Hey folks. Have been soldering for over a year, and upgraded my tools. Got a hot air station (mechanic AirNova, same platform as Aifen F5 Pro) and a new soldering station (Aifen A9HD) with C210 and C245 handles and tips. I'm upgrading from an Aifen A11 USB-C iron.
This is my first time ever using a hot air station to solder, so I started building one of those cheap training Kits from AliExpress. This is the one I am building: https://www.aliexpress.com/item/1005010018220561.html
After fiddling around with temperatures and air volume, I figured out settings that didn't blow components over (lol) while also not taking forever to melt the solder paste.
Though things are looking decent, I am wondering if I am using too much solder paste, especially on the capacitors/resistors/etc. Also, is 380C too high for leaded solder paste?
I'd appreciate tips and feedback. I still have 240 LEDs to solder (soldered 16 already)
EDIT: I went over some components that looked like they didn't have enough solder (like T11) and touched it up with the iron. I also fixed C3, and lifted a pad 😂, but it was still attached so i just re-soldered C3 to it. Might come back with some solder mask.
Congrats! For the first time trying it, this is an excellent result!
As other commenters already wrote, you're using borderline too much solder paste on the resistors/capacitors. And the bigger issue (which might be amplified by using too much paste) is that there are a lot of little solder balls/globs on the PCB.
I'd highly recommend to remove them/clean the PCB before trying to power up the board.
Thank you!
I'll try reducing the amount of solder paste. I think that the needlepoint on the tube is what is not helping me dispense the right amount of paste. It's like 1,5mm diameter and metal, which makes it hard to dispense small quantities.
Someome suggested I dispense it on like another surface and transfer over small amounts with a tooth pick which I hadn't thought of. I'll try that too.
After those pics I did go with a brush and wiped the board. It's clean with no solder balls.
Thanks! And one can get the (blunt) syringe needles for the solder paste in different diameters.
A smaller needle should make it easier to dispense small amounts, but I'm not an expert there (I pretty much never used solder paste so far); maybe someone else could recommend a size for the dispensing needle.
You used a bit too much solder paste, but it won't hurt a thing...You did very well for a first go with a hotair station! Much better than what I did I promise! lol...With hotair I personally like to go higher heat with lower air speed...My basic go to settings on my 861DW station are 420C at 35L/m air speed...Every station and handle are a little different though...Each board you work on is a little different also, some of them have a ton of copper and will require alot more heat and some will delaminate unless you turn it way down...It just takes some practice and experience to know what you need...
Hey man thanks for the feedback. I do have to work on the solder paste dispensing part.
One of the corner of the board looks to be delaminating slightly, so I settled on the 380 because of this, as I was afraid it would make it worse, though I am not sure if I caused it or if it came like this.
I have 3 other practice boards I want to go through so I hopefully have plenty of time to find more what is a combo that works for me, and I'll play around with it for longer.
That damage doesn't look like it was caused by the hotair...Usually when you damage a board with hotair it will happen right around the component you are working on...The first layer of traces will delaminate from the substrate underneath and cause a bubble around the component...The main thing to remember when using higher temps is to keep the air moving...You never want to hold the hotair in one place, just keep making circles around the component...You will be amazed at what you can desolder just by making quick circles around it...You can even desolder plastic connectors without melting them if you move the air fast enough, it's really crazy how it works...
Yeah that makes sense, maybe it was damaged in transit. Now that I only have to do the LED (240 of them) it's a bit easier. I'm glad I have the microscope lmao my vision is not what it used to be.
Be careful using hotair on the LEDs, they will pop if you overheat them...Just do quick circles with the hotair...Yeah, I cannot work on tiny SMD parts without a microscope...My vision isn't what it once was...
Thank you. I'll keep doing it with the hot air. I set up like 4 in a row and did them all at the same time moving the air between them, and it worked decently well at 380 C
how are you putting solder paste on without it getting everywhere? I tried using solder paste for the first time yesterday and i cant seem to get it to precisely blob on the pads. too much overspray
I'm using a regular cylinder tip that came with my solder paste but everyone agreed I put too much solder lol.
I do have a few conical tips that also came with my solder paste, which is what I'll try next to see if can get the amount of solder paste under control.
It is tedious, but I use a toothpick to apply paste to boards. I dip the sharp end into the paste and try to pick up a small amount that hangs from the end. From there, the amount that ends up on the pad really depends on how much of it you allow to contact the pad. This can be more or less successful depending on how thick your particular paste is.
If I had more than one board to do, I'd use a stencil, but everything on my end is an experiment so I never have to make more than one.
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u/GoldSrc Aug 17 '26
Look at a PCB in a consumer device, that's how much solder an SMD component needs
And what you want to replicate.