TECHNET Archives

March 2008

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:
R Sedlak <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, R Sedlak <[log in to unmask]>
Date:
Fri, 21 Mar 2008 09:17:52 -0700
Content-Type:
text/plain
Parts/Attachments:
text/plain (46 lines)
Louis:   A flux is meant to remove oxides, but is limited both in capacity and power.   When a board approaches HASL, it typically has just been baked for quite a while at high temperature.   The oxide is thick and tough.  You need a lot more oxide removal power than is generated by your average flux.  The flux removes the oxide which reforms between cleaning, and immersion into molten solder.

It certainly could be argued that you do not need both the acid clean and etch.  Most people microetch, and then into flux application.   We have had some customers acid clean only, but this takes a serious acid cleaner.

Rudy Sedlak
RD Chemical Company

Louis Hart <[log in to unmask]> wrote: TechNetters, a question has come up in our plant about cleaning copper surfaces before HASL. (Solder used is the standard tin-lead.) We've been putting panels through a light acid clean and etch, then through a Quicksilver flux applicator with two rollers that appear to be saturated with Enthone 757 SG flux. Someone has asked if that acid clean and etch are really necessary, since what is flux supposed to do?

Any comments on the need for the acid clean and etch would be most welcome.

Many thanks - Louis

Louis Hart
Compunetics
Monroeville, PA
USA
[log in to unmask]
412-858-1272


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


       
---------------------------------
Looking for last minute shopping deals?  Find them fast with Yahoo! Search.

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