Intro: Magnetic PCB Holder
This simple holder keeps a PCB level for soldering, yet it doesn't hamper your ability to flip or rotate the pcb.
Step 1: Sometimes You Need to Step Up Your Game
I'm currently working on a project that centers around a large pcb with very tall components. As I was soldering the first prototype board, I found out my usual method of stabilizing a double-sided pcb wasn't cutting it. "No problem," I thought. "I'll just pull out the bench vice." That's when I first became aware that my adjustable bench vice doesn't even come close to horizontal. I suffered through it by clamping the board to the edge of my bench with a C clamp. As it turned out, I didn't suffer long by the time I noticed I had wired an IC in reverse.
Step 2: Idea
So while waiting for parts for the revised board, I got back to some of my other projects. After having completed my mini router table upgrade, I got the itch to use it. One of the projects I had kicking around was to upgrade my vertical etch tank PCB holder. (Bear with me, I'm telling a story. I'll get to the magnetic PCB holder in a minute.) My previous PCB holder did not want to hold the thinner pcb's unless I stuck a shim in there. And it seemed like every other etch, I dropped a board into the bottom of the tank. And it's a real pain getting a pcb out of the bottom on a 3/4" wide tank that is 11" deep! My new design incorporates a pcb vice using nylon nuts and bolts. It will hold any thickness of pcb quite firmly, even down to a piece of paper. I was so impressed that it got me thinking about my previous problem...
Step 3: The Idea Struck
I sketched this out last night. Today, I found the note on the center of my bench. So I gathered the materials and said to myself, "Let's make some mistakes!" It actually turned out pretty good.
Step 4: Base + PCB Clamp
So here's a pic of the base. The next pic shows the PCB vice attached.
Step 5: Clamp the PCB
Step 6: Theory of Operation
Don't get me wrong. There are a lot of great pcb holder designs already out there. And I admit, I have tried none of them. I have a basic beef with them all. I use a lot of SMD caps, LEDs, and resistors. Whenever I'm soldering those, there's a basic issue of orientation. I put a bead of solder on a bunch of pads, at once. But only one of the pair. Then I put the component on with tweezers and hold it to the pad while I reflow the solder. To do this, the pad with the solder must be oriented somewhere to the right (cuz I hold the tweezers in my left hand, and I'm not a contortionist). Now some pads run up/down, some left/right. So in addition to flipping the board over, I also end up turning the board 90 degrees, quite frequently. In most of the other designs, you can tilt a pcb (not a big deal for me), and it might be easy to rotate it. Or to flip it. But not both. I actually went to bed dreaming of an electric PCB holder with gimbals and servos, fit for Tony Starks lab. And then I woke up.
Step 7: How Do You Make It?
Easy. The clip is made from 3mm foam board. There's a strip of 0.064" FR-4 (cutoff from a PCB!) superglued between them for a spacer. Then you start drilling holes. 2 for the bolts, 2 for the magnets. Then you superglue the magnets in there, observing proper polarity. The base is just wood. Cut. Glued together. Glue magnets in. You already saw that in step 4. Don't forget the wings.
Step 8: Does It Work?
IT looks like it will get the job done. The foam board isn't ideal. The vice only grips a large board well if you get the pcb all the way in against the bolts, so you need a free edge of about a 1/4" or so to get a good grip. I'm sure there are various aspects that can be improved. Here are more photos from various angles. Now, go and make one!