晶圆级LED驱动电路系统

Wafer level LED drive circuit system

发光二极管(LED)是恒流工作的器件,并且随着LED功率的不断增加,散热问题变得越加突出,温度控制十分必要。当LED功率比较小时,可以用温度传感器来检测它的温度;而当LED做到晶圆级发光二极管(WLED),功率达到千瓦,传统的驱动方式、散热方式以及温度的控制已不再适用。晶圆级发光二极管有多条支路,采用多路恒流以保证每条支路的电流相同。对于温度的控制,将晶圆级发光二极管平均结温变化量的测量转换为对冷却液温度的变化量的测量,进而通过与冷却液温度变化量的关系进行控制。本设计解决了晶圆级发光二极管因工艺问题导致的"抢电流"的问题,并将复杂的温度控制变得简单化,而且节省成本。

Light Emitting Diode（LED） is a constant current device. With the increase of power of LED,heat dissipation issues become increasingly prominent, and the temperature control is necessary. When the power of LED is relatively small,the temperature sensor can be used to detect its temperature;but the power of wafer level LED reaches kilowatts,the traditional methods of drive,heat dissipation and temperature control are no longer applicable. The Wafer level LED has multiple branches, therefore multi-channel constant current is adopted to guarantee the same current of each branch. For temperature control,the wafer level LED average junction temperature measurement of the change is converted to a measurement of the coolant temperature change. The temperature is further controlled by the relationship with the coolant temperature change. This design solves the problem of“current concentration”caused by the manufacturing issues of wafer level LED,simplifies the sophisticated temperature control,and cuts the cost as well.