Have a lot of 0402 work coming up, worth buying some soldering tweezers? - Page 1
Forum section: electronics / general

author: jnz
author_rank: Frequent Contributor
timestamp: June 29, 2022, 05:18:07 am
content: For the first time I have more than a few 0402 parts on a board. Mostly populating new boards, some rework. Is it worth getting a soldering tweezer unit?It’s have a JBC Compact unit for soldering, love it, but can’t afford to also buy their tweezer + new base or their compact tweezer standalone. So I have pretty high expectations for soldering, never used tweezers.So if it might be worth getting some, which is the best value? Looking to stay under $400, but fine with used.Thoughts?

author: Kleinstein
author_rank: Super Contributor
timestamp: June 29, 2022, 06:26:16 am
content: Tweezers are usually not that expensive and one usually already needs them with 0805 or smaller.For the small parts the question is between classical mechanical tweezers and a vaccum version. With the vaccum parts the costs are usually not for the actual part you hold in the hand, but the vaccum pump. For the pump it is mainly about noise and durability - the normal function is usually OK even with the very cheap ones.Which type is preferred depends and one may want different ones for didderent jobs (e.g. depending on the space and parts and tools to use with them). The spacing between the parts may be more important the the actual parts to grab.

author: ebastler
author_rank: Super Contributor
timestamp: June 29, 2022, 09:45:30 am
content: I believe the OP was thinking about tweezer-style tips for the soldering iron itself, while Kleinstein may be talking about "cold" tweezers just to position the components?To solder passives onto the board, I can't see how soldering tweezers would be helpful. Wouldn't it be very likely that you drag the component along or pull it upward the moment you lift the soldering prongs, while the solder is still molten on both joints? Personally I prefer using solder paste and hot air when I have to populate multiple small passives. Or I hand-solder them one side at a time with a conventional iron, holding the component in place with tweezers while I solder the first joint.For unsoldering, I find that actually gets easier for the small 0402s: You can heat both joints at once by holding a flat tip to the long side of the part, then lift off or push away the part. I have felt more of a need for soldering tweezers with larger parts where I can't otherwise reach both joints at once. (But then I'm cheap and just a hobbyist, so I simply use two separate soldering irons in those cases...)

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 29, 2022, 09:51:06 am
content: Soldering tweezers won't be much use for 0402s. The package is small enough that you can just use a larger single tip to flow both ends for removal.

author: eugene
author_rank: Frequent Contributor
timestamp: June 29, 2022, 02:08:56 pm
content: As already stated, hot tweezers are mainly useful for rework. They are by far the fastest way to remove a passive that is already soldered down. If you do a lot of rework they can save time over hot air or other tricks, but lots of rework gets done without them.If you have $400 to spend, I would suggest getting a stereo zoom microscope. Amscope is common source for adequate quality at a good price. Be sure to get a 0.5 Barlow lens. This cuts the power in half but doubles the working distance between the lens and the work. It's important to have room for your soldering iron etc.

author: jnz
author_rank: Frequent Contributor
timestamp: June 29, 2022, 04:58:52 pm
content: I had figured the thermal tweezer recommendations for my needs might be "don't bother". It would be really nice to grab a part and remove, but I do have an air rework station, and I can paste these boards.Quote from: eugene on June 29, 2022, 02:08:56 pmWell, shoot this does seem like a better idea. I'll research. The Amscope models I checked quickly were no where near $400, but for a microscope, I could increase budget.

author: bson
author_rank: Unknown
timestamp: July 01, 2022, 06:35:02 pm
content: Soldering tweezers are handy to remove parts. The problem is the surface tension will make 0402 components stick to the tweezers as much as the pads and it quickly gets messy.What you need is a good pair of tweezers for placing parts, a 3-5X (or 5X-10X) "inspection" microscope, leaded solder paste and hot air. For hot air you need low air flow, while a lot of units brag about how much they can blow. The latter is counterproductive and will just blow 0402 parts all over. Paste, place, reflow - it's quick and easy, but if new to reflowing get some random cheap boards off eBay to practice on until you have a feel for it.

author: PlainName
author_rank: Super Contributor
timestamp: July 01, 2022, 08:10:42 pm
content: Tweezers are fab for placing parts too - heating both sets of pads/contacts at the same time, and being able to position with one hand too. A fine pointer (or toothpick) to hold the part down when you leave go (although surface tension sometimes works alone) and the job's a good'un.

author: SteveyG
author_rank: Unknown
timestamp: July 03, 2022, 01:00:55 pm
content: Quote from: dunkemhigh on July 01, 2022, 08:10:42 pmWhat about applying the solder though?

author: PlainName
author_rank: Super Contributor
timestamp: July 03, 2022, 02:33:59 pm
content: That's why they're fabPre-solder the pads and it melts as you place the part. Or you can put plain paste down and the same happens.

author: Electro Fan
author_rank: Super Contributor
timestamp: July 03, 2022, 04:41:10 pm
content: Quote from: jnz on June 29, 2022, 04:58:52 pmThere are lots of variations to consider but these are two popular baseline models. With either of these you would probably want to add a 0.5 Barlow lens to get some useful working space and add some lighting. Sometimes Amscope offers discounts beyond what they show on their web site. If you ask for a quote they will work with you. I don’t solder a lot but there is no doubt that the microscope improved my soldering skills a bunch by enabling me to see in real time with clear detail. With the microscope, good lighting, a decent soldering iron/tip, tweezers, and something to hold the PCB soldering (and desoldering) down to 0402 is feasible.https://amscope.com/products/sm-4bhttps://amscope.com/products/sm-3b

author: nomead
author_rank: Contributor
timestamp: July 04, 2022, 12:04:51 pm
content: Thermal tweezers are useful in systematic removal job in production environment. You can fine tune tip geometries and working positions to match the job. Problem could be large ground planes, most tweezer tips are quite thin. In this case using large single tip, some flux and using the component as thermal route is safest for the PCB.

author: tautech
author_rank: Super Contributor
timestamp: July 16, 2022, 03:04:52 am
content: Quote from: jnz on June 29, 2022, 04:58:52 pmInvest in some K style tips.They're like a 45ochisel and this long face can easily reach across both pads of a 1206 passive package and allow you to pick it off with tweezers or just wipe it from the pads.While you can solder with them their profile doesn't allow for the best thermal transfer and if the layout is compact you might need to swap tips or better still, get a second iron to swap over onto on your base station.