Grass Fed PCBs

March 17, 2017, Episode #59

• MacroFab and Mouser Electronics have teamed up to create a free monthly meetup in Houston for anyone involved with hardware & electronics engineering or manufacturing. Hosted on the last Wednesday of every month, these meetups are designed to build a community of professionals who want to learn from one another, gain new insights on emerging electronics technologies, and expand their network.
  • Sign up here!
  • What to expect
    •  Networking
    • Fireside chats with Q&A
    • Individual project sharing and discussion
    • Door prizes
    • Refreshments
    • Free parking
• Christian Aurich writes: “Could you talk about differences in surface finishes on PCBs? I am especially wondering what difference ENIG makes to other ‘flat’ finishes… so everything else than HAL.”
  • HASL (Leadfree and Leaded)
  • ENIG
  • Immersion Tin
  • Immersion Silver
  • OSP (Organic Solderability Preservative)
  • Gold – Hard Gold
  • PDF on pros and cons
• Parker
  • Working on a LVDS output board for the RPI 3
  • Parallel Display Interface on the RPI3
  • Config.txt parameters and by enabling the correct Linux Device Tree
  • Using the Ti DS90C365A. It converts a RGB666 signal to a LVDS signal for LCD panels. You give it 6 bits for ever color, pixel clock, H clock and V clock and poof LVDS.
• Stephen
  • Bench Stats:
    • 80/20 construction
    • 1 5/8″ plastic laminate table top
    • 60″x30″ with adjustable height between 30.625″ to 32.625″
    • Total Length of 80/20 per bench: 40.33 feet
    • 42 angle brackets
    • 84 nuts/bolts
    • ~68.5 lbs
• Particles from outer space are wreaking low-grade havoc on personal electronics
  • Click bait? In many instances, however, these operational failures may be caused by the impact of electrically charged particles generated by cosmic rays that originate outside the solar system.
  • This is called a single-event upset or SEU
  • SEU failure rates for consumer electronic devices performed by Ritesh Mastipuram and Edwin Wee at Cypress Semiconductor on a previous generation of technology shows how prevalent the problem may be. Their results were published in 2004 in Electronic Design News and provided the following estimates:
    • A simple cell phone with 500 kilobytes of memory should only have one potential error every 28 years.
    • A router farm like those used by Internet providers with only 25 gigabytes of memory may experience one potential networking error that interrupts their operation every 17 hours.
    • A person flying in an airplane at 35,000 feet (where radiation levels are considerably higher than they are at sea level) who is working on a laptop with 500 kilobytes of memory may experience one potential error every five hours.
  • The engineer’s bottom line: “This is a major problem for industry and engineers, but it isn’t something that members of the general public need to worry much about.”

Figure 1: PCB Surface Finishes. Left to Right: HASL, OSP, ENIG.

Figure 2: Bench Design Stephen is working on.

About the Hosts

  Parker Dillmann

  Stephen Kraig