Prototype to Circuit Card Assembly, Score Board and Shot Clock

In this Instructable, I will show the many steps: starting with a prototype of an electronic circuit, developing the design, working out all the bugs, testing the software, making the required changes and component selection, and then developing the circuit to a fully optimized circuit card assembly. This process can be very rewarding, educational and fun. I hope that this will be a good example to others who are starting in the world of electronics, like a 'lessons learned', tips and tricks and a 'how to' for beginners so that they can understand and avoid common issues when making a printed circuit board. The end goal is to have your electronic device will be made to be rugged, usable without failures and presentable as a final product.

Supplies

I used PCB123 software for my schematic capture and board layout. (Full service PCB manufacturing company)

A fine tooth jig saw blade (if you are cutting the printed circuit board into a shape)

Jig saw

Fine tooth file (Clean the edge of the board if you are cutting out a shape)

Solder iron

Solder

Tweezers (for component placement and to hold the component when soldering)

Wire nips (Diagonal wire cutters)

Electronic components for your project

Step 1: Prototype on a Perfboard

I have done several circuit card assemblies and all begin with a prototype either on a development board, breadboard, or a perfboard.

My Frankenstein of a circuit was done on a perfboard. Wires were used to connect the components and placement of each component was based on an idea of usability for the end user and trying to make it balanced which would help when placing the final components on the printed circuit board.

This prototype is one of the more complex designs and had helped in the software development, so it had to have sockets for the micro-controller. If the software changed the ICs could be pulled out of the sockets and reprogrammed and placed back into the socket. Marking the micro-controllers if there are multiple should be done so that they are not placed into the wrong socket. Some of the components are the actual components that will be used in the final design and others will be surface mount, make sure you bill of materials is double and then triple checked for accuracy.

You can see in the video, when I was building the circuit I got the two displays backwards, the minute should be on the left and the second on the right side of the board, these are the type of things that help you understand the circuit and not make the error in the board design. Having the prototype allowed me to check the design AND the software.

You can see that the prototype board is really just to get a working design. But you want to make sure it is robust enough to be used for troubleshooting software and can take input from the user without breaking.

There is other prototype boards available, one other example is the breadboard that allows you to stick the leads of the components and wires into a socket. Assembly is quick but is not a permanent circuit, but allows testing the circuit.

Step 2: Schematic Capture and Board Layout

I used PCB123 software to make the printed circuit board. Start by building your schematic in the software, make sure to wire all the components correctly and use the Bill of Material list to check off all your components.

Next select you board size and place your components where they make the most sense for usability (displays, switches, buttons, LEDs). the rest of the components (resistors, capacitors, and other miscellaneous parts) can be automatically placed by the software to speed up the process.

Once the components are all placed you can allow the software to auto route with defined attributes.

Double check it is exactly how you want your board to look and you are sure all your connections and components are placed.

Order your boards!

Step 3: Circuit Card Assembly

When soldering your circuit, makes sure you verify polarity on LEDs, diodes, capacitors, ICs and other components that require correct placement. Solder your components and test the circuit board.

The final circuit card assembly used SMT (surface mount technology) components and some through hole components and makes a robust user friendly completed circuit card assembly.