Considering Production Runs#

I’ve been thinking in terms of prototyping lately, but there does come a time where I need to consider moving to a small production run (or larger, if something becomes wildly successful).

While I mainly focus on prototyping and getting things up and running, I need to keep production in mind from the very beginning of a design.

A few questions I’ve started asking myself early on:

  • Is this part available in smaller packages?
  • Does it actually need to be this size?
  • Will this part still be available in 6–12 months?
  • Does it have second-source alternatives?

It’s very easy to build a prototype around whatever is convenient at the time. It’s much harder to turn that into something you can reliably build 50, 100, or 1000 times.

Part Selection#

When I prototype, I mainly use 1206 parts (3.2mm × 1.6mm), and occasionally 0603 parts (1.6mm × 0.8mm), as they are far easier to handle and solder than smaller components.

At this stage, practicality matters — I want parts I can place, adjust, and rework without fighting the hardware (and yes, glasses are now very much part of the toolchain). Larger parts also tend to stay where you put them, which helps before soldering.

PCB manufacturers, however, prefer smaller packages such as:

  • 0603 — a very common production default
  • 0402 — used when density or performance matters

These reduce board size (which lowers PCB manufacturing cost), and in some cases offer slightly better electrical performance due to lower parasitic effects (such as inductance and capacitance). They are also more suitable for automated optical inspection during assembly.

Another factor to consider is how components are supplied. Assembly houses typically prefer components on reels rather than cut tape, as this allows for efficient automated placement. It’s a small detail, but choosing parts that are readily available in reel format can make a noticeable difference when moving to production.

This also ties into lead times — parts that are only available sporadically or in limited quantities can quickly become a bottleneck when building in volume.

The Trade-offs#

Moving to smaller components isn’t a free win.

You still need to consider:

  • Heat dissipation — smaller parts handle less power
  • Trace widths — especially for power paths
  • Voltage/current requirements
  • Mechanical constraints — connectors, mounting, etc.

This is where reality kicks in — not everything should be shrunk.

For example, anything involving power regulation, current handling, or thermal load will often dictate larger packages and more copper area, regardless of how compact you’d like the board to be.

A Note on Voltage Levels#

There’s also a broader trend that influences design decisions.

Older systems often ran at 5V, but modern designs tend to favour 3.3V, and increasingly 1.8V or lower.

The reason is simple:

  • Lower voltage → lower power consumption (provided current remains the same or less)
  • Lower power → less heat to manage

Don’t get me wrong, 5V is still very much needed and it’s still widely used for:

  • USB power
  • Sensors and peripherals
  • Interfacing with older systems

In practice, most modern boards end up being mixed-voltage systems, and you need to design accordingly.

Designing With Intent#

What I’m starting to realise is that good prototyping isn’t just about getting something working — it’s about not painting yourself into a corner.

If I:

  • Choose sensible, widely available components
  • Avoid unnecessary footprint sizes
  • Think about assembly early

then moving to production becomes an evolution rather than a costly redesign.

I run Protoworks (NI) in Northern Ireland, helping small businesses design prototypes and build custom software. If you have a hardware or software idea you’d like to sketch out, feel free to get in touch.