Last option (larger pkg.) is safest choice for us. It is available in 1MM
or 0.8MM (don't remember which off hand). Fairly high volume/harsh
environment (automotive). The unfortunate aspect of that decision is, of
course, the impact of the larger pkg. in the available space. But we stay
pretty far behind the bleeding edge because of the potentially catastrophic
problems that can come up after something's been out in the field for a
while.
Thanks for your input!
-Chris
"David Greig"
<[log in to unmask]> To: "'(Designers Council Forum)'"
<[log in to unmask]>, Chris
12/08/2005 08:52 AM BALL/AuburnHills/VSDS/VALEO@VALEO
cc:
Subject: RE: [DC] Info for routing 0.5mm
BGA's
Hi Chris
Some of the options are:
L1-L2 microvia, great for smaller parts (4x4 array).
Selective outer layer plating and ~75um tracks for fanout of larger parts
(might as well have L1-L2 microvia as well) - but this
restricts the number of fab shops that would take on the job.
L1-L2 and L1-L3 non-sequential - aspect ratio really restricts the
impedance options available for L2 tracks. Pitch calls for
small capture pad so either L1 clearances are going to be tight or risk of
breakout will be higher or aspect ratio is "leading
edge" (the latter is not a good idea for smaller holes!)
L1-L2 and L2-L3 sequential build/plate for larger arrays. Within the
capabilities of many fabs, more processing so more
expensive. Stacked microvia will improve SI but reduce the fab options.
Multiple layer stacked uvia - costly so only really worth considering if
the intrinsic properties are desirable for other
reasons such as SI (useful alternative to back drilling when combined with
surface contact connectors)
Full blown HDI on flex - not always desirable for large circuits especially
if there are a lot of chunky parts!
LCP with sandwiched silver bump interconnects - not compatible with
conventional solder attach (certainly not PB free), but
really worth considering for wire bond and adhesive attach. Layer count
restrictions apply.
Last option - are the same parts available in large pitch or leadframes
packages? Do your volumes allow ordering chips packaged
to your Requiremnts?
Best Regards
David Greig
______________________________
GigaDyne Ltd
Buchan House
Carnegie Campus
Dunfermline KY11 8PL
United Kingdom
t: +44 (0)1383 624 975
www.gigadyne.co.uk
______________________________
-----Original Message-----
From: DesignerCouncil [mailto:[log in to unmask]] On Behalf Of Chris
Ball
Sent: 08 December 2005 13:16
To: [log in to unmask]
Subject: Re: [DC] Info for routing 0.5mm BGA's
Hello Andre-
We just starting a design using same. So far, have found no recommendation
other than micro-vias. If you discover an
alternative, please let me know about it.
Best Regards
-Chris
Andre Demers
<[log in to unmask]> To:
[log in to unmask]
Sent by: DesignerCouncil cc:
<[log in to unmask]> Subject: [DC]
Info for routing 0.5mm
BGA's
12/07/2005 02:58 PM
Please respond to
"(Designers Council
Forum)"; Please respond to
Andre Demers
Hi,
I would like some idea's or suggestions concerning a board that has a 0.5mm
BGA.
Specifically, I would like to know what type of via was used to break out.
We are currently designing a board that will have 12 layers and we are
going to use micro-vias for this type of BGA.
Is there any other way ?
Thanks in advance,
Andre Demers, C.I.D.
Senior PCB Designer, Coordinator
cmrsummit Technologies
329 March Road, Suite 203
Kanata ON K2K 2E1
Canada
Telephone: 613.599.3881
Toll Free: 877.428.1229
Pager: 613.368.0506
Fax: 613.599.7889
[log in to unmask] <mailto:[log in to unmask]> www.cmrsummit.com <
http://www.cmrsummit.com/>
---------------------------------------------------------------------------------
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
---------------------------------------------------------------------------------
---------------------------------------------------------------------------------
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
---------------------------------------------------------------------------------
--
Virus scanned by Lumison.
---------------------------------------------------------------------------------
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
---------------------------------------------------------------------------------
|
