TWI417976B - The detection system and detection method of cluster LED chip - Google Patents

Description

Cluster type LED chip detection system and detection method

The invention relates to a detection system for a cluster LED chip, in particular to a detection system for checking the working state of a cluster LED chip.

With the maturity of Light Emitting Diode (LED) technology, LEDs have been widely used in the field of illumination, and in order to provide a more diverse illumination method, a cluster of multiple LEDs on a single wafer is concentrated. LED chips are also valued by many manufacturers.

However, compared with LED chips with only a single LED unit, there is always a blind spot in the detection of cluster LED chips. Please refer to the first figure. The first picture is a schematic diagram of a cluster LED chip, and a cluster LED chip 100 will Including a plurality of LED units 11 , when a small number of LED units 11 in the cluster LED chip 100 are abnormal, the cluster LED chip 100 may cause partial brightness to be low when lighting, which is used in the prior art. The electrical detection method has a considerable probability that such abnormal conditions cannot be detected, because a few LED unit 11 abnormalities may only cause a very small drop in the total current, and the total current falls within the qualified range of detection. .

In addition, the prior art also uses a spectrometer to detect the optical characteristics of the LED chip. However, such optical inspection can only check whether the overall color and brightness of the light emitted by the cluster LED chip 100 is correct, and the cluster LED cannot be detected yet. A small range of dark areas on the wafer 100.

Accordingly, the main object of the present invention is to provide a detection system and a detection method for inspecting an operation state of a cluster LED chip, wherein the detection system and the detection method can detect a working state of a cluster LED chip at the time of lighting to determine Whether the clustered LED chip is defective in actual use.

A cluster LED chip detection system for detecting the working state of a cluster LED chip, the detection system comprising a carrier unit, a power supply, and an optical detector; the carrier unit is configured to carry the cluster LED chip; The power supply system is configured to provide a rated operating current of the clustered LED chip, so that the cluster LED chip emits a working beam; the optical detecting machine is configured to receive the working beam and determine the working state accordingly.

In a preferred embodiment of the invention, the optical inspection machine is an Automated Optical Inspection (AOI).

In a preferred embodiment of the present invention, the optical detecting device comprises an image capturing unit and a determining unit, wherein the image capturing unit is configured to receive the working beam to obtain a working image, and send the working image; The working image is received from the image capturing unit, and the working state is determined accordingly. In the preferred embodiment, the determining unit can be an industrial computer.

In a preferred embodiment of the present invention, the determining unit divides the working image into a plurality of comparison intervals, and discriminates the brightness of the comparison intervals.

In a preferred embodiment of the present invention, the detection system of the cluster LED chip may further include an attenuating sheet disposed in front of the optical detector to attenuate the working beam.

In a preferred embodiment of the present invention, the detection system of the cluster LED chip may further include a current adjustment unit electrically coupled between the power supply and the cluster LED chip to adjust The rated operating current.

The invention further discloses a method for detecting a cluster LED chip, comprising the steps of: (a) providing a rated operating current to a cluster LED chip, thereby causing the cluster LED chip to emit a working beam; (b) The optical detector receives the working beam to obtain a working image; and (c) discriminates the working image by the optical detector to obtain an operating state.

Compared with the conventional detection method of detecting a cluster LED chip by using an electric or spectrometer, the detection system and the detection method of the cluster LED chip of the present invention can discriminate whether the cluster LED chip has a cluster LED chip when it is lit. Unusual dark areas are generated, so the reliability of the detection cluster LED chip can be effectively improved.

The specific embodiments of the present invention will be further described by the following examples and drawings.

The invention relates to a detection system for a cluster LED chip, in particular to a detection system for checking the working state of a cluster LED chip. The invention is illustrated by the following description of the preferred embodiments of the invention, and is not intended to limit the invention. The contents of this preferred embodiment are detailed below.

Please refer to the second and third figures. The second figure is a schematic diagram of a first preferred embodiment of the detection system of the present invention, and the third figure is a schematic diagram of a second preferred embodiment of the detection system of the present invention. The detection system of the cluster LED chip 100 of the present invention is for detecting the working state of a cluster LED chip 100. The detection system includes a carrier unit 21, a power supply 22, and an optical detector 23.

The load unit 21 is used to carry the cluster LED chip 100; the power supply 22 is used to provide a rated operating current of the cluster LED chip 100, so that the cluster LED chip 100 emits a working beam.

The optical detector 23 is configured to receive the working beam and determine the working state. The optical detector may be an automated optical inspection (AOI). However, in the prior art, the AOI machine is used to detect whether the appearance of the object to be tested is flawed, and the detection method is that the external light source illuminates the object to be tested, and then the surface of the object to be tested is judged to be flawed. The advantage of the AOI machine is that it can simultaneously determine the position of the cymbal when detecting the appearance. However, if the brightness of the appearance of the object to be tested is too high, the AOI machine cannot correctly judge whether the appearance of the object to be tested is defective or not.

Therefore, if the AOI machine is used as the optical detector 23 in the present invention, in the preferred embodiment, the detection system may further include an attenuator 24, which is disposed before the optical detector 23. The current adjustment unit 25 is electrically coupled between the power supply 22 and the cluster LED chip 100 to adjust the rated operating current. The current adjustment unit 25 is electrically coupled between the power supply 22 and the cluster LED chip 100. Both of the above methods can reduce the brightness of the light received by the optical detector 23, so that the optical detector 23 can correctly determine the operating state of the cluster LED chip 100.

In order to make the detection more efficient, the attenuating sheet 24 may be composed of at least one attenuation filter and filter for one or more wavelengths of light, and the most ideal condition is to have the optical detector 23 on the cluster LED chip. The difference in brightness of light received by 100 during normal operation is less than 1%, and the exposure time required for optical detector 23 to receive the working beam can be controlled within 5 ms, and when dark area of clustered LED chip 100 is generated, dark area The brightness is only 10%~80% of the normal brightness; if the current adjustment unit 25 is used to reduce the brightness of the working beam and the rated operating current is reduced to 50%, the brightness of the working beam will be reduced to 60%. Therefore, the amplitude of the rated operating current must be adjusted so that the exposure time required by the optical detector 23 can be controlled within 5 ms.

Please refer to the fourth figure. The fourth picture is a schematic diagram of the partitioning of the working images. Preferably, the optical detector 23 includes an image capturing unit 231 and a determining unit 232. The image capturing unit 231 is configured to receive the working beam to obtain a working image P1, and send the work. The image P1, the determining unit 232 is configured to receive the working image P1 from the image capturing unit 231, and determine the working state according to the image; and in the preferred embodiment, the determining unit may be an industrial computer; The determining unit 232 can distinguish the working image P1 into a plurality of comparison intervals Z1 and Z2, and determine the brightness of the comparison intervals Z1 and Z2, so that the cluster LED chip 100 has a dark area. It is emphasized that the alignment intervals Z1 and Z2 can be designed according to the distribution position of the LED units 11 on the cluster LED chip 100, but of course, it can be designed in any shape and size.

Please also refer to the fifth figure, which is a flow chart of the detection method of the present invention. The method for detecting a cluster LED chip of the present invention comprises the following steps: S101: lighting the cluster LED chip 100 to cause the cluster LED chip 100 to emit a working beam; S103: when the optical detector 23 is an AOI machine, The attenuating sheet 24 attenuates the working beam, or reduces the rated operating current through the current adjusting unit 25, thereby reducing the intensity of the light received by the optical detector 23; S105: the optical detecting machine 23 receives the working beam emitted by the cluster LED chip 100; And S107: the optical detector 23 obtains the working image P1 after receiving the working beam, and discriminates the working image P1.

Compared with the conventional method for detecting the detection mode of the cluster LED chip 100 by using an electric or spectrometer, the detection system and the detection method of the cluster LED chip 100 of the present invention can discriminate the cluster LED when the cluster LED chip 100 is lit. Whether the wafer 100 has an abnormal dark area is generated, and if the AOI machine is used in the detection system and the detection method of the present invention, the shortcomings of the conventional AOI machine can only detect the passive illumination of the object to be tested, and the above Advantages, it can be seen that the present invention can very effectively improve the reliability of the detection cluster LED chip 100.

The features and spirit of the present invention will be more apparent from the detailed description of the preferred embodiments. On the contrary, the intention is to cover various modifications and equivalents within the scope of the invention as claimed.

100. . . Cluster LED chip

11. . . LED unit

twenty one. . . Bearer unit

twenty two. . . Power Supplier

twenty three. . . Optical detector

231. . . Image capture unit

232. . . Judging unit

twenty four. . . Attenuator

25. . . Current adjustment unit

P1. . . Working image

Z1, Z2. . . Comparison interval

S101~S107. . . Detection method flow chart

The first figure is a schematic diagram of a clustered LED chip;

The second drawing is a schematic diagram of a first preferred embodiment of the detection system of the present invention;

The third drawing is a schematic diagram of a second preferred embodiment of the detection system of the present invention;

The fourth picture is a schematic diagram of the partitioning of the working images;

The fifth figure is a flow chart of the detection method of the present invention.

100. . . Cluster LED chip

twenty one. . . Bearer unit

twenty two. . . Power Supplier

twenty three. . . Optical detector

231. . . Image capture unit

232. . . Judging unit

twenty four. . . Attenuator

Claims (8)

A detection system for a Light Emitting Diode (LED) chip for detecting a working state of a cluster LED chip, the detection system comprising: a carrying unit for carrying the cluster An LED power supply is provided for providing a rated operating current of the clustered LED chip, so that the cluster LED chip emits a working beam; an optical detecting machine is configured to receive the working beam, and Determining the working state; and an attenuating sheet disposed in front of the optical detector to attenuate the working beam. The detection system of the cluster LED chip of claim 1, wherein the optical inspection machine is an Automatic Optical Inspection (AOI). The detection system of the cluster LED chip of claim 1, wherein the optical inspection system comprises: an image capturing unit for receiving the working beam to obtain a working image, and transmitting the working image And a determining unit for receiving the working image from the image capturing unit, and determining the working state accordingly. The detection system of the cluster LED chip of claim 3, wherein the determining unit is an industrial computer. The detection system of the cluster LED chip of claim 3, wherein the determining unit divides the working image into a plurality of comparisons. The interval is determined by the brightness of the comparison intervals. The detection system of the clustered LED chip of claim 1, further comprising a current adjustment unit electrically coupled between the power supply and the cluster LED chip, thereby adjusting the Rated operating current. A method for detecting a cluster LED chip, comprising: (a) providing a rated operating current to a cluster LED chip, thereby causing the cluster LED chip to emit a working beam; (b0) providing an attenuating sheet for the optical inspection Before the machine, the working beam is attenuated; (b) receiving the working beam by an optical detector to obtain a working image; and (c) using the optical detector to divide the working image into a plurality of comparison intervals, and The brightness of the comparison intervals is determined to obtain an operating state; wherein the magnitude of the rated operating current is proportional to the brightness of the working beam. The method for detecting a cluster LED chip according to claim 7, wherein in the step (a), the method further comprises: providing a current adjustment unit, the current adjustment unit being electrically connected to the power supply and the cluster Between the LED chips, to adjust the rated operating current.