THE WIRE conglomerate build thread, impressions and gallery

[Jarno]

So, I'm soldering the PSU for The Wire, and I am getting nowhere trying to solder the heatsinks with my soldering iron. I've noticed before that it is a bit underpowered for the bigger stuff, so I am going to bite the bullit and get a bigger one to solder thicker wire and heatsinks. What are you guys using? 40W, 100W?

[merlin2069er]

It took me an hour to mount 10 diodes on the back of the PSU. Hopefully, I can get everything else mounted on the psu and tested.

[Jarno]

Yes, to say the layout isn't conducive to hand soldering is putting it mildly. Couldn't properly solder two legs of each trimpots because of the big ground plane, no love with the two heatsinks, hence my question on what people are using.

[qusp]

nothing wrong or awkward about the layout i'm sorry to say, something wrong with your tools and possibly technique, its not what i would call a big ground plane. my hakko 936 handles it just fine and its hardly industrial strength, probably you guys dont have suitable tips either? you are much more likely to do damage with not enough heat, nor enough mass and exposing the parts to the heat for extended periods

[opc]

Hi Guys,

Practice makes perfect, but in the case of your iron Jarno, it's definitely time for a new one!

Thermal spokes were used on all ground plane joints, so they should be no harder to solder than any of the other joints. If your iron is struggling with soldering the pots, then there's something badly wrong with the iron!

I personally use the following iron, and would strongly recommend it:

Catalog No. WD1001 Product Detail

It's an 85 watt iron and I typically solder at 740F for SMD work, and 850F for things like the heatsink pins. I found mine at a local electronics store for $269. Before that, I use a Hakko 50W which also worked very well.

The heatsink pins are quite difficult to solder, even with a powerful iron, so I'm not surprised you were having trouble. They don't absolutely need to be soldered, however, as the benefit is mostly just mechanical integrity.

Another option would be to pull the pins out using a vice or pliers, and use some small self-tapping metal screws to affix the heatsinks to the PCB.

Overall, there is indeed a learning curve if you've never done SMD work before, but it's certainly worth learning. Once you get better at it, you'll find it faster and easier than PTH work, and the resulting layouts are almost always better with SMD. Take your time, keep at it, and remember that this step is a big part of the DIY experience! Think of it like a model car or a ship in a bottle, it doesn't matter if it takes a month to complete, the important part is to do a good job and make sure everything is in the correct place.

Cheers,
Owen

[opc]

qusp is also correct with his points on using the correct tips. I know I've written at least four times before, but i'll write it here again:

DON'T USE FINE POINT TIPS, EVER!!!!!!!!

The single biggest mistake you can make is thinking "SMD parts are small, so I should get a really small pointy tip to solder them with!"

Always use a 2-4mm chisel tip for all SMD work. Anything smaller than this doesn't have enough thermal mass to allow for proper joints. You'll end up overheating the joints waiting for the iron to get back up to temp, and you'll get cold solder joints everywhere because the solder won't get hot enough to flow properly.

You want a lot of heat, a large thermal mass, and you want to heat the joint quickly, get the solder to flow well, then get the heat source off the joint quickly. This prevents thermal damage to the parts, and allows for good solid joints.

Cheers,
Owen

[merlin2069er]

I should invest in a good digital soldering station. Where did you get that Weller
Digital 85W Soldering Station, 120 V?

Ebay has them from about $300 - a bit more than I wanted to spend.

[opc]

Here in Canada I found that Active Electronics had the best price on Weller stuff. The above mentioned iron is on sale for $249 here:

http://www.active123.com/WD1002-Digi...-Prodview.html

They have locations in Ottawa, Montreal, Toronto and a few other big cities.

Cheers,
Owen

[merlin2069er]

This thing any good?

NEW 2in1 SMD Soldering ReWork Station HOT AIR & IRON 852D+ - Mississauga / Peel Region Tools & Hardware For Sale - Kijiji Mississauga / Peel Region Canada.

[qusp]

i'm going to say no, if you only have that much to spend, just get something that does soldering well, rather than being a **** soldering iron and hotair rework station in one.