Best Tutorial on Complete PCB Design Process

In this tutorial, we are going to learn about Complete PCB Design Process

  • Project Review – If we start any project then first should take place between all applicable disciplines: like that hardware Engineer, Project Management, Layout, and Mechanical & Manufacturing. Here PCB designer have the most following information needs to be determined such as Layer stack-up & plane layers, PCB thickness & board material, default trace width, component complexity & qty of new components, proto board or production, auto route or manual route, high speed rules, impedance control, testability and Schedule.
  •  All Parts Datasheet – When we start the schematic then all component data sheets prior to the start date of a PCB layout, of all of the components that can’t be located in library.
  • MECHANICAL DATA SHEET – In PCB design mechanical is most important part which provide a Board Outline constraint drawing if one is available/ as soon as possible. The mechanical  drawing should be drawn from the top side, include all mounting holes, fixed connector locations, indicate the Layer Stack-up & board thickness of the PCB. The origin for the constraint drawing should be the lower left mounting or tooling hole.
  • PART NUMBER & BOARD NAME ASSIGNMENT –  When we start the any PCB then there should be first decide the part no. & board name on PCB as per project.
  • LIBRARY MANAGEMENT – When create library parts, there should be proper name of components so that there will not be any confusion when we use the parts in PCB design as per schematic with BOM.
  • CUSTOM BOARD OUTLINE – When we start the any PCB design then first create the board outline as per below steps:
  • Enter the Board Outline.
  • Add all Mounting/Tooling Holes & Fiducially that are necessary then glue them down.
  • Move the Targets to the outer extremities of the board outline.
  • Fully dimension the board edges & at least one mounting hole.
  • Create the “Auto router Keep-in or out” inside the Board Outline.
  • NETLIST – Here below are the point for net-list create in PCB design:
  • At the start of the PCB design, the Research Dept will provide a net list, from the schematic capture tool.
  • The net list should be all of the correct Shape Names.
  • The net list should not contain Pin Names over 4 characters long.
  • There is some common name of components pins such as Collector = C, Emitter = E, Base = B, Anode = A, Cathode = K, Source = S, Drain = D, S= Source and G= Gate, Import the net list into Package. If errors are found, in the net list, the Designer will report them to the Project Engineer. After the net list is successfully imported into layout, the Designer will disperse the parts.
  • Proper Documents –
  • Make the proper folder and review with Project Engineer Unused Pins, Part List 2 & Statistic Reports.
  • PCB Designer must review Unused Pins list for 2 pin components.
  • Project Engineer must review Unused Pins list for possible schematic errors.

  • PART PLACEMENT
  • PCB Designer & Engineer should be have knowledge the part placement or Engineers suggested layout.
  • The placement must meet the design guidelines & design rules. Hardware design engineer will provide the DRC.
  • The placement should be meet all manufacturing requirements.
  • The placement must meet all rout ability requirements.
  • Tools/Verify Design – check clearance to ensure no over lapping parts.
  •  SPLIT PLANES – Always separate the different Plane Nets, or use the Split or Mixed Plane option. Try to Use the Nets feature to discriminate different nets by color.
  • SILKSCREEN – Create Silkscreen (use 0.1mm snap grid) and bottom side etches text. All Reference designators must be moved outside component, & must not exceed 2 different rotations. All company identification & REV Blocks must be placed inside the board outline. Default text height/width is .080”/.008” Minimum height/width is .060”/.006”. All connectors must be text to identify the end-pins. Add connector & jumper text names, if any.
  • SET OF QUALITY CONTROL PRINTS – 1:1 scale Drill & Assembly drawing laser print/bond paper. All new Library Decals must be checked for Solder Pattern accuracy. Print Split Planes if applicable for Project Engineer to check.
  • FINAL PART PLACEMENT – After Split Planes & New library parts are checked, Designer makes final part placement adjustments.PCB Designer will make final silkscreen adjustments.
  • PREPARE LAYOUT FOR TRACE ROUTING – Must be Schematic net list with the PCB Design net list using Net-check Tools.
  • SETUP DESIGN RULES – Setup DRC on “Default Clearance” rules and Setup DRC on “Net Clearance” rules are to be set up for Voltage, GND & Critical Nets. Set class rules for high speed technology.
  • MANUAL ROUTING – Manually Bus route memory sections using Copy or Paste command. Use the manual for all powers that connect to an inner layer plane using Via Share technique. Manually fan out all GND connections so that every GND Pin gets its own Via. Always try to manually route all other Voltages which require large trace widths. Manually route all high-speed matched length traces and critical nets. Use Tools or Verify Design or Check Planes to insure 100% fan out of all SMT Plane Pins. Use design rule check for Clearances to insure no short circuits. If the design is a 2-Layer board, all voltages should be manually routed/Engineers spec.
  • SIGNAL INTEGRITY OUTPUT – Generate a Hyperlink file for signal analysis
  • FIX ENGINEERS RED-LINED PRINTS – Incorporate all of the Project Engineers corrections. If there were many corrections, PCB Designer will create a new set of check prints.
  • Test of PCB:- Hardware Engineer will be responsible for informing the PCB Designer the Testability Rules, early in the Process. This includes the following rules:
  • Every Net need a test point/just some of the nets.
  • Voltage nets require extra test points?
  • Non-connected pins need to be testable?
  • Hardware Project Engineer add selective test points to the schematic?
  • Can vias be used as test points, or do they have to be “Bottom Side” non-drilled Pads?
  • What is size do the test points have to be, what is the point to point spacing requirements & amount of pins per square inch?
  • Are there vacuum requirements for the test fixture?
  • If PCB Design requires testability on every net, the Designer will add a test point for every net, using
  • DFT program & place the test points, near the pins, of the net it belongs to.
  • ROUTE REMAINDER OF NON-CRITICAL ROUTES
  • If the PC Board has a large number of production boards made, it must be 100 % manually routed to reduce trace length, reduce via count and reduce layers.
  • If Engineer requested a quick turn prototype; use an auto router to route remainder of PCB. If auto routing used, clean up the traces on all layers after the router has completed 100%, Make and save a pre-auto routed version of the PCB. This will be use for future revisions.
  • FINAL DRC CHECKS – For final PCB, PCB Designer & Hardware Engineer, Verify Design – Check Clearances, Continuity & Panes.
  • Final Gerber File – final print file of AutoCAD Assembly & Drill Drawings
  •  Final make the Fabrication Data that contains Gerber Data, Drill Data & Fabrication Drawing.  ̈ Import the PADS ASCII file into CAM350 to extract an IPC-D-356 Net-list.
  • Create Assembly X/Y Coordinate Data.

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