JP2005140584A - Three-dimensional measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three-dimensional measuring device capable of exactly measuring three-dimensional shape of an object, by properly setting the height reference of the object. <P>SOLUTION: A printed board 1 where a cream solder is formed by printing is irradiated with plurality of light patterns by an illumination device 10. The light irradiated from the illumination device 10 is ultraviolet and is reflected on the surface of cream solder, resist film, etc. of the printed board 1. By having the ultraviolet of the reflection light imaged by a CCD camera 11, image data are acquired. The image data are processed with a controller 2, the height of cream solder from reference surface of the resist film, quantity, etc. are calculated, and the quality of printed state of the cream solder is decided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a three-dimensional measuring apparatus that measures a three-dimensional shape or the like of a measurement object.

  Generally, a printed circuit board has an electrode pattern on a base substrate made of glass epoxy resin, and the surface is protected by a resist film. When an electronic component is mounted on the printed board, cream solder is first printed at a predetermined position on the electrode pattern that is not protected by a resist film. Next, an electronic component is temporarily fixed on the printed circuit board based on the viscosity of the cream solder. Thereafter, the printed circuit board is guided to a reflow furnace, and soldering is performed through a predetermined reflow process. In recent years, it is necessary to inspect the printing state of the cream solder in the previous stage of being guided to the reflow furnace, and a three-dimensional measuring device is sometimes used for such inspection.

In recent years, various so-called non-contact type three-dimensional measuring apparatuses using light have been proposed. For example, in a three-dimensional measurement apparatus using a phase shift method, an object to be measured (in this case, a printed circuit board) is irradiated with a light pattern having a striped light intensity distribution using visible light as a light source. Then, the object to be measured is imaged with a CCD camera, and the three-dimensional shape, particularly the height of the cream solder is measured by analyzing the phase difference of the stripes of the light pattern from the obtained image (for example, Patent Document 1). reference.).
JP-A-5-280945

  However, the resist film of the printed circuit board has unstable transmission characteristics with respect to visible light. That is, the resist film may or may not transmit visible light irradiated by the irradiation unit. Visible light is reflected by the base substrate or the like when passing through the resist film, and reflected by the surface of the resist film when not passing through the resist film. In such a case, in the resist film region in the image obtained by the CCD camera, it is difficult to determine whether the reflecting surface is the resist film or the base substrate, and it may be difficult to measure the height of the resist film region. There is. Originally, in order to measure the height of the cream solder printed on the substrate with higher accuracy, it is desirable to take a height reference in the substrate. However, since the resist film region cannot be properly used as the height reference plane, there is a risk that a height reference cannot be taken in the substrate.

  Therefore, the present invention has been made to solve the above-mentioned problems, and its purpose is to appropriately set a height reference in the object when measuring the three-dimensional shape of the object, etc. Therefore, it is intended to provide a three-dimensional measuring apparatus that can measure more accurately.

  In the following, each means suitable for solving the above-mentioned purpose will be described in terms of items. In addition, the effect etc. peculiar to the means to respond | correspond as needed are added.

  Means 1. Irradiation means capable of irradiating at least one of blue light and ultraviolet light to the object to be measured on the substrate, and reflected light from the object to be measured irradiated with the light is irradiated by at least the irradiation means. A three-dimensional measuring apparatus comprising: an imaging unit capable of imaging a measured wavelength; and an arithmetic unit that calculates at least the height of the object to be measured based on image data captured by the imaging unit.

  According to the means 1, the measurement object on the substrate is irradiated with blue light or ultraviolet light by the irradiation means. Such light having a relatively short wavelength is easily reflected on the surface of an object. Some visible light having a wavelength longer than that of the irradiation light has unstable transmission characteristics and may or may not be transmitted. In this respect, the means 1 can more reliably reflect the surface of the measurement object even if the transmission characteristic of the measurement object is unstable. For this reason, the surface of the measurement object can be captured as an image by the imaging means. And the height which is the position of the surface of a to-be-measured object can be calculated more correctly by calculating by the calculating means based on image data. In addition, the board | substrate in each means is the meaning containing a printed circuit board, a wafer board | substrate, a mounting board | substrate, etc.

  Mean 2. Irradiation means capable of irradiating at least one of blue light and ultraviolet light to a substrate provided with a base substrate, a surface coating of the base substrate, a flat coating, and an object to be measured; Of the reflected light from the irradiated substrate, an imaging unit capable of imaging at least the wavelength irradiated by the irradiation unit, and a plane formed by the coating based on image data captured by the imaging unit A three-dimensional measuring apparatus comprising a calculating means for calculating at least the height of an object to be measured based on a height reference.

  According to the means 2, the substrate is irradiated with blue light or ultraviolet light by the irradiation means. Such light having a relatively short wavelength is easily reflected on the surface of an object. For example, when visible light having a wavelength longer than that of the light is irradiated by the irradiating means, the coating covering the substrate exhibits unstable transmission characteristics such that the irradiated visible light may or may not be transmitted. There is. In this case, it is difficult to determine the light reflection position, and there is a possibility that the height reference cannot be set in the coating region. In this respect, the means 2 can more reliably reflect the surface even if the film has an unstable transmission characteristic. For this reason, the surface of the film and the surface of the object to be measured can be captured as images by the imaging means. Then, the height, which is the position of the surface of the object to be measured, can be calculated by performing the calculation based on the image data by the calculation means, using the surface of the film as the height reference. Therefore, since the height reference can be appropriately set in the substrate on which the object to be measured is provided, the height of the object to be measured can be measured more accurately. In addition, the film can be measured simultaneously with the measurement of the object to be measured. For this reason, it is not necessary to measure the height of the coating film or a separate height reference by a separate means, and the apparatus can be prevented from becoming complicated.

  Means 3. Irradiation means capable of irradiating only ultraviolet rays to a substrate provided with a base substrate, a surface coating of the base substrate, a flat coating, and an object to be measured, and reflection from the substrate irradiated with the light Based on the imaging means capable of imaging only ultraviolet rays of light, and the image data captured by the imaging means, the height of the object to be measured is calculated based on the height formed by the plane formed by the film. A three-dimensional measuring apparatus comprising an arithmetic means.

  According to the means 3, the substrate is irradiated with ultraviolet rays by the irradiation means. Such light having a relatively short wavelength is easily reflected on the surface of an object. For example, when visible light having a wavelength longer than that of the ultraviolet rays is irradiated by the irradiation means, the coating film covering the substrate exhibits unstable transmission characteristics such that the irradiated visible light may or may not be transmitted. There is. In this case, it is difficult to determine the light reflection position, and there is a possibility that the height reference cannot be set in the coating region. In this respect, the means 3 can more reliably reflect the surface even if the coating has unstable transmission characteristics. For this reason, the surface of the film and the surface of the object to be measured can be captured as images by the imaging means. Then, the height, which is the position of the surface of the object to be measured, can be calculated by performing the calculation based on the image data by the calculation means, using the surface of the coating as a reference. Accordingly, since the height reference can be set in the substrate on which the object to be measured is provided, the height of the object to be measured can be measured more accurately. In addition, the film can be measured simultaneously with the measurement of the object to be measured. For this reason, it is not necessary to measure the height of the coating film or a separate height reference by a separate means, and the apparatus can be prevented from becoming complicated. Furthermore, since the imaging means can image only ultraviolet rays, even when visible light from other than an illumination device such as an indoor illumination device hits the substrate, appropriate image data can be obtained without being affected by the visible light. Can be obtained. In addition, when visible light is irradiated, the amount of light reflected by the color of the film decreases, and image data obtained by imaging cannot be used, or the wavelength of visible light is changed according to the color of the film There is a concern that it may be necessary to do so. In this respect, since the means 3 can perform surface reflection regardless of the color of the coating film, the concern can be eliminated. In place of “irradiation means capable of irradiating only ultraviolet rays”, “irradiation means capable of irradiating light including ultraviolet rays” may be used. Even in this case, the ultraviolet rays of the irradiated light are reflected by the surface of the coating, and only the ultraviolet rays are imaged by the imaging means. For this reason, the surface of the film can be captured as an image.

  Means 4. The substrate is a printed circuit board, and the computing means computes at least the height of the cream solder as the object to be measured with respect to the height of the surface of the resist film as the coating, 4. The three-dimensional measuring apparatus according to means 2 or 3, further comprising a judging means for judging whether the printing state is good or not based on the height.

  According to the means 4, the height of the cream solder is calculated on the basis of the surface of the resist film of the printed circuit board, and the quality determination is performed based on the calculated height. For this reason, the said effect is show | played at the time of the measurement of cream solder, and also the quality determination can be performed more correctly.

  Means 5. The substrate is a wafer substrate, and the calculation means calculates at least the height of the solder bump as the object to be measured with respect to the height of the surface of the oxide film as the coating, 4. The three-dimensional measuring apparatus according to means 2 or 3, further comprising a determining means for determining the quality of the shape based on the height.

  According to the means 5, the height of the solder bump is calculated on the basis of the surface of the oxide film on the wafer substrate, and the quality is determined based on the calculated height. For this reason, the above-mentioned effect is exhibited at the time of measuring the solder bump, and the quality determination can be performed more accurately.

  Means 6. The calculation means uses a plurality of image data for one height calculation, and the irradiation means irradiates light of the same wavelength every time imaging is performed to obtain the plurality of image data. The three-dimensional measuring apparatus according to any one of means 1 to 5, characterized by:

  According to the means 6, the light with the same wavelength is used as the light irradiated by the irradiating means without changing the wavelength of the light every time the image is taken. For this reason, even if the imaging means has a lens, the light refraction does not change. Therefore, it is possible to suppress a problem that a deviation occurs in an image obtained depending on the illumination wavelength. As a result, the calculation accuracy of the height of the object to be measured can be improved.

  Mean 7 The three-dimensional measuring apparatus according to any one of means 1 to 6, wherein the irradiating means irradiates light having a wavelength of 250 nm or more and 430 nm or less.

  According to the means 7, light having a wavelength of 250 nm or more and 430 nm or less is irradiated by the irradiation means. For this reason, surface reflection can be more reliably performed even when the transmission characteristics are unstable. Therefore, the imaging means can reliably capture the surface of the coating film or the object to be measured as an image. Instead of “250 nm or more and 430 nm or less”, “300 nm or more and 380 nm or less” or “300 nm or more and 350 nm or less” may be used. In this case, it is possible to more reliably reflect the surface even with an unstable transmission characteristic. Further, instead of “light having a wavelength of 250 nm or more and 430 nm or less”, “light having a wavelength peak in a range of 250 nm or more and 430 nm or less”, “300 nm or more and 380 nm or less. The same action and effect can be obtained also for “light having a wavelength peak at” or “light having a wavelength peak within a range of 300 nm or more and 350 nm or less”.

  Means 8. The three-dimensional measuring apparatus according to any one of means 1 to 7, wherein the irradiating means irradiates light in a wavelength region of 60 nm or less.

  According to the means 8, the wavelength range of the light irradiated by the irradiation means is set to be relatively narrow within 60 nm. In general, the refraction of light when passing through a lens differs depending on the wavelength, and there is a risk of causing chromatic aberration when the wavelength range is wide. In this respect, the means 8 has a narrow wavelength range even when the illumination device or the imaging means has a lens, and can suppress chromatic aberration that occurs during irradiation or imaging. That is, sharp image data can be obtained without blurring of irradiated light or blurring of captured image data. Therefore, it is possible to improve the calculation accuracy of the height of the measurement object based on the image data. Note that “within 30 nm” may be used instead of “within 60 nm”. In this case, chromatic aberration can be further suppressed, and as a result, the accuracy of calculating the height of the object to be measured based on the image data can be further improved.

  Means 9. Irradiation means capable of irradiating at least one of red light and infrared light to the object to be measured on the substrate and reflected light from the object to be measured irradiated with the light is irradiated by at least the irradiation means. A three-dimensional measuring apparatus comprising: an imaging unit capable of imaging a measured wavelength; and an arithmetic unit that calculates at least the height of the object to be measured based on image data captured by the imaging unit.

  According to the means 9, the measurement object on the substrate is irradiated with red light or infrared light by the irradiation means. Such light having a relatively long wavelength has a property of being easily transmitted through an object. Some visible light having a wavelength shorter than that of the irradiation light has unstable transmission characteristics and may or may not be transmitted. For example, even if the transmission characteristic of the object to be measured is stable and visible light can be reflected from the surface, the transmission characteristic of an object other than the object to be measured on the substrate may be unstable. In this respect, since the irradiation light is red light or infrared light, the means 9 can transmit the irradiation light to an object with unstable transmission characteristics. For this reason, it is possible to more reliably capture only the surface of an object (such as an object to be measured) that can reliably reflect the surface by the imaging means. And the height which is the position of the surface of a to-be-measured object can be calculated more correctly by calculating by the calculating means based on image data. In addition, the board | substrate in each means is the meaning containing a printed circuit board, a wafer board | substrate, a mounting board | substrate, etc.

  Means 10. A substrate including a base substrate, an electrode pattern formed on the base substrate, a film covering the surfaces of the base substrate and the electrode pattern, and a measurement object, and at least one of red light and infrared light Irradiating means capable of irradiating light, imaging means capable of imaging at least the wavelength irradiated by the irradiating means among reflected light from the substrate irradiated with the light, and image data captured by the imaging means And a calculation means for calculating at least the height of the object to be measured with the electrode pattern or the base substrate as a height reference.

  According to the means 10, the substrate is irradiated with red light or infrared light by the irradiation means. Such light having a relatively long wavelength has a property of being easily transmitted through an object. For example, when visible light having a wavelength shorter than that of the light is irradiated by the irradiation means, the coating film covering the substrate exhibits unstable transmission characteristics such that the irradiated visible light may or may not be transmitted. There is. In this case, it is difficult to determine the light reflection position, and there is a possibility that the height reference cannot be set in the coating region. In this respect, in the means 10, since the irradiation light is red light or infrared light, the irradiation light is more surely transmitted through the coating with unstable transmission characteristics and reflected by the electrode pattern or the base substrate under the coating. Can be made. For this reason, not only an object to be measured but also an electrode pattern and a base substrate can be captured as an image by the imaging means. Then, the height, which is the position of the surface of the object to be measured, can be calculated by performing a calculation based on the image data by the calculation means, using the electrode pattern and the base substrate as a height reference. Therefore, since the height reference can be appropriately set in the substrate on which the object to be measured is provided, the height of the object to be measured can be measured more accurately.

  Means 11. Irradiation means capable of irradiating only infrared rays to a substrate provided with a base substrate, an electrode pattern formed on the base substrate, a coating covering the surfaces of the base substrate and the electrode pattern, and an object to be measured Based on the image data captured by the imaging means and the image data captured by the imaging means, the electrode pattern or the base substrate as a height reference based on the reflected light from the substrate irradiated with the light, A three-dimensional measuring apparatus comprising at least a calculating means for calculating the height of an object to be measured.

  According to the means 11, the substrate is irradiated with infrared rays by the irradiation means. Such light having a relatively long wavelength has a property of being easily transmitted through the surface of an object. For example, when irradiating means irradiates visible light having a wavelength shorter than that of the infrared rays, the coating covering the substrate exhibits unstable transmission characteristics such that the irradiated visible light may or may not be transmitted. There is. In this case, it is difficult to determine the light reflection position, and there is a possibility that the height reference cannot be set in the coating region. In this respect, in the means 11, since the irradiation light is red light or infrared light, the irradiation light is more reliably transmitted to the coating with unstable transmission characteristics and reflected by the electrode pattern or the base substrate under the coating. Can be made. For this reason, not only an object to be measured but also an electrode pattern and a base substrate can be captured as an image by the imaging means. Then, the height, which is the position of the surface of the object to be measured, can be calculated by performing a calculation based on the image data by the calculation means, using the electrode pattern and the base substrate as a height reference. Therefore, since the height reference can be appropriately set in the substrate on which the object to be measured is provided, the height of the object to be measured can be measured more accurately. Furthermore, since the imaging means can only pick up infrared rays, even when visible light from a lighting device such as an indoor lighting device hits the substrate, appropriate image data can be obtained without being affected by the visible light. Can be obtained. In addition, when visible light is irradiated, the amount of light reflected by the color of the film decreases, and image data obtained by imaging cannot be used, or the wavelength of visible light is changed according to the color of the film There is a concern that it may be necessary to do so. In this respect, since the means 11 can transmit the irradiation light to the film and reflect it on the electrode pattern or the base substrate under the film, regardless of the color of the film, the concern can be eliminated. In place of “irradiating means capable of irradiating only infrared rays”, “irradiating means capable of irradiating light including infrared rays” may be used. Even in this case, infrared rays of the irradiated light are transmitted through the surface of the coating and reflected by the electrode pattern or the base substrate, and only the infrared rays are imaged by the imaging means. For this reason, the electrode pattern and base substrate used as a height reference can be captured as an image without forming the film as an image.

  Means 12. The substrate is a printed circuit board, and the calculation means calculates at least the height of the cream solder as the object to be measured with respect to the electrode pattern under the resist film as the film or the base substrate. The three-dimensional measuring apparatus according to means 10 or 11, further comprising a determining means for determining whether the printing state is good or not based on the height of the cream solder.

  According to the means 12, the height of the cream solder is calculated on the basis of the electrode pattern under the resist film of the printed circuit board or the base substrate, and the quality is determined based on the calculated height. For this reason, the said effect is show | played at the time of the measurement of cream solder, and also the quality determination can be performed more correctly.

  Means 13. The substrate is a wafer substrate, and the calculation means calculates at least a height of a solder bump as the object to be measured with reference to a wafer surface under the oxide film as the coating, and the solder bump The three-dimensional measuring apparatus according to means 10 or 11, further comprising a determining means for determining the quality of the shape based on the height of the shape.

  According to the means 13, the height of the solder bump is calculated on the basis of the wafer surface under the oxide film of the wafer substrate, and the quality determination is performed based on the calculated height. For this reason, the above-mentioned effect is exhibited at the time of measuring the solder bump, and the quality determination can be performed more accurately.

  Means 14. The calculation means uses a plurality of image data for one height calculation, and the irradiation means irradiates light of the same wavelength every time imaging is performed to obtain the plurality of image data. The three-dimensional measuring apparatus according to any one of means 9 to 13, characterized by:

  According to the means 14, the light with the same wavelength is used as the light irradiated by the irradiating means without changing the wavelength of the light every time the image is taken. For this reason, even if the imaging means has a lens, the light refraction does not change. Therefore, it is possible to suppress a problem that a deviation occurs in an image obtained depending on the illumination wavelength. As a result, the calculation accuracy of the height of the object to be measured can be improved.

  Means 15. The three-dimensional measuring apparatus according to any one of means 9 to 14, wherein the irradiating means irradiates light having a wavelength of 680 nm or more and 1500 nm or less.

  According to the means 15, light having a wavelength of 680 nm or more and 1500 nm or less is irradiated by the irradiation means. For this reason, surface reflection can be more reliably performed even when the transmission characteristics are unstable. Therefore, the imaging means can reliably capture the surface of the coating film or the object to be measured as an image. In place of “680 nm or more and 1500 nm or less”, “680 nm or more and 1000 nm or less” or “1000 nm or more and 1500 nm or less” may be used. Furthermore, “780 nm or more and 900 nm or less” or “ It may be “1100 nm or more and 1400 nm or less”. In addition, instead of “light having a wavelength of 680 nm or more and 1500 nm or less”, “light having a wavelength peak in the range of 680 nm or more and 1500 nm or less”, “range of 680 nm or more and 1000 nm or less "Light having a wavelength peak in the range" or "light having a wavelength peak in the range of 1000 nm or more and 1500 nm or less", and "wavelength peak in the range of 780 nm or more and 900 nm or less" Or “light having a wavelength peak in the range of 1100 nm or more and 1400 nm or less”.

  Means 16. The three-dimensional measuring apparatus according to any one of means 9 to 15, wherein the irradiating means irradiates light in a wavelength region of 60 nm or less.

  According to the means 16, the wavelength range of the light irradiated by the irradiation means is set to be relatively narrow within 60 nm. In general, the refraction of light when passing through a lens differs depending on the wavelength, and there is a risk of causing chromatic aberration when the wavelength range is wide. In this respect, the means 16 has a narrow wavelength range even when the illumination device or the imaging means has a lens, and can suppress chromatic aberration that occurs during irradiation or imaging. That is, sharp image data can be obtained without blurring of irradiated light or blurring of captured image data. Therefore, it is possible to improve the calculation accuracy of the height of the measurement object based on the image data. Note that “within 30 nm” may be used instead of “within 60 nm”. In this case, chromatic aberration can be further suppressed, and as a result, the accuracy of calculating the height of the object to be measured based on the image data can be further improved.

  Hereinafter, an embodiment will be described with reference to the drawings. As shown in FIG. 2, a printed circuit board 1 as a substrate has a flat plate shape (having a flat surface), and a base substrate 2 made of glass epoxy or the like is provided with an electrode pattern 3 made of copper foil. Further, cream solder 4 as an object to be measured is printed on the electrode pattern 3. Further, the printed circuit board 1 is coated with a translucent resist film 5 as a film so that the cream solder 4 is not applied to any part other than the predetermined wiring portion of the electrode pattern 3. Note that the surface of the resist film 5 is a plane having a substantially constant height.

  FIG. 1 is a schematic configuration diagram schematically showing a printing state inspection apparatus 8 including a three-dimensional measuring apparatus according to the present embodiment. As shown in the figure, the printing state inspection device 8 includes a table 9 for placing the printed circuit board 1 and an irradiation means for irradiating the surface of the printed circuit board 1 with a predetermined light component pattern obliquely from above. Various controls, image processing, and arithmetic processing in the printing state inspection device 8 are performed in the illumination device 10 that constitutes, the CCD camera 11 that constitutes an imaging means for imaging the irradiated portion on the printed circuit board 1. And a control device 12 for this purpose.

  The table 9 is provided with motors 15 and 16, and when the motors 15 and 16 are driven and controlled by the control device 12, the printed circuit board 1 placed on the table 9 can move in any direction (X Axial direction and Y-axis direction).

  As shown in FIG. 3, the illumination device 10 is disposed between a light source 17, a condensing lens 18 that collects light from the light source 17, an irradiation lens 19, and both lenses 18 and 19. And a liquid crystal optical shutter 21. The light from the light source 17 is irradiated onto the printed circuit board 1 through the liquid crystal optical shutter 21, and in particular, the printed circuit board 1 is irradiated with a striped light pattern whose illuminance changes in a sine wave shape. Further, the liquid crystal optical shutter 21 can change the phase of the light pattern by a predetermined pitch.

  Furthermore, the wavelength of the light emitted from the light source 17 is set so that it is reflected not only on the surface of the cream solder 4 but also on the surface of the resist film 5 as shown in FIG. However, in the present embodiment, the light source 17 emits ultraviolet rays, and for example, an LED, a UV lamp, or the like is used. Since light having a relatively short wavelength such as ultraviolet rays is easily reflected on the surface, even a semi-transparent material such as the resist film 5 can be more reliably reflected on the surface. The condensing lens 18 and the irradiation lens 19 can transmit light having the above-described wavelength, and the CCD camera 11 can image only ultraviolet rays.

  In particular, the wavelength range of the irradiated light is set to be relatively narrow. In general, the refraction of light when passing through a lens differs depending on the wavelength, and there is a risk of causing chromatic aberration when the wavelength range is wide. In this respect, in the present embodiment, by narrowing the wavelength region, chromatic aberration that occurs during irradiation or imaging can be suppressed, and a sharp image can be obtained.

  Here, an inspection procedure in the printing state inspection apparatus 8 will be described. First, when the printed circuit board 1 is placed on the table 9, the control device 12 drives and controls the motors 15 and 16 to move them to a predetermined position, thereby moving the printed circuit board 1 to the initial position. This initial position is, for example, one position in which the surface of the printed circuit board 1 is divided in advance with the size of the field of view of the CCD camera 11 as one unit.

  And the control apparatus 12 drives and controls the illuminating device 10, and starts irradiation of a light pattern. The irradiated light is reflected by the surface of the printed circuit board 1 such as the cream solder 4 and the resist film 5, and the reflected light is imaged by the CCD camera 11. At this time, the phase of the light pattern is shifted by, for example, a quarter pitch, and the four types of light patterns are sequentially switched and controlled. Further, while the light patterns are being irradiated in this way, the control device 12 drives and controls the CCD camera 11 to pick up the inspection area portion for each of these light patterns, and images for four screens, respectively. Get the data.

  The control device 12 includes an image memory and stores image data sequentially. Based on the stored image data, the control device 12 performs various image processing. While the image processing is being performed, the control device 12 controls the motors 15 and 16 to move the table 9 to the next inspection area. The control device 12 also stores the image data here in the image memory. On the other hand, when the image processing in the image memory is once completed, since the next image data is already stored in the image memory, the control device 12 can quickly perform the next image processing. That is, in the inspection, the movement to the next inspection area (m + 1) and the image input are performed on the one hand, and the m-th image processing and comparison determination are performed on the other hand. Thereafter, the same parallel processing is repeated alternately until the inspection in all the inspection areas is completed. Thus, in the printing state inspection device 8 of the present embodiment, the printing state of the cream solder 4 on the printed circuit board 1 is changed by sequentially performing image processing while moving the inspection area under the control of the control device 12. High-speed and reliable inspection can be performed.

  Next, image processing and calculation processing and comparison determination processing performed by the control device 12 will be described. The control device 12 calculates the height in the inspection area using the obtained four-screen image data. With respect to the light pattern projected on the inspection area, a phase shift occurs due to the difference in height. Therefore, the control device 12 calculates the height of the reflecting surface based on the principle of the phase shift method (the fringe scanning method) using the image data of each light pattern. The height data obtained in this way is calculated for each pixel of the imaging screen and stored in the memory of the control device 12.

  Of the obtained height data, the height of the solder film 4 printed on the printed circuit board 1 is calculated using the height of the resist film 5 region forming a plane as the height reference of the printer circuit board 1. Further, the amount of the printed cream solder 4 is calculated by integrating the height of the cream solder 4. Then, the data such as the height and amount of the cream solder 4 obtained in this way is compared with the reference data stored in advance, and whether or not the comparison result is within the allowable range in the inspection area. The quality of the printed state of the cream solder 4 is determined.

  As described above in detail, according to the present embodiment, even if the resist film 5 is translucent, light can be reliably reflected by the surface of the resist film 5 by irradiating the ultraviolet ray with the illumination device 10. . For this reason, while being able to detect the surface of the resist film 5 in the printed circuit board 1 on which the cream solder 4 to be judged whether the printed state is good or not can be detected, the surface can be used as a reference height. As a result, the height of the cream solder 4 can be calculated more accurately than when the height reference other than the same printed circuit board 1 is adopted.

  In addition, the height of the resist film 5 can be measured simultaneously with the measurement of the height of the cream solder 4. For this reason, it is not necessary to measure the height of the resist film or the separate height reference by a separate means, and the apparatus can be prevented from becoming complicated.

  Furthermore, the printing state inspection device 8 is generally provided indoors with an indoor lighting device. Generally, in the indoor lighting device, the radiant energy of visible light is large, and the radiant energy of light having a short wavelength as employed in the present embodiment is sufficiently smaller than that of visible light. For this reason, even if the light from the indoor lighting device is irradiated onto the printed circuit board 1, it is difficult to cause a problem that an image captured by the CCD camera 11 cannot be processed.

  Further, when visible light is irradiated, the amount of light reflected by the color of the resist film 5 decreases, and image data obtained by imaging cannot be used, or visible light depends on the color of the resist film 5. There is a concern that it may be necessary to change the wavelength of the light. In this regard, in the present embodiment, since the surface reflection can be performed regardless of the color of the resist film 5, the concern can be eliminated.

  In addition, the wavelength range of light emitted from the illumination device 10 is set to be relatively narrow as described above. Therefore, chromatic aberration is unlikely to occur, and sharp image data can be obtained without blurring of the light pattern or blurring of the captured image data. Accordingly, it is possible to improve the calculation accuracy of the height and amount of the cream solder 4 based on the image data.

  In addition, light having the same wavelength is used for the light pattern without changing the wavelength of light for each light pattern. That is, even when the light pattern is changed, the refraction of light when passing through the lens is not changed. For this reason, the malfunction that the shift | offset | difference arises in the image obtained by the wavelength of illumination can be suppressed. As a result, the calculation accuracy such as the height and amount of the cream solder 4 based on the image data can be improved.

  In the embodiment described above, for example, a part of the configuration can be appropriately changed as follows. Of course, other modifications not exemplified below are also possible.

  (A) In the above embodiment, the illumination device 10 is irradiated with ultraviolet rays, but blue light may be used as long as it can be reflected by the surface of the resist film 5. In this case, the CCD camera needs to be able to capture blue light. In addition, the light irradiated by the illuminating device 10 has a preferable wavelength of 250 nm or more and 430 nm or less. More preferably, the wavelength is 300 nm or more and 380 nm or less, and still more preferably, the wavelength is 300 nm or more and 350 nm or less. Instead of the wavelength of 250 nm or more and 430 nm or less, light having a wavelength peak in the range of 250 nm or more and 430 nm or less, light having a wavelength peak in the range of 300 nm or more and 380 nm or less, or 300 nm or more and Similar effects can be obtained even when the light has a wavelength peak within a range of 350 nm or less.

  (B) Although the ultraviolet light is irradiated from the light source 12, the wavelength of the light reaching the printed circuit board 1 only needs to be a predetermined wavelength, and the wavelength of the light from the light source 12 is not necessarily predetermined. It is not necessary to have only the wavelength of. For example, the light source emits light in a wide wavelength range including a predetermined wavelength, and only a predetermined wavelength (a predetermined narrow wavelength range) is provided between the illumination device 10 and the printed circuit board 1 or in the illumination device 10. It is good also as providing the filter which can permeate | transmit only this wavelength.

  (C) In the above embodiment, the wavelength range of light is not particularly numerically mentioned, but is preferably within 60 nm, and more preferably within 30 nm.

  (D) In the above embodiment, the light applied to the printed circuit board 1 is ultraviolet light. However, it is possible to irradiate light of other wavelengths in addition to ultraviolet light so that the light to be imaged is only ultraviolet light. In this case, of course, the CCD camera 11 may be capable of imaging only ultraviolet rays, or a filter capable of transmitting only ultraviolet rays may be provided between the CCD camera and the printed circuit board 1.

  (E) In the above embodiment, the number of times of imaging is four, but it may be three or five or more.

  (F) In the above-described embodiment, the present invention is embodied when measuring the height or the like of the cream solder 4 printed on the printed circuit board 1, but the present invention can also be applied to an inspection apparatus such as a wafer substrate or a mounting substrate. For example, in the case of a wafer substrate, the height, shape, volume, etc. of the solder bumps can be calculated with the surface of the oxide film as the reference height.

  (G) In the above embodiment, the phase shift method is adopted as the three-dimensional measurement method. However, the light cutting method, the moire method, the focusing method, the confocal method, the spatial code method, and the lattice fringe projection method are also used. Various three-dimensional measurement methods such as these can also be adopted.

  (H) Instead of the illumination device 10 of the above embodiment, the printed circuit board 1 is irradiated with light having a wavelength that passes through the resist film 5 and is reflected by the surface of the cream solder 4, the electrode pattern 3, and the like. You may make it image the light of. That is, the irradiation light may be infrared or red light instead of the ultraviolet light in the above embodiment, and infrared or red light may be imaged. Since light having a relatively long wavelength such as infrared light and red light is relatively easy to transmit through an object, it can be transmitted through a translucent material such as the resist film 5.

  By doing so, as shown in FIG. 5, infrared rays are reflected by the surface of the cream solder 4, transmitted through the semitransparent resist film 5, and reflected by the electrode pattern 3 and the like. Therefore, for example, the height of the cream solder 4 can be calculated with the electrode pattern 3 as a height reference. Further, when the reflected light can be obtained also for the base substrate 2, the base substrate 2 can be used as a height reference.

  In this case, the irradiation light preferably has a wavelength of 680 nm or more and 1500 nm or less. Note that the wavelength may be 680 nm or more and 1000 nm or less, or the wavelength may be 1000 nm or more and 1500 nm or less, and may be 780 nm or more and 900 nm or less, or 1100 nm or more and 1400 nm or less. Further, instead of the wavelength of 680 nm or more and 1500 nm or less, light having a wavelength peak in the range of 680 nm or more and 1500 nm or less, light having a wavelength peak in the range of 680 nm or more and 1000 nm or less, 1000 nm or more and 1500 nm or less Even if the light has a wavelength peak in the range of 780 nm, the light has a wavelength peak in the range of 780 nm or more and 900 nm or less, or the light has a wavelength peak in the range of 1100 nm or more and 1400 nm or less. An effect is obtained.

  In addition, of course, the present invention can be implemented with appropriate modifications as in the above (b), (c), (e), (f), and (g).

It is a schematic block diagram which shows typically the structure of a printing condition inspection apparatus. It is a fragmentary sectional view of a printed circuit board. It is a schematic block diagram which shows typically the structure of a more detailed printing state inspection apparatus. It is a schematic diagram for demonstrating reflection of the light irradiated from the illuminating device in a printed circuit board. It is another embodiment, and is a schematic diagram for explaining reflection of irradiated light when infrared rays or red light is irradiated.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Print substrate as a board | substrate, 2 ... Base substrate, 4 ... Cream solder as a to-be-measured object, 5 ... Resist film as a film, 8 ... Print state inspection apparatus provided with the three-dimensional measuring apparatus, 10 ... As illumination means Illumination device, 11... CCD camera as imaging means, 12...

Claims (8)

Irradiation means capable of irradiating at least one of blue light and ultraviolet light on the measurement object on the substrate;
An imaging unit capable of imaging at least a wavelength irradiated by the irradiation unit among the reflected light from the measurement object irradiated with the light;
A three-dimensional measurement apparatus comprising: a calculation unit that calculates at least a height of the measurement object based on image data captured by the imaging unit. An irradiating means capable of irradiating at least one of blue light and ultraviolet light on a substrate provided with a base substrate, a surface coating of the base substrate, a flat coating, and an object to be measured;
An imaging unit capable of imaging at least a wavelength irradiated by the irradiation unit among the reflected light from the substrate irradiated with the light;
A three-dimensional measurement comprising: a calculation means for calculating at least the height of the object to be measured based on the height of the plane formed by the film based on the image data picked up by the image pickup means apparatus. Irradiation means capable of irradiating only ultraviolet rays to a substrate provided with a base substrate, a surface coating of the base substrate, a flat coating, and a measurement object;
Among the reflected light from the substrate irradiated with the light, imaging means capable of imaging only ultraviolet rays,
A three-dimensional measurement comprising: a calculation means for calculating at least the height of the object to be measured based on the height of the plane formed by the film based on the image data picked up by the image pickup means apparatus. The substrate is a printed circuit board;
The computing means computes at least the height of the cream solder as the object to be measured, based on the height of the resist film surface as the coating,
4. The three-dimensional measuring apparatus according to claim 2, further comprising a determining unit that determines whether the printing state is good or not based on the height of the cream solder. The substrate is a wafer substrate;
The computing means computes at least the height of the solder bump as the object to be measured, based on the height of the surface of the oxide film as the coating,
4. The three-dimensional measuring apparatus according to claim 2, further comprising a determination unit that determines whether the shape is good or not based on the height of the solder bump. The calculation means uses a plurality of image data for one height calculation,
The three-dimensional measurement apparatus according to claim 1, wherein the irradiating unit irradiates light having the same wavelength every time imaging is performed to obtain the plurality of image data.   The three-dimensional measurement apparatus according to claim 1, wherein the irradiation unit irradiates light having a wavelength of 250 nm or more and 430 nm or less.   The three-dimensional measuring apparatus according to claim 1, wherein the irradiating unit irradiates light having a wavelength range of 60 nm or less.

Images