Datasheet

LUXEON LED Assembly and Handling Application Brief AB32 20121217 4
1. Component
1.1. Description
A LUXEON LED is a revolutionary, ultra-compact, surface mount, high-power LED which comes in two different mechanical configurations:
- Configuration A: A LUXEON LED with this configuration has a flat surface area outside the silicone lens. This configuration is used for all
LUXEON Rebel Color and LUXEON Rebel White LEDS (datasheets DS58, DS63, DS64, and DS68).
- Configuration B: A LUXEON LED with this configuration has a transient voltage suppressor chip in a separate pocket on the ceramic
substrate. This configuration is used for all LUXEON Rebel ES, LUXEON A, and LUXEON R LEDs (datasheets DS61, DS100, and DS101).
Cross sections for both configurations are shown in Figure 1, highlighting the main components of a LUXEON LED.
Each LUXEON LED contains a high brightness LED chip on a ceramic substrate. The ceramic substrate provides mechanical support and thermally
connects the LED chip to a heat pad on the bottom of the substrate. An electrical interconnect layer connects the LED chip to a cathode and anode
(not visible in the cross sections) on the bottom of the substrate. A silicone lens above the LED chip extracts the light that is generated inside the
LED chip. All InGaN LUXEON LEDs contain a transient voltage suppressor (TVS) chip which protects the LED chip against electrostatic dischage
(ESD) events.
1.2. Optical Center
A LUXEON LED contains three feature sets that locate the theoretical optical center. These features are the topside fiducials, backside metallization,
and LED outline.
Fiducial marks on a LUXEON LED (configuration A)
The fiducial marks on a LUXEON LED (configuration A) provide the most accurate methodology to locate the theoretical optical center as shown
in Figure 2. To find the optical center of a LUXEON LED, use the fiducials on the LED package as follows:
1. Draw an imaginary line between the centers of fiducials F1 and F2.
2. Using fiducial F2 as the pivot point, rotate the line 19.66º counter clockwise.
3. The theoretical optical center lies on this line and is 2.248mm above the center of F2.
Once the theoretical optical center has been located, the actual optical center of a LUXEON LED (configuration A) is within a circular diameter of
0.29mm with respect to the theoretical optical center.
Note that the nominal position of the fiducials on a LUXEON LED (configuration A) is identical for all colors. However, there is a difference
in the metallization pattern between InGaN and AlInGap LUXEON LEDs, as indicated in Figure 3.
Ceramic Substrate
Thermal Pad (electrically isolated)
Metal Interconnect Layer
Bond Layer
LED Chip
Cathode
TVS
Silicone Lens
TVS
Cathode
Figure 1. A LUXEON LED comes in two different configurations. Configuration A (left) has a planar surface outside the silicone lens while
configuration B (right) has a TVS which resides inside a special pocket on the ceramic substrate outside the silicone lens (right).