Imaging system for MLED wafer spectrum and appearance synchronous detection

Abstract

The invention provides an MLED wafer spectrum and appearance synchronous detection imaging system, a light source module comprises a light source, a lens, a sensor, a first beam splitter prism, a second beam splitter prism, a high-power objective lens and a sample, the light source is used for collimating through the lens, sequentially passing through the sensor, a first central optical axis of the first beam splitter prism and the high-power objective lens, and then passing through a second central optical axis of the second beam splitter prism and the high-power objective lens; irradiating the sample to form fluorescent light, and splitting the fluorescent light into first fluorescent light and second fluorescent light respectively through a first central optical axis of the second beam splitter prism and a second central optical axis of the second beam splitter prism after passing through the high-power objective lens, a second central optical axis of the first beam splitter prism and a second central optical axis of the second beam splitter prism; the AOI defect detection module comprises a first image receiving objective lens and an array image sensor, and the first fluorescent light enters the array image sensor through the first image receiving objective lens; the spectral analysis module comprises a second image receiving objective lens and an imaging spectrometer, and the second fluorescent light enters the imaging spectrometer through the second image receiving objective lens. The light path for simultaneously detecting spectrum and appearance defects is realized.

Description

Technical Field

[0001] The invention relates to the technical field of MLED, and in particular to an imaging system for synchronously detecting spectrum and appearance of an MLED wafer. Background Art

[0002] At present, the spectrum and appearance inspection of Micro-LED mainly rely on electroluminescence (EL) technology and traditional AOI (automatic optical inspection) methods. However, electroluminescence inspection requires physical contact between the probe and the chip electrode, which damages the chip surface and the electrode, and cannot provide inspection results for appearance defects. Although AOI technology can effectively detect appearance defects, it cannot directly obtain spectral characteristics.

[0003] Therefore, the current MLED wafer cannot fully evaluate the performance of the chip. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides an imaging system for synchronously detecting the spectrum and appearance of an MLED wafer, so as to solve the technical problem in the prior art that the MLED wafer cannot fully evaluate the chip.

[0005] The present invention provides an imaging system for synchronously detecting spectrum and appearance of an MLED wafer, comprising:

[0006] A light source module comprises a light source, a lens, a sensor, a first beam splitter prism, a second beam splitter prism, a high-power objective lens and a sample, wherein the light source is used to be collimated by the lens, and then sequentially passes through the sensor, the first central optical axis of the first beam splitter prism and the high-power objective lens, and then irradiates the sample to form fluorescence, and the fluorescence passes through the high-power objective lens, the second central optical axis of the first beam splitter prism and the second beam splitter prism, and is split into a first fluorescence and a second fluorescence by the first central optical axis of the second beam splitter prism and the second central optical axis of the second beam splitter prism respectively;

[0007] The AOI defect detection module comprises a first imaging lens and an array image sensor, wherein the first fluorescence enters the array image sensor via the first imaging lens;

[0008] The spectrum analysis module comprises a second imaging objective lens and an imaging spectrometer, and the second fluorescence enters the imaging spectrometer via the second imaging objective lens.

[0009] Optionally, the light source module further includes:

[0010] A short-wave pass filter is arranged between the first beam splitter prism and the second beam splitter prism, and the short-wave pass filter is coaxially arranged with the second central optical axis of the first beam splitter prism and the first central optical axis of the second beam splitter prism.

[0011] Optionally, the focal length of the lens includes:

[0012] f=D / (2·tan(θ / 2))

[0013] Where f is the focal length, D is the aperture, and θ is the divergence angle of the light source.

[0014] Optionally, the lens comprises:

[0015] The wavelength range is λ=400-700nm.

[0016] Optionally, the light transmittance of the short-wave pass filter includes:

[0017] The transmittance of the short-wave pass filter satisfies λ1≤400nm reflection, λ1=400-700nm transmission, and λ1>700nm reflection.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] The present invention includes an AOI defect detection module and a spectrum analysis module. Not only can the AOI defect detection module effectively detect appearance defects, but the spectrum analysis module can also collect the sample luminescence spectrum, thereby realizing the correspondence between the spectrum and the luminescence position. The optical path for simultaneously detecting the spectrum and appearance defects satisfies the comprehensive detection of the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0022] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0023] Figure 2 for Figure 1 The enlarged structural diagram at A in the middle;

[0024] Figure 3 The sample image and spectrum diagram collected by the imaging spectrometer in the present invention;

[0025] Figure 4 It is a schematic structural diagram of another embodiment of the present invention.

[0026] Description of reference numerals:

[0027] 1. Light source; 2. Lens; 3. Sensor; 4. First beam splitter prism; 5. Second beam splitter prism; 6. High-power objective lens; 7. Sample; 8. First image-receiving objective lens; 9. Array image sensor; 10. Second image-receiving objective lens; 11. Imaging spectrometer; 12. Short-wave pass filter; 13. Dichroic mirror. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other implementation cases obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The functional units with the same labels in the examples of the present invention have the same and similar structures and functions.

[0029] See also Figure 1 and Figure 2 The present invention provides an imaging system for synchronously detecting spectrum and appearance of MLED wafers, comprising:

[0030] A light source 1 module comprises a light source 1, a lens 2, a sensor 3, a first beam splitter prism 4, a second beam splitter prism 5, a high-power objective lens 6 and a sample 7. The light source 1 is used to be collimated by the lens 2, and then sequentially passes through the sensor 3, the first central optical axis of the first beam splitter prism 4 and the high-power objective lens 6, and then irradiates the sample 7 to form fluorescence. The fluorescence passes through the high-power objective lens 6, the second central optical axis of the first beam splitter prism 4 and the second beam splitter prism 5, and is split into a first fluorescence and a second fluorescence by the first central optical axis of the second beam splitter prism 5 and the second central optical axis of the second beam splitter prism 5, respectively.

[0031] The AOI defect detection module includes a first imaging lens 8 and an array image sensor 9, wherein the first fluorescence enters the array image sensor 9 via the first imaging lens 8;

[0032] The spectrum analysis module includes a second imaging objective lens 10 and an imaging spectrometer 11 , and the second fluorescence enters the imaging spectrometer 11 via the second imaging objective lens 10 .

[0033] In this embodiment, the system can illuminate the sample 7 by adapting the excitation light source 1 of different wavelengths. After the light source 1 is collimated through the lens 2, it passes through the sensor 3, the first central optical axis of the first beam splitter prism 4 and the high-power objective lens 6 in sequence, and then illuminates the sample 7 to form fluorescence. The fluorescence passes through the high-power objective lens 6, the second central optical axis of the first beam splitter prism 4 and the second beam splitter prism 5, and is split into the first fluorescence and the second fluorescence through the first central optical axis of the second beam splitter prism 5 and the second central optical axis of the second beam splitter prism 5, respectively. The first fluorescence enters the array image sensor 9 through the first image receiving objective lens 8 to realize imaging, and the generated image can be used for appearance defect detection through the connected intelligent electronic device; the second fluorescence enters the imaging spectrometer 11 through the second image receiving objective lens 10, see Figure 3 The imaging spectrometer 11 can image the sample 7 and simultaneously collect the luminescence spectrum of the sample 7, thereby achieving correspondence between the spectrum and the luminescence position.

[0034] See also Figure 4 Different light sources 1, lenses 2, sensors 3 and dichroic mirrors 13 may also be added to achieve different detection imaging.

[0035] Among them, the light source 1 can select a single wavelength or a multi-wavelength light source 1 according to the characteristics of the sample 7, and realize a coaxial configuration through a mechanical structure to ensure efficient excitation.

[0036] The high-power objective lens preferably adopts an infinite conjugate high-power objective lens 6. While achieving high resolution, the optical path length can be adjusted to reduce the risk of mechanical design interference, and objective lenses of different magnifications can be switched according to needs.

[0037] The first beam splitter prism 4 and the second beam splitter prism 5 can be replaced by corresponding components such as a plane beam splitter for light separation. The incident angle, distance and light uniformity of the light source 1 and the sample 7 are optimized to avoid shadow or reflection interference. The collimator can shape the light beam, enhance the light effect, reduce the light spot and improve the light utilization rate.

[0038] The sensor 3 is used to monitor the state of the sample 7 and automatically adjust the incident angle and intensity of the light source 1 to optimize the detection conditions and improve the detection accuracy.

[0039] The image sensor may be a high-resolution, high-sensitivity image sensor (such as CCD, sCCD, CMOS, etc.) to ensure that tiny defects of the LED sample 7 can be captured. The image sensor should also have a high frame rate to cope with dynamic detection tasks.

[0040] In another embodiment, it also includes:

[0041] A short-wave pass filter 12 is disposed between the first beam splitter prism 4 and the second beam splitter prism 5 , and the short-wave pass filter 12 is coaxially disposed with the second central optical axis of the first beam splitter prism 4 and the first central optical axis of the second beam splitter prism 5 .

[0042] The short-wave filter 12 is provided to further reduce the influence of ambient light on the detection result, improve the detection accuracy by controlling the ambient light illumination, and can effectively filter out the ambient light to ensure the purity of the fluorescence detection.

[0043] In another embodiment, the focal length of lens 2 includes:

[0044] f=D / (2·tan(θ / 2))

[0045] Wherein, f represents the focal length, D represents the clear aperture, and represents the divergence angle of the light source 1.

[0046] In another embodiment, the lens 2 transmits light in the wavelength range of λ=400-700 nm.

[0047] In another embodiment, the light transmittance of the short-wave pass filter 12 includes:

[0048] The transmittance of the short-wave filter 12 satisfies the following conditions: λ1≤400nm for reflection, λ1=400-700nm for transmission, and λ1>700nm for reflection.

[0049] The present invention is based on the AOI defect detection module and the central wavelength detection module. Not only can the appearance defects be effectively detected through the AOI defect detection module, but also the spectrum analysis of a single pixel can be realized through the central wavelength. At the same time, the spectrum of each chip can be located. The brightness, color and defects of the chip can be efficiently detected, and the detection requirements of different types of chips can be adapted. Combined with high-resolution sensors and intelligent automatic adjustment functions, the system can adjust the light source and light path conditions in real time, thereby improving detection efficiency and accuracy.

[0050] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0051] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An imaging system for simultaneous detection of spectrum and appearance of MLED wafers, characterized in that: include: A light source module comprises a light source, a lens, a sensor, a first beam splitter prism, a second beam splitter prism, a high-power objective lens and a sample, wherein the light source is used to be collimated by the lens, and then sequentially passes through the sensor, the first central optical axis of the first beam splitter prism and the high-power objective lens, and then irradiates the sample to form fluorescence, and the fluorescence passes through the high-power objective lens, the second central optical axis of the first beam splitter prism and the second beam splitter prism, and is split into a first fluorescence and a second fluorescence by the first central optical axis of the second beam splitter prism and the second central optical axis of the second beam splitter prism respectively; The AOI defect detection module comprises a first imaging lens and an array image sensor, wherein the first fluorescence enters the array image sensor via the first imaging lens; The spectrum analysis module comprises a second imaging objective lens and an imaging spectrometer, and the second fluorescence enters the imaging spectrometer via the second imaging objective lens.

2. The imaging system for simultaneous detection of spectrum and appearance of MLED wafers according to claim 1, characterized in that: The light source module further includes: A short-wave pass filter is arranged between the first beam splitter prism and the second beam splitter prism, and the short-wave pass filter is coaxially arranged with the second central optical axis of the first beam splitter prism and the first central optical axis of the second beam splitter prism.

3. The imaging system for simultaneous detection of spectrum and appearance of MLED wafers according to claim 1, characterized in that: The focal length of the lens includes: f=D / (2·tan(θ / 2)) Where f is the focal length, D is the aperture, and θ is the divergence angle of the light source.

4. The imaging system for simultaneous detection of spectrum and appearance of MLED wafers according to claim 1, characterized in that: The lens comprises: The wavelength range is λ=400-700nm.

5. The imaging system for simultaneous detection of spectrum and appearance of MLED wafers as claimed in claim 2, characterized in that: The light transmittance of the short-wave pass filter includes: The transmittance of the short-wave pass filter satisfies λ1≤400nm reflection, λ1=400-700nm transmission, and λ1>700nm reflection.

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