JPH11142109A - Three-dimensional measurement apparatus and tree-dimensional measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional measurement apparatus and a three- dimensional measurement method which can accurately measure the height data on the surface of an object to be measured. SOLUTION: A three-dimensional sensor 101 and an arithmetic unit 107 are installed. The three-dimensional sensor 101 amplifies the information of a light receiving position and a received light amount of a laser beam of a PSD element receiving a reflected laser beam, by using a plurality of amplification factors, and the optimum information is selected from the amplified light receiving positions and the received light amounts by using an output conversion circuit. On the basis of the selected light receiving position and received light amount, the operation equipment 107 calculates and stores the height of unevenness of a surface to be measured. In the conventional method, the height of unevenness of the surface to be measured is calculated, on the basis of the light receiving position and the received light amount which are obtained by one kind of amplification factor. By selecting the height from the light receiving positions and light receiving amounts obtained by a plurality of the amplification factors, the height can be more accurately measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional measuring device for measuring height information of an object to be measured, and a three-dimensional measuring method executed by the three-dimensional measuring device.

[0002]

2. Description of the Related Art FIG. 8 shows a configuration of a conventional three-dimensional measuring device 15. The three-dimensional measuring device 15 is roughly divided into a three-dimensional sensor 1 for measuring the height of the unevenness on the surface to be measured of the object 2 to be measured, and a calculating device 3 for calculating the height of the unevenness from the output of the three-dimensional sensor 1. And The three-dimensional sensor 1 is a line scanning type three-dimensional measurement sensor having a light emitting and receiving element for laser light, and emits a laser beam 8 to an object 2 mounted on a stage 11 to receive a laser beam. The height of the unevenness on the surface to be measured of the measurement object 2 is measured. The three-dimensional sensor 1 itself is a line scanning type as described above, and measures the height in the Z direction, for example, along the X direction, that is, performs two-dimensional measurement. In order to perform three-dimensional scanning over the entire surface of the measurement surface, the entire surface of the workpiece 2 is scanned by moving the stage 11 in a direction orthogonal to the scanning, for example, in the Y direction. The specific structure of the three-dimensional sensor 1 will be described with reference to FIG. 3D sensor 1
Is a laser transmitter 21, a polygon mirror 22, and f-
θ lens 23, origin detection sensor 24, PSD element 2
6 and an output conversion circuit 27.

[0003] Such a three-dimensional sensor 1 operates as follows. The laser beam 25 emitted from the laser transmitter 21 is reflected by the reflection surface 22 a of the polygon mirror 22, and is emitted to the measured object 2 through the lens 23. Since the polygon mirror 22 rotates in the direction of arrow I, the angle of the laser beam 25 incident on the polygon mirror 22 changes, thereby irradiating the laser beam 25 in the direction of arrow II onto the line to be measured of the object 2 to be measured. It becomes possible to do. When the polygon mirror 22 is rotated in the direction of arrow I, the laser light 25 reflected on the reflection surface 22a of the polygon mirror 22 is rotated.
Is first emitted to the origin detection sensor 24. This is the origin of scanning by each reflection surface 22a of the polygon mirror 22, and when each reflection surface 22a reaches a certain angle, the origin detection sensor 24 outputs an origin signal 28. After the laser light is projected onto the measurement target 2 via the lens 23, the scattered light from the measurement target 2 is converted into a PSD for detecting the height of unevenness on the measurement target surface 2a of the measurement target 2.
The PSD element 26 outputs the PSD output signals 31 and 32, which are the basis of the height information, to the output conversion circuit 27. The output conversion circuit 27 outputs the analog signal PS
The D output signals 31 and 32 are converted into digital signals.

FIG. 10 shows an internal circuit of the output conversion circuit 27. The PSD element 26 outputs each of the position on the PSD element irradiated with the reflected laser light and the amount of received light as a current, which is a first input current 31 and a second input current.
The input current 32 is supplied to the output conversion circuit 27.
The output conversion circuit 27 includes the first input current 31 and the second
The I / V converters 34,
35, amplifiers 36 and 37, and A / D converters 38 and 39 are provided, respectively. That is, the first input current 31 is I
After being converted into a voltage by the / V converter 34 and adjusted by the amplifier 36, the data is converted into a digital signal by the A / D converter 38 in accordance with the image clock 33 sent from the clock generator 42, and becomes output data 40. Similarly, the second input current 32
Is converted into a voltage by the I / V converter 35 and adjusted by the amplifier 37, and then converted into a digital signal by the A / D converter 39 in accordance with the image clock 33 to become output data 41. The output data 40 and the output data 41 are sent to the arithmetic unit 3, and the arithmetic unit 3 outputs P based on the ratio between the output data 40 and the output data 41 as described later in detail.
The irradiation position of the laser beam on the SD element 26 is calculated,
The height data is calculated by correcting the calculated value. The calculation of the ratio between the output data 40 and the output data 41 is performed by the height calculator 5 in the arithmetic unit 3.

[0005] The arithmetic unit 3 performs various processing calculations based on output data 40 and output data 41 sent from the three-dimensional sensor 1. The output data 40 and the output data 41 supplied from the three-dimensional sensor 1 are provided in the arithmetic device 3.
Are converted into the actual height of the irregularities, and the height calculators 5 and 3 perform correction calculation and the like of the converted height.
The origin signal 2 indicating the origin of the line scanning of the dimension sensor 1
A timing generation circuit 4 for generating an address to be supplied to the image memory 6 by using the origin synchronization signal 8 as a horizontal synchronization signal and a height data supplied from the height calculation unit 5 and supplied from the timing generation circuit 4 Based on the address, the image memory 6 for storing the irregularities on the measurement surface 2a of the measurement object 2 as three-dimensional image data, and a CP for performing image processing based on the image data in the image memory 6
U (central processing unit) 7. If the movement of the stage 11 is stopped, two-dimensional height data can be stored in the image memory 6.

[0006]

FIG. 11 and FIG.
The figure shows how the amount of light received by the PSD element 26 changes depending on the reflection position of the laser beam on the measurement surface 2a of the measurement object 2. For example, when the slope 46 of the protrusion 45 present on the measurement surface 2a of the DUT 2 faces the light receiving surface 26a of the PSD element 26, the laser beam 48 passing through the lens 23 irradiates the slope 46. In some cases, the amount of laser light 49 reflected on the slope 46 and incident on the light receiving surface 26a of the PSD element 26 increases. On the other hand, when the laser beam 48 irradiates the inclined surface 47 of the projection 45 which is not facing the light receiving surface 26a of the PSD element 26, the laser light reflected by the inclined surface 47 is almost completely reflected on the light receiving surface 26a. Does not enter, and the amount of light received by the PSD element 26 is small. As described above, the amount of light received by the PSD element 26 changes due to the shape of the measurement surface 2a of the object 2 to be measured. When the amount of light received by the PSD element 26 is excessive, the output data of the output conversion circuit 27 Since the saturation occurs, it becomes impossible to accurately calculate the irradiation position of the laser beam on the light receiving surface 26a of the PSD element 26, and correct detection cannot be performed. On the other hand, when the amount of light received by the PSD element 26 is too small, the output data of the output conversion circuit 27 is too small, so that not only the calculation accuracy of the height data is deteriorated, but also the influence on the noise increases.
Correct detection cannot be performed. In addition, factors that determine the amount of light received by the PSD element 26 vary depending on not only the shape of the measurement surface 2a of the measurement object 2 but also the material of the measurement object 2 as described above. That is, if the light reflectance of the measured surface 2a of the measured object 2 is high, the amount of light received by the PSD element 26 increases, while if the light reflectance is low, the amount of received light decreases. When the device under test 2 is, for example, an electronic component, a lead made of metal and a body made of plastic are mixed, and even if the above-mentioned lead is focused on, the surface condition is large. There are various cases such as a case where the surface is almost smooth like a mirror surface and a case where these are mixed. Therefore, the amount of laser light received by the PSD element 26 is likely to be partially supersaturated or partially insufficient, and as a result, correct measurement or high-precision measurement of the height data cannot be performed. There is. The present invention has been made in order to solve such a problem, and the laser light receiving amount is oversaturated.
It is an object of the present invention to provide a three-dimensional measuring device and a three-dimensional measuring method that can accurately measure height data of a measurement object on a measurement surface by reducing excess and deficiency as much as possible.

[0007]

According to a first aspect of the present invention, there is provided a three-dimensional measuring apparatus comprising: a photodetector for detecting a laser beam reflected on a surface to be measured; A three-dimensional measuring device, comprising: a calculating device that converts the output information of the photodetector into information to be supplied to the calculating device. A plurality of amplifying means for amplifying the light at a plurality of different amplification factors, and among the output information of the amplifying means, select the output information in the measurable state other than the light quantity lower limit state or the light quantity saturation state in the photodetector. Data switching means for transmitting the data to the arithmetic device.

A three-dimensional measuring method according to a second aspect of the present invention detects a laser beam reflected on a surface to be measured, and converts the detected laser beam into height information on the unevenness of the surface to be measured. A dimension measurement method, wherein information corresponding to the detected light amount of laser light is amplified at a plurality of amplification factors, and information corresponding to the detected light amount of laser light is measured in a state other than the light amount lower limit state or the light amount saturated state. The method includes the steps of selecting output information in a possible state and using the information for calculating the height information.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A three-dimensional measuring apparatus according to an embodiment of the present invention and a three-dimensional measuring method executed by the three-dimensional measuring apparatus will be described below with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals. Further, in the present embodiment, an electronic component mounted on a printed circuit board is taken as an example of an object to be measured, but the object to be measured is not limited to the above electronic component. Also, the "photodetector" described in the section of "Means for Solving the Problems" above
Is equivalent to the PSD element in the present embodiment, an example that fulfills the function of “converting means” is equivalent to the output conversion circuit in the present embodiment, and one example that fulfills the function of “amplifying means” is the present embodiment. And an example that fulfills the function of “data switching means” corresponds to the data switching circuit in the present embodiment. The three-dimensional measuring apparatus 100 of the present embodiment is, for example, a semiconductor device such as a QFP.
(Lead in the Quad Flat Gull Wing Leaded Package)
It can be used to measure with an accuracy of about 0 μm.

FIG. 1 shows a configuration of a three-dimensional measuring apparatus 100 according to the present embodiment. The three-dimensional measuring device 100
Is roughly divided into a three-dimensional sensor 101 for measuring the height of the unevenness on the measured surface 102a of the measured object 102, and an arithmetic unit 107 for calculating the unevenness height based on the output of the three-dimensional sensor 101. First, the three-dimensional sensor 101
Will be described. The three-dimensional sensor 101 is a line scanning type three-dimensional measurement sensor including a light emitting and receiving element for laser light, and projects the laser light 103 onto an electronic component 102 which is an object to be measured mounted on a stage 114. The light is emitted to measure the height of the unevenness on the measurement surface 102a of the electronic component 102. Note that the three-dimensional sensor 101 itself is a line scanning type as described above, and measures the height in the Z direction, for example, along the X direction, that is, performs two-dimensional measurement.
In order to perform three-dimensional scanning over the entire surface to be measured 102a of the electronic component 102, the stage 114 is moved in a direction orthogonal to the scanning, for example, in the Y direction, so that the entire surface to be measured 102a of the electronic component 102 is scanned. The specific structure of the three-dimensional sensor 101 will be described with reference to FIGS. That is, the three-dimensional sensor 101 includes the laser transmitter 121, the polygon mirror 123, and the f-θ lens 1
24, an origin detection sensor 125, and a PSD element 126
, And an output conversion circuit 130, the general configuration of which is the same as the configuration of the conventional three-dimensional sensor 1, but the configuration inside the output conversion circuit 130 is significantly different from the conventional one. The output conversion circuit 130 sends output data 104 and 105 as the output of the three-dimensional sensor 101. The configuration and operation of the output conversion circuit 130 will be described later.

The operation of the three-dimensional sensor 101 excluding the output conversion circuit 130 is the same as the operation of the above-described conventional three-dimensional sensor 1, and will be briefly described below. The laser light 122 emitted from the laser transmitter 121 is reflected by the polygon mirror 123,
The light travels toward the electronic component 102 through the f-θ lens 124. Laser light 103 is projected on electronic component 102 and the reflected light is detected by PSD element 126. PSD element 12
6 outputs a current 128 and a current 129 according to the position and the amount of light reflected by the electronic component 126. The current 128 and the current 129 are converted into digital values by the output conversion circuit 130, and the output data 104 and the output data
05. By rotating the polygon mirror 123, it becomes possible to irradiate the laser beam 122 along a straight line. When the polygon mirror 123 is rotated in the direction of the arrow, first, the origin detection sensor 125
Is irradiated with a laser beam 122. This is the origin of each surface of the polygon mirror 123. When each of the surfaces reaches a certain angle, the origin signal 106 is output.

Next, the output conversion circuit 130 will be described with reference to FIG. As described above, the output conversion circuit 130 supplies the current 128 and the current 129 from the PSD element 126 in accordance with the position and amount of reflected light of the electronic component 126.
And an image clock is supplied from the clock generator. Such an output conversion circuit 130 is
The I / V converters 131 and 132 and the I / V converter 13 correspond to the current 128 and the current 129, respectively.
Amplifiers 133 and 134 respectively connected to
And A / Ds respectively connected to the amplifiers 133 and 134
Converters 135 and 136 and A / D converters 135 and 136
And a data switching circuit 137 connected to the

The I / V converters 131 and 132 convert a current into a voltage. The current 128 output from the PSD element 126 becomes a voltage 138 by the I / V converter 131, and the current 129 becomes an I / V. The voltage becomes 139 in the V converter 132. In this embodiment, the amplifiers 133 and 134 are respectively three amplifiers 133-1, 133-2 and 133-3.
And amplifiers 134-1, 134-2, and 134-3, each having a different amplification factor. That is, when the amplification factors of the amplifier 133-2 and the amplifier 134-2 are “A”, the amplifier 133-1 and the amplifier 134
−1 is set to “A / 10” and the amplifier 133
−3 and the amplification factor of the amplifier 134-3 are set to “A × 10”. Note that the number of amplifiers is not limited to the above-mentioned three, but may be two or more, and the amplification factor is not limited to the above-mentioned numerical value. In this way, the voltages 138 and 139 are amplified by the amplifiers 133 and 134 to different degrees of amplification, respectively, and then supplied to the 12-bit A / D converters 135 and 136. A / D converters 135 and 136 are also connected to each amplifier 13.
3 and 134, and the A / D converter 1
35 is an A / D converter 135-1, 135-2, 135
-3, and the A / D converter 136 includes A / D converters 136-1, 136-2, and 136-3. Therefore, the amplifiers 133-1, 133-2, 133-
3 are the A / D converters 135-1 and 135-
At 2,135-3, data 141, 142, 1 which are 12-bit digital data in accordance with the image clock 140
43, and the amplifiers 134-1, 134-2, 13
The respective voltage values of 4-3 are A / D converters 136-1 and 136.
At −2, 136-3, 12 according to the image clock 140
Data 144, 145, which are digital data of bits
146. The data switching circuit 4 stores data generated with the same amplification factor, that is, data 141 and data 1
44, the data 142 and the data 145, and the data 143 and the data 146, and select an optimum pair from the three pairs.
The output information of the three-dimensional sensor 101 is output to the arithmetic unit 107 as output information of the three-dimensional sensor 101.

The configuration and operation of the data switching circuit 137 will be described with reference to FIG. The light intensity saturation detection circuits 151 to 156 have a maximum value of 4095 of 12-bit data.
Is "H" when this signal is supplied, and "L" otherwise. Light intensity saturation detection circuit 151
Is supplied with the output data 141 of the A / D converter 135-1 connected to the amplifier 133-1 having the amplification factor of A / 10, and the light intensity saturation detection circuit 152 has the amplification factor of A / D. A / D connected to amplifier 134-1 which is 10
The output data 144 of the converter 136-1 is supplied. That is, the output data 1 generated at the lowest amplification rate among the three amplification rates is output to the light intensity saturation detection circuits 151 and 152.
41 and 144 are supplied. Note that these output data 1
Data 41 and 144 are data generated at the lowest amplification rate, and are used when the illuminance of the laser light on the light receiving surface of the PSD element 126 is high. The output data 142 of the A / D converter 135-2 connected to the amplifier 133-2 having the amplification factor A is supplied to the light intensity saturation detection circuit 153.
Also, the output data 145 of the A / D converter 136-2 connected to the amplifier 134-2 having the amplification factor A is supplied. That is, the light intensity saturation detection circuits 153 and 154
Output data 142 and 145 generated at an intermediate amplification rate among the types of amplification rates are supplied. Since these output data 142 and 145 are data generated at an intermediate amplification factor, they are data used when the illuminance of the laser light on the light receiving surface of the PSD element 126 is intermediate. The amplification factor is A × 10 in the light intensity saturation detection circuit 155.
A / D converter 13 connected to amplifier 133-3
The output data 143 of 5-3 is supplied to the amplifier 1 and the amplification factor is A × 10 to the light intensity saturation detection circuit 156.
The output data 146 of the A / D converter 136-3 connected to 34-3 is supplied. That is, the light intensity saturation detection circuit 15
5, 156 are supplied with output data 143 and 146 generated at the highest amplification rate among the three types of amplification rates. Since these output data 143 and 146 are data generated at the highest amplification rate,
This data is used when the illuminance of the laser beam on the light receiving surface of the element 126 is low.

These light intensity saturation detection circuits 151 to 156
, The light intensity saturation detection circuits to which the data amplified at the same amplification factor are supplied are OR circuits 161 to 163, respectively.
Connected to. That is, the light intensity saturation detection circuits 151 and 152
Is connected to the OR circuit 161 and the light intensity saturation detection circuit 15
3 and 154 are connected to the OR circuit 162, and the light intensity saturation detection circuits 155 and 156 are connected to the OR circuit 163.

The light amount lower limit detection circuits 157 and 158
This is a circuit for detecting the lower limit of the amount of light such that the calculation accuracy is not high for data smaller than this or the influence of noise becomes too large. In this embodiment, when the digital value of the supplied data is 100 or less, “H” is set. And output
Otherwise, it is a circuit that outputs "L". The light amount lower limit detection circuits 157 and 158 have the output data 143 and 146 having the maximum amplification factor of A × 10 among the amplification factors, that is, the laser light on the light receiving surface of the PSD element 126. Data 1 used when illuminance is low
43 and 146 are supplied respectively. Further, an OR circuit 164 is connected to the output side of the light quantity lower limit detection circuits 157 and 158.

The selectors 171 to 178 are circuits for switching a 12-bit bus, and when the “H” level is supplied to the S terminal, select the bus connected to the terminal A.
When the “L” level is supplied, the bus connected to the terminal B is selected. Specifically, the selectors 171, 1
75, the terminal A is supplied with the output data 142 and 145 generated at the amplification factor A, and the terminal B
Is the output data 14 generated at the amplification factor A × 10.
3,146 are supplied, and the OR circuit 1 is connected to the terminal S.
63 output data are provided. In such a state, for example, in the selectors 171 and 175, the OR circuit 16
When an H level signal from 3 is supplied to the terminal S,
The output data 142 and 145 are selected, and the OR circuit 1
When an L-level signal is supplied from 63 to the terminal S, the output data 143 and 146 are selected. Functionally describing this operation, the selectors 171 and 175 output the H level signal from the OR circuit 163, that is, the output data 143 and 146 generated at the maximum amplification rate in the present embodiment. That is, the PSD element 12
When the data 143 and 146 used when the illuminance of the laser light is low on the light receiving surface of No. 6 are determined to be light quantity saturation, the above amplification factor is set as one paragraph. The output data 142, 145, that is, the data 142, 145 used when the illuminance of the laser beam is intermediate on the light receiving surface of the PSD element 126 is selected. On the other hand, when an L-level signal is output from the OR circuit 163, that is, when the output data 143 and 146 are not in the light amount saturation state, that is, when the current amplification factor is maintained, P
When the illuminance of the laser beam on the light receiving surface of the SD element 126 is appropriate, the output data 143, 14
Select 6.

Thereafter, the OR operation is performed in the order of the selectors 172 and 176, the selectors 173 and 177, and the selectors 174 and 178.
Based on the output levels of the circuit 162, the OR circuit 164, and the OR circuit 161, the terminal A
Alternatively, the selection of the terminal B is sequentially performed. The selector 1
Output data selected by the selectors 171 and 175 are supplied to terminals B of 72 and 176,
The output data selected by the selectors 172 and 176 is supplied to a terminal B of the selector 177.
The terminal B is supplied with the output data selected by the selectors 173 and 177. Also, selectors 173 and 177
, When the terminal A is selected, that is, the output data 143 and 146 generated at the maximum amplification rate, that is, P
If it is determined that the amount of light is small even for the data 143 and 146 used when the illuminance of the laser beam is low on the light receiving surface of the SD element 126, the data at the terminal A is forcibly set to zero. Further, when the terminal A is selected by the selectors 174 and 178, that is, the output data 141 and 144 generated at the minimum amplification rate, that is, the PSD
Even if the data 141 and 144 used when the illuminance of the laser beam is high on the light receiving surface of the element 126 is determined to be too large, the data at the terminal A is forcibly changed to the maximum value of the 12-bit data. Is set to “4095”.

A more specific operation of the data switching circuit 137 will be described with reference to a timing chart shown in FIG. The output signal of the OR circuit 163 is a signal 181 and the output signal of the OR circuit 162 is a signal 182.
And the output signal of the OR circuit 164 is signal 183,
The output signal of the R circuit 161 is referred to as a signal 184. There are five types of data patterns (1) to (5) in image clock units, and each performs a different operation. In the first section, the amplification factor is 1
Output data 1 generated with the largest A × 10 amplification factor
Since 43 and the data 146 are larger than the lower limit of light amount 100 and are not 4095 which is the light saturation value, both the signal 181 of the OR circuit 163 and the signal 183 of the OR circuit 164 become “L” level. . Therefore, the selector 171 and 175 select the terminal B, and the selector 1
Output data 143 and 146 are supplied to terminals B of 72 and 176. The terminals B are also selected by the selectors 173 and 177. Further, since the output data 142 and 145 and the output data 141 and 144 generated at the amplification factor of A and the amplification factor of A / 10 have not reached the light amount saturation, the signals of the OR circuit 162 and the OR circuit 161 are output. 182 and the signal 184 become “L” level. Accordingly, the terminal B is selected in the selectors 172 and 176, and the selector 17
Output data 143 and 146 are supplied to terminals B of 3,177. Since the terminals B are selected in the selectors 173 and 177 as described above, the output data 143 and 146 are supplied to the terminals B of the selectors 174 and 178. Since the terminal B is selected by the selectors 174 and 178, the output data 104 and 105 of the data switching circuit 137 are output.
Output data 143 and output data 146 are selected and output.

In the section of, both the output data 143 and the output data 146 are not lower than the lower limit of the light amount, that is, 100, so that the signal 183 becomes “L” level. On the other hand, the output data 143 is 4095, which is the light intensity saturation value, and is in the light intensity saturated state, so that the signal 181 becomes “H” level. Since the output data 141, the output data 142, the output data 144, and the output data 145 have not reached the above-mentioned light intensity saturation, the signals 182 and 184 become “L” level. Therefore, in the selectors 171 and 175, the terminal A
Are selected, and the selectors 172 and 176 and the selector 17
3, 177 and the selectors 174, 178 select the terminal B, respectively. Therefore, the output data 142 and the output data 145 are selected and output as the output data 104 and the output data 105, respectively.

In the section (1), since both the output data 143 and the output data 146 are not 100 or less, the signal 183 becomes "L". On the other hand, since the output data 143, the output data 145, and the output data 146 are the above-mentioned 4095 and are in the light amount saturated state, the signal 181 and the signal 18
2 becomes "H" level. Since the output data 141 and the output data 144 have not reached the light amount saturation state,
The signal 184 becomes "L" level. Therefore, selector 1
The terminal A is selected by the selectors 171 and 175 and the selectors 172 and 176.
At 78, the terminals B are respectively selected. Therefore, data 141 and data 144 are selected and output as output data 104 and output data 105, respectively.

In the section (1), the output data 146 is
Since it is 00 or less, the signal 183 becomes “H” level.
Further, the output data 143 and the output data 146, and the output data 142 and the output data 145 are also 100 or less, so that the signals 181 and 182 become "L" level. In addition, since the output data 141 and the output data 144 have not reached the above-mentioned light-saturation state, the signal 184 becomes “L” level. Therefore, the selectors 171 and 17
5. The terminal B is selected by the selectors 172 and 176.
On the other hand, the selector 173, 177 selects the terminal A,
Terminals B are selected by the selectors 174 and 178, respectively. Therefore, the output data 104 and the output data 10
5, "0" is selected and output. Signal 1
When the signal 83 is at the “H” level and the signal 184 is at the “L” level, the fixed value “0” is forcibly output in this manner.
Since the output data 144 has reached the light amount saturation in the section of, “4095” is forcibly selected and output for both the output data 104 and the output data 105. As described above, when the signal 184 is at the “H” level, the fixed value “4” is set.
095 "is output.

Next, the arithmetic unit 107 will be described.
The arithmetic unit 107 performs various processing calculations based on the output data 104, 105, and 106 sent from the three-dimensional sensor 101. The arithmetic unit 3 converts the output data 104 and the output data 105 supplied from the three-dimensional sensor 101 into the actual height of the irregularities, and further calculates the corrected height. A height calculating unit 108 for performing the operation; an origin synchronizing signal 106 indicating the origin of the line scanning of the three-dimensional sensor 101 as a horizontal synchronizing signal; an address generating unit 109 for generating an address 113 to be supplied to the image memory 110; An image memory for storing the irregularities on the measurement surface 102a of the measurement object 102 as three-dimensional image data based on the height data 112 supplied from the height calculation unit 108 and the address 113 supplied from the address generation unit 109 110 and image memory 11
Arithmetic processing unit 1 for performing image processing based on the image data of 0
11 are included. If the movement of the stage 114 is stopped, two-dimensional height data can be stored in the image memory 110. Also, the above actual height dimension is
The distance from a reference height within a range that can be measured by the three-dimensional measuring apparatus 100 in the present embodiment to a surface to be measured on which a laser beam of a measurement target is irradiated.

The height calculator 108 will be described with reference to FIG. The height calculation unit 108 includes an operation unit 191 and
Light intensity saturation detection circuit 192 and light intensity lower limit detection circuit 193
And a data selection circuit 194. The above-described output data 104 and output data 105 output from the three-dimensional sensor 101 are supplied to the arithmetic unit 191.
The reference numeral 91 calculates the actual height of the irregularities on the measured surface 102 a of the electronic component 102 based on the output data 104 and the output data 105, corrects the height, and outputs the result to the terminal A of the data selection circuit 194. However, the result output is 8 bits and has a value of 1 to 254. The output data 104 and the output data 105 described above are also supplied to the light intensity saturation detection circuit 192. When the output data 104 and the output data 105 both have the value “4095”, the light intensity saturation detection circuit 192 outputs the “H” level signal. Otherwise, an “L” level signal is output to the terminal sb of the data selection circuit 194. The output data 104 and the output data 105 described above are also supplied to the light quantity lower limit detection circuit 193. The light quantity lower limit detection circuit 193 outputs an “H” level signal when both the output data 104 and the output data 105 are “0”. Otherwise, an "L" level signal is output to the terminal sc in the data selection circuit 194. The data selection circuit 194 is an 8-bit bus switching circuit, and selects data supplied to the terminals A, B, and C based on the signal levels supplied to the terminals sb and sc. A value of “0” is supplied to the terminal B, and a value of “255” is supplied to the terminal C. In such a data selection circuit 194, the data is supplied to the terminal sb.
When the output level of the light intensity saturation detection circuit 192 is “H”,
When the value of “255” supplied to the terminal B is selected and the output level of the light quantity lower limit detection circuit 193 supplied to the terminal sc is “H”, the value of “0” supplied to the terminal C Is selected, and when an “L” level signal is supplied to both the terminals sb and sc, the output signal of the arithmetic unit 191 supplied to the terminal A is selected.

Accordingly, in the above-mentioned section in FIG. 6, since the output data 104 and the output data 105 are both “0”, the light quantity lower limit detection circuit 193 is set to “H”.
The level is output to the terminal sc, and the data selection circuit 6 selects the terminal C. Therefore, a fixed value “0” appears in the height data 112 sent from the data selection circuit 194. On the other hand, in the above section in FIG. 6, since both the output data 104 and the output data 105 are “4095”, the light intensity saturation detection circuit 192 outputs “H” level to the terminal sb, and the data selection circuit 194 outputs the terminal B Select Therefore, the height data 112 has a fixed value of “255”.
Becomes In the above-mentioned section (1) to (4) in FIG.
Is selected, and the calculation result of the arithmetic unit 191 is output from the data selection circuit 194 as the height data 112. As described above, the values 1 to 254 are stored in the image memory 110, and these values respectively correspond to the height information. By calculating these values, the values from the reference plane to the measured plane are calculated. You can get the distance.

The height data 112 is stored in the image memory 110. Therefore, by checking the value of the image memory 110, if the value is in the range of 1 to 254, it can be determined that the calculation result is normal. On the other hand, if its value is 0
If it is, the light quantity is insufficient, and if it is 255, the light quantity is saturated, that is, it can be determined that it is error data. Therefore, if the processing excluding the error data is performed by the arithmetic processing unit 111, accurate height measurement can be performed.

The operation of the three-dimensional measuring apparatus 100 according to the present embodiment configured as described above will be described. The electronic component 102 to be measured is placed on the stage 114, and the polygon mirror 123 is rotated in the arrow direction as described above, so that the measurement surface 102 of the electronic component 102 is
a is scanned in the X direction by the laser beam 103. At this time, when the scanning is started, the origin of the scanning is set to the origin detection sensor 125.
It is detected by. The laser light reflected by the surface to be measured 102a by the above scanning is received by the PSD element 126,
The light receiving position and the light receiving amount are sent to the output conversion circuit 130 as currents 128 and 129. As described in detail above, the output conversion circuit 130 converts the currents 128 and 129 into voltages, and then amplifies the voltages using a plurality of amplifiers. The optimum voltage value is selected by the data switching circuit 137 from the voltage values thus variously amplified and converted into digital values, and the selected data is calculated as output data 104 and 105 of the three-dimensional sensor 101. The data is sent to the height calculator 108 of the device 107.
Details As described above, the arithmetic unit 107 records the height information of the unevenness on the surface to be measured 102a in the image memory 110 based on the output data 104 and 105. Thus, one scan is completed along the X direction. Next, after the stage 114 is moved by a predetermined amount in the Y direction, scanning in the X direction by rotation of the polygon mirror 123 is started again. Thereafter, scanning in the X direction, measurement,
By repeating the movement in the Y direction, the height of the unevenness is measured for the entire surface to be measured 102a of the electronic component 102.

As described above, in the three-dimensional measuring apparatus 100 of the present embodiment, the output of the PSD element 126 is
After amplification at three different amplification rates, such as 1 ×, A / 10 ×, and A × 10 ×, an optimum value is detected among these. As compared with the above, detection can be performed in a wider range from a state where the reflectance of the laser beam is low to a state where the reflectance is high. Therefore, by increasing the number of amplifiers having different amplification factors, it is possible to detect a wider range. Further, as described above with reference to FIG. 5, the data generated at a high amplification rate is sequentially converted from the data generated at a high amplification rate to data generated at a low amplification rate using selectors 171 to 178 in a stepwise manner. Since the selection is performed, the largest data among the output data necessary for the height calculation can be automatically selected within a range where the light amount is not saturated. Therefore,
The effective value of the output data sent from the three-dimensional sensor 101 increases, and the calculation accuracy also improves. Further, selectors 173, 177 and 174, 1 shown in FIG.
When the light quantity is saturated by the PSD element 126 or when the light quantity becomes equal to or less than the lower limit, the height data is forcibly converted into an error code regardless of the calculated height. Therefore, the arithmetic processing unit 111 in the arithmetic unit 107
Thus, it is possible to determine whether or not error information is included in the image information stored in the image memory 110, and erroneous data is not used in arithmetic processing such as height calculation and position calculation.

In the above-described embodiment, when a plurality of output data 141, data 142, data 143, and the like exist in the measurable range other than the light amount saturated state and the light amount lower limit state, specifically, for example, the selector 171 , 175, the output data 14 generated at the highest amplification rate.
3, 146 is selected, but is not limited to this. Although a structure different from the structure of the data switching circuit 137 shown in FIG. 5 is required, when three or more output data generated at different amplification factors are supplied to the selector, the maximum amplification factor in the selector is considered. Instead of selecting the output data generated by the above, the output data generated by any other amplification factor may be selected.

Further, in the output conversion circuit 130 in the above embodiment, as shown in FIG.
/ V converter 131, amplifier 133, A / D converter 135
, But after digitally converting the voltage generated by the I / V converter 131 by the A / D converter, the digital value is changed in accordance with the amplification factor. Can also. Such circuit changes, and even
In this embodiment, the height information is obtained by hardware processing using a circuit as described above, but the processing operation in the output conversion circuit 130 is configured to be processed by software. Such modifications of the range that can be made by those skilled in the art by using known techniques are included in the scope of the present invention.

[0031]

As described above in detail, according to the three-dimensional measuring apparatus of the first aspect and the three-dimensional measuring method of the second aspect of the present invention, a plurality of amplifying means and a data switching means are provided. The output of the photodetector is amplified to a plurality of amplification factors by the plurality of amplifying means, and when the light amount is not saturated in the photodetector, the maximum output is output from the outputs amplified by the plurality of amplification factors. It was configured to be. Therefore, compared to the conventional one using a single amplification factor, it is possible to detect the height of the laser light in a wide range from low to high reflectivity, and it depends on the surface condition and material of the measured object. However, stable measurement is possible.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a three-dimensional measurement device according to an embodiment of the present invention.

FIG. 2 is a front view showing a configuration of a three-dimensional sensor part shown in FIG.

FIG. 3 is a side view of a three-dimensional sensor part shown in FIG. 2;

FIG. 4 is a block diagram illustrating a configuration of an output conversion circuit illustrated in FIG. 2;

FIG. 5 is a block diagram illustrating a configuration of a data switching circuit illustrated in FIG. 4;

FIG. 6 is an operation timing chart of the data switching circuit shown in FIG. 5;

FIG. 7 is a block diagram showing a configuration of a height calculator shown in FIG.

FIG. 8 is a diagram showing a configuration of a conventional three-dimensional measuring device.

9 is a diagram showing a configuration of the three-dimensional sensor shown in FIG.

10 is a configuration diagram of the output conversion circuit shown in FIG.

FIG. 11 is a diagram for explaining a change in the amount of received laser light.

FIG. 12 is a diagram for explaining a change in the amount of received laser light.

[Explanation of symbols]

100: three-dimensional measuring device, 101: three-dimensional sensor, 10
2 ... measurement object, 102a ... measurement surface, 107 ... arithmetic device, 126 ... photodetector, 130 ... output conversion circuit, 13
3,134 amplifier, 137 data switching circuit.

Claims (7)

[Claims] 1. A photodetector (126) for detecting a laser beam reflected on a surface to be measured (102a), an arithmetic unit (107) for calculating a height of the unevenness of the surface to be measured, and a light detector A conversion unit (130) for converting output information of the detector into information to be supplied to the arithmetic device, wherein the conversion unit converts the output information of the photodetector into a plurality of different pieces of information. A plurality of amplifying means (133, 134) for amplifying at an amplification factor, and, among the output information of the amplifying means, output information in a measurable state other than a light quantity lower limit state or a light quantity saturation state in the photodetector is selected. A three-dimensional measuring device, comprising: a data switching means (137) for transmitting the data to the arithmetic device. 2. When there are a plurality of pieces of output information other than the light quantity lower limit state or the light quantity saturation state, the data switching means sets a maximum amplification factor among all output information sent by the plurality of amplification means. The three-dimensional measurement apparatus according to claim 1, wherein the output information according to (1) is selected and the maximum output information is transmitted to the arithmetic device. 3. The light quantity saturation detecting device (151 to 156) to which the data switching means is supplied with output information of the amplifying means, judges whether the output information is in the light quantity saturated state, and sends out the judgment result. Is provided for each output information of each of the amplifying means, and among the amplifying rates, each output transmitted by an amplifying means having a higher amplifying rate and an amplifying means having an amplifying rate one lower than the amplifying rate is provided. Information, and the determination result transmitted by the light intensity saturation detection device is supplied, and when the output information relating to the higher amplification factor is the light intensity saturation state based on the determination result, the output information relating to the lower amplification factor is output. On the other hand, the first selector (171, 175, 1) that sends out the output information related to the higher amplification factor when the measurement is in the measurable state.
The three-dimensional measurement device according to claim 1 or 2, further comprising (72, 176). 4. The data switching means is further supplied with output information sent by an amplifying means having the highest amplification factor, and forcibly sends error data when the output information is in the light quantity lower limit state. The second selector (1
73, 177) and the third selector (1) which forcibly sends error data when the output information sent by the amplifying means having the lowest amplification rate is in the light quantity saturation state.
74, 178). The three-dimensional measuring apparatus according to claim 3, further comprising: 5. A three-dimensional measuring method, comprising detecting a laser beam reflected on a surface to be measured (102a), and converting the detected laser beam into height information on the unevenness of the surface to be measured. The information corresponding to the detected light amount of the laser light is amplified by a plurality of amplification factors, and the output information in which the information corresponding to the detected light amount of the laser light is in a measurable state other than the light amount lower limit state or the light amount saturated state is selected. And a step of using the information for calculating the height information. 6. The method according to claim 5, wherein when there are a plurality of output information in the measurable state, the maximum output information relating to the amplification factor is selected and the maximum output information is used for calculating the height information. 3D measurement method. 7. The three-dimensional measurement method according to claim 5, wherein error information is forcibly transmitted when the information corresponding to the detected light amount of the laser light is the light amount lower limit state or the light amount saturated state.