PCB Prototype Design Tips and Tricks - Workbench Wednesdays 

We've started up a PCB Design, Prototype and Production group on the element14 Community, where you can share what you've been working on in blogs, and ask for help on the forums, here's the link: bit.ly/3cN3TaJ to check it out.

Love this idea of marking all ground pins, and copying silk designators from front to back!

Really nice tips, specially the test points and ground pad markers.

I admit I'm new to PCB building. However one thing I have learnt is to 'sleep on it' for a couple of nights before sending in my gerbers. I find doing that helps reduce the 'Oh oh, I forgot the ... !' factor. I also have a number of modified footprints with enlarged holes/pads to assist with my soldering of my PCBs. I hate trying to solder when the pad looks like a thin ring around the component leg.

I have one: Never use 2 Layer boards in prototyping. Manage your GND and power planes from the beginning. This will making component and design choices a lot easier, because you can actually measure the EMI/EMC performance.

That was helpful, thanks for the quick tutorial :)

Fantastic tips, greatly appreciated

Some great tips, thank you for sharing them

The great thing now about PCB design is it is so cheap to spin a new board that you can dedicate boards just to be prototypes. Too many times I have seen designers try to shrink board dimensions down to some minimum they are striving for in the final product. Instead what you want to do in the prototype is give yourself enough room so you can probe signals and solder on power, test points and programming headers. If you have spare space then add a grid of 0.1" pads. Lots of times this will give a prototype a second chance of getting through multiple trace cuts and component changes before it needs to go in the bin. Another feature of a prototype board should be a number of LEDs. You want one for each power rail and at least one tied to a GPIO from any micro-controller. This way you won't have to drag out a multimeter every time you power up your design to determine that the fault is not in the board.

These are excellent tips, thanks!

Nice tips! 🔌💡

Great video

Great!

Replying to the software comment question, because that is more my background. Tell the reader what you were TRYING to do, or what state you EXPECT. Don’t say what the code DOES (e.g. “increment counter”), say>> what it’s FOR, e.g. “parse next transaction”). Hardware equivalents might be “3.7v pwr gd”, “MOV > 1M”, “Ppr Sense”, “MSP (Magic Smoke Port)”.

HI! I want to know what the most common BJT transistor MOSFET power transistor and power MOSFET I should have as a beginner.

I make many isolated power supply on the pcb. For every supply i always add test poin n led. For analog circuits test point to attach multi meter is very helpful too

The common misconception about how PCBs are used in prototype work is that they are all cut (or trimmed) to the final shape and, when they are delivered, you have a little stack of same size boards. This is one way to do prototypes, but is really not all that helpful. The better approach is to panelize many of the same board or board types (same number of layers and stack up). Why, because a panel will have areas which are not occupied by the boards themselves, called the excess or coupon area, where you will occupy with dedicated testing circuits and other PCB manufacturing tests (like silk-screen line size and consistency with smaller and smaller line widths), and a layer stack window. When a panel arrives for production the first step is to characterize the complete panel using the test circuits (like transmission lines test traces, e.g. strip-line, microstrip), then the boards themselves are tested (usually flying lead test machine for continuity). By testing a panel at a time you know every board on the panel will act the same. For prototype board test waveform integrity the design might include SMT high frequency test sockets, or dedicated SMT test headers for logic analyzer attachment. Usually, once the board goes to production these specialty test points (headers and jacks) are not populated (due to cost, if not needed for end of line bed-of-nails testing, which they usually are not), but can easily be soldered to the board to help in testing a field return. A thru hole test point is not usually the best choice because it produces a stub, and it also takes up more overall space (because you are going thru layers to the other side of the board), so, you are usually dealing with an SMT approach to a test points. To further reduce costs you can use SMT pads to connect a spring loaded programming header. For analyzing field returns that have conformal coat during production, you can use a very sharp point version of the spring pins (it will penetrate the conformal coat), although this may be a special order for the more popular spring pin JTAG+Debug round tipped pins. The other old school testing connection is using an edge connector, this too is relatively inexpensive, although not as popular as in the past.

Make a TestPoint symbol that is a dot and connect on schematic inline to wire. The goal is to reduce the schematic clutter of TestPoint symbols distracting from the schematic flow. Make TP symbol as unobtrusive as possible!

I just can't understand it