PCB and heat sink on the back

If calculated TJ TJmax bigger than design requirements, and on the structure and not allowed to increase area, can consider to stick on the back of the PCB on the aluminum '∪' form ( Or aluminum sheet stamping) , or stick on the radiator, as shown in figure 10. The two methods is more commonly used in the design of high power LED lamps and lanterns. For example, the calculation example, the calculated TJ = 103 ℃ PCB paste behind a 10 ℃ / W heat sink, its TJ to around 80 ℃.

figure 10 '∪' form aluminum

here to explain that the TC is measured at room temperature ( Room temperature is generally 15 ~ 30 ℃) 。 If the ambient temperature of LED lights use TA than at room temperature, then the actual TJ than at room temperature is calculated after measuring the TJ, so when the design should take this factor into consideration. When testing in the constant temperature box, its temperature is transferred to the highest temperature when using, for the best.

in addition, the PCB is installed horizontally or vertically, the different cooling condition, has certain influence on the measurement of TC, lamps and lanterns of the shell material, size, and presence of ventilation to cooling may also be affected. Therefore, when the design scope.

Sophy

China lighting network