Hangzhou Xuhong Technology Co.,Ltd
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中文
The English spelling of CTP is' Capacitive Touch Panel ', and the Chinese name translates to' Capacitive Touch Screen '. Capacitive touch screens are currently the mainstream of touch screen technology. Compared to resistive touch, capacitive touch is more sensitive, supports multi touch, has strong anti-interference ability, and is less affected by air, humidity, oil stains, and other factors. Therefore, capacitive touch screens are widely used in commercial, medical, industrial and other fields. Next, we will introduce the composition structure and manufacturing process of CTP capacitive touch screens based on Guangdong Dexingwei's own production line.
1、 Structure of CTP capacitive touch screen
Before introducing the structure of CTP capacitive touch screen,
let's first understand the principle of capacitive touch. The key to implementing touch function in CTP is to utilize
the principle of induced current in the human body. The four sides of the capacitive touch module will be coated
with narrow electrodes. When a finger touches the screen, a coupling capacitance is generated between the finger
and the conductive layer of CTP. At this point, the four electrodes will emit current to reach the touch point, and the
distance between the touch point and the four electrodes can be calculated based on the strength of the current.
Through the calculation of the controller, the precise positioning of the touch point can be obtained. After
understanding the principle of capacitive touch, we can have a more vivid understanding of its composition and
structure. The structure of a capacitive touch screen, to put it simply, is to coat a transparent thin film conductive
layer on ordinary glass, and then add a protective glass on the outside of the conductive layer. Therefore, the structure
of CTP capacitive touch screen is divided into: cover glass, sensor glass, and LCM LCD module.
Cover glass: It is the top glass cover of the capacitive touch screen, providing mechanical protection.
Its material can be divided into ordinary glass and tempered glass, and can be selected according to
customer needs. The cover glass not only protects the touch sensor, but also prevents external factors
from affecting the touch performance, such as dust, oil stains, moisture, and so on.
Sensor glass: Its structure is achieved by etching a layer of conductive layer on a piece of ordinary glass,
which is arranged in vertically staggered rows and columns to form a matrix, thus realizing touch sensing.
We call this conductive layer glass ITO conductive glass or sensor glass. The cover glass and sensor glass
are bonded together using OCA optical adhesive. Of course, there are FPC and driver IC that need to be
bonded between the cover glass and sensor glass.
LCM LCD module: After the cover glass and sensor glass are bonded together, we call it CTP capacitive touch
module. After bonding the CTP module and LCM LCD module with OCA optical adhesive, the final product is
the CTP capacitive touch screen.
2、 The manufacturing process of CTP capacitive touch screen
The production process of CTP capacitive touch screens is as rigorous and meticulous as LCM LCD modules.
Below, we will introduce the production process of CTP capacitive touch screens.
The production process of CTP touch module: Our incoming material is finished sensor glass, and the first step is to perform plasma cleaning on the sensor glass to prepare for subsequent bonding. The second step is the ACF attachment of the sensor glass, as well as the bonding of the driver IC and FPC. The bonding principle here is the same as that of LCM LCD modules, using ACF conductive adhesive hot pressing technology to firmly bond the driver IC and FPC flexible circuit board onto the sensor glass. The function of the driver IC of the touch module is to detect and receive touch signals, and input the signals into the device computer. Afterwards, the sensor glass bound with FPC will undergo power on testing and program burning. The third step is to use OCA optical adhesive to fully bond the cover glass and sensor glass. We use professional automation equipment for bonding, which provides a good guarantee for the accuracy of bonding. The next step is to use machine equipment to perform defoaming treatment on the CTP touch module after bonding, detecting and eliminating any bubbles that may exist during the bonding process. The final step is to conduct a CTP marking test, mainly to detect the accuracy of touch positioning, observe whether there is any misalignment between the vertical and horizontal axes, as well as the phenomenon of marking breakpoints. At this point, the qualified CTP touch module has been produced.
LCM full bonding process: Before bonding the CTP module to the LCM module, we need to manually observe and clean the CTP module to prepare for bonding. The next step is to use professional automation equipment for full bonding between CTP touch modules and LCM LCD modules, using OCA optical transparent adhesive as the medium. After the bonding is completed, proceed to the second step of material bonding. The main purpose is to supplement the dust-proof and waterproof adhesives, which play a sealing role and prevent dust and water vapor from entering the screen. At this point, the CTP capacitive touch screen finished product is completed, and the subsequent work includes quality final inspection, appearance cleaning, protective film bonding, and packaging and storage.
The above is a detailed introduction to the composition structure and manufacturing process of CTP capacitive touch screens. Of course, there is still a lot of knowledge about CTP capacitive touch, such as G+G structure, G+F structure, AG glass cover plate, capacitive screen wet hand touch, salt water touch, and so on. Customers can choose the appropriate CTP capacitive touch screen based on their budget and needs.
