JP3322521B2 - Printed circuit board pattern inspection method and apparatus, and printed circuit board manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for inspecting a pattern of an etching resist ink applied to a printed circuit board made of a copper-clad laminate so as to correspond to a circuit pattern.
The present invention also relates to a method for manufacturing a printed circuit board using the method and apparatus for inspecting a pattern of a printed circuit board.

[0002]

2. Description of the Related Art First, a method of forming a circuit pattern (using a copper foil) on a printed circuit board by a conventional printing technique will be described below. Copper-clad laminate formed by laminating copper foil to cut the surface of the insulating plate into a predetermined size, uniformly roughened by the copper foil surface in order to improve the print adhesion to the copper foil surface brushing, etc. And perform cleaning and cleaning. Next, an etching resist ink corresponding to the circuit pattern is formed by applying (printing) an etching resist ink through a screen plate having a printed pattern (corresponding to the circuit pattern) on the copper foil surface by a screen printing machine. Then, the etching resist ink is dried. Subsequently, a copper foil other than the circuit pattern portion is etched using the etching resist ink as a mask, and the etching resist ink is peeled and removed with an organic solvent or the like to form a copper foil circuit pattern by exposing the copper foil. I have.

A printed circuit board manufactured by this printing technique is less expensive than a printed circuit board manufactured by an exposure technique using a dry film resist, and has a high cycle time of usually 6 to 12 seconds per sheet in a mass production line. Produced in. However, in recent years, with the miniaturization and high density of electronic devices, circuit patterns on printed circuit boards have been miniaturized and densified. In printing technology, the circuit line width is 200 μm and the line gap is 200 μm. High-density circuit patterns are required, and it is expected that the required level of further miniaturization and higher density will increase in the future.

As circuit patterns become finer and denser, dust in the air in the manufacturing process, foreign matter from machines and people, scratches on printed circuit boards, etching resist ink, etc. Due to fluctuations in the application conditions of the substrate or the like, defects easily occur in the etching resist pattern, and as a result, the defective rate of the printed circuit board increases.

Here, it is pointed out that there are many continuous failures as a feature of the occurrence of circuit pattern failures by the printing technique.
One of the causes of the continuous failure is that the above-mentioned dust and foreign matter adhere to a part of the blank pattern of the screen plate. In such a case, defective products such as an etching resist pattern formed corresponding to the pattern for punching out the screen plate being cut off in the middle occur continuously. Therefore, when the copper foil is etched using the etching resist ink as a mask, defective products in which a circuit pattern is cut off in the middle are continuously generated, and inspection is performed after the etching of the copper foil to determine the defective product. Printed circuit boards cannot be reclaimed,
Because it is discarded, it costs a lot of money.

In order to prevent the occurrence of such defective products, in the process of manufacturing a printed circuit board, the working environment is cleaned, and the appearance of the circuit pattern after the printing of the etching resist ink or the etching of the copper foil is visually inspected (hereinafter, visually inspected). ) And electrical short (short circuit) / open (open) inspections. However, the size of the printed circuit board is usually 250 × 500 to 500 × 600 mm, for example, a printed circuit board having a size of 500 × 500 mm usually requires several tens of minutes to visually inspect a circuit pattern. If an attempt is made to reduce the time required for the visual inspection, there is a high possibility that defectives will be overlooked frequently. Therefore, in the printing step, since the cycle time is short and 6-12 seconds, withdrawing a printed board in one piece a rate of several tens after etching resist ink dried, the etching resist Lee <br/> down Kuyori comprising etching resist The reality is that the pattern is visually inspected.

However, since a certain degree of defective loss occurs in the sampling visual inspection, as a fundamental measure, it is desired to perform a pattern inspection of all the printed boards by a printed board pattern inspection apparatus during the printed board manufacturing process. ing. At present, as a pattern inspection apparatus for printed circuit boards, an apparatus for inspecting a dry film pattern or a circuit pattern after copper foil etching is commercially available.

[0008] Further, since a printed circuit board using a printing technique is produced at a low cost and at a high speed, the pattern inspection apparatus must have a low-cost and high-speed inspection function. is needed.

[0009]

However, there is no practical pattern inspection apparatus for inspecting an etching resist pattern (printing pattern) at high speed before etching a copper foil. This is because the etching resist pattern inspection before copper foil etching requires a different pattern inspection method and apparatus than the dry film pattern and the pattern inspection after copper foil etching due to the following unique problems. is there.

(1) Since a large number of polishing streaks of irregularities on the order of μm are formed on the surface of the copper foil along the polished direction, light irregularly reflected by the polishing streaks is incident on the image sensor, and the etching resist is formed. Difficult to detect patterns. (2) The plurality of recesses on the copper foil surface of the copper-clad laminate are not completely removed by polishing, and fine burrs of the copper foil and edges of the copper foil also remain. This makes it difficult to detect the etching resist pattern.

(3) As the etching resist ink, an ultraviolet (UV) curable ink comprising a bluish pigment and a resin is usually used. Therefore, although the etching resist pattern has a bluish color, the edge of the etching resist pattern becomes thinner and more colorless and transparent because the etching resist ink becomes thinner, and it is difficult to detect the edge.

(4) The types of defects in the etching resist pattern are as follows:
There is a defect that the thickness of the etching resist ink becomes thinner than a normal thickness due to protrusion, scattering, and the like, and a portion where the etching resist ink is thin turns from a pale blue color to almost colorless and transparent. Since such a thin portion of the etching resist ink also serves as a mask during copper foil etching, it is necessary to detect the thin portion of the etching resist ink.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method and apparatus for inspecting a printed circuit board pattern with high accuracy and high speed, and a method for manufacturing a printed circuit board.

[0014]

According to the first aspect of the present invention, in order to achieve the above object, a circuit pattern corresponding to a circuit pattern is formed on a copper foil after polishing a copper foil surface of a printed circuit board made of a copper-clad laminate. A pattern inspection method for inspecting the pattern formation state of the applied etching resist ink, wherein the polishing direction of the copper foil is one direction and parallel to the polishing direction.
The inspection area of the printed circuit board is illuminated obliquely with respect to the printed circuit board surface from each of two opposite directions, and the inspection area is imaged by an image sensor from above the inspection area . Lighting from downstream side
The illuminance of the first illumination to be compared to the illuminance of the second illumination
It is characterized by being enlarged .

[0015]

[0016]

[0017]

The invention according to claim 2 is the invention according to claim 1.
Te, wherein the imaging by the imaging device through a color filter to adjust the transmittance of the color components as the luminance level of a thick portion and a thin portion of the thickness of the etch ring resist ink is uniform. The invention of claim 3 is the invention of claim 1
Wherein the illumination is performed by adjusting the illuminance of the color components so that the luminance levels of the thick and thin portions of the etching resist ink are uniform.

The invention according to claim 4 is the invention according to claim 1.
Te, and illuminated by adjusting the illuminance of the color component so that the luminance level is uniform and the thickness of the thick portion and thin portion of the etching resist ink, of a thick portion and a thin portion of the thickness of the etching resist ink It is characterized in that an image is picked up by an image pickup device via a color filter whose transmittance of a color component is adjusted so that a luminance level becomes uniform.

The invention according to claim 5 is the same as the invention according to claims 1-4.
In addition, using a line light illuminating means for illumination and a line sensor for an image sensor for detection, a partial inspection area is detected in a line shape, and the printed circuit board is moved in a direction orthogonal to the line sensor, and the entire inspection area is detected. Is captured by the line sensor. In the invention of claim 6 , the copper foil surface is
In parallel with the polishing direction of the copper foil on the printed circuit board on which the etching resist ink has been applied .
Or oblique direction with respect to two directions each surface of the printed circuit board from the people that
And 2 recruited in illumination means you illuminate Luo inspecting region linearly, a line sensor for imaging the inspection area illuminated in the linear direction perpendicular to the line sensor by placing the printed circuit board Bei and moving means for moving the
The one to illuminate the inspection area from the downstream side in the polishing direction
The other line light illumination which opposes the illuminance of the line light illumination means
It is characterized in that the illuminance is made larger than the illuminance of the means .

According to a seventh aspect of the present invention, after polishing the copper foil surface of the copper-clad laminate, an etching resist ink corresponding to a circuit pattern is applied on the copper foil, and the copper foil is coated with the etching resist ink as a mask. Etching,
2. A method of manufacturing a printed circuit board for removing said etching resist ink, wherein a circuit pattern formed by said etching resist ink is formed before said copper foil is etched.
The inspection is performed by the printed circuit board pattern inspection method according to any one of the above items ( 5 ) to ( 5 ).

[0022]

[0023]

According to the first aspect of the present invention, a method for polishing a copper foil is provided .
Direction is one direction, two opposite directions parallel to the polishing direction
To print the substrate surface from each illuminate the inspection region of the printed circuit board from an oblique direction, the area to be inspected from above of the inspection region to image by the image pickup device
And the illuminance of the first illumination that is illuminated from the downstream side in the polishing direction.
Since the illuminance of the second illumination is set to be larger than that of the second illumination, the illumination light from the oblique direction to the surface of the printed circuit board is specularly reflected in the oblique direction in a region where the copper is exposed, and the image is darkly picked up by the image pickup device. Irradiation light is refracted, reflected, and scattered in the resist ink region, and the image is picked up brightly by the image pickup device. As a result, the pattern of the etching resist ink can be inspected before etching the copper foil . Also, printed circuit boards
From the direction parallel to the polishing direction of the copper foil
Illuminates the area to be inspected, the
Can prevent irregular reflection of light, and can reduce the S / N of the output video signal of the image sensor.
Ratio is improved, and the etching resist
The reliability of the pattern inspection of the ink is improved. And polishing
Printed circuit board table from each of two opposite directions parallel to the direction
The area to be inspected on the printed circuit board is
Lighting, so that the illuminance of each light is half that of one direction.
As a result, concaves and fine bumps on the exposed copper foil surface
, The brightness of each bright spot noise component from the edge can be reduced,
The S / N ratio of the output video signal of the image sensor has been improved,
The reliability of the pattern inspection of the resist ink is improved.
Further, the illumination of the first illumination illuminated from the downstream side in the polishing direction.
Since the illuminance was made larger than the illuminance of the second illumination,
Utilizing the characteristics of the shape of the part and the burr
Increasing the illuminance of the illumination on the upstream side enables
The outgoing S / N ratio is improved.

[0024]

[0025]

[0026]

[0027]

[0028] According to the invention of claim 2, adjusted the transmittance of the color components as the luminance level of a thick portion and a thin portion of the thickness of the etching down <br/> grayed resist ink becomes uniform Since the image is picked up by the image pickup device via the color filter, the accuracy and reliability of the pattern inspection of the etching resist ink are improved.

According to the third aspect of the present invention, the illumination is performed by adjusting the illuminance of the color components so that the luminance level of the thick and thin portions of the etching resist ink is uniform. The accuracy and reliability of ink pattern inspection are improved. According to the configuration of the fourth aspect of the present invention, the illuminance of the color component is adjusted and illuminated so that the luminance level of the thick portion and the thin portion of the etching resist ink becomes uniform, and the thickness of the etching resist ink is increased. since imaged by the imaging element through a color filter to adjust the transmittance of the color components as the luminance level of a thick portion and a thin portion of is made uniform, the etching resist than the invention of claim 2 and claim 3 The accuracy and reliability of ink pattern inspection are improved.

According to the fifth aspect of the present invention, the partial inspection area is detected linearly by using the line light illuminating means for illumination and the line sensor for the image pickup device for detection, and the printed circuit board is connected to the line sensor. By moving in the orthogonal direction and imaging the entire inspection area with the line sensor, the line light illumination and the line sensor can realize wide parallel oblique illumination and upward imaging of the line-shaped partial area, and are also uniform in the width direction at the same time. Stable detection is obtained, and by moving this in the orthogonal direction, high-speed and high-precision inspection of the pattern of the etching resist ink can be performed.

According to the structure of the invention of claim 6 , the surface of the copper foil is provided.
Is parallel to the polishing direction of the copper foil on the printed circuit board coated with etching resist ink in one direction
Oblique direction from most two directions respectively relative to the printed circuit board surface against
And 2 recruited in illumination means you illuminate the inspection region in a line shape from the direction, a line sensor for imaging the inspection area illuminated on the line-shaped, perpendicular to the line sensor by placing the printed circuit board Moving means to move in the direction
To illuminate the inspection area from the downstream side in the polishing direction
Of the other line light illuminating device
Since then larger than the illuminance of the light unit, can be inspected pattern with high precision etching resist ink to a high velocity.

[0032] wherein, according to the structure of the invention in claim 7, printed circuit board pattern inspection of the described circuit pattern forming state by etching resist ink of the printed circuit board to any one of claims 1 to 5 before the etching of the copper foil Since the inspection is performed by the method, the occurrence of the occurrence of the failure of the printed circuit board can be quickly detected, and the defective product can be reproduced, so that the loss of the failure can be reduced.

[0033]

[0034]

The present invention will be described below with reference to examples. (Example 1) pattern inspection apparatus of a printed circuit board of an embodiment of the present invention, FIGS. 1 (a), (b) (Here, FIG. 1 (a) 1
As shown in FIG. 1B, a line sensor 1 including a plurality of charge-coupled device (CCD) cameras provided in a line shape for imaging a substrate 8 to be inspected formed of a printed circuit board, and a line sensor 1. A first color filter 2a attached to the front of the lens, line light illuminators A and B for illuminating the surface of the substrate 8 to be inspected in a line, and a first color filter 2a attached before the light emitting surface of each of the line light illuminators A and B. The second color filter 2b, the third color filter 2c, and the image detection processing unit 3
A defect determination unit 4, a control unit 5, a numerical control (NC) table 7 as a moving means, and a numerical control (NC) driving unit 6 for driving the NC table 7.

The substrate 8 to be inspected has an etching resist pattern printed on the surface of the copper foil of the copper-clad laminate polished in one direction with a brush or the like by a screen printer. The substrate 8 to be inspected is placed on the NC table 7. Is done. However, the substrate 8 to be inspected is arranged such that the polishing streaks of the copper foil of the substrate 8 to be inspected are orthogonal to the longitudinal direction of the line sensor 1.

In the present embodiment, the (vertical)
The line sensor 1 is disposed above, that is, above the substrate 8 to be inspected, and one line sensor is disposed on both sides of the line sensor 1 in the longitudinal direction.
A pair of line light illuminating means A and B are arranged, and the line L to be inspected is line sensor 1 in a state where the inspected area (inspection line L) of the inspected substrate 8 is illuminated by the line light illuminating means A and B. To capture an image. In other words, the line L to be inspected of the substrate 8 to be inspected is detected, the substrate 8 to be inspected is moved in a direction orthogonal to the line L to be inspected, and the entire inspection region is imaged by the line sensor 1, so that the surface of the copper foil 8b The effect of the oblique illumination parallel to the polishing streaks can be greatly exerted over a wide range, and pattern inspection can be performed at high speed.

Each of the line light illumination means A and B is 550 m
This is a line type optical fiber illumination with an m-width condensing lens, and a halogen lamp is used as each light source. Each of the line light illuminating means A and B is 10 ° with respect to the surface of the substrate 8 to be inspected.
The line L to be inspected under the line sensor 1 is illuminated from both sides by being obliquely arranged at an angle of up to 45 °. That is, each of the line light illuminating units A and B illuminates the obliquely lower portion, respectively, and illuminates the imaging surface on the substrate 8 to be inspected. However, each line light illumination means A,
The angle at which each B is inclined with respect to the substrate 8 to be inspected is 15 °.
３０30 ° is optimal.

The illuminance of the illumination of each of the line light illuminators A and B is larger in the line light illuminator B on the downstream side of the polishing stripe. Further, a second color filter 2b and a third color filter 2c for cutting a copper-based color are provided in front of the light emitting surfaces of the respective line light illuminating means A and B. The line sensor 1 uses five CCD cameras to share a visual field of about 100 mm each. This is because the image resolution is increased and the positional deviation and expansion / contraction of the etching resist pattern are divided into regions for each CCD camera and inspected in detail.

Each CCD camera of the line sensor 1 has a first color filter 2a in which a color component is adjusted so that a detection profile of an ink portion of an etching resist pattern has a uniform luminance level for each lens for imaging. Is attached to the front of each CCD camera lens. Inspection substrate 8
Are positioned and arranged on the one-axis NC table 7,
When the NC table 7 is moved by a signal from the NC drive unit 6, the entire inspection area of the substrate 8 to be inspected becomes the line sensor 1.
Is imaged. Here, the NC drive unit 6 sends an encoder signal for driving the NC table 7 to the control unit 5, and the scan timing of the substrate 8 to be inspected by the line sensor 1 is synchronized with the encoder signal.

The control section 5 controls the sequence and timing of the image detection processing section 3, the defect determination section 4, and the NC drive section 6. Further, the control unit 5 receives an encoder signal from the NC drive unit 6 to generate an imaging timing signal, and inputs the imaging timing signal to the image detection processing unit 3. The imaging signal from the line sensor 1 is input to the image detection processing unit 3 and stored as image data.
The image processing by the PU is compared with a reference pattern of the etching resist pattern which is input in advance, and a pattern defect candidate portion is extracted.

The defect judging section 4 judges the quality of the extracted pattern defect candidate portion, recognizes the type of defect and the position of occurrence, and outputs the result as an inspection result. In this embodiment, the polishing streaks on the surface of the copper foil 8b of the substrate 8 to be inspected are shown in FIG.
As shown in (a), the substrate 8 to be inspected is
A line light illumination means A,
Illumination is performed by B, and an image of the inspection area is taken by the line sensor 1 from above the inspection target substrate 8 vertically. Then
Since the illumination light that is obliquely incident on the surface of the substrate 8 to be inspected is specularly reflected in the oblique direction on the flat copper foil 8b surface, the specularly reflected light does not enter the line sensor 1 and the copper foil The surface 8b is darkly imaged by the line sensor 1.
On the other hand, on the surface of the etching resist ink 8f, a part of the illuminating light incident from an oblique direction is reflected upward and is imaged brightly by the line sensor 1, so that the S / N ratio at the time of detection by the line sensor 1 is good, The etching resist pattern can be inspected with high accuracy.

As shown in FIG. 3A, if there is a concave portion 8c made of copper, fine burrs 8d, or edges 8e on the surface of the substrate 8 to be inspected, it will be shown in FIG.
As shown in the figure, the illumination light from the oblique direction is
d, line sensor 1 refracted / reflected / scattered at edge 8e
The brightness of the light incident on the light source becomes high and becomes a bright spot noise component, and the S / N ratio at the time of detection by the line sensor 1 decreases. In such a case, a filter that cuts a copper-based color is used as the first color filter 2a, and an image is captured by the line sensor 1 via the first filter 2a, or illumination with less copper-based color is used. Thus, the bright spot noise component is reduced, and S / S at the time of detection by the line sensor 1 is reduced.
By improving the N ratio, highly accurate pattern inspection can be performed.

By dispersing the illumination in two directions on both sides, the number of bright spots increases, but the luminance per bright spot (that is, the magnitude of the bright spot noise) can be reduced. The S / N ratio at the time of detection by the sensor 1 can be improved. In addition, when the inspection area of the inspection target substrate 8 is illuminated only from one direction, the brightness of the both ends of the etching resist pattern orthogonal to the polishing stripes becomes asymmetric, but from two directions (the line light illuminating means A , B)
Illuminating the area to be inspected can improve the asymmetry. Further, the brightness of the bright spot peak can be reduced by imaging the object with the focus blurred by the line sensor 1, and the S / N ratio at the time of detection by the line sensor 1 can be improved.

On the surface of the copper foil 8b of the substrate 8 to be inspected,
As shown in FIG. 2 (b), a burr 8d made of copper is formed on the copper recess 8c along the rotating direction of the buff or the brush by polishing.
May have occurred. In such a case, the S / N ratio at the time of detection by the line sensor 1 is often better when illuminated from the downstream side in the rotation direction (in this embodiment, illuminated by the line light illuminating means B). Therefore, in the case of one-sided illumination, the use of the line light illuminating means B provided on the downstream side in the rotation direction is less susceptible to the burr 8d, so that the S / N ratio at the time of detection by the line sensor 1 can be improved. it can.
In the case of double-sided illumination by the line light illuminating means A and B, the illuminance of the line light illuminating means A arranged in a direction opposite to the illuminance of the line light illuminating means B arranged on the downstream side in the rotation direction. If the image is picked up by the line sensor 1, the influence of the burr 8d can be reduced, so that the S / N ratio at the time of detection by the line sensor 1 can be improved.

As the etching resist ink, a UV curable ink composed of a blue pigment and a resin is used. For this reason, the etching resist pattern becomes bluish at the center, but becomes bluish and colorless and transparent at the end, and it is difficult to detect the end by the conventional pattern inspection method. However, in the present embodiment, for example, as shown in FIG. 2A, a case where a thick etching resist ink 8f (blue color) and a thin etching resist ink 8g (colorless and transparent) are mixed on the substrate 8 to be inspected. Even so, the line sensors 1 above the substrate 8 to be inspected can make the respective etching resist inks 8f, 8g uniform in level by scattering the oblique illumination of the line light illuminating means A and B appropriately above the substrate 8 to be inspected. (Bright). In this case, the illumination light of each of the line light illumination means A and B is specularly reflected on the surface of the copper foil 8b, so that the surface of the copper foil 8b is imaged dark by the line sensor 1. As described above, when the surface of the copper foil 8b is dark and the surface of the etching resist inks 8f and 8g are detected bright by the line sensor 1, it is thinner than the surface of the copper foil 8b is detected bright and the surface of the etching resist ink 8f and 8g is dark. The detection of the ink state is easy, and the detection performance of the etching resist ink can be improved. Further, the detection performance is high even for fine fibrous foreign matter defects.

FIG. 3A shows an etching resist ink 8.
FIG. 5F is a top view of the etching resist pattern on the copper foil 8b by f, and it is assumed that the edge of the etching resist pattern (ink) has changed from a pale blue color to almost colorless and transparent. Here, C- of the etching resist pattern
The case where the C ′ line is imaged will be described below. When a blue transmission filter is used as the first color filter 2a and an image is taken by the line sensor 1 through the first color filter 2a, as shown in FIG. The etching resist ink portion) has a high blue luminance level, but the blue luminance level is low at the end of the etching resist pattern,
Since the end of the etching resist pattern cannot be detected, accurate detection of the etching resist pattern cannot be performed.

When a red transmission filter is used as the first color filter 2a and an image is picked up by the line sensor 1 through the first color filter 2a, as shown in FIG. The luminance level of red is low, the luminance level of red at the end is high, and the bright spot noise level due to the concave portion 8c on the surface of the copper foil 8b is high with the red filter, so that an accurate etching resist pattern cannot be detected.

When a green transmission filter is used as the first color filter 2a and an image is picked up by the line sensor 1 through the first color filter 2a, as shown in FIG. The (green portion) has a high luminance level of green but has a low luminance level of green at the end, and the end of the etching resist pattern cannot be detected, so that an accurate etching resist pattern cannot be detected.

Therefore, if an image is picked up by the line sensor 1 through a blue color transmission filter that transmits only blue color, the detection level (luminance) of the pattern edge portion of the etching resist can be obtained.
However, if the image is taken by the line sensor 1 through a color filter in which the transmittance of a color component is adjusted so as to transmit a little copper-based color as the first color filter 2a,
It is possible to detect the etching resist pattern at a uniform luminance level at the center and the end of the etching resist pattern.

In this embodiment, a light blue filter and a light green filter are used as the first color filter 2a in an overlapping manner, and the image is picked up by the line sensor 1 as shown in FIG.
A substantially uniform luminance level as shown in FIG. By detecting at a uniform luminance level, the pattern inspection of the etching resist pattern up to its end can be performed with high accuracy. Note that the bright spot noise generated in FIG. 3E can be countered by image processing by the CPU of the image detection processing unit 3.

(Embodiment 2) A method of manufacturing a printed circuit board according to this embodiment will be described with reference to FIG. As shown in FIG. 4 (a), a copper-clad laminate is charged, and the copper foil 8
b. Polishing for roughening and cleaning the surface by brush polishing, etc.
A cleaning step 11, a printing step 12 of printing an etching resist ink through a screen plate having a cut pattern corresponding to a circuit pattern on the surface of the copper foil 8b by a screen printing machine, and a drying step 13 of drying the etching resist ink are sequentially performed. Before the etching step 16 of etching the copper foil 8b using the etching resist ink as a mask, an inspection step 14 of inspecting the appearance of the etching resist pattern by the etching resist ink by the printed board pattern inspection method of the first embodiment.
And taking out 15 of the defective board (substrate 8 to be inspected) determined to be defective in the inspection step 14 are sequentially performed. If a continuous failure occurs in the inspection process 14, an alarm is issued to the printing process 12, the printing process 12 is stopped, and the cause of the failure is confirmed and its countermeasures are taken. At this time, several defective substrates stay in the drying step 13.

Further, as shown in FIG. 4B, a copper-clad laminate is put in, a polishing / cleaning step 11 and a printing step 12 are sequentially performed, and an inspection step 14 and an inspection step 14 are performed before the drying step 13. Then, the defective substrates determined to be defective are sequentially taken out. If a continuous failure occurs, the printing is stopped immediately, and the cause of the failure is confirmed and countermeasures are performed near the printing process 12. At this time, continuous occurrence of defective substrates is minimized. However, since the etching resist ink of the defective substrate is not dried, it is necessary to pay attention so that the ink does not adhere to the surroundings and workers. In this case, the defective substrate can be regenerated by wiping off the etching resist ink with an organic solvent or the like. Therefore, there is no need to discard the defective substrate, and loss due to the defect can be reduced.

Further, as shown in FIG. 4C, a copper-clad laminate is put in, a polishing / cleaning step 11 and a printing step 12 are sequentially performed, and an inspection step 14 is performed before a drying step 13. If a continuous failure occurs at 14, an alarm is issued and printing is stopped immediately, and the defective substrate determined to be defective in the inspection step 14 is removed after drying 13 is performed. At this time, the continuous occurrence of defective substrates is minimized, handling of the defective substrates is facilitated, and work for checking and correcting defects is facilitated. The timing of picking up a defective substrate is controlled by a pattern inspection apparatus.

[0054]

According to the first aspect of the present invention , the polishing direction of the copper foil is one.
Direction and two opposing directions parallel to the polishing direction
Luo illuminates the inspecting region of the printed circuit board from an oblique direction with respect to print the substrate surface, and the inspection region from above of the inspection area to be imaged by the imaging device, the polishing
The illuminance of the first illumination illuminating from the downstream side in the direction
Since the illuminance of the second illumination is larger than that of the second illumination, the illumination light from the oblique direction with respect to the printed circuit board surface is specularly reflected in the oblique direction in the area where the copper is exposed, and the image is darkly picked up by the image sensor. In the region, the irradiation light is refracted, reflected, and scattered, so that the image is brightly picked up by the image pickup device. As a result, the pattern of the etching resist ink can be inspected before etching the copper foil . Also, pudding
From the direction parallel to the polishing direction of the copper foil on the printed circuit board.
Illuminates the area to be inspected on the printed circuit board.
Irregular reflection of light due to the
The S / N ratio is improved, and the etching register
The effect that the reliability of the inspection of the pattern of the strike ink improves.
There is fruit. Moreover, two opposite directions parallel to the polishing direction
Each of the pre-
Illuminates the area to be inspected on the printed circuit board.
Half of the one-way case, resulting in exposed copper
Bright spot noise generation from recesses, fine burrs, and edges on the foil surface
, The brightness of the image signal output from the image sensor can be reduced.
N ratio is improved and pattern detection of etching resist ink
The effect is that the reliability of the inspection is improved. Further polishing
The illuminance of the first illumination illuminating from the downstream side in the direction
Since the illuminance of the second illumination is larger than that of the second illumination,
Utilizing the features of the shape, the lighting on the downstream side in the polishing streak generation direction
S / N at the time of detection by the image sensor by increasing the illuminance
This has the effect of improving the ratio.

[0055]

[0056]

[0057]

[0058]

The invention according to claim 2 is the invention according to claim 1.
Te, since the image pickup by the image pickup device via a color filter to adjust the transmittance of the color components as the luminance level of a thick portion and a thin portion of the thickness of the etch ring resist ink is uniform pattern of the etching resist ink This has the effect of improving the accuracy and reliability of the inspection. According to a third aspect of the present invention , in the first aspect of the present invention, the illumination is performed by adjusting the illuminance of the color component so that the luminance level of the thick portion and the thin portion of the etching resist ink is uniform. This has the effect of improving the accuracy and reliability of ink pattern inspection.

The invention of claim 4 is the invention according to claim 1.
Te, and illuminated by adjusting the illuminance of the color component so that the luminance level is uniform and the thickness of the thick portion and thin portion of the etching resist ink, of a thick portion and a thin portion of the thickness of the etching resist ink Since the image is picked up by the image pickup device via the color filter in which the transmittance of the color component is adjusted so that the luminance level becomes uniform, the accuracy and reliability of the pattern inspection of the etching resist ink can be improved as compared with the inventions of the second and third aspects. There is an effect that is improved.

The invention according to claim 5 is the invention according to claims 1 to 4.
In the invention, a line inspection part is detected in a line shape using a line light illuminating means for illumination and a line sensor as an image pickup element for detection, and a printed circuit board is moved in a direction orthogonal to the line sensor to obtain an entire inspection area. Is imaged by the line sensor, so that the line light illumination and the line sensor can realize a wide parallel and oblique illumination in a linear partial area, an upper image, and a uniform and stable detection can be simultaneously obtained in the width direction.
By moving this in the orthogonal direction, there is an effect that the pattern of the etching resist ink can be inspected at high speed and with high accuracy.

According to the invention of claim 6 , the copper foil surface is ground in one direction.
Prints polished and etched with resist ink
Two opposing directions parallel to the polishing direction of the copper foil on the substrate
And 2 recruited in illumination means you illuminate the inspection region in a line from an oblique direction with respect to the printed circuit board surface from respectively
A polishing method comprising: a line sensor that images the inspection area illuminated in a line shape; and a moving unit that mounts the printed circuit board and moves the printed circuit board in a direction perpendicular to the line sensor.
One line illuminating the inspection area from the downstream side
The illuminance of the other line light illuminating means that opposes the illuminance of the bright means
Since then larger, there is an effect that inspection of a pattern of high precision etching resist ink to a high speed can be.

According to a seventh aspect of the present invention, a printed circuit board pattern inspection method according to any one of the first to fifth aspects of the present invention inspects a circuit pattern formation state of the printed circuit board using the etching resist ink before etching the copper foil. Therefore, it is possible to quickly find out the occurrence of a defect on a printed circuit board and to reproduce a defective product, thereby reducing a defect loss.

[0064]

[Brief description of the drawings]

FIG. 1 (a) is a top view of an embodiment of the present invention. (B) It is a block diagram showing the composition of the example of the present invention.

FIGS. 2A and 2B are explanatory diagrams showing the principle of the present invention.

FIGS. 3A to 3E are explanatory views showing the principle of the present invention.

FIGS. 4A to 4C are explanatory views of a printed circuit board manufacturing process including an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Line sensor 2a 1st color filter 2b 2nd color filter 2c 3rd color filter 3 Image detection processing part 4 Defect judgment part 5 Control part 6 NC drive part 7 NC table 8 Inspection board (printed board) A 1st line light illuminating means B 2nd line light illuminating means

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-282302 (JP, A) JP-A-2-82141 (JP, A) JP-A-6-3282 (JP, A) JP-A-4-282 290292 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01N 21/84-21/958 H05K 3/02-3/08

Claims (7)

(57) [Claims] A pattern inspection method for inspecting a pattern formation state of an etching resist ink applied to a copper foil so as to correspond to a circuit pattern after polishing a copper foil surface of a printed board made of a copper-clad laminate. Oh , copper
The polishing direction of the foil is one direction, the relative direction parallel to the polishing direction
The inspection area of the printed circuit board is illuminated obliquely with respect to the surface of the printed circuit board from each of two directions, and the inspection area is imaged by an image sensor from above the inspection area, and the downstream side in the polishing direction. The first to illuminate from
The illuminance of the lighting was made larger than the illuminance of the second lighting opposing
A method for inspecting a pattern of a printed circuit board, comprising: 2. The etching resist ink has a large thickness.
Color so that the brightness level of
Image sensor through a color filter whose transmittance has been adjusted
2. The method for inspecting a pattern of a printed circuit board according to claim 1, further comprising: 3. The etching resist ink has a large thickness.
Color so that the brightness level of
Claim, characterized in that illuminating the minute illumination controls to 1
The printed circuit board pattern inspection method described in the above. 4. The etching resist ink has a large thickness.
Color so that the brightness level of
Adjust the illumination of the minute
The brightness level of the thick and thin parts is uniform
Claim 1 Symbol made as through a color filter to adjust the transmittance of the color components, characterized in that the image pickup by the image pickup device
Pattern inspection method of a printed circuit board mounting. 5. A line light illuminating means for illumination, and imaging for detection.
Using a line sensor for the element, partial inspection area in a line
And make the printed circuit board orthogonal to the line sensor
Direction, and the entire inspection area is
Claim 1, characterized in that the imaging
Pattern inspection method of a printed circuit board according to. 6. The copper foil surface is polished in one direction and etched.
Copper foil on printed circuit board coated with resist ink
Print from each of two opposing directions parallel to the polishing direction
The area to be inspected is lined up obliquely to the substrate surface
Two line light illuminating means for illuminating;
A line sensor for capturing an image of the inspected area,
Place the lint board in the direction perpendicular to the line sensor
And a moving means for moving the workpiece from the downstream side in the polishing direction.
Check the illuminance of one line light illuminating device that illuminates the inspection area.
Make sure that the illuminance of the other line light
A pattern inspection apparatus for a printed circuit board. 7. After polishing the copper foil surface of the copper-clad laminate
Etching resist corresponding to the circuit pattern on the copper foil
And apply the etching resist ink.
The copper foil is etched as a mask,
A method for manufacturing a printed circuit board that removes distant ink.
Pattern formation with etching resist ink
The state before etching of the copper foil is defined in any one of claims 1 to 5.
Inspection by the printed circuit board pattern inspection method described in section
A method for manufacturing a printed circuit board, comprising: