Salvaging parts from old PCBs is one of the most important things that a hacker or a creative electronic enthusiast must have high in his agenda. I used to hack parts with the soldering iron, de-soldering pump and wick, but that is time-consuming and absolutely inefficient. Here is one cool (HOT) way to completely strip a PCB from it's parts in no time, no matter how difficult it looks.
What you are about to see may put you into danger. You need to take all precautions before. Wear heat-protective gloves and googles. Do this hack ONLY IN WELL VENTILATED AREAS and avoid the fumes. Wear protective mask if nessecary!!!!!!!!!
I made this video and uploaded this blog entry, after a conversation i had with a pcbheaven reader from China, who told me that he strips parts from old PCBs. I thought that this might be a nice tip.
Why make the effort if i can simply buy them?
Well, first of all because you CAN'T buy them all! There are many parts that are difficult to find, while some others are simply not sold to individuals. Also, this is the best way to recycle your electronic waste. And speaking of which, i encourage you to read the BLOG entry that a friend of mine wrote a long time ago regarding electronic waste and recycling.
But the most important reason, is because hacking PCBs is absolutely educational. Some time ago, i hacked a photo-copy machine. It had like a dozen stepper motors, which i hacked with pleasure :D. And then i began salvaging parts from it's PCBs. I came across some integrated chips with the code STK672-110 and STK672-080. Being curious by nature, i searched for the datasheets. They turned out to be the coolest small and medium size stepper motor controllers i've ever seen! Thy are very small in size, and need only a few external components to operate! Within a few days, i managed to make some cool circuits with them:
The instruction staff at Cleveland Institute of Electronics posted a how-to video that covers working with printed circuit boards too. It covers some of the material in this video plus a little more that beginners can use. It's free and is about 15 minutes long.
This is an excellent way to get stuff you just can't buy anymore.
BIG TIP: dont go "mad" heating with the gun right up against the board. Just slowly cafully heat away from the board and then adjust it closer if the solder is not quite melting.
I've tried a similar method, using a blowlamp, with mixed results, so I gave this a go, and was pleased with the results. Very important to only use the half heat setting, and keep the gun moving, to avoid damaging the components. Thanks for the tip !
This is a great idea and I'm glad you could justify it irrespective of a pure cost analysis (reuse and not wasting always appeals to me instinctively!).
That said, I got thinking about when this would be best or when it might be counter-productive... Anyone got any good sources to establish component rarity, non-availability (to individuals) and post-removal reliability (I'm guessing some items could get more easily damaged in removal and others may simply have shorter reliable lifetimes)?
When you remove plastic part and through-hole components you can put rest in oven at 200-250 C (maybe too hot). The idea is to use contra reflow technique :) There is couple of youtube videos involving mobile phones and ovens.
The old PCBs that I have obtained is produced before 1990, many dirts attached on the parts and found that they are quite difficult to clear when it is found out, but I solved this now, except the dry green patches which came from leakage of the NiCd battery. For the "polluted" soldered pads which are covered by those patches, will this method work?
In the video, what is the actual time spent to liquefy the solder?
@Rob sure age makes difference. You will do this only in well ventilated area, preferably outdoors. If there are fumes, wear protective mask. As @Dave said, remove battery. The trick is to have the correct temperature, high enough to liquify the solder, but not to high to burn the board. You need to practice for this.
Are there any components to avoid? Do some contain mercury? I have some old motherboards that were created before 2000 that I would do this to? Age makes a difference from what I read in the Electronic waste and recycling article correct?
Just wondering if I'm going to have a few years taken off my life for some parts
Thank you so much for the demonstration. I never considered using a heat gun to pull parts, but I promise you I will from now on. I totally agree with your statement that this is the most green act possible for an old motherboard. We are such a throwaway society, I am so pleased to see these parts used again. Great video !!
Back in the Pb solder and through-hole days, a friend of mine used to float boards on hot peanut oil. He would wiggle large components to detect when the solder starts to melt. Then he would quickly pull off electrolytic caps and large components, then pick up the board with pliers and slap the edge against the floor of his garage, component side down, creating a mess of flying parts. Peanut oil might or might not handle the extra several degrees Pb-free solder requires, and QFP leads and the like would probably be wrecked when they hit the floor.