Abrasive treatment such as grinding and lapping is an important process in the processing of semiconductor chips. It mainly uses chemical polishing fluid to mix abrasives to precisely process the semiconductor surface, but the polishing will cause the integrity of the chip surface to deteriorate. Therefore, polishing uniformity, uniformity and surface roughness are very important for the production of chips. Polishing and grinding play an important role in semiconductor production.
1. The difference between grinding and polishing
Grinding uses the abrasive particles coated or press-embedded on the grinding tool to finish the processing surface through the relative movement of the grinding tool and the workpiece under a certain pressure. Grinding can be used to process various metal and non-metal materials. The processed surface shapes include flat surfaces, inner and outer cylindrical surfaces and conical surfaces, convex and concave spherical surfaces, threads, tooth surfaces and other profiles.
Polishing is a processing method that uses mechanical, chemical or electrochemical effects to reduce the surface roughness of the workpiece to obtain a bright and smooth appearance.
The main difference between the two is that the surface finish obtained by polishing is higher than that of grinding, and chemical or electrochemical methods can be used. Grinding simply uses mechanical methods, and the abrasive particle size used is coarser than polishing. That is, the particle size is large. Therefore, grinding and polishing are essential for chip production.
Using micron particles with higher hardness than the processed material, micro-cutting is produced under the effect of the hard grinding disc, and the trace data on the surface of the processed chip is removed, so that the dimensional accuracy of the workpiece can meet the requirements.
Abrasive: Grinding fluid generally uses particles larger than 1 micron and is composed of surface active agents, pH regulators, dispersants and other components, and each component exerts different effects.
The effect of the polishing liquid: After a small amount of the polishing liquid is dropped into the drum and stirred by water, it will adhere to the surface of the parts and the abrasive during smoothing.
The effects are as follows:
①Softening effect: the chemical effect on the metal surface oxide film, Make it soft and easy to remove from the surface grinding to increase the grinding power.
②Smoothing effect: It is the same as grinding lubricating oil, which has a smooth effect between the grinding block and the metal parts, and then obtains a smooth appearance.
③ Scrubbing effect: Same as scrubbing agent, it can remove the oil stains on the surface of metal parts.
④Anti-rust effect: the parts after grinding process have certain anti-rust effect in a short time before cleaning.
⑤ Buffering effect: In the smoothing operation, stirring with water will ease the collision between parts.
3. Polishing Treatment
The use of physical grinding and chemical corrosion of micro-abrasives, with the auxiliary effect of soft polishing cloth, does not achieve a smooth appearance, reduces or eliminates the processing deterioration layer, and then obtains a high-quality processing method.
The polishing liquid is a water-soluble polishing agent that does not contain any sulfur, phosphorus, and chlorine additives. The polishing liquid has good degreasing, rust prevention, cleaning and face-lifting properties, and can make metal products show a real metallic luster. Stable performance, non-toxic, no pollution to the environment and other advantages.
It can be seen that both the polishing liquid and the polishing liquid play an important role in the polishing and polishing of semiconductor production. It not only improves the polishing rate, good flatness, and high surface uniformity, but also facilitates subsequent cleaning, so that the abrasive particles will not remain on the surface of the particles.