JP3314781B2 - Appearance inspection method of soldered part - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for inspecting the appearance of a soldered portion for inspecting a soldered portion of a printed circuit board or the like.

[0002]

2. Description of the Related Art As a conventional appearance inspection apparatus for a soldered portion, there is known an apparatus as disclosed in Japanese Patent Application Laid-Open No. 58-60593. In this method, a spot-like spot is illuminated on a soldered portion, and the spot is scanned to extract a light cutting line of the soldered portion.

According to this method, the cross-sectional shape of the solder can be measured regardless of the state of the solder surface, so that defects such as no solder or excessive solder can be inspected.

[0004] Japanese Patent Application Laid-Open No. 61-122022 introduces an apparatus capable of measuring a three-dimensional shape using a confocal optical system. In this method, a two-dimensional image is created from a light intensity signal detected by scanning a light beam in a plane perpendicular to a traveling direction in an xy direction, and a stage on which a sample is mounted is further scanned in a Z direction. The value of Z that maximizes the light intensity detected for each (x, y) coordinate is obtained, and thereby, Z
This is to detect the profile in the direction.

[0005]

In the former prior art,
Since only the cross-sectional shape of the solder surface is used, there was a problem that the amount of solder could not be measured and the evaluation of excessive or insufficient solder could not be accurately performed.

Further, the latter prior art has a problem that the measurement range is small because it is a microscope utilizing the high resolution of the confocal optical system. Also, since the solder surface is close to the mirror surface, the reflected light will not return to the detector depending on the angle of the measurement surface, and depending on the angle, almost 100%
Return to the detector. Therefore, there is a problem that a dynamic range of many digits is required for the detector.

[0007] An object of the present invention is to solve the above problems.
A method for inspecting the appearance of a soldered part, which determines the three-dimensional shape of the soldered part, and enables high-speed, high-reliability inspection of defects such as no solder, too much or too little solder, and short-circuiting of the soldered part. It is to provide a device.

[0008]

According to the present invention, in order to achieve the above object, in a method for inspecting the appearance of a soldered portion, a table is driven based on position coordinate data stored in advance and placed on the table. A desired area including a region where the electronic component is solder-connected to the surface of the substrate is soldered into a field of view of the microscope, and a laser beam emitted from a laser light source to a desired area of the substrate within the field of view of the microscope Irradiates and scans, irradiates a laser beam and takes an image of the scanned area through a microscope, and, from the image of the desired area of the board obtained by the imaging, obtains a three-dimensional image of the area where the electronic components of the board are connected by soldering. Shape information is obtained, and the state of the solder connection of the electronic component to the substrate is inspected based on the obtained three-dimensional shape information of the region where the electronic component is soldered.

In the present invention, the laser beam is scanned in two directions using a galvanometer mirror. The microscope used in the present invention is a confocal microscope, and an image of a desired area is obtained by imaging an area in the field of view of the confocal microscope via a polarizing element or a spatial filter.

According to the present invention, in a visual inspection method, a desired region of a sample is imaged to obtain an image of the desired region, the image is stored, and the stored image is processed to process the desired region of the sample. Are obtained, and the image of the desired area is classified based on the obtained feature amounts.

[0011]

By the way, the surface of the solder sample 14 has minute irregularities, and the scattered reflected light scattered and reflected from the surface of the solder sample contains 9 to 10% of linearly polarized light (S-polarized light).
The light is converted into a polarized light component (P-polarized light) in a direction rotated by 0 °. Further, since the surface of the solder sample 14 has minute irregularities, light scattered to a direction of -180 ° with respect to the incident direction exists. In the present invention, low N.I. A. The use of polarized light with the objective lens of (1), the dynamic range required by the detection system to simultaneously detect both the case where specular reflected light enters the detection system and the case where it does not enter is 3 to 4 digits. Can be reduced. Therefore, even when the surface of the solder sample when scanning in the Z direction is close to the mirror surface, the intensity of light detected from the solder sample can be increased, and the inspection means can correctly determine the peak position of the signal obtained from the sensor. As a result, the three-dimensional shape of the surface of the solder sample can be calculated correctly.

Further, the shading of the specularly reflected light can be realized by a spatial filter without using a polarizing element.

When detecting the surface shape of a solder sample,
In order to increase the intensity of scattered light generated by minute irregularities on the surface of the solder sample and reduce the component of specular reflection light, the wavelength of illumination light should be shorter than visible light, including visible light (700 to 400 nm) ( 700 nm or less).

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the method and apparatus for inspecting the appearance of solder according to the present invention will be described below with reference to FIGS. That is, the soldering appearance inspection method and apparatus of the present invention are roughly classified into a stage section 10, a scanning light creation section 30,
It comprises an optical system section 50, a detection section 70, and a detection signal processing section 90. The stage 10 includes a sample support 11 for mounting and supporting a sample 14 having a three-dimensional soldering portion, and an XYZ stage for mounting the sample support 11 and moving in the X, Y, and Z directions. 12 and X, Y, Z stage 12
XY stage controller 13 for controlling The X, Y, and Z stage controller 13 automatically carries a previously programmed inspection location of the sample 14 to an inspection area of the optical system unit 50 based on a signal from the microcomputer 91 in the detection signal processing unit 90 (positioning). Do). The scanning light generation unit 30 includes, for example, He-Ne
Laser light source 31, beam expander 32, X scanning drive system (X scanning drive source and its control device) 36, X scanning mirror 33, polarization beam splitter 34, Y scanning drive system (Y
Scanning drive source and its control device) 37, Y scanning mirror 35
It is composed of Here, for example, a He-Ne laser light source 3
In addition, it is desirable that the laser light source 1 output short-wavelength laser light such as an Ar laser light source or a He—Cd laser light source. That is, as the laser light source 31, visible light (700 to 40
It is desirable to emit a laser beam having a wavelength (700 nm or less) shorter than visible light, including 0 nm). However, for inspecting the three-dimensional shape of the soldered portion as in the present invention, He-Ne laser light (633 nm) is sufficient. The beam expander 32 is for transmitting a light beam having a specific spread to the optical system unit 50. The spread of the light beam is determined by the N.D. of incident light, which is the core of the idea of the present invention. A. (NumericalAperture). The X-scanning drive system 36, the Y-scanning drive system 37, the X-scanning mirror 33, and the Y-scanning mirror 35 use galvanometer mirrors here, but need not be galvanometer mirrors, and may be polygon mirrors, holographic scanners, Other optical scanning means such as an optical element may be used. Further, in order to enlarge the scanning range and enlarge the field of view, the Y scanning mirror 35 used is long in the X direction. This can also be made shorter in other scanning directions. Also, as shown in FIG.
It is also possible to adopt a configuration in which the scanning drive system 36 performs rotational scanning, and this system further performs rotational scanning with the Y scanning drive system 37. This method requires high reproducibility of the X scanning drive system 36. In other words, the method shown in FIG.
Since the coordinates are determined, there is an advantage that high reproducibility is not required for the X scanning drive system 36.

The optical system 50 includes a condenser lens 51, a field lens 52, an objective lens 53, and a Z-direction scanning lens 5.
4 and a Z-direction scanning drive system 55 for moving and scanning the Z-direction scanning lens 54 in the Z direction.

The light scanned in the X and Y directions by the scanning light generator 30 is condensed by a condenser lens 51 to a field lens 5.
2 are collected. This image is formed near the solder sample 14 by the objective lens 53 and the Z-direction scanning lens 54.

Here, the light beam between the objective lens 53 and the Z-direction scanning lens 54 is designed to be a parallel light beam. Thus, the distance L from the Z-direction scanning lens 54 to the focal point near the sample is always kept constant. That is, by scanning the Z-direction scanning lens 54 in the Z direction, the relative position in the Z direction between the solder sample 14 and the focal point can be scanned (moved).

However, it is not always necessary to use the Z-direction scanning lens 54 for scanning in the Z-direction, and the objective lens 53 and the Z-direction scanning lens 54 are fixed as one lens, and scanning (moving) in the Z-direction is performed. Is X, Y, Z
The Z stage of the stage 12 may be used.

The condenser lens 51 and the field lens 52 are for obtaining a necessary observation field of view. However, if a sufficient field of view can be obtained, the objective lens 53 is directly used without using the condenser lens 51 and the field lens 52.
Obviously, the light may be incident on

The detecting section 70 comprises an imaging lens 71 and a one-dimensional linear sensor 72. Here, the imaging lens 7
1 is combined with a Z-direction scanning lens 54, an objective lens 53, a field lens 52, and a condenser lens 51, and the light-converging position near the sample and the light-receiving surface of the detector (one-dimensional linear sensor) 72 have a conjugate relationship. That is, they have an image forming relationship. That is, the above optical system forms a confocal optical system. The one-dimensional linear sensor 72 is arranged in a direction that matches the scanning of the X scanning mirror 33. By the way, as shown in FIG. 2, when the X scanning mirror 35 is performed by the same scanning mirror 38, a pinhole 73 and a detector 74 are used instead of the one-dimensional linear sensor 72.

Further, the polarization beam splitter 34 has an effect of suppressing interference between light returning from the solder sample 14 and light reflected by the polarization beam splitter 34 and entering the one-dimensional linear sensor 72.

The detection signal processing section 90 comprises a microcomputer 91, a detection signal storage means 92 formed of a normal memory or the like, a comparator 93, a Z coordinate storage means 74 and the like.

The detection signal storage means 92 stores X,
A frame memory that stores the value of the signal detected by the one-dimensional linear sensor 72 corresponding to the respective x and y coordinates in accordance with the Y scanning, and updates and stores the value output from the comparator 93. is there. The comparator 93 detects each detection signal detected by the one-dimensional linear sensor 72 for each x and y coordinate each time scanning (moving) in the Z direction and the same detection signal stored in the detection signal storage means 92. Compare the value of the signal corresponding to the x, y coordinates and output the larger value,
The value of the detection signal storage means 92 is rewritten, and at the same time, the Z (x, y) coordinates at that time are output to the Z coordinate storage means 94. As a result, Z (x, y) at which the detection signal is maximized
The coordinates are stored in the Z coordinate storage means 94 for each of the x and y coordinates. Therefore, the Z coordinate storage means 94
The stored Z (x, y) coordinates for each x, y coordinate show the three-dimensional profile of the solder sample 14 as it is.

Therefore, if the Z (x, y) coordinates of the positions of the X and Y coordinates programmed in advance are integrated as in the following equation, the result is the volume V, that is, the amount of solder in the soldered portion.

V = ∬Z (x, y) dxdy The present invention utilizes the fact that the surface of the soldered portion has minute irregularities. For this reason, the inspection with higher accuracy can be performed if there are many such fine irregularities. Therefore, immediately after the soldering process, an oxygen gas is sent to oxidize the soldering surface, and the surface irregularities due to the oxide film are increased, so that the solder inspection can be easily performed. By oxidizing the solder surface in this way, minute irregularities increase, the solder surface becomes dull from the mirror state, and scattered light is easily generated.

As a method of accelerating the oxidation of the surface of the solder, there is a method of mixing an oxidizing agent into the solder. By mixing the oxidizing agent into the solder in this way, it is easy to oxidize the solder surface, forming minute irregularities,
Scattered light can be easily generated.

Next, the operation and operation of the above embodiment will be specifically described. That is, the solder sample 14 is
Place on. At this time, the microcomputer 91 issues commands to the X, Y, and Z stage controllers 13 according to a program created based on design data and the like in advance and input.
And the X, Y, and Z stage controller 13 controls the stage 10 to convert the solder sample 14 into the programmed x
Move to the yz position (position for each solder sample 14).
Then, the microcomputer 91 gives a drive command to the X scan drive system 36 and the Y scan drive system 37, and
6 rotates the X scanning mirror 33, and the Y scanning driving system 37 rotates the Y scanning mirror 35. On the other hand, for example, He-Ne
The He-Ne laser beam oscillated from the laser light source 31 is converted into a light beam (beam) having a specific spread by the beam expander 32, scanned in the X direction by the X scanning mirror 33, and linearly polarized in the specific direction. Only the laser beam passes through the polarization beam splitter 34 and passes through the Y scanning mirror 35
Are scanned in the Y direction, and are incident on the optical system unit 50. The incident linearly polarized (for example, S-polarized) laser beam is condensed on a field lens 52 by a condensing lens 51, and this image is placed near the solder sample 14 by an objective lens 53 and a Z-direction scanning (moving) lens 54. It is imaged. Here, since the linearly polarized laser beam (beam) between the objective lens 53 and the Z-direction scanning (moving) lens 54 is formed so as to be a parallel beam, soldering is performed from the Z-direction scanning (moving) lens 54. The distance L to the focal point on the sample 14 is always kept constant. Then, regular reflection light and scatter reflection light generated from the surface of the solder sample 14 are generated. But,
The specularly reflected light returns as the irradiated and condensed linearly polarized light (for example, S-polarized light), and the scattered reflected light includes the linearly polarized light component (for example, S-polarized light) and a polarization component perpendicular to the linearly polarized light (for example, P-polarized light). ) And return. Therefore, the image of the light reflected back from the surface of the solder sample is reflected by the field lens 5.
An image is formed on the light beam 2, reflected and scanned by the Y-scanning mirror 35 through the condenser lens 51, and the S-polarized light, which is regular reflection light, is shielded by the polarization beam splitter 34, and only the P-polarization included in the scattered reflection light is reflected. The light enters the detection unit 70 and is imaged on the one-dimensional linear sensor 72 by the imaging lens 71.
An optical image is received by the one-dimensional linear sensor 72, and a signal is detected from the one-dimensional linear sensor 72.

The reflected light from the solder sample 14 is detected and stored in the detection signal storage means 92.

Further, the condensing point is scanned by one step in the Z direction by the Z direction scanning drive system 55, and the above X and Y scanning is performed. At this time, the detection signal is compared with the already stored detection signal by the comparator 93, and the larger value is stored in the detection signal storage means 92, and at the same time, the Z value Z at that time is stored.
(X, y) is stored in the Z coordinate storage means 94.

Hereinafter, this operation is repeated while scanning Z one step at a time. The amount of solder having a predetermined defect is calculated by integration from the three-dimensional shape thus created.

An optical scanning microscope unit using a confocal optical system formed in the scanning light generating unit 30 and the optical system unit 50 includes:
Numerical aperture of illumination light flux (NA: Numerical A)
depth determines the depth of focus. If the solder sample surface moves away from the focal point in either the positive or negative direction, the detection signal becomes weak. Therefore, if the detection signal processing unit 90 detects the Z coordinate of the position where the detection signal becomes maximum by scanning (moving) the solder focal point position relative to the solder sample 14 in the Z direction, the Z coordinate Z of the solder surface is obtained.
(X, y). In the inspection of the soldered portion as in the present invention, a resolution of about 10 μm in the x and y directions and a resolution of about a few μm in the Z direction is sufficient, and the size of the inspection object is several mm.
A field of view of about 数 10 mm is required.

In order to obtain this field of view and resolution, a film transfer lens is used as the objective lens 53 instead of a microscope objective lens. Specifically, for example, a He—Ne laser having a wavelength λ = 633 nm is used, and an N.P. A. The depth of focus ΔZ when using a lens of = 0.15 can be calculated by the following equation (1).

ΔZ = 0.5 × (λ / NA) ² ≒ 8.9 (μm) (1) Next, since the solder surface is close to a mirror surface, specularly reflected light enters the detector. In order to solve the problem that a dynamic range of many digits is required in the case and when it does not enter, a polarized illumination composed of a He-Ne laser light source 31, a beam expander 32, and a polarization beam splitter 34, Z-direction scanning lens 54, objective lens 53, field lens 52, condenser lens 51, polarization beam splitter 34, imaging lens 71, and one-dimensional linear sensor 72
The operation with the polarization detection system will be described. That is,
If the illuminated surface is an ideal mirror, the reflected light will be reflected and polarized in a direction determined by the angle of incidence and exit and the refractive index of the material.

The polarization angle will be calculated for the above example. When the incident angle θi, the angle between the incident surface and the polarization plane of the incident light beam are αi, and the refractive index of the solder is ns, the angle α ₀ between the polarization surface of the reflected light beam and the incident surface is given by the following equation (2). Can be calculated.

S = sinαi · (−sin (θi−θi ′) / sin (θi + θi ′) p = cosαi · (tan (θi−θi ′) / tan (θi + θi ′) n sin θi ′ = sin θi tan α ₀ = S / P (2) Then, when the NA of the objective lens 53 is 0.15, the maximum value of θi at which the specularly reflected light returns into the lens is 8.6 °.
It is. At this time, the refractive index of the solder was assumed to be 4.0 and α ₀ −
αi becomes maximum when αi = 45 °, and α ₀ −αi =
0.32 °. This angle change is such that the polarization is disturbed only by the component shown in the following equation (3): sin (α ₀ −αi) ≒ 0.0055 (3) The component whose polarization is disturbed is probably 0.5%. Focusing on this fact, the polarization filter 34 is provided on the detection optical system side.
Is installed, it is possible to shield up to 99.5% of the specularly reflected light. Here, in equation (2), θi is, for example, 6
In the case of 0 °, α ₀ −αi = 20 ° sin (α ₀ −αi) = 0.34. Even if a polarizing filter is inserted, only 66% of the specularly reflected light can be blocked. N. of optical system A. May be satisfied under special conditions (the NA of the objective lens 53 is reduced to about 0.2 or less by expanding the field of view as the objective lens 53 from the above relationship). Understand. That is, the surface has minute irregularities like the solder sample 14, and according to the experiment, the scattered reflected light scattered and reflected from the solder sample surface is linearly polarized light (S-polarized light).
Is converted into a polarized light component (P-polarized light) in a direction rotated by 90 °. In addition, since the surface of the solder sample 14 has minute irregularities, -180 with respect to the incident direction.
There is light scattered to the direction of °. (E. Wolf
Other: Principles of Optics pp
950-962) As described above, when polarized light is used, the dynamic range between the case where specularly reflected light reflected on the surface of the solder sample 14 enters the detection unit 70 and the case where it does not enter is 3 to 4 digits. Can be reduced. Accordingly, the intensity of light detected from the surface of the solder sample 14 when scanning in the Z direction can be increased, and the peak position of the signal obtained from the sensor 72 can be correctly obtained by the comparison means 93. 94 can correctly calculate the three-dimensional shape of the surface of the solder sample 14.

When detecting the surface shape of the solder sample 14, in order to increase the intensity of scattered light caused by minute irregularities on the surface of the solder sample 14 and reduce the component of specular reflection light,
Shorten the wavelength of illumination light (700 nm shorter than visible light)
It is desirable to increase the scattered light intensity by the following). This is based on the formulas (2) and (E. Wolf et al .: Princip
Les of Optics pp950-962).

Next, an example of an algorithm for performing a solder inspection from the three-dimensional shape of the solder sample 14 detected as described above will be described with reference to FIGS.

FIG. 5 is a perspective view of the solder sample 14. Normal part 121, small amount of solder 122, large amount of solder 12
3. There is a defective solder part 124. FIG. 6 is a side view of FIG. Windows 125, 126, 127, 128
And cutout lines 129, 130, 131, 132 are shown in an overlapping manner. 7A is a cross-sectional view of the normal portion 121, FIG. 7B is a cross-sectional view of the small amount of solder 122, FIG. 7C is a cross-sectional view of the large amount of solder 123, and FIG. FIG. 124 is a cross-sectional view of FIG. FIG. 8 shows the cut line 12.
9, 130, 131 and 132 parts according to the present invention. FIG. 9 is a differential value of FIG. This is 133
The pass / fail can be determined.

Consider the case where the solder sample 14 shown in FIG. 5 is inspected. The microcomputer 91 is programmed in advance with the positions of the soldering portions to be inspected from the design data of the printed circuit board.

In accordance with this program, the window 125 is placed at a predetermined position of the three-dimensional shape generated on the memory 94.
１２８128 is provided, and the volume in the window is changed to the Z value Z (x,
It is calculated by integrating y).

If this value is within a predetermined range, it is determined to be good. Further, the shapes of the cutout lines 129 to 132 in the window are obtained, and the case where the differential value changes discontinuously as shown in FIGS. 8B, 8C, and 8D is regarded as defective, and FIG. As shown in ()), a case where it changes smoothly is defined as a non-defective product.

FIG. 3 shows a third embodiment of the present invention. First
In the example, the specular reflected light was shielded by a polarizing plate,
The third embodiment actively takes in specularly reflected light. That is, as shown in FIG. 3, the spherical mirror 56 is set so that its center coincides with the focal point 57, and does not enter the objective lens 58 from the focal point 57 by the objective lens 58 on the surface of the solder sample 14. The light beam emitted in the direction
Thus, the light is reflected toward the converging point 57 and returned within the visual field of the objective lens 58. With this configuration, solder sample 1
The dynamic range for the surface direction of No. 4 was relaxed. That is, almost all of the irregularly reflected light enters the field of view of the objective lens 58 without being affected by the direction of the surface of the solder sample 14, and the three-dimensional shape of the solder sample surface can be detected with high sensitivity. Here, the focusing point 57 is fixed to the sample support 1 which is a wiring board having the solder sample 14.
It is necessary to scan (move) 1 by driving and controlling the X, Y, and Z stage 12. Therefore, the X scan drive system 36, the Y scan drive system 37, and the Z scan drive system 55 can be omitted.
The objective lens 53 and the Z-direction scanning lens 54 can be combined into an objective lens 58. This method scans the sample support table 11 on which the wiring board having the solder sample 14 is mounted by driving and controlling the X, Y, and Z stages 12.
A large and high-precision X, Y, and Z stage 12 is required.

FIG. 4 shows a fourth embodiment of the present invention. That is, in the fourth embodiment, instead of the polarizing element (polarizing beam splitter 34) shown in the first and second embodiments, specularly reflected light is shielded by the spatial filter 59. Thereby, the image of the scattered and reflected light from the converging point on the solder sample surface is detected by the sensor (detector) 74, and has the same operation and effect as those of the apparatus shown in FIGS. That is, for example, the laser light emitted from the He-Ne laser light source 31 is
The beam diameter is expanded by the beam expander 32, reflected by a mirror (also serving as a spatial filter) 59 provided between the objective lens 53 and the Z-direction scanning lens 54, and scanned by the Z-scan drive system 55. The light is focused on the surface of the solder sample 14 via the driven Z-direction scanning lens 54. Here, when the He-Ne laser 31, the beam expander 32, the mirror 59, the objective lens 53, and the Z-direction scanning lens 54 are fixed two-dimensionally (X-direction and Y-direction), the X-Y-Z stage Obviously, 12 may be scanned in the X and Y directions. The detection system 7
0 uses a pinhole 73 and a sensor 74 as in the embodiment shown in FIG. Clearly, this sensor 74 need not be a one-dimensional linear sensor.

[0044]

According to the present invention, a low N.I. A. With a microscope having a confocal optical system using an objective lens, the specular reflection light is shielded by a polarizing element or a spatial filter, and the three-dimensional shape of the solder sample surface close to the mirror surface is measured. This has the effect that the soldered portion can be inspected with high reliability and at high speed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an appearance inspection apparatus for a soldered portion according to the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of a soldering portion appearance inspection apparatus according to the present invention.

FIG. 3 is a configuration diagram showing a third embodiment of a soldering portion appearance inspection apparatus according to the present invention.

FIG. 4 is a configuration diagram showing a third embodiment of the soldering portion appearance inspection apparatus of the present invention.

FIG. 5 is a perspective view showing a solder sample according to the present invention.

FIG. 6 is a plan view of FIG. 5;

FIG. 7 is a side view showing a solder sample according to the present invention.

FIG. 8 is a view showing a shape signal waveform calculated by the present invention for the solder sample shown in FIG. 7;

9 is a view showing a differentiated signal waveform obtained by differentiating the shape signal shown in FIG. 8;

[Explanation of symbols]

10: Stage, 11: Sample support, 12: XY
Z stage, 13 ... X, Y, Z stage controller,
14 solder sample, 30 scanning light generator, 31 laser light source, 32 beam expander, 33 X scanning mirror, 34 polarization beam splitter, 35 Y scanning mirror, 50 optical system, 51 collection 52, a field lens, 53, an objective lens, 54, a Z-direction scanning lens, 70, a detection unit, 71, an imaging lens, 72, a one-dimensional linear sensor, 90, a detection signal processing unit, 91, a microcomputer

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Satoshi Fushimi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside Production Technology Research Laboratory, Hitachi, Ltd. Hitachi, Ltd. Hitachi, Ltd. Tokai Plant (72) Inventor Tsuneo Hayashi 1410, Inada, Katsuta, Ibaraki Prefecture Hitachi, Ltd. Hitachi, Ltd. Tokai Plant (56) References JP 1-2219656 (JP, A) JP JP-A-1-265143 (JP, A) JP-A-1-282410 (JP, A) JP-A-2-21248 (JP, A) JP-A-2-21372 (JP, A) JP-A-62-284206 (JP JP-A-63-37245 (JP, A) JP-A-62-136899 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 21/956 G01B 11/24 G06T 1/00 305 H05K 3/34 512 B23K 1 / 00

Claims (6)

(57) [Claims] An electronic unit is driven on a surface mounted on a table by driving a table based on position coordinate data stored in advance.
The electronic component of the board to which the product was soldered was soldered
A desired region including a region is placed in a field of view of a microscope, and a laser light source is applied to a desired region of the substrate in the field of view of the microscope.
The laser beam is scanned by irradiation with the emitted laser beam.
The area scanned by irradiating the beam is imaged through the microscope, before the image of a desired region of the substrate obtained by imaging
The three-dimensional shape of the area where the electronic components of the substrate are soldered
Obtained information, tertiary of the area where the obtained electronic components were soldered
Based on the information of the original shape, the electronic component
Soldering part characterized by inspecting the state of solder connection
Appearance inspection method. 2. The method according to claim 1, wherein the laser beam is applied to a galvanomirror.
And scanning in two directions.
Inspection method of soldering part . Wherein the microscope is a confocal microscope, the co-focus
Polarizing element or spatial filter for the area within the field of view of the point microscope
2. An appearance inspection method according to claim 1, wherein an image of the desired area is obtained by taking an image via a computer. 4. A substrate having an electronic component soldered on a surface thereof.
A laser light source fires on the area where electronic components are soldered.
Scanning by irradiating the laser beam
Change the focal position of the beam with respect to the soldered area
Repeated while scanning, irradiating the laser beam and scanning
Imaging a region and the focal point of the laser beam obtained by the imaging
From the multiple images at different positions, the electronic components on the board are
The information of the three-dimensional shape of the connected region is obtained, and the obtained three-dimensional shape is obtained.
Soldering of the electronic component to the substrate based on shape information
A method for inspecting the appearance of a soldered portion, characterized by inspecting the state of the solder connection . 5. An area scanned by irradiating the laser beam.
Imaging using light that has blocked specular reflection light from the reflected light from
3D of the area where the electronic components of the board are soldered
5. The solder according to claim 4, wherein shape information is obtained.
How to inspect the appearance of the attachment . 6. A galvanomirror for scanning the laser beam.
The solder connection of the laser beam was performed using
Changing the focus position with respect to the area is defined as
5. The method according to claim 4, wherein the height is changed.
The method for inspecting the appearance of the soldered part described .