PCB design process [PCB design]
Update date：2012-8-3
Many people, especially novice PCB design is how designed, and PCB design process.
A planning board
Before drawing the printed circuit board, the user must be on the circuit board used in the initial planning. Such as the use of a single panel, double sided or multilayer circuit board, circuit boards require much size, what kind of connectors, components, what kind of package, dual in-line or surface-mount form, components of the installation location and so on. This is a very important, it directly affects the conduct of follow-up. If a problem occurs, is likely to have the work behind a lot of trouble, and even make the design work can not continue.
(2) set the parameters
Protel PCB editor is started, the user must first component layout parameters, the parameters of the lamellar wiring parameters appropriate settings. Some majority can directly use the system default values, some parameters must be modified according to design requirements, and some parameters can be set according to user habits.
(3) Import the netlist and component packaging
This step is a very important part of the design. The front has repeatedly stressed that the netlist is an important part of the wiring schematic editing environment with the printed circuit board design software interfaces and bridges. For each load component must also have the corresponding shape of the so-called package, wiring indispensable. Even package instructions included in the netlist file. Therefore, only after the load of the network table and components package f can be printed circuit board wiring work.
Layout and placement of components
Set the size and shape of rape board and load the netlist, the program will automatically load the components, components and automatically arranged on the circuit board within the boundaries. Although the program can automatically depending on where the form factor of the circuit board layout good components, but after all, can not fully meet the design requirements, so the user but also the location of the components for manual adjustment, in order to smoothly carry out the following wiring. Closely related to the layout and placement of components, wiring focus on the overall wiring refer to the details. Layout have a large impact on the complexity of the circuit wiring, and also reflects the level of the entire PCB design.
5 Cabling
Wiring of automatic routing and manual routing in two ways, automatic routing using Protel software features automatic routing, so that all of the electrical network linking; manual wiring is to use the connection tool alignment, and complete the electrical connection. Protel's automatic routing feature is very powerful, as long as the variety of the majority of settings are reasonable, the layout of the components properly, automatic routing success rate of close to 100%. However, due to the limitations of the algorithm and the special requirements of users or habits, automatic routing is often much to be desired, the designer must also be adjusted by hand. Hand-wiring, there are many vital tips leather pinched by hand wiring techniques be considered truly learned the printed circuit board design.
6 Comparison of the network table
In general, the circuit board and the principles drawn diagram in accordance with the principle of the imported netlist diagram is consistent; However, in order to be safe can be PCB generated netlist and schematic netlist compare, to see if exactly the same. If exactly the same, just check the schematic can be concluded that the correctness of the design, the PCB only with its production process related.
7 Save the result output
The design is complete, saving the document should be saved, and print the results of processing all questioning and inspection, in addition to PCB files (preferably Gerber production files) to the PCB manufacturer to produce circuit boards.
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