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When we begin your project, there will be many questions we'll have to ensure you get the best product in the most timely manor. The more information that is handed off up front, the fewer questions and delays there will be later on.  The following list might also spark some internal questions that you haven't considered yet.  Let's get started.

For Simple Boards - Most of the things listed below will not apply, but it might be a good idea to read through the list anyway.

 

 

 

  1. General Information:
    1. Project Name:
    2. Board Name:
    3. PWB Number / Fab Drawing Number (if different)
    4. PCB Assembly Number / Assembly Drawing Number (if different)
    5. Schematic Drawing Number
    6. Bill of Materials (BOM) Number
    7. Assembly Panel Number / Panel Drawing Number (if different)
  2. Mechanical
    1. Board Dimensions and Thickness (include tolerances)
    2. Mounting and Tooling holes: locations and sizes (include tolerances)
    3. Locations of critical components
      1. Connectors
      2. LED's
      3. Switches
      4. Tall components
      5. Heatsinks
      6. Others ...
    4. Max Component Heights
      1. Top Side
      2. Bottom Side
    5. Keepouts
      1. Components
      2. Copper
      3. Traces / Etch
      4. Vias
      5. Component height restriction
    6. Components requiring special clearances
      1. For Heatsinks
      2. For Sockets: programming , emulator,  etc...
      3. For SIMM or DIMM modules
      4. For large mating connectors
  3. Electrical
    1. Expected number of layers
    2. Stackup:
      1. Is there an existing one?
      2. Do you need us to generate one?
    3. Copper weights per layer
    4. Board Technology
      1. Thru Hole
      2. SMT
      3. Blind / Buried Via technology?
      4. HDI or Sequential Lamination?
    5. Please list any Noisy or sensitive nets or buses
    6. List any components that will not be on production boards
      1. Test / Debug Headers
      2. Sockets
      3. Others ....
    7. Do you desire the outer layers to be flooded with copper for shielding?
    8. Grounding scheme
      1. Signal ground
      2. Earth ground
      3. Safety Ground
      4. Analog and Digital ground
    9. Do the mounting holes need to be tied to ground? If so, which one?
  4. High Speed Requirements
    1. Single ended impedance requirement
    2. Diff pair impedance
    3. Special dielectrics
    4. Buried Capacitance
    5. Clock Speeds
    6. Special Rules
      1. Delay
      2. Matched Delay
      3. Relative Propagation Delay
      4. Max Via Count
      5. Max Stub Lengths
      6. Nets and Topologies
    7. Ground Stitching at board edge
    8. Crosstalk limits or concerns
    9. Are there buses or nets that must or can't reference a particular voltage?
    10. Hand Routing critical nets or net priorities
  5. Thermal
    1. Specify Air flow direction
    2. Copper Areas for thermal dissipation
    3. Heatsink requirements
    4. List of the hot parts so we won't place them downstream
  6. Power and Planes
    1. Input Voltage.  Is it high voltage?
    2. Do you have a preference on what supply voltage goes on what layer?
    3. For Split planes, do you have an idea of what voltages to combine on a layer?
    4. Are there any high current nets? How many Amps?
    5. List any special Creepage & Clearances
  7. Panel Layout
    1. Panel Tooling Holes: size and locations
    2. Panel Fiducials: size and locations
    3. Depanalization scheme
      1. V-Score with pizza cutter
      2. breakaway tabs, mouse bites, dog bones
  8. Manufacturing and Assembly
    1. List any Special Silkscreen
      1. Logos
      2. Assembly number and Box for dash numbers
      3. Serial Number Outline
      4. LED Labels
      5. Voltage labels
      6. HIGH VOLTAGE or WARNING labels
      7. Switch, Reset, Dipswitch, Jumpers, Programming, etc..
    2. Wave solder
      1. Direction if bottom side parts will be waved
      2. Will a Selective Solder Pallet be used
    3. Notes
      1. Special Fab notes
      2. Special Assembly notes
    4. Special Details on Assembly Drawing
    5. A list of all names and positions to be on the drawings. Here are some options:
      1. Electrical Engineer
      2. Mechanical Engineer
      3. Compliance / Safety
      4. Manufacturing Engineer
      5. Project Engineer
      6. Power Engineer
      7. CAD Engineer - That's us :-)
    6. Surface Finish
      1. HASL
      2. Silver
      3. Gold
      4. White Tin
      5. Other ...
    7. Special Soldermask or Silkscreen colors (default is green mask and white ink)
  9. Test Strategy
    1. Do you need test points for ICT Fixture (bed of nails)?
    2. Do you need test points for flying probe?
    3. Do you require 100% TP coverage?
    4. Is JTAG and Boundary Scan in the test plan?
    5. Are there nets that will not require test access?
  10. Files we will need
    1. Netlist
    2. Datasheets for anything that is not standard (0603, so-8, etc..)
    3. Mechanical drawings
    4. Schematic in .pdf format (notes or instructions can be on the schematic)
    5. A block diagram showing basic functionality, data flow, and clock trees can be helpful

Extra Notes:

Decoupling:

It's makes much easier reading if the decoupling for specific devices is placed on the same sheet as (or preferably next to) the device it is intended for. Where a great deal of decoupling is needed, and space is an issue, then we sometimes use a separate sheet with some text indicating which device the decoupling is for. General board decoupling is marked as such.

These are just examples but a well marked-up schematic can greatly improve and speed up the whole design.

Junctions:

Steering clear of cross-junctions will help eliminate possible misunderstandings.

e.g.

we don't we do
we don't we do

PCB Layout

PCB layout is where we excel, we have extensive experience in a wide variety of technologies and sectors.

Design Types:

  • Analog
  • Digital
  • High Speed Design
  • High Power
  • High Voltage
  • Low Power

PCB Types:

  • Flexi PCB
  • Flexi-rigid PCB
  • Rigid PCB
  • Thick Film PCB
  • Aluminium backed PCB
  • Ceramic PCB
  • Hybrid PCB

PCB Component mounting strategies:

  • Single sided Through Hole PCB's
  • Single sided Surface Mount PCB's
  • Single sided Mixed Technology PCB's
  • Double sided Mixed Technology PCB's
  • Double sided Surface mount PCB's

 

We also have a great deal of experience with:

  • Single layer PCBs
  • Multi layers PCBs
  • Matched length designs
  • Differential pairs
  • High Density Interconnects (HDI)
  • High layer count designs
  • Blind vias, buried vias, and micro-vias
  • Back Planes
  • Design for Test (DFT)
  • Lead Free
  • EMC Critical Designs

Reverse Engineering:

We understand that sometimes all you have available from an old design are Gerber files, and you could really do with making some changes to the PCB.

Perhaps:

  • Component obsolescence is forcing you to choose another device.
  • Cheaper components are available and will improve your profit margin.
  • Manufacturability needs improving.
  • Additional functionality is needed.

Whatever the reason we can help. We can take your Gerber files and reverse engineer them back into intelligent design format, allowing your changes to be made. If required we can also create a set of schematics from this, and generate a full documentation package including new Gerber files, ODB++, BOM etc…

We can also create custom outputs and reports tailored to your needs.

 

Trident-Enterprises

 

 

   

 

 

 

 

Last updated: 04/15/2009