What if you made "Inner4" 1/2 oz Cu?  On Inner5 you could put hatch (a
grid of unconnected lines) in any unused areas.  It seems to me the
stackup would be balanced then.

It seems like your stackup would be impossible without a piece of core
that has different thicknesses on each side.  I do not know if they make
core like that.

A good fab house will recommend a stackup if you tell them what you are
trying to do.


-----Original Message-----
From: DesignerCouncil [mailto:[log in to unmask]] On Behalf Of ert
ert
Sent: Tuesday, August 29, 2006 10:02 AM
To: [log in to unmask]
Subject: [DC] symmentric and asymmentric layer stack up

Hi All,

I got a 10layer stackup as below,

Top  (1/2 oz+1/2 oz)
Inner1--gnd (1 oz)
inner2--signal 1 (1/2 oz)
inner3- pwr (1 oz)
inner4- gnd (1 oz)
inner5- signal 2 (1/2 oz)
inner6- pwr (1 oz)
inner7- signal 3 (1/2 oz)
inner8- gnd (1 oz)
Bottom (1/2 oz+1/2 oz)

if I divide this into two halves and see the prepreg tickness, core
thickness both are equal. But if I look at the copper thickness the
thickness is not balanced on either halves (4.5 oz on upper half and 4
oz on lower half). what issues this could cause in FAB and Assembly?

Can I mark this stackup as asymmentric?

Looking for your suggestions.

Thanks,
Nagaraj.






---------------------------------
 Here's a new way to find what you're looking for - Yahoo! Answers

------------------------------------------------------------------------
---------
DesignerCouncil Mail List provided as a free service by IPC using
LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text
in
the BODY (NOT the subject field): SIGNOFF DesignerCouncil.
To temporarily stop/(restart) delivery of DesignerCouncil send: SET
DesignerCouncil NOMAIL/(MAIL)
Search previous postings at: www.ipc.org > On-Line Resources & Databases
> E-mail Archives
Please visit IPC web site
http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100
ext.2815
------------------------------------------------------------------------
---------
 Send FREE SMS to your friend's mobile from Yahoo! Messenger Version 8.
Get it NOW

---------------------------------------------------------------------------------
DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF DesignerCouncil.
To temporarily stop/(restart) delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL/(MAIL)
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
---------------------------------------------------------------------------------