Spindle unit and wafer processing apparatus including same

Abstract

An embodiment of the present invention provides a spindle unit comprising: a spindle including a shaft, which extends in the vertical direction, and a first bearing coupling part, which has a shape extending from the central portion of the shaft and protruding in the circumferential direction of the shaft; a first bearing part coupled to the upper surface and lower surface of the first bearing coupling part; and a first sensor part for measuring a gap between the first bearing coupling part and the first bearing. The first bearing part is provided as a magnetic bearing, and adjusts the orientation of the spindle by adjusting the gap between the first bearing coupling part and the first bearing part according to the power supplied from a power supply unit.

Description

Spindle unit and wafer processing device including the same

[0001] An embodiment of the present invention relates to a spindle unit and a wafer processing device including the spindle unit.

[0002] In general, a wafer is a thin disc that serves as a semiconductor material, and is a round plate obtained by slicing a single-crystal rod such as silicon or gallium arsenide. These wafers are manufactured through a series of process steps, including a slicing process that thinly slices a rod-shaped single-crystal silicon ingot, a lapping process that maintains the thickness and flatness of the sliced ​​wafer, an etching process to remove impurities or defects, a polishing process to remove surface damage or improve flatness, and a subsequent cleaning process.

[0003] The manufactured wafers are then fed into the post-processing for semiconductor package assembly. This process begins with the wafer back-grinding process. Back-grinding typically involves removing a portion of the back of the wafer (the non-patterned surface) using laser, etching, or mechanical grinding to create a very thin wafer. Back-grinding reduces wafer thickness and weight, improves the thermal and electrical performance of the final device, reduces manufacturing costs, and enables the production of smaller, more compact devices. As semiconductor miniaturization approaches its limits, its importance is growing.

[0004] Meanwhile, in wafer surface grinding equipment, the precision of the equipment is determined by the total thickness variation (TTV) of the wafer after processing. Recently, the diversification and miniaturization of semiconductor devices have led to the need for thinner wafers (thickness less than 50 μm), which has led to the need for grinding technology that satisfies the standard of a total wafer thickness variation of ±0.5 μm or less. To achieve precise wafer thickness, the position and angle of the table base on which the wafer is held during processing and the grinding wheel that comes into contact with the wafer surface are very important.

[0005] However, conventionally, a spindle on which a grinding wheel or table base is installed is supported by three points, one of the three points is fixed as a fixed end, and the posture and angle of the grinding wheel or table base are adjusted by adjusting the height of each of the remaining two points. This causes many errors in implementing the tilting angle of the grinding wheel or table base, and there are problems such as defects such as the occurrence of a defect in which the center thickness of the wafer increases.

[0006] Embodiments of the present invention are intended to solve the above-mentioned problems, and an object of the present invention is to provide a spindle unit capable of adjusting a tilting angle based on the center point of a table base or the center point of a grinding wheel.

[0007] Additionally, it aims to provide a spindle unit capable of measuring the exact posture and angle of a table base or grinding wheel and making precise corrections.

[0008] However, these tasks are exemplary and the scope of the present invention is not limited thereby.

[0009] One embodiment of the present invention provides a spindle unit including a shaft extending in a vertical direction and a first bearing coupling portion formed in a shape extending from a center of the shaft and protruding in a circumferential direction of the shaft, a first bearing portion coupled to upper and lower surfaces of the first bearing coupling portion, and a first sensor portion measuring a gap between the first bearing coupling portion and the first bearing, wherein the first bearing portion is provided as a magnetic bearing and adjusts the gap with the first bearing coupling portion according to power supplied from a power supply unit to adjust the posture of the spindle.

[0010] A spindle unit according to one embodiment of the present invention can adjust the tilting angle based on the center point of the table base, thereby easily adjusting the posture of the table base and reducing the time and cost required for the back grinding process.

[0011] In addition, the spindle unit according to one embodiment of the present invention can precisely measure the posture and tilting angle of the table base, enable real-time monitoring, enable immediate correction, and is easy to maintain, reducing the time and cost required for maintenance.

[0012] Of course, the scope of the present invention is not limited by these effects.

[0013] Figure 1 is a perspective view illustrating a wafer processing device according to conventional technology.

[0014] FIG. 2 is a drawing showing a state in which the table base is tilted in the wafer processing device illustrated in FIG. 1.

[0015] FIG. 3 is a drawing illustrating a spindle unit according to one embodiment of the present invention.

[0016] Fig. 4 is a drawing showing a state in which the table base is tilted by the spindle unit illustrated in Fig. 3.

[0017] FIG. 5 is a drawing for explaining a control unit and a power supply unit connected to a spindle unit according to one embodiment of the present invention.

[0018] One embodiment of the present invention provides a spindle unit including a shaft extending in a vertical direction and a first bearing coupling portion formed in a shape extending from a center of the shaft and protruding in a circumferential direction of the shaft, a first bearing portion coupled to upper and lower surfaces of the first bearing coupling portion, and a first sensor portion measuring a gap between the first bearing coupling portion and the first bearing, wherein the first bearing portion is provided as a magnetic bearing and adjusts the gap with the first bearing coupling portion according to power supplied from a power supply unit to adjust the posture of the spindle.

[0019] In one embodiment of the present invention, the spindle is connected to a table base and can tilt the table base based on a center point of the table base.

[0020] In one embodiment of the present invention, the spindle is connected to a grinding wheel and can tilt the grinding wheel around a center point of the grinding wheel.

[0021] In one embodiment of the present invention, a second bearing part coupled to the shaft and a second sensor part measuring a gap between the second bearing part and the shaft are further included, wherein the second bearing part is provided as a magnetic bearing, and the gap with the shaft can be adjusted according to power supplied from the power supply part, thereby adjusting the posture of the spindle.

[0022] In one embodiment of the present invention, the first bearing part and the second bearing part can generate external forces in different directions to the spindle.

[0023] In one embodiment of the present invention, the first sensor unit may include three or more first sensors spaced at equal intervals.

[0024] In one embodiment of the present invention, a control unit that controls the first bearing unit according to first gap information measured from the first sensor unit may be further included.

[0025] In one embodiment of the present invention, the control unit obtains and stores initial position information of the first bearing unit from the first sensor unit, and can control the posture of the spindle using the initial position information and the first gap information.

[0026] In one embodiment of the present invention, the first bearing portion may include an upper ring and a lower ring respectively coupled to the upper surface and the lower surface of the first bearing coupling portion, and the first sensor portion may include a plurality of first-first sensors arranged on the upper ring and a plurality of first-second sensors arranged on the lower ring.

[0027] In one embodiment of the present invention, the first-1 sensor and the first-2 sensor may be provided in the same number.

[0028] In one embodiment of the present invention, the plurality of first-1 sensors and the plurality of first-2 sensors may be arranged at equal intervals from the central axis of the shaft.

[0029] In one embodiment of the present invention, the plurality of first-1 sensors and the plurality of first-2 sensors may be arranged so as not to overlap each other.

[0030] In one embodiment of the present invention, the control unit can adjust the posture of the spindle using the first-first gap information measured from the first-first sensors, and evaluate the posture of the spindle and generate a feedback signal using the first-second gap information measured from the first-second sensors.

[0031] Another embodiment of the present invention provides a wafer processing device including a processing unit including a grinding wheel and a first spindle unit connected to the grinding wheel, and a work unit including a table base on which a wafer is placed and a second spindle unit connected to the table base, wherein the first spindle unit or the second spindle unit includes a spindle including a shaft extending in a vertical direction and a first bearing coupling portion formed in a shape extending from the center of the shaft and protruding in a circumferential direction of the shaft, a first bearing portion non-contactably coupled to upper and lower surfaces of the first bearing coupling portion, and a first sensor portion measuring a gap between the first bearing coupling portion and the first bearing, wherein the first bearing portion is provided as a magnetic bearing, and adjusts the gap with the first bearing coupling portion according to power supplied from a power supply unit, thereby adjusting the posture of the spindle.

[0032] Hereinafter, the following embodiments will be described in detail with reference to the attached drawings. When describing with reference to the drawings, identical or corresponding components are given the same drawing reference numerals, and redundant descriptions thereof will be omitted.

[0033] These embodiments are capable of various modifications. Specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of these embodiments, as well as the methods for achieving them, will become clearer with reference to the detailed descriptions below, along with the drawings. However, these embodiments are not limited to the embodiments disclosed below and may be implemented in various forms.

[0034] In the drawings, parts unrelated to the description are omitted to clearly explain the present invention, and similar parts are designated by similar drawing reference numerals throughout the specification.

[0035] In the examples below, the terms first, second, etc. are not used in a limiting sense, but are used for the purpose of distinguishing one component from another.

[0036] In the examples below, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0037] In the examples below, terms such as “include” or “have” mean that a feature or component described in the specification exists, and do not preclude the possibility that one or more other features or components may be added.

[0038] In the examples below, when a part such as a unit, region, or component is said to be on or above another part, this includes not only the case where it is directly above the other part, but also the case where another unit, region, component, etc. is interposed in between.

[0039] In the examples below, terms such as connect or combine do not necessarily mean a direct and / or fixed connection or combination of two members, unless the context clearly indicates otherwise, and do not exclude the presence of another member between the two members.

[0040] The terms indicating directions such as up, down, left, right, front, and back used in this specification are only used to easily describe the relationship between each component shown in the drawing, and do not limit the direction in which each component is arranged.

[0041] FIG. 1 is a perspective view showing a wafer processing device (10) according to a conventional technology, and FIG. 2 is a drawing showing a state in which a table base (220) is tilted in the wafer processing device (10) shown in FIG. 1.

[0042] Before describing the embodiments of the present invention, a wafer processing device (10) according to the prior art will be described with reference to FIGS. 1 and 2, and the main differences in configuration between the wafer processing device (10) according to the prior art and the embodiments of the present invention will be described below.

[0043] First, referring to FIGS. 1 and 2, a wafer processing device (10) according to the prior art includes a processing unit (100) and a work unit (200). The processing unit (100) is rotatable and is provided to be able to move up and down. The processing unit (100) moves downward toward the work unit (200) on which the wafer is mounted, and processes the wafer while applying pressure to the wafer.

[0044] The processing unit (100) includes a first spindle unit (110) and a grinding wheel (120) coupled to the first spindle unit (110). The grinding wheel (120) is formed in a circular flat plate shape and is coupled to the lower end of the first spindle unit (110) to rotate and ascend and descend together with the first spindle unit (110). The grinding wheel (120) rotates in conjunction with the rotation of the first spindle unit (110) and grinds a wafer placed on the work unit (200).

[0045] The work unit (200) is positioned at a predetermined distance below the processing unit (100). The work unit (200) includes a second spindle unit (210), a table base (220) on which a wafer is placed, and a drive unit (230). The table base (220) is coupled to the upper end of the second spindle unit (210) and rotates in conjunction with the rotation of the second spindle unit (210). The table base (220) can allow a wafer to be placed and fixed on its upper surface. The table base (220) may be equipped with a means for absorbing the wafer with vacuum pressure or a means for fixing the wafer with electrostatic force.

[0046] A plurality of driving units (230) are provided and are arranged on the outer surface of the second spindle unit (210). One end of the driving unit (230) is connected to the table base (220) and can support the table base (220). The driving unit (230) can be extended in length by including a driving member such as a motor, and can be arranged at at least two locations around the table base (220) to support the table base (220).

[0047] At this time, the table base (220) can be supported at three points via the second spindle unit (210) and the drive unit (230). One of the three points is fixed in position as a fixed point (FP), and the drive unit (230) is connected to the remaining two points, thereby adjusting the height of the remaining two points excluding the fixed point using the drive unit (230).

[0048] That is, the table base (220) can have a tilted posture with respect to the second spindle unit (210) through the length expansion and contraction of the driving units (230). At this time, the tilting angle (θ) at which the table base (220) is tilted is determined based on the fixed end (FP). When the table base (220) is tilted by θ around the fixed end (FP), the end of the table base (220) opposite to the fixed end (FP) moves upward by d1.

[0049] However, in the case of the conventional technology of tilting the table base (220) with respect to the fixed end (FP) using the driving unit (230) as described above, when the table base (220) is tilted by a certain angle or more, a problem occurs in that the calculated tilting angle and the actual tilting angle of the table base (220) are different. Accordingly, the conventional technology essentially requires a process of tilting the table base (220) by the calculated tilting angle and then verifying the posture of the table base (220), i.e., the tilted angle.

[0050] The verification of the table base (220) is performed by adjusting the attitude of the table base (220) and then installing and verifying an indicator for verifying the tilting angle of the table base (220). If the measured value of the indicator does not match the target tilting angle value, the attitude of the table base (220) must be readjusted and re-verified. In addition, once the attitude adjustment of the table base (220) is completed, a test wafer is polished to verify whether the tilting angle of the table base (220) is appropriate. If the processing condition of the test wafer does not reach the target level, the attitude adjustment of the table base (220) must be performed again from the beginning, which causes a problem in that the process time is long. In addition, since the worker must install and measure the indicator one by one during the attitude verification process of the table base (220), there is a problem in that the worker's fatigue is considerable and there is a high possibility of measurement errors and human errors.

[0051] Moreover, in the case of the conventional technology, as the tilting angle (θ) of the table base (220) increases, the center line (CL) of the table base (220) gradually deviates from the center axis of the second spindle unit (210), which causes a problem in that the center thickness of the wafer increases during wafer processing.

[0052] Meanwhile, in FIG. 1, a conventional technology in which the table base (220) of the work unit (200) is tilted by a drive unit (230) provided on the outer surface of the second spindle unit (210) is described as an example, but the same technical principle can be applied to the processing unit (100). That is, the movable unit (100) may also be provided with a drive unit (not shown) installed on the outer surface of the first spindle unit (110) to tilt the grinding wheel (120), and when the grinding wheel (120) is tilted, a problem occurs in which an error in the tilting angle occurs and a problem in which the center line of the grinding wheel deviates from the center axis of the first spindle unit (110).

[0053] Meanwhile, bearings used in the first spindle unit (110) and the second spindle unit (210) are mainly air bearings in consideration of the load degree and rigidity of the grinding process. Air bearings have the advantage of being able to realize high speed, low load, high precision, and high rigidity because there is no friction, but they have the disadvantage of being greatly affected by compressed air. For example, if compressed air containing contaminated water flows into the air bearing, the inside of the air bearing may corrode, causing malfunctions such as clogging. In addition, spindle units using air bearings have limitations in that they form an air gap between the spindle and the bearing to implement non-contact operation, making it impossible to measure the exact gap value or predict the precursor symptoms of spindle damage due to changes in the gap.

[0054] In addition, in spindle units using air bearings, since the gap is inferred based on the pressure measured by the pressure sensor, there was a problem that the pressure could remain the same even if the spindle gap changed due to air leakage, making it difficult to accurately measure the gap, and there was a problem that the response speed for measuring pressure changes was slow, making it difficult to immediately compensate when the gap changed.

[0055] Hereinafter, embodiments of the present invention that solve the problems of the prior art will be described in detail. However, for convenience of explanation, the same reference numbers are used for the same components as the wafer processing device (10) in the prior art, and redundant descriptions are omitted.

[0056] FIG. 3 is a drawing showing a spindle unit (300) according to one embodiment of the present invention, FIG. 4 is a drawing showing a state in which a table base (220) is tilted by the spindle unit (300) shown in FIG. 3, and FIG. 5 is a drawing for explaining a control unit (350) and a power supply unit (360) connected to the spindle unit (300) according to one embodiment of the present invention.

[0057] Referring to FIGS. 3 to 5, a spindle unit (300) according to one embodiment of the present invention may include a spindle (310), a first bearing unit (320), and a first sensor unit (330), and may further include a control unit (350) and a power unit (360). The spindle unit (300) according to one embodiment of the present invention may be applied to the first spindle unit (110) of the processing unit (100) or the second spindle unit (210) of the work unit (200) in the wafer processing apparatus (10) described above in FIG. 1. That is, the spindle unit (300) may be connected to a grinding wheel (120) to form the processing unit (100), or may be connected to a table base (220) to form the work unit (200).

[0058] The spindle (310) may include a shaft (311) extending in a vertical direction and a first bearing coupling portion (312) formed in a shape extending from the center of the shaft (311) and protruding in the circumferential direction of the shaft (311). The first bearing coupling portion (312) may be formed in the center of the longitudinal direction of the shaft (311) and may have a cylindrical shape protruding in the circumferential direction from the outer peripheral surface of the shaft (311). The shaft (311) and the first bearing coupling portion (312) may be formed integrally, but are not limited thereto.

[0059] The spindle (310) can rotate around a rotation axis (Ax) formed at the center of the circumference of the shaft (311). The spindle (310) may include a magnetic material. In one embodiment, the spindle (310) may be formed entirely of permanent magnets, but the present invention is not limited thereto, and the spindle (310) may be formed so that permanent magnets are placed only at a portion where the first bearing part (320) and the second bearing part (350, see FIG. 5) to be described later are coupled.

[0060] The first bearing part (320) can be coupled to the first bearing coupling part (312). The first bearing part (320) can be coupled to the first bearing coupling part (312) in a non-contact manner with a gap therebetween. The first bearing part (320) can be a magnetic bearing, and can be coupled to the first bearing coupling part (312) with a gap therebetween by a magnetic force generated between the first bearing coupling part (312) and the power supply part (360).

[0061] The first bearing part (320) can adjust the gap with the first bearing coupling part (312) according to the power supplied from the power supply part (360). The first bearing part (320) can adjust the posture of the spindle unit (300) by adjusting the gap with the first bearing coupling part (312).

[0062] The first bearing part (320) may include an upper ring (321) coupled to the upper surface of the first bearing coupling part (312) and a lower ring (322) coupled to the lower surface of the first bearing coupling part (312). That is, the upper ring (321) and the lower ring (322) may be arranged to face each other with the first bearing coupling part (312) interposed therebetween.

[0063] In addition, the upper ring (321) and the lower ring (322) may be arranged to be spaced apart from the first bearing coupling portion (312) by a predetermined distance, respectively. Specifically, in the initial position, the upper ring (321) may be spaced apart from the upper surface of the first bearing coupling portion (312) by a gap of g1, and the lower ring (322) may be spaced apart from the lower surface of the first bearing coupling portion (312) by a gap of g2. The gaps (g1, g2) by which the upper ring (321) and the lower ring (322) are spaced apart from the first bearing coupling portion (312) may be the same as each other, or may be different from each other.

[0064] The first sensor unit (330) is arranged in the first bearing unit (320) and can measure the gap between the first bearing unit (320) and the first bearing coupling unit (312). The first sensor unit (330) can measure the gap between the first bearing unit (320) and the first bearing coupling unit (312) at three or more locations within the first bearing unit (320).

[0065] In one embodiment, the first sensor unit (330) may include three or more first sensors spaced at equal intervals. At this time, the plurality of first sensors may be arranged at equal intervals from the rotation axis (Ax). In other words, the plurality of first sensors may be arranged at equal intervals along a virtual circle having a predetermined radius centered on the rotation axis (Ax) on the first bearing unit (320). For example, the first sensor may be a capacitance sensor or an eddy current sensor capable of gap measurement, but is not limited thereto.

[0066] Specifically, the first sensor unit (330) may include a plurality of first-first sensors (331) arranged in the upper ring (321) and a plurality of first-second sensors (332) arranged in the lower ring (322). The first-first sensors (331) may be arranged inside the upper ring (321) to measure a gap between the upper ring (321) and the upper surface of the first bearing coupling portion (312), and the first-second sensors (332) may be arranged inside the lower ring (322) to measure a gap between the lower ring (322) and the lower surface of the first bearing coupling portion (312).

[0067] In one embodiment, the plurality of first-first sensors (331) and the plurality of first-second sensors (332) may be provided in the same number. For example, when three first-first sensors (331) are provided in the upper ring (321) and three first-second sensors (332) are provided in the lower ring (322), the first sensor unit (330) may measure the gap between the upper ring (321) and the first bearing joint (312) and the gap between the lower ring (322) and the first bearing joint (312) using a three-point measurement method. However, the present invention is not limited to the above-described embodiment, and the plurality of first-first sensors (331) and the plurality of first-second sensors (332) may be provided in different numbers.

[0068] Meanwhile, the plurality of 1-1 sensors (331) and the plurality of 1-2 sensors (332) may be arranged so as not to overlap each other. In other words, when the upper ring (321) and the lower ring (322) are viewed from above, the plurality of 1-1 sensors (331) and the plurality of 1-2 sensors (332) may not overlap each other. For example, the 1-1 sensors (331) may be arranged on the upper ring (321) to be spaced apart at equal intervals, and the 1-2 sensors (332) may be arranged on the lower ring (322) between adjacent 1-1 sensors (331) so as to prevent the plurality of 1-1 sensors (331) and the plurality of 1-2 sensors (332) from overlapping each other. However, the present invention is not limited thereto, and a plurality of first-1 sensors (331) and a plurality of first-2 sensors (332) may be arranged so as to overlap each other, or only some of them may be arranged so as to overlap each other.

[0069] Meanwhile, the spindle unit (300) may include a second bearing part (340) disposed adjacent to an end of the shaft (311) and a second sensor part disposed on the second bearing part (340). The second bearing part (340) may be coupled to the upper or lower side of the shaft (311) extending in the vertical direction, and may be coupled in a non-contact manner. The second bearing part (340) may be a magnetic bearing, and may be coupled to the shaft (311) with a gap by a magnetic force generated between the second bearing part (340) and the power supply part (360).

[0070] The second bearing unit (340) can adjust the gap with the shaft (311) according to the power supplied from the power supply unit (360). The second bearing unit (340) can adjust the posture of the spindle unit (300) by adjusting the gap with the shaft (311). The second bearing unit (340) may be provided in multiple pieces. For example, the second bearing unit (340) may include a 2-1 bearing unit coupled to the upper side of the shaft (311) and a 2-2 bearing unit coupled to the lower side of the shaft (311).

[0071] The second sensor unit is arranged on the second bearing unit (340) and can measure the gap between the second bearing unit (340) and the shaft (311). The second sensor unit may include a plurality of second sensors. The plurality of second sensors may be arranged at equal intervals along the circumferential direction on the second bearing unit (340), but is not limited thereto. For example, the second sensor may be a capacitance sensor or an eddy current sensor capable of gap measurement, but is not limited thereto.

[0072] The first bearing part (320) and the second bearing part (340) can adjust the gap with the spindle (310) and tilt the spindle (310) to one side with respect to the rotation axis (Ax). That is, the first bearing part (320) and the second bearing part (340) can generate an external force by magnetic force on the spindle (310) and tilt the spindle (310).

[0073] At this time, the directions of the external forces applied to the spindle (310) by the first bearing part (320) and the second bearing part (340) may be different. For example, the first bearing part (320) can tilt the spindle (310) by generating an external force in the up-and-down direction to the first bearing coupling part (312), and the second bearing part (340) can tilt the spindle (310) by generating an external force in the left-right direction to the upper and / or lower side of the shaft (311). When the spindle unit (300) includes the second bearing part (340), the spindle unit (300) can more precisely adjust the posture of the spindle (310) by controlling the first bearing part (320) and the second bearing part (340) together.

[0074] The control unit (350) can change the size of the power supplied from the power supply unit (360) to the first bearing unit (320) based on the first gap information measured from the first sensor unit (330), and adjust the gap between the first bearing coupling unit (312) and the first bearing unit (320). In addition, the control unit (350) can change the size of the power supplied from the power supply unit (360) to the second bearing unit (340) based on the second gap information measured from the second sensor unit, and adjust the gap between the shaft and the second bearing unit (340). Here, the first gap information and the second gap information can include real-time gap values ​​measured by the first sensor and the second sensor, respectively.

[0075] The control unit (350) can control the posture of the spindle (310) by adjusting the gap between the first bearing coupling unit (312) and the first bearing unit (320) based on the first gap information, and can control the posture of the spindle (310) by adjusting the gap between the shaft (311) and the second bearing unit (340) based on the second gap information.

[0076] In addition, the control unit (350) can obtain and store the initial position information of the first bearing unit (320) and the second bearing unit (240) measured from the first sensor unit (330) and / or the second sensor unit, and can control the posture of the spindle (310) using the initial position information together with the first gap information and / or the second gap information. Here, the initial position information can include a gap value between the first bearing unit (320) and the first bearing coupling unit (312) and / or between the second bearing unit (340) and the shaft (311) when the spindle (310) is not tilted and is in a fixed posture.

[0077] Meanwhile, in one embodiment, the control unit (350) may control the posture of the spindle (310) using the first-first gap information measured from the first-first sensors (331) of the first sensor unit (330), and after the posture of the spindle (310) is adjusted, may evaluate the posture of the spindle (310) using the first-second gap information measured from the first-second sensors (332) of the first sensor unit (330). At this time, the posture evaluation of the spindle (310) may be performed simultaneously with the posture control of the spindle (310).

[0078] That is, the spindle unit (300) can measure the gap between the first bearing part (320) and the first bearing coupling part (312) using a plurality of first-first sensors (331) arranged on the upper ring (321) of the first bearing part (320), and adjust the posture of the spindle (310) by changing the gap, and can evaluate whether the posture adjustment of the spindle (310) is appropriate using a plurality of first-second sensors (332) arranged on the lower ring (322) of the first bearing part (320). The control unit (350) can generate a feedback signal based on the evaluated posture of the spindle (310). However, the control unit (350) of the present invention is not limited to the above-described embodiment, and can control the posture of the spindle (310) and evaluate the posture of the spindle (310) using both the first-first gap information and the first-second gap information.

[0079] Meanwhile, the control unit (350) may be connected to the wafer processing device control unit (400), and the wafer processing device control unit (400) may predict abnormal symptoms such as failure of the spindle unit (300) and provide maintenance-related information to the user, or may provide an alarm to the user when an abnormal symptom occurs. For example, the wafer processing device control unit (400) may receive first gap information and second gap information including the buoyancy gap values ​​of the first bearing unit (320) and the second bearing unit (340) from the control unit (350), determine a reference value to be input based on the buoyancy gaps of the first bearing unit (320) and the second bearing unit (340), establish reference power data, and then provide an abnormality alarm to the user when the power input amount for each buoyancy gap deviates from the reference value.

[0080] The power supply unit (360) is connected to the first bearing unit (320) and the second bearing unit (340) and can supply power to the first bearing unit (320) and the second bearing unit (340). The power supply unit (360) can include a current meter (361) and a current controller (362). The current meter (361) can measure the amount of current supplied from the power supply unit (360) to the first bearing unit (320) and the second bearing unit (340). The current controller (362) can control the current supplied to the first bearing unit (320) and the second bearing unit (340) according to a control signal of the control unit (350).

[0081] Meanwhile, in one embodiment, when the spindle unit (300) is connected to the table base (220) to form the work unit (200), the spindle unit (300) can tilt the table base (220) based on the center point (CP) of the table base (220). Specifically, the table base (220) is placed above the spindle unit (300), and can be aligned so that the center line (CL) of the table base (220) forms the same line as the rotation axis (Ax) of the spindle unit (300). The table base (220) rotates in conjunction with the rotation of the spindle unit (300), and tilts as the spindle (310) of the spindle unit (300) tilts.

[0082] At this time, the spindle unit (300) can control the posture of the spindle (310) using the first bearing part (320) and / or the second bearing part (340) so that the table base (220) tilts with respect to the center point (CP). As illustrated in FIG. 4, when the table base (220) is tilted by θ by the spindle unit (300), one end of the table base (220) moves upward by d2. When FIG. 4 is compared with FIG. 2, d2, which is the distance by which one end of the table base (220) moves, has a smaller value than d1.

[0083] That is, the spindle unit (300) according to one embodiment of the present invention tilts the table base (220) based on the center point (CP), so that when the table base (220) is to be tilted at a predetermined angle, the distance by which both ends of the table base (220) move up and down becomes smaller, and the tilting of the table base (220) becomes easier.

[0084] In addition, the spindle unit (300) according to one embodiment of the present invention can maintain alignment with the processing unit (100) by preventing the center line (CL) of the table base (220) from deviating from the center point (CP) when the table base (220) is tilted, thereby preventing defects in the center area that occur during the wafer processing process.

[0085] Meanwhile, the technical idea of ​​the present invention for tilting the table base (220) by the spindle unit (300) according to one embodiment of the present invention can be similarly applied to the case where the spindle unit (300) is connected to the grinding wheel (120) to form the processing unit (100). That is, when the grinding wheel (120) is connected to the lower end of the spindle unit (300) to form the processing unit (100), the spindle unit (300) can control the tilting angle of the processing unit (100) by controlling the posture of the spindle (310) using the first bearing part (320) and / or the second bearing part (340), and can control the angle formed by the grinding wheel (120) with the wafer placed on the table base (220).

[0086] Specifically, the grinding wheel (120) is connected to the spindle unit (300) so that its center line is aligned on the same line as the rotation axis (Ax) of the spindle unit (300), and as the spindle (310) of the spindle unit (300) tilts, the grinding wheel (120) can be tilted with respect to the center point (the center in the height direction and the diameter direction). At this time, the spindle unit (300) allows the grinding wheel (120) to be tilted with respect to the center point, thereby reducing the vertical movement distance of the grinding wheel (120) and easily tilting the grinding wheel (120), and the angle at which the grinding wheel (120) is tilted with respect to the wafer can be adjusted more accurately and precisely, thereby improving the quality of wafer processing.

[0087] In addition, the spindle unit (300) according to one embodiment of the present invention has a first sensor unit (330) and a second sensor unit to monitor the float gap between the first bearing unit (320) and the second bearing unit (340) in real time, and can precisely measure the posture of the spindle (310), the tilting angle of the grinding wheel (120), and the tilting angle of the table base (220), and intuitively determine the amount of correction. In addition, since there is no need to verify the tilting angle of the grinding wheel (120) or the table base (220) using an indicator, the time and cost required for the backgrinding process can be reduced.

[0088] In addition, the spindle unit (300) according to one embodiment of the present invention can simplify the configuration by not including a drive unit installed on the outside to adjust the angle of the polishing wheel (120) or the table base (220), and can reduce the size of the wafer processing device (10). In addition, the spindle unit (300) according to one embodiment of the present invention is easy to maintain, and the time and cost required for maintenance can be reduced.

[0089] In addition, the spindle unit (300) according to one embodiment of the present invention can monitor changes in the lift gap between the first bearing part (320) and the second bearing part (340) due to thermal deformation occurring during long-term operation or high load and vibration occurring during processing of high-hardness wafers, and compensate for the lift gap in real time.

[0090] While the present invention has been described with reference to the embodiments illustrated in the drawings, these are merely exemplary, and those skilled in the art will appreciate that various modifications and variations of the embodiments are possible. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the appended claims.

[0091] The present invention relates to a spindle unit and a wafer processing device including the spindle unit, which can be used in a wafer manufacturing process.

Claims

1. A spindle including a shaft extending in a vertical direction and a first bearing joint formed in a shape extending from the center of the shaft and protruding in the circumferential direction of the shaft; A first bearing part coupled to the upper and lower surfaces of the first bearing joint; and It includes a first sensor unit for measuring a gap between the first bearing joint unit and the first bearing unit; A spindle unit in which the first bearing part is equipped with a magnetic bearing and adjusts the gap with the first bearing joint part according to power supplied from the power supply part to adjust the posture of the spindle.

2. In paragraph 1, The spindle unit is connected to the table base and tilts the table base based on the center point of the table base.

3. In paragraph 1, A spindle unit in which the above spindle is connected to a grinding wheel and tilts the grinding wheel based on the center point of the grinding wheel.

4. In paragraph 1, a second bearing part coupled to the above shaft; and It further includes a second sensor section for measuring the gap between the second bearing section and the shaft; A spindle unit in which the second bearing part is equipped with a magnetic bearing and adjusts the gap with the shaft according to the power supplied from the power supply part to adjust the posture of the spindle.

5. In paragraph 4, A spindle unit, wherein the first bearing portion and the second bearing portion generate external forces in different directions to the spindle.

6. In paragraph 1, A spindle unit, wherein the first sensor section includes three or more first sensors spaced at equal intervals.

7. In paragraph 6, A spindle unit further comprising a control unit that controls the first bearing unit according to first gap information measured from the first sensor unit.

8. In paragraph 7, A spindle unit, wherein the control unit obtains and stores initial position information of the first bearing unit from the first sensor unit, and controls the posture of the spindle using the initial position information and the first gap information.

9. In paragraph 7, The above first bearing part includes an upper ring and a lower ring respectively coupled to the upper surface and lower surface of the above first bearing joint part. A spindle unit, wherein the first sensor section includes a plurality of first-1 sensors arranged on the upper ring and a plurality of first-2 sensors arranged on the lower ring.

10. In paragraph 9, A spindle unit in which the above-mentioned 1-1 sensor and the above-mentioned 1-2 sensor are provided in the same number.

11. In Article 10, A spindle unit, wherein the plurality of first-1 sensors and the plurality of first-2 sensors are arranged at equal intervals from the central axis of the shaft.

12. In paragraph 11, A spindle unit in which the plurality of first-1 sensors and the plurality of first-2 sensors are arranged so as not to overlap each other.

13. In paragraph 9, A spindle unit in which the control unit adjusts the posture of the spindle using the 1-1 gap information measured from the 1-1 sensors, and evaluates the posture of the spindle and generates a feedback signal using the 1-2 gap information measured from the 1-2 sensors.

14. A processing unit including a grinding wheel and a first spindle unit connected to the grinding wheel; and A work unit including a table base on which a wafer is placed and a second spindle unit connected to the table base; The first spindle unit or the second spindle unit, A spindle including a shaft extending in a vertical direction and a first bearing joint formed in a shape extending from the center of the shaft and protruding in the circumferential direction of the shaft; A first bearing part that is non-contactably joined to the upper and lower surfaces of the first bearing joint; and It includes a first sensor unit for measuring a gap between the first bearing joint and the first bearing; A wafer processing device, wherein the first bearing part is equipped with a magnetic bearing, and the gap with the first bearing coupling part is adjusted according to the power supplied from the power supply part to adjust the posture of the spindle.

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