Gorilla Glass

Gorilla Glass is a brand of chemically strengthened glass developed and manufactured by Corning Inc. Currently in its ninth generation, it is designed to be thin, light, and damage-resistant. Its surface strength and crack-resistance are achieved through immersion in a hot potassium-salt ion-exchange bath.[1]

The alkali-aluminosilicate sheet glass is primarily used as cover glass for portable electronic devices, including smartphones, smartwatches, portable media players, portable computer displays, and television screens.[2] It is manufactured in Harrodsburg, Kentucky; Asan, South Korea;[3] and Taiwan. As of October 2017, Gorilla Glass was used in approximately five billion devices worldwide.[4] Despite its market dominance, Gorilla Glass faces competition from similar products, including AGC Inc.'s Dragontrail, Schott AG's Xensation, and synthetic sapphire.[5][6]

Background and development

Corning experimented with chemically strengthened glass in 1960 as part of a "Project Muscle" initiative. Replacement of smaller sodium ions with larger potassium ones by a chemical treatment in order to improve the compressive strength of the surface layer of a glass was first developed by Steven Kistler in 1962.[8][9] Soon Corning researchers found that addition of aluminium and zirconium oxides improved the qualities even further.[10][9]

Within a few years they had developed a "muscled glass"[11] marketed as Chemcor. The product was used until the early 1990s in commercial and industrial applications, including automotive, aviation and pharmaceutical uses,[11]

Manufacture

During its manufacture, the glass is toughened by ion exchange. The material is immersed in a molten alkaline potassium salt at a temperature of approximately 400 °C, wherein smaller sodium ions in the glass are replaced by larger potassium ions from the salt bath. The larger ions occupy more volume and thereby create a surface layer of high residual compressive stress, giving the glass surface increased strength, the ability to contain flaws,[25] and overall crack-resistance,[26] making it resistant to damage from everyday use.[27]

Generations

Gorilla Glass, first used on the original iPhone upon its release in June 2007,[14] was formally unveiled in February 2008.[18] By 2010, the glass had been used in approximately 20% of mobile handsets worldwide, or about 200 million units.[28]

Gorilla Glass 2 was introduced in January 2012[29] 20% thinner than the original Gorilla Glass.[30] It was first used on the Samsung Galaxy S III.[31] In October 2012, Corning said that over one billion mobile devices used Gorilla Glass.[32]

Related products

Superfest is a chemically hardened glass also known as Ceverit and CV-Glas. It was developed in East Germany in the 1970s.

On October 26, 2011, Corning announced the commercial launch of Lotus Glass, designed for OLED and next-generation LC displays.[80] The intrinsic thermal consistency of Lotus Glass allows it to retain its shape and quality during high-temperature processing. Decreased compaction and variation during the crystallization and activation step further reduce stress and distortions to the substrate. This enables tighter design rules in advanced backplanes for higher resolution and faster response time.[81] According to Corning, Gorilla Glass is specifically a cover glass for the exterior of display devices while Lotus Glass is designed as a glass substrate to be used within liquid crystal display panels; a product could use both Gorilla Glass and Lotus Glass.[82]

On February 2, 2012, Corning and Samsung signed an agreement to establish a new equity venture for the manufacture of specialty glass substrates for the OLED device market in Korea, based on Lotus Glass.[83]

See also

• Overflow downdraw method
• Tempered glass
• Aluminium oxynitride

External links

• Lotus Glass product page at Corning