Touch panel laminating process
The main process routes for touch screen lamination are OCA and foam adhesive, with OCA lamination being the most widely used
What is the OCA laminating process？
The OCA process is the use of PSA, also known as optical clear adhesive (OCA).
clear Adhesive (OCA) is an optically clear adhesive or a substrate free optical adhesive. The main application is for LCM, Cover and Touch Panel lamination.
It is simply a double-sided adhesive with high light transmission. The main component of this adhesive is Acrylic, which has the advantages of high adhesion, high light transmission (>90%) and good weather resistance (UV resistance).
It is suitable for laminating transparent materials and is mostly used in the T/P industry for 2-7″ products.
Advantages and disadvantages of different structures of CTP
There are three commonly used CTP structures:1. G+G: glass cover + glass sensor, 2. P+G: plastic cover + glass sensor,3. OGS: on glass sensor
The performance comparison is shown in the following table, 1 represents the best performance, 2 represents the better performance, and 3 represents the general performance
Cover lense substrate : PMMA/PC/PMMA
Glass surface treatment :AG/ARAF/AGARAF
IC: COF (ATMEL/Cypress)/COB
glass substrate : Asahi sodalime/Asahi dragontrail /Corning)
Glass surface treatment :AG/ARAF/AGARAF
*IC: COF (ATMEL/Cypress)/COB
glass substrate : Asahi sodalime/Asahi dragontrail /Corning)
Glass surface treatment :AG/ARAF/AGARAF
*IC: COF (ATMEL/Cypress)/COB
item | GG | PG | OGS |
thickness | 2 | 2 | 3 |
Mechanical strength | 2 | 3 | 1 |
Optical | 2 | 2 | 3 |
Touch performance | 3 | 2 | 2 |
reliability | 3 | 2 | 2 |
cost | 2 | 1 | 3 |
Printing/Drilling | 3 | 3 | 2 |
Touch panel process flow chart
First, the ACF is attached to the sensor, then the touch screen FPC is laminated to the sensor, then the OCA is attached to the laminated sensor, and finally the protective cover is laminated to the sensor to get the finished product.
OCA process flow
The OCA process requires two laminations, Sensor glass and PSA lamination and Sense glass and Cover glass lamination respectively
sensor glass with PSA lamination
PAS/OCA (optical clear adhesive) is first placed on the stencil, sensor glass is adsorbed on the reversible board, after alignment, the roller rises to laminate OCA and sensor glass together.
Sense glass and Cover glass lamination
Similar to the previous process, the cover lens is placed on the stencil, and the product after the previous process is attached to the reversible plate, and after alignment, the rollers rise to fit the two together.
