Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Non-Rohs PCB

Views: 2980

aj

#43852

Non-Rohs PCB | 11 September, 2006

Hi All,

this has not happened but I would like to know what the possible effects would be if we ran a non-rohs pcb (hasl) thru a leadfree Process.

We have a customer who cannot confirm if the board is rohs compliant or not and we are waiting on confirmation from supplier but they are very slow at getting back ! The bom is compliant.

Apart from the fact that the product would be non-compliant what other issues would be likely to see?

Thanks inadvance.

aj...

reply »

Amol Kane

#43854

Non-Rohs PCB | 11 September, 2006

lead-free processes involve higher temperatures. if you run this PCB thru the reflow oven, the worst possible scenario is that the board may melt and deform. even if it doesnt, it may delam internally (and or the bare board reliability might be compromised, and i am just talking reflow. you may/maynot have TH components or hand soldered components on it which will cause further thermal exposure to the board at higher LF temps. if you know the laminate and the prepreg part #, you can easliy find out if they are lead-free compatible or not.

a related questions arises. why do u want to run a LF profile on the board? do you have LF BGAs on the BOM?, if not, even though the components have a lF finish, they can be run on a SnPb profile (except Bi finishes)

just my 2 cents worth

reply »

C.K.

#43855

Non-Rohs PCB | 11 September, 2006

So, your scenario is:

* Lead Free Solder Paste * Lead Free Reflow Profile * RoHS Components * Non-RoHS (Sn-Pb HASL plated)PCB

If that's the case, you should be just fine running your Lead-Free process. There is literature on the topic of lead contamination of your solder joint (google this), but IMO, the lead content in your Sn-Pb HASL is such a small percentage of the overall solder joint, that you should still be making pretty reliable solder joints. There is a mathematical formula that you can use to estimate the lead %-age as well.

Obviously, the only consequence is that your product will NOT be RoHS compliant.

reply »


RDR

#43865

Non-Rohs PCB | 11 September, 2006

if you did not take PCB temp over about 245 C you got no probs buddy. just non compliance most likely.

Fiberglass and copper, not much can happen there

Russ

reply »

Large PCB Dispensing System

Global manufacturing solutions provider