Production technology of mobile phone explosion-proof film

Abstract

A production technology of a mobile phone explosion-proof film relates to the technical field of 3C product accessories. The production technology comprises the following steps: 2, laminating: laminating a transparent film to the lower surface of a glass cover plate through a transparent optical pressure-sensitive adhesive to obtain an assembly, forming a recess between the outer edge of the filmand the inner edge of the arc-shaped part of the glass cover plate, and overlapping the periphery of the film to a black ink layer silk-screened on the lower surface of the glass cover plate; 2, injecting a polyurethane foam sealing agent: injecting the polyurethane foam sealing agent into the recess of the assembly; 3, performing in-mold foaming: placing the assembly with the recess injected withthe polyurethane foam sealing agent in a foaming mold, and completing foaming of the polyurethane foam sealing agent in the mold to form a foamed buffer cushion in the recess; and 4, demolding and post-treating: taking out the foamed assembly from the foaming mold, spraying an oil stain-resistant coating layer on the upper surface of the glass cover plate, and coating the lower surface of the film and the foamed buffer cushion with an AB adhesive to obtain the mobile phone explosion-proof film. The mobile phone explosion-proof film having a high adhesion and being a full-glass contact surfaceis produced through the technology, and has a high yield.

Description

technical field [0001] The invention relates to the technical field of 3C product accessories, in particular to a production process of explosion-proof film for mobile phones. Background technique [0002] Most of the early explosion-proof films for external screens were made of PET or PC film. Due to the poor wear resistance of plastic materials (even if the surface is hardened, the wear resistance is still not ideal), it is prone to scratches and has basically been eliminated. Tempered glass has relatively better scratch and wear resistance. Currently, the use of tempered glass to make explosion-proof membranes has become the mainstream process direction in the market. [0003] The production process of tempered glass explosion-proof film is mainly divided into three stages. The first stage is to use a pure flat glass substrate to directly cut it into the required size, then CNC opens the earpiece hole and the sensor hole, and then sends it to the tempering furnace for st...

AI Technical Summary

Problems solved by technology

The first stage is to use a pure flat glass substrate to directly cut it into the required size, then CNC opens the earpiece hole and the sensor hole, and then sends it to the tempering furnace for strengthening treatment. The explosion-proof film produced by this process is a whole Since most of the outer screens of current smart phones use 2.5D curved glass (that is, there are rounded corners around the edge of the glass), the pure flat explosion-proof film cannot cover the curved and rounded parts of the outer screen (that is, explosion-proof The film cannot fully cover the touch screen), and the overall visual effect will be affected after the film is applied, which has become a low-end product (the price is about 10 yuan / piece)

The second stage is to process the cut flat glass around it by hot bending to fit the rounded corners around the touch screen of the mobile phone (that is, the so-called 2.5D curved full glass explosion-proof film in the industry). The explosion-proof film produced by this process has the following defects in actual use: 1. Since the arc-shaped rounded corners around the smartphone are only to ensure the comfort of the grip, the brand allows the foundry to have a large manufacturing error, which leads to market The rounded corners of mobile phones of the same model sold on the Internet are not all the same, so we often encounter the same explosion-proof film. This mobile phone can fit perfectly, but another mobile phone with the same model can not fit completely. Happening

2. In the same mobile phone, the rounded corners on the four sides of the outer screen are not exactly the same. It is also a common situation that the rounded corners of one side cannot be completely fitted

3. The manufacturing error of the explosion-proof film itself (such as the manufacturing error of the glass during hot bending and the change in the curvature of the arc part caused by the tempering process in the furnace) is superimposed on the manufacturing error of the outer screen of the mobile phone, which further leads to the explosion-proof film. Poor fit of curved and rounded corners

In order to solve the problem that the plastic frame is not wear-resistant and splicing white lines, some manufacturers of explosion-proof membranes have added short glass fibers to the plastic to improve the dimensional stability and wear resistance of the frame, and at the same time improved the splicing structure to an overlapping structure ( For the cross-sectional structure of the explosion-proof membrane of the overlapping figure 1 shown), by leaving a step on the side of the black arc-shaped frame A, and then lapping the glass sheet B under the step (that is, a part of the arc-shaped frame rests on the upper surface of the glass sheet), from When looking up and down, the outline of the glass sheet B is covered by the black curved frame A, so as to completely avoid the white stitching line, but this brings other problems. First, it will lead to a significant increase in cost (this The explosion-proof price of the lap joint structure basically reaches more than 90 yuan / piece), and secondly, because the arc-shaped frame A is higher than the glass sheet B, it is easy to accumulate dust at the lap joint and it is not easy to clean

Finally, most of the above-mentioned explosion-proof films using tempered glass will be coated with a layer of AB glue on the bonding surface. The side of the AB glue and the tempered glass is OCA optical glue, and the side of the touch screen is silica gel. The van der Waals force between the silicone surface and the smooth glass of the touch screen realizes adsorption and bonding. In order to improve the self-adsorption of the explosion-proof film during bonding, the silicone bonding surface of some explosion-proof films has been electrostatically treated, but due to the AB glue pole Thin and its back is made of glass (AB glue is attached to the glass sheet of the explosion-proof film), and the improvement of self-adsorption is not obvious for electrostatic treatment (it is still necessary to press by hand to help adsorption during the film sticking process)

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