Re: [SI-LIST] : PCB Build

Diane A. Delute (ddelute@ISI.EDU)
Thu, 28 Aug 97 17:10:50 PDT

Hi,

I use FR4 for PCB designs under 200MHz all the time. I have used FR4
for up to 2.4GHz signals, but it takes abit of finesse and sometimes 2
& 3 tries to get it right. One thing is to ask for a controlled
impedance such that when you switch layers you do not get as many
strange reflections. (Have good ground return paths) Another is to
leave room for terminations on clocks and other distributed signals.

I am not familiar with "PPE". I do know that teflons and polymides
are more expensive. One reason the teflons are prefered for high
frequency is because the materials have a lower dielectric constant.

Diane

> Hi,
>
> During the course of designing PCBs for operation at frequencies >70MHz
> our OCB manufacturer has offered us the use of 'PPE' rather than FR4.
>
> Does anyone out there have any experience or info about PPE including
> what it stands for!
>
> Best regards,
> Vince Harradine.
>