Apple, BaTiO3, BOM, Ceramic Capacitors, Dialog Semiconductor, GreenFET, iOS, MacroRoundup, MEP, MRI, Rework, Vention
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MacroFab Roundup for October 12th, 2018

Welcome back everyone! This week on the MacroFab Roundup: GreenFET technology, Relaxing ceramic capacitors, Avoiding component availability problems, and can an MRI machine destroy Apple devices?

Interesting Links and Articles

  • GreenFET by Dialog Semiconductor
    • High side power supply switching using N-channel mosfets with intergrated gate drivers
    • Typically for high side power switching a P-channel mosfet is used but they typically have a higher on resistance compared to N-channel mosfets
  • Apple inks $600M deal to license IP, acquire assets and talent from Dialog to expand chipmaking in Europe
    • Apple purchases the IP, assets, and talent that Dialog Semiconductor owned to make integrated circuits for Apple
  • Does the capacitance of ceramic capacitors change over time?
    • After reflow, ceramic capacitors need to “relax” to regain their specified capacitance
    • This is due to the crystalin structure of the ceramic material BaTiO3
  • Vention
    • Design aluminum extrusion based machines online and have the material ordered and pre-cut for assembly
    • Offer a combined control system and software package for automation
  • Top 5 Ways to Mitigate PCB Component Availability Problems
    • Check part availability before submitting your BoM
    • Alternate part numbers for passives is a must
    • Pick parts with better availability
    • Redesign to use a smaller or different package
    • Respond quickly to component availability problems with your contract manufacture
    • Rework techniques for surface mount capacitors
    • Under no conditions should the iron touch the part
  • MRI disabled every iOS device in facility
    • I newly installed MRI machine disabled and potentially killed multiple Apple i devices including iWatches, iPhones, and iPads
    • Other devices like computers and android devices where fine
    • Two current theories
      • The shielding on the machine was not installed correctly and the EMI burst fried the wireless charging of the devices
      • Due to a helium leak during installation of the MRI the atmosphere was rich in helium
        • i Devices use a MEMs oscillator which has a vacuum inside the IC to maintain the frequency
        • Helium entered the oscillator causing the frequency to drift and causing the devices to not work
  • Fastening Hardware Using Surface Mount Technology
    • How to use reflowable surface mount fasteners to reduce the time during post assembly of enclosures

MacroFab Engineering Podcast

This week on MEP EP #141: It Depends – An In Depth Look at MLCCs with James Lewis – James Lewis aka the Bald Engineer joins Parker and Stephen on a leap into the deep end on Ceramic Capacitors (MLCCs)

MacroFab IRL Events