JP2006084446A - Apparatus and method for detecting circuit pattern, and apparatus and method for inspection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To image highly accurate images of circuit patterns of the uppermost layers of a multi-layer wiring board by a substantially one apparatus, even with respect to works having different properties. <P>SOLUTION: The apparatus for optically detecting a circuit pattern of the uppermost layer of a work 21, made of a multi-layer wiring board for semiconductor packages, is replaceably provided with a λ/4 wavelength plate 20, an optical plate 26 of the same refractive index, and a polarizing plate 27. The λ/4 wavelength plate 20 is used for a work having a certain property, and linearly polarized light (n) guided by a polarization beam splitter 18 is irradiated, after circular polarization by the λ/4 wavelength plate 20. The optical plate 26 of the same refractive index is used for a work of another property in place of the λ/4 wavelength plate 20, and linearly polarized light (n) is irradiated via the optical plate 26 of the same refractive index. Furthermore, the polarizing plate 27 is used for a work of yet separate properties in place of the λ/4 wavelength plate 20, and linearly polarized light (n) is irradiated, after vector resolution by the polarizing plate 27, to image the light reflected by the work 21. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the multilayer wiring board for a semiconductor package in which a plurality of wiring patterns are laminated by a plurality of layers having transparency such as a polyimide insulating layer, the present invention optically extracts the uppermost layer wiring pattern, The present invention relates to a wiring pattern detection apparatus, a detection method, an inspection apparatus, and an inspection method that perform imaging with resolution and automatically inspect the pattern.

  In general, wiring patterns formed on multilayer wiring boards for semiconductor packages, which are used for the purpose of reducing the size and weight of electrical equipment, are obtained by laminating a copper foil on a polyimide film with an adhesive, and then subtracting or semi-additively. The thickness is 5 to 15 μm and the width is about 10 μm at the most integrated part.

  In this patterning process, there is a possibility that serious defects such as thinning (chips), disconnection, short circuit, and thickening (projections) of the wiring pattern may occur. For this reason, conventionally, the presence or absence of these defects has been determined by open / short continuity inspection and visual inspection. However, the visual inspection requires pattern miniaturization and skill, and the inspection results may vary depending on the physical condition of the inspector. Therefore, various automatic inspection apparatuses that automatically inspect for defects using a camera have been proposed recently. In addition, it is possible to visually inspect various defects existing in a wiring pattern having a minimum width of 10 μm in the multilayer wiring board for semiconductor packages. However, the visual inspection takes time to inspect, and the product cost increases due to an increase in labor costs. Since there is a concern, automatic inspection is necessary. For example, in order to detect a defect of 1/3 or more within a width of 10 μm, an imaging resolution of 1 μm must be realized. Therefore, it is necessary to search for an imaging method and an inspection method globally from the relationship between the imaging resolution and the imaging field of view (target work size).

  As an invention made based on such circumstances, there is an invention of Patent Document 1. FIG. 10 is a configuration diagram of an apparatus disclosed in Patent Document 1. In FIG. For example, when light is emitted from a light source 10 using high-intensity illumination that emits light over the entire visible range, such as a white light source or a metal halide lamp, the light is emitted from the light guide 11, the condenser lens 40, and the heat ray cut filter 12. Then, the light enters the polarization beam splitter 31. The heat ray cut filter 12 blocks light on the long wavelength side (for example, a wavelength of 700 nm or more) and makes other light incident on the polarization beam splitter 31.

  The light emitted from the light source 10 is so-called random light having various light components. When this random light enters the polarizing beam splitter 31, linearly polarized light is extracted by the polarizing beam splitter 31. The polarization beam splitter 31 guides the extracted linearly polarized light to the polarization beam splitter 32.

  In the polarizing beam splitter 32, the light guided from the polarizing beam splitter 31 also includes some light whose electric field vector direction is other than the front and back directions on the paper surface. . The imaging lens 33 and the polarizing filter 34 convert this linearly polarized light into light having an angle component with a polarization angle of 40 to 50 °, and irradiate the light toward the work 51 fixed by the work fixing drive mechanism 50. . A light component obtained by vector-decomposing the linearly polarized light incident at this time in accordance with a predetermined polarization angle is irradiated toward the work 51.

  The light component irradiated to the work 51 is reflected by the work 51, and the light component obtained by vector-decomposing the reflected light according to the polarization angle of the polarizing filter 34 passes through the polarizing filter 34 and the imaging lens 33, and is a polarization beam splitter. 32 is incident. At this time, linearly polarized light having an electric field vector direction in the light guide direction is extracted in the polarization beam splitter 32, and this linearly polarized light is incident on the bandpass filter 42.

  The band pass filter 42 extracts a wavelength region in which the difference between the reflected light amount of the uppermost wiring pattern and the amount from the polarization beam splitter 32 due to the reflected light of the polyimide insulating layer portion is the largest, and only the light in the extracted wavelength region is extracted. Is incident on the CCD element 41 in the sensor camera 30.

  Then, the light passing through the band pass filter 42 is imaged by the CCD element 41. The intensity of the light component reflected from the work 51 depends on copper and polyimide, and since copper has a higher reflection intensity, the uppermost copper pattern portion is imaged brightly. Moreover, when irradiating the work 51, the image of the uppermost layer wiring pattern is captured more clearly by increasing the polarization ratio and irradiating the wiring pattern and the polyimide insulating layer.

By such an invention of Patent Document 1, it becomes possible to optically remove the influence of the inner layer wiring pattern on the multilayer wiring substrate for semiconductor packages, and a high-definition image of the uppermost layer wiring pattern is picked up. Wiring patterns can be inspected automatically and with high reliability. Further, the inspection and detection of the uppermost layer wiring pattern can be performed in a short time even for the uppermost layer wiring pattern having a large area.
International Publication Number WO 2004/040281 A1

  However, the technique disclosed in Patent Document 1 does not work universally for any multilayer wiring substrate for semiconductor packages, and depends on the manufacturing method, material, and polarization characteristics of the base film material used for the multilayer wiring substrate for semiconductor packages. It has been found that the uppermost layer wiring pattern may not be optically revealed with high accuracy.

  For example, in the wiring pattern inspection apparatus configured as shown in FIG. 10, the uppermost wiring pattern is decomposed and extracted for a multilayer wiring board for a semiconductor package composed of a wiring pattern in which a copper foil is laminated on a polyimide film with an adhesive. High-accuracy image data can be acquired, but for multilayer wiring boards for semiconductor packages having a wiring pattern formed by depositing copper plating, a high-accuracy image obtained by separating and extracting the uppermost wiring pattern The data cannot be obtained.

  The present invention has been made in view of such circumstances, and even with a workpiece having a different manufacturing method, material, and polarization characteristics of a base film material used for a multilayer wiring board for a semiconductor package, it is substantially a single device. Another object of the present invention is to provide a wiring pattern inspection apparatus, inspection method, detection apparatus, and detection method capable of acquiring highly accurate image data obtained by separating and extracting the uppermost layer wiring pattern.

  In order to achieve the above object, the present invention takes the following measures.

  That is, the invention of claim 1 is a wiring pattern detection device for optically detecting a top layer wiring pattern of a work comprising a multilayer wiring board for a semiconductor package having a wiring pattern on a light transmissive base film, comprising: a light source; Parallel light guiding means for guiding light from the light source substantially in parallel, infrared blocking means for blocking the infrared component of the light from the light source, and collecting the light whose infrared component is blocked by the infrared blocking means A first lens; a diffusion plate that diffuses the light collected by the first lens so that the intensity is uniform; a second lens that collects the light diffused by the diffusion plate; The light collected by the lens is extracted with a polarizing filter that extracts first linearly polarized light whose electric field vector direction is orthogonal to the light guiding direction, and with the first linearly polarized light extracted by the polarizing filter. A polarization beam splitter that guides the light in the direction perpendicular to the light guide direction and the electric field vector direction.

  Further, a detachable λ / 4 wavelength plate that converts the first linearly polarized light guided by the polarizing beam splitter into circularly polarized light, or a λ / 4 wavelength plate that guides the first linearly polarized light guided by the polarizing beam splitter. The first linearly polarized light guided by a detachable same refractive index optical plate having substantially the same refractive index as that of the optical member or a polarizing beam splitter is applied to a polarization component having a predetermined polarization angle through a polarizing plate having a predetermined polarization angle. An optical member which is any one of the detachable polarization component extracting means for extracting is provided.

  Furthermore, when a λ / 4 wave plate is used as the optical member, circularly polarized light converted by the λ / 4 wave plate is used. When the same refractive index optical plate is used as the optical member, the same refraction is used. When the polarization component extraction means is used as the optical member for the first linearly polarized light guided by the index optical plate, the polarization components extracted by the polarization component extraction means are respectively condensed and irradiated onto the workpiece. 3 lenses are provided.

  Further, when a λ / 4 wavelength plate is used as the optical member, the circularly polarized light irradiated by the third lens is reversed by the work and the rotation direction is reversed, and then the third lens and the λ / 4 wavelength are reversed. When the same refractive index optical plate is used as the optical member after passing through the plate, the reflected light formed by reflecting the first linearly polarized light irradiated to the workpiece by the third lens by the workpiece is the third. When the polarization component extraction means is used as an optical member after passing through the lens and the same refractive index optical plate, the reflected light formed by reflecting the polarization component irradiated to the workpiece by the third lens is reflected by the workpiece. Then, after passing through the third lens, it is guided to the polarization component extraction means and the polarization component extraction means performs vector decomposition according to the predetermined polarization angle of the polarizing plate, and then guides it to the polarization beam splitter. The liter includes a fourth lens for condensing the second linearly polarized light after the second linearly polarized light whose electric field vector direction is orthogonal to the direction of the first linearly polarized light is extracted.

  And a selection means for selecting a wavelength region in which the difference between the reflected light amount in the uppermost wiring pattern and the reflected light amount in the base film and the wiring pattern is the largest from the second linearly polarized light collected by the fourth lens. Imaging means for imaging light in the wavelength range selected by the selection means.

  Further, the wiring pattern detection device of the invention of claim 2 has a configuration in which the polarization filter in the wiring pattern detection device of the invention of claim 1 is omitted by extracting the first linearly polarized light by the polarization beam splitter.

  According to a third aspect of the present invention, in the wiring pattern detection apparatus according to the first or second aspect of the present invention, two light guide plates set in crossed Nicols and a half mirror are used instead of the polarization beam splitter.

  In such a wiring pattern detection device according to the first to third aspects of the invention, by taking the above-described means, the manufacturing method, material, and polarization characteristics of the base film material used for the multilayer wiring board for semiconductor packages can be improved. Accordingly, by properly using the λ / 4 wavelength plate, the same refractive index optical plate, or the polarization component extraction means, the image of the uppermost wiring pattern is optically accurately separated from any multilayer wiring board for semiconductor packages. be able to.

  In addition, since the λ / 4 wavelength plate, the same refractive index optical plate, and the polarization component extraction means are configured to be interchangeable with each other, a substantially single device can be used without using a separate device for each inspection target. It is possible to optically separate the image of the uppermost wiring pattern with high accuracy from all types of multilayer wiring substrates for semiconductor packages that differ in the manufacturing method, material, polarization characteristics, etc. of the base film material used for the multilayer wiring substrate for semiconductor packages. it can.

  According to a fourth aspect of the present invention, in the wiring pattern detection device according to any one of the first to third aspects, the frequency component synthesized with the voltage supplied to the discharge lamp provided in the light source is imaged as noise. Noise removing means is added so as not to affect the means.

  Therefore, in the wiring pattern detection device according to the fourth aspect, by taking the above-described means, it is possible to prevent noise from entering the captured image, thereby improving the inspection accuracy. It becomes.

  According to a fifth aspect of the present invention, there is provided an imaging provided in the wiring pattern detection device according to any one of the first to fourth aspects and the wiring pattern detection device according to any one of the first to fourth aspects. The wiring pattern inspection apparatus includes inspection means for checking whether or not the uppermost wiring pattern is a non-defective product by comparing an image captured by the means with a predetermined good product image.

  Therefore, in the wiring pattern inspection apparatus according to the invention of claim 5, by taking the above-described means, any semiconductor package having different manufacturing method, material, polarization characteristics, etc. of the base film material used for the multilayer wiring board for semiconductor packages. It is possible to accurately inspect whether or not the uppermost wiring pattern is a non-defective product with respect to the multilayer wiring board for use.

  The invention according to claim 6 is a wiring pattern detection method for optically detecting the uppermost wiring pattern of a work composed of a multilayer wiring board for a semiconductor package having a wiring pattern on a light-transmitting base film, which is emitted from a light source. The inspection light is guided substantially parallel, the infrared component is removed from the inspection light guided substantially parallel, and the electric field vector direction is orthogonal to the light guide direction of the inspection light from which the infrared component is removed. The first linearly polarized light is extracted by a polarizing filter, and the first linearly polarized light extracted by the polarizing filter is extracted in a direction orthogonal to the light guiding direction and the direction of the electric field vector of the first linearly polarized light using a polarizing beam splitter. Lead.

  Then, the first linearly polarized light guided by the polarizing beam splitter is converted into circularly polarized light by using a detachable λ / 4 wavelength plate, or the first linearly polarized light guided by the polarizing beam splitter is converted into λ / The first linearly polarized light guided by a detachable refractive index optical plate having substantially the same refractive index as that of the optical member of the four-wavelength plate or guided by the polarization beam splitter is provided with a polarizing plate having a predetermined polarization angle. Either of extracting a polarization component of a predetermined polarization angle is performed using a detachable polarization component extraction means.

  When a λ / 4 wavelength plate is used, circularly polarized light converted by the λ / 4 wavelength plate is guided by the same refractive index optical plate when the same refractive index optical plate is used. When the polarization component extraction unit is used for the first linearly polarized light, the workpiece is irradiated with the polarization component extracted by the polarization component extraction unit.

  Furthermore, when a λ / 4 wavelength plate is used, the irradiated optically polarized light is reversed by the work and the direction of rotation is reversed and then transmitted through the λ / 4 wavelength plate. In the case where the polarized light component extraction means is used after the reflected light formed by reflecting the first linearly polarized light irradiated to the work is transmitted through the same refractive index optical plate, The reflected light formed by reflecting the irradiated polarization component by the work is guided to the polarization component extraction means and vector-decomposed according to the predetermined polarization angle of the polarizing plate, and then guided to the polarization beam splitter. The second linearly polarized light whose electric field vector direction is orthogonal to the direction of the first linearly polarized light is extracted from the guided light.

  Then, from the extracted second linearly polarized light, a wavelength region in which the difference between the reflected light amount in the uppermost layer wiring pattern and the reflected light amount in the base film and the wiring pattern is the largest is selected, and light in the selected wavelength region is selected. Take an image.

  Further, the wiring pattern detection method of the invention of claim 7 is configured such that the polarization filter in the wiring pattern detection method of the invention of claim 6 is omitted by extracting the first linearly polarized light by the polarization beam splitter.

  The invention according to claim 8 is the wiring pattern detection method according to claim 6 or 7, wherein two light guide plates and half mirrors set in crossed Nicols are used instead of the polarization beam splitter.

  In such a wiring pattern detection method of the inventions of claims 6 to 8, by taking the above-described means, the base film material used for the multilayer wiring board for a semiconductor package is manufactured according to the manufacturing method, material, and polarization characteristics. By properly using the λ / 4 wavelength plate, the same refractive index optical plate, or the polarization component extraction means, it is possible to optically separate the image of the uppermost wiring pattern with high accuracy from any multilayer wiring board for semiconductor packages. it can.

  In addition, since the λ / 4 wavelength plate, the same refractive index optical plate, and the polarization component extraction means are configured to be interchangeable with each other, a substantially single device can be used without using a separate device for each inspection target. It is possible to optically separate the image of the uppermost wiring pattern with high accuracy from all types of multilayer wiring substrates for semiconductor packages that differ in the manufacturing method, material, polarization characteristics, etc. of the base film material used for the multilayer wiring substrate for semiconductor packages. it can.

  A wiring pattern detection method according to a ninth aspect of the present invention is the wiring pattern detection method according to any one of the sixth to eighth aspects, wherein the frequency is synergistic with a voltage supplied to a discharge lamp provided in the light source. The frequency component is removed so that the component does not affect imaging as noise.

  Therefore, in the wiring pattern detection method according to the ninth aspect, by taking the above-described means, it is possible to prevent noise from entering the captured image, and thus to improve the inspection accuracy. It becomes.

  The invention of claim 10 is an image captured by the wiring pattern detection method according to any one of claims 6 to 9 and the wiring pattern detection method according to any one of claims 6 to 9. And a predetermined good product image to check whether the uppermost wiring pattern is a good product or not.

  Accordingly, in the wiring pattern inspection method of the invention of claim 10, by taking the above-mentioned means, any semiconductor package having different manufacturing method, material, polarization characteristics, etc. of the base film material used for the multilayer wiring board for semiconductor packages It is possible to accurately inspect whether or not the uppermost wiring pattern is a non-defective product with respect to the multilayer wiring board for use.

  According to the present invention, the top layer wiring pattern is separated and extracted with substantially one apparatus even for workpieces having different manufacturing methods, materials, and polarization characteristics of the base film material used for the multilayer wiring board for semiconductor packages. A wiring pattern inspection apparatus, inspection method, detection apparatus, and detection method capable of acquiring accurate image data can be realized.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing an example of a wiring pattern detection apparatus to which a wiring pattern detection method according to an embodiment of the present invention is applied and a wiring pattern inspection apparatus to which the wiring pattern inspection method according to the embodiment is applied. .

  That is, the wiring pattern detection apparatus to which the wiring pattern detection method according to the embodiment is applied optically applies the uppermost wiring pattern of the workpiece 21 formed of a multilayer wiring board for a semiconductor package having a wiring pattern on a light transmissive base film. The light source 10, the light guide 11, the heat ray cut filter 12, the illumination lens 13a, the diffusion plate 15, the illumination lens 13b, the polarization filter 16, the polarization beam splitter 18, and the λ / 4 wavelength plate 20, front group lens 13 c, rear group lens 13 d, bandpass filter 14, imaging unit 23, and noise removal unit 25. Here, the polarizing filter 16 can be omitted. Furthermore, by adding the image processing unit 24 to such a wiring pattern detection device, a wiring pattern inspection device to which the wiring pattern inspection method according to the embodiment is applied is obtained.

  The light source 10 emits inspection light K. Such a light source 10 is preferably high-luminance illumination that emits light over the entire visible range, such as a metal halide lamp. A sufficient amount of light is necessary for imaging with high resolution. Therefore, for example, the light source 10 can be changed from a metal halide lamp having a power consumption of 250 W to a metal halide lamp having a power of 350 W, or the light guide 11 can be integrated with the inspection light K from a plurality of light sources 10 and output from one end. Are preferred. The inspection light K emitted from such a light source 10 is so-called random light having various light components. When the inspection light K composed of such random light is emitted from the light source 10, it enters the light guide 11.

  The light guide 11 guides the inspection light K emitted from the light source 10 substantially parallel to the light guide direction F shown in the drawing.

  The heat ray cut filter 12 blocks light on the long wavelength side (for example, a wavelength of 700 nm or more) and guides other light, and an infrared filter is suitable. Inspection light guided by the light guide 11 Blocks the infrared component of K. Then, the inspection light k from which the infrared component has been removed in this way is guided to the illumination lens 13a.

  The illumination lens 13 a is composed of one or more lenses, collects the inspection light k from which the infrared component has been removed by the heat ray cut filter 12, and guides it to the diffusion plate 15.

  The diffusion plate 15 diffuses the inspection light k collected by the illumination lens 13a so as to make the intensity uniform, and guides it to the illumination lens 13b. As the diffusion plate 15, a frost type diffusion plate having high permeability is suitable.

  The illumination lens 13 b is composed of one or more lenses, collects the inspection light k guided by the diffusion plate 15, and guides it to the polarizing filter 16. The inspection light k collected by the proof lens 13b is substantially parallel light. When the polarizing filter 16 is omitted, the substantially parallel light is directly guided to the polarizing beam splitter 18.

  The polarizing filter 16 converts the inspection light k guided from the illumination lens 13b into first linearly polarized light m (front and back directions in the figure) in which the direction of the electric field vector is orthogonal to the light guiding direction, and the polarizing beam splitter 18 Lead to. The polarization filter 16 is the same as the polarization beam splitter 18, but an appropriate filter is selected in consideration of the applicable wavelength range, extinction ratio, polarization ratio, outer size, and the like. In addition, in order to capture an image with high resolution, the greater the total amount of transmitted light in the system, the better. Therefore, for example, as the polarizing filter 16, a wire grid polarizing filter having a high transmittance is suitable.

  The polarization beam splitter 18 extracts linearly polarized light n whose electric field vector direction is orthogonal to the light guide direction F from linearly polarized light m guided from the polarizing filter 16 or from substantially parallel light guided from the illumination lens 13b. The linearly polarized light n is guided in a light guide direction F and a direction V orthogonal to the electric field vector direction.

  The λ / 4 wavelength plate 20 converts the linearly polarized light n guided by the polarization beam splitter 18 into circularly polarized light p and guides it to the front group lens 13c. Such a λ / 4 wavelength plate 20 is preferably disposed between the polarization beam splitter 18 and the front group lens 13c as shown in FIG. 1, but the present invention is not limited to this. It may be arranged between the workpiece 21.

  The front group lens 13c is composed of one or two or more lenses, and condenses the circularly polarized light p guided from the λ / 4 wavelength plate 20 and irradiates the work 21 with it. The circularly polarized light p irradiated to the work 21 is inverted by the work 21, and the direction of rotation is reversed, passes through the front lens group 13 c and the λ / 4 wavelength plate 20, and reaches the polarization beam splitter 18.

  Then, the polarization beam splitter 18 extracts the linearly polarized light q having the electric field vector direction orthogonal to the linearly polarized light n from this light, and guides the linearly polarized light q to the rear lens group 13d. Instead of the polarization beam splitter 18, as shown in FIG. 6, an optical member constituted by two polarizing plates 53 and 54 and a half mirror 52 set to crossed Nicols may be used.

  The rear group lens 13 d is composed of one or more lenses, collects the linearly polarized light q guided from the polarization beam splitter 18, and guides it to the band pass filter 14.

  The band pass filter 14 selects a wavelength region where the difference between the reflected light amount in the uppermost wiring pattern and the reflected light amount in the base film and the wiring pattern is the largest from the linearly polarized light q guided by the rear group lens 13d. The component light g in the wavelength range is guided to the imaging unit 23. Specifically, attention is focused on a wavelength of 550 nm, which is a green component. The band pass filter 14 also has an action of cutting ultraviolet rays. Therefore, the ultraviolet component is efficiently cut from the light in the selected wavelength range (for example, light having a green component of 550 nm).

  The imaging unit 23 images the component light g guided by the bandpass filter 14. As a result, the image data of the wiring pattern in which the uppermost layer wiring pattern information is revealed is acquired, and the acquired image data is sent to the image processing unit 24.

  The image processing unit 24 includes a personal computer, a keyboard, a mouse, a display, an image processing board, and the like (not shown). When the image data of the wiring pattern in which the uppermost layer wiring pattern information is made visible is sent from the imaging unit 23, the image data is displayed from the display. Further, various calculations using the displayed image data and normal design wiring pattern data, recognition processing, and comparison processing are performed, and the quality of the wiring pattern of the imaged image data is determined.

  FIG. 2 shows an uppermost wiring pattern of a multilayer wiring board for a semiconductor package comprising a wiring pattern obtained by laminating a copper foil on a polyimide film with an adhesive, and patterning this by a subtractive method or a semi-additive method. ) Images showing a case where the image is picked up by a ring illumination method as a conventional technique, and (b) a case where the image is picked up by a wiring pattern detection device and an inspection device having the above-described configuration.

  As shown in FIG. 2A, in the conventional ring illumination method, it is understood that not only the uppermost wiring pattern A but also the inner wiring pattern C existing via the polyimide insulating layer B is imaged. . Furthermore, since the uppermost layer wiring pattern A and the inner layer wiring pattern C have the same brightness, the uppermost layer wiring pattern A and the inner layer wiring pattern C cannot be separated even by binarization processing, for example. As a result, it is difficult to discriminate which pattern is present on the upper side from the image where the uppermost layer wiring pattern A and the inner layer wiring pattern C intersect.

  On the other hand, as shown in FIG. 2B, in the case of an image captured by the wiring pattern detection device and inspection device having the above-described configuration, the inner layer wiring pattern C is not imaged, and the uppermost polyimide insulating layer B, Only the uppermost wiring pattern A disposed thereon is imaged. In addition, since the uppermost wiring pattern A is bright and the polyimide insulating layer B is dark, it is not affected by the inner wiring pattern C. For example, by using a simple image processing technique called binarization, The regions of the uppermost wiring pattern A and the polyimide insulating layer B can be classified with high accuracy.

  Then, in a state where both areas can be classified in this way, the image processing unit 24 performs comparison processing using CAD data (pattern design information) and non-defective work (work on which a wiring pattern is correctly formed) as a reference master image. By using the feature extraction method or the like, it is possible to determine a portion having a difference as a defect.

  In this way, the wiring pattern detection device and inspection device using the λ / 4 wavelength plate 20 is a workpiece obtained by laminating a wiring substrate prepared by laminating polyimide as a base film and copper as a wiring layer. 21 is suitable for detection and inspection.

  Further, in the wiring pattern detection device and inspection device having the above-described configuration, the λ / 4 wavelength plate 20 is detachably disposed, and the λ / 4 wavelength plate is disposed at a position where the λ / 4 wavelength plate 20 is disposed. In addition to 20, the same refractive index optical plate 26 or polarizing plate 27 can be freely replaced and arranged. Further, the same refractive index optical plate 26 and the polarizing plate 27 are also detachable, and the once arranged same refractive index optical plate 26 is replaced with the λ / 4 wavelength plate 20 and the polarizing plate 27. Alternatively, the polarizing plate 27 once arranged can be freely replaced with the λ / 4 wavelength plate 20 or the same refractive index optical plate 26 to be arranged freely.

  FIG. 3 is a block diagram illustrating a configuration example of a detection device and an inspection device in which the λ / 4 wavelength plate 20 is replaced with the same refractive index optical plate 26. Differences from the detection apparatus and inspection apparatus configured as shown in FIG. 1 will be described below.

  The refractive index optical plate 26 has substantially the same refractive index as the optical member of the λ / 4 wavelength plate, and guides the linearly polarized light n guided by the polarization beam splitter 18 to the front lens group 13c.

  In this case, the front lens group 13 c collects the linearly polarized light n guided from the same refractive index optical plate 26 and irradiates the work 21. The linearly polarized light n irradiated to the work 21 is reflected by the work 21, passes through the front lens group 13 c and the same refractive index optical plate 26, and reaches the polarization beam splitter 18.

  Then, the polarization beam splitter 18 extracts the linearly polarized light q having the electric field vector direction orthogonal to the linearly polarized light n from this light, and guides the linearly polarized light q to the rear lens group 13d.

  The rear group lens 13 d collects the linearly polarized light q guided from the polarization beam splitter 18 and guides it to the bandpass filter 14.

  The bandpass filter 14 selects a wavelength region where the difference between the reflected light amount in the uppermost wiring pattern and the reflected light amount in the base film and the wiring pattern is the largest from the linearly polarized light q thus derived. The component light g in is guided to the imaging unit 23.

  Then, the imaging unit 23 images the component light g guided by the bandpass filter 14. As a result, the image data of the wiring pattern in which the uppermost wiring pattern information is revealed is acquired.

  FIG. 4 shows an example of image data taken for the uppermost wiring pattern of a multilayer wiring board for a semiconductor package having a wiring pattern formed by depositing copper plating, as shown in FIG. It is an image which shows the case where it images with the detection apparatus and inspection apparatus of a wiring pattern using the refractive index optical plate 26.

  As shown in FIG. 4, it can be seen that only the uppermost wiring pattern is optically manifested and imaged. In FIG. 2B, the uppermost wiring pattern A is bright and the polyimide insulating layer B is captured dark, whereas in the image data shown in FIG. 4, the uppermost wiring pattern A is darker. The polyimide insulating layer B is imaged brightly. This is because linearly polarized light having only one direction of polarization component repeats multiple reflections inside the polyimide insulation layer B, and has a polarization component in all directions, so that the polyimide insulation layer B portion is bright and the uppermost wiring pattern A Because it becomes dark.

  In this way, the wiring pattern detection device and inspection device using the same refractive index optical plate 26 is a workpiece 21 formed by laminating a multilayer wiring substrate for a semiconductor package having a wiring pattern formed by depositing copper plating in particular. Suitable for detection and inspection.

  FIG. 5 is a block diagram illustrating a configuration example of a detection device and an inspection device in which the λ / 4 wavelength plate 20 is replaced with a polarizing plate 27. Differences from the detection apparatus and inspection apparatus configured as shown in FIG. 1 will be described below.

  The polarizing plate 27 extracts a vector-decomposed component s corresponding to the polarization angle of the polarizing plate 27 from the linearly polarized light n guided by the polarizing beam splitter 18, and guides the vector-resolved component s to the front lens group 13c.

  In this case, the front lens group 13 c collects the vector decomposition component s guided from the polarizing plate 27 and irradiates the workpiece 21 with it. The vector decomposition component s irradiated to the workpiece 21 is reflected by the workpiece 21, passes through the front lens group 13c, and reaches the polarizing plate 27.

  Then, the polarizing plate 27 further vector-decomposes this vector decomposition component s according to the polarization angle of the polarizing plate 27, and guides this vector decomposition component u to the polarization beam splitter 18. Then, the polarization beam splitter 18 extracts the linearly polarized light q in which the direction of the electric field vector is orthogonal to the linearly polarized light from the vector decomposition component u, and guides this linearly polarized light q to the rear group lens 13d.

  The rear group lens 13 d collects the linearly polarized light q guided from the polarization beam splitter 18 and guides it to the bandpass filter 14.

  The bandpass filter 14 selects a wavelength region where the difference between the reflected light amount in the uppermost wiring pattern and the reflected light amount in the base film and the wiring pattern is the largest from the linearly polarized light q thus derived. The component light g in is guided to the imaging unit 23.

  Then, the imaging unit 23 images the component light g guided by the bandpass filter 14. As a result, the image data of the wiring pattern in which the uppermost wiring pattern information is revealed is acquired.

  Furthermore, in the obtained image data, it is ideal that there is no noise component that can be an overdetection factor. Therefore, FIG. 7A shows image data obtained by using a metal halide lamp as the light source 10 and imaging under the condition where the noise removing unit 25 is not provided. Thus, when imaging was performed without providing the noise removing unit 25, occurrence of horizontal stripe noise was confirmed. In the case of this example, a white horizontal stripe occurs once in 30 lines, which is difficult to say with high-precision image data. Further, in the state where the wiring pattern is formed in an oblique direction, the intersection of the horizontal stripe noise and the wiring pattern. In this case, the phenomenon that the edge of the wiring pattern undulates is also confirmed, which becomes a false detection element and causes a problem. As a result of verifying this cause, it was found that it was caused by 100 Hz noise that was synergistic with the voltage supplied to the metal halide lamp.

  In FIG. 7, since horizontal stripe noise is difficult to understand, a description will be given using a graph of luminance values. It can be seen from the image data shown in FIG. 8 that a white line exists throughout. When white line information existing in the X-X ′ line shown in FIG. 8 is emphasized (integrated), data as shown in FIG. 9 is obtained. As shown in FIG. 9, it can be seen that bright portions (white lines) are generated at a constant period. If this noise component is present, the image quality deteriorates and the image can be seen, but the wiring pattern is wavy at the intersection of the white line and the wiring pattern. If such undulations exist, erroneous detection increases and stable pattern inspection cannot be performed. Therefore, it is indispensable to remove horizontal stripe noise.

  Therefore, the wiring pattern inspection apparatus to which the wiring pattern inspection method according to the present embodiment is applied is provided with a noise removing unit 25 that removes the voltage noise generated at 100 Hz in a circuit manner. FIG. 7B is image data obtained by imaging the same part as that in FIG. 7A obtained when such a noise removing unit 25 is provided. In this manner, by providing the noise removing unit 25, 100 Hz noise that is synergistic with the voltage supplied to the light source 10 is removed in a circuit, and it becomes possible to obtain more accurate image data.

  In this way, the λ / 4 wavelength plate 20 or the same refractive index optical plate depending on the workpiece, even for workpieces having different manufacturing methods, materials, and polarization characteristics of the base film material used for the multilayer wiring board for semiconductor packages 26 or the polarizing plate 27 can be selected, so that for any workpiece, only the uppermost layer wiring pattern is optically separated with high accuracy by a single device, so that the uppermost layer wiring pattern Detection and inspection can be performed with high accuracy.

  The best mode for carrying out the present invention has been described above with reference to the accompanying drawings, but the present invention is not limited to such a configuration. Within the scope of the invented technical idea of the scope of claims, a person skilled in the art can conceive of various changes and modifications. The technical scope of the present invention is also applicable to these changes and modifications. It is understood that it belongs to.

The block diagram which shows an example of the wiring pattern inspection apparatus to which the wiring pattern detection method which applied the wiring pattern detection method which concerns on embodiment of this invention, and the wiring pattern inspection method which concerns on the embodiment. 1 is an example of an image captured by an apparatus having the configuration shown in FIG. 1 with respect to the uppermost wiring pattern of a multilayer wiring board for a semiconductor package comprising a wiring pattern in which copper foil is laminated on a polyimide film with an adhesive. The block diagram which shows the structural example of the detection apparatus and test | inspection apparatus which replaced the (lambda) / 4 wavelength plate in FIG. 1 with the same refractive index optical plate. FIG. 4 is an example of image data captured by an apparatus having the configuration shown in FIG. 3 with respect to the uppermost wiring pattern of a multilayer wiring board for a semiconductor package having a wiring pattern formed by depositing copper plating. The block diagram which shows the structural example of the detection apparatus and test | inspection apparatus which replaced the (lambda) / 4 wavelength plate in FIG. 1 with the polarizing plate. The arrangement figure showing the example of composition of the optical member constituted by two polarizing plates set as crossed Nicols, and a half mirror. Comparative image data showing the effect of the noise removal unit. Image data that has noise. The figure which shows the relationship between the brightness | luminance and position in the X-X 'part shown in FIG. The block diagram of the apparatus currently disclosed by patent document 1. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Light source, 11 ... Light guide, 12 ... Heat ray cut filter, 13a, 13b ... Illumination lens, 13c ... Front group lens, 13d ... Rear group lens, 14 ... Band pass filter, 15 ... Diffusing plate, 16 ... Polarizing filter, DESCRIPTION OF SYMBOLS 18 ... Polarizing beam splitter, 20 ... Wave plate, 21 ... Workpiece, 23 ... Imaging part, 24 ... Image processing part, 25 ... Noise removal part, 26 ... Same refractive index optical plate, 27 ... Polarizing plate, 30 ... Sensor camera, DESCRIPTION OF SYMBOLS 31 ... Polarizing beam splitter, 32 ... Polarizing beam splitter, 33 ... Imaging lens, 34 ... Polarizing filter, 40 ... Condensing lens, 41 ... CCD element, 42 ... Band pass filter, 50 ... Work fixed drive mechanism, 51 ... Work 52 ... Half mirror, 53, 54 ... Polarizing plate

Claims (10)

A wiring pattern detection device for optically detecting the uppermost wiring pattern of a work composed of a multilayer wiring substrate for a semiconductor package having a wiring pattern on a light-transmitting base film,
A light source;
Parallel light guide means for guiding light from the light source substantially in parallel;
Infrared blocking means for blocking an infrared component of light from the light source;
A first lens for condensing the light whose infrared component is blocked by the infrared blocking means;
A diffusion plate for diffusing the light collected by the first lens so as to make the intensity uniform;
A second lens for condensing the light diffused by the diffusion plate;
A polarization filter that extracts light collected by the second lens from a first linearly polarized light whose electric field vector direction is orthogonal to the light guide direction;
A polarization beam splitter that guides the first linearly polarized light extracted by the polarizing filter in a direction orthogonal to the light guide direction and the electric field vector direction;
A removable λ / 4 wavelength plate for converting the first linearly polarized light guided by the polarizing beam splitter into circularly polarized light, or the λ / 4 wavelength for guiding the first linearly polarized light guided by the polarizing beam splitter. A detachable same-index optical plate having substantially the same refractive index as the optical member of the plate, or the first linearly polarized light guided by the polarizing beam splitter is passed through a polarizing plate having a predetermined polarization angle. An optical member that is one of detachable polarization component extraction means for extracting the polarization component;
When a λ / 4 wave plate is used as the optical member, circularly polarized light converted by the λ / 4 wave plate is used. When the same refractive index optical plate is used as the optical member, the same light is used. When the polarization component extraction means is used as the optical member for the first linearly polarized light guided by the refractive index optical plate, the polarization components extracted by the polarization component extraction means are respectively condensed to collect the workpiece. A third lens for irradiating
When the λ / 4 wavelength plate is used as the optical member, the circularly polarized light irradiated by the third lens is reversed by the work and the rotation direction is reversed, and then the third lens and the When the same refractive index optical plate is used as the optical member after passing through a λ / 4 wavelength plate, the first linearly polarized light irradiated to the workpiece by the third lens is the workpiece. When the polarized light component extraction means is used as the optical member after the reflected light that has been reflected passes through the third lens and the same refractive index optical plate, the work is performed by the third lens. Reflected light formed by reflecting the polarized component irradiated to the workpiece by the work is guided to the polarized component extracting unit after passing through the third lens, and the polarized component extracting unit determines the predetermined polarization of the polarizing plate. After being subjected to vector decomposition according to the light angle, each is guided to the polarization beam splitter, and the second linearly polarized light whose electric field vector direction is orthogonal to the direction of the first linearly polarized light is extracted from the polarized beam splitter. And a fourth lens for condensing the second linearly polarized light,
Selection for selecting a wavelength region in which the difference between the reflected light amount in the uppermost wiring pattern and the reflected light amount in the base film and the wiring pattern is the largest from the second linearly polarized light collected by the fourth lens Means,
The wiring pattern detection apparatus provided with the imaging means which images the light of the wavelength range selected by the said selection means. A wiring pattern detection device for optically detecting the uppermost wiring pattern of a work composed of a multilayer wiring substrate for a semiconductor package having a wiring pattern on a light-transmitting base film,
A light source;
Parallel light guide means for guiding light from the light source substantially in parallel;
Infrared blocking means for blocking an infrared component of light from the light source;
A first lens for condensing the light whose infrared component is blocked by the infrared blocking means;
A diffusion plate for diffusing the light collected by the first lens so as to make the intensity uniform;
A second lens for condensing the light diffused by the diffusion plate;
From the light collected by the second lens, first linearly polarized light whose electric field vector direction is orthogonal to the light guide direction of the light is extracted, and the light guide direction and the direction orthogonal to the electric field vector direction are extracted. A polarizing beam splitter that leads to
A removable λ / 4 wavelength plate for converting the first linearly polarized light guided by the polarizing beam splitter into circularly polarized light, or the λ / 4 wavelength for guiding the first linearly polarized light guided by the polarizing beam splitter. A detachable same-index optical plate having substantially the same refractive index as the optical member of the plate, or the first linearly polarized light guided by the polarizing beam splitter is passed through a polarizing plate having a predetermined polarization angle. An optical member that is one of detachable polarization component extraction means for extracting the polarization component;
When a λ / 4 wave plate is used as the optical member, circularly polarized light converted by the λ / 4 wave plate is used. When the same refractive index optical plate is used as the optical member, the same light is used. When the polarization component extraction means is used as the optical member for the first linearly polarized light guided by the refractive index optical plate, the polarization components extracted by the polarization component extraction means are respectively condensed to collect the workpiece. A third lens for irradiating
When the λ / 4 wavelength plate is used as the optical member, the circularly polarized light irradiated by the third lens is reversed by the work and the rotation direction is reversed, and then the third lens and the When the same refractive index optical plate is used as the optical member after passing through a λ / 4 wavelength plate, the first linearly polarized light irradiated to the workpiece by the third lens is the workpiece. When the polarized light component extraction means is used as the optical member after the reflected light that has been reflected passes through the third lens and the same refractive index optical plate, the work is performed by the third lens. Reflected light formed by reflecting the polarized component irradiated to the workpiece by the work is guided to the polarized component extracting unit after passing through the third lens, and the polarized component extracting unit determines the predetermined polarization of the polarizing plate. After being subjected to vector decomposition according to the light angle, each is guided to the polarization beam splitter, and the second linearly polarized light whose electric field vector direction is orthogonal to the direction of the first linearly polarized light is extracted from the polarized beam splitter. And a fourth lens for condensing the second linearly polarized light,
Selection for selecting a wavelength region in which the difference between the reflected light amount in the uppermost wiring pattern and the reflected light amount in the base film and the wiring pattern is the largest from the second linearly polarized light collected by the fourth lens Means,
A wiring pattern detection apparatus comprising: imaging means for imaging light in the wavelength range selected by the selection means. In the wiring pattern detection apparatus according to claim 1 or 2,
A wiring pattern detection apparatus using two light guide plates and a half mirror set in crossed Nicols instead of the polarizing beam splitter. In the wiring pattern detection apparatus according to any one of claims 1 to 3,
The wiring pattern detection apparatus which added the noise removal means which prevents the frequency component synthesize | combined with the voltage supplied to the discharge lamp provided in the said light source from affecting the said imaging means as noise. The wiring pattern detection device according to any one of claims 1 to 4,
An inspection for checking whether or not the uppermost wiring pattern is a non-defective product by collating an image captured by the wiring pattern detection device according to any one of claims 1 to 4 with a predetermined good product image. And a wiring pattern inspection apparatus. A wiring pattern detection method for optically detecting the uppermost wiring pattern of a work consisting of a multilayer wiring board for a semiconductor package having a wiring pattern on a light transmissive base film,
The inspection light emitted from the light source is guided almost in parallel,
Removing the infrared component from the inspection light guided substantially in parallel;
The inspection light from which the infrared component has been removed is extracted by a polarizing filter with a first linearly polarized light whose electric field vector direction is orthogonal to the light guiding direction of the light,
The first linearly polarized light extracted by the polarizing filter is guided to a direction orthogonal to the direction of the light guide and the electric field vector of the first linearly polarized light using a polarization beam splitter,
The first linearly polarized light guided by the polarizing beam splitter is converted into circularly polarized light using a detachable λ / 4 wavelength plate, or the first linearly polarized light guided by the polarizing beam splitter is converted into the λ The first linearly polarized light guided by the polarizing beam splitter is guided to a polarizing plate having a predetermined polarization angle by using a removable refractive index optical plate having substantially the same refractive index as the optical member of the / 4 wavelength plate. Using the detachable polarization component extraction means provided, to perform any one of extracting the polarization component of the predetermined polarization angle,
When the λ / 4 wavelength plate is used, circularly polarized light converted by the λ / 4 wavelength plate is guided by the same refractive index optical plate when the same refractive index optical plate is used. When the polarization component extraction unit is used, the first linearly polarized light is irradiated onto the workpiece with the polarization component extracted by the polarization component extraction unit,
When the λ / 4 wavelength plate is used, the irradiated circularly polarized light is inverted by the work and the rotation direction is reversed, and then transmitted through the λ / 4 wavelength plate. When a plate is used, the polarized light component extraction unit uses the reflected light formed by reflecting the first linearly polarized light irradiated on the workpiece through the same refractive index optical plate. In this case, after the polarized light applied to the workpiece is reflected by the workpiece, the reflected light is guided to the polarization component extraction means and subjected to vector decomposition according to a predetermined polarization angle of the polarizing plate. , Respectively, guided to the polarization beam splitter, and the polarization beam splitter extracts, from the guided light, second linearly polarized light whose electric field vector direction is orthogonal to the direction of the first linearly polarized light,
From the extracted second linearly polarized light, a wavelength region in which the difference between the reflected light amount in the uppermost layer wiring pattern and the reflected light amount in the base film and the wiring pattern is the largest is selected, and the selected wavelength region A wiring pattern detection method for imaging light. A wiring pattern detection method for optically detecting the uppermost wiring pattern of a work consisting of a multilayer wiring board for a semiconductor package having a wiring pattern on a light transmissive base film,
The inspection light emitted from the light source is guided almost in parallel,
Removing the infrared component from the inspection light guided substantially in parallel;
From the inspection light from which the infrared component has been removed, first linearly polarized light whose electric field vector direction is orthogonal to the light guiding direction of the light is extracted by a polarization beam splitter, and the light guiding direction and the first linearly polarized light are extracted. Led in a direction perpendicular to the direction of the electric field vector of
The first linearly polarized light guided by the polarizing beam splitter is converted into circularly polarized light using a detachable λ / 4 wavelength plate, or the first linearly polarized light guided by the polarizing beam splitter is converted into the λ The first linearly polarized light guided by the polarizing beam splitter is guided to a polarizing plate having a predetermined polarization angle by using a removable refractive index optical plate having substantially the same refractive index as the optical member of the / 4 wavelength plate. Using the detachable polarization component extraction means provided, to perform any one of extracting the polarization component of the predetermined polarization angle,
When the λ / 4 wavelength plate is used, circularly polarized light converted by the λ / 4 wavelength plate is guided by the same refractive index optical plate when the same refractive index optical plate is used. When the polarization component extraction unit is used, the first linearly polarized light is irradiated onto the workpiece with the polarization component extracted by the polarization component extraction unit,
When the λ / 4 wavelength plate is used, the irradiated circularly polarized light is inverted by the work and the rotation direction is reversed, and then transmitted through the λ / 4 wavelength plate. When a plate is used, the polarized light component extraction unit uses the reflected light formed by reflecting the first linearly polarized light irradiated on the workpiece through the same refractive index optical plate. In this case, after the polarized light applied to the workpiece is reflected by the workpiece, the reflected light is guided to the polarization component extraction means and subjected to vector decomposition according to a predetermined polarization angle of the polarizing plate. , Respectively, guided to the polarization beam splitter, and the polarization beam splitter extracts, from the guided light, second linearly polarized light whose electric field vector direction is orthogonal to the direction of the first linearly polarized light,
From the extracted second linearly polarized light, a wavelength region in which the difference between the reflected light amount in the uppermost layer wiring pattern and the reflected light amount in the base film and the wiring pattern is the largest is selected, and the selected wavelength region A wiring pattern detection method for imaging light. In the wiring pattern detection method according to claim 6 or 7,
A wiring pattern detection method using two polarizing plates and a half mirror set in crossed Nicols instead of the polarizing beam splitter. In the wiring pattern detection method according to any one of claims 6 to 8,
A wiring pattern detection method for removing the frequency component so that a frequency component combined with a voltage supplied to a discharge lamp provided in the light source does not affect the imaging as noise. A wiring pattern detection method according to any one of claims 6 to 9,
The image picked up by the wiring pattern detection method according to any one of claims 6 to 9 and a predetermined good product image are collated to inspect whether or not the uppermost wiring pattern is a good product. Wiring pattern inspection method to be done.

Images