Datasheet

LUXEON LED Assembly and Handling Application Brief AB32 20121217 31
5.5 Placement Accuracy
In order to achieve the highest placement accuracy Philips Lumileds recommends using an automated pick and place tool with a vision system that
can recognize the bottom metallization of a LUXEON LED (3 pads). If available use the SOT32 profile from the component library, and modify the
lead dimensions and pitch according to the dimensions in Figure 39. The recognition tolerance can be set to 30%. A lower percentage improves
placement accuracy but may reduce recognition yield.
For high density placement (e.g. spacing between components below 0.5mm) Philips Lumileds recommends using the outline dimensions of
a LUXEON LED (see Figure 39) for recognition. Reducing the tolerance on the outline dimensions to 5% eliminates the risk of staggering
components.
Philips Lumileds recommends a minimal spacing of 0.3 mm between LUXEON LEDs. This avoids the risk of neighboring components touching each
other after reflow. Note, though, that the light output for each LED may drop due to optical absorption between LED packages.
For manual placement, the fiducials on the top side assist in locating the optical center. Figure 2 serves as a guideline to find the optical center on
the top side.
Figure 39. Mechanical dimensions of the LUXEON LED. All dimensions are in mm.