CN109001228A - A kind of substrate defects detection rotary table with back lighting - Google Patents

Abstract

The invention provides a substrate defect detection rotary workbench with backlighting. The positioning device includes ring trays for substrates of different sizes. The ring trays are equipped with scales to realize circular substrates of different specifications. Positioning; the cylindrical connecting bracket is used to connect the substrate positioning device and the backlighting device to realize the sealing of the light source; the backlighting device provides various forms of light sources while ensuring uniform lighting; the circular adapter plate realizes the lighting device and the fixation of the rotary table; the rotary table can drive the backlighting device and the substrate positioning device to realize rotary motion; the base with detachable function is used to fix the substrate positioning device and connect with the detection platform. Compared with the existing devices, the present invention can not only realize accurate positioning and rotary motion of substrate wafers of various specifications for full-field scanning test, but also provide a variety of uniformly illuminated backlight sources to meet the needs of different defect detection. lighting needs.

Description

A rotary table for substrate defect detection with backlighting

technical field

The invention relates to the field of substrate defect measurement, in particular to a substrate defect detection rotary table with backlighting.

Background technique

With the rapid development of semiconductor materials, there is a great demand for high-performance semiconductor materials, especially in LED lighting, power electronic devices, new energy vehicles and other fields; the semiconductor substrate is the support of the entire device, and the quality of the substrate is directly related to device performance. During the processing of the substrate material, damage will inevitably occur, leaving defects on the surface of the substrate, and the substrate is mostly in a circular transparent/translucent state, with strong light transmission, and the color contrast between the defect and the substrate itself Smaller, which puts forward higher requirements for non-destructive optical inspection.

In the detection system of the substrate defect, the lighting device, the positioning device and the movement mode of the worktable occupy a pivotal position. The way, angle, uniformity and intensity of light directly affect the measurement effect and the difficulty of post-image processing; the way of substrate placement, the flatness of placement and the repeatability of measurement directly affect the positioning accuracy; The choice of the movement mode of the table directly affects the detection speed, especially in the high-precision measurement system, when the detection field of view is small, the rotary motion is added to reduce the detection time of the whole field.

In the existing detection devices, such as the optical lens surface defect detection system designed by the patent CN 204064972 U, the system has three light sources and three cameras, which respectively complete the positioning, front detection and reverse detection of the optical lens. Through the combination of the thimble structure and the manipulator, the exchange of the front and back of the optical lens is completed, and the automatic detection of the defects on the front and back of the optical lens is realized at different stations. However, the whole system adopts frontal direct incident and single light source for illumination. If backlight is used, the light source is not sealed, and it is easily interfered by external light during front and back detection, which will affect the accuracy of the detection results. The semiconductor wafer detection device designed by the patent CN 204359271U, the device controls the movement through the calculation and analysis of the semiconductor wafer profile image by the computer, realizes that the detection light is projected on the specific position of the semiconductor wafer, and uses the optical path collection system to combine the light intensity and The spectral information is sent to the computer to form an information map of light intensity and spectral data corresponding to the position. The light source of the device is embedded in the detection system, there is only one lighting option, and only the light intensity and spectral information corresponding to the wafer position can be obtained. The wafer defect measurement device designed by patent CN 106574900 A uses upper and lower blowers to spray air onto the wafer surface to fix the wafer, and is equipped with three measuring devices to complete the defect detection of the upper, lower and side surfaces of the wafer. However, this device is only suitable for wafer detection of a single size, and the positioning accuracy cannot be guaranteed. Therefore, under the single-light source lighting mode, a single-sized workbench and positioning device cannot meet the inspection requirements of transparent or translucent substrate materials with different specifications and different types of defects.

Contents of the invention

The main technical problem to be solved by the present invention is to provide a rotary table for detecting substrate defects with backlighting and a rotary table for detecting substrate defects with backlighting.

In order to solve the above-mentioned technical problems, the present invention provides a substrate defect detection rotary table with backlight, including: a base, a rotary table, a circular adapter plate, a backlight device, a cylindrical connection Bottom positioning device;

The bottom end surface of the turntable forms a detachable fixed connection with the upper surface of the base; the upper surface of the turntable is linked with the circular connection plate; the motor drives the rotary table to drive the circular connection plate turn;

The backlight lighting device is arranged on the side of the circular connecting plate away from the rotary table, and the light output direction of the backlight lighting device is a direction away from the circular connecting plate; the backlight lighting device is away from the circular connecting plate One side of one side is connected with the substrate positioning device through the cylindrical connecting bracket;

The cylindrical connecting bracket irradiates the output light of the backlighting device in the cylindrical connecting bracket, and blocks ambient light from entering the cylindrical connecting bracket.

In a preferred embodiment: the substrate positioning device includes a plurality of positioning ring trays arranged in concentric circles.

In a preferred embodiment: the positioning ring tray has a chamfered slope with an inclination angle of 45° on its inner side; the upper surface of the positioning ring tray has an arc groove near the inner circle, which is convenient for the ring Tray and substrate handling.

In a preferred embodiment: the upper surface of the positioning ring tray has scales, and the scales of each positioning ring tray are evenly spaced along the radial direction, and are arranged at intervals along the circumferential direction in the shape of a rice for Position analysis and read relative position of substrate defect, track position during measurement.

In a preferred embodiment: the inner wall of the positioning ring tray has a substrate positioning edge; the inner wall of the positioning ring tray has a ring-shaped step for supporting the substrate.

In a preferred embodiment: the cylindrical connecting bracket has a hollow structure in the middle, and a step is provided on the inner side of the hollow structure for connecting the substrate positioning device and the backlighting device;

In a preferred embodiment: the lighting methods of the backlighting device include direct backlighting, low-angle lighting and high-angle lighting, all of which are uniform lighting, and the lighting method is selected according to the defect type of the substrate material.

In a preferred embodiment: the light intensity adjustment method of the backlight lighting device includes adjusting the area of the entire lighting device. The entire lighting device is divided into 8 areas on average according to the shape of "m", and each area has a Gear switch, select the intensity and angle of illumination according to the substrate material to be tested and the type and orientation of defects.

In a preferred embodiment: the circular adapter plate is used to fix the backlight device and the rotating table through the counterbore, so as to reduce the rotation during the turning process.

In a preferred embodiment: trapezoidal grooves are provided on both sides of the detachable base, which is convenient for manual access to the workbench.

The advantages and positive effects of the present invention are: a rotary workbench with backlighting for substrate defect detection, which meets the detection requirements of substrates of various specifications and sizes, provides various lighting modes, and meets the detection requirements of various defect types. The rotary table for detection is simple in structure, light and convenient, and can be used just by placing it on the displacement table, and has strong practicability.

Description of drawings

Fig. 1 is a schematic structural diagram of a rotary table for detection of substrate defects with backlighting in the present invention;

Fig. 2a-Fig. 2b are structural cross-sectional views of the rotary table for detecting substrate defects with backlighting in the direction A-A of the present invention;

3 is a top view of the substrate positioning device;

Figure 4 is an exploded view of the substrate positioning device;

Figure 5a-Figure 5b is a sectional view of a single positioning ring tray in the B-B direction;

Figure 6a-Figure 6b is a cross-sectional view of the cylindrical connection bracket in the C-C direction;

7a-7b are cross-sectional views of the backlighting device in the D-D direction;

Figure 8 is a top view of the backlighting device;

Fig. 9 is a schematic diagram of a substrate defect;

Figure 10a-Figure 10b is a cross-sectional view of the circular connecting plate in the E-E direction;

Figure 11a-Figure 11c are three views of the rotating table;

12a-12c are three views of the base.

In the picture:

1. Substrate positioning device 2. Cylindrical connecting bracket 3. Backlighting device

4. Ring connecting plate 5. Rotary table 6. Detachable base

11. Ring tray 1 12. Ring tray 2 13. Ring tray 3

111. Ring tray support steps 112. Ring tray slope groove 113. Ring tray scale line

114, circular tray arc groove 115, substrate positioning edge 21, 22 steps

23. Cylindrical bracket scale line 31. Low-angle backlight lighting method 32. High-angle backlight lighting method

33. Straight-down backlighting method 41. 42 Positioning sink holes 51. Main body of the rotating table

52. Rotary table motor 61, 62 Positioning holes 63. Trapezoidal groove

Detailed ways

In order to further explain the purpose, technical solution and features of the present invention, the structure and working principle of the rotary table for detecting substrate defects with backlight according to the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation examples.

Fig. 1 and Fig. 2 are schematic structural diagrams and cross-sectional views of a rotary table for detecting substrate defects with backlighting according to the present invention. The substrate defect detection rotary table with backlight includes a substrate positioning device 1 , a cylindrical support 2 , a backlight lighting device 3 , an annular connecting plate 4 , a rotary table 5 and a detachable base 6 . The substrate positioning device 1 is above the backlight lighting device 3, and the two are connected and fixed by a cylindrical bracket 2; the annular connecting plate 4 is used to connect and fix the lighting device 3 and the rotary table 5; the rotary table 5 can drive the lighting device 3 and the cylindrical bracket 2 and the substrate positioning device 1 to perform rotary motion together; the rotary table 5 is fixed on the top of the detachable base 6, and a positioning hole is left under the detachable base 6, which is convenient for fixing the entire detection workbench above the translation stage.

For the positioning of the substrate material, the top view and exploded view of the substrate positioning device 1 are shown in FIG. 3 and FIG. 4 . The present invention takes 2-inch, 4-inch and 6-inch substrates as examples, but is not limited to these 3 sizes of substrate wafers. It can be seen from Fig. 3 that the positioning device is mainly composed of a positioning ring tray. When detecting a 6-inch substrate, only the positioning ring tray 13 is required. When detecting a 4-inch substrate, it is necessary to add a positioning circle to the positioning ring tray 13. Ring tray 12, when detecting a 2-inch substrate, a positioning ring tray 11 is added to the tray for detecting a 4-inch substrate; each positioning ring tray has a scale line 114 with an interval of 5mm, and the scale line 114 is in a circle. The center of the ring tray is centered and spread out in the form of a "meter" word line. On the other side, there is a substrate positioning edge scale mark, which is convenient for the positioning of the circular substrate. When measuring, the relative position of the defect can be obtained for further Measurement. As shown in Figure 5, the inner side of each ring tray has a substrate positioning edge 115, which can fix the substrate and position it; the inner side of each ring tray has three annular steps 111, and the substrate wafer When testing, it is used to support the substrate or support the ring tray; the inner side of the ring tray has a chamfer slope 112 not greater than 45°, which is convenient for picking and placing between the ring trays and between the substrate and the ring tray. Picking and placing: There are also symmetrical arc-shaped grooves 113 on the surface of the ring tray to facilitate manual picking and placing of substrate wafers.

The cylindrical connecting bracket 2 is shown in FIG. 6 , and has a hollow structure in the middle. Steps 21 and 22 are provided on the inner wall of the hollow structure. The substrate positioning device 1 is embedded in the upper part, and the lighting device 3 is embedded in the lower part. . The upper surface of the cylindrical connection bracket has a scale line 23 along the circumferential direction, which is used for the positioning of the ring tray.

As shown in FIG. 7 , the lighting device 3 mainly provides three types of lighting: direct backlighting 33 , high-angle backlighting 32 and low-angle backlighting 31 . When detecting defects in the entire field of the substrate, select the direct backlight 33; when detecting defects such as chipping and pitting of the substrate, select the high-angle backlight 32; when detecting defects such as scratches and cracks, select the low Angled backlighting31. The direct-type backlight 33 adopts a circular arrangement (triangular, rhombus, and "meter" shapes are also acceptable), and the distance between each small bulb is equal. The uniformity of the lighting device 3 is related to several parameters: the distance between the tested sample and the lighting device 3, the light angle between the tested sample and the light source, the arrangement of the light sources, the light intensity distribution of each light source, and the like.

Each LED light source in the lighting device 3 is identical, and the light intensity distribution of each light source conforms to the Lambertian distribution. Compared with the entire optical system, the size of a single LED is small, so a single LED can be regarded as a point light source. Arrangement of multiple LEDs in an array can increase the total luminous flux. The arrangement of LEDs can be ring, line, triangle, rectangle, rhombus, etc. The present invention takes ring as an example. The illuminance at a certain point in the space should be the superposition of the illuminance emitted by each LED in the array at that point. To ensure uniformity, the number of LEDs should be an even number. The distribution function of the light intensity of a single LED is

I _θ =I ₀ cosθ (1)

Since the light intensity distribution of the light source is a cosine function of the luminous angle, the illuminance of the light shining on the target surface is also a cosine function, that is, the illuminance distribution on the target surface is expressed as:

E(r,θ)＝E ₀ (r)cos ^m θ (2)

Where θ represents the angle between the light emitted by the LED light source to a certain point on the target surface and the normal line of the light-emitting surface, E ₀ (r) represents the illuminance value at the distance r between the normal direction of the light-emitting surface and the light source, and the value of m depends on the LED chip and LED The relative position of the center of the encapsulated lens surface is related to the primary optical design. N LEDs are arranged in a circular array in the Cartesian coordinate system, and the radius of the circular ring is r, then the coordinates of the LEDs are n=0, 1, 2, . . . , N. The illuminance at any point in the space illuminated by the LED is expressed as:

It can be seen that the illuminance emitted to the substrate is the superposition of N LED illumination, adjusting the radius r of the ring array can determine that the uniformity of the illuminance distribution in the central area is the largest when the substrate plane is away from the light source z, and the E(x, y, z) to find the second differential, let x=0, y=0 place, It can be seen that the condition for maximum uniformity is:

It can be seen from the above formula that the radius of the ring array has nothing to do with the number of LEDs, and it can be considered that the size of N (>3) does not change the maximum uniformity condition. Therefore, the direct-lit backlight 31 satisfies the uniformity condition.

There are two ways to adjust the lighting intensity in the lighting device 3, one is to adjust the lighting intensity of each small bulb through a button; As shown in Figure 8, each area is equipped with a switch, which can control the switch and adjust the lighting intensity. When the lighting intensity is weak, in addition to adjusting the brightness of each small bulb, you can also only turn on the symmetrical part of the area. , such as zone 1, 3, 5, 7. For defects of different shapes in different areas, during detection, by controlling the light intensity of a single area, an image with higher contrast is obtained. If the defect is in the position of area 1 as shown in Figure 9, a stronger light intensity is required to detect this defect , you can individually increase the light intensity of area 1.

The annular connecting plate 4 is shown in FIG. 10 , the upper part fixes the lighting device 3 on the annular connecting plate 4 through the positioning counterbore 41 , and the lower part connects with the rotary table 5 through the positioning counterbore 42 . Make a permanent connection.

As shown in Figure 11, the rotary table 5 is controlled by a stepping motor 52 to drive the substrate positioning device 1 and the backlighting device 3 to perform rotary motion. Field defect detection.

The detachable base 6 is shown in Figure 12. There is a trapezoidal groove 63 on the inside to facilitate the movement of the workbench. There is a positioning hole 61 on the top, which can be fixed with the annular connecting plate. There is a positioning hole 62 below, which directly fixes the workbench in the displacement on stage. A circular hole 65 is opened in the middle part, and a groove 64 is opened in the bottom, through which the wire of the light source is connected to the control switch on the outside.

The rotary workbench for substrate defect detection with backlight illumination of the present invention has a simple and compact structure and strong practicability, and is suitable for a multi-size, multiple defect and all-round substrate defect detection system. It is flexible to replace different detection optical systems according to different measurement requirements.

The above is only a preferred embodiment of the present invention, but the design concept of the present invention is not limited thereto. Any person familiar with the technical field can use this concept to carry out the present invention within the technical scope disclosed in the present invention. Non-substantial changes all belong to the act of violating the protection scope of the present invention.

Claims (11)

1. a kind of substrate defects detection rotary table with back lighting, characterized by comprising: pedestal, turntable, circle Annular pinboard, backlighting arrangement, cylindrical connecting bracket and substrate positioning device；

The bottom face of the turntable is formed with the upper surface of pedestal and is removably fixedly connected；The upper surface of the turntable with The circular ring shape connecting plate is connected；Motor driven turntable drives the circular ring shape connecting plate rotation；

The backlighting arrangement is arranged in one side of the circular ring shape connecting plate far from turntable, and the backlighting arrangement Light direction is the direction far from the circular ring shape connecting plate；One side of the backlighting arrangement far from circular ring shape connecting plate is logical The cylindrical connecting bracket is crossed to connect with the substrate positioning device；

The light that goes out of backlighting arrangement is radiated in cylindrical connecting bracket by the cylinder connecting bracket, and stops environment light Into in cylindrical connecting bracket.

2. a kind of substrate defects detection rotary table with back lighting according to claim 1 it is characterized by: The substrate positioning device includes multiple positioning annulus pallets in concentric arrays.

3. a kind of substrate defects detection rotary table with back lighting according to claim 2, it is characterised in that: The positioning annulus pallet, the chamfering slope for being 45 ° with inclination angle on the inside of it；The upper surface of the positioning annulus pallet is close Inner circle has arc groove, convenient for the pick-and-place of annulus pallet and substrate.

4. a kind of substrate defects detection rotary table with back lighting according to claim 2, it is characterised in that: The positioning annulus tray upper surface has scale, and the scale of each positioning annulus pallet is set along evenly spaced radial It sets, and circumferentially interval setting is in M shape, for the relative position of positioning analysis and reading substrate defects, in measurement process Middle tracing positional.

5. a kind of substrate defects detection rotary table with back lighting according to claim 2, it is characterised in that: The positioning annulus pallet inner sidewall positions side with substrate；The positioning annulus pallet inner sidewall has circular platform Rank is used to support substrate.

6. a kind of substrate defects detection rotary table with back lighting according to claim 1, it is characterised in that: The cylindrical connecting bracket, centre are hollow structure, and the inside of hollow structure is equipped with step, for connecting substrate positioning dress It sets and backlighting arrangement.

7. a kind of substrate defects detection rotary table with back lighting according to claim 1, it is characterised in that: The lighting method of the backlighting arrangement includes downward back optical illumination, low angle illumination and high angle illumination, and is Uniform Illumination chooses the mode of illumination according to the defect type of substrate material.

8. a kind of substrate defects detection rotary table with back lighting according to claim 7, it is characterised in that: The light intensity regulating mode of the backlighting arrangement includes adjusting to the region of entire lighting device, entire lighting device according to " rice " font is divided into 8 regions, and each region is equipped with driving switch, according to the material of tested substrate and defect Type, orientation choose the intensity and angle of illumination.

9. a kind of substrate defects detection rotary table with back lighting according to claim 1, it is characterised in that: The circular ring shape pinboard is reduced in turning course by the counterbore fixed backlighting arrangement and turntable Rotation.

10. a kind of substrate defects detection rotary table with back lighting according to claim 1, feature exist In: the two sides of the detachable base have trapezoidal groove, are convenient for manual manipulation workbench.

11. the substrate defects detection rotary table according to claim 1 with back lighting, it is characterised in that: institute The substrate stated is the Circular wafer of transparent/translucent, and the size of substrate is current mainstream size: 2 inches, 4 inches, 6 inches, 8 inches, but it is not limited to these four sizes.