Prepreg and core dielectric styles in PCB stackup

E

engr_joni_ee

Advanced Member level 3
Joined
Nov 3, 2018
Messages
822
Helped
2
Reputation
4
Reaction score
7
Trophy points
18
Activity points
6,875
I read that "common core dielectric thicknesses are 3mils, 4mils, 5mils, 6mils, 8mils, etc. Common prepreg glass styles are 106, 1080, etc. See the thickness and the dielectric constant of the generic prepreg glass styles in the table"

Does this means that the glass styles 106, 1080, etc are only applicable to prepreg and not to core, right ? This means we do not need to specify the glass styles in the stackup for core materials in stackup in degign tools ? as they are only for prepreg.

 

Sort by date Sort by votes
Cloth style apply also to laminates (core) but isn't always specified. Panasonic R-156 datasheet e.g. does.
 

Attachments

  • ipcdatasheet_R-1566s.pdf
    123.9 KB · Views: 108
Upvote 0 Downvote

PCB Material Selector | Sierra Circuits

Use this PCB material selector before you send your design to manufacturing and find materials that suit your application. Try it now!
www.protoexpress.com

Many material properties; mechanical, electrical, thermal
Choose between required speeds and low loss. (which affects cost)
Rigid, Flex,

Cores have more fibreglass for strength.
Prepregs have more resin for filling around tracks. If no tracks then more fibre-prepregs can be used.
 
Last edited:
Upvote 0 Downvote
Another related question to core and prepreg thickness. Is that ture that we avoid using prepreg more then 10 mils ? but we have have cured core available in different thickness that can be up to 40 mil. Any reason for not having prepreg more then 10 mil ?
 

Upvote 0 Downvote
There's no specific reason, although 10 mil is quite a lot. Criteria for chosing prepreg and core are overall PCB thickness for the intended number of layers, impedance considerations, in some cases also voltage strength, economic design. 10 mil or more prepreg means combining at least two sheets for the layer.
--- Updated ---

Generally you'll use PCB house standard stackup as long as it complies with your requirements.
 
Upvote 0 Downvote
You must log in or register to reply here.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…