LISTSERV - TECHNET Archives - LISTSERV.IPC.ORG

TECHNET Archives

March 2007

TechNet@IPC.ORG

	LISTSERV Archives
	TECHNET Home
	TECHNET March 2007

	Log In
	Register

	Subscribe or Unsubscribe

	Search Archives

Options:	Use Monospaced Font Show Text Part by Default Show All Mail Headers
Message:	[<< First] [< Prev] [Next >] [Last >>]
Topic:	[<< First] [< Prev] [Next >] [Last >>]
Author:	[<< First] [< Prev] [Next >] [Last >>]

Subject:	Re: Comps on opposite side of PCB sharing GND vias
From:	"Upton, Shawn" <[log in to unmask]>
Reply To:	TechNet E-Mail Forum <[log in to unmask]>, Upton, Shawn
Date:	Tue, 13 Mar 2007 08:25:10 -0400
Content-Type:	text/plain
Parts/Attachments:	text/plain (46 lines)

When you say "comps", you mean components, right?  I'm assuming two SMT
devices, correct?  If it's not a via in a pad, the only reason I can
think of is ground bounce from a high di/dt on one device interacting
with the other.  And, if the trace from the pad to the via is too short,
it could intefere with soldering--but that'd be true if there was only 1
component feeding that via.

In short, I'm not coming up with reasons myself.

Shawn Upton, KB1CKT
Test Engineer
Allegro MicroSystems, Inc
[log in to unmask]
603.626.2429/fax: 603.641.5336

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Terry Kozlyk
Sent: Tuesday, March 13, 2007 7:10 AM
To: [log in to unmask]
Subject: [TN] Comps on opposite side of PCB sharing GND vias

Yesterday a colleague of mine at work said 2 comps on opposite sides of
the PCB could NOT share a GND via which was nailed down to a solid plane
in between. After thinking about it for an hour or so, I came up with my
own several reasons. Just wanted to hear anyone elses opinions about
this practice. I do it mainly to economize on vias taking up less space.
Of course, the via has to be close to each comps GND pad. The comps are
literally placed coincident to each other, for the main purpose of
sharing a GND via.

 

TDK (Terry)

 

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/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
-----------------------------------------------------

ATOM RSS1 RSS2

LISTSERV.IPC.ORG