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tangxianyu 发表于 2012-10-30 15:32 ( j! A. S" p7 u3 ~4 L. |$ t7 d) Y
不是看不明白,是我和认证公司的工程师有分歧。他说那个PWB指的是板子内部的距离,例如双层版的top layer ...
4 d" j' l: i# R6 k. ~0 sCTI>175的PWB才可以Column 3來判定(有UL認可的PWB的CTI值大多在175以上);
8 |: \- n# a( ?多層板內部距離被認為是Solid insulation,經受住如下測試就OK.1 k# c( I" [/ \0 y
7.3.7.8.2 Requirements for electrical withstand capability of solid insulation
* P x3 A4 x3 `8 c7.3.7.8.2.1 Basic, supplemental, reinforced, and double insulation6 V. q# A+ T" Z, a8 B
Solid insulation shall withstand the applicable impulse withstand voltage test according to j6 Y( T& k* o- ]1 @8 x/ f
7.5.1 and the a.c. or d.c. voltage test according to 7.5.2.0 ^9 w( W) [& W) G& [; Y
In addition, double and reinforced insulation shall withstand the partial discharge test
* C; T/ {. D: n4 h5 p0 Naccording to 7.5.3, if the recurring peak working voltage across the insulation is greater than7 p& O5 x/ E3 L
700 V and the voltage stress on the insulation is greater than 1 kV/mm. |
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