What will your EMS partner expect to see in your build pack?

In an increasingly fast-paced and competitive electronics manufacturing marketplace, customers have come to expect even better quality products delivered in ever shorter turn-around times.

The speed and the flexibility with which electronics manufacturers are able to respond to customer demand can in many cases be the difference between success and failure.

The need to make changes to products or processes can impact manufacturers in a variety of ways, whether it's responding to the growing desire for product customisation, being able to address design issues, or looking to improve functionality.

As original equipment manufacturers (OEMs) seek to streamline their operations, gain firmer control of their costs and bring quality products to market more quickly, the decision to join forces with an electronics manufacturing services (EMS) provider can be a logical next step.

But if you do choose to outsource your manufacturing operations, how can you trust that your outsourcing partner clearly understands your requirements and your expectations?

And how can you be sure that your printed circuit board, box build or electro-mechanical assembly will continue to be delivered to the same high standard that your customers have come to expect? 

There are many factors that will contribute to a successful outsourcing partnership. But one specific element that will have a central role to play is the detail and the quality of the information that you provide in your build pack.

So what should it ideally include?

The essential elements of a build pack

1. Bill of Materials (BOM) - This is the detailed list of all the materials, parts, sub-assemblies and sub-components (along with the quantities of each) that will be required to manufacture your end product.

As well as including all the approved manufacturer part numbers for each of these items, you may also want to provide the details of your preferred supplier to ensure consistency.

2. PCB Gerber files - These are the standard files used by PCB industry software in order to describe the images (copper layers, solder mask, legend etc) that make up your circuit board.

Gerber files will communicate key information between your design engineer and your contract manufacturer to ensure that the design requirements of each element of your circuit board are fully understood.

3. CAD data - Having a visualisation of a finished item can be hugely helpful, particularly when it comes to the box build process.

By providing computer-aided design (CAD) data you can give your manufacturing partner a precise visual representation of your product, whether in the form of a 3D model or a 2D drawing.

4. Drill files - This information will ensure that the correct location and size of all drill holes are all clearly identified and adhered to.

5. Assembly drawings - These will demonstrate to your manufacturing partner the relationship between the individual components and how they fit together.

6. Wiring schematics - This will be crucial information in highlighting the significant components of your product, as well as their relative positioning, their functionality and their point-to-point electrical connectivity.

7. Custom drawings - Provision of custom drawings enables you to define all of the unique, bespoke or made to order elements that may be contained in your build - such as machined parts, plastic enclosures, front panels or metal cases.

8. Revision levels - It is so important to clearly state the revision levels that apply to each element of the build pack, as well as to the finished product itself.

Keeping tight control of your revision levels will avoid any risk of a product being built to out-of-date specifications as well as giving you the flexibility to be able to offer your customers differing versions of a product to suit their specifications.

From a design perspective too, it can also add the reassurance of knowing that you can revert to an earlier revision of a product if a new design development proves unworkable.


Even a seemingly straight-forward box build assembly may have undergone a dozen or more iterations over its lifetime, so the clearer the instructions that you can provide to your EMS partner the more confident you can be that you will receive the right product manufactured to the right standard.

A build pack plays a vital role in organising all the core documents that will be essential in the successful manufacture of your physical item.

And it can also provide a valuable means of bringing together all of the "intangibles" - the knowledge, the experience and the lessons learned - that will have been accumulated throughout the design, development and delivery of your product.

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Written by Neil Sharp

Neil has over 25 years’ experience in Electronics Manufacturing Services and Component Distribution. During his career, Neil has held a range of leadership positions in sales, marketing, and customer service. Neil is currently part of the ESCATEC Senior Management Team and is responsible for setting and delivering the overall Group Marketing strategy. Neil heads up the marketing department and is responsible for both the strategy and the implementation of innovative marketing campaigns designed to deliver high quality content to those seeking outsourcing solutions.