Author Topic: Handling SMD components  (Read 2676 times)

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Offline karoruTopic starter

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Handling SMD components
« on: July 22, 2016, 10:35:02 pm »
I'm a guy that learned all this soldering stuff before that "surface mount" era. I learned that SMD components don't bite and with my very shaky hands I can do 0805 resistors by hand without any problems (I know it ain't any serious achievement but I'm just a klutz;)). As long as I actually place the component on board. I have no problems using small parts in my designs if they're cheap - if I drop random resistor on the floor I just get next and let the vacuum cleaner to take care of the original part. But my problem is for example these SOT223 nice chips that cost 10$ or so for a piece. Any ideas for semi-disabled person how to handle them in a way so I don't actually lose them in the process? Spending an hour with a magnifying glass looking for them after dropping them on the floor ain't exactly the most joyful way to spend one's time ;)
 

Offline Kjelt

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Re: Handling SMD components
« Reply #1 on: July 22, 2016, 10:43:17 pm »
Keep them in their original strip till you need them. For beginner, if you need only one, cut one still closed from the strip, put that piece in the strip on the pcb around where you want to place it and then and there remove the plastick shield and place the part where it needs to be placed. Best under a stereo microscope, you can use tweezers or preferably a vacuum pincet.
When you get more and more skilled in this you can place a longer plastick strip with more components aside the pcb and move the parts from there on the pcb where it needs to be placed (longer distance), keep the height short so if it drops it will stay on the pcb and not jump half a meter in the air to the floor.
 

Offline KL27x

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Re: Handling SMD components
« Reply #2 on: July 22, 2016, 11:31:01 pm »
Sot 223? That's gigantic. Haha.
search for mikeselectronicstuff on youtube. He has a video that covers 99% of what you want to know.

Also, IMO buy this: http://www.hakko.com/english/products/hakko_394.html
 
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Offline Habropoda

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Re: Handling SMD components
« Reply #3 on: July 23, 2016, 12:06:47 am »
I have had shaky hands my entire life.  Here are some soldering techniques I use:

  • Use a silicon baking sheet.  It keeps parts from sliding around.  Can be cut to size.
  • Use a stereo microscope with good lighting.
  • Use sloppy drop soldering , pioneered by KL27x.  https://www.eevblog.com/forum/reviews/hand-soldering-technique/  It reduces the number of hands needed for soldering.  One for the iron, one for the solder (this one not needed) and one for the part.  Works great!
  • Amtech NC-559-V2-TF tacky flux works well.  Helps hold the parts, wets the solder nicely, cleans up easy.  Use it with the sloppy drop method.
  • Use curved tweezers.  With these I can brace back end of the tweezers on the work surface while placing the part.
  • Tweezers that are too hard to close make it hard to tell when you have a grip on the part.
  • For some forms of tremor, imbibing a small amount of alcohol helps.
  • Coffee does not help.
  • Bracing helps.  Wooden blocks, tape rolls, etc.
  • Take a break if the work becomes too frustrating.
  • Use hand weights.  I have not done this yet but I notice my hand is steadier when I am holding a half pound roll of solder.
  • Deep Brain Stimulation.  Flip a switch and the tremors disappear.
  • There are millions of people with shaky hands out there:  http://www.essentialtremor.org/
 
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Offline Cerebus

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Re: Handling SMD components
« Reply #4 on: July 23, 2016, 12:15:01 am »
Work in a tray lined with something that parts won't bounce off, quilted kitchen paper works quite well. I haven't felt forced to do this yet for SMD parts but it's a technique I've used successfully for mechanical things with tiny parts that try to get lost at the first opportunity.

If you're a repeat offender for scattering small parts onto the carpet try putting some white paper on the floor where you're working - it makes finding things again easier.

Also, if you do drop something on the floor and can't find it - get a torch and aim the beam horizontally at floor level, it creates a grazing light that throws long shadows from quite small parts. It will also convince you that your floor is much less clean than you thought it was as it magnifies tiny dust particles into apparent boulders.
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 
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Offline Rerouter

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Re: Handling SMD components
« Reply #5 on: July 23, 2016, 12:44:06 am »
A good pair of tweezers can make most of the different, to me these are the best i have so far found, you can actually feel when you have a grip on the tiniest stuff, e.g. manouving a single strand of wire that is only single digit microns thick,

http://www.jaycar.com.au/anti-magnetic-precision-tweezers/p/TH1754

the other thing i strongly recommend is a good tacky flux, and a hot air station, you dont need to worry about shaky hands with hot air, and the flux hold them in place when you keep the air set low,
 

Offline derGoldstein

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Re: Handling SMD components
« Reply #6 on: July 23, 2016, 04:40:08 am »
I have a shaky hand problem that comes and goes, so I'll sometimes change the soldering strategy depending on how stable my hands are on a given day.
For the specific problem you're talking about, when you have a very small part that can look like a dozen other parts and its labeling isn't clear, and at the same time costs several dollars a pop, I use dedicated containers.
Look at these types of small connectable boxes:
http://www.ebay.com/itm/High-Quality-10pcs-Electronic-Component-Parts-Case-Storage-Small-Box-Anti-Static-/162029712267?hash=item25b9b9338b:g:BtoAAOSwsN9XBHXJ
http://www.ebay.com/itm/Electronic-Component-Parts-Case-Laboratory-Storage-Small-Box-SMT-SMD-/301619690394?var=&hash=item4639ef3b9a:m:mQBps8h4SBKwUJKL_99J-Hg
http://www.ebay.com/itm/New-10pcs-Lot-Electronic-Components-Boxes-Patch-Laboratory-Storage-Box-SMT-SMD-/311463943215?hash=item4884b29c2f:g:uZYAAOSw9mFWHN0E
(You can also find them on amazon)

When I get the small expensive chips, I grab one of those boxed, empty the strip of them into it, and then label it. When it's time to place it on a board, I use bluetack to hold the little box in place before I open it, so that it won't tip over and spill its contents all over the place. The latch that holds these boxes close is spring-loaded, so holding it firmly when you open it is very important (here again bluetack helps).
The downside to this is that you don't get the moisture protection that the sealed SMT strip provides, but you can place a tiny packet of silica gel into the box with the chips.

Also, when using hot-air soldering the hot end can sometimes blow tiny parts away, so make sure you set the air flow to a minimum.
 
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Offline Assafl

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Re: Handling SMD components
« Reply #7 on: July 23, 2016, 06:21:09 am »
Look at how watchmakers work. Very high tables at elbow height. Or lower your seat as low as possible.

That enables you to use the lowest magnification possible that you can still see but have a wide as possible field of view. Micro tremors are aggravating if the parts keep disappearing from the frame.

I always solder a single corner SMD pin first thing - then I do alignment and other foolery.

Keep clutter away from work area. Makes room for elbows and prevents parts from being pushed around.

And lastly - good quality bent tweezers. Non aligned tweezers will send parts flying.
 
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