PCB Design: Four-layer PCB Board Drawing Process
2019 04/24
A, four-layer PCB board drawing process:
1. Draw a circuit schematic and generate a netlist.
The process of drawing the schematic diagram involves the drawing of elements and the drawing of packages. It is basically not a problem to master these two drawing schematics. For the elimination of errors and warnings, the general issues should be solved. Complex schematics can be drawn using hierarchical schematics.
Shortcuts used here: CTRL+G (set the grid spacing), CTRL+M (measure the distance between two points)
2, planning circuit board
How many layers should I draw? Is it single-sided or double-sided? What is the board size? and many more
3, set a variety of parameters
Arrangement parameters, slab parameters, basically according to the system default, only need to set a small number of parameters.
4, load the network table and component package
Design ->Update PCB Document USB.PcbDoc
Note: If an error occurs in the drawing of the schematic, but the layout of the PCB has been fixed, and you want to change the error without affecting the PCB layout, then this step is also operated, but in the last Add ROOMS That one before the Add do not check! ! ! Otherwise it will be re-layout, it is painful! !
The network table is the interface between the circuit schematic editing software and the printed circuit board PCB design software. Only after the network table is loaded, the circuit board can be automatically wired.
5, the layout of the components
In most cases it is a manual layout, or a combination of automatic and manual.
If you want to place components on both sides: Select the device and press and hold the left mouse button, then press the L key; or point the component under the PCB interface, and modify the attribute to bottom layer.
note:
The components are discharged evenly for installation, plug-in, and welding operations. The text is discharged at the current character layer, and the position is reasonable. Attention is paid to the orientation to avoid occlusion and facilitate production.
6, wiring
Automatic routing, manual routing (planning layout before wiring, and with the internal electrical layer, and first hide the inner electrical layer for wiring, the inner electrical layer is usually a full piece of copper film, and the same network name with the copper film pad When the internal electrical layer is passed through, the system will automatically connect it to the copper film. The connection form of the pad/via and the internal electrical layer and the copper film and other pads and safety gaps that do not belong to the network can be in the rule. set up.
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