Chapter 5
Working with Traces and Copper
©
National Instruments Corporation
5-13
Adding and Removing Teardrops
A teardrop is a flair that you can add to a trace where the trace connects to
a pad. This is typically used with very small sized traces, to prevent
possible breakage in the copper between the trace and the pad.
Complete the following steps to add teardrops:
1.
Select
Design»Add Teardrops
. The
Teardrops
dialog box displays.
2.
Select the
Units
for the teardrop length.
3.
In the
Length
box, enter the
Preferred
and
Minimum
length for the
teardrops. The preview area changes as the lengths are changed.
4.
In the
Apply to
box, select the following as desired:
•
Selected pads
radio button—Teardrops will be added to the pads
that are currently selected on the workspace.
•
All of the following
radio button—When selected, enables the
SMT pins
,
THT pins
and
Standard vias
checkboxes; check as
desired.
5.
In the
On DRC error
box, select the desired radio button. Choices are
Do not create teardrop
;
Ask for confirmation
;
Create teardrop
.
6.
Enable or disable the
Ignore pad without net
checkbox as desired.
7.
Click
OK
to add the teardrops are added.
To remove all teardrops select
Edit»Copper Delete»All Teardrops
.
Viewing and Editing Copper Properties
All copper elements (traces, copper areas, and powerplanes) share the same
three properties tabs (
Attributes
,
General
, and
Position
). The fourth tab
for traces is
Line
, and the fourth tab for copper areas and powerplanes is
Copper Area
.
The
General
tab is where you edit the properties of the selected copper
element.
Complete the following steps to edit the contents of the
General
tab:
1.
In the
Measurements
box, set the desired
Width
.
Net
shows the net
to which the element is connected, if any. It is read-only.
2.
In the
Autorouter Settings
box, select either
Trace is Fixed
or
Trace
can be Moved
. User-placed traces are fixed (default setting) so that
they will not be moved when autorouting is performed.
