Joints weird. Not enough burnishing?

[Abraxas3d]

Here’s some photos of the Hello World. I’m concerned about some of the joints.

Not enough ink? Not enough burnishing? Some joints filleted during reflow and look good, and on some the solder paste wicked up on the part and not much at all was on the pad.

Since some of the joints look ok, it must have gotten hot enough?

Also, I understand some of the nonplanar behavior is expected (LEDs topsy turvy).

https://www.flickr.com/photos/w5nyv/albums/72157690517118992

[mewertow]

Hi @Abraxas3d,

For a better-looking solder fillet, my guess would be to up the flow rate a bit (with the + button) when printing the paste. More solder paste will give you a better looking fillet for the resistors / caps, since the paste prefers to wet the components first (since they’re pre-tinned). However, those solder joints will still give you good electrical connection between the ink and the components, since there is a connection underneath the component lead.

• Matt

[Abraxas3d]

Will try more paste - thank you for taking a look!