JP2008073736A - Laser beam machining method and method for manufacturing electrode for biosensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellent laser beam machining method which can form an electrode by completely removing simultaneously both surfaces of a metallic layer of a metallized film. <P>SOLUTION: This laser beam machining method is directed to remove the metallic layer of the metallized film comprising a polymeric film substrate, which has a total light transmittance of not less than 80%, and whose both surfaces have been metallized. The method is characterized in that a Q switch pulse laser is used as a laser which transmits the polymeric film substrate to simultaneously remove the metallic layer provided on both surfaces of the film. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laser processing method for providing an arbitrary shape on a substrate on which thin films are laminated, and more particularly to a laser processing method for removing a metal layer formed on both surfaces of a metallized film into an arbitrary shape. It is.

  Moreover, this invention relates to the manufacturing method of the electrode for biosensors which removes the metal layer of a double-sided metallized film with the said laser processing method.

  An enzyme electrode method has been proposed as a measurement method of a biosensor for easily quantifying a specific component in a biological sample.

  This enzyme electrode method uses an enzyme electrode in which an electrode composed of a measurement electrode, a counter electrode and a reference electrode is formed on an insulating substrate, and an enzyme layer containing an oxidoreductase and an electron mediator is formed on this electrode. When a sample solution containing a specific component that is a substrate for an enzyme reaction is dropped on the enzyme layer of the enzyme electrode thus prepared, the enzyme layer dissolves in the sample solution, the enzyme and the substrate react, and the electron mediator Is reduced. The substrate concentration in the sample solution can be determined from the value of current flowing to the electrode when the reduced electron mediator is oxidized electrochemically.

  As an example, a glucose sensor has been developed (Patent Document 1, etc.). Glucose oxidase or glucose dehydrogenase is used as the enzyme, and potassium ferricyanide is used as the electron mediator. Since the amount of glucose contained in a sample solution such as blood can be measured, it is widely used mainly for the purpose of measuring self blood glucose in diabetic patients.

  The electrode member of the enzyme electrode is formed by laminating a noble metal layer such as gold, platinum or palladium on an insulating polymer film substrate by sputtering or the like, and removing a part of the noble metal layer by laser processing. (Patent Document 2 etc.).

  Furthermore, a biosensor having a method of forming enzyme electrodes on both surfaces of an insulating base material has been proposed (Patent Document 3). According to the biosensor, quantitative reliability can be improved by using the same enzyme for a plurality of enzyme electrodes. Further, by using different enzymes for the plurality of enzyme electrodes, a plurality of components in the sample solution can be quantified simultaneously.

  On the other hand, a method has been proposed in which metal layers are laminated on both sides of a transparent insulating substrate and the metal layers on both sides are removed simultaneously by laser processing (Patent Document 4).

However, when an electrode is formed by removing the metal layers on both sides of the metallized film using such a method, the metal layers on both sides cannot be completely removed by a single laser scan. However, there was a problem that remained on the insulating substrate.
Japanese Patent Laid-Open No. 5-196595 (page 2, column 1, line 20 to column 2, line 2) JP 2001-305096 A (Claim 5) JP-A-5-196596 (Claim 1) Japanese Patent Laid-Open No. 1-251689 (Claims)

  In view of the background of the prior art, the present invention is to provide an excellent laser processing method for forming an electrode by simultaneously and completely removing the metal layer of a metallized film.

  A biosensor in which a plurality of sets of enzyme electrodes are formed on different surfaces of an insulating substrate is usually configured in the order of cover / spacer / electrode / insulating substrate / electrode / spacer / cover (Patent Document 4). etc). In particular, the present invention intends to provide a laser processing method for obtaining an electrode such as a biosensor.

  The present invention employs the following means in order to solve such problems. That is, the laser processing method in the present invention is a laser processing method for removing a metal layer of a double-sided metallized film composed of a polymer film substrate having a total light transmittance of 80% or more, and the polymer film A Q-switched pulse laser is used as a laser that passes through the substrate, and the metal layers on both sides are removed simultaneously.

  Moreover, this invention is a manufacturing method of the electrode for biosensors which removes the metal layer of a double-sided metallized film with the said laser processing method.

  According to the present invention, the metal layer can be removed simultaneously and completely on both sides by a single laser scan. Therefore, in a biosensor such as a glucose sensor, a biosensor having electrodes on both sides. It is possible to provide an excellent laser processing method for forming an electrode used in the above.

  The present invention, as a result of intensive studies on the above-mentioned problem, that is, a method of forming an electrode by simultaneously and completely removing the metal layers of the metallized film, transmits the polymer film substrate of the metallized film. When a special laser called a Q-switched pulse laser was used as the laser, it was investigated that this problem could be solved at once.

  In this invention, a metallized film means the film which laminated | stacked the metal layer on both surfaces of the polymer film base material. According to the present invention, the metal layers on both sides of the metallized film are removed at the portion irradiated with the laser, and the polymer film substrate is exposed.

  A sectional view of the metallized film before laser processing in the present invention is shown in FIG. The metallized film comprises a polymer film substrate (1) and metal layers (2) and (3).

  A cross-sectional view of the metallized film after laser processing in the present invention is shown in FIG. A laser processing part (4) is a part irradiated with the laser, the metal layers on both sides are removed, and the polymer film substrate (1) is exposed.

  The polymer film substrate of the metallized film in the present invention needs to be composed of a material that transmits such a laser. That is, the total light transmittance measured based on JIS-K-7105 (1981 version) needs to be 80% or more, preferably 85% or more, more preferably 87% or more. When the total light transmittance is lower than 80%, heat is accumulated in the polymer film substrate and is damaged.

  The material constituting the polymer film substrate in the present invention can be appropriately selected from known plastic film substrate materials. For example, as a material for such a plastic film substrate, polyester, polyethylene, polypropylene, diacetate, triacetate, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyether ethyl ketone, polyimide Resins selected from resins such as fluorine-based, fluorine-based, nylon-based, methacrylic-based, and polylactic acid-based resins can be used. Among these resins, it is preferable to use a polyester film made of a polyester resin from the viewpoint of mechanical strength and uniformity.

  As the polyester of the polyester film, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, or the like can be used. In addition, those polyesters obtained by copolymerizing other dicarboxylic acid components and diol components in a range of 20 mol% or less can also be used. These constituent components may be used singly or in combination of two or more, but polyethylene terephthalate is particularly preferably used in view of quality, economy and the like.

  The thickness of the polymer film substrate is not particularly limited, but is preferably 5 to 800 μm, more preferably 10 to 250 μm from the viewpoint of mechanical strength.

  In addition, the metallized film of the present invention can be subjected to a surface treatment on the surface of the polymer film substrate before laminating the metal layer. For example, as such surface treatment, etching treatment, vapor treatment, ion beam treatment, surface roughening treatment, and corona discharge treatment can be performed. Similarly, a surface coating can be applied before laminating the metal layer. For example, resins such as polyurethane, polyester, polyester acrylate, polyurethane acrylate, and polyepoxy acrylate, titanate compounds, and the like can be coated. Such surface treatment and / or surface coating can enhance the adhesion of the metal layer to the polymer film substrate.

  As the metal material constituting the metal layer, any metal can be used as long as it is difficult to be oxidized and has electrical conductivity. In particular, since the chemical stability is good, gold, platinum, Precious metals such as palladium, silver, ruthenium, rhodium, osmium and iridium are preferable because they can be suitably used for electrode applications for electrically capturing changes due to chemical reactions, for example, enzyme electrodes for biosensors. Moreover, the metal raw material which comprises this metal layer may be 1 type, or may use 2 or more types together. Further, a plurality of metal layers may be laminated, or an alloy may be used. In addition, the raw material which comprises a metal layer may differ on both surfaces of a metallized film, and the number of metal layers may differ on both surfaces.

  The thickness of the metal layer is preferably 50 nm or less on both sides, more preferably 40 nm or less, and particularly preferably 30 nm or less. Further, the thickness of the metal layer may be different on both sides as long as it is within such a range. However, if the thickness of the metal layer on at least one side is larger than 50 nm, the metal layer on both sides may not be completely removed by a single laser scan.

  Examples of the method for laminating the metal layers on both sides of the metallized film in the present invention include sputtering, vacuum deposition, electron beam deposition, and ion plating. Among these, the sputtering method is particularly preferable from the viewpoint of uniformity of the thickness of the metal layer, adhesion, and the like.

  For laser processing in the present invention, it is necessary to use a Q-switch pulse laser. The Q-switched pulse laser means a laser that emits a pulse having a half-value width of 10 nanoseconds or more and 300 nanoseconds or less. By using such a Q-switched pulse laser, both metal surfaces can be simultaneously and completely removed by a single laser scan. A pulsed laser with continuous oscillation or a half-width greater than 300 nanoseconds is not preferable because the metal layers on both sides cannot be completely removed by a single laser scan. Further, a pulse laser having a half-value width of less than 10 nanoseconds is not preferable because heat accumulates rapidly on the metallized film and is damaged.

  Such a Q-switch pulse laser is described in detail, for example, on pages 9 to 10 of “Laser processing technology” (Toshiyuki Miyazaki et al., Published by an industrial book).

〔Evaluation methods〕
The thickness of the metal layer, the total light transmittance of the film base material, the surface resistance value, and the laser processing part of both sides (laser incident surface and back surface) of the metallized film prepared in each example and comparative example The depth was measured. The measurement was performed in an atmosphere having a temperature of 25 ° C. and a relative humidity of 45 to 55% RH. Ten film samples were cut into a square shape with a size of 100 mm × 100 mm and used for each measurement. The measured value was an average value of the 10 film samples.

(1) Thickness of metal layer It measured using the spectroscopic ellipsometer (M-2000 by JA Woollam Japan Co., Ltd.). The wavelength range of incident light was 245 to 1000 nm, the light diameter was 2 mmφ, and the incident angle was 60 °.
Light was incident from one side of the metallized film, and the thickness of each metal layer on both sides was measured at once.

(2) Total light transmittance of film base material The total light transmittance of a film base material is based on JIS-K-7105 (1981 edition) using a turbidimeter (NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd.). Measured.

(3) Surface resistance value It was evaluated by the surface resistance value whether the metal layer of the laser-processed part was completely removed.
The surface resistance value was measured at a test voltage of 100 V using a surface resistivity meter (Digital Hitester 3256 manufactured by Hioki Electric Co., Ltd.) based on JIS-C-2151 (2006 version).
The value at the center was measured for each side of the film. With respect to the metallized film after laser processing, the measurement was performed by installing two electrode probes so as to sandwich the linear laser scanning part. The average value of the surface resistance value of each surface of ten different film samples was taken as the measured value of each surface. When the ratio of the surface resistance values calculated by the following formula is 1000 or more, the metal layer of the laser processed part is removed well.
Ratio of surface resistance value = surface resistance value after laser processing (Ω / □) / surface resistance value before laser processing (Ω / □).

(4) Depth of laser processed part In order to evaluate the presence or absence of damage to the film base in the laser processed part, the depth of the laser processed part (distance from the film base surface to the bottom of the concave portion of the laser processed trace) was measured. . The depth of the laser processed part was measured using a high precision thin film level gauge (ET-10 manufactured by Kosaka Laboratory Ltd.) with a stylus tip radius of 0.5 μm and a needle pressure of 5 mg.
When the depth of the laser processed portion is 1.5 μm or less, the base material of the metallized film is not damaged, and the metal layer is well removed. Moreover, when it can confirm visually that the metal layer is unremoved, it is unsatisfactory.
In this measurement method, the distance from the surface of the metal layer to the bottom surface of the concave portion of the laser processing trace is measured, and strictly speaking, the depth of only the laser processing portion is not provided. However, since the thickness of the metal layer is very small with respect to the depth of the laser processed portion, in this application, the value obtained by this measurement method is regarded as the depth of the laser processed portion.

[Examples 1, 2, 3 and Comparative Example 1]
Using a transparent polyester film with a thickness of 100 μm (Lumilar (registered trademark) # 100S10 manufactured by Toray Industries, Inc.) as a film base, a palladium film with a thickness of 10 nm is laminated on both sides of the film base using a magnetron sputtering apparatus. did. As the target, palladium having a purity of 99.99 mass% (manufactured by Furuuchi Chemical Co., Ltd.) was used. The ultimate back pressure was 5 × 10 ⁻³ Pa or less. Argon having a sputtering pressure of 0.7 Pa was used as the sputtering gas.

Laser processing was performed with a YVO ₄ laser marker (MD-V9600, manufactured by Keyence Corporation). The wavelength of the laser marker device was 1064 nm, and the half width of the pulse laser was 10 nanoseconds.

  The laser conditions were set such that the Q switch pulse frequency was 10 kHz and the laser intensity was 40%. Laser scanning was performed in a straight line parallel to an arbitrary side of the square at a scanning speed of 200 mm / second, passing through the center of a 100 mm × 100 mm square film sample. A film sample obtained by such processing was referred to as Example 1.

  In Example 1, a film sample in which the thickness of the palladium film was 20 nm on both sides of the film was set as Example 2, and a film sample in which the thickness of the palladium film was 50 nm on both sides of the film was set as Example 3. Furthermore, in Example 1, a film sample in which the thickness of the palladium film was 100 nm on both sides of the film was taken as Comparative Example 1.

Example 4
Using a transparent polyester film with a thickness of 125 μm (Lumirror (registered trademark) # 125T60 manufactured by Toray Industries, Inc.) as the film base, a 10 nm thick palladium film is laminated on both sides of the film base using a magnetron sputtering device. did. As the target, palladium having a purity of 99.99 mass% (manufactured by Furuuchi Chemical Co., Ltd.) was used. The ultimate back pressure was 5 × 10 ⁻³ Pa or less. Argon having a sputtering pressure of 0.7 Pa was used as the sputtering gas.

Laser processing was performed with a YVO ₄ laser marker (MD-V9600, manufactured by Keyence Corporation). The wavelength of the laser marker device was 1064 nm, and the half width of the pulse laser was 10 nanoseconds.

  The laser conditions were set such that the Q switch pulse frequency was 10 kHz and the laser intensity was 40%. Laser scanning was performed in a straight line parallel to an arbitrary side of the square at a scanning speed of 200 mm / second, passing through the center of a 100 mm × 100 mm square film sample. A film sample obtained by such processing was referred to as Example 4.

[Comparative Example 2]
Using a 100 μm thick white polyester film (Lumirror (registered trademark) # 100E20 manufactured by Toray Industries, Inc.) as the film base, a 50 nm thick palladium film is laminated on both sides of the film base using a magnetron sputtering apparatus. did. As the target, palladium having a purity of 99.99 mass% (manufactured by Furuuchi Chemical Co., Ltd.) was used. The ultimate back pressure was 5 × 10 ⁻³ Pa or less. Argon having a sputtering pressure of 0.7 Pa was used as the sputtering gas.

Laser processing was performed with a YVO ₄ laser marker (MD-V9600, manufactured by Keyence Corporation). The wavelength of the laser marker device was 1064 nm, and the half width of the pulse laser was 10 nanoseconds. The laser conditions were set such that the Q switch pulse frequency was 10 kHz and the laser intensity was 40%. Laser scanning was performed in a straight line parallel to an arbitrary side of the square at a scanning speed of 200 mm / second, passing through the center of a 100 mm × 100 mm square film sample. The film sample obtained by such processing was referred to as Comparative Example 2.

[Comparative Example 3]
A transparent polyester film with a thickness of 100 μm (Lumirror (registered trademark) # 100S10 manufactured by Toray Industries, Inc.) is used as a film substrate, and a palladium film with a thickness of 50 nm is laminated on both surfaces of the film substrate using a magnetron sputtering apparatus. did. As the target, palladium having a purity of 99.99 mass% (manufactured by Furuuchi Chemical Co., Ltd.) was used. The ultimate back pressure was 5 × 10 ⁻³ Pa or less. Argon having a sputtering pressure of 0.7 Pa was used as the sputtering gas.

Laser processing was performed with a YVO ₄ laser marker (MD-V9600, manufactured by Keyence Corporation). The wavelength of the laser marker device was 1064 nm. The laser was continuously oscillated and the laser intensity was set to 40%. The laser scan was performed in a straight line parallel to an arbitrary side of the square at a scanning speed of 200 mm / second, passing through the center of a 100 mm × 100 mm square film sample. A film sample obtained by such processing was referred to as Comparative Example 3.

  The evaluation results of each Example and Comparative Example are shown in Table 1.

  In Examples 1 to 4, the palladium layers on both sides were completely removed, and damage to the film base material was not observed in the laser processed part.

  In Comparative Example 1 in which the palladium layer was 100 nm, although the palladium layer on the laser incident surface was completely removed, the palladium layer on the back surface was not removed, which was defective.

  In Comparative Example 2 in which a white film was used as the base material of the metallized film, the palladium layer on the laser incident surface was completely removed, but the palladium layer on the back surface was not removed, and the laser incident surface was processed. The film base was damaged because of damage to the film base.

  In Comparative Example 3 in which laser scanning was performed with continuous oscillation, although the palladium layer on the laser incident surface was completely removed, the palladium layer on the back surface was not removed, which was defective.

  The present invention is particularly suitably used as an excellent laser processing method for forming an electrode used for a biosensor having a shape provided with electrodes on both sides in a biosensor such as a glucose sensor.

It is the schematic which shows an example of the metallized film cross section before the laser processing in this invention. It is the schematic which shows an example of the metallized film cross section after the laser processing in this invention.

Explanation of symbols

1: Polymer film base material 2: Metal layer 3: Metal layer 4: Laser processed part

Claims (3)

  A laser processing method for removing a metal layer of a double-sided metallized film composed of a polymer film substrate having a total light transmittance of 80% or more, wherein a Q-switched pulse laser is used as a laser that transmits the polymer film substrate A laser processing method that simultaneously removes the metal layers on both sides using a laser.   The laser processing method according to claim 1, wherein the thickness of the metal layer is 50 nm or less on both surfaces.   The manufacturing method of the electrode for biosensors which removes the metal layer of a double-sided metallized film with the laser processing method of Claim 1 or 2.

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