Solder problems

[Janernst]

Yesterday I did a good job with soldering a pcb. Today it will not. The solderpaste will not stick to the same type of board.
I brushed the board several times. I cleaned the board several times with IPA. All without results. I changed the hight of the needle a bit. I changed the volume of the paste a bit.
It looks like the needle wipes/smears the paste over the board, but the paste will hardly stick to it. I don’t know what too do. Is there any advice to give??
The only difference with yesterday is the ambiant temperature. It is extreme hot today for us in the Netherlands (+/- 32 C). I don’n know if that is of some influence?

[mewertow]

Hi @Janernst ,

If paste isn’t sticking to the board, it’s almost always a sign that some of the paste in the nozzle has dried out a bit. If it’s hot out and the solderpaste wasn’t stored in the fridge, it sounds like a reasonable situation.

The fix for this is pretty straightforward, just purge the solder paste cartridge for about 60 seconds.

See this article for instructions: https://support.voltera.io/hc/en-us/articles/360006363174-Solder-Paste-Does-Not-Stick-to-Pads

• Matt

[Janernst]

Sorry, but after a month of experiances, a lot of mistakes and misunderstandings, I have to tell you that it al was done already. The solderpast came from the fridge, I let it come about 30 minutes to the right temperature, pressed some paste out (it had a good consistancy) and screwed a totaly clean nozzle on. Than press constantly some nice looking and thin paste out of the nozzle. What more can I do??

[mewertow]

If you used a new nozzle, that’s sounds like a different problem. Which lot of solder paste are you using? It should say on the sticker on the cartridge.

Any chance you can take some pictures of your board and the resulting paste deposits? High-quality pictures close to the pads will be best.

Also, can you take a picture of your cartridge, taken out from the dispenser?

[AlanDewey]

Was this problem a board you printed with the Voltera or a commercially made board?

This happened to me three days ago when I wanted to put down tin-lead paste that I just received earlier in the week from Voltera. It was to go on a commercially made board (tin-lead, not lead free.)

The machine was squishing out paste but it just would not stick.

I cleaned the board with acetone a few times, wiping with paper only one direction. Started over and then the paste stuck properly.

I don’t know if the acetone cleaning did the trick or if it was a coincidence.

[sneaks]

I ran into this issue a week ago when putting paste on a 3rd party PCB. In my case, my shop environment is always around 65F which I think is part of the problem. If I take the solder cartridge out of the dispenser, cap it, and run it under some warm water for a minute, it works flawlessly.

I do run into issues with clogged nozzles which I am not sure how to solve yet. I typically put the clogged one in a drawer and put a new one on. Hopefully someday I’ll find a good solution to unclog them.