Sean, I would also like to point out that there is some derating for frequency, although I don't have a reference for what the factor is. High voltage is not very well behaved at high frequencies, and you'll need to avoid sharp corners at all costs. I have personally seen less than 50kV @ ~1Mhz puncture 1/4" plate glass in under 30 minutes at a ragged conductor edge.
Frank At 02:48 PM 3/18/2002 -0800, you wrote: >Sean, > the standard answer from IPC for general purpose (Epoxy E-glass) FR4 >(is there such a thing today?)is 39,400 Volts/mm (approx. 62,500V at >0.062"). This is derived from a test using 0.125mm and they warn that it >should not be considered linear for high voltage applications with minimal >dielectric spacing, i.e. less then 0.09mm (0.0035"). Don't think that counts >for most general designs, that would be 3.5mil laminate. > > Now a word of warning. This would be through the dielectric, not >around the edge of the material, through air, nor over the surface(s). >Considering most applications and the means for contamination of these >surfaces, I would be checking the surface or around the edge requirements as >well. Especially is there is copper near the board edges. > >Sincerely, >Brad Velander. > >Lead PCB Designer >Norsat International Inc. >Microwave Products >Tel (604) 292-9089 (direct line) >Fax (604) 292-9010 >email: [EMAIL PROTECTED] >http://www.norsat.com > >See us at Booth S8155 at NAB 2002 in Las Vegas April 8 - 11. > > >-----Original Message----- >From: Sean James [mailto:[EMAIL PROTECTED]] >Sent: Monday, March 18, 2002 2:15 PM >To: Protel EDA Forum >Subject: [PEDA] Voltage standoff of FR4 > > >What is the voltage standoff (front to back) for .062" FR4? > >Sean James >PCB Designer >Telecast Fiber Systems >102 Grove Street >Worcester, MA 01603 >TEL 508-754-4858 x33 >FAX 413-541-6170 Frank Gilley Dell-Star Technologies (918) 838-1973 Phone (918) 838-8814 Fax [EMAIL PROTECTED] http://www.dellstar.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[email protected] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
