JP2010184288A - Laser processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and easy laser processing method capable of processing a workpiece with excellent processing accuracy. <P>SOLUTION: A laser processing method includes a step for forming a workpiece containing body to form a workpiece containing body 1 having a plurality of workpieces by fixing the periphery of a plurality of workpieces 11 with a workpiece fixing material 12, and a pattern forming step for forming a pattern on the workpiece by irradiating a laser beam while rotating the workpiece containing body. It is preferable that the workpieces are fixed by filling the workpiece fixing material between the workpieces and a workpiece fixing tool which has a plurality of fitting parts for fitting the workpieces, in the step for forming the workpiece containing body. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laser processing method for forming a pattern on a processed surface of a workpiece by irradiating a workpiece such as a substrate on which an LED element is formed with laser light.

Up to now, it is possible to improve the processing efficiency by allowing multiple workpieces to be processed at the same time, and as a laser micromachining device capable of high-precision processing without being aware of the rotation center of the turntable An apparatus using a workpiece fixing jig in which a plurality of mounting holes for regulating the position of a workpiece is provided has been proposed (see, for example, Patent Document 1).
However, in this proposal, there is a step between the processed surface of the workpiece and the non-adsorption surface of the workpiece fixing jig, or the workpiece and the workpiece fixing jig are mounted. There may be a gap between the holes. For this reason, there is a problem that the focus servo is disengaged during laser processing, a portion that cannot be processed occurs, and the processing accuracy of the workpiece decreases.

In addition, as a laser micro-machining device that can maintain the machining accuracy of the workpiece without deviating the focus servo even if there is a step or gap, a plurality of focus servo means, and the workpiece and workpiece are fixed There has been proposed an apparatus including boundary detection means for detecting a boundary of a jig or a vicinity of the boundary, and focus servo switching means for switching the focus servo means based on detection by the boundary detection means (for example, Patent Document 2). reference).
However, this proposal has a problem that special control is required to control the focus servo, and the workpiece cannot be easily processed.

  Therefore, at present, there is a strong demand for providing a laser processing method that is simple and can process a workpiece with excellent processing accuracy.

JP 2008-93723 A JP 2008-200755 A

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, an object of the present invention is to provide a laser processing method that is simple and can process a workpiece with excellent processing accuracy.

Means for solving the problems are as follows. That is,
<1> A workpiece-containing body forming step of fixing a periphery of a plurality of workpieces with a workpiece fixing material and forming a workpiece-containing body having a plurality of workpieces;
A pattern forming step of forming a pattern on the workpiece by irradiating a laser beam while rotating the workpiece-containing body,
The laser processing method characterized by including.
In the laser processing method according to <1>, a workpiece-containing body having a plurality of workpieces is formed in the workpiece-containing body forming step. In the pattern forming step, a pattern is formed on the workpiece by irradiating laser light while rotating the workpiece-containing body. At this time, since the workpiece is integrated as a workpiece containing body and is recognized as one structure, there is a problem that the focus servo is lost when the workpiece is irradiated with laser light. Absent.
<2> The workpiece containing body forming step fills a workpiece fixing material between the workpiece and a workpiece fixing jig having a plurality of mounting portions on which the workpiece is mounted. The laser processing method according to <1>, wherein the workpiece is fixed.
<3> The laser processing method according to any one of <1> to <2>, wherein a gap between the workpiece and the workpiece fixing material is 100 μm or less.
<4> The laser according to any one of <1> to <3>, wherein a step (AB) between the workpiece fixing material surface (A) and the workpiece surface (B) is 4 μm or less. It is a processing method.
<5> The laser processing method according to any one of <1> to <4>, wherein a refractive index of the surface of the workpiece fixing material is within ± 50% of a refractive index of the surface of the workpiece.
<6> The laser processing method according to any one of <1> to <5>, wherein the reflectance of the workpiece fixing material surface is within ± 50% of the reflectance of the workpiece surface.
<7> The laser processing according to any one of <1> to <6>, wherein the workpiece fixing material is at least one selected from an acrylic resin, an epoxy resin, a urethane resin, a silicon resin, and a polyester resin. Is the method.
<8> The laser processing method according to any one of <1> to <7>, wherein the workpiece surface is a layer capable of changing a heat mode shape.

  According to the present invention, there is provided a laser processing method that can solve the above-described problems and can achieve the above-described object, is simple, and can process a workpiece with excellent processing accuracy. Can do.

FIG. 1A is a diagram for explaining an example of a workpiece-containing body, and is a view of the workpiece-containing body as viewed from above. FIG. 1B is a cross-sectional view taken along line A-A ′ of the workpiece-containing body in FIG. 1A. FIG. 2A is a view for explaining an example of the workpiece-containing body, and is a view of the workpiece-containing body as viewed from above. FIG. 2B is an A-A ′ cross-sectional view of the workpiece containing body in FIG. 2A. FIG. 3A is a diagram illustrating an example of a method for forming a workpiece-containing body. FIG. 3B is a diagram illustrating an example of a method for forming a workpiece-containing body. FIG. 3C is a diagram illustrating an example of a method for forming a workpiece-containing body. FIG. 3D is a diagram illustrating an example of a method for forming a workpiece-containing body. FIG. 3E is a diagram illustrating an example of a method for forming a workpiece-containing body. FIG. 4A is a diagram illustrating an example of a method for forming a workpiece-containing body. FIG. 4B is a diagram illustrating an example of a method for forming a workpiece-containing body. FIG. 5 is a diagram for explaining steps between a workpiece and a workpiece fixing material, and steps between the workpiece fixing material surface and the workpiece surface. FIG. 6A is a diagram illustrating the relationship between the diameter of the recess and the pitch. FIG. 6B is a diagram illustrating the relationship between the laser light emission time and the period.

(Laser processing method)
The laser processing method of the present invention includes at least a workpiece containing body forming step and a pattern forming step, and further includes other steps as necessary.

<Workpiece-containing body forming step>
The workpiece containing body forming step is a step of fixing a periphery of a plurality of workpieces with a workpiece fixing material to form a workpiece containing body having a plurality of workpieces.

-Aspect-
The aspect of the workpiece-containing body is not particularly limited and may be appropriately selected depending on the purpose. For example, the aspect including a plurality of workpieces and a workpiece fixing material (hereinafter referred to as “No. 1) ”, an aspect comprising a plurality of workpieces, a workpiece fixing material, and a workpiece fixing jig (hereinafter, referred to as“ second embodiment ”). ) And the like.
FIG. 1A is a view for explaining an example of the first aspect, and is a view of a workpiece containing body (“1” in FIG. 1A) viewed from above. FIG. 1B is a cross-sectional view taken along line AA ′ of the workpiece-containing body in FIG. 1A.
FIG. 2A is a view for explaining an example of the second aspect, and is a view of a workpiece-containing body (“2” in FIG. 2A) viewed from above. 2B is a cross-sectional view taken along line AA ′ of the workpiece-containing body in FIG. 2A.
In FIG. 1A to FIG. 2B, “11” indicates a workpiece, “12” indicates a workpiece fixing material, and “13” indicates a workpiece fixing jig.

-Workpiece-containing body-
The workpiece containing body includes at least a plurality of workpieces and a workpiece fixing material, and further includes other workpieces such as a workpiece fixing jig as necessary.
The workpiece-containing body has both a front surface (surface irradiated with a laser beam in a pattern forming step described later) and a back surface (a surface opposite to a surface irradiated with laser light in a pattern forming step described later). A flat surface is preferable in that it can be processed while maintaining parallelism.
There is no restriction | limiting in particular as a shape of the said workpiece containing body, Although it can select suitably according to the objective, Circular is preferable.
There is no restriction | limiting in particular as a magnitude | size of the said workpiece containing body, According to the objective, it can select suitably.

There is no restriction | limiting in particular as a minimum of the number of the workpieces which the said workpiece containing body has, Although it can select suitably according to the objective, 2 or more are preferable, 3 or more are more preferable, 4 sheets The above is particularly preferable.
The upper limit of the number of workpieces contained in the workpiece-containing body is not particularly limited and can be appropriately selected according to the purpose, but is preferably 1,000 or less, more preferably 100 or less, 50 or less is more preferable, and 20 or less is particularly preferable.
When the number of the workpieces included in the workpiece-containing body is less than 2, it is difficult to efficiently process the workpieces. When the number of workpieces exceeds 1,000, it takes too much time for installation. Overall efficiency may be reduced. On the other hand, when the upper limit and the lower limit of the number of workpieces contained in the workpiece-containing body are within the particularly preferable range, it is advantageous in that the processing efficiency is increased.

  The sizes of the plurality of workpieces included in the workpiece-containing body may be the same or different.

--- Workpiece--
There is no restriction | limiting in particular as said workpiece, According to the objective, it can select suitably, For example, the board | substrate in which the LED element was formed, the board | substrate in the middle of forming an LED element, the oscillator in the middle of formation or formation Examples include a substrate and a substrate on which a semiconductor is formed or being formed.
The substrate is not particularly limited as to the material, shape, structure, size, etc., and can be appropriately selected according to the purpose. Examples of the material include inorganic materials, organic materials, and the like. As the structure, a single layer structure or a laminated structure may be used as the structure, and the size may be appropriately selected according to the use or the like.
Examples of the inorganic material include glass, sapphire, silicon (Si), and quartz (SiO ₂ ).
Examples of the resin include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), low-melting fluororesin, polymethyl methacrylate (PMMA), triacetate cellulose (TAC), and the like.

The substrate may be appropriately synthesized or a commercially available product may be used.
There is no restriction | limiting in particular as thickness of the said board | substrate, According to the objective, it can select suitably, 100 micrometers or more are preferable and 500 micrometers or more are more preferable.

As an example of the multi-layer structure of the workpiece, a form in which a layer capable of changing the shape of the heat mode is laminated on the surface of the substrate can be mentioned.
The layer capable of changing the shape in the heat mode is a layer in which light is converted into heat by irradiation with strong light, and the shape of the material is changed by the heat to form a recess.

Examples of the layer capable of changing the shape in the heat mode include an organic layer.
The material for the organic layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include cyanine-based, phthalocyanine-based, quinone-based, squarylium-based, azurenium-based, thiol complex-based, and merocyanine-based materials. be able to.
Suitable examples include methine dyes (cyanine dyes, hemicyanine dyes, styryl dyes, oxonol dyes, merocyanine dyes, etc.), macrocyclic dyes (phthalocyanine dyes, naphthalocyanine dyes, porphyrin dyes, etc.), azo dyes (azo metal chelate dyes, etc.) ), Arylidene dyes, complex dyes, coumarin dyes, azole derivatives, triazine derivatives, 1-aminobutadiene derivatives, cinnamic acid derivatives, quinophthalone dyes, and the like. Among these, methine dyes and azo dyes are particularly preferable.

In addition, the organic layer can select a pigment | dye suitably according to the wavelength of a laser light source, or can modify | change a structure.
For example, when the oscillation wavelength of the laser light source is around 780 nm, it is advantageous to select from pentamethine cyanine dye, heptamethine oxonol dye, pentamethine oxonol dye, phthalocyanine dye, naphthalocyanine dye, and the like.
When the oscillation wavelength of the laser light source is around 660 nm, it is advantageous to select from trimethine cyanine dye, pentamethine oxonol dye, azo dye, azo metal complex dye, pyromethene complex dye, and the like.
Further, when the oscillation wavelength of the laser light source is around 405 nm, monomethine cyanine dye, monomethine oxonol dye, zero methine merocyanine dye, phthalocyanine dye, azo dye, azo metal complex dye, porphyrin dye, arylidene dye, complex It is advantageous to select from dyes, coumarin dyes, azole derivatives, triazine derivatives, benzotriazole derivatives, 1-aminobutadiene derivatives, quinophthalone dyes, and the like.

  In the following, examples of compounds preferable as the organic layer are given in the case where the oscillation wavelength of the laser light source is around 405 nm. The compounds represented by the following III-1 to III-15 are compounds when the oscillation wavelength of the laser light source is around 405 nm. In addition, when the oscillation wavelength of the laser light source is around 780 nm, preferred compounds in the case of around 660 nm include the compounds described in paragraphs [0024] to [0028] of JP-A-2008-252056. It is done. In addition, this invention is not limited to the case where these compounds are used.

<Example of compound when the oscillation wavelength of the laser light source is around 405 nm>

<Example of compound when the oscillation wavelength of the laser light source is around 405 nm>

<Example of compound when the oscillation wavelength of the laser light source is around 405 nm>

  JP-A-4-74690, JP-A-8-127174, 11-53758, 11-334204, 11-334205, 11-334206, 11-334207 The dyes described in JP-A No. 2000-43423, JP-A No. 2000-108513, JP-A No. 2000-158818, and the like are also preferably used.

Such a dye-type organic layer is prepared by dissolving the dye in a suitable solvent together with a binder or the like to prepare a coating solution, and then coating the coating solution on the substrate surface to form a coating film. It can be formed by drying. In that case, it is preferable that the temperature of the surface which apply | coats a coating liquid is the range of 10 to 40 degreeC. The lower limit is more preferably 15 ° C. or higher, further preferably 20 ° C. or higher, and particularly preferably 23 ° C. or higher. Moreover, as an upper limit, it is more preferable that it is 35 degrees C or less, It is still more preferable that it is 30 degrees C or less, It is especially preferable that it is 27 degrees C or less. Thus, when the coated surface temperature is within the above range, it is possible to prevent the occurrence of coating unevenness and coating failure and to make the thickness of the coating film uniform. Each of the upper limit value and the lower limit value can be arbitrarily combined.
Here, the organic layer may be a single layer or a multilayer. In the case of a multilayer structure, the organic layer is formed by performing the coating process a plurality of times.
The concentration of the dye in the coating solution is preferably 0.3% by mass or more and 30% by mass or less, more preferably 1% by mass or more and 20% by mass or less, more preferably tetrafluoropropanol. It is particularly preferable to dissolve in 1 mass% or more and 20 mass% or less.

There is no restriction | limiting in particular as a solvent of a coating liquid, According to the objective, it can select suitably, For example, Esters, such as butyl acetate, ethyl lactate, and cellosolve acetate; Ketones, such as methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone; Dichloromethane, 1 Chlorinated hydrocarbons such as 1,2-dichloroethane and chloroform; Amides such as dimethylformamide; Hydrocarbons such as methylcyclohexane; Ethers such as tetrahydrofuran, ethyl ether and dioxane; Ethanol, n-propanol, isopropanol, n-butanol diacetone alcohol Alcohols such as: Fluorine solvents such as 2,2,3,3-tetrafluoropropanol; Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol mono Glycol ethers such as Chirueteru; and the like. Among these, butyl acetate, ethyl lactate, cellosolve acetate, methyl ethyl ketone, isopropanol, and 2,2,3,3-tetrafluoropropanol are particularly preferable.
The said solvent can be used individually or in combination of 2 or more type in consideration of the solubility of the pigment | dye to be used. In the coating solution, various additives such as an antioxidant, a UV absorber, a plasticizer, and a lubricant may be added according to the purpose.

Examples of the coating method include a spray method, a spin coating method, a dip method, a roll coating method, a blade coating method, a doctor roll method, a doctor blade method, and a screen printing method. In addition, it is preferable to employ the spin coating method in terms of excellent productivity and easy control of the film thickness.
The organic layer is preferably dissolved in an amount of 0.3% by mass or more and 30% by mass or less, and preferably 1% by mass or more and 20% by mass or less, with respect to the organic solvent, because it is advantageous for formation by spin coating. It is more preferable.
Further, the dye preferably has a thermal decomposition temperature of 150 ° C. or higher and 500 ° C. or lower, and more preferably 200 ° C. or higher and 400 ° C. or lower.
During coating, the temperature of the coating solution is preferably 23 ° C to 50 ° C, more preferably 24 ° C to 40 ° C, and further preferably 25 ° C to 30 ° C.

When the coating solution contains a binder, the binder is not particularly limited and may be appropriately selected depending on the intended purpose. For example, natural organic polymer substances such as gelatin, cellulose derivatives, dextran, rosin, and rubber; Hydrocarbon resins such as polyethylene, polypropylene, polystyrene, polyisobutylene, vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl chloride / polyvinyl acetate copolymer, polymethyl acrylate, polymethyl methacrylate, etc. And synthetic organic polymers such as acrylic resins, polyvinyl alcohol, chlorinated polyethylene, epoxy resins, butyral resins, rubber derivatives, and initial condensates of thermosetting resins such as phenol / formaldehyde resins.
When a binder is used in combination as the material for the organic layer, the amount of the binder used is generally preferably 0.01 to 50 times (mass ratio) with respect to the dye, and 0.1 to 5 times. The amount (mass ratio) is more preferable.

The organic layer can contain various anti-fading agents in order to improve the light resistance of the organic layer.
As the antifading agent, a singlet oxygen quencher is generally used. As the singlet oxygen quencher, those described in publications such as known patent specifications can be used.
Specific examples thereof include JP-A Nos. 58-175893, 59-81194, 60-18387, 60-19586, 60-19587, and 60-35054. 60-36190, 60-36191, 60-44554, 60-44555, 60-44389, 60-44390, 60-54892, JP-A-60-47069, JP-A-63-209995, JP-A-4-25492, JP-B-1-38680, JP-A-6-26028, etc., German Patent No. 350399, Journal of the Chemical Society of Japan Examples include those described in the October 1992 issue, page 1141 and the like.
The amount of the anti-fading agent such as the singlet oxygen quencher used is preferably in the range of 0.1% by mass to 50% by mass and more preferably in the range of 0.5% by mass to 45% by mass with respect to the amount of the dye. The range of 3% by mass to 40% by mass is more preferable, and the range of 5% by mass to 25% by mass is particularly preferable.

  Although the organic layer solvent coating method has been described above, the organic layer can also be formed by a film forming method such as vapor deposition, sputtering, or CVD.

In addition, the pigment | dye has a higher light absorptivity in the wavelength of the laser beam used for the pattern formation process mentioned later than other wavelengths. In particular, it is desirable that the light absorptance is higher at the wavelength of the laser beam during processing than the emission wavelength of the light emitting element such as an LED element.
The wavelength of the absorption peak of the dye is not necessarily limited to that in the visible light wavelength range, and may be in the ultraviolet range or the infrared range.

In particular, when the refractive index of the material constituting the light emitting surface of the light emitting element is high, it is preferable that the organic layer constituting the recess has a high refractive index.
The dye has a wavelength range with a high refractive index on the long wave side of the peak wavelength of the absorption wavelength, and it is preferable to match this wavelength range with the emission wavelength of the light emitting element. For this purpose, the dye absorption wavelength λa is preferably shorter than the center wavelength λc of the light emitting element (λa <λc). The difference between λa and λc is preferably 10 nm or more, more preferably 25 nm or more, and even more preferably 50 nm or more. This is because if λa and λc are too close, the absorption wavelength region of the dye is applied to the center wavelength λc of the light emitting element, and light is absorbed. In addition, the upper limit of the difference between λa and λc is preferably 500 nm or less, more preferably 300 nm or less, and even more preferably 200 nm or less. This is because if λa and λc are too far apart, the refractive index for the light emitted from the light-emitting element becomes small.

The wavelength λw for forming the concave portion with the laser is preferably in a relationship of λa <λw. In such a relationship, the light absorption amount of the dye is appropriate, the recording efficiency is increased, and a clean uneven shape may be formed in some cases. Further, it is preferable that λw <λc. Since λw should be the wavelength that the dye absorbs, the light emitted from the light-emitting element is not absorbed by the dye and the transmittance is improved by having the center wavelength λc of the light-emitting element on the longer wavelength side than the wavelength of λw. As a result, the luminous efficiency can be improved.
From the above viewpoint, it can be said that the relationship of λa <λw <λc is most preferable.

  Note that the wavelength λw of the laser light for forming the recess may be a wavelength that provides a large laser power. For example, when a dye is used for the organic layer, 193 nm, 210 nm, 266 nm, 365 nm, 405 nm, 488 nm, 1,000 nm or less is preferable, such as 532 nm, 633 nm, 650 nm, 680 nm, 780 nm, and 830 nm.

  The laser beam may be any laser such as a gas laser, a solid laser, or a semiconductor laser. However, in order to simplify the optical system, it is preferable to employ a solid laser or a semiconductor laser. The laser light may be continuous light or pulsed light, but it is preferable to employ laser light whose emission interval can be freely changed. For example, it is preferable to employ a semiconductor laser. When the laser cannot be directly on / off modulated, it is preferable to modulate with an external modulation element.

  Further, the laser power is preferably higher in order to increase the processing speed. However, as the laser power is increased, the scanning speed (speed at which the organic layer is scanned with laser light) must be increased. Therefore, the upper limit value of the laser power is preferably 100 W in consideration of the upper limit value of the scanning speed, more preferably 10 W, still more preferably 5 W, and particularly preferably 1 W. The lower limit of the laser power is preferably 0.1 mW, more preferably 0.5 mW, and even more preferably 1 mW.

  Further, the laser light is preferably light that has excellent transmission wavelength width and coherency, and can be narrowed down to a spot size equivalent to the wavelength. In addition, it is preferable to adopt a strategy such as that used in optical discs as the light pulse irradiation conditions for properly forming the recesses. That is, it is preferable to adopt conditions such as recording speed, the peak value of the irradiated laser beam, and the pulse width as used in an optical disc.

  There is no restriction | limiting in particular as thickness of the said organic layer, According to the objective, it can select suitably.

The principle of forming the recess is as follows.
When the organic layer is irradiated with laser light having a wavelength at which the material absorbs light (wavelength absorbed by the material), the organic layer absorbs the laser light, and the absorbed light is converted into heat, which is irradiated with light. The temperature of the part rises. As a result, the organic layer undergoes chemical or / and physical changes such as softening, liquefaction, vaporization, sublimation, and decomposition. And the recessed part is formed because the material which caused such a change moves or / and lose | disappears.

  In addition, as a formation method of a recessed part, the formation method of a pit known for a write-once optical disk, a write-once optical disk, etc. can be applied, for example. Specifically, for example, by detecting the intensity of the reflected light of the laser that changes depending on the pit size, and correcting the output of the laser so that the intensity of the reflected light is constant, a uniform pit is formed. A known running OPC technique (Japanese Patent No. 3096239) can be applied.

  Further, the vaporization, sublimation or decomposition of the organic layer as described above preferably has a large rate of change and is steep. Specifically, the mass reduction rate by differential thermal balance (TG-DTA) at the time of vaporization, sublimation or decomposition of the dye is preferably 5% or more, more preferably 10% or more, and further preferably 20% or more. . Further, the slope of mass decrease by differential thermal balance (TG-DTA) at the time of vaporization, sublimation or decomposition of the pigment (the mass decrease rate per 1 ° C. temperature rise is preferably 0.1% / ° C. or more, and 2% / ° C or more is more preferable, and 0.4% / ° C or more is more preferable.

  Further, the transition temperature of chemical or / and physical change such as softening, liquefaction, vaporization, sublimation, and decomposition has an upper limit of preferably 2,000 ° C. or lower, more preferably 1,000 ° C. or lower. Preferably, it is 500 degrees C or less. If the transition temperature is too high, a large laser power may be required. Further, the lower limit of the transition temperature is preferably 50 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 150 ° C. or higher. If the transition temperature is too low, the temperature gradient with respect to the surroundings is small, and it may be impossible to form a clear hole edge shape.

---- Refractive index ----
There is no restriction | limiting in particular as a refractive index of the said workpiece surface, Although it can select suitably according to the objective, 1.3-2 are preferable, 1.4-1.8 are more preferable, and 1.45. -1.7 is particularly preferred.
When the refractive index of the workpiece surface is less than 1.3, the reflectance is low, and it may be difficult to control autofocusing, etc. When the refractive index exceeds 2, the reflectance with the periphery of the workpiece changes. In other words, it may be difficult to control the autofocus or the like. On the other hand, when the refractive index of the surface of the workpiece fixing material is within the particularly preferable range, it is advantageous in that automatic focus control is stabilized.
Here, the refractive index can be measured by ellipsometry.

---- Reflectance ---
There is no restriction | limiting in particular as the reflectance of the said workpiece surface, Although it can select suitably according to the objective, 0.1%-90% are preferable, 1%-60% are more preferable, 5%- 40% is particularly preferred.
If the reflectance of the workpiece surface is less than 0.1%, it may be difficult to control such as autofocus, and if it exceeds 90%, the signal intensity to the control circuit becomes excessive and the control is unstable. May be. On the other hand, when the reflectance of the workpiece surface is within the particularly preferable range, it is advantageous in that control such as autofocus is stably applied.
Here, the reflectance can be measured by a spectral reflectometer.

The size of the longest part of the workpiece is not particularly limited and may be appropriately selected according to the purpose, but is preferably 1 mm to 350 mm, more preferably 10 mm to 220 mm, and further preferably 25 mm to 160 mm, 50 mm to 110 mm is particularly preferable.
If the size of the longest part of the workpiece is less than 1 mm, control such as auto-focusing may become unstable, and if it exceeds 350 mm, the accuracy of laser scanning on the workpiece may be reduced. There is. On the other hand, when the size of the longest portion of the workpiece is within the particularly preferable range, it is advantageous in that control such as autofocus becomes stable and the accuracy of laser scanning is improved.

-Workpiece fixing material-
There is no restriction | limiting in particular as said workpiece fixing material, Although it can select suitably according to the objective, Curable resin is preferable.
There is no restriction | limiting in particular as said curable resin, According to the objective, it can select suitably, For example, a thermosetting resin, a photocurable resin, an air curable resin etc. are mentioned. The curable resin may be cast.
Examples of the curable resin include phenol resin, epoxy resin, melamine resin, urea resin, urea resin, polyester resin, alkyd resin, polyurethane resin, polyimide resin, polyethylene resin, polypropylene resin, polyvinyl chloride resin, and polyvinyl chloride. Vinylidene resin, polystyrene resin, polyvinyl acetate resin, fluororesin, ABS resin, AS resin, acrylic resin, polyamide resin, nylon resin, polyacetal resin, polycarbonate resin, polyphenylene ether resin, polybutylene terephthalate resin, polyethylene terephthalate resin, cyclic polyolefin Resin, polyphenylene sulfide resin, polytetrafluoroethylene resin, polysulfone resin, polyether sulfone resin, polyarylate resin, liquid crystal polymer resin Polyether ether ketone resin, polyamide-imide resins.
The curable resin is particularly preferably at least one selected from an acrylic resin, an epoxy resin, a urethane resin, a silicon resin, and a polyester resin.

---- Refractive index ----
There is no restriction | limiting in particular as a refractive index of the said workpiece fixing material surface, Although it can select suitably according to the objective, 1.3-2 are preferable, 1.4-1.8 are more preferable, 1 .45 to 1.7 is particularly preferred.
When the refractive index of the surface of the workpiece fixing material is less than 1.3, the reflectance is low, and it may be difficult to control the autofocus or the like. The reflectivity may change too much, making it difficult to control autofocus and the like. On the other hand, when the refractive index of the surface of the workpiece fixing material is within the particularly preferable range, it is advantageous in that automatic focus control is stabilized.
Here, the refractive index can be measured in the same manner as the method for measuring the refractive index of the workpiece surface.

Further, the refractive index of the workpiece fixing material surface is preferably within ± 50% of the refractive index of the workpiece surface, more preferably within ± 30%, and more preferably within ± 20%. More preferably, it is particularly preferably within ± 10%.
When the refractive index of the surface of the workpiece fixing material exceeds ± 50% of the refractive index of the surface of the workpiece, the reflectivity of the both changes too much, and it may be difficult to control autofocus and the like. On the other hand, if the refractive index of the workpiece fixing material surface is within ± 10% of the refractive index of the workpiece surface, it is advantageous in that automatic focus control is stabilized.

---- Reflectance ---
There is no restriction | limiting in particular as a reflectance of the said workpiece fixing material surface, Although it can select suitably according to the objective, 0.1%-90% are preferable, 1%-60% are more preferable, 5 % To 40% is particularly preferred.
When the reflectance of the workpiece fixing material surface is less than 0.1%, it may be difficult to control such as autofocus, and when the reflectance of the workpiece surface exceeds 90%, The signal strength to the control circuit may be excessive and the control may become unstable. On the other hand, when the reflectance of the surface of the workpiece fixing material is within the particularly preferable range, it is advantageous in that control such as autofocus is stably applied.
Here, the reflectance can be measured in the same manner as the method for measuring the refractive index of the workpiece surface.

The reflectance of the workpiece fixing material surface is preferably within ± 50% of the reflectance of the workpiece surface, more preferably within ± 30%, and more preferably within ± 20%. More preferably, it is particularly preferably within ± 10%.
When the reflectance of the surface of the workpiece fixing material exceeds ± 50% of the reflectance of the surface of the workpiece, the reflectance of both may change too much, and control of autofocus and the like may be difficult. On the other hand, if the reflectance of the workpiece fixing material surface is within 10% of the reflectance of the workpiece surface, it is advantageous in that automatic focus control is stabilized.

-Workpiece fixing jig-
The workpiece fixing jig is a jig having a plurality of mounting portions for mounting the workpiece.
There is no restriction | limiting in particular as a shape of the said workpiece fixing jig, Although it can select suitably according to the objective, A circular shape is preferable.
There is no restriction | limiting in particular as a magnitude | size and material of the said workpiece fixing jig, According to the objective, it can select suitably.

-Formation method-
There is no restriction | limiting in particular as a formation method of the said workpiece containing body, According to the objective, it can select suitably.

  3A to 3E illustrate an example of a method for forming a workpiece-containing body when the workpiece-containing body is in the first mode (a mode including a plurality of workpieces and a workpiece fixing material). Based on

First, the workpiece 11 is placed on the workpiece-containing body manufacturing substrate 31 and is brought into close contact with a vacuum pack (see FIG. 3B). In FIG. 3B, “32” indicates a vacuum pump, and “33” indicates a vacuum pack equipment.
There is no restriction | limiting in particular as said board | substrate for workpiece containing body preparation, According to the objective, it can select suitably, For example, a glass substrate etc. are mentioned.
Moreover, it is preferable that the said workpiece containing body preparation board | substrate has a type | mold so that a circular workpiece containing body can be formed. Having the mold makes it possible to form a circular workpiece-containing body, which is advantageous in that the balance during rotation is improved in the pattern forming process described later, and that high-speed processing by high-speed rotation is possible. It is.
By fixing the workpiece-containing body manufacturing substrate and the workpiece, the workpiece fixing material enters on the workpiece surface (surface irradiated with laser light in a pattern forming process described later). Can be prevented.
Moreover, when making it adhere | attach with the said vacuum pack, it is preferable to prevent dust from entering between a to-be-processed object and the board | substrate for workpiece containing body preparation. There is no restriction | limiting in particular as a method of preventing the said dust from entering, According to the objective, it can select suitably, For example, static elimination blow etc. are mentioned.

Thereafter, the workpiece fixing material 12 is added to the workpiece-containing body preparation substrate 31 to which the workpiece 11 is adhered (see FIG. 3C), and then the workpiece-containing body preparation substrate 34 is used. The workpiece to which the fixing material is added is sandwiched (see FIG. 3D).
The workpiece fixing material is preferably added immediately after the workpiece is brought into close contact with the workpiece-containing body.
The means for sandwiching the workpiece to which the workpiece fixing material is added in the workpiece-containing body production substrate is not particularly limited and can be appropriately selected depending on the purpose. Etc.
There is no particular limitation on the pressure when sandwiching the workpiece to which the workpiece fixing material is added in the workpiece-containing body preparation substrate, and it can be appropriately selected according to the purpose, for example, 10 kPa, etc. Is mentioned.

  Thereafter, the workpiece-containing body manufacturing substrates 31 and 34 are removed, and the workpiece-containing body 1 (see FIG. 3E) including a plurality of workpieces and a workpiece fixing material can be obtained. In this case, in the pattern forming process described later, the surface irradiated with the laser light is an arrow “38” in FIG. 3E.

  The method for forming a workpiece-containing body in the case where the workpiece-containing body is the second mode (a mode comprising a plurality of workpieces, a workpiece fixing material, and a workpiece fixing jig). An example will be described with reference to FIGS. 4A to 4B.

First, the workpiece fixing material 12 is added to the mounting portion 41 for mounting the workpiece of the workpiece fixing jig 13 (see FIG. 4A). Thereafter, the workpiece 11 is mounted on the mounting portion. Thereby, the space between the workpiece and the workpiece fixing jig having a plurality of mounting portions for mounting the workpiece can be filled with the workpiece fixing material, and the workpiece can be fixed. A workpiece-containing body 2 (see FIG. 4B) including a workpiece, a workpiece fixing material, and a workpiece fixing jig can be obtained. In this case, in the pattern forming process described later, the surface irradiated with the laser light is an arrow “48” in FIG. 4B.
The workpiece fixing material may be added after the workpiece is mounted on the workpiece fixing jig.
In the second aspect, the workpiece may be removed from the workpiece fixing jig, and a new workpiece may be mounted on the workpiece fixing jig to form the workpiece containing body.

In addition, when the workpiece has a layer capable of changing the shape of the heat mode on the surface, the timing for forming the layer capable of changing the shape of the heat mode is not particularly limited and is appropriately selected according to the purpose. can do.
For example, a layer capable of changing the shape of the heat mode may be formed on the surface of the workpiece in advance, or the shape of the heat mode may be formed on the surface of the workpiece after removing the workpiece-containing body manufacturing substrate. A layer capable of changing may be formed, or a layer capable of changing the shape of the heat mode may be formed on the surface of the workpiece after being mounted on the workpiece fixing jig.

-Between work piece and work piece fixing material-
The space between the workpiece and the workpiece fixing material (see “G” in FIG. 5) is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 100 μm or less, preferably 50 μm. Below, 10 micrometers or less are especially preferable.
If the distance between the workpiece and the workpiece fixing material exceeds 100 μm, the focus servo may be lost. On the other hand, when the distance between the workpiece and the workpiece fixing material is within the particularly preferable range, it is advantageous in that control such as auto-focusing becomes stable.

--Step difference (A-B) between workpiece fixing material surface (A) and workpiece surface (B)-
The step (A-B) (see “D” in FIG. 5) between the workpiece fixing material surface (A) and the workpiece surface (B) is not particularly limited and is appropriately selected according to the purpose. -4 μm to 4 μm is preferable, −2 μm to 2 μm is preferable, and −1 μm to 1 μm is particularly preferable.
When the step (A-B) between the workpiece fixing material surface (A) and the workpiece surface (B) is less than −4 μm or exceeds 4 μm, the focus servo may be lost. On the other hand, if the step (AB) between the workpiece fixing material surface (A) and the workpiece surface (B) is within the particularly preferred range, control such as autofocusing is stable. It is advantageous.
In addition, the said workpiece surface means the surface (pattern formation surface) processed with a laser beam. Further, the surface of the workpiece fixing material refers to the same surface as the surface of the workpiece.

<Pattern formation process>
The pattern forming step is a step of forming a pattern on the workpiece by irradiating a laser beam while rotating the workpiece containing body.
In the pattern forming step, a concave portion is formed on the surface of the workpiece by irradiating the workpiece containing body with a laser beam on the basis of the surface of the workpiece.

The means for performing the pattern forming step is not particularly limited and may be appropriately selected depending on the purpose. For example, an apparatus having a configuration similar to that of a conventionally known optical disc drive can be used.
As a configuration of the optical disc drive, for example, a configuration described in Japanese Patent Laid-Open No. 2003-203348 can be given.
Hereinafter, an embodiment of the pattern forming process using such an optical disk drive will be described.

The workpiece containing body formed in the same shape as the optical disk is loaded into a disk drive. And according to the material of the said workpiece surface, a laser beam is irradiated to the workpiece surface with an output suitable for deforming this. Further, a pulse signal or a continuous signal may be input to the laser light source so that this irradiation pattern matches the pattern to be formed on the surface of the workpiece. As shown in FIG. 6B, the duty ratio (light emission time τ / period T) of the laser light emitted at a predetermined period T is equal to the duty ratio of the actually formed recess 15 (the recess 15 in the scanning direction of the laser light). Length d / pitch P; see FIG. 6A). Here, the laser beam shown in a circle in FIG. 6A contributes to the formation of the elliptical recess 15 by moving at a predetermined speed during the emission time τ. For example, when the length d of the recess 15 is 50 when the pitch P of the recess 15 is set to 100, the laser beam is irradiated at a duty ratio lower than 50%. That's fine. In this case, the upper limit value of the duty ratio of the laser beam is preferably less than 50%, more preferably less than 40%, and still more preferably less than 35%. The lower limit is preferably 1% or more, more preferably 5% or more, and still more preferably 10% or more. As described above, by setting the duty ratio, it is possible to accurately form the recesses 15 having a specified pitch.
In addition, by using the same focusing technology as the optical disk drive, for example, the astigmatism method, even if the workpiece has waviness or warpage, it can be easily focused on the surface of the workpiece. is there.
Moreover, since the workpiece containing body of the present invention fixes the periphery of the workpiece with the workpiece fixing material, the distance between the workpiece and the workpiece fixing material is short, and the workpiece is processed. The level difference (A-B) between the object fixing material surface (A) and the workpiece surface (B) is short. Therefore, the focus servo is not disengaged around the work piece, and the work piece can be machined easily and with excellent machining accuracy.

  In this way, the laser beam is condensed and irradiated onto the surface of the workpiece by the optical system of the disk drive. As in the case of recording information on the optical recording disk, a concave portion can be formed on the entire surface of the workpiece by moving the optical system in the radial direction while rotating the workpiece-containing body.

The processing conditions for manufacturing the recess 15 are as follows.
The lower limit of the numerical aperture NA of the optical system is preferably 0.4 or more, more preferably 0.5 or more, and still more preferably 0.6 or more. Further, the upper limit of the numerical aperture NA is preferably 2 or less, more preferably 1 or less, and still more preferably 0.9 or less. This is because if the numerical aperture NA is too small, fine processing cannot be performed, and if it is too large, the margin for the angle during recording decreases.

  There is no restriction | limiting in particular as a wavelength of the said optical system, According to the objective, it can select suitably, For example, 405 +/- 30nm, 532 +/- 30nm, 650 +/- 30nm, 780 +/- 30nm is mentioned. This is because these wavelengths are easy to obtain a large output. A shorter wavelength is preferable because fine processing can be performed.

  The lower limit of the output of the optical system is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.1 mW or more, more preferably 1 mW or more, further preferably 5 mW or more, and particularly preferably 20 mW or more. preferable. There is no restriction | limiting in particular as an upper limit of the output of the said optical system, Although it can select suitably according to the objective, 1,000 mW or less is preferable, 500 mW or less is more preferable, 200 mW or less is still more preferable. This is because if the output is too low, processing takes time, and if it is too high, the durability of the members constituting the optical system is lowered.

  There is no restriction | limiting in particular as a minimum of the linear velocity which moves an optical system relatively with respect to the workpiece surface, Although it can select suitably according to the objective, 0.1 m / s or more is preferable and 1 m / s is preferable. The above is more preferable, 5 m / s or more is further preferable, and 20 m / s or more is particularly preferable. There is no restriction | limiting in particular as an upper limit of the said linear velocity, Although it can select suitably according to the objective, 500 m / s or less is preferable, 200 m / s or less is more preferable, 100 m / s or less is further more preferable, 50 m / s Particularly preferred is s or less. This is because if the linear velocity is too high, it is difficult to increase the processing accuracy, and if it is too slow, the processing takes time and the processing cannot be performed into a good shape.

  As an example of a specific optical processing machine including the optical system, NE0500 manufactured by Pulstec Industrial Co., Ltd. can be used, for example.

<Other processes>
The other steps are not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected depending on the purpose.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
<Workpiece-containing body forming step>
Two sapphire substrates having a thickness of 0.5 mm and 2 inches were used as substrates of workpieces. A solution obtained by dissolving 15 mg of an oxonol organic compound represented by the following structural formula (1) in 1 ml of 2,2,3,3-tetrafluoro-1-propanol was applied onto the substrate at a rotation speed of 300 rpm using a spin coater. Then, it was dried at a rotational speed of 1,000 rpm, an organic layer having a thickness of 70 nm was formed, and a workpiece was produced.

The workpiece was brought into close contact with a glass substrate (substrate for producing a workpiece-containing body) with a vacuum pack. The workpiece and the glass substrate were kept in close contact even after being removed from the vacuum pack. A crystal resin (manufactured by Nissin Resin, epoxy resin) was added as a workpiece fixing material on the workpiece that was in close contact with the glass substrate, and was sandwiched between glass substrates to cure the crystal resin in a disk shape.
Next, the glass substrate was removed to obtain a disk-shaped workpiece containing body (diameter: about 15 cm, thickness: about 1 mm) composed of the workpiece and crystal resin.
The distance between the workpiece in the workpiece-containing body and the workpiece fixing material was measured by a micro length measuring machine (MM400 manufactured by Nikon Corporation), and was 2 μm.
Further, the step (A-B) between the workpiece fixing material surface (A) and the workpiece surface (B) was measured with a micro length measuring instrument (MM400 manufactured by Nikon Corporation), and found to be 0.2 μm. It was.
Moreover, the refractive index of the workpiece surface was 1.6, and the refractive index of the workpiece fixing material surface was 1.5. Moreover, the reflectance of the workpiece surface was 5%, and the reflectance of the workpiece fixing material surface was 4%.
The refractive index was measured with an ellipsometer (VASE manufactured by JA Woollam), and the reflectance was measured with a spectral reflectometer (U3100 manufactured by Hitachi).

<Pattern formation process>
Laser irradiation was performed on the workpiece surface of the workpiece-containing body with NEO1000 (manufactured by Pulstec Industrial Co., Ltd.) at 5 m / s, 15 mW, a pitch of 0.3 μm in both the circumferential direction and the radial direction.

  As described above, a recess having a depth of 50 nm and a shortest distance (pitch) of 0.3 μm between the centers of adjacent recesses could be formed on the entire surface of the workpiece.

(Example 2)
<Workpiece-containing body forming step>
The same substrate as that used in Example 1 was used as the workpiece substrate.
A few drops of oil (impression oil type A, manufactured by cargill laboratories) were dropped on the surface of the substrate. A glass substrate (workpiece-containing body preparation substrate) was placed on and adhered to the substrate, and air between the substrate and the glass substrate was excluded.
Crystal resin (manufactured by Nissin Resin, epoxy resin) was added as a workpiece fixing material on the substrate that was in close contact with the glass substrate, and was sandwiched between glass substrates to cure the crystal resin in a disk shape.

After removing the glass substrate, the oil was washed with a solvent. Thereafter, a solution obtained by dissolving 15 mg of the oxonol organic compound represented by the structural formula (1) in 1 ml of 2,2,3,3-tetrafluoro-1-propanol on the surface of the substrate was rotated at 300 rpm using a spin coater. Then, it is dried at a rotational speed of 1,000 rpm to form an organic layer having a thickness of 70 nm, and a disc-shaped workpiece containing body (diameter of about 15 cm, thickness) comprising a workpiece and a crystal resin. About 1 mm).
The distance between the workpiece in the workpiece-containing body and the workpiece fixing material was measured by a micro length measuring machine (MM400 manufactured by Nikon Corporation), and was 2 μm.
Further, the step (A-B) between the workpiece fixing material surface (A) and the workpiece surface (B) was measured with a micro length measuring instrument (MM400 manufactured by Nikon Corporation), and found to be 0.2 μm. It was.
Moreover, the refractive index of the workpiece surface was 1.6, and the refractive index of the workpiece fixing material surface was 1.5. Moreover, the reflectance of the workpiece surface was 5%, and the reflectance of the workpiece fixing material surface was 4%.
The refractive index was measured with an ellipsometer (VASE manufactured by JA Woollam), and the reflectance was measured with a spectral reflectometer (U3100 manufactured by Hitachi).

<Pattern formation process>
The pattern forming process was performed in the same manner as in Example 1.

  As described above, a recess having a depth of 50 nm and a shortest distance (pitch) of 0.3 μm between the centers of adjacent recesses could be formed on the entire surface of the workpiece.

(Example 3)
<Workpiece-containing body forming step>
The same substrate as that used in Example 1 was used as the workpiece substrate. Further, a disk-shaped jig having two mounting portions was used as the workpiece fixing jig.
Crystal resin (manufactured by Nissin Resin, epoxy resin) was added to the workpiece fixing jig as a workpiece fixing material, and then the substrate was mounted to cure the crystal resin.

Thereafter, a solution obtained by dissolving 15 mg of the oxonol organic compound represented by the structural formula (1) in 1 ml of 2,2,3,3-tetrafluoro-1-propanol on the surface of the substrate was rotated at 300 rpm using a spin coater. And then dried at a rotational speed of 1,000 rpm to form an organic layer having a thickness of 70 nm, containing a disk-shaped workpiece comprising a workpiece, a crystal resin, and a workpiece fixing jig A body (diameter about 15 cm, thickness about 1 mm) was obtained.
The distance between the workpiece in the workpiece-containing body and the workpiece fixing material was measured by a micro length measuring machine (MM400 manufactured by Nikon Corporation), and was 2 μm.
Further, the step (A-B) between the workpiece fixing material surface (A) and the workpiece surface (B) was measured with a micro length measuring instrument (MM400 manufactured by Nikon Corporation), and found to be 0.2 μm. It was.
Moreover, the refractive index of the workpiece surface was 1.6, and the refractive index of the workpiece fixing material surface was 1.5. Moreover, the reflectance of the workpiece surface was 5%, and the reflectance of the workpiece fixing material surface was 4%.
The refractive index was measured with an ellipsometer (VASE manufactured by JA Woollam), and the reflectance was measured with a spectral reflectometer (U3100 manufactured by Hitachi).

<Pattern formation process>
The pattern forming process was performed in the same manner as in Example 1.

  As described above, a recess having a depth of 50 nm and a shortest distance (pitch) of 0.3 μm between the centers of adjacent recesses could be formed on the entire surface of the workpiece.

(Comparative Example 1)
<Workpiece-containing body forming step>
A workpiece-containing body of Comparative Example 1 was produced in the same manner as in Example 3 except that the workpiece fixing material was not used in Example 3.
It was 100 micrometers when it measured between the workpiece in the said workpiece containing body and the workpiece fixing jig with the micro length measuring machine (MM400 by Nikon Corp.).
Further, the step (C-B) between the workpiece fixing jig surface (C) and the workpiece surface (B) was measured by a micro length measuring machine (MM400 manufactured by Nikon Corporation), and was 30 μm. .
Moreover, the refractive index of the workpiece surface was 1.6, and the refractive index of the workpiece fixture jig surface was 1.5. Moreover, the reflectance of the workpiece surface was 6%, and the reflectance of the workpiece fixing jig surface was 5%.
The refractive index was measured with an ellipsometer (VASE manufactured by JA Woollam), and the reflectance was measured with a spectral reflectometer (U3100 manufactured by Hitachi).

<Pattern formation process>
The pattern forming process was performed in the same manner as in Example 1.

As described above, a recess having a depth of 50 nm and a shortest distance (pitch) of 0.3 μm between the centers of adjacent recesses could be formed on a part of the surface of the workpiece.
However, the periphery of the work piece fixing jig in the work piece is out of focus servo, and a recess cannot be formed.

  From the above results, it was shown that the laser processing method of the present invention is simple and can process a workpiece with excellent processing accuracy.

  Since the laser processing method of the present invention is simple and can process a workpiece with excellent processing accuracy, for example, it can be used for laser processing of a workpiece such as a substrate on which an LED element is formed. Can do.

DESCRIPTION OF SYMBOLS 1 Workpiece containing body 2 Workpiece containing body 11 Workpiece 12 Workpiece fixing material 13 Workpiece fixing jig 31 Workpiece containing body preparation substrate 32 Vacuum pump 33 Vacuum pack equipment 34 Workpiece Substrate for containing body 38 Laser light irradiation surface 41 Mounting portion 48 Laser light irradiation surface G Between workpiece and workpiece fixing material D Step difference between workpiece fixing material surface and workpiece surface P Pitch d Concave length 15 Concave τ Light emission time T Period

Claims (8)

A workpiece-containing body forming step of fixing a periphery of a plurality of workpieces with a workpiece fixing material and forming a workpiece-containing body having a plurality of workpieces;
A pattern forming step of forming a pattern on the workpiece by irradiating a laser beam while rotating the workpiece-containing body,
A laser processing method comprising:   The workpiece-containing body forming step fills the workpiece with a workpiece fixing material between the workpiece and a workpiece fixing jig having a plurality of mounting portions for mounting the workpiece. The laser processing method according to claim 1 to be fixed.   The laser processing method according to claim 1, wherein a distance between the workpiece and the workpiece fixing material is 100 μm or less.   The laser processing method according to any one of claims 1 to 3, wherein the step (A-B) between the workpiece fixing material surface (A) and the workpiece surface (B) is 4 µm or less.   The laser processing method according to claim 1, wherein a refractive index of the surface of the workpiece fixing material is within ± 50% of a refractive index of the surface of the workpiece.   6. The laser processing method according to claim 1, wherein the reflectance of the surface of the workpiece fixing material is within ± 50% of the reflectance of the surface of the workpiece.   The laser processing method according to claim 1, wherein the workpiece fixing material is at least one selected from an acrylic resin, an epoxy resin, a urethane resin, a silicone resin, and a polyester resin.   The laser processing method according to claim 1, wherein the surface of the workpiece is a layer capable of changing a shape in a heat mode.