Stubborn Flow

[sabbathfan0220]

I'm hoping you guys can give me some pointers based on the following photo:



Do you ever run into some spots where the solder just doesn't want to flow through? It just blobs up one side and never really sinks in? I don't know what I'm doing wrong. I've tried different soldering temps, different tip sizes, etc. but every once in a while I run into a spot on the board that just won't flow. Thoughts?

 

[Barry]

Are you using additional flux? What temps have you tried? Are you cleaning and tinning your tip every 2-3 joints? Looks to me like the resistor leads are getting heated and not the pads

 

[Barry]

Would like to see the other side of the board

 

[sabbathfan0220]

Hey Barry. I've played with temps around 260-340C and I'm using 63/37 solder. Would you recommend hotter?

I am cleaning and tinning very regularly, and did try adding extra flux. I would take a photo of the other side but I already desoldered these components (trying to resolder them tonight).

 

[Nostradoomus]

What tip shape are you using? As long as one side is soldered decently it doesn’t really matter if it’s flowing all the way through, connectivity wise anyway.

 

[sabbathfan0220]

The tip is a very small chisel. I've tried wider chisel as well as small point tips and had the most luck with the small chisel. What temp do you guys use? I'm finding a wide range of recommended temps.

 

[Barry]

800F

 

[Nostradoomus]

650F

 

[sabbathfan0220]

Looks like it might be worth trying higher temps. I'll report back with the results.

 

[benny_profane]

Do those pads connect to ground? I’ve found that the relatively smaller pad size on the PPCB boards makes it so that the solder doesn’t completely fill the plated through hole on ground pads with my typical iron temp (350°C). There’s still connectivity, but it doesn’t flow through to the component side.

 

[TheSin]

I’ve noticed too that I always seem to get a couple that don’t flow like the rest on every build. I do get a good connection though. I chalk it up to a dirty pad or component lead.