Too less solder tin on pad? Does not stick enough? IC/Mosfet resoldering

[eevblogger88]

Hello everyone, I have removed a (supposedly broken) Mosfet and want to solder a new one on it.
Its my first time.

Question:
Am I correct, that there is to less solder tin sticking on the pads? (The solder tin on the pads is very flat)
The middle is full of tin, but on the outside not more tin does stick onto the pad, on the picture is the maximum amount I get onto it.

Is it enough solder tin for the SMD IC or does I do anything wrong and there should be more?
I thought it has to be a "rounded" ball on the pads, before I solder the IC onto it.

https://imgur.com/a/CLCi3S4

I would love to hear your thoughts!

PS.:
Equipment used:
Amtech ASM Flux, Hakko tip ("lead free" does stand onto it, 420 Degree on solder station), mechanical leaded HX-T 100 solder tin

Maybe its a problem to use leaded tin with unleaded solder tips? (I only have unleaded solder tips, since I bought everything new and iam just starting out)

[tooki]

(FYI, “tin” = Zinn (the element) and the verb “verzinnen”, and “solder” = Lötzinn and the verb “löten”. But we never say “tin” or “solder(ing) tin” to mean Lötzinn.)

Anyway, I think you’re asking if that’s enough solder on the pad, and I would say that if anything, it’s far too much. You don’t want the component floating on a sea of molten solder. Solder is something where you want as much as needed, but as little as possible.

A better way to solder something like this is to remove all the solder from the pads, then to apply solder paste (the gray stuff that’s actually solder powder in a flux paste) and reflow with hot air. If you don’t have solder paste and want to preload the pads with solder, then you need to add separate flux.

As for temperature: 420C is very high, especially for leaded. Either you’re running the iron much too hot, or your tip is too small for the job. “Lead-free” tips, by the way, are simply tips with thicker, more durable plating that can withstand the higher temperatures of lead-free soldering better. There’s no problem using them with leaded solder.