What Is Electronic Prototyping?

Prototyping is making a small number of first-off samples for testing. This allows you to evaluate the design to ensure its effectiveness.

If your prototype is electronics-based, you may subject it to various tests. However, if it’s more mechanical, you can test it and perform a few stress tests.

Ultimately, it’s a first-time attempt at creating a solution.

What Are the Different Stages of Electronic Prototyping?

For prototyping, we typically create an A model, a B model, and – depending on the project's complexity – a C Model. From here, we’ll move on to unit production models.

It’s worth acknowledging that the A model will be wrong. The A model is the first time you combine all the design efforts. You are integrating different people’s pieces of IP onto the board, and each person’s IP will typically come with different data sheets.

The data sheets could be wrong or differ from those of others. For example, a footnote on page 173 could be relevant to your application but not to others.

You stitch these devices onto a printed circuit board, manufacture a few prototypes, and test them.

We always advise only making a handful of prototypes. Do not, under any circumstances, make hundreds of these, even if your project is late. They will be wrong, and you will have to modify them. There will inevitably be some problems.

You want those prototype boards in the hands of the engineers as fast as possible so they can test them and then work out design solutions. If there’s any strange, unexpected behaviour, it needs to be understood because it will come back to haunt you at some point during the development process!

When every piece of functionality has been tested on the A model, you can move to a B model, which incorporates all the changes you’ve made and all the problems you’ve identified and gives you a far more solid base.

At that point, you might wish to make additional prototypes to potentially get into the hands of users, and indeed for your development teams.

From here, you’ll be looking at getting your prototype into scale-up and production. You may wish to produce some new product introduction models. While you’ve got a B model designed for production in mind, your manufacturer might need some tweaks and adjustments to ensure they can produce the product effectively.

How to Design a Prototype Demonstrator Model

For a prototype demonstrator model, you must determine what you want to demonstrate and why.

Do you want to prove the functionality works? Or are you looking to go down the MVP (minimum viable product) route where you want user feedback? Regardless of your intentions, these questions must be considered to ensure you do things for the right reason.

Ultimately, you need to nail down the specific purpose of your demonstrator model and do that. Don’t try to do everything in one go.

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Why You Shouldn’t Put an A Model into Production

A model prototypes are highly likely to have something wrong with them.

For example, perhaps the specification has changed. You might realise that this product iteration isn’t what you really want. This realisation can come after you’ve shown it to a user or made the prototype and put it on the workbench.

But it would be best if you also considered that there will be changes in the electronics themselves.

Device values will be amended between the A and production models, printed circuit board tracks may also be altered, and you may even make changes to the device itself. It would be best if you considered the ongoing global semiconductor shortage, which could force you to design one chip out and another one in, depending on availability.

Because of this, ordering many A model prototypes for production can be incredibly costly.

Critical Differences Between Electronic Prototyping and Scale-Up

Prototyping proves you can make a few models that demonstrate the right functionality and behaviours in a benign environment. They’re usually tested in a lab environment that’s likely to be air-conditioned. Testing often occurs with users who know how the product should be used or have worked out the use cases, which adds an unintended bias to how the product is tested.

There’s a significant difference between having a handful of prototype demonstrators and scaling up to high-volume manufacturing. At the manufacturing stage, you must have resolved problems associated with temperature, variations, tolerances, and usability.

Somebody, without prior knowledge of use cases, will do something that you never thought they would, and that will break your device, “That’s often me! If someone gives me a product to test, I can pick it up and break it in a few minutes!”

The critical point is that the test and validation, the scale-up stage, includes compliance and quality control considerations. Having peace of mind that every batch off the production line will be okay is vital to preventing many product recalls and customer complaints.

Once you’ve tested the product yourself, over the range of temperatures it’s advertised to perform at, and with end users, you’ve got a product you can consider shipping.

Skipping this crucial stage will create a whole world of pain.

Testing Your Device Against Temperature and Humidity

You have a few options for testing temperature.

You can either take the device to every country and environment throughout the seasons in which you want it to perform, or you can leave it at home.

You can hope for the best and throw it into production, looking at the specs of each component and hoping that it works in practice. Or—and this is the right option—you can do temperature control testing in an environmental chamber.

An environmental chamber allows you to test and control humidity and temperature over a range. Verifying each of the essential parameters builds confidence.

Fletcher’s Law of Prototyping

Fletcher’s Law is a bit tongue-in-cheek, but essentially, it says that the higher the number of prototypes initially made, the worse the product and those prototypes will be.

This is usually due to cultural or environmental pressures. It is typically the result of businesses compressing the product development process to get a product out of the door ASAP. In short, it is a culture of trying to do as much as possible, in as short a time as possible, to meet a fixed launch date.

Sure, the product might be launched on time, but this usually means that the design, prototyping, and testing have all been rushed. Because of this, crucial steps such as a design review may also have been skipped to save time.

Because of this, you’re saddled with poor-quality prototypes, and all these prototypes now need to be hand-modified, with components added and removed, PCB tracks cut, soldering, and more.

This means that your engineering team wastes time modifying boards that go out for test instead of working on testing and getting your prototype closer to a B model standard that would take your product to market in a reliable fashion faster.

Fletcher’s Law acknowledges that rushing actually slows you down. You spend more money, and while you feel like you’re making progress, you’re just wasting time and money.

Electronics prototyping is not like writing code. You can’t just compile it and get away with it. There is a lead time to get components, which is currently extensive due to the global chip shortage.

Next, you’ve got to manufacture and test them. So, every time you do a PCB prototype, you can lose up to 2, 4, 6, or even 8 weeks. You are better off focusing on getting the quality right on the first run and scaling up.

Why Choose Ignys for Electronic Prototyping?

We can help with the electronic prototyping stage in various ways.

Ideally, the best place to start is right at the beginning of a project, when you have an idea and considerations on how to deliver it. At this point, we can help inform design choices, architectures, and device choices and then work out the risks and feasibility and roadmap the process.

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However, we are unsure which part of the process you’re in. Ultimately, we have experienced hardware, firmware, and software engineers with the expertise to support you – no matter which stage of your journey.

With new projects, we typically run an idea generation workshop before moving onto the feasibility stage, where we’ll assess challenges around power consumption, radio, and thermal performance speed. We then take you through various parts of electronics design to get you to that prototype demonstrator.

With software prototyping, you may already have a software or hardware team. Regardless, we can use either of these skill sets to fit around your team. And suppose you don’t have in-house capability in either area. In that case, we can help ensure that the necessary due diligence has been followed, including software regression testing, and that things are tested as thoroughly as possible.

You can test forever with diminishing returns, but there are key parts of testing that can’t be avoided; for example, you must perform a certain level of testing against use cases, such as supporting compliance through EMC and the radio equipment directive.

Moving into production, we examine quality control using test fixtures, test plans, and our SAM subscription for post-launch support. This means you can get ongoing support for the products you’ve designed.

Once you launch the product, you’ll find that you may need extra features, a bug that’s found, or a chip that you need an alternative for. SAM helps ensure you are not waiting for our typical lead times and have rapid access to our engineering service.

Ultimately, many customers come to us later in the process with projects running late or needing expert support. We’re more than capable of supporting those customers and rescuing them from difficult positions, but it’s far easier for all parties to begin at the start!

To look at the services we offer to help you have a look at our website https://ignys.com