Analysis of common mistakes in PCB design and schematic drawing

- Sep 13, 2017-

In the PCB design, wiring is an important step of product design, it can be said in front of the preparatory work is done for it, in the whole PCB, wiring design process maximum limit, the maximum workload, fine skills. PCB wiring has one side wiring, double sided wiring and multilayer wiring.

There are two kinds of methods: automatic wiring wiring and interactive wiring, in the automatic wiring before, to more stringent requirements for interactive pre wiring line, input and output lines should be avoided so as to avoid the interference of adjacent parallel.

If necessary, the ground wire shall be isolated, and the wiring of the two adjacent layers shall be perpendicular to each other and parallel to each other, so that parasitic coupling is easy to occur.

1.PCB schematics common mistakes:

(1) the ERC report pins do not have access signals:

When A. creates a wrapper, the I/O attribute is defined to the pin;

When B. creates components or puts elements, the inconsistent grid attributes are modified and the pins are not connected to the wires;

When C. creates components, the pin reverses direction, and must be non pin name end connections.

(2) components went to the drawings profession: failed to create a component in the component library graph paper center.

(3) the construction file network table can only be partially transferred to PCB: when generating netlist, there is no selection for global.

(4) do not use annotate. when using components that you create

Common errors in 2.PCB:

(1) report NODE is not found when network is loaded:

The components in the A. schematic use a package that is not available in the PCB library;

The components in the B. schematic use a package that does not have a different name in the PCB library;

The components in the C. schematic use an inconsistent package of pin number in the PCB library. Such as triode: Sch in pinnumber, e, B, C, and PCB in 1, 2, 3.

(2) printing can not always be printed on one page:

A. did not create the PCB library at origin;

B. multiple moving and rotating components, the PCB board has a hidden character out of bounds. Select to display all hidden characters, reduce PCB, and then move characters to the border.

(3) the DRC report network is divided into several parts:

Indicates that the network is not connected. Look at the report file and use the select CONNECTEDCOPPER lookup.

In addition to remind friends to make use of WIN2000, reduce the chance of a blue screen; several export documents into the new DDB file to reduce the file size and PROTEL dead opportunity. If you have a more complicated design, try not to use automatic routing.

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