大约200000个镀通孔，主要覆盖电镀，但也包括化学镀技术，暴露在几个不同的热循环中。对一些PTH直径、板结构和镀层厚度进行了评估。

Approximately 200,000 plated through-holes, covering primarily electroplated but also electroless technology, were exposed to several different thermal cycles. A number of PTH diameters, board constructions and plating thicknesses were evaluated.