I gained a deeper understanding on the wafer sawing process and the corresponding machines involved. First off, I noticed that the amount of wafer sawing machine is considerably more than that of wafer washer machine. After some lucid explanations from Miss Manggala, this is because one wafer washer can be shared by several wafer sawing machines as the washing process is a brief process. In a wafer washer machine, water is shot at high velocity at sawn wafer which is rotated swiftly. Although such conditions may seem to be destructive to the dies, the dies are actually unaffected! However, if we were to touch the surface of the wafer, though this condition seems to be less extreme than the previous instance, the dies will be damaged by our electrostatic charge as well as oxidation.
Next, in each wafer sawing machine, chemicals are used to clean impurities on the wafer surface. When the sawing blade is blunt or different blade is needed, the suitable blade will be changed manually by operators. After the new blade is installed, a dummy wafer is used for blade dressing. In other words, it means blade seasoning or to smoothen the blade edge. If this step is neglected, wafer sawn would have cracked dies.
After the sawing process, as I had mentioned earlier, wafer washing ensues. Then, that piece of wafer will be stored in cupboards. These cupboards are annexed with gas hose that channels nitrogen gas into the cupboards which can prevent oxidation of dies.
Oh! Ya! How can I not talk about the irksome bonding diagrams? I managed to complete the re-updating of SOT457P and SOT753P bonding diagrams.
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