# Automatic PCB depopulation machine



## kjavanb123 (Jan 10, 2017)

Hi,

I have talked to Tina the sales person for Suny that manufactures this 500-kg per hour automatic dismantling machine. 

This could be a good solution to clean up boards and sort the components.

Here is the video showing in detail how the machine works,
https://youtu.be/p-GM5_y7jJA

Here is the video showing their full system that recovers copper from depopulated PCBs,
https://youtu.be/S5A3cpJiRIM

I really like their stuff. 

Regards
Kj


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## Egyman873 (Oct 27, 2017)

I contacted them few months back but they didnot give me clear process for electric components 
I understand that the clean Pcb processed by crusher and electrostatic separator 
What about the components ( MLCC, ic chips,... )


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## kjavanb123 (Oct 27, 2017)

In one of their old documents, they mentioned hydrometallurgy methods using acids.


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## Egyman873 (Oct 29, 2017)

Direct or its processed as well by mechanical methods (electrostatic) before chemicals


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## nrg91720 (Nov 11, 2019)

How does this depopulator work?


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## GoIdman (Oct 28, 2021)

I have made a small depopulator mainly for depopulating RAM chips from boards, which is operated with a 700 C(degrees) (3kW) heat gun. It does the job very well but the operation cost can be high if it is operated more than 3 hours a day. 
Using a gas operated depopulator, i belive will rise the recovery costs even higher, since the gas and electricity prices are at historical hights.
Allthough it makes depopulation very easy, (both methods gas and electric), and very fast, the costs involved in the operation cannot be neglected. (unless u have free energy whatsoever)


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## Marcel (Oct 29, 2021)

There are sooo many ways on how to depopulate PCBs, one could write almost a book on that ;-)
Using a heat gun vs the return of RAMs is not costly at all. It goes very quick, if done right, since it takes only a few seconds per board. I wonder why you estimate the costs so high?
If you have time and hard work is not an obstacle, you can use a chisel, or even an electric chisel. Some members have done that and it works well.
A third very easy but not environmentally clean method is to dip the boards in dilute Sulfuric Acid. This will also dissolve lead and much of the tin. All you need to do is wait and the components will fall off.
One disadvantage of the heat gun are the problematic fumes. That is why I do not use this method very often anymore. PCBs contain hundreds of chemical substances from the manufacturing process, resins and more. So ensure to have a very good ventilation if you do it that way.

Edit: Why on earth are you using a temperature of 700 °C ??
That is really dangerous, because the PCB will "gas out" and* toxic fumes will be created.*
The melting point of tin alloys are lower than 350 °C and some alloys (Bi) are even around 140 °C. Maybe that is why it takes you so long and so much energy. 
Instructions: Preheat the PCBs to let's say a bit below 100 °C, then quickly give them a shot with the heat gun with a max. temperature of around 350 °C. All components should fall off within 5 seconds.
700 °C is far too much! A strong blower will just blow the heat (and the fumes) elsewhere.
Use a slow or medium stage of the blower, not the strongest one.
You can add vibration to speed up the depopulation.
I have developed such a machine, when I worked as an engineer in an electronic manufacturing company in the early 2000s. At that time there were no other solutions known to me.
Today there are very simple made "machines", I would not call them a machine btw, from China. They consist of a stainless steel drum and a large heat blower. The drum turns and hot air is blown into it. as the tin melts, it drops trough small holes in the drum to the bottom. PCBs and components remain inside the drum until the cycle has finished. You can find them on AliBaba, but they are so simple, you can build one by yourself (I guess)


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## GuyGuyGuythe1st (Jan 7, 2022)

I used a induction coil bought on eBay for 25$. I put it under a piece of plate steel. Wired to a digital output for temperature control. Just let it warm-up to 400F. All SMD can be smacked off. Throughhole can be tweezed. Most solders even exotic alloys no more than 212-600F which is easy to achieve with an induction coil. Also use a simple 220v oven bought at a thrift store. Get them to temp and smack or tweeze the components. Process easily as a 1 man show 20-50lbs daily of high and low grade PCB for depopulation. Cost like 250$ total and some elbow grease. Toxic gas is real. Bought an industrial fume hood from an laboratory going out of business for 1k. Gases released from the process will cause permanent lung damage and have other irreversible health issues. Especially going higher than 200- 300F can start to release carcinogens. You will get flux’s, adhesives and polymers to reach a combustible state.


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## orvi (Jan 8, 2022)

I thought a long time about purely mechanical depopulation of RAM sticks.
Make an U-shaped steel plate, with a slit that match the thickness of the board of RAM. On the bottom of the instrument, you will place a RAM stick and press the U-shaped steel plate (sharpened on the open side of the U) down the RAM stick with kind of a "lever". This will depopulate both sides of the stick in second, leaving only naked board without MLCCs and IC chips.
Not for middle-large operation, but I can imagine using it for few kg lots of material per day.
Just a thought. Useless for cards and motherboards tho :/

I personally don´t like heating the boards very much. So much organic toxic junk is emmited, if done somewhere on the backyard or so. But it is what it is, the speed of the process and ease of performing it can´t stand a chance to the one to one processing mechanically.


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## orvi (Jan 8, 2022)

GoIdman said:


> I have made a small depopulator mainly for depopulating RAM chips from boards, which is operated with a 700 C(degrees) (3kW) heat gun. It does the job very well but the operation cost can be high if it is operated more than 3 hours a day.
> Using a gas operated depopulator, i belive will rise the recovery costs even higher, since the gas and electricity prices are at historical hights.
> Allthough it makes depopulation very easy, (both methods gas and electric), and very fast, the costs involved in the operation cannot be neglected. (unless u have free energy whatsoever)


Be carefull when heating to that high temperature. Any BGA chips present could partially melt - and if the base of any chip is fiberglass - the glass start to soften at that temperature, entrapping gold bonding wires inside - lower the yield quite significantly if more than 700°C is reached 
Not a big problem with typical RAMs tho. Just feel bit unnecessary to heat it that high. Like 300° is more than enough I think.


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## Yggdrasil (Jan 8, 2022)

orvi said:


> Be carefull when heating to that high temperature. Any BGA chips present could partially melt - and if the base of any chip is fiberglass - the glass start to soften at that temperature, entrapping gold bonding wires inside - lower the yield quite significantly if more than 700°C is reached
> Not a big problem with typical RAMs tho. Just feel bit unnecessary to heat it that high. Like 300° is more than enough I think.


400 F is quite low so I believe it is ok


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## orvi (Jan 8, 2022)

Yggdrasil said:


> 400 F is quite low so I believe it is ok


I mean he wrote 700C, but re-reading it... He mentioned heat gun. I think he wanted to say degrees F, but i dont argue 
Most of the tin/lead solders melt below 250°C.


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## GoIdman (Jan 11, 2022)

orvi said:


> I mean he wrote 700C, but re-reading it... He mentioned heat gun. I think he wanted to say degrees F, but i dont argue
> Most of the tin/lead solders melt below 250°C.



I meant 700 C (Celsius), it is a rotating drum actually, the rams are roating inside, chips are falling off and out of the drum at the sides, PCB remains inside. I recover also the solder which is shaken off by rotation and low melting.

Pete.


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## Yggdrasil (Jan 11, 2022)

I see now that we are commenting two different posts.
I was commenting on the induction heated system, you on the OP.
Sorry mate I stand corrected.


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## orvi (Jan 11, 2022)

GoIdman said:


> I meant 700 C (Celsius), it is a rotating drum actually, the rams are roating inside, chips are falling off and out of the drum at the sides, PCB remains inside. I recover also the solder which is shaken off by rotation and low melting.
> 
> Pete.


Interesting. 700C... I imagine this whole system smoking s***ty suffocating smoke with burning pieces of half-baked chips falling down from it. But I could be wrong. If the contact time with the burner/heat gun is minimal, then all of this could be minimized. The 700°C temperature is only on the output of the heatgun/burner or inside the whole apparatus ?


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## Yggdrasil (Jan 11, 2022)

orvi said:


> I mean he wrote 700C, but re-reading it... He mentioned heat gun. I think he wanted to say degrees F, but i dont argue
> Most of the tin/lead solders melt below 250°C.


You were right, check my post further down.
Sorry mate


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## orvi (Jan 12, 2022)

Yggdrasil said:


> You were right, check my post further down.
> Sorry mate


Everything OK


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## GoIdman (Jan 12, 2022)

orvi said:


> Interesting. 700C... I imagine this whole system smoking s***ty suffocating smoke with burning pieces of half-baked chips falling down from it. But I could be wrong. If the contact time with the burner/heat gun is minimal, then all of this could be minimized. The 700°C temperature is only on the output of the heatgun/burner or inside the whole apparatus ?



The 700C is the maximum output of the heatgun, inside the apparatus the temperature is between 280 and 400 C. The drum contains holes (25mm) around so much of the heat gets out carrying the fumes to the fumehood and away on a high chimney. The sticks are removed after depopulation and dont stick around to be roasted, the chips fall out of the drum when separated from the boards and dont stay inside to be roasted as well. 
If I set up correctly (and not being lazi on it) almost no fumes and burned material occurs.

Pete.


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## orvi (Jan 12, 2022)

GoIdman said:


> The 700C is the maximum output of the heatgun, inside the apparatus the temperature is between 280 and 400 C. The drum contains holes (25mm) around so much of the heat gets out carrying the fumes to the fumehood and away on a high chimney. The sticks are removed after depopulation and dont stick around to be roasted, the chips fall out of the drum when separated from the boards and dont stay inside to be roasted as well.
> If I set up correctly (and not being lazi on it) almost no fumes and burned material occurs.
> 
> Pete.


This explain whole thing  
Be aware of that smoke/fumes created, even at 300°C, classic resin-epoxy-lacquer stuff combine with chlorinated/brominated fire retardants also present in PCBs, depolymerize and emmit low-molecular weight s**t like various chlorinated/brominated aromatic hydrocarbons, possibly dioxins, nitrogen/oxygen heterocycles, hydrogen chloride and bromide etc... :/ One exposition probably won´t do very much, but it all adds up in the terms of developing diseases and eventually cancer. This is one of the things that are nearly impossible to trace and possibly link to the disease, even if they clearly were a major factor. When you smell that familiar "burnt stuff", not good. 
Just say´n  look like your setup as you describe is safe enough.


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