Ok don't laugh!
I actually witnessed an engineer use a wire brush bit in the dremel to remove oxidation today. A matter of fact it is SOP for bare copper PCBs in our shop. I have done it myself with sucess.
Eva
-----Original Message-----
>From: Ioan Tempea <[log in to unmask]>
>Sent: Mar 20, 2008 8:08 AM
>To: [log in to unmask]
>Subject: Re: [TN] Shelf life of bare copper boards
>
>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
>
>
>
>
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