Summary Of Surface Treatment Technology Of Mobile Phone Plastic Shell -- Huawei Enjoy 9S Surface Treatment Technology Revealed

- Apr 19, 2019-

Summary of surface treatment technology of mobile phone plastic shell -- huawei enjoy 9S surface treatment technology revealed


On March 25, the huawei vision 9S series was released, using the plastic surface treatment process: ceramic spraying +NCVM process, 8 layers of gradient electroplating process, together with the soft and cool skin-friendly paint, bringing a very rich texture of ceramic touch. Now I will make a brief analysis on the surface treatment of the plastic shell.


Enjoy 9S process flow: injection molding plastic molding material polishing/polishing cleaning ceramic spraying cleaning NCVM baking cleaning CNC post-processing (such as SPK hole, key hole, cato hole, USB hole, MIC hole processing) cleaning full inspection finished product packaging


Ceramic spraying and NCVM process


One.ceramic spraying


1. Process principle:


Through multi-coating and multi-baking, the ceramic slurry is sprayed onto the plastic shell, and after baking and curing, a dense ceramic paint film is formed to achieve the hand feeling and appearance effect of ceramic material.


2. Material polishing section before spraying


Grasp the rule of grinding amount by grinding data, and then adjust the parameters of the manipulator, control the grinding amount;


The use of mechanical hand finishing, completely replace artificial polishing, to reduce the workload of artificial polishing, to ensure the consistency of the material;


3. The following focuses on the matters needing attention in ceramic slurry spraying:


1) ceramic slurry curing process introduction

Ceramic coating due to the product storage period is not long, so it is generally made into semi-finished products, divided into A,B,C three groups classification, and then by the customer in accordance with the operating instructions after adding, on their own on the rolling machine curing reaction, made of finished products can be sprayed.


2) processing flow of plastic materials before spraying

Before spraying, clean the plastic substrate, do not have any dirt, grease, acid/alkali marks.


3) spraying and baking process:

1) : the substrate shall be preheated with spraying

Preheat temperature control in 45 to 55 , at the actual temperature in the base (summer temperature is higher, preheating can be adjusted to 45 to 50 )

a: temperature is too high, easy to coarse, influence burnish, since the dry too fast, easy spraying thick and cracking;

b: the temperature is too low, easy to hang, easy to shrink, and reduce the luster;


2) : film thickness control
Standard for single coat thickness: 30-35um, double primer: 25-30um, top coat: 5-10um;


3) : film curing temperature and time control
After spraying, the product needs to be baked and solidified to form a compact ceramic paint film. The spraying product is baked in two stages: low-temperature surface drying stage, high-temperature baking and curing stage. After baking and curing, the product will form a dense paint film.


Two.NCVM is not conductive to vacuum plating

1. Process principle

NCVM, also known as discontinuous coating technology or non-conductive electroplating technology, is to use the discontinuous properties of metal and insulating compound films plated, so as to obtain the final appearance with both metal texture and without affecting the effect of wireless communication transmission. The process of coating metal materials on the surface of substrate by vacuum evaporation. General coating metal target material for pure indium and other materials, can ensure the non-conductive characteristics.


2. Process features:

(1) the product is non-conductive and can pass the high-voltage test of tens of thousands of volts in the high-voltage meter without conducting or being broken down;
(2) the surface of the product can achieve semi-transparent control while having a metallic texture;
(3) the cost is relatively low compared with the metal housing;
The above is the process introduction of changxiang 9S ceramic spraying and NCVM. Other plastic surface treatment processes are also introduced below


Three.PPVD decoating


1. Process principle:

Photosensitive ink in the absorption of exposure energy can enhance the principle of ink adhesion, need to retain the pattern for protection; The ink that does not absorb light energy will be removed without curing. The pattern that needs to be protected will be retained as the surface ink is cured. The desired coating pattern can be obtained by removing the ink on the surface of the pattern.


2. Process flow:

Material (plastic shell, glass, ceramic) to cleaning, painting/printing photosensitive ink film thickness (10-15 um) and baking, baking temperature 60 plus or minus five degrees, 5-10 min) and film exposure (energy, 30-80 mj/cm3) time: 3-5 s) - > development (concentration of alkaline solution development: 0.5 to 0.8% of Na2CO3 solution, temperature of 30 + 2 , time of 25-45 s) - etching (acidic solvent etching time 3-10 s) - > back membrane (alkaline solution annealing membrane, temperature 30 plus or minus 2 degrees, 60-120 - s) - pure water cleaning - finished products


3. Process features:

(1) extremely dense and exquisite nano-dot pattern and other arbitrary patterns can be easily realized on the mobile phone shell;
(2) strong sense of metal, three-dimensional, artistic and fashion sense. ;
(3) the process is generally used for large flat battery cover;


Four.PVD ion coating


Ion plating is under vacuum conditions, the use of gas discharge gas or vaporized material partial ionization, and in the gas ion or vaporized material ion bombardment, the vaporized material or its reactants plated on the surface of the substrate. The difference between ion plating and vacuum plating is that the target is bombarded by ionized particles.


IKS PVD ion coating equipmentany question about ion coating




One.Injection molding of IML insert

1. Process principle:

IML (In Molding Label) mould insert Molding is to have good printing within the diaphragm into the metal mold design, injection forming with the resin into the metal mould and diaphragm joint, make the printing patterned membrane and resin to form an organic whole and a forming method is solidified into finished products. Its surface is a layer of hardened transparent film, the middle is a printing pattern layer, the back is a plastic layer, because the ink sandwiched in the middle, can make the product to prevent the surface is scratched and friction resistance, and can maintain the color of the bright color is not easy to fade.


2. IML process:

Film processing effect processing (including UV transfer, AR coating) background printing protective layer printing adhesive layer printing Forming Triming injection molding CNC machining side hole inspection packaging shipment


3. Process features:

(1) the IML process can achieve the effect of imitating aluminum alloy anode, with better contrast effect of particle feeling and luster;
(2) high definition, good stereoscopic sense, scratch resistance on the surface, free to change the design pattern, enhance the aesthetic appearance of the product;
(3) consistent color pattern, backlight, various colors and shall be reflected in various curved surfaces, cambered surfaces and inclined surfaces;




1. Process principle:

IMT (Insert Mold Three - dimensional) brings together a variety of advantages of decoration process, adopted on IML technology in FILM production advantages, absorb the advantage of IMR technology transfer within injection ChengMo, combined with the digital printing and offset printing effect with the traditional screen printing technology, make the IMT technology applicability, wide application, makes up for the limitations of the appearance of the traditional decoration process, satisfying the requirements of product appearance illuminative high-level innovative.


The new IMT process can be understood as IMR process: after 3D molding, IML injection molding is adopted, and then the carrier layer PET is dead, leaving 3D optical nano-decorative layer on the plastic surface. Compared with the traditional IMR, 3D optical texture and PVD color film layer are added, with a larger radian. IMT will drive the striding innovation of the product appearance industry, realizing the three-dimensional, color gradient, R Angle and other irregular product appearance decoration effect, and provide better innovation and platform realization for the appearance process design industry!


Representative model: enjoy 8 new model, OPPO A79



2. Process flow:

Base material (PET, PC) - > UV transfer (grain can diversify)) - > screen printing mold release agent (for base material and the plastic strip) to screen printing LOGO, optical plating (can do many colors, gradients) - > screen printing color (one or two black, or other color) - > screen printing light oil (the main wash it in order to prevent ink, one or more) - printing adhesive (in order to combine with plastic) - sheet more than hot bending forming and sheet material cutting to tore to diaphragm, sheet and plastic injection molding and uncovered part of diaphragm vacuum coating (box) - part stripping IMT sheet, after spray UV - CNC machining


3. Process features:

(1) IMT process combines the advantages of traditional coating process, IMT,IMR and IMF processes;
(2) pictorial pattern decoration effect reaches the digital level of pixels, rich color gradient effect is good;
(3) the thickness of decorative film is 30um, and the product is stable and consistent;
(4) diversified styles, can create metal plating or natural styles according to customer needs;


To meet the needs of 5 g signal, the low-end models mobile phone architecture basically is the following two kinds: one kind is inner cavity die casting/appearance molding box + TP/composite plate decoration + battery cover glass, one kind is die-casting lumen/appearance before the injection molding shell + plastic box + injection battery cover, the above two types of architecture, also shows that the plastic material is the mainstream in the future material, plastic chassis as a mobile phone material penetration will be more in-depth, is expected to reach 70%, the current low-end models have all to metallization, mid-range models are also accelerate penetration, certainly will is the outbreak of the plastic as the year of 2019!