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Welcome to the LEA KiCad library

This repository contains a KiCad library for symbols, footprints and 3D-models including mouser material numbers to auto-generate BOMs (bill of materials) by using KiCost.

Features:

  • Reviewed symbols and footprints trough pull-requests,
  • all symbols are hard linked to a footprint, this avoids miss matching symbol and footprint,
  • symbol names follow a type code, for improved searchability,
  • symbols containing mouser material numbers to auto-generate a BOM using KiCost,
  • using KiCost together with this library can make requests to mouser, to see if all PCB components are on stock.

Install the library

Set library file path

Add this library to your project. Make sure that you use exactly the same Nicknames as shown here:

  • Preferences -> Manage Symbol Libraries -> Project Specific Libraries: Nickname: LEA_SymbolLibrary, Library Path: your/path/LEA_KiCad_Library/LEA_Symbol_Library/LEA_Symbol_Library.kicad_sym
  • Preferences -> Manage Footprint Libraries -> Project Specific Libraries: Nickname: LEA_FootprintLibrary, Library Path: your/path/LEA_KiCad_Library/LEA_Footprint_Library.pretty

It is also possible to add both libraries to the Global Libraries.

Set environment variable for 3D models:

In the KiCad main menu, first select Preferences and then Configure Path. Replace the environment variable MODEL_3D with the current location of the 3D-models, e.g. /path/LEA_KiCad_Library/LEA_3D_Models. This should be the 3D-models for the LEA_KiCad_Library repository.

Note: if there is a variable KICADx_3DMODEL_DIR, ignore this variable and add MODEL_3D as mentioned above.

Using the library

Adding components

The main branch is protected. To add new components, open a new separate branch

git branch my-new-branch

Open KiCad, add your new symbols and footprints to the library. Each symbol should have the keys Manufacturer, manf# (manufacturer order number) and mouser# (mouser order number). Link the footprint and the 3D model. The 3D-model file path needs to be a relative path with the above mentioned environment variable. The 3D file path is e.g. ${MODEL_3D}/my3dmodel.stp. Run git status to see your changed files. Add the example files symbolfile and my3dmodel.stp to the staging area and commit the changes. Afterwards, use git push to publish the changes to the new branch.

git add symbolfile my3dmodel.stp
git commit -m "add new component xyz and 3D-model"
git push

Open the GitHub page, choose your branch and create a pull request.

BOM generation

The component library is aligned to use the add-on KiCost. Therefore the above mentioned keys Manufacturer, manf# and mouser# are mandatory in the symbol. In the schematic, navigate Tools -> create BOM and run a random one, e.g. bom_csv_grouped_by_value. Install KiCost, navigate via terminal to your KiCad project folder and enter kicost to your terminal. As input file, choose the .xml file what was created by the BOM command. After that, the KiCost BOM will be created. To get the prices and stock information from Mouser, create a Mouser API key on the Mouser homepage and enter it into the configuration file.

Pin labels

Connectors

  • All pins should be passive (no power or bidirectional, as the usage changes from schematic to schematic)

Library type labels

For a better findability and sorting of the many components, it is necessary to use a type code. Some examples are given here.

SMD resistors

Differences:

  • Type: SMD / THT
  • Values: _100R / __4R7 / 0R001
  • Size: 0603 / 0704 / 0403
  • Technology: Thin film _THIN / Thick film THICK
  • HINT: e.g. SHUNT
  • Derivation in percent: _1P / _5P / 10P / 20P
  • Voltage: 75V / 100V

Examples:

  • R_0805_100R__THIN_20P_150V
  • R_0603_100R__THIN__1P__75V
  • R_0403__4R7_THICK_10P__50V

THT resistors

Differences:

  • Values: _100R / __4R7 / 0R001
  • Size: 0603 / 0704 / 0403
  • Derivation: _1P / _5P / 10P / 20P
  • RM: _RM5 / RM10 / RM12
  • HINT: e.g. SHUNT

Examples:

  • R_THT_0704__RM5_10P____1k
  • R_THT_0704_RM10__1P_0R001_SHUNT

Capacitors

  • Type: SMD / THT
  • Values: 100u / 4u7 / 10n
  • Size: 0603 / 0704 / 0403
  • Voltage: 25V / 100V / 600V

Examples:

  • C_SMD_0603_100V__1u0
  • C_SMD_0805__25V__10u
  • C_SMD_1206__16V__4u7

Diodes

  • Start with D_
  • Housing: 0603 / 0704 / 0403 / SOD / DFN / SMB / ...
  • Current capability: 1A0 / 0A125 / ...
  • last key: exact type, e.g. B140HW-7 / TS4448_RGG / ...

Examples:

  • D_0603_0A125_TS4448_RGG
  • D_SOD_1A0_B140HW-7

Drivers

Hard to find general rules.

  • Channels: Single/ Dual

Examples:

  • Driver_Dual_TI_value
  • Driver_Single_TI_value
  • Driver_Single_TI_value

Microcontrollers

Examples:

  • uC_FPGA_

Logic ICs

Schmitt-trigger

Examples:

  • ST_6CH_CMOS_SOIC14_MC74HC14ADG

Checklist Layout order

Schematic

  • generate BOM, check if all components are available using KiCost
  • all potentials have a NetClass
  • free of failures and warnings using Electrical Rules Checker (ERC)

PCB

  • fiducials (2 on top layer, 2 on bottom layer)
  • spacing rules generation using KiClearance
  • free of failures and warnings in Design Rules Checker (DRC)
  • For double-sided SMD assembly: Two edges should each have 2 mm space so that the PCB can be placed in the corresponding holder during the vapor phase.

Ordering process

  • Stencil: Pad reduction of 10 %
  • Stencil: The edge of the stencil must be 30 mm on both sides to ensure that it can be clamped in the stencil printer.