Artistic PCB Design for Terrified Beginners workshop

Hello and welcome to Artistic PCB Design for Terrified Beginners

If you're not familiar with some of those concepts:

• PCBs stands for Printed Circuit Boards, the things that electronic devices are build on
• Art means people creating wonderful (or awful) things for other people to enjoy
• A terrified beginner is someone who we all either are or have been at some point

I'm Kliment, and I'm doing this workshop to achieve one or more of the following things:

1. Get art people to play with electronics
2. Get electronics people to play with art
3. Give the two groups above a common language so they can talk to each other
4. Get people to build something cute and have fun

We're going to be making a so-called "Shitty addon". A shitty addon is a small circuit board that gets attached as a decorative or functional addition to one of the many badges that are so popular at hacker events. We're going to make one that doesn't do much (except light up). Except it won't be shitty! It will be pretty! So let's call it a pretty addon!

What you're going to need to be able to follow along. Please make sure the following software is installed and working on your computer *BEFORE YOU START*.

1. Kicad 5.1.6 ( https://kicad-pcb.org/ )
2. Inkscape (any version https://inkscape.org/ )
3. Krita (any version https://krita.org )

I made an hour-long video where I explain a bit about what PCBs are and what they're made of and go through the process of converting graphics to PCBs. I'm sorry about the awful sound quality, and I had to speed it up and cut it quite a bit to get it to fit into one hour. This is like my second screencast ever, so sorry about that! Please watch it anyway!

It's at https://www.youtube.com/watch?v=Stp5BqUI48U and you can watch it right now, or during the workshop, up to you. If you watch it beforehand that's fine.

I've put some materials for you at: [todo add link]

Here's a cheat sheet of the process, and a quick summary of the main techniques we're using.

Very broadly, here's what we're going to do:

1. Create art
2. Create PCB from art
3. Generate manufacturing files from our PCB and optionally have it manufactured
4. Enjoy your new superpowers

Step One: Create, borrow, or steal art I can't help you a whole lot with this one, except the borrow/steal bit. I've put some pictures you can use in the workshop materials. Feel free to use those! Alternatively, bring your own photos, drawings, sketches, whatever. Scribble something on some paper and photograph it. Doesn't matter, as long as it's a picture you like. Make sure this is in one of two formats:

1. Vector drawing that Inkscape can read (ideally svg) OR
2. A raster image format like PNG or JPG or something else that Krita can read

Step Two: Create PCB from art The main thing to understand when converting art to a circuit board is that circuit board manufacturers and PCB design software doesn't think in art - it's designed for making circuit boards that meet their functional technical requirements. We do still care about functional requirements, but we mostly care about how it's going to look. So, we need to understand the PCB as the manufacturers and design software sees it, so we can adapt our art to that. So from now on, we're thinking in layers and manufacturing processes.

Here is what happens when a circuit board is made (very roughly):

1. The manufacturer takes a big sheet of fiberglass with thin layers of copper either side. (note: fiberglass is beige-brown, translucent. Copper is metallic and opaque.)
2. A bunch of holes are drilled into the sheet, and some nasty chemistry is applied to cover the inside walls of the holes with more copper
3. The copper is printed over with an acid-resistant material in a pattern we provide (front and back copper layer)
4. All the copper that is not part of the pattern is dissolved away
5. The board is covered with a thin layer of paint in a specific color. This is called soldermask. The paint is removed in a pattern we provide (front and back mask layer). Note that any place that has the mask removed will expose either copper or fiberglass.
6. The board gets printed with another ink, usually white (unless you have white soldermask, in which case it's black). This is called silkscreen and is printed in a pattern we provide (front and back silkscreen layer).
7. The board gets a "surface treatment" to prevent corrosion of any exposed copper - this is normally either HASL or ENIG. HASL stands for Hot Air Solder Leveling - it's the cheapest process. The entire board gets dipped into molten solder, and then a blade of really hot air passes across the board and blows the molten solder away, leaving the surface mostly level. HASL surface finish is silver in color, and slightly uneven, giving you a moon-like surface of reflective metal. ENIG is a more expensive process that deposits a microscopically thin layer of nickel and then an even more microscopically thin layer of gold on top of the copper. This gives you a perfectly flat, slightly matte gold surface wherever you have exposed copper. You don't get to choose where the surface treatment goes - it gets applied to all exposed copper.
8. The board gets some more holes drilled into it, and then it gets milled - a rotating blade that looks a lot like a drill bit goes around the shape of the board and cuts it from the sheet. The shape of the board is something we provide - however the milling bit is fairly large (about the size of the fat end of a sharpie) so we can't have any inside corners with sharp angles.

So here are the things that we need to provide the manufacturer:

1. Board outline (what shape the board should be milled into)
2. Copper layers (where they should leave the copper on)
3. Mask layers (where they should take the soldermask off)
4. Silkscreen layers (where they should print silkscreen)
5. Drill file (where we want holes to go, and whether they should be filled with copper or not)

Luckily, our PCB design software can do most of the work for us, but we still need to tell it what we want on there. Now, PCB design software works with slightly different concepts. Here's what we have available:

1. Component footprints - combination of holes and copper patterns and mask openings and silkscreen that are combined together and can be moved and placed as a whole
2. Traces - lines in the copper that electrically connect various things
3. Copper pours - shapes that get filled with copper, optionally connected electrically to something on the board
4. Keepout areas - shapes that prevent copper pours and traces from entering them
5. Mask and silkscreen lines and polygons - shapes that create openings in the mask layer, or add paint to the silkscreen layer
6. Board outline - a bunch of lines that form a closed shape that defines the shape of the board
7. Imported raster art - this goes on either the mask layer, creating an opening there, or on the silkscreen layer

Because we want our PCB to also have a function (in this case, it has two light-emitting diodes that light up) we are going to add some components and connect them together. To keep track of what is connected to what, we have a schematic. In our case, we won't be doing much with the schematic - you can leave it as-is.

[WIP]