More than 90% of consumers who just got their new mobile phones will put a screen protector on their beloved mobile phones. However, we have seen that many consumers do not know much about what kind of mobile phone screen protectors they choose, especially the 3D tempered glass screen protector. Indeed, the market for mobile phone screen protectors is very chaotic, it does not have a unified standard in the industry. The various concepts created by merchants are spreading in the market, consumers are really confused at all as most of them are buying it for the first time. However, touch feeling and applying operation may vary in different types of screen protectors, especially the 3D tempered glass screen protector.

We have previously introduced what 2.5D and 3D tempered glass are. 3D tempered glass screen protectors for mobile phones are mainly used in phones with curved screens (although many manufacturers have also launched their 3D tempered glass for iPhone). 3D tempered glass screen protectors are developing along with curved screen mobile phones. Since Samsung launched its first curved screen mobile phone GALAXY Round in 2013, it has adhered to the development path of curved screens. Today, curved screen design is featured on most Samsung mobile phones, which also drives the development of curved screens. Although Apple has not launched any mobile phones with curved screens so far, in today’s Android mobile phone camp, curved screen phones are still popular. In addition to Samsung, other mobile phone manufacturers such as Huawei, Xiaomi has launched its mobile phones with curved screens.

Then, while curved screen mobile phones are becoming popular, there is also a huge demand for the 3D tempered glass screen protector. Think about it if a flat 2.5D mobile phone tempered glass film is applied on a curved screen mobile phone, naturally, the 2.5D screen protector itself will definitely not be able to play its due effect. A variety of 3D curved tempered glasses have been introduced to solve the pain points of difficulty in covering the edges of curved screens. At the same time, some 3D tempered glass screen protectors can better cover the edges of the new iPhones.

In the field of the 3D tempered glass screen protector, depending on the manufacturing process, there are many types of 3D tempered glass. Secondly, there are different types according to the way of applying the screen protector. It brings consumers totally different experiences in touch feeling, price, workmanship, or applying the screen protector when different 3D tempered glass screen protector types are chosen.

Types of 3D tempered glass screen protector by the manufacturing process

Currently, there are mainly four different manufacturing processes for making 3D tempered glass screen protectors.

1. 3D hot bending tempered glass screen protector

What is 3D hot bending tempered glass? 3D is a description of shape, hot bending is a kind of manufacturing process, the tempered glass screen protector is ordinary glass that has been tempered at high temperature. The hot bending process is to bend the tempered glass by a hot bending machine. Put the tempered glass on the arc molds of the hot bending machine, heat it to a certain temperature through several stations to soften the glass. Under certain pressure, the softened glass will gradually adhere to the mold, and then pass the pressure maintaining and gradual cooling. It is cold-cut to obtain 3D curved glass.

A custom mold for 3D hot bending tempered glass

3D hot bending tempered glass is also the most common process for making 3D curved tempered glass, which is mainly used in large curved screen phones in the Android camp such as Samsung.

2. Cold laser engraving process

The iPhone 11 was released in 2019, its one-piece glass back cover is made of cold engraving process. The appearance is extremely stunning, but it requires a very high industrial design and manufacturing level, and the processing is extremely complicated. Driven by Apple, the cold engraving CNC machine has gradually emerged, now, there are also 3D tempered glass screen protectors made of cold engraving process.

Tempered glass with laser engraving process for iPhone

The laser engraving process on 3D tempered glass film is to directly thin and carve a flat tempered glass by CNC machine, cutting out a considerable chunk of the middle part, make the four edges of the tempered glass form a 3D arc.

The price of laser engraving tempered glass screen protector is much higher than ordinary ones. The reason is that laser engraving tempered glass is carefully carved by a precision carving machine bringing a stronger sense of craftsmanship and relatively high quality.

However, due to the complex process and high cost, it is still rare for the mobile phone film manufacturer to use cold engraving technology to produce tempered film products, and it can hardly ensure complete flatness for a tempered glass made by laser engraving technology – it generates bubbles while applying the screen protector if it is not flat.

3. Etching process

The etching process is often used in combination with the laser engraving process. Etching glass is to apply etchant (hydrofluoric acid) to etch the glass (thinning the glass) and leave the four edges of glass a 3D curved arc, and then finely carved by CNC machine. The combination of etching and laser engraving can effectively reduce the unit price of the product, but the product is not inferior to the laser engraving process, it is currently the main solution for the high-end tempered glass screen protector.

Comparing with other processes, the 3D tempered glass screen protector made of etching & engraving process can fit the arc edges of the mobile phone screen to the greatest extent. It is the best fit & coverage screen protector among various types of mobile phone protective films. However, etching or laser engraving tempered glass screen protectors are only made for iPhone as such 3D tempered glass with manufacturing process can only be cut out in small curves, they are not suitable for a mobile phone screen with big curves such as Samsung’s curved screen.

4. Dispensing glue process

The dispensing glue process is also known as drop glue or dispensing technology, the dispensing glue process is to dispense glue (resin) directly on the edges of the flat tempered glass film to make a 3D effect. The dispensing process is also considered as “fake 3D”. The edges of the tempered glass are dispensed by resin to make the glass appear curved.

Some vendors on the market take advantage of consumers’ weak perception of 3D tempered glass and sell fake 3D as a 3D tempered glass film. In fact, the cost of the glue dispensing process is cheaper than other 3D tempered glass processes such as hot bending or laser engraving.


Differences between 3D tempered glass with dispensing glue process and 3D

In the current market, hot bending 3D tempered glass is the mainstream, the etching process is generally customized according to customer needs. The production efficiency of the hot bending process ranks first among the four processes and can be made in large arcs, 3D tempered glass with hot bending process is the only one that can be used for Samsung’s big curved mobile phones at present. Among the four processes, the production efficiency of hot bending is high; the cold engraving production efficiency is low, the quality and the price are high for those with laser engraving process; the appearance of 3D tempered glass with dispensing glue process is slightly worse, but it is easier to expel bubbles; the output of tempered glass with etching process is higher than pure laser engraving.

Classified by applying method or the back glue on tempered glass

There are different types of 3D tempered glass screen protectors when we talk about the back glue of tempered glass. The classification is mainly for the curved screen tempered glass of the Android camp and has little to do with the tempered glass of the iPhone.

UV glue 3D tempered glass screen protector

While applying a UV glue 3D tempered glass, UV glue (a kind of liquid glue) need to be applied on the surface of the mobile phone screen before pasting the tempered glass, and then curing the UV glue with ultraviolet light.

Compared with the conventional solid glue tempered film, the UV glue tempered film has the advantages of strong adhesion and it is not easy to fall off. The pasting operation is relative simple, it’s getting popular recently.

UV glue 3D tempered film also has disadvantages: one is that it is troublesome to peel off if it is broken because the glue is too sticky and does not fall off easily. The other is that the UV glue is a liquid glue, the liquid glue tends to penetrate into the phone when applying on the mobile phone screen, such as the volume button, power button, earpiece. Some users have feedback that the glue sticks on the side buttons or the keys are corroded, and some users report that the touch screen is malfunctioning.

Side-glue 3D tempered glass screen protector

The side-glue 3D tempered film is laminated with the mobile phone on the four edges with double-sided adhesive. There is no glue in the other area, it attaches to the mobile phone screen through electrostatic adsorption, the touch control needs to rely on the dots on the tempered film, so it is also called the dotted tempered film.

Dots on the tempered glass film with side glue process

The side-glue tempered film has the advantages of the traditional tempered film. Since there is no adhesive in the middle area, the pasting operation is relatively simple, and the production cost is lower, so the price is low.

However, the tempered film of the visible window in the middle is separated from the mobile phone, which may lead to insensitive touch and poor fingerprint recognition under the screen.

In addition, the double-sided adhesive of only four edges may not stick firmly, or it may easily fall off. If the tempered film is pasted slightly biased, it will also cause insensitive touch.

Water ripples appear on the screen after the screen is turned off

Furthermore, due to the black dots on the side-glue tempered film, the phone screen looks bad after the film is attached, and it is easy to generate bubbles if it is not properly applied. Some customers report that the reflection is serious under sunshine after the film is attached, water ripples may appear after the screen is off.

Full glue 3D tempered glass screen protector

The 3D full glue tempered glass screen protector is generally featured with the hot bending tempered glass + silk print process + AB glue. The whole glass is glued, which can make the whole tempered film attached to the mobile phone screen tightly, the touch effect is completely sensitive, just like a flat 2.5D tempered film.

The backside of a 3D full glue tempered glass is pasted with AB glue, obviously, the full glue 3D tempered film can better fit on the mobile phone display when comparing to side glue tempered film, it doesn’t have the issue of insensitive touch which might happen on side-glue tempered glass. Anyway, the manufacturing process and raw material cost are more complicated, so that the production cost is more expensive than the side glue.

Full glue 3D tempered glass screen protector with punched hole for supporting fingerprint

But there was also a problem for mobile phones with in-display fingerprint supported when a full glue 3D tempered glass film was applied at an earlier stage, it was not sensitive to recognize the in-display fingerprint when the full glue tempered film was applied especially on Samsung Galaxy S10 or up (ultrasonic fingerprint sensor), it was due to the issue of the AB glue. Manufacturers’ solution was to punch a hole in the center of the tempered glass so that the finger can touch the mobile phone screen directly when user was going to unlock the phone. But it brought another pain point, the appearance and touch experience were so bad after such kind of tempered film was applied, imagining who the hell like their good-looking new smartphone with a hole-like pattern in the center of the mobile phone display after a tempered film was applied? And it might scrape your finger when you slide at the position of the hole.

Nowadays, the latest full glue 3D tempered film solves the problem, the hole in the center is removed. Like a 2.5D tempered film, the 3D full glue tempered film completely fits the mobile phone display, and it can perfectly support smartphones with in-display fingerprint feature such as Samsung phones even the latest Samsung S21 Ultra, the only drawback is that it requires experience or auxiliary tool to fix position when applying the film. In addition, the price is the highest among the three. Anyway, 3D full glue tempered film is now the best tempered film solution for mobile phones with curved screens.