thanks Harry & Jeff the guidlines were good i am not doing impedance control, and they show more thicknesses than i had imagined - glad i'm not a fab shop!
looks like i can pick one that will be plenty close and run that by my fab now that i am not just picking numbers out of the air Dennis Saputelli "H. Selfridge" wrote: > > The standard thickness of core material depends on who makes the laminates > used by your fab. > > If your fab can't make the board to your required dimensions, you need to > call around and see what other fabs can get/do. > > An example of available material from one laminate manufacturer can be seen at: > http://www.chemitalic.dk/content/articles/dfmmatsel.htm > A table of available laminates can be seen in design guidelines from a fab at: > http://www.tru-lon.co.uk/pdf/guidelines.pdf > > Finished thickness for prepreg and some cores can be different from the raw > thickness as supplied. When heated and pressed in the laminating press, > some reduction in thickness of the individual layers tends to occur. The > data sheet from the laminate manufacturer gives the raw and finished > thicknesses. Again, the best source of information is from the fab. If > you're controlling impedance, the finished thickness data is essential for > modeling stripline and microstrip characteristics. > > At 11:56 AM 10/3/04, you wrote: > > >is there a table of standard core thicknesses somewhere? > > > >i have a 6 layer stackup > > > >top > > prepreg > >sig > > core > >gnd > > prepreg > >pwr > > core > >sig > > prepreg > >bott > > > >and am trying to hit 062" overall thickness within +-005 > > > >what are all the material thickness possibilities out there? > >(well maybe not ALL of them :) ) > > > >given 007 prepreg and 021 cores > >my vendor tells me that once you add the copper thickness at 1oz > >the overall is about 071" thick > > > >sounds like 017 cores would do it, but that also sounds like a wierd number > > > >thanks for any help > > > > > >Dennis Saputelli > > > > > >-- > >_______________________________________________________________________ > >Integrated Controls, Inc. Tel: 415-647-0480 EXT 107 > >2851 21st Street Fax: 415-647-3003 > >San Francisco, CA 94110 www.integratedcontrolsinc.com > > > > > > -- _______________________________________________________________________ Integrated Controls, Inc. Tel: 415-647-0480 EXT 107 2851 21st Street Fax: 415-647-3003 San Francisco, CA 94110 www.integratedcontrolsinc.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] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
