Introduction: Salvage Surface Mount Components

I shall tell you how I rescue components from old circuit boards and store them for reuse. A board from an old (relatively new, that is) hard disk drive shall be shown for an example. The photo (taken using my scanner) shows one such board, after I removed the IDE connector.

Step 1: Desoldering

I have a movie showing my process. I am attacking a tantalum capacitor in the video, but the same process works for all other components too.

First bend a piece of thick copper (or other solderable metal) wire to fit around the component, and contact all its solder pads. Solder it in place. This is done to make thermal contact.

Then heat the wire at a central place with your soldering iron, and lift the component away with tweezers. Or push it away using a wooden toothpick. Only don't be too enthusiastic with the push or it will fly across the room and be lost forever in the crud that covers the (in my case anyway) floor.

These are best stored inside foam cutouts in a suitcase. Miniature, of course.

Step 2: Tantalum Capacitors

These are the electrolytic capacitors usually found on surface mounted boards. They have to be connected the right way round. The positive terminal is marked with a band. If there are two numbers on it, one is the rated voltage and the other is the capacitance.

I'm sorry, I do not have further info on identifying them other than checking them in a multimeter which has a capacitance range.

They usually look like little bricks with metal strips issuing from their ends, folded over the bottom.

On the left of the picture are ceramic capacitors - MLCs - short for Multi Layer Ceramic - usually they are this brown colour, though I have seen black and white, and the ends look as if dipped in metal. There are usually no markings at all, so measurement is the only way to classify them.

Step 3: Ceramic Capacitors

Ceramic Capacitors look like bricks dipped in metal at the ends. The usual colour is brown.

Ferrite beads (or inductors) look almost exactly the same, exept that these have continuity and are magnetic. And black.

The photo shows a bunch of ceramic capacitors, and a few inductors (lower left).

If you aren't confused already, there is more to come.

Step 4: Resistors

In contrast to capacitors, resistors are easy. They are usually white on the underside, black on top and have the value printed on them. The last digit is the number of zeroes. The first two or three digits are the figures before the zeroes. In ohms.

560 means fifty six ohms. 561 would be five hundred and sixty ohms. 564 would be five hundred and sixty Kilohms, or, more concisely, point five six Meg.

These are also seen as arrays, pictured here are 33 ohm arrays I soldered together because I did not find any use for them.

When kept loose in a box, they tend to obey Murphy's law and all of them will be hiding white side up. And the one you want will be the one you turn up last.










Because when you find the one you want you stop looking.

Step 5: Storing Resistors

So the easiest method of storing chip resistors is this one, which I have developed after much experimentation.

And countless times fighting against the urge to flush the lot down the toilet and forget about it and do something worthwhile, like watering the plants.

And saying hello to the wife and kids.

Take a piece of transparent plastic, arrange the little buggers face down on it and, suddenly, while they are least expecting it, place a piece of sticky tape over them. This holds them immobile and you can look over them leisurely, identify the one you want, then peel back the tape and lift off that one with tweezers. The others will remain stuck to the tape.

Step 6: Diodes, Transistors and ICs

Diodes and transistors generally come packed in the SOT package. This is the "small outline transistor" package, with three leads.

So a device with three leads sitting on the board might be a diode. It might be a transistor. Or it might be an integrated circuit, like a three terminal voltage regulator.

A bit of probing with the multimeter (hold the thing down with a croc clip) will usually tell you whether it is a diode, or npn or pnp transistor. Small canisters could be used for storing them.

A thing with many legs is usually an integrated circuit. Or a resistor array.

I find that using a vintage IC involves poring over data sheets, finding components, and much design work, and that the end result is some gizmo which does some ancient job poorly, which is why that board ended up in the junk. The effort is just not worth it. But I do keep the ones I remove, because they might come handy one day - to build into a sculpture perhaps.

So - start desoldering, and have fun.

Comments

author
neelandan (author)2011-07-27

This the method to use when you need to extract just one component from a circuit board. It complements the "Bulk extraction" methods of using hot air or a toaster oven, because extracted components are a bit fiddly to handle and store for later use.

author
darrenah (author)2016-03-01

Hey, thanks for the ideas. In return, I'll share one with you which I got while reading your instructable. In the picture where you've taped the resistors to the clear plastic, you mention peeling the tape back to get the ones you want when you need them. In stead of peeling the tape back, which the tape would eventually lose it's effectiveness and you're freeing ones you don't intend to; you could spread them out just a little when taping them the first time. After that, you could use an razor or sharp knife to slice free the one you are seeking at the time.

Thanks again for the great ideas for recovering smd items.

author
Yonatan24 (author)2015-12-30

Wow! They are SOOOOOO tiny!

author
jparis1 (author)2013-06-14

try sticking the small resistors to a piece of elec. tape or duct tape right side up. no more hunting, when u want one jus use tweezers to get it off the tape. jus a lil tip, might help u guys.

author
eric m (author)2009-04-11

IC's are such a waste. I wanted an led display and chip but you know the chip is impossible to figure out. just a waste. Ofcourse component makers don't want a used market undercutting them.

author
AJMansfield (author)eric m2013-02-22

The main consumer of parts in not hobbyists anyway, but factories. The reason the ICs can be so difficult to work with is either because they are cheaper to make that way, or the particular pinout order was easier to connect to some other specific chip without crossing races or stuff.

author
AJMansfield (author)2013-02-22

What about sub-ohm resistance values?

author
tanmanknex (author)2009-08-22

isn't the one you want always going to be the one you turn over last? why would you keep looking after that? jk ;D

author
AJMansfield (author)tanmanknex2013-02-22

So that you can find the one you don't want.

author
AJMansfield (author)2013-02-22

Just google search "capacitance markings" for more tables than you could ever possibly need.

author
TzarIgor (author)2013-01-22

To find more information about coding SMD-components read the book Turuta E., Turuta M. C. SMD-codes. Active SMD semiconductor components marking codes.
And then you can download apropriate datasheet from  http://www.datasheet4u.com
I use thise steps and save a lot of money while making a lot of gadjets from old electronics! 

author
zaphar (author)2012-05-12

I'm interested in salvaging ICs and whatever I can for educational projects, however, which parts are worth saving. The ICs seem like a no-brainer (at least the ones that have datasheets) but what about other components? I think I read somewhere that some SMD components are not worth salvaging due to lack of information on them (no datasheets or info). Could any knowledgeable individuals chime in on this?

author
Jimmy Proton (author)2010-12-05

so how do you remove those IC's with 5000 pins?

author
ratgod (author)Jimmy Proton2010-12-14

You can use a paint stripping heat-gun if you don't have access to a solder reflow workstation. It worked fine for me until I got mine a few months ago :)

author
Jimmy Proton (author)ratgod2010-12-15

what about a toaster oven, i have removed components off a board with one (accidentally) but it is reliable? and what it a solder reflow workstation?

author
ratgod (author)Jimmy Proton2011-11-04

sorry for very delayed response,
its a hot air gun for working with surface mount components.

author
Terrean (author)2011-08-14

A correction needs to be made in your Instructable.
A 564 resistor is actually 560,000 ohms(560 Kohms) and NOT "five hundred and sixty thousand Kilohms".

author
neelandan (author)Terrean2011-08-15

Edited to "560 Kilohms".

Thanks.

author
robonut625 (author)2007-01-30
author
SinAmos (author)robonut6252011-07-26

The Iron Is Genius!

author
beehard44 (author)robonut6252010-08-29

thanks for the clothes iron video! i just have a crappy soldering iron and i think the clothes iron trick will do nicely!

author
nullsmack (author)robonut6252009-12-14

That clothes iron video is amazing. Thanks for sharing it.

author
ReCreate (author)robonut6252009-06-15

Genius!

author
SinAmos (author)2011-07-26

I love you. Good work.

author
zack247 (author)2011-07-25

ive found a partially successful way to remove SMD leds with no chance of melting them and a small chance of breaking/losing them is not with a soldering iron, but a small exacto knife.

just slce under the LED and it will slide off the board with the knife, but dont put too much pressure on the knife or else you will either hurt yourself, other components on the board, or the surface you are working on.

i used this technique and out of 14 blue leds from a cell phone board, i got 10.
the other 4 were lost among the floor that happens to match their color.

i lost a few while learning to solder them, but it was a learning experience for getting them off, and it does wirk with patience.

i usually store my smd components in a small plastic bag (like you get those perfboards in @ radioshack), but a better storage method will have to be in order since the bag has a few holes in it.

author
devinmccloud (author)2010-08-22

The easiest way is to lock the board on a vice. Use a heat gun at high speed on the backside. Slowly remove the components with tweezer or needle nose pliers. Store components on an aluminum surface to cool fast. 99% of the components are good and reusable. Use google to look up datsheets for IC's. Then organize components by type and size. I can strip a motherboard in 3 minutes this way.

author
zack247 (author)2010-03-27

how to do leds??? wont it melt from the heat?

author
TheMadScientist (author)2007-09-04

aha! so that is an old harddrive board!

author
Derin (author)TheMadScientist2008-07-22

"so that is an old fujitsu harddrive board!"

author
zack247 (author)Derin2010-03-27

ahh... i have 2 dead fujitsus, they were very good quality if you ask  me...

author
eric m (author)2009-04-11

nicde. marx generator

author
eric m (author)2009-04-11

nice

author
altomic (author)2009-01-08

-big pot -cooking oil -stove -scooping net thing. put pot on stove add oil turn on stove when it it super hot throw in your pcb. stuff will melt off. IC are made to withstand hightemperatures. solder will melt before there is damage to the IC. scoop out IC with skimmer thing. party on.

author
jackillac92 (author)altomic2009-02-01

Are there any noxious fumes from doing this? Will I still be able to get regular resistors from this or willt hey melt? Will anything bad melt? Do an instructable on this please!

author
Sandisk1duo (author)jackillac922009-04-06

plastics might melt

author
geeklord (author)2009-03-18

I'm so proud of myself, I desoldered some 8 pin SOIC's with a $16 40 watt soldering iron! They didn't even melt(I lifted half the pad on a couple pins, though)! My iron has a nice tiny tip, and i keep it cleen. That helped a lot!

author
Sandisk1duo (author)2008-02-25

wow... i thought the brown capacitors were resistors, and the capacitors with stripes were diodes

author
1up (author)2008-02-16

Awesome! Great method for desoldering them! I may use this sometime.

author
WirelessMonk (author)2008-02-15

Excellent! I bought a few SMD LED laden gift cards for a $1.50. I figured at a dozen leds per card it was worth seeing if I could harvest them off the pcbs. Now I know how! Gracias!

author
fingers (author)2007-12-27

I do thr same as a hobby and keep the bad stuff out of the landfills..It also makes good art stuff..

author
Sawbones (author)2007-09-04

check this link for storage

http://www.engineeringlab.com/supkiten.html

or you can do it on the cheap like me and get those small plastic coin holders for dimes....

author
The Real Elliot (author)2007-09-03

This is a great technique. Complements the hot-air stripper gun method perfectly. (Like, when you really just want one piece out of a given area.) Thanks.

author
lightpacker (author)2007-03-24

Trust me on this get a cheap 15-25 dollar butane torch/soldering iron and if your desoldering parts i recommend getting good butane and just keep the torch constantly moving and the solder will easily melt Just get it anywhere but radioshack their torch's fuel tank is way too small i got a bernzomatic for 15 dollars totally worth it

author
Ragman (author)2007-02-25

Ya'know, I just use a toaster oven, wipe 'em all of when the solders hot then sort it all out. I realy like you storage idea with the sticky tape.

author
primoescobar (author)2007-02-05

This is awesome for those cheap bastards like me who can't afford a heat gun. This is great. Thank you.

author
neelandan (author)2007-01-30

Yes, it would be easier to use a heat gun - if I had one. I pulled the IC before all the joints were fully melted and this was the result. It still works, it is a 74HC04, date code 8809. I should wire it up into something, just to show it off.

author
bmlbytes (author)neelandan2007-02-05

I was about to say something about you breaking the IC. But if you notice, you hadn't goten to the circuit yet.

author
uCHobby (author)2007-02-01

I have an article and some pages devoted to heat gun scrounging. The following link leads to a How-To and FAQ section and a post about scrounging a rack mount router.

http://www.uchobby.com/index.php/scrounging/

author
Masher1 (author)2007-01-30

After you try it you will kick your self how easy it is to remove even the most complex SMC bit. The trick is to use a chisel to work the components pins loose of the solder. any SHARP small chisel will provide just enough force on the solder to BREAK the joint. Use the flat side to the PCB and angle as low as is convenient to force the chisel at the base of the solder joint. just gentle pressure is usually enough to crack the part loose. If you can hold the chisel totally flat you can even remove the real large chips without damage from a botched solder attempt.. if you go after a large chip or other ESD sensitive bit i would recommend using a grounding clip on the chisel. As i said you will love this method to build the really small tek.

author
cirano (author)2007-01-30

Great instructions and a sense of humour to boot! Thanks for sharing it with us.

About This Instructable

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Bio: I'm Chandra Sekhar, and I live in India. I am interested in electronics, and building small one-off circuits around tiny chips (the electronic kind).
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