Forum Home
PC World Chat
Thread ID: 123237	2012-02-12 22:54:00	Dispensing solder paste, where to buy syringe etc?	Agent_24 (57)	PC World Chat

Post ID	Timestamp	Content	User
1258900	2012-02-12 22:54:00	Now that I'm starting to get into working with SMD parts, I want to get a syringe and tips to get solder paste onto the PCB. I bought a jar of solder paste a while back, and would rather use it than buying a whole new lot already in a syringe. Apparently plastic tapered tips\needles are better than metal (less pressure needed): www.microbuilder.eu but I have no idea where to buy them, or even metal ones (at least, in small quantities\prices) RS Components at least does seem to sell them, but only if you want to buy them in bulk for at least 100 for $100 or so - which is of course overkill. eBay has better prices, but I'm not sure if that would work, I wouldn't be surprised if the NZ customs are paranoid about any kind of needle\syringe related items, and would throw them away. Besides, I want to try different sizes, and most sellers seem to have them in packs of 50 or more which is again overkill. Anyone here got any good ideas?	Agent_24 (57)
1258901	2012-02-12 23:42:00	Try www.hobbiesplus.co.nz :)	Zippity (58)
1258902	2012-02-13 07:08:00	Try www.hobbiesplus.co.nz :) Thanks but I want solder paste, not paste flux. Also, the tip of that looks a little big. Some SMD component pads are <=1.0mm wide, and that looks like it would swamp them.	Agent_24 (57)
1258903	2012-02-13 07:21:00	May sound silly ... but go ask a dentist. They use a disposable syringe with a twisted (like the tip of a corkscrew) tip to flush out abscesses (root canals) after drilling through the tooth ... I know from personal experience and have a couple of the syringes myself. They come in extremely handy for applying small amounts of grease, oil, pastes, etc into tight places.	SP8's (9836)
1258904	2012-02-13 07:26:00	As far as I know with a syringe it's hard to get the right amount to come out. If you're doing more than a few boards, just get a stencil made up. The way I've applied solder paste for prototype boards is to apply the paste using a very fine tip from a pair of tweezers, under a microscope. This has worked (for me at least, YMMV) for parts down to 0.5mm pad pitch. Do let us know how you get on	forrest44 (754)
1258905	2012-02-13 07:29:00	Pharmacies sell them - including the ones with a curved plastic tip.	somebody (208)
1258906	2012-02-13 23:34:00	As far as I know with a syringe it's hard to get the right amount to come out. If you're doing more than a few boards, just get a stencil made up. The way I've applied solder paste for prototype boards is to apply the paste using a very fine tip from a pair of tweezers, under a microscope. This has worked (for me at least, YMMV) for parts down to 0.5mm pad pitch. Do let us know how you get on I've tried that method with a very small screwdriver etc and it just made a mess and was quite hard to do. Didn't think to try tweezers though. At the moment I think stencils would be overkill, because I'm not even thinking about doing any sort of production run, just one-off boards and rework. Anyway, to continue the story... I bought a syringe from the pharmacy yesterday (and now I'm thinking they probably think I'm a drug addict :lol:) Came with a 26 gauge needle that I ground down with my Proxxon tool to make it flat on the end. I read on Wikipedia that 26 gauge = 0.26mm inner diameter which seemed to be what I wanted, but when it came to actually trying to squeeze the solder paste out, it was practically impossible. I see now why the author of that site says: "Personally, though, I have a preference for the plastic tips because: I find it takes a lot less pressure to start the flow of paste with the 'conical' plastic tips" - This is a very accurate statement! So until I find a good source for the plastic ones it looks like I'm a bit stuck for now...	Agent_24 (57)
1258907	2012-02-14 03:06:00	I use to use fine syringes and pipettes when working with micro samples of chemicals, inks, and adhseives. Their are plastic, metal, and glass including disposables, and come in different styles and size. Use to buy from chemical suppliers like lab supply (labsupply.co.nz/) or global science nz. (http:) May have what you want. You probably want a vacuum assisted set up, of which rubber bulb glass/plastic pipettes (purge air then easily squeeze the liquid out) were ideal for that. I'm sure I have seen some at chemists or a vet once.	kahawai chaser (3545)
1258908	2012-02-14 03:51:00	Also any farm supplies place, or vet.	pine-o-cleen (2955)
1258909	2012-02-14 09:07:00	hmm you could try applying it using a (non-hollow) needle tip or pin... do you have a microscope?	forrest44 (754)
1 2