Printed Circuit Board Assembly (PCBA)

Design Considerations

M&M Qualtech has been producing complex electronics for the past 30 years and one of the design elements that cause most confusion is the Printed Circuit Board (PCB). The PCB is the “brain” of the electronics product and is central to its design and functionality.

As technology becomes more sophisticated and challenging, an integrated approach to technology design and product development is critical. Often a new technology start-up will have expertise in a specific area e.g. software or firmware and hardware design is a secondary consideration. Product success and speed to market requires that all are co-developed concurrently as decisions made later in the process may necessitate a redesign if other design elements were not considered.

Here we examine the key general classifications necessary for Printed Circuit Board Assembly as you embark on your technology development process. Over the coming months, we will be publishing further detailed updates on each of these considerations. In the meantime should you wish to discuss anything related to this technical series, please email us at info@mmqualtech.ie.

Design Review Elements

The below design elements need to be evaluated collectively as they overlap and are contingent on each other in many respects.

Printed Circuit Board Assembly (PCBA)

Documentation Overview

 

The documentation requirements listed below are central to any design review to assure that the design meets the necessary market certification requirements such as CE, UL and FDA. Documentation is a critical consideration before beginning on any design journey and includes all or some of the following:

  • Assembly Drawings
  • Bills of Material
  • Schematics
  • Purchased Part Drawings
  • Test Specification Drawings
  • Bare PCB Drawings/Artwork
  • Special Workmanship Standards
  • List of parts on tape and reel

 Component Design Considerations

 

Component design is a major pathway to product development. Choosing sub-optimal components for your design in the early phases can impact your product success due to availability and lead-times. It can also have a major impact on your total product cost in later development phases. Considerable consideration needs to be given to component design and selection as it may significantly impact your product’s time to market, cost and threaten future business continuity.

In PCB assembly the following components should be considered:

  • Surface Mount Pads and Orientation
  • Axial Part Pads and Spacing
  • Radial Part Pads and Spacing
  • DIP Parts Pads and Spacing
  • Manual Inserted Parts
  • Wiring and Cables
  • Plastic Molded Parts
  • Cleaning
  • Fiducials
  • PCB/PWB material and soldermask
  • Stiffeners and tooling
  • Tooling Holes
  • Connectors/Terminals
  • Via size and Spacing
  • Programmed Parts
  • Labeling/Serialization
  • Panelization
  • Manufacturing Flow
  • No Post Wave Assembly
  • Potting
  • Adhesives

 Test Considerations

 

How you test your product design and verify its ongoing performance is integral
to its quality. A product development program must ensure that ISO/ASTM
and market-specific test requirements (e.g. FDA/CE) are designed for
early in the development cycle. This will avoid costly redesigns
and time delays further along the development cycle.
Tests to consider include:

  • Node Access (Test Points)
  • Incircuit Test Compatibility
  • Functional Test Compatibility
  • Boundary Scan
  • Burn-in Test Compatibility
  • Hypot Test Requirements
  • ESS Test Requirements
Printed Circuit Board Assembly (PCBA)

 Logistics & User Considerations

Designing your products so it meets logistical requirements (packaging/ shipping) can often be an afterthought. However, it will delay getting your finished products to your end customers if not considered early. Decisions here are influenced by market specific and geographical requirements and expectations. Your design and manufacturing partner can assist you in this process and will support decisions for:

  • Shipping/Packing Requirements
  • Product Manuals
  • Long Lead Purchased Parts
  • Purchased Part Commonality
  • High Cost Purchased Parts
M&M Qualtech PCBA

 Regulatory Agency Requirements

 

The documentation requirements listed below are central to any design review to assure that the design meets the necessary market certification requirements such as CE, UL and FDA. Documentation is a critical consideration before beginning on any design journey and includes all or some of the following:

Hand in hand with documentation requirements are regulatory considerations. From the outset these requirements and constraints influence your design choices. Across markets there are increased expectations and regulations governing the choice of materials, safety, efficacy and certification. In some markets these may be very onerous and hamper component selection and product performance. It’s imperative these are understood and designed for accordingly from the start. Regulatory considerations include those relating to:

  • Materials
  • Manufacturing environment(s)
  • Required certifications
  • Documentations

Functional Performance Requirements

 

Component design is a major pathway to product development. Choosing sub-optimal components for your design in the early phases can impact your product success due to availability and lead-times. It can also have a major impact on your total product cost in later development phases. Considerable consideration needs to be given to component design and selection as it may significantly impact your product’s time to market, cost and threaten future business continuity.

In PCB assembly the following components should be considered:

It may sound like common sense but balancing function with its operating environment is central to design success. Especially in regulated and constrained environments your choices are curtailed. This is especially relevant where size and mechanical function is challenging and safety needs to be assured as in the medical device market. Product development teams need to rely on experts that have a varied and deep specific knowledge to bring an innovative and high performing design to fruition.

A balance is needed for:

  • Size Constraints
  • Mechanical Needs
  • Material limitations (biocompatibility etc.)
  • Compatibility with other design components/systems
  • Delivery/site functionality constraints

While PCBA design and engineering for new technology may appear daunting to the unfamiliar, assistance is close at hand when partnering with M&M Qualtech. We will assist you through every step of the process and map out an integrated technology development strategy.

Providing design, engineering and manufacturing services for complex electronics – talk to us today about how we can get your innovative device to market quickly.

James Feehilly,
Electronics Engineering Manager

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