Chemically strengthened and textured glass housing member

An electronic device comprising:

• a processor;
• a display;
• and
• a housing comprising a chemically strengthened glass member, the chemically strengthened glass member comprising:
• an aluminosilicate glass substrate defining a first surface of the chemically strengthened glass member, the first surface having a first average surface roughness (Ra) below 1 micron;
• and
• a fused composite coating bonded to the aluminosilicate glass substrate and comprising:
• an amorphous glass matrix having a softening temperature that is lower than a softening temperature of the aluminosilicate glass substrate and a coefficient of thermal expansion that is greater than a coefficient of thermal expansion of the aluminosilicate glass substrate;
• and
• particles of a crystalline material having a softening temperature that is higher than the softening temperature of the amorphous glass matrix and a coefficient of thermal expansion that is less than the coefficient of thermal expansion of the amorphous glass matrix, the particles of the crystalline material dispersed in the amorphous glass matrix and protruding from a surface of the amorphous glass matrix, thereby defining a textured second surface of the chemically strengthened glass member, the textured second surface having a second average surface roughness (Ra) between 1 micron and 10 microns;
• a first ion-exchanged layer extending into the glass member and through the fused composite coating;
• and
• a second ion-exchanged layer extending into the glass member from the first surface.

A method comprising:

• providing an aluminosilicate glass substrate defining a first surface, the first surface having a first average surface roughness (Ra) below 1 micron;
• applying to a second surface of the aluminosilicate glass substrate a composite coating comprising:
• a glass frit having a softening temperature that is lower than a softening temperature of the aluminosilicate glass substrate and a coefficient of thermal expansion that is greater than a coefficient of thermal expansion of the aluminosilicate glass substrate;
• a crystalline material having a softening temperature that is higher than the softening temperature of an amorphous glass matrix formed by fusing the glass frit and having a coefficient of thermal expansion that is less than the coefficient of thermal expansion of the amorphous glass matrix;
• a solvent;
• and
• a resin;
• drying the composite coating to remove the solvent;
• heating the aluminosilicate glass substrate and the composite coating to fuse the glass frit, thereby producing a fused composite coating including the amorphous glass matrix, and to bond the fused composite coating to the aluminosilicate glass substrate and define a textured surface having an average surface roughness (Ra) between 1 micron and 10 microns and defined at least in part by the crystalline material protruding from a surface of the amorphous glass matrix, thereby forming a textured glass member;
• and
• chemically strengthening the textured glass member thereby producing:
• a first ion-exchanged layer extending into the textured glass member and through the fused composite coating;
• and
• a second ion-exchanged layer extending into the textured glass member from the first surface.