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What is the standard for setting the line width and line spacing of the board?

What is the standard for setting the line width and line spacing of the board?

The signal line that needs to be impedance should be set strictly according to the line width and line spacing calculated by the stack. For example, RF signal (conventional 50R control), important single-ended 50R, differential 90R, differential 100R and other signal lines, through the stack can calculate the specific line width line spacing (below)

The line width and line spacing of the design should consider the production process capability of the selected PCB production factory. If the line width and line spacing are designed to exceed the process capability of the cooperating PCB manufacturer, it is necessary to add unnecessary production costs, and the design will be caused by the design. Unable to produce. Under normal circumstances, the line width is controlled to 6/6mil, and the via is 12mil (0.3mm). Basically, more than 80% of PCB manufacturers can produce it with the lowest cost. The line width is controlled to a minimum of 4/4mil, and the via is 8mil (0.2mm). Basically, more than 70% of PCB manufacturers can produce it, but the price is slightly more expensive than the first case, not too expensive. The line width is controlled to a minimum of 3.5/3.5mil, and the via is 8mil (0.2mm). At this time, some PCB manufacturers can’t produce it, and the price will be more expensive. The line width is controlled to a minimum of 2/2mil, and the via is 4mil (0.1mm, which is usually a HDI blind buried hole design, which requires laser via). At this time, most PCB manufacturers can’t produce the price, which is the most expensive. of. The line width line spacing here refers to the size between the line to the hole, the line to the line, the line to the pad, the line to the via, the hole to the disk and the like.

Set the rules to consider the design bottlenecks in the design file. If there is a 1mm BGA chip, the pin depth is shallow, only one signal line needs to be taken between the two rows of pins, which can be set 6/6mil, the depth of the pin is deep, and two pins need to be taken between the two rows of pins. The signal line is set to 4/4mil; there is a 0.65mm BGA chip, generally set to 4/4mil; there is a 0.5mm BGA chip, the general line width line spacing must be set to 3.5/3.5mil; there is a 0.4mm BGA Chips generally need to do HDI design. Generally, for the design bottleneck, the area rule can be set (for the setting method, see the end of the article [AD software setting ROOM, ALLEGRO software setting area rule]), the local line width is set to a small point, and the other rules of the PCB are set larger for production. Improve the PCB pass rate.

4月-10-2019

FASTPCBA