How to prevent the window of membrane switch from being scratched

Thin film switches with display windows have very strict transparency requirements from users, and there is no room for any flaws, especially when users use the quality of eyeglass lenses to inspect the display window of the thin film switch. Remember someone said that the user is always right. How do we control the window of the membrane switch?

Firstly, there must be a high level of quality awareness and strict control over all production processes. The window of the membrane switch is integrated with the key. The production process of the key is complex and there are many processes. Every production link of the membrane switch should consider protecting the window from scratches.

Control of raw materials and conduct transparency and scratch resistance tests on the purchased raw materials. In the selection of materials for membrane switch with display window, anti scratch materials must be selected. The front anti scratch grade is particularly important. When raw materials are purchased, there is a protective film on both sides of certain materials. When materials are cut, they will not damage the materials. If materials are not selected properly, it is difficult to control the scratch of the window.

For printing environment, printing is usually done in a dust-free workshop, and dust-free is only relative. Semi automatic silk screen printing machine is used for printing, and windows are exposed for a long time, especially for membrane switch with many colors. We can consider printing water-based protective paint at the window position in the second printing process, so that the subsequent printing process can protect the window to avoid dust sticking on the window, and then cover the protective film after the last printing process is completed. Automated printing requires a protective film for each printing process, and attention should be paid to preventing dust particles from sticking to the glue roller to prevent window scratches.

The standardization of homework requires that every step of the production process must prohibit touching the window area and wiping the window. Since it comes into contact with the window area with finger cots, it will leave marks, and even a slight wipe may cause the window to become scratched.

The production of membrane switch involves many molds. The window area of the mold must be bright and flat. During the production process, repeatedly check whether there is debris on the mold to prevent the window from being damaged. Special attention should be paid to the window area of silk screen printing to prevent sand holes and prevent oil leakage in the window area.

After printing, the panel must be double-sided coated and enter the assembly and gluing process. Usually, after the circuit assembly is completed, the next process is to stick the panel, remove the protective film on the back of the panel, and immediately cover the protective film in the window area.

Indeed, even with strict production control, there are still flaws in the windows. Users are making judgments

There are different standards above, and the following standards are for reference only:

Scratch area of 0.08mm × 2cm shall not exceed 5 places, area of 0.08mm × 3cm shall not exceed 2 places, area of 0.08mm × 1cm shall not exceed 10 places, and the scratch area shall not be in the center of the window. The inspection area range is 90m × 50mm, and the acceptance criteria are adjusted accordingly according to the increase or decrease of the area. The standards for black spots, stains, and miscellaneous points are: no more than three with a diameter of 0.1mm or less, no more than 10 with a diameter of 0.05mm or less, and the defect area is not in the center of the window. (The area range of this standard panel is 180 × 170mm, and the acceptance criteria will be adjusted accordingly based on the increase or decrease in area.)