The structure of capacitive touch screen is mainly to plate a transparent film on the glass screen, and then add a protective glass on the conductor layer. The double glass design can completely protect the conductor layer and the sensor. The capacitive touch screen is coated with long and narrow electrodes on all sides of the touch screen, forming a low-voltage AC electric field in the conductive body. When touching the screen, due to the electric field of the human body, a coupling capacitance will be formed between the finger and the conductive layer, the current from the four electrodes will flow to the contact, and the current strength is proportional to the distance between the finger and the electrode.
The controller behind the touch screen will calculate the proportion and strength of the current, and accurately calculate the position of the touch point. The double glass of capacitive touch screen can not only protect the conductor and sensor, but also effectively prevent the external environmental factors from affecting the touch screen. Even if the screen is stained with dirt, dust or oil, the capacitive touch screen can still accurately calculate the touch position. Capacitive touch screen is a special transparent metal conductive material on the surface of glass. When the finger touches the metal layer, the capacitance of the contact will change, so that the frequency of the oscillator connected to it will change. By measuring the frequency change, the touch position can be determined to obtain information.
One component: lens (toughened glass) + sensor (several components) + shielding layer (some are, some are not) + FPC (IC and circuit)
II. Sensor composition: glass + glass, pet + pet, single-layer glass
III. process flow
1 glass cutting, single sensor glass 0.55mm,
2 coating: After the glass is cut, it will be coated on the whole. The sequence is ITO first, then molybdenum, then aluminum, and then molybdenum. After the front is coated, the back is coated. The reverse is the same. Four layers need to be coated.
3 etching: First, the sensor's Mo, Al and Mo wires are plated, the front is etched, and then ITO front is plated. ITO pattern is regular prism. Again, etch the reverse.
It is worth noting that the wiring beside the sensor of glass structure is made of molybdenum, aluminum and molybdenum, which may be different from each other. All we know, the factory will plating a layer of molybdenum on the sensor, then an aluminum layer, then a molybdenum layer, and then etching. Before etching ITO, Mo, Al and Mo are etched off.
The second thing is worth mentioning is that there will be a certain gap between the two layers of ITO patterns, which is to avoid misoperation when touching the repeated places
4 binding: After the sensor is coated, it will be bound with FPC. It will be pasted with a special glue (to make the circuit open and not short circuit each other). I forgot the name of the glue
5 fit: After the sensor is finished, it will fit lens. There are two ways to fit lens: solid glue or liquid glue. It is important to prevent bubbles.
Contact us
Name:Selina Chan
Tel:0086-596-2607595
Email:sales09@wiwotouch.com