User Guide

You should not draw any objects in layer 17, Pads, or 18, Vias! They will
not be recognized, nor by the DRC, neither by polygons drawn in the lay
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out,andcanleadtoshortcircuits!
For a SMD resistor, select SMD, and set the pad dimensions in the pa
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rameter toolbar. You can either select one of the offered values, or di
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rectlytypethelengthandbreadthintotheentryfield.
SMDcommand:Parametertoolbar
All properties can be altered after placement using the CHANGE com
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mandorbytypingthecommanddirectlyonthecommandline.
Select To p as the layer, even if the component will later be placed on the
underside of the board. SMD components are located on the other side
of a board using the MIRROR command. This moves the elements in all
the t..-layersintothecorresponding b..-layers.
Place the two SMD pads (which in EAGLE are just called SMDs) at the
desired distance. It may be necessary first of all to alter the grid setting
to a suitable value. The SMD can be rotated with the right mouse button
beforeitisplaced.
The parameter ROUNDNESS specifies whether the corners of the
SMDs are to be rounded. By default this value is set to 0% (no round-
ing). This value is usually kept, since the final roundness of SMDs is
specified in the Design Rules. The help system provides you with more
informationaboutthisparameter.
The INFO command provides you here with a quick summary of the cur
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rentpropertiesofaSMDorpad.
PadName
You can now enter the names, such as 1 and 2, for the pads or SMDs us
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ingtheNAMEcommand.
Silkscreenand DocumentationPrint
Now use the WIRE command to draw the silkscreen symbol in layer 21,
tPlace. This layer contains what will be printed on the board. It is up to
you how much detail you give to the symbol. Set a finer grid size if it
helps.
Take the information provided in library.txt as a guideline for the design
of components.. The line thickness for the silk screen is usually 0.01
inch(0.254mm).
You can also use the ARC, CIRCLE, RECT and POLYGON com
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mandstodrawthesymbolsforthesilkscreen.
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ComponentDesignExplainedthroughExamples