The Surface Investigation Of Single Crystal SiC Sawed By Electroplated Diamond Wire

The rapid development of electronic industry makes a big challenge for thesemiconductor materials. The traditional semiconductor material (Si) is hardto meet new requirements. The three-generation semiconductor material (SiC)is a better choice with a wide band gap, high integration, high power and highheat dissipation. However, the high hardness and wear resistance makes SiChard to be processed. The sawing process of SiC is the first stage formachining. It has an influence on the machining stages followed.The article investigated the process of electroplated diamond wire sawingsingle crystal SiC under a wide range of sawing speed. It studied the rulesbetween processing parameters and sawing forces using a piezoelectricdynamometer. It also made an analysis about the special energy in sawingprocess. In this article, it also discussed the wire vibration in horizontal andvertical direction using a laser displacement sensor. In the aspect of surfacequality, it studied the surface roughness by using a surface roughness tester,the surface profile and cracks by using white-light interferometer and SEM.Based the results, the generate mechanism of surface profile and cracks indiamond wire sawing single crystal SiC have been got. The main results canbe described as follows:1. Sawing forces increase linearity with the increasing of feed speed, whiledecrease nonlinearity with the increasing of wire speed. The relationshipbetween sawing forces and tension force is not obvious. Though the sawinglength and wire diameter have an influence on sawing forces, there is noeffect on the sawing unit area forces. The special energy in sawing process isaffected by the material remove rate of unit length of diamond wire.2. The diamond wire vibrates during sawing process. There are twocomponents in the frequency feature. The low frequency component comesfrom rollers, while the high frequency component comes from nature frequency of diamond wire. The low frequency increases with the wire speedincrease and the high frequency increases with the tension force increase.There is no rule between RMS of diamond wire and processing parameters.3. The typical waviness feature can be found on the SiC surface sawed bydiamond wire saw. The generation of waviness feature can be related to themovement of wire sawing process. In which the length of waviness isdepended on the wire speed, feed speed and the length of sawing wire.4. The single crystal SiC is removed mainly in brittle style in the diamondwire sawing process. Higher wire speed turns the remove style into bothbrittle and ductile style, and enlarges the ductile area. The ductile area can beeasily found in the peaks and valleys of surface profile. The brittle materialremove style can be always found on the surface because of the movement ofwire saw.5. Brittle fracture morphology can be found in the saw kerf of diamond wiresawing. The cracks can be found in the sawing surface of SiC sawed bydiamond wire saw. The vibration of diamond wire and wire speed are the keyfactors of the surface generation.