Nowadays, electronic products are progressively becoming thinner, lighter, and more convenient for people to use. Printed circuit boards, and especially integrated circuit (IC) substrates, are among the essential component of these products. The IC substrate not only protects circuits, fixes lines, and conducts heat, but is also the critical component that provides signal connectivity between the chip, the printed circuit boards, and other crucial parts during the packaging process. The process capability index C_pm is commonly used to assess the product quality loss for decision making in modern semiconductor packaging manufacturing. For high‐definition products, packaging processes often have very strict quality requirements and thus the quality inspection procedure is time‐consuming and complicated. Therefore, because of the limitation of manpower and capacity of the inspection instruments, the collected sample for quality assessment may be with small to moderate sample sizes. In this paper, we introduce an unbiased estimator for C_pm and provide a step‐by‐step parametric bootstrap procedure for obtaining a composite lower confidence bound on C_pm. To compare with the approaches discussed in the literature, numerical simulations are conducted under various process parameter settings. The results show that for small to moderate sample sizes, the proposed method applying the unbiased estimator has more accurate coverage rates than the existing methods. At the end of this paper, an application of quality loss assessment in notching processes is demonstrated.

中文翻译：

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缺口加工过程中质量损失的改进度量

如今，电子产品正逐渐变得更薄，更轻，更便于人们使用。印刷电路板，尤其是集成电路（IC）基板，是这些产品的基本组成部分。IC基板不仅保护电路，固定线路并传导热量，而且还是在封装过程中在芯片，印刷电路板和其他关键部件之间提供信号连通性的关键组件。工艺能力指数C _pm通常用于评估产品质量损失，以进行现代半导体封装制造中的决策。对于高清晰度产品，包装过程通常具有非常严格的质量要求，因此质量检查过程既耗时又复杂。因此，由于检查工具的人力和能力的限制，用于质量评估的采集样品可能只有小到中等的样品量。在本文中，我们介绍了C _pm的无偏估计量，并提供了逐步的参数自举程序，以获取C _pm的复合下置信度。为了与文献中讨论的方法进行比较，在各种过程参数设置下进行了数值模拟。结果表明，对于中小样本量，与现有方法相比，所提出的应用无偏估计量的方法具有更准确的覆盖率。在本文的最后，展示了质量损失评估在刻痕过程中的应用。