Circuit Break Podcast #427: Food Device Contest Wrap up

Podcast Title: Food Device Contest Wrap up

Release Date: 2024-04-19

Episode: #427

In this episode of Circuit Break, we wrap up the Food Device Design Derby. We celebrate the innovation and creativity of contest entries like the JavAqua, Pizza Pouch, and the winner, BarBuddy, a personal robotic bartender. Notable discussions include a look at podcast statistics, with an impressive 86% of listeners tuning in for entire episodes. We also introduced a new email notification system for podcast releases, moving from Tuesday to Friday releases, and encouraged listeners to engage with reviews. There is also a brief discussion about if PCB assembly drawings are still relevant.


Podcast Audio:

Podcast Notes:

  • Introduction of “Breakers” as a nickname for the podcast listeners.
  • Discussion of the podcast’s high listener engagement stats.
  • Introduction of an email notification system for new podcast episodes.
  • Results and highlights from the Food Device Design Derby:
    • Third place: Pizza Pouch
    • Second place: JavAqua
    • First place: BarBuddy
  • The importance and challenges of creating accurate assembly and fabrication drawings for PCBs and PCAs.
  • Discussion on potential improvements in EDA tools for automating assembly and fabrication drawings.

Relevant Links:

Community Questions:

  • What new innovations or devices would you like to see in future contests?
  • Have you ever had a DIY project that you turned into a functional everyday tool? Tell us about it!
  • What are your thoughts on the need for more automation in EDA tools for producing assembly and fabrication drawings?

Random comments to the questions in this episode in no particular order.

  • Altium and KiCAD produce PDFs (schemaitcs, drawings) that are searchable. I find this very useful if you have an assembly drawing with designators to quickly find the location of a part on the board. OrCAD Allegro can also be convinced to have searchable PDFs but it is more painful (as everything).
  • Altium can be configured to produce a full data package of the design (SCH, drawings, ZIPs of Gerbers/NCdrill and ODB++, Bill of materials) on the press of a button. You even need to put in e.g. part number or the revision in only one place to be populated everywhere. Takes time to set up once and then just saves so much time at the end of every revision.
  • When it became a thing, I was always surprised that both ends ( customer and board house) accepted PCB files instead of Gerber packages. The customer does not know how the CM generates Gerbers/ODB++, so they don’t know if the board is identical to the board file. With a Gerber/ODB package sent to the board house, I alsways assumed, they used this dataset with no changes. I was so wrong. Data gets tweaked all the time (trace dimensions for differential impedance, solder mask openings, paste layers ). It would be nice to close the loop and get a dataset back from the CM, what they really used for production of the PCBA.
  • For me it is always a game to place the part designators on the silkscreen/assembly drawing to make it unambiguous which number belongs to which footprint.

Yeah this is something we are working on at the Fab. Closing the loop. Trace dimensions and solder mask openings are typically changed at the PCB Fab level and the paste layer is adjusted for the process.

Yup! Big part for me as well. @Stephen.K brought up some good points when the board is too compact however.

PDFs are fine…ish but we where mainly talking about the antiquated gerber “text” files that contain a drawing frame and a bunch of text that defines PCB specifications.

I agree, outputing this info as Gerber is useless. You are not getting a panel with the assembly drawing in copper and fab drawing in silkscreen.:rofl:
They all start as mech or user layers in the PCB file. Export to pdf just just a different button to click. And you were right, specifying all parameters in the ordering form makes the drawings obsolete. That reminds me to test the new Macrofab interface…

Side tangent: not too long ago i saw a picture of a board that had the dimensions printed on the top copper layer in addition to the traces, shorting out everything. Looked cool and painful at the same time.

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Seen this way to many times!

I haven’t actually used IPC-2581 for my designs, but it does have the ability to embed notes and specifications that are typically found on FAB and Assembly drawings. You can also tag traces with requirements like the impedance and tolerance

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I didn’t know about the tagging for specific traces and nets. That is a cool feature!

Here are the properties you can add IPC-2581 (Atl least in Allegro):

Compliance: ROHS, Conflict_minerals, WEEE, REACH, Halogen_free, Other

Conductor: Surface_roughness_upfacing, Surface_roughness_downfacing, Surface_roughness_treated, Etch_factor, Finished_height, Other

Dielectric: Dielectric_Constant, Loss_tangent, Glass_type, Glass_style, Resin_content, Processability_temp, Other

EdgeChamfer: Angle, Width, Side

General: Electrical, Thermal, Material, Instruction
Impedance: Impedance, Line_width, Spacing, Coplanar_Ground_Spacing, REF_PLACE_LAYER_ID, OTHER

Technology: RIGID, RIGID_FLEX, FLEX, HDI, Embedded_Component, Other

Temperature: Thermal_Delamination, Expansion_Z_Axis, Expansion_X_Y_Axis, other

Tool: Carbide, Router, Laser, Flatnose, Extension, V_CUTTER

Thieving: Keep_In, Keep_Out

V_Cut: Angle, Thickness Remaining