CN211426290U

CN211426290U - Optical device for simultaneously detecting semiconductor crystal grain top surface and side surface

Info

Publication number: CN211426290U
Application number: CN201922179727.1U
Authority: CN
Inventors: 廖廷俤; 苏龙龙; 颜少彬; 段亚凡
Original assignee: Quanzhou Normal University
Current assignee: Quanzhou Normal University
Priority date: 2019-12-09
Filing date: 2019-12-09
Publication date: 2020-09-04
Anticipated expiration: 2029-12-09

Abstract

The utility model relates to an optical device for simultaneously detecting the top surface and the side surface of a semiconductor crystal grain, which comprises a camera, a telecentric imaging lens, a beam splitter with an angle of 45 degrees, a semiconductor crystal grain to be detected and a transparent glass objective table which are sequentially arranged in the direction perpendicular to an optical path; the system comprises a right-angle rotating image prism, a beam splitter and an illumination light source, wherein the right-angle rotating image prism, the beam splitter and the illumination light source share an angle of 45 degrees with a vertical light path, and the beam splitter and the illumination light source are sequentially arranged in the direction of the horizontal light path. The utility model provides an optical device that detects is carried out simultaneously to semiconductor crystalline grain roof and side, simple structure can realize detecting simultaneously object (semiconductor crystalline grain) side and roof.

Description

Optical device for simultaneously detecting semiconductor crystal grain top surface and side surface

Technical Field

The utility model relates to an optical device for simultaneously detecting the top and the side of a semiconductor crystal grain, which belongs to the field of machine vision and optical automatic detection.

Background

The conventional machine vision optical detection device mainly comprises a camera, an imaging lens, an illumination light source, image processing algorithm software, electrical control, a mechanical structure, an object to be detected (such as a semiconductor crystal grain) and the like. The object is illuminated by a light source, the object obtains an image of the object on the CCD detector surface through an optical imaging lens, the image is transmitted to a computer through an image acquisition card and an A-D conversion module, finally, required image information is obtained through a digital image processing technology, and the size, the shape and the color are distinguished and measured according to information such as pixel distribution, brightness, color and the like, so that the field equipment operation is controlled. If two faces of a single object are to be detected simultaneously, the current universal detection method is that one camera occupies one station to detect one face, and if two faces or more than two faces are to be detected simultaneously, a plurality of cameras need to occupy a plurality of stations to detect, so that the mechanism installation space is large, a plurality of sets of mechanism installation modules and a plurality of sets of circuit modules are needed simultaneously, the installation complexity is increased, and the system reliability is reduced.

The invention 2019101574716 discloses an apparatus and method for simultaneously optically inspecting both the top and bottom surfaces of an object (semiconductor die).

Patent 2019102070162 discloses an apparatus and method for optically inspecting two adjacent surfaces of a side surface and a bottom surface of an object (semiconductor die) simultaneously.

The prior art is limited to: a lens for inspection of a surface of an object (semiconductor die), or a lens for simultaneous inspection of the top and bottom surfaces of a semiconductor die, or a lens for simultaneous inspection of the side and bottom surfaces of a semiconductor die. The simultaneous detection of the side and the top of an object (semiconductor die) by one lens cannot be realized.

SUMMERY OF THE UTILITY MODEL

In view of the deficiencies of the prior art, the technical problem to be solved of the present invention is to provide an optical device for simultaneously detecting the top and the side of a semiconductor die, which can realize the simultaneous detection of the side and the top of an object (semiconductor die) by a lens.

In order to solve the technical problem, the technical scheme of the utility model is that: an optical device for simultaneously detecting the top surface and the side surface of a semiconductor crystal grain comprises a camera, a telecentric imaging lens, a beam splitter with an angle of 45 degrees, a semiconductor crystal grain to be detected and a transparent glass objective table which are sequentially arranged in the direction vertical to an optical path; the system comprises a right-angle rotating image prism, a beam splitter and an illumination light source, wherein the right-angle rotating image prism, the beam splitter and the illumination light source share an angle of 45 degrees with a vertical light path, and the beam splitter and the illumination light source are sequentially arranged in the direction of the horizontal light path.

Preferably, the illumination light source is positioned at the side part of the beam splitter with an angle of 45 degrees to realize an external horizontal optical axis, and the beam splitter adopts a semi-transparent semi-reflective beam splitter.

Preferably, the illumination light source is positioned at the side part of the coaxial illumination beam splitter arranged in the telecentric imaging lens to realize the built-in same-level optical axis.

Preferably, the 45 ° angle transflective beam splitter is designed to have a partial transmission, transmittance T, a partial reflection, reflectance R of 1-T, and T of 50%.

Preferably, the 45 ° beam splitter is designed such that half of the area is a highly reflective mirror and the other half is a flat transparent glass plate, forming a combined beam splitter.

Preferably, the transparent glass plate is plated with an AR antireflection film, and the inclined plane of the right-angle relay prism is also plated with the AR antireflection film.

Preferably, the camera comprises a sensor CCD or CMOS, and the camera and telecentric imaging lens are disposed downward above the 45 ° angle beam splitter.

Preferably, the right-angle relay prism is disposed at one side of the 45 ° beam splitter and the semiconductor die to be tested, and an inclined surface of the right-angle relay prism forms a 45 ° angle with the 45 ° beam splitter and faces the surface to be tested of the semiconductor die to be tested.

Compared with the prior art, the utility model discloses following beneficial effect has: the utility model provides an optical device that detects is carried out simultaneously to semiconductor crystalline grain roof and side, simple structure can realize detecting simultaneously object (semiconductor crystalline grain) side and roof.

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Drawings

Fig. 1 is a schematic structural diagram of a first embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a second embodiment of the present invention.

Fig. 3 is a schematic diagram of the optical path length calculation of fig. 2.

In the figure: the system comprises a 1-camera, a 2-telecentric imaging lens, a 3-semi-transparent semi-reflective beam splitter, a 4-semiconductor crystal grain to be tested, a 5-transparent glass objective table, a 6-right-angle rotating image prism, a 7-illumination light source, an 8-high reflection mirror surface, a 9-transparent glass flat plate and a 10-combined beam splitter.

Detailed Description

In order to make the aforementioned and other features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

All embodiments of the present invention are shown in fig. 1-3:

an optical device for simultaneously detecting the top surface and the side surface of a semiconductor crystal grain comprises a camera 1, a telecentric imaging lens 2, a beam splitter with an angle of 45 degrees, a semiconductor crystal grain 4 to be detected and a transparent glass objective table 5 which are sequentially arranged in the direction vertical to an optical path; a right-angle rotating image prism 6, a beam splitter sharing an angle of 45 degrees with the vertical light path and an illumination light source 7 which are arranged in sequence in the direction of the horizontal light path.

In the embodiment of the utility model provides an in, the camera contains sensor CCD or CMOS, and camera and telecentric imaging lens set up downwards in the top of the beam splitter at 45 jiaos.

The embodiment of the utility model provides an in, right angle reprint prism sets up in one side of beam splitter at 45 jiaos and the semiconductor crystalline grain that awaits measuring, and right angle reprint prism inclined plane becomes 45 contained angles and towards the surface that awaits measuring of the semiconductor crystalline grain that awaits measuring with the beam splitter at 45 jiaos.

As shown in fig. 1, on the basis of the above, the first embodiment of the present invention is distinguished as follows: the illumination light source is located at the side part of the beam splitter with an angle of 45 degrees to realize an external horizontal optical axis, the beam splitter adopts a semi-transmitting and semi-reflecting beam splitter 3, the semi-transmitting and semi-reflecting beam splitter with the angle of 45 degrees is designed to have a partial transmission and transmittance T, the partial reflection and reflectance R is 1-T, and T is usually selected to be 50%. The illumination with the illumination of approximately equal illumination of the side surface and the sky surface is obtained by properly and optimally designing the proportion of the local illumination of the upper half area and the lower half area of the illumination light source and the proportion of the transmittance (T) and the reflectivity (R) of the beam splitter.

As shown in fig. 2, on the basis of the above, the second embodiment of the present invention is distinguished as follows: the illumination light source is positioned at the side part of the coaxial illumination beam splitter arranged in the telecentric imaging lens to realize the built-in same horizontal optical axis, the beam splitter with an angle of 45 degrees is designed to be a high-reflection mirror surface 8 in one half area and a transparent glass plate 9 in the other half area to form a combined beam splitter 10, the transparent glass plate is plated with an AR anti-reflection film, and the inclined plane of the right-angle rotating image prism is also plated with an AR anti-reflection film. The method solves the problem of image recognition and processing difficulties caused by different illumination of two surfaces to be detected of the side surface and the sky surface in the existing double-surface detection technology, and can obtain illumination with illumination of the side surface and the sky surface which are approximately equal to each other. By means of the aplanatic imaging of the imaging light paths of the two adjacent surfaces of the side surface and the sky surface, imaging with the same definition of the side surface and the sky surface is obtained, and the depth of field requirement on the telecentric imaging lens can be reduced. If the aplanatic imaging of two adjacent object planes of the left side surface and the sky surface cannot be completely obtained, a telecentric imaging lens with certain depth of field can be selected to further obtain double-sided simultaneous clear imaging.

As shown in fig. 1, the method for testing an optical device for simultaneously testing a pair of semiconductor die top and side surfaces according to an embodiment of the present invention comprises the following steps: (1) the lower half part of an illumination beam emitted from an illumination light source is reflected by a 45-degree semi-transparent semi-reflective beam splitter to illuminate the sky surface of the semiconductor crystal grain to be detected on the transparent glass object stage, and the illuminated sky surface is imaged on the left half area of the camera sensor surface by a telecentric imaging lens after passing through the 45-degree semi-transparent semi-reflective beam splitter; (2) the illumination light beam emitted from the illumination light source, the upper half part of the illumination light beam penetrates through the 45-degree angle semi-transparent semi-reflective beam splitter and then is incident to the upper half part clear aperture of the inclined plane of the right-angle imaging prism, the illumination light beam is turned by the right-angle imaging prism and then illuminates the left side surface of the semiconductor crystal grain to be detected, the illuminated left side surface is sequentially turned by the secondary reflection of the right-angle imaging prism and the 90-degree reflection of the 45-degree angle semi-transparent semi-reflective beam splitter and then is imaged on the right half area of the sensor surface of the camera by the telecentric imaging lens; (3) and simultaneously obtaining images of the left side surface and the top surface of the semiconductor crystal grain to be tested from an imaging surface of the camera, wherein the images of the left side surface and the top surface are separated by a small distance.

As shown in fig. 2, the method for testing an optical device for simultaneously testing the top and the side of two pairs of semiconductor dies according to the embodiment of the present invention comprises the following steps: (1) a horizontal illumination light beam emitted from an illumination light source is firstly turned to 90 degrees by a built-in coaxial illumination beam splitter and then is emitted after being converted by a telecentric imaging lens, the left half part of the horizontal illumination light beam is transmitted by a 45-degree combined beam splitter and then illuminates the sky surface of a semiconductor crystal grain to be detected on a transparent glass objective table, and the illuminated sky surface is imaged on the left half area of a camera sensor surface by the telecentric imaging lens after passing through the 45-degree combined beam splitter; (2) the right half part of the illuminating light beam is reflected to the upper half part clear aperture of the inclined plane of the right-angle rotating image prism through the combined beam splitter with an angle of 45 degrees, the illuminating light beam is turned to illuminate the left side surface of the semiconductor crystal grain to be detected through the secondary reflection of the right-angle rotating image prism, the illuminated left side surface is turned to the right side surface through the secondary reflection of the right-angle rotating image prism and the 90-degree reflection of the combined beam splitter with the angle of 45 degrees along the original light path in sequence, and finally the illuminating light beam is imaged to the right half area of the camera sensor surface through the telecentric imaging lens; (3) and simultaneously obtaining images of the left side surface and the top surface of the semiconductor crystal grain to be tested from the imaging surface of the camera, wherein the images of the left side surface and the top surface are separated by a small distance.

As shown in fig. 3, the optical path calculation principle takes a second embodiment of the present invention as an example:

assuming that the length × width × height of the semiconductor die to be detected is i × j × k, the side of the semiconductor die is imaged on the right side of the camera view, the horizontal distance between the top surface and the side surface light path on the combined beam splitter is d, the optical axis length of the secondary reflection right-angle relay prism is L, the thickness of the combined beam splitter is t, the refractive indexes of the secondary reflection right-angle relay prism and the combined beam splitter are n, the calculation principle is shown in fig. 3, it can be known that JI is FG, the equivalent optical path of the side surface light path in the right-angle relay prism is L/n, and the equivalent optical path of the top surface light path in the right-The equivalent optical path of the light path refracted by the combined beam splitter is as follows:

the height difference of the skyward light path between the incident point and the emergent point of the combined beam splitter is as follows:

in order to make the die all able to be imaged on the camera through the right-angle relay prism, there must be:

minimum clear aperture of combined beam splitter:

assuming that the equivalent geometric optical path of the imaging optical path of the sky surface is S1, the equivalent geometric optical path of the imaging optical path of the die bottom surface is S2, and the equivalent geometric optical path difference between the two imaging optical beams is D, the following are:

according to the above requirements, assuming that a right-angle relay prism and a combined beam splitter made of K9 glass are used, the refractive index n is 1.5163, and if the length, width and height of the crystal grain to be detected are 2.10 × 1.30 × 1.30.30 mm, the image is formed on the top and side surfacesThe spacing is 1mm, the thickness of the combined beam splitter is 2mm, and the minimum clear aperture of the combined beam splitter is 6.14 × 2.1mm²The optical path HJ is greater than 5.76mm, therefore, 1 clear aperture of 7 × 7mm is selected²The thickness is 2 mm's combination beam splitter, 1 right angle face is long 30 mm's (the long L of skew surface is 42.4mm) right angle reprint prism, 1 CCD target surface size 2/3 ", and the camera that the pixel size is 3.45um changes the optical path difference through adjusting the horizontal distance between right angle reprint prism and the crystal grain, matches resolution ratio>The lens with the depth of field larger than the optical path difference of 100LP/mm can realize the simultaneous detection of the crystal grain top surface and side surface.

Adjusting and fixing the vertical position of the right-angle relay prism to enable HJ to be 40 mm; the horizontal position of the combined beam splitter is adjusted and fixed, the imaging distance d between the top surface and the side surface is 1mm, and according to the formula (4), when the distance AB between the right-angle relay prism and the crystal grain is 4.49mm, the optical path difference between the two imaging optical paths of the top surface and the side surface is zero.

In the embodiments of the present invention, the optical device can be used for simultaneously detecting the top surface and the side surface of the semiconductor die, but is not limited thereto.

The present invention is not limited to the above preferred embodiments, and any one can obtain various other optical devices for simultaneously detecting the top and side surfaces of a semiconductor die. All the equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims

1. An optical device for simultaneously inspecting a top surface and a side surface of a semiconductor die, comprising: the device comprises a camera, a telecentric imaging lens, a beam splitter with an angle of 45 degrees, a semiconductor crystal grain to be tested and a transparent glass objective table which are sequentially arranged in the direction vertical to an optical path; the system comprises a right-angle rotating image prism, a beam splitter and an illumination light source, wherein the right-angle rotating image prism, the beam splitter and the illumination light source share an angle of 45 degrees with a vertical light path, and the beam splitter and the illumination light source are sequentially arranged in the direction of the horizontal light path.

2. The optical device for simultaneously inspecting the top and sides of a semiconductor die of claim 1, wherein: the illumination light source is positioned on the side part of the beam splitter with an angle of 45 degrees to realize an external horizontal optical axis, and the beam splitter adopts a semi-transmitting semi-reflecting beam splitter.

3. The optical device for simultaneously inspecting the top and sides of a semiconductor die of claim 1, wherein: the illumination light source is positioned at the side part of the coaxial illumination beam splitter arranged in the telecentric imaging lens to realize a built-in same-level optical axis.

4. The optical device for simultaneously inspecting the top and sides of a semiconductor die of claim 2, wherein: a 45 ° angle transflective beam splitter is designed for partial transmission, transmittance T, partial reflection, reflectance R =1-T, T = 50%.

5. The optical device for simultaneously inspecting the top and sides of a semiconductor die of claim 3, wherein: the 45-degree beam splitter is designed to be a high-reflection mirror surface in one half area and a transparent glass flat plate in the other half area, so that a combined beam splitter is formed.

6. The optical device for simultaneously inspecting the top and sides of a semiconductor die of claim 5, wherein: the transparent glass plate is coated with an AR antireflection film, and the inclined plane of the right-angle relay prism is also coated with the AR antireflection film.

7. The optical device for simultaneously inspecting the top and sides of a semiconductor die as recited in any of claims 1-6, wherein: the camera comprises a sensor CCD or CMOS, and the camera and the telecentric imaging lens are arranged downwards above the beam splitter with an angle of 45 degrees.

8. The optical device for simultaneously inspecting the top and sides of a semiconductor die as recited in any of claims 1-6, wherein: the right-angle relay prism is arranged on one side of the beam splitter at the angle of 45 degrees and the semiconductor crystal grain to be detected, and the inclined surface of the right-angle relay prism forms an included angle of 45 degrees with the beam splitter at the angle of 45 degrees and faces the surface to be detected of the semiconductor crystal grain to be detected.