The
following response 1W white LED commercially available to interface
thermal resistance analysis, the samples from the Lumileds company
production, packaging structures generally include grain, solder balls,
substrate, silver plastic, and cooling block and so on, as shown in
Figure 10. As each part from different materials with different geometric dimensions and composed, and therefore the structure function will show a different slope of the graph changes. Structure function by measuring the cumulative figure that the size of each layer of thermal resistance. One solder ball thermal resistance of 0.8K / W, silicon plate 0.2K / W, silver plastic is about 9.1K / W, thermal block of 2.3K / W, shown in Figure 11. Cumulative
structure function diagram for the thermal resistance of the horizontal
coordinates, vertical coordinates for the heat capacity value. By the SEM results and the cumulative structure
function corresponds to the comparison chart, you can clearly determine
package body layers of materials distribution curve.
|
