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?