Silicone materials are polysiloxanes with a silicon-oxygen bond ( -Si-O-Si-) chemical structure as the backbone, which have excellent physical properties due to its methyl groups, such as good weather resistance, wide temperature range, water repellency, corrosion resistance, non-toxic and odorless, and physiological inertness, etc. They are widely used in the additive manufacturing process of touch screens. With the development of touch screens to flexible, curved and large size, the development and application of new silicone materials have increased.
But how silicone materials are used in touch screens？
The traditional touch screen can be structurally divided into 3 parts, from top to bottom are the protective glass, touch screen and LCD display. Silicone raw materials (silicone oil, silicone resins, silicone rubbers) can be used according to the different requirements of each layer and the corresponding performance improvements to provide the best solution for touchscreen products.
- Screen protection silicone material
- Silicone material for frame bonding
- Screen lamination silicone materials
- Thermal interface silicone materials
- Thermal Conductive Silicone Grease
- Thermal pads
- Thermally conductive silicone adhesive
- Thermal conductive mud
- Blue light-blocking silicone material
- XJY--First choice supplier of silicone materials for touchscreen
Screen protection silicone material
Screen protection silicone material is a kind of coating with a combination of active silyl groups and fluorine-modified organic groups. After coating on the screen, it forms a transparent film layer with a thickness of 10nm to 20nm, which has the characteristics of oleophobic and low friction coefficient of fluoropolymer, and the hydrophobic and weathering characteristics of siloxane.
The protective film layer has excellent anti-fouling, water and oil-repellent properties, reducing fingerprints and various stains adhesion, and improving the ability to wipe clean. The doping of nano-silicon dioxide in the silicone protective coating also improves the hardness and abrasion resistance of the material after film formation. In addition, the addition of titanium dioxide nanoparticles to silicone coatings by physical blending, where titanium dioxide nanoparticles photocatalyze the generation of strong free radicals, can be used to create a protective coating for cover material anti-pollution sterilization.
Silicone material for frame bonding
The low-solvent one-component moisture-curing silicone hot melt adhesive is mainly used in the frame bonding of touch screens, which can help designers achieve the concept and manufacturing goals of waterproof and narrow frames in the design of touch screen structures.
Silicone hot melt adhesive is a reactive material. When applied by heat, very thin glue lines up to 0.5 mm wide can be achieved by liquid silicone rubber glue application, which gives instant initial bond strength and cures quickly at room temperature, accelerating product assembly efficiency. When fully cured, silicone hot melt adhesives provide excellent adhesion to common plastic and metal substrates without the need for a primer.
Compared with reactive polyurethane hot-melt adhesives (PUR), silicone hot-melt adhesives can not only add ultraviolet light markers to the colloid, which is convenient for automatic ultraviolet light inspection of finished products, but also has a long operating time and can be reworked within 24 hours. It has the advantages of recoating, high-temperature resistance, non-toxic and tasteless and low volatile content. After the silicone hot melt adhesive is fully cured, it has excellent chemical resistance, water resistance and dust resistance, which improves the chemical stability of electronic products.
Silicone hot-melt adhesives VS OCA
When designing and assembling other innovative ideas for smart devices, silicone hot melt adhesives offer advantages over double-sided adhesive tapes (OCA) in terms of narrow bezel fit, high initial bond strength and strong post-cure bonding, and have been found to reduce overall costs by up to 20% in bezel bonding tests on 100 million 0. 8mm narrow bezel smartphone glass covers
Screen lamination silicone materials
The silicone liquid optically transparent water glue can completely stick on the panel and touchscreen together in a seamless full-fit manner, avoiding the air between the screens, which helps to reduce the reflection, dispersion, and scattering between the display panel and the glass. light loss and interference, so as to achieve the effect of low reflection display.
The production process of silicone liquid optically transparent water glue is simple, and the production process is environmentally friendly and non-toxic. It can be divided into two curing methods: low-temperature thermosetting and UV curing. Among them, low-temperature thermosetting does not require special packaging, transportation and curing equipment. It also solves the problem of light in the black edge area, simplifies the assembly process, and can achieve continuous production through drying tunnels, which is beneficial to reduce costs; silicone materials can adjust the viscosity of the product in a very wide range, and choose the corresponding viscosity according to the different viscosity. Advanced construction technology can well solve the problem of glue overflow and air bubbles in the production process.
After the touch screen is fully laminated with silicone liquid optically transparent water glue, the screen will no longer enter the dust; the close combination of the touch module and the panel can effectively reduce the interference caused by the noise of the display panel to the touch signal; the fully laminated module and the assembly with the whole machine can be directly fixed by means of snaps or locking screws, which reduces the assembly problems caused by the deviation of the fit. The cured silicone optical adhesive is extremely weather-resistant, it will not turn yellow even if it is exposed to light for a long time, and the volume shrinkage rate after curing is less than 0.2%, which solves the high-temperature yellowing and high rate of dimensional shrinkage problem of the acrylic optical transparent glue. Screens bonded with silicone liquid clear water glue have been tested to have 3 times the impact strength and 2 times the flexural strength of acrylics in a steel ball drop test, enabling thinner and more drop-resistant screens fuselage.
It is expected that with the investment of manufacturers in full lamination equipment technology, the reduction of material costs, the development of various technical paths and the improvement of full lamination yield, the future market space is large.
Thermal interface silicone materials
With the continuous improvement of the integration degree and assembly density of electronic components in the touch screen module, while the product can provide high function and high efficiency, the working power consumption and operating temperature of each component also increase sharply. Excessive temperature will have a detrimental effect on the reliability of electronic components and shorten the service life of electronic components. In order to ensure the long-term stable operation of electrical components, it is necessary to prevent the continuous rise of the working temperature, so timely and effective heat dissipation has become an urgent problem to be solved.
Silicone materials are one of the earliest and most widely used thermal interface materials, which are divided into four categories: thermal silicone resin, thermal adhesive, thermal pads and thermal elastomers according to the differences in material forms.
Among them, the thermal conductive silicone grease is mainly used in the heat dissipation of a single module with high heat generation in large-area devices such as central processing units (CPU), graphics processing units (GPU) and game control chips;
Thermal pads are mainly used for heat dissipation of non-coplanar multi-modules, and generally need to be clamped by an external force to reduce the thermal resistance of thermal interface contact.
- Thermally conductive silicone adhesive
Thermally conductive silicone adhesive is mainly used to solve the heat dissipation problem of small-area devices, which can be effectively fixed on the surface of chips and other surfaces, simplifying the assembly process. Silicone thermal elastomer is the most widely used high-performance elastomer of thermal interface material, there is almost no limit to the applicable area of the device, it can be cut according to the size very conveniently, is suitable for surface contact at relatively low contact pressure, can fully fill the gap between the surface of electronic components and the surface of the mounting part, form an efficient heat exchange channel, and at the same time, this highly resistant elastomer plays a role in damping and vibration damping of electronic equipment.
- Thermal conductive mud
In recent years, a new type of silicone thermal interface material has also emerged, thermal conductive mud, whose physical form is semi-solid silicone rubber, similar to plasticine. Its characteristics are mainly three aspects: First, it breaks through the limitation of the coating thickness of thermal grease, even if it is coated very thickly, it will not flow or leak; Second, it breaks through the compression limit of the thermal pad, and its compression rate can be almost close to 100%; Third, the requirements of rework and repair can be easily realized. It can not only be used as a next-generation material for thermal pads on large-area high-power devices, so that thermal pads can completely bid farewell to the bottleneck of compression ratio, but also play the role of planar heat sinks on medium-area devices, which is a versatile new heat dissipation material.
Blue light-blocking silicone material
The white light effect of the touch screen is generally in the mode of blue LED excitation yellow phosphor, so this white light in the blue spectrum has a wave peak, thus creating the problem of blue light injury to the eyes, that is, the relatively strong penetrating blue light will cause the atrophy of the retinal pigment epithelium, which leads to the death of photosensitive cells, bringing great harm to the eyes.
Software blue light filtering was the original means of eye protection, requiring users to manually turn on the blue light shielding function and set the level of the shielding function, which is prone to color shift. 2014 saw the introduction of hardware blue light filtering, which optimizes the wavelength of blue light in the white backlight from 444nm to 460nm by means of display glass coating, removing 90% of the eye-damaging short-wave blue light. This method solves the problem of warm colors in traditional displays when the eye protection function is turned on, but the coating process is complex and costly, and is not yet widely used.
By modifying the silicone encapsulation material in the backlight of the display or the silicone liquid transparent glue in the full lamination, a new type of silicone LED encapsulation material or silicone liquid transparent glue with blue light blocking function can be prepared by adding functional additives of a specific structure. The silicone LED packaging materials can be used directly in the packaging process of the backlight to optimize the spectrum of light emitted by the chip and to achieve blue light rejection. The silicone liquid transparent adhesive is laminated to the touch screen and absorbs blue light at wavelengths between 380nm and 450nm, converts it into energy, releases the energy as heat or at longer wavelengths that are harmless, and quickly returns the blue light excited free radicals to a stable ground state, thus achieving selective shielding of the blue light emitted by the backlight. Both methods are simple and easy to implement without additional processes, and are the most cost-effective and promising ways to achieve blue light shielding.
XJY--First choice supplier of silicone materials for touchscreen
|XJY Silicones, one of China's leading silicone material manufacturers, has 30+ years of R&D and manufacturing experience and 15+ related patents in the silicone industry, also can customize the products according to your silicone requirements.