PCBNEW: Routing PCBs


Heading:

8 - Routing PCBs

8.1 - Choosing routing parameters and routing a PCB

8.2 - Typical dimensions for different PCB classes

8.2.1 - Track width

8.2.2 - Insulation (clearance)

8.3 - Some typical combinations

8.3.1 - 'Rustic'

8.3.2 - 'Standard'

8.4 - Manual routing


8 - Routing PCBs

8.1 - Choosing routing parameters and routing a PCB

The choice is made in the menu: Dimensions ->Tracks et Vias.

The dimensions are given in inches or mm, depending upon the active units.

Reminder: 2.54 cm = 1 inch (or " ) = 1000 mils = 10000 tenths of mils.

8.2 - Typical dimensions for different PCB classes

8.2.1 - Track width

Use the largest possible value and conform to the minimum sizes given here:

Units

CLASS 1

CLASS 2 

CLASS 3

CLASS 4

CLASS 5

mm 

0,8 

0,5 

0,4 

0,25 

0,15

1/10mils 

310 

200 

160 

100 

60

8.2.2 - Insulation (clearance)

Unité 

CLASS 1

CLASS 2

CLASSE3

CLASS 4

CLASS 5

mm 

0,70 

0,5 

0,35 

0,23

0,20

1/10mils 

270 

200 

140 

90 

80

Usually, the minimum clearance is very similar to the minimum track width.

8.3 - Some typical combinations

8.3.1 - 'Rustic'

8.3.2 - 'Standard'

8.4 - Manual routing

Manual routing is recommended, because it is the only method offering control of routing priorities. For example, is is preferable to start by routing power tracks, making them wide and short and keeping analog and digital supplies well separated. Then sensitive signal tracks should be routed. Amongst other problems, automatic routing often requires many vias. However, automatic routing can offer useful insight into the positioning of modules. With experience, you will probably find that the automatic router is useful for quickly routing the 'obvious' tracks, but the remaining tracks will best be routed by hand.

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