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:
Guy Ramsey <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Guy Ramsey <[log in to unmask]>
Date:
Thu, 6 Mar 2008 09:29:32 -0500
Content-Type:
text/plain
Parts/Attachments:
text/plain (279 lines)
Interesting, we have observed changes in soldering performance on immersion silver boards when we first change our DI beds. 

Our DPMO count goes up until the resistivity level of the water settles down to less than 10 Meg. Our perception, though not measured, was that this was also true for immersion tin. We don't often solder to immersion tin. 

We observe no measurable change in performance of Gold Flash protected patterns. 

We change our beds when they are unable to return the tank to something higher than 1 Meg. 

We have seen a measureable change in performance of very sensitive RF circuits if we allow cleaning water to drop below 500K.



-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Terry L. Munson
Sent: Thursday, March 06, 2008 8:31 AM
To: [log in to unmask]
Subject: Re: [TN] Cleaning No-clean

Well it seems that the questions of water quality for cleaning are far  
reaching.  But to address the question of will 18 meg ohm DI water cause  the 
soldering issues. We have cleaned thousands of assemblies  after  part removal 
(water intolerant parts cleaned with saponifier)  using DI water STEAM (from 18 
meg ohm source) and rinsed  with final rinse at 16-18 meg ohm. with no 
solderability problems.  We  have recovered thousands of connectors with a tin plating 
and an oxide film  causing them to be unsolderable. By running them through 
the inline  Aquastorm 200 with the EnviroGold 816 saponifier at 10% (not any of 
the other  saponifiers) we were able to remove the oxide film that was causing 
 the solder wetting problem and all of the connectors were 100%  solderable 
after rinsing with 18 meg ohm final rinse water.  We then baked  the connectors 
in a cross flow oven at 85 C and the connectors were still 100%  solderable.  
If DI water is so aggressive that in a normal inline cleaning  process where 
it is not sitting in pools of DI water for 10-15 minutes, then it  should not 
have allowed these connectors or boards to meet solderability issues  for both 
SMT and through hole.  Everyone seems to have their opinion about  water 
quality and for those of you that are effectively cleaning with tap water  and no 
saponifier, more power to you. I have not been able to achieve the needed  
level of quality without using the above cleaning parameters. 
 
Terry Munson
Foresite
765-457-8095
 
 
In a message dated 3/6/2008 7:31:27 A.M. Eastern Standard Time,  
[log in to unmask] writes:

I agree  with Brian on this aspect of water purity for cleaning and would 
add: Very  pure water can actually cause soldering problems when used in cleaning 
 sequences between the secondary and primary or hand soldering steps.  

-----Original Message-----
From: TechNet [mailto:[log in to unmask]]  On Behalf Of Brian Ellis
Sent: Thursday, March 06, 2008 7:21 AM
To:  [log in to unmask]
Subject: Re: [TN] Cleaning No-clean

I have had  customers clean very successfully assemblies with ordinary 
tap water,  although I don't recommend it. If the bulk (>95%) of the 
water is  removed mechanically (efficient air knives or centifuges), then 
you can  get away with quite impure water. If you just allow the water to 
evaporate  on the surface, then the cleaner the water the better. I wrote 
a number of  pages on this subject in my book (pp 204 ff). I suggested 1 
µS-cm was OK  for most applications. Then it also depends on the application.

Another  "how long is a piece of string" question.

Brian

Schaefer, Chris  wrote:
> Terry,
> 
> A little off the subject. How important  do you think it is to use high 
quality DI water as opposed to using 200K DI  water in an Inline Aqueous System? 
I typically use something in the range of  12-18Mohm DI water at a minimum at 
the final rinse whether its a chemistry  inline wash or purely a water wash. 
We produce Class 3 product that requires  zero residuals at 10-40X, with less 
than 10.06NaCl/ sq.in. ionics. The company  I am currently working for does not 
believe 10-18Mohm water is necessary, but  we continue to have cleaning 
issues that are caused by poor process, old  chemistry, and likely the water.
> 
> Any thoughts?
>  
> Thank You,
> 
> Chris - AKA Booker
> 
>  
> 
> Chris Schaefer
> Suntron Corporation
> Process  Engineer
> 
> 800 N. Brutscher Street
> Newberg, OR  97132
> Work Phone: 503.554.6270
> Cell Phone:  785.248.9016
> Email: [log in to unmask]
> 
>  -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On  Behalf Of Terry L. Munson
> Sent: Wednesday, March 05, 2008 8:22  AM
> To: [log in to unmask]
> Subject: Re: [TN] Cleaning  No-clean
> 
> Dan and Brian
> We have qualified clients who  clean a no clean and have since the mid 90's 
(Les Hymes was one of the first).  But we have found that with a rescue 
cleaning  and only if you have water  tolerant parts (if not those need to be 
removed) that  you can  effectively clean a residue that was not designed to be 
cleaned.  
>   These residues do need a good saponifier, low pressure  inline (not able 
to do in  a standard batch system), heated to 140-150 F  wash and rinse with 
DI water at 10  meg ohm or better, but this is not  enough by itself but we 
found that if we use  DI steam after wash and  before rinse then we are able to 
clean under low  standoff components,  BGA's, and with a little help QFN and 
PQFN 
> packages.   We  presented this information at the IPC Midwest Expo 2007, 
authored 
>  by  Eric Camden.  We have successfully been rescue cleaning for the  last 
7 years no clean assemblies that were 6-12 months old.  So it is  very doable  
but standard batch cleaning with a saponifier has not proven  to us or our 
customers who we have help implement this type of cleaning that  batch or  
standard inline cleaning is able to do the job.   
>  
> Terry Munson
> Foresite
>  765-457-8095
>  
>  
>  
>   
> In a message dated 3/5/2008 10:53:25 A.M. Eastern Standard Time,  
[log in to unmask] writes:
> 
> "Generally speaking I have not  seen good results in trying to clean  off 
no-clean flux. They call it  "no-clean" for a reason."
> 
> Agreed!!!  Even if you succeed  to do the job well - it can be done with 
some fluxes -  it will not be  very easy and may be quite costly. I have always 
said, if  you clean, use  a flux which was designed from the start for easy  
cleaning.
>  
> €0.02 worth
> 
> Brian
> 
> Dan Mauro  wrote:
>>  Folks,
>>
>>   
>>
>> I have a need to clean  No-clean residue from  PCBA's. Can this be 
>> achieved with water washer  and some  type of saponifier ? Can anybody 
>> suggest a batch   process?
>>
>>  
>>
>>  Thanks,
>>
>>   Dan
>>
>>
>>   ---------------------------------------------------
>> 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
>>   -----------------------------------------------------
>>   
> 
> ---------------------------------------------------
>  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
>  -----------------------------------------------------
> 
>  
> 
> 
> **************It's Tax Time! Get tips, forms, and  advice on AOL Money & 
> Finance.       (http://money.aol.com/tax?NCID=aolprf00030000000001)
> 
>  ---------------------------------------------------
> 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
>  -----------------------------------------------------
> 
>  ---------------------------------------------------
> 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
>  -----------------------------------------------------
>  

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

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




**************It's Tax Time! Get tips, forms, and advice on AOL Money & 
Finance.      (http://money.aol.com/tax?NCID=aolprf00030000000001)

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

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