The difference between optical transparent adhesive OCA, OCR, and OCF?
Date:2025-11-27
Optical transparent adhesive is mainly divided into three categories: OCA, OCR, and OCF, each with its own characteristics in form, process, and application.
Below is a table and detailed explanation to clearly demonstrate their differences.
Comparison Table of Core Differences
Characteristic dimension | OCA (Optical Clear Adhesive Tape) | OCR (Optical Transparent Liquid Adhesive) | OCF (Optical Transparent Film)/Thermosetting OCA |
Physical form | Solid state thin film | liquid | Liquid solid film (usually with release film) |
Core Process | Die cutting, pasting, vacuum pressing | Glue dispensing, bonding, UV curing | Die cutting, pasting, hot pressing curing |
Main advantages | • Mature technology with high yield • No glue overflow, clean • Uniform thickness and stable optical performance • Suitable for large-scale automated production | • Borderless fit, suitable for curved surfaces/complex structures • Strong ability to fill gaps • Low stress, high adhesive strength • Can achieve thinner interlayer thickness | •Combining the ease of operation of OCA with the high strength of OCR •Excellent weather resistance and reliability (high temperature and humidity resistance) •After curing, there is no interface and the optical effect is good |
Main drawbacks | • High requirements for substrate flatness • Not suitable for curved surfaces and complex 3D structures • There is a risk of delamination and bubbles (if not cleaned properly) • Limited thickness selection | •The process is complex and prone to producing bubbles and impurities •There is a risk of glue overflow pollution and it needs to be cleaned •UV curing equipment is required • There is fluidity before curing, and it is difficult to control the uniformity of thickness | •Heating and pressurization equipment is required •The process time is longer than UV curing • Costs are usually higher |
Typical Applications | •Flat display module (mobile phone, tablet) •Touch screen and cover glass are attached together •LCD/OLED panel and cover lens bonding | • 2.5D/3D curved cover plate fitting • Car display screen (large size, irregular shape) • Fill gaps with steps or unevenness | • Scenarios with extremely high reliability requirements •Car display screen (must pass rigorous environmental testing) •Flexible OLED module packaging and bonding • Metal mesh touch sensors, etc |
Detailed description
1. OCA - Optical Transparent Adhesive Tape
Form and essence: This is a solid, substrate free double-sided adhesive film pre made to a specific thickness. It is like a roll of tape, cut into the desired shape by a die-cutting machine, and then peeled off the release film for bonding.
Process features: This is the most classic dry bonding process. The requirements for environmental and equipment cleanliness are extremely high, and any dust can cause bubbles. After bonding, it is necessary to eliminate interlayer air through a vacuum bonding machine.
Applicable scenarios: Mainly used for flat or simple 2.5D curved display devices, it is the mainstream technology for smartphone and tablet screen fitting. Its advantages lie in mature technology, high efficiency, and precise thickness control.
2. OCR - Optical Transparent Liquid Adhesive
Form and essence: Essentially, it is a liquid resin adhesive that needs to be cured and hardened by ultraviolet radiation. The "touch screen glue" you asked earlier belongs to this category (LOCA is a type of OCR).
Process characteristics: It belongs to wet bonding. Apply liquid glue onto a substrate using dispensing equipment such as glue machines or spray machines, then bond it to another substrate, fill all gaps with the fluidity of the glue, and finally cure it by UV light irradiation.
Applicable scenarios: Mainly used for fitting irregular shapes, large sizes, or complex surfaces. For example, the 3D curved cover plate on mobile phones, the curved screen on smart watches, and the large area of the car's central control screen can all be well covered and eliminated by OCR, achieving a "borderless" visual effect.
3. OCF - Optical Transparent Film/Thermosetting OCA
Form and essence: This is a solid film that looks very similar to OCA in appearance. But their chemical mechanisms are completely different: OCA is a pressure-sensitive adhesive (bonded by pressure), while OCF is a thermosetting adhesive film.
Process characteristics: The first half of its process flow is the same as OCA (die-cutting attachment), but heat and pressure need to be applied simultaneously during pressing. Under hot pressing conditions, the adhesive film undergoes a chemical reaction to crosslink and solidify, changing from the initial solid state to the final solid state, but its adhesive strength and reliability will undergo a qualitative leap.
Applicable scenarios: This is a technology designed for ultra-high reliability requirements. For example, in the automotive industry, display screens are required to withstand long-term cyclic impacts of -40 ℃ to 85 ℃ and high temperature and humidity environments. OCF has much better weather resistance than OCA and OCR. It is also commonly used in fields such as flexible OLEDs that require high packaging standards.
Summary and selection suggestions
Pursuing efficiency and graphic design → Choose OCA
If your product is a traditional flat structure that pursues high efficiency and low risk in large-scale production, OCA is the most mature and economical choice.
Dealing with curved surfaces and complex structures → Choose OCR
If your product is a 2.5D/3D curved screen, large size, or irregular shape that requires seamless bonding, then OCR (liquid water-based adhesive) is the only option.
Require ultimate reliability and weather resistance → Choose OCF
If your product needs to face harsh environments (such as automotive, outdoor, military), or is used in cutting-edge fields such as flexible displays, OCF's ultra-high adhesive strength and stability are irreplaceable.
I hope this detailed explanation can help you understand the difference between these three clearly.
Touch screnn：https://www.auo-lcd.com/products/touch/
TFT LCD:https://www.auo-lcd.com/products/auo-lcd-screen/
