TECHNET Archives

July 2010

TechNet@IPC.ORG

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 >>]

Print Reply
Subject:
From:
Robert Kondner <[log in to unmask]>
Reply To:
Date:
Tue, 13 Jul 2010 16:18:12 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (125 lines)
Hi,

 The MAX condition is, IMHO, excessive unless you get a component at MAX
conditions. In general the IPC 782 pad dimension are quite large and you
could get tomb stone parts. But there are other variable that are involved,
placement accuracy and flux properties come to mind first.

 You can also look into the "Home Plate" design for solder paste apertures
though 0201 is getting small from the get go.

 Sorry, wish I could be of more help.

Bob Kondner

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Brad Saunders
Sent: Tuesday, July 13, 2010 3:59 PM
To: [log in to unmask]
Subject: Re: [TN] 0201 footprint requirements

Howdy Bill,
I was delighted to see Werner's answer on this question.  I had done very
exhaustive reliability study on solder joint reliability specifically
related to footprint design and we concluded exactly what Werner was able to
say so eloquently.  I found later the footprint also was a political
platform and to satisfy a consensus I constructed a formula that would give
a bit of pad to the sides and ends.  I knew it would not subtract from
reliability and -so long as it didn't get to big I was OK- it did allow me
to round off pad sizes which is very nice, also I was able to manipulate
center spacing which additional benefits.
But don't grow that length under your parts... and don't get me going on
radius lands verses square.

Boston Brad
  ----- Original Message -----
  From: Brooks, Bill<mailto:[log in to unmask]>
  To: [log in to unmask]<mailto:[log in to unmask]>
  Sent: Wednesday, July 07, 2010 2:37 PM
  Subject: [TN] 0201 footprint requirements


  I am looking for some assistance with the pad geometries for 0201 caps
  and resistors...

  Is there or is there not an industry consensus on what the optimum pad
  geometry should be for them?

  What I am hearing from our assembly houses differs greatly from what is
  published in IPC-7351 and the land pattern tool from PCB Matrix.

  Is the max material condition footprint actually a recipe for
  tombstoning?

  What have you folks seen? What do you recommend?



  Bill Brooks | Datron World Communications, Inc.
  PCB Designer/Engineer | Office: 760-602-7004| Fax: 760-597-3777 |
  [log in to unmask]<mailto:[log in to unmask]>
  1808 Aston Avenue, Suite 230, Carlsbad, CA 92008 |
www.dtwc.com<http://www.dtwc.com/>

  Performance You Require. Value You ExpectTM



  ______________________________________________________________________
  This email has been scanned by the MessageLabs Email Security System.
  For more information please contact helpdesk at x2960 or
[log in to unmask]<mailto:[log in to unmask]>
  ______________________________________________________________________

  ---------------------------------------------------
  Technet Mail List provided as a service by IPC using LISTSERV 15.0
  To unsubscribe, send a message to
[log in to unmask]<mailto:[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]<mailto:[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]<mailto:[log in to unmask]>: SET Technet Digest
  Search the archives of previous posts at:
http://listserv.ipc.org/archives<http://listserv.ipc.org/archives>
  Please visit IPC web site
http://www.ipc.org/contentpage.asp?Pageid=4.3.16<http://www.ipc.org/contentp
age.asp?Pageid=4.3.16> for additional information, or contact Keach Sasamori
at [log in to unmask]<mailto:[log in to unmask]> or 847-615-7100 ext.2815
  -----------------------------------------------------

______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________

---------------------------------------------------
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
-----------------------------------------------------


______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________

---------------------------------------------------
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