2024 Conference - Chris Turner

Chris Turner

Principal DFT Consultant - Redback Test Services

Since the first vacuum tube dimly sprang into life over a century ago, there has been a relentless search for an illusory “Holy Grail”; ‘The Quest for the Perfect Assembly Process’ — a process that makes only good electronic assemblies. Why? To eliminate the significant aggravation and expense of inspection, test, scrap, training and quality assurance steps that management label ‘non-value add’ activities.

Despite a century of effort, this goal remains entirely elusive. My presentations explore the challenge in finding a combination of design, parts, process, and quality assurance activities to help us further towards our industries Holy Grail.

You can find out more about Chris here: LinkedIn

Presentation 1

Creating an optimal PCBA design and manufacturing process

  • “Know your enemy and yourself” [Sun Tzu - The Art of War] Lets work through the many and often conflicting attributes of projects across the OEM and EMS, including:
    Who are the decision makers? “Are they on your page”
    • Final product use, the Quality/Risk limits
    • Regulatory Obligations
    • Cost Ceiling
    • Volume
    • Timelines (“just get it out fast” isn’t for everyone!)
    • Technology
    • Product Life
    • Design and Manufacturing skills (OEM and EMS!)
    • Availability of suitable tools
    • How to find experts in areas outside your domain (tricky!)
    • Boltng it all together in some examples to see what we get!
  • Dismantling the “wall” between Design and Manufacture. “However clever a design might be, if it cannot be assembled into a functioning unit and sold at a profit, it has no value to the company and could even be damaging”.
  • Assuming a perfect design, what are the process errors we can expect and a􀆩empt to mitigate in design and or test?
  • The apocryphal order of magnitude rule, Test early or pay big! “Shift-Left” (upstream) and save!
  • Evaluation of aptitude, having the tools is not enough!
  • The OEM design must dovetail with the EMS process and people, if you want maximum success.
  • The design process, who to involve?
  • How to visualise a projects likely success while still in the design stage.
  • Test methods, Specifications and Test Coverage Reporting.
  • Initial and ongoing Test Limits, stats are probably unavoidable and easy to misunderstand.

Presentation 2

Examples of Design For Test (DfT)

  • Making AOI & 2DX friendly layouts
  • ICT & FCT tricks of the trade
  • What is a good test anyway?
  • Concurrent testing e.g. Flashing while testing elsewhere.
  • Fast, Accurate Diagnostics; that your mum could understand
  • Onboard SN & Test Logs (very helpful)
  • Safe power-up (really safe!)
  • Protection circuit checks (over temp/voltage/current/watchdogs etc)
  • End Of Line (EoL) Test, what should we do here?
  • We’ll run through some typical circuits and their DfT opportunities.

Attendees for Presentation #2 should ideally have attended #1.