Coupling control method and device for functional area and light source of chip to be tested

Abstract

The invention provides a coupling control method and device for a functional area and a light source of a to-be-detected chip, and the method comprises the steps: collecting a light reflection part picture which is obtained through the photographing of a light reflection surface by a camera when the light source irradiates the light reflection surface of a light reflection part; extracting a light spot in the light reflecting part picture according to a preset extraction strategy; and based on the area of the light spot on the reflecting part, controlling the movement of a functional area of a chip to be detected and / or the movement of the light source, so that the light spot falls into the functional area of the chip to be detected, and the light source and the functional area are in a coupling state to detect the performance index of the chip to be detected. Compared with the prior art, according to the technical scheme, the precision of detecting the performance indexes of the chip to be detected is improved, and the situation of inaccurate test data caused by artificial differences is eliminated.

Description

Technical Field

[0001] The present invention relates to the technical field of chip testing, and in particular, to a method and device for coupling control between a functional area of a chip under test and a light source. Background Art

[0002] In the continuous research and development and experimental production of semiconductor detectors, the performance test of the detector (PD) is an essential process. Among them, the responsivity is one of the important parameters reflecting the quality of the product performance. To test the responsivity, the light source of the device and the functional area of the product need to be in a highly coupled state. Through the coupled state, it is judged whether there are defects in the design and process of the product.

[0003] In the prior art, the coupling degree between the functional area of the product and the light source is determined by the experience of the tester, that is, by the way of human observation, to judge whether the light spot of the light source completely falls into the functional area of the product. This detection method depends on the experience of the staff and is prone to large observation errors. Summary of the Invention

[0004] In view of this, one of the purposes of the embodiments of the present application is to provide a method for coupling control between a functional area of a chip under test and a light source, which can improve the problem that the existing test method will generate large errors; the second purpose is to provide a coupling device between a functional area of a chip under test and a light source.

[0005] To achieve the above technical purposes, the technical solutions adopted in the present application are as follows: In a first aspect, the embodiments of the present application provide a method for coupling control between a functional area of a chip under test and a light source, and the method includes: Collect a picture of a reflector, where the picture of the reflector is obtained by a camera shooting the reflecting surface when the light source irradiates the reflecting surface of the reflector; Extract the light spot in the picture of the reflector with a preset extraction strategy; Based on the area of the light spot on the reflector, control the movement of the functional area of the chip under test and / or the movement of the light source, so that the light spot falls into the functional area of the chip under test, and the light source and the functional area are in a coupled state to detect the performance index of the chip under test.

[0006] Further, the controlling the movement of the functional area of the chip under test and / or the movement of the light source based on the area of the light spot on the reflector, so that the light spot falls into the functional area of the chip under test includes: Obtain the edge line of the light spot according to the edge detection algorithm; Fit the figure enclosed by the edge line into a preset figure; Calculate the area of the preset figure; When the area of the preset pattern is less than or equal to the area of the functional area of the chip under test, control the movement of the functional area of the chip under test and / or the movement of the light source to make the center of the functional area of the chip under test coincide with the center of the preset pattern, where the height of the position where the chip under test is located is the same as the height of the position of the reflector.

[0007] Further, after calculating the area of the preset pattern, the method further includes: When the area of the preset pattern is greater than the area of the functional area of the chip under test, reduce the area of the light spot until the area of the preset pattern is less than or equal to the area of the functional area of the chip under test.

[0008] Further, the extracting the light spot in the reflector image with a preset extraction strategy includes: Obtain all pixel points in the reflector image; Screen out the pixel points with a gray level greater than a set threshold from all the pixel points, and all the pixel points with a gray level greater than the set threshold form the light spot.

[0009] In a second aspect, an embodiment of the present application further provides a coupling control device for the functional area of a chip under test and a light source, including a processor, which is used to execute the above method when running.

[0010] Further, it further includes: A light source; A stage, located below the light source, and the tabletop of the stage is used to place the chip under test; A reflector, fixed on the stage, and the height of the tabletop of the stage is the same as that of the reflector; The stage is movable so that the stage can drive the functional area of the chip under test to be directly below the light source and drive the reflective surface of the reflector to be directly below the light source; A vision terminal, fixed on the stage, and the camera of the vision terminal is used to photograph the reflective surface of the reflector.

[0011] Further, the light source is connected with a light spot size modulator, and the light of the light source is output to the reflector or the functional area of the chip under test through the light spot size modulator to form a light spot.

[0012] The invention adopting the above technical solution has the following advantages: In the technical solution provided by this application, a picture of a reflective member is collected. When a light source irradiates the reflective surface of the reflective member, the light spot in the picture of the reflective member is extracted. Based on the area of the light spot on the reflective member, the movement of the functional area of the chip to be tested and / or the movement of the light source are controlled, and the light spot falls into the functional area of the chip to be tested. In this application, based on the area of the light spot, the movement of the light source and / or the functional area is controlled to make the light source and the functional area in a coupled state, replacing the existing technical means of coupling the light source and the functional area by human eye observation. Compared with the existing technology, this technical solution improves the accuracy of detecting the performance indicators of the chip to be tested and eliminates the inaccurate test data caused by human differences.

[0013] In the technical solution provided by this application, the edge line of the light spot is accurately extracted through an edge detection algorithm to avoid manual judgment errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] This application can be further illustrated by the non-limiting embodiments given in the drawings. It should be understood that the following drawings only show some embodiments of this application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0015] Figure 1 It is a flowchart of the method provided in Embodiment 1 of this application.

[0016] Figure 2 It is a schematic diagram of the light spot provided in Embodiment 1 of this application.

[0017] Figure 3 It is a flowchart of step 120 provided in Embodiment 1 of this application.

[0018] Figure 4 It is a flowchart of step 130 provided in Embodiment 1 of this application.

[0019] Figure 5 It is a schematic diagram of the edge line of the light spot provided in Embodiment 1 of this application.

[0020] Figure 6 It is a schematic diagram of the device structure provided in Embodiment 2 of this application (the stage is directly below the light source).

[0021] Figure 7 It is a schematic diagram of the device structure provided in Embodiment 2 of this application (the reflective member is directly below the light source).

[0022] ICON: 1 - Light source; 2 - Light spot size modulator; 3 - Stage; 4 - Reflective member; 5 - Visual terminal. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The present application will be described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that in the accompanying drawings or the description of the specification, similar or identical parts are all denoted by the same reference numerals. The implementation manners not depicted or described in the accompanying drawings are in the forms known to those of ordinary skill in the art. In the description of the present application, terms such as "first" and "second" are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance. Embodiment 1

[0024] Please refer to Figure 1 , an embodiment of the present application provides a method for coupling a functional area of a chip under test with a light source. The method for coupling the functional area of the chip under test with the light source may include the following steps: Step 110: Acquire a picture of the reflecting member, which is obtained by a camera photographing the reflecting surface of the reflecting member when the light source irradiates the reflecting surface of the reflecting member; Step 120: Extract the light spot in the picture of the reflecting member according to a preset extraction strategy; Step 130: Control the movement of the functional area of the chip under test and / or the movement of the light source based on the area of the light spot on the reflecting member, so that the light spot falls into the functional area of the chip under test, and the light source and the functional area are in a coupled state to detect the performance index of the chip under test.

[0025] In the above implementation manner, the functional area refers to a specific area on the chip that needs to be irradiated by the light source and tested, such as an optical sensor, a receiving window, a photosensitive element, or other working areas that need to interact with the light source. This is the core functional part of the product.

[0026] The following will elaborate on each step of the method in detail as follows: In step 110, the reflecting member may be a reflector or other objects with reflective properties. When the light source irradiates the reflecting surface of the reflecting member, a light spot will be generated. Here, the light spot refers to a visible bright area formed on the reflecting surface of the reflector after the light emitted by the light source is reflected, refracted, or scattered.

[0027] Before performing step 110, move the reflecting member to directly below the light source, make the light rays output by the light source project onto the reflecting surface of the reflecting member, and then photograph the reflecting surface directly through the vision terminal to obtain a picture of the reflecting member. The vision terminal in this embodiment may be a camera, a camera, etc.

[0028] In this embodiment, the vision terminal photographs the reflecting surface directly, avoiding the deviation of the size of the light spot on the reflecting surface caused by the deviation of the photographing angle of the vision terminal, and further avoiding the distortion of determining the coupling degree between the functional area of the chip under test and the light source.

[0029] In this embodiment, the size of the light spot output by the light source can be clearly known through the image of the reflector, replacing the existing method of coupling the light source by human eye observation, and eliminating the inaccurate test data caused by human differences.

[0030] In step 120, the light spot on the reflector picture in this embodiment can be as Figure 2 shown. Figure 2 The white part in it represents the light spot.

[0031] In this embodiment, as Figure 3 shown, the method for obtaining the light spot may include the following steps: Step 121: Obtain all pixel points in the reflector picture; Step 122: Screen out the pixel points whose gray level is greater than the set threshold from all the pixel points, and the combination of all the pixel points whose gray level is greater than the set threshold constitutes the light spot. In this embodiment, the pixel points whose gray level is greater than the set threshold are considered as the positions of the reflector that can be irradiated by the light source.

[0032] In this embodiment, the reflector picture is input into the picture processing program, and the picture processing program can traverse each pixel point of the picture using nested for loops or array slicing operations of NumPy. Then, screen out the pixel points whose gray level is greater than the set threshold from all the pixel points, and delete the other pixel points. At this time, the combination of the pixel points whose gray level is greater than the set threshold in all the pixel points constitutes the light spot.

[0033] In the image processing process, especially when processing the reflector picture to extract the light spot, the main reasons for screening out the pixel points whose gray level is greater than the set threshold as the light spot are as follows: 1. Distinguish the light spot from the background: Since the light spot is usually brighter than the background, its gray level value will also be correspondingly higher. Therefore, by setting a threshold, the pixel points with gray level values higher than this threshold can be regarded as the light spot part, while the pixel points lower than this threshold are regarded as the background. This method can effectively distinguish the light spot from the complex background.

[0034] 2. Reduce noise interference: The image may contain various noises, such as random bright spots, miscellaneous points, etc. The gray level values of these noises may be low or similar to the light spot. By setting a reasonable threshold, most of the noise interference can be excluded, improving the accuracy of light spot extraction.

[0035] 3. Improve processing efficiency: When processing a large number of pixel points, screening out the pixel points whose gray level is greater than the set threshold can greatly reduce the number of pixel points to be processed, thus improving the efficiency of the entire image processing process.

[0036] 4. Adapt to different lighting conditions: By adjusting the threshold value, different lighting conditions can be adapted. For example, in the case of stronger lighting, the threshold value can be appropriately increased; in the case of weaker lighting, the threshold value can be appropriately decreased. In this way, regardless of how the lighting conditions change, the accurate extraction of the light spot can be ensured.

[0037] In this embodiment, step 130 may include the following steps, as Figure 4 shown, specifically including: Step 131: Obtain the edge line of the light spot according to the edge detection algorithm; Step 132: Fit the figure enclosed by the edge line into a preset figure; Step 133: Calculate the area of the preset figure; Step 134: When the area of the preset figure is less than or equal to the area of the functional area of the chip to be measured, control the movement of the functional area of the chip to be measured and / or the movement of the light source to make the center of the functional area of the chip to be measured coincide with the center of the preset figure, where the height of the position where the chip to be measured is located is the same as the height of the position of the reflector.

[0038] In step 132, the preset figure may be a circle or an ellipse. In at least one embodiment, when the preset figure is a circle, the fitted circle is as Figure 5 shown, and the fitting line is Figure 5 the red circular line in

[0039] In step 133, the method for calculating the area of the circle may be based on the following formula: Fitted circle area = the number of pixel points with a gray level greater than the set threshold × the area of a single pixel point with a gray level greater than the set threshold.

[0040] For example, if the length of a single pixel point with a gray level greater than the set threshold is 0.8um and the number of pixels of the fitted circle is 10000 pcs, then the area of a single pixel is 0.8um × 0.8um = 0.64um², and the total area is 0.64um² × 10000 = 6400um².

[0041] When the preset figure is an ellipse, the above method can also be used to calculate the area of the fitted ellipse.

[0042] Step 134 in this embodiment specifically includes the following steps: When the area of the preset pattern is less than or equal to the area of the functional area of the chip under test, move the functional area of the chip under test directly below the light source, with the center of the functional area of the chip under test coinciding with the center of the circle, and the height of the position where the functional area of the chip under test is located being the same as the height of the reflector. In this embodiment, the center of the functional area of the chip under test coincides with the center of the fitted circle or the center of the fitted ellipse, indicating the relative position based on the center of the preset pattern. Move the functional area of the chip under test below the light source output to ensure that the light output by the light source is completely within the functional area of the chip under test, ensuring accurate test data.

[0043] When the area of the preset pattern is greater than the area of the functional area of the chip under test, reduce the area of the light spot until the area of the preset pattern is less than or equal to the area of the functional area of the chip under test. Embodiment 2

[0044] This embodiment proposes a coupling device for the functional area of a chip under test and a light source. The device includes a processor that, when running, can execute the method described in Embodiment 1.

[0045] As Figure 6 shown, the device further includes a light source 1, a light spot size modulator 2, a stage 3, a reflector 4, and a vision terminal 5.

[0046] The stage 3 is located below the light source 1 and is used to place the chip.

[0047] The reflector 4 is fixed on the surface of the stage 3, and the surface of the stage 3 has the same height as the reflector 4.

[0048] The stage 3 is movable, enabling the stage 3 to drive the functional area of the chip under test directly below the light source 1 and drive the reflecting surface of the reflector 4 directly below the light source 1.

[0049] The vision terminal 5 is fixed on the stage 3, and the camera of the vision terminal 5 is directed at the reflecting surface of the reflector 4.

[0050] The light spot size modulator 2 is connected to the light source 1, and the light of the light source is output through the light spot size modulator 2.

[0051] The light spot size modulator is a device that can adjust the size of the laser beam spot and is mainly used to finely adjust the divergence angle and spot size of the laser beam. Specifically, the light spot size modulator can finely adjust the divergence angle of the input laser beam by 80% - 120%, enabling the output light spot to be adjusted proportionally. For example, for a beam shaper, an output light spot of 100um can be adjusted proportionally to 80 - 120um; for a beam splitter, a divergence angle of 1° can be adjusted proportionally to 0.8 - 1.2°1.

[0052] The spot size modulator adjusts the spot size by changing the propagation path and optical properties of the laser beam. Common adjustment methods include using optical elements such as convex lenses, concave lenses, beam expanders, etc., and changing the position and focal length of these elements to change the spot size2. In addition, some advanced spot size modulators can also be used in combination with other optical elements (such as flat-top beam shapers, homogenizers, multi-focus DOEs, etc.) to achieve more complex beam adjustment functions.

[0053] In this embodiment, the spot size can be modulated by the spot size modulator 2.

[0054] In this embodiment, the method for realizing chip testing based on the functional area of the chip under test and the light source coupling device includes the following steps, specifically: 1. Place the chip on the stage 3.

[0055] 2. As Figure 7 shown, move the stage 3 to make the reflector 4 directly below the light source 1, and the light emitted by the light source 1 is projected onto the reflector 4; 3. The vision terminal 5 takes a picture of the light source spot on the light receiving plate to obtain a reflector picture; 4. Send the reflector picture to the picture processing module to obtain a fitted circle; 5. According to the reflector picture with the fitted circle, judge the area of the spot and the area of the functional area of the chip under test; 6. When the functional area of the chip under test is greater than or equal to the spot, control the functional area of the chip under test on the stage 3 to be directly below the light source, so that the center of the functional area of the chip under test coincides with the center of the circle, and start the test.

[0056] The above are only the embodiments of the present application and are not used to limit the protection scope of the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A coupling control method between a functional area of ​​a chip to be tested and a light source, characterized in that: The method comprises: Collecting a reflective member image, wherein the reflective member image is obtained by photographing the reflective surface of the reflective member by a camera when a light source is irradiated on the reflective surface of the reflective member; Extracting the light spot in the reflective element image using a preset extraction strategy; Based on the area of ​​the light spot on the reflective element, the functional area of ​​the chip to be tested and / or the light source are controlled to move so that the light spot falls into the functional area of ​​the chip to be tested, so that the light source and the functional area are in a coupled state to detect the performance indicators of the chip to be tested.

2. The method according to claim 1, characterized in that: The controlling the movement of the functional area of ​​the chip to be tested and / or the movement of the light source based on the area of ​​the light spot on the reflector, wherein the light spot falls within the functional area of ​​the chip to be tested, comprises: According to an edge detection algorithm, an edge line of the light spot is obtained; Fitting the figure enclosed by the edge lines into a preset figure; Calculating and obtaining the area of ​​the preset figure; When the area of ​​the preset pattern is less than or equal to the area of ​​the functional area of ​​the chip to be tested, the functional area of ​​the chip to be tested and / or the light source are controlled to move so that the center of the functional area of ​​the chip to be tested coincides with the center of the preset pattern, and the height of the position of the chip to be tested is consistent with the height of the position of the reflective element.

3. The method according to claim 2, characterized in that: After the area of ​​the preset figure is obtained by calculation, the method further includes: When the area of ​​the preset pattern is larger than the area of ​​the functional area of ​​the chip to be tested, the area of ​​the light spot is reduced until the area of ​​the preset pattern is smaller than or equal to the area of ​​the functional area of ​​the chip to be tested.

4. The method according to claim 1, characterized in that: The step of extracting the light spot in the reflective element image by using a preset extraction strategy includes: Obtaining all pixels in the reflective element image; Pixels with grayscales greater than a set threshold are screened out from all the pixel points, wherein all the pixel points with grayscales greater than the set threshold constitute the light spot.

5. A coupling control device between a functional area of ​​a chip to be tested and a light source, characterized in that: The method comprises a processor, wherein the processor is used to execute the method according to any one of claims 1 to 4 when running.

6. The device according to claim 5, characterized in that: Also includes: light source; A carrier, located below the light source, the surface of the carrier being used to place the chip to be tested; A reflective member is fixed on the carrier, and the height of the carrier surface is the same as that of the reflective member; The stage is movable so that the stage can drive the functional area of ​​the chip to be tested to be located directly below the light source, and drive the reflective surface of the reflective element to be located directly below the light source; A visual terminal is fixed on the platform, and a camera of the visual terminal is used to photograph the reflective surface of the reflective element.

7. The device according to claim 6, characterized in that: The light source is connected to a light spot size modulator, and the light of the light source is output to the reflective element or the functional area of ​​the chip to be tested through the light spot size modulator to form a light spot.

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