Display device having a glass substrate and method of manufacture

Abstract

A display device includes a display module having a folding area and a non-folding area adjacent to the folding area. A glass substrate is disposed on the display module and comprises a first layer and a second layer disposed on the first layer. The second layer has a compressive strength that is higher than a compressive strength of the first layer. The first layer and the second layer of the glass substrate each include a folding portion overlapping the folding area and having a first thickness and a non-folding portion overlapping the non-folding area and having a second thickness greater than the first thickness. The second layer of the non-folding portion has a thickness that is greater than a thickness of the second layer of the folding portion.

What is claimed is: 
     
         1 . A method of manufacturing a display device, comprising:
 providing a base glass substrate comprising a first portion and a second portion disposed adjacent to the first portion and having a thickness that is greater than a thickness of the first portion;   performing a first chemical reinforcement process of the base glass substrate and a second chemical reinforcement process of the base glass substrate, the first chemical reinforcement process and the second chemical reinforcement process are performed in any order, wherein:   the first chemical reinforcement process comprises a chemical reinforcement of the second portion of the base glass substrate; and   the second chemical reinforcement process comprises a chemical reinforcement of both the first portion and the second portion of the base glass substrate.   
     
     
         2 . The method of  claim 1 , wherein the thickness of the second portion is in a range of about 40 micrometers to about 100 micrometers. 
     
     
         3 . The method of  claim 1 , wherein:
 the base glass substrate comprises a first alkali metal cation, and each of the first chemical reinforcement process and the second chemical reinforcement process comprises replacing the first alkali metal cation of the base glass substrate with a second alkali metal cation having an ionic radius that is greater than an ionic radius of the first alkali metal cation.   
     
     
         4 . The method of  claim 3 , wherein the replacing of the first alkali metal cation of the base glass substrate with a second alkali metal cation comprises:
 providing a solution in which the second alkali metal cation is dissolved to a surface of the base glass substrate, and   heating the solution in which the second alkali metal cation is dissolved at a temperature in a range of about 350° C. to about 500° C.   
     
     
         5 . The method of  claim 3 , wherein the second alkali metal cation comprises at least one cation selected from Na + , K + , Rb + , and Cs + . 
     
     
         6 . The method of  claim 1 , wherein the chemical reinforcement of the second portion in the first chemical reinforcement process comprises:
 covering the first portion with a heat resistant member;   providing an alkali metal cation to the second portion; and   removing the heat resistant member.   
     
     
         7 . The method of  claim 6 , wherein the heat resistant member is a heat resistant tape.