(wait for it...)
"it depends" on what the circuit design requires, on what the engineer
specifies, on what the EMS specifies, and/or on the part itself, etc. A
0402 package needs to be treated differently than, say, a TO-263 package
requiring much heatsinking (big copper, and vias, too!)
Roger
-----Original Message-----
From: DesignerCouncil [mailto:[log in to unmask]] On Behalf Of
Allen T. Maddox
Sent: Friday, July 29, 2005 10:57 AM
To: [log in to unmask]
Subject: Re: [DC] Trace width ratio to pad
Yes, this is the train of thought and the argument for wider traces. But
is it necessary for all nets?
Allen Maddox C.I.D.
Sr. PC Board Designer
GAI-Tronics, Corp
610-796-5854
PO Box 1060
Reading, PA 19607-1060
[log in to unmask]
www.gai-tronics.com
>>> [log in to unmask] 07/29/05 10:45AM >>>
Ummm, I'm not so sure about Joe's statement. Shouldn't that read "more
copper will give less resistance and result in less impedance (less
inductance, more capacitance) all else being the same?"
Roger
-----Original Message-----
From: DesignerCouncil [mailto:[log in to unmask]] On Behalf Of
Matthew Lamkin
Sent: Friday, July 29, 2005 10:32 AM
To: [log in to unmask]
Subject: Re: [DC] Trace width ratio to pad
Ah, that's it, bamboozle him with his own techno babble..
Now that's the best suggestion yet.
You can also get the assembly department to define their preferences and
whatever assembly want is usually enough to make it a law written in
stone :-)
<snip>
For Signal traces you might what to use the argument that more copper
will give him more resistance and actually will cause more impedance to
the rise time on his circuit. This may cause him to rethink his
request. Sometimes if you talk their language you can get your point
across without having to use other drastic measures. ;-)
Joe J. - C.I.D.
<snip>
------------------------------------------------------------------------
---------
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
------------------------------------------------------------------------
---------
*******************************************************************
This email and any files transmitted with it are confidential and
intended solely for the use of the individual or entity to whom they are
addressed. If you have received this email in error please notify the
system manager.
This footnote also confirms that this email message has been swept for
the presence of computer viruses.
www.hubbell.com - Hubbell Incorporated
------------------------------------------------------------------------
---------
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
---------------------------------------------------------------------------------
|
