Membrane switch is a new type of high-tech switch, which has been widely used in various fields, including basic living equipment. As a functional and decorative electronic component, membrane switches have been widely used in various fields and products, including household appliances, instruments, mechanical equipment, electrical equipment, medical instruments, etc. An important component of the membrane switch is the membrane panel. The following focuses on the assembly steps of the membrane switch and summarizes it.
1. Put the silk-screen printed circuit into the oven for 40 minutes, the temperature is 115 degrees Celsius. (Note that the silk-screened circuit should be dried naturally) After the circuit is baked, simply assemble it and test the circuit for short circuit, open circuit, excessive resistance, etc.
2. Paste the tail wire: After testing the single-wire resistance of the baked line, put a layer of insulating tape on the tail wire from the outlet hole to the place where the carbon slurry overlaps by 1 mm (do not paste it on the button as much as possible in the direction of the button) paste some).
3. Punch the tail line: Punch out the tail line with a knife die, and the two sides of the tail line should be even (the membrane switch manufacturer Tike Precision Electronics reminds to pay special attention to the tail line with small line spacing). For sample making, use a ruler with glue to align the inside of the outlet hole and draw from top to bottom to the edge of the tail. Note that the ruler should be glued to the reverse side of the circuit, so as to avoid sticking the silver paste.
4. Make the interlayer (sample): find a piece of waste circuit and spread it on the interlayer of appropriate size to stick it, use an awl to pierce the center point of the line key, and then use a compass to draw a circle with a diameter of 10 on the center point (special circumstances can change), it is knocked down. After the circle is knocked out, use a blade to knock out a ventilation groove with a width of 2 mm between the circles. Note that there should be at least 3 or more circles connected, and you should try not to pass through the intersection of the upper and lower lines while knocking on the ventilation slot. If there is, it should be sealed with transparent glue. (The interlayer where the dome pieces are placed should be square with the size of the dome). The mold is formed at one time during mass production.
5. Assembling the circuit: first paste the lower circuit with the tail line on the interlayer. When pasting, the silver paste point should be placed in the middle of the interlayer hole without air bubbles. Then paste the lines. Note that the positioning of the upper and lower circuits should be aligned, and the contacts should not be misplaced.
6. Adhesive paste: Paste the prepared adhesive on the lower circuit. When pasting, the tail line should be taken out, and the glue position should cover the 4 corner lines. There must be no air bubbles in all pasting processes.
7. Facing glue: Paste the punched surface glue on the upper line. Note that the glue hole should be aligned with the key and cover the 4 corners. (The production of the surface glue is the same as that of the interlayer. If the panel has a large bulge, the circle can be enlarged. The glue for the metal dome can also be knocked into a 2mm strip).
8. Punching: Find a waste panel and paste it on the assembled circuit, align the 4 corners, expand the transparent hole by 1mm in 4 circles, staple it on the assembled circuit, and knock it off with a suitable blade. When knocking, pay attention to whether the line is knocked.
9. Paste the panel: Paste the detected panel on the upper line. Zhuhai film line reminds to pay attention to the alignment of the four corners when pasting, and the air bubbles on the surface glue should be scraped off, and pasted to a transparent window to see if the window is stuck. Pay attention to protect the transparent window after pasting.
10. Tail wire treatment: cut the tail wire flat, and paste a layer of 0.125 single-sided adhesive PET on the back of the carbon paste for reinforcement if the terminal is not used. . (Note that the double-layer tail line should cut a rounded outlet with a height of about 1-1.5 cm at the bottom of the tail line where there is no line).
11. Forming: Stamping (machine) forming is an indispensable process for membrane switches. The size requirements are accurate, and the design of the mold is the guarantee. The size should be variable according to the size provided by the customer, as well as the thickness, size, and shape of the substrate, so as to produce accurate structural dimensions. The quality of the mold is the key to the forming quality of the membrane switch. During the embossing operation, the mold should reflect all the lines on the original plate. High-quality embossing requires hot pressing. The advantage is that the embossed lines are not deformed and have layers and three-dimensional effects.
12. Inspection: First, visually inspect to see if there is any deviation in the appearance and the silk screen is bad. Then use the tester to test each button one by one according to the circuit principle. Check whether there are problems such as open circuit, short circuit, excessive resistance, etc., and pay attention to the sensitivity of the buttons (if you have a metal dome, pay attention to whether there is a double boiler). Whether the detection light with LED is on or always on and the brightness is different, please check with the sample. Each product should be continuously sampled for life testing (usually 500,000 times can be confirmed as qualified).
13. Paste the label on the package and leave the factory. The packaging should be neat, beautiful, delicate and generous.
After the above thirteen steps, the assembly of the membrane switch is completed. There are many assembly steps for membrane switches, and many details cannot be listed one by one. Carefulness, conscientiousness, and quality inspection are the keys to do a good job in membrane switch assembly.
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