Short wave infrared detection device

Abstract

The invention provides a short-wave infrared detection device in the field of semiconductor chip detection, which is characterized in that the side edge of a mirror tube is connected with a laser sensor, the mirror tube is connected with a microscope through a liquid lens, and the microscope is arranged corresponding to backlight; the laser sensor detects the linear distance between the laser sensor and the surface layer of the chip, the liquid lens performs focusing according to the detected linear distance, backlight lights from the bottom of the chip, and the short-wave infrared camera detects the surface of the chip. According to the invention, the liquid lens performs autonomous focusing according to the distance to the surface layer of the chip measured by the laser sensor, the image capturing precision is improved, the combination of the special short-wave infrared camera, the special lens tube and the special short-focus SWIR microscope is adopted, the FOV: 3.53 mm * 2.83 mm is realized, the depth of field of field is 6 [mu] m, the precision is 1.38 / pixel, the liquid lens can penetrate through the surface layer of the chip to perform high-definition detection, and the problem of out-of-focus is effectively solved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor chip detection, in particular to a short-wave infrared detection device. Background Art

[0002] There are two problems with the existing reel to reel appearance inspection system: First, the field of view of the existing infrared camera is 1.28mm*1.025mm, which is too small to detect large chips. Second, the depth of field of the existing infrared camera is 20μm, and the image clarity is very poor. The existing infrared camera has a depth of field of 20μm and the image clarity is very poor. Due to the silicon layer on the cover film and the chip surface, the general visible light (wavelength 400~700nm) and near infrared light (wavelength 700~1000) cannot effectively penetrate the chip, so invisible light is needed. Invisible light is divided into short wavelengths (such as X-ray) and long wavelengths (such as SWIR), both of which can penetrate the retaining wall, but X-ray has strong energy and poses a safety risk to human cells, so there are greater requirements for mechanism design and space use (such as the environment requires lead plates, operators need to have a license to use, and operators need monthly health checks), so it is more practical to use long wavelengths (wavelength greater than 1000nm).

[0003] Because the carrier tape + cover film thickness is about 0.3mm (may reach 0.45mm), the space for the tape to pass through the track must be greater than 0.5mm. Therefore, when the tape is conveyed, there may be a 0.2mm Z-axis height error, which is greater than the 0.006mm depth of field of the lens and causes defocus. Therefore, a boss is designed just below the detection area of ​​the track to allow the pocket to sink on the boss, which can maximize the Z-axis stability. However, the thickness of the chip itself and the thickness of the bottom of the pocket will have errors, which may reach 0.01mm, so this method cannot 100% completely and effectively solve the defocus problem. Summary of the invention

[0004] In view of the defects in the prior art, an object of the present invention is to provide a short-wave infrared detection device.

[0005] A short-wave infrared detection device provided by the present invention comprises: a short-wave infrared camera, a mirror tube, a short-focal-length SWIR microscope, a laser sensor, a backlight and a liquid lens, wherein the short-wave infrared camera is connected to the mirror tube, the side of the mirror tube is connected to the laser sensor, the mirror tube is connected to the microscope via the liquid lens, and the microscope and the backlight are arranged correspondingly;

[0006] The laser sensor detects the straight-line distance between it and the surface of the chip, the liquid lens focuses according to the detected straight-line distance, the backlight illuminates from the bottom of the chip, and the short-wave infrared camera detects the surface of the chip.

[0007] Preferably, the distance between the laser sensor and the microscope is 16 Nmm, where N is a positive integer.

[0008] Preferably, the short-wave infrared camera adopts a 5.32 million high-pixel SWIR camera, and the pixel size of the short-wave infrared camera is 3.45μm*3.45μm, and the effective pixel is 2560W*2048H.

[0009] Preferably, the short focal length SWIR microscope adopts a 5x infrared microscope with a depth of field of 6 μm.

[0010] Preferably, the mirror tube adopts a customized 0.5x mirror tube.

[0011] Preferably, the accuracy of the short-wave infrared camera = pixel size of the short-wave infrared camera / magnification of the lens tube / magnification of the short-focal-length SWIR microscope;

[0012] The FOV of a shortwave infrared camera = the accuracy of the shortwave infrared camera * the effective pixels of the shortwave infrared camera.

[0013] Preferably, the accuracy of the short-wave infrared camera = 3.45 μm / 0.5 / 5 = 1.38 μm;

[0014] FOV of short-wave infrared camera = 1.38μm*2560*1.38μm*2048

[0015] Preferably, the FOV of the short-wave infrared camera is 3.53 mm*2.83 mm.

[0016] Preferably, the coaxial light source in the mirror tube is an LED light source.

[0017] Preferably, the spot range of the inner coaxial light in the mirror tube is greater than or equal to the FOV to form a rectangular circumscribed circle.

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

[0019] The liquid lens in the present invention performs autonomous focusing according to the distance to the chip surface measured by the laser sensor to improve the imaging accuracy. The combination of a special short-wave infrared camera + a special mirror tube + a special short-focal-length SWIR microscope achieves a FOV of 3.53mm*2.83mm, with a depth of field of 6um and an accuracy of 1.38 / pixel. It can penetrate the chip surface for high-definition detection and effectively solve the problem of out-of-focus. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the clarity of the image taken by the device in Example 1;

[0023] Figure 3 This is a schematic diagram of the clarity of the photos taken by the device in the comparative example.

[0024] The figure shows: a short-wave infrared camera 201 , a lens tube 202 , a short-focus SWIR microscope 203 , a laser sensor 204 , a backlight 205 , and a liquid lens 206 . DETAILED DESCRIPTION

[0025] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0026] Example 1

[0027] According to a short-wave infrared detection device provided by the present invention, Figure 1 As shown, it includes: a short-wave infrared detection device provided according to the present invention, including: a short-wave infrared camera 201, a mirror tube 202, a short-focus SWIR microscope 203, a laser sensor 204, a backlight 205 and a liquid lens 206, the short-wave infrared camera 201 is connected to the mirror tube 202, the side of the mirror tube 202 is connected to the laser sensor 204, the mirror tube 202 is connected to the microscope 203 through the liquid lens 206, and the microscope 203 and the backlight 205 are correspondingly arranged.

[0028] The laser sensor 204 detects the linear distance between it and the surface of the chip, and the liquid lens 206 focuses according to the detected linear distance. The backlight 205 illuminates from the bottom of the chip, and the short-wave infrared camera 201 detects the surface of the chip. During the detection process, the focus is on the chip surface ±3μm, and other places cannot be photographed, which effectively prevents interference. The laser sensor 204 detects the linear distance between the laser sensor 204 and the surface of the chip in the tape, and the liquid lens 206 adjusts the focus according to the detected linear distance.

[0029] The distance between the laser sensor 204 and the microscope 203 is 16Nmm, where N is a positive integer. Preferably, the distance between the laser sensor 204 and the infrared microscope 203 is a common multiple of 2 / 4 / 8. For example, taking 2pitch as an example, the laser sensor 204 detects the first chip, and the laser sensor 204 needs to detect all 8N chips, upload the data and make a table. When the first chip arrives at the first station, the laser sensor 204 is called to detect the first height, and then the liquid lens 206 focuses.

[0030] More specifically, the laser sensor 204 measures the distance to the surface of the chip, and the short-wave infrared light inspection station 13 also inspects the surface of the chip. Since the depth of field of the microscope 203 is only 6 μm, it is easy to lose focus, so an auto-focus liquid lens 206 is added. Before each short-wave infrared light inspection station 13 takes a photo, it is necessary to call the distance data measured by the laser sensor 204, and then the liquid lens 206 automatically focuses to ensure that it is not out of focus.

[0031] Example 2

[0032] This embodiment 2 is completed on the basis of embodiment 1, mainly limiting the model of the detection device to make the shooting effect clearer, such as Figure 2 As shown, specifically:

[0033] The short-wave infrared camera 201 uses a 5.32 million high-pixel SWIR camera with a pixel size of 3.45μm*3.45μm and an effective pixel of 2560W*2048H. The lens tube 202 uses a customized 0.5x lens tube, and the short-focus SWIR microscope 203 uses a 5x infrared microscope with a depth of field of 6μm. The short-wave infrared camera 201 is connected to the lens tube 202. The inner coaxial light source in the lens tube 202 uses an LED light source. The spot range of the inner coaxial light is greater than or equal to the FOV to form a rectangular circumscribed circle. The lens tube 202 is connected to the short-focus SWIR microscope 203, and the short-focus SWIR microscope 203 is correspondingly connected to the backlight 205.

[0034] The accuracy of the short-wave infrared camera 201 = pixel size of the short-wave infrared camera 201 3.45μm / magnification of the lens tube 202 / 0.5 magnification of the short-focus SWIR microscope 203 5 = 1.38μm; the FOV field of view of the short-wave infrared camera 201 = accuracy of the short-wave infrared camera 201 * effective pixels of the short-wave infrared camera 201 = (1.38μm*2560)*(1.38μm*2048) = 3.53mm*2.83mm.

[0035] The backlight 205 illuminates from the bottom of the tape, so that the bottom of the tape can be seen more clearly. The short-wave infrared camera 201 expands the FOV of the chip in the tape through the combination of the lens tube 202 and the short-focus SWIR microscope 203; combined with the 6μm depth of field, the imaging clarity is improved.

[0036] like Figure 2 As shown, the detection system in this embodiment has clear shooting effect. When short-wave photography is performed, the focus is on the chip surface, and the range of 3μm above and below can be photographed. Other places cannot be photographed, which will not interfere with the final result.

[0037] Comparative Example

[0038] The existing camera combination in this comparative example uses a 1.3 million pixel infrared camera, a 0.5x lens tube, and a 10x infrared microscope. Figure 3 As shown, the shooting effect is not clear. The specific FOV is as follows:

[0039] The 1.3-megapixel infrared camera has a pixel size of 5μm*5μm and an effective pixel size of 1280W*2024H;

[0040] The camera accuracy is 5 / 0.5 / 10=1μm;

[0041] FOV length = 1*1280 = 1280 μm = 1.28 mm;

[0042] FOV width = 1*2024 = 2024 μm = 1.024 mm;

[0043] The FOV is very small because it is a 10x infrared microscope, and the photo quality is not as good as that of a 5x microscope, and is not clear enough.

[0044] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0045] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A short-wave infrared detection device, characterized in that: include: A short-wave infrared camera (201), a mirror tube (202), a short-focal-length SWIR microscope (203), a laser sensor (204), a backlight (205), and a liquid lens (206), wherein the short-wave infrared camera (201) is connected to the mirror tube (202), a side of the mirror tube (202) is connected to the laser sensor (204), the mirror tube (202) is connected to the microscope (203) via the liquid lens (206), and the microscope (203) and the backlight (205) are arranged correspondingly; The laser sensor (204) detects the linear distance between the laser sensor and the surface of the chip, the liquid lens (206) focuses according to the detected linear distance, the backlight (205) illuminates the chip from the bottom, and the short-wave infrared camera (201) detects the surface of the chip.

2. The short-wave infrared detection device according to claim 1, characterized in that: The distance between the laser sensor (204) and the microscope (203) is 16 Nmm, where N is a positive integer.

3. The short-wave infrared detection device according to claim 1, characterized in that: The short-wave infrared camera (201) adopts a 5.32 million high-pixel SWIR camera; the pixel size of the short-wave infrared camera (201) is 3.45 μm*3.45 μm, and the effective pixel size is 2560W*2048H.

4. The short-wave infrared detection device according to claim 3, characterized in that: The short focal length SWIR microscope (203) is a 5-fold infrared microscope with a depth of field of 6 μm.

5. The short-wave infrared detection device according to claim 4, characterized in that: The mirror tube (202) is a customized 0.5x mirror tube.

6. The short-wave infrared detection device according to claim 5, characterized in that: The accuracy of the short-wave infrared camera (201) = the pixel size of the short-wave infrared camera (201) / the magnification of the mirror tube (202) / the magnification of the short-focus SWIR microscope (203); The FOV field of view of the short-wave infrared camera (201) = the accuracy of the short-wave infrared camera (201) * the effective pixels of the short-wave infrared camera (201).

7. The short-wave infrared detection device according to claim 6, characterized in that: The accuracy of the short-wave infrared camera (201) = 3.45 μm / 0.5 / 5 = 1.38 μm; The FOV of the short-wave infrared camera (201) = (1.38 μm*2560)*(1.38 μm*2048).

8. The short-wave infrared detection device according to claim 7, characterized in that: The FOV field of view of the short-wave infrared camera (201) is 3.53 mm*2.83 mm.

9. The short-wave infrared detection device according to claim 1, characterized in that: The inner coaxial light source in the mirror tube (202) is an LED light source.

10. The short-wave infrared detection device according to claim 9, characterized in that: The spot range of the inner coaxial light in the mirror tube (202) is greater than or equal to the FOV, forming a rectangular circumscribed circle.

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