Frequently Asked Questions

• Question 1. How to work with Largo?

  Click here for more details.

• Question 2. What do we need for quote?

  • Board size
  • Schematics
  • BOM (parts list)
  • Special layout instructions (if any)
  • Any special restriction that apply to the design, like:
    • Height restriction
    • Keep out zones
    • Number of layers
    • High current
    • High voltage

• Question 3. What do we need to start working?

  It is best to start a job when all the items listed on the “Standard input” are available. This way the “clock starts ticking” and the work can be continuous and flow uninterrupted.

  Minimal input: (We can start working once we have these items)

  • Purchase Order number.
  • Any one of the following:
    • Mechanical drawing
    • Netlist
    • BOM
    • Available data sheets

  Standard input: (All this data will eventually be needed)

  • Mechanical drawing with all dimensions clearly noted and fixed components location specified
  • Readable schematics with all reference designations shown.
  • Netlist or .DAT files
  • Data sheets for all components. The data sheets should provide the following information:
    • Part body and pins dimensions
    • Internal electrical description
    • Pin numbers and polarity
      (The pin numbering on the data sheet must match the netlist provided!)
  • Placement guidelines:
    • Block diagram
    • Suggested placement if available
    • Height restrictions
    • Keep outs
    • Parts grouping and associations
  • Special routing instructions:
    • Controlled impedance lines
    • High current lines
    • Clock lines
    • Shielded lines
    • Length controlled lines
    • Matched length lines
    • Differential pairs
    • Connection sequences
    • Noise sensitive lines
    • Special lines to layer assignment
  • Applicable documents if different than IPC-2221
  • Layer stackup requirement
  • Any other information, documents, samples, etc. that can help us better understand the nature of the project and its requirements

• Question 4. Can you also build the boards for us?

  Yes, we have various subcontractors on our AVL.

  We can provide partial and full turnkey services for PCB fabrications, components kitting and PCB assembly.

  We support quickturn prototypes as well as scheduled production.

  Please note on purchase order when only customer approved special process suppliers can be used.

• Question 5. What if, after the layout started, we find that we have design changes?

  Most projects have design changes. The quote price provides for some design changes (8 hours, or 10% of the quoted hours, whichever is less). Changes beyond what is included are charged based on our hourly rate.

• Question 6. How does the design process progress?

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• Question 7. What standards are used for layout?

  Unless otherwise instructed, Largo will follow the standards published by the Association of Connecting Electronics Industries (IPC).
  IPC-2221A is the main standard. Other IPC standards are used for different aspects of the design, like footprints creation, impedance calculations, current carrying capacity and so on.

• Question 8. What CAD Tools do you use?

  We use Cadence Allegro, Mentor Graphics Expeditions and Altium Designer.

• Question 9. Do you accept credit cards?

  Yes, we accept Visa and Master Card.
  A 3.5% processing fee will be added to invoice paid by credit card.