Reclaimable Circuit Assembly Process

about 1 year ago by ShaneOberloier

Which problem are you trying to solve?

There will be 92 billion pounds of e-waste generated in 2017 alone. The waste can be hard to process, making recycling
an expensive ordeal.

How are you going to solve the problem?

By eliminating the need for solder. Instead, thermoform a plastic sheet under vacuum around the board, and seal it. To
recycle, remove the plastic and dump out the parts. Copper can be scraped off.

What is the impact of your project?

Drastically simplifying the recycling process will make inevitable e-waste easier to recycle. It will also yield fully
reusable parts. Reduce costs of prototype iterations, as parts can be reused.

How can the project be manufactured in the OpenLab?

The thermoforming machine must be milled or cut from metal in order to endure high temperatures. Some components to the
machine may be 3D printed. Test boards may be milled.

Describe your project in detail

The project is to define and create all necessary apparatuses to make a fully reclaimable circuit board. To start, a
relatively simple SMD circuit (perhaps a simple 555 timer blink circuit) will be designed. The board will be adjusted to
include holes to insure sufficient vacuum distribution. This board can be milled in the OpenLab, as multiple iterations
may be needed. The circuit-thermoformer, or “Circuit Bagger” will somewhat resemble an electric cooking grill.
Nichrome wire will be energized at the top and bottom of the machine heating up plastic sheets. The board will be placed
on the vacuum fixture, and the vacuum will be enabled, pulling the pliable bottom layer of the bag and creating a vacuum
at part locations (effectively holding the parts in place to prevent shifting). The parts can then be placed on the
board. Glue can be placed around connectors and heat-sinks. Finally, the top layer can be lowered onto the board, and
the vacuum will tightly form around the components, holding them tight against the board. The bag can then be cooled and
removed from the apparatus. Connectors and Heat-sinks can then be exposed from the bag. Some experimentation must go
into this process. The minimum vacuum draw and optimal heating temperatures must be obtained. Also, various types of
plastic may need to be tested (Styrene, PETG, etc). Lastly, a good method to apply and remove vacuum must be
developed.
In terms of manufacturing at the FabLab, an aluminum enclosure (can be reasonably small) must be cut and
folded. The two halves of the enclosure will be fastened together with a hinging system. Handles for the system can be
cut from any common wood. Then, NiChrome wire will be weaved along the top and bottom part of the enclosure. The wire
will be connected to a power supply with a switch in series. Fixtures must be made for holding the circuit board and
plastic sheets in place (as pictured in the model). These can be milled from aluminum as well. Lastly a vacuum tube
opening must be custom made (perhaps milled from aluminum) to properly distribute and draw the vacuum. The circuit
boards being tested can be milled at the FabLab (given the CNC mill has sufficient precision. If not, I can acquire them
before visiting the FabLab.
(PLEASE SEE THE ATTACHED PDF FOR A CONDENSED DESCRIPTION OF THIS PROCESS)

Attachments

Comments

Othman about 1 year ago
Really challenging project but if you make it this will be an amazing project for the environment.
All the best!
diego about 1 year ago
If it is great to recover circuit to make plates
si es genial recuperar circuito para hacer placas
TechUser about 1 year ago
Looking forward to see more of your project. No solder, sounds cool. Did you build a prototype? How can I repair the
circuit, e.g. if the heat sink is broken? Is it still easy to repair minor defects?
Omarhasayn89 about 1 year ago
A great project .. It can help a lot in reducing the cost and quantity of materials in the process of recycling .. It is
possible to work sections for all kinds of materials, which works to solve the problem radically
SabineFabLabIng about 1 year ago
How do you solve the problem with height temperatures of some parts? I am thinking of my portable computer, which alerts
me frequently because of height temperature :)
yassineaskri about 1 year ago
Nice idea , good luck !
ShaneOberloier (Submitter) about 1 year ago
Hi TechUser,
I have not prototyped this yet. And you raise a good point, this does slightly hinder repair-ability of the
circuit boards. That will require more experimentation and creative thinking :)
SabineFabLabIng,
I have proposed
provisions for heat-sinks, so the high temperature components can dissipate heat without altering the plastic
enclosure.
Everyone else,
Thanks for you comments and support!
IndigoTech about 1 year ago
That is a project indeed, a nice job there. But when it comes to manufacturability , I suppose it will be a little hard
making the thermoforming machine. Since the board sizes are different. and per observation dont you think some of the
component on the plastic panel may go out of place after a long time causing serious disaster to uses. You sure have a
solution to this please can I know.