The LED on membrane switch usually serves as an indicator. When a certain function is running normally or an error occurs, the operator can sense it through the color feedback of the LED. For an example of household appliance, the LED on membrane switch can provide timely feedback on whether a button is successfully pressed, or whether a certain function is running normally.

Sometimes, LEDs in different positions show different functions, and they feed back different machine statuses. LEDs come in different colors, and the colors have their own meanings. Under normal circumstances, red light serves as a warning. It is easier to detect abnormalities with LEDs. Finding abnormalities is a must for preventing safety hazards.

Design

Membrane switch with LED is composed of LED, metal domes, double-sided tape, ink, PET/PC/FPC/PCB, etc. The product has a wide range of applications, such as medical equipment, household appliances, industrial equipment, transportation, and electronics.

If the product is complex, there will be more production processes. We use a lighting machine to install the LEDs, and then manually add photosensitive adhesive to fix them. The design of the product is not simple either. Pay attention to the direction and order of the product buttons and LED lights. They need to be the same. Otherwise, the existence of the LEDs will be meaningless.

Installation

LEDs are installed on the circuit. The installation is in lighting machine. Place the raw material (LED lights) in the lighting machine, and then place the circuit in the corresponding position. The holes on the circuit must correspond to the bumps on the machine so that the LEDs can be fixed. Then start the machine. Everything will go on according to the set procedure.

After installing the LED lights, there is usually the next step. It is to add UV glue. Use air pressure equipment to drop the UV glue on the bottom of the LED light, and then let it solidify through the ultraviolet irradiator. It prevents the LEDs from problems such as poor contact, looseness, and falling off.

According to the color, LED can usually be divided into white light, red, orange, yellow, green, blue light, etc. In addition, some light-emitting diodes contain chips of two or three colors. LEDs can work continuously for 50000 to 80000 hours, which is more than 10 times the lifespan of traditional fluorescent lamps.

The working current of the LED in membrane switch is usually below 20mA, while the working current of the low-current LED is below 2mA (the brightness is the same as that of ordinary light-emitting tubes).

Issues

If LED on membrane switch does not light up, there may be some reasons.

1. LEDs are not packaged well, causing the beads to be damaged due to impact during transportation.

2. The solder joints of the LEDs have a weak solder phenomenon. The vibration during transportation causes the solder joints to fall off.

3. The LED has a small amount of solder, and the solder joints are easy to fall off.

4. The welding of LEDs is not good. The solder joints of LED flexible light strips are prone to brittleness and falling off during the bending process.

5. When the LED is installed, the bending angle is too large, causing the solder joints to separate from the copper foil, resulting in no light.

6. Excessive squeezing when installing the LED may cause the chip to be damaged, or the solder joints to deform and fall off and not light up.

7. The solder mask layer of the circuit is too thick. The solder and circuit cannot be completely integrated during welding, which is also the weak soldering phenomenon.