PCB News - Allegro's misunderstandings in pcb layout learning

As the saying goes, one skill is in hand, and you have no worries about eating and drinking. The following editor of YJBYS has sorted out the misunderstandings about Allegro in PCB layout learning for everyone, I hope it will be helpful to you.

1. Single panel is easier to make than double panel.

mistaken. It is much more difficult to make a single-sided board in Allegro-PCB Editor than a double-sided board. This is proved by the fact that the layout rate of PCB LAYOUT is very low when using the automatic routing function.

2. The main purpose of ORCAD is to get a beautiful circuit diagram.

mistaken. The purpose of ORCAD drawing is mainly to obtain a network list to prepare for the next printed board design. In fact, it is difficult to obtain a beautiful and national-standard circuit diagram with ORCAD. Many people only know simple drawings. I don’t understand the specifications at all, which brings a lot of inconvenience to PCB design.

3. The package library of components in Allegro-PCB Editor is very comprehensive, and there is generally no need to increase the package library by yourself.

mistaken. There are indeed many components in Allegro-PCB Editor, but they are still a bit less than the many component packages we use. Sometimes an electrolytic capacitor will not find a ready-made package. Therefore, it is common to use Allegro-PCB Editor to design printed boards and add package libraries. Fortunately, it is very convenient to add package libraries in Allegro-PCB Editor. It should be noted here: the package can't just look at the similar appearance. The name of the pad must be the same as the pin name of the component in the schematic, otherwise the pin will be lost or an error will occur when importing the netlist.

4. To use Edit Router for automatic wiring, you must first draw a circuit diagram with ORCAD.

mistaken. Edit Router automatic routing does not require schematic support, not to mention that it cannot be drawn with ORCAD. Edit Router just needs a netlist (.asc) file. The network table can be drawn into a schematic diagram by ORCAD and generated. After understanding the network table, you can also manually compile the network table file.

5. The line laid out with Edit Router's automatic wiring function is definitely correct.

mistaken. The automatic wiring of Edit Router cannot completely guarantee the correctness of the wiring. Sometimes, ‘serious’ errors, such as power supply short-circuits, may be made. After the wiring is completed, a thorough inspection and careful modification must be made.

6. It is more reasonable to use the automatic wiring function of Edit Router to lay out the line.

mistaken. The lines laid out by the automatic wiring function of its practical Edit Router are very messy, and are not comparable to the manual wiring of experienced people, especially the wiring of analog circuits, which almost have to be modified manually. Even full manual wiring can meet the requirements. Automatic wiring is not recommended for PCB LAYOUT training.

7. When wiring in Allegro, you must ‘regularly’ wiring according to the wiring method provided, otherwise you will not be able to get a complete printed board diagram.

mistaken. In fact, as long as you draw a line or put a solder joint in the BOTTOM LAYER or TOP LAYER of Allegro>PCB Editor, this line or solder joint can be made onto the PCB board, no matter how the line is drawn, Or how the solder joint is made, the solder joint can be on a certain component.