Successfully Managing a PCB design/build project
(A two system approach)



The mission of ENGINEERING GRAPHICS is to produce the highest quality printed circuit layouts and prototype boards in accordance with their client's schedule and budget. The company has perfected systems complete with written procedures that supports this mission and assists in managing each project to ensure a complete understanding of the customer's requirements. The goal of this organization is to exceed their client's highest expectations. The staff at ENGINEERING GRAPHICS assumes full responsibility for clear and precise communications with their customers.

This document provides a general description of the six phases and their related documentation requirements on a typical design/build project. It is intended to familiarize the client engineer with the design process at ENGINEERING GRAPHICS and to enhance the communication between the design service bureau personnel and the cognizant client engineer.

ENGINEERING GRAPHICS has perfected two unique systems to handle the client's printed circuit board requirements. Throughout this document the terms "FAST TRACK" and "TLC" (Total Layout Collaboration) will be used to differentiate these systems. FAST TRACK service will produce printed circuit prototypes in the shortest possible timeframe. Formal approvals are waived and absolute minimal fabrication documentation is created. The FAST TRACK system produces bare board prototypes from schematic sketch in usually 3 to 5 days. Fast tracking is reserved strictly for "down 'n dirty" prototypes. It is rare that FAST TRACK circuit boards will move directly into production. Conversely, the TLC system provides various checkpoints and client approval cycles prior to the generation of complete formal fabrication and assembly documentation along with the construction of fully assembled prototype printed circuit boards.


Preferred documentation (when conveniently available):


* Board size.
* "Back-of-napkin" schematic sketch.


* Board size.
* Parts list (BOM).
* Schematic diagram and netlist (if available).
* Technology description (SMT, ECL, FLEX, etc.).
* Layer pairing.
* Controlled impedance considerations.
* Mandatory component placement.
* Component placement restrictions.
* Special routing requirements.
* Test point requirements.
* ATE file formatting.
* Client PCB layout specifications.



Required documentation:


* Purchase Order number.
* Board outline sketch.
* Schematic sketch and/or netlist.



* Mechanical drawing dimensioned to show overall board size, mandatory component locations, mounting holes, and any "off grid" features.
* Hard copy schematic diagram pinned and gated.
* Netlist file in ASCII format.
* Bill of materials.
* Manufacturer data sheets for all components not currently in EG library.
* Formal purchase order.



After all necessary data has been received and processed, the board parts placement will be completed, a complete mechanical review is performed by the Technical Services Manager, and the following items sent to the client for approval:


* E-mailed scaled pdf drawing of placement.



* Placement and fabrication plots including fabrication notes in your choice of format (see below).
* Critical routing plots: Showing locations and size of any special routing considerations such as; clock lines, differential pairs, impedance matching, and high current conductors, etc in your choice of format (see below).
* Density analysis Layer count.
(a) scaled paper plots
(b) dxf or dwg files (graphics only)
(c) pdf files
(d) gerber files



At the completion of board routing and clean up, the Technical Services Manager scrutinizes the layout for any breach in specifications. Once he is satisfied that the layout is in accordance with generally acceptable design standards and meets the needs of the client, the following items will be sent to the client for approval:

FAST TRACK: (approvals are waived)


* Multi-color check plots of all layers, fabrication dwg and assembly dwg in your choice of formats:
(a) scaled paper plots
(b) dxf or dwg files (graphics only)
(c) pdf files
(d) gerber files
Along with any other document that you require at this time (see the design outputs section).



After routing approval is received and any necessary client-incurred revisions are incorporated, all manufacturing documentation is generated. Using an extensive checklist, the Technical Services Manager reviews all aspects of the design and documents any discrepancies for the designer and project file. After all revisions are made, the design is back-checked and the following documentation package is created:


* Photoplot files.
* Apertures lists.
* NC drill data.
* Drill plot.


* Photoplot files, RS274X format.
* Apertures lists.
* NC drill data.
* Formal fabrication drawing - PDF, Gerber, or DXF (graphics only).
* Formal assembly drawing - PDF, Gerber, or DXF (graphics only).
* Test point files (if required).
* Autoplace files in excel format (if required).
* Specific output files (see the design outputs section).
* CAD database.



If prototype fabrication and assembly are part of the order, the manufacturing of the prototypes to IPC standards will commence immediately after the design package is completed, unless otherwise instructed by the client.




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