Electronic Prototype Fabrication. Part 1: Why making electronic PCB prototype is useful

In this blog post, you will learn what are the different steps of making electronic prototype board and why we do it.

Why making electronic prototype is important

If you have already led an electronic product development project, you probably know there is a long way between idea and product being ready for manufacturing. First you will  go trough design, engineering, then prototyping, then manufacturing.

Arriving at manufacturing stage, because quantities are scaling, you can not afford to scale some defectives products. Imagine that 10000 pieces being produced for manufacturing occur to have a defective which make your product unsellable or unreliable: cost for recall, correction and so on is then becoming very high. You simply can not afford this. Hence, before pushing your nwly developped product to manufacturing you want to ensure your product is stable.

On an electronic product, a keystone of the product is the electronic part mostly being electronic board (PCBA), input and output peripherals, power supply, display etc... Because the electronic part is like a full complex machine, if one of those parts or process doesn't work properly, then your product is at risk.

When we develop electronic product, part of the development is made on simulation, theory, design on EDA software. Most of time, modeling and simulating on computer is reliable enough but in some particular occasion, particularly when physics such as radio wave enter into consideration, then verifying in real world rather than just in theory is just necessary.

Performing electronic prototyping got several advantages because it allows to:

1./ Validate electronic hardware

  • Verify components compatibility between each other: As you may have chosen some components in your electronic bill of material, having them to be tested individually may help to make sure the PCBA will work properly.
  • Testing your board: As components being tested in real situation, it allows you to determinate what are tolerances and treshold (security margin) on your components (for signal for example). Testing is the most important part of prototyping post activities because it aims to validate engineering against specifications.
  • Pre-certify your board: As your PCBA is assembled and almost as similar than your futur production one, you can perform pre-certification with your PCBA prototype against different standard (EMC/EMI, FCC etc...).

2./ Validate firmware / embedded software

  • Testing embedded software core function: Passing from simulator or emulator to real world semiconductor real time operating system will allow you to test the core function of your system in real time on real board. Keep in mind that simulator and emulator are usefull but since they are approximating, they will never replace a real system in live
  • Debugging your embedded software: As you may test your system, you may find out some issues or some bug. Linking your prototype to your computer to debug your embedded software will allow to fine tune your system to stick with your requirement

3./ Validate mechanical constraints

  • Spacing and interference: Normally, your mechanical engineer performing part modeling and assembly in CAD should have received your PCBA 3D CAD from your electronic hardware engineer after PCB layout to be done. Hence, your mechanical engineer should have integrated the volume and spacing of your PCBA in the enclosure of your product, making sure your PCBA can fit perfectly into it. Prototyping allow to verify this point, and particularly to verify tolerances and margin gap between parts. I have seen many times some design where the PCBA could not fit properly into enclosure because mechanical engineers didn't consider properly margin gap in their 3D CAD files.

4./ Validate thermal constraints due to PCBA

  • Heat dissipation: Yes, you probably know that most of electronic components are dissipating heat when they are running. Thermal consideration are important because it can influence the life cycle and the performance of your product. If your components are working hard then it might heat up quite a lot. And if your enclosure is too tight to dissipate and evacuate this heat properly then your chip and other components might be submitted to improper environment in terms of temperatures.  How much does it dissipate depends on its activity and it needs to be measured physically because there are no real simulator for this (or rarely).

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About Christopher Oliva 59 Articles
Christopher Oliva is an Engineer based in Shenzhen since 2008 involved in Product Development, Supply Chain, Sourcing, Quality Management and Manufacturing activities. With a Msc Electrical Engineering and a Business Administration background, an ISO 9001 Lead Auditor Certification, a Six Sigma Certification and a Quality Engineering Certification, he works as a consultant on mission and contract oriented to Product Development, Manufacturing Management, Quality Assurance & Quality Management System setup. He works in the product development and engineering field, and as well as an advisor and quality consultant for several quality control and quality assurance companies.