If you check the box for either home base or Trapezoidal apertures, your surface mount solder paste pad will be cut as shown in one of the images shown below.
If you want to have the original shape, you do not need to check the boxes for home base or Trapezoidal. If you are not sure which one you should use, please review the FAQ below:
Q: What are home base apertures and why would I need them?
A: Home base apertures are used to control solder balling and tomb-stoning of chip components.
Q: What are Trapezoidal Apertures and why would I need them?
A: Trapezoidal Apertures are created by distorting the beam on the laser, creating a draft in the aperture wall. Trapezoidal Apertures are effective if you plan on a long dwell time between printing of solder paste and placement of components. The taper in the aperture wall causes the paste to sit on top of itself, rather than sliding out the sides.
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