New to SMD: What size to use?

[Krumlink]

I have known about SMD components, but now I have decided to try my hand at them. I wanted to know what is a good starting set of tools/things to have that are cheap? I am a good solderer, so That may not be too much of a problem. I have also heard of using a toaster as a reflow and ovens??? I know this is to "bake" the components to solder them, but what is a practical way of starting SMD? Such questions as follow:

Where should I get the capacitors and resistors from?
What size should they be?
How do I solder the really small stuff (aka the griddle/toaster)?
What other stuff should I get?

 

[bananasiong]

Hi,
I've tried 1208 SMT components without any problem. What you need is a soldering iron with a sharper tip.
You can get those components from any distributor.

 

[j.p.bill]

805 is also pretty easy to work with. Tin one of the pads beforehand, and just touch the iron to the conponent to tack it to that pad. Then you can flow on solder to the other side. And touch up the first as necessary.

Keep your parts in well-marked containers, though - the markings can be real hard to see.

 

[dknguyen]

805 tends to be the most common and mid-sized so it's the cheapest. SMD Is very easy even with a regular soldering iron. I thought it was hard, but during my summer job I was forced to do it and ended up wondering what I was staying away from. I was using a soldering iron a couple times wider than the SMD component and it was just peachy.

THe only time you might run into problems is with fine pitched ICs where bridges can occur, but things like resistors and caps...dead easy. Flux it, dab a bit of solder onto the iron, press down on the SMD with a tweezer to keep it in place and just dab the solder into one end of the SMD. Once it's tacked on, you can do pretty much whatever you want.

Stay away from reflow if you can being working with solder paste is a pain, inconvenient, and messy.

Just buy a crap breadboard and some SMD whatever and just try soldering them all over some garbage board. You'll see how easy it really is with a regular (~1mm) soldering iron. Don't forget the flux! Now...removing an SMD component...is a bit harder.

 

[xxxxxxxxxxxxxx]

Yeah, 805 SMDs are fairly straightforwad, provided you have small enough iron tip, however you wont be needing a reflow oven anytime soon unless you want to solder QTHIN (tm) and MicroSMD (tm) little things, which any hobbyist does not. Steer clear of these kinds of packages when purchaing SMDs.

 

[3v0]

Sparkfun has a very good intro on doing SMD with a soldering iron. Lots of pics. Maybe video I do not recall. They also show how to do reflow in a fry pan. They say the like it better then the toaster oven. Go figure...

 

[kjennejohn]

I install and remove 1206 components and SOIC ICs at work all day. SOIC has pin centers on 50 mils, half the standard DIP IC we've all come to know and love. The fancy stuff, like hot air removal systems, are nice, but not necessary for small chips, like 14 and 16 pinners. A decent pair of solder tweezers will do these as well as components. You can buy broader tips that bridge all the pins at once. 20 pins and larger start to get hard. Use flux and thin copper braid to get most of the solder off. Then apply lots of flux and go pin to pin with your soldering iron and a fine probe. Heat the pin while QUICKLY prying the pin up. Take too long to do this and the pad comes up with the pin (or,worse yet, off!). Installing SMT chips is easy to do with a standard gun, 20 to 40Watts, using a standard tip. Be sure it's ESD (ElectroStatic Discharge) proof. ESD will kill a CMOS chip fast. Worse, it could could just weaken the chip and make it erratic or intermittent, a technician's nightmare.

I've seen people recommend preheating the board with hair dryers or heat shrink guns before any SMT work. We have some fancy heating doodad at work, cost hundreds, blows hot air on the bottom of the board just under the spot you're working on. No one uses it. For the bigger ICs, like PLCC, I use a hot air removal system. It's not terribly complex, just a box with control of air temperature and air flow rate, with a hose and custom nozzle. I have one at home, less than $300, Atten brand, got it off of Ebay. The custom nozzles are the killer part, money wise. You'll get a few free with the station, but nozzles quickly go from $75 to >$200. And the ones I got don't fit as well as the expensive Hakko models at work. I use the hot air station for all the SMT IC work, but only because I'm too lazy to swap out the tweezer tips.

Go ahead. As long as you stay with 1206 and 0805 components and SOIC ICs you should be able to handle all these handilly, with some practice. Even finer pitch ICs are possible, but you have to have a deft touch and lotsa flux.

Hope that helped.
kenjj

 

[picbits]

As above - I'd start on the 1208/1210 as they are a piece of cake to solder and once you've got more experienced then the 0805 is relatively easy to solder by hand.

I have been using both for years now for hand soldering.

 

[Hero999]

I wouldn't go any smaller than 805.

I love SMT components, as it saves me having to drill loads of holes. The only thing that keeps me away from them is I have so many through hole devices that buying SMT versions doesn't mke much sense. Having said that, it's pretty easy to surface mount most non-SMT components, although I tend not to do it as it isn't so robust as soldering them through hole style.

 

[3v0]

I found that SMT work was easier once I had a good hemostat. You may have to file the jaws to get them to hold parts without too much pressure. Maybe a different one for each part size. I mostly use 805 parts. The 1206s are large enough that you may not need one.

 

[yngndrw]

I'm currently getting a collection of SMD components too, about to start using them when I can be bothered making a PCB to parctice on.

One thing to look at is that a standard 0805 SMD resistor is only 1/32Watt and the 1206 size is 1/16Watt. (Source: SureElectronics, my supplier for SMD components. It should be the same for most SMD components though.)

Having said that, I've found it easier to find SMD inductors which have a much higher DC current rating than their through hold conterparts, of the same size and cost.

Don't know why, maybe it's because SMD parts suit DC/DC converters better due to the high frequencys and shorter lead length.

 

[Optikon]

Buy some kits online. My lab contains all of E192 series for 1210,1206,0805,0603,0402 and other SMD types.

 

[bobledoux]

Dan's Small Parts has the best prices on SMD caps. For .1uf he gets $3 per hundred. He sells good assortments quite reasonably.

http://www.danssmallpartsandkits.net/

SMD is at the bottom of his web page

 

[Speakerguy]

You'll want to start off using 0805 and SOIC parts. You'll get proficient with these fairly quickly. The only trick with SMT parts is the combo of GOOD TWEEZERS and SMALL SOLDER. Buy a pair of EREM AASA tweezers (Digikey has the Pakistani version for only $3 and they are good) and .015" solder. I cannot emphasize enough the importance of good tweezers. I work in a small design/prototype group at a small company and I have tried LOTS of tweezers, most are crap. Buy the Erem's. Also get some solder wick for desoldering.

BTW, IIRC 0805 resistors will take 0.1W, not the 1/32 mentioned earlier.

 

[Speakerguy]

Also, don't worry about reflow ovens yet. TSSOP packages are the next smaller step and can still be done by hand albeit with difficulty. TQFP and QFN parts will make you want to use a reflow. We use a toaster oven at work and it works well enough that we've never had a failure.

 

[Stellarcore]

If you're soldering a fine pitch IC, dont worry about bridging or excess solder. Just get it lined up, and make sure each pin is properly connected to its pad. When every pin has been soldered, take some solder wick and suck up any extra solder and clean up and bridged connections. This seems to work well for me, but you have to be careful to wick up the extra solder quickly or you risk damaging the IC.

Also, for removing components (especially fine pitched ICs), simply glob on a bunch of solder so that all the pins on each side of the chip are bridged. Then melt one of the solder blobs, and then the other. Move your iron tip back and forth between the two (relying on the thermal momentum of the large blobs of solder so that they dont solidify immediately). When both sides are molten just give the component a small flick with the iron tip and it will come off. Then clean up the board with solder wick. This is handy, but tends to destroy the component your removing.

 

[yngndrw]

You'll want to start off using 0805 and SOIC parts. You'll get proficient with these fairly quickly. The only trick with SMT parts is the combo of GOOD TWEEZERS and SMALL SOLDER. Buy a pair of EREM AASA tweezers (Digikey has the Pakistani version for only $3 and they are good) and .015" solder. I cannot emphasize enough the importance of good tweezers. I work in a small design/prototype group at a small company and I have tried LOTS of tweezers, most are crap. Buy the Erem's. Also get some solder wick for desoldering.

Have you tried CK Precision tweezers ? Just wondering because I have some and if they aren't any good I'll get the ones you mentioned.

BTW, IIRC 0805 resistors will take 0.1W, not the 1/32 mentioned earlier.

I'm just stating what I was told by my supplier, although they also said that they can handle more if they have enough air space for cooling. Maybe it's 1/32Watts with no cooling and upto 1/10Watts when they are in an open space ?

 

[Speakerguy]

I'll have to look at the other tweezers we still have, but we've tossed most of the bad ones once I found those $3 Pakistani made ones at Digikey and ordered several pair. The Swiss and Italian made ones are much more expensive and so far the $3 ones are fine. If the CK work for you then they're fine, but if you happen to be placing a digikey order $3 isn't a whole lot.

As far as power, the Susumu's we use are all .1W 0805. But I never use them near full power, so they might get hot.

 

[Krumlink]

Ok sounds like Im going to buy the following from newark:

0805 Caps and Resistors:
0.1uf
0.01uf
1uf
10uf
100uf

100ohm
1kohm
330ohm
10kohm
100kohm
1milohm
10milohm
and specialty parts for my next robot

Tools:
Soldering wick
015 solder
Hemostat

Anyother things? I will need some suggestions, because I am new to this whole thing

 

[picbits]

Magnifying glass and tweezers !!!!