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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Pb-free wave soldering with SMD

Views: 1464

#38086

Pb-free wave soldering with SMD | 26 November, 2005

Hi,

Does any body have the experience with wave soldering a "Gold" plated PCB with SMD assembled on it? I`m experiencing massive bridging,icicles,Shadowing & Skipping.

The present soldering angle is 6 deg:,pre heating rate is 2 deg/sec , Dwell time is 2.5 Sec, Pot Temperature 260 Celsious, PCB temperature is 130 Deg: when reaching the solder pot. Used flux is IF2005C.

reply »

lupo

#38102

Pb-free wave soldering with SMD | 28 November, 2005

Just change the flux. I have had bad experience with IF2005

reply »

#38104

Pb-free wave soldering with SMD | 28 November, 2005

I have waved gold (ENIG) boards. That's a pretty hot pot at 260C, wow. I have used 245C with good results. All other parameters look OK a glance. Well, PCB temp looks a little hot too at 130C before pot. 90-100C is typical for most No-Clean flux. At that high pot temp a 1.6mm thick PCB will warp pretty bad I would think. At that temp you can delaminate board. Warping changes contact time / band width. Consider trying difference fluxes too.

reply »

#38109

Pb-free wave soldering with SMD | 28 November, 2005

Hi,

What would be the standard band width for Pb-free soldering? As per my knowledge this should be 3cm to 6cm.

What is best?

reply »

#38117

Pb-free wave soldering with SMD | 29 November, 2005

Band width relates to conveyor speed to achive a 2 second contact time for Sn/Pb wave soldering. A typical conveyor speed is 150cm/min with a band width (contact band width between PCB and solder) of 5cm. Now for Pb-Free wave soldering a longer contact time is reccomended, like 3 seconds or a little more. So at the 150cm/min conveyor speed, the band width should be 7.5cm - 8cm. I will e-mail you a Optimum Contact Time chart for reference.

reply »

reflow oven profiler