The High-Granularity Timing Detector (HGTD), with a time resolution of approximately 30 ps, is proposed for the ATLAS Phase II upgrade to address the challenge of greatly increased pile-up interactions. The HGTD is based on the technology of Low Gain Avalanche Detectors (LGADs). The current–voltage (IV) and capacitance–voltage (CV) measurements are important methods to study the main characteristics that can be exploited for quality controlling LGADs during production. A single probe can be controlled via computer to switch channels when using an automatic probe station, but this leaves the remaining, adjacent channels floating and results in inaccurate measurements due to the punch-through effect. We designed the digital switch boards for the IV and CV measurements of 5 $\times$ 5 and 15 $\times$ 15 LGADs arrays. With the digital switch board and probe cards, channels on a large-array LGADs can be scanned automatically during the measurement, which greatly improves the measurement efficiency. The results show that the leakage currents and noise of all channels induced by the two digital switch boards are lower than 10 pA. We show the IV and CV curves of all channels on two LGADs from Hamamatsu Photonics K. K. (HPK) with our digital switch boards. Compared with the results measured by HPK with an automatic probe station, the IV and CV curves that we measured have better uniformity and accuracy, demonstrating that the quality control of the large-array LGADs can be conducted well with our digital switch board.

建议将高粒度定时检测器（HGTD）的时间分辨率约为30 ps，用于ATLAS II期升级，以解决堆积交互作用大大增加的挑战。HGTD基于低增益雪崩检测器（LGAD）技术。电流电压（IV）和电容电压（CV）测量是研究生产过程中可用于LGAD质量控制的主要特性的重要方法。使用自动探针台时，可以通过计算机控制单个探针来切换通道，但是这会使其余的相邻通道浮动，并且由于穿通效应而导致测量不准确。我们设计了用于5级IV和CV测量的数字开关板$\times$ 5和15 $\times$15个LGAD阵列。使用数字开关板和探针卡，可以在测量过程中自动扫描大型LGAD上的通道，从而大大提高了测量效率。结果表明，两个数字开关板引起的所有通道的泄漏电流和噪声均低于10 pA。我们用数字开关板显示了Hamamatsu Photonics KK（HPK）的两个LGAD上所有通道的IV和CV曲线。与使用自动探针台HPK测得的结果相比，我们测得的IV和CV曲线具有更好的均匀性和准确性，这表明使用我们的数字开关板可以很好地进行大阵列LGAD的质量控制。