# Measuring the Positions of the Solder Pins of Electrical Connectors from the Side
## 4 Conclusions  
When using machine vision to measure the positions of the solder pins from the bottom of an electrical connector or similar electronics components, it must be noted that the light reflection may affect the results. Nevertheless, measuring from the side may solve the problem. In particular, this research developed a machine vision system and the associated algorithm to address the issue. From the discussion in the paper, it can be understood that the proposed method can be applied to various electrical connectors or electronic components with solder pins and a reference peg. In validating the measurement results of this proposed method, a 2D VMM is used to measure the positions from the bottom of the connectors so that the results can be compared to the positions obtained using the proposed method. From the two examples presented in the paper, the difference between the measurement results using the proposed method and the 2D VMM was about \(\pm\)0.03 mm. Considering all the possible causes of difference between measuring from the bottom and from the side of the connector, we can conclude that the proposed method in the paper  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multicolumn{2}{c}{**Deviation**} & \multicolumn{1}{c}{**Pin 1**} & \multicolumn{1}{c}{**Pin 2**} & \multicolumn{1}{c}{**Pin 3**} & \multicolumn{1}{c}{**Pin 4**} & \multicolumn{1}{c}{**Pin 5**} & \multicolumn{1}{c}{**Pin 6**} \\ \hline \multirow{2}{*}{**Sample 1**} & **side** & 0.062 & 0.062 & 0.071 & 0.051 & 0.036 & 0.029 \\ \cline{2-8}  & **bottom** & 0.086 & 0.064 & 0.064 & 0.040 & 0.034 & 0.030 \\ \hline \multirow{2}{*}{**Sample 2**} & **side** & 0.055 & 0.095 & 0.070 & 0.298 & 0.019 & 0.270 \\ \cline{2-8}  & **bottom** & 0.084 & 0.078 & 0.048 & 0.300 & 0.013 & 0.297 \\ \hline \multirow{2}{*}{**Sample 3**} & **side** & 0.026 & 0.024 & 0.025 & 0.043 & 0.158 & 0.073 \\ \cline{2-8}  & **bottom** & 0.007 & 0.037 & 0.051 & 0.067 & 0.177 & 0.086 \\ \hline \hline \end{tabular}
\end{table}
Table 2: The deviations of the first six pins of the three samples measured in case study two. “Side” means that the measurement was performed from the side of the samples using the proposed method, and “bottom” means that the measurement was performed from the bottom of the samples using the 2D VMM.  
can be used as an alternative for measuring the position of the solder pins of connectors, especially when the measurement from the bottom of the connectors is not feasible.  
Conceptualization, W.-c.L. and K.-C.H.; methodology, W.-c.L. and K.-C.H.; software, K.-C.H.; validation, K.-C.H.; formal analysis, K.-C.H.; investigation, K.-C.H.; resources, W.-c.L.; data curation, K.-C.H.; writing--original draft preparation, W.-c.L. and K.-C.H.; writing--review and editing, W.-c.L.; visualization, W.-c.L. and K.-C.H.; supervision, W.-c.L.; project administration, W.-c.L.; funding acquisition, W.-c.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Science and Technology Council, Taiwan, Republic of China, grant number MOST 110-2218-E-011-011.  
Not applicable.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to their use in future research activities.  
The authors declare no conflict of interest.