Abstract: The present disclosure provides a light emitting diode driving circuit, comprising: a power conversion module having an input end, a control end and an output end, wherein the input end receives a voltage, the control end controls the regulation of the duty cycle signal therein according to a received control signal, and the output end outputs a DC voltage having a constant current and a variable voltage value; an overcurrent protection circuit having a switch module and a first resistor connected in series, wherein the overcurrent protection circuit and a LED load connected in series with each other are connected to the power conversion module, so as to turn off the electrical channel between the LED load and the power conversion module when overcurrent occurs; and an overvoltage protection circuit for outputting the control signal when overvoltage occurs and thereby protecting the LED load.

Abstract: A test pattern structure including a first conductive layer and a second conductive layer is provided. The second conductive layer is directly disposed on the first conductive layer and connected to the first conductive layer through a plurality of connection interfaces. The test pattern structure of the present invention can detect the interconnection failure quickly and correctly without SEM identification.

Abstract: A test pattern structure including a first conductive layer and a second conductive layer is provided. The second conductive layer is directly disposed on the first conductive layer and connected to the first conductive layer through a plurality of connection interfaces. The test pattern structure of the present invention can detect the interconnection failure quickly and correctly without SEM identification.