Making Graphene With A DVD Burner

December 21, 2012 by Mike Szczys 64 Comments

A group of researchers have figured out how to produce graphene using a DVD drive. This discovery helps clear the path for mass production of the substance, which was discovered in the late 1980’s. More recently, the 2010 Nobel Prize for Physics was awarded to a team that produced two-dimensional graphene; a substance one just atom thick. One method of doing so used Scotch tape and is mentioned in the video after the break as a technique that works but is not feasible for large-scale production.

The process seen here starts with graphite oxide because it can be suspended in water. This allows a lab technician to evenly distribute the substance on a plastic surface. Note the use of optical discs. The second part of the process involves hitting the dried layer of graphite oxide with a laser. It just so happens that this can be done with a consumer DVD drive. The result is graphene that can be used in circuits and may have potential as a fantastic super-capacitor.

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Comprehensive Home PCB Fabrication Tutorial

December 19, 2012 by Mike Szczys 15 Comments

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From what we’ve seen we’d say [Jianyi Liu] is really good at etching PCBs at home. Now you can learn from his experience. He just published a mammoth guide to fabricating your own PCBs at home. That link goes to his index page which leads to all eight parts of the guide.

He starts off by mentioning that fab house boards are rather inexpensive these days. This will save you a lot of trouble (like acquiring the equipment and raw materials needed to get up and running) but you can’t beat the turnaround time of doing it yourself.

After discussing the particulars about trace width, copper thickness, and a few design considerations he lays out his board and prints the artwork to a sheet of transparency film. A pre-sensitized board is cut to size before a trip through an exposure rig with the film taped onto it. The image above shows him rinsing the board after applying the developer chemical. From here he uses cupric chloride he mixed himself to etch the board. [Jianyi] recommends populating the components before cutting the panel apart — a task which he accomplishes with a hack saw.

10 Ways To Etch PCBs At Home

December 10, 2012 by Brian Benchoff 46 Comments

[youtube=http://www.youtube.com/watch?v=Q4tWEse2rDI&w=580]

There are a ton of benefits for etching your own circuit boards at home, chief among them the ability to design a circuit in the morning and have a prototype in your hand by lunch. There’s always the question of how to etch the board, but [NurdRage] over on Youtube has all the chemistry covered on ten different etchant solutions for DIY PCB manufacturing.

The peroxide-based methods use simple over-the-counter Hydrogen Peroxide to remove all the copper on a PCB. By combining H2O2 with either Hydrochloric (muriatic) acid or Sulfuric acid, you’ll get a relatively easy to acquire and somewhat safe etching solution.

Historically, the favorite etchant for the home PCB manufacturer has been Ferric Chloride and is still surprisingly available at a few Radio Shacks around the US. Another chloride etchant – Copper Chloride – is one of the most reusable etchants available, able to be regenerated by simply bubbling air through the solution. You can actually make Copper Chloride etchant by reducing down the products of an H2O2 + HCl etchant, making this a very good etchant for PCB pros.

In the ‘miscellaneous’ category, [NurdRage] goes over some alternative etchants such as Bleach and HCl, Nitric acid, and potassium nitrate and HCl; the potassium nitrate etchant is fairly similar to aqua regia, so if you’ve ever wanted a gold PCB, this is the way to go.

Balancing the ease of production and safety of all these etchants, we’ll stick with our Hydrogen Peroxide and HCl etchant for now, at least until we move up to CuCl for the best etching machine we’ve ever seen.

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Acoustic Levitation Of Water Droplets

December 6, 2012 by Mike Szczys 62 Comments

acoustic-levitation-water-droplets

These water droplets are not falling; they’re actually stuck in place. What we’re seeing is the effects of an acoustic levitator. The device was initially developed by NASA to simulate microgravity. Now it’s being used by the pharmaceutical industry do develop better drugs.

The two parts of the apparatus seen in the image above are both speakers. They put out a sound at about 22 kHz, which is beyond the human range of hearing. When precisely aligned they interfere with each other and create a standing wave. The droplets are trapped in the nodes of that wave.

So are these guys just playing around with the fancy lab equipment? Nope. The levitation is being used to evaporate water from a drug without the substance touching the sides of a container. This prevents the formation of crystals in the solution. But we like it for the novelty and would love to see someone put one of these together in their home workshop.

Don’t miss the mystical demo in the clip after the break.

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Boiling Acid Used To See Chip Die

November 21, 2012 by Mike Szczys 35 Comments

When a project starts off by heating acid to its boiling point we say no thanks. But then again we’re more for the projects that use ones and zeros or a hot soldering iron. If you’re comfortable with the chemistry like [Michail] this might be right up your alley. He used boiling acid to expose and photograph the die from several integrated circuits.

The title of our feature is a play on words. In this case, die refers to the silicone on which the IC has been etched. To protect it the hardware manufacturer first attaches the metal pins to the die, then encapsulates it in plastic. [Michail] removes that plastic case by heating sulfuric acid to about 300 degrees Celsius (that’s 572 Fahrenheit) then submerges the chips in the acid inside of a sealed container for about forty minutes. Some of the larger packages require multiple trips through the acid bath. After this he takes detailed pictures of the die and uses post processing to color enhance them.

This isn’t the only way to get to the guts of a chip. We’ve seen nitric acid and even tree sap (in the form of bow rosin) do the trick.

DIY Tin Plating For Bus Bars

October 14, 2012 by Eric Evenchick 37 Comments

Copper bus bars are commonly used instead of wire for carrying high currents. [Dane] needed some bus bars for a project, but he was worried about corrosion. His solution was tin electroplating the bus bars to lower the risk of corrosion while keeping the conductivity high.

The process requires only two chemicals: hydrochloric acid and tin. The electrolyte solution is made by dissolving tin into the acid. Then the bus bar is placed in a diluted solution and a 1 A current is run through it. The result is a fine coating of tin on the copper, which will not corrode in water.

[Dane] mentions that he’d like to try the process with silver solder in the future, since it is easier to find than tin. He also wants to find a way to measure the amount of tin deposited onto the bus bars. This process could be helpful for anyone who needs some corrosion resistant high current conductors.

Check out a video of the plating process after the break.

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Through-hole Electroplating In Your Home Lab

October 3, 2012 by Mike Szczys 19 Comments

For the few double-sided PCBs we’ve actually etched at home we simply soldered a piece of wire to either side of a via and clipped off the excess. But if you want to go the extra mile you can’t beat electroplated through holes. The setup seen above is an electroplating tank build from simple materials which [Bearmos] has been working on.

The two sets of copper structures are both used as anodes. Some copper water pipe (like you’d use for a refrigerator ice maker) was cut into short rods and soldered onto pieces of bus wire. The portion of the metal which will stick above the chemical bath was coated with a generous layer of hot glue. This will protect it from corrosion cause by the off-gassing during the plating process. The traces of the etched PCB act as the anodes, but the holes themselves must be conductive in order for the plating process to work. A water proof glue with powdered graphite mixed in is applied to all of the holes in the substrate. This technique is based on the huge electroplating guide published by Think & Tinker.