PDF《WK73-RT》

5 ― 用含硫3.5%的工业油浸渍105℃±3℃ 500h Soaked in industrial oil with sulfur substance 3.5% contained 105℃ ±3℃ 500h 使用注意事项 Precautions for Use z 片状电阻器的基材是氧化铝,由于和安装基板的热膨胀系数不同,在反复施加热循环等热应力时,接合部的焊锡(焊接部)有时会发生龟裂.由于WK73系列本身的发热量很大,如果环境温度反复发生很大的变动,并且载荷反复进行ON/OFF,则需要注意龟裂的发生.因热应力而发生的龟 裂,取决于所安装的焊盘的大小、焊锡量、安装基板的散热性等,因此在环境温度有很大的变化或载荷ON/OFF的条件下使用时,请充分注意以 进行设计. z The substrate of chip resistors is alumina. Cracks may occur at the connection of solder (solder fillet portion) due to the difference of the coefficient of thermal expansion from a mounting board when heat stress like heat cycle, etc. are repeatedly given to them. Care should be taken to the occurrence of the cracks when the change in ambient temperature or ON/OFF of load is repeated, especially when WK73 series which have self-heating. The occurrence of the crack by heat stress may be influenced by the size of a pad, solder volume, heat radiation of mounting board etc., so please pay careful attention to designing when a big change in ambient temperature and conditions for use like ON/OFF of load can be assumed. Mar. 2015 ........