# Study on Preparation and Processing Properties of Mechano-Chemical Micro-Grinding Tools
## 3 Analysis of Micro-Grinding Force
### Experimental Study of Grinding Force  
To verify the model's accuracy, the grinding force of the surface of the silicon wafer ground by the micro-grinding tool was measured experimentally. The experiment was performed on the MKC2945C continuous trajectory coordinate grinder. The experimental silicon wafer is commercially purchased (100) crystalline single-crystal silicon with a size of 15 \(\times\) 10 \(\times\) 3 mm; The sensor is a KISTLER load cell. In this experiment, the end-face grinding method is adopted, and Figure 6 is the diagram of the experimental device. In the experiment, the fixture of the silicon wafer was first designed and fixed to the sensor with a countersunk bolt, and the silicon wafer was fixed on the fixture for the grinding force test. The grinding force on the silicon wafer is transmitted to the sensor through the fixture, resulting in force signal data in three spatial coordinate directions. After the tool was set between the tool and the workpiece, a single 1 \(\upmu\)m axial feed was carried out, followed by a reciprocating lateral feed, and the above process was repeated to complete the grinding process. The processing parameters are shown in Table 2.  
Figure 6: Device diagram of the grinding force experiment. After the grinding state was stable, the data was collected. Figure 7 shows the normal and tangential grinding forces under different cutting depth conditions after filtering treatment, and the sensor data acquisition time is 10 s. The variable for this grinding force measurement experiment is the depth of cutting. From the grinding force measurement results in Figure 7, it can be seen that after filtering, both the normal grinding force and the tangential grinding force will show fluctuations within a certain range. The cause of this phenomenon may be fluctuations in force caused by the system's vibration. In addition, from the grinding force measurement results of Figure 7a,b, it can be seen that when the grinding depth is 1-3 um, the grinding force will decrease to a certain extent as the grinding process progresses. Illustrating that at a given cutting depth, material removal occurs at the contact surface of the micro-grinding tool and silicon wafer, decreasing the contact pressure between the two contact surfaces. When the cutting depth is 4-5 um, the grinding force does not show a decreasing trend, which may be due to the average particle size of cerium oxide abrasive grain being 5 um; when the cutting depth reaches 4-5 um, it has exceeded the cutting edge height of cerium oxide abrasive grain. At this time, the deformation degree of the abrasive grain is large, and there is a more serious extrusion phenomenon between the micro-grinding tool and the silicon wafer, so the measured grinding force is large. To reflect the grinding force more realistically, the average data points within 0.5-4 s after the rising stage of each force measurement result were compared, and the results after adjusting the selected interval are shown in Figure 8. \begin{table}
\begin{tabular}{c c} \hline \hline
**Project** & **Parameter** \\ \hline Speed (r/min) & 1500 \\ Axial feed speed (μm/min) & 1 \\ Processing time (h) & 1 \\ No feed light grinding times & 10 \\ Transverse feed speed (mm/min) & 10 \\ Grinding method & Dry grinding \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Processing parameters of the grinding experiment. Figure 7: The grinding force under different depths of cut conditions. (**a**) Tangential grinding force. (**b**) Normal grinding force. It can be seen from the results of Figure 8 that after changing the sampling time range of the grinding force, the experimental value and theoretical value of the grinding force at a cutting depth of 1-3 \(\upmu\)m were greatly reduced, both of which were about 10%. In contrast, the error at a cutting depth of 4-5 \(\upmu\)m increased.