Introduction: Silkscreening Sexy Circuits
Copper is beautiful, plain and simple. Not only has humanity marveled at its beauty for thousands of years, but we have mastered how to harness the powerful properties of such an element to better our daily lives. Here in the following few steps, YOU can learn how to blur the lines between form and function, creating elegant and technical facades for any variety of fine art object or product you desire.
Before we begin, let's ask ourselves: "Why silkscreen? Is this method worth my time?" Short answer: YES. Absolutely. Materials for the method can be acquired on the cheap, and the speed of which the average person can produce piles of work is second to only the most expensive of industrial fabrication techniques, although I must admit technology is getting much cheaper and more accessible hint hint: https://www.instructables.com/member/othermachine/
On board and hungry to produce? Let's begin!
Step 1: Tools and Materials
- copper pcb (radioshack for the curious first timer, Jameco or other specialists for better options)
- silkscreen (230-305 mesh count depending on design intricacy)
- water based silkscreen ink (TW graphics flat red HIGHLY reliable, but many others can be used)
- ferric chloride
- glass dish/container for ferric chloride
- steel wool
- masking tape
- garden hose
- safety goggles
- latex/nitrile gloves
The following materials are optional if you want to get more in depth with the art of screen printing.
Word of warning: There is indeed a decent amount of knowledge needed to truly master screen printing, so the contents of this particular Instructable will only pertain to the specifics of screen printing and etching copper. If you are lucky enough to have a local silkscreen shop in the area you want to support in exchange for them coating and burning your screen for ~20 dollars (shout out to the awesome guys at Anthem Screen Printing), this can save you a huge amount of time,and you can continue to step 3 when your screen is ready. If however you are a true DIYer and want to designate a small portion of your garage to printmaking, acquiring tools for the entire process will empower you to work how and when you please, and enable you create much more than what we will discuss here.
- exposure unit/UV light source (can range in price from free - using the sun! - to thousands of dollars in a pro vacuum table. a good compromise can be a cheap flood light with the UV-proof glass removed, or a fluorescent tube array)
- pressure washer
- screen opener
- exposure calculator/step wedge
Included below are some useful learning resources for screen printing, but I highly encourage you to go into the world and collaborate! Learning the movements from more experienced is invaluable.
Ok! Enough of the nitty gritty, let's move on to the action and make something beautiful.
Step 2: Design and Screen Construction
Some brief tips on designing an image and setting up your screen for printing on copper. If your design is purely aesthetic, feel free to use any method you like to create your image, hand drawing, Illustrator, Corel, whatever you're most comfortable with will work. If however you are designing a functional circuit board that will have current flowing through it and or components soldered to the board, you must think about electron flow, resistance, and a bunch of other electromagnetic phenomena I'm sure you're aware of if you're venturing out that far. Be water my friend... err, I mean... think flow, be an electron, have fun with your design.
get EAGLE if you're serious about functional design and want to go pro with powerful and friendly software.
Now that we have a design, we can choose a screen, expose, prepare our substrate and get printing
Screen mesh count matters!!
I cannot stress this enough, laying down too much or too little ink on your copper will result in poor and washed out looking etchings. If you have large open areas of fiberglass or copper in your design, letting more ink pass through with a 230 screen can be the sweet spot, if you have finer line work, halftones, or a photographic image, 305 is the way to go.
Step 3: Print!
Now the magic happens, let's get going. Working with precision and speed is crucial if you are to maximize your output in one printing session. Done right, hundreds of prints can be made by one person in a few hours work.
First start by degreasing your copper. Ajax or Comet work fine, this is also rarely an issue straight out of the package, but if you see fingerprints on your board, best to clean it. Set all of your boards in an easy to reach area, and designate an area to place freshly printed boards.
Clean off a very flat area for printing if this is your first time, secure your board to your hinges, your carousel, or in a pinch just be very very mindful of the registration between your screen and boards, a good registration system is the #1 way to increase your accuracy and productivity. Even something as simple as cardboard tabs outlining the corners of your board placement can do wonders. Place a board in this designated printing area, lower your frame, check registration is snug.
One huge tip, make sure your screen has room for "snapback." This means that your screen should not actually be touching your board whatsoever until the moment you apply pressure to your squeegee. There is no easier way to ruin your prints than to have the board come off the table and be stuck to your screen.
Double check everything, take a deep breath and phew! We are ready to print! Apply a line of your ink above your image, quickly grab your squeegee at a 45 degree angle and "flood" your screens open areas with ink, making sure that every area is properly filled. Follow this with a firm application of pressure, pulling the blade of the squeegee toward yourself and over your image. Hear that screen snap back and very quickly lift your screen and replace your board with a fresh one. Flood, stroke, rinse, repeat.
After a few dozen prints, you might run into the issue of ink staying in the screen, this can be initially remedied with double stroking your print, but pretty soon, you are going to want to remove your screen and clean out the ink with a garden hose or pressure washer and screen opener. If all you have is a garden hose, no worry, just clean your screen upon the first signs of stubborn ink.
That's it for printing! You're a machine! Feels good right? Now let's move on to the more ancient printmaking method, the etching.
Step 4: Etching
Ferric Chloride is toxic and highly corrosive. Wear goggles and gloves, dispose at your local waste management or neutralize if needed with excess sodium bicarbonate (baking soda).
The above being said, ferric chloride can be stored safely for long stretches of time for reuse, is relatively easy to handle, and poses no serious risks if skin is exposed, other than a slight irritation and staining, but do not try to find out, wear proper protective equipment and dirty clothes.
Now, allow your boards to dry sufficiently before etching. Even if it appears dry to the touch, loose ink under the surface may lead to the ferric chloride finding its way into unwanted places and ruining your board. This is where time is best spent preparing our ferric chloride bath.
Choosing a container for your ferric chloride bath will depend on the size and quantity of boards to be etched, a glass, pyrex or plastic dish will suffice, but laying your boards down flat in the bath is not optimal for reducing etching times, and can also drastically reduce your etching quality if left to sit. If keeping costs as low as possible is a priority then this method will work if you gently agitate the solution every so often. Standup baths are a great advantage, add in an aquarium bubbler to permanently agitate the solution and you're golden. Now we play the waiting game, depending on the strength of your etchant and the surface area required for removal, expect to wait anywhere from 2-24 hours. Time to go dream up new ideas
When all of the target areas are removed, it's now time to clean our board and unveil the fruits of our labor!
Let all excess FeCl3 drip off into your bath, and now either spray or wash with a mixture of baking soda and water to neutralize any left over. Now simply grab your steel wool, and imagine you're scratching off the biggest gas station scratcher you've ever seen, a winner every time!
Sit back, soak in the joy of creation for a brief second, giggle and play with your new shiny object, and move on to whatever you deem is next!
If your creation is simply fine art, you may be done. If however you plan on throwing some function into that board, you may still have a ways to go. Now that we have covered the basics of making our own circuit boards, we can move on to new Instructables on how to connect components and combine boards to make even more exciting objects. Feel free to view my future Instructables on how to use your circuit boards to create touch or audio responsive installations, light fixtures and furnishings.
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