What are the bonding technologies for industrial touch screens

What are the bonding technologies for industrial touch screens?

With the development of LCD touch technology, industrial control touch screens are increasingly being applied in the industrial field. Currently, the main industrial touch screens on the market are capacitive touch screens and resistive touch screens. So, how is the touch panel fixed on the LCD screen? This involves a concept, industrial touch screen bonding technology.
We usually divide LCD touch screens into three components, from top to bottom: glass cover, touch panel, and LCD screen. After these three parts are bonded together using bonding technology, a complete industrial touch screen is formed. Industrial touch screen bonding technology is divided into three types: full bonding technology, frame bonding technology, and 0-bonding technology.

Industrial touch screen bonding technology

1、 Full lamination technology for industrial touch screens

Full bonding technology: a bonding process in which the LCD screen and touch panel are seamlessly bonded together using water glue or optical glue. OCA glue and LOCA water-based glue are usually used.

OCA adhesive is mainly suitable for bonding small-sized LCD products, but the bonding cost is high, and after a long screen time, yellowing may occur, and bubbles are easily generated at ink level differences. The advantages lie in high production efficiency, uniform thickness, no glue overflow problem, controllable bonding area, no corrosion problem, and simple maintenance.

LOCA water-based adhesive is mainly suitable for bonding large-sized LCD products, curved surfaces, or more complex structures. The cost is lower than OCA adhesive. The advantage lies in the ability to bond curved or uneven surface materials, insensitivity to ink thickness, easy rework, and relatively low cost.

Overall, the main disadvantages of full lamination are complex process, low production yield, and high equipment investment cost.

2、 Frame pasting technology for industrial touch screens

Frame bonding technology: The most widely used bonding technology on the market, which uses double-sided tape to fix the touch panel (TP) to the four sides of the LCD screen. Due to its low cost and simple process, it is favored by small and medium-sized LCD screen manufacturers. The disadvantage is that there is an air layer between the LCD screen and the touch panel, resulting in unsatisfactory display performance.

3、 Zero paste technology for industrial touch screens

0-bonding technology: Its bonding method is between full bonding and frame bonding, mainly filling a non adhesive transparent medium with a refractive index equivalent to glass between the touch panel and the LCD screen. On the one hand, there is no gap between the TP and the LCD screen, which improves the display effect. On the other hand, because it has no stickiness, assembly and maintenance are very simple, and the overall cost is relatively low.