Thanks TN for your answers!

My questions come from our ups and downs in assembling a few double sided FR-4 boards, with exposed copper layers. We see variable batch to batch soldering quality and believe it is the variable degree of surface oxidation that is causing the problem.

This product is medium to high volume, so acid dipping or any other conditioning of the surface would have a large impact on the assembly costs and eventually on delivery dates.

Of course the double side reflow does not really help and I would hesitate doing acid dipping when there are components and solder joints on the boards already.

So what would help me even more would be a few ideas on the packaging we should request and the handling of the boards. Mike named a few, are there more suggestions out there?

Best regards and Happy Easter,

Ioan


-----Message d'origine-----
De : Hfjord [mailto:[log in to unmask]] 
Envoyé : 19 mars 2008 14:06
À : 'TechNet E-Mail Forum'; Ioan Tempea
Objet : SV: [TN] Shelf lif of bare copper boards

Have no idea what strange things you are doing, but an easy way to activate
the copper is to dip the boards in a weak acid solution, strength depending
on the time the boards have been exposed to the atmosphere. Rinse rigorously
in DI !
/Inge

-----Ursprungligt meddelande-----
Från: TechNet [mailto:[log in to unmask]] För Ioan Tempea
Skickat: den 19 mars 2008 13:42
Till: [log in to unmask]
Ämne: [TN] Shelf lif of bare copper boards

Dear Technos,

 

Anybody using PCbs with bare copper pads and traces, no plating, no OSP,
not even solder mask? Because I have a few questions:

 

What is their shelf life?

Are they suited for double side SMT reflow? I mean, during the first
reflow the oxidizing is accelerated...

What storing/handling procedures you use?

Does the copper require any particular specifications, in order to
perform better in soldering?

Anything else?

 

Thank you,

 

Ioan

 


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