FreeLists / si-list / [SI-LIST] Re: What happen to FR4 if exposed under strong E field or H field?

[steve weir <weirsp@xxxxxxxxxx>]

How big is big?  to get any real mechanical stress you need some 
ferromagnetic material to raise B.  Planes don't lend themselves to big B 
concentrations.   I would think thermal issues will get you long before 
magnetostrictive stress.

Steve.
At 10:03 AM 6/14/2004 +0800, =?big5?B?Sm9obiBMaW4gKKpMtMK31yk=?= wrote:
>Dear all,
>Do somebody understand  what big E-Field will affect FR4 for PCB if it is 
>over the FR4 breakdown voltage?
>Also, What will a strong Magnetic field  impact  a FR4 PCB. The  big 
>H-Field, magnetic field is caused by big current but low voltage on the 
>power planes sandwiching FR4?  Here, my point is  the influence to the FR4 
>material itself , not crosstalk among signals.
>
>Thanks,
>John
>
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