There are many questions that this raises. Are you reflowing? Are you
specifying to have all components glued? Are these 1206's, 0805's, 0603's
or 0402's? Are your traces weight balanced on either side of the component?
Are you pads the same width as the part or wider? Are you pushing their
design rules for spacing?
I'm guessing they are probably not gluing the parts. Taking the trace out
the corner can causes a "pull" in the direction of your trace exit on the
component - if the component is small. With as close as we all like to
place parts, that can cause some migration of the components into each
other. SMT components used to be glued all the time. That's not happening
as much - everyone is trying to reduce their costs and this eliminates a
process. It is also difficult (not impossible) for many assembly companies
to glue 0603's & 0402's.
Sounds like they're mode of operation is probably "Re-work", and not
"Process Control". If you're doing any CPLD's or BGA's, don't use them or
ask them to make some adjustments. Look at the assembly error reports and
see what's going on. Sometimes we can make things smoother with some minor
adjustments to our thinking and sometimes they can.
My 3cents worth. (inflation, ya know--)
Cherie
-----Original Message-----
From: [log in to unmask] [mailto:[log in to unmask]]
Sent: Wednesday, August 07, 2002 2:30 PM
To: [log in to unmask]
Subject: Re: [DC] PREFERED TRACE DIRECTION INTO PAD
One bit of advice... "find another place to do your boards." If this
company has problems with corner-exit on discretes, I can assume they've
got other problems they'll want to address. Been doing boards for quite
some time, and I have yet to hear that one, even from the smallest of
assembly shops.
There are plenty of assembly shops trampling themselves to get work, so
go forth and prosper...
Mitch
---------Included Message----------
> Date: Wed, 7 Aug 2002 11:10:19 -0700
> From: "Denis Lefebvre" <[log in to unmask]>
> Reply-To: ""(Designers Council Forum)""
<[log in to unmask]>, "Denis Lefebvre"
<[log in to unmask]>
> To: <[log in to unmask]>
> Subject: Re: [DC] PREFERED TRACE DIRECTION INTO PAD
>
> Did you ask them WHY? It's fine for a vendor to take a position
such as this - but they really need to justify it when they do. We do it
all the time without any problem.
>
> -----Original Message-----
> From: john wheeler [mailto:[log in to unmask]]
> Sent: Wednesday, August 07, 2002 10:22 AM
> To: [log in to unmask]
> Subject: [DC] PREFERED TRACE DIRECTION INTO PAD
>
>
> We had a board reviewed by an assembly company that
> said traces should not come out the corner of chip
> resistors and capacitors (45 degrees). I thought that
> this was I good way to keep trace lengths shorter.
> What problems does this cause coming out of the
> corner? Is a side or end the preferred way?
>
> Thanks,
>
>
>
>
>
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! Health - Feel better, live better
> http://health.yahoo.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 set a vacation stop for delivery of DesignerCouncil send: SET
DesignerCouncil NOMAIL
> Search previous postings at: www.ipc.org > On-Line Resources &
Databases > E-mail Archives
> Please visit IPC web site http://www.ipc.org/html/forum.htm for
additional
> information, or contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
>
----------------------------------------------------------------------------
-----
>
>
----------------------------------------------------------------------------
-----
> 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 set a vacation stop for delivery of DesignerCouncil send: SET
DesignerCouncil
> NOMAIL
> Search previous postings at: www.ipc.org > On-Line Resources &
Databases >
> E-mail Archives
> Please visit IPC web site http://www.ipc.org/html/forum.htm for
additional
> information, or contact Keach Sasamori at [log in to unmask] or
847-509-9700
> ext.5315
>
----------------------------------------------------------------------------
-----
>
---------End of Included Message----------
_____________________________________________________________
----------------------------------------------------------------------------
-----
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 set a vacation stop for delivery of DesignerCouncil send: SET
DesignerCouncil NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
Please visit IPC web site http://www.ipc.org/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
----------------------------------------------------------------------------
-----
---------------------------------------------------------------------------------
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 set a vacation stop for delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site http://www.ipc.org/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------
|
