A device and method for grinding pressure adjustment control

Abstract

This invention discloses a device and method for adjusting and controlling grinding pressure. By attaching a pressure sensing element to the grinding head, the device acquires the first and second output pressures of multiple pressure zones on the grinding head. The first output pressure corresponds to the initial input pressure of the multiple pressure zones, and the second output pressure corresponds to the adjusted input pressure of the multiple pressure zones. A control module determines the adjustment ratio of the output pressure of the multiple pressure zones based on the measured thickness of the multiple process zones on the grinding object corresponding to the multiple pressure zones. The initial input pressure of the multiple pressure zones is then adjusted to the target input pressure, ensuring that the rate of change of the second output pressure relative to the first output pressure matches the adjustment ratio. Mass production grinding is then performed using the target input pressure. This allows for more accurate adjustment of the pressure in each area, achieving optimal flattening, improving pressure adjustment efficiency, and reducing the risk of adjustment errors.

Description

Technical Field

[0001] This invention relates to the field of semiconductor integrated circuit technology, and in particular to an apparatus and method for adjusting and controlling grinding pressure. Background Technology

[0002] Chemical mechanical polishing (CMP) in chip manufacturing processes controls the surface morphology of the wafer by adjusting the pressure applied to it by the polishing head during the polishing process.

[0003] Chemical mechanical polishing (CMP) is characterized by its high material removal capacity and demanding requirements on film thickness and morphology. The polishing head directly contacts the wafer during the polishing process, applying pressure to the back side of the wafer to control the surface morphology of the wafer film and achieve better planarization. Therefore, pressure control of the polishing head plays a crucial role in maintaining wafer film thickness and planarization during the polishing process.

[0004] With continuous technological advancements, chemical mechanical polishing (CMP) demands increasingly higher surface morphology. The number of chambers on the polishing head for pressure zone control has increased from the initial 3 or 5 chambers to the current 7 chambers. Additionally, a separate chamber is included for overall pressure control of the retaining ring. Due to the increasing number of pressure zones, the pressure control area of ​​each process zone is becoming smaller, leading to greater pressure interaction between adjacent zones.

[0005] Currently, the detection of grinding head pressure can only measure the input pressure at the air inlet of each chamber, meaning it cannot accurately represent the actual output pressure exerted by each chamber on the corresponding area of ​​the wafer. This makes adjusting the pressure for each process zone in the grinding process menu relatively uncontrollable, often relying on experience and multiple trials to achieve the required grinding planarization. Therefore, existing grinding pressure adjustments are time-consuming, consume a significant amount of wafers and consumables for pressure adjustment experiments, and are also inefficient. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned defects in the prior art and to provide a device and method for adjusting and controlling grinding pressure.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] This invention provides a device for adjusting and controlling grinding pressure, comprising:

[0009] A pressure sensor is attached to the lower surface of the grinding head to obtain the first output pressure and the second output pressure of multiple pressure zones of the grinding head. The first output pressure corresponds to the initial input pressure of the multiple pressure zones, and the second output pressure corresponds to the adjusted input pressure of the multiple pressure zones.

[0010] The control module is used to determine the adjustment ratio of the output pressure of the plurality of pressure zones based on the post-grinding thickness measurement values ​​of the plurality of process zones corresponding to the plurality of pressure zones on the grinding object; and to adjust the initial input pressure of the plurality of pressure zones to the target input pressure, so that the pressure change rate of the second output pressure relative to the first output pressure is consistent with the adjustment ratio.

[0011] Furthermore, the pressure sensing sheet includes a substrate and a pressure sensing module disposed on the back of the substrate. The pressure sensing module is provided with multiple pressure sensing units, and each pressure zone contains at least one pressure sensing unit in its vertical projection area.

[0012] Furthermore, the pressure sensing units are arranged on the back side of the substrate to form a pressure sensing unit array; or, the pressure sensing units are arranged on the back side of the substrate to form a plurality of pressure sensing unit rings extending outward from the center of the substrate.

[0013] Furthermore, the pressure sensing unit is coupled to the control module; the control module is used to calculate a set of thickness difference rate data between the thickness measurement value after each grinding and a reference thickness, and to use each thickness difference rate as the adjustment ratio of the output pressure of the multiple pressure zones.

[0014] Further, the reference thickness is the post-grinding thickness measurement value of one of the plurality of process zones; or, the reference thickness is the average post-grinding thickness measurement values ​​of the plurality of process zones.

[0015] The present invention also provides a method for adjusting and controlling grinding pressure, comprising:

[0016] Based on the post-grinding thickness measurement values ​​of multiple process zones corresponding to multiple pressure zones on the grinding object and the grinding head, the adjustment ratio of the output pressure of the multiple pressure zones is determined.

[0017] Obtain the first output pressure of the plurality of pressure zones, wherein the first output pressure corresponds to the initial input pressure of the plurality of pressure zones;

[0018] The initial input pressure of the plurality of pressure zones is adjusted and the second output pressure of the plurality of pressure zones is obtained during the pressure adjustment, until the pressure change rate of the second output pressure relative to the first output pressure is consistent with the adjustment ratio.

[0019] Further, determining the adjustment ratio of the output pressure of the multiple pressure zones based on the post-grinding thickness measurement values ​​of the multiple process zones corresponding to the multiple pressure zones on the grinding object and the grinding head specifically includes:

[0020] By grinding, the thickness measurement values ​​of the multiple process zones on the grinding object after grinding are obtained;

[0021] Based on the thickness measurements after each grinding, a set of thickness difference rate data between the thickness and a reference thickness is calculated.

[0022] The thickness difference rate is determined as the adjustment ratio of the output pressure of the plurality of pressure zones.

[0023] Further, the reference thickness is the post-grinding thickness measurement value of one of the plurality of process zones; or, the reference thickness is the average post-grinding thickness measurement values ​​of the plurality of process zones.

[0024] Furthermore, the step of obtaining the first output pressure of the plurality of pressure zones and the second output pressure of the plurality of pressure zones during pressure adjustment specifically includes:

[0025] A pressure sensor is attached to the lower surface of the grinding head, and the first output pressure and the second output pressure of each pressure zone are obtained by simulating grinding.

[0026] The adjustment of the initial input pressure of the multiple pressure zones specifically includes:

[0027] The initial input pressure of the multiple pressure zones is adjusted in the direction indicated by the adjustment ratio until the rate of change of the second output pressure relative to the first output pressure is consistent with the adjustment ratio, at which point the adjustment ends.

[0028] The product is ground using the input pressure of the multiple pressure zones obtained at the end of the adjustment as the target input pressure.

[0029] Furthermore, the pressure sensing sheet includes a substrate and a pressure sensing module disposed on the back of the substrate. The pressure sensing module is provided with multiple pressure sensing units, and each pressure zone contains at least one pressure sensing unit in its vertical projection area.

[0030] As can be seen from the above technical solution, this invention utilizes a pressure sensing element attached to the lower surface of the grinding head and obtains the output pressure from each pressure zone on the grinding head through simulated grinding. This characterizes the actual output pressure experienced by the product during grinding, thus more accurately representing the actual pressure state of the product under pressure from the grinding head. Furthermore, this invention determines the adjustment ratio of the output pressure of each pressure zone based on the post-grinding thickness measurement of each process zone of the grinding object. The target input pressure for each pressure zone is obtained by comparing the rate of change of output pressure in each pressure zone with the adjustment ratio, obtained by the pressure sensing element before and after input pressure adjustment. This allows for more accurate adjustment of the pressure in each area during subsequent grinding. Compared to the traditional method of relying on experience and repeated overpressure trials, this invention provides more ideal control over the surface morphology during product grinding, achieving optimal flattening and enabling faster and more accurate adjustment of the required optimal pressure. This improves pressure adjustment efficiency and reduces the risk of incorrect adjustment. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a device for adjusting and controlling grinding pressure according to a preferred embodiment of the present invention.

[0032] Figures 2-3 This is a schematic diagram of the structure of a pressure sensing element according to a preferred embodiment of the present invention;

[0033] Figure 4 This is a flowchart illustrating a preferred embodiment of a method for adjusting and controlling grinding pressure according to the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects.

[0035] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0036] Please see Figure 1 , Figure 1This is a schematic diagram of a device for adjusting and controlling grinding pressure according to a preferred embodiment of the present invention. Figure 1 As shown, a device for adjusting and controlling grinding pressure according to the present invention may include a pressure sensing plate 20 and a control module 30 disposed on the grinding head 10 of the grinding equipment.

[0037] The grinding head 10 has multiple air chambers 103 for pressure zone control, such as seven chambers Z1 to Z7, but not limited to these, located within the bottom surface of the grinding head 10. The air chambers Z1 to Z7 are arranged in a closed ring shape, distributed sequentially from the center outwards along the bottom surface of the grinding head 10. These include a first air chamber Z1 located at the center of the bottom surface of the grinding head 10, and second air chambers Z2, Z3, Z4, Z5, Z6, and Z7 located sequentially outside the first air chamber Z1. This forms seven pressure zones on the bottom surface of the grinding head 10, distributed sequentially from the center outwards: the first pressure zone corresponding to the first air chamber Z1, the second pressure zone corresponding to the second air chamber Z2, the third pressure zone corresponding to the third air chamber Z3, the fourth pressure zone corresponding to the fourth air chamber Z4, the fifth pressure zone corresponding to the fifth air chamber Z5, the sixth pressure zone corresponding to the sixth air chamber Z6, and the seventh pressure zone corresponding to the seventh air chamber Z7.

[0038] Thus, seven process zones Y1 to Y7 corresponding to the aforementioned pressure zones (each air chamber 103) can be divided on the grinding object, namely: the first process zone Y1 corresponding to the first pressure zone (first air chamber Z1), the second process zone Y2 corresponding to the second pressure zone (second air chamber Z2), the third process zone Y3 corresponding to the third pressure zone (third air chamber Z3), the fourth process zone Y4 corresponding to the fourth pressure zone (fourth air chamber Z4), the fifth process zone Y5 corresponding to the fifth pressure zone (fifth air chamber Z5), the sixth process zone Y6 corresponding to the sixth pressure zone (sixth air chamber Z6), and the seventh process zone Y7 corresponding to the seventh pressure zone (seventh air chamber Z7).

[0039] In addition, the grinding head 10 is provided with an eighth air chamber 101 for overall pressure control of the retaining ring 102.

[0040] By adjusting the input pressure (inlet pressure) of each pressure zone (each air chamber 103) on the grinding head 10, indirect control of the actual pressure acting on the corresponding process zone can be achieved.

[0041] For information about grinding heads and grinding equipment, please refer to existing technologies.

[0042] The object being ground can be a circular, sheet-like product, such as a wafer. Alternatively, the object being ground can be a sheet-like product of other shapes. The invention will now be described using the example of adjusting and controlling the grinding pressure on a wafer product.

[0043] Please see Figure 1 The pressure sensing element 20 can adopt a sheet-like structure with the same external dimensions as the actual wafer product (including experimental wafers) to more accurately simulate the actual grinding state of the wafer product. Therefore, the pressure sensing element 20 is also divided into the aforementioned seven process zones Y1 to Y7, corresponding to their positions on the wafer product. Taking a wafer product size of 300mm as an example, the pressure sensing element 20 can also be manufactured with a diameter of 300mm and a thickness similar to that of the wafer product.

[0044] When it is necessary to adjust and control the grinding pressure, since detecting the pressure at the air inlet of each air chamber 103 cannot accurately characterize the actual pressure applied by the grinding head 10 to the corresponding area of ​​the wafer product, the output pressure data of each pressure zone on the grinding head 10 can be obtained by using a pressure sensing plate 20.

[0045] Specifically, during use, a pressure sensing plate 20 can be used instead of a wafer product. The back of the pressure sensing plate 20 is attached to the lower surface of the grinding head 10 to simulate the actual grinding state of the wafer product. By simulating grinding, the actual pressure (i.e., the output pressure of each pressure zone) formed by the pressure action of each pressure zone on the grinding head 10 can be sensed by the pressure state of the pressure sensing plate 20 in contact with the grinding pad, and pressure data can be obtained.

[0046] Furthermore, the pressure sensor 20 can be used to obtain the first output pressure from each pressure zone on the grinding head 10. The first output pressure is the output pressure of each pressure zone obtained by the pressure sensor 20 when the input pressure of each pressure zone is the initial input pressure.

[0047] In an optional embodiment, before utilizing the pressure sensing element 20, a wafer test piece can be used for grinding during the debugging phase to obtain the post-grinding thickness measurements of each process partition Y1 to Y7 on the wafer test piece corresponding to each pressure partition. Based on the post-grinding thickness measurements of each process partition Y1 to Y7, the control module 30 can further determine the adjustment ratio of the output pressure of each pressure partition.

[0048] After the pressure sensor 20 acquires the first output pressure of each pressure zone on the grinding head 10, and the control module 30 determines the adjustment ratio of the output pressure of each pressure zone, the control module 30 adjusts the initial input pressure of each pressure zone. Then, it can continue to acquire the second output pressure from each pressure zone through the pressure sensor 20. The second output pressure is the output pressure of each pressure zone acquired by the pressure sensor 20 after the input pressure of each pressure zone has been adjusted. The control module 30 can continuously adjust the input pressure of each air chamber 103 on the grinding head 10 until the rate of change of the second output pressure relative to the first output pressure matches the adjustment ratio.

[0049] In a preferred embodiment, the pressure sensor 20 feeds back the sensed pressure signal to the control module 30 via coupling. The control module 30 is connected to the pressure adjustment device of the grinding head 10. The control module 30 can be installed on the grinding equipment. The control module 30 is used to calculate a set of thickness difference rate data between the measured thickness values ​​of each process partition Y1 to Y7 after grinding using a wafer experimental piece and a reference thickness. The control module 30 uses each thickness difference rate as an adjustment ratio for the output pressure of each pressure partition, and adjusts the input pressure of each pressure partition through the pressure adjustment device of the grinding head 10 until the rate of change of the second output pressure relative to the first output pressure matches the adjustment ratio.

[0050] When the rate of change of the second output pressure relative to the first output pressure is consistent with the adjustment ratio, the control module 30 will use the input pressure of each pressure zone at this time as the menu pressure input value when the wafer product is actually ground in the future, and perform mass production grinding.

[0051] In an optional embodiment, the post-grinding thickness measurement of one of the seven process partitions Y1 to Y7 on the wafer experimental piece can be used as the reference thickness. For example, the post-grinding thickness measurement of the first process partition Y1 can be used as the reference thickness.

[0052] In an optional embodiment, the average value of the thickness measurements after grinding of the seven process zones Y1 to Y7 on the experimental piece can also be used as the reference thickness.

[0053] Please see Figure 2In a preferred embodiment, the pressure sensing plate 20 may include a substrate 201 and a pressure sensing module disposed on the back side of the substrate 201. The pressure sensing module may have multiple pressure sensing units 202. Furthermore, when the pressure sensing plate 20 is attached to the grinding head 10, it should be ensured that at least one pressure sensing unit 202 is present in the vertical projection area of ​​each pressure zone. That is, the position of each pressure sensing unit 202 on the pressure sensing plate 20 corresponding to each process zone Y1 to Y7 should correspond vertically to the position of each pressure zone on the grinding head 10, so as to enable the detection of the output pressure from each pressure zone.

[0054] In an optional embodiment, the number of pressure sensing units 202 on the pressure sensing sheet 20 located below each pressure zone can be the same. For example, one or more pressure sensing units 202 can be equally distributed on each process zone of the pressure sensing sheet 20.

[0055] In an alternative embodiment, the number of pressure sensing units 202 corresponding to the pressure sensing sheet 20 located below each pressure zone can also be different. For example Figure 2 As illustrated, a pressure sensing unit 202 is provided on each of the first process partition Y1, the second process partition Y2, and the fifth to seventh process partitions Y5 to Y7 (taking the left side of the center of the pressure sensing plate 20 as an example), while three pressure sensing units 202 are provided on the third process partition Y3, and two pressure sensing units 202 are provided on the fourth process partition Y4. However, this is not the only example.

[0056] It should be noted that, since the pressure zone and the process zone form a ring, in order to obtain output pressure data more accurately, the pressure sensing unit 202 on each process zone can be extended and distributed on the ring-shaped process zone. Figure 2 The diagram shown is for reference only when illustrating the configuration of the pressure sensing unit 202.

[0057] In other alternative embodiments, the pressure sensing units 202 on the pressure sensing sheet 20 located below each pressure zone are of the same size.

[0058] Furthermore, the size of the pressure sensing unit 202 corresponding to the pressure sensing plate 20 located below each pressure zone can also be different. For example... Figure 2 As exemplified, since the horizontal range of the first process partition Y1 and the second process partition Y2 is relatively wide, larger pressure sensing units 202 can be respectively provided on the first process partition Y1 and the second process partition Y2, while smaller pressure sensing units 202 can be respectively provided on other process partitions, but not limited thereto.

[0059] In one example, taking a wafer size of 300mm as an example, the horizontal width of the smallest seventh process partition Y7 can be as small as, for example, less than 5mm. Then, the pressure sensing unit 202 located in this seventh process partition Y7 of the pressure sensing sheet 20 can be, for example, 2×2mm in size, to achieve pressure detection on a smaller area.

[0060] Please see Figure 3 In a preferred embodiment, the pressure sensing units 202 can be arranged on the back side of the substrate 201 to form a pressure sensing unit array, thereby enabling more accurate acquisition of the output pressure data of each pressure zone. With this configuration, the average value of the output pressure signals fed back by each pressure sensing unit 202 in each process zone can be used as the output pressure data for each pressure zone. Alternatively, common statistical methods such as weighted averaging or averaging several maximum values ​​can be used for calculation. Figure 3 The mapping status of each pressure zone corresponding to each process zone Y1 to Y7 on the pressure sensing plate 20 is shown by dashed circles.

[0061] It should be noted that, Figure 3 The array configuration of the pressure sensing units 202 shown is only for the purpose of illustrative purposes when describing the embodiments of the present invention, and should not be misinterpreted as the actual structural configuration of the pressure sensing unit array.

[0062] In a preferred embodiment, the pressure sensing units 202 can be arranged on the back surface of the substrate 201 to form multiple concentric pressure sensing unit rings extending outward from the center of the substrate 201. That is, each pressure sensing unit ring is formed by multiple pressure sensing units 202 surrounding a circle. Among them, a central pressure sensing unit 202 can be provided at the center of the substrate 201.

[0063] In a preferred embodiment, the pressure sensing unit 202 may be a piezoelectric sensor. Using a piezoelectric sensor, pressure can be sensitively detected, and the received pressure can be fed back as a voltage value, which is then transmitted to the control module 30 for data recording.

[0064] In an alternative embodiment, the pressure sensing unit 202 may be embedded on the back of the substrate 201.

[0065] In an alternative embodiment, the pressure sensing unit 202 may also be fabricated directly on the back side of the substrate 201 using semiconductor processing technology.

[0066] In an optional embodiment, a protective film layer may also be provided on the pressure sensing unit 202 on the back side of the substrate 201.

[0067] The following detailed description of a method for adjusting and controlling grinding pressure according to the present invention, with reference to the accompanying drawings and specific embodiments, is provided in detail.

[0068] Please see Figure 4 And in conjunction with reference Figure 1 A method for adjusting and controlling grinding pressure according to the present invention can be implemented using the aforementioned device for adjusting and controlling grinding pressure, and may include the following steps:

[0069] Step S1: Based on the post-grinding thickness measurements of each process zone Y1 to Y7 corresponding to each pressure zone on the wafer experimental piece and the grinding head 10, determine the adjustment ratio of the output pressure of each pressure zone.

[0070] In a preferred embodiment, a wafer test piece can be used, and grinding is performed during the debugging phase according to the initial pressure setting in the menu. After grinding, the wafer test piece can be removed from the grinding equipment for thickness measurement, obtaining the post-grinding thickness measurement values ​​of each process partition Y1 to Y7 on the wafer test piece corresponding to each pressure partition on the grinding head 10. Multiple measurements can be performed on the post-grinding thickness of each process partition Y1 to Y7, and the average value can be used as the post-grinding thickness measurement data for each process partition Y1 to Y7.

[0071] Alternatively, the thickness measurements after grinding for each process zone Y1 to Y7 can be calculated by using a weighted average or by taking the average of several maximum thickness measurements after grinding.

[0072] The control module 30 calculates the thickness difference rate (in percentage) between each post-grinding thickness measurement and the selected reference thickness. Specifically, when the post-grinding thickness measurement of a certain process zone is greater than the reference thickness, the calculated thickness difference rate for that process zone is positive; conversely, when the post-grinding thickness measurement of a certain process zone is less than the reference thickness, the calculated thickness difference rate for that process zone is negative.

[0073] At this point, the control module 30 determines the calculated thickness difference rate of each process zone Y1 to Y7 as the adjustment ratio (in percentage) of the output pressure from each pressure zone that the product experiences during grinding.

[0074] Based on the linear direct proportional relationship between grinding rate and grinding pressure, it can be deduced that there is also a linear direct proportional relationship between thickness difference rate and grinding pressure adjustment ratio. Therefore, the thickness difference rates of each process zone Y1 to Y7 calculated above can be used as the adjustment ratio of the output pressure of each pressure zone and applied to the actual adjustment and control of grinding pressure.

[0075] It's important to note that both the adjustment ratio and the thickness difference rate have positive and negative signs. For example, when the thickness difference rate is negative, it indicates that the grinding rate of a certain process zone is greater than the grinding rate corresponding to the reference thickness. Therefore, the grinding rate of that process zone needs to be adjusted to match the grinding rate corresponding to the reference thickness. In this case, the actual input pressure of the corresponding pressure zone should be reduced according to the value of the thickness difference rate. That is, the adjustment ratio is also a negative value with the same magnitude as the thickness difference rate.

[0076] Step S2: Obtain the first output pressure of each pressure zone through the pressure sensor.

[0077] In a preferred embodiment, the pressure sensing sheet 20 described above can be used to attach the back side of the pressure sensing sheet 20 having the pressure sensing unit 202 to the lower surface of the grinding head 10.

[0078] Then, following the same initial pressure settings as the wafer experimental piece, the pressure sensor 20 is pressed onto the polishing pad to simulate polishing using the initial input pressure of each pressure zone.

[0079] During the simulated grinding process, the pressure sensor 20 collects the first output pressure signal of each pressure zone and transmits it to the control module 30. The control module 30 uses the acquired first output pressure as the initial actual output pressure of the grinding process, and can also use it as the initial pressure input value when performing PID control on the grinding pressure.

[0080] Step S3: Adjust the input pressure of each pressure zone and obtain the second output pressure of each pressure zone during pressure adjustment until the pressure change rate of the second output pressure relative to the first output pressure is consistent with the adjustment ratio.

[0081] The control module 30 adjusts the input pressure of each pressure zone through the pressure adjustment device of the grinding head 10.

[0082] When adjusting and controlling the grinding pressure, the input pressure of each pressure zone is adjusted in a direction consistent with the adjustment ratio. For example, a negative adjustment ratio indicates that the input pressure of the corresponding pressure zone should be reduced, and vice versa.

[0083] For example, assuming the thickness of regions Y4 to Y6 in the fourth to sixth process partitions on the experimental wafer is 10% thinner than the thickness of the first process partition Y1, which serves as the reference thickness, i.e., the thickness difference rate from the fourth process partition Y4 to the sixth process partition Y6 is -10%, then the adjustment ratio is also -10%. When adjusting the pressure, the input pressure in the fourth to sixth gas chambers Z4 to Z6 located in the fourth to sixth pressure partitions should be adjusted in a decreasing direction until the rate of change between the second and first output pressures of the fourth to sixth gas chambers Z4 to Z6, as fed back by the pressure sensor 20, also decreases by 10%.

[0084] When adjusting the input pressure of the corresponding pressure zone, the pressure sensor 20 will continuously collect the changing second output pressure signal from each pressure zone and feed it back to the control module 30 in real time.

[0085] The control module 30 continuously compares the second output pressure of each pressure zone with the first output pressure and calculates the rate of change of the second output pressure relative to the first output pressure. When the rate of change of the second output pressure relative to the first output pressure is consistent with the determined adjustment ratio through pressure adjustment, the control module 30 will issue a stop adjustment command to terminate the adjustment.

[0086] Based on the correspondence between the second output pressure and the input pressure of the pressure zone, when the control module 30 obtains the second output pressure that meets the adjustment ratio, it obtains the target input pressure of the corresponding pressure zone. At this time, the control module 30 uses the target input pressure of each pressure zone obtained at the end of the adjustment through the pressure adjustment device of the grinding head 10 as the menu pressure input value (target value) for subsequent actual grinding of the wafer product, and performs mass production grinding.

[0087] In summary, this invention utilizes a pressure sensing element 20 attached to the lower surface of the grinding head 10 and obtains the output pressure from each pressure zone on the grinding head 10 through simulated grinding. This characterizes the actual output pressure experienced by the product during grinding, thus more accurately representing the actual pressure state of the product under pressure from the grinding head 10. Furthermore, based on the post-grinding thickness measurements and calculated thickness difference rates of each process zone Y1-Y7 of the experimental piece, this invention determines the adjustment ratio of the output pressure for each pressure zone. The target input pressure for each pressure zone is obtained by comparing the output pressure change rate of each pressure zone with the adjustment ratio obtained by the pressure sensing element 20 before and after input pressure adjustment. This allows for more accurate adjustment of the pressure in each area during subsequent product grinding. Compared to traditional methods relying on experience and repeated overpressure trials, this invention provides more ideal control over the surface morphology during product grinding, achieving optimal flattening and enabling faster and more accurate adjustment of the required optimal pressure. This improves pressure adjustment efficiency and reduces the risk of incorrect adjustments.

[0088] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A device for adjusting and controlling grinding pressure, characterized in that, include: A pressure sensor is attached to the lower surface of the grinding head to obtain the first output pressure and the second output pressure of multiple pressure zones of the grinding head. The first output pressure corresponds to the initial input pressure of the multiple pressure zones, and the second output pressure corresponds to the adjusted input pressure of the multiple pressure zones. The control module is used to determine the adjustment ratio of the output pressure of the multiple pressure zones based on the post-grinding thickness measurement values ​​of the multiple process zones on the grinding object corresponding to the multiple pressure zones; And for adjusting the initial input pressure of the plurality of pressure zones to the target input pressure, such that the rate of change of the second output pressure relative to the first output pressure is consistent with the adjustment ratio.

2. The device for adjusting and controlling grinding pressure according to claim 1, characterized in that, The pressure sensing sheet includes a substrate and a pressure sensing module disposed on the back of the substrate. The pressure sensing module is provided with multiple pressure sensing units, and each pressure zone contains at least one pressure sensing unit in its vertical projection area.

3. The device for adjusting and controlling grinding pressure according to claim 2, characterized in that, The pressure sensing units are arranged on the back side of the substrate to form a pressure sensing unit array; or, the pressure sensing units are arranged on the back side of the substrate to form a plurality of pressure sensing unit rings that extend outward from the center of the substrate.

4. The device for adjusting and controlling grinding pressure according to claim 2, characterized in that, The pressure sensing unit is coupled to the control module; The control module is used to calculate a set of thickness difference rate data between the thickness measured after each grinding and a reference thickness, and to use each thickness difference rate as the adjustment ratio of the output pressure of the plurality of pressure zones.

5. The device for adjusting and controlling grinding pressure according to claim 4, characterized in that, The reference thickness is the measured thickness of one of the multiple process zones after grinding; or, the reference thickness is the average of the measured thicknesses of the multiple process zones after grinding.

6. A method for adjusting and controlling grinding pressure, characterized in that, include: Based on the post-grinding thickness measurement values ​​of multiple process zones corresponding to multiple pressure zones on the grinding object and the grinding head, the adjustment ratio of the output pressure of the multiple pressure zones is determined. Obtain the first output pressure of the plurality of pressure zones, wherein the first output pressure corresponds to the initial input pressure of the plurality of pressure zones; The initial input pressure of the plurality of pressure zones is adjusted and the second output pressure of the plurality of pressure zones is obtained during the pressure adjustment, until the pressure change rate of the second output pressure relative to the first output pressure is consistent with the adjustment ratio.

7. The method for adjusting and controlling grinding pressure according to claim 6, characterized in that, The step of determining the adjustment ratio of the output pressure of the multiple pressure zones based on the post-grinding thickness measurement values ​​of the multiple process zones corresponding to the multiple pressure zones on the grinding object and the grinding head specifically includes: By grinding, the thickness measurement values ​​of the multiple process zones on the grinding object after grinding are obtained; Based on the thickness measurements after each grinding, a set of thickness difference rate data between the thickness and a reference thickness is calculated. The thickness difference rate is determined as the adjustment ratio of the output pressure of the plurality of pressure zones.

8. The method for adjusting and controlling grinding pressure according to claim 7, characterized in that, The reference thickness is the measured thickness of one of the multiple process zones after grinding; or, the reference thickness is the average of the measured thicknesses of the multiple process zones after grinding.

9. The method for adjusting and controlling grinding pressure according to claim 6, characterized in that, The process of obtaining the first output pressure of the plurality of pressure zones and obtaining the second output pressure of the plurality of pressure zones during pressure adjustment specifically includes: A pressure sensor is attached to the lower surface of the grinding head, and the first output pressure and the second output pressure of each pressure zone are obtained by simulating grinding. The adjustment of the initial input pressure of the multiple pressure zones specifically includes: The initial input pressure of the multiple pressure zones is adjusted in the direction indicated by the adjustment ratio until the rate of change of the second output pressure relative to the first output pressure is consistent with the adjustment ratio, at which point the adjustment ends. The product is ground using the input pressure of the multiple pressure zones obtained at the end of the adjustment as the target input pressure.

10. The method for adjusting and controlling grinding pressure according to claim 9, characterized in that, The pressure sensing sheet includes a substrate and a pressure sensing module disposed on the back of the substrate. The pressure sensing module is provided with multiple pressure sensing units, and each pressure zone contains at least one pressure sensing unit in its vertical projection area.

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