TECHNET Archives

May 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:
Gregg Owens <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Gregg Owens <[log in to unmask]>
Date:
Fri, 28 May 2010 21:32:50 -0700
Content-Type:
text/plain
Parts/Attachments:
text/plain (89 lines)
U.Nagaraj:

With a holiday weekend upon us (and only the dumb still working) you likely won't get much of a response for a few days. 

First, photos or any attachments can't be sent through TechNet. They must be posted somewhere else. You will need to submit them at the IPC TechNet photo repository at:

http://ipc-technet.groupsite.com/main/summary

Now, to your real questions. Per the IPC-A-610E (and previous revisions) SMT solder connections did not specify the amount of land area to be wetted by solder. 

Through-hole lands have requirements for solder wetting, but not specifically SMT. For SMT the requirement is the land area covered by the component lead or metalized area is required to have visual evidence of good wetting. The specific solder coverage requirements is relative to the lead or metalized areas, not specifically the land area.  

Without seeing the photographs its harder to get more specific. Once you get the photographs up and when people return I am sure you will get more specific answers. 

Gregg Owens
Technical Writer - Avionics
Space Exploration Technologies, Corp.
(310) 363-6533

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Uppina Nagaraj
Sent: Friday, May 28, 2010 9:04 PM
To: [log in to unmask]
Subject: [TN] Query on Solder wetting

Hello All,

We have some issue on the solder wettability
and I need your inputs on this.

One of our customer has informed us that there
is a problem with solder wetting of SMT pads.

The said PCBs are with 1.6mm thick and we've used
63Sn/37Pb for HASL.

We had taken some samples for solder paste printing
and conducted reflow (without component) at our customer's
premises. Our customer is telling us that the solder wetting
is not acceptable to them.

I've attached the photos of the said phenomenon.

I have a few questions on this solder wetting issue.....

a) Is this level of wetting where the solder has not completely
   wetted until the perepheriy of the SMT pads considered
   as reject?

b) If we do a reflow with the components mounted, will the
   components lead "push" the solder paste completely to
   cover the SMT pads completely.

Your reply on the above queries and/or any other relevant
inputs will be of great help to me.

Thanks & Best Regards,
U.Nagaraj

______________________________________________________________________
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