Where to get solder paste for SMD soldering?

[TV-Engineer]

Hi,

I need a syringe of solder paste (with nice thin needle) so I can mount SMD ICs using the method which can be seen on the net, involving laying a thin line of the paste over the IC pads, placing the IC and then heating the legs and pads with a suitable device (in my case, hot air station).

I've seen pictures of the syringes of this paste on the websites mentioned above but cannot find a supplier in the UK or even in the US where I'd be happy to order from if necessary.

Does anyone know where I can get some suitable for the tasks I have in mind?

Thanks mucho. 8)

 

[Nigel Goodwin]

Hi,

I need a syringe of solder paste (with nice thin needle) so I can mount SMD ICs using the method which can be seen on the net, involving laying a thin line of the paste over the IC pads, placing the IC and then heating the legs and pads with a suitable device (in my case, hot air station).

I've seen pictures of the syringes of this paste on the websites mentioned above but cannot find a supplier in the UK or even in the US where I'd be happy to order from if necessary.

Does anyone know where I can get some suitable for the tasks I have in mind?

Thanks mucho. 8)

Try RS Components, or Farnell, they will probably stock it. However, you should be aware it's fairly expensive, and has a short shelf live!.

 

[TV-Engineer]

Thanks for the suggestions. I've tried RS, but not Farnell. Farnell have the minimum order amount which puts me off even checking their site usually.

I heard that it had a shortish shelf life, but since my repair work involves mounting tiny SMD ICs with pins so close together my iron shorts them together when soldering, I'm unsure as to what else can be done to make the task easier...

 

[Nigel Goodwin]

Thanks for the suggestions. I've tried RS, but not Farnell. Farnell have the minimum order amount which puts me off even checking their site usually.

I heard that it had a shortish shelf life, but since my repair work involves mounting tiny SMD ICs with pins so close together my iron shorts them together when soldering, I'm unsure as to what else can be done to make the task easier...

The Pace soldering station I use at work has a spoon shaped bit, you flood the pins of the chip with liquid flux and draw the loaded bit across the pins - the flux makes the solder flow nicely, and pins don't short together!.

 

[TV-Engineer]

Is it one you'd recommend? I think I must get a new soldering station, and I'd like one with bits available for such tasks, like the spoon-type bit. Would you mind giving me the model number please, or of one which is affordable yet as good?

 

[theinfamousbob]

You'll find this interesting...




I've been hunting at the local second-hand store for my own toaster oven... (usually see them for about $4 US, but I haven't seen any in a while )

 

[Roboticinfo]

reply

Over here in america we have a store called radio shack that has them

Here is the website.

www.radioshack.com

you can order from uk I think

 

[Oznog]

Zephyrtronics sells a paste designed specifically for hand work. It does a great job and you can call them up for support on how to work it.

http://www.zeph.com/zt5_dir.htm

 

[Nigel Goodwin]

Is it one you'd recommend? I think I must get a new soldering station, and I'd like one with bits available for such tasks, like the spoon-type bit. Would you mind giving me the model number please, or of one which is affordable yet as good?

I'm not at work today, so I can't check on the model, but it came from SEME - the complete station was about £3000 :cry:

 

[Guerrero]

I like SMT solder wire, good for surface mount stuff.

 

[TV-Engineer]

Thanks for the URL links, I'm trying them out now. $10 for 10ml of paste isn't too bad at all, and a 6-month shelf life is quite good especially without refridgeration. Whether they'll supply to the UK though, I don't know.

£3000 for a soldering station? :shock: I was thinking perhaps £100 for a decent one. 8) That must be one hell of a soldering station...

 

[Nigel Goodwin]

Thanks for the URL links, I'm trying them out now. $10 for 10ml of paste isn't too bad at all, and a 6-month shelf life is quite good especially without refridgeration. Whether they'll supply to the UK though, I don't know.

Try CPC at http://www.cpc.co.uk, they are part of Farnell, look for order code SASMSP10SL, it's £9.25+vat for a syringe full.

£3000 for a soldering station? :shock: I was thinking perhaps £100 for a decent one. 8) That must be one hell of a soldering station...

Pace ones are expensive, ours includes four different types of soldering 'irons', plus various tips etc. for removing surface mount chips, most of the tips cost £50-60 each!.

It soon adds up! - it was required to meet the requirements of being a Sony Service Dealer.

 

[iso9001]

DO NOT USE THE RADIOSHACK PASTE


It is NOT water sol. and dies not for for crap in oven baking. The flux they have it is horrible stuff, expect bridged pins, non wet joints, and a lot of smoke at temps around 320F

I tried it 4 times, each time I had to fix joints. Its syringe is not fine tipped and the stuff doesn't sqeeze out easily.

It took longer to get the solder on and the parts in place then it does just soldering them on with an iron. I will not be using it again.

That stuff is meant to solder wires togather in tight places. It shouldn't even be called solder paste, more like "horrible solder product".

If you want solder paste order it from a real supplier.

 

[TV-Engineer]

I can't tell if the CPC paste comes with a fine needle tip or not. Considering the hassle with getting solder paste, I'm thinking of just doing what you said you do, fluxing the pins (just received two big pots of rosin flux I ordered) and then passing a loaded solder tip across the pins.

Is it a fairly easy technique to pick up, or might I be looking at a fair bit of practising? At will it matter if I can't use a spoon-shaped bit, only a wide flat bit?

 

[bmcculla]

In my experience with fine pitch SMD the soler paste really isn't that much better than a fine point soldering iron and really thin solder. It's gives you about the same number of bridges and takes longer to setup.

Solderwick is the key to nice fine pitch soldering. Just solder all the pins as best you can and then go back and use the solderwick to remove any bridges.

 

[TV-Engineer]

I've heard of that method and have had to do it myself before when soldering with 22SWG solder (have now obtained 0.4mm SMT solder), but I've always been concerned that the solder wick has removed too much solder from the tiny legs, leaving the leg looking like it's just sitting on the pad waiting to be soldered... :roll:

 

[bmcculla]

Just get a nice little magnifying glass ang go through and do a little inspection on all the pins. They may look unsoldered to the naked eye but its fairly easy to see the solder if you have a good magnifier.

 

[Nigel Goodwin]

I can't tell if the CPC paste comes with a fine needle tip or not. Considering the hassle with getting solder paste, I'm thinking of just doing what you said you do, fluxing the pins (just received two big pots of rosin flux I ordered) and then passing a loaded solder tip across the pins.

Is it a fairly easy technique to pick up, or might I be looking at a fair bit of practising? At will it matter if I can't use a spoon-shaped bit, only a wide flat bit?

It's pretty easy, when changing a chip I cover the pads with liquid flux (comes from SEME in a small bottle with a built-in brush) then carefully place the chip - moving it until it's aligned correctly, then tack each corner with a touch from a very fine point soldering iron.

I confirm it's the right way round (don't ASK!!) then cover the pins with more liquid flux. Then it's just a matter of slowly dragging the spoon shaped bit over the pins - you don't get any solder bridges at all, but I double check using high magnification, and also to make sure I haven't missed a pin.

I don't think a flat bit would work very well, it's got no where to hold the solder, I think it's the surface tension holding the solder in the 'spoon' which makes it work.

 

[TV-Engineer]

I must find a soldering station that has spoon-shaped bits available then.

The flux I have bought came from the US as I can't order from Seme, but it's fairly solid in a tub (kind of like wax). Hopefully that'll be just as good(?).

Thanks for taking the time to search CPC and explain the method to me, and to everyone else who offered advice.

 

[Nigel Goodwin]

I must find a soldering station that has spoon-shaped bits available then.

The flux I have bought came from the US as I can't order from Seme, but it's fairly solid in a tub (kind of like wax). Hopefully that'll be just as good(?).

I don't know, I wouldn't have thought so as it won't flow like a liquid. As far as I'm aware SEME accept cash orders from the public?, you don't need an account.

Presumably CPC stock liquid flux as well, and RS or Farnell, it's not really rare stuff.