OCA film adhesive (solid) vs LOCA water-based adhesive (liquid OCR)
Film adhesive=Solid state optical double-sided adhesive OCA; Water glue=liquid UV optical glue LOCA/OCR. The core differences in the selection of industrial screens, industrial control/vehicle/outdoor screens are as follows:
Touch screen full lamination: OCA film adhesive (solid) vs LOCA water-based adhesive (liquid OCR)
Film adhesive=Solid state optical double-sided adhesive OCA; Water glue=liquid UV optical glue LOCA/OCR. The core differences in the selection of industrial screens, industrial control/vehicle/outdoor screens are as follows:
I Differences in Basic Form and Craftsmanship
1. OCA film adhesive (solid film adhesive)
Form: Prefabricated solid transparent adhesive film, die cut according to screen size, coil/sheet stock.
Process: Vacuum coating → Roll pressing → High pressure defoaming, no UV curing required, one-time pressing to complete bonding.
Equipment: Simple vacuum bonding machine+defoamer, with fewer processes and fast production on the assembly line.
2. LOCA water-based adhesive (liquid water-based adhesive)
Form: Transparent liquid resin, barrel packaged raw materials, on-site dispensing, no pre made specifications.
Process: Vacuum chamber dispensing → Cover plate/TP → Leveling → UV whole surface+side segmented curing, multi process flow
Equipment: dispensing machine, vacuum bonding chamber, UV curing line, with higher production line investment.
II Comparison of core performance advantages and disadvantages
✅ Advantages of OCA film adhesive
Uniform adhesive thickness, no overflow, clean edges, stable yield, and high efficiency in small-scale production (preferred for mobile phones and 5/7-inch consumer screens)
The dust-free environment has a lower threshold, simple storage, short-term use after unpacking, fewer defects, and low material loss.
Fit without leveling deviation, preferred for small flat cover plates (flat glass), easy to rework after sales (low-temperature tearing).
❌ OCA adhesive short board
Poor filling: LCD with metal iron frame, raised ink on cover plate, uneven glass, curved screen cannot be filled with OCA, insufficient glue filling in gaps is prone to bubbles, rebound and delamination.
Large size (≥ 10 inches) adhesive is prone to bubble accumulation, causing rebound after bubble removal and a sharp drop in yield; The larger the size, the higher the cost of a single piece of adhesive (requiring separate die-cutting).
Wide temperature range, vehicle vibration environment: high temperature is prone to shrinkage and delamination, and weather resistance is weaker than that of silicone water-based adhesives.
Advantages of LOCA water-based adhesive (main industrial wide temperature screen, commonly used by AU/Innolux industrial control screens).
Self leveling filling is extremely strong, suitable for LCD screens with iron frames, ink steps, and irregular/curved glass, filling small gaps. It is the only preferred option for industrial framed screens.
Resistant to wide temperature range (-40 ℃~105 ℃), vibration, and humidity of 85 ℃/85RH. Comes standard with car and outdoor charging stations, medical and engineering machinery screens, and can withstand long-term adhesion without fogging.
A glue that can be used in multiple sizes without the need for repeated die-cutting. Large sizes (10 inches to 55 inches) are more cost-effective than OCA
After solidification, the colloidal buffer is strong, improving the screen's resistance to falling and explosion, and reducing the probability of glass breakage.
LOCA water-based adhesive short board
Difficulty in controlling the dispensing volume, prone to overflow at the edges, and high cleaning time for overflow; FPC wiring and dead corners of the frame are difficult to fully cure with UV, requiring secondary side UV exposure.
The process is complicated, the flow level control is strict, the cleanliness requirements are higher, and the efficiency of small-scale mass production is lower than OCA.
III Cost&Selection Scenarios (Key to Industrial Screens)
1. Prioritize OCA sheet adhesive
Size: ≤ 8-inch flat screen without iron frame (consumer tablet, small home touch screen).
Structure: Full flat cover plate, no thick ink steps, no metal frame.
Requirement: Large scale production, low cost, and regular indoor room temperature use.
2. Priority should be given to using LOCA water-based adhesive (you make mainstream industrial screens such as AU 8.4-inch G084SAN01.0)
Size: 8 inches or more, with LCD iron frame, wide temperature industrial/vehicle/outdoor (industrial HMI, charging station, medical monitoring, engineering machinery).
Structure: Thick ink cover, 2.5D curved surface, concave convex glass, irregular shape.
Environment: -30~+85 ℃ temperature difference, vibration, humidity, strong light outdoors, requiring 5-10 years of long-term reliability.
IV Summary of Wide Temperature Industrial Screens (Suitable for AUO/G150, G085VW Series)
Conventional indoor industrial control, flat cover without frame: OCA sheet adhesive.
Equipped with iron frame LCD, car/outdoor/medical wide temperature range: Water glue LOCA is required (the vast majority of AU industrial touch assemblies on the market are fully bonded with water glue).
