Solder in wave soldering: Which one is the best?

#32924

Solder in wave soldering: Which one is the best? | 28 February, 2005

Actually we're using ALPHA METAL Vaculoy 63SN/37Pb solder bars in our WAVE (ELECTROVERT ULTRAPACK 650C). With that solder, we use the ALPHA METAL LONCO SLS 65C flux. With this combination, we have many bridges and sometimes, the solder do not full completely the hole of a part (around 75% only). I want to know what you're using in solder and flux to reach good results! And if you have some tips for us, let me know!

Thank you

jbrower

#32925

Solder in wave soldering: Which one is the best? | 28 February, 2005

Hi Ing, My suggestion is to take a good look at your profile(s). The Wave solder machine that I use is an Electrovert EPK I. I use Aim ultra pure 63/37 solder with an older kester flux, 920CFX. I recently switched from kester ultrapure to the aim bar solder due to pricing. With the profile that I am running, we are hitting zero defect quality on a majority of our through hole assemblies. Again I would recommend that you first take a look at your profile, you might also check your solder pot for contamination. Hope this helps, Jay

#32927

Solder in wave soldering: Which one is the best? | 28 February, 2005

I have another question:

Does the slope of the conveyor is an important parameter in the solder joint quality? What is the standard in degree? Does that parameter can resolve my problem of partial fulling hole (between 50 and 75%)?

jbrower

#32928

Solder in wave soldering: Which one is the best? | 28 February, 2005

Hi Ing, Yes, slope of the conveyor is important. What type of assemblies are you having 50-75% fill on. Are they single sided? Plated through hole? Is this a recent problem? I'm more than happy to help, but I need more information. Best regards, Jay

#32930

Solder in wave soldering: Which one is the best? | 28 February, 2005

This sounds a lot like a profile that is killing flux activity prior to wave immersion.

What is your topside preheat temp just prior to hitting the wave?

What type of preheat do you have, convection or radiant?

Are you using a chip/turbulent wave in addition to the laminar flow wave?

What is your dwell time on the wave(s)?

How thick is your board?

What is the lead to hole ratio for the problem areas?

What is your conveyor angle?

How is the flow off of the wave in regards to back flow?

Are there any liquid residues remaining on the board after soldering?

What is your flux application method?

Have you tried other fluxes from Alpha and/or other Mfgrs?

Lets get these answered and we can then get this figured out.

I am pretty confident that your question is really related to flux as opposed to the actual solder. Vacualloy 63/37 is fine for almost every application that there is.

#32935

Solder in wave soldering: Which one is the best? | 28 February, 2005

TO JAY: What type of assemblies are you having 50-75% fill on. - Capacitor, resistor Are they single sided? - Yes Plated through hole? - No Is this a recent problem? - Yes, first time, but we don't know how long it last.

TO RUSS:

What is your topside preheat temp just prior to hitting the wave? - 220 to 210 What type of preheat do you have, convection or radiant? - Radiant Are you using a chip/turbulent wave in addition to the laminar flow wave? - Just using a lambda wave What is your dwell time on the wave(s)? - 2.5 sec at 500 degree How thick is your board? - 60 mil What is the lead to hole ratio for the problem areas? - ratio is : 30/50mil= 0.6 What is your conveyor angle? - 6 degree How is the flow off of the wave in regards to back flow? - Can you be more specific? (more details) Are there any liquid residues remaining on the board after soldering? - Sometimes we have some residues on the bottom side, we don't know why and how ... What is your flux application method? - Spray fluxer (lateral movement) Have you tried other fluxes from Alpha and/or other Mfgrs? - Not for the moment

#32936

Solder in wave soldering: Which one is the best? | 28 February, 2005

If you don't have Plated through holes you will not get any hole fill! There is nothing for the solder to wet to. Problem solved?

Russ

#32937

Solder in wave soldering: Which one is the best? | 28 February, 2005

Sorry, I mismatched my answer, yes they are plated.... Sorry another time...

#32938

Solder in wave soldering: Which one is the best? | 28 February, 2005

ING, you had to nake it difficult didn't ya! It appears that all of your parameters are okay. When you state that "sometimes there is a residue" is it liquidous or dry? Is your spray fluxer an ultrasonic or a spray gun head? You may not be getting good atomization therefore counting on 100% capillary action for the flux.

What I mean by back flow is the amount of solder that is pouring off of the back/trailing edge of your wave when a board is present on it. There should be a very minimal flow off of this that in a perfect world will only flow when the board is on it and it will stop flowing when the board leaves the wave. this may be part of your problem as far as bridging is concerned.

Do you know what the immersion depth is on the wave? It should be about halfway up the edge of the board or .03".

Since I am not familiar with your particular flux, I would recommend that you try Indium 3592. It seems to have a very large process window and works very well.

russ

#32942

Solder in wave soldering: Which one is the best? | 28 February, 2005

I am using this same flux and haven't had too many problems. I think Russ is steering you right on your wave flow and I would also check the fluxer performance to make sure it's getting to the top of your board. Are you sure these aren't sunken joints? That could be PCB related and not necessarily a flux problem or related to the shorts. (just happen to be fighting this at the moment). Bob Willis has pictures on his website of sunken joints. I would also check the nitrogen for performance.

good luck, pr

#32943

Solder in wave soldering: Which one is the best? | 28 February, 2005

PR, are you using the Indium or the Alpha Flux, I couldn't tell by your response.

Russ

#32944

Solder in wave soldering: Which one is the best? | 28 February, 2005

Sorry for the ambiguity, we are using the Alpha, Lonco SLS-65.

Alex

#32945

Solder in wave soldering: Which one is the best? | 28 February, 2005

I use to have that kind of problems with other type of machines and here are the causes: 1- Spray fluxer head partially obstructed (check flow rate) 2- Defective pre-heater probe (manually check temps) 3- PROFILE (last preheat to 280) 4- we sometimes hand spray flux on hard to wet pcb

#32946

Solder in wave soldering: Which one is the best? | 28 February, 2005

Thanks a lot to all of you! I found my problem: It was the pressure of the ultrsonic spray fluxer who was to low. The flux didn't wet all the hole and the solder didn't fill completly the hole. No one in my area knew the solution.

Thanks one more time!