What is Box Build Assembly? Your Complete Guide

Inside a typical box-build PCB assembly

A box build assembly offers circuit boards in their end-use condition. That means assembling the boards into custom enclosures together with other parts. If you’re here, you want to know more about the PCB box-build assembly process. This article will help you get started; here’s what you’ll learn:

  • The box build meaning
  • Examples of box build products
  • What is included in a box build assembly
  • The box board manufacturing steps, from design to testing
  • About box build assembly services and what they mean for your project

What is Box Build Assembly?

Box build assembly is where a manufacturer fabricates an enclosure, installs a PCBA (or PCBAs), and supplies it with electrical components such as cables and connectors or control switches.

A box build assembly may also mean the enclosure after being assembled with components to make it a functional product.

Depending on the end use or application type, a box-build PCB assembly can have different designs: It can be a simple device with only a few components, for example, designed for use inside a device or system.

It can also be a sizeable floor-standing cabinet with sub-assemblies and complex interconnections or electromechanical parts.

A box build is ready for use in various applications when built into a functioning product. Typical box build examples include:

  • A small PDU for use in a computing device or medical instrument
  • A large power distribution cabinet for a commercial or industrial system
  • A control panel for use with large electrical equipment or systems
  • A functioning assembly that you can integrate into an existing
Box Build Assembly
Box-build assembly components, such as cables and PCB boards
Resource: https://www.youtube.com/watch?oahwBMnbqhQ

What is in Box Build Assembly?

A box-build assembly is a ready-to-use product. The manufacturer mounts your PCB (or PCBs) in an enclosure. The enclosure is a specially designed box the manufacturer tailors to fit your project requirements.

All components that the assembly needs to operate or become a part of another system are then added. These typically include the following:

  • Prototype Wire Harness
  • Different types of connectors
  • Various electronic components
  • Electronic controllers
  • Heat sinks if needed
  • Mounting brackets and screws.
  • Fans, if required, to cool the assembly.

Large box builds may include switches, transformers, contactors, and even protective equipment and devices such as circuit breakers. Learn the process of custom-building a typical assembly next.

Full box build assembly
Full box build assembly
Resource: https://youtu.be/VUiAHyP24Pc?si=2ShGkG2C68bjcwlT

PCB Box Build Assembly Process

Upon placing your order, the manufacturer embarks on making your box-build product. The process involves various steps, from design to testing the assembled box. Usually, it includes these essential stages:

  • Design
  • Material selection
  • Pre-assembly Stage
  • Component placement
  • Loading the required software
  • Parts calibration and component or assembly tests.

Box Build Design

Box build design is where you design the product using CAD software. Alternatively, the manufacturer may create the plan for you from scratch.

A 3D model of the required product is produced during the design phase. The most important considerations are enclosure dimensions, product shape, etc.

Bill of Materials

The manufacturer identifies components or materials your project requires, including their source and the costs to procure them.

All this information is contained in a detailed document called a BOM. A carefully and correctly prepared bill of materials should precede all other stages.

Usually, your manufacturer relies on the box build design to come up with the BOM, among other factors.

Pre-Assembly Stage

The next step involves preparing the enclosure for the different parts and the assembled circuit boards (PCBAs). The box is machined to the required finish and other box-build body requirements.

Holes are also usually drilled to accommodate the various components. Note that before full-fledged production, a prototype may be necessary.

Creating a prototype allows both the manufacturer and the client to make corrections. It also allows both parties to suggest improvements to the enclosure structure or the entire product’s functionality.

Component Integration

All components, including the PCB (or several boards), are assembled into the enclosure. These are connectors and cables or electrical devices, such as transformers. Other parts may include switches, user interfaces such as screens, and many others.

In other words, the manufacturer adds everything the box-build assembly needs to function when used in a product or electronic system.

Software Loading

The box-build PCB assembly process often involves embedding a custom program in its memory. The software provides instructions for the assembly to operate or integrate into an existing system.

Calibration and Testing

Finally, the manufacturer configures different parts of the box build assembly. They also carry out tests to check for quality and reliability. The manufacturer uses in-house testing methods, or you can specify the tests you need to be performed.

Essential procedures during this process include visual inspection, functional testing, and the electrical safety test. After several checks and tests, workers can now package the box for shipping.

Electronic box build assembly for power control applications
Electronic box build assembly for power control applications
Resource: https://www.youtube.com/watch?FL1fY_2_VPo

Box Build Assembly Services

Some manufacturers in the electronic industry offer PCB box-build assembly services. This service allows you to have an assembly designed and built to meet your application needs.

You may want a box-build assembly for your product or system for several reasons. Here is a look at some of the benefits of this service.

  • The manufacturer can quickly make a device for your electronic product or electrical and other systems.
  • You’re assured of final, usable product quality as opposed to when only a PCBA is made without integrating it with other parts.
  • With box build services, you can significantly reduce costs by sourcing all your product’s services from one manufacturer.
  • Box-build assembly manufacturers ensure your product passes the necessary compliance requirements and can use various standards to make the assembly.


A box-build assembly is a more straightforward and economical way of integrating your PCBA into a final product or system. It has all the necessary parts installed and may even contain electromechanical components for function and safety. We hope this post has helped you better understand the box-build assembly process.


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