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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Connector leads plating

Vijay

#22635

Connector leads plating | 10 December, 2002

We are having solder fillet finish issue. The solder looks like rough solder on the connector leads .The plating of the leads is Nickel (99.9% purity) and the PCB plating is imersion gold. I have tried fine tuning my reflow profiles an have used N2 in the reflow oven but there is no significant improvement. The connector is available in Gold plating , Tin plating and Copper gold flash. Please advise which is the better connector leads plating to be mounted on Gold plated board pads. Thanks,

reply »

#22637

Connector leads plating | 10 December, 2002

Questions are: * What is the current plating on the connector that is over the "plating of the leads is Nickel (99.9% purity)"? * What are the temperatures and durations at those temperatures that you read on these connector leads? * What solder alloy and flux are you using? * Is this connector PTH or SMD? [If PTH, what is the connector pin size? What is the plated hole diameter?] * What material[s] [and thickness[es]] are plated on the copper of the "Gold plated board pads"? * When you say "rough", do you mean "smooth, grainy" or "bumpy, shiney" or what?

reply »

Randy Villeneuve

#22643

Connector leads plating | 10 December, 2002

Tin is pretty standard. I would doubt your leads are only Nickel plated as Nickel will oxidize very quickly.

This message was posted Add this forum to your site! Click to learn more. the Electronics Forum @

reply »

Vijay

#22646

Connector leads plating | 10 December, 2002

Hi Dave, The peak temp on the leads is 216-218 Deg C and duration above MP (179 degC) is 55-60 sec. Alloy(solder paste) used 62 Sn,36 Pb 2Ag (Alpha WS 609 Ty 3 Water eash) This is a SMT connector wth Gulwing leads Gold plating on the PCB is 2-5 microns on the pads. The joints looks bumpy and shiny and it looks as leads of the connectors are not wetting perfectly.

Thanks,

This message was posted Add this forum to your site! Click to learn more. the Electronics Forum @

reply »

#22647

Connector leads plating | 10 December, 2002

Vijay,

Sounds like you're not spending enough time at liquidous plus 20*C. And you need to stay there for 5 to 10 seconds.

I know, I know. We have used bucketsful of WS609 over the years.

See, as you say, the melting point of your solder alloy is 179*C, but the liquidous of the alloy on your pads has a higher temperature. Things increasing the liquidous temperature of the alloy on your pads are: * Gold on your pads * Tin, gold, or whatever's on your connector leads

Welcome to the lead-free generation.

reply »

#22648

Connector leads plating | 10 December, 2002

Randy's correct. If you were soldering to nickel with WS609, you would be complaining about non-wetting, not lumpy solder flow.

reply »

Vijay

#22650

Connector leads plating | 10 December, 2002

Please correct me if wrong. It means I have to increase the temp. further ?

reply »

#22653

Connector leads plating | 11 December, 2002

I'd guess that you need to sit at your current 216-218*C peak for that 5 to 10 seconds that I mentioned earlier. Increasing your peak is the easiest way to do that, as you say.

reply »

#22682

Connector leads plating | 12 December, 2002

Have you considered the plating of the component could be Pb free as this generally wont be liquidus until 232C typically. seeing more and more of these unmarked components coming through so worth checking latest batch of problems on unmarked QFP's and TSOTS. Seriously doubt if it was Nickel only. If Pb free then profile peak around 255C is more in order very dificult to establish but worth checking to see what plating actually is.

reply »

Precision Auger Dispense Pump

PCB Rework / Repair Services