Wafer single-side polishing device
By combining the polishing disc assembly, internal gear ring assembly, and central gear assembly, and adjusting the rotation speed and pressure, the problems of uneven grinding amount and low efficiency in single-sided wafer polishing were solved, achieving precise control of grinding amount and efficient polishing.
Patent Information
- Application Number
- CN202520618742.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2035-04-03
AI Technical Summary
Existing wafer single-sided polishing technology suffers from problems such as uneven grinding amount, low polishing efficiency, and inaccurate control of grinding amount.
The design employs a combination of a polishing disc assembly, an internal gear ring assembly, a central gear assembly, and a polishing head assembly. By adjusting the speeds of motors two and three, the linear velocity ratio between the internal gear ring and the central gear is controlled. Combined with the spring compression, the positive pressure during the grinding process is adjusted, thereby achieving precise control of the grinding amount.
It achieves precise control of the grinding amount during the wafer polishing process, avoids the slope phenomenon of thinner outer and thicker inner wafers, improves polishing quality and efficiency, and meets the requirements of high-precision polishing.
Smart Images
Figure CN223947606U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to wafer polishing technical field especially relates to a wafer single side polishing device. BACKGROUND
[0002] For the single side polishing of wafer, the following technical routes mainly exist: 1) wafer is fixed, and polishing disc rotates in situ; 2) polishing disc is fixed, and wafer rotates in situ; 3) wafer rotates in situ, and polishing disc rotates in situ.
[0003] For the first polishing mode, the singleness of relative motion direction leads to the existence of big difference in grinding amount between the inner side and the outer side of wafer. For the second polishing mode, the linear speed of wafer rotation is small, leading to low polishing efficiency. For the third polishing mode, although polishing efficiency and polishing uniformity are considered, but the accurate control of grinding amount cannot be realized. UTILITY MODEL CONTENTS
[0004] The utility model aims at providing a wafer single side polishing device to solve the problems existing in the above related technologies, and realize the accurate control of grinding amount while guaranteeing polishing efficiency and polishing uniformity.
[0005] To realize the above-mentioned purpose, the utility model provides the following scheme:
[0006] The utility model discloses a wafer single side polishing device, which comprises:
[0007] A polishing disc assembly comprises a motor one and a polishing disc, and the motor one is in transmission connection with the polishing disc.
[0008] An inner gear ring assembly comprises a motor two and an inner gear ring, and the motor two is in transmission connection with the inner gear ring, and the inner gear ring is concentrically arranged with the polishing disc.
[0009] A central gear assembly comprises a motor three and a central gear, and the motor three is in transmission connection with the central gear, and the central gear is concentrically arranged with the polishing disc.
[0010] A polishing head assembly comprises a suction disc and a planetary gear, wherein the suction disc is located on the side of the wafer away from the polishing disc and is used for adsorbing the wafer, the planetary gear is circumferentially limited with the suction disc to drive the suction disc to rotate, and the planetary gear is in meshing with the inner gear ring and the central gear to be displaced and rotated under the driving of the inner gear ring and the central gear.
[0011] Preferably, the planetary gear has a central through hole, and the suction disc is located in the central through hole; the polishing head assembly further comprises a pressing disc and a guide pin, the pressing disc is located above the planetary gear and is fixedly connected with the suction disc, and the guide pin penetrates the pressing disc along the vertical direction, and the lower end of the guide pin is fixedly connected with the planetary gear.
[0012] Preferably, the polishing head assembly further comprises a column, a spring, a sliding disc and a limiting disc; the lower end of the column is fixedly connected with the pressing disc, the spring and the sliding disc are sleeved outside the column, and the spring is located between the pressing disc and the sliding disc; the limiting disc is fixedly connected with the column and is used for limiting the limit position of the sliding disc when the sliding disc slides upward; and the sliding disc is connected with the guide pin.
[0013] The distance between the pressing disc and the polishing disc is greater than the thickness of the planetary gear, so that the planetary gear can be in contact with and separated from the polishing disc along with the length change of the spring.
[0014] Preferably, the polishing head assembly further comprises a connecting piece and a connecting disc, the upper end of the connecting piece is fixedly connected with the sliding disc, the lower end of the connecting piece is fixedly connected with the connecting disc, and the connecting disc is fixedly connected with the upper end of the guide pin, so as to indirectly connect the sliding disc with the guide pin.
[0015] Preferably, the connecting piece is a sleeve, and the spring is located inside the sleeve.
[0016] Preferably, the polishing head assembly further comprises a counterweight, and the counterweight is fixedly connected with the limiting disc.
[0017] Preferably, the rotating speed of the polishing disc ranges from 0 to 50 revolutions per minute.
[0018] Preferably, the rotating speed of the inner ring gear ranges from 0 to 50 revolutions per minute.
[0019] Preferably, the rotating speed of the central gear ranges from 0 to 100 revolutions per minute.
[0020] Preferably, the polishing head assembly exerts a pressure on the wafer ranging from 0.1 to 10 newtons per square centimeter.
[0021] Compared with the related art, the polishing head assembly has the following technical effects:
[0022] During the wafer polishing process, the speed ratio of the inner ring gear and the central gear can be adjusted by adjusting the rotating speeds of motor two and motor three, so that the grinding amount can be accurately controlled, and the polishing quality is improved. Since the wafer rotates around the central gear while rotating itself, the phenomenon of the wafer being thinner on the outside and thicker on the inside can be avoided.
[0023] In the preferred embodiment of the polishing head assembly, when the planetary gear is in contact with the polishing disc, the planetary gear can press the polishing disc in the area around the wafer to a certain extent, so that the edge part of the wafer is not excessively ground.
[0024] In the preferred scheme of the utility model, the compression amount of the spring is adjusted, the normal pressure of the wafer grinding process is adjusted, and the grinding amount in unit time is more accurately controlled. BRIEF DESCRIPTION OF DRAWINGS
[0025] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or related technologies, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained by those skilled in the art without creative labor on the premise of the drawings.
[0026] Figure 1 It is a schematic view of the wafer single-side polishing device in the embodiment of the utility model;
[0027] Figure 2 It is Figure 1 It is a schematic view of the local structure in the direction of top view;
[0028] Figure 3 It is the trajectory of the wafer edge and wafer center relative to the polishing disc Figure 1 ;
[0029] Figure 4 It is the trajectory of the wafer edge and wafer center relative to the polishing disc Figure 2 .
[0030] In the drawing: 1-wafer;2-motor one;3-polishing disc;4-motor two;5-inner gear ring;6-motor three;7-center gear;8-suction disc;9-planetary gear;10-pressing disc;11-guiding pin;12-stand;13-spring;14-sliding disc;15-limiting disc;16-connecting piece;17-connecting disc;18-counterweight. DETAILED DESCRIPTION
[0031] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only some embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.
[0032] The utility model discloses a wafer single-side polishing device, to solve the problems in the related technologies, realize the accurate control of grinding amount while guaranteeing the polishing efficiency and polishing uniformity.
[0033] In order to make the above-mentioned purpose, features and advantages of the utility model more obvious and easy to understand, the utility model will be further described in detail in combination with the drawings and specific embodiments.
[0034] Referring to Figures 1-4 The embodiment provides a wafer single-side polishing device, which comprises a polishing disc assembly, an inner ring gear assembly, a center gear assembly and a polishing head assembly.
[0035] The polishing disc assembly comprises a motor 2 and a polishing disc 3, and the motor 2 is in transmission connection with the polishing disc 3.
[0036] The inner ring gear assembly comprises a motor 4 and an inner ring gear 5, and the motor 4 is in transmission connection with the inner ring gear 5, and the inner ring gear 5 is arranged concentrically with the polishing disc 3.
[0037] The center gear assembly comprises a motor 6 and a center gear 7, and the motor 6 is in transmission connection with the center gear 7, and the center gear 7 is arranged concentrically with the polishing disc 3.
[0038] The polishing head assembly comprises a suction disc 8 and a planetary gear 9. The suction disc 8 is located on the side of the wafer 1 away from the polishing disc 3 and is used for adsorbing the wafer 1. The planetary gear 9 is circumferentially limited with the suction disc 8 and is used for driving the suction disc 8 to rotate. The planetary gear 9 is in meshing with the inner ring gear 5 and the center gear 7 and is used for being displaced and rotated under the driving of the inner ring gear 5 and the center gear 7.
[0039] The working principle of the wafer single-side polishing device is as follows:
[0040] The suction disc 8 carries the wafer 1 in a vacuum adsorption mode, and then the side surface of the wafer 1 is in contact with the polishing disc 3, the motor 2 is started, and the polishing of the wafer 1 is realized. During the polishing of the wafer 1, the speed ratio of the inner ring gear 5 and the center gear 7 can be adjusted by adjusting the rotating speeds of the motor 4 and the motor 6, so that the accurate control of the grinding amount is realized, and the polishing quality is improved. Since the wafer 1 rotates around the center gear 7 while revolving, the phenomenon of the wafer 1 being thin on the outside and thick on the inside can be avoided.
[0041] The speed ratio of the inner ring gear 5 and the center gear 7 can be converted into the ratio of the angular velocities of the inner ring gear 5 and the center gear 7, and the angular velocities of the inner ring gear 5 and the center gear 7 are respectively measured through corresponding magnetic encoders, so that the real-time monitoring of the speed ratio of the inner ring gear 5 and the center gear 7 is realized. During actual processing, the rotating speeds of the motor 4 and the motor 6 can be adjusted according to the real-time monitoring result, so that the speed ratio of the inner ring gear 5 and the center gear 7 is kept within a certain range.
[0042] It should be noted that, during the grinding process, the rotating speeds of the polishing disc 3, the inner ring gear 5 and the center gear 7 can be adjusted, and the three rotating speed variables have multiple combination modes, so that the accurate control of the grinding amount is realized.
[0043] In order to more clearly show the influence of the speed ratio of the inner ring gear 5 and the center gear 7 on the grinding track,Figure 3 The trajectory graph is shown when the linear velocity ratio is a certain value, Figure 4 The trajectory graph is shown when the linear velocity ratio is another value.
[0044] Figure 3 And Figure 4 In the figure, the circular line in the center position is the trajectory of the center of the wafer 1, Figure 3 In the figure, the dashed line, Figure 4 In the figure, the thick line), the other line (non-circular) is the trajectory of a certain position of the edge of the wafer 1. Obviously, when the linear velocity ratio changes, the trajectory of the edge of the wafer 1 changes, so that by designing the trajectory of the edge of the wafer 1, the grinding amount of the edge of the wafer 1 can be accurately controlled.
[0045] As a possible example, in the embodiment, the planetary gear 9 has a central through hole, and the chuck 8 is located in the central through hole. The polishing head assembly further comprises a pressure plate 10 and a guide pin 11. The pressure plate 10 is located above the planetary gear 9 and is fixedly connected to the chuck 8. The guide pin 11 penetrates the pressure plate 10 in the vertical direction, and the lower end of the guide pin 11 is fixedly connected to the planetary gear 9.
[0046] In the embodiment, the circumferential limiting of the pressure plate 10 and the planetary gear 9 is realized by the guide pin 11, and then the circumferential limiting of the chuck 8 fixedly connected to the pressure plate 10 and the planetary gear 9 is realized, that is, the synchronous rotation of the chuck 8 and the planetary gear 9 is realized. According to different actual needs, those skilled in the art can also choose other circumferential limiting methods, such as circumferential limiting by welding, bonding and the like.
[0047] As a possible example, in the embodiment, the polishing head assembly further comprises a column 12, a spring 13, a sliding disc 14 and a limiting disc 15. The lower end of the column 12 is fixedly connected to the pressure plate 10. The spring 13 and the sliding disc 14 are sleeved outside the column 12, and the spring 13 is located between the pressure plate 10 and the sliding disc 14. The limiting disc 15 is fixedly connected to the column 12 and is used to limit the limit position of the sliding disc 14 when the sliding disc 14 slides upward. The sliding disc 14 is connected to the guide pin 11.
[0048] The distance between the pressure plate 10 and the polishing disc 3 is greater than the thickness of the planetary gear 9, so that the planetary gear 9 can be in contact with and separated from the polishing disc 3 according to the length change of the spring 13.
[0049] When the planetary gear 9 is in contact with the polishing disc 3, the planetary gear 9 can press the polishing disc 3 around the wafer 1 to a certain extent, so as to avoid that the edge of the wafer 1 is excessively ground. When the spring 13 is compressed, since the sliding disc 14, the guide pin 11 and the planetary gear 9 are connected as an integral structure, part of the gravity of the integral structure is transmitted to the pressure plate 10 through the spring 13, and then transmitted to the chuck 8 and the wafer 1 below, so as to increase the positive pressure in the wafer 1 grinding process and improve the grinding efficiency.
[0050] By replacing the spring 13 with different initial length, the compression of the spring 13 can be adjusted, so as to adjust the positive pressure of the wafer 1 grinding process, in order to control the grinding amount per unit time more accurately.
[0051] By combining the rotation speed control and the pressure control, the TTV (Total Thickness Variation) and the surface shape of the polished wafer 1 can be accurately controlled, the polishing quality of the wafer 1 is improved, and the requirement of high-precision polishing is met.
[0052] In actual processing, the rotation speed control and the pressure control are adjusted according to the detection result of the wafer size after each processing, so as to maintain the relative constancy of the polishing removal rate.
[0053] The planetary gear 9 rises to a certain height and abuts against the limit of the pressure plate 10, so as to limit the height of the planetary gear 9 through the pressure plate 10, and ensure that the planetary gear 9 always meshes with the inner gear ring 5 and the central gear 7 at the same time.
[0054] By fixing the pressure plate 10 and the suction plate 8 together, the gravity center is lowered, and the angle of the suction plate 8 is maintained as horizontal as possible by combining the mutual limiting of the pressure plate 10 and the lower planetary gear 9, so as to ensure that the wafer 1 below is subjected to uniform downward pressure, and the uniformity of the wafer 1 grinding effect is ensured.
[0055] As a possible example, in the embodiment, the polishing head assembly further comprises a connecting piece 16 and a connecting disc 17, the upper end of the connecting piece 16 is fixedly connected with the sliding disc 14, the lower end of the connecting piece 16 is fixedly connected with the connecting disc 17, and the connecting disc 17 is fixedly connected with the upper end of the guide pin 11, so as to indirectly connect the sliding disc 14 and the guide pin 11.
[0056] In the embodiment, the sliding disc 14 is not directly connected with the upper end of the guide pin 11, but the connecting piece 16 and the connecting disc 17 are added. Since the sliding disc 14, the connecting piece 16, the connecting disc 17, the guide pin 11 and the planetary gear 9 are connected as a whole structure, the pressure of the wafer can be adjusted by the compression and stretching of the spring 13. The setting of the connecting piece 16 and the connecting disc 17 makes the whole structure have greater weight, so as to expand the adjustment range of the wafer 1 grinding pressure.
[0057] As a possible example, in the embodiment, the connecting piece 16 is a sleeve, and the spring 13 is located inside the sleeve. The diameter of the sleeve is smaller than the connecting disc 17, so that the weight distribution of the whole structure is more concentrated in the center position, and the setting of the connecting disc 17 makes the weight distribution of the whole structure more concentrated in the lower part, so that the whole structure is more stable and is not easy to tilt. At the same time, since the area of the gear 9 is larger than the area of the wafer, the polishing pad around the wafer can be flattened during the polishing process, so that the polishing pressure received by the wafer is more uniform, and the edge effect is reduced.
[0058] For example, the limiting disc 15 is connected with the column 12 in a separable manner, and the sliding disc 14 is connected with the sleeve in a separable manner, so as to facilitate replacement of the spring 13. The separable connection here can be flexibly selected, for example, threaded connection, or connection through fasteners such as screws.
[0059] As a possible example, in the embodiment, the polishing head assembly further comprises a counterweight 18, and the counterweight 18 is fixedly connected with the limiting disc 15. By arranging the counterweight 18, the adjustment range of the grinding pressure of the wafer 1 can be further expanded, so as to meet the needs of different grinding processes.
[0060] As a possible example, in the embodiment, the rotating speed of the polishing disc 3 is 0-50 revolutions per minute, and is preferably 20 revolutions per minute. The rotating speed of the inner ring gear 5 is 0-50 revolutions per minute, and is preferably 5 revolutions per minute. The rotating speed of the center gear 7 is 0-100 revolutions per minute, and is preferably 15 revolutions per minute.
[0061] The motor one 2, the motor two 4 and the motor three 6 are preferably speed reducer motors provided with speed reducers, so as to realize low-speed stable operation.
[0062] As a possible example, in the embodiment, the polishing head assembly applies a pressure of 0.1-10 Newton per square centimeter to the wafer 1, and the pressure is preferably 1 Newton per square centimeter.
[0063] The principle and implementation mode of the specific examples are described in the utility model, and the above embodiment is only used to help understand the method and core idea of the utility model; meanwhile, for those skilled in the art, according to the idea of the utility model, the specific implementation mode and application range will be changed. In conclusion, the content of the specification should not be understood as the limitation of the utility model.
Claims
1. A wafer single-sided polishing apparatus, characterized in that, The application relates to a polishing head assembly and a polishing device. The polishing head assembly comprises a polishing disc assembly, an inner ring assembly and a center gear assembly. The polishing disc assembly comprises a motor one and a polishing disc, the motor one is in transmission connection with the polishing disc. The inner ring assembly comprises a motor two and an inner ring, the motor two is in transmission connection with the inner ring, and the inner ring is concentrically arranged with the polishing disc. The center gear assembly comprises a motor three and a center gear, the motor three is in transmission connection with the center gear, and the center gear is concentrically arranged with the polishing disc.
2. The wafer single-side polishing apparatus according to claim 1, wherein: The polishing head assembly comprises a chuck and a planetary gear.
3. The wafer single-side polishing apparatus according to claim 2, wherein: The chuck is arranged on the side of a wafer away from the polishing disc and is used for adsorbing the wafer. The planetary gear is circumferentially limited with the chuck and is used for driving the chuck to rotate.
4. The wafer single-side polishing apparatus according to claim 3, wherein: The planetary gear is in mesh with the inner ring and the center gear and is driven to move and rotate by the inner ring and the center gear.
5. The wafer single-side polishing apparatus according to claim 4, wherein: The planetary gear has a center through hole, and the chuck is arranged in the center through hole.
6. The wafer single-side polishing apparatus according to claim 3, wherein: The polishing head assembly further comprises a pressing disc and a guide pin.
7. The wafer single-side polishing apparatus according to claim 1, wherein: The pressing disc is arranged above the planetary gear and is fixedly connected with the chuck.
8. The wafer single-side polishing apparatus according to claim 1, wherein: The guide pin vertically penetrates the pressing disc, and the lower end of the guide pin is fixedly connected with the planetary gear.
9. The wafer single-side polishing apparatus according to Claim 1, wherein: The polishing head assembly further comprises a column, a spring, a sliding disc and a limiting disc.
10. The wafer single-side polishing apparatus according to Claim 1, wherein: The lower end of the column is fixedly connected with the pressing disc. The spring and the sliding disc are arranged outside the column, and the spring is arranged between the pressing disc and the sliding disc. The limiting disc is fixedly connected with the column and is used for limiting the limit position of the sliding disc when the sliding disc slides upward. The sliding disc is connected with the guide pin. The distance between the pressing disc and the polishing disc is greater than the thickness of the planetary gear, so that the planetary gear can be in contact with and separated from the polishing disc according to the length change of the spring. The polishing head assembly further comprises a connecting piece and a connecting disc. The upper end of the connecting piece is fixedly connected with the sliding disc. The lower end of the connecting piece is fixedly connected with the connecting disc. The connecting disc is fixedly connected with the upper end of the guide pin, so as to indirectly connect the sliding disc with the guide pin. The connecting piece is a sleeve, and the spring is arranged inside the sleeve. The polishing head assembly further comprises a counterweight, and the counterweight is fixedly connected with the limiting disc. The rotating speed of the polishing disc ranges from 0 to 50 rpm. The rotating speed of the inner ring ranges from 0 to 50 rpm. The rotating speed of the center gear ranges from 0 to 100 rpm. The pressure applied by the polishing head assembly to the wafer ranges from 0.1 to 10 N / cm2.