Method for separating multiple layers of materials attached with OCA (Optically Clear Adhesive) through laser

Abstract

The invention provides a method for separating multiple layers of materials attached with OCA (Optically Clear Adhesive) through laser. The method is characterized in that the OCA in layer clearances of the attached material layers is radiated through oil conduction laser, so that the OCA is molten, and therefore the attached material layers are separated; the oil conduction laser is formed by coupling laser beams into oil beams, and the oil beams are oil jet flows; and the method is applicable to separation of a liquid crystal screen and a touch screen which are attached with the OCA. Compared with a diamond wire or liquid nitrogen cooling separation technology in the prior art, the oil conduction laser processing technology is advantaged in that high-efficient undamaged separation of an inner screen and an outer screen can be realized; a heat affected zone and an OCA secondary solidification phenomenon can be obviously reduced; a focusing problem does not need to be considered during oil conduction laser processing; the effective lengths of oil beam optical fibers formed by jetted oil can reach a few or more than ten millimeters; and adhesive residues formed after melting of the OCA can be effectively carried away by scouring of the oil jet flows.

Description

technical field [0001] The invention belongs to the field of laser application technology, and relates to a method for separating multi-layer materials bonded by OCA optical glue by laser, in particular to a method for separating material layers by irradiating OCA optical glue between different material layers with oil-guided laser. Background technique [0002] OCA (Optically Clear Adhesive) optical adhesive is a special adhesive used to bond transparent optical components. It is usually a double-sided adhesive tape without a matrix material and is one of the important raw materials for touch screens. [0003] At present, the penetration rate of smart phones (including mobile display devices such as smart phones and tablet computers) has exceeded 95%. In the production process of the display screen used in smart phones, the LCD screen (inner screen) and the touch screen (outer screen) need to be passed through OCA optical glue. When they are bonded together, problems such a...

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Problems solved by technology

[0003] At present, the penetration rate of smart phones (including mobile display devices such as smart phones and tablet computers) has exceeded 95%. In the production process of the display screen used in smart phones, the LCD screen (inner screen) and the touch screen (outer screen) need to be passed through OCA optical glue. Fitting together, problems such as bubbles, wrinkles, and rings are likely to occur during the bonding process, resulting in a decrease in the yield rate

In order to rework to reproduce defective products, it is necessary to separate the bonded LCD screen from the touch screen. The commonly used separation methods include diamond wire separation method and liquid nitrogen cooling separation method, among which: diamond wire separation is to heat the LCD screen and touch screen first. After reaching a certain temperature, use diamond wire to straighten and pull from one end to the other along the gap between the inner and outer screens to separate the inner and outer screens. The heating temperature of this separation method is uncontrollable, and it is easy to cause secondary solidification, and it is easy to scratch the LCD screen, resulting in defective products. The efficiency is high, but the efficiency is poor; the liquid nitrogen separation method uses liquid nitrogen as the refrigerant to cool the OCA optical glue to the characteristic temperature where the glue fails to separate the inner and outer screens. The liquid nitrogen cooling and cooling process of the separation method is slow, and the controllability is not high. And it is easy to cause mis-separation of other components

[0004] At present, laser processing technology has been widely used. However, due to the large amount of slag generated in the conventional laser processing process, and the heat-affected zone and micro-fission will be generated in the laser-irradiated area of ​​the workpiece, the laser is used in hard materials and Applications in fields such as thin slice precision micromachining are limited

[0005] In view of the many defects of the traditional OCA optical glue separation technology, and the conventional laser processing technology is difficult to apply to the separation of display screens, it is urgent to develop a new OCA optical glue separation technology using laser

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