Xiaomi Mi8 smartphone owners often face the need to replace or repair the back, especially after a bad fall. The question of what exactly is made of the back cover of this flagship 2018, becomes critical when choosing components for recovery. Understanding the structure of materials allows you not only to choose the right part, but also to avoid errors in the operation, as the physical properties of glass and plastic are radically different.
Many users mistakenly believe that the budget and mid-budget models Xiaomi is ubiquitous polycarbonate. However, Xiaomi Mi8 positioned as a flagship device, which left an imprint on the choice of engineering solutions for the assembly of the case. In this article, we will discuss in detail the multilayer structure of the rear panel, consider the chemical composition of the coating and answer questions that arise when disassembling the device.
Knowing the exact composition of materials is not only essential for aesthetic restoration, but also for understanding the thermal conductivity and strength of a device. Glass, unlike plastic, reacts differently to temperature extremes and mechanical shocks. Let's delve into the technical details of the design so that you can make an informed decision when buying spare parts.
Basic material: tempered glass against plastic
The back cover of the Xiaomi Mi8 is made of high-quality tempered glass, not just a decorative element, but a complex engineering structure that has undergone special chemical treatment to improve strength. Unlike cheaper counterparts, which can use acrylic or polycarbonate, it uses technology that provides a premium tactile response and glossy shine that lasts for years.
Glass use in 2018 became the standard for wireless charging flagships. Plastic or metal with a thick layer of paint could shield the signal or create excess resistance during inductive power transfer. That is why Xiaomi engineers chose a glass panel that also contributes to better heat dissipation from the Snapdragon 845 processor.
⚠️ Attention: Glass back cover Xiaomi Mi8 It's extremely sensitive to point impacts, and even if the panel looks intact, microcracks can cause it to collapse completely when it falls or heats up.
When choosing a replacement part, it is important to pay attention to the strength marking. The original panels often have a "9H" or similar hardness designations on the Mohs scale. Cheap copies made from ordinary silicate glass without hardening will break on the first careless movement, while the original is able to withstand significant loads.
Frame design: aluminum alloy
Glass itself doesn't exist in a vacuum, it's glued or fixed in a metal frame. In the case of the Xiaomi Mi8, it uses a strong aluminum alloy that serves as the supporting frame of the entire structure. It's not a coincidence that this metal is lightweight, has high thermal conductivity and is perfectly anodized, which allows you to get durable body colors.
The frame acts as a cellular antenna and Wi-Fi, and you may have noticed the slots at the top and bottom of the ends of the device, and these areas are filled with a special dielectric so that the radio signal can pass through the metal body without any problems, and the quality of processing these joints directly affects the tightness and waterproofness of the smartphone.
- 🔩 Type of alloy: Aluminum 6000 or 7000 series with addition of magnesium and zinc for strength.
- 🎨 Coating: Micro-augural oxidation or quality paint to prevent scratches.
- 📡 Function: Screening internal components and working as an antenna.
When disassembling the device, careless use of metal tools can leave dents that will spoil the appearance even with a new glass panel.Be extremely careful when bending edges or peeling off glass.
Oleophobic coating and its properties
One of the key characteristics of the Xiaomi Mi8’s back cover is that it has an oleophobic coating, which is a thin layer of chemical applied to the surface of glass that repels fats and water, leaving fewer fingerprints on the back, and any contaminants easily removed by dry fabric.
Unfortunately, oleophobic coatings are consumables, and over time, especially with frequent contact with your hands in your pockets or with hard-inner covers, this layer wears off, the back cover gets dirty faster, and the finger doesn't slide as confidently as it did in the first months of using a smartphone.
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To prolong the life of the oleophobic coating, wipe the back cover with a microfiber and avoid the use of alcohol-containing aggressive cleaning products.
There's a myth that the presence or absence of a slip immediately gives you a fake, but cheap copies can also have a coating, low-quality albeit, that will be erased in a couple of weeks, while the original retains its properties much longer thanks to the use of high-quality fluoride polymers.
Double Glass Technology and Wireless Charging
The concept of Double Glass, implemented in the Xiaomi Mi8, involves the use of glass panels both in front and behind the device, a solution dictated not only by aesthetics, but also by the technical need to support the Qi standard for wireless charging.
The electromagnetic field generated by the charging station passes freely through the dielectric (glass), but is blocked by metal. If the back cover were metal, wireless charging would be impossible without creating complex and cumbersome bypasses for the antenna, and the glass provides an ideal signal transmission ratio.
| Parameter | Glass (Original) | Polycarbonate (Copy) | Normal glass |
|---|---|---|---|
| Strength of impact | High (hardening) | Medium (flexibility) | Low (fragility) |
| Thermal conductivity | Good. | Low. | Medium |
| Support for Qi | Complete. | Possible. | Complete. |
| Tactile sensations | Cold, smooth. | Warm, soft. | Cold, rough. |
Glass use also affects work. NFC-a module whose antenna is often located at the top of the back cover or integrated into the battery but operates through the back panel. The quality of the material here plays a secondary role compared to the metal, but the thickness of the glass must meet standards so as not to disrupt the inductive coupling.
Visual identification of the original
How do you distinguish the original Xiaomi Mi8 back from a cheap copy without opening the packaging? First of all, pay attention to the quality of the Mi logo. The original is made by laser engraving or deep printing under glass, it can not be erased with acetone or alcohol. On copies, the logo is often painted on top and can get crawly over time.
The second feature is color and depth of shade: original glass has a complex gradient or a rich uniform color that changes at different angles of light due to the special structure of the substrate. Cheap plastic or glass of low quality often looks flat and has an unnatural, yellowish or blue hue.
It is also worth checking the geometry of the notches under the camera and the fingerprint scanner (if it is on this modification, although in the Mi8 it is optical and under the screen, but the cutout for the camera module should be perfect). The gaps between the frame and the glass on the original are minimal and uniform throughout the perimeter, while on copies there are often distortions.
Replacement process and necessary tools
Replacing the back cover Xiaomi Mi8 is a procedure that requires accuracy and the presence of special tools. Glass is attached to a special glue sealant that softens when heated. To work, you will need a hair dryer (or heating plate), a suction cup, thin plastic blades and, preferably, a new layer of glue B-7000 or similar.
Before starting work, be sure to turn off the device. Heating the smartphone on can damage the display matrix or battery. Warm the perimeter of the back cover evenly, without holding the hair dryer for a long time at one point to avoid local overheating of internal components.
☑️ Tools for lid replacement
Once the old lid is removed, you need to thoroughly clean the frame of the residue of the old glue. Use isopropyl alcohol and a plastic card. Metal tools are best avoided so as not to scratch the aluminum. Only after perfect cleaning can you apply new glue and press the new panel.
⚠️ Warning: Don't use superglue (cyanacrylate) to fix the back cover! It highlights the pairs that settle on the camera lens and speaker, irrevocably spoiling them, and also makes re-disassembly almost impossible.
Frequently encountered problems in operation
Even the strong glass Xiaomi Mi8 is not immune to damage, and the most common problem is the appearance of a "web" cracks in the corner opposite the camera module, which is because when you fall on a rib or angle, the glass experiences maximum stress in these areas.
Another problem is the detachment of glass from the frame, which can be due to factory failure (insufficient glue), heavy heating of the device during games or charging, and mechanical stress (bending of the case in the pocket of jeans), in which case there is a characteristic crunch or a gap.
Can I use a smartphone with a cracked lid?
Sometimes users complain about a deterioration in signal reception after the lid is replaced, this can be due to the use of poor-quality glass, which contains metal impurities, or improper installation of antenna contacts. If after the replacement you notice a drop in the network level, it is worth checking the density of the contact areas.
Care for the glass surface
To keep the back cover of your Xiaomi Mi8 retains its original look as long as possible, it is recommended to use protective accessories. Silicone cases with a soft, fluffy coating inside are the best choice, as they extinguish the impacts and do not scratch the glass when put on.
Regularly cleaning the surface with soft cloth will help preserve the properties of the oleophobic layer. Avoid contact with sand and abrasive materials that leave micro scratches that make the glass matte and less durable. Even one deep scratch can become the center of tension, which will cause a crack.
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Glass back cover Xiaomi Mi8 is a consumable material of high strength, requiring careful handling and high-quality replacement in case of damage to maintain tightness and functionality.
In conclusion, the Xiaomi Mi8 back cover is a complex composite, where glass acts as a protective and functional layer, and the aluminum frame provides structural integrity. Understanding what it is made of helps to take care of the device and competently approach the issue of its repair.