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Topic: Surface mount part kits and soldering (Read 139080 times) previous topic - next topic

Surface mount part kits and soldering

I've never tried to solder SMD chips, and was wondering if one of you guys can recommend some low cost smd soldering learning kits, or suggestions on where to start learning?  do i need a special ultra small tip on my iron?  I've always been a through-hole kinda guy, but want to expand my options.

Re: SMD Practice?

Reply #1
Not to discourage you from learning yourself, but I found a couple of assembly shops in my area who can do this work with all of the rights tools.  I've paid as little as $45 for some work, and as much as $300 for a batch of about ten boards.  Maybe you can even get a tour of the facility for a peek at the kinds of equipment needed to do this without making a mess or destroying parts.

Yes, I'm spoiled, because I live in Seattle and there is an assembly house within walking distance!

P.S.  I do have Weller WMRT soldering tweezers with a RTW4 tip in the tool set for parts up to SOIC-8, but rework is a bit different from initial assembly.

Re: SMD Practice?

Reply #2
Well, I first learned SMD soldering with the christmas card kit then moved to Web Platform (I especially ordered the kit and assembled myself but screwed up the FTDI IC pads!). I got good results and I'm trying to do most of my prototyping in SMD since that day.

You can check Sparkfun's tutorials for SMD soldering. No need for ultra small tip, just use lots of flux (that was my problem, I learned the hard way).

Re: SMD Practice?

Reply #3
Lots and lots of flux, after that I find it way easier than through-hole.

Steady hands (using tweezers) comes with practice. I don't usually drink coffee/tea/cola, but when I do, I shake too much to do 0603 :)
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Re: SMD Practice?

Reply #4
Quote
I've never tried to solder SMD chips, and was wondering if one of you guys can recommend some low cost smd soldering learning kits

Don't waste your cash..... just go out find a 'scrap'/ ANY modern product with the required SMT size then practice all you like , take the bits off and put the bits back.


you will need

1. Solder braid , for cleaning up the pads
2. good quality tweezers of various size.
3. A 'borg' hat (magnifier ,possibly head mounted, or a bigger desk model), I use a slide viewer eye piece , tied on with string
4. Desolder pump
5. range of soldering iron bits shaped for SMT.


there are some "tricks"

1. dont actually solder.. glue , I.E  SMT adhesive the bits down, bake ,  THEN solder one end , go back solder other end, the advantage is you don't have to fight  capillary stiction,  and because the glue requires a trigger, you can get the bits just right before soldering.
2.  'super glue' and a pin, but you have to be faster, pin into super glue, get a REALLY small amount on pin, touch board and place, superglue will degenerate when heated, so you might not want to breathe fumes.

The real issue is the damned IC's and not getting the pins bridged, for that it takes a good bit of practice, lots of flux and a quick wipe and flick..... use a different size bit for ic's

Re: SMD Practice?

Reply #5
[quote author="ian"]Lots and lots of flux, after that I find it way easier than through-hole.

Steady hands (using tweezers) comes with practice. I don't usually drink coffee/tea/cola, but when I do, I shake too much to do 0603 :)[/quote]

Now that i have had experience with SMD, I agree.  As long as you have a 5-gallon bucket of flux on hand (maybe a slight exaggeration) and some IPA to clean up the flux mess, it's pretty easy.  I'm definitely going to start using SMT for all my special projects (ones that i need to order parts for anyway, since locally i can only purchase through-hole parts and i don't have a collection of SMT parts yet).

One site i would highly recommend to learn about SMT stuff from is curious inventor: http://store.curiousinventor.com/guides ... _Soldering
It's what gave me the courage to start playing with it.


Re: SMD Practice?

Reply #7
[quote author="arhi"]wrt "ordering parts" I found this:

http://www.sureelectronics.net/goods.php?id=153
http://www.sureelectronics.net/goods.php?id=159

EXTREMELY useful :D ... I am so sorry I have not found that earlier...[/quote]

Only the boxed versions are usefull. I had the 0603 assortment, but they came in little plastic bags. Those little resistor seems to stick inside the little plastic bag (static?). The values are also a bit wierd, not the usual range you find.

Re: Re: SMD Practice?

Reply #8
I have the same in strips, better than the bags. I agree though, the range is generally not useful. There are some really good ones out of poland though. I'll see if I can find a current link.
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Re: Re: SMD Practice?

Reply #9
I don't get it, range is "standard" .. I always use that range?!

I btw ordered 2 packages of boxed ones and then repacked them all in single boxes (0805) and then I ordered 1206 and put them in empty boxes. So now I have one set of 0805 and one set of 1206 both in boxes ... took me below one hour to repackage them all and to remove all the paper markings and to write them with pcb pen (as those paper markings tend to get dirty + they are bit larger then the box lid)

Anyhow, I find this "assortments" very useful. I usually order from farnell and I get them in paper rolls (like those that go into pnp machine) but they take more space and are not as nicely organised (yes, much easier to get out :D )... but having "bunch of capacitors and bunch of resistors" is a must .. so now I don't need to worry if I have that 4k7 i 1206 or 0805 ..

Re: SMD Practice?

Reply #10
having a basic e12 or e24 set of resistors is a must, as for smd caps i like to keep only a few values in bulk,
1u, 0.1u, 4.7u, 10u, 0.01u, 22p, 27p, 33p have been the most used from my parts box

Re: Re: SMD Practice?

Reply #11
For single prototypes the technique I use is actually applying the solar paste like paint with a toothpick, sometimes diluted with IPA. I agree with Ian when there are many holes it is easier than though hole.

The other way you can go is to pre-tin everything with a tip then apply flux and use hot air (if you have it).

If you don't have hot air pretty much just do your best and then use wick to remove bridging. You must have flux to do SMD while not everyone who does PHY has it, as people get away with the flux core solders.

Re: SMD Practice?

Reply #12
extremely thin solder will help you control the amount it will feel like your using a lot of solder. i only tin the first pad so i can align it with a free hand.

Re: SMD Practice?

Reply #13
There's nothing wrong with the range. For me though, I already stock reels of the most common stuff (100,2K, 10K, 100K, etc) so the kits are to fill in for strange values I need, like for analog stuff. It prevents the 'last minute' order to Mouser for 200x 0805 39ohm resistors. The 0603 kits (scans attached) always have the values I need, but the 0805 from sure seems to lack it and I end up using a lot of 0603 kit parts on 0805 boards.
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Re: SMD Practice?

Reply #14
Those are some pretty big resistor and caps collections!
Willing to share the links to get one kit of each in 0805?