Future mobile terminals, wearable devices, smart home appliances and other products have a strong demand for touch panels, while large and small, DiJiaHua, touch panels and traditional ITO films cannot be used in flexible applications, electrical conductivity and light transmission The rate is not easy to overcome, as natural, panel manufacturers began to replace ITO, including silver nanowires, metal mesh, such as carbon nanotubes and graphene materials. The rise of thin film panels will also be traced.
The new material technology can be extended from the general panel size of smart phones to 20-inch or more devices with better resistance, extension, and bending than ITO films. However, the new material technology cannot completely replace the ITO film in a short period of time, but the new material technology has enormous advantages. From the perspective of market reaction, the share of application of film new material technology has increased year by year. At present, graphene is in the research and development stage, far away from mass production. The industrial production technology of carbon nanotubes is not yet perfect, and its electrical conductivity cannot reach the level of normal ITO membranes. Therefore, from the comprehensive evaluation of technology development and market application, the metal mesh and nano silver wire technology will become the two main features of the recent emerging touch technology.
Metal mesh (metal mesh) technology uses silver, copper and other metal materials or oxides to easily obtain and inexpensive raw materials, such as PET plastic film formed by pressing a conductive metal grid. The theory's minimum resistance can reach 0.1 ohm/square inch, with good electromagnetic interference shielding effect. However, due to the limitation of the printing technology level, the touch sensor adopts a relatively thick metal line width, which is usually larger than 5 um. In the case of high pixels (usually greater than 200 ppi), the interference of the Moiré-Moore is very obvious. Murray interference refers to the pixel on the digital product display, the metal pattern of the aperture and the touch hole knife. In the horizontal and vertical directions, the pixel alignment rules and the detailed rules of the object pattern are superimposed with a small deviation. The interference moire pattern will appear. Due to Murray's interference, the metal grid technology of thin-film products is not suitable for high-resolution smart phones. The high resolution of the flat panel is only used to observe the display screens, such as desktops, laptops, and smart TVs.
If the width of the metal grid graphic in the movie can be greatly reduced, the Murray interference problem of the metal grid technology can be effectively reduced. In particular, the line width of the metal grid graphic is reduced to about um. This movie can also be performed by technology. High resolution smart device. At present, South Korea's Samsung Company uses a fine line width and pattern (pattern) technology to reduce the line width of metal mesh from 5um to 6um to 3um. However, it is not easy to cut lines widely. The traditional press printing process cannot meet the requirements. Yellow process technology is needed. The production cost will increase significantly, but raw materials will also be wasted. When the external force is pressed, the thickness of the wire is easily broken. The resistance of the grid increases, and the sensitivity of the downstream control chip is higher. Therefore, how to reduce the cost of metal mesh technology is to solve the problem of downstream applications in multiple scenarios. The entire industry chain needs further development and improvement.
Nanosilver wire (SNW, silver nanowire) technology is the use of nanosilver ink materials in plastic or glass substrates, and then using laser lithography technology, using nanowires to produce nanoscale features, transparent conductive film conductive network design. Because of its special physical mechanism, the line width of nano silver wire diameter is very small, about 50 nm, much smaller than 1 um, so Murray has no interference problem and can be used on various sizes of display screens. In addition, due to the small line width, compared with the metal mesh technology, silver wire technology made of conductive film can achieve high light transmittance of the film. For example, 3 m companies can use micro-printing machine to make film products, which can reach 89% The light transmittance. Thirdly, the nano-silver film has a smaller bending radius and less bending resistance than the metal mesh film, and has greater advantages in surface applications of display devices, such as smart watches and bracelets.
In the film, the total area of the metal lines that can reflect visible light is not large. However, the nanowires are not grid-like but are distributed in an irregular pattern covering the entire surface of the glass substrate. In contrast, the reflection of the nanowire film is more scattered, which is haze. The hazy problem on the screen causes the screen to glow strongly under the light, allowing the user to see the screen in a serious way. However, some techniques can be used to reduce the spread of light and solve the problem of fog. For example, Nissan Chemical Co., Ltd. has developed a high refractive index material that can be used to reduce the haze on nanosilver wire films and effectively reduce haze. In addition, the surface of the black nanosilver wire reduces the intensity of the reflection, and the surface of the nanosilver wire and other techniques can effectively increase the haze.
Metal grid technology, due to the use of common silver, copper and other metal materials or oxidation and other raw materials, the traditional legal system of thin film panel printing pressure, its raw materials and production costs are low, but the product has not overcome Murray's interference, the application is limited . If you want to reduce the metal line width in the metal mesh, you need to change the technology to make it, the cost will increase, and there will be easy breakage and other problems. Compared with metal mesh technology, nano-silver steel wire technology is used to form nano-silver inks. Silver nano-wire materials are supplied to a small number of people in Cambrios Technologies. For example, the cost of raw materials is high, but the manufacturing process is simple and the printing process is fast. In the production area, the overall cost is not high. With large-scale production, the cost will be further reduced.
Therefore, nanowire technology has advantages over metal meshes. In the current market, there are two major technology camps. Silver Nanoline camp, Taiwan's panel supplier TPK nanosilver technology provider, the company is the flagship, combined with upstream suppliers of silver nanowire materials Cambrios Technologies, photo and production technology companies, Japan set up a subsidiary to focus on expanding nanotechnology Silver technology R&D, application and manufacturing. TPK is expected to make nanowire film production in the second quarter of 2014.
The metal mesh technology camp has a large number of companies, such as sudwiig and eufil, as well as Korea's Samsung. These companies are involved in R&D and manufacturing. However, compared with the metal grid camp, all companies in the nanowire camp are leading companies. They have strong business expertise and are closely linked with the middle and lower layers of the industry chain.
Hangzhou Kaike Electronics Co., Ltd.
Address: No. 2. Dadi Road, Haining Agricultural External Development Zone 314408,
Contact Person: May Wong
Telephone: 86-571-86830690 Fax: 86-571-86687367
Cell Phone: 86-15158112598