Anyone used solder paste?

[Digsy]

I may be doing an electronics project in the near future that will require some very delicate and very neat soldering. As I am neither of these things when I have a soldering iron in my hand I was considering using solder paste (A.K.A "wire glue") instead.

My only reservation is that for my needs I will require the joints to have a good degree of mechanical strength as well as simply conducting electricity (approx 4V, 20mA). Normal solder would obviously be fine for this but I have no idea what solder paste is like. I believe that in SMT circuit boards the components themselves are held in place with "normal" glue and the solder paste just forms the electrical joint. But I may be wrong.

[Noz]

when I have done SMT in the past, the solder paste is enough to keep the component in place. most surface mount components will be small enough just to use the paste alone.

 

i think a very fine soldering iron and some practice is all you need. i soldered in surface mount components before with a soldering iron, and apart from cooking a few tiny caps you do get used to it, its just practice.

 

paste can get really messy as well, unless you have a good pick and place set up.

 

i think the conclusion will depend on what equipment you will be using, it might be alot easier to use paste if you have some good equipment to apply the paste.

[Digsy]

Thanks for the fast reply

I probably should have been a bit more specific about what I will be doing. I want to create some lights from LEDs which will be supported only on very thin wires which also take the current to them. The idea is that the LEDs will appear to be suspended in space.

I have actually done a lot of soldering on PCBs but nothing that has ever been "on show" so I can get away with the odd botched joint here and there. I had assumed that paste would be neater, but it sounds otherwise. I suppose at least with normal solder I can suck the excess away with a desoldering tool and re-make the joint.

[Chris Wilson]

It was not until I tried a proper soldering station of my pal's with knob operated thermostatic control that I realised there's a world of difference between a cheap Ebay soldering iron and a pro bit of kit. The UN soldering vac pump was very neat, too. Having the right sized iron for various jobs makes a huge difference, as well. It's on my (large) list of desirable, but not essential, things to have

[BazzaAlpine]

Paste is better for SMT components and if it's going through an oven to melt the paste. If you are doing it by hand with an iron then i would definately use normal solder.

[edge]

As said. More practise. Decent iron and some quality tips if various sizes to suit the job.

Like chris said and if you do a fair bit get a base stationed iron. I love mine and it makes things alot easier once you get to know the temperatures as too much heat will damage things and give a poor join aswel as too little.

Try "tinning" the ends first to give you a better join.

I had 4 years of soldering IC's onto boards in the aircraft repair game. Give me a chunky bit of wire anytime

[Digsy]

Good feedback guys. Old-skool solder it is then

[bigbloodyturbo]

if your looking to solder surface mount try a hot air pencil. Get some good quality flux (not the gay stuff in the marker pen) and use the air pencil, its non-contact soldering and is a life saver when trying to solder things when you cant even see the solder pad with the device placed on it. Try pre-heating what your working on aswell with a hot air gun and if your trying to hold it down while soldering use something that wont suck all the heat out of what your working on. Before doing what I do now I was 8 years populating/soldering downhole logging equipment for the oilfield and half of it was prototype so no thought put into how someone was supposed solder it, worst thing they ever did was make things smaller lol.