直接加热负温度系数热敏电阻 - 第2部分:分段规格 - 表面贴装负温度系数热敏电阻

[中文适用范围]： 本部分IEC 60539适用于表面贴装式直接加热负温度系数热敏电阻，通常由具有半导体特性的过渡金属氧化物材料制成。这些热敏电阻具有金属化连接焊盘或 soldering 条带，旨在直接安装在混合电路的基板上或印刷电路板上。 [外文原描述]： IEC 60539-2:2019 is applicable to surface mount directly heated negative temperature coefficient thermistors, typically made from transition metal oxide materials with semiconducting properties. These thermistors have metallized connecting pads or soldering strips and are intended to be mounted directly on to substrates for hybrid circuits or on to printed boards. This edition includes the following significant technical changes with respect to the previous edition: a) revision for the structure in accordance with ISO/IEC Directives, Part 2:2016 (seventh edition) to the extent practicable, and for harmonizing with IEC 60539-1:2016; b) the upper category temperatures of 175 °C, 200 °C, 250 °C, 315 °C, 400 °C in Table 1 have been added; c) the dimensions of 0402M in Annex A have been added.