JPH04221705A - Visual inspection device - Google Patents

Abstract

PURPOSE:To enable correct visual inspection by correctly measuring the height of a substrate. CONSTITUTION:A light scanning means 1 is adapted to apply optical beams substantially vertically or obliquely to a sample 2 in which parts are mounted on a substrate having diffuse transmission, and a light irradiation point is scanned on the sample 2. A height/brightness measuring means 3 is adapted to make scattered light from the light irradiation point into image for the substantially vertically irradiation and make regular reflection light from the irradiation point into an image for the oblique irradiation and measure the height and brightness of the light irradiation point from the position and brightness of an image formation point concerning each image formation point. A substrate judging means 4 judges whether the light irradiation point is on a substrate 2a or not from the measured brightness. A height select means 5 is adapted to select a height measured by oblique irradiation in a portion where the light irradiation point is judged to be on a substrate 2b by the means 4 and select a height measured by the substantially vertical irradiation in a portion where the light irradiation point is judged to be not on the substrate 2a by the means 4. A correct visual inspection can be made by using the selected height.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an appearance inspection apparatus for inspecting the appearance of a sample having components mounted on a diffusely transparent substrate.

0002

2. Description of the Related Art FIG. 10 shows a light scanning optical system of a conventional visual inspection apparatus.

[0003] A sample 2 to be inspected has a surface-mounted component 2b mounted on a multilayer substrate 2a made of glass epoxy, ceramic, or the like having diffusion transmittance. This sample 2
is placed on an XY stage 12, and a light scanning optical system is placed above the sample 2.

A laser beam emitted from the laser 14 is reflected by a galvano mirror 16a of a galvano scanner 16, passes through an fθ lens 18, and is focused and irradiated onto the sample 2 substantially perpendicularly. The scattered light from the irradiation point is transmitted through the imaging lens 20
a and is imaged onto a optical position detector (PSD) 20b. By processing the output signal of this PSD 20b, the height and brightness of the light irradiation point are measured. In addition, by shaking the galvano mirror 16a with the rotary vibrator 16b of the galvano scanner 16, the light irradiation point is main-scanned on the sample 2, and by driving the X-Y stage 12 one step for each scan, The light irradiation point is sub-scanned.

As shown in FIG. 5(A), a silk-screen printing section 2c for forming marks and a copper wiring pattern section 2d are provided on the multilayer substrate 2a. The imaging device 20 is shown in FIG.
It is equipped with an imaging lens 20a and a PSD 20b shown in FIG. FIGS. 5(B) and 5(C) show changes in height and brightness when the light irradiation point is scanned on this sample 2.

[0006]

[Problems to be Solved by the Invention] Conventional visual inspection devices have been unable to accurately measure the height of the multilayer substrate 2a. The dotted line in FIG. 5(B) indicates the true height of the multilayer substrate 2a.

The reason why it was not possible to accurately measure the height of the multilayer substrate 2a is that the incident light permeates into the multilayer substrate 2a, as shown in FIG. This is because the scattered light from inside the multilayer substrate 2a is imaged on the PSD 20b shown in FIG. 10, and the PSD 20b outputs a signal of the average position. If the penetration depth of the light incident on the multilayer substrate 2a is constant, the height of the multilayer substrate 2a can be corrected, but this depth depends on the material of the multilayer substrate 2a and the multilayer substrate below the light irradiation point. It cannot be corrected accurately because it differs depending on whether or not the wiring pattern portion 2d exists inside the wiring pattern portion 2a. Since the height of the surface mount type component 2b is measured based on the height of the multilayer board 2a, it is necessary to accurately measure the height of the multilayer board 2a regardless of the material or part of the multilayer board 2a. .

SUMMARY OF THE INVENTION In view of these problems, it is an object of the present invention to provide an appearance inspection apparatus that can more accurately measure the height of a substrate, thereby making it possible to perform inspections more accurately.

[0009]

[Means for Solving the Problems and Their Effects] FIG. 1 shows the basic configuration of an appearance inspection apparatus according to the present invention.

[0010] This visual inspection device is equipped with the following components.

Reference numeral 1 denotes a light scanning means, which irradiates a light beam approximately perpendicularly and obliquely to a sample 2 on which components are mounted on a diffusely transparent substrate, and scans the light irradiation point on the sample 2.

3 is a height/brightness measuring means, which forms an image of scattered light from the light irradiation point for the substantially vertical irradiation;
For the oblique irradiation, specularly reflected light from the irradiation point is imaged, and the height and brightness of each imaged point are measured from the position and brightness of the imaged point.

Reference numeral 4 denotes a substrate determining means, which determines from the measured brightness whether or not the light irradiation point is on the substrate 2a. The brightness may be measured by at least one of the substantially vertical irradiation and the oblique irradiation.

Reference numeral 5 denotes height selection means, and board determination means 4
For the portion determined to be on the substrate 2a by the method, the height measured by the oblique irradiation is selected, and for the portion determined by the substrate determination means 4 to be not on the substrate 2a, the height measured by the approximately vertical irradiation is selected. Select height.

[0015] The present invention equipped with such components performs an external appearance inspection of the sample using the selected height.

Next, the operation of the present invention will be explained based on FIG. 2.

When the sample surface A1 is at the standard height, the laser beams LA and LB form a light irradiation point on the same point P1 on the sample surface A1, and the scattered light from the point P1 is transmitted to the imaging lens 20a, for example. An optical system is arranged so that the image is formed on point Q1 on the PSD 20b through the light. For sample surface A2 higher than sample surface A1, laser beams LA and LB
The two light irradiation points on the sample surface A2 do not coincide, and become points P2 and P3, respectively. The scattered lights from points P2 and P3 pass through the imaging lens 20a and are focused on points Q2 and Q3, respectively.

Since the laser beam LA is perpendicular to the sample surface, the light irradiation point is the same regardless of the height of the sample surface.
preferable. However, when the laser beam LA irradiates the substrate 2a having diffuse transmittance, the laser beam LA
seeps into the substrate 2a, and the scattered light is also emitted from the inside of the substrate 2a, making the height of the surface-mounted component 2b measured by the PSD 20b inaccurate.

On the other hand, since the light irradiation point formed on the sample surface by the laser beam LB changes depending on the height of the sample surface,
Undesirable. However, the specularly reflected light, which is considerably stronger than the scattered light, passes through the imaging lens 20a and is imaged on the PSD 20b, so the scattered light from within the substrate 2a can be ignored. Therefore, the height of the substrate 2a can be measured more accurately.

The height of the component 2b differs depending on the location due to its warpage, but for example, as shown in points P2 and P3 in FIG. are close to each other, so even if it is assumed that the heights of points P2 and P3 are the same, the error can be ignored.

In the present invention, the height of the substrate 2a is determined by using the laser beam LB that obliquely irradiates the sample 2, and the heights of other parts, such as the component 2b, the silk-printed part 2c, the wiring pattern part 2d, etc. are determined by: Since the laser beam LA is used, which is irradiated substantially perpendicularly to the sample 2, the height of the substrate can be measured more accurately than in the past, and thereby the appearance inspection can be performed more accurately.

The optical scanning means 1, for example, alternately irradiates the sample 2 with a light beam approximately perpendicularly and obliquely.

In this configuration, the height/brightness measuring means 3
Since only one imaging device is required to image the scattered light from the light irradiation point for the substantially vertical irradiation and to image the regular reflected light from the light irradiation point for the oblique irradiation, the hardware configuration is simple. It gets easier.

The optical scanning means 1 includes, for example, a double-sided galvano mirror, a light source that irradiates light beams from opposite directions to both sides of the double-sided galvano mirror, and one of the light beams reflected by the galvano mirror. Fold sample 2
It has a first fixed mirror that irradiates the light beam substantially perpendicularly to the galvano mirror, and a second fixed mirror that bends the other light beam reflected by the galvanometer mirror and irradiates the sample 2 from an oblique direction. Two light sources may be used as shown in FIG.
It is also possible to use only one, split the light beam into two with a beam splitter, bend the light beam with a mirror, and irradiate the double-sided galvano mirror with the light beams from opposite directions.

In the case of this configuration, only one galvano mirror needs to be used, and there is no need to synchronize the two optical scanning devices, so the configuration is simplified.

The optical scanning means 1, for example, irradiates the sample 2 with a light beam of wavelength λ1 substantially perpendicularly, and λ2≠λ1.
A light beam with a wavelength λ2 is irradiated obliquely, and the height/brightness measuring means 3 transmits the light with the wavelength λ1 and blocks the light with the wavelength λ2, which is the scattered light from the light irradiation point for the substantially vertical irradiation. A first imaging device that forms an image through a filter and specularly reflected light from a light irradiation point for the oblique irradiation with a wavelength λ
and a second imaging device that forms an image through a filter that transmits light of wavelength λ1 and blocks light of wavelength λ1.

[0027] With this configuration, since the vertical irradiation and oblique irradiation laser beams can be scanned simultaneously, the appearance inspection can be performed at high speed.

The substrate determining means is, for example, a window comparator that determines whether the measured brightness is within a reference range, and the height selecting means 5, based on the determination result of the window comparator, This is a selector for selecting the height measured by the substantially vertical irradiation and the height measured by the oblique irradiation.

In this configuration, the software configuration is simplified and the processing speed is improved, so that visual inspection can be performed at high speed.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the visual inspection apparatus according to the present invention will be described based on the drawings.

(1) First Embodiment FIG. 3 shows the overall configuration of a visual inspection apparatus according to a first embodiment. Components that are the same as those in Sample 2 are given the same reference numerals and their explanations will be omitted.

An optical scanning device 22A is arranged above the sample 2. The optical scanning device 22A bends the laser beam emitted from the laser 14 to form a laser beam LA, vertically irradiates the sample 2 with the laser beam LA, and converges the laser beam onto the sample 2.
In addition, the light irradiation point is scanned in a direction perpendicular to the paper surface. An optical scanning device 22B is arranged on the side of the optical scanning device 22A. The optical scanning device 22B bends the laser beam emitted from the laser 14B to form a laser beam LB, irradiates the sample 2 with the laser beam at an incident angle θ, and converges the laser beam onto the sample 2.
Also, the irradiation point is scanned in a direction perpendicular to the paper surface. This angle of incidence θ is equal to the angle θ between the optical axis of the imaging lens 20a and the normal to the multilayer substrate 2a. Optical scanning devices 22A and 22
B is arranged so that the light cutting lines formed by scanning the light irradiation points coincide with the multilayer substrate 2a of standard height.

[0033] The optical scanning devices 22A and 22B each have
For example, it is an apparatus using a galvano scanner 16, a hologram disk, a polygon mirror, etc. shown in FIG. In this embodiment, a case will be described in which the optical scanning devices 22A and 22B are galvano scanners.

The clock generator 24 divides the clock CK0 and outputs the clock CK as shown in FIG. 4(A),
Based on this, the optical scanning control circuit 26 operates as shown in FIGS.
A scanning signal S1 and laser on/off signals S2 and S3 as shown in C) and (D) are generated. Then, the scanning signal S1 is supplied to the driver 28, and the laser on/off signal S
2 and S3 are supplied to lasers 14A and 14B, respectively. The driver 28 amplifies this scanning signal S1 and supplies it to the optical scanning devices 22A and 22B.

As a result, the optical scanning device 22A scans the sample 2 downward in the plane of the paper with the positive slope portion of the triangular wave of the scanning signal S1, and then the optical scanning device 22B scans the specimen 2 with the negative slope portion of the triangular wave. scans the sample 2 in the upward direction of the paper. Thereafter, the X-Y stage 12 is driven one step in the left-right direction in FIG. 3 until the next positive inclination start point of the scanning signal S1.

The output signal of the PSD 20b is supplied to the height calculation circuit 32 and the brightness calculation circuit 34, and
The height H and brightness I of the light irradiation point formed by 2A and 22B are determined. The height H and the brightness I are stored in a height image storage section 36a and a brightness image storage section 36b of the computer 36, respectively. In FIG. 3, the configuration of the computer 36 is shown by functional blocks 36a to 36f. The storage addresses of the height image storage section 36a and the brightness image storage section 36b are generated by a circuit (not shown) based on the clock CK0 and the pulses that drive the XY stage 12.

The reference range determining unit 36c determines the optical scanning based on the value of the brightness I when optically scanning a specific part on the multilayer board 2a where the surface mount type component 2b, the silk-printed part 2c, and the wiring pattern part 2d are not present. For each of the optical scanning by the devices 22A and 22B, the lower limit value I as shown in FIG.
11. Determine an upper limit value I12, a lower limit value I21, and an upper limit value I22 as shown in FIG. 6(C). These upper and lower limits are
For example, it is determined as a value of ±10% of the average value of brightness I. Moreover, the same value is used for these upper and lower limit values for the entire scanning range on the sample 2 thereafter.

The height correction section 36d includes the brightness image storage section 3.
From the image stored in 6b, ranges R11 and R12, etc. between the lower limit value I11 and the upper limit value I12 shown in FIG.
The ranges R21 and R22, etc. between the lower limit value I21 and the upper limit value I22 shown in FIG. 6(C) are determined, and the common ranges R01 and R02, etc. between the two are determined as shown in FIG. 6(B). The height H within these common ranges is shown in Figure 6 (
The height H shown in B) is read out from the height image storage section 36a and stored in the height image storage section 36e. In addition, Fig. 5 (C
), the range where I>I12 is shown in Figure 5 (
The height H shown in B) is read out from the height image storage section 36a and stored in the height image storage section 36e. Since the height H in other ranges has low accuracy, a code indicating that the height is undefined is stored in the height image storage section 36e. This storage is performed by initializing the height image storage section 36e with the code.

The inspection section 36f has a brightness image storage section 36b.
And based on the image stored in the height image storage section 36e,
Use the same method as before to remove solder bridges and loose leads.
Inspects the presence or absence of soldering, etc., and outputs the results.

In FIG. 2, when the sample surface A1 is at the standard height, the laser beams LA and LB are at the same point P on the sample surface A1.
An optical system is arranged so that a light irradiation point is formed on PSD 20b, and the scattered light from point P1 passes through the imaging lens 20a and forms an image on point Q1 on PSD 20b. For sample surface A2 higher than sample surface A1, laser beams LA and L
The two light irradiation points on the sample surface A2 by B do not coincide, and become points P2 and P3, respectively. The scattered lights from points P2 and P3 respectively pass through the imaging lens 20a and reach the point Q2.
and Q3.

Since the laser beam LA is perpendicular to the sample surface, the light irradiation point is the same regardless of the height of the sample surface.
preferable. However, when the laser beam LA irradiates onto the multilayer substrate 2a having diffuse transmittance, the laser beam LA permeates into the multilayer substrate 2a and the scattered light is transmitted to the multilayer substrate 2a.
The height of the surface-mounted component 2b measured by the PSD 20b becomes inaccurate.

On the other hand, since the light irradiation point formed on the sample surface by the laser beam LB changes depending on the height of the sample surface,
Undesirable. However, since the specularly reflected light, which is much stronger than the scattered light, passes through the imaging lens 20a and is imaged on the PSD 20b, the scattered light from within the multilayer substrate 2a can be ignored. Therefore, the height of the multilayer substrate 2a can be measured more accurately.

The height of the surface mount type component 2b differs depending on the location due to its warpage, but for example, as shown in points P2 and P3 shown in FIG. Since the irradiation points are close to each other, the error can be ignored even if it is assumed that the heights of points P2 and P3 are the same.

In this embodiment, the height of the multilayer substrate 2a is determined using the laser beam LA from the optical scanning device 22A.
Since the heights of the surface-mounted component 2b, the silk-printed part 2c, and the wiring pattern part 2d are determined using the laser beam LB from the optical scanning device 22B, the height of the sample 2 can be measured more accurately than with conventional devices. I can do it. This makes the quality determination in the inspection section 36f more accurate.

(2) Second Embodiment FIG. 7 shows a light scanning optical system of a visual inspection apparatus according to a second embodiment. The same figure (A) is a top view, and the same figure (B) is a front view.

Lasers 14A and 14B are arranged opposite to each other via a double-sided galvano mirror 16a' of the galvano scanner 16. The galvano scanner 16 is arranged so that the axis of rotation of its rotary vibrator 16b is perpendicular to the sample 2. Further, fixed mirrors 38A and 38B are arranged at positions perpendicular to the optical axes of the lasers 14A and 14B via the double-sided galvanometer mirror 16a'. fθ lenses 18A and 18B are arranged diagonally below the fixed mirror 38A and directly below the fixed mirror 38B, respectively.

Lasers 14A and 14B are alternately turned on and off as in the first embodiment. That is, when the double-sided galvano mirror 16a' is rotating in one direction, the laser 14A is turned on, and the double-sided galvano mirror 16a'
The rotary vibrator 16b is turned on when the is rotating in the other direction.

The laser beam emitted from the laser 14A is reflected by the double-sided galvano mirror 16a' and the fixed mirror 38A, passes through the fθ lens 18A, is vertically irradiated onto the sample 2, and is converged onto the sample 2. The laser beam emitted from the laser 14B is transmitted to the double-sided galvano mirror 16.
a', reflected by fixed mirror 38B, fθ lens 18B
The light beam is irradiated onto the sample 2 at an incident angle θ and is focused onto the sample 2.

[0049] Such a light scanning optical system uses a multilayer substrate 2a.
It is arranged so that both optical cutting lines formed on the sample 2 by the laser beams LA and LB coincide when the laser beams LA and LB are at a standard height.

In the second embodiment, the galvano scanner 16
It is only necessary to use one optical scanning device, and since there is no need to operate two optical scanning devices synchronously as in the first embodiment, there is an advantage that the configuration is simpler than in the first embodiment. .

(3) Third Embodiment FIG. 8 shows the overall configuration of a visual inspection apparatus according to a third embodiment. Components that are the same as those in FIG. 3 are given the same reference numerals and their explanations will be omitted.

In this third embodiment, in addition to the imaging lens 20a and PSD 20b, another set of imaging lens 40a and PSD 40b is arranged. The optical axis of the imaging lens 40a is the same as that of the imaging lens 2 when the multilayer substrate 2a has a standard height.
It is arranged so as to intersect with the optical axis of 0a on the multilayer substrate 2a.

An interference filter 42a is arranged between the imaging lens 20a and the PSD 20b, and the imaging lens 40a
An interference filter 42b is arranged between the PSD 40b and the PSD 40b. The center wavelength of the interference filter 42a is
The interference filter 42 matches the wavelength of the laser beam LA.
The passage center wavelength of b matches the wavelength of the laser beam LB.

Therefore, the light irradiation point on the sample 2 by the laser beam LA is imaged only on the PSD 40b, and the light irradiation point on the sample 2 by the laser beam LB is focused on the PSD 20b.
The image is formed only on b. For this reason, the lasers 14A and 1
4B can be always turned on to simultaneously scan the laser beams LA and LB.

In the third embodiment, since the laser beams LA and LB can be scanned simultaneously, there is an advantage that the appearance inspection can be performed faster than in the first embodiment.

(4) Fourth Embodiment FIG. 9 shows a height correction circuit of a visual inspection apparatus according to a fourth embodiment. In this embodiment, the height correction of the third embodiment is performed using a hardware configuration.

That is, the brightness IA is supplied from the brightness calculation circuit 34A to the window comparator 48A, and the window comparator 48A makes its output high level when I21≦IA≦I22. Similarly, brightness calculation circuit 3
The brightness IB is supplied from 4B to the window comparator 48B, and the window comparator 48B
When ≦I12, the output is set to high level. The outputs of the window comparators 48A and 48B are supplied to an AND gate 50, and the output of the AND gate 50 causes a selector 52 to be output.
is controlled to switch. The selector 52 is connected to the height calculation circuit 32
The height HA output from A and the height HB output from the height calculation circuit 32B are selectively supplied to the height image storage section 46e of the computer 46 shown in FIG. The other points are the same as the third embodiment.

In the fourth embodiment, by providing such a configuration, the height image storage sections 46a1 and 4 shown in FIG.
6a2, brightness image storage unit 46b2, reference range determination unit 4
6c and the height correction unit 46d are not required, and there is an advantage that the processing speed of the computer 46 can be improved compared to the third embodiment.

[0059]

As explained above, in the appearance inspection apparatus according to the present invention, a light beam is irradiated substantially perpendicularly and obliquely to a sample in which components are mounted on a substrate having diffuse transmittance. For oblique irradiation, the scattered light from the irradiation point is imaged, and for oblique irradiation, the specularly reflected light from the irradiation point is imaged, and the height and brightness of the light irradiation point are determined from the position and brightness of each image formation point. For parts where it is determined that the light irradiation point is on the substrate based on the brightness, the height measured by oblique irradiation is selected, and for other parts, the height measured by approximately vertical irradiation is selected. Since this method is selected, the advantages of both vertical irradiation and oblique irradiation are organically utilized, and the height of the board can be measured more accurately than before, which is an excellent effect and contributes to improving the quality of visual inspection. There's a lot to do.

If the optical scanning means is configured to alternately irradiate the sample with a light beam approximately perpendicularly and obliquely, only one image pickup device is required, so that the hardware configuration can be simplified. play.

The optical scanning means includes a double-sided galvano mirror, a light source that irradiates light beams from opposite directions to both sides of the double-sided galvano mirror, and one light beam reflected by the galvano mirror that is bent to approximately strike the sample. If it is composed of a first fixed mirror that irradiates vertically and a second fixed mirror that bends the other light beam reflected by the galvanometer mirror and irradiates the sample from an oblique direction, the galvanometer mirror can be
It is sufficient to use only one optical scanning device, and there is no need to synchronize the two optical scanning devices for this purpose, resulting in an effect that the configuration is simplified.

The light scanning means irradiates the sample with a light beam of wavelength λ1 substantially perpendicularly, the light beam of wavelength λ2 where λ2≠λ1 irradiates the sample obliquely, and the height/brightness measuring means irradiates the sample almost vertically. a first imaging device that images the scattered light from the light irradiation point for the oblique irradiation through a filter that transmits the light with the wavelength λ1 and blocks the light of the wavelength λ2; If configured with a second imaging device that forms an image through a filter that transmits light with wavelength λ2 and blocks light with wavelength λ1, it is possible to scan vertically and obliquely irradiated laser beams simultaneously, making it possible to perform visual inspections. This has the effect of being able to perform the process at high speed.

The board determining means is composed of a window comparator that determines whether the measured brightness is within a reference range, and the height selecting means is configured to perform measurement by approximately vertical irradiation based on the determination result of the window comparator. If the software is configured with a selector that selects the height measured by the measured height and the height measured by oblique irradiation, the software configuration will be simplified and the processing speed will be improved, resulting in the ability to perform visual inspections at high speed. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the principle configuration of a visual inspection device according to the present invention.

FIG. 2 is an optical path diagram for explaining the operation of the present invention.

FIG. 3 is a block diagram of the visual inspection apparatus of the first embodiment.

FIG. 4 is a waveform diagram of an optical scanning control signal.

FIG. 5 (A) shows the cross-sectional shape of the sample, and (B) shows the change in height when the sample is irradiated with a laser beam perpendicularly and the light irradiation point is scanned along this cross-section; (C) is a diagram showing changes in brightness when scanning is performed in the same manner.

FIG. 6 (A) shows the cross-sectional shape of the sample, and (B) shows the change in height when the sample is irradiated with a laser beam obliquely and the light irradiation point is scanned along this cross section; (C)
is a diagram showing changes in brightness when scanning is performed in the same manner.

FIG. 7 shows a light scanning optical system of a visual inspection apparatus according to a second embodiment, in which (A) is a plan view and (B) is a front view.

FIG. 8 is a block diagram of a visual inspection device according to a third embodiment.

FIG. 9 is a height correction circuit diagram of the visual inspection apparatus of the fourth embodiment.

FIG. 10 is a perspective view showing a light scanning optical system of a conventional visual inspection apparatus.

FIG. 11 is a cross-sectional view of a sample showing the cause of height detection error by a conventional device.

[Explanation of symbols]

2a Multilayer board 2b Surface-mounted component 2c Silk printing section 2d Wiring pattern section 14, 14A, 14B Laser 16a Galvano mirror 16a' Double-sided galvano mirror 18, 18A, 18B fθ lens 20 Imaging device 20a, 40a Imaging lens 20b, 40b PSD 22A, 22B Optical scanning device 36, 46 Computer 36a, 36e, 46a1, 46a2, 46e Height image storage section 36b, 46b1, 46b2 Brightness image storage section 36
c, 46c Reference range determination section 36d, 46d Height correction section 36f Inspection section 38A, 38B Fixed mirror 42a, 42b Interference filter 48A, 48B Window comparator 50 AND gate 52 Selector

Claims (5)

[Claims] Claim 1: A light beam is irradiated substantially perpendicularly and obliquely to a sample (2) in which a component (2b) is mounted on a substrate (2a) having diffuse transmittance, and the light irradiation point is scanned on the sample. A light scanning means (1) forms an image of scattered light from the light irradiation point for the substantially vertical irradiation, forms an image of specularly reflected light from the irradiation point for the oblique irradiation, and height/brightness measuring means (3) for measuring the height and brightness of the light irradiation point from the position and brightness of the image formation point; A substrate determining means (4) that determines whether or not the part is on the substrate, and the height measured by the oblique irradiation is selected for the part determined to be on the substrate, and the height measured by the oblique irradiation is selected. The part includes a height selection means (5) for selecting a height measured by the substantially vertical irradiation, and the selected height is used to conduct an appearance inspection of the sample. Inspection equipment. 2. The optical scanning means (1) scans the sample (
2) is alternately irradiated with a light beam substantially vertically and diagonally, and the height/brightness measuring means (3) forms an image of the scattered light from the light irradiation point for the substantially vertical irradiation, and 2. The external appearance inspection apparatus according to claim 1, further comprising one imaging device that forms an image of specularly reflected light from a light irradiation point. 3. The light scanning means (1) includes a double-sided galvanometer mirror (16a') and a light source (that irradiates light beams from opposite directions to both sides of the double-sided galvanometer mirror).
14A, 14B), a first fixed mirror (38A) that bends one of the light beams reflected by the galvanometer mirror and irradiates the sample (2) approximately perpendicularly, and the other light beam reflected by the galvanometer mirror. 3. The visual inspection apparatus according to claim 1, further comprising a second fixed mirror (38B) that bends the beam and irradiates the sample from an oblique direction. 4. The optical scanning means (1) scans the sample (
2), a light beam of wavelength λ1 is irradiated almost perpendicularly, and λ
2≠λ1, and the height/brightness measuring means (3) transmits the scattered light from the light irradiation point with respect to the substantially vertical irradiation, and transmits the light with the wavelength λ1 to determine the wavelength. A first imaging device (40a, 40b, 42B) that forms an image through a filter that blocks light of wavelength λ2, and specularly reflected light from the light irradiation point for the oblique irradiation, transmits light of wavelength λ2 and forms an image of light of wavelength λ1. a second imaging device (20a, 20b, 42A) that forms an image through a filter that blocks light;
Any one of claims 1 to 3, characterized in that it has
Appearance inspection device described in. 5. The substrate (2a) determining means is a window comparator (48A, 48B) that determines whether the measured brightness is within a reference range, and the height selecting means (5) is a , a selector (52) for selecting the height measured by the substantially vertical irradiation and the height measured by the oblique irradiation based on the determination result of the window comparator. The appearance inspection device described.