A device and method for non-contact photoelectric detection of LED chips

Abstract

The invention discloses a device and method for non-contact photoelectric detection of LED chips. The device includes a reference LED chip, a shorting device, an oscilloscope, an induction coil, an optical measurement device, a resistor, a first current source and a second current source. Wherein, the oscilloscope is connected in parallel at both ends of the resistor, the resistor, the first current source and the induction coil are connected in series to form a first closed loop, and the short-circuit device is used to place the LED chip to be tested and make the two electrodes of the LED chip to be tested short-circuited to form a second circuit. For a closed loop, the reference LED chip is connected in series with the second current source to form a third closed loop, and the second closed loop and the third closed loop are coaxial with the magnetic field direction of the induction coil. The optical measurement device is located on one side of the short-circuit device and the light-collecting direction is aligned with the LED chip to be tested. The device records the parameter changes of the circuit during the two mutual inductance effects, calculates the voltage data and current data of the LED chip to be tested, and then obtains the optical parameters of the LED chip to be tested to realize non-contact photoelectric detection of the LED chip.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a device and method for non-contact photoelectric detection of LED chips. Background technique [0002] LED (Light Emitting Diode) is a semiconductor light-emitting element that can convert electrical energy into light energy. It has the characteristics of high luminous efficiency, small size, long life, fast response, good monochromaticity, power saving and environmental protection, etc. The fourth-generation light sources after incandescent lamps, fluorescent lamps and high-intensity gas discharge lamps are widely used in signal lights, landscape lighting, display technology and other fields. In recent years, they have become a research hotspot in the field of lighting and display. and business attention. [0003] The current detection technology for LED chips is mainly divided into two directions: contact type and non-contact type. The basic core content of the contact...

AI Technical Summary

Problems solved by technology

[0005] However, since LEDs are driven by electricity in practical applications, it is easy to excite non-recombination layer carriers by using light excitation, which is quite different from the electric drive mode and has a high false detection rate.

Moreover, the LED spectrum is measured by photoluminescence. Due to the influence of the excitation light, the spectrometer needs to add a filter, so the test process is cumbersome and the test results are not very accurate.

However, the method of electrically exciting the LED chip by injecting displacement current through the field plate drives all the wafers at one time, and the current density is not uniform, which cannot reflect individual differences.

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