuator function.  
     
     
         19 . The anodic bonding apparatus of  claim 16 , wherein the first actuator function results in initial contact between the first and second material sheets along the respective surfaces thereof.  
     
     
         20 . The anodic bonding apparatus of  claim 16 , wherein the lift and press mechanism includes: first and second actuators operable to provide the first and second actuator functions, respectively, wherein the first and second actuators are in axial alignment with the first bonding plate mechanism.  
     
     
         21 . The anodic bonding apparatus of  claim 20 , wherein the first and second actuators are disposed such that actuation of the first actuator imparts the coarse displacement of both the second actuator and the first bonding plate mechanism.  
     
     
         22 . The anodic bonding apparatus of  claim 21 , wherein actuation of the second actuator does not impart any displacement of the first actuator.  
     
     
         23 . An anodic bonding apparatus, comprising: 
 a first bonding plate mechanism operable to engage a first material sheet and a second bonding plate mechanism operable to engage a second material sheet, the first and second bonding plate mechanisms each including a bearing surface, each bearing surface defining a bearing plane for engaging a respective one of the first and second material sheets; and    an open and close mechanism operatively coupled to the second bonding plate mechanism and operable to: 
 (i) assist, when in a closed orientation, in achieving controlled pressure of the first and second material sheets against one another along respective surfaces thereof; and  
 (ii) provide a dual motion opening profile, where a first motion separates the second bonding plate mechanism from the first bonding plate mechanism in a direction substantially perpendicular to the respective bearing planes thereof, and a second motion tilts the second bonding plate mechanism away from the first bonding plate mechanism such that the bearing plane of the second bonding plate mechanism is oblique to the bearing plane of the first bonding plate mechanism.  
   
     
     
         24 . The anodic bonding apparatus of  claim 23 , wherein the bearing planes of the first and second bonding plate mechanisms remain substantially parallel throughout substantially all of the first opening motion of the second bonding plate mechanism.  
     
     
         25 . The anodic bonding apparatus of  claim 23 , wherein the open and close mechanism includes: 
 a lift assembly operable to extend and retract in a direction substantially perpendicular to the bearing plane of the first bonding plate mechanism; and    a mount plate having first and second ends, the second bonding plate mechanism being disposed toward the first end thereof, and the mount plate being pivotally coupled to the lift assembly at a position intermediate to the first and second ends.    
     
     
         26 . The anodic bonding apparatus of  claim 25 , wherein: 
 the open and close mechanism includes one or more stop arms extending in substantially parallel orientation to the lift assembly and slideably engaged at first ends thereof with the second end of the mount plate; and    the stop arms permits movement of the second end of the mount plate as the lift assembly extends for limited travel during the first motion such that the second bonding plate mechanism separates away from the first bonding plate mechanism in the direction substantially perpendicular to the respective bearing planes thereof.    
     
     
         27 . The anodic bonding apparatus of  claim 26 , wherein the one or more stop arms are operable to prohibit movement of the second end of the mount plate beyond the limited travel such that continued extension of the lift assembly produces a lever action at the second end of the mount plate about the pivot coupling of the mount plate and the lift assembly.  
     
     
         28 . The anodic bonding apparatus of  claim 27 , wherein the lever action at the second end of the mount plate tilts the second bonding plate mechanism away from the first bonding plate mechanism.  
     
     
         29 . The anodic bonding apparatus of  claim 27 , wherein retraction of the lift assembly from the open orientation of the first and second bonding plate mechanisms tilts the second bonding plate mechanism toward the first bonding plate mechanism via the lever action at the second end of the mount plate.  
     
     
         30 . The anodic bonding apparatus of  claim 29 , wherein the retraction of the lift assembly is operable to cause the second end of the mount plate to reach the limited travel movement such that continued retraction of the lift assembly such that the second bonding plate mechanism separates away from the first bonding plate mechanism in the direction substantially perpendicular to the respective bearing planes thereof.  
     
     
         31 . An anodic bonding apparatus, comprising: 
 a first bonding plate mechanism operable to engage the first material sheet, and to provide at least one of controlled heating, voltage, and cooling thereto;    a second bonding plate mechanism operable to engage the second material sheet, and to provide at least one of controlled heating, voltage, and cooling thereto; and    a spacer mechanism including a plurality of movable shim assemblies, the spacer mechanism being coupled to the first bonding plate mechanism, and being operable to symmetrically move the shim assemblies toward and between the first and second material sheets to prevent peripheral edges of the first and second material sheets from touching one another.    
     
     
         32 . The apparatus of  claim 31 , wherein the first material sheet is at least one of a glass substrate and a glass ceramic substrate, and the second material sheet is a donor semiconductor wafer.  
     
     
         33 . The apparatus of  claim 31 , wherein the spacer mechanism is of substantially annular construction and includes: 
 a mount ring fixedly coupled with respect to the first bonding plate mechanism; and    a swivel ring rotationally coupled to the mount ring,    wherein the plurality of shim assemblies are slideably coupled to the mount ring such that they may move synchronously into and/or out of a space between the first and second material sheets in response to forward and rearward rotation of the swivel ring.    
     
     
         34 . The apparatus of  claim 33 , wherein: 
 the swivel ring includes one or more cams disposed at a peripheral edge thereof;    the respective shim assemblies each include one or more cam guides that engage the one or more cams of the swivel ring such that when the swivel ring rotates the shim assemblies move synchronously into and/or out of the space between the first and second material sheets.    
     
     
         35 . The apparatus of  claim 34 , wherein the swivel ring includes one cam slot for each shim assembly, each cam slot spiraling away from a center of the spacer mechanism.  
     
     
         36 . The apparatus of  claim 31 , wherein: 
 the first and second bonding plate mechanisms each include a bearing surface, each bearing surface defining a bearing plane for engaging a respective one of the first and second material sheets; and    the spacer mechanism is operable such that the shim assemblies move substantially parallel to at least the bearing surface of the first bonding plate mechanism to interpose between or move out from between the first and second material sheets.    
     
     
         37 . The apparatus of  claim 31 , wherein the spacer mechanism is operable to move the shim assemblies between the first and second material sheets in order to enable bonding only in a central region of the first and second material sheets.  
     
     
         38 . The apparatus of  claim 37 , wherein the spacer mechanism is operable to move the shim assemblies out from between the first and second material sheets after bonding has been achieved in the central region of the first and second material sheets.  
     
     
         39 . The apparatus of  claim 37 , further comprising at least one preload plunger having at least an electrode extending through an aperture of the first bonding plate mechanism, the electrode being operable to electrically connect to the first material sheet.  
     
     
         40 . The apparatus of  claim 39 , wherein the preload plunger is operable to bias against and move the first material sheet against the second material sheet in the central region thereof.  
     
     
         41 . The apparatus of  claim 40 , wherein the preload plunger is operable to provide a seed voltage to the first material sheet to induce bonding between the first and second material sheets in the central region thereof.  
     
     
         42 . An apparatus, comprising: 
 a first bonding plate mechanism operable to engage a material sheet, and to provide at least one of controlled heating, voltage, and cooling thereto;    a second bonding plate mechanism operable to engage an embossing tool having micro-structures thereon, and to provide at least one of controlled heating, voltage, and cooling thereto;    a pressure mechanism operatively coupled to the first and second bonding plate mechanisms and operable to urge the first and second bonding plate mechanisms toward one another to achieve controlled pressure of the embossing tool against the material sheet along respective surfaces thereof;    a control unit operable to produce control signals to the first and second bonding plate mechanisms and the pressure mechanism to provide a heating profile sufficient to cause the material sheet to flow into the micro-structures of the embossing tool.