## 4 Design of Laser Processing Control System for MCR Frequency Modulation
### Prototype and Function Verification of Laser Processing Control System for MCR Frequency Modulation  
In order to ensure the positioning accuracy of the movement of the carrier platform and verify the correctness of the motion control module, after the wafer is fixed on the carrier platform, the actual motion position of the carrier platform is tracked and displayed. The detection results are shown in Table 6. The digital signal resolution of the ATOM grating used in the linear motor can reach 1 nm after subdivision. The carrier platform is controlled to realize single-stroke 100 mm linear motion in the X and Y directions. The positioning error of the X-shaft is between 0.8 \(\upmu\)m and 1.7 \(\upmu\)m, and the positioning error of the Y-shaft is between 0.7 \(\upmu\)m and 1.6 \(\upmu\)m, both below 10 \(\upmu\)m, reaching the positioning accuracy required by the carrier platform.  
In order to verify the motion control accuracy of the carrier platform and ensure that the error between the actual position and the target position of the MCR is within the target range, whether the MCR is transported to the appropriate position can be determined by observing the contact point position of the frequency detection probe and the MCR. The photograph of the contact point is shown in Figure 12.  
In order to verify the laser output function, in the manual tuning interface of the host computer software, the laser photo paper is used to test the functions of laser spotlight output, short-line segment scanning and top scanning to detect whether the laser can output specified light patterns to meet the specified requirements. The length of short-line segment scanning is compared with the set length in the parameters, and  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**X-Shaft Actual Displacement(mm)** & \multicolumn{2}{c}{**Y-Shaft Actual Displacement(mm)**} \\ \hline
**(a)** & **(b)** & **(a)** & **(b)** \\ \hline
100.0012 & 100.0007 & 100.0007 & 100.0013 \\
100.0008 & 100.0013 & 99.9986 & 99.9984 \\
100.0017 & 99.9985 & 100.0009 & 100.0012 \\
100.0017 & 100.0011 & 99.9985 & 100.0010 \\
99.9991 & 100.0012 & 100.0009 & 100.0028 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Actual displacement distance of each shaft.  
Figure 12: Verification of actual contact point position: (**a**) Row 1; (**b**) Row 8; (**c**) Row 16.  
adjusted accordingly if the length cannot meet the set value. At the same time, the laser power is measured by a power meter and compared with the set power to ensure that the laser output power is appropriate. Finally, the electrode part of the MCR is processed by laser and whether the frequency of the MCR changed is verified.  
After each function verification is completed, the automatic operation function verification is carried out. At the automatic processing interface, the functions of automatic measurement of all MCRs, automatic processing of a piece and processing of a specified row are tested to ensure that the automatic operation functions can be realized normally. The data in the processing statistics interface are verified to be consistent with the results obtained by actual processing.