JPH06258234A - Surface inspection device - Google Patents

Abstract

PURPOSE:To prevent such error detection as detects dust, a stain, or the like, which adheres to the surface of a matter to be examined, as a defective part such as a pinhole. CONSTITUTION:Permeating illuminating light 3 is radiated from the lower side of an inner lead 1 to be examined and auxiliary illuminating light 10 is radiated from the side face of the inner lead 1 to the surface of the inner lead 1 at the same time. Reflected light 17, which is reflected by a stain and the like on the surface of the inner lead 1 irradiated by the auxiliary illuminating light 10, is received by an image pickup camera 12, and the image is picked up.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface inspection apparatus for inspecting a surface defect of a plate-like article such as an inner lead or an outer lead joined to a semiconductor component.

[0002]

2. Description of the Related Art As is well known, some inner leads and outer leads joined to a semiconductor component by a bonding device have a width of 0.1 mm.
A measuring device is used that automatically measures in a non-contact manner with an accuracy of several microns.

On the other hand, in the manufacture of inner leads, press working to etching are used in accordance with the miniaturization of the lead pattern. In some cases, voids, scratches, etching residue, defects, and other defects may occur on the inner leads due to this etching.

Further, there are cases in which stains and dust formed by leaving scratches and etching liquid remain on the surface. Due to the size of a few microns to a few tens of microns, it is sometimes difficult to identify whether they are the above-mentioned defects or due to the adhesion of dust. On the other hand, due to the demands of the times, the number of products that use semiconductors is increasing, and the number of semiconductor parts produced is also increasing.

[0005]

However, the inspection of such fine inner lead defects has hitherto been made by the naked eye of a trained inspector. This work is tedious and takes a long time, and it depends largely on patience and attention. Depending on the individual difference of the inspector and the physical condition of the day, the criterion for judging whether the work is good or not due to fatigue of the work for a long time. May vary.

If a defective product is determined to be a non-defective product, it can hardly be found in a subsequent process, and the defective product may be incorporated in the printed circuit board. It may be found in the circuit check test of the printed circuit board, but if it is not found, there is a possibility that it will be directly incorporated into the product and shipped. Then, during long-term operation of this product, there is a possibility that the characteristics and life of the product may be shortened. On the contrary, if the stains or scratches due to the remaining etching solution are judged to be defective products, the yield of semiconductor components is reduced and the waste is increased.

Therefore, a surface inspection apparatus as shown in FIG. 8 has also been proposed. In FIG. 8, inner lead 1H
The convex portion 1a is formed on the surface of the inner lead 1L
A concave portion 1b is formed on the surface of the. These ridges 1
When the incident light 2 is applied to the surfaces of the inner leads 1H and 1L on which the a and the recessed portions 1b are formed, the projections 1a and the recessed portions 1b obliquely reflect the reflected light 2a2 shown by a dotted line with respect to the incident light 2.
2a3 is reflected.

On the other hand, in the inner leads 1G, 1J, 1K in which the convex portion 1a and the concave portion 1b are not formed, the reflected light 2a1 which is inverted with respect to the incident light 2 as shown by the solid line.
Is reflected.

Further, each inner lead 1G, 1H, 1
Shadow between J, 1K, 1L and each inner lead 1G, 1
In order to make it easy to discriminate the defective portions formed at the end portions of H, 1J, 1K, and 1L, these inner leads 1
The transmitted illumination light 3 is emitted from below G, 1H, 1J, 1K, and 1L.

In this surface inspection apparatus, the reflected light from these inner leads is imaged by an image pickup camera, the analog signal of the image pickup camera is converted into a digital signal, and then binarized with a predetermined threshold value to form an image. Then, the convex portion 1a or the concave portion 1b is displayed as an image on the image as a dark shadow portion to detect a defective portion.

On the other hand, in the inner lead formed by etching, the defects as shown in FIG. 10 are formed as described above. In FIG. 10, (b) is a partially enlarged plan view showing a defective portion on the surface of the inner lead, and (a)
[Fig. 6] is a cross-sectional view taken along line CC of (b).

10A and 10B, a pinhole 4 is formed on the surface of the inner lead 1M at the left end due to overetching. Inner lead 1N in the middle
Similarly, an etching defect portion 5 is formed at the end portion of the surface of, and a remaining portion 6 due to insufficient etching is formed at the right end of the right inner lead 1P.

Among them, in the inner lead 1M, the reflected light 2b1 reflected obliquely upward is obtained from the pinhole 4 by the irradiation of the incident light 2, and similarly, in the inner lead 1N, obliquely upward from the defective portion 5. Reflected light 2b2 that is reflected is obtained, and similarly, in the inner lead 1P, reflected light 2b3 that is reflected obliquely upward from the remaining 6 is obtained. Therefore, also in this case, the pinhole 4, the defective portion 5, and the remaining portion 6 can be represented as a shadow portion on the image.

However, in this surface inspection apparatus,
As shown in FIG. 11, even the inner leads having scratches, stains, or dust formed / attached on the surface thereof with a small degree of unevenness change may be mistaken for defective products, as described in detail below.

FIG. 11B is a partially enlarged plan view showing an example of such an inner lead, and FIG. 11A is a D- portion of FIG.
It is a D sectional view. In FIGS. 11A and 11B, a thin rod-shaped abrasion 7 is formed on the surface of the left inner lead 1R, and a spot 8 is formed on the surface of the middle inner lead 1S. On the surface of 1T,
Garbage 9 is attached.

Of these, in the inner lead 1R, as shown by the dotted line, the reflected light 2d is reflected obliquely upward.
1 is obtained by the incident light 2 almost in the same manner as the reflected light 2b1 shown in FIG. 10A, the same reflected light 2d2 is obtained also in the inner lead 1S, and the same reflected light 2d3 is also obtained in the inner lead 1T.

Therefore, even in this case, the scratches 7, the stains 8 and the dust 9 appear on the image due to the reflected lights 2d1, 2d2 and 2d3 as dark shadows, and therefore the pinhole 4 shown in FIG. However, the defective portion 5 and the remaining portion 6 cannot be discriminated from each other and may be mistakenly recognized as a defective product. Therefore, it is an object of the present invention to provide a surface inspection apparatus capable of preventing a decrease in yield due to erroneous recognition of a defective portion of an inspection object product.

[0018]

According to a first aspect of the present invention, there is provided an epi-illumination unit for irradiating the surface of a work with incident light, an auxiliary illuminator for irradiating the surface of the work from a side surface, and reflection from the surface of the work. It is characterized by comprising an image pickup section for picking up the reflected light thus picked up and an image processing section for picking up a defect on the surface of the work when a signal of the reflected light of the work inputted from the image pickup section is inputted.

Further, in the invention according to claim 2, the epi-illumination unit for irradiating the front surface of the work with the incident light, the auxiliary illuminator for irradiating the front surface of the work from the side surface, and the transmitted illumination light from the rear surface of the work. A transmission illumination unit, an image capturing unit that captures the reflected light reflected from the surface of the work, and an image processing unit that receives the signal of the reflected light of the work input from the image capturing unit and extracts defects on the surface of the work. It is characterized by having.

Further, in the invention according to claim 3, from the back surface of the work, an epi-illumination part for collecting the incident light transmitted through the spatial filter with a condenser lens, reflecting it with a half mirror and irradiating it on the surface of the work. A transmitted illumination unit that emits transmitted illumination light, an imaging unit that captures the reflected light reflected from the surface of the workpiece, and a signal of the reflected light of the workpiece that is input from this imaging unit is input to extract defects on the surface of the workpiece. It is characterized by comprising an image processing unit for performing.

[0021]

In the inventions of claims 1 and 2, the light radiated from the auxiliary illumination section onto the adhered matter on the surface of the work is reflected perpendicularly to the surface of the work and is incident on the image pickup section. The captured image of the kimono is an image with the same brightness as the normal surface.

In the invention according to claim 3,
The light that has passed through the spatial filter and is emitted from the half mirror to the adhered matter on the surface of the work is reflected perpendicularly to the surface of the work and enters the imaging unit, and the captured image of the adhered matter is as bright and dark as a normal surface. It becomes an image of the degree.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the surface inspection apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a surface inspection apparatus according to the first and second aspects of the invention. In FIG. 1, a mirror box 11 is provided above the inner lead 1 to be inspected, and a lens barrel 11a is attached to the upper part of the mirror box 11.

Inside the mirror box 11, a half mirror 11b is stored under the lens barrel 11a with a tilt of 45 °, and on the right side of the mirror box 11, the half mirror 11b is placed.
On the other hand, a reflection illumination unit 14 for irradiating light from a halogen lamp from the right side is provided laterally. In this reflection illumination unit 14,
Power supply 13A is connected.

Below the inner lead 1, a transillumination unit for irradiating the lower surface of the inner lead with the light of a halogen lamp.
A power supply 13C is connected to the transillumination unit 15.

At the top of the lens barrel 11a, a CCD (charge cou
Imaging camera with built-in pled device, charge-coupled device 12
Is provided vertically, and the output signal line 18 of the imaging camera 12 is
It is connected to the input side of an A / D converter 20 inside an image processing device 19 separately provided. This A / D converter 20
The output signal line of is connected to the input side of the binarization processing unit 21,
The output signal line of the binarization processing unit 21 is connected to the defect extraction processing unit 22.
Is connected to the input side of. The output signal line 23 of the defective product extraction processing unit 22 is connected to a display device (not shown) or a gripping unit described later.

In the surface inspection apparatus having the above-mentioned structure, the light emitted from the reflection illumination section 14 to the lower surface of the half mirror 11b is reflected by the half mirror 11b and is reflected vertically by the inner lead 1 as epi-illumination light 2. Is irradiated on the surface of.

The surface of the inner lead 1 is irradiated with the epi-illumination light 2 and the auxiliary illumination light 10 emitted from the auxiliary illumination section 16, and each of these illumination lights includes a defective portion on the surface of the inner lead 1 and its defect. It is illuminated around and reflected upwards. A combined light 17 of the reflected light and the passing light emitted from the transmissive illumination unit 15 and passing between the inner leads 1 is incident on the imaging camera 12.

The image signal of the inner lead 1 picked up by the image pickup camera 12 is input as an analog signal to the A / D converter 20 via the signal line 18, and is converted into a digital signal by the A / D converter. After that, it is input to the binarization processing unit 21.

In this binarization processing portion 21, a bright portion due to the light reflected from the flat portion of the surface of the inner lead 1 and a dark portion due to the light reflected from the defective portion of the surface of the inner lead 1 which will be described later in detail. The difference between the lightness and the darkness is binarized with a certain threshold as a boundary, and the image is output to the defect extraction unit 22.

In the defect extraction unit 22, the image input from the binarization processing unit 21 is compared with the shape and size of the defective portion which is a reference for determining whether the defective portion is good or defective, and if When it is larger than the criterion, the gripper (not shown) to which a signal is input as the defect information via the signal line 23 is driven, and the inner lead is carried into the defective product storage box (not shown).

Next, FIG. 2 is a partial explanatory view showing an operation when the inner lead having a defective portion on the surface is detected by the surface detecting device thus constructed, and FIG.
Is an enlarged plan view corresponding to FIG. 10 (b), and FIG. 2 (a) is a sectional view taken along the line AA of FIG. 2 (b) and is also a view corresponding to FIG. 10 (a).

2A and 2B, a pinhole 4 is formed on the surface of the left inner lead 1A due to excessive etching, and a pinhole 4 is also formed on the right end of the middle inner lead 1B due to excessive etching. 5 is formed, and the remaining 6 is formed at the right end of the inner lead 1C at the right end due to insufficient etching.

Of these, in the inner lead 1A, the reflected light 2b is reflected obliquely upward by the incident light 2.
1 is obtained, and the auxiliary illumination light 10 emitted from the right side is shown by arrows 10a on the upper surfaces of the inner leads 1A, 1B, 1C, respectively.
Pass as shown in. On the other hand, the transmitted illumination light 3 is transmitted between the leads as shown by arrows 3A, 3B, 3C, and 3D in the same manner as in the conventional case, and a part of the light transmitted through the right side of the inner lead 1C remains. Blocked by 6.

Next, FIG. 3 is a partial explanatory view showing the operation when inspecting an inner lead having a scratch or dirt on the surface.
FIG. 3B corresponds to FIG. 11B, and FIG.
11B is a sectional view taken along line BB of FIG. 11B and corresponds to FIG.

In FIGS. 3A and 3B, a scratch 7 is formed on the surface of the inner lead 1D at the left end, and a stain 8 is attached to the surface of the inner lead 1E in the middle, and the inner lead at the right end is formed. Dust 9 adheres to the surface of 1F as in FIG.

Of these, in the inner lead 1D, the reflected light 2c1 is reflected obliquely upward by the incident light 2.
Is obtained corresponding to the surface shape of the scratch 7, and further, the auxiliary illumination light 10 emitted from the right side is reflected on the upper surface of the scratch 7 and a reflected light which is inverted upward as shown by an arrow 10b1 is obtained.

Also in the inner lead 1E, the reflected light 2c2 corresponding to the spot 8 is obtained by the incident light 2, and similarly, the auxiliary illumination light 10 from the right is reflected on the upper surface of the spot 8 and goes upward. The reflected light that is inverted as shown by the arrow 10b2 is obtained.

Further, in the inner lead 1F,
A reflected light 2c3 that is reflected by the incident light 2 according to the dust 9;
The auxiliary illumination light 10 hits the surface of the dust 9 and the arrow 10b3 moves upward.
Reflected light that is reflected as shown in FIG. In addition, the transmitted illumination light 3 from below passes between the leads by arrows 3A, 3B, 3
It is transparent as shown in C and 3D.

Therefore, abrasion 7, stain 8 and dust 9
2c1, 2c, 2c reflected obliquely by
3, the illuminance at which the reflected light of the incident light 2 incident on the image pickup camera becomes small is indicated by the arrows 10b1 and 10b1 by the auxiliary illumination light 10.
Since it can be compensated by b2 and 10b3, it is possible to prevent the image of the places of the scratches 7, the stains 8 and the dust 9 from being darkened, and it is possible to prevent misidentification that the product is a defective product. It is possible to prevent a decrease in yield in the process.

FIG. 4 is a block diagram showing a surface inspection apparatus according to a third aspect of the present invention, which corresponds to FIG. In FIG. 4, a mirror box 11 is provided above the inner lead 1 to be inspected, as in FIG. 1, and a lens barrel 11a is attached to the upper portion of the mirror box 11.

As in FIG. 1, the half mirror 11b is housed inside the mirror box 11 under the lens barrel 11a with an inclination of 45 °, and the lens box 24 is provided on the right side surface of the mirror box 11. On the right side surface of the lens box 24, a reflection illumination section 14 for irradiating the half mirror 11b with light of a halogen lamp from the right side is provided laterally as in FIG. A power source 13A is also connected to the reflection illumination unit 14. A condenser lens 26 is vertically housed inside the lens box 24, and on the right side of the condenser lens 26,
The spatial filter 25 is housed vertically.

Below the inner lead 1, as in FIG. 1, there is provided a transillumination part 15 for irradiating the lower surface of the inner lead with light from a halogen lamp.
The power supply 13C is connected.

Similarly, the CCD (ch
An image pickup camera 12 having a large coupled device therein is vertically provided, and an output signal line 18 of the image pickup camera 12 has an A / D converter 20 inside an image processing device 19 separately provided. Is connected to the input side of. This A
The output signal line of the D converter 20 is connected to the input side of the binarization processing unit 21, and the output signal line of this binarization processing unit 21 is connected to the input side of the defect extraction processing unit 22. . The output signal line 23 of the defective product extraction processing unit 22 is connected to a display device (not shown) or a gripping unit described later.

In the surface inspection apparatus constructed as described above, the spatial filter 25 and the condenser lens 26 are provided from the reflection illumination section 14.
The light radiated to the lower surface of the half mirror 11b through the above is reflected by the half mirror 11b and is vertically radiated to the surface of the inner lead 1 as epi-illumination light 2. The combined light 27 of the reflected light and the light emitted from the transmissive illumination unit 15 and passing between the inner leads 1 is incident on the imaging camera 12.

The image signal of the inner lead 1 picked up by the image pickup camera 12 is input as an analog signal to the A / D converter 20 through the signal line 18 and converted into a digital signal by the A / D converter. After that, it is input to the binarization processing unit 21.

In the binarization processing portion 21, a bright portion due to the light reflected from the flat portion of the surface of the inner lead 1 and a dark portion due to the light reflected from the defective portion of the surface of the inner lead 1 which will be described later in detail. The difference between the lightness and the darkness is binarized with a certain threshold as a boundary, and the image is output to the defect extraction unit 22.

In the defect extraction unit 22, the image input from the binarization processing unit 21 is compared with the shape and size of the defective portion which is a reference for judging whether the defective portion is good or defective, and if When it is larger than the criterion, the gripper (not shown) to which a signal is input as the defect information via the signal line 23 is driven, and the inner lead is carried into the defective product storage box (not shown). Next, FIG. 5 is a diagram showing an operation when the inner lead having a defective portion on the surface is detected by the surface detecting device configured as described above.

In FIG. 5, the epi-illumination light 2 emitted from the linear light source 30A passes through the spatial filter 25 and the condenser lens.
The combined light of the reflected light and the transmitted illumination light 3 from the lower portion, which is condensed by 26 and irradiated to the inner lead 1 by the half mirror 11b, is imaged by the imaging camera 12, and is described above with reference to FIGS. 8 and 9. Defect detection.

FIG. 6 shows a sectional view of the light amount distribution due to the difference in the spatial filters 25 at this time. FIG. 6A shows a light amount distribution 31A when nothing is put in the spatial filter 25 and the epi-illumination light 2 having a uniform illuminance is applied to the entire surface. The light amount distribution at this time has an inverted conical shape, and the inner lead 1 is irradiated with the inverted conical incident illumination light 2 from all angles.

On the other hand, FIG. 6B shows a light quantity distribution 31B when a semitransparent film 25a or the like is inserted in order to modulate the light quantity at the center of the spatial filter 25.
Is shown. At this time, the light amount of the central portion of the epi-illumination light 2 is weakened, the light amount from the outer peripheral portion is the same as in FIG. 6A, and the light amount distribution has a heart-shaped cross section.

By shining the epi-illumination light having such a heart-shaped light quantity distribution, the pinhole 4, the defective portion 5, and the remaining 6 which are the original defects shown in FIG. 10 are surely detected as defective parts. At the same time, it is possible to determine that the inner lead on which the scratches 7, the stains 8 and the dust 9 that are excessive detection factors adhere is formed as a good product.

That is, in FIG. 7B, when the pinhole 4 is irradiated with epi-illumination light having a heart-shaped light amount distribution, even for epi-illumination light having an angle from the outer peripheral portion, Diffuse reflected light 2b equivalent to the reflected lights 2b1 to 2b3 described in FIG. 10 is generated, and is detected as a black portion by the image processing apparatus. On the other hand, when epi-illumination light with heart-shaped light intensity distribution is applied to scratches 7, stains 8 and dust 9 that are not formed in the depth direction, part of the light is diffusely reflected in the opposite direction by 180 °. The reflected light 10b becomes
In the image processing device, a bright image is obtained as a result, and it is possible to prevent erroneous detection that is a defect detection.

In the above embodiment, the object to be inspected is the inner lead joined to the semiconductor component. However, the unacceptable irregularities and the acceptable irregularities are formed or adhered on the flat surface. Any component that can be applied can be similarly applied.

Further, in the above-mentioned embodiment, the case where the transmitted illumination light 3A, 3B, 3C, 3D is transmitted from the lower side of each inner lead has been described. However, the inspection target surface is wide, and the defect portion or the stain is an end surface. When it does not adhere to the
The transmitted illumination light may be omitted and the invention according to claim 1 may be adopted.

[0057]

As described above, according to the invention of claim 1,
An epi-illumination unit that irradiates the surface of the work with incident light, an auxiliary illuminator that irradiates the surface of the work from the side, an imaging unit that images reflected light reflected from the surface of the work, and an input from this imaging unit. The surface inspection device is equipped with an image processing unit that receives the signal of the reflected light of the workpiece and extracts defects on the surface of the workpiece. Since the image pickup surface of the adhering substance is made to have an image with the same brightness as a normal surface, it is possible to prevent a decrease in yield due to erroneous recognition of a defective portion of the inspection object. It is possible to obtain a surface inspection device that can be used.

According to the second aspect of the invention, the epi-illumination unit for irradiating the front surface of the work with the incident light, the auxiliary illuminator for irradiating the front surface of the work from the side surface, and the transmitted illumination light from the back surface of the work. A transmission illumination unit for irradiating the object, an imaging unit for imaging the reflected light reflected from the surface of the work, and image processing for extracting a defect on the surface of the work by inputting the signal of the reflected light of the work input from the imaging unit By equipping the surface inspection device with the section, the light emitted from the auxiliary illumination section to the adhered matter on the surface of the work is reflected perpendicularly to the surface of the work and made incident on the imaging section, and the imaging surface of the adhered matter is Since the image has the same brightness as that of the normal surface, it is possible to obtain the surface inspection device capable of preventing the reduction of the yield due to the erroneous recognition of the defective portion of the inspection object product.

Further, according to the invention of claim 3,
An epi-illumination unit that collects the incident light that has passed through the spatial filter with a condenser lens and reflects it with a half mirror to irradiate the surface of the work. From the auxiliary lighting unit, an imaging unit that captures the reflected light reflected from the image processing unit and an image processing unit that receives the signal of the reflected light of the workpiece input from this imaging unit and extracts defects on the surface of the workpiece are provided. The light irradiated to the adhered matter on the surface of the work is reflected perpendicularly to the surface of the work and is incident on the image pickup unit, and the image pickup surface of the adhered matter is made into an image with the same brightness as the normal surface. It is possible to obtain a surface inspection device capable of preventing a decrease in yield due to erroneous recognition of a defective portion of a target product.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a surface inspection apparatus of the invention according to claim 1 and claim 2;

2A and 2B are diagrams showing the operation of the surface inspection apparatus according to the first and second aspects of the present invention, in which FIG. 2B is a partial plan view of the inspection object, and FIG. Sectional view.

3A and 3B are diagrams showing an operation different from FIG. 2 of the surface inspection apparatus according to the first and second aspects of the present invention, in which FIG. 3B is a partial plan view of the inspection object, and FIG. ) BB sectional drawing.

FIG. 4 is a block diagram showing an embodiment of a surface inspection device according to the invention as defined in claim 3;

FIG. 5 is an explanatory view showing the operation of the surface inspection apparatus according to the third aspect of the invention.

FIG. 6A is a partial explanatory view showing an operation when the surface inspection device of the invention according to claim 3 and a spatial filter portion are different. FIG. 6B is an explanatory diagram showing a main part of the surface inspection apparatus according to the third aspect of the invention.

FIG. 7 is an explanatory view showing the operation of the surface inspection device according to the third aspect of the invention.

FIG. 8 is a partial vertical cross-sectional view showing the operation of a conventional surface inspection device.

FIG. 9 is a diagram showing an image showing the operation of a conventional surface inspection device.

FIG. 10 is a view showing an operation different from FIGS. 8 and 9 of the conventional surface inspection apparatus, FIG. 10B is a partial plan view of the inspection object,
(A) is CC sectional drawing of (b).

FIG. 11 is a view showing an operation different from that of FIGS. 8, 9 and 10 of the conventional surface inspection apparatus, FIG. 11B is a partial plan view of the inspection object, and FIG. D sectional view.

[Explanation of symbols]

1, 1A, 1B, 1C ... Inner leads, 2 ... Epi-illumination light, 2b1, 2b2, 2b3, 2c1, 2c2, 2c3
... Reflected light, 3,3A, 3B, 3C, 3D ... Transmitted illumination light,
4 ... Pinhole, 5 ... Missing part, 6 ... Remaining, 7 ... Scratch,
8 ... stains, 9 ... dust, 10 ... auxiliary illumination light, 11 ... mirror box, 11b ... half mirror, 25 ... spatial filter, 26 ... condensing lens.

Claims (3)

[Claims] 1. An epi-illumination unit that irradiates the surface of the work with incident light, an auxiliary illuminator that irradiates the surface of the work from a side surface, and an imaging unit that captures the reflected light reflected from the surface of the work. A surface inspection apparatus comprising: an image processing unit that receives a signal of reflected light of the work input from the imaging unit and extracts a defect on the surface of the work. 2. An epi-illumination unit that irradiates the front surface of the work with incident light, an auxiliary illuminator that irradiates the front surface of the work from a side surface, and a transmissive illumination unit that irradiates transmitted light from the back surface of the work. An image pickup unit for picking up the reflected light reflected from the surface of the work, and an image processing unit for receiving the signal of the reflected light of the work input from the image pickup unit and extracting defects on the surface of the work. Characteristic surface inspection device. 3. An epi-illumination unit that condenses incident light that has passed through a spatial filter by a condenser lens, reflects it by a half mirror, and irradiates the front surface of a work, and transmitted illumination that irradiates transmitted light from the back surface of the work. A portion, an imaging unit that images reflected light reflected from the surface of the work, and an image processing unit that receives a signal of the reflected light of the work input from the imaging unit and extracts defects on the surface of the work. A surface inspection device characterized by being provided.