Strengthened glass articles formed from a glass composition comprising less than 1.0 mol % R.sub.2O, where R is an alkali ion, are disclosed. In various embodiments, the glass articles have a dielectric constant of less than 6.25 and a dielectric loss tangent of less than 0.01 at 30 GHz. Electronic devices, such as consumer electronic products, including the strengthened glass articles, as well as methods of making the strengthened glass articles are also disclosed.

Methods for strengthening edges of a laminated glass article comprising a glass core layer positioned between a first glass clad layer and a second glass clad layer are disclosed. The methods may comprise polishing the cut edges of the laminated glass article with a slurry of polishing media applied to the edges of the laminated glass article with brushes. An edge strength of the laminated glass article is greater than or equal to about 400 MPa after polishing.

A glass substrate for a high-frequency device, which contains SiO.sub.2 as a main component, the glass substrate having a total content of alkali metal oxides in the range of 0.001-5% in terms of mole percent on the basis of oxides, the alkali metal oxides having a molar ratio represented by Na.sub.2O/(Na.sub.2O+K.sub.2O) in the range of 0.01-0.99, and the glass substrate having a total content of alkaline earth metal oxides in the range of 0.1-13% in terms of mole percent on the basis of oxides, wherein at least one main surface of the glass substrate has a surface roughness of 1.5 nm or less in terms of arithmetic average roughness Ra, and the glass substrate has a dielectric dissipation factor at 35 GHz of 0.007 or less.

A system includes an overflow distributor (200) including a weir (245, 247). The system further includes a thermal exchange unit positioned in proximity to the weir. The thermal exchange unit (300) includes a tubular focusing member (310) and a thermal member (330) disposed at least partially within a lumen of the focusing member. The focusing member extends distally beyond a distal end of the thermal member by a distance It. In an embodiment the thermal exchange unit comprises several focusing members and thermal members to control a thermal profile of a glass stream flowing over the weir, particularly of a portion of the glass stream in contact with the weir.

A system includes an overflow distributor (200) including a weir (245, 247). The system further includes a thermal exchange unit positioned in proximity to the weir. The thermal exchange unit (300) includes a tubular focusing member (310) and a thermal member (330) disposed at least partially within a lumen of the focusing member. The focusing member extends distally beyond a distal end of the thermal member by a distance It. In an embodiment the thermal exchange unit comprises several focusing members and thermal members to control a thermal profile of a glass stream flowing over the weir, particularly of a portion of the glass stream in contact with the weir.

Scratch and damage resistant laminated glass articles are disclosed. According to one aspect, a laminated glass article may include a glass core layer formed from core glass composition and includes a core glass elastic modulus E.sub.C and at least one glass clad layer fused directly to the glass core layer. The at least one glass clad layer may be formed from an ion exchangeable clad glass composition different than the core glass composition and includes a clad glass elastic modulus E.sub.CL. The laminated glass article may have a total thickness T and the at least one glass clad layer may have a thickness T.sub.CL that is greater than or equal to 30% of the total thickness T. E.sub.C may be at least 5% greater than E.sub.CL.

A process for forming glass planar waveguide structure includes producing or obtaining a fusion drawn glass laminate (10) comprising a core glass layer (10) and a first clad glass layer (14) and a second clad glass layer (16) then removing or thinning portions of at least the second glass clad layer (16) leaving remaining or thicker portions of the second glass clad layer (16), the remaining or thicker portions corresponding to a planar waveguide pattern and resulting in a glass planar waveguide structure.

Apparatuses for making a laminated glass ribbon may include an upper forming body including an outer forming surface bounded by a pair of upper dams, and a lower forming body disposed downstream of the upper forming body and including an outer forming surface spaced from the outer forming surface of the upper forming body by an interior gap. An edge guide may be disposed along an interior upper dam wall and spaced apart in the interior gap from the lower forming body. Surfaces exterior to the outer forming surfaces of the upper and lower forming bodies may abut and be joined. A formed glass ribbon having a core glass layer and a pair of clad glass layers may include inner and outer portions that have substantially equal thickness ratios based on a glass core layer thickness compared to a combined glass cladding layer thickness in each portion.

Apparatuses for making a laminated glass ribbon may include an upper forming body including an outer forming surface bounded by a pair of upper dams, and a lower forming body disposed downstream of the upper forming body and including an outer forming surface spaced from the outer forming surface of the upper forming body by an interior gap. An edge guide may be disposed along an interior upper dam wall and spaced apart in the interior gap from the lower forming body. Surfaces exterior to the outer forming surfaces of the upper and lower forming bodies may abut and be joined. A formed glass ribbon having a core glass layer and a pair of clad glass layers may include inner and outer portions that have substantially equal thickness ratios based on a glass core layer thickness compared to a combined glass cladding layer thickness in each portion.

Methods of manufacturing a glass ribbon include moving a ribbon of glass-forming material along a travel path in a travel direction. Methods include sensing a thickness of the ribbon of glass-forming material at a plurality of locations of the ribbon of glass-forming material. Methods include identifying a location of the plurality of locations in which a corresponding thickness at the location exceeds a target thickness. Methods include correlating a rate of thickness change and a thickness difference between the corresponding thickness and the target thickness to a laser power. Methods include directing a laser beam at the laser power toward the ribbon of glass-forming material to decrease a viscosity at the location and attain the target thickness at the location.