Contact measuring device and wafer thinning equipment

Abstract

The present application provides a contact measuring device and a wafer thinning device. The contact measuring device includes: a first mounting base configured with a mounting hole; a first measuring rod mounted to the mounting hole and horizontally extending above the carrier stage, with a first measuring head provided at its end. The first measuring rod can be lifted and lowered in the mounting hole to make the first measuring head contact the wafer and lift and lower with the change of the wafer thickness; a protective air pipe and a protective liquid pipe. The protective air pipe is configured with a downward-opening air vent groove extending along its length, and the protective liquid pipe is configured with a downward-opening liquid vent groove extending along its length. The air vent groove discharges air downward to form an air curtain to block the processing debris from entering the mounting hole, and the liquid vent groove discharges liquid downward to form a liquid curtain to block the processing debris passing through the air curtain from entering the mounting hole. The technical solution of the present application can effectively reduce the accumulation of debris at the mounting hole, avoid interfering with the movement of the measuring rod, and thus improve the measurement accuracy.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor wafer processing, and in particular to a contact measuring device and a wafer thinning device. Background Art

[0002] In the back-end process stage of integrated circuit manufacturing, in order to reduce the packaging and mounting height, reduce the chip packaging volume, improve the thermal diffusion efficiency, electrical performance, mechanical performance of the chip, and reduce the processing amount of dicing, the wafer needs to be thinned on the back side before subsequent packaging.

[0003] During the above-mentioned back thinning process, a set of on-line wafer thickness detection device is usually used to measure the thickness of the wafer, so as to correct the feed amount of the main shaft during the thinning process. The on-line thickness detection device generally uses a contact measurement module. During the grinding and thinning process, a large amount of silicon powder and crystal slag will be generated. Under the high-speed rotation of the main shaft, some silicon powder will be blown into the mounting hole at the root of the mounting measuring rod. After a period of accumulation, the problem that the measuring rod cannot descend normally will occur, thus affecting the normal operation of the equipment. Summary of the Invention

[0004] The present application provides a contact measuring device and a wafer thinning device to solve or alleviate at least some of the problems mentioned above.

[0005] According to one aspect of the present application, a contact measuring device is provided. The contact measuring device is configured to contact the surface of a wafer in a wafer thinning device to measure the thickness of the wafer, and it includes:

[0006] A first mounting seat, which is arranged on the side of the carrier table for carrying the wafer and is constructed with a mounting hole;

[0007] A first measuring rod, which is installed in the mounting hole and horizontally extends above the carrier table. A first measuring head extending vertically is arranged at the end of the first measuring rod. The first measuring rod is configured to be able to lift and lower in the mounting hole so that the first measuring head contacts the wafer and lift and lower with the change of the wafer thickness during the wafer processing;

[0008] A protective air pipe and a protective liquid pipe, both of which are located between the mounting hole and the first measuring head and horizontally extend perpendicular to the first measuring rod above the first measuring rod. The protective air pipe is closer to the first measuring head than the protective liquid pipe; the protective air pipe is constructed with a downward-opening air vent groove extending along its length, and the protective liquid pipe is constructed with a downward-opening liquid vent groove extending along its length. The air vent groove is configured to discharge air downward to form an air curtain to block processing debris from entering the mounting hole, and the liquid vent groove is configured to discharge liquid downward to form a liquid curtain to block the processing debris passing through the air curtain from entering the mounting hole.

[0009] Optionally or alternatively, the contact measurer includes a base fixedly mounted to the base of the wafer thinning equipment, and the first mounting seat is mounted on the side of the base facing the carrier of the wafer thinning equipment; a bracket extending above the first mounting seat is fixedly connected to the top of the base, a flow dividing block is mounted on the bracket, and the protective air pipe and the protective liquid pipe are mounted to the flow dividing block and are respectively in fluid communication with a flow dividing air path and a flow dividing liquid path in the flow dividing block.

[0010] Optionally or alternatively, the protective air pipe is electrically connected to an actuator configured to actuate the protective air pipe to rotate about its axis based on the pressure of the airflow carrying the processing debris, so as to adjust the angle between the air vent groove and the vertical plane.

[0011] Optionally or alternatively, the protective air pipe is fluidly connected to a gas supply source, and a pressure regulator is provided between the protective air pipe and the gas supply source, and the pressure regulator is configured to adjust the outlet air pressure of the air vent groove based on the pressure of the airflow carrying the processing debris.

[0012] Optionally or alternatively, the protective liquid pipe is fluidly connected to a liquid supply source, and a flow regulator is provided between the protective liquid pipe and the liquid supply source, and the flow regulator is configured to adjust the liquid outlet speed of the liquid passage groove based on the pressure of the airflow carrying the processing debris.

[0013] Optionally or alternatively, the contact measurer includes a pressure sensor provided on the first probe head, and the pressure sensor is arranged in the oncoming direction of the airflow carrying the processing debris and is configured to detect the pressure of the airflow carrying the processing debris.

[0014] Optionally or alternatively, the outlet air pressure of the air vent groove is 0.3 to 0.7 MPa; and / or the liquid outlet flow rate of the liquid passage groove is 1 - 2 L / min.

[0015] Optionally or alternatively, the wall surface of the air vent groove is configured to be inclined 0 to 15 degrees away from the first mounting seat to form a counterflow with the airflow carrying the processing debris flowing towards the first mounting seat.

[0016] Optionally or alternatively, the positions of the protective air pipe and the protective liquid pipe are both higher than the mounting hole, and the height of the protective air pipe is equal to or higher than the height of the protective liquid pipe.

[0017] Optionally or alternatively, the carrier adsorbs and fixes the wafer by means of vacuum adsorption; the projection of the axis of the protective liquid pipe on the surface of the carrier is tangent to the projection of the outer circumference of the wafer on the surface of the carrier, so that the liquid curtain flushes the processing debris at the contact between the edge of the wafer and the carrier.

[0018] Optionally or alternatively, the contact measuring device further includes a second protective air pipe disposed between the protective liquid pipe and the first mounting base. The second protective air pipe extends horizontally perpendicular to the first measuring rod above the first measuring rod. The second protective air pipe is configured with a second air vent groove opening downward along its length, and the second air vent groove discharges air downward to form an air curtain to block machining debris and droplets from entering the mounting hole.

[0019] Optionally or alternatively, the position of the second protective air pipe is higher than the mounting hole, and the positions of the second protective air pipe, the protective liquid pipe, and the protective air pipe increase in sequence.

[0020] Optionally or alternatively, an air outlet channel fluidly connected to the mounting hole is configured in the first mounting base, and the air outlet channel is configured to blow air into the mounting hole to blow out machining debris or droplets entering the mounting hole.

[0021] Optionally or alternatively, the mounting hole is configured as a reamed hole with a cross-section gradually expanding towards the carrier table, and its bottom wall surface gradually slopes downward to facilitate the discharge of machining debris or droplets.

[0022] Optionally or alternatively, the contact measuring device includes a second mounting base having the same structure as the first mounting base and a second measuring rod having the same structure as the first measuring rod. A second measuring head extending vertically is provided at the end of the second measuring rod, and the second measuring head is configured to contact the carrier table to measure the height of the surface of the carrier table. The contact measuring device obtains the thickness of the wafer based on the difference between the height of the surface of the wafer measured by the first measuring head and the height of the surface of the carrier table measured by the second measuring head.

[0023] According to another aspect of the present application, there is provided a wafer thinning device, which includes a grinding module. The grinding module includes: a rotary table provided with a carrier table for carrying a wafer; a grinding device for grinding the wafer; and a contact measuring device as described in the foregoing aspect.

[0024] Optionally or alternatively, there are three carrier tables arranged in an annular array on the rotary table. The rotary table rotates so that two of the three carrier tables are located at two processing positions below the grinding device. The wafer thinning device includes two contact measuring devices disposed between the two processing positions, and the two contact measuring devices are arranged back to back to be respectively used for measuring the thickness of the wafers on the two carrier tables at the two processing positions.

[0025] According to the contact measuring device and wafer thinning equipment of the present application, by providing a protective air pipe and a protective liquid pipe, at least two protective curtains are formed between the mounting hole and the probe head. The airflow carrying the machining debris is blocked by the air curtain and the liquid curtain in turn during the process of flowing towards the mounting seat, significantly reducing the accumulation of machining debris in the mounting hole, avoiding the interference or obstruction of the machining debris to the lifting of the measuring rod, and being able to reduce the contamination near the root of the measuring rod, effectively improving the working effectiveness of the contact measuring device and the accuracy of measuring the grinding thickness of the wafer, thereby providing an accurate basis for controlling the feed rate of the grinding wheel or the remaining grinding time during the grinding process, ensuring the machining accuracy of the wafer, and being conducive to achieving sub-nanometer or even nanometer machining accuracy in wafer grinding and thinning. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments described in the embodiments of the present application, and those of ordinary skill in the art can also obtain other drawings based on these drawings.

[0027] Figure 1 Shows a three-dimensional schematic diagram of a wafer thinning equipment according to an embodiment of the present application;

[0028] Figure 2 Shows a measurement principle diagram of a contact measuring device, Figure 2 Figure a in it is a schematic diagram of zero adjustment before measurement, Figure 2 Figure b in it is a schematic diagram during measurement;

[0029] Figure 3 Shows Figure 2 A schematic diagram of the contact measuring device during operation in it;

[0030] Figure 4 Shows Figure 2 A partial three-dimensional view of the contact measuring device in it;

[0031] Figure 5 Shows a top view schematic diagram of a contact measuring device according to an embodiment of the present application;

[0032] Figure 6 Shows Figure 5 A bottom view schematic diagram of the protective air pipe of the contact measuring device in it;

[0033] Figure 7 Shows Figure 5 A partial three-dimensional schematic diagram of the contact measuring device in it;

[0034] Figure 8 Shows Figure 5Schematic diagram of the contact measuring device during operation;

[0035] Figure 9 The figure shows a schematic diagram of a contact measuring device.

[0036] Reference numerals:

[0037] W, wafer; 1, wafer thinning equipment; 2, grinding device; 21, rough grinding section; 211, rough grinding wheel; 22, fine grinding section; 221, fine grinding wheel; 31, turntable; 32, carrier table; 5, cleaning unit; 6, manipulator; 4, measuring unit; 100, contact measuring device; 110, first mounting base; 1101, mounting hole; 111, first measuring rod; 112, first measuring head; 120, second mounting base; 121, second measuring rod; 122, second measuring head; 10, base; 11, diverter; 20, bracket; 30, diverter block; 130, protective air pipe; 131, ventilation groove; 140, protective liquid pipe; 201, air curtain; 202, liquid curtain; 101, pressure sensor; 151, first spray pipe; 152, second spray pipe. Detailed implementation manners

[0038] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art shall fall within the protection scope of the embodiments of the present application.

[0039] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application.

[0040] In addition, in the description of the present application, unless otherwise specified and limited, it should be noted that the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it may be a mechanical connection or an electrical connection, or it may be the communication inside two elements. It may be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific situations.

[0041] Figure 1A wafer thinning device 1 provided by an embodiment of the present invention is schematically shown in a three-dimensional view and includes: a turntable 31 that is rotatable and supports a plurality of carrier platforms 32; a carrier platform 32 that holds a wafer W by vacuum adsorption and can drive the wafer W to rotate; a grinding device 2, the grinding device 2 includes a main shaft unit and a grinding wheel connected to the main shaft unit, the grinding wheel abuts against the wafer W to perform a grinding and thinning process on the wafer W, and the main shaft unit can be vertically and / or horizontally fed and adjusted to tilt forward and backward or left and right to adjust the feed amount of the grinding wheel. Specifically, the grinding device 2 may include a rough grinding section 21 and a fine grinding section 22, the rough grinding section 21 includes a rough grinding main shaft unit and a rough grinding wheel 211, and the fine grinding section 22 includes a fine grinding main shaft unit and a fine grinding wheel 221.

[0042] Specifically, a plurality of carrier platforms 32 for holding the wafer W and driving the wafer W to rotate are arranged on the turntable 31. The turntable 31 can rotate around its vertical central axis so that the turntable 31 drives the plurality of carrier platforms 32 to rotate and move integrally, thereby realizing the position conversion of the carrier platforms 32 between different workstations. Each carrier platform 32 can also rotate itself. As Figure 1 shown, as an implementable manner, three rotatable carrier platforms 32 are evenly distributed on the turntable 31, each having a chuck for adsorbing the wafer W. The three chucks can be porous ceramic chucks to realize vacuum adsorption of the wafer W. Moreover, the three carrier platforms 32 form an annular array centered on the center of the turntable 31, and the included angle between two adjacent carrier platforms 32 is 120°. The three carrier platforms 32 correspond to three workstations, namely a rough grinding workstation, a fine grinding workstation, and a loading and unloading workstation. Among them, the rough grinding workstation and the fine grinding workstation are two processing workstations, which are respectively located below the rough grinding section 21 and the fine grinding section 22 of the grinding device 2, and the remaining one workstation is used for the loading, unloading, and cleaning of the wafer W. By rotating the turntable 31, the three carrier platforms 32 can be driven to switch between these three workstations, so as to realize the cyclic movement of the carrier platforms 32 carrying the wafer W in the order of loading and unloading workstation - rough grinding workstation - fine grinding workstation - loading and unloading workstation. In this embodiment, the full-automatic loading and unloading of the wafer W and continuous grinding and cleaning are realized through repeated cycles. Using the rotary turntable 31 for wafer W grinding has the advantages of high material removal rate, small surface damage of the wafer W, and easy realization of automation.

[0043] The wafer thinning device 1 may further include a cleaning unit 5, and the cleaning unit 5 includes a first cleaning part and a second cleaning part. The first cleaning part, for example, uses an oilstone to clean and polish the carrier table 32, and the second cleaning part, for example, uses a brush to clean the wafer W. The wafer thinning device 1 may further include a manipulator 6, and the manipulator 6 is used to place the wafer W on the carrier table 32 at the loading and unloading position, and take out the wafer W from the carrier table 32 after grinding and cleaning for subsequent transfer. As an implementable manner, a pipeline for vacuum pumping is provided inside the manipulator 6 to achieve vacuum adsorption of the wafer W. Additionally, in a specific implementation, the wafer thinning device 1 further includes a grinding fluid supply unit, which is used to spray grinding fluid on the surface of the wafer W during rough grinding and / or fine grinding to assist in grinding, and the grinding fluid can be deionized water.

[0044] As Figure 1 shown, the wafer thinning device 1 further includes a measurement unit 4, which may include a contact type measurer 100 and a non-contact optical measurer (not shown), and can achieve on-line monitoring of the thickness of the wafer W. The probe of the contact type measurer 100 contacts the surface of the wafer W to measure the thickness of the wafer W. The measurement unit 4 may include two contact type measurers 100 arranged back to back with respect to each other, respectively used for measurement at two processing positions. The non-contact optical measurer can irradiate the wafer W with infrared light and calculate the thickness of the wafer W based on the different reflected lights on the upper and lower surfaces of the wafer W.

[0045] Figure 2 shows a detection principle diagram of a contact type measurer 100. The contact type sensor may include a first mounting seat 110 and a first measuring rod 111. The first mounting seat 110 is arranged on the side of the carrier table 32 for carrying the wafer W and is configured with a mounting hole 1101 (see Figure 4 ). The first measuring rod 111 is installed in the mounting hole 1101 and horizontally extends above the carrier table 32. A vertically extending first probe 112 is provided at the end of the first measuring rod 111. The first measuring rod 111 is configured to be able to lift in the mounting hole 1101 so that the first probe 112 contacts the wafer W and lifts with the change of the thickness of the wafer W during the processing of the wafer W. The contact type measurer 100 may further include a second mounting seat 120 having the same structure as the first mounting seat 110 and a second measuring rod 121 having the same structure as the first measuring rod 111. The horizontal extension distance of the second measuring rod 121 may be less than that of the first measuring rod 111. A vertically extending second probe 122 is provided at the end of the second measuring rod 121. The second probe 122 is configured to contact the carrier table 32 to measure the height of the surface of the carrier table 32. The contact type measurer 100 obtains the thickness of the wafer W based on the difference between the height of the surface of the wafer W measured by the first probe 112 and the height of the surface of the carrier table 32 measured by the second probe 122. Specifically, as Figure 2In the figure a, zeroing can be performed before measurement. When no wafer is placed on the carrier 32, the first probe 112 and the second probe 122 are both made to contact the surface of the carrier 32, and the measurement heights of both the first probe 112 and the second probe 122 are set to zero. As Figure 2 In the figure b, during measurement, the height measured by the first probe 112 minus the height measured by the second probe 122 is the real-time thickness of the wafer W. The grinding device 2 can correct the feed amount of the grinding wheel during the thinning process based on the thickness of the wafer W measured by the contact measuring device 100, realizing real-time monitoring and control of the grinding and thinning process, and ensuring the processing accuracy of the wafer W.

[0046] In addition, in an optional embodiment, the second mounting base 120 and the second measuring rod 121 can also be omitted, and only the first mounting base 110 and the first measuring rod 111 are used. At this time, before measurement, the first measuring rod 111 can be extended and retracted to make the first probe 112 contact the surface of the carrier 32 for measurement, and the height of the surface of the carrier 32 measured is used as the reference height. Then, the first measuring rod 111 is extended and retracted again to make the first probe 112 contact the surface of the wafer W for real-time measurement. The height of the surface of the wafer W measured by the first probe 112 minus the reference height is the real-time thickness of the wafer W.

[0047] Figure 3 shows Figure 2 A schematic diagram of the contact measuring device 100 during operation. During the grinding and thinning process of the wafer W, a large amount of processing debris, such as silicon powder and crystal slag, is generated. Under the high-speed rotation of the spindle unit (such as the rough grinding spindle unit), the generated air flow will drive the processing debris to flow towards the contact measuring device 100, and some of the processing debris will be blown into the mounting hole 1101 of the contact measuring device 100. As Figure 4 shows Figure 2 A partial perspective view of the contact measuring device 100 in the figure can be seen. The processing debris accumulated in the mounting hole 1101 (shown by the solid black pattern) will hinder the normal descent of the first measuring rod 111, making the first measuring rod 111 unable to lower as the thickness of the wafer W decreases during measurement, causing the contact measuring device 100 to malfunction, resulting in inaccurate measurement of the thickness of the wafer W, and thus unable to correctly guide the grinding device 2 to adjust the feed amount of the grinding wheel, affecting the normal operation of the wafer thinning equipment.

[0048] Therefore, the present application provides a contact measuring device 100, Figure 5 A top view schematic diagram of the contact measuring device 100 according to an embodiment of the present application is shown, Figure 6 shows Figure 5 A bottom view schematic diagram of the protective air pipe 130 of the contact measuring device 100 in the figure; Figure 7 shows Figure 5Partial perspective view of the contact measuring device 100 in Figure 5 The contact measuring device 100 in includes a base 10, a first mounting seat 110, a first measuring rod 111, a first measuring head 112, a second mounting seat 120, a second measuring rod 121, a second measuring head 122, etc. The base 10 can be fixedly installed on the base of the wafer thinning equipment. The first mounting seat 110 and the second mounting seat 120 are installed side by side on the side of the base 10 facing the carrier 32 of the wafer thinning equipment. A bracket 20 (see Figure 9 ) extending above the first mounting seat 110 is fixedly connected to the top of the base 10. A flow dividing block 30 is installed on the bracket 20. The protective air pipe 130 and the protective liquid pipe 140 are installed on the flow dividing block 30 and can be fluidly connected to the flow dividing air path and the flow dividing liquid path in the flow dividing block 30 through pipes respectively.

[0049] Specifically, see Figure 7 , the first mounting seat 110 is arranged on the side of the carrier 32 carrying the wafer W and is constructed with a mounting hole 1101. The first measuring rod 111 extends horizontally above the carrier 32. A vertically extending first measuring head 112 is arranged at the end of the first measuring rod 111. The first measuring rod 111 is configured to be able to lift in the mounting hole 1101 so that the first measuring head 112 contacts the wafer W and lifts with the change of the thickness of the wafer W during the processing of the wafer W. The second mounting seat 120 has the same structure as the first mounting seat 110, the second measuring rod 121 has the same structure as the first measuring rod 111, a vertically extending second measuring head 122 is arranged at the end of the second measuring rod 121. The second measuring head 122 is configured to contact the carrier 32 to measure the height of the surface of the carrier 32. The contact measuring device 100 obtains the thickness of the wafer W based on the difference between the height of the surface of the wafer W measured by the first measuring head 112 and the height of the surface of the carrier 32 measured by the second measuring head 122.

[0050] Also as Figure 7 , the protective air pipe 130 and the protective liquid pipe 140 are located between the mounting hole 1101 and the first measuring head 112, and horizontally extend perpendicular to the first measuring rod 111 above the first measuring rod 111 and the second measuring rod 121 (not shown). That is, from the Figure 5 top view, the protective air pipe 130 and the protective liquid pipe 140 are parallel, and both are cross-shaped with the first measuring rod 111 and the second measuring rod 121 respectively. The protective air pipe 130 is closer to the first measuring head 112 than the protective liquid pipe 140. As Figure 6 shown, the protective air pipe 130 is constructed with a downward-opening ventilation groove 131 extending along its length. Similarly, the protective liquid pipe 140 is constructed with a downward-opening liquid passage groove (not shown) extending along its length. In addition, Figure 6 the pipe perpendicular to the protective air pipe 130 shown in is one implementation manner of the pipe for fluid connection between the protective air pipe 130 and the flow dividing block 30. Back toFigure 7 As can be seen, the air vent groove 131 is configured to discharge air downward to form an air curtain 201 to block machining debris from entering the mounting hole 1101, and the liquid vent groove is configured to discharge liquid downward to form a liquid curtain 202 to block the machining debris passing through the air curtain 201 from entering the mounting hole 1101. It should be understood that Figure 7 in, multiple parallel curves are used to schematically show the air curtain 201, and multiple parallel dashed lines are used to schematically show the liquid curtain 202. In an actual embodiment, both the air curtain 201 and the liquid curtain 202 are continuous entire curtains. Although Figure 6 the air vent groove 131 shown in is a straight and narrow groove, in an alternative embodiment, the air vent groove 131 and the liquid vent groove can also be curved or wavy narrow grooves. The gas ejected from the air vent groove 131 can be compressed air, and the liquid ejected from the liquid vent groove can be deionized water.

[0051] Figure 8 shows Figure 5 a schematic diagram of the contact measuring device 100 in during operation. When the airflow carrying machining debris flows towards the first mounting seat 110 and the second mounting seat 120, it is successively blocked by the air curtain 201 and the liquid curtain 202, thereby significantly reducing the accumulation of machining debris in the mounting hole 1101, reducing the contamination near the roots of the first measuring rod 111 and the second measuring rod 120, effectively improving the cleanliness, working effectiveness and measurement accuracy of the contact measuring device 100, facilitating the reasonable regulation of the grinding wheel feed amount during the grinding process, and ensuring the machining precision of the wafer W.

[0052] In a specific embodiment, the protective air pipe 130 is fluidly connected to an air supply source, and a pressure regulator is provided between the protective air pipe 130 and the air supply source. The pressure regulator is configured to adjust the air outlet pressure of the air vent groove 131 based on the pressure of the airflow carrying machining debris, and this outlet air pressure can be between 0.3 and 0.7 MPa. The protective liquid pipe 140 is fluidly connected to a liquid supply source, and a flow regulator is provided between the protective liquid pipe 140 and the liquid supply source. The flow regulator is configured to adjust the liquid outlet flow rate of the liquid vent groove based on the pressure of the airflow carrying machining debris, and this outlet liquid flow rate can be between 1 - 2 L / min. As Figure 7 shown, the contact measuring device 100 can include a pressure sensor 101 provided on the first measuring head 112 or the second measuring head 122. The pressure sensor 101 can be oriented towards the grinding device 2, specifically towards the incoming flow direction of the airflow carrying machining debris, preferably facing the incoming flow direction of the airflow carrying machining debris, and is configured to detect the pressure of the airflow carrying machining debris and communicate with the pressure regulator and the flow regulator to provide adjustment reference information for both of them.

[0053] In a preferred embodiment, the protective air duct 130 is electrically connected to an actuator, which can be configured to communicate with the pressure sensor 101 and actuate the protective air duct 130 to rotate about its axis based on the pressure of the airflow carrying the machining debris, so as to adjust the angle between the ventilation slot 131 and the vertical plane. In a specific implementation, a rotary joint can be used to connect the pipeline between the protective air duct 130 and the flow splitting block 30, or a flexible connection with support, such as a corrugated pipe, can be used between the pipeline between the protective air duct 130 and the flow splitting block 30 and the protective air duct 130, so as to achieve a small degree of rotatability of the protective air duct 130 and ensure the connection tightness.

[0054] In a further embodiment, the wall surface of the ventilation slot 131 is configured to be inclined 0 to 15 degrees away from the first mounting seat 110, that is, inclined 0 to 15 degrees towards the main shaft unit, so that the air curtain 201 is inclined towards the main shaft unit to form a counter flow with the airflow carrying the machining debris flowing towards the first mounting seat 110, slowing down the speed of the airflow carrying the machining debris, thereby reducing the machining debris passing through the air curtain 201 and the liquid curtain 202 and entering the mounting hole 1101. Optionally, the wall surface of the liquid passage groove can also have an inclination angle away from the first mounting seat 110, such as 0 to 15 degrees, preferably 1 to 10 degrees.

[0055] In terms of the setting height, the positions of the protective air duct 130 and the protective liquid pipe 140 are both higher than the mounting hole 1101, and the height of the protective air duct 130 is equal to or higher than the height of the protective liquid pipe 140, so as to form a double protection structure and prevent the machining debris above from directly passing over the protective air duct 130 due to the protective air duct 130 being lower than the protective liquid pipe 140. Preferably, the height of the protective air duct 130 is higher than the height of the protective liquid pipe 140, which is convenient for the pipeline connection between the protective air duct 130 and the protective liquid pipe 140 and the flow splitting block 30, and avoids the protective liquid pipe 140 interfering with the connection of the protective air duct 130.

[0056] In a preferred embodiment, the projection of the axis of the protective liquid pipe 140 on the surface of the carrier 32 is tangent to the projection of the outer circumference of the wafer W on the surface of the carrier 32, that is, the protective liquid pipe 140 is arranged directly above the outer circumference of the wafer W, so that the liquid curtain 202 flushes the machining debris at the contact position between the edge of the wafer W and the carrier 32. Since the carrier 32 adsorbs and fixes the wafer W by means of vacuum adsorption, the machining debris is easily sucked into the porous adsorption plate of the carrier 32 from the edge of the wafer W, resulting in poor adsorption or blocking of the pores of the porous adsorption plate. By arranging the protective liquid pipe 140 directly above the tangent of the outer circumference of the wafer W, the liquid curtain 202 can flush the machining debris at the contact position between the edge of the wafer W and the carrier 32, avoiding the accumulation of machining debris at the edge of the wafer W from scratching or contaminating the wafer, and avoiding the machining debris being adsorbed into the carrier 32 resulting in poor adsorption.

[0057] In a preferred embodiment, the contact measuring device 100 further includes a second protective air pipe (not shown) disposed between the protective liquid pipe 140 and the first mounting base 110. The second protective air pipe extends horizontally perpendicular to the first measuring rod 111 above the first measuring rod 111. The second protective air pipe is configured with a second air vent groove opening downward along its length. The second air vent groove discharges air downward to form an air curtain 201 to block machining debris and droplets from entering the mounting hole 1101, that is, the structures of the second protective air pipe and the protective air pipe 130 can be substantially the same. The position of the second protective air pipe is higher than the mounting hole 1101, and the positions of the second protective air pipe, the protective liquid pipe 140, and the protective air pipe 130 can be successively raised to form a stepped triple protection structure.

[0058] In a preferred embodiment, an air outlet channel fluidly communicating with the mounting hole 1101 is formed in the first mounting base 110. The air outlet channel can be connected to a compressed air source, and the air outlet channel is configured to blow air into the mounting hole 1101 to actively blow out machining debris or droplets entering the mounting hole 1101.

[0059] In a preferred embodiment, the mounting hole 1101 is configured as a reamed hole with a cross-section gradually expanding towards the bearing table 32, and its bottom wall gradually slopes downward to facilitate the discharge of machining debris or droplets along the inclined bottom wall under the action of gravity.

[0060] As Figure 9 shown, a contact measuring device includes two contact measuring devices 100 arranged back to back with respect to each other. The two contact measuring devices 100 can be directly combined back to back, or as Figure 9 shown, their respective bases 10 are integrally formed into a common base 10. In Figure 9 it can be seen the bracket 20 for supporting the flow dividing block 30, and a flow divider 11 can also be installed on the top of the base 10. The interface at the top of the flow divider 11 is used to connect to a gas source or a liquid source in a wafer thinning device, and the interfaces on the side of the flow divider 11 are used to fluidly communicate with the flow dividing gas path and the flow dividing liquid path in the flow dividing block 30 through pipes (not shown) correspondingly. Through the arrangement of the flow divider 11 and the flow dividing block 30, the pipes can be reduced from being bent, interfered with, or wound due to changing directions, the pipe vibration can be reduced, the smoothness of the contact measuring device 100 itself can be ensured, the jitter deviation of the measurement result can be reduced, the smoothness and stability of the fluid flow in the pipes can be increased, thereby reducing the occurrence of fluid turbulence phenomena in the pipes, and ensuring that the speed or fluid pressure of the gas or liquid flowing out of the air outlet groove and the liquid outlet groove is uniform and controllable.

[0061] In a preferred embodiment, as Figure 9As shown, a first spray pipe 151 and a second spray pipe 152 that extend parallel thereto can be respectively arranged directly above the first measuring rod 111 and the second measuring rod 121 to respectively perform spray washing and cooling on the first measuring rod 111 and the second measuring rod 121.

[0062] The contact measuring device 100 described above can be applied to a wafer thinning device, such as Figure 1 shown in the wafer thinning device as the measuring unit 4 or a part of the measuring unit 4.

[0063] The above embodiments are only used to illustrate the embodiments of the present application, rather than to limit the embodiments of the present application. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the spirit and scope of the embodiments of the present application. Therefore, all equivalent technical solutions also belong to the scope of the embodiments of the present application. The patent protection scope of the embodiments of the present application shall be defined by the claims.

Claims

1. A contact measuring device, characterized in that, The contact measuring device is configured to contact the surface of a wafer in a wafer thinning device to measure the thickness of the wafer, and includes: A first mounting base, which is arranged on the side of a carrier table that vacuum-sucks the wafer and is constructed with a mounting hole; A first measuring rod, which is mounted to the mounting hole and horizontally extends above the carrier table. A first measuring head that vertically extends is provided at the end of the first measuring rod. The first measuring rod is configured to be able to lift and lower in the mounting hole so that the first measuring head contacts the wafer and lifts and lowers with the change of the wafer thickness during the wafer processing; A second mounting base and a second measuring rod that have the same structures as the first mounting base and the first measuring rod respectively. A second measuring head that vertically extends is provided at the end of the second measuring rod. The second measuring head is configured to contact the carrier table. The contact measuring device obtains the thickness of the wafer based on the difference between the height of the wafer surface measured by the first measuring head and the height of the carrier table surface measured by the second measuring head; A protective air pipe and a protective liquid pipe, which are located between the mounting hole and the first measuring head, horizontally extend perpendicular to the first measuring rod above the first measuring rod and the second measuring rod and are respectively in a cross shape with the first measuring rod and the second measuring rod. The protective air pipe is closer to the first measuring head than the protective liquid pipe; the protective air pipe and the protective liquid pipe are respectively constructed with an air vent groove and a liquid vent groove that open downward along their respective lengths. The air vent groove is configured to discharge air downward to form an uninterrupted air curtain to block the processing debris from entering the mounting hole, and the liquid vent groove is configured to discharge liquid downward to form an uninterrupted liquid curtain to block the processing debris that passes through the air curtain from entering the mounting hole; A pressure sensor provided on the first measuring head, which faces the oncoming flow direction of the airflow carrying the processing debris and is configured to detect the pressure of the airflow carrying the processing debris; the protective air pipe is electrically connected to an actuator, and the actuator actuates the protective air pipe to rotate around its axis based on the pressure of the airflow carrying the processing debris to adjust the angle between the air vent groove and the vertical plane; The projection of the axis of the protective liquid pipe on the surface of the carrier table is tangent to the projection of the outer circumference of the wafer on the surface of the carrier table, so that the liquid curtain flushes the processing debris at the contact area between the edge of the wafer and the carrier table; the air outlet pressure of the air vent groove is 0.3 to 0.7 MPa and the liquid outlet flow rate of the liquid vent groove is 1 - 2 L / min; an air outlet channel that is in fluid communication with the mounting hole is constructed in the first mounting base, and the air outlet channel is configured to blow air into the mounting hole to blow out the processing debris or liquid droplets that enter the mounting hole.

2. The contact measuring device according to claim 1, characterized in that, The contact measuring device includes a base, the base is fixedly installed on the base of the wafer thinning device, and the first mounting base is mounted to the side of the base facing the carrier table of the wafer thinning device; a bracket that extends above the first mounting base is fixedly connected to the top of the base, a flow dividing block is mounted on the bracket, and the protective air pipe and the protective liquid pipe are mounted to the flow dividing block and are respectively in fluid communication with the flow dividing air path and the flow dividing liquid path in the flow dividing block.

3. The contact type measuring device according to claim 1, characterized in that, The protective air pipe is fluidly connected to an air supply source, and a pneumatic regulator is provided between the protective air pipe and the air supply source. The pneumatic regulator is configured to adjust the outlet air pressure of the air vent groove based on the pressure of the air flow carrying the processing debris.

4. The contact measuring device according to claim 1, characterized in that, The protective liquid pipe is fluidly connected to a liquid supply source, and a flow regulator is provided between the protective liquid pipe and the liquid supply source. The flow regulator is configured to adjust the liquid outlet speed of the liquid passage groove based on the pressure of the air flow carrying the processing debris.

5. The contact type measuring device according to any one of claims 1-4, characterized in that, The wall surface of the air vent groove is configured to be inclined 0 to 15 degrees away from the first mounting seat to form a countercurrent with the air flow carrying the processing debris flowing towards the first mounting seat.

6. The contact measuring device according to any one of claims 1-4, characterized in that, The positions of the protective air pipe and the protective liquid pipe are both higher than the mounting hole, and the height of the protective air pipe is equal to or higher than the height of the protective liquid pipe.

7. The contact type measuring device according to any one of claims 1-4, characterized in that, The contact measuring device further includes a second protective air pipe provided between the protective liquid pipe and the first mounting seat. The second protective air pipe extends horizontally perpendicular to the first measuring rod above the first measuring rod. The second protective air pipe is configured with a second air vent groove with an opening downward extending along its length. The second air vent groove discharges air downward to form an air curtain to block the processing debris and liquid droplets from entering the mounting hole.

8. The contact type measuring device according to claim 7, characterized in that, The position of the second protective air pipe is higher than the mounting hole, and the positions of the second protective air pipe, the protective liquid pipe, and the protective air pipe increase in sequence.

9. The contact type measuring device according to any one of claims 1-4, characterized in that, The mounting hole is configured as a reamed hole with a cross-section gradually expanding towards the bearing table, and its bottom wall surface gradually slopes downward to facilitate the discharge of processing debris or liquid droplets.

10. A wafer thinning device, characterized in that, The wafer thinning device includes a grinding module, and the grinding module includes: A rotary table provided with a bearing table for carrying a wafer; A grinding device for grinding the wafer; The contact measuring device according to any one of claims 1-9.

11. The wafer thinning device according to claim 10, characterized in that, There are three of the bearing tables arranged in an annular array on the rotary table. The rotary table rotates so that two of the three bearing tables are located at two processing positions below the grinding device. The wafer thinning device includes two of the contact measuring devices provided between the two processing positions. The two contact measuring devices are arranged back to back to be respectively used for measuring the thickness of the wafers on the two bearing tables at the two processing positions.

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