The chip manufacturing process can be divided into Wafer Fabrication, Wafer Probe, Packaging, Initial Test and Final Test. The wafer processing and wafer needle testing processes are Front End processes, while the assembly and testing processes are Back End processes.
1. Wafer treatment process: The main task of this process is to fabricate circuit and electronic components (transistors, capacitors, logic switches, etc.) on wafers. The processing procedures are usually related to the product type and the technology used. However, the general basic step is to clean the wafer properly, then oxidize and chemical vapor deposition on its surface, and then coat, expose, develop and etch it. After repeated steps such as etching, ion implantation and metal sputtering, several layers of circuits and components are processed and fabricated on the wafer.
2. Needle measuring process: After the previous process, the wafer has formed a small lattice, that is, grains. Generally, in order to facilitate testing and improve efficiency, the same wafer can be made on the same variety, specifications of products; but also according to the need to produce several different varieties, specifications of products. The electrical characteristics of each grain were detected by Probe, and the unqualified grain was marked. After that, the wafer was cut into individual grains, which were then classified according to their electrical characteristics and loaded into different pallets. The unqualified grains were discarded.
3. Constructing process: fix single grain on the chip base made of plastic or ceramics, and connect some lead terminals etched on the grain with sockets protruding from the base to connect with external circuit boards. Finally cover the plastic cover plate and seal it with glue. Its purpose is to protect grain from mechanical scratch or high temperature damage. Only then can we make an integrated circuit chip (that is, those black or brown rectangular blocks with many pins or leads on both or four sides that we can see in the computer).
4. Testing process: The last process of chip manufacturing is testing, which can be divided into general testing and special testing. The former is to test the electrical characteristics of the packaged chip in various environments, such as power consumption, running speed, voltage withstand, etc. The tested chips are divided into different grades according to their electrical characteristics. The special test is based on the technical parameters of customers'special needs, and takes out some chips from the similar parameters, specifications and varieties, and makes specific tests to see if it can meet the special needs of customers, so as to decide whether it is necessary to design special chips for customers. After general testing, the qualified products can be put on the label of specifications, models and date of leaving the factory, and packaged before leaving the factory. Chips that fail to pass the test are designated as degraded products or wastes depending on the parameters they reach.