JP7408336B2 - feeler gauge - Google Patents

Description

The wafer, on which multiple devices such as ICs and LSIs are divided by division lines and formed on the front surface, is ground on the back side using a grinding machine to form a predetermined thickness, and is then diced into individual device chips using a dicing machine and a laser processing machine. It is used in electrical equipment such as mobile phones and computers.

The grinding device includes a chuck table that holds a wafer, a grinding means rotatably equipped with a grinding wheel having a grinding wheel disposed in a ring shape for grinding the wafer held on the chuck table, and a grinding means that connects the grinding means to the chuck table. A wafer can be ground with high precision (see, for example, Patent Document 1).

Furthermore, before grinding the wafer, the gap between the holding surface of the chuck table and the grinding wheel is measured using a gap gauge, and a reference value for operating the grinding means is calculated.

Japanese Patent Application Publication No. 2005-246491

As the above-mentioned gap gauge, for example, a thickness gauge is known, in which a plurality of thin metal plates called leaves are inserted in a stacked manner according to the gap, and the metal plates can be inserted while adjusting the number of insertable leaves. The dimensions of the gap are measured based on the total number of . Further, as another example of a gap gauge, a taper gauge is known that measures the gap by inserting a taper formed in the thickness direction or the width direction into the gap.

In the thickness gauge described above, the operator who actually performs the measurement adjusts the number of thin metal plates to determine the number of thin metal plates to be inserted into the gap, and manually inserts the thin metal plates to measure the gap size. At this time, the operator adjusts the number of sheets to be inserted and determines the limit, which is not only complicated, but also prone to errors depending on the operator. Furthermore, when using a taper gauge, there is not necessarily enough space in the area where the chuck table and the grinding wheel face each other to measure the gap to visually check the memory of the taper gauge. It may be difficult to insert a taper gauge into the machine and check to what position it has been inserted. Therefore, in measurements using the thickness gauge and taper gauge described above, variations (errors) in the measurement values occur depending on the individual differences of the workers performing the measurement, and the reference value of the gap when carrying out the grinding process may not be set correctly. First, there is a problem that the grinding process is not performed with high precision.

The above-mentioned problem of errors occurring during measurement is not limited to problems when measuring the gap between the chuck table of the grinding device and the grinding wheel and setting a reference value, but also when measuring the gap size. can occur in any gap.

The present invention has been made in view of the above facts, and its main technical problem is to provide a gap gauge that does not cause variations in measured values due to individual differences or that can be easily measured visually.

In order to solve the above-mentioned main technical problem, the present invention provides a gap gauge for measuring a gap, which includes a wedge body consisting of a bottom part and a slope sloped at a predetermined angle from the bottom part; A measurement unit equipped with a variable resistance sheet whose resistance value changes depending on the position of the variable resistance sheet, a power source that supplies electricity to the variable resistance sheet, and a detector that detects voltage or current passing through the variable resistance sheet. , a calculation unit that calculates the height of the slope at the position where the variable resistance sheet is pressed according to the correlation between the position at which the variable resistance sheet is pressed and the voltage value or current value detected by the detector; The variable resistance sheet includes a display section that displays the value of the height of the slope calculated by the calculation section , and the variable resistance sheet includes a conductive plate made of a conductor, a resistor, and an external force acting on the variable resistance sheet. a spacer made of an insulator that forms a cavity in a region sandwiched between the conductor and the resistor in a steady state in which the detector A feeler gauge is provided that detects voltage or current in a circuit through a point of contact with the body .

It is preferable to further include a recording section that records the value calculated by the calculation section, and an erasing section that erases the value recorded in the recording section.

The gap gauge of the present invention is a gap gauge that measures a gap, and includes a wedge body consisting of a bottom and a slope inclined at a predetermined angle with respect to the bottom, and a position disposed on the slope of the wedge to provide resistance. A measurement unit equipped with a variable resistance sheet whose value changes; a power source that supplies electricity to the variable resistance sheet; a detector that detects voltage or current passing through the variable resistance sheet; and a detector that presses the variable resistance sheet. a calculation unit that calculates the height of the slope at the position where the variable resistance sheet is pressed according to the correlation between the position and the voltage value or current value detected by the detector; and the slope calculated by the calculation unit. The variable resistance sheet includes a conductive plate made of a conductor, a resistor, and a display section that displays the height value of the variable resistance sheet. and a spacer made of an insulator that forms a cavity in a region sandwiched between the resistor and the resistor, and the detector includes a spacer made of an insulator that forms a cavity in a region sandwiched between the resistor and the resistor, and the detector is configured such that an external force is applied to the variable resistance sheet and passes through a point where the conductor and the resistor come into contact with each other. Since it detects the voltage or current of the circuit , it is possible to measure the gap by simply inserting a wedge into the gap, but there is a problem that measurement errors occur due to individual differences, or it is difficult to measure visually. The problem is resolved.

(a) A perspective view showing an example of the gap gauge of the present embodiment, and (b) a perspective view showing another example of the gap gauge. (a) A cross-sectional view of the variable resistance sheet shown in Fig. 1, and a block diagram showing the outline of the configuration of the display tool shown in Fig. 1, (b) An external force F is applied to the position P of the variable resistance sheet shown in (a). A cross-sectional view showing a state in which the display tool is pressed, a block diagram schematically showing the configuration of the display tool, (c) a cross-sectional view of a variable resistance sheet that is an embodiment different from the embodiment shown in (a), and the configuration of the display tool. FIG. It is a correlation table or a correlation diagram showing the correlation between the position where the variable resistance sheet is pressed and the voltage value or current value passing through the variable resistance. It is a side view seen from the side when measuring a gap with a gap gauge of this embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a gap gauge constructed based on the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1(a) shows a first embodiment of a gap gauge 1A constructed based on the present invention. The gap gauge 1A includes a measuring section 10A and a display tool 100A.

The measuring section 10A includes a wedge body 30A and a variable resistance sheet 20. The wedge body 30A includes a bottom portion 32A and a slope 34A inclined at a predetermined angle θ with respect to the bottom portion 32A. As shown in FIG. 1(a), the variable resistance sheet 20 is mounted on the slope 34A with the front surface 20a facing upward and the back surface 20b facing downward, with the tip 20c matching the tip 36A of the wedge body 30A. .

A sensor circuit 40 whose resistance value changes depending on the pressed position is housed inside the variable resistance sheet 20. The sensor circuit 40 is connected to the display tool 100A by wires 22 and 24, and is powered by a power source to be described later. The display tool 100A is based on the fact that the resistance value of the sensor circuit 40 of the variable resistance sheet 20 changes depending on the pressed position in the longitudinal direction. , or detect the current, and detect the pressed position according to the correlation between the pressed position of the variable resistance sheet 20 and the voltage value or current value. Then, based on the pressed position, the height of the slope at the pressed position of the variable resistance sheet 20 is calculated, and the calculated value is displayed on the display section 110A. Note that the display tool 100A is provided with buttons 50A for turning the power on and off and for executing predetermined processing described later.

The variable resistance sheet 20 disposed on the slope 34A of the wedge body 30A and the display tool 100A will be described in more detail with reference to FIG. 2. FIG. 2A is a longitudinal cross-sectional view taken along the center of the variable resistance sheet 20 in the longitudinal direction, and a circuit diagram showing a schematic configuration of the display tool 100A.

As shown in FIG. 2(a), the variable resistance sheet 20 includes a sensor circuit 40 including a conductive plate 42 made of a thin conductor and a resistor 44 (resistance value=R ₀ ). A spacer 46 made of an insulator is arranged around the outer periphery of the area sandwiched between the conductive plate 42 and the resistor 44, and in a steady state where no external force is applied to the variable resistance sheet 20, the conductive plate 42 and the resistor A cavity is formed between the conductive plate 42 and the resistor 44, and the conductive plate 42 and the resistor 44 are separated from each other. The sensor circuit 40 is covered with a thin film sheet for protecting the sensor circuit 40, and the thin film sheet is composed of a front surface 20a, a back surface 20b, and a tip 20c. The thickness of the variable resistance sheet 20 of this embodiment is, for example, 0.5 mm or less, but for convenience of explanation, FIG. 2 is not drawn according to the actual size ratio. Further, the surface of the conductive plate 42 does not necessarily need to be covered with the thin film sheet (20a), and the conductive plate 42 may be exposed on the surface.

As shown in FIG. 2(a), the display tool 100A includes a power source 102 whose output voltage is V ₀ that causes electricity to flow through the variable resistance sheet 20, and a detector 104 that detects the voltage (V ₁ ) passing through the variable resistance sheet 20. , a resistor 106 is provided on the ground side opposite to the resistor 44 across the detection position of the detector 104. Note that in this embodiment, the resistance value of the resistor 106 is the same as the resistance value realized by the entire resistor 44 (=R ₀ ). In addition, the display tool 110A further calculates the height of the slope on which the variable resistance sheet 20 is pressed according to the correlation between the position where the variable resistance sheet 20 is pressed and the voltage value detected by the detector 104. 122, a recording section 124 that records the value calculated by the calculation section 122, and an erasing section 126 that erases the value recorded in the recording section 124 as necessary. , or a display section 110A that displays the value of the recording section 124 that records the value calculated by the calculation section 122. Note that the calculation section 122 and the erasing section 126 described above are realized by a control program, and are realized by the microcomputer 120 for executing the control program. Further, the recording unit 124 includes a random access memory (RAM) provided in the microcomputer 120 and used to temporarily store calculation results and the like.

The resistor 44 constituting the sensor circuit 40 has a length L of, for example, 100 mm, and an overall resistance value R ₀ of, for example, 10 kΩ. Therefore, the resistance value of the resistor 106 is also 10 kΩ. Further, the output voltage of the power supply 102 is V ₀ =10V. The procedure for calculating the position P when the variable resistance sheet 20 is pressed by the external force F as shown in FIG. 2(b) will be described below.

As shown in FIG. 2(b), by applying an external force F to an arbitrary position P of the variable resistance sheet 20, the conductive plate 42 and the resistor 44, which are kept separated in a steady state, are separated. , touch at point Q. By connecting the conductive plate 42 and the resistor 44 at point Q, the side connected to the power supply 102 via the wiring 22 connected to the conductive plate 42 and the resistor 106 connected to the resistor 44 are arranged. An electric circuit is formed between the ground side of the wiring 24 and the ground side. Here, if the distance from the tip 20c of the variable resistance sheet 20 to the position P is x, the resistor 44 is connected to the resistor in a region defined by a length of (L-x) mm from the point Q to the ground side. Therefore, the resistance value R ₁ formed in the region is calculated as follows, assuming that the resistance value of the entire resistor 44 is R ₀ .
R ₁ = ((L-x)/L)・R ₀ ...(1)

When the variable resistance sheet 20 is pressed at the above-described position P, the voltage _V1 detected by the detector 104 shown in FIG. 2(b) is calculated from the above formula (1) and the partial pressure calculation formula: It is calculated as follows.
V ₁ =(R ₁ /(R ₁ +R ₀ ))・V ₀
=((L-x)/(2L-x))・V ₀ ...(2)

As mentioned above, since V ₀ =10V, x is calculated as follows based on equation (2).
x=(2LV ₁ -10L)/(V ₁ -10)...(3)

The above equation (3) expresses the correlation between the position P where the variable resistance sheet 20 is pressed and the voltage value at the position passing through the variable resistance sheet 20, and as mentioned above, L = 100 mm. By applying the voltage _V1 detected by the detector 104 and the above-mentioned L=100 mm to the above equation (3), the distance x from the tip 20c to the position P, that is, the pressed position P is calculated. .

In addition, the above-mentioned formula is used to express the correlation between the position P where the variable resistance sheet 20 is pressed (distance x [mm] from the tip 20c) and the voltage value _V1 at the position passing through the variable resistance sheet 20. Not limited to (3), for example, as shown in _FIG . The correlation diagram 140 may be created based on the table 130 or the correlation table 130, or created experimentally. When using the correlation table 130 or the correlation diagram 140 instead of applying the voltage value V ₁ detected by the detector 104 to the above equation (3), the correlation table 130 or the correlation diagram 140 is stored in the memory of the microcomputer 120. The position P( _x [mm]) can be calculated. In addition, when using the correlation table 130 shown in _FIG . [mm]) can be obtained.

The calculation unit 122 of the display tool 100A of this embodiment further calculates the variable resistance sheet when the measuring unit 10A is inserted into an arbitrary gap with the gap gauge 1A using x [mm] indicating the above-mentioned position P. The height H of the slope at the position P where 20 is pressed is calculated. Below, with reference to FIG. 4, a procedure for calculating the height H of the slope at the position P where the variable resistance sheet 20 is pressed in order to measure the dimension of the gap W using the gap gauge 1A will be explained. .

In the embodiment shown in FIG. 4, a grinding wheel S is positioned between the surface Ta of the chuck table T and above the surface Ta with a gap W in between. When measuring the gap W, as shown in FIG. 4(a), the measuring part 10A of the gap gauge 1A is moved in the direction shown by the arrow R and inserted from the side into the gap W. . At this time, the bottom portion 32A of the wedge body 30A constituting the measuring section 10A is brought into close contact with the surface Ta of the chuck table T.

As shown in FIG. 4(b), the measuring section 10A is inserted into the gap W, and the surface 20a of the variable resistance sheet 20 is brought into contact with the corner Sc of the grinding wheel S. When the corner portion Sc of the grinding wheel S comes into contact with and presses the surface 20a of the variable resistance sheet 20, the conductive plate 42 and the resistor 44 of the sensor circuit 40 are brought into position, as explained based on FIG. 2(b). They contact directly below P (point Q) to form a circuit, current from power source 102 flows through variable resistance sheet 20, and voltage value _V1 is detected by detector 104. As described above, when _the voltage value V ₁ is detected, the variable resistance sheet 20 is The distance x [mm] from the tip 20c to the position P is calculated. By the way, as shown in FIG. 4(b), the variable resistance sheet 20 is interposed between the corner portion Sc of the grinding wheel S and the wedge body 30A of the measuring section 10A, and the bottom portion 32A of the wedge body 30A It has a constant thickness (=H ₂ ) at a position passing through position P in a direction perpendicular to . Then, assuming that the height of the wedge body 30A in the direction passing through the position P and perpendicular to the bottom 32A of the wedge body 30A is _H1 , the dimension of the gap W formed between the surface Ta of the chuck table T and the grinding wheel S. The height H is calculated as follows.
H=H ₁ +H ₂ =x・sinθ+H ₂ ...(4)

Here, in this embodiment, the angle θ formed by the bottom 32A of the wedge body 30A and the slope 34A is 11.5°, and the calculation is performed with sin θ=2.0. Further, the value of H ₂ is determined by actually measuring the thickness when pressed, and in this embodiment, H ₂ =0.1 mm. Therefore, the above equation (4) becomes the following equation.
H=2.0x+0.1 [mm]...(5)

As described above, information indicating the correlation between the position P at which the variable resistance sheet 20 is pressed and the voltage value _V1 (the above equation (3), or The variable resistance sheet ₂₀ is pressed by storing either the correlation table 130 or the correlation diagram 140 shown in FIG. According to the correlation between the position P and the voltage value _V1 , the height H of the slope at the position P where the variable resistance sheet 20 is pressed, that is, the dimension of the gap W can be calculated.

As described above, once the height H of the slope at the position P where the variable resistance sheet 20 is pressed is calculated in the calculation unit 122 of the microcomputer 120, the height H is displayed on the display unit 110A connected to the microcomputer 120. indicate. At this time, the value calculated by the calculation unit 122 may be displayed as is, but in this embodiment, the value of the height H recorded in the recording unit 124 that constitutes the microcomputer 120 is is displayed on the display section 110A. The value of the height H once recorded in the recording unit 124 is retained unless an operation for erasing the information in the recording unit 124 (for example, a long press on the button 50A, etc.) is performed. When an operation for erasing information in the recording section 124 is instructed, the erasing section 126 configured by a control program set in the microcomputer 120 is executed and the information on the recording section 124 is erased.

According to the present invention, various modifications are provided without being limited to the above-described embodiments. For example, in the embodiment shown in FIG. 1(a), the display tool 100A is configured outside the measuring section 10A and is connected to the measuring section 10A by wirings 22 and 24, but the present invention is not limited to this. As shown in FIG. 1(b), a wedge body 30B includes a bottom portion 32B and a slope 34B inclined at a predetermined angle θ, and a variable resistance sheet 20 disposed on the slope 34B of the wedge body 30B. A display tool 100B having the same function as the above-mentioned display tool 100A is built into the measuring section 10B, and the height H of the slope calculated as the gap W calculated by the display tool 100B is displayed in the measuring section 10B. The gap gauge 1B may be displayed on a display section 110B disposed in the gap gauge 1B. In this case, the wirings 22 and 24 are housed inside the wedge body 30B, and a switch 50B is provided on the wedge body 30B of the measurement section 10B to turn on and off the power of the display tool 100B, and to turn on and off the power of the display tool 100B and the erasing section 126. It may also be possible to instruct the execution of .

For example, in the embodiment described above, the voltage (V ₁ ) passing through the variable resistance sheet 20 is detected by the detector 104 disposed in the display tools 100A and 100B, and the position P at which the variable resistance sheet 20 is pressed is determined. Although the height H of the slope at the position P where the variable resistance sheet 20 is pressed was calculated according to the correlation with the voltage value _V1 , the present invention is not limited thereto. In another embodiment shown in FIG. 2(c), instead of the detector 104 provided in the display tools 100A and 100B, an ammeter that detects the current (A ₁ ) passing through the variable resistance sheet 20 is used. A functional detector 108 is provided, and the height H of the slope at the position P where the variable resistance sheet 20 is pressed is determined by the calculation unit 122 according to the correlation between the position P where the variable resistance sheet 20 is pressed and the current value _A1 . It is also possible to use display tools 100A' and 100B' that calculate . Note that the configurations of the display tools 100A' and 100B' are the same as those of the display tools 100A and 100B described above except for the detector 108. Below, the procedure for calculating the height H based on the current value _A1 detected by the detector 108 will be explained in more detail.

The output voltage of the power supply 102 disposed in the display tools 100A' and 100B' is _V0 , and the resistance value ( _R1 ) of the resistor 44, which changes depending on the pressed position P, is expressed by the above equation (1). As stated in. Here, as shown in FIG. 2(c), when the variable resistance sheet 20 is pressed by the external force F at the position P, the current value _A1 detected by the detector 108 is calculated as follows. .
A ₁ =V ₀ /(R ₁ +R ₀ )
=V ₀ /(((L-x)/L)・R ₀ +R ₀ )
=(L/(2L-x))・(V ₀ /R ₀ )...(6)

Furthermore, in this embodiment, since V ₀ = 10V and R ₀ = 10kΩ, based on the above equation (6), x indicating the position of the above position P can be calculated by the equation shown below. Ru.
x=(2A ₁ L-10 ^-3 L)/A ₁ ...(7)

Equation (7) above expresses the correlation between the position P where the variable resistance sheet 20 is pressed and the current value _A1 at the position passing through the variable resistance sheet 20. By applying the current _A1 detected by 108 to the above equation (7), the distance x from the tip 20c to the position P is calculated.

As described above, once the pressed position P on the variable sheet 20 has been calculated, the surface Ta of the chuck table T and the grinding wheel The height H in the gap W formed between S and S is calculated. Note that in this embodiment as well, as in the previously described embodiment, the method for calculating x is not necessarily limited to calculating based on the above-mentioned formula (7), but as shown in FIG. 3, A correlation table 130 showing the correlation between the position P (x [mm]) of the variable resistance sheet 20 and the current value _A1 detected by the detector 108, or created based on the correlation table 130, or experimentally Using the created correlation diagram 140, it is also possible to calculate the position P (x [mm]) where the variable resistance sheet 20 is pressed. Note that when using the correlation table 130 shown in FIG. 3, the position P (x [mm]) where the variable resistance sheet 20 is pressed can be determined in finer units by performing interpolation calculations etc. as appropriate. Can be done.

As described above, if the calculation unit 122 of the microcomputer 120 calculates the height H of the slope at the position P where the variable resistance sheet 20 is pressed, the display unit 110A' (or 110B') connected to the microcomputer 120 The height H is displayed. At this time, the value calculated by the calculation unit 122 may be displayed as is, but in this embodiment, the storage unit 124 (random access memory) for temporarily storing the calculation results etc. that constitute the microcomputer 120 is used. The height H value recorded in the recording section 124 may be displayed on the display section 110A' (or 110B'). The value of the height H once recorded in the recording unit 124 is retained unless an operation for erasing the information in the recording unit 124 is performed. When an operation for erasing information in the recording section 124 is instructed, the erasing section 126 configured by a control program set in the microcomputer 120 is executed and the information on the recording section 124 is erased.

1A, 1B: Feeler gauge 10A, 10B: Measuring section 30A, 30B: Wedge body 32A, 32B: Bottom section 34A, 34B: Slope 40: Sensor circuit 42: Conductive plate 44: Resistor body 100A, 100B, 100A', 100B': Display tool 102: Power supply 104: Detector 106: Resistor 108: Detectors 110A, 110B, 110A', 110B': Display section 120: Microcomputer 122: Calculation section 124: Recording section 126: Erasing section

Claims (2)

A gap gauge for measuring gaps,
a measuring unit comprising a wedge body comprising a bottom and a slope inclined at a predetermined angle with respect to the bottom, and a variable resistance sheet disposed on the slope of the wedge whose resistance value changes depending on the pressed position;
a power source that supplies electricity to the variable resistance sheet;
a detector that detects voltage or current passing through the variable resistance sheet;
a calculation unit that calculates the height of the slope at the position where the variable resistance sheet is pressed according to the correlation between the position where the variable resistance sheet is pressed and the voltage value or current value detected by the detector;
a display unit that displays the value of the height of the slope calculated by the calculation unit;
Equipped with
The variable resistance sheet includes a conductive plate made of a conductor, a resistor, and an insulator that forms a cavity in a region sandwiched between the conductor and the resistor in a steady state when no external force is applied to the variable resistance sheet. A spacer consisting of;
The detector is a gap gauge that detects the voltage or current of the circuit through the point where the conductor and the resistor come into contact when an external force acts on the variable resistance sheet . The gap gauge according to claim 1, further comprising a recording section that records the value calculated by the calculation section, and an erasing section that erases the value recorded in the recording section.