Instrument and method for detecting LED chip

Abstract

The invention discloses an instrument and method for detecting an LED chip. The instrument comprises an ultraviolet excitation light source, a test area of the tested LED chip and an electric characteristic detector. The test area of the tested LED chip is arranged opposite to the ultraviolet excitation light source and located in a radiation range of the ultraviolet excitation light source, and the electric characteristic detector is electrically connected to the test area of the tested LED chip. The method includes the steps that 1, the ultraviolet excitation light source irradiates the tested LED chip, wherein the wavelength of the tested LED chip is greater than that of the ultraviolet excitation light source; 2, an electric characteristic value of the tested LED chip is detected; 3, according to a corresponding relationship between the electric characteristic value of the tested LED chip and an irradiation illuminance value of the ultraviolet excitation light source, test conditions of the tested LED chip are determined. According to the instrument and method for detecting the LED chip, the detection of the LED chip can be realized without an external power supply, and meanwhile the abnormal conditions of the LED chip can be accurately detected.

Description

technical field [0001] The invention relates to the detection field of LED chips, in particular to an instrument and method for detecting LED chips. Background technique [0002] LED (light-emitting diode) is widely used in lighting, indication and other fields due to its long life, no pollution, and low energy consumption. In order to ensure the normal use of LED chips, it is generally necessary to test the electrical properties of LED chips. Existing The detection methods of LED chips include the following: [0003] The first detection method is to package the LED chip into an LED light source, and then connect a driving power supply at both ends of the LED light source, and then test the voltage at the test point of the LED light source to determine whether the electrical characteristics of the LED chip are within a reasonable range. However, this method requires the LED chip to be packaged into a finished product and then tested, and a driving power supply needs to be c...

AI Technical Summary

Problems solved by technology

[0003] The first detection method is to package the LED chip into an LED light source, and then connect a driving power supply at both ends of the LED light source, and then test the voltage at the test point of the LED light source to determine whether the electrical characteristics of the LED chip are within a reasonable range. However, this method requires the LED chip to be packaged into a finished product and then tested, and a driving power supply needs to be connected to both ends of the LED light source, so that if the driving power is not selected properly or is unstable, it will easily cause damage to the LED chip, resulting in inaccurate testing;

[0004] The second detection method, such as the US invention patent US006670820B2, discloses a method for detecting the electroluminescence characteristics of semiconductor materials and devices, specifically disclosing that excitation light is applied to the LED chip, and a forward direction is applied between the P region and the N region. The bias voltage forms a traction electric field to attract electrons in the P region and N region to move to the active region in the middle, and then radiative recombination occurs in the active region to emit light, and then the light receiving device is used to combine the intensity of the excitation light and the absorption of the chip coefficient, calculate the concentration of photogenerated carriers, combine the radiation luminescence of the active region and the concentration of carriers that are actually injected into the active region, and then quantitatively analyze the electronic luminescence performance of the measured LED chip. The detection method needs to remove the bias voltage applied to the chip, so it is easily affected by the bias voltage, which leads to the accuracy of the test part;

[0005] The third detection method, such as the Chinese patent application number CN200810070112.9, the announcement date is 2010.11.10, specifically discloses that by detecting the luminescence of the PN junction of the device under test under the irradiation of controllable excitation light, the luminescence characteristics and electric current of the LED chip can be improved. The characteristics are detected, wherein the electrical characteristic parameters include forward current and forward voltage, wherein the forward current is obtained by converting between the measured photoluminescence intensity and the photoluminescence intensity of the reference sample, and the forward bias voltage is obtained by The measured wavelength of the PN junction of the device under test is obtained through conversion, so the forward voltage must first obtain the optical characteristics of the PN junction of the test device, which mainly uses a light receiving device to obtain the optical characteristics of the LED chip and then determine the electrical characteristics, but due to the optical receiver It is located on one side of the chip under test to collect the optical signal of the chip under test, which makes it impossible to collect all the optical signals of the chip under test. In addition, the controllable excitation light is not completely isolated from the light emission of the chip under test, so that the controllable excitation light The light emitted by the chip under test will interact with each other, so that the optical signal of the chip under test cannot be accurately collected. In addition, if the entire LED chip needs to be tested, the light emitted by the entire LED chip will affect each other, resulting in the inability to accurately collect the light signal. Collect the optical signal of the chip under test; therefore, a test method with high test accuracy and no external power supply is required

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