A current variable polishing machine for through silicon via wafer

Abstract

The utility model relates to a through silicon via wafer polishing technical field, concretely relates to a kind of electro-rheological polishing machine of through silicon via wafer, it includes rack, object table, first rotary drive mechanism, electrode mounting plate, polishing head and second rotary drive mechanism, second rotary drive mechanism is used to drive object table rotation, the rotation axis of electrode mounting plate does not coincide with the rotation axis of object table, the projection of polishing head on object table passes through the rotation axis of object table.Polishing head can produce the sliding track of continuous change on wafer surface, and can sweep the edge and the center of circle of wafer, eliminate zero speed area, finally make the metal layer on wafer surface be completely removed.In addition, polishing head uses two tool electrodes, respectively connects positive and negative high voltage power supply, adjusts the proportion of gap between tool electrode and the spacing of tool electrode and workpiece, when tool electrode below is metal, there is higher electric field, tool electrode below is insulator, there is no strong electric field, to realize selective polishing.

Description

Technical Field

[0001] This utility model relates to the field of through-silicon via (TSV) wafer polishing technology, and more specifically, to an electrorheological polishing machine for TSV wafers. Background Technology

[0002] Through-Silicon Vias (TSV) wafers are silicon wafers with vertically drilled holes and filled with metal to achieve vertical interconnects between chips. During the manufacturing process, after the metal is filled into the drilled holes of the silicon wafer, a metal layer is left on the surface of the silicon wafer. This metal layer needs to be removed without damaging the insulating layer underneath.

[0003] The prior art discloses a polishing method for through-silicon via (TSV) products, which includes the following steps: S1: Determine an electrorheological polishing machine, an elastic conductive element, an insulating support plate with a through cavity, and a workpiece to be polished; S2: Fix the insulating support plate to the workpiece support platform of the electrorheological polishing machine; place the elastic conductive element into the through cavity; ensure that the outer surface of the elastic conductive element is coated with conductive grease; S3: Fix the workpiece to be polished on the insulating support plate; ensure that the other end of the elastic conductive element abuts against a TSV, with the center line of the TSV coinciding with the rotation axis of the polishing electrode; S4: Pour electrorheological polishing fluid; S5: Connect the polishing electrode to the positive terminal of a voltage source, and connect the workpiece support platform to the negative terminal of the voltage source or ground; then drive the polishing electrode to rotate; S6: Remove small metal dots from the surface of the workpiece to be polished.

[0004] The disadvantages of the above technology are that the method of grounding the metal layer is relatively cumbersome, requiring drilling a hole in the middle of the substrate and connecting a ground wire. In addition, there is a zero-speed zone on the polishing electrode, and a small metal dot on the wafer surface cannot be completely removed after polishing, requiring additional processing. Summary of the Invention

[0005] To address the problem that the metal layer on the wafer surface cannot be completely removed in the prior art, this invention provides an electrorheological polishing machine for through-silicon via (TSV) wafers, which can completely remove the metal layer on the surface of TSV wafers.

[0006] To solve the above-mentioned technical problems, the technical solution provided by this utility model is as follows:

[0007] An electrorheological polishing machine for through-silicon via (TSV) wafers includes a frame, a stage, a first rotary drive mechanism, an electrode mounting plate, and a polishing head. The stage is mounted on the frame. The first rotary drive mechanism is mounted on the frame and drives the electrode mounting plate to rotate. The polishing head is located between the stage and the electrode mounting plate and is connected to the electrode mounting plate. The machine also includes a second rotary drive mechanism mounted on the frame and driving the stage to rotate. The rotation axis of the electrode mounting plate does not coincide with the rotation axis of the stage, and the projection of the polishing head onto the stage passes through the rotation axis of the stage.

[0008] In the above technical solution, before polishing begins, the wafer is fixed to the stage with paraffin wax, aligning the center of the wafer with the rotation center of the stage. Simultaneously, one end of the polishing head is flush with or protrudes from the outer edge of the wafer, meaning the projected length of the polishing head on the wafer is greater than the wafer's radius. After the electrorheological fluid is poured onto the wafer surface, the first rotational drive mechanism drives the electrode mounting plate to rotate; simultaneously, the second rotational drive mechanism drives the stage to rotate, thus rotating the wafer on the stage. The wafer's rotation causes the polishing head to generate a continuously changing sliding trajectory on the wafer surface, while the rotation of the electrode mounting plate allows the polishing head to sweep across the wafer's edge and center, ultimately eliminating the zero-velocity zone. This ensures the wafer surface is completely covered by the polishing trajectory of the polishing head, ultimately completely removing the metal layer from the wafer surface, avoiding metal residue, and eliminating the need for post-processing steps. The principle of the electrorheological fluid forming a "flexible polishing head" between the polishing head and the wafer's metal layer is existing technology and will not be elaborated upon.

[0009] Preferably, the polishing head includes a first tool electrode and a second tool electrode, which are parallel to each other and both connected to the electrode mounting plate. The rotation axis of the electrode mounting plate is located between the first and second tool electrodes. It is understood that if the polishing head has only one tool electrode, the polishing head needs to be connected to a voltage source and the metal layer grounded, but grounding the metal layer is cumbersome. Connecting the first and second tool electrodes to a positive DC high-voltage power supply with an output potential higher than ground and a negative DC high-voltage power supply with an output potential lower than ground, respectively, not only eliminates the need to ground the metal layer but also allows the metal layer to act as an intermediate electrode, forming two series-connected strong electric field regions with the two tool electrodes. This ultimately increases the electric field strength on the surface of the wafer's metal layer, which is beneficial for increasing the shear stress of the electrorheological fluid, thereby improving the metal layer removal efficiency.

[0010] Preferably, it further includes a first locking structure, a second locking structure, and a lifting drive mechanism; the first tool electrode and the second tool electrode are both slidably connected to the electrode mounting plate along the horizontal line connecting the first tool electrode and the second tool electrode; the first locking structure is used to lock the first tool electrode on the electrode mounting plate, and the second locking structure is used to lock the second tool electrode on the electrode mounting plate; the lifting drive mechanism is disposed on the frame for driving the stage or the electrode mounting plate to rise and fall.

[0011] Before polishing, an electric field simulation is performed based on data such as the material, shape, size, wafer size, thickness, and layered structure of the first and second tool electrodes to determine the optimal spacing between them and between the two tool electrodes and the wafer's metal layer. Then, the spacing between the two tool electrodes and the wafer's metal layer, as well as the spacing between the two tool electrodes themselves, is adjusted based on the optimal spacing data. After adjustment, when the tool electrodes are below a metal layer, a high electric field intensity is concentrated on the surface of the metal layer; when the tool electrodes are below an insulating layer, there is no strong electric field on the insulating layer. This achieves selective polishing, allowing the "flexible polishing head" between the first and second tool electrodes and the metal layer to remove the metal layer more efficiently without damaging the insulating layer beneath it. When the simulation input parameters change (e.g., by changing to a different batch of wafers), the simulation is repeated, and the spacing between the two tool electrodes and the upper surface of the wafer's metal layer is adjusted again based on the new optimal spacing data, thus meeting the requirements for efficient and non-destructive polishing under different working conditions and for different wafers. When adjusting the relevant spacing, a lifting drive mechanism is used to drive the stage or electrode mounting plate to rise and fall to adjust the spacing between the two tool electrodes and the wafer metal layer. When adjusting the spacing between the two tool electrodes, the first locking structure and the second locking structure are released, and the first tool electrode and the second tool electrode are slid by the same sliding distance. Then, the first locking structure and the second locking structure are locked to fix the first tool electrode and the second tool electrode.

[0012] Preferably, the electrode mounting plate is provided with a plurality of first sliding grooves and a plurality of second sliding grooves. Both the first locking structure and the second locking structure are provided in multiples, each corresponding one-to-one with a first sliding groove and a second sliding groove. Each first locking structure includes a first screw portion and a first fastening head. The first screw portion passes through the first sliding groove and is slidably connected to it. One end of the first screw portion is threadedly connected to the first tool electrode, and the other end is connected to the first fastening head. The first fastening head is located above the first sliding groove and abuts against the electrode mounting plate. Each second locking structure includes a second screw portion and a second fastening head. The second screw portion passes through the second sliding groove and is slidably connected to it. One end of the second screw portion is threadedly connected to the second tool electrode, and the other end is connected to the second fastening head. The second fastening head is located above the second sliding groove and abuts against the electrode mounting plate. When adjusting the first tool electrode, screw the first screw to separate the first fastening head from the electrode mounting plate, thereby unlocking the first tool electrode. After adjusting the position of the first tool electrode, screw the first screw in the opposite direction to bring the first fastening head into contact with the electrode mounting plate, thereby locking the first tool electrode. The adjustment process for the second tool electrode is similar to that for the first tool electrode, and therefore will not be described further.

[0013] Preferably, the top of the electrode mounting plate is provided with a plurality of first receiving grooves and second receiving grooves, the first fastening heads are located in the corresponding first receiving grooves, and the second fastening heads are located in the corresponding second receiving grooves. Concealing the first and second fastening heads within the first and second receiving grooves respectively avoids exposing the first and second fastening heads and thus preventing them from affecting the connection between the electrode mounting plate and the first rotary drive mechanism.

[0014] The lifting drive mechanism can be one of the following: a motor screw drive mechanism, an electric push rod drive mechanism, a synchronous belt drive mechanism, a gear and rack drive mechanism, or a cylinder drive mechanism.

[0015] Preferably, the lifting drive mechanism includes an electric push rod mounted on the frame and a lifting seat connected to the power output end of the electric push rod; the first rotary drive mechanism is mounted on the lifting seat; and the electrode mounting plate is connected to the power output end of the first rotary drive mechanism. The structure and working principle of the electric push rod are existing technologies and will not be described in detail. In implementation, the power output end of the electric push rod pushes the lifting seat to rise and fall, and the lifting seat then drives the first rotary drive mechanism and the electrode mounting plate to rise and fall. The electric push rod has high adjustment precision and can achieve fine-tuning of the lifting distance.

[0016] Preferably, the system further includes a bearing. The lifting seat has a guide cavity, the electrode mounting plate is connected to the inner ring of the bearing, and the outer ring of the bearing is slidably connected to the guide cavity in the vertical direction. The bearing avoids friction between the electrode mounting plate and the inner wall of the guide cavity, and makes the rotational movement of the electrode mounting plate smoother, thus keeping the two tool electrodes on the electrode mounting plate stable during the polishing of the metal layer. The guide cavity guides the lifting and lowering of the bearing, while limiting the bearing's wobbling and offset in the horizontal direction, thereby ensuring that the two tool electrodes on the electrode mounting plate can maintain a constant posture in a constant position for polishing, avoiding uneven removal of the metal layer due to tilting of the two tool electrodes.

[0017] Preferably, the frame is provided with a support column, the top of which is higher than the platform. The support column is located below the lifting seat and is used to abut against the lifting seat. The support column can limit the lowest descent position of the lifting seat, ensuring a safe distance between the first and second tool electrodes and the platform, and preventing the lifting seat from descending excessively and accidentally damaging the platform.

[0018] Preferably, the first tool electrode is provided with a first liquid passage chamber, and the second tool electrode is provided with a second liquid passage chamber. The first and second liquid passage chambers allow electrorheological fluid to pass through, making the flow of the electrorheological fluid on the wafer surface smoother, which helps to improve the uniformity of the distribution of the electrorheological fluid throughout the polishing area and make the polishing force on the wafer surface more uniform.

[0019] Preferably, the portion of the first tool electrode located below the first fluid passage chamber has a first arc-shaped surface, and the portion of the second tool electrode located below the second fluid passage chamber has a second arc-shaped surface. The arc-shaped surfaces can reduce turbulence and bubble accumulation in the electrorheological fluid during flow, thus avoiding the impact of bubble accumulation on the polishing effect.

[0020] The first rotary drive mechanism and the second rotary drive mechanism can both be one of the following: motor drive mechanism, rotary cylinder drive mechanism, synchronous belt drive mechanism, gear and rack drive mechanism, etc.

[0021] Preferably, the first rotary drive mechanism includes a first motor mounted on the frame, with its power output end connected to the electrode mounting plate; the second rotary drive mechanism includes a second motor and a rotating disk, the second motor mounted on the frame, the rotating disk rotatably connected to the frame, and the output end of the second motor connected to the rotating disk; the stage is parallel to the rotating disk and connected to its top surface. The first motor directly drives the electrode mounting plate to rotate, and the second motor drives the rotating disk to rotate, thereby rotating the stage. The rotating disk improves the stability of the stage's rotation.

[0022] The beneficial effects of this utility model are:

[0023] 1. A second rotary drive mechanism is set up. When polishing the wafer, the first rotary drive mechanism and the second rotary drive mechanism drive the polishing head and the stage to rotate respectively. The rotation of the wafer on the stage can make the polishing head produce a continuously changing sliding trajectory on the wafer surface. The rotation of the electrode mounting plate can make the polishing head sweep over the edge and center of the wafer, ultimately eliminating the zero-speed zone, so that the wafer surface can be completely covered by the polishing trajectory of the polishing head, and finally the metal layer on the wafer surface is completely removed, avoiding metal material residue and eliminating the need for post-processing steps.

[0024] 2. The polishing head includes a first tool electrode and a second tool electrode. The first tool electrode and the second tool electrode are used to connect to a positive DC high voltage power supply and a negative DC high voltage power supply, respectively. This not only eliminates the need to ground the metal layer, but also allows the metal layer to act as an intermediate electrode, forming two series strong electric field regions with the two tool electrodes. Ultimately, this increases the electric field strength on the surface of the wafer metal layer, which is beneficial for increasing the shear stress of the electrorheological fluid, thereby improving the removal efficiency of the metal layer.

[0025] 3. The spacing between the first and second tool electrodes, as well as the spacing between the first and second tool electrodes and the stage, are all adjustable. The spacing between the two tool electrodes and the spacing between the two tool electrodes and the wafer on the stage can be adjusted according to the optimal spacing data determined by the electric field simulation results. When there is a metal layer below the tool electrode, a high electric field intensity is concentrated on the surface of the metal layer. When there is an insulating layer below the tool electrode, there is no strong electric field on the insulating layer, thereby achieving selective polishing and removing the metal layer more efficiently without damaging the insulating layer below the metal layer. Attached Figure Description

[0026] Figure 1 A schematic diagram of the structure of an electrorheological polishing machine for through-silicon via (TSV) wafers;

[0027] Figure 2 A longitudinal cross-sectional view of an electrorheological polishing machine for through-silicon via (TSV) wafers;

[0028] Figure 3 A schematic diagram of the polishing principle of an electrorheological polishing machine for through-silicon via wafers;

[0029] Figure 4 A schematic diagram of the top structure of the electrode mounting plate;

[0030] Figure 5 A schematic diagram showing the first tool electrode and the second tool electrode connected to the first locking structure and the second locking structure, respectively.

[0031] Figure 6 This is a side view of the first tool electrode and the second tool electrode.

[0032] In the attached figures: 1-Frame; 2-Stage; 3-First rotary drive mechanism; 4-Electrode mounting plate; 401-First slide; 402-Second slide; 403-First receiving groove; 404-Second receiving groove; 5-First tool electrode; 501-First liquid passage cavity; 502-First arc-shaped surface; 6-Second tool electrode; 601-Second liquid passage cavity; 602-Second arc-shaped surface; 7-Rotating disk; 8-First locking structure; 801- First screw section; 802-First fastening head; 9-Second locking structure; 901-Second screw section; 902-Second fastening head; 10-Lifting drive mechanism; 1001-Electric push rod; 1002-Lifting seat; 1003-Drag chain; 1004-Connecting frame; 1005-Guide cavity; 11-Bearing; 12-Support column; 13-Wafer; 1301-Insulating layer; 1302-Through silicon via; 1303-Metal layer. Detailed Implementation

[0033] The accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. To better illustrate this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0034] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "long," and "short" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0035] The technical solution of this utility model will be further described in detail below through specific embodiments and with reference to the accompanying drawings:

[0036] Example 1

[0037] This embodiment is a first embodiment of an electrorheological polishing machine for through-silicon via (TSV) wafers, such as... Figures 1 to 3As shown, it includes a frame 1, a stage 2, a first rotary drive mechanism 3, an electrode mounting plate 4, and a polishing head; the stage 2 is mounted on the frame 1; the first rotary drive mechanism 3 is mounted on the frame 1 to drive the electrode mounting plate 4 to rotate; the polishing head is located between the stage 2 and the electrode mounting plate 4 and is connected to the electrode mounting plate 4; it also includes a second rotary drive mechanism, which is mounted on the frame 1 to drive the stage 2 to rotate, the rotation axis of the electrode mounting plate 4 does not coincide with the rotation axis of the stage 2, and the projection of the polishing head on the stage 2 passes through the rotation axis of the stage 2.

[0038] Furthermore, the stage 2 is provided with a receiving tank (not shown in the figure) for placing the wafer 13 and containing the electrorheological fluid. The receiving tank is circular, and its center line coincides with the rotation axis of the stage 2.

[0039] Specifically, the first rotary drive mechanism 3 includes a first motor mounted on the frame 1, with its power output end connected to the electrode mounting plate 4. The second rotary drive mechanism includes a second motor (not shown in the figure) and a rotating disk 7. The second motor is mounted on the frame 1, and the rotating disk 7 is rotatably connected to the frame 1. The output end of the second motor is connected to the rotating disk 7. The stage 2 is parallel to the rotating disk 7 and connected to its top surface. The first motor directly drives the electrode mounting plate 4 to rotate, and the second motor drives the rotating disk 7 to rotate, thereby rotating the stage 2. The rotating disk 7 improves the stability of the stage 2's rotation.

[0040] The working principle or workflow of this embodiment is as follows: Figure 3 As shown, wafer 13 includes an insulating layer 1301, on which multiple through-silicon vias 1302 for filling with metal are provided. Above the insulating layer 1301 is a metal layer 1303 left after metal filling, which needs to be removed by grinding. Figures 1 to 3 As shown, before the polishing work begins, combined with Figures 1 to 4As shown, wafer 13 is fixed to stage 2 with paraffin wax, so that the center of wafer 13 coincides with the rotation center of stage 2; at the same time, one end of the first tool electrode 5 protrudes from the outer edge of wafer 13, that is, the projection length of the polishing head on wafer 13 is greater than the radius of wafer 13; and the rotation axis of electrode mounting plate 4 passes through the midpoint of the radius line of wafer 13. After the electrorheological fluid is poured onto the surface of wafer 13, the first rotation drive mechanism 3 drives electrode mounting plate 4 to rotate, thereby driving the first tool electrode 5 to rotate; at the same time, the second rotation drive mechanism drives stage 2 to rotate, thereby rotating wafer 13 on stage 2. The rotation of wafer 13 allows the polishing head to generate a continuously changing sliding trajectory on the surface of wafer 13, while the rotation of electrode mounting plate 4 allows the polishing head to sweep across the edge and center of wafer 13, ultimately eliminating the zero-velocity zone, so that the surface of metal layer 1303 can be completely covered by the polishing trajectory of the polishing head, thereby being completely removed, eliminating the need for post-processing steps. The principle of forming a "flexible polishing head" between the electrorheological fluid and the metal layer 1303 is existing technology and will not be elaborated here.

[0041] Example 2

[0042] This embodiment is a second embodiment of an electrorheological polishing machine for through-silicon via (TSV) wafers. This embodiment is similar to Embodiment 1, except that it combines... Figures 1 to 5 As shown, the polishing head includes a first tool electrode 5 and a second tool electrode 6. The first tool electrode 5 and the second tool electrode 6 are parallel to each other and both are connected to the electrode mounting plate 4. The rotation axis of the electrode mounting plate 4 is located between the first tool electrode 5 and the second tool electrode 6. In this embodiment, the first tool electrode 5 and the second tool electrode 6 are symmetrical about the rotation axis of the electrode mounting plate 4. It is understood that if the polishing head has only one tool electrode, then the polishing head needs to be connected to a voltage source and the metal layer 1303 needs to be grounded, but the operation of grounding the metal layer 1303 is relatively troublesome. The first tool electrode 5 and the second tool electrode 6 are respectively connected to a positive DC high-voltage power supply with an output potential higher than the ground wire and a negative DC high-voltage power supply with an output potential lower than the ground wire. In this way, not only is it not necessary to ground the metal layer 1303, but the metal layer 1303 can also act as an intermediate electrode to form two series strong electric field regions with the two tool electrodes, which ultimately increases the electric field strength on the surface of the metal layer 1303, which is beneficial to increasing the shear stress of the electrorheological fluid, thereby improving the removal efficiency of the metal layer 1303.

[0043] Furthermore, it also includes a first locking structure 8, a second locking structure 9, and a lifting drive mechanism 10; the first tool electrode 5 and the second tool electrode 6 are both slidably connected to the electrode mounting plate 4 along the horizontal line connecting the first tool electrode 5 and the second tool electrode 6. The first locking structure 8 is used to lock the first tool electrode 5 onto the electrode mounting plate 4, and the second locking structure 9 is used to lock the second tool electrode 6 onto the electrode mounting plate 4; the lifting drive mechanism 10 is mounted on the frame 1 to drive the platform 2 or the electrode mounting plate 4 to lift.

[0044] Before polishing, an electric field simulation is performed based on data such as the material, shape, size, wafer size, thickness, and layered structure of the first tool electrode 5 and the second tool electrode 6 to determine the optimal spacing between the first tool electrode 5 and the second tool electrode 6, as well as the optimal spacing between the two tool electrodes and the metal layer 1303. Then, the spacing between the two tool electrodes and the metal layer 1303, and the spacing between the two tool electrodes themselves, are adjusted based on the optimal spacing data. After adjusting the spacing, when the tool electrode is below the metal layer 1303, a high electric field intensity is concentrated on the surface of the metal layer 1303; when the tool electrode is below the insulating layer 1301, there is no strong electric field on the insulating layer 1301. This achieves selective polishing, allowing the "flexible polishing head" between the first tool electrode 5 and the second tool electrode 6 and the metal layer 1303 to efficiently remove the metal layer 1303 without damaging the insulating layer 1301 below it. When the simulation input parameters change, such as when a different batch of wafers 13 is used, the simulation is repeated. The spacing between the two tool electrodes and the spacing between the two tool electrodes and the upper surface of the metal layer 1303 are then adjusted based on the new optimal spacing data to meet the requirements of efficient and non-destructive polishing under different working conditions and for different wafers. When adjusting the relevant spacing, the stage 2 or electrode mounting plate 4 is raised or lowered using the lifting drive mechanism 10 to adjust the spacing between the two tool electrodes and the metal layer 1303. When adjusting the spacing between the two tool electrodes, the first locking structure 8 and the second locking structure 9 are released, and the first tool electrode 5 and the second tool electrode 6 are slid by the same sliding distance. Then, the first locking structure 8 and the second locking structure 9 are locked again, thereby fixing the first tool electrode 5 and the second tool electrode 6.

[0045] In this embodiment, the distance between the first tool electrode 5 and the second tool electrode 6 is adjusted to be greater than the distance between the two tool electrodes and the metal layer 1303. Under this distance relationship, the surface of the metal layer 1303 exhibits a stronger electric field intensity.

[0046] Specifically, in combination Figure 3 and Figure 5As shown, the electrode mounting plate 4 is provided with multiple first sliding grooves 401 and multiple second sliding grooves 402. Multiple first locking structures 8 and multiple second locking structures 9 are provided, each corresponding one-to-one with a first sliding groove 401 or a second sliding groove 402. Each first locking structure 8 includes a first screw portion 801 and a first fastening head 802. The first screw portion 801 passes through and is slidably connected to the first sliding groove 401. One end of the first screw portion 801 is threadedly connected to the first tool electrode 5, and the other end is threadedly connected to the first fastening head 802. The first fastening head 802 is connected to the electrode mounting plate 4 and is located above the first sliding groove 401, abutting against the electrode mounting plate 4. The second locking structure 9 includes a second screw portion 901 and a second fastening head 902. The second screw portion 901 passes through and is slidably connected to the second sliding groove 402. One end of the second screw portion 901 is threadedly connected to the second tool electrode 6, and the other end is connected to the second fastening head 902. The second fastening head 902 is located above the second sliding groove 402 and abuts against the electrode mounting plate 4. When adjusting the first tool electrode 5, the first screw portion 801 is screwed to separate the first fastening head 802 from the electrode mounting plate 4, thereby unlocking the first tool electrode 5. After adjusting the position of the first tool electrode 5, the first screw portion 801 is screwed in the opposite direction to make the first fastening head 802 abut against the electrode mounting plate 4, thereby locking the first tool electrode 5. The adjustment process for the position of the second tool electrode 6 is similar to that of the first tool electrode 5, and therefore will not be described further.

[0047] Furthermore, the top of the electrode mounting plate 4 is provided with multiple first receiving grooves 403 and second receiving grooves 404. First fastening heads 802 are located in the corresponding first receiving grooves 403, and second fastening heads 902 are located in the corresponding second receiving grooves 404. Concealing the first fastening heads 802 and second fastening heads 902 within the first receiving grooves 403 and second receiving grooves 404 respectively prevents the first fastening heads 802 and second fastening heads 902 from being exposed and affecting the connection between the electrode mounting plate 4 and the first rotary drive mechanism 3.

[0048] Furthermore, such as Figure 1 and Figure 2 As shown, the lifting drive mechanism 10 includes an electric push rod 1001 mounted on the frame 1 and a lifting seat 1002 connected to the power output end of the electric push rod 1001; a first rotary drive mechanism 3 is mounted on the lifting seat 1002; and an electrode mounting plate 4 is connected to the power output end of the first rotary drive mechanism 3. The structure and working principle of the electric push rod 1001 are existing technologies and will not be described in detail. In implementation, the power output end of the electric push rod 1001 pushes the lifting seat 1002 to rise and fall, and the lifting seat 1002 then drives the first rotary drive mechanism 3 and the electrode mounting plate 4 to rise and fall. The electric push rod 1001 has high adjustment precision and can achieve fine-tuning of the lifting distance.

[0049] Furthermore, the lifting drive mechanism 10 also includes a cable chain 1003 and a connecting frame 1004. One end of the cable chain 1003 is connected to the top of the housing of the electric push rod 1001, and the other end is connected to the connecting frame 1004. Wrapping the cable inside the cable chain 1003 can prevent damage caused by direct friction between the cable and mechanical parts.

[0050] Furthermore, it also includes a bearing 11, a guide cavity 1005 on the lifting seat 1002, an electrode mounting plate 4 connected to the inner ring of the bearing 11, and an outer ring of the bearing 11 slidably connected to the guide cavity 1005 in the vertical direction. The bearing 11 can prevent friction between the electrode mounting plate 4 and the inner wall of the guide cavity 1005, and can make the rotational movement of the electrode mounting plate 4 more stable, thereby keeping the two tool electrodes on the electrode mounting plate 4 stable during the polishing of the metal layer 1303. The guide cavity 1005 can guide the lifting and lowering of the bearing 11, while limiting the wobbling and offset of the bearing 11 in the horizontal direction, thereby ensuring that the two tool electrodes on the electrode mounting plate 4 can maintain a constant posture in a constant position for polishing, and avoiding uneven removal of the metal layer 1303 due to the tilting of the two tool electrodes.

[0051] Furthermore, the frame 1 is equipped with two support columns 12, which are located on the left and right sides of the rotary disk 7, respectively. The top of the support columns 12 is higher than the platform 2, and the support columns 12 are located below the lifting seat 1002 to abut against the lifting seat 1002. The support columns 12 can limit the lowest descent position of the lifting seat 1002, so that the first tool electrode 5 and the second tool electrode 6 maintain a safe distance from the platform 2, and prevent the lifting seat 1002 from descending excessively and accidentally damaging the platform 2.

[0052] Other features, working principles, and beneficial effects of this embodiment are the same as those of Embodiment 1.

[0053] Example 3

[0054] This embodiment is a third embodiment of an electrorheological polishing machine for through-silicon via (TSV) wafers. This embodiment is similar to embodiment 2, except that, as... Figure 5 and Figure 6 As shown, the first tool electrode 5 is provided with a first liquid passage chamber 501, and the second tool electrode 6 is provided with a second liquid passage chamber 601. The first liquid passage chamber 501 and the second liquid passage chamber 601 can allow electrorheological fluid to pass through, making the flow of electrorheological fluid on the surface of wafer 13 smoother, which is beneficial to improving the uniformity of the distribution of electrorheological fluid in the entire polishing area and making the polishing force on the surface of wafer 13 more uniform.

[0055] Furthermore, the portion of the first tool electrode 5 located below the first liquid passage cavity 501 is provided with a first arc-shaped surface 502, and the portion of the second tool electrode 6 located below the second liquid passage cavity 601 is provided with a second arc-shaped surface 602. The arc-shaped surfaces can reduce turbulence and bubble accumulation in the electrorheological fluid during the flow process, thus avoiding the impact of bubble accumulation on the polishing effect.

[0056] Other features, working principles, and beneficial effects of this embodiment are the same as those of Embodiment 2.

[0057] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0058] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description, and it is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A current-ratio polishing machine for through-silicon via (TSV) wafers, comprising a frame (1), a stage (2), a first rotary drive mechanism (3), an electrode mounting plate (4), and a polishing head; wherein the stage (2) is disposed on the frame (1); the first rotary drive mechanism (3) is disposed on the frame (1) for driving the electrode mounting plate (4) to rotate; and the polishing head is located between the stage (2) and the electrode mounting plate (4) and connected to the electrode mounting plate (4); characterized in that, It also includes a second rotary drive mechanism, which is mounted on the frame (1) to drive the stage (2) to rotate. The rotation axis of the electrode mounting plate (4) does not coincide with the rotation axis of the stage (2), and the projection of the polishing head on the stage (2) passes through the rotation axis of the stage (2).

2. The electrorheological polishing machine for through-silicon via (TSV) wafers according to claim 1, characterized in that, The polishing head includes a first tool electrode (5) and a second tool electrode (6). The first tool electrode (5) and the second tool electrode (6) are parallel to each other and are both connected to the electrode mounting plate (4). The rotation axis of the electrode mounting plate (4) is located between the first tool electrode (5) and the second tool electrode (6).

3. The electrorheological polishing machine for through-silicon via (TSV) wafers according to claim 2, characterized in that, It also includes a first locking structure (8), a second locking structure (9), and a lifting drive mechanism (10); the first tool electrode (5) and the second tool electrode (6) are both slidably connected to the electrode mounting plate (4) along the horizontal line connecting the first tool electrode (5) and the second tool electrode (6); the first locking structure (8) is used to lock the first tool electrode (5) on the electrode mounting plate (4); the second locking structure (9) is used to lock the second tool electrode (6) on the electrode mounting plate (4); the lifting drive mechanism (10) is set on the frame (1) to drive the platform (2) or the electrode mounting plate (4) to lift.

4. The electrorheological polishing machine for through-silicon via (TSV) wafers according to claim 3, characterized in that, The electrode mounting plate (4) is provided with a plurality of first sliding grooves (401) and a plurality of second sliding grooves (402). The first locking structure (8) and the second locking structure (9) are each provided with a plurality of first sliding grooves (401) and second sliding grooves (402), respectively corresponding one-to-one. Each of the first locking structures (8) includes a first screw portion (801) and a first fastening head (802). The first screw portion (801) passes through the first sliding groove (401) and is slidably connected to it. One end of the first screw portion (801) is threadedly connected to the first tool electrode (5), and the other end is threadedly connected to the first fastening head (802). 802) connection, the first fastening head (802) is located above the first slide groove (401) and abuts against the electrode mounting plate (4); the second locking structure (9) includes a second screw part (901) and a second fastening head (902), the second screw part (901) passes through the second slide groove (402) and is slidably connected to the second slide groove (402), one end of the second screw part (901) is threadedly connected to the second tool electrode (6), and the other end is connected to the second fastening head (902), the second fastening head (902) is located above the second slide groove (402) and abuts against the electrode mounting plate (4).

5. The electrorheological polishing machine for through-silicon via (TSV) wafers according to claim 4, characterized in that, The electrode mounting plate (4) has a plurality of first receiving grooves (403) and second receiving grooves (404) on its top. The first fastening head (802) is located in the corresponding first receiving groove (403), and the second fastening head (902) is located in the corresponding second receiving groove (404).

6. The electrorheological polishing machine for through-silicon via (TSV) wafers according to claim 3, characterized in that, The lifting drive mechanism (10) includes an electric push rod (1001) mounted on the frame (1) and a lifting seat (1002) connected to the power output end of the electric push rod (1001); the first rotary drive mechanism (3) is mounted on the lifting seat (1002); and the electrode mounting plate (4) is connected to the power output end of the first rotary drive mechanism (3).

7. The electrorheological polishing machine for through-silicon via (TSV) wafers according to claim 6, characterized in that, It also includes a bearing (11), the lifting seat (1002) is provided with a guide cavity (1005), the electrode mounting plate (4) is connected to the inner ring of the bearing (11), and the outer ring of the bearing (11) is slidably connected to the guide cavity (1005) in the vertical direction.

8. The electrorheological polishing machine for through-silicon via (TSV) wafers according to claim 2, characterized in that, The first tool electrode (5) is provided with a first liquid passage chamber (501), and the second tool electrode (6) is provided with a second liquid passage chamber (601).

9. A current-ratio polishing machine for through-silicon via (TSV) wafers according to claim 8, characterized in that, The first tool electrode (5) is provided with a first arc-shaped surface (502) in the portion below the first liquid passage cavity (501), and the second tool electrode (6) is provided with a second arc-shaped surface (602) in the portion below the second liquid passage cavity (601).

10. A current-ratio polishing machine for through-silicon via (TSV) wafers according to any one of claims 1 to 9, characterized in that, The first rotary drive mechanism (3) includes a first motor, which is mounted on the frame (1) and the power output end of the first motor is connected to the electrode mounting plate (4); the second rotary drive mechanism includes a second motor and a rotating disk (7), which is mounted on the frame (1) and the rotating disk (7) is rotatably connected to the frame (1) and the output end of the second motor is connected to the rotating disk (7); the stage (2) is parallel to the rotating disk (7) and connected to the top surface of the rotating disk (7).

Images