Summary
This video demonstrates using Inkscape with the svg2shenzhen plugin to create Printed Circuit Board (PCB) designs for export to KiCad. It covers the fundamental layers of a PCB, including fiberglass, copper, solder mask, and silkscreen. The presenter shows how to draw custom shapes in Inkscape, representing different PCB layers like edge cuts and copper traces, and then export them to KiCad for further refinement and visualization using the 3D viewer. The process allows for creative PCB design, pushing manufacturing limits.
Key Insights
The svg2shenzhen plugin enables PCB design in Inkscape, exporting to KiCad.
The svg2shenzhen plugin, a fork of KiCad's bitmap-to-component tool, allows users to draw PCB designs within Inkscape and export them for use in KiCad. It processes Inkscape drawings to create different PCB layers.
The svg2shenzhen plugin offers a creative, direct way to design PCBs for those who prefer graphical tools.
This plugin, developed by 'ioc aka bad geek', provides a desired workflow for users who enjoy graphical design tools like Inkscape for creating PCBs. It's presented as an accessible and enjoyable method for PCB design, encouraging support for the developer via Patreon if users find value in it.
Sections
PCB Layer Overview
PCBs are built on a base layer, commonly FR4 fiberglass, with copper layers on top.
The base layer of a PCB is typically made of FR4 fiberglass, available in various thicknesses, with 1.6mm being the most common. Other substrates are also available, but FR4 is standard. Layers of copper are then applied on top of this base layer, and the PCB manufacturing process involves etching this copper to achieve the desired circuit design.
Industrial PCBs involve multiple copper and fiberglass layers, with precise drilling.
In the industrial PCB manufacturing process, multiple layers of copper and fiberglass are stacked. This structure requires accurate drilling to create connections between layers. The process also incorporates a solder mask layer, which provides color and protection, and a silkscreen layer for component references and information.
Solder mask defines the PCB's color and protects copper, while silkscreen adds information.
The solder mask layer gives PCBs their typical color, which can be varied. Transparent masks are also possible. Multiple masks can be used for complex color effects but increase cost. The silk screen layer is for information, usually white text on green boards, displaying component references or personal touches. While many drill sizes exist, manufacturers prefer fewer, standard sizes for simplicity.
Gerber files, which detail all PCB layers, are the standard output for manufacturers.
Manufacturers require Gerber files to produce PCBs, as these files specify all the different layers of the design. KiCad is a software tool that can export designs into these Gerber file formats.
DIY PCB etching can be done by drawing designs on transparencies and using lithography.
For home etching, PCBs can be designed by drawing directly onto transparencies or paper and then transferring the design. This manual method, using lithography, allows for drawing PCBs without specialized software if one is careful about connections and processing. Mark, who runs workshops, scales up components onto transparencies for larger manual drawing/designing.
Manually preparing PCBs for manufacturing is labor-intensive, involving hand-drawing, scanning, and conversion.
Creating PCB designs manually, like the oscillator example provided, can be labor-intensive. This process involves hand-drawing, scanning, and then using tools like KiCad's bitmap-to-component feature to convert the drawn elements into usable PCB layers. This is contrasted with the desire for a more streamlined graphical tool-based process.
Using Inkscape with svg2shenzhen
The svg2shenzhen plugin enables PCB design in Inkscape, exporting to KiCad.
The svg2shenzhen plugin, a fork of KiCad's bitmap-to-component tool, allows users to draw PCB designs within Inkscape and export them for use in KiCad. It processes Inkscape drawings to create different PCB layers.
Inkscape's drawing tool can be used to define the PCB's edge cut layer.
Users start by preparing an Inkscape document, where the grid can be turned off. The edge cut layer is then defined by drawing any shape, such as a spiral or rectangle, which must be combined into a single, connected path for manufacturability. The plugin processes these shapes into the edge cut layer for KiCad.
Unusual or overly tight outlines can challenge PCB manufacturing processes like CNC milling.
Complex or tight outline shapes drawn in Inkscape might not be manufacturable as intended. For example, if the path chosen for the outline is too tight for the CNC mill used by manufacturers, they might attempt to interpret or modify the design, potentially leading to unexpected results. Manufacturers may not always provide feedback on such issues due to the speed and low cost of modern production.
Exporting from Inkscape to KiCad requires awareness of file naming and export options.
When exporting from Inkscape using the plugin, users can choose to output a KiCad PCB design or a module. The export process might require specifying a directory and can be affected by the SVG's saved name; unsaved files default to 'drawing'. If issues arise during export, re-exporting and confirming file overwrites or existence in KiCad is necessary.
Other PCB layers, like copper, are less restrictive in Inkscape than the edge cut layer.
Unlike the edge cut layer, other PCB layers (like copper traces) created in Inkscape are more flexible. Users can draw freely without needing to convert to a single path or worry about colors, as the plugin converts darkness thresholds into copper layers. This allows for more creative freedom when designing traces and patterns.
The exported KiCad design can be visualized in the 3D viewer for design validation.
After exporting the design from Inkscape to KiCad, the result can be immediately viewed in KiCad's 3D viewer. This allows designers to get a quick and direct visual representation of the final PCB, helping to identify potential issues or confirm the design's appearance before manufacturing.
Complex designs can push the limits of PCB manufacturing, sometimes causing issues with CAM software.
Pushing the boundaries with complex or unusual PCB designs, such as the 'PCB ruler' example, can sometimes lead to problems. In one instance, a design was so complex it crashed the manufacturer's CAM software. However, the low cost of modern PCB manufacturing encourages experimentation to test these limits.
The svg2shenzhen plugin offers a creative, direct way to design PCBs for those who prefer graphical tools.
This plugin, developed by 'ioc aka bad geek', provides a desired workflow for users who enjoy graphical design tools like Inkscape for creating PCBs. It's presented as an accessible and enjoyable method for PCB design, encouraging support for the developer via Patreon if users find value in it.
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