Methods and apparatuses for roll-on coating

Abstract

Coating rollers accepting liquid media provide liquid chemicals to substrates for depositing a thin coating layer on the flat substrates, such as semiconductors or panels. The liquid media is cooled to a life-preserving temperature while shielded from the thermal energy heating the substrates to prevent degrading the liquid media. Physical barrier or temperature barrier can be established in vicinities of the rollers to further limit exposing the liquid media to high temperature.

What is claimed is: 
     
         1 . A method comprising:
 providing a liquid in a liquid container;   heat a first portion of the liquid to generate a temperature difference with a second portion of the liquid;   transferring a liquid from the first portion to at least one roller, wherein the at least one roller is configured to form a liquid coating on a substrate.   
     
     
         2 . A method as in  claim 1  further comprising
 cooling the second portion of the liquid to a temperature below room temperature. 
 
     
     
         3 . A method as in  claim 1  further comprising
 restricting a liquid flow between the first and second portions. 
 
     
     
         4 . A method as in  claim 1  further comprising
 stirring the liquid in the second portion to equalize the temperature. 
 
     
     
         5 . A method as in  claim 1  further comprising
 heating the substrate using a heating source, 
 shielding the liquid container from the heating source. 
 
     
     
         6 . A method as in  claim 1   wherein the at least one coating roller comprises a porous layer for accepting and retaining the liquid to transfer to the substrate by rollingly contact.   
     
     
         7 . A method as in  claim 1   wherein heating a first portion comprises disposing and heating a barrier in the liquid container.   
     
     
         8 . A method as in  claim 7  further comprising
 cooling a side of the barrier opposite the heating side. 
 
     
     
         9 . A method as in  claim 1   wherein the liquid comprises a chemical having a degradation characteristic when exposed to temperature above room temperature.   
     
     
         10 . A method comprising:
 cooling a liquid in a liquid container;   transferring the liquid to at least one roller, wherein the at least one roller is configured to form a liquid coating on a substrate;   locally heating the liquid at a vicinity of the at least one roller.   
     
     
         11 . A method as in  claim 10  further comprising
 restricting a liquid flow between the heating portion and the cooling portion of the liquid. 
 
     
     
         12 . A method as in  claim 10   wherein the at least one coating roller comprises a porous layer for accepting and retaining the liquid to transfer to the substrate by rollingly contact.   
     
     
         13 . A method as in  claim 10   wherein locally heating the liquid comprises disposing and heating a barrier in the liquid container.   
     
     
         14 . A method as in  claim 13  further comprising
 cooling a side of the barrier opposite the heating side. 
 
     
     
         15 . A method comprising:
 providing at least one roller, wherein the at least one roller is configured to form a liquid coating on a substrate;   positioning the at least one roller for contacting a liquid in a liquid container;   isolating an area at a vicinity of a contact area between the at least one roller and the liquid;   heating the liquid inside the isolated area to a temperature at or above room temperature to generate a temperature difference with the liquid outside the isolated area.   
     
     
         16 . A method as in  claim 15  further comprising
 cooling the liquid outside the isolated area to a temperature below room temperature. 
 
     
     
         17 . A method as in  claim 15  further comprising
 restricting liquid flow across the isolated area. 
 
     
     
         18 . A method as in  claim 15   wherein isolating an area comprises disposing a barrier in the liquid container.   
     
     
         19 . A method as in  claim 15   wherein heating the liquid comprises heating the barrier.   
     
     
         20 . A method as in  claim 19  further comprising
 cooling a second side of the barrier opposite the first side.