Harvesting Electronic Components

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Introduction: Harvesting Electronic Components

About: Retired Electronic Design Engineer. Member of The MakerBarn.

With stores like Radio Shack disappearing, it is getting hard to find simple electronic components. The web, particularly eBay, has been a great help, but shipping can get costly. Consumer electronics, like VCRs and Microwave Ovens can be a source of parts, but consumer electronics tends to very highly integrated. Many parts are special made, or so specialized they are not useful.

Lately, however, the recycling move has produced a wonderful source of high-grade electronics. Check around you area for electronic recycling centers. These businesses take electronic equipment from companies and take responsibility for bring the material into the recycling stream. They typically disassemble the equipment separating the various metals and other valuable contents into various bins for sale to refiners. The circuit boards get thrown into a large container and are usually shredded for reprocessing.

Commercial equipment is built to a much higher standard than consumer electronics. Cost is not so much a factor, and since the volume of production is lower, they tend to use standard components.

One large recycler in Houston charges about $1 a pound for circuit boards, but quite often just gives then to me when I tell them the boards are for our makerspace. Another place I've been to seems to be glad to see the boards go. He has never charged me for a used circuit board.

Step 1: Selecting Boards for the Harvest

Be picky when selecting boards, remember you will need to dispose of the waste properly. It depends on the type of prototyping you will be wanting to do. You may want only through hole components, or maybe you would like to experiment with some surface mount components. I tend to look for board with a lot of analog circuitry. The board above is excellent. It has some digital logic, but it has quite a few high quality op-amps and trim-pots.

Avoid boards that are conformal coated. These boards have a tough coating both front and back and the part are very difficult to remove. Conformal coating is common in surplus military boards

Step 2: Some Tools You Will Need

A metal tray is great for catching the parts as they come off the board. Since we will be using a good bit of heat, a welding glove is good to have. Other holding tools such as small vises, vise-grip pliers. and board holders come in handy. Don't forget eye protection, the wrap-around safety glasses are best.

Finally, you will need a heat source. I use a small butane torch, big torches are too hard to control. Also a high-temperature heat gun works well.

You need anything that works well at grabbing the parts. Needle-nose pliers, IC pullers, slip-joint pliers, and hemostats work well.

Plan to work outside with a light breeze. You will be hitting the circuit board with a lot of heat, so fiberglass will be burning and smoking a bit. Eye protection is a must. Bit of hot solder will be flying about.

Step 3: Getting Started

Examine each board and plan a strategy for the board. Be sure to remove any fasteners that are securing components. Plan to work on the parts that are easiest to remove first. Many straight legged parts fall right out when heat melts the solder. Some components, such as resistors, are crimped on the board before the board is soldered. It's best the leave these behind.

Step 4: Easy Parts First

Heat the board gently and as evenly as possible under the component you wish to remove. Some components will just fall out of the board once the solder melts. I tap the board against the wooden bloc to help jar part loose. Get as many parts off as possible using the heat and tap technique.

Step 5: Smaller Parts Can Be Removed With the Needle Nose Pliers

Try the needle nose first. Clear out the small capacitors near the ICs. Needle nose pliers also work well on the 8-pin DIP packages.

Step 6: Remove the Larger ICs

Slip-joint pliers work well for pulling ICs off. ICs are usually not crimped, but there leads are bent outward to hold then in the board while being soldered. Wiggle the IC and it will come loose, almost like pulling teeth.

Step 7: Give the SMT Parts the Brush-Off

SMT parts can be removed with a small needle nose. Another way that works well is to brush them off the board with a disposable acid brush. Heat the board from the back and keep the brush moving. As soon as the solder melts, the parts will brush off and fall in the tray.

Step 8: Cleaning Off the Board

After a few minutes, you should have almost all the parts off the board and in the pan. Notice I left the resistors. These were all clinched to the board and simply not worth all the effort it would take to remove them.

Step 9: Big Pile of Parts, Now What?

In the photo you see the result of harvesting two circuit boards. Now it's time to sort the parts and look up those you don't know. Thanks to the Internet, finding data on most of these devices will be easy.

Surface mount ICs can be difficult to catalog. SMT resistors are usually marked, but capacitor are not. I use a DER EE DE-5000 LCR meter to test and sort capacitors. It works great and comes with a tweezers type probe for test SMT componets. They are about $140 from eBay and Amazon suppliers.

Happy Hunting!!

2 People Made This Project!

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126 Discussions

I am always using salvaged parts and have saved a small fortune.

0
user
Man Up

12 months ago

I have two major criticisms of this 'ible.

First, this method of heating up the solder puts as much heat into the component as it does the joint itself. A butane torch can concentrate well over 2,000° F onto the surface of the PCB, and the component will sink several hundred degrees through the pins and into the device being removed. Most components fail when exposed to temps over 350° F. Your fingers will barely register much heat in such a small area, but the internal junctions will be toasted.

The proper way to remove components is through the use of a soldering pencil of between 25 and 45 watts watts, a desoldering device (either a 'solder sucker' or preferably a high quality copper braid "solder wick"). For components with multiple connections, a clamp-on heat sink (you can make one from an old heat sink and a binder clip) should be used to protect the component from excess heat.

Secondly, there is that there is no mention of ESD precautions. Anyone who has ever walked across a carpet in winter then got the dickens shocked out of them understands the idea of static electricity. But even when the air is humid, we can still carry several thousands of volts of electrostatic charge on us. This static charge perforates the thin metal oxide layer that most modern semiconductor MOSFET devices utilize. Precautions might be as simple as using a cheap $2 grounding strap, or they could involve layering your work area with a rubber ESD mat and grounding everything.

Please, please include some discussion of these two items. I appreciate that you're promoting recycling (I personally have saved $80 in the last month salvaging rando IC's and micro-relays form PCB's I dug out of the trash at work), but for someone getting started in the electronics hobby, this can add to their frustrations.

4 replies

I disagree about the torch part. You can because the torch is so hot the solder melts before the heat manages to travel up to the component, actually unlike a soldering iron where you have to hold it on the leads for a long time. Not sure how you're doing it but I'm done it several times and it works great. I've been able to salvage some components without even wrecking the PCB!

Another strategy would be to use heat guns specifically designed for components (such as the ones found in soldering stations). It applies heat in a very specific area and is good for removing components from pcbs.

I second the motion of using "copper braid solder-wick." The stuff is pretty olde school and many people don't know what it is anymore, but it works well (especially the wider, thicker stuff) for sopping up the solder off the board before you pull the components using any heat source - and to me (being too cheap to have a temperature-regulated soldering station) it's indispensable for everyday soldering, getting into places a solder-sucker can't. It's impregnated with rosin to make the old solder flow better and "wick up" onto the copper braid by capillary action. Comes in varying widths and lasts a long time.

Soder-wick works well for removing single components, but it's too expensive and tedious to use for cleaning off an entire board. The small butane torch produces a gentle flame that is much like a heat gun. The heat is spread over a large area and components release as soon as their solder melts. So the exposure to heat is not much greater than the melting point of solder. If you have ever worked with flow solder machines or reflow ovens, you will get a better idea of how much heat electronic components are designed to go through. It's amazing.

If you don't know what you are doing, please be VERY careful around the capacitors!!! They can deliver leathal shock.

This would only apply to through hole parts I want, though it might work with smd stuff. When the weather is good outside, I usually place the board with the component side down. Then, with safety glasses on and my compressor turned on as well, will heat a small area about 2 inches or so in diameter with my mini butane torch. As soon as I see a solder puddle, in one motion, I remove the torch and blow the solder away with a shot of air from my compressor. The parts don't stay hot long enough to get damaged, and usually fall into the bin below automatically. Just make sure there's nothing in the direction you're blowing the solder. Again, it's not for all parts, but it's been good for me. Others mileage will vary for sure. 8c)

0
user
RayW52

11 months ago

I did it with a craft knife and some pilers. Really messy, as you have to cut the solder carefully and not slice the component in half.(My parents won't get me a solder iron or any other heat source in fear of setting our home on fire).

1 reply

I use several methods but the heat gun is the most effective for SMT and most pin-soldered devices. I heat the part until the solder begins to change color then rap the board on a hard surface. The heat gun I bought was at Walmart which used 120 VAC and has two settings. Since the gun only heats up while pressing the trigger, it is safer than a soldering iron or propane torch, and faster than a soldering gun. Most have a shield to prevent touching it to anything that can burn so it isn't a fire hazard unless it is improperly used. The trigger may tire your finger but I do recommend taking a break every ten minutes or less.

Inventory your treasure so you know what you have, an excell spread sheet works great.

after reading many comments, it looks like what one person said about heating the board from the back and letting the parts fall into a box sounds like a good idea. also sand in an old frying pan is the most effective and quickest way to remove parts. also quick and easy.

1 reply

Sand in the frying pan! -- I'm definitely trying that! Thanks!

Cool I like the idea

also I am SOOOOOOOOOOOOO upset that RadioShack is going out of business :'(

PS: one of the employees told me that iPhones "Killed" them

6 replies

Did he explain how the iPhone put them I of business? I guess I don't understand the connection

They used to sell cameras iPhones are cameras (he gave some other reasons to but I don't remember them

I would have to say that what has hurt them the most is Amazon. Having the ability to order large quantities of electrical components from vendors vying for your dollar has most likely taken a huge chunk of RS market. Not to mention that RS used to carry the latest technology, but the internet and Amazon has brought that market to your fingertips. Low prices and 2 day shipping are such a great deal that even Walmart had to follow Amazon's lead. Barnes' and Noble, along with most other chain bookstores have had to close down because the business model doesn't work due to the high overhead. Best Buy can still compete because people want to see or "check out" many of the items they sell prior to purchase.

Don't get me wrong, I love Radio Shack. The other day when I needed thermal paste that day to get a CPU back up and running, my local RS was there to save the day. But all things considered, the music lyric "video killed the radio star" can be reapplied here: "Amazon killed your local store."

I miss radio shack , that was the only store i could buy a great sortwave radio at and i build radios myself , my first radio was a crystal radio i built from a kit i bought from radio shack ,

My first electronic project [EARLY 50S?] was a crystal radio KIT, from Archer [mail order], which later was bought-out and ruined by Tandy Leather [Radio Shack]. And then RS committed suicide by switching emphasis [and shelf-space] FROM COMPONENTS to stereo and hi-fi sets, and games, and computers, and etc, ad nauseum!!!

I see you calling the store Radio Shack; am I to presume from what you say they dropped the name "The Shack"? The only local or fairly local stores that carried a lot of electronics parts were owner run and not corporate. I heard they hadn't closed *all* the stores; but, I can't find them here in South Carolina anymore.