Sierra Circuits’ PCB Fab and Assembly - Required design data and documentation guide

Oct 28, 2026

Upload by Jacob

A manufacturing-focused design documentation guide explaining how to communicate PCB fabrication and assembly requirements to a manufacturing partner. It covers required design data for PCB fab and assembly, what specifications must be documented, and special manufacturing requirements such as primitive board documentation, stack-up details for standard and HDI builds, controlled-impedance inputs, and impedance-related fab notes. It also outlines component assembly specifications, the design files a contract manufacturer needs, and design testing analysis to support reliable production.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages33

Reading Time1 h 23 min

AccessFree to download

Required design data for PCB fab and assembly

Specifications that need to be documented

Special manufacturing requirements

Component assembly specifications

Design files your CM needs

Design testing analysis

Design Documentation and How to Communicate Design Intent with your Manufacturing Partner 14 December 2022 All Rights Reserved © Sierra Circuits Table of Contents 1. Required design data for PCB fab and assembly 2. Specifications that need to be documented 3. Special manufacturing requirements 4. Component assembly specifications 5. Design files your CM needs 6. Design testing analysis 14 December 2022 All Rights Reserved © Sierra Circuits 14 December 2022 All Rights Reserved © Sierra Circuits Sierra Circuits’ PCB Fab and Assembly Capabilities Required design data for PCB fab and assembly • Documenting your manufacturing requirements ensures a successful production without any shadow of faults • PCB design document integrates the details such as: o Hardware dimensional drawings o Schematic representation o BOM, and layout file o Pick and place file o Assembly drawings o Gerber files 14 December 2022 All Rights Reserved © Sierra Circuits Specifications that need to be documented 14 December 2022 All Rights Reserved © Sierra Circuits Primitive documentation for manufacturing • Mention the class of the board (class 2 or 3) • Include board outline in X-Y coordinates • Specify slots, notches, and cutouts that need to be generated during fabrication • Add the date, version, and the author of the drawing • Company logo and name if required • Clearly mention the orientation of pin 1/ cathode for polarized components 14 December 2022 All Rights Reserved © Sierra Circuits Stack-up information • Stack-up should provide information related to: o Number of signal and ground/power layers o Dielectric spacing and copper weight o Material type o Operating frequency o Sequence of the layers o Finished board thickness • For HDI build-up, additional requirements are: o Type and layer arrangement of microvia o Number of BGAs o Number of lamination cycles 14 December 2022 All Rights Reserved © Sierra Circuits Sierra Circuits’ PCB Stackup Designer 14 December 2022 All Rights Reserved © Sierra Circuits • Includes library of stack-up with single and sequential lamination build-ups (HDI-1, HDI-2, HDI-3, and HDI-4) • Involves a variety of material databases • Automatically chooses the type of board construction • Offers 3 technology levels (level I/II/III) with respect to different parameters such as trace geometry, drill sizes, spacing, and cost index [https://www.protoexpress.com/tools/pcb-stackup-designer/](https://www.protoexpress.com/tools/pcb-stackup-designer/) Controlled impedance details • Your CI data should include: o Target impedance o Trace width/height o Layers on which the impedance traces are present o Spacing between components on controlled traces (for coplanar or differential calculations) o Copper weights, and layer thicknesses o Differential pair spacing • Include CI table to specify SE and differential pair impedance values 14 December 2022 All Rights Reserved © Sierra Circuits Impedance requirements in fab notes Impedance table Sierra Circuits’ Impedance Calculator • Uses 2D numerical solution of Maxwell's equations • Calculates line parameters adding to the characteristic impedance • Determines coupling coefficient, even and odd mode parameters for differential pairs • Assures greater accuracy considering the trace's trapezoidal shape or the effect of multiple 14 December 2022 dielectric materials All Rights Reserved © Sierra Circuits [https://www.protoexpress.com/tools/pcb-impedance-calculator/](https://www.protoexpress.com/tools/pcb-impedance-calculator/)

FAQs

What design data should be provided for successful PCB fabrication and assembly?

Provide complete manufacturing requirements, including hardware dimensional drawings, schematics, BOM and layout files, pick-and-place files, assembly drawings, and Gerber files. Clear documentation reduces the risk of production faults.

Which documentation elements are considered basic for fabrication drawings?

Include the board class (e.g., class 2 or 3), board outline in X-Y coordinates, slots/notches/cutouts, and drawing metadata such as date, version, and author. Add company logo/name if required and specify the orientation of pin 1/cathode for polarized components.

What information is needed for controlled impedance and impedance-related fab notes?

Include target impedance, trace width/height, relevant layers, spacing for coplanar or differential calculations, copper weights and layer thicknesses, and differential pair spacing. Provide a CI table with SE and differential impedance values, plus impedance calculator inputs tied to Maxwell-based line parameter calculations.

Oct 28, 2026

Upload by Jacob