Electrical discharge slicing of single crystal SiC by utilizing ultra-thin foil tool electrode

利用超薄箔工具电极对单晶 SiC 进行放电切片

基本信息

批准号：
15H06138
负责人：
趙永華
金额：
$ 1万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Research Activity Start-up
财政年份：
2015
资助国家：
日本
起止时间：
2015-08-28 至 2016-03-31
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15H06138/
关键词：
EDM slicing Single crystal SiC wafer Foil tool electrode Kerf loss

项目摘要

Electrical discharge slicing (EDS) of SiC ingot using thin foil tool electrodes (copper or brass) with thickness of 0.03mm was conducted successfully. Kerf width less than 0.1mm was achieved.In foil EDS method, when the foil running speed is sufficiently high, the foil tool wear is little and can be neglected and the slicing process is similar to common wire electrical discharge machining (EDM). On the other hand, at a low foil running speed, the foil tool wear is significant owing to a long dwelling time. At steady state, the foil tool wear shape is an inclined straight line at the working area. The tool wear length is proportional to the tool area wear ratio, workpiece thickness and inversely proportional to the foil running speed.Negative polarity of tool electrode and short pulse duration are confirmed more suitable for foil EDM slicing of SiC which can result in a higher machining speed and a lower tool wear ratio. Thinner foil electrode can result in a higher area cutting speed, however the tool wear ratio also increases. When the ingot workpiece is fixed upside relative to the tool electrode and fed downwards to the tool, higher machining rate can be obtained. In addition, it was confirmed that both enchantment of flushing and higher foil running speed can improve the machining rate by improving the discharge gap conditions.Foil EDM of SiC in deionized water featured higher cutting speed, higher tool wear ratio and larger kerf width compared to those in EDM oil. On the other hand, the surface integrity is better by EDM oil.

使用厚度为 0.03mm 的薄箔工具电极（铜或黄铜）成功对 SiC 锭进行放电切片 (EDS)。切口宽度小于0.1mm。在箔片EDS方法中，当箔片运行速度足够高时，箔片刀具磨损很小，可以忽略不计，切片过程与普通线切割放电加工（EDM）类似。另一方面，在低箔运行速度下，由于停留时间长，箔工具磨损显着。在稳定状态下，箔片刀具磨损形状在工作区域是一条倾斜的直线。刀具磨损长度与刀具面积磨损率、工件厚度成正比，与箔片运行速度成反比。工具电极的负极性和短脉冲持续时间被证实更适合SiC箔片电火花切割，可带来更高的加工性能速度和较低的刀具磨损率。较薄的箔电极可导致更高的面积切削速度，但刀具磨损率也会增加。当锭状工件相对于工具电极向上固定并向下送至工具时，可以获得更高的加工速率。此外，还证实了冲洗的魅力和较高的箔运行速度都可以通过改善放电间隙条件来提高加工速率。与传统的相比，去离子水中SiC箔电火花加工具有更高的切削速度、更高的刀具磨损率和更大的切缝宽度。电火花加工油中的那些。另一方面，电火花加工油的表面完整性更好。