Data Sheet

LABCENTER ELECTRONICS LTD.
110
4) The diameter of the pad is 180th or 0.18in.The drill mark is the size of the mark output in a
drill plot, 30th would be fine. The drill hole needs to be 3mm and the guard gap should be
enlarged to 20
th
. The guard gap (or solder mask expansion) is the amount by which the pad
diameter is expanded on the resist plot.
5) At the bottom of the dialogue form we have the choice whether to make this pad style
permanent for future designs (Update Defaults option) or local only to this design (Local Edit
option). Unless there is a particular reason for a local edit only we recommend that you leave
this on the default setting.
6) When you exit the dialogue form you should see that the new pad style is available for
placement from the Object Selector.
When entering specific values you may find it easier to simply type in the values that you want
rather than using the up and down arrows beside the controls.
We are going to want to place two mounting holes at the top and bottom left of the board and
then a third at a specific location (for mini-locking PCB supports). You may therefore have to
move some circuitry out of the way to make room; for example, the crystal block at the bottom
or the pressure transducer at the top. As we’ve seen earlier we can easily do this by entering
selection mode, drawing a selection box around the circuitry and then dragging to a new
position. This is shown below with the crystal circuitry.