WO2011037121A1

WO2011037121A1 - Method for inspecting surface of resin substrate having metal pattern formed thereon, and method for manufacturing the resin substrate

Info

Publication number: WO2011037121A1
Application number: PCT/JP2010/066352
Authority: WO
Inventors: 伊裕横沢; 智吉野
Original assignee: 宇部興産株式会社
Priority date: 2009-09-25
Filing date: 2010-09-22
Publication date: 2011-03-31
Also published as: TW201131161A

Abstract

Disclosed is a method for inspecting the surface of a resin substrate having metal patterns formed thereon, by which the resin substrate surface between the metal patterns can be easily and accurately observed and failure products can be accurately discriminated. A method for manufacturing the resin substrate having the metal patterns formed thereon is also disclosed. At least excitation light is applied to the resin substrate having the metal patterns formed thereon, and light emitted from the resin substrate surface of the resin substrate having the metal patterns formed thereon and light reflected by the metal patterns are detected by means of a detection system wherein the sensitivity to the excitation light is lower than the sensitivity to the light emitted from the resin substrate surface. The resin substrate is inspected in this manner, and the resin substrate is manufactured by rejecting the failure products.

Description

Surface inspection method and manufacturing method of metal pattern forming resin substrate

The present invention relates to a method for inspecting a surface of a metal pattern forming resin substrate obtained by patterning a metal layer on a resin substrate, and a method for manufacturing a metal pattern forming resin substrate.

A metal pattern forming resin substrate such as a circuit board is manufactured by removing a part of the metal layer by a method such as etching from a laminated substrate obtained by laminating a metal layer on a resin substrate. However, between the metal patterns from which the resin layer is exposed by removing the metal layer, a so-called skirt residue in which the vicinity of the bottom portion of the metal pattern remains thin or a rough metal layer embedded in the resin due to factors such as defective etching. There may be a so-called root residue that remains partially, or a foreign substance such as resin or metal that exists at the interface between the resin substrate and the metal layer may remain. Furthermore, foreign matter may adhere from the outside after pattern formation. In addition, etching residues and chemical residues that cannot be confirmed immediately after etching, or new foreign matters such as abnormal precipitation may be generated in the subsequent plating process using the foreign matter as a nucleus. Since these foreign matters cause defects such as a decrease in insulation reliability and short-circuits, it is necessary to inspect the surface state and select those having foreign matters between metal patterns as defective products. Further, these foreign substances are present not only between the metal patterns but also on the surface of the metal pattern, and similarly, there is a possibility of adversely affecting subsequent processes such as a decrease in insulation reliability, mounting defects, and appearance defects. For this reason, abnormalities on the surface of the metal pattern, that is, foreign matters, discoloration, deformation, etc. need to be selected as defective products.

As a method of inspecting the surface state of the metal pattern forming resin substrate, there is a method of inspecting the surface state by irradiating the metal pattern forming resin substrate with visible light and detecting the reflected light. In this method, the abnormality of the metal pattern surface can be observed relatively clearly.

However, many foreign objects between metal patterns are not smooth, and the reflected light cannot be clearly detected due to the fact that the surface is not parallel to the surface of the metal layer, the surface is rough and less glossy, or is irregular. is there.

Further, when a metal layer is formed by laminating a metal foil on a resin substrate, a metal foil whose surface to be bonded to the resin substrate is roughened is often used in order to increase the adhesion between the resin substrate and the metal layer. . When a metal layer is formed using such a roughened metal foil, the roughened surface of the metal foil is transferred to the surface of the resin substrate, resulting in unevenness. For this reason, the surface reflection of the resin substrate is also scattered, and the reflected light becomes indistinct, so that it is difficult to distinguish the foreign material from the resin substrate.

In recent years, in order to improve the formation of ultra-high-definition patterns and high-frequency signal transmission characteristics, a metal pattern in which a so-called low profile metal foil is laminated without forming a roughened layer or forming a very weak roughened layer. A so-called metallized type metal pattern-forming resin substrate is also manufactured in which a very thin metal layer is formed on a resin substrate by sputtering or the like, and then a conductive metal layer is formed by electrolytic metal plating if necessary. In such a metal pattern forming resin substrate, since the surface of the resin substrate is very smooth, foreign substances and the resin substrate can be clearly distinguished, but there is a glossy component such as a metal layer on the back side. Since the structure on the back side can be clearly seen, it is difficult to distinguish the foreign material on the front side from the structure on the back side.

Also, there is a method of observing a metal pattern and foreign matter between patterns by irradiating light from the back side of the metal pattern forming resin substrate and detecting transmitted light. However, a double-sided substrate having metal patterns on both sides of the resin substrate, a multilayer substrate in which metal pattern-forming resin substrates are multilayered, and a metal pattern-forming resin substrate in which a shielding layer such as a shielding material is formed on the back side In this case, transmitted light cannot be detected. For this reason, the range of use is limited and lacks versatility.

Further, Patent Documents 1 and 2 listed below disclose a method for inspecting a metal pattern by irradiating a metal pattern forming resin substrate with excitation light to cause the resin substrate to exhibit fluorescence and detecting a light emission amount or a light emission state of the resin substrate. It is disclosed.

JP-A-3-2258 Japanese Patent Laid-Open No. 5-9309

However, as described in Patent Documents 1 and 2, in the method of detecting the light emission amount and the light emission state of the resin substrate by irradiating the metal pattern forming resin substrate with the excitation light and causing the resin substrate to exhibit fluorescence, Therefore, it is difficult to distinguish the foreign substance on the surface of the resin substrate to be originally identified. In addition, the light emitted from the resin substrate is affected by interference with reflected light or scattered light of excitation light, and the observed image tends to be unclear. For this reason, for example, when the metal pattern is made finer, the presence or absence of foreign matters between the metal patterns cannot be accurately determined, and it may not be possible to examine manufacturing conditions that do not cause defective products without foreign matters. It was.

Moreover, the surface state of the metal pattern could not be observed by the methods of Patent Documents 1 and 2. For this reason, in order to inspect the surface state of the metal pattern, it is necessary to take measures such as separately irradiating visible light to detect a reflected image, and there is a problem that the number of inspection processes increases.

Therefore, an object of the present invention is to provide a method for inspecting a surface of a metal pattern forming resin substrate, which can easily and accurately observe the surface of the resin substrate between metal patterns, and can accurately identify defective products, and metal pattern formation It is providing the manufacturing method of a resin substrate.

In order to achieve the above object, the method for inspecting a surface of a metal pattern-formed resin substrate according to the present invention comprises: patterning a metal layer on a resin substrate made of a resin material that emits fluorescence or phosphorescence when irradiated with excitation light. A method for inspecting the surface of a metal pattern forming resin substrate,
The metal pattern forming resin substrate is irradiated with at least excitation light, and the light emitted from the resin substrate surface and the light reflected from the metal pattern are less sensitive to the excitation light than the light emitted from the resin substrate surface. It is detected by a detection system.

By irradiating the metal pattern forming resin substrate with the excitation light, the resin substrate absorbs the excitation light and emits light. However, since the light emission of the resin substrate has no directionality, unevenness on the surface of the resin substrate and the inclination of the object to be measured Even if there is, it is hard to be affected. For this reason, the portion where the resin substrate is exposed becomes a substantially uniform bright image. Since the light emitted from the resin substrate surface and the light reflected by the metal pattern are detected by the detection system in which the sensitivity to the excitation light is lower than the sensitivity to the light emitted from the resin substrate surface, the reflected light of the excitation light It is possible to observe an extremely clear image that is not affected by light or scattered light. Moreover, since the light emitted from the resin substrate surface is detected, the resin substrate surface can be clearly observed without being substantially affected by the inside of the resin substrate or the components under the resin substrate. In addition, the portion where the metal pattern is formed or the portion where the foreign matter exists becomes a dark image because light emission from the resin substrate is blocked. Even when the foreign material is transparent and transmits excitation light, the light emitted from the resin base material is refracted by the foreign material to cause directionality, so that an image clearly different from the image of the resin base material is observed. Therefore, according to the present invention, it is possible to easily and accurately inspect whether or not a normal metal pattern is formed and whether or not a foreign object remains between metal patterns, and accurately determine a defective product. It can be carried out.

The first of the preferred embodiments of the method for inspecting the surface of the metal pattern forming resin substrate of the present invention is to excite only the excitation light on the metal pattern forming resin substrate and the light emitted from the resin substrate surface and the light reflected by the metal pattern. The detection is performed with a detection system that does not have sensitivity to light but has sensitivity to fluorescence or phosphorescence. According to this aspect, since the light emission image of the resin substrate can be observed more clearly, it is possible to more accurately inspect whether a normal metal pattern is formed and whether foreign matter remains between the metal patterns. it can.

A second preferred embodiment of the method for inspecting the surface of a metal pattern-formed resin substrate of the present invention is to irradiate only the excitation light to the metal pattern-formed resin substrate, and to emit light emitted from the resin substrate surface and light reflected by the metal pattern. Or it is detecting with the detection system by which the sensitivity with respect to excitation light was reduced rather than the sensitivity with respect to phosphorescence. According to this aspect, only the excitation light is irradiated to the metal pattern forming resin substrate to detect the light emitted from the resin substrate surface, and the light reflected by the metal pattern is more sensitive than the light emitted from the resin substrate surface. Therefore, the emission image of the resin substrate can be observed without being buried in the fog of the reflection image of the metal pattern. That is, the portion where the resin substrate is exposed can be observed as a substantially uniform bright image, and the portion where the metal pattern exists can be observed as a reflection image of the metal pattern by reflecting the excitation light on the surface of the metal pattern. For this reason, the surface state of the resin substrate and the surface state of the metal pattern can be inspected at the same time, and the surface state of the resin substrate and the metal pattern can be inspected with high accuracy and with a small number of inspection processes.

A third preferred embodiment of the method for inspecting the surface of a metal pattern-formed resin substrate according to the present invention is that the metal pattern-formed resin substrate is irradiated with excitation light and visible light simultaneously, and the light emitted from the resin substrate surface and the visible metal pattern are reflected. The light is detected by a detection system having no sensitivity to excitation light and having sensitivity to fluorescence or phosphorescence and visible light. According to this aspect, a substantially uniform and bright image is obtained at the portion where the resin substrate is exposed, and the skirt residue, root residue portion, etching residue, etc. of the metal pattern are clearly different from the portion where the resin substrate is exposed. Can be observed. For this reason, the foreign material between metal patterns is detectable. Further, the metal pattern reflects visible light, and a visible light reflection image of the metal pattern is obtained. In many cases, abnormalities on the surface of the metal pattern result in a dark image because the reflection of the metal is blocked. However, since the reflected image is observed, an image corresponding to the abnormal state can be observed. In addition, the light emitted from the resin substrate surface and the visible light reflected by the metal pattern include reflected light and scattered light of excitation light. In this aspect, there is no sensitivity to excitation light, and fluorescence is not emitted. Alternatively, since detection is performed with a detection system having sensitivity to phosphorescence and visible light, the surface state of the resin substrate can be inspected from the light emitted from the resin substrate surface while suppressing the influence of reflected or scattered light of the excitation light, and the metal The surface state of the metal pattern can be inspected from the reflected image of visible light reflected by the pattern. For this reason, the surface state of the resin substrate and the surface state of the metal pattern can be inspected at the same time, and the surface state of the resin substrate and the metal pattern can be inspected with high accuracy and with a small number of inspection processes.

The method for inspecting the surface of a metal pattern-formed resin substrate according to the present invention includes, in the first and second embodiments, a filter having a low transmittance for excitation light and a high transmittance for fluorescence or phosphorescence as a detection system. Is preferably used.

The method for inspecting the surface of a metal pattern-formed resin substrate according to the present invention is the above first and second aspects, wherein the metal pattern-formed resin substrate has a metal pattern on both surfaces of the resin substrate, and excitation light should be inspected. It is preferable to irradiate from the surface side.

According to the surface inspection method for a metal pattern forming resin substrate of the present invention, in the second aspect, the detection level of the excitation light reflected by the metal pattern in the state where the metal pattern forming resin substrate is irradiated with the excitation light is set to V1. In the state where the detection system is set so that V2 / V1 is 0.1 or more and 10 or less, where V2 is a detection level of light obtained by removing excitation light reflected from the resin substrate surface from light emission of the substrate surface. It is preferable to perform an inspection. When emphasizing the inspection of the metal pattern surface, V2 / V1 is set to be smaller than 1 and 0.1 or more, and the reflected light from the metal pattern may be detected strongly, or the resin substrate surface, that is, the metal pattern When emphasizing the inspection in between, V2 / V1 may be set to be larger than 1 and 10 or less, and light emission from the resin substrate surface may be detected strongly. When V2 / V1 is near 1, the intensity of the emitted light from the resin substrate surface and the intensity of the excitation light reflected from the metal pattern are approximately the same, but the light emission from the resin substrate surface is almost uniform. On the other hand, the reflection image of the metal pattern is an actual observation image and can be distinguished.

In the third aspect, the surface inspection method for a metal pattern forming resin substrate according to the present invention is configured such that the intensity of visible light applied to the metal pattern forming resin substrate is 0 of the intensity of excitation light applied to the metal pattern forming resin substrate. Preferably, the content is 0.0001 to 1%. According to this, the surface state of the resin substrate and the metal pattern can be detected with higher accuracy.

In the third aspect of the method for inspecting the surface of a metal pattern forming resin substrate of the present invention, it is preferable that the metal pattern forming resin substrate is irradiated with excitation light and visible light from the same light source.

In the third aspect, the surface inspection method for a metal pattern forming resin substrate of the present invention includes, as the detection system, a filter having a low transmittance for excitation light and a high transmittance for fluorescence or phosphorescence and visible light. It is preferable to use one.

The method for inspecting the surface of a metal pattern forming resin substrate according to the present invention is the above third aspect, wherein the metal pattern forming resin substrate has a metal pattern on both surfaces of the resin substrate, and excitation light and visible light should be inspected. It is preferable to irradiate from the surface side.

In the method for inspecting the surface of a metal pattern forming resin substrate according to the present invention, in the first to third aspects, the metal pattern forming resin substrate is preferably a circuit board having a metal wiring formed by patterning a metal layer. . Moreover, it is more preferable that it is a board | substrate obtained by removing a metal from the laminated body of a metal and a resin base material. Further, a substrate obtained by removing a metal from a laminate of a metal and a resin base material by etching is particularly preferable.

The method for inspecting the surface of a metal pattern-formed resin substrate according to the present invention is the above first to third embodiments, wherein the resin substrate is selected from aromatic polyimide, polyurethane containing an imide group, aromatic polyamide, and polyamideimide. The excitation light is preferably light having a wavelength of 430 nm or less.

The method for inspecting the surface of a metal pattern-formed resin substrate according to the present invention is the above-described first to third aspects, wherein the arithmetic average height Ra of the surface portion where the resin substrate is exposed exceeds 0.1 μm, or 0.1 μm or less. It is preferable that If the arithmetic average height Ra of the exposed portion of the resin substrate exceeds 0.1 μm, the surface reflection of the resin substrate is significantly scattered, and the detection by the reflected light of the visible light is reflected even if no foreign matter is present. Since the light is shaded and is not clear, it becomes more difficult to distinguish the foreign material from the resin substrate. In addition, since the amount of reflected light itself is also dark, it is difficult to distinguish from foreign objects or discolored metal residues. According to the method of the present invention, since the light emission of the resin substrate surface is detected by irradiating the excitation light to the metal pattern forming resin substrate, the light emission of the resin substrate does not have directionality. It becomes a nearly homogeneous bright image and is not easily affected by surface irregularities of the resin substrate. Further, when the arithmetic average height Ra of the exposed portion of the resin substrate is 0.1 μm or less, in the surface inspection by reflected light of visible light, the metal present in the resin substrate or in the lower layer components, particularly the back surface side However, according to the method of the present invention, components and foreign matter on the inside or the back side of the resin substrate, particularly metal, could not be distinguished from the image due to the foreign matter on the surface of the resin substrate. It can be detected without being affected by the layer. As described above, the present invention is suitable for surface inspection of a metal pattern-formed resin substrate in which the arithmetic average height Ra of the surface portion where the resin substrate is exposed exceeds 0.1 μm or is 0.1 μm or less.

The method for producing a metal pattern forming resin substrate of the present invention is characterized in that the metal pattern forming resin substrate is inspected by the above method and defective products are removed.

According to the surface inspection method for a metal pattern forming resin substrate of the present invention, it is possible to easily and accurately inspect whether a normal metal pattern is formed and whether a foreign substance remains between metal patterns. In addition, 1) a transparent substrate, an opaque substrate, or a substrate having a metal layer, a metal wiring, a light opaque member, etc. on the back side of the substrate surface to be measured without being affected by the light transmission of the substrate. 2) It can be inspected without being significantly affected by unevenness on the surface of the substrate to be observed, and 3) It can be inspected without being greatly affected by unevenness on the surface opposite to the surface of the substrate to be observed. it can. Furthermore, it can be used for studying production conditions such as etching and cleaning, and a production method that does not cause defective products can be studied.

It is a schematic block diagram of 1st Embodiment of the surface inspection method of the metal pattern formation resin substrate of this invention. It is a schematic block diagram of 2nd Embodiment of the surface inspection method of the metal pattern formation resin substrate of this invention. It is a schematic block diagram of 3rd Embodiment of the surface inspection method of the metal pattern formation resin substrate of this invention. 2 is a camera image of a circuit board obtained by the method of Example 1-1. It is a camera image of the circuit board obtained by the method of Example 1-2. 2 is a camera image of a circuit board obtained by the method of Example 2-1. It is a camera image of the circuit board obtained by the method of Example 2-2. 3 is a camera image of a circuit board obtained by the method of Example 3-1. It is a camera image of the circuit board obtained by the method of Example 3-2. It is a camera image of the circuit board obtained by the method of Example 3-3.

First, a metal pattern forming resin substrate to be inspected according to the present invention will be described.

The metal pattern forming resin substrate is not particularly limited as long as a metal layer is patterned on the resin substrate. Any of a single-sided substrate having a metal pattern on one side of the resin substrate, a double-sided substrate having a metal pattern on both sides of the resin substrate, and a multilayer substrate obtained by laminating a plurality of these can be preferably used.

The surface inspection method for a metal pattern-formed resin substrate of the present invention is particularly effective in surface inspection of a metal substrate having a metal pattern on both surfaces represented by a double-sided wiring board or a multilayer wiring board. A preferred example of the metal pattern forming resin substrate includes a circuit substrate having a metal wiring formed by patterning a metal layer on the surface of the resin substrate.

The resin material used for the metal pattern forming resin substrate is not particularly limited as long as it emits fluorescence or phosphorescence from the surface when irradiated with excitation light (preferably light having a wavelength of 430 nm or less, more preferably light having a wavelength of 400 nm or less). There is no limitation. Among such resin materials, those having excellent physical properties such as insulation, heat resistance and strength can be preferably used for circuit boards.

For example, polyimide, polyurethane containing imide group, wholly aromatic polyester, polyethylene terephthalate, polyethylene naphthalate, polyetherketone, polyetheretherketone, polysulfone, polyethersulfone, polyamide, polyamideimide, polyetherimide, polycarbonate, polyphenylene ether , Polyphenylene sulfide, polymethylpentene, polyarylate, epoxy resin, phenol resin, polytetrafluoroethylene, fluorinated ethylene propylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, polychlorotrifluoroethylene, ethylene tetrafluoroethylene copolymer, Examples thereof include polyvinylidene fluoride and polyvinyl fluoride. Among these, the absorption of excitation light is large, and when irradiated with excitation light, it emits fluorescence or phosphorescence, and further, because it is a resin material that is excellent in various physical properties such as insulation, strength, and heat resistance, Polyimide, polyurethane containing imide group, wholly aromatic polyester, polyethylene naphthalate, polyether ketone, polyether ether ketone, polyether sulfone, aromatic polyamide, polyamide imide, polyether imide, polycarbonate, epoxy resin, phenol resin are preferable. . Furthermore, resins having aromatic rings, typically aromatic polyimides, polyurethanes containing imide groups, aromatic polyamides, and polyamideimides, have strong absorption for light having a short wavelength of 430 nm or less, particularly ultraviolet light having a wavelength of 400 nm or less. When these lights are irradiated, strong fluorescence or phosphorescence is emitted, which is more preferable. Among them, the aromatic polyimide is particularly preferable because it is thin but has sufficient strength and is strong against bending, and absorbs excitation light by the surface layer of the resin substrate and emits particularly strong fluorescence or phosphorescence from the surface.

Examples of the aromatic polyimide include a reaction product of tetracarboxylic dianhydride and diamine. As tetracarboxylic dianhydride, pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, oxydiphthalic dianhydride, diphenylsulfone tetracarboxylic dianhydride, bis (dicarboxyphenyl) sulfide dianhydride, 2,2-bis (dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, benzophenone tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) methane Anhydride, 2,2-bis (dicarboxyphenyl) propane dianhydride, p-phenylenebis (trimellitic acid monoester acid anhydride), p-biphenylenebis (trimellitic acid monoester acid anhydride), terphenyl -3,4,3 ', 4'-tetracarboxylic dianhydride, 1,3-bis (3,4-dicarboxyl Noxy) benzene dianhydride, 1,4-bis (dicarboxyphenoxy) benzene dianhydride, 1,4-bis (dicarboxyphenoxy) biphenyl dianhydride, 2,2-bis [(dicarboxyphenoxy) phenyl] Examples thereof include propane dianhydride, naphthalene tetracarboxylic dianhydride, (2,2-hexafluoroisopropylidene) diphthalic dianhydride, and the like. One or more of these can be used. Examples of the diamine include diamines having 1 to 4 benzene nuclei. Examples of the diamine having one benzene nucleus include phenylenediamine, tolylenediamine, and diaminobenzoic acid. Diamines having two benzene nuclei include diaminodiphenyl ether, diaminodiphenylmethane, dimethyldiaminobiphenyl, bis (trifluoromethyl) diaminobiphenyl, dimethyldiaminodiphenylmethane, dicarboxydiaminodiphenylmethane, tetramethyldiaminodiphenylmethane, diaminodiphenyl sulfide, and diaminobenzanilide. , Dichlorobenzidine, dimethylbenzidine, dimethoxybenzidine, diaminodiphenylsulfone, diaminobenzophenone, diaminodimethoxybenzophenone, 2,2-bis (aminophenyl) propane, bis (aminophenyl) -1,1,1,3,3,3- Examples include hexafluoropropane and diaminodiphenyl sulfoxide. Diamines having three benzene nuclei include bis (aminophenyl) benzene, bis (aminophenoxy) benzene, bis (aminophenoxy) trifluoromethylbenzene, diaminophenylphenoxybenzophenone, diaminodiphenylphenoxybenzophenone, bis (aminophenyl sulfide) Examples thereof include benzene, bis (aminophenylsulfide) benzene, bis (aminophenylsulfone) benzene, and bis (2-aminophenylisopropyl) benzene. Examples of diamines having four benzene nuclei include bis (aminophenoxy) biphenyl, bis (aminophenoxy) phenyl ether, bis (aminophenoxy) phenyl ketone, bis (aminophenoxy) phenyl sulfide, bis (aminophenoxy) phenyl sulfone, , 2-bis (aminophenoxy) phenylpropane, 2,2-bis (aminophenoxy) phenyl-1,1,1,3,3,3-hexafluoropropane, and the like. These diamines can be used alone or in combination of two or more. Among them, one or more tetramellitic acid selected from pyromellitic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid. An aromatic composed of a combination of carboxylic dianhydride and one or more diamines selected from p-phenylenediamine, 4,4′-diaminodiphenyl ether, and 1,3-bis (4-aminophenyl) benzene Since polyimide emits light particularly strongly, it can be used particularly preferably in the present invention.

The metal material used for the metal pattern forming resin substrate is not particularly limited. Metals such as copper, nickel, chromium, manganese, aluminum, iron, molybdenum, cobalt, tungsten, vanadium, titanium, tantalum, silicon, etc., or alloys thereof, or oxides or carbides of these metals Is mentioned. Copper which has a low electrical resistance and is easily available is preferably used.

In order to form a metal layer on the resin substrate, for example, a method of forming a metal layer by pressing a metal foil on the surface of the resin substrate, or after forming a very thin metal layer on the surface of the resin substrate by sputtering or the like, Examples include a method of forming a metal layer by performing electrolytic metal plating as necessary. In addition, when a metal layer is formed on a resin substrate using a metal foil on which a roughened layer having an arithmetic average height Ra exceeding 0.1 μm is formed, stable adhesion between the resin substrate and the metal layer is obtained. However, the roughened layer is transferred to the surface of the resin substrate to form an uneven shape. For this reason, when removing a metal layer and forming a metal pattern, a metal tends to remain in the recessed part of the resin substrate surface. When the metal pattern is highly refined, when the pattern pitch is 100 μm or less, preferably 10 to 100 μm, careful inspection of the remaining foreign matter between the metal patterns is important. Furthermore, when the metal pattern is made ultra-high definition, particularly when the pattern pitch is 40 μm or less, the arithmetic average height Ra of the joint surface between the metal layer and the resin substrate is preferably 0.1 μm or less. If the arithmetic average height Ra is a flat joint surface of 0.1 μm or less, the maximum unevenness can be kept low and the root residue between the wirings can be prevented. As described above, the excitation light has a low transmittance through the resin substrate, and the light emission of the resin substrate due to the excitation light irradiation occurs almost uniformly near the surface of the resin substrate. Therefore, according to the present invention, even if the arithmetic average height Ra of the portion where the resin substrate is exposed exceeds 0.1 μm, it is not affected by scattering due to the unevenness of the resin substrate surface. Further, even when the arithmetic average height Ra of the exposed portion of the resin substrate is 0.1 μm or less, the inspection is performed without being affected by the reflection from the back surface of the resin substrate or the components in the resin substrate. It is possible to accurately observe whether foreign matter is present on the surface of the resin substrate between the power metal patterns.

The method for forming the metal pattern on the resin substrate is not particularly limited. It can be formed using a conventionally known method. For example, a subtractive method, a semi-additive method, etc. are mentioned. In the subtractive method, a metal layer having a predetermined thickness is formed on a resin substrate, the surface of the metal layer is washed, a photoresist layer is formed, exposed and developed to form an etching mask, and an etching solution such as iron chloride is applied. The metal pattern forming resin substrate can be manufactured by removing the metal between the patterns by dipping or spraying and removing the unnecessary photoresist. In the semi-additive method, a very thin metal layer of about 0.2 to 3 μm is formed by laminating a thin metal foil on the surface of a resin substrate or performing sputtering or the like. Next, after cleaning the surface of the metal layer, a thick photoresist layer is formed and exposed and developed to form a pattern mold. And after stacking the metal that becomes the metal wiring by electrolytic plating on the part where the photoresist is not formed using the metal layer as the power feeding layer, the photoresist is removed, and the metal layer is removed by immersion in an etching solution or spraying. A metal pattern forming resin substrate can be manufactured.

In addition, when the metal pattern forming resin substrate manufactured in this way is used as, for example, a circuit board, the metal pattern portion is made of gold or tin to prevent oxidation or to join with a mounted component as necessary. Electrode plating may be performed.

Also, the metal pattern forming resin substrate may be independent by itself, or may be formed on a structure that becomes another base. The metal pattern and the resin substrate surface are preferably exposed from the clearness of the image, but a protective layer or the like may be formed as long as the inspection is not affected. Specifically, it is sufficient that the protective layer does not emit fluorescence or phosphorescence in response to excitation light irradiation at the time of inspection, and there is no absorption or scattering that disturbs the image.

Next, regarding the first embodiment of the surface inspection method for the metal pattern forming resin substrate of the present invention,

metal patterns

3 and 4 are formed on both surfaces of the resin substrate 2 as the metal pattern forming resin substrate 1 with reference to FIG. A case where a double-sided substrate is used will be described as an example. In FIG. 1, 11 is an excitation light source, 12 is a light guide, 14 is a light receiving unit, 15 is an excitation light removing filter, and 21 is a support base.

First, the metal pattern forming resin substrate 1 is arranged on the support base 21 so that the inspection surface is the upper surface.

Next, the light from the excitation light source 11 is transmitted through the light guide 12 and emitted from the tip of the light guide 12, and the excitation light a 1 is applied to the measurement site of the metal pattern forming resin substrate 1 (in the elliptic frame A in FIG. 1). Irradiate.

The excitation light source 11 is not particularly limited. Any one of a single wavelength light source, a plurality of wavelength light sources, and a continuous wavelength spectrum light source can be used as long as it has a wavelength absorbed by the resin substrate surface layer. A light source capable of emitting light having a wavelength of 430 nm or less, particularly ultraviolet light having a wavelength of 400 nm or less, which is easily absorbed by the resin substrate surface layer, is preferable. Examples of such a light source include a high-pressure mercury lamp, an ultraviolet light emitting diode, a black light, a Xe—Hg lamp, and a metal halide lamp. Here, when a light source having a plurality of wavelengths or a continuous wavelength spectrum light source is used, the light absorbed by the resin substrate surface layer is transmitted and the wavelengths that are not absorbed by the resin substrate surface layer are blocked with respect to the light emitted from the light source. It is more preferable to use only the wavelength absorbed by the resin substrate surface layer through the filter as excitation light because a clearer luminescent image can be obtained. Here, various types of filters can be used, such as an absorption type, a reflection type, or a necessary wavelength bent through 45 degrees, for example. However, it is only necessary to guide light having a necessary wavelength to a necessary position. . In this embodiment, a filter 13 that selectively increases the transmittance of the excitation light a 1 is attached to the tip of the light guide 12. Further, in order to increase the excitation light intensity, a condensing lens may be used to collect light on the observation site.

As the excitation light a1 irradiated to the metal pattern forming resin substrate, it is preferable to use light having a short wavelength that has a large absorption of the resin material constituting the resin substrate of the metal pattern forming resin substrate. More preferably, light is used. Since most of the excitation light is absorbed by the resin substrate surface layer, light emission from the inside of the resin substrate is suppressed and light is emitted only from the vicinity of the resin substrate surface. The exposed portion of the resin substrate can be observed as a clearer image, and the surface state of the resin substrate can be detected with higher accuracy. The resin substrate surface layer that emits light by absorbing excitation light differs depending on the thickness and configuration of the resin substrate. There is no particular limitation as long as it can be treated as a substantially surface layer without reaching the back surface or internal components of the resin substrate. The thickness is preferably within 10 μm from the surface of the resin substrate, more preferably within 5 μm, and particularly preferably within 3 μm. The amount of excitation light absorbed by the resin substrate surface layer should be substantially not affected by the inside or the back surface. Preferably, if 50% or more, more preferably 80% or more of the excitation light is absorbed by the resin substrate surface layer, light emission from the inside of the resin substrate is suppressed, and light emission from the vicinity of the resin substrate surface layer becomes clearer. Specifically, the excitation light is preferably light having a wavelength of 430 nm or less, and more preferably ultraviolet light having a wavelength of 400 nm or less. In addition, for ultraviolet light with a wavelength of 350 nm or less, the sensitivity of the image sensor is often not constant, the optical system also requires expensive special materials, and plastic and optical adhesives deteriorate due to long-term irradiation, so 350 nm To 400 nm is particularly preferred.

The irradiation method of the excitation light is preferably from the surface side to be inspected of the metal pattern forming resin substrate. Any irradiation method can be preferably used as long as it is irradiation from the surface side to be inspected. For example, the metal pattern forming resin substrate may be irradiated obliquely from above or may be irradiated from directly above through the objective lens. In this embodiment, the excitation light a 1 is applied to the measurement site from obliquely above the metal pattern forming resin substrate 1. In addition, since the excitation light has low transparency and is easily absorbed by the resin substrate, depending on the thickness of the metal pattern forming resin substrate, when the excitation light is irradiated from the side surface side or the back surface side, In some cases, phosphorescence cannot be generated, internal light emission is strong, internal components are observed, light emission is weak, and accurate surface inspection cannot be performed.

When the metal pattern forming resin substrate 1 is irradiated with excitation light a1, the excitation light a1 is absorbed by the resin substrate, and fluorescence or phosphorescence is emitted from the surface of the resin substrate 2. A part of the excitation light a 1 is reflected or scattered on the surface of the resin substrate 2 or the surface of the metal pattern 3. That is, the light b1 generated from the metal pattern forming resin substrate 1 by irradiating the metal pattern forming resin substrate 1 with the excitation light a1 includes fluorescence or phosphorescence emitted when the resin substrate 2 absorbs the excitation light, and the resin substrate. 2 and excitation light reflected or scattered on the surface of the metal pattern 3 are mixed. Since the emission intensity of the excitation light is stronger than the emission intensity of fluorescence or phosphorescence emitted from the resin substrate 2, images observed by detecting the light b1 as they are overlapped with each other or light components act. As a result, the image of the interface between the resin substrate and the metal layer tends to become unclear.

Therefore, in the first embodiment of the present invention, the light b1 is detected by a detection system that does not have sensitivity to excitation light but has sensitivity to fluorescence or phosphorescence. In the present invention, “having no sensitivity to excitation light and sensitivity to fluorescence or phosphorescence” means that the sensitivity to excitation light is sufficiently low relative to the sensitivity to fluorescence or phosphorescence, preferably excitation light. It is only necessary to detect only light emission such as fluorescence and phosphorescence without substantially detecting the influence of excitation light without detecting. When the final detection means of the detection system is the naked eye, the light emission needs to be visible light. Therefore, when the excitation light contains a visible light component, it is necessary not to disturb the observation by the light emission and enter the naked eye. It is preferable that the sensitivity of the entire detection system is adjusted with an optical system such as a wavelength filter as necessary so that the intensity of the visible light component of the excitation light is 10% or less of the intensity of the visible light component of the emitted light at the time. . When the final detection means of the detection system is to convert it into an electrical signal, the sensitivity to the excitation light is preferably 1% or less, more preferably 0.5% or less of the sensitivity to the emission. A clear light emission image can be obtained while suppressing the influence of fogging. In addition, as a detection system, a camera having the naked eye or an image sensor can be used, and the detection system is configured with a system having low sensitivity to light having a wavelength of excitation light and high sensitivity to light having a wavelength of fluorescence or phosphorescence. Although there is no particular limitation, a CCD or CMOS sensor used as a naked eye or an image sensor generally has sensitivity in a wide wavelength range. In this case, the transmittance in the wavelength range of excitation light is low, and fluorescence or What is necessary is just to detect through the filter with the high transmittance | permeability of phosphorescence. Again, a wide variety of types of filters can be used as described above. The term “transmittance” used here is used in the sense of selecting a wavelength for a necessary optical path, and is not limited to the transmittance with respect to the straight travel of light. The sensitivity of the detection system is the sensitivity of the entire system including optical systems such as sensors, filters, and lenses. When the excitation light is ultraviolet light, when a plastic material or an optical adhesive is used for the optical system, the light is often absorbed and attenuated, and the amount of reduction may be set by incorporating this attenuation. Since plastic optical systems and optical adhesives may deteriorate when irradiated with strong ultraviolet light for a long period of time, it is more preferable that light partially reduced by a filter or the like is incident on them. It is important that when the light emitted from the measurement object is detected and determined by the sensor, it can be determined substantially only by fluorescence or phosphorescence.

In this embodiment, the light receiving unit 14 detects the light b 2 in which the excitation light is reduced to a detection threshold value or less or a determination threshold value or less through the filter 15 having a low excitation light transmittance and a high fluorescence or phosphorescence transmittance. Then, the surface inspection of the metal pattern forming resin substrate 1 is performed.

As the excitation light removal filter 15, it is preferable to use a filter having a transmittance of irradiated excitation light of 0.5% or less and a transmittance of emitted light composed of fluorescence or phosphorescence of 50% or more. It is more preferable that the transmittance is 0.35% or less and the transmittance of the emitted light is 70% or more because the emission image can be clearly observed.

In this way, the image obtained by detecting the light b2 that has passed through the excitation light removal filter 15 is not affected by the reflected light or scattered light of the excitation light, and the exposed portion of the resin substrate has a high contrast, It is observed as a clear, almost homogeneous bright image. In addition, the portion where the metal pattern 3 is present or the portion where the foreign matter is present is a dark image because light emission from the resin substrate 2 is blocked, or even if the foreign matter is transparent and transmits excitation light, Since light emitted from the resin substrate 2 below the foreign matter is refracted by the foreign matter to cause directionality, an image clearly different from the portion where the resin substrate 2 is exposed is observed.

Therefore, the homogeneous bright portion can be recognized as a portion where the resin substrate is exposed, that is, an image between the metal patterns, and the homogeneous dark portion can be recognized as an image of the metal pattern. Thereby, the space | interval of a metal pattern and a pattern defect can be determined. In addition, it is possible to determine a local or peculiar dark part or a part with different brightness as a foreign object.

Then, the light b2 obtained through the excitation light removal filter 15 is received by the light receiving unit 14, and the obtained image is inspected. As the inspection method, a conventionally known method can be used. For example, the image pattern may be recognized by magnifying with a microscope or a microscope and detected with the naked eye, or may be detected with a camera such as a CCD, processed as necessary, and observed on a display. The image may be recognized by a known image recognition system. Of course, an inspection camera integrated with a magnifying lens can be used, and the image signal can be automatically discriminated by taking it into an AOI system or the like. In addition, in the case of visual inspection by an inspector, it can be easily determined empirically. In the case of automatic inspection by image processing, a normal pattern image may be registered for comparison and determination, or may be determined based on a pattern created from CAD drawing data.

In the method for inspecting a surface of a metal pattern forming resin substrate according to the present invention, since a certain area of the metal pattern forming resin substrate 1 is measured by an image, a wider field of view is better from the viewpoint of inspection efficiency. For example, if the area is 0.1 mm square or more, a plurality of 40 μm pitch wiring lines / spaces are preferable, and if it is 0.4 mm square or more, 10 lines / spaces are preferable, which is more preferable for inspection. In this way, when the field of view is widened by limiting the magnification, it is extremely difficult to distinguish the foreign material from the scattered light on the resin substrate surface and the reflected light on the back surface of the resin substrate in the visible light reflection measurement. The effect of the invention is remarkable.

In the manufacturing process of the metal pattern forming resin substrate, the surface of the metal pattern forming resin substrate is inspected in this way, and it is determined that the interval between the metal patterns is narrow, the pattern is defective, or there is a foreign object between the metal patterns. The metal pattern forming resin substrate is selected as a defective product and removed to obtain a metal pattern forming resin substrate with extremely few defective products as a final product.

Next, a second embodiment of the surface inspection method for a metal pattern forming resin substrate of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same location as 1st Embodiment, and description is abbreviate | omitted.

Next, the light from the excitation light source is transmitted through the light guide 12 and emitted from the tip of the light guide 12, and the excitation light a1 is irradiated to the measurement site (the elliptical frame B region in FIG. 2) of the metal pattern forming resin substrate 1. To do.

The excitation light source 11 is not particularly limited. The thing similar to what was used in 1st Embodiment can be used. In this embodiment, a filter 13 that selectively increases the transmittance of the excitation light a 1 is attached to the tip of the light guide 12. In addition, in order to raise excitation light intensity | strength, you may condense on an observation site | part with a condensing lens.

As the excitation light a1 applied to the metal pattern forming resin substrate, the same light as that used in the first embodiment can be used. That is, it is preferable to use light having a short wavelength that has a large absorption of the resin material constituting the resin substrate of the metal pattern forming resin substrate, and more preferably light having a wavelength that is absorbed by the resin material surface layer. Specifically, light having a wavelength of 430 nm or less is preferable, ultraviolet light having a wavelength of 400 nm or less is particularly preferable, and light centering on a range of 350 nm to 400 nm is particularly preferable.

The irradiation method of the excitation light is preferably from the surface side to be inspected of the metal pattern forming resin substrate. Any irradiation method can be preferably used as long as it is irradiation from the surface side to be inspected. For example, the metal pattern forming resin substrate may be irradiated obliquely from above, or may be irradiated from directly above through the objective lens. In this embodiment, the excitation light a 1 is applied to the measurement site from obliquely above the metal pattern forming resin substrate 1.

When the excitation light a1 is irradiated onto the metal pattern forming resin substrate 1, the excitation light a1 is absorbed by the resin substrate as described above, and fluorescence or phosphorescence is emitted from the surface of the resin substrate 2. A part of the excitation light a 1 is reflected or scattered on the surface of the resin substrate 2 or the surface of the metal pattern 3. Therefore, the light b1 generated from the metal pattern forming resin substrate 1 by irradiating the metal pattern forming resin substrate 1 with the excitation light a1 includes fluorescence or phosphorescence emitted when the resin substrate 2 absorbs the excitation light, and the resin. Excitation light reflected or scattered on the surface of the substrate 2 and the metal pattern 3 is mixed. In this embodiment, the light b1 is detected by a detection system in which the sensitivity to excitation light is reduced relative to the sensitivity to fluorescence or phosphorescence.

In the detection system, it is important to adjust the intensity range in which the light emission image on the resin substrate surface and the reflection image of the metal pattern can be observed simultaneously. Fluorescence and phosphorescence emit light on the longer wavelength side than excitation light, and most emit light in the visible light region, so the detection system needs to have sensitivity across the excitation light wavelength and the emission wavelength. The intensity of the light emitted from the resin substrate by the excitation light irradiation is extremely weak compared to the intensity of the excitation light reflected by the metal pattern. Therefore, if the detection system with reduced sensitivity to the excitation light does not detect, the reflection of the metal pattern The image becomes dominant, and the light emission image of the resin substrate may be buried in the fog of the reflection image of the metal pattern.

The means for reducing the sensitivity to the excitation light can be realized by using a detection system in which a filter for selectively attenuating the excitation light is inserted between the object to be inspected and the camera as the final detection means. Of course, if the spectral characteristic itself of the final detection means is highly sensitive to light emission and appropriately low to excitation light, it may not be adjusted by a filter or the like.

Further, the detection system is not particularly limited as long as a detection system having a high sensitivity to the wavelength of fluorescence or phosphorescence and a reduced sensitivity to the wavelength of excitation light is configured. Although cameras with an unaided eye or image sensor can be used, the excitation light is preferably ultraviolet light or short-wavelength visible light, so the visual sensitivity to the unaided eye is low, and the final detection of the detection system The means is preferably a camera or the like. CCD and CMOS sensors used as image sensors for cameras generally have sensitivity in a wide wavelength range. In this case, a small amount of excitation light wavelength range is transmitted, and the transmittance of fluorescence or phosphorescence is high. What is necessary is just to detect through a filter. A wide variety of types of filters can be used. The term “transmittance” used here is used in the sense of selecting a wavelength for a necessary optical path, and is not limited to the transmittance with respect to the straight travel of light. The sensitivity of the detection system is the sensitivity of the entire system including optical systems such as sensors, filters, and lenses. When the light emitted from the measurement target is detected and determined by the sensor, the signal level of the reflection part of the excitation light metal pattern and the signal level of the light emitting part of the resin substrate surface are within the detection intensity range of the sensor and can be determined simultaneously. is important.

In this embodiment, the light b3 with reduced excitation light is detected by the light receiving unit 14 through the excitation light reduction filter 16 that transmits a small amount of the wavelength range of the excitation light and has high transmittance of fluorescence or phosphorescence, and the metal pattern forming resin. A surface inspection of the substrate 1 is performed.

Specifically, the sensitivity of the detection system is set such that the detection level of the excitation light reflected by the metal pattern in the state where the metal pattern-formed resin substrate is irradiated with the excitation light is V1, and the resin substrate surface is detected from the light emission of the resin substrate surface. It is preferable that the inspection is performed in a state where the detection system is set so that V2 / V1 is 0.1 or more and 10 or less when the detection level of light excluding the reflected excitation light is V2. By setting in this way, the light emission image on the resin substrate surface and the reflection image of the metal pattern can be detected simultaneously, and each can be clearly discriminated. In the setting within this range, the portion where the resin substrate is exposed is observed as a substantially uniform bright image, and the reflection image having the brightness determined by V2 / V1 is observed in the metal pattern portion. When V2 / V1 is smaller than 0.1, reflection of excitation light becomes dominant even on the surface of the resin substrate, so that the light emission image on the surface of the resin substrate becomes unclear. When V2 / V1 exceeds 10, the reflection image on the surface of the metal pattern becomes dark, and it becomes difficult to identify abnormal portions on the metal pattern.

When V2 / V1 is near 1, the intensity of the emitted light from the resin substrate is approximately the same as the intensity of the excitation light reflected by the metal pattern, but the light emission on the surface of the resin substrate is almost uniform. On the other hand, the reflection image of the metal pattern is an actual observation image and can be distinguished. In particular, when V2 / V1 is less than 1 and 0.1 or more, or V2 / V1 is greater than 1 and 10 or less, the brightness of the light emission image on the resin substrate surface and the reflection image of the metal pattern Can be clearly distinguished from each other. And by setting V2 / V1 to be smaller than 1 and 0.1 or more, the excitation light reflected by the metal pattern becomes stronger than the emitted light on the surface of the resin substrate, and the reflected image of the metal pattern becomes the resin. Since it is detected brighter than the light emission image on the substrate surface, it is particularly effective when emphasizing the surface inspection of the metal pattern. Further, by setting V2 / V1 to be greater than 1 and 10 or less, the emission light of the resin substrate becomes stronger than the excitation light reflected by the metal pattern, and the emission image on the surface of the resin substrate is dominant. Thus, since the reflection image of the metal pattern is detected darkly, the foreign matter between the metal patterns can be observed particularly clearly, which is particularly effective when emphasizing the surface inspection between the metal patterns. Among these ranges, when V2 / V1 is greater than 1 and 10 or less, foreign matter between metal patterns can be observed particularly clearly, and the surface of the metal pattern is also observable.

In these level settings, when the final detection means converts to an electrical signal such as an image sensor, it has a large number of pixels and outputs an output signal corresponding to each pixel, but detection from all target pixels or representative pixels What is necessary is just to determine V1 and V2 by the average value of a level. That is, in a state where the excitation light is irradiated onto the metal pattern forming resin substrate, the detection system field of view is the metal pattern, the detection level of the excitation light reflected by the metal pattern is V1, and the detection system field of view is the resin substrate surface. The light detection level obtained by dividing the light emitted from the resin substrate surface from the excitation light reflected by the resin substrate surface may be V2.

Specifically, in FIG. 2, a resin substrate from which the metal pattern has been removed is placed instead of the metal pattern forming resin substrate 1, and in addition to the excitation light reduction filter 16, a filter that removes substantially all of the excitation light is disposed. The obtained intensity signal level is averaged to V2 for all effective pixels, and then the metal layer side of the substrate from which the metal pattern has not been removed is placed on top, and the intensity signal level obtained from the image sensor is What is necessary is just to adjust the characteristic of the excitation light reduction filter 16 so that V1 is averaged by pixels and V2 / V1 is in the predetermined range. Alternatively, when the signal intensities of a plurality of pixels can be individually determined, it is possible to simply cut out the part from the image of the metal pattern forming resin substrate 1 and replace it with the average level of the representative pixels.

The adjustment of the excitation light reduction filter 16 may be performed by a variable filter or by adjusting the number of filters.

Also, the excitation light reflectivity of the metal pattern and the emission intensity of the resin substrate vary depending on the DUT, but it is cumbersome to directly adjust the output level corresponding to this, such as when the substrate material is frequently switched. In some cases, substantially the same effect can be obtained by attenuating the reflection of the excitation light by setting the sensitivity to the excitation light wavelength region in the range of 0.0001% to 1% with respect to the sensitivity to the emission wavelength region. Is obtained.

The image obtained by detecting the excitation light b3 reduced to a level at which the emission image of the resin substrate and the reflection image of the metal pattern can be simultaneously detected and observed through the excitation light reduction filter 16 in this way is The exposed portion is observed as a bright image with high contrast, extremely clear and almost uniform. Moreover, the part in which the metal pattern 3 exists is obtained as a reflected image of excitation light, and the surface state of the metal pattern 3 can be observed by observing the reflected image. Further, the skirt residue, root residue, etching residue and the like of the metal pattern are generally observed as a dark image. Further, even when a reflection image of the excitation light applied to the foreign material is detected, it can be clearly distinguished from the surrounding light emitting substantially uniformly. Furthermore, even when the foreign matter is transparent and transmits excitation light or visible light, the light emitted from the resin substrate 2 below the foreign matter is refracted by the foreign matter to cause directionality. A distinctly different image is observed. On the other hand, the abnormality on the metal pattern is often a dark image because the reflection of the metal is blocked, but since it is a natural reflection image, an image corresponding to the abnormal state is naturally obtained.

Therefore, the uniform bright portion can be recognized as a portion where the resin substrate is exposed, that is, an image between the metal patterns, and an image of the metal pattern can be recognized as a reflection image of the excitation light. Thereby, the space | interval of a metal pattern and a pattern defect can be determined. In addition, it is possible to determine a local or peculiar dark part or a part with different brightness as a foreign object.

Then, the light b3 obtained through the excitation light reduction filter 16 is received by the light receiving unit 14, and the obtained image is inspected. As an inspection method, the same method as that of the first embodiment described above can be used.

Then, in the manufacturing process of the metal pattern forming resin substrate, the surface of the metal pattern forming resin substrate is inspected in this way, and the interval between the metal patterns is narrow, the pattern is defective, or the foreign matter on the resin substrate surface between the metal patterns. A metal pattern forming resin substrate that is determined to have a defect or has an abnormality such as having a foreign substance on the surface of the metal pattern is selected as a defective product, and this is removed to eliminate the presence of a mixture of defective products. An extremely small number of metal pattern forming resin substrates can be obtained as a final product.

Next, a third embodiment of the surface inspection method for a metal pattern forming resin substrate according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same location as 1st Embodiment, and description is abbreviate | omitted.

Next, the light from the light source is transmitted through the light guide 12 and emitted from the tip of the light guide 12, and the excitation light a1 and the visible light a2 are simultaneously measured on the metal pattern forming resin substrate 1 (in FIG. 3, an elliptical shape). (Frame C region) is irradiated.

In order to irradiate the excitation light a1 and the visible light a2 at the same time, for example, as shown in FIG. 3, the excitation light source 11 and the visible light source 17 are provided, and the light guide 12 is transmitted from each light source, and each light guide is transmitted. And the like.

The excitation light source 11 is not particularly limited. The thing similar to what was used in 1st Embodiment can be used. In this embodiment, a filter 13 that selectively increases the transmittance of the excitation light a 1 is attached to the tip of the light guide 12 extending from the excitation light source 11, and the excitation light a 1 having a specific wavelength is measured by the condenser lens 18. It is configured so that it can be focused and irradiated with high intensity.

The visible light source 17 is not particularly limited. What is necessary is just to be able to observe the reflection image of the metal pattern. Any of a single wavelength light source, a plurality of wavelength light sources, and a continuous wavelength spectrum light source can be used. For example, fluorescent lamps, halogen lamps, tungsten lamps, LED light sources, Xe lamps and the like can be mentioned. In addition, when an irradiation light source is a several wavelength light source and a continuous wavelength spectrum light source, it can be used as a light source which has both components of excitation light and visible light. High-pressure mercury lamps, Xe-Hg lamps, metal halide lamps, Xe lamps, etc. have a continuous spectrum (white light) of ultraviolet light components and visible light components suitable for excitation light. It is possible to irradiate light. When directly irradiating from these light sources, since visible light tends to be too strong, it is preferable to attenuate the visible light with a wavelength filter or the like to irradiate the metal pattern forming resin substrate.

As the excitation light a1 applied to the metal pattern forming resin substrate, the same light as that used in the first embodiment can be used. That is, it is preferable to use light having a short wavelength that is highly absorbed by the resin material constituting the resin substrate of the metal pattern forming resin substrate, and more preferably light having a wavelength that is absorbed by the resin material surface layer. Specifically, light having a wavelength of 430 nm or less is preferable, ultraviolet light having a wavelength of 400 nm or less is particularly preferable, and light centering on a range of 350 nm to 400 nm is particularly preferable.

The intensity of the visible light a2 applied to the metal pattern forming resin substrate 1 may be adjusted so that the light emission image of the resin substrate and the visible light reflection image of the metal pattern can be easily observed simultaneously. Although visible light is also reflected from the surface of the resin substrate, it is weaker than the reflection from the metal pattern. Therefore, if it is easy to observe simultaneously as described above, the light emission image is dominant on the surface of the resin substrate. Therefore, in the above adjustment, it is more preferable to adjust so that the reflection image on the surface of the metal pattern is darker than the light emission image of the resin substrate. If the intensity of the visible light a2 is too strong, the light emission image of the resin substrate is covered with the reflection image from the front surface and the back surface of the resin substrate, making it difficult to observe the resin substrate surface. On the other hand, when the intensity of the visible light a2 is too weak, the identification of the abnormal part on the metal pattern becomes unclear. The intensity ratio between the visible light a2 and the excitation light a1 varies depending on the light emission efficiency of the resin material, the surface state of the metal pattern, and the reflectance depending on the irradiation method of the excitation light and visible light. Irradiation is sufficient. Preferably, the intensity of the visible light a2 is 0.0001 to 1%, more preferably 0.001 to 1% of the intensity of the excitation light a1. If the intensity of the visible light a2 is less than 0.0001% of the intensity of the excitation light a1, it is difficult to observe the surface of the metal pattern with the reflected image of the visible light a2. Further, when the intensity of the visible light a2 exceeds 1% of the intensity of the excitation light a1, the reflected image of the visible light a2 becomes dominant and the surface of the resin substrate tends to be difficult to observe.

The excitation light a1 and visible light a2 are preferably irradiated from the surface side to be inspected of the metal pattern forming resin substrate. Any irradiation method can be preferably used as long as the irradiation is performed from the surface side to be inspected. If the excitation light is irradiated from the surface, it hardly depends on the irradiation angle, but the visible image may change greatly depending on the relationship between the surface shape of the substrate and the irradiation angle. Also good. For example, the metal pattern forming resin substrate may be irradiated obliquely from above, or may be irradiated from directly above through a magnifying lens. In this embodiment, the excitation light a 1 and the visible light a 2 are applied to the measurement site from obliquely above the metal pattern forming resin substrate 1. In addition, since the excitation light a1 has low transparency and is easily absorbed by the resin substrate, fluorescence or phosphorescence cannot be generated from the surface side to be inspected when the excitation light a1 is irradiated from the side surface side or the back surface side. In other cases, the amount of emitted light is weak and accurate surface inspection cannot be performed. Furthermore, even if visible light a2 is irradiated from the side surface side or the back surface side, a reflection image of the metal pattern on the surface side to be inspected cannot be obtained, and the surface state of the metal pattern cannot be inspected.

When the metal pattern forming resin substrate 1 is simultaneously irradiated with excitation light a1 and visible light a2, the excitation light a1 is absorbed by the resin substrate, and fluorescence or phosphorescence is emitted from the surface of the resin substrate 2. Further, a part of the excitation light a 1 and the visible light a 2 are reflected or scattered on the surface of the resin substrate 2 or the surface of the metal pattern 3. That is, the light b4 generated from the metal pattern forming resin substrate 1 by simultaneously irradiating the metal pattern forming resin substrate 1 with the excitation light a1 and the visible light a2 includes fluorescence emitted when the resin substrate 2 absorbs the excitation light, or Phosphorescence, excitation light reflected or scattered on the surfaces of the resin substrate 2 and the metal pattern 3, and reflection of visible light on the surface of the metal pattern 3 are mixed. For this reason, in the image observed by detecting the light b4, the image of the interface between the resin substrate and the metal layer tends to become unclear due to the interaction of each light component. Since the excitation light intensity is stronger than the visible light intensity, if the reflected light or scattered light of the excitation light is detected, there is a possibility that a light emission image or a reflected image for observation is buried. Therefore, in this embodiment, the light b4 is detected by a detection system that does not have sensitivity to excitation light but has sensitivity to fluorescence or phosphorescence and visible light.

In the present invention, “detection with a detection system having no sensitivity to excitation light, fluorescence or phosphorescence, and sensitivity to visible light” means that the sensitivity of the detection system to excitation light is fluorescence or phosphorescence, and By detecting using a detection system that can detect light emission and visible light by substantially excluding the influence of excitation light. is there. In addition, the wavelength range of fluorescence or phosphorescence is often visible light, and in this case, detection is performed using a detection system that can substantially detect the visible light without the influence of excitation light. When the final detection means of the detection system is the naked eye, the light emission needs to be visible light. Therefore, when the excitation light contains a visible light component, it is necessary not to disturb the observation by the light emission. It is preferable that detection is performed by adjusting the sensitivity of the entire detection system with an optical system such as a wavelength filter as necessary so that the intensity of the visible light component of the excitation light is 10% or less of the intensity of the visible light component of the emitted light. When the final detection means of the detection system is to convert it into an electrical signal, the sensitivity to the excitation light is preferably 1% or less, more preferably 0.5% or less of the sensitivity to the emission. This is preferable because a clear emission image can be obtained while suppressing the influence of fogging.

As the detection system, a camera having the naked eye or an image sensor can be used, and the detection system is particularly limited as long as it is composed of a system with low sensitivity to excitation light, high fluorescence or phosphorescence wavelength, and high sensitivity to visible light. There is no. Since CCD and CMOS sensors used for the naked eye and image sensors generally have sensitivity in a wide wavelength range, in this case, the transmittance for the wavelength range of excitation light is low, and fluorescence or phosphorescence, and visible light What is necessary is just to detect through a filter with high transmittance.

In this embodiment, the light b5 whose excitation light is reduced to a detection limit value or less or a determination threshold value or less through the excitation light removal filter 15 having a low excitation light transmittance and high fluorescence or phosphorescence and visible light transmittance. Is detected by the light receiving unit 14 and the surface of the metal pattern forming resin substrate 1 is inspected.

The excitation light removing filter 15 is preferably a filter having a transmittance of 0 to 0.5% for excitation light and a transmittance of 50 to 100% for emitted light and visible light composed of fluorescence or phosphorescence. More preferably, the light transmittance is 0 to 0.35% and the light transmittance and the visible light transmittance are 70 to 100%.

The image obtained by detecting the light b5 that has passed through the excitation light removal filter 15 in this way is not affected by the reflected or scattered light of the excitation light, and the exposed portion of the resin substrate has a high contrast and is extremely clear. It is observed as an almost homogeneous bright image. Moreover, the part in which the metal pattern 3 exists is obtained as a reflected image of visible light, and the surface state of the metal pattern 3 can be observed by observing the reflected image. Also, the skirt residue, root residue, etching residue, etc. of the metal pattern may be bright because it is a reflected image of visible light, but it is clearly different from the light emission of the resin substrate surface and can be clearly discriminated. is there. In addition, even when the foreign matter is transparent and transmits excitation light or visible light, the light emitted from the resin substrate 2 below the foreign matter is refracted by the foreign matter to cause directionality. A distinctly different image is observed. On the other hand, the abnormality on the metal pattern is often a dark image because the reflection of the metal is blocked, but since it is a natural reflection image, an image corresponding to the abnormal state is naturally obtained.

Therefore, a uniform bright portion can be recognized as a portion where the resin substrate is exposed, that is, an image between metal patterns, and an image of the metal pattern can be recognized as a reflected image of visible light. Thereby, the space | interval of a metal pattern and a pattern defect can be determined. In addition, it is possible to determine a local or peculiar dark part or a part with different brightness as a foreign object.

The light b5 obtained through the excitation light removal filter 15 is received by the light receiving unit 14, and the obtained image is inspected. The inspection by the light receiving unit 14 can be performed by the method described in the first embodiment.

Then, in the manufacturing process of the metal pattern forming resin substrate, the surface of the metal pattern forming resin substrate is inspected in this way, and the interval between the metal patterns is narrow, the pattern is defective, or the foreign matter on the resin substrate surface between the metal patterns. Metal pattern forming resin substrates that have been determined to have a defect or that have been found to have an abnormality such as a foreign object on the surface of the metal pattern are sorted as defective and removed to remove very few defective products. A metal pattern-formed resin substrate is obtained as the final product.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Measuring method)
Measuring method of arithmetic average height Ra: Based on JIS B0601 (2001), a length of 30 μm was measured using a confocal laser microscope VK-8500 (manufactured by Keyence Corporation).

[Test Example 1]
(Example 1-1)
A 9 μm thick electrolytic copper foil (trade name “USLP”, manufactured by Nippon Electrolytic Co., Ltd.) with a roughened layer formed on one side is a polyimide film (trade name “UPILEX VT”, manufactured by Ube Industries, Ltd.) having a heat-sealing layer. ) Using a metal laminated polyimide film (trade name “Iupicel N”, manufactured by Ube Nitto Kasei Co., Ltd.) laminated so that the roughened layer side is in contact with the polyimide film on both sides, and removing unnecessary copper on both sides in the etching process. A circuit board was obtained by forming a wiring pattern with a pitch of 40 μm on one surface and leaving a part of copper from the other surface. The arithmetic average height Ra of the portion where the polyimide film was exposed was 0.28 μm.

A filter (UTVAF) that passes through a light guide from the Xe-Hg lamp house to the surface to be inspected of the circuit board manufactured in this way and transmits 60% or more of ultraviolet light (360 nm) provided at the tip to block visible light. -36U (manufactured by Sigma Kogyo Co., Ltd.) was passed through and irradiated with ultraviolet light (excitation light) having a wavelength of 400 nm or less, and fluorescent light was emitted from the polyimide film surface layer. Then, the surface of the circuit board is a filter provided on the objective lens of the actual microscope (the transmittance of ultraviolet light having a wavelength of 400 nm or less is 0.1% or less, the transmittance of emitted light having a wavelength of 450 to 700 nm is 85% or more, SCF -42L (manufactured by Sigma Kogyo Co., Ltd.) was observed, and the surface state of the circuit board in the range of 0.8 mm square or more was observed. FIG. 4 is a camera image of the circuit board 300 observed in this way. The portion 301 where the polyimide film surface was exposed showed bright fluorescence in response to ultraviolet light. Further, the metal pattern portion 302 is shown dark because there is no fluorescence emission. This circuit board 300 had a root remaining portion in the vicinity of the metal pattern portion 302, and the line width of the metal pattern portion 302 on the image was shown to be extremely thick (inside the oval frame 303 in the figure), and it was determined that the foreign matter was defective. Note that a copper foil was present on the entire back surface of the circuit board of the camera image.

(Example 1-2)
Only the visible light was irradiated to the same part of the circuit board used in Example 1-1 as in Example 1-1, and the reflected light of the visible light was detected with a microscope to observe the surface state. FIG. 5 is a camera image of the circuit board 400 observed in this way. As shown in FIG. 5, in this camera image, the metal pattern portion 402 is shown brightly, and the amount of return of the reflected light is small in the remaining part of the root (inside the oval frame 403 in the figure). For this reason, it is difficult to distinguish from the portion 401 where the polyimide film surface is exposed, and the interval between the metal pattern portions 402 cannot be accurately and clearly captured.

[Test Example 2]
(Example 2-1)
Electrolytic copper foil (trade name “NADFF”, manufactured by Mitsui Kinzoku Co., Ltd.) with a thickness of 2 μm without a roughening layer is applied to both sides of a polyimide film (trade name “UPILEX VT”, manufactured by Ube Industries, Ltd.) having a heat-sealing layer. From the laminated metal laminated polyimide film (trade name “Iupicel N”, manufactured by Ube Nitto Kasei Co., Ltd.), a copper pattern on both sides is formed by a semi-additive process, and unnecessary base copper foil is removed by etching. A circuit board was obtained by forming a wiring pattern with a pitch of 40 μm and leaving most of the copper on the opposite surface. The arithmetic average height Ra of the portion where the polyimide film was exposed was 0.06 μm.

The surface to be inspected of the circuit board manufactured in this way is irradiated with ultraviolet light (excitation light) having a wavelength of 400 nm or less in the same manner as in Example 1-1, and a metal microscope is used instead of the actual microscope. The emission image was observed through a filter (SCF-42L, manufactured by Sigma Kogyo Co., Ltd.) provided later, and the surface state of the circuit board in a range of 0.4 mm square or more was observed. FIG. 6 is a camera image of the circuit board 500 observed in this way. The portion 501 where the polyimide film surface was exposed showed bright fluorescent emission in response to ultraviolet light. Further, the metal pattern portion 502 is shown dark because there is no fluorescence emission. Then, only a defective etching residue between the wirings was clearly seen as a dark spot (inside the oval frame 504 in the figure) in a part of the portion 501 where the polyimide film surface was exposed, and it was determined that the foreign matter was defective. FIG. 6B is an enlarged image obtained by cutting out a portion having foreign matters from the entire image of FIG. 6A, and small foreign matters can be observed. Note that a copper foil was present on almost the entire surface on the back side of the circuit board of the camera image.

(Example 2-2)
Only the visible light was irradiated to the same portion of the circuit board used in Example 2-1, and the surface state was observed by detecting the reflected light of the visible light with a microscope. FIG. 7 is a camera image of the circuit board 600 observed in this way. As shown in FIG. 7, in this camera image, the metal pattern portion 602 is shown bright, and the portion 601 where the polyimide film surface is exposed is shown dark. In addition, in the portion 601 where the polyimide film surface is exposed, a bright spot due to the reflection of copper unevenness on the opposite surface as well as the bright spot due to the metal reflection remaining in the etching between the wirings (in the elliptical frame 604 in the figure) (Inside the square frame 605 in the figure) are mixed, and it is difficult to determine a defective etching residue.

[Test Example 3]
(Example 3-1)
A 9 μm thick electrolytic copper foil (trade name “USLP”, manufactured by Nippon Electrolytic Co., Ltd.) with a roughened layer formed on one side is a polyimide film (trade name “UPILEX VT”, manufactured by Ube Industries, Ltd.) having a heat-sealing layer. ) Using a metal laminated polyimide film (trade name “Iupicel N”, manufactured by Ube Nitto Kasei Co., Ltd.) laminated so that the roughened layer side is in contact with the polyimide film on both sides, and removing unnecessary copper on both sides in the etching process. A circuit board was obtained by forming a wiring pattern with a pitch of 40 μm on one surface and leaving a part of copper from the other surface. The arithmetic average height Ra of the portion where the polyimide film was exposed was 0.28 μm. A foreign object was adhered on the substrate to obtain an object to be measured.

A filter (blocking visible light by passing 60% or more of ultraviolet light (360 nm) provided at the tip through the light guide from the high-pressure mercury lamp house to the surface to be inspected of the circuit board thus manufactured ( UTVAF-36U (manufactured by Sigma Kogyo) passes through and irradiates ultraviolet light (excitation light) with a wavelength of 400 nm or less with a lens and adjusts the intensity of white light (visible light) through a light guide from a white LED lamphouse. ) And the polyimide wiring board surface was irradiated with excitation light and visible light simultaneously. The intensity of excitation light was 1.5 W / cm ² and the intensity of visible light was 0.15 mW / cm ² (the intensity of visible light was 0.001% of the intensity of excitation light). Then, a filter provided on the surface of the circuit board after the objective lens of the microscope (the transmittance of ultraviolet light having a wavelength of 400 nm or less is 0.1% or less, the transmittance of emitted light having a wavelength of 450 to 700 nm is 85% or more, SCF Excitation light was removed through -42L (manufactured by Sigma Kogyo Co., Ltd.), and the surface state of the circuit board in a range of 0.4 mm square or more was observed as a light emission image and a visible light reflection image.

FIG. 8 is a camera image of the circuit board 700 observed in this way. A portion 701 where the polyimide film surface was exposed was brightly observed in response to ultraviolet light, and fluorescence emission was dominantly observed. Further, the metal pattern portion 702 did not emit fluorescence, and a reflected image of visible light could be observed. Further, the foreign matter 704 between the metal patterns is shown dark because the excitation light is blocked and no fluorescence emission is seen, and the foreign matter 703 on the metal pattern portion is shown dark because the reflection of visible light is hindered. As described above, the foreign matter between the metal patterns and the foreign matter on the metal pattern could be clearly and simultaneously identified. Note that a copper foil was present on the entire back surface of the circuit board of the camera image.

(Example 3-2)
The surface state of the circuit board was observed in the same manner as in Example 3-1, except that only the visible light was irradiated to the same part of the circuit board used in Example 3-1. FIG. 9 is a camera image of the circuit board 800 observed in this way. The portion 801 where the polyimide film surface was exposed was shown dark with a small amount of reflected visible light. In addition, the metal pattern portion 802 was brightly shown by a reflected image of visible light. The foreign matter 803 on the metal pattern portion was clearly recognized because it was shown dark because the reflection of visible light was hindered. However, the identification of the foreign material 804 between the metal patterns was unclear.

(Example 3-3)
The surface state of the circuit board was observed in the same manner as in Example 3-1, except that only the ultraviolet light having a wavelength of 400 nm or less was irradiated to the same part of the circuit board used in Example 3-1. FIG. 10 is a camera image of the circuit board 900 observed in this way. The portion 901 where the polyimide film surface was exposed was shown bright when fluorescence emission was observed in response to ultraviolet light. Further, the metal pattern portion 902 is shown dark with no fluorescence emission. The foreign matter 904 between the metal patterns was shown dark because no fluorescence was observed, and could be clearly recognized. However, the foreign matter 903 on the metal pattern is shown dark as in the normal pattern, and the foreign matter on the metal pattern portion cannot be recognized.

1: Metal pattern forming resin substrate 2: Resin substrate 3, 4: Metal pattern 11: Excitation light source 12: Light guide 13: Filter 14: Light receiving unit 15: Excitation light removal filter 16: Excitation light reduction filter 17: Visible light source 18: Condensing lens 21: support base

Claims

A method for inspecting a surface of a metal pattern-formed resin substrate obtained by patterning a metal layer on a resin substrate made of a resin material that emits fluorescence or phosphorescence when irradiated with excitation light,
The metal pattern forming resin substrate is irradiated with at least excitation light, and the light emitted from the resin substrate surface and the light reflected from the metal pattern are less sensitive to the excitation light than the light emitted from the resin substrate surface. A method for inspecting a surface of a metal pattern-formed resin substrate, wherein the detection is performed by a detection system.
A detection system that irradiates only the excitation light to the metal pattern-formed resin substrate, and does not have sensitivity to excitation light, but has sensitivity to fluorescence or phosphorescence, and light emitted from the resin substrate surface and light reflected by the metal pattern. The surface inspection method of the metal pattern formation resin substrate of Claim 1 detected by these.
The method for inspecting a surface of a metal pattern-formed resin substrate according to claim 2, wherein foreign matter remaining between the metal patterns is detected by fluorescence or phosphorescence emitted from the surface of the resin substrate.
The metal pattern forming resin substrate is irradiated only with excitation light, and the light emitted from the resin substrate surface and the light reflected by the metal pattern are detected by a detection system in which the sensitivity to excitation light is lower than the sensitivity to fluorescence or phosphorescence. The surface inspection method of the metal pattern formation resin substrate of Claim 1 which does.
The detection level of excitation light reflected by the metal pattern in the state where the metal pattern-formed resin substrate is irradiated with excitation light is V1, and the detection level of light obtained by dividing excitation light reflected by the resin substrate surface from light emission of the resin substrate surface is V1. 5. The surface inspection method for a metal pattern-formed resin substrate according to claim 4, wherein the inspection is performed in a state where the detection system is set so that V2 / V1 is 0.1 or more and 10 or less when V2 is V2.
The foreign matter remaining between the metal patterns is detected by fluorescence or phosphorescence emitted from the resin substrate surface, and an abnormality of the metal surface of the metal pattern is detected by excitation light reflected by the metal pattern. The surface inspection method of the metal pattern formation resin substrate of description.
The metal pattern formation according to any one of claims 2 to 6, wherein the detection system includes a filter having a low transmittance with respect to excitation light and a high transmittance with respect to fluorescence or phosphorescence emitted from the resin substrate surface. Resin substrate surface inspection method.
The metal pattern forming resin according to any one of claims 2 to 7, wherein the metal pattern forming resin substrate has a metal pattern on both surfaces of the resin substrate and irradiates excitation light from a surface side to be inspected. Substrate surface inspection method.
The metal pattern forming resin substrate is simultaneously irradiated with excitation light and visible light, and the light emitted from the resin substrate surface and the visible light reflected by the metal pattern have no sensitivity to the excitation light, and are fluorescent or phosphorescent, and visible light. The surface inspection method of the metal pattern formation resin substrate of Claim 1 detected by the detection system which has the sensitivity with respect to.
The foreign matter remaining between the metal patterns is detected by fluorescence or phosphorescence emitted from the resin substrate surface, and abnormality of the metal surface of the metal pattern is detected by visible light reflected by the metal pattern. Surface inspection method for metal pattern-formed resin substrate.
The metal pattern forming resin according to claim 9 or 10, wherein the intensity of visible light applied to the metal pattern forming resin substrate is 0.0001 to 1% of the intensity of excitation light applied to the metal pattern forming resin substrate. Substrate surface inspection method.
12. The method for inspecting a surface of a metal pattern forming resin substrate according to claim 9, wherein the metal pattern forming resin substrate is irradiated with excitation light and visible light from the same light source.
The metal pattern forming resin substrate according to any one of claims 9 to 12, wherein the detection system includes a filter having low transmittance for excitation light and high transmittance for fluorescence or phosphorescence and visible light. Surface inspection method.
The metal according to any one of claims 9 to 13, wherein the metal pattern-formed resin substrate comprises a metal pattern on both surfaces of the resin substrate, and irradiates excitation light and visible light from the surface side to be inspected. A method for inspecting the surface of a patterned resin substrate.
15. The method for inspecting a surface of a metal pattern forming resin substrate according to claim 1, wherein the metal pattern forming resin substrate is a circuit substrate having metal wiring formed by patterning a metal layer.
The surface inspection of a metal pattern forming resin substrate according to any one of claims 1 to 15, wherein the metal pattern forming resin substrate is a substrate obtained by removing a metal from a laminate of a metal and a resin base material. Method.
The metal pattern forming resin substrate surface inspection method according to claim 16, wherein the metal pattern forming resin substrate is a substrate obtained by removing a metal from a laminate of a metal and a resin base material by etching.
The resin substrate is made of one selected from aromatic polyimide, polyurethane containing an imide group, aromatic polyamide, and polyamideimide, and the excitation light is light having a wavelength of 430 nm or less. The surface inspection method of the metal pattern formation resin board | substrate as described in any one.
The method for inspecting a surface of a metal pattern-formed resin substrate according to any one of claims 1 to 18, wherein the arithmetic average height Ra of the surface portion where the resin substrate is exposed exceeds 0.1 μm.
19. The method for inspecting a surface of a metal pattern-formed resin substrate according to claim 1, wherein the arithmetic average height Ra of the surface portion where the resin substrate is exposed is 0.1 μm or less.
21. A method of manufacturing a metal pattern forming resin substrate, wherein the metal pattern forming resin substrate is inspected by the method according to claim 1 to remove defective products.