In the 1990’s, in order to solve the processing problem of large size silicon wafer, jigsaw machining technology are widely used to cut large size silicon wafer into segments and pieces in the international marketing. Early jigsaw machining technology applied bare wire and free abrasive. In the process of machining, the free abrasive are added into wire and mechanical parts as the third party to cut. This technique is successfully used in processing of silicon and silicon carbide. In order to further shorten processing time, as well as on other hard material and ceramic, diamond abrasive will be fixed to a metal wire in a certain way, which compose a fixed diamond wires saw.

   As shown in figure, cutting lines with high-speed reciprocating motion drive the slurry to the cutting area, which makes the abrasive particles (SiC particles) in the mortar and the surface of silicon rod make high speed grinding. Because the abrasive particles have very sharp edges and its hardness is greater than the hardness of silicon rods, the contact area of silicon rod and diamond wires saw are grinded out gradually by mortar. Thus the effect of cutting will be achieved, and meanwhile the mortar also can take away a lot of hot produced in the grinding.

   In the process of cognition of diamond wire saw cutting mechanism, many researchers believe that the micro cutting movement of diamond grits is a scroll and embedded process. They put forward the "scroll - embedded" model. Li and some reachers put forward diamond wire sawing force drives on the abrasive grits rolling along the cutting surface, squeezing and embedded abrasive cutting surface at the same time. Consequently there is a flake piece of chip and surface crack, forming the big cutting function. Kao and other researchers pointed out that in "scroll - embedded" model, the particle movement also includes scratches, in addition to the rolling and embedded. All three work together for cutting. Bhagavat and some researchers considered the effect of pulping in this model and believe that the diamond saw wire leads free abrasive cutting silicon ingot of small area, and the movement of diamond wires saw and grinding pulping form a elastic fluid dynamic environment. They can use the finite element method (fem) to analysis the elastic fluid dynamics model of diamond wires saw and silicon ingot to get the function of diamond wire walking speed, viscosity of grinder and cutting conditions. Then they draw the conclusion: pulping film thickness is greater than the average particle size, is the flow of the abrasive cutting.
 
 
Back to Top