Apparatus for bonding an optical disk substrate

Abstract

A method and an apparatus for bonding optical disk substrates, includes placing a pair of optical disk substrates on a stage while securing a height difference at an upper face of the stage loading the substrates between an upper face at a side of a center of the substrates and an upper face at a side of an outer circumference of the substrates. The method and the apparatus also includes photosetting the adhesive layer on the stage by irradiating a setting light to the substrate pair, thereby photosetting the adhesive layer and bonding the substrates.

What is claimed is:  
     
         1 . A method for bonding optical disk substrates, comprising: 
 placing a pair of optical disk substrates on a stage while securing a height difference at an upper face of the stage loading the substrates between an upper face at a side of a center of the substrates and an upper face at a side of an outer circumference of the substrates; and    photosetting the adhesive layer on the stage by irradiating a setting light to the substrate pair, thereby photosetting the adhesive layer and bonding the substrates.    
     
     
         2 . A method for bonding optical disk substrates according to  claim 1 , wherein in the photosetting, warp deforimation caused when the substrate pair finishes photosetting operation is offset by deforming the substrate pair tracing the height difference at the upper face of the stage because of a weight of the substrate pair.  
     
     
         3 . A method for bonding optical disk substrates according to  claim 1 , wherein the height difference of the stage is realized by a step whereby the substrates are made higher at the center than at the outer circumference.  
     
     
         4 . A method for bonding optical disk substrates according to  claim 1 , wherein the height difference of the stage is realized by a taper whereby the substrates are lowered from the center to the outer circumference.  
     
     
         5 . A method for bonding optical disk substrates according to  claim 1 , further comprising: controlling temperature of at least a front surface side one of the substrates thereby reducing a temperature difference between both faces of the substrate pair when the adhesive layer is photoset.  
     
     
         6 . A method for bonding optical disk substrates according to  claim 1 , further comprising: uniforming a temperature distribution of the substrates in a plane direction through controlling of temperature of the substrates when the adhesive layer is photoset.  
     
     
         7 . A method for bonding optical disk substrates according to  claim 1 , wherein in the photosetting, the setting light is irradiated in a step of temporarily setting the adhesive layer with a less quantity of light than required for completely setting the adhesive layer and a succeeding step of practically setting the adhesive layer with the required quantity of light for completely setting the adhesive layer.  
     
     
         8 . A method for bonding optical disk substrates according to  claim 1 , further comprising: controlling a humidity of the substrate pair when the adhesive layer is photoset.  
     
     
         9 . An apparatus for bonding optical disk substrates, said apparatus comprising: 
 a stage having a front face on which a substrate pair comprising optical disk substrates in a pair with a photosetting adhesive layer located in between is placed when the photosetting adhesive layer is to be photoset, said stage being structured to secure a height difference between a center of the substrate pair and an outer circumference of the substrate pair so as to correct a warp deformation of the substrate pair by tracing the height difference at said front face of said stage due to a weight of the substrate pair; and    a light source operable to irradiate a setting light to the substrate pair, thereby to photoset the photosetting adhesive layer and to bond the pair of optical disk substrates,    wherein said front face is gradually tapered such that a center of said front face is higher than an outer circumference of said front face.    
     
     
         10 . An apparatus for bonding optical disk substrates according to  claim 9 , further comprising a spacer detachably disposed to said stage at a center of said front face and projecting from said front face of said stage.  
     
     
         11 . An apparatus for bonding optical disk substrates according to  claim 10 , wherein a projection amount of said spacer from said front face of said stage is adjustable.  
     
     
         12 . An apparatus for bonding optical disk substrates, said apparatus comprising: 
 a stage having a front face on which a substrate pair comprising optical disk substrates in a pair with a photosetting adhesive layer located in between is placed when the photosetting adhesive layer is to be photoset, said stage being structured to secure a height difference between a center of the substrate pair and an outer circumference of the substrate pair so as to correct a warp deformation of the substrate pair by tracing the height difference at said front face of said stage due to a weight of the substrate pair; and    a light source operable to irradiate a setting light to the substrate pair, thereby to photoset the photosetting adhesive layer and to bond the pair of optical disk substrates,    wherein said light source initially irradiates a lower quantity of the setting light then is required to completely set the photosetting adhesive layer, and then irradiates a required quantity of the setting light for completely setting the photosetting adhesive layer.    
     
     
         13 . An apparatus for bonding optical disk substrates according to  claim 12 , further comprising a shutter part located to be between the substrate pair and said light source, said shutter part being operable to control passage of the setting light so as to initially irradiate the lower quantity of the setting light than is required to completely set the photosetting adhesive layer, thereby temporarily setting the photosetting adhesive layer, and then irradiating the required quantity of setting light, thereby completely setting the photosetting adhesive layer.