Black technology inside the glass! Development status and technical achievements analysis of ultra-thin glass

With the continuous development of the display industry, electronic glass processing technology has also been updated and advanced. In the coming years, the overall market for electronic glass processing products will show a stable and developing trend. Ultra thin electronic glass, as one of the display panel raw materials for electronic products such as smartphones, televisions, and computers, has a huge market demand in China and is showing an increasing trend year by year.

The thickness of ultra-thin glass can reach 2mm or less, even thinner than hair strands. Ultra thin glass has the advantages of lightweight, good weather resistance and thermal stability, high flexibility, and is widely used in many industries such as automobiles, electrical and electronic, biotechnology, renewable energy, and construction.

Institutional analysis is based on the thickness of ultra-thin glass, with products in the 0.5-1.0 mm thickness range occupying market share. The market size of ultra-thin glass in most countries is expected to reach 20.7998 billion US dollars in 2024, with a compound annual growth rate of 11.88%. Touch screens are the main application area.

The traditional market for ultra-thin electronic glass processing products mainly refers to existing markets such as smartphones, smart TVs, and computers. Smartphones include a variety of electronic glass processing products, including substrate glass, colored filter glass, ITO conductive glass, light guide plate glass, and front and rear cover glass of mobile phones. They are one of the important application areas of electronic glass. The large-scale, intelligent, and high-definition development of smartphones, especially in 5G communication, has brought huge market demand for electronic glass processing.

The problems existing in ultra-thin electronic glass processing products mainly include two aspects: market problems brought about by new display technologies; Equipment raw materials and technical issues applied during the processing. Although TFT-LCD has remained the mainstream display technology in the past 5 years, OLED display technology, as an emerging technology market, is growing rapidly, with market share increasing from 4.0% in 2018 to 13.8% in 2023.

Another issue with ultra-thin electronic glass processing products is the use of equipment, raw materials, and technical issues during the processing. Our country can already produce various screens, which cannot be separated from the progress of electronic glass processing technology. However, the core equipment and some core raw materials used in the electronic glass processing process need to be imported, which is not conducive to current and future development, and will seriously hinder the development of electronic glass processing technology and the expansion of corresponding product markets.

Classification of ultra-thin glass

According to different chemical compositions, ultra-thin glass can be divided into alkali containing ultra-thin glass and alkali free ultra-thin glass.

Alkali containing ultra-thin glass refers to ultra-thin glass containing alkali metal oxides in its chemical composition, namely sodium calcium silicate glass or aluminum silicate glass. Alkali free ultra-thin glass usually refers to hard borate glass, which contains B2O3 in its glass composition and has advantages such as high transmittance and good photoelectric performance.

Processing technology of ultra-thin glass

Ultra thin electronic glass processing refers to the use of flat electronic glass raw materials, modern scientific and technological methods such as physical and chemical methods and their combinations, to reprocess glass into glass products with new structures, functions or forms, improve the technical content and added value of glass products, and expand the application fields of glass materials.

The preparation methods for ultra-thin glass wafers mainly include float method, overflow pull-down method, and vertical pull-up method.

1. The cutting and processing of ultra-thin electronic glass mainly includes two parts: first, the cutting of the original glass sheet; The second is the cutting of processed electronic glass.

At present, there are two main cutting methods for ultra-thin electronic glass: traditional hard alloy or diamond wheel cutting, and emerging laser cutting.

2. When ultra-thin electronic glass is used as protective screen glass, it needs to have high impact strength and wear resistance. However, the glass is a brittle material with defects such as Griffith cracks on the surface, and it is prone to fracture when subjected to small external stresses. Strengthening is needed to improve the strength and wear resistance of the glass.

Chemical strengthening is the process of placing glass in a molten alkali salt to exchange small ions on the surface of the glass with large ions in the molten salt. Due to the change in volume after exchange, compressive stress is formed on the surface of the glass, while tensile stress is formed internally, thereby improving the strength of the glass.

3. Glass coating refers to the process of coating one or more layers of metal, metal compounds, or other substances on the surface of glass. The coating technology of glass can be divided into chemical vapor deposition method, physical vapor deposition method and sol gel method according to the production method. Among them, the magnetron sputtering method in the physical vapor deposition method is widely used as the coating method of ultra-thin electronic glass because of its advantages of high film forming rate, low coating temperature, good film adhesion, and large-area coating.

Hot bending process is the process of heating and softening flat glass in a mold, and then annealing it to produce curved glass (also known as 3D glass). The process includes heating, forming, annealing, cooling, etc.

Domestic ultra-thin products

Luobo Group launched 0.5mm glass products in 2009, and every year thereafter, Luobo launched ultra-thin glass products. In 2015, it developed innovative 0.28mm and 0.25mm glass products; After launching 0.3mm ultra-thin products in 2014, Bengbu Institute also launched 0.2mm glass products in 2015; Dongxu Group successfully produced glass products with a thickness of 0.4mm in 2014, and is currently conducting research to produce ultra-thin products with thinner thickness. In 2018, China National Building Materials Group's subsidiary Bengbu Zhongcai made 0.12mm ultra-thin electronic touch glass.