TW202007931A - Thickness measurement device, correction method and correction fixture thereof capable of reducing the error caused by environmental factors and greatly improving the measurement accuracy - Google Patents

Abstract

Provided is a correction method for a thickness measurement device, which includes the following steps of: (a) driving a correction fixture to move from a retracted position to a correction position with respect to at least two optical measurement devices, in which, at the correction position, the two reference planes of the correction fixture are located in the optical path range of the optical measurement devices and, at the retracted position, the reference planes of the correction fixture are separated from the optical path range of the optical measurement devices; (b) receiving two measurement signals of the reference planes measured from the optical measurement devices; (c) calculating a reference thickness between the reference planes based on the measurement signals; and (d) driving the correction fixture to move from the correction position to the retracted position. As a result, the correction operation and the subsequent measurement operations are completed in such a manner that the optical measurement devices are fixed and the correction fixture is movable, which not only reduces the error caused by environmental factors, but also greatly improves the measurement accuracy.

Description

Thickness measuring device, its correction method and correction jig

The invention relates to a thickness measuring device, in particular to a thickness measuring device for measuring the thickness of a sheet, a correction method and a correction jig.

The traditional method of obtaining the size data of an object can only be achieved through a vernier ruler, which is not only less accurate and easy to damage the surface of the object. Today's technology has been able to obtain the size data of the object through the optical measuring device, with the change of the laser or different light source projection. However, although the optical measuring instrument has high accuracy, it is susceptible to environmental factors and may cause errors. Taking the environmental temperature difference of 3 degrees as an example, the thickness error measured by the aforementioned laser measuring instrument will reach 2.5 μm.

Referring to FIG. 1, a conventional dual-laser non-contact thickness measurement system 1 disclosed in Patent No. I372234 of the Republic of China is used to measure the thickness of a sheet 2, mainly including a direction X that can be driven Displaced two laser measuring devices 11, and a calibration jig 12 at a fixed point. The calibration jig 12 and the sheet 2 are arranged in the movement path of the laser measuring devices 11 and have two surfaces 121 separated by a distance.

When measuring the thickness of each sheet 2, the laser measuring devices 11 will first be moved to the two sides of the calibration jig 12, after measuring the reference thickness between the surfaces 121 of the calibration jig 12, and then along the direction X Displace and scan the sheet 2 located in the movement path, thereby taking the reference thickness of the correction jig 12 as a correction reference value to compensate for the error caused by the aforementioned environmental factors, and calculate the thickness of the object 2. However, although the aforementioned correction method provides a compensation mechanism, it still has the following disadvantages:

1. As disclosed in the specification of Patent No. I372234, the laser measuring devices 11 achieve the purpose of movement through the cooperation of the slider and the linear rail, and there is a sliding gap between the slider and the linear rail itself. There will be different measurement results at different positions. Therefore, even if the laser measuring devices 11 in the displacement have been calibrated relative to the position of the calibration jig 12, but during the displacement to the lamella 2 It is easy to cause measurement errors due to the aforementioned sliding gap.

2. Since the laser measuring devices 11 are driven by different timing belts, if the laser measuring devices 11 on the upper and lower sides are positioned so that they can face each other up and down after being moved, The laser light emitted by the laser measuring device 11 is projected at the common point, the required assembly accuracy and component processing accuracy are very high, not only the cost is too high, but also easy to produce measurement errors, that is, up and down The laser light emitted by the laser measuring device 11 on the side is projected on the upper and lower surfaces of the sheet 2 in the direction X, and the light points are easily offset from each other in the direction X, so that the calculated thickness is not exactly obtained from the same point position .

3. Limited by the displacement method of these laser measuring devices 11, if a plurality of moving radio measuring devices 11 are to be installed, the complexity and cost of the transmission components will be increased. Therefore, the patent case No. I372234 only Two laser measuring devices 11 are installed. Therefore, only a set of multiple thickness measurement values distributed along the axis X can be obtained along the axis X. There are problems of uneven sampling distribution, inaccurate measurement accuracy, and poor efficiency.

Therefore, the object of the present invention is to provide a thickness measuring device, a calibration method and a calibration jig that can greatly improve the measurement accuracy.

Therefore, the method for calibrating the thickness measurement device of the present invention includes at least one measurement group and a control unit communicating with the measurement group. The at least one measurement group includes a relative configuration and is suitable for measuring an object unit Two optical measuring instruments of thickness. The calibration method uses a calibration jig as a tool. The calibration tool has at least two reference planes separated by a distance. The calibration method implements the following steps by the control unit:

(a): driving the calibration jig relative to the at least one measurement group from a retracted position to a calibration position, and at the calibration position, the reference planes of the calibration jig are located in the optical path range of the optical measuring devices At the retracted position, the reference planes of the calibration jig deviate from the optical path range of the optical measuring instruments.

(b): Receive two measurement signals from the optical measuring instruments to measure the reference planes.

(c): Based on the measurement signals, calculate a reference thickness between the reference planes.

(d): Drive the correction jig from the correction position to the retracted position.

The calibration jig of the thickness measurement device of the present invention includes a platform and at least one measurement group, and the at least one measurement group includes two optical measurements relatively disposed on both sides of the platform and suitable for measuring the thickness of an object The calibration jig includes: at least one stage and at least one reference sheet.

The at least one carrier is disposed on the platform and is displaced between a retracted position and a calibration position relative to the at least one measurement group. In the calibration position, the at least one carrier is relative to the at least one measurement group. When returning to the position, the at least one carrier is separated from the at least one measurement group.

The at least one reference sheet includes two reference planes disposed on the stage and separated by a distance. When the at least one stage is in the retracted position, the reference planes deviate from the optical path range of the optical measuring devices. When at least one stage is located at the calibration position, the reference planes are located in the optical path range of the optical measuring devices, so that the optical measuring devices can measure a reference thickness between the reference planes.

The thickness measuring device of the present invention is suitable for measuring the thickness of an object unit. The object unit includes at least one object. The thickness measuring device includes: a platform unit, a measuring unit, a calibration jig, a driving unit, and a conveying unit , And a control unit.

The platform unit includes a platform.

The measurement unit includes at least one measurement group. The measurement group has two optical measuring devices for measuring thickness. The optical measuring devices are relatively arranged on two sides of the platform and output a measuring signal respectively.

The calibration jig is disposed on the platform, and includes at least one stage displaced relative to the at least one measurement group between a retracted position and a calibration position, and at least one reference sheet disposed on the at least one stage, the The reference sheet has two reference planes separated by a distance. When the at least one stage is at the retracted position, the reference planes deviate from the optical path range of the optical measuring devices, and when the at least one stage is at the correction position, The reference planes are located in the optical path range of the optical measuring devices.

The driving unit is installed on the platform and is used to drive the displacement of the at least one stage.

The conveying unit is installed on the platform and is used to convey the at least one object to the optical path range of the optical measuring devices.

The control unit communicates with the measurement group and is electrically connected to the calibration jig and the conveying unit, and calculates a reference thickness between the reference planes based on the measurement signals, and uses the reference thickness as a correction value To calculate the thickness of the at least one object.

The effect of the present invention is that the optical measuring instruments are fixed and the calibration jig is moved to complete the calibration operation and subsequent measurement operations, which can not only reduce the errors caused by environmental factors, but also greatly improve the measurement accuracy .

Referring to FIGS. 2, 3 and 6, an embodiment of the thickness measuring device of the present invention is suitable for measuring thin objects 3 (see FIGS. 12 and 13 ). In this embodiment, the object 3 (as shown in FIGS. 12 and 13) is a 5-inch wafer, and is transported to the thickness measurement device one by one by a transport device (not shown). The thickness measuring device includes a platform unit 4, a measuring unit 5, a calibration jig 6, a driving unit 7, a conveying unit 8, and a control unit 9.

The direction of arrow X in FIG. 2 is a predetermined direction. In this embodiment, the predetermined direction is set as a first direction X, and the direction of arrow Z in FIG. 2 perpendicular to the first direction X is a second direction Z , And the direction of the arrow Y perpendicular to the first direction X and the second direction Z is a third direction Y. It should be noted that the foregoing first direction X and third direction Y are not limited to being perpendicular, and in other aspects of this embodiment, they may also form an angle with each other.

The platform unit 4 includes a platform 41 extending along the first direction X, and two rails 42 (see FIG. 9). The platform 41 has two mesas 411 and 412 separated by a distance along the second direction Z, and three notches 413 penetrating the mesas 411 and 412 and arranged along the third direction Y (see FIG. 8 ). The rails 42 (see FIG. 9) are fixed on the table 412 (see FIG. 9) and extend along the first direction X.

2 to 5 and 7, the measurement unit 5 includes two brackets 51 spaced apart along the third direction Y and located on both sides of the platform 41, connecting the brackets 51 and separated by one along the second direction Z The two rails 52 at a distance, the two positioning groups 53 disposed on the rails 52, and the three measuring groups 54. Each rail 52 has two chute groups 521 extending along the third direction Y and separated by a distance. Each sliding slot group 521 has two sliding slots 522 separated by a distance along the second direction Z. Each positioning group 53 has three positioning frames 531 arranged along the third direction Y. In this embodiment, the positioning brackets 532 are slidably engaged with the sliding groove sets 521 of the corresponding rail brackets 52 and positioned on the corresponding rail brackets 52. Each measuring group 54 has two optical measuring devices 541 for measuring the thickness and facing up and down along the second direction Z. Each optical measuring device 541 is fixed on a separate positioning frame 531, and is used to output a measurement signal S, and has an emitting portion 542 for emitting sensing light 552, and a sensing portion for receiving reflected light 554 543. The emitting portion 542 and the sensing portion 541 are relative to the slot 413 of the platform 41. The paths of the sensing light and the reflected light form an optical path range, and the incident direction of the sensing light is toward the slot 413.

In this embodiment, the optical measuring devices 541 are a kind of laser measuring devices, and are mounted on the respective positioning frames 531 at an inclination angle. The inclination angle can make the incident angles α, β of the sensing light 552 with respect to a plane It is approximately equal to the reflection angle γ of the reflected light 554, so that the sensing portion 543 directly senses the reflected light 554. The aforementioned incident angles α and β may be the same or different, and the angle is within 45 degrees, preferably within 25 degrees. The smaller the angle, the smaller the volume occupied by the optical measuring device 541 and the light beam reflecting the light 554 The more concentrated it is, the more accurate the measurement signal. It is important that the optical measuring devices 541 of the measuring groups 54 are opposed to each other in the second direction Z through the positioning frames 532. Therefore, the sensing light emitted by the optical measuring devices 541 facing upward and downward can be made Both 552 are projected at the position of the common point (as shown in Figure 4, the sensing ray 552 is projected to the same normal L). Since the upper and lower opposite optical measuring devices 541 have been fixed on the positioning frames 531, each sensing ray 552 can be continuously projected at a common position, and there will be no deviation of the sensing ray like the conventional technology This leads to the problem that common points cannot be accurately shared. In addition, a dimming mirror 544 can be selectively disposed between the optical measuring device 541 and the object 3 to reduce the intensity of the sensing light 552 or the reflected light 554 to prevent signal interference caused by excessive light.

In addition, the number of such measurement groups 54 is not limited to three groups, and in other aspects of this embodiment, it may be one group, two groups, or more than four groups.

Referring to FIG. 8, FIG. 9 and FIG. 10, the calibration jig 6 is disposed on the platform 41 and includes a stage 61, two rails 62, a magnet 63, and three reference plates 64.

The stage 61 is opposite to the measurement group 54 along the first direction X and the reverse direction of the first direction X between a retracted position (as shown in FIGS. 5 and 12) and a corrected position (as shown in FIGS. 4 and 9) Displacement, and has three convex portions 611 movably disposed in the notches 413 of the platform 41. Each convex portion 611 has a ring wall 612 defining a window 610. The ring wall 612 has a mounting groove 613. The mounting groove 613 of the convex portion 611 located on the two outer sides along the third direction Y extends along the third direction Y, and the groove width is larger than the groove width of the mounting groove 613 of the convex portion 611 located in the middle. It is worth noting that the stage 61 in this embodiment is not limited to displacement along the first direction X or the reverse displacement along the first direction X. In other aspects of this embodiment, the stage 61 may also Displace along the third direction Y, the reverse of the third direction Y, or other directions, and displace between a retracted position and a corrected position (not shown). Even, the number of the carrier 61 is not limited to one. In other aspects of this embodiment, a plurality of carriers 61 (not shown) may be provided, for example, two carriers 61 are provided on both sides of the platform 41 And, the carrier 61 can be displaced along a third direction Y and a reverse direction of the third direction Y (or along other directions) between a retracted position and a corrected position.

When the stage 61 is in the retracted position, the windows 610 are out of the optical path range of the optical measuring devices 641, and when the stage 61 is in the correction position, the windows 610 are located on the optical measuring devices 541 Optical path range.

The rails 62 are fixed on the carrier 61 and slide with the rails 42 of the platform unit 4.

The magnets 63 are disposed on the ring wall 612 of the convex portions 611 relative to the mounting grooves 613 of the stage 61.

The diameter width of each reference piece 64 along the third direction Y is not greater than the groove width of the respective installation groove 613, and is detachably installed in the corresponding installation groove 613 to cover a part or all of the corresponding window 610 , And has two reference planes 641 separated by a distance along the second direction Z. The reference planes 641 face the optical measuring devices 541 upward and downward, respectively. In this embodiment, the reference pieces 64 are a magnetic material, and are attracted to the stage 61 by the magnets 63. The aforementioned magnetic conductive element may be, for example, high carbon chromium alloy steel, but it is not limited to this, as long as it is a material with stable properties and a small amount of deformation due to temperature. When the stage 61 is at the retracted position, the reference surfaces 641 are out of the optical path range of the optical measuring devices 541, and when the stage 61 is at the correction position, the reference surfaces 641 are located at the optical measuring devices The optical path range of 541.

The groove width of the mounting groove 613 on the second outer side of the carrier 61 can be designed to be the same as or larger than the groove width of the middle mounting groove 613. Therefore, when the groove width of the mounting groove 613 on the outer side of the carrier 61 is wider than the middle When the groove width of the mounting groove 613 is larger, the corresponding reference plate 64 can be installed in a first dimension along the third direction Y or along a fourth direction (not shown) different from the third direction Y Displacement between the position (as shown in Figures 8 and 11) and a second size position (as shown in Figure 14). At the first size position, the total distance L1 of the reference plates 64 along the third direction Y (as shown in Figure 11) ) Is the smallest, at the second size position, the total distance L2 of the reference pieces 64 along the third direction Y (as shown in FIG. 14) is the largest. The total distances L1 and L2 are located on one side of the stage 61 The distance from the outermost edge of the reference sheet 64 to the outermost edge of the reference sheet 64 on the other side of the stage 61. This design can be adapted to the measurement needs of objects 3 of different sizes. For example, the reference sheet 64 at the first size position can be used to measure a 5 inch wafer, and the reference sheet 64 at the second size position can be used to measure 6 Inch wafers. That is to say, the groove width of the mounting groove 613 can be designed according to requirements, so as to position the reference sheet 64 according to the measurement requirements of different wafer sizes. That is, the groove width of the aforementioned mounting groove 613 may be larger than the width of the corresponding reference piece 64, for example, in this embodiment, the groove width of a mounting groove 613 is twice the width of a reference piece 64, whereby the design can change the reference piece The position of 64, for example, the corresponding reference piece 64 is changed from a position near the center of the stage 61 to a position near the outside of the stage 61, and even the reference piece 64 can be rotated as long as the position of the reference piece 64 is changed It is within the scope of the present invention that the total distance L2 can be greater than the total distance L1.

It should be noted that, as stated in paragraph [0027], the aforementioned fourth direction different from the third direction Y and the first direction X are sandwiched by a preset angle, so that the mounting groove 613 of the stage 61 can be along the first The four directions extend at an inclination. The preset angle ranges from 0 degrees to 180 degrees. In this way, the correspondingly installed reference plates 64 can also be displaced between the first size position and the second size position along the fourth direction, thereby changing the total distance of the reference plates 64 along the third direction Y.

Referring to FIGS. 9 and 10, the driving unit 7 is installed on the platform 41 and includes two pulleys 71 pivotally mounted on the platform 41 and separated by a distance along the first direction X, and a loop surrounding the pulleys 71 The belt 72 and a correction motor 73 which drives one of the pulleys 71 to rotate forward and backward. The surrounding belt 72 is divided into two surrounding portions 721 passing around the pulleys 72, and two linear portions 722 moving between the surrounding portions 721 along the first direction X. The linear portion 722 is connected to the stage 61, so that the surrounding belt 72 and the stage 61 are linked.

Referring to FIGS. 3 and 8, the conveying unit 8 is installed on the platform 41, and includes two rotating shaft groups 81 arranged on both sides of the platform 41 along the first direction X, and a number of tension wheels 82 pivotally arranged on the platform unit 4 4. Four conveyor belts 83 that surround the rotating shaft groups 81, the tension wheels 82 and the platform 41 along the first direction X, and a conveying motor 84 that drives one of the rotating shaft groups 81 to rotate. The conveyor belts 83 are arranged along the third direction Y for each object 3 to straddle the conveyor belts 83 above the table 411 of the platform 41, and to convey each object 3 to be displaced along the first direction X The optical path range of the optical measuring device 541 is passed. Preferably, during the continuous movement of the object 3, the surface of the object 3 is simultaneously illuminated by the sensing light 552 from the upper and lower sides (the second direction Z) and the reflected light 554 is formed to return to the measuring group 54.

Referring to FIGS. 2, 3 and 6, the control unit 9 communicates with the measurement groups 54 and is electrically connected to the conveyance motor 84 of the conveyance unit 8 and the calibration motor 73 of the drive unit 7 and according to the measurements The signal S calculates the thickness of an object to be measured.

Referring to FIG. 15, before or after measuring the thickness of each batch of the same objects 3 (as shown in FIGS. 12 and 13) in the present invention, calibration will be performed. The steps of the calibration method and the measuring method of the thickness measuring device of the present invention are as follows:

Step 101: Refer to FIG. 3 to FIG. 5, FIG. 8, FIG. 9 and FIG. 10, control the correction motor 73 to drive the pulley 71 and the encircling belt 72 to rotate clockwise/counterclockwise, and pass the encircling belt 72 The linear portion 722 drives the stage 61, so that the stage 61 of the correction jig 6 moves toward the optical measuring devices 541 along the first direction X through the sliding relationship between the rails 62 and the rails 42 To the correct position. Thereby, as shown in FIG. 8, the convex portions 611 on the stage 61 will be displaced from the right side of the notch 413 of the platform 41 to the left side; as shown in FIG. 9, the convexities on the stage 61 The part 611 will be displaced from the left side of the notch 413 of the platform 41 to the right side.

At this time, the reference planes 641 of the reference sheets 64 of the calibration jig 6 are respectively located in the optical path range of the optical measuring devices 541 and face the optical measuring devices 541 respectively. In other words, the two reference surfaces 641 (upper surface and lower surface) of each reference sheet 64 respectively face the two optical measuring devices 541 located above and below the reference sheet 64 and are located in the optical path range of the optical measuring devices 541 .

Step 102: Referring to FIG. 4, FIG. 5, FIG. 7 and FIG. 11, the optical measuring devices 541 are controlled to generate the sensing light 552 through the emitting portions 542, so that the sensing light 552 is directly projected on the reference plates 64 toward the top Three first measurement points P11 are formed by the reference surface 641 of the base, and three second measurement points P12 are formed by the reference surface 641 of the reference plate 64 projected downward through the window 610 of the stage 61, whereby the After the optical measuring device 541 senses the reflected light 554 reflected by the reference surfaces 641 through the sensing parts 541, it outputs six measurement signals S.

The positions of the first measuring point P11 near the edge of the object 3 and the second measuring point P12 near the edge of the object 3 are counted from the edge of the object 3, and are generally located in the third direction Y within the width of one third of the width of the object 3, Therefore, the positioning position of each reference piece 64 is preferably designed in such a way that the position can be adjusted. In this way, the entire set of stages can be disassembled and replaced without much expense to adapt to wafers of different sizes.

Step 103: Receive the measurement signals S from the optical measuring devices 541.

Step 104: Based on the measurement signals S of step 103, calculate three reference thicknesses T ₀ located between the reference planes 641 and distributed along the third direction Y within a range corresponding to the total distance L1.

In other words, when a first measurement point P11 and a second measurement point P12 are penetrated by the normal line L of the same vertical reference surface 641, the first measurement point P11 and the second measurement point P12 are measured at this time The position of is regarded as a common point, and the thickness (measured thickness T1) of the object 3 at this common point can be calculated from the two measured signals S obtained by the reflected light 554.

The thickness of the object 3 can be calculated in various ways. For example, the measurement signal S obtained by the reflected light 554 can be converted into a distance value. When the fixed distance value between two corresponding optical measuring devices 541 is subtracted from the two The two distance values obtained by the corresponding optical measuring devices 541 can know the measured thickness T ₁ of the object 3, but the calculation method of the measured thickness T ₁ of the object 3 of the present invention is not limited to this. Furthermore, the aforementioned technique of measuring the thickness by light, such as laser, is the same as the conventional one, and is not the technical feature of the application of this application. Since those with ordinary knowledge in the art can infer extended details based on the above description, no more explanation is needed.

Step 105: Referring to FIG. 9 and FIG. 12, the correction motor 73 is controlled to drive the pulley 71 and the surrounding belt 72 to rotate in a counterclockwise direction, and the stage 61 is driven by the linear portion 722 of the surrounding belt 72, The stage 61 of the correction jig 6 is displaced in the reverse direction along the first direction X to the retracted position through the sliding relationship between the rails 62 and the rails 42. Thereby, as shown in FIG. 12, the convex portions 611 (as shown in FIG. 9) on the stage 61 will be displaced from the left side of the notch 413 of the platform 41 to the right side.

At this time, the reference planes 641 of the reference sheets 64 of the calibration jig 6 respectively deviate from the optical path range of the optical measuring devices 541.

Step 106: Referring to FIG. 12, the conveying motor 84 is controlled to drive the rotating shaft groups 81 and the conveying belts 83 to rotate, so that one or more objects 3 above the table 411 of the platform 41 are conveyed one by one from the right side to the left side of FIG. Up to the conveyor belts 83, and moves along the first direction X from the right side of FIG. 12 to the left side of FIG. 12, and then passes through the optical path range of the optical measuring devices 541. The stage 61 is shifted back and forth between the corrected position and the retracted position. The timing of performing this displacement action depends on the needs. The stage 61 can be activated after each object 3 is measured, or after multiple objects 3 are measured. Execution, for example, measuring 50 wafers and performing displacement to perform thickness correction, which can speed up the inspection and increase productivity.

Since the conveyor belts 83 surround the surfaces 411 and 412 of the platform 41, and the convex portion 611 of the carrier 61 passes through the slot 413 of the platform 41, the objects 3 are conveyed along the conveyor belts 83 During the movement in the first direction X, the object 3 will pass above the stage 61 and the reference pieces 62 without interfering with each other.

Step 107: While each object 3 passes through the optical path range of the optical measuring devices 541, the optical measuring devices 541 are controlled to generate the sensing light 552 through the emitting parts 542, so that the sensing light 552 is directly projected on An upper surface 31 of the object 3 (see FIG. 5) forms at least three first measuring points P21, and a notch 413 of the platform 41 is projected on a lower surface 32 of the object 3 (see FIG. 5) to form at least three The three second measurement points P22, through which the optical measuring devices 541 sense the reflected light 554 reflected by the reference surfaces 641 through the sensing parts 543, and output a digital measurement signal S.

As shown in FIG. 5, in this embodiment, when the object 3 is within the optical path range of the optical measuring devices 541, at least one object 3 is not stopped along a predetermined direction (such as the first direction X) In the state of the image, the vehicle travels to the left side of the drawing. Therefore, the object 3 is irradiated with the sensing light 552 while moving. At this time, the stage 61 of the correction jig 6 is at the retracted position. In another embodiment, the object 3 may also travel toward the right side of the drawing without stopping in the reverse direction of the predetermined direction (such as the first direction X). In yet another embodiment, the object 3 may also stop at a preset position when traveling along the first direction X toward the left side of the drawing within the optical path range of the optical measuring devices 541 and receive the illumination of the sensing light 552 After that, continue to the left of the picture.

Step 108: Receive the measurement signals S from the optical measuring devices 541.

Step 109: Calculate several measured thicknesses T ₁ of the object 3 based on the measurement signals S of step 108 and the aforementioned reference thickness T ₀ as the compensation value.

The number of measurement signals S in step 108 is set according to the practice and the size of the object 3, and at least includes the optical measuring devices 541 measuring the three first measurement points P21 and the three second measurement points P22 before output Of six measurement signals S to obtain three thicknesses T ₁ distributed along the third direction Y within the range corresponding to the total distance L1. It should be noted that the aforementioned measurement signals S are not limited to six, in this implementation In other variations of the example, the object 3 may be scanned along the first direction X by the optical measuring devices 541 while the object 3 travels along the first direction X, on the upper surface 31 of the object 3 A plurality of first measurement points P21 and a plurality of second measurement points P22 are formed with the lower surface 32, and a plurality of measurement signals S are output, and a plurality of matrix distributions along the first direction X and the third direction Y are obtained Several thicknesses T _{1 at a location} , such as six thicknesses T ₁ , nine thicknesses T ₁ , twelve thicknesses T ₁ , or more than twelve thicknesses T ₁ . Each measurement signal S in the above embodiment may be defined as the information received within a predetermined time.

The above steps are illustrated with three measurement groups 54, three first measurement points P11, and three second measurement points P12, but the invention is not limited as long as at least one measurement group 54 and at least one first measurement point P11 And at least one second measurement point P12 is covered by the scope of the present invention.

It is worth noting that the positions of the first measurement points P11, P21, and the second measurement points P12, P22 are not limited to only one. Referring to FIGS. 10 and 14, when changing the measurement points, you only need to release the Wait for the positioning frame 531, and extend the distance between the positioning frames 531 located on the second outer side along the third direction Y in accordance with the chute group 521 of the rails 52, and then position the positioning frames located on the second outer side 531 is on the rail 52, thereby maintaining the optical measuring devices 541 in a fixed position.

Then, the reference pieces 64 located on the second outer side are set at the second size position of the mounting groove 613 of the stage 61 located on the second outer side.

During calibration, the driving unit 7 can also be used to drive the stage 61 to the calibration position for the optical measuring devices 541 to measure the reference sheets 62 through the window 61 of the stage 61 to calculate the reference plane 641 Three reference thicknesses T ₀ distributed between the total distance L2 and along the third direction Y.

When measuring the object 3, the optical path range of the object 3 through the optical measuring devices 541 is also conveyed by the conveying unit 8, and the reference thickness T ₀ is used as a reference value, and the distribution along the third direction Y is calculated to be equivalent Three thicknesses T ₁ within the total distance L2. In this way, it is possible to measure objects 3 of different sizes, such as 5 inch wafers or 6 inch wafers.

It should be noted that the position changes of the first measurement points P11 and the second measurement points P12 of the calibration jig 6 are not limited to the installation of the reference pieces 64 at the first size position or the second As for the size and position method, in other variations of this embodiment, the reference pieces 64 may be extended along the third direction Y. Even if the size of the reference pieces 64 becomes larger, there is no need to change In the case of the positions of the reference sheets 64, it is only necessary to adjust the fixed positions of the optical measuring devices 541 to measure the thickness at different positions along the third direction Y.

Through the above description, the advantages of the foregoing embodiments can be summarized as follows:

1. When measuring the thickness of the reference sheet 61 or the thickness of the object 3, the optical measuring devices 541 of the present invention are respectively positioned on the rails 52 and fixed, therefore, after completing the calibration step , The error caused by environmental factors has been compensated, and the accuracy of the measurement can be greatly improved.

2. Since the optical measuring devices 541 are fixed during the measurement process, after positioning, the sensing light can be located at the common point, which is not only easy to assemble, but also low in cost, and can further improve the accuracy of measurement.

3. When calibrating or measuring the thickness of the object 3, only the calibration jig 6 and the object 3 will move between the optical measuring devices 541, or the optical measuring devices 541, the object 3, and the calibration jig 6 There is no interference with each other, but multiple measurement groups 54 can be provided to obtain several thicknesses T ₁ at several locations distributed in a matrix along the first direction X and the third direction Y, which can greatly improve the sampling Value, and improve detection efficiency.

However, the above are only examples of the present invention, and the scope of implementation of the present invention cannot be limited by this, any simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification are still classified as Within the scope of the invention patent.

3‧‧‧Object 31‧‧‧Upper surface 32‧‧‧Lower surface 4‧‧‧Platform unit 41‧‧‧Platform 411‧‧‧Platform 412‧‧‧Platform 413‧‧‧Slot 42‧‧‧rail 5‧‧‧Measurement unit 51‧‧‧Bracket 52‧‧‧Rack 521‧‧‧Chute group 522‧‧‧Chute 53‧‧‧ Positioning group 531‧‧‧Placement frame 54‧‧‧Measurement group 541‧ ‧‧Optical measuring instrument 542‧‧‧Emitting part 543‧‧‧ Sensing part 544‧‧‧Reducing mirror 552‧‧‧Sensed light 554‧‧‧Reflected light 6‧‧‧Calibration fixture 61‧‧‧ Table 610‧‧‧Window 611‧‧‧Convex part 612‧‧‧Ring wall 613‧‧‧Mounting groove 62‧‧‧Track 63‧‧‧Magnet 64‧‧‧Reference piece 641‧‧‧Reference surface 7‧‧‧ Drive unit 71 ‧‧‧ pulley 72 ‧ ‧ ‧ wrap belt 721 ‧ ‧ ‧ wrap section 722 ‧ ‧ ‧ linear section 73 ‧ ‧ ‧ correction motor 8 83‧‧‧Conveyor belt 84‧‧‧Convey motor 9‧‧‧Control unit X‧‧‧ First direction Z‧‧‧ Second direction Y‧‧‧ Third direction S‧‧‧Measurement signal L1‧‧‧ Distance L2‧‧‧Total distance T ₀ ‧‧‧ Base thickness T ₁ ‧‧‧Measured thickness P11‧‧‧ First measurement point P12‧‧‧ Second measurement point P21‧‧‧First measurement point P22‧‧‧ Two measurement points 101~109‧‧‧ Step flow α‧‧‧incidence angle β‧‧‧incidence angle γ‧‧‧reflection angle

Other features and effects of the present invention will be clearly presented in the embodiment with reference to the drawings, in which: FIG. 1 is a schematic diagram illustrating the conventional double laser exposure disclosed in the Patent Case No. I372234 of the Republic of China Contact thickness measurement system; FIG. 2 is a perspective view illustrating an embodiment of the thickness measurement device of the present invention and its calibration method and calibration jig; FIG. 3 is a front view of the embodiment; FIG. 4 is a schematic diagram , Illustrating that the three measurement groups in the implementation measure a reference thickness of each reference sheet; FIG. 5 is a schematic diagram illustrating that the measurement groups in the embodiment measure the measured thickness of an object; FIG. 6 is a part of the embodiment A block diagram; FIG. 7 is a partial perspective exploded view illustrating a measuring unit in this embodiment; FIG. 8 is a perspective view illustrating a platform unit, a conveying unit, a control unit in this embodiment, and A correction jig, and the correction jig is located at a correction position; FIG. 9 is a perspective view similar to FIG. 8, but viewed from another angle; FIG. 10 is an incomplete partial perspective exploded view illustrating the implementation A calibration jig in the example; FIG. 11 is a schematic diagram illustrating that three measurement groups in this embodiment are used to measure the thickness of three reference pieces of the calibration jig, and two of the reference pieces are located at a first size position; FIG. 12 is an incomplete top view illustrating that the calibration jig in this embodiment is in a retracted position; FIG. 13 is a schematic diagram illustrating that three measurement groups in this embodiment are used to measure the thickness of an object; FIG. 14 Is a side view illustrating that the measurement distances of the measurement groups along a third direction in this embodiment are enlarged, and two of the reference plates are located at a second size position; and FIG. 15 is a flowchart of the embodiment .

5‧‧‧Measurement unit

51‧‧‧Bracket

52‧‧‧Rack

521‧‧‧Chute group

522‧‧‧Chute

53‧‧‧Positioning group

531‧‧‧Locating frame

610‧‧‧window

611‧‧‧Convex

612‧‧‧ring wall

64‧‧‧ benchmark

L1‧‧‧Total distance

P11‧‧‧ First measuring point

P12‧‧‧Second measuring point

54‧‧‧Measurement Team

541‧‧‧ optical measuring instrument

61‧‧‧ stage

Z‧‧‧Second direction

Y‧‧‧ third direction

Claims (19)

A method for calibrating a thickness measurement device. The thickness measurement device includes at least one measurement group and a control unit that communicates with the measurement group. The at least one measurement group includes two optics arranged relatively and suitable for measuring the thickness of at least one object. Measuring instrument, the calibration method uses a calibration jig as a tool, the calibration jig has at least two reference planes separated by a distance, the calibration method realizes the following steps by the control unit: (a): driving the calibration jig relative to the at least A measurement group is displaced from a retracted position to a calibration position. In the calibration position, the reference planes of the calibration jig are located in the optical path range of the optical measuring instruments. In the retracted position, the calibration jig The reference planes deviate from the optical path range of the optical measuring devices; (b): Receive the two measurement signals from the optical measuring devices to measure the reference surfaces; (c): Calculate the location based on the measurement signals A reference thickness between the reference planes; and (d): driving the correction jig to move from the correction position to the retracted position. The method for correcting the thickness measurement device according to claim 1, wherein steps (a) to (d) are performed before or after measuring the thickness of the at least one object. The calibration method of the thickness measuring device according to claim 2, wherein the at least one object travels in a predetermined direction within the optical path range of the optical measuring devices, and the calibration jig is located at the retracted position. A calibration jig for a thickness measurement device. The thickness measurement device includes a platform and at least one measurement group. The at least one measurement group includes two optical measuring devices that are relatively disposed on both sides of the platform and are suitable for measuring the thickness of an object. The calibration jig includes: at least one carrier set on the platform and displaced relative to the at least one measurement group between a retracted position and a calibration position. In the calibration position, the at least one carrier is relative to the at least one A measurement group, in the retracted position, the at least one stage is separated from the at least one measurement group; and at least one reference sheet is provided on the stage and includes two reference planes separated by a distance between the at least one stage When the stage is in the retracted position, the reference planes deviate from the optical path range of the optical measuring devices, and when the at least one stage is in the correction position, the reference planes are in the optical path range of the optical measuring devices. The optical measuring devices measure a reference thickness between the reference planes. The calibration jig of the thickness measurement device according to claim 4, wherein the at least one stage has at least one window, and the at least one reference sheet covers at least a part of the at least one window, so that the reference planes pass through the at least one The windows face the optical measuring devices respectively. The calibration jig of the thickness measurement device according to claim 5, wherein the calibration jig includes a number of reference pieces, and the at least one stage has a number of windows, and the reference pieces are respectively detachably covering the windows At least partly. The calibration jig of the thickness measurement device according to claim 6, the calibration jig includes three reference sheets, and the at least one stage has three windows arranged at intervals, and the platform has three notches, wherein the at least one stage The table also has three convex parts displaceably disposed in the notches, each convex part has a ring wall defining the window, the ring wall has a mounting groove, and each datum piece is mounted on the corresponding mounting groove . The calibration jig of the thickness measuring device according to claim 6, wherein the reference pieces are displaced between a first size position and a second size position, and at the first size position, the reference pieces are along a The total distance in the third direction is the smallest, and in the second size position, the total distance of the reference pieces along the third direction is the largest. The calibration jig of the thickness measurement device according to claim 7, wherein the calibration jig further includes a number of magnets provided on the ring walls, the reference pieces are respectively a magnetic material, and are attracted to the magnets on. A thickness measurement device is suitable for measuring at least one object. The thickness measurement device includes: a platform unit including a platform; a measurement unit including at least a measurement group having two optical measuring devices for measuring thickness, The optical measuring instruments are relatively arranged on both sides of the platform, and respectively output a measurement signal; a calibration jig is provided on the platform and includes a displacement between a retracted position and a corrected position relative to the at least one measurement group At least one stage, and at least one reference sheet provided on the at least one stage, the at least one reference sheet having two reference planes separated by a distance, when the at least one stage is at the retracted position, the reference planes Out of the optical path range of the optical measuring devices, when the at least one stage is at the calibration position, the reference planes are located in the optical path range of the optical measuring devices; a drive unit, installed on the platform, and used for Driving the displacement of the at least one carrier; a conveying unit installed on the platform and used to convey the displacement of the at least one object to the optical path range of the optical measuring devices; and a control unit communicating with the measuring group and It is electrically connected to the calibration jig and the conveying unit, and calculates a reference thickness between the reference planes based on the measurement signals, and uses the reference thickness as a correction value to calculate the thickness of the at least one object. The thickness measuring device according to claim 10, wherein the at least one stage is displaced in a predetermined direction. The thickness measuring device according to claim 10, wherein the predetermined direction is a first direction, one of the directions opposite to the first direction, and the optical measuring devices are arranged on opposite sides of the platform along a second direction , The first direction is perpendicular to the second direction. The thickness measuring device according to claim 10, wherein the correction jig includes a plurality of reference pieces, and the at least one stage has a number of windows, and the reference pieces respectively detachably cover at least a part of the windows. The thickness measuring device according to claim 13, wherein the platform has a number of notches, and the at least one stage has a number of convex parts, each convex part penetrates in the corresponding notch and has a window defined A ring wall, the ring wall has a mounting groove, and each fiducial plate is detachably mounted on the corresponding mounting groove and covers at least a part of the corresponding window, so that the fiducial surfaces of each fiducial plate respectively face through the window Such optical measuring devices. The thickness measuring device according to claim 14, wherein the platform unit further includes a plurality of rails, and the platform has two tables facing the optical measuring devices at a distance, and the rails are fixed on one of the tables In the above, the correction jig also has several rails fixed on the at least one carrier and slidingly sliding with the rails, the at least one object straddles the conveyor belts and is located above the other table. The thickness measuring device according to claim 12, wherein the correction jig includes a plurality of reference pieces, the reference pieces are displaced between a first size position and a second size position, when the reference pieces are in the first At the size position, the total distance of the reference pieces along a third direction is the smallest, and when the reference pieces are at the second size position, the total distance of the reference pieces along the third direction is the largest, and the first direction is perpendicular In this third direction. The thickness measurement device according to claim 16, wherein the measurement unit further includes two brackets spaced apart along the third direction and located on both sides of the platform, connected to the brackets and spaced apart along the second direction Two rails, and two positioning groups provided on the rails, each rail has at least one chute group, each positioning group has a number of positioning brackets arranged along the third direction, the positioning brackets are used for The optical measuring instruments are installed, and are slid with the corresponding chute groups of the corresponding rail frame to be positioned on the corresponding rail frame. The thickness measurement device according to claim 11, wherein the driving unit includes two pulleys pivotally arranged on the platform and separated by a distance along the predetermined direction, a surrounding belt that sleeves the pulleys, and driving one of the belts A correction motor that rotates in the forward and reverse directions of the wheel, the surrounding belt is divided into two surrounding parts passing around the belt wheels, and two linear parts located between the surrounding parts, wherein the linear part is connected to the at least one Stage. The thickness measuring device according to claim 11, wherein the conveying unit includes two rotating shaft groups arranged on both sides of the platform in the predetermined direction, a number of conveyor belts surrounding the rotating shaft groups in the predetermined direction, and driving one of them A conveying motor rotated by the rotating shaft group, the conveying belts are used to convey the at least one object, so that the at least one object is displaced along the predetermined direction to the optical path range of the optical measuring devices.

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