Not sure if this site is still current, but it is on the side of the box: LCR Meter Smart Tweezers - Digital RCL, Impedance and ESR Meter,SMD Component Tester/Multimeter
It's an "L-C-R meter integrated with tweezers".
I appreciate a freebie as much as the next "bum", kgrleeThanks Guru Brad. But this beach bum was hoping for a free internet tutorial.
... had a bit of a wander, turned up this fellow, looks quite reasonable: Computer Exercises Manual: Device Parameters in SPICE - http://www.oup.com/us/companion.websites/9780195131864/pdf/cem.pdfFrank
Last edited:
I only use them for testing components, and they work adequately. I have other tweezers for handling parts.
A somewhat less costly solution, RC only :
Wholesale New CEM SMD-100 Smart Electronic Components Tester, Free shipping, $38.29-47.01/Piece | DHgate
CEM SMD 100 Smart Electronic Components Tester | eBay
Patrick
Wholesale New CEM SMD-100 Smart Electronic Components Tester, Free shipping, $38.29-47.01/Piece | DHgate
CEM SMD 100 Smart Electronic Components Tester | eBay
Patrick
Attachments
aha, as I thought, I think a decent scope and signal generator is first off the ranks, they do look good though and would certainly simplify testing and identification. I wonder if there are similar things that can be plugged in as scope probes? guess i'll have a google.
Thanks Frank. Exactly what I want.I appreciate a freebie as much as the next "bum", kgrlee
This is the first SMT project I have tried to assemble. Are there tweezers that fit SOT parts exactly (to keep you from dropping them) to place them on a board. And where do you obtain the solder paste-reflux wax to stick them to the board. Brand? Jobber? Can hemostats be used as a heat sinking while soldering? Max temp? They just seem like they will move around if not stuck down while soldering. Will a heat gun like a heat shrink gun melt the solder and work better on a reflow solder plated board than a soldering iron held by fumble fingers? Thanks for the help. Ray
Hi Ray,
SMT-101:
No need for anything fancy, regular stainless steel tweezers with fine tips are all that is required. Of course you have keep squeezing the part to solder the first lead to the pad/land. make sure this done over a large desk/bench area, if the part drops on the floor, good luck finding it. I order my PCB's with HASL plating, just for this very reason, so that I can easily solder small SMT parts. HASL is not recommended for SMT because of the copanarity problems, but in this case, it helps with hand assembly.
Forget the solder paste, waste of time and the stuff dries up, has to be cooled to keep its life = nothing but problems. Once it smugizes you are toast and pissed to boot.
In all my years doing SMT, since the 80's, I have never ever used solder paste, this is for a production lines using a squeegy & a screen application process for reflow applications.
I use 0.015" solder and melt a little on one pad, then centre/place the part with small tipped tweezers, then still holding the part in place, melt the solder so that the first lead gets soldered to the land/pad, then continue with the rest of the leads, finally going back the first lead soldered and add a little bit more, since you should have not put too much on in the first place = done. I do this for all leaded SMT parts. For 0.025"/0.5mm pitch, I use a jewelers 10x magnifier, kinda tricky. Always good to use the magnifier to inspect the solder joints, to check for shorts, small solder blobs.
Once you master this, I'll give you advise for those damn DFN/QFN packages!!
Also, forget the lead free solder, just a pain in the a$$, use regular 60/40 eutectic solder, so what it ain't ROHS!! this is an exception!!
Make sure you have a supply of solder wick as well, in various widths, this is your friend, if you have a solder bridge or have too much solder on a pad.
Found the solder, that I use, nice that Mouser has a project manager to keep track of my orders,
Mouser # 738-13368
Solder, Fluxes & Accessories Sn63/Pb37 GLOWCORE2% .015 DIA 1/2 lb.
Good luck & happhy soldering
Rick
SMT-101:
No need for anything fancy, regular stainless steel tweezers with fine tips are all that is required. Of course you have keep squeezing the part to solder the first lead to the pad/land. make sure this done over a large desk/bench area, if the part drops on the floor, good luck finding it. I order my PCB's with HASL plating, just for this very reason, so that I can easily solder small SMT parts. HASL is not recommended for SMT because of the copanarity problems, but in this case, it helps with hand assembly.
Forget the solder paste, waste of time and the stuff dries up, has to be cooled to keep its life = nothing but problems. Once it smugizes you are toast and pissed to boot.
In all my years doing SMT, since the 80's, I have never ever used solder paste, this is for a production lines using a squeegy & a screen application process for reflow applications.
I use 0.015" solder and melt a little on one pad, then centre/place the part with small tipped tweezers, then still holding the part in place, melt the solder so that the first lead gets soldered to the land/pad, then continue with the rest of the leads, finally going back the first lead soldered and add a little bit more, since you should have not put too much on in the first place = done. I do this for all leaded SMT parts. For 0.025"/0.5mm pitch, I use a jewelers 10x magnifier, kinda tricky. Always good to use the magnifier to inspect the solder joints, to check for shorts, small solder blobs.
Once you master this, I'll give you advise for those damn DFN/QFN packages!!
Also, forget the lead free solder, just a pain in the a$$, use regular 60/40 eutectic solder, so what it ain't ROHS!! this is an exception!!
Make sure you have a supply of solder wick as well, in various widths, this is your friend, if you have a solder bridge or have too much solder on a pad.
Found the solder, that I use, nice that Mouser has a project manager to keep track of my orders,
Mouser # 738-13368
Solder, Fluxes & Accessories Sn63/Pb37 GLOWCORE2% .015 DIA 1/2 lb.
Good luck & happhy soldering
Rick
Last edited:
yep, you can get decent tweezers for 25-30, wouldnt really spend any less than that though. I spent just over $170AUD on some titanium ones just because I like nice things and I was doing a big job, someone nicked my stainless ones and I felt like treating myself. the stainless ones are great but cheaper ones I found I had to straighten the points with pliers every now and then, dont have that problem now.
its worth getting some curved ones to IMO, I use straight pointy ones most but use the curved ones ~15-20% of the time.
I second the notion of using leaded quad eutectic solder in a ventilated room, get tacky flux and as mentioned a magnifier. the digital ones are getting pretty good these days too, even a digital camera with a macro setting will work in a pinch for examination, just view on your computer and zoom in
its worth getting some curved ones to IMO, I use straight pointy ones most but use the curved ones ~15-20% of the time.
I second the notion of using leaded quad eutectic solder in a ventilated room, get tacky flux and as mentioned a magnifier. the digital ones are getting pretty good these days too, even a digital camera with a macro setting will work in a pinch for examination, just view on your computer and zoom in
Last edited:
I keep my stainless ones with a little booty of shrink tubing protecting the tips when not in use. I don't do a huge amount of assembly, but it's easy to damage the tips if they are just tossed around with the other tools.
On the other hand a client stopped by and decided to use a cruder pair of tweezers as a prying instrument and utterly ruined them. The last time someone did something that stupid was when an office partner used a nice pair of diagonal cutters to cut a small bolt. At least the client pays my invoices.
For really fine-pitch packages with lots of leads I use a little rosin flux and flow solder over the area, then selectively use wicking material to remove the excess. But I don't have to do that very often.
On the other hand a client stopped by and decided to use a cruder pair of tweezers as a prying instrument and utterly ruined them. The last time someone did something that stupid was when an office partner used a nice pair of diagonal cutters to cut a small bolt. At least the client pays my invoices.
For really fine-pitch packages with lots of leads I use a little rosin flux and flow solder over the area, then selectively use wicking material to remove the excess. But I don't have to do that very often.
I had to look up HASL and found this
HASL vs. Immersion Gold
BTW.
HASL = Hot Air Solder Leveled
and it can be either rohs or leaded.
HASL vs. Immersion Gold
BTW.
HASL = Hot Air Solder Leveled
and it can be either rohs or leaded.
I agree mostly with what Rick says. I do rework of SMT down to 402s and 48 pin QFPs every day. You can use fine wire solder (.01-.015") and a fine tip iron with practice, on the passives and low lead count parts.
The paste part however is his preferance. Paste can easily be used with the iron and standard tools. Store it in the fridge. Use a 2-3cc syringe with a 20Ga. needle to apply it. You can easily get low temp paste also wich helps alot to avoid over temping the parts if your not fast enough, and when you are working with heavy copper traces and planes. Use soder-wick # 1, 2 or 3 as any larger sucks the heat off a tiny tip iron to much. A hot air pencil is another tool that works well but you don't need to $pend the money if your not going to do those QFPs.
You can get single footprint stencils and use paste and a squeegy apparatus. Ever tried!!
I bought a hot air machine from Sparkfun for $100, a good deal, works as good as a Hakko unit from before. There is another place selling all the various nozzles. Problem with paste, is accurately centering the part. Need a suction device to hold the part. A mechanical device is needed to place the part, optics to see what going on, gets expensive. My method costs peanuts and time. Your hand is way to shaky for 0.5mm parts. I have one of those hand held suction pencils, no good, too shaky. Certainly a lot faster if you can paste a board, place and then off to the easy bake oven!! Elektor has a bunch of stuff. Anyone got a Fuji pick & place machine at home, I'll check what the going rate is on eBay
P.S. We/I should start a solder thread? I put in enough years to learn a few things, to share. Can we get the admins to move our conversations to a new thread?
@AndrewT, I am surprised that you had to look up HASL, but you did state that you are an ME by profession, after all
Cheers
Rick
I bought a hot air machine from Sparkfun for $100, a good deal, works as good as a Hakko unit from before. There is another place selling all the various nozzles. Problem with paste, is accurately centering the part. Need a suction device to hold the part. A mechanical device is needed to place the part, optics to see what going on, gets expensive. My method costs peanuts and time. Your hand is way to shaky for 0.5mm parts. I have one of those hand held suction pencils, no good, too shaky. Certainly a lot faster if you can paste a board, place and then off to the easy bake oven!! Elektor has a bunch of stuff. Anyone got a Fuji pick & place machine at home, I'll check what the going rate is on eBay
P.S. We/I should start a solder thread? I put in enough years to learn a few things, to share. Can we get the admins to move our conversations to a new thread?
@AndrewT, I am surprised that you had to look up HASL, but you did state that you are an ME by profession, after all
Cheers
Rick
Last edited: