PCB Tech - Software QUICKPCB 2005 V3.0 and PCB ground wire technology

1. The motherboard copy software QUICKPCB 2005 V3.0 is recommended

The software conforms to the operating habits of most designers, can greatly improve the efficiency of the motherboard, and reduce the testing pain of the operator.

The one-time pass rate of plate reading can further ensure the software function and usage introduction:

Place pad, hole, line, arc, hole, component, fill, POLYGON, text;

Each element attribute setting, grid setting;

The CTRL key automatically captures the grid and element center;

Shift key selection, selection, cut, copy, delete, rotate, mirror and repeat functions;

32-layer setting function, zoom display;

Set the origin at any point;

Design accuracy: 1mil;

With its own b2p format, you can read bmp, jpg pictures, and can automatically read the resolution of bmp.

Call Protel2.5-2.8 to format the component library file

Output protel2.5-2.8 format files.

Introduce the new functions of the software (V3.0):

Added the function of setting any blind and buried holes.

Added the function of creating a component library;

Added the function of self-made components;

Added the function of vector characters.

2. PCB board power cord and ground wire processing technology

In the PCB board wiring, the processing of power lines and ground lines is very important. It is necessary to minimize the noise interference caused by power lines and ground lines to ensure the quality of the product.

The wiring rules for the power cord and ground wire are as follows. ·

Add a decoupling capacitor between the power supply and ground. ·

Widen the power line and ground width as much as possible, preferably the ground line is wider than the power line. ·

The digital circuit PCB board can use a wide ground wire to form a loop, that is, form a grounding network for use. The analog circuit cannot use this method. ·

Use a large area of copper as a ground wire, connect it to the ground as a ground wire on the printed circuit board in an unused place, or be made of a multilayer board, power supply and ground wire, each occupying one layer.

Inspection rules

After the wiring design is completed, it is necessary to carefully check whether the wiring design complies with the rules set by the designer, and confirm whether the rules set meet the needs of the printed board production process. Generally, check the following. aspect. ·

Whether the distance between wire and wire, wire and component gasket, wire and penetration hole, component gasket, through hole, through hole and through hole is reasonable, and whether it meets the production requirements.

Regardless of whether the width of the power line and the ground line are appropriate, whether the power supply and the ground line are tightly coupled (low wave impedance), there is still a place to widen the ground line on the PCB.

Whether the best measures have been taken for the key signal lines, such as the shortest length, adding protection lines, and clearly separating the input lines and output lines. ·

Whether the analog circuit and digital circuit part have their own independent ground wires. ·

Whether the graphics (such as icons, annotation labels) added to the PCB board will cause signal short circuits. ·

Modify some ideal linearity. ·

Whether there is a production line on the PCB, whether the resistance welding meets the requirements of the PCB production process, whether the resistance welding size is appropriate, whether the character mark is pressed on the equipment pad, etc. ·The outer frame of the power layer in the multi-layer board is reduced. For example, the copper foil exposed to the power supply is easy to cause a short circuit.