pcb layer stackup

[cobrasv]

Hi,

I need to know how the thickness of the cores and pre-preg laminates is decided when designing multiple layer boards. for example, if i want an 8-layer board of total thickness 1.6mm, what would be the respective thicknesses of the pre-pregs, core, copper as shown in fig below??

is there a Standard for this?? if yes, which one and where can i download it? Need urgent help here.
<a href="http://www.imagehosting.com/"><img src="http://img92.imageshack.us/img92/1246/stackupnr9.jpg" border="0" alt="Image Hosting"></a>

http://img92.imageshack.us/img92/1246/stackupnr9.jpg (http://www.imagehosting.com/)

[cobrasv]

re- attaching picture .............please reply

[cobrasv]

Sumbody Please Answer

[varora]

See attached or consult with your fab house.

[Skip Yutkus]

Vaora's example certainly works, you'll need to compensate for Cu thickness and soldermask, however the most important question is what is the trace impedance you require, if any.

Skip

[blackstick.co.uk]

There isn't a standard for a 1.6 mm 8 layer board as such. However the IPC-4101B(specification for base materials for rigid and multilayer printed boards) has some good information on core and prepreg thicknesses and should allow you to achive your desired board build.

Luke