JP2006297717A - Method and apparatus for inspecting thin film made of resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for inspection which enables the inexpensive, simple and accurate inspection on whether or not a specified microstructure is formed in a thin film made of a resin even under a vacuum atmosphere just after the microstructure is formed, and to provide an apparatus for inspection which can execute such a method for inspection and can guarantee the quality. <P>SOLUTION: The method for inspection is characterized in that an electrostatic capacity of the thin film made of the resin in which the microstructure is formed is measured between conductive bodies, and a condition that the microstructure in the thin film made of the resin is formed is inspected by the measured value of the electrostatic capacity and the distance between the conductive bodies. It is possible by this method for inspection to inspect the thin film made of the resin having a through-hole in the thickness direction. On the inspection, an embodiment for measuring independently the electrostatic capacities of the thin film made of the resin at a plurality of positions, is preferable. The apparatus for inspection executes such the method for inspection as this. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inspection method and an inspection apparatus capable of inspecting a resin thin film made of plastic or the like having a fine structure with high accuracy and low cost. The present invention also relates to a fine hole inspection method and inspection apparatus that can be used for highly functional fine parts such as inkjet printer nozzles, medical nebulizer nozzles, precision filters for ultrafine fillers, and high-density printed circuit boards. The present invention also relates to a method for inspecting micropores that can be used for inspecting the thickness of highly functional micro components such as microlenses and light guide plates with strict thickness accuracy.

  In order to manufacture highly functional fine parts such as an ink jet printer nozzle or a medical nebulizer nozzle, it is necessary to accurately form fine through holes in a resin thin film. There is a laser processing method as a method for forming a fine through-hole. For example, this method forms a photoresist at a position where a through-hole is formed on the plate, but does not form a photoresist on the plate. A mask is formed in the region. Since the mask can block high energy rays such as laser, the photoresist is removed, and high energy rays such as laser are irradiated through the mask to form a through hole in the plate (see Patent Document 1). . However, in the laser processing method, it is necessary to irradiate a high-intensity laser, and the irradiation position must be adjusted with high accuracy. Therefore, the processing apparatus is very expensive, and the laser is used to form a through hole. Since this is a method, the throughput is small.

  There is an injection molding method as a method of forming a resin thin film having fine through-holes, but this method uses an abutment made of an elastic member such as silicon resin on the part where the through-holes of the mold to be used are formed. The mold is abutted and injection molding is performed with the abutting mold abutting. By using a resin with good fluidity that flows into a gap of several μm in the mold, fine through holes can be formed. Moreover, even if a thin and easy-to-bend abutting mold having a diameter of 50 μm or less is used, the abutting mold is made of an elastic member, so that it does not break at the time of injection molding, and the mold releasability is good (Patent Document) 2). However, in this method, the types of resin that can be used are greatly limited, and when the diameter of the through hole is reduced and the pitch is narrowed, the abutment mold that abuts increases the flow resistance, so uniform resin injection It becomes difficult.

There is a punching method as a method of forming fine through holes in a resin thin film. In this method, a metal film is formed on the surface of a punch that is a ceramic fiber, and discharge is performed between the tip of the punch and the surface of the die material. By discharging, a fine through-hole through which the punch can be inserted is formed in the die material without contacting the punch with the die material. Since the positional relationship between the die and the punch does not change after the formation of the die hole, the punch can be surely inserted into the die hole, and a through hole corresponding to the thickness of the punch is easily formed in a thin plate in a short time. (See Patent Document 3). However, in this method, since the diameter of the through hole that can be formed is determined by the diameter of the ceramic fiber, there is a limit to miniaturization of the through hole. In addition, since one through hole is formed by one corresponding punch, it is difficult to maintain the pitch accuracy of the punch when assembling each punch into the holder, and the manufacturing efficiency is low. Furthermore, it is difficult to maintain and recover from damage, so mass productivity is low.
JP-A-6-122203 JP 2000-71459 A JP 2004-114228 A

  As a method for improving these fine processing techniques, there is a hot embossing method. In this method, a resin thin film is set between a pressing die and a counter substrate, and the resin thin film is heated to a flow start temperature or higher between the mold and the counter base material, The resin thin film is pressed between the pressing die and the counter substrate to form a fine structure. The hot embossing method can easily form a high-precision fine structure using the flow phenomenon of resin, and the manufacturing cost is low.

  However, the fine structure forming step is usually performed continuously in a vacuum atmosphere in order to maintain high accuracy. Since it is not possible to inspect the formation state of the fine structure by frequently releasing to the atmosphere to increase manufacturing efficiency, if defective parts such as non-through holes or hole connection occur due to clogging of the pressing die, the defective parts will continue in a vacuum atmosphere. Occur. Therefore, it is necessary to inspect immediately after formation of the fine structure.

  As an in-line inspection method, there is an inspection method using image recognition. However, the fine structure formed on the resin thin film has a pore diameter of several to several tens of microns, and is a tens of thousands of holes, so it has a clear contrast. Cannot be obtained, and processing time is required. Therefore, it is not suitable for inspection of defective products such as non-through holes or hole connections. On the other hand, there is a method in which an inspection head having an airtight structure is sequentially pressed against a molded resin thin film and a filtration test is performed, but the degree of vacuum in the vacuum chamber deteriorates and air is caught. Since an adverse effect on molding occurs, it is not preferable as an inspection method.

  An object of the present invention is to provide an inspection method capable of performing an inexpensive, simple and accurate inspection immediately after forming a fine structure, whether or not a predetermined fine structure is formed on a resin thin film even under a vacuum atmosphere. It is to provide. Moreover, it is providing the inspection apparatus of the resin-made thin films which enforces this inspection method.

  The inspection method of the present invention measures the capacitance of a resin thin film having a microstructure formed between conductors, and inspects the formation state of the microstructure in the resin thin film based on the measured capacitance value and the distance between the conductors. It is characterized by doing. By this inspection method, a resin thin film having a through hole in the thickness direction can be inspected. In the inspection, it is preferable to independently measure the capacitance at a plurality of locations on the resin thin film. The inspection apparatus of the present invention is an apparatus that performs such an inspection method.

  According to the present invention, even in a vacuum atmosphere, immediately after forming a fine structure on a resin thin film, the formation state of the fine structure can be inspected inexpensively, simply and accurately.

  The inspection method of the present invention inspects the microstructure of the resin thin film by measuring the capacitance of the resin thin film having a fine structure between the conductors and examining the measured capacitance value and the distance between the conductors. It is characterized by doing. After forming the fine structure, the capacitance of the resin thin film is measured, and the formation state of the fine structure can be inspected inexpensively, simply and accurately based on the measured value and the distance between the conductors. Capacitance measurement can be performed in a vacuum atmosphere immediately after formation of a fine structure, so that a situation in which defective portions are continuously generated can be avoided, and fine processing in a resin thin film is thoroughly performed. While managing, manufacturing efficiency can be maintained high. Resin thin films that have been finely processed by such quality control methods are high-performance fine components such as inkjet printer nozzles, medical nebulizer nozzles, precision filters for ultrafine fillers, high-density printed circuit boards, and microlenses. Useful as. The inspection apparatus of the present invention is an apparatus for performing such an inspection method, and can provide high-performance fine parts processed with high accuracy at a low cost by a simple system.

  Capacitance is a storage capacity of electric energy, and is a value indicating how much charge Q can be stored in a certain potential difference V. When an insulator is inserted between two conductors, the insulator absorbs electrical energy and changes the molecular arrangement, so that more electrical energy is required to maintain a constant potential difference, and static electricity between the two conductors is required. Electric capacity increases. Therefore, when a resin thin film as an insulator is sandwiched between two conductors and the capacitance is measured, for example, as shown in FIG. 5, the capacitance changes depending on the fine structure of the resin thin film, and the resin The capacitance gradually increases as the total thickness of the thin film decreases. On the other hand, for a thin film with a constant thickness, if the total area of the micropores formed in the thickness direction of the resin thin film increases, the apparent dielectric constant of the resin thin film decreases. Capacity decreases. Therefore, by measuring the capacitance of the resin thin film and examining the measured capacitance value and the distance between the conductors, the formation state of fine structures such as micropores in the resin thin film can be inspected with high accuracy in-line. Further, it is possible to control the molding system by feeding back inspection data to the molding system.

  The capacitance can be measured by an LCR meter (reactance capacitance resistance meter). An LCR meter can measure the capacitance of a capacitor containing a sample and evaluate the complex dielectric constant at that frequency. As an LCR meter, there is HP4284A manufactured by Agilent Technologies Inc., and HP4284A can perform measurement from 20 Hz to 1 MHz. For example, as shown in FIG. 6, after forming a fine structure such as a through-hole in the thickness direction of the resin thin film (FIG. 6A) (FIG. 6B), between the two conductors 64a and 64b. It is possible to inspect the formation state of the fine structure by measuring the electrostatic capacity with an LCR meter (FIG. 6C).

  By independently measuring the capacitance at a plurality of locations on the resin thin film, the formation state of the microstructure at each location can be inspected. For example, as shown in FIG. 7, when inspecting a resin thin film having a fine structure, the upper and lower conductors sandwiching the resin thin film are divided so that the upper and lower positions correspond to each other, and the edges are electrically cut. By independently measuring the electrostatic capacity of each of the LCR meters 1 to 3, the resolution of the inspection can be improved, whether a predetermined fine structure is formed at each location, and where the defective location is. It becomes possible to easily inspect whether or not this occurs. Which range is to be cut out and inspected independently can be determined according to the pattern of the pressing die, for example.

  The inspection method of the present invention is a method for inspecting a resin thin film having a fine structure, and a hot embossing method is preferable as a method for forming a fine structure because a highly accurate fine structure can be formed easily and inexpensively. FIG. 1 illustrates a method for inspecting the formation state of the fine structure after forming the fine structure by the hot embossing method. First, as shown in FIG. 1A, the resin thin film 1 is set between the pressing die 2 and the counter substrate 3. Next, as shown in FIG. 1 (b), the resin thin film 1 is heated to a flow start temperature or higher between the pressing die 2 and the counter substrate 3. Next, as shown in FIG. 1 (c), a resin thin film having a flow starting temperature or higher is pressed between the pressing die and the opposing base material in the direction of the arrow, as shown in FIG. 1 (d). Fine pores are formed. In FIG.1 (d), a through-hole is illustrated as a fine hole. Thereafter, as shown in FIG. 1 (e), the resin thin film in which the fine holes are formed is sandwiched between the two conductors 4a and 4b, and the capacitance is measured by an LCR meter.

  The resin thin film is heated between the pressing die and the counter substrate. For example, the resin thin film 1 is heated between the pressing die 2 and the counter substrate 3 (FIG. 1B). ), A method in which only the resin thin film is heated in a non-contact state in advance, or a method in which the resin thin film is brought into contact with the opposing substrate and then heated. The resin thin film 1 can be heated by, for example, a heater (not shown) installed immediately below the counter substrate 3. Moreover, it can also carry out by introduce | transducing a heating function in the inside of the opposing base material 3. FIG. Further, in the process of supplying the resin thin film, it can be preheated using a non-contact heater or the like.

  Since it is heated after the flow start temperature of the resin thin film is applied and then pressed, high-precision microstructures such as micropores can be easily formed in the resin thin film using the flow phenomenon, and the manufacturing cost Can be reduced. Although it depends on the precision of the die used, a fine structure having a pore diameter of 0.1 μm or more can be formed by the processing method of the present invention. Also, a horizontally long groove-like structure having a line width of 0.1 μm or more can be formed. Therefore, it is possible to provide a high-functional fine structure such as an inkjet printer nozzle, a medical nebulizer nozzle, a cell trapping filter, an ultrafine filler filter, or an ultrafine circuit on a high-density printed circuit board at low cost.

  As the material of the resin thin film, a plastic that melts within a relatively narrow temperature range and rapidly cures when cooled is preferable in terms of high throughput. For example, polycarbonate, polyimide, polymethyl methacrylate (PMMA), polyether sal Perforation processing and uneven processing can be performed on thin films such as phon, polysulfone, and polyetherimide. The thickness of the resin thin film is not particularly limited, but is preferably 1 μm to 10 mm, more preferably 10 μm to 200 μm. For example, a plastic flat plate having a thickness of several millimeters or a plastic film having a thickness of several tens of microns can be used as the material.

  In addition to heat molding, UV curing molding can be used. In the case of performing UV curing molding, for example, a transparent pressing die made of quartz or the like can be used, and UV irradiation can be performed from the transparent pressing die side. Moreover, it can carry out by irradiating UV from the transparent opposing base material side using a transparent opposing base material side. Further, it can be molded by a pressing die and a counter substrate, and cured by irradiation with UV immediately after demolding.

  The inspection method of the present invention is also useful for a microstructure formed by nanoimprinting. Nanoimprint is set on a resin thin film with a nano-level fine unevenness on the surface, and after heating the resin thin film above the glass transition temperature, the mold is pressed against the resin thin film and held for a certain period of time. In this method, the mold is peeled off from the resin thin film after the resin thin film is cooled to a glass transition temperature or lower, and the unevenness on the surface of the mold can be transferred to the resin thin film by nanoimprinting. In addition, nanoimprinting allows a nano-order three-dimensional fine shape to be easily formed by a simple processing step, which can reduce manufacturing costs and facilitate mass production.

  There is a method in which a resin thin film is supplied from a reel, formed into a fine structure, inspected, and then wound on a reel. The reel-to-reel method is also preferable in that the mutual positional relationship between the resin thin film and the opposing base material does not change once set. The resin thin film can be supplied, for example, by feeding a thick flat plate in a batch manner.

  FIG. 8 shows an example of a manufacturing method in which a resin thin film is supplied from a reel 86 in a vacuum chamber 85 and wound around a reel 89 through a fine structure forming step 87 and an inspection step 88. As shown in FIG. 8, in the case of the reel-to-reel method, it is preferable that the fine structure forming step 87 and the inspection step 88 including the reels 86 and 89 are performed in a vacuum atmosphere. According to this aspect, it is possible to prevent the resin thin film from being lifted on the counter substrate and mixing of bubbles between the resin thin film and the counter substrate, thereby enabling fine microfabrication. Further, by installing the inspection process in the vacuum chamber, it is possible to inspect immediately after forming the microstructure in a vacuum atmosphere. Therefore, it is possible to avoid a situation where defective products continue to be produced, and to maintain high manufacturing efficiency because the product is not returned to atmospheric pressure.

  The stamping die is manufactured by a method including a step of forming a resin die by lithography, a step of forming a layer made of a metal material on the resin die on a conductive substrate by electroforming, and a step of removing the resin die. Can do. Since the manufactured stamping die is a precise metal microstructure, an ultrafine hole structure can be formed in the resin thin film, and it can sufficiently cope with a narrow pitch of holes. Further, it can be manufactured with good reproducibility and can be formed integrally.

  The manufacturing method of a stamping die is illustrated in FIGS. In the manufacturing method of the pressing mold shown in FIG. 2, first, as shown in FIG. 2A, the resin layer 22 is formed on the conductive substrate 21. For example, a metal substrate made of copper, nickel, stainless steel, or the like is used as the conductive substrate. In addition, a silicon substrate on which a metal material such as titanium or chromium is sputtered is used. For the resin layer, a resin material mainly composed of polymethacrylate such as polymethyl methacrylate (PMMA), or a chemically amplified resin material sensitive to X-rays or ultraviolet rays (UV) is used. The thickness of the resin layer can be arbitrarily set according to the thickness of the pressing die to be formed, and can be several hundred microns.

  Next, a mask 23 is disposed on the resin layer 22, and X-rays 24, UV, or the like is irradiated through the mask 23. When obtaining a pressing die having a high aspect ratio, an embodiment using X-rays (wavelength 0.4 nm) which is shorter than UV (wavelength 365 nm or the like) is preferable. Also, X-rays of synchrotron radiation (hereinafter referred to as “SR”) are preferable because of high directivity among X-rays. The LIGA (Lithographie Galvanoformung Abformung) method using SR is capable of deep lithography, and can produce a large number of micro-pressing molds with a height of several hundreds of micrometers with high precision on the order of submicrons. A pressing die for a thin film can be obtained. In this embodiment mode, an example of irradiating X-rays is illustrated.

  The mask 23 is composed of an X-ray absorption layer 23a formed according to a pressing pattern and a translucent substrate 23b. SiN, SiC, diamond, titanium, or the like is used for the translucent substrate 23b. For the X-ray absorption layer 23a, a heavy metal such as gold, tungsten, or tantalum or a compound thereof is used. When the resin layer 22 on the conductive substrate 21 is, for example, a positive resist, the resin layer 22a of the resin layer 22 is exposed and deteriorated (molecular chain is cut) by irradiation with the X-ray 24. 22b is not exposed by the X-ray absorption layer 23a. For this reason, only the part which changed in quality by X-rays 24 is removed by development, and the resin type which consists of resin layer 22b as shown in Drawing 2 (b) is obtained.

  Next, electroforming is performed, and a metal material layer 25 is deposited on a resin mold as shown in FIG. Electroforming refers to forming a layer made of a metal material on a conductive substrate using a metal ion solution. By performing electroforming using the conductive substrate 21 as a power feeding portion, the metal material layer 25 can be deposited on the resin mold. By performing electroforming beyond the height of the resin mold, it is possible to form a pedestal base. Nickel, copper, iron, rhodium, or an alloy thereof is used as the metal material, and nickel or nickel alloy such as nickel manganese is preferable in terms of enhancing the wear resistance of the pressing die.

  After electroforming, as shown in FIG. 2D, the conductive substrate 21 is removed by wet etching with acid or alkali, or by machining. Subsequently, when the resin mold 22b is removed by wet etching or plasma ashing, a pressing mold that can be used effectively in the processing method of the present invention as shown in FIG. 2 (e) is obtained.

  In the manufacturing method shown in FIG. 2, the conductive substrate 21 is removed (FIG. 2D) to manufacture the pressing die 25, but the conductive substrate is removed as in the manufacturing method shown in FIG. 3. It is also possible to manufacture a pressing die. First, as shown in FIG. 3A, a resin layer 32 made of a positive resist is formed on a substrate 31a. Next, a mask 33 is disposed on the resin layer 32, and lithography is performed in the same manner as described above. By the exposure, the resin layer 32a of the resin layer 32 is exposed and deteriorated, but the resin layer 32b is not exposed. For this reason, the resin mold which consists of the resin layer 32b as shown in FIG.3 (b) is obtained by image development.

  Next, as shown in FIG. 3C, a conductive substrate 31b is formed on the top of the resin layer 32b, the substrate 31a is removed (FIG. 3D), electroforming is performed, and FIG. As shown in e), a metal material layer 35 is deposited on a resin mold using the conductive substrate 31b as a plating electrode. After electroforming, if necessary, the resin mold is removed by wet etching or plasma ashing after the thickness is adjusted to a predetermined thickness by polishing or grinding to obtain a pressing mold as shown in FIG. Since this stamping die uses the conductive substrate as a pedestal for the mold, the electroforming time required for forming the pedestal can be omitted. Further, since the pedestal is not formed by electroforming, there is little warpage of the mold due to internal stress.

  FIG. 4 shows another method for manufacturing a stamping die without removing the conductive substrate. This method can be used when the material of the conductive substrate is close to the material of the metal material layer formed by electroforming and the adhesion strength between the conductive substrate and the metal material layer is high. First, lithography is performed in the same manner as shown in FIG. 2 (FIG. 4A), and a resin mold 42b is formed on the conductive substrate 41 (FIG. 4B). Next, electroforming is performed to form a metal material layer 45a on the resin mold 42b (FIG. 4C), and polishing or grinding is performed to planarize (FIG. 4D). Finally, when the resin mold 42b is removed by wet etching or plasma ashing, a pressing mold with the conductive substrate 41 as shown in FIG. 4E is obtained.

  The stamping die includes a step of forming a non-conductive master by silicon etching or stereolithography, a step of making the non-conductive master conductive, a step of forming a metal material layer on the conductive master by electroforming, and a conductive master. It can form by the method including the process of removing.

In the method of forming a non-conductive master by silicon etching, first, a SiN film is formed on the surface of a silicon substrate by plasma CVD. Next, a resin layer made of a positive resist is formed on the SiN film. Subsequently, a mask is placed on the resin layer and lithography is performed. The exposed portion of the resin layer is removed by exposure and development. Next, after dry etching with SF ₆ gas and patterning the SiN film, the resin layer is peeled off and silicon etching is performed with a KOH aqueous solution to obtain a non-conductive master. Thereafter, a metal material such as Pd is sputtered to make the non-conductive master conductive, and after electroforming, the conductive master is removed by wet etching to obtain a stamping die.

  The method of forming a non-conductive master by stereolithography is as follows. First, a liquid photo-curable resin (such as SCR701 manufactured by DEMEC) is cured one by one with a light beam in a micro stereolithography apparatus and laminated to be non-conductive. Form a master. Next, when a non-conductive master is sputtered to make Pd or the like conductive, electroformed onto the conductive master, and then removed by wet etching or plasma ashing, a stamping die can be obtained. The stamping die can also be manufactured by dicing or cutting. Unlike a method using lithography, since a mask is not used, a stamping die can be manufactured in a short period of time. In addition, a stamping die made of ceramics such as zirconia can be manufactured.

  The stamping die may be formed by a method including a step of forming a conductive master by dicing or cutting, a step of forming a metal material layer on the conductive master by electroforming, and a step of removing the conductive master. it can. Compared to the above-described method in which the stamping die is directly manufactured by dicing or cutting, it is advantageous in that a plurality of stamping dies can be obtained from an expensive dicing or cutting product. The conductive master can be made of, for example, copper or brass.

  The processing equipment that forms the fine structure in the resin thin film starts the flow of the means for setting the resin thin film between the mold and the counter substrate, and the resin thin film between the mold and the counter substrate. An aspect provided with a means for heating to a temperature or higher and a means for forming a fine structure by pressurizing a resin thin film at a flow start temperature or higher between the pressing die and the counter substrate. Since heating and pressurization are performed at a temperature equal to or higher than the flow start temperature of the resin thin film, a highly accurate and fine pore structure can be easily formed in the resin thin film, and the manufacturing cost can be reduced. Further, in the means for forming a fine structure, if the in-plane maximum pressure difference at the time of pressurization is ± 10% or less, even if a large number of in-plane fine holes are processed at once, such as non-through holes It is more preferable that the defective portion hardly occurs and the in-plane maximum pressure difference is adjusted to ± 5% or less.

  As a means for forming the fine structure, an embodiment having a means for cooling at least one of the resin thin film, the pressing die, and the counter substrate after the fine structure is formed is preferable. After the formation of the fine structure, by cooling the member that is at or above the flow start temperature and speeding solidification, the processing throughput can be increased, and mass production and cost reduction can be achieved. For cooling, there is a method in which cooling water is circulated through the counter substrate and indirectly cooled.

  It is preferable that the means for setting the resin thin film, the means for heating the resin thin film, and the means for forming a fine structure on the resin thin film have independent drive systems. By separating the drive systems of the respective means, it is possible to minimize mutual positional deviation due to repetitive operations in the machining process, and it becomes easy to always keep the in-plane maximum pressure difference within ± 10%. For example, the accuracy can be improved by preventing the X-axis stage, the Y-axis stage, and the Z-axis stage in the processing apparatus from overlapping each other and separating them.

  The means for setting the resin thin film, the means for heating the resin thin film, the means for forming a fine structure on the resin thin film, and the means for inspecting the formation state of the fine structure are preferably installed in a vacuum chamber. . By carrying out the processing operation in a vacuum atmosphere, it is possible to suppress the lift of the resin thin film on the opposing substrate and prevent air bubbles from entering between the resin thin film and the opposing substrate. Is possible. Further, by installing the inspection means in the vacuum chamber, it is possible to inspect immediately after forming the microstructure in a vacuum atmosphere. Therefore, it is possible to avoid a situation in which defective products are continuously made and to maintain high manufacturing efficiency.

Example (Preparation of Sample 1)
The stamping die used in this example was manufactured by the method shown in FIG. First, an acrylic resin layer 42 having a thickness of 80 μm is formed on a nickel substrate having a thickness of 5 mm and a diameter of 3 inches as the conductive substrate 41, a mask 43 is disposed on the resin layer 42, and the X The line 44 was irradiated (FIG. 4 (a)). As the mask 43, a light-transmitting area of 50 μm × 50 μm is drawn at a vertical and horizontal pitch of 100 μm, a light-transmitting base material 43b is made of silicon nitride having a thickness of 2 μm, and an X-ray absorption layer 43a is made of tungsten nitride having a thickness of 3 μm. It was. Further, SR was used for the X-ray 44 and lithography was performed in a range of 20 mm × 20 mm.

  Next, after developing with methyl isobutyl ketone, rinsing with isopropanol, and washing with pure water, only the exposed resin layer 42a of the resin layer 42 is removed, and a resin as shown in FIG. A resin mold composed of the layer 42b was obtained. Next, electroforming was performed, and a metal material layer 45a was deposited on the resin mold as shown in FIG. 4 (c). Electroforming was performed by dipping in a nickel sulfamate plating bath, and a metal material layer 45a was deposited beyond the top of the resin mold.

  After electroforming, as shown in FIG. 4 (d), it was flattened by polishing to a thickness of 70 μm. Subsequently, the resin mold 42b was removed by ashing with oxygen plasma to obtain a pressing mold as shown in FIG. In this pressing die, prisms with a length of 50 μm × width of 50 μm × height of 70 μm were planted in a range of 20 mm × 20 mm with a pitch of 100 μm, and each prism had a forward taper of 0.1 °.

  Next, polymethyl methacrylate (dielectric constant: 3.0) having a length of 20 mm, a width of 20 mm, and a thickness of 50 μm was formed as a resin thin film on a Cu substrate as a counter substrate. Subsequently, the above-described Ni-made die manufactured by the LIGA method is set on the resin thin film, and the resin is heated to 160 ° C. which is higher than the flow start temperature (about 100 ° C.) of the resin thin film made of polymethyl methacrylate. The thin film was heated. The resin thin film was heated by a heater installed immediately below the opposing base material. Thereafter, the resin thin film was pressurized at 10 MPa between the pressing die and the counter substrate to form a through hole. The through holes were 50 μm long × 50 μm wide and 100 μm in pitch. Further, the processing accuracy was ± 1 μm, and it was found that the processing was extremely high accuracy.

  The capacitance of the obtained resin thin film (hereinafter referred to as “sample 1”) was measured by an LCR meter. As the LCR meter, HP 4284A manufactured by Agilent Technologies was used, a resin thin film was sandwiched between two flat plate electrodes of 50 mm in length and 50 mm in width, and the capacitance was measured at a voltage of 1 V and a frequency of 1 kHz. As a result, the capacitance of Sample 1 was 1.107 μF.

(Preparation of sample 2)
Assuming a defective part where a part of the pattern of the resin thin film is broken, a sample is formed except that a through hole corresponding to 1% of the area is connected among the resin thin film of 20 mm long × 20 mm wide × 50 μm thick. Fine processing was performed in the same manner as in No. 1 to obtain a resin thin film (hereinafter referred to as “Sample 2”), and the capacitance was measured in the same manner. As a result, the capacitance of Sample 2 was 1.088 μF.

(Preparation of sample 3)
Assuming the occurrence of non-through holes, Sample 1 was used except that the hole structure was not a through hole, and a hole structure with a length of 50 μm × width 50 μm × depth 45 μm and a pitch of 100 μm was formed so that a remaining film having a thickness of 5 μm was generated. The resin thin film (hereinafter referred to as “sample 3”) was obtained, and the capacitance was measured in the same manner. As a result, the capacitance of Sample 3 was 1.129 μF.

  From the results of Samples 1 to 3, by measuring the capacitance of the microfabricated resin thin film and examining the measured capacitance value and the distance between the conductors, the formation state of the microstructure can be inspected, It was found that the occurrence of defective parts such as non-through holes and hole connections can be inspected by changing the capacitance.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  High-functional fine parts such as inkjet printer nozzles, medical nebulizer nozzles, precision filters for ultrafine fillers, high-density printed circuit boards, and microlenses can be provided at low cost.

It is process drawing which shows the method of this invention which test | inspects the formation state of a microstructure after forming a microstructure in a resin thin film. It is process drawing which shows the manufacturing method of the press die used when forming a fine structure in a resin-made thin film. It is process drawing which shows the manufacturing method of the press die used when forming a fine structure in a resin-made thin film. It is process drawing which shows the manufacturing method of the press die used when forming a fine structure in a resin-made thin film. It is a figure which shows the relationship between the total amount of the thickness of a resin-made thin film, and an electrostatic capacitance. It is process drawing which shows the method of this invention which test | inspects the formation state of a microstructure after forming a microstructure in a resin thin film. It is a figure which shows the method of this invention which test | inspects the formation state of a microstructure. It is a figure which shows the method of this invention which test | inspects the formation state of a fine structure, after forming a fine structure in a resin-made thin film by the reel-to-reel system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Resin thin film, 2 pressing mold, 3 opposing base material, 4a, 4b, 64a, 64b conductor, 21, 31b conductive substrate, 22, 32 resin layer, 23, 33 mask, 25, 35 Metal material layer.

Claims (4)

  A method for inspecting a resinous thin film, in which the capacitance of a resinous thin film having a microstructure is measured between conductors, and the formation state of the microstructure is inspected based on the measured capacitance value and the distance between the conductors.   The resin thin film inspection method according to claim 1, wherein the resin thin film has a through hole in a thickness direction.   The method for inspecting a resinous thin film according to claim 1 or 2, wherein electrostatic capacity at a plurality of locations of the resinous thin film is independently measured.   The inspection apparatus of the resin-made thin films which enforces the inspection method in any one of Claims 1-3.

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