Precision OEM of iPhone 15 cases is a complex and delicate process involving multiple steps and processes. The following are the general steps and key processes of iPhone 15 case precision machining, which are organized according to the available information:

　　1. Material selection and preparation

　　Material selection: The materials for phone cases are usually aluminum alloy or other metal alloys, which have good strength, hardness and ductility. For iPhone 15 cases, different series of aluminum alloys, such as 7000 series aluminum alloy, may be selected according to specific design requirements to improve the durability and bending resistance of the cases.

　　Material Preparation: The selected metal material will be pre-treated by cutting, grinding, etc. to ensure that its surface is flat, free of defects and meets the requirements of subsequent processing.

　　2. Precision machining

　　CNC machining: CNC (numerical control machine tool) is used for precision machining, through the preset program to control the machine tool for milling, drilling, etc. to form the basic shape and internal structure of the phone case.CNC machining can ensure the accuracy and consistency of machining, which is the key link in the precision machining of the phone case.

　　Die casting molding: For some parts of the phone case that require complex shapes or structures, the die casting process may be used. Die casting is the process of pouring molten metal into a mold and die casting it into the desired shape through high pressure. This process is capable of producing a large number of parts with complex shapes, but care needs to be taken to control parameters such as temperature, pressure and speed during the die-casting process to ensure product quality and consistency.

　　3. surface treatment

　　Anodic oxidation: Anodic oxidation is a commonly used metal surface treatment technology, through the electrochemical effect on the metal surface to form a layer of dense oxide film. This oxide film can improve the hardness, abrasion resistance and corrosion resistance of the metal surface, and at the same time, it can also give the metal surface rich colors and luster. For iPhone 15 cases, anodizing can significantly improve their appearance and durability.

　　Sandblasting and Polishing: Sandblasting removes tiny bumps and burrs from the metal surface, making the surface flatter and smoother. Polishing further enhances the gloss and texture of the surface. These processes can make the appearance of the phone case more exquisite and beautiful.

　　4. Assembly

　　Assembly: assembling all parts of the processed phone case, including the installation of keys, screws and other parts. During the assembly process, we need to pay attention to the matching precision and sealing between the parts to ensure the overall performance and appearance quality of the phone case.

　　The assembled cell phone case is carried out, including appearance inspection, size measurement, function test and so on. Ensure that the phone case meets the design requirements and quality standards before the next step of packaging and shipping.