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PCBA Prototyping from Engineering to Box Builds

PCBA prototyping
PCBONLINE Team Fri, Jan 13, 2023

PCBA or printed circuit board assembly is an electrical board assembled with components. A PCBA can be a module, a part of a system, or even a semi-product. For a new project, it is impossible to manufacture PCBA in batches in the beginning because possible design or production defects can happen. You will need PCBA prototyping to ensure the product's function and quality before bulky PCBA manufacturing.

PCBA prototype

This blog is an ultra guide on PCBA prototyping updated in 2023. Let's dive in to see everything about PCBA prototyping!

Part 1: What is PCBA Prototyping

PCBA prototyping is manufacturing PCBA samples. Usually, 1 to 5 pieces of samples are manufactured in the PCBA prototyping stage.

PCBA prototyping is low-volume PCBA production. It can involve the whole electronic manufacturing process, including engineering, PCB prototype fabrication, PCB assembly, and box build assembly. Besides, unexpected technical issues can happen in the PCBA prototyping stage, and the PCBA manufacturer has to solve the issues.

PCBA engineering

Due to the low volume and tricky technical issues, PCBA prototyping is a blind point in the electronic manufacturing industry. However, this is a necessary step to ensure electrical design functionality and quality in case of economic losses in bulky manufacturing.

So what to do? For solving PCBA prototyping problems, the EMS manufacturer PCBONLINE provides a one-stop solution.

From PCB fabrication to completing end product samples, including component sourcing, you can get PCBA samples in the fastest 3 days.

From the PCBA manufacturer PCBONLINE, PCB prototypes refer to the total size of rigid PCBs such as FR4 PCBs and metal-core PCBs within 0.2square meters, flexible PCBs (including rigid-flex PCBs) with 0.12square meters.

Ceramic PCBs and high-frequency PCB prototypes are calculated by the PCB pieces and you need to send your Gerber to the PCBA manufacturer for a quote.

aluminum PCBA prototyping

Part 2: Design of PCBA Prototyping

Design of PCBA prototyping refers to the design for manufacturing (DFM) for PCB and design for testing (DFT) for PCBA.

When you complete the PCB design and send your Gerber and BOM to a PCBA manufacturer, this is not the end of the design for your project. The CAM engineer from the PCBA manufacturer PCBONLINE will check your files and do the PCB DFM and PCBA DFT.

If you order box build assembly as well, PCBONLINE does the design for excellence (DFX) for your product.

The PCB DFM ensures the feasibility of project manufacturing, and the PCBA DFT ensures your PCBA can undergo electrical testing to ensure the PCBA achieves the expected functions.

One of the common questions asked by you may be:

Question: How to design pads on the PCB for PCBA electrical testing on critical components?

PCBA electrical testing

Here's a detailed explanation of the above question - a PCBA can achieve expected electrical functions because of its critical components. In the PCBA prototyping stage, the PCBA manufacturer will use a multimeter to inspect the critical components. How to enable the two probes of a multimeter to inspect the components on a PCBA? It requires additional PCB pads around the critical components so that the two probes can touch the pads.

For example, you can check part of the design below for the DFT of PCBA prototyping.

PCBA testing design pad

No worries about the DFM, DFT, and DFX, as the PCBA manufacturer PCBONLINE provides one-on-one engineering support and can solve engineering problems.

Part 3: PCBA Prototyping Process from PCBs to Box Builds

When both you and your PCBA manufacturer confirm to put the design into fabrication, the PCBA manufacturer fabricates the PCB prototypes first. Meanwhile, it purchases electronic components as fast as it can. If you need 5 PCBA samples, your manufacturer purchases five sets of components.

PCB prototype

PCB prototype fabrication: PCBs in different substrate materials, different layers, and different component mounting sides are fabricated differently. However, the essence of PCB fabrication is generating copper circuit traces on the non-conductive material layers and interconnecting them with copper-filled vias. The most common way is etching circuits on the PCB core, and then laminating the outer layers on the core.

Purchasing components for PCBA prototyping: due to the short delivery time, a PCBA manufacturer usually purchases components as fast as possible. The supply team of the PCBA manufacturer PCBONLINE in Hong Kong quickly purchases the electronic components and ships them to the EMS production factory in Shenzhen. Due to the short distance, the components can arrive during the PCB fabrication period.

PCB prototype assembly: on an automatic SMT line, the PCBs are silk screen printed with solder paste and placed with SMDs. And the PCBA is reflow soldered and AOI inspected. On a THT line, the technicians insert THT component pins through the PCB holes, wave solder the PCBA, and add tin to the board if necessary.

First article inspection (FAI): FAI uses the probe of the FAI inspector to touch the component pins to automatically display and record component values in a computer. For PCBA prototyping, PCBONLINE randomly picks up a piece of PCBA from the samples to do the FAI test. After that, an FAI report is automatically generated. PCBONLINE will send the FAI report with the PCBA samples to you for review and approval for batch production.

PCBA prototype

Testing and value-added services: after PCB assembly, the EMS manufacturer conducts functional testing, peelable testing, burn-in testing, and other tests according to your project requirements. From PCBONLINE, you can avail of value-added services for your PCBA samples, such as IC programming and conformal coating.

Box build assembly: box builds are end products labeled and packaged in your brand. You send the enclosure design or enclosure sample to the PCBA manufacturer, and the PCBA manufacturer has them manufactured. If you don't have an enclosure design, the PCBA manufacturer PCBONLINE can design it for you. Then the PCBA manufacturer installs the PCBAs with enclosures to form box builds. Later, the PCBA manufacturer conducts field application simulation testing for the PCBA box builds. After quality confirmation, the box builds are delivered to you.

camera PCBA field application simulation testing

Part 4: Get Free PCBA Prototyping from An EMS Manufacturer

If you order bulky PCBA manufacturing from PCBONLINE, you can get free PCBA samples. The project engineering, PCB prototypes, electronic components, PCB assembly, and box build assembly for the PCBA samples are all free.

PCBONLINE is a one-stop PCBA manufacturer providing EMS manufacturing for middle and high-end applications. The PCBA factory in Shenzhen serves EMS production, including SMT and THT assembly, testing, value-added services, and box-build assembly.

Its two large advanced PCB manufacturing bases fabricate PCBs from prototypes to bulky production. You can avail of FR4 PCBs of any Tg, aluminum PCBs, copper base PCBs, flexible PCBs, rigid-flex PCBs, ceramic PCBs, high-frequency PCBs, and glass PCBs.

EMS manufacturer
Details of PCBA prototyping at PCBONLINE:

One-stop EMS manufacturing from prototyping to batch production from engineering to PCBA box builds.

All-round financial support. You no longer have to worry about the cash payment process when purchasing PCBA in small batches.

Relying on lots of clients' PCBA inquiries, PCBONLINE can integrate BOMs to source them together to lower component costs.

High-quality PCB, PCBA, and box build assembly certified with ISO 9001:2015, IATF 16949, RoHS, REACH, and UL.

Traceable EMS manufacturing and complete testing/value-added services to meet every demand of your project.

The PCBA manufacturer PCBONLINE has more than 10 years of experience in EMS manufacturing. You can have PCBA prototyping from PCBONLINE for industrial, automotive, defense, medical, aerospace, communications, computer, and consumer electronics. If you need PCBA prototyping, feel free to send your inquiry by email to info@pcbonline.com.


PCBA prototyping is fabricating PCBA samples from 1 to 5 pieces. It is low volume and has many design and engineering issues to solve, so you may find it a little difficult to find a reliable PCBA prototype manufacturer. The EMS manufacturer PCBONLINE not only has no quantity limit to your PCBA orders but also provides one-stop manufacturing services. By working with this source factory PCBA manufacturer, you can have cost-effective and quality PCBA prototyping that meets your expectations.

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