A device and method for realizing imaging detection of the front and rear end surfaces of semiconductor grains in the direction of travel

Abstract

The present invention relates to a device and method for realizing imaging detection of the front and rear end faces of a semiconductor crystal grain in the direction of its movement. The device is characterized in that a camera, a telecentric imaging lens, a combining prism, a first group of image rotation prism assemblies, a second group of image rotation prism assemblies, a semiconductor crystal grain and a glass object turntable are sequentially arranged in the direction of the optical path of the optical device, and the combining prism is located on the optical axis of the telecentric imaging lens. The detection device can realize dynamic detection of the front and rear end faces of the semiconductor crystal grain in the direction of its movement, while reducing the requirements for the field of view of the imaging lens and effectively controlling the cost of the detection device. The third and fourth right-angle image rotation prisms used in the detection device of the present invention are installed above the glass object turntable and the semiconductor crystal grain, without contacting the surface of the semiconductor crystal grain and without interfering with the glass object turntable, and can realize dynamic detection of the front and rear end faces of the semiconductor crystal grain in the direction of its movement.

Description

Technical Field

[0001] The invention relates to a device and method for realizing imaging detection of the front and rear end surfaces of a semiconductor crystal grain in its moving direction. Background Art

[0002] Traditional machine vision optical inspection devices mainly include cameras, imaging lenses, lighting sources, image processing algorithm software, electrical control, mechanical structure, and objects to be tested (such as semiconductor refrigeration device grains). The light source illuminates the object, and the object obtains its image on the CCD detector surface through the optical imaging lens. The image is then transmitted to the computer through the image acquisition card and AD conversion module. Finally, the required image information is obtained through digital image processing technology. Based on pixel distribution, brightness, color and other information, the size, shape, and color are judged and measured, thereby controlling the operation of the equipment on site.

[0003] Currently published patents have proposed a variety of methods for achieving double-sided imaging detection of objects to be tested (semiconductor grains), such as Figure 1 This is an invention patent application with application number 201911369257.3. Figure 2 The invention patent application number is 202010133044.7, and Figure 3 It is an invention patent application with application number 202010250856.X, but the methods proposed so far are only applicable to imaging detection of two adjacent sides or two relative sides of semiconductor grains, or using two detection stations to obtain detection of four sides.

[0004] In order to improve detection efficiency, semiconductor grain screening machines need to be able to detect defects on six surfaces, including two end surfaces. However, the imaging detection of the front face (or rear face) of the object along the movement direction of the object turntable has not yet been solved; the main difficulty encountered is that it is difficult to install the imaging optical device directly in front of the end face of the object to be tested on the object turntable, and it cannot contact the object glass turntable. The optical axis of the imaging optical device needs to form a small angle with the normal of the object end face in order to obtain the image of the end face, which addresses the difficulties in the current object end face detection. Summary of the Invention

[0005] In view of the above problems in the prior art, the present invention provides a device and method for realizing imaging detection of the front and rear end surfaces of a semiconductor crystal grain in the direction of travel.

[0006] The present invention implements an apparatus for imaging and detecting the front and rear end faces of a semiconductor crystal grain in its traveling direction, characterized in that a camera, a telecentric imaging lens, an image combining prism, a first set of image relay prism assemblies, a second set of image relay prism assemblies, a semiconductor crystal grain, and a glass object turntable are sequentially arranged in the optical path direction of the optical device, wherein the image combining prism is located on the optical axis of the telecentric imaging lens;

[0007] The first group of image-reversing prism assemblies comprises a first right-angle image-reversing prism and a second right-angle image-reversing prism symmetrically arranged on either side of the combining prism, wherein the first right-angle sides of the first and second right-angle image-reversing prisms are parallel to the optical axis of the telecentric imaging lens, the second right-angle sides of the first and second right-angle image-reversing prisms are perpendicular to the optical axis of the telecentric imaging lens, and the oblique surfaces of the first and second right-angle image-reversing prisms face away from the optical axis of the telecentric imaging lens and form an angle of 45 degrees therewith.

[0008] The second group of image-relay prisms comprises a third right-angle image-relay prism and a fourth right-angle image-relay prism symmetrically arranged below the first group of image-relay prisms; the first right-angle sides of the third and fourth right-angle image-relay prisms are away from the optical axis of the telecentric imaging lens, the second right-angle sides of the third and fourth right-angle image-relay prisms are close to the second right-angle side of the first or second right-angle image-relay prisms, and the oblique surfaces of the third and fourth right-angle image-relay prisms are close to the optical axis of the telecentric imaging lens;

[0009] The semiconductor crystal grain is supported by a glass object turntable and rotates therewith, and the front and rear end surfaces of the semiconductor crystal grain in the moving direction, that is, the first end surface and the second end surface of the semiconductor crystal grain are parallel to the optical axis of the telecentric imaging lens.

[0010] In one embodiment, the first right-angle sides of the third and fourth right-angle image-reversing prisms are parallel to the optical axis of the telecentric imaging lens, the second right-angle sides are perpendicular to the optical axis of the telecentric imaging lens, and the inclined surfaces face the optical axis of the telecentric imaging lens and form a 45-degree angle with the optical axis of the telecentric imaging lens.

[0011] In one embodiment, the third and fourth right-angle rotating prisms rotate by an angle θ, so that the inclined surfaces of the third and fourth right-angle rotating prisms form an angle of 45-θ with the optical axis of the telecentric imaging lens.

[0012] In one embodiment, glass wedges are respectively provided between the first right-angle image-reversing prism, the second right-angle image-reversing prism, and the image-combining prism, and the two glass wedges are symmetrically arranged to cause the optical axis of the semiconductor grain to be refracted and deflected at a certain angle.

[0013] In one embodiment, the glass wedge is a right triangle, with one right-angled side parallel to the optical axis and an inclined surface facing the combining prism. The right-angled side and the inclined surface are spaced apart from the first right-angle image rotation prism, the second right-angle image rotation prism, and the combining prism.

[0014] In one embodiment, the glass wedges are integrated and connected to the first right-angle sides of the first right-angle image-reversing prism and the second right-angle image-reversing prism, and the inclined surfaces are spaced apart from the image-reversing prism.

[0015] In one embodiment, the image-combining prism is in the shape of a rectangle, and its sky surface close to the camera is the imaging output plane and is perpendicular to the optical axis of the telecentric imaging lens. The left and right planes of the image-combining prism are respectively imaging input surfaces parallel to the optical axis of the telecentric imaging lens; the middle part of the bottom surface of the image-combining prism away from the camera and perpendicular to the optical axis has total reflection surfaces at 90 degrees to each other, and the total reflection surfaces form a V-shaped groove.

[0016] The present invention provides a method for imaging and detecting the front and rear end faces of a semiconductor die in the direction of travel, characterized in that: the device for imaging and detecting the front and rear end faces of the semiconductor die in the direction of travel comprises, in sequence along the optical path, a CMOS camera, a telecentric imaging lens, a combining prism, a first set of image relay prism assemblies, a second set of image relay prism assemblies, the semiconductor die, and a glass object turntable, wherein the combining prism is located on the optical axis of the telecentric imaging lens;

[0017] The first group of image-reversing prism assemblies comprises a first right-angle image-reversing prism and a second right-angle image-reversing prism symmetrically arranged on either side of the combining prism, wherein the first right-angle sides of the first and second right-angle image-reversing prisms are parallel to the optical axis of the telecentric imaging lens, the second right-angle sides of the first and second right-angle image-reversing prisms are perpendicular to the optical axis of the telecentric imaging lens, and the oblique surfaces of the first and second right-angle image-reversing prisms face away from the optical axis of the telecentric imaging lens and form an angle of 45 degrees therewith.

[0018] The second group of image-relay prisms comprises a third right-angle image-relay prism and a fourth right-angle image-relay prism symmetrically arranged below the first group of image-relay prisms; the first right-angle sides of the third and fourth right-angle image-relay prisms are away from the optical axis of the telecentric imaging lens, the second right-angle sides of the third and fourth right-angle image-relay prisms are close to the second right-angle side of the first or second right-angle image-relay prisms, and the oblique surfaces of the third and fourth right-angle image-relay prisms are close to the optical axis of the telecentric imaging lens;

[0019] The semiconductor die is supported by a glass object turntable and rotates therewith. The front and rear end faces of the semiconductor die in the direction of travel, i.e., the first end face and the second end face of the semiconductor die, are parallel to the optical axis of the telecentric imaging lens. When the semiconductor die is located on the left side of the detection device, the distance between its first end face and the third right-angle rotation prism is a given working distance. The first end face is imaged on the camera sensor after being imaged by the third right-angle rotation prism, the first right-angle rotation prism, and the image combining prism. When the semiconductor die moves to the right side of the detection device, the distance between its second end face and the fourth right-angle rotation prism is a given working distance. The second end face is imaged by the fourth right-angle rotation prism, the second right-angle rotation prism, and the image combining prism.

[0020] The first right-angle sides of the third and fourth right-angle image-reversing prisms are parallel to the optical axis of the telecentric imaging lens, the second right-angle sides are perpendicular to the optical axis of the telecentric imaging lens, and the inclined surfaces face the optical axis of the telecentric imaging lens and form a 45-degree angle with the optical axis of the telecentric imaging lens. When the semiconductor die is located on the left side of the detection device, and the distance between its first end face and the third right-angle image-reversing prism is a given working distance, the first end face is imaged on the left side of the camera sensor after being imaged by the third right-angle image-reversing prism, the first right-angle image-reversing prism, and the image combining prism. When the semiconductor die moves to the right side of the detection device, and the distance between its second end face and the fourth right-angle image-reversing prism is a given working distance, the second end face is imaged on the right side of the camera sensor after being imaged by the fourth right-angle image-reversing prism, the second right-angle image-reversing prism, and the image combining prism.

[0021] Adjust the given working distance and the focal length of the telecentric imaging lens so that the end faces of the front and rear two semiconductor grains meet the imaging conditions at the same time point, and obtain simultaneous imaging detection of the two end faces of the two semiconductor grains on the camera sensor. By intercepting the right image in the previous image and the left image in the next image, the two images are spliced together to form an image of the front and rear end faces in the moving direction of the semiconductor grain, thereby realizing imaging detection of the two end faces of the semiconductor grain.

[0022] In one embodiment, the third and fourth right-angle image-reversing prisms rotate through an angle θ so that the inclined surfaces of the third and fourth right-angle image-reversing prisms form an angle of 45°-θ with the optical axis of the telecentric imaging lens, thereby converting off-axis object imaging to on-axis object imaging. When the semiconductor die is located on the left side of the detection device and the distance between its first end face and the third right-angle image-reversing prism is a given working distance, the first end face is imaged on the left side of the camera sensor after being image-reversed by the third right-angle image-reversing prism, the first right-angle image-reversing prism, and the image-reversing prism. When the semiconductor die moves to the right side of the detection device and the distance between its second end face and the fourth right-angle image-reversing prism is a given working distance, the second end face is imaged on the right side of the camera sensor after being image-reversed by the fourth right-angle image-reversing prism, the second right-angle image-reversing prism, and the image-reversing prism.

[0023] In one embodiment, glass wedges are respectively disposed between the first right-angle image rotation prism, the second right-angle image rotation prism, and the combining prism. The two glass wedges are symmetrically arranged to cause the optical axis of the semiconductor die to refract and deflect by a certain angle, thereby converting the imaging of an off-axis object into the imaging of an on-axis object. When the semiconductor die is located on the left side of the detection device, and the distance between its first end face and the third right-angle image rotation prism is a given working distance, the first end face is imaged on the left side of the camera sensor after being imaged by the third right-angle image rotation prism, the first right-angle image rotation prism, and the combining prism. When the semiconductor die moves to the right side of the detection device, and the distance between its second end face and the fourth right-angle image rotation prism is a given working distance, the second end face is imaged on the right side of the camera sensor after being imaged by the fourth right-angle image rotation prism, the second right-angle image rotation prism, and the combining prism.

[0024] The glass wedge is a right triangle, with a right-angled side parallel to the optical axis and an inclined surface facing the combining prism. The right-angled side, the inclined surface, the first right-angle image rotation prism, the second right-angle image rotation prism and the combining prism are spaced apart.

[0025] Alternatively, the glass wedges are integrally connected to the first right-angled sides of the first and second right-angle image-reversing prisms, with the inclined surfaces spaced apart from the image-reversing prism. As can be seen from the above description of the structure of the present invention, compared to the prior art, the present invention has the following advantages:

[0026] 1. The third and fourth right-angle image-rotating prisms used in the detection device of the present invention are installed above the glass turntable and the semiconductor die. They do not need to contact the surface of the semiconductor die and will not interfere with the glass turntable. They can realize dynamic detection of the front and rear end surfaces of the semiconductor die in the direction of travel.

[0027] 2. The imaging detection device for the front and rear end surfaces in the direction of travel proposed in the present invention realizes a detection station for detecting the front and rear end surfaces in the direction of travel of a moving object by using two sets of image rotation prism assemblies and image combination prisms, thereby reducing the requirements for the field of view size of the imaging lens and effectively controlling the cost of the detection device.

[0028] 3. The detection device of the present invention can be equipped with two other stations for detecting the four sides of the object, so that simultaneous imaging detection of six sides of the object can be completed on one screening machine, effectively reducing the missed detection ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 、 2 It is a schematic diagram of the structure of an existing optical device for detecting two surfaces of a semiconductor crystal grain;

[0030] Figure 3 It is a schematic diagram of the structure of an existing optical device for detecting adjacent surfaces of semiconductor grains;

[0031] Figure 4 is a schematic structural diagram of an embodiment of the device of the present invention (i.e., a case where a right-angle side of the third right-angle image-reversing prism and the fourth right-angle image-reversing prism is perpendicular to the optical axis of the telecentric imaging lens);

[0032] Figure 5 is a schematic structural diagram of another embodiment of the device of the present invention (i.e., a case where the inclined surfaces of the third and fourth right-angle-reversing prisms face the optical axis and are rotated by an angle);

[0033] Figure 6 is a schematic structural diagram of another embodiment of the device of the present invention (i.e., a case where glass wedges are respectively provided between the first right-angle image rotation prism, the second right-angle image rotation prism, and the image combining prism);

[0034] Figure 7 is a schematic structural diagram of another embodiment of the device of the present invention (i.e., a case where a glass optical wedge is integrally connected to a right angle edge of the first right-angle image-reversing prism and the second right-angle image-reversing prism);

[0035] Figure 8 yes Figure 5 A schematic structural diagram of a local specific embodiment;

[0036] Figure 9 This is the end face image collected by the semiconductor grain end face imaging detection device experimentally in the present application;

[0037] Figure 10 yes Figure 4 A partial view of the . DETAILED DESCRIPTION

[0038] The present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0039] like Figure 4-10 The present invention realizes an apparatus for imaging and detecting the front and rear end faces of a semiconductor crystal in the direction of its travel. A camera 1, a telecentric imaging lens 2, an image combining prism 3, a first group of image relay prism assemblies 4, a second group of image relay prism assemblies 5, a semiconductor crystal 6, and a glass object turntable 7 are sequentially arranged in the direction of the optical path of the optical device. The image combining prism 3 is located on the optical axis A of the telecentric imaging lens 2. Preferably, the image combining prism 3 is symmetrical about the optical axis A.

[0040] The camera 1 can be a CCD or CMOS camera, and the semiconductor crystal 6 usually refers to a rectangular or cube-shaped semiconductor crystal, which is placed on a glass turntable 7 as an object to be measured. The glass turntable 7 is rotated by a driving device to realize the circular rotation of the semiconductor crystal 6 on the glass turntable 7. Of course, the glass turntable 7 can also be a glass table that moves in a straight line.

[0041] The first group of image-relay prisms 4 comprises a first right-angle image-relay prism 4a and a second right-angle image-relay prism 4b symmetrically arranged on either side of the combining prism 3. The first right-angled sides 401 of the first right-angle image-relay prism 4a and the second right-angle image-relay prism 4b are parallel to the optical axis of the telecentric imaging lens 2, and the second right-angled sides 402 of the first right-angle image-relay prism 4a and the second right-angle image-relay prism 4b are perpendicular to the optical axis of the telecentric imaging lens. The inclined surfaces 403 face away from the optical axis of the telecentric imaging lens 2 and form a 45-degree angle with the optical axis.

[0042] The second image-relay prism assembly 5 comprises a third right-angle image-relay prism 5a and a fourth right-angle image-relay prism 5b symmetrically arranged below the first image-relay prism assembly 4. A first right-angle side 501 of the third right-angle image-relay prism 5a and the fourth right-angle image-relay prism 5b is away from the optical axis of the telecentric imaging lens. A second right-angle side 502 of the third right-angle image-relay prism and the fourth right-angle image-relay prism is close to the second right-angle side of the first right-angle image-relay prism or the second right-angle image-relay prism. An inclined surface 503 of the third right-angle image-relay prism and the fourth right-angle image-relay prism is close to the optical axis of the telecentric imaging lens.

[0043] like Figure 4 This is an embodiment structure, the first right-angle side 501 of the third right-angle image-reversing prism and the fourth right-angle image-reversing prism is parallel to the optical axis A of the telecentric imaging lens, the second right-angle side 502 is perpendicular to the optical axis of the telecentric imaging lens, and the inclined surface 503 faces the optical axis of the telecentric imaging lens and forms a 45-degree angle with the optical axis of the telecentric imaging lens.

[0044] The semiconductor crystal grain 6 is supported by the glass object turntable 7 and rotates therewith, and moves below the second set of image relay prism components 5 and in a direction perpendicular to the optical axis A. The front and rear end faces of the semiconductor crystal grain in the direction of travel, i.e., the first end face 6a and the second end face 6b of the semiconductor crystal grain, are parallel to the optical axis A of the telecentric imaging lens.

[0045] When the inspection begins (e.g. Figure 4As shown, when the semiconductor die 6 moves to the left side of the inspection device and its first end face 6a is at a given working distance WD from the third right-angle image rotation prism 5a, the first end face 6a is imaged by the third right-angle image rotation prism 5a, the first right-angle image rotation prism 4a, and the combining prism 3a, forming an image on the sensor of the camera 1. When the semiconductor die 6 moves to the right side of the inspection device and its second end face 6b is at a given working distance WD from the fourth right-angle image rotation prism 5b, the second end face 6b is imaged by the fourth right-angle image rotation prism 5b, the second right-angle image rotation prism 4b, and the combining prism 3b, forming an image on another area of the sensor of the camera 1. Clear images can be obtained for different semiconductor die sizes by adjusting the WD distance, the working distance of the imaging lens, the focal length of the camera, and other factors. Thus, imaging inspection of the first and second end faces of the semiconductor die 6 can share a single optical inspection station, allowing images of the two end faces of the same semiconductor die 6, which is moving on the glass sample turntable 7, to be obtained at different imaging time points.

[0046] During the detection process, at a certain point in time, only one end face of a semiconductor grain (the right end face of the semiconductor grain on the left side of the detection device or the left end face of the semiconductor grain on the right side of the detection device) is imaged and detected. If at the same point in time, the end faces of two semiconductor grains meet the imaging conditions at a certain working distance, then simultaneous imaging detection of the two end faces of the two semiconductor grains can be obtained on the camera sensor. By splitting and splicing the detected front and back images (i.e., capturing the right image in the previous image and the left image in the next image, and splicing the two images to form an image of the front and back end faces in the moving direction of a semiconductor grain), imaging detection of the two end faces of the semiconductor grain is achieved.

[0047] Since the semiconductor crystal grain 6 of the above-mentioned detection device is located in the off-axis area of the imaging system, a lens with a larger field of view is required to obtain the imaging of the end face, thereby increasing the complexity of the detection device and the cost of the camera in the detection device. In order to reduce the requirement for the field of view of the telecentric imaging lens 2, the side of the camera is reduced. Another embodiment of the present invention is as follows: Figure 5 As shown, the third and fourth right-angle image-reversing prisms are rotated by an angle θ (which can be 3 degrees) so that the inclined surfaces of the third and fourth right-angle image-reversing prisms form an angle of 45-θ (42 degrees) with the optical axis of the telecentric imaging lens, thereby satisfying the conversion of off-axis object imaging into on-axis object imaging. In addition to the above, the other structures are the same as Figure 4 The third right angle image rotation prism and the fourth right angle image rotation prism and the distance WD2 from the upper surface of the semiconductor crystal grain 6 may be 1.1mm, the third right angle image rotation prism and the fourth right angle image rotation prism and the distance WD1 from the lower end of the semiconductor crystal grain 6 end surface may be 65mm (eg Figure 8 shown).

[0048] When this embodiment is in operation, when the semiconductor die 6 is located on the left side of the detection device and the distance between its first end face 6a and the third right-angle image rotation prism 5a is a given working distance WD, the first end face 6a is imaged by the third right-angle image rotation prism 5a, the first right-angle image rotation prism 4a, and the combining prism 3a and then formed on the left side of the sensor of the camera 1; when the semiconductor die 6 moves to the right side of the detection device and the distance between its second end face 6b and the fourth right-angle image rotation prism 5b is a given working distance WD, the second end face 6b is imaged by the fourth right-angle image rotation prism 5b, the second right-angle image rotation prism 4b, and the combining prism 3b and then formed on the right side of the sensor of the camera 1, thereby achieving the effect of reducing the imaging field of view. During detection in this embodiment, two end faces of semiconductor die (such as Figure 5 When the right end face of the previous semiconductor grain and the left end face of the next semiconductor grain meet the imaging conditions at a certain working distance, simultaneous imaging detection of the two end faces of the two semiconductor grains can be obtained on the camera sensor, and imaging detection of the two end faces of the semiconductor grains is achieved by splitting and splicing the detected front and back images (that is, capturing the right image in the previous image and the left image in the next image, and splicing the two images to form an image of the front and back end faces in the moving direction of the semiconductor grain).

[0049] Another embodiment of the present invention is Figure 6 and Figure 7 As shown, glass wedges are respectively provided between the first right-angle image-reversing prism 4a, the second right-angle image-reversing prism 4b and the combining prism 3, and the two glass wedges 8a and 8b are symmetrically arranged to cause the optical axis of the semiconductor crystal grain 6 to be refracted and deflected at a certain angle, thereby converting the imaging of an off-axis object into the imaging of an on-axis object. Figure 6 and Figure 7 There are two glass wedge configurations, one embodiment of which is as follows: Figure 6 As shown, the glass wedge is a right triangle, with one right-angled side parallel to the optical axis and the inclined surface facing the combining prism. The right-angled side and the inclined surface are spaced apart from the first right-angle image turning prism, the second right-angle image turning prism, and the combining prism. In another embodiment, the glass wedges are integrally connected to the first right-angled sides of the first and second right-angle image turning prisms, and the inclined surfaces are spaced apart from the combining prism.

[0050] In this embodiment, the two glass wedges 8a and 8b are integrated and connected to the right-angle sides of the first right-angle image-reversing prism 4a and the second right-angle image-reversing prism 4b that are parallel to the optical axis of the telecentric imaging lens 2 (e.g., Figure 7As shown in FIG, the semiconductor die 6 is located on the left side of the detection device. When the distance between its first end face 6a and the third right-angle image rotation prism 5a is a given working distance WD, the first end face 6a is imaged by the third right-angle image rotation prism 5a, the first right-angle image rotation prism 4a, the glass wedge 8, and the combining prism 3a, and is formed on the left side of the sensor of the camera 1. The semiconductor die 6 moves to the right side of the detection device. When the distance between its second end face 6b and the fourth right-angle image rotation prism 5b is a given working distance WD, the second end face 6b is imaged by the fourth right-angle image rotation prism 5b, the second right-angle image rotation prism 4b, the glass wedge 8, and the combining prism 3b, and is formed on the right side of the sensor of the camera 1, thereby achieving the effect of reducing the imaging field of view. Similarly, in this embodiment, during detection, two end faces of semiconductor die (as shown in FIG) may be formed at the same time point. Figure 7 When the right end face of the previous semiconductor grain and the left end face of the next semiconductor grain meet the imaging conditions at a certain working distance, simultaneous imaging detection of the two end faces of the two semiconductor grains can be obtained on the camera sensor, and imaging detection of the two end faces of the semiconductor grains is achieved by splitting and splicing the detected front and back images (that is, capturing the right image in the previous image and the left image in the next image, and splicing the two images to form an image of the front and back end faces in the moving direction of the semiconductor grain).

[0051] In the above embodiments, the combining prism 3 is rectangular and can be made of a single prism or formed by two small pieces symmetrically bonded together (with a total reflection surface in the middle). The sky surface of the combining prism 3 close to the camera 1 is the imaging output plane and is perpendicular to the optical axis of the telecentric imaging lens 2. The left and right planes of the combining prism 3 are respectively the imaging input surfaces parallel to the optical axis of the telecentric imaging lens 2. The center of the bottom surface of the combining prism 3, which is away from the camera 1 and perpendicular to the optical axis, is a total reflection surface at 90 degrees to each other. The total reflection surfaces form a V-shaped groove. The dimensions of the combining prism 3 are 20x10x20mm, wherein the width of the V-shaped groove opening on the bottom surface is 8-12mm. The right-angled sides of the first, second, third, and fourth right-angle image-transferring prisms 4a, 4b, 5a, and 5b can all be 10-25mm in length.

[0052] During use, the distance between the images of the two end faces of the semiconductor crystal grain 6 and the center of the imaging sensor of the camera 1 can be adjusted by adjusting the position of the image combining prism 3 up and down, so that the off-axis object can be imaged to the center area of the field of view of the camera 1.

[0053] This detection device can be combined with an existing optical detection device for iso-optical imaging of the two relative surfaces of semiconductor grains or a confocal imaging detection device for simultaneous and completely iso-optical imaging of adjacent surfaces of cooled grains using glass wedge imaging. The two workstations for detecting four sides form a screening machine, which can achieve simultaneous imaging detection of six surfaces of an object on one screening machine, effectively reducing the missed detection rate of semiconductor grains.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention. They should all be included in the scope of the technical solution for protection of the present invention.

Claims

1. A device for imaging and detecting the front and rear end faces of a semiconductor die in its traveling direction, characterized by: A camera, a telecentric imaging lens, a combining prism, a first group of image relay prism assemblies, a second group of image relay prism assemblies, a semiconductor die, and a glass object turntable are sequentially arranged in the optical path direction of the device, and the combining prism is located on the optical axis of the telecentric imaging lens; The first group of image-reversing prism assemblies comprises a first right-angle image-reversing prism and a second right-angle image-reversing prism symmetrically arranged on either side of the combining prism, wherein the first right-angle sides of the first and second right-angle image-reversing prisms are parallel to the optical axis of the telecentric imaging lens, the second right-angle sides of the first and second right-angle image-reversing prisms are perpendicular to the optical axis of the telecentric imaging lens, and the oblique surfaces of the first and second right-angle image-reversing prisms face away from the optical axis of the telecentric imaging lens and form an angle of 45 degrees therewith. The second group of image-relay prisms comprises a third right-angle image-relay prism and a fourth right-angle image-relay prism symmetrically arranged below the first group of image-relay prisms; the first right-angle sides of the third and fourth right-angle image-relay prisms are away from the optical axis of the telecentric imaging lens, the second right-angle sides of the third and fourth right-angle image-relay prisms are close to the second right-angle side of the first or second right-angle image-relay prisms, and the oblique surfaces of the third and fourth right-angle image-relay prisms are close to the optical axis of the telecentric imaging lens; The semiconductor crystal grain is supported by a glass object turntable and rotates therewith, and the front and rear end faces of the semiconductor crystal grain in the direction of travel, that is, the first end face and the second end face of the semiconductor crystal grain are parallel to the optical axis of the telecentric imaging lens; the image-forming prism is rectangular and is made of a single prism or formed by two small pieces symmetrically bonded together.

2. The device for realizing imaging detection of the front and rear end surfaces of a semiconductor die in the direction of travel according to claim 1, characterized in that: The first right-angle sides of the third and fourth right-angle image-reversing prisms are parallel to the optical axis of the telecentric imaging lens, the second right-angle sides are perpendicular to the optical axis of the telecentric imaging lens, and the inclined surfaces face the optical axis of the telecentric imaging lens and form an angle of 45 degrees with the optical axis of the telecentric imaging lens.

3. The device for realizing imaging detection of the front and rear end surfaces of a semiconductor die in the direction of travel according to claim 1, characterized in that: The third and fourth right-angle image-reversing prisms rotate by an angle θ, so that the inclined surfaces of the third and fourth right-angle image-reversing prisms form an angle of 45-θ with the optical axis of the telecentric imaging lens.

4. The device for realizing imaging detection of the front and rear end surfaces of a semiconductor crystal grain in the direction of travel according to claim 1 or 2, characterized in that: Glass wedges are respectively provided between the first right-angle image-reversing prism, the second right-angle image-reversing prism and the image-combining prism, and the two glass wedges are symmetrically arranged to cause the optical axis of the semiconductor grain to be refracted and deflected at a certain angle.

5. The device for realizing imaging detection of the front and rear end surfaces of a semiconductor crystal in the direction of travel according to claim 4, characterized in that: The glass wedge is a right triangle, with a right-angled side parallel to the optical axis and an inclined surface facing the combining prism. The right-angled side, the inclined surface, the first right-angle image rotation prism, the second right-angle image rotation prism and the combining prism are spaced apart.

6. The device for realizing imaging detection of the front and rear end surfaces of a semiconductor die in the direction of travel according to claim 4, characterized in that: The glass wedges are integrated and connected to the first right-angle sides of the first right-angle image-reversing prism and the second right-angle image-reversing prism, and the inclined surfaces are spaced apart from the image-combining prism.

7. The device for realizing imaging detection of the front and rear end surfaces of a semiconductor crystal grain in the direction of travel according to claim 1, 2, 3, 5 or 6, characterized in that: Its sky surface close to the camera is the imaging output plane and is perpendicular to the optical axis of the telecentric imaging lens. The left and right planes of the image-combining prism are respectively the imaging input surfaces parallel to the optical axis of the telecentric imaging lens; the middle part of the bottom surface of the image-combining prism away from the camera and perpendicular to the optical axis has total reflection surfaces at 90 degrees to each other, and the total reflection surfaces form a V-shaped groove.

8. A method for imaging and detecting the front and rear end faces of a semiconductor die in its moving direction, characterized by: The device for realizing imaging detection of the front and rear end surfaces of the semiconductor crystal grain in the direction of travel is provided with a CMOS camera, a telecentric imaging lens, an image combining prism, a first group of image relay prism assemblies, a second group of image relay prism assemblies, a semiconductor crystal grain and a glass object turntable in sequence along the optical path direction, wherein the image combining prism is located on the optical axis of the telecentric imaging lens; The first group of image-reversing prism assemblies comprises a first right-angle image-reversing prism and a second right-angle image-reversing prism symmetrically arranged on either side of the combining prism, wherein the first right-angle sides of the first and second right-angle image-reversing prisms are parallel to the optical axis of the telecentric imaging lens, the second right-angle sides of the first and second right-angle image-reversing prisms are perpendicular to the optical axis of the telecentric imaging lens, and the oblique surfaces of the first and second right-angle image-reversing prisms face away from the optical axis of the telecentric imaging lens and form an angle of 45 degrees therewith. The second group of image-relay prisms comprises a third right-angle image-relay prism and a fourth right-angle image-relay prism symmetrically arranged below the first group of image-relay prisms; the first right-angle sides of the third and fourth right-angle image-relay prisms are away from the optical axis of the telecentric imaging lens, the second right-angle sides of the third and fourth right-angle image-relay prisms are close to the second right-angle side of the first or second right-angle image-relay prisms, and the oblique surfaces of the third and fourth right-angle image-relay prisms are close to the optical axis of the telecentric imaging lens; The semiconductor die is supported by a glass object turntable and rotates therewith. The front and rear end faces of the semiconductor die in the direction of travel, i.e., the first end face and the second end face of the semiconductor die, are parallel to the optical axis of the telecentric imaging lens. When the semiconductor die is located on the left side of the detection device, the distance between its first end face and the third right-angle rotation prism is a given working distance. The first end face is imaged on the camera sensor after being imaged by the third right-angle rotation prism, the first right-angle rotation prism, and the image combining prism. When the semiconductor die moves to the right side of the detection device, the distance between its second end face and the fourth right-angle rotation prism is a given working distance. The second end face is imaged by the fourth right-angle rotation prism, the second right-angle rotation prism, and the image combining prism. The first right-angle sides of the third and fourth right-angle image-reversing prisms are parallel to the optical axis of the telecentric imaging lens, the second right-angle sides are perpendicular to the optical axis of the telecentric imaging lens, and the inclined surfaces face the optical axis of the telecentric imaging lens and form a 45-degree angle with the optical axis of the telecentric imaging lens. When the semiconductor die is located on the left side of the detection device, the distance between its first end face and the third right-angle image-reversing prism is a given working distance, and the first end face is imaged on the left side of the camera sensor after being imaged by the third right-angle image-reversing prism, the first right-angle image-reversing prism, and the image combining prism. When the semiconductor die moves to the right side of the detection device, the distance between its second end face and the fourth right-angle image-reversing prism is a given working distance. When the working distance is fixed, the second end face is imaged on the right side of the camera sensor after being imaged by the fourth right-angle image rotation prism, the second right-angle image rotation prism, and the image combining prism. The given working distance and the focal length of the telecentric imaging lens are adjusted so that the end faces of the front and rear semiconductor crystal grains meet the imaging conditions at the same time point, and simultaneous imaging detection of the two end faces of the two semiconductor crystal grains is obtained on the camera sensor. By intercepting the right image in the previous image and the left image in the next image, the two images are spliced to form an image of the front and rear end faces of the semiconductor crystal grain in the direction of travel, thereby realizing imaging detection of the two end faces of the semiconductor crystal grain.

9. The method for realizing imaging detection of the front and rear end surfaces of a semiconductor die in the direction of travel according to claim 8, characterized in that: The third and fourth right-angle image-reversing prisms rotate through an angle θ, so that the inclined surfaces of the third and fourth right-angle image-reversing prisms form an angle of 45°-θ with the optical axis of the telecentric imaging lens, thereby converting off-axis object imaging into on-axis object imaging. When the semiconductor die is located on the left side of the detection device, and the distance between its first end face and the third right-angle image-reversing prism is a given working distance, the first end face is imaged on the left side of the camera sensor after being image-reversed by the third right-angle image-reversing prism, the first right-angle image-reversing prism, and the image-reversing prism. When the semiconductor die moves to the right side of the detection device, and the distance between its second end face and the fourth right-angle image-reversing prism is a given working distance, the second end face is imaged on the right side of the camera sensor after being image-reversed by the fourth right-angle image-reversing prism, the second right-angle image-reversing prism, and the image-reversing prism.

10. A method for imaging and detecting the front and rear end faces of a semiconductor die in the direction of travel according to claim 8, wherein glass wedges are respectively provided between the first and second right-angle image rotation prisms and the combining prism, and the two glass wedges are symmetrically arranged to cause the optical axis of the semiconductor die to refract and deflect by a certain angle, thereby converting off-axis object imaging into on-axis object imaging; when the semiconductor die is located on the left side of the detection device, and the distance between its first end face and the third right-angle image rotation prism is a given working distance, the first end face is imaged on the left side of the camera sensor after being imaged by the third right-angle image rotation prism, the first right-angle image rotation prism, and the combining prism; when the semiconductor die moves to the right side of the detection device, and the distance between its second end face and the fourth right-angle image rotation prism is a given working distance, the second end face is imaged on the right side of the camera sensor after being imaged by the fourth right-angle image rotation prism, the second right-angle image rotation prism, and the combining prism; The glass wedge is a right triangle, with one right-angled side parallel to the optical axis, an inclined surface facing the combining prism, and a gap between the right-angled side and the inclined surface and the first right-angle image turning prism, the second right-angle image turning prism, and the combining prism; or the glass wedges are integrally connected to the first right-angled sides of the first and second right-angle image turning prisms, and a gap between the inclined surfaces and the combining prism.

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