PCB News - Common precautions for pcb technology

1. Common errors in schematic diagrams:

(1) There is no signal connected to the ERC report pin:
a. I/O attributes are defined for the pins when the package is created;
b. Inconsistent grid attributes are modified when components are created or placed, and the pins and wires are not connected;
c. When creating the component, the pin direction is reversed, and the non-pinname end must be connected.
(2) The component went out of the drawing boundary: no component was created in the center of the diagram paper of the component library.
(3) The network table of the created project file can only be partially imported into the PCB: when the netlist is generated, global is not selected.
(4) When using multi-part components created by yourself, never use annotate.
2. Common errors in PCB board:
(1) It is reported that NODE is not found when loading the network:
a. The components in the schematic diagram use packages that are not in the PCB library;
b. The components in the schematic diagram use packages with inconsistent names in the PCB library;
c. The components in the schematic diagram use packages with inconsistent pinnumbers in the PCB library. Such as triode: pin in sch
The number is e, b, c, and the PCB is 1, 2, 3.
(2) It can't always be printed on one page when printing:
a. It is not at the origin when creating the PCB library;
b. The component has been moved and rotated many times, and there are hidden characters outside the boundary of the PCB board. Select to show all hidden characters, zoom out
PCB, and then move the character to the boundary.
(3) The DRC reporting network is divided into several parts:
Indicates that this network is not connected. Look at the report file and use CONNECTEDCOPPER to find it.
In addition, remind friends to use WIN2000 as much as possible to reduce the chance of blue screen; export the file several times to make a new DDB file,
Reduce the file size and the chance of PROTEL deadlock. If you make a more complicated design, try not to use automatic wiring.

In PCB design, wiring is an important step to complete product design. It can be said that the previous preparations are done for it.
In the entire PCB, the wiring design process has the highest limit, the finest skills, and the largest workload. PCB wiring has single-sided cloth
Wire, double-sided wiring and multilayer wiring. There are also two ways of wiring: automatic wiring and interactive wiring.
Before, you can use interactive to pre-wire the more stringent lines, and the edges of the input end and the output end should be avoided adjacent
Parallel to avoid reflection interference. If necessary, the ground wire should be added for isolation, and the wiring of two adjacent layers should be perpendicular to each other, and it is easy to be parallel.
Generate parasitic coupling.

The layout rate of automatic routing depends on a good layout. The routing rules can be preset, including the number of bending,
The number of vias, the number of steps, etc. Generally, explore the warp thread first, connect the short threads quickly, and then carry out
In labyrinth wiring, the wiring to be laid is first optimized for the global wiring path, and it can disconnect the laid wires as needed.
And try to re-wire to improve the overall effect.

The current high-density PCB design has felt that the through-hole is not suitable for it, and it wastes a lot of valuable wiring channels.
To resolve this contradiction, blind via and buried via technologies have emerged, which not only fulfill the role of vias, but also save many wiring channels
Make the wiring process more convenient, smoother and more complete. The PCB board design process is a complex and simple
If you want to master it well, you still need a large number of electronic engineering designers to experience it yourself, and then you can get the truth.
meaning.

The above is an introduction to the common precautions of PCB technology. Ipcb is also provided to PCB manufacturers and PCB manufacturing technology.