As a TP bonding manufacturer, Shenzhen PowerDe Automation Precision Technology Co., Ltd. will conduct an in-depth analysis of full bonding technology below! As is well known, touch panels are lighter and thinner. Touch panel manufacturers not only focus on the layer between the display panel and the glass protective layer, but also provide various stacking methods and technologies for mobile phone and tablet manufacturers to use, such as various embedded touch solutions (such as On cell, In cell, etc.), introducing new ITO replacement materials, and striving for breakthroughs in bonding technology.
The demand for thin and fully laminated touch panels has emerged:
In terms of bonding technology, there are two commonly used methods in the industry: "mouth glue bonding" and "full plane bonding".
Kouzi adhesive bonding (also known as "frame bonding", edge lamination, air bonding, air gap, etc.) is the process of using double-sided tape to firmly attach the four sides of the Touch Sensor Panel (TSP) and the Cover Lens layer. The advantages are easy operation, low cost, and low technical threshold. However, the disadvantage is that only four sides are attached, creating an air gap in the middle. After being refracted by light, it will produce overlapping images, resulting in slightly poor visual presentation and making it difficult to attract the interest of mobile phone/tablet manufacturers.
Full plane bonding (also known as "surface bonding," "full lamination," "direct bonding," "optical bonding," or "non airgap") is the use of OCA (Optically Clear Adhesive) or OCR (Optically Clear Resin) to achieve complete bonding between the touch panel and the glass protective layer. Due to the complete sealing of the two layers without any gaps or air layers, the backlight of the display panel can penetrate the glass surface smoothly without the overlapping caused by light refraction, presenting high brightness and high quality, while also reducing the overall thickness.
In addition, there are many benefits, such as the screen not getting dusty, the touch module being tightly integrated with the panel to increase strength, and effectively reducing the interference of noise generated by the display panel on touch signals. Full plane bonding, with the advantages mentioned above, has become the best bonding solution for mainstream and high-end mobile/tablet products in the past two years.
Analysis of full lamination technology: yield is the biggest key
Although full lamination technology has better display effects, its coating materials and processing costs are relatively high. Compared to the overall cost of adhesive bonding, there is a price difference of about 15% to 20% between the two.
In terms of yield, full bonding technology is obviously not as high as mouth glue bonding, and the larger the bonding area, the lower the yield. With the increasing size of smartphone screens nowadays, touch module manufacturers must purchase high-precision bonding equipment to effectively increase yield and gross profit. Because during the bonding process, any bonding defects, OCR glue infiltration into the panel, or uneven UV curing will result in the inability to rework and render the entire panel unusable.
In terms of bonding materials, there are currently two types of adhesives, OCR and OCA, both of which are adopted by industry players. The factors that determine the production yield depend on the bonding technology of each industry and the efficiency of the bonding machines they purchase. It is necessary to achieve stable adhesive properties, high bonding accuracy, symmetry, and no bubbles. The touch panel and protective glass must be seamlessly attached in order to be considered good products.
The above is an introduction to the in-depth analysis of full lamination technology by TP lamination manufacturers. Baode Precision is a solution provider and equipment integrator that focuses on vacuum technology and covers manufacturing equipment for display touch series, hydrogen fuel cells, thin-film solar energy, solar photovoltaics, semiconductor series, and factory automation series.
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