An SMD Breadboard

The electronics Breadboard is definitely one of those things that electronics hobbyists use quite a lot. It allows you to prototype your design relatively easily, with the use of breakout modules, wires and leaded components.

While this seems like a good thing, these breadboards are also unfortunately not perfect. The wires and connectors add electrical noise, and stray capacitance, as well as a certain level of unreliability.

My biggest issue with breadboards is not that though. it is the fact that you can only use through-hole components. Breakout PCBs is sort of a middle ground, as they allow you to connect SMD chips to stuff on a breadboard with wires, but that is not the issue here.

Doing a lot of prototyping, having a lot of components lying around, and then having to still try and find TH versions of everything to prototype with becomes costly in terms of time and space. If you have a larger project, but you are not yet at a stage to have a PCB made, adding another breadboard to the already cluttered setup is sometimes quite a challenge.

To get rid of this major point of frustration to me, I decided to try to solve it for myself by designing a SMD breadboard Hybrid.

What is on the board?

Quick Specifications

-300-hole solderable breadboard (dual layer, plated through-hole pads)

-64 0805 SMD pads, with plated through hole pads for connectors

-8 BJT/Mosfet footprint pads (SOT233/SOD23-3) with 3 plated through-hole pads per terminal

– 3 Power rails, 30 holes each for Vcc and Ground (Common ground on all)

– Mesh-style ground plane on both sides of the PCB.

– 4 mounting holes

Details

To address all of the various issues that I have with breadboarding, I did the following:

I hardly ever use more than a 300-hole breadboard for single stage of a project.

Many of these circuit blocks could benefit from being a permanent soldered solution, but does not warrant the time and expense to design a dedicated PCB to hold them.

The first thing to do was thus to design a 300-hole PCB breadboard, complete with top and bottom power rails.

My next issue was SMD components. Chips have many footprints, and to try and design for each of them would turn into a nightmare. Breakout PCB’s would thus still be used for those. My biggest issue was BJT’s Mosfets Capacitors, diodes and resistors.

These can be bought in lead versions, but that was exactly what I tried to get away from, so it needed some thinking.

Resistors, capacitors and diodes have only two terminals, and could thus easily be soldered onto 0805 resistor pads (depending of course on the capacitor size )

BJTs and Mosfets need their own footprint.

Each of the SMD components has a corresponding through-hole pad, to easily connect it to a different part of the board as needed. BJT’s and Mosfets have 3 per leg.

Hopefully this will make things a bit more organised in future, and save me some time;