Rooms - For Clearance Exceptions

Rooms are useful for creating exceptions. 

For example this Ethernet design called for 18 mils of clearance from the differential pairs to adjacent copper pours.

The diff pair nets were placed in class and a clearance rule was created to hold polygon pours back 18 mils.

click on images to view

This took care of the 18 mil (~3 x W) copper clearance requirement.


However as shown above, now there is a clearance error where the differential pairs connect to U500.

We can use a room to define a clearance exception for the differential pair at U500.

Define the Room

Design > Rooms

Tip: Use Shift + Click to Select an Existing Room

Tip: Select a handle on the Room > Drag Handle > Tab Key

Take note of the settings used for the room above, specifically:

Name RX_TX_ROOM

Not InComponent('U500') 

'Keep Objects Outside' 


Clearance Rule

That's It.