![Youtube Inkscape Tutorials Youtube Inkscape Tutorials](http://www.filedudes.com/images/screenshots/inkscape_table_support-23896.jpeg)
Editing an SVG image for a Fritzing part using Inkscape. A PCB can be multi. (Seen by editing the file with a text editor.) This means the drawing.
Introduction This is an incomplete tutorial, a FAQ, and is IN PROGRESS. A specification for an electronic component (part) in Fritzing comprises five files, including several image files in the SVG format. This is about editing an image file for the PCB, the image of a part’s lands on a printed circuit board. The example describes an SMD part. The example file is distributed with Fritzing, at this location on a typical Linux installation of Fritzing: ~/Fritzing/parts/svg/core/pcb/QFN-20-0.4MM_pcb.svg I am not an expert, and this could have mistakes.
Printed circuit board layers A PCB has layers. From the top: • artwork: labels (text and guides) to help solder parts to the PCB • solder mask • top copper • epoxy/glass structure • bottom copper (optional) A PCB can be multi-layer: having additional layers of copper and glass. Fritzing is NOT capable of designing multi-layer PCB’s, only the layers listed above. What PCB layers are represented in a Fritzing SVG file The artwork and copper layers are usually represented. The solder mask is NOT represented. (Fritzing generates it automatically in the PCB view and when going to fab.) The example file includes only the top copper layer, because it is an SMD package. Some SMD parts also require the bottom SMD layer (for heat sinks connected by vias.) Viewing Fritzing PCB layers in Inkscape Inkscape supports layers, but Inkscape layers are not the same as PCB layers.
The example file does not have named Inkscape layers. Instead, the PCB layers are represented as groups ( using the tag.) The groups have ID’s which name the PCB layer: • “copper1” meaning the top or front layer of copper • “silkscreen” meaning artwork To view a PCB layer as a group, select some shape. Inkscape will draw a bounding box that encloses the group of the selected shape.
See elsewhere for instructions on managing groups in Inkscape. (The SVG standard does not define layers, only groups.
Inkscape implements its layers using groups. Other SVG editors may implement layers differently. Thus the disconnect.) Seeing the white artwork PCB layer in Inkscape A PCB artwork layer is traditionally white to contrast with the traditionally green solder mask layer. Unfortunately, the default background color in Inkscape is also white, often hiding the PCB artwork layer. To better see the artwork: • choose View>Display mode> outline. • OR set the documents background color to non-white, opaque (choose File>Document Properties>Page>Background) Following the Fritzing graphics standards You should follow the that Fritzing developers have defined for image files that define a part. The standards define colors, fonts, dimensioning, and so forth.
You should copy an existing image, that already follows the graphic standards. Canvas, document size, page size, and viewbox The canvas is the available drawing area. In Inkscape, it is practically infinite. You can’t set the canvas dimensions.
The document size is the size of the contents, what you have drawn. You can’t set it either, except to draw more, outside the current drawing. The page size helps define how the contents will be paginated when printed to paper. The viewbox defines a mapping between internal coordinates (unitless) to the document size coordinates (in some unit.) In the example file, the document size and viewbox are: width='0.134in' x='0in' version='1.2' y='0in' height='0.134in' viewBox='0 0 9.648 9.648' (Seen by editing the file with a text editor.) This means the drawing describes a part which is 0.134 inches wide, and that an internal coordinate of 9.648 corresponds to 0.134 inches. The units don’t really matter, since all numbers are in floating point.