JP2008049380A - Method for forming microstructure of surface by laser beam - Google Patents
Method for forming microstructure of surface by laser beam Download PDFInfo
- Publication number
- JP2008049380A JP2008049380A JP2006229867A JP2006229867A JP2008049380A JP 2008049380 A JP2008049380 A JP 2008049380A JP 2006229867 A JP2006229867 A JP 2006229867A JP 2006229867 A JP2006229867 A JP 2006229867A JP 2008049380 A JP2008049380 A JP 2008049380A
- Authority
- JP
- Japan
- Prior art keywords
- laser
- periodic structure
- fine
- forming
- wavelength
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 46
- 230000000737 periodic effect Effects 0.000 claims abstract description 84
- 239000000463 material Substances 0.000 claims abstract description 48
- 230000010287 polarization Effects 0.000 claims abstract description 31
- 230000001678 irradiating effect Effects 0.000 claims description 9
- 230000015572 biosynthetic process Effects 0.000 claims description 4
- 238000003754 machining Methods 0.000 abstract 1
- 239000000758 substrate Substances 0.000 description 14
- 238000000635 electron micrograph Methods 0.000 description 8
- 229910001220 stainless steel Inorganic materials 0.000 description 7
- 239000010935 stainless steel Substances 0.000 description 7
- 238000003672 processing method Methods 0.000 description 5
- 230000003287 optical effect Effects 0.000 description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 3
- 238000003384 imaging method Methods 0.000 description 3
- 229910052719 titanium Inorganic materials 0.000 description 3
- 239000010936 titanium Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052594 sapphire Inorganic materials 0.000 description 1
- 239000010980 sapphire Substances 0.000 description 1
- 230000037303 wrinkles Effects 0.000 description 1
Landscapes
- Laser Beam Processing (AREA)
- Diffracting Gratings Or Hologram Optical Elements (AREA)
Abstract
Description
本発明はレーザによる表面微細構造形成方法に関し、特に材料表面にレーザを照射して微細な畝状周期構造を形成し、その後この畝状周期構造が形成された領域に、先に照射したレーザと同じまたは異なる波長のレーザを、先に形成した畝状周期構造に対して任意の角度になるような畝状周期構造が形成できる条件で照射し、その結果、当該照射領域に例えば微細突起構造を形成する表面微細構造形成方法に関するものである。 The present invention relates to a method for forming a surface fine structure by a laser, and in particular, irradiates a material surface with a laser to form a fine saddle-like periodic structure, and then irradiates the region where the saddle-like periodic structure is formed with the previously irradiated laser Irradiate lasers of the same or different wavelengths under conditions that allow the formation of a saddle-like periodic structure with an arbitrary angle with respect to the previously formed saddle-like periodic structure. The present invention relates to a surface microstructure forming method to be formed.
材料基板上に直線偏光のフェムト秒レーザを加工閾値近傍のエネルギで集光しスキャン照射することで、偏光方向に依存した方向に微細な周期構造を形成可能であることが知られている（例えば、特許文献１参照）。この周期構造は凹部あるいは凸部が延在するいわゆる畝状構造である。このような畝状微細周期構造は、例えばマイクロマシンなどの極小部品間の付着力低減や、各種機械部品摺動面の潤滑特性の向上に大きな効果があるといわれている。
前述した材料の表面畝状微細周期構造は所定方向に延在する凹凸構造である。この凹凸構造が延在する方向とそれに直交する方向とでは表面形状が異なるため、表面特性に異方性が現れるという問題がある。 The surface ridge-like fine periodic structure of the material described above is an uneven structure extending in a predetermined direction. Since the surface shape is different between the direction in which the concavo-convex structure extends and the direction perpendicular thereto, there is a problem that anisotropy appears in the surface characteristics.
あるいは、表面畝状微細周期構造は凹部と凸部が同じ間隔で単純に繰り返される構造であるので、単一の表面特性しか材料表面に付与することができないという解決すべき課題があった。 Alternatively, since the surface ridge-like fine periodic structure is a structure in which the concave portion and the convex portion are simply repeated at the same interval, there is a problem to be solved that only a single surface characteristic can be imparted to the material surface.
そこで、本発明は、材料基板表面に偏光方向の異なるレーザを複数段階で照射することにより、材料表面に複数の畝状微細周期構造を混在させることで、各種材料表面に、多様な、周期的に配列した微細構造形成方法を提供することを目的とする。 Therefore, the present invention irradiates various periodic surfaces on various material surfaces by irradiating the material substrate surface with lasers having different polarization directions in a plurality of stages, thereby mixing a plurality of cage-like fine periodic structures on the material surface. It is an object of the present invention to provide a method for forming a microstructure arranged in a row.
本発明の請求項１に記載の表面微細構造形成方法は、材料表面に加工閾値近傍の照射強度で直線偏光のレーザを集光照射すると共に当該照射部をオーバラップさせながら所定方向にスキャンして、前記材料表面に自己組織的に畝状微細周期構造を形成する第一工程と、前記畝状微細周期構造が形成された材料表面に対して、先のレーザを当該畝状微細周期構造が形成された材料表面に対する加工閾値近傍の照射強度で前記第一工程の偏光方向と異なる方向の直線偏光で照射すると共に当該照射部をオーバラップさせながら所定方向にスキャンして、前記畝状微細周期構造に前記畝状微細周期構造の方向と異なる方向の畝状微細周期構造を自己組織的に形成する第二工程と、を有することを特徴とするものである。 The surface microstructure forming method according to claim 1 of the present invention condenses and irradiates a linearly polarized laser beam with an irradiation intensity in the vicinity of a processing threshold on a material surface, and scans in a predetermined direction while overlapping the irradiated portions. A first step of forming a cage-like fine periodic structure on the surface of the material in a self-organized manner, and forming the previous laser on the material surface on which the cage-like fine periodic structure is formed. Irradiation with linearly polarized light in a direction different from the polarization direction of the first step with irradiation intensity in the vicinity of the processing threshold on the surface of the formed material, and scanning in a predetermined direction while overlapping the irradiation part, the saddle-like fine periodic structure And a second step of forming a saddle-like fine periodic structure in a direction different from the direction of the saddle-like fine periodic structure in a self-organizing manner.
ここで、レーザは、アルゴンレーザや、ＹＡＧレーザ、エキシマレーザなどのピコ秒やナノ秒パルスレーザなどの各種レーザを用いることができるが、例えば、チタンサファイアレーザを使用することができる。チタンサファイアレーザパルスは、例えば、パルス幅１２０ｆｓ、中心波長８００ｎｍ、繰り返し周波数１ｋＨｚ、パルスエネルギー０．２５〜４００μＪ／ｐｕｌｓｅのフェムト秒超短パルスレーザである。 Here, various lasers such as picosecond and nanosecond pulse lasers such as an argon laser, a YAG laser, and an excimer laser can be used as the laser. For example, a titanium sapphire laser can be used. The titanium sapphire laser pulse is, for example, a femtosecond ultrashort pulse laser having a pulse width of 120 fs, a center wavelength of 800 nm, a repetition frequency of 1 kHz, and a pulse energy of 0.25 to 400 μJ / pulse.
本発明の請求項２に記載の表面微細構造形成方法は、前記第二工程で使用するレーザ波長を、前記第一工程で用いたものよりも短いものを用いることを特徴とするものである。 The surface microstructure forming method according to claim 2 of the present invention is characterized in that the laser wavelength used in the second step is shorter than that used in the first step.
本発明の請求項３に記載の表面微細構造形成方法は、前記第二工程で使用するレーザ波長を、前記第一工程で用いたものの１／２のものを用いることを特徴とするものである。 The method for forming a surface microstructure according to claim 3 of the present invention is characterized in that the laser wavelength used in the second step is one half that used in the first step. .
本発明の請求項４に記載の表面微細構造形成方法は、前記第二工程で使用するレーザ波長を、前記第一工程で用いたものよりも長いものを用いることを特徴とするものである。 The surface microstructure forming method according to claim 4 of the present invention is characterized in that the laser wavelength used in the second step is longer than that used in the first step.
本発明の請求項５に記載の表面微細構造形成方法は、前記第二工程で使用するレーザ波長を、前記第一工程で用いたものの二倍のものを用いることを特徴とするものである。 The surface microstructure forming method according to claim 5 of the present invention is characterized in that the laser wavelength used in the second step is twice that used in the first step.
本発明の請求項６に記載の表面微細構造形成方法は、前記第一工程と第二工程のレーザの偏光方向を直交させることを特徴とするものである。 The method for forming a surface microstructure according to claim 6 of the present invention is characterized in that the polarization directions of the lasers in the first step and the second step are orthogonal to each other.
本発明の請求項７に記載の表面微細構造形成方法は、前記第一工程と第二工程のレーザの偏光方向のなす角が０°超〜９０°未満の任意の角度になるように第二工程のレーザの偏光方向を回転させて前記第二工程を実施することを特徴とするものである。 In the method for forming a surface microstructure according to claim 7 of the present invention, the second step is performed so that the angle formed by the polarization directions of the laser in the first step and the second step is an arbitrary angle greater than 0 ° and less than 90 °. The second step is performed by rotating the polarization direction of the laser in the step.
本発明の請求項８に記載の表面微細構造形成方法は、前記第一工程の後に前記材料をその面方向に４５°回転させるとともに前記第二工程のレーザの偏光方向を前記材料の回転方向と逆方向の４５°の向きになるように回転させて前記第二工程を実施することを特徴とするものである。 In the surface microstructure forming method according to claim 8 of the present invention, after the first step, the material is rotated by 45 ° in the plane direction, and the polarization direction of the laser in the second step is set as the rotation direction of the material. The second step is carried out by rotating in a reverse direction of 45 °.
本発明の請求項９に記載の表面微細構造形成方法は、前記第一工程の後に前記材料をその面方向に任意の角度回転させるとともに前記第二工程のレーザの偏光方向を、前記材料表面の畝状微細周期構造と同じ方向の畝状微細周期構造が形成されないような任意の角度に回転させて前記第二工程を実施することを特徴とするものである。 In the surface microstructure forming method according to claim 9 of the present invention, after the first step, the material is rotated by an arbitrary angle in the plane direction, and the polarization direction of the laser in the second step is set on the surface of the material. The second step is carried out by rotating at an arbitrary angle such that no saddle-like fine periodic structure in the same direction as the saddle-like fine periodic structure is formed.
本発明の請求項１０に記載の表面微細構造形成方法は、前記第一工程の後に前記材料をその面方向に９０°回転させて前記第二工程を実施することを特徴とするものである。 The method for forming a surface microstructure according to claim 10 of the present invention is characterized in that after the first step, the second step is performed by rotating the material by 90 ° in the plane direction.
本発明の請求項１０に記載の表面微細構造形成方法は、前記第一工程の後に前記材料をその面方向に任意の角度回転させて前記第二工程を実施することを特徴とするものである。 The method for forming a surface microstructure according to claim 10 of the present invention is characterized in that, after the first step, the second step is performed by rotating the material in the plane direction by an arbitrary angle. .
本発明の請求項１２に記載の表面微細構造形成方法は、請求項１の第一工程と第二工程を施した材料表面に、前記第一工程あるいは第二工程のレーザの偏光方向と異なる直線偏光の前期表面微細構造に対する加工閾値近傍のレーザを照射すると共に当該照射部をオーバラップさせながら所定方向にスキャンして前記材料表面に前記畝状微細周期構造の方向と異なる方向の畝状微細周期構造を自己組織的に形成する第三工程と、
を有することを特徴とするものである。
According to a twelfth aspect of the present invention, there is provided a surface microstructure forming method in which a straight line different from the polarization direction of the laser in the first step or the second step is formed on the surface of the material subjected to the first step and the second step. Irradiate a laser in the vicinity of the processing threshold for the polarized surface structure of the front surface, and scan in a predetermined direction while overlapping the irradiated portion, and the surface of the material has a saddle-like fine period in a direction different from the direction of the saddle-like fine periodic structure. A third step of self-organizing the structure;
It is characterized by having.
本発明の請求項１に記載の表面微細構造形成方法のように、レーザ照射による第一工程で材料表面に畝状周期構造を形成し、第一工程とは異なる偏光方向で前記畝状周期構造形成領域を照射すると、当該照射領域に二つの異なる方向の畝状周期構造が混在する表面微細構造を形成することができる。 As in the method for forming a surface microstructure according to claim 1 of the present invention, a saddle-like periodic structure is formed on the material surface in a first step by laser irradiation, and the saddle-like periodic structure has a polarization direction different from that of the first step. When the formation region is irradiated, it is possible to form a surface fine structure in which two ridge-like periodic structures in different directions are mixed in the irradiation region.
本発明の請求項２に記載の表面微細構造形成方法のように、前記第一工程で使用する波長よりも第二工程で使用する波長を短くすると、畝状周期構造の間隔は照射レーザの波長に依存するので、当該照射領域に二つの異なる方向をもち、それぞれは異なる間隔をもつ畝状周期構造が混在する表面微細構造を形成することができる。 When the wavelength used in the second step is shorter than the wavelength used in the first step as in the surface microstructure forming method according to claim 2 of the present invention, the interval between the cage-like periodic structures is the wavelength of the irradiation laser. Therefore, it is possible to form a surface fine structure having two different directions in the irradiation region, each of which has a cage-like periodic structure with different intervals.
本発明の請求項３に記載の表面微細構造形成方法のように、前記第一工程で使用する波長よりも第二工程で使用する波長を１／２にすると、畝状周期構造の間隔は照射レーザの波長に依存するので、当該照射領域に二つの異なる方向をもち、一方は他方の１／２の間隔をもつ畝状周期構造が混在する表面微細構造を形成することができる。 As in the method for forming a surface microstructure according to claim 3 of the present invention, when the wavelength used in the second step is halved compared to the wavelength used in the first step, the interval between the cage-like periodic structures is irradiated. Since it depends on the wavelength of the laser, it is possible to form a surface fine structure in which the irradiation region has two different directions, one of which has a half-periodic structure having a ½ interval of the other.
本発明の請求項４に記載の表面微細構造形成方法のように、前記第一工程で使用する波長よりも第二工程で使用する波長を長くすると、畝状周期構造の間隔は照射レーザの波長に依存するので、当該照射領域に二つの異なる方向をもち、それぞれは異なる間隔をもつ畝状周期構造が混在する表面微細構造を形成することができる。 When the wavelength used in the second step is made longer than the wavelength used in the first step as in the surface microstructure forming method according to claim 4 of the present invention, the interval between the ridge-like periodic structures is the wavelength of the irradiation laser. Therefore, it is possible to form a surface fine structure having two different directions in the irradiation region, each of which has a cage-like periodic structure with different intervals.
本発明の請求項５に記載の表面微細構造形成方法のように、前記第一工程で使用する波長よりも第二工程で使用する波長を二倍にすると、畝状周期構造の間隔は照射レーザの波長に依存するので、当該照射領域に二つの異なる方向をもち、一方は他方の二倍の間隔をもつ畝状周期構造が混在する表面微細構造を形成することができる。 When the wavelength used in the second step is doubled compared to the wavelength used in the first step as in the method for forming a surface microstructure according to claim 5 of the present invention, the interval between the saddle-like periodic structures is irradiated laser. Therefore, it is possible to form a surface fine structure in which the irradiation region has two different directions, one of which is a mixture of cage-like periodic structures having twice the interval of the other.
本発明の請求項６に記載の表面微細構造形成方法のように、前記第一工程と第二工程のレーザの偏光方向を直交させると、当該照射領域に二つの異なる方向の畝状周期構造が混在する表面微細突起構造を形成することができる。 As in the method for forming a surface microstructure according to claim 6 of the present invention, when the polarization directions of the lasers in the first step and the second step are orthogonal to each other, two directional periodic structures in two different directions are formed in the irradiation region. A mixed surface fine protrusion structure can be formed.
本発明の請求項７に記載の表面微細構造形成方法のように、前記第一工程と第二工程のレーザの偏光方向のなす角が０°超〜９０°未満の任意の角度になるように前記第一工程と第二工程のレーザの偏光方向を回転させて前記工程を実施すると、当該照射領域に二つの異なる方向の畝状周期構造が混在する表面微細構造を形成することができる。 As in the method for forming a surface microstructure according to claim 7 of the present invention, an angle formed by the polarization directions of the lasers in the first step and the second step is an arbitrary angle greater than 0 ° and less than 90 °. When the step is performed by rotating the polarization directions of the lasers in the first step and the second step, it is possible to form a surface fine structure in which saddle-like periodic structures in two different directions are mixed in the irradiation region.
本発明の請求項８に記載の表面微細構造形成方法のように、前記第一工程の後に前記材料をその面方向に４５°回転させるとともに前記第二工程のレーザの偏光方向を前記材料の回転方向と逆方向の４５°の向きになるように回転させて前記第二工程を実施すると、当該照射領域に二つの異なる方向の畝状周期構造が混在する表面微細突起構造を形成することができる。 As in the surface microstructure forming method according to claim 8 of the present invention, after the first step, the material is rotated by 45 ° in the plane direction, and the polarization direction of the laser in the second step is rotated. When the second step is performed by rotating it so that the direction is 45 ° opposite to the direction, it is possible to form a surface fine protrusion structure in which two vertical ridge structures in different directions are mixed in the irradiation region. .
本発明の請求項９に記載の表面微細構造形成方法のように、前記第一工程の後に前記材料をその面方向に任意の角度回転させるとともに前記第二工程のレーザの偏光方向を、前記材料表面の畝状微細周期構造と同じ方向の畝状微細周期構造が形成されないような任意の角度に回転させて前記第二工程を実施すると、当該照射領域に二つの異なる方向の畝状周期構造が混在する表面微細構造を形成することができる。 As in the method for forming a surface microstructure according to claim 9 of the present invention, after the first step, the material is rotated by an arbitrary angle in the plane direction, and the polarization direction of the laser in the second step is changed to the material. When the second step is carried out by rotating at an arbitrary angle such that the ridge-like fine periodic structure in the same direction as the surface-like ridge-like fine periodic structure is not formed, the ridge-like periodic structure in two different directions is formed in the irradiation region. A mixed surface microstructure can be formed.
本発明の請求項１０に記載の表面微細構造形成方法のように、前記第一工程の後に前記材料をその面方向に９０°回転させて前記第二工程を実施すると当該照射領域に二つの異なる方向の畝状周期構造が混在する表面微細突起構造を形成することができる。 As in the method for forming a surface microstructure according to claim 10 of the present invention, when the second step is carried out by rotating the material by 90 ° in the plane direction after the first step, there are two differences in the irradiation region. A surface fine protrusion structure in which ridge-like periodic structures in the direction are mixed can be formed.
本発明の請求項１１に記載の表面微細構造形成方法のように、前記第一工程の後に前記材料を９０°回転させて前記第二工程を実施すると当該照射領域に二つの異なる方向の畝状周期構造が混在する表面微細突起構造を形成することができる。 As in the method for forming a surface microstructure according to claim 11 of the present invention, when the second step is performed by rotating the material by 90 ° after the first step, the corrugations in two different directions are formed in the irradiation region. A surface fine protrusion structure in which periodic structures are mixed can be formed.
本発明の請求項１２に記載の表面微細構造形成方法のように、請求項１の第一工程と第二工程を施した材料表面に、前記第一工程および第二工程のレーザの偏光方向と異なる直線偏光の前記表面微細構造に対する加工閾値近傍のレーザを照射すると共に当該照射部をオーバラップさせながら所定方向にスキャンして前記材料表面に前記畝状微細周期構造の方向と異なる方向の微細周期構造を自己組織的に形成する第三工程を実施すると、当該照射領域に三つの異なる方向の畝状周期構造が混在する表面形状を形成することができる。 As in the surface microstructure forming method according to claim 12 of the present invention, the polarization direction of the laser in the first step and the second step is applied to the surface of the material subjected to the first step and the second step of claim 1. A fine period in a direction different from the direction of the saddle-like fine periodic structure on the surface of the material by irradiating a laser in the vicinity of a processing threshold for the surface fine structure of different linearly polarized light and overlapping the irradiated part When the third step of forming the structure in a self-organized manner is performed, a surface shape in which three-dimensional ridge-like periodic structures in a different direction are mixed in the irradiation region can be formed.
以上のように、レーザの偏光方向を交差させる方法は一種類に限定されないし、交差させるレーザの数も二つに限定されない。 As described above, the method of crossing the polarization directions of the lasers is not limited to one type, and the number of lasers to be crossed is not limited to two.
以下、本発明の表面加工方法について図面に基づき説明する。なお、以下の説明について、具体的数値は理解を助けるためにあくまでも一例として記載したものであり、特に限定するものではないことを予め断っておく。 Hereinafter, the surface processing method of the present invention will be described with reference to the drawings. In the following description, specific numerical values are described as examples only to help understanding, and it should be noted in advance that they are not particularly limited.
本発明の表面微細構造形成方法は図１および図２と同じ構成のフェムト秒レーザ表面加工装置を使用する。すなわち図１が波長８００ｎｍのフェムト秒レーザ表面加工装置、図２が波長４００ｎｍのフェムト秒レーザ表面加工装置である。チタンサファイアフェムト秒レーザ発生器１で発生したレーザ（パルス幅：１２０ｆｓ、中心波長８００ｎｍ、繰り返し周波数：１ｋＨｚ、パルスエネルギー：０．２５〜４００μＪ／ｐｕｌｓｅ）は、ミラー２により加工材料８に向けて折り返され、メカニカルシャッタ３に導かれる。レーザ照射時はメカニカルシャッタ３を開放し、レーザ照射強度は１／２波長板４と偏光ビームスプリッタ６によって調整可能とし、１／２波長板５によって偏光方向を調整し、集光レンズ（焦点距離：１５０ｍｍ）７によって、ＸＹθステージ９上の加工材料８表面に集光照射した。また図２において１０は第二次高調波すなわち半波長のレーザ光（パルス幅：３００ｆｓ、中心波長４００ｎｍ、繰り返し周波数：１ｋＨｚ、パルスエネルギー：０．０５〜１２０μＪ／ｐｕｌｓｅ）を発生させるための波長変換用非線形光学結晶、１１は波長８００ｎｍを反射し波長４００ｎｍを透過する波長選択用光学素子、１２は集光レンズ（焦点距離：５０ｍｍ）である。 The surface microstructure forming method of the present invention uses a femtosecond laser surface processing apparatus having the same configuration as that shown in FIGS. 1 is a femtosecond laser surface processing apparatus with a wavelength of 800 nm, and FIG. 2 is a femtosecond laser surface processing apparatus with a wavelength of 400 nm. The laser (pulse width: 120 fs, center wavelength 800 nm, repetition frequency: 1 kHz, pulse energy: 0.25 to 400 μJ / pulse) generated by the titanium sapphire femtosecond laser generator 1 is folded toward the work material 8 by the mirror 2. Then, it is guided to the mechanical shutter 3. At the time of laser irradiation, the mechanical shutter 3 is opened, the laser irradiation intensity can be adjusted by the half-wave plate 4 and the polarization beam splitter 6, the polarization direction is adjusted by the half-wave plate 5, and the condenser lens (focal length) : 150 mm) 7, the surface of the work material 8 on the XYθ stage 9 was condensed and irradiated. In FIG. 2, reference numeral 10 denotes a second harmonic wave, that is, wavelength conversion for generating a half-wavelength laser beam (pulse width: 300 fs, center wavelength 400 nm, repetition frequency: 1 kHz, pulse energy: 0.05 to 120 μJ / pulse). Nonlinear optical crystal 11, 11 is a wavelength selecting optical element that reflects a wavelength of 800 nm and transmits a wavelength of 400 nm, and 12 is a condenser lens (focal length: 50 mm).
加工材料の走査速度は、レーザの集光スポット径とレーザの強度に応じて設定する。なお、レーザのスキャンは、レーザを固定して加工材料８を支持するＸＹθステージ９を移動させてもよいし、ＸＹθステージ９を固定してレーザを移動させてもよい。あるいは、レーザとＸＹθステージ９を同時移動させてもよい。 The scanning speed of the processing material is set according to the focused spot diameter of the laser and the intensity of the laser. The laser scanning may be performed by moving the XYθ stage 9 that supports the workpiece 8 while fixing the laser, or may move the laser while fixing the XYθ stage 9. Alternatively, the laser and the XYθ stage 9 may be moved simultaneously.
加工材料８としてステンレス基板を用いた。 A stainless steel substrate was used as the processing material 8.
図３と図４は、波長８００ｎｍの直線偏光のフェムト秒レーザパルスをステンレス基板の表面に集光しスキャン照射することによって形成された表面畝状微細周期構造を電子顕微鏡で撮像した図である。図３と図４でレーザの偏光方向を９０°変えている。このため表面畝状微細周期構造の方向が図３と図４で９０°回転している。レーザ照射回数は、単位面積あたりに所定のパルス数が照射されるように設定する。照射の仕方は、レーザパルスをオーバラップさせながらスキャン照射する。 FIG. 3 and FIG. 4 are images obtained by imaging an electron microscopic image of a surface ridge-like fine periodic structure formed by condensing a linearly polarized femtosecond laser pulse having a wavelength of 800 nm on the surface of a stainless steel substrate and performing scanning irradiation. 3 and 4, the laser polarization direction is changed by 90 °. For this reason, the direction of the surface ridge-like fine periodic structure is rotated by 90 ° in FIGS. The number of times of laser irradiation is set so that a predetermined number of pulses are irradiated per unit area. As a method of irradiation, scan irradiation is performed while overlapping laser pulses.
図５と図６は、波長４００ｎｍの直線偏光のフェムト秒レーザパルスをステンレス基板の表面に集光しスキャン照射することによって形成された表面畝状微細周期構造を電子顕微鏡で撮像した図である。図５と図６でレーザの偏光方向を９０°変えている。このため畝状微細周期構造の方向が図５と図６で９０°回転している。レーザ照射回数と照射の仕方は前述の図３と図４の場合と同様である。 FIG. 5 and FIG. 6 are images obtained by imaging an electron microscopic surface superficial fine structure formed by condensing a linearly polarized femtosecond laser pulse having a wavelength of 400 nm on the surface of a stainless steel substrate and performing scanning irradiation. 5 and 6, the laser polarization direction is changed by 90 °. Therefore, the direction of the bowl-shaped fine periodic structure is rotated by 90 ° in FIGS. 5 and 6. The number of times of laser irradiation and the method of irradiation are the same as those in FIGS. 3 and 4 described above.
図３、図４と図５、図６を比較すると、レーザの波長が短い図５、図６のほうが畝状周期構造が細かい。これは畝状周期構造の間隔が、レーザ波長に依存するためである。ちなみに波長８００ｎｍのレーザ照射で６６０ｎｍ前後の間隔の表面畝状微細周期構造が、波長４００ｎｍのレーザ照射では３３０ｎｍ前後の間隔の表面畝状微細周期構造がそれぞれ形成された。 Comparing FIGS. 3 and 4 with FIGS. 5 and 6, FIGS. 5 and 6, where the laser wavelength is short, have a finer periodic structure. This is because the interval of the saddle-like periodic structure depends on the laser wavelength. Incidentally, a surface ridge-like fine periodic structure with an interval of about 660 nm was formed by laser irradiation with a wavelength of 800 nm, and a surface ridge-like fine periodic structure with an interval of about 330 nm was formed with laser irradiation with a wavelength of 400 nm.
図７は波長８００ｎｍの直線偏光のレーザパルスをステンレス基板に対して二段階で照射することによって形成された表面微細構造を電子顕微鏡で撮像した図である。すなわち、第一工程のレーザパルス照射により図３の表面畝状微細周期構造を基板上に形成し、この表面畝状微細周期構造上に、第二工程として図４の表面畝状微細周期構造を形成するレーザパルスを照射したものである。結果として、突起状の構造が周期的に配列する表面微細構造が形成された。ただし、第一工程で形成された表面畝状微細周期構造を完全に破壊しないように第二工程のレーザ照射強度とスキャン速度を調整してある。 FIG. 7 is an image of a surface microstructure formed by irradiating a stainless steel substrate with a linearly polarized laser pulse having a wavelength of 800 nm in two stages, using an electron microscope. 3 is formed on the substrate by laser pulse irradiation in the first step, and the surface wrinkled fine periodic structure in FIG. 4 is formed on the surface wrinkled fine periodic structure as a second step. The laser pulse to be formed is irradiated. As a result, a surface fine structure in which protruding structures are periodically arranged was formed. However, the laser irradiation intensity and the scanning speed in the second step are adjusted so as not to completely destroy the surface ridge-like fine periodic structure formed in the first step.
図８は波長４００ｎｍの直線偏光のレーザパルスをステンレス基板に対して二段階で照射することによって形成された表面微細構造を電子顕微鏡で撮像した図である。すなわち、第一工程のレーザパルス照射により図５の表面畝状微細周期構造を基板上に形成し、この表面畝状微細周期構造上に、第二工程として図６の表面畝状微細周期構造を形成するレーザパルスを照射したものである。結果として、突起状の構造が周期的に配列する表面微細構造が形成された。ただし、第一工程で形成された表面畝状微細周期構造を完全に破壊しないように第二工程のレーザ照射強度とスキャン速度を調整してある。 FIG. 8 is an image of a surface microstructure formed by irradiating a stainless steel substrate with a linearly polarized laser pulse having a wavelength of 400 nm in two stages using an electron microscope. 5 is formed on the substrate by laser pulse irradiation in the first step, and the surface hook-like fine periodic structure of FIG. 6 is formed as a second step on the surface hook-like fine periodic structure. The laser pulse to be formed is irradiated. As a result, a surface fine structure in which protruding structures are periodically arranged was formed. However, the laser irradiation intensity and the scanning speed in the second step are adjusted so as not to completely destroy the surface ridge-like fine periodic structure formed in the first step.
図９は波長８００ｎｍと４００ｎｍの直線偏光のレーザパルスをステンレス基板に対して二段階で照射することによって形成された表面微細構造を電子顕微鏡で撮像した図である。すなわち、第一工程のレーザパルス照射により図３の表面畝状微細周期構造を基板上に形成し、この表面畝状微細周期構造上に、第二工程として図６の表面畝状微細周期構造を形成するレーザパルスを照射したものである。結果として、突起状の構造が周期的に配列する表面微細構造が形成された。特にこの場合は、前記および後記の加工形態を含めて、個々の突起形状が最も均一な表面微細突起構造が得られた。短波長レーザパルスは長波長レーザパルスに比べて、表面に形成できる畝状微細周期構造の畝の深さと幅が小さい。このため、第一工程で形成された畝状微細周期構造の原形を、第二工程で大きく破壊することがない。ただし、第一工程で形成された表面畝状微細周期構造を完全に破壊しないように第二工程のレーザ照射強度とスキャン速度を調整してある。 FIG. 9 is an image obtained by imaging the surface microstructure formed by irradiating the stainless steel substrate with linearly polarized laser pulses having wavelengths of 800 nm and 400 nm in two stages with an electron microscope. 3 is formed on the substrate by laser pulse irradiation in the first step, and the surface wrinkled fine periodic structure in FIG. 6 is formed on the surface wrinkled fine periodic structure as a second step. The laser pulse to be formed is irradiated. As a result, a surface fine structure in which protruding structures are periodically arranged was formed. In particular, in this case, a surface fine protrusion structure with the most uniform individual protrusion shape was obtained, including the processing forms described above and below. The short wavelength laser pulse has a smaller depth and width of the wrinkles of the wrinkled fine periodic structure that can be formed on the surface than the long wavelength laser pulses. For this reason, the original shape of the bowl-shaped fine periodic structure formed in the first step is not greatly broken in the second step. However, the laser irradiation intensity and the scanning speed in the second step are adjusted so as not to completely destroy the surface ridge-like fine periodic structure formed in the first step.
図１０は波長４００ｎｍと８００ｎｍの直線偏光のレーザパルスをステンレス基板に対して二段階で照射することによって形成された表面微細構造を電子顕微鏡で撮像した図である。すなわち、第一工程のレーザパルス照射により図５の表面畝状微細周期構造を基板上に形成し、この表面畝状微細周期構造上に、第二工程として図４の表面畝状微細周期構造を形成するレーザパルスを照射したものである。結果として、突起状の構造が周期的に配列する表面微細構造が形成された。ただし、第一工程で形成された表面畝状微細周期構造を完全に破壊しないように第二工程のレーザ照射強度とスキャン速度を調整してある。 FIG. 10 is an image of a surface microstructure formed by irradiating a stainless steel substrate with linearly polarized laser pulses having wavelengths of 400 nm and 800 nm in two stages, using an electron microscope. 5 is formed on the substrate by laser pulse irradiation in the first step, and the surface hook-like fine periodic structure of FIG. 4 is formed on the surface hook-like fine periodic structure as a second step. The laser pulse to be formed is irradiated. As a result, a surface fine structure in which protruding structures are periodically arranged was formed. However, the laser irradiation intensity and the scanning speed in the second step are adjusted so as not to completely destroy the surface ridge-like fine periodic structure formed in the first step.
以上、本発明の実施形態について説明したが、本発明は前記実施形態に限定されることなく特許請求の範囲に記載の技術的思想に基づき種々の変形が可能である。例えば前記実施形態ではレーザの波長を８００ｎｍと４００ｎｍの二種類としたが、その他の波長の二種類ないし三種類以上のレーザを使用してもよい。また各工程で同じ波長を使用してもよいし、異なる波長を使用してもよい。異なる波長を使用する場合は長波長から短波長を順次使用してもよいし、短波長から長波長を順次使用してもよい。使用する波長の順序の組み合わせは自由であることは勿論である。 Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made based on the technical idea described in the claims. For example, in the above-described embodiment, the laser wavelengths are two types of 800 nm and 400 nm, but two to three or more types of lasers having other wavelengths may be used. Further, the same wavelength may be used in each step, or different wavelengths may be used. When different wavelengths are used, the short wavelength may be used sequentially from the long wavelength, or the long wavelength may be used sequentially from the short wavelength. Of course, the combination of the order of the wavelengths used is free.
また、図１および図２のレーザの加工材料への入射角は０°であるが、その他の角度を選択してもよいことは勿論である。 In addition, although the incident angle of the laser shown in FIGS. 1 and 2 with respect to the processing material is 0 °, it is needless to say that other angles may be selected.
さらに、レーザの偏光方向または基板、あるいはその両方を回転させることによって、第一工程と第二工程で形成されるそれぞれの表面畝状微細周期構造の相対的な方向を直交させるほか、任意角度で交差させる場合も本発明に含まれる。 Furthermore, by rotating the polarization direction of the laser and / or the substrate, the relative directions of the surface periodic fine periodic structures formed in the first step and the second step are orthogonal to each other, and at an arbitrary angle. The case of crossing is also included in the present invention.
１ フェムト秒レーザ発生器
２ ミラー
３ メカニカルシャッタ
４、５ １／２波長板
６ 偏光ビームスプリッタ
７ 集光レンズ（焦点距離：１５０ｍｍ）
８ 加工材料
９ ＸＹθステージ
１０ 波長変換用非線形光学結晶
１１ 波長選択用光学素子（波長８００ｎｍ反射／波長４００ｎｍ透過）
１２ 集光レンズ（焦点距離：５０ｍｍ）
DESCRIPTION OF SYMBOLS 1 Femtosecond laser generator 2 Mirror 3 Mechanical shutter 4, 5 1/2 wavelength plate 6 Polarizing beam splitter 7 Condensing lens (focal length: 150 mm)
8 Processing Material 9 XYθ Stage 10 Nonlinear Optical Crystal for Wavelength Conversion 11 Optical Element for Wavelength Selection (wavelength 800 nm reflection / wavelength 400 nm transmission)
12 condenser lens (focal length: 50mm)
Claims (12)
前記畝状微細周期構造が形成された材料表面に対して、先のレーザを当該畝状微細周期構造が形成された材料表面に対する加工閾値近傍の照射強度で前記第一工程の偏光方向と異なる方向の直線偏光で照射すると共に当該照射部をオーバラップさせながら所定方向にスキャンして、前記畝状微細周期構造に前記畝状微細周期構造の方向と異なる方向の畝状微細周期構造を自己組織的に形成する第二工程と、
を有することを特徴とするレーザによる表面微細構造形成方法。 Condensing and irradiating a linearly polarized laser beam with an irradiation intensity near the processing threshold on the surface of the material and scanning it in a predetermined direction while overlapping the irradiated area, forms a self-organized cage-like fine periodic structure on the surface of the material The first step to
A direction different from the polarization direction of the first step with an irradiation intensity near the processing threshold for the material surface on which the saddle-like fine periodic structure is formed with respect to the material surface on which the saddle-like fine periodic structure is formed The ridge-like fine periodic structure in a direction different from the direction of the ridge-like fine periodic structure is self-organized in the ridge-like fine periodic structure by scanning in a predetermined direction while irradiating with the linearly polarized light of A second step to form,
A method for forming a surface microstructure using a laser.
を有することを特徴とするレーザによる表面微細構造形成方法。 The surface of the material subjected to the first step and the second step of claim 1 is irradiated with a laser in the vicinity of a processing threshold for the surface microstructure of the linearly polarized light different from the polarization direction of the laser in the first step or the second step. A third step of self-organizing forming a saddle-like fine periodic structure in a direction different from the direction of the saddle-like fine periodic structure on the material surface by scanning in a predetermined direction while overlapping the irradiation part;
A method for forming a surface microstructure using a laser.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006229867A JP4781941B2 (en) | 2006-08-25 | 2006-08-25 | Surface fine structure forming method by laser |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006229867A JP4781941B2 (en) | 2006-08-25 | 2006-08-25 | Surface fine structure forming method by laser |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2008049380A true JP2008049380A (en) | 2008-03-06 |
| JP4781941B2 JP4781941B2 (en) | 2011-09-28 |
Family
ID=39233899
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2006229867A Expired - Fee Related JP4781941B2 (en) | 2006-08-25 | 2006-08-25 | Surface fine structure forming method by laser |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4781941B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010162545A (en) * | 2009-01-13 | 2010-07-29 | Panasonic Corp | Method for forming periodical structure |
| WO2011096356A1 (en) | 2010-02-05 | 2011-08-11 | 株式会社フジクラ | Substrate having surface microstructure |
| WO2014176643A1 (en) * | 2013-05-03 | 2014-11-06 | Newsouth Innovations Pty Limited | Surface structuring of metals |
| CN111975202A (en) * | 2020-07-23 | 2020-11-24 | 江苏大学 | Laser welding method for dissimilar metal materials |
| CN113146051A (en) * | 2021-04-23 | 2021-07-23 | 吉林大学 | High-flexibility preparation method of large-area microstructure on surface of amorphous alloy |
| KR20210151216A (en) * | 2019-04-16 | 2021-12-13 | 아뻬랑 | A method for producing an iridescent effect on a surface of a material and an apparatus for carrying out said method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07266071A (en) * | 1994-03-30 | 1995-10-17 | Aida Eng Ltd | Laser beam machining device |
| JP2003211400A (en) * | 2002-01-22 | 2003-07-29 | Japan Science & Technology Corp | Refining method using ultra-short pulse laser and workpiece therefor |
-
2006
- 2006-08-25 JP JP2006229867A patent/JP4781941B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07266071A (en) * | 1994-03-30 | 1995-10-17 | Aida Eng Ltd | Laser beam machining device |
| JP2003211400A (en) * | 2002-01-22 | 2003-07-29 | Japan Science & Technology Corp | Refining method using ultra-short pulse laser and workpiece therefor |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010162545A (en) * | 2009-01-13 | 2010-07-29 | Panasonic Corp | Method for forming periodical structure |
| WO2011096356A1 (en) | 2010-02-05 | 2011-08-11 | 株式会社フジクラ | Substrate having surface microstructure |
| WO2014176643A1 (en) * | 2013-05-03 | 2014-11-06 | Newsouth Innovations Pty Limited | Surface structuring of metals |
| KR20210151216A (en) * | 2019-04-16 | 2021-12-13 | 아뻬랑 | A method for producing an iridescent effect on a surface of a material and an apparatus for carrying out said method |
| KR102642806B1 (en) | 2019-04-16 | 2024-02-29 | 아뻬랑 | Method for producing an iridescent effect on the surface of a material and apparatus for performing the method |
| CN111975202A (en) * | 2020-07-23 | 2020-11-24 | 江苏大学 | Laser welding method for dissimilar metal materials |
| CN113146051A (en) * | 2021-04-23 | 2021-07-23 | 吉林大学 | High-flexibility preparation method of large-area microstructure on surface of amorphous alloy |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4781941B2 (en) | 2011-09-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6022038B2 (en) | Workpiece processing method and processing apparatus using laser beam | |
| EP2465634B1 (en) | Laser machining device and laser machining method | |
| US10807197B2 (en) | Method of, and apparatus for, laser blackening of a surface, wherein the laser has a specific power density and/or a specific pulse duration | |
| JP6249225B2 (en) | Laser processing apparatus and laser processing method | |
| JP4781941B2 (en) | Surface fine structure forming method by laser | |
| TW201343296A (en) | Laser scribing system and method with extended depth affectation into a workpiece | |
| JP2010142862A (en) | Method for producing nano-periodic structure on surface of dielectric material | |
| US20140175067A1 (en) | Methods of forming images by laser micromachining | |
| CN104625416B (en) | Based on square hole auxiliary electron dynamic regulation crystal silicon surface periodic micro-nano structure method | |
| JP2011098384A (en) | Laser beam machining method | |
| JP2011091322A (en) | Laser dicing method and laser dicing device | |
| JP2008036641A (en) | Laser beam machining apparatus and method | |
| Allegre et al. | Real-time control of polarisation in ultra-short-pulse laser micro-machining | |
| JP6382154B2 (en) | Laser processing method and laser processing apparatus | |
| JP5819149B2 (en) | Periodic structure creation method and periodic structure creation apparatus | |
| JP2006289441A (en) | Method and apparatus for laser beam machining | |
| JP2007237210A (en) | Laser beam machining method and apparatus | |
| JP2006110587A (en) | Laser interference machining method and device | |
| JP5383342B2 (en) | Processing method | |
| JP2007012733A (en) | Dividing method of substrate | |
| JP5318909B2 (en) | Laser dicing method | |
| JP2004306127A (en) | Processing method for patterning thin film | |
| Choi et al. | Femtosecond laser-induced line structuring on mold stainless steel STAVAX with various scanning speeds and two polarization configurations | |
| JP2004098120A (en) | Method and device of laser beam machining | |
| JP2003255262A (en) | Specialized optical system using femtosecond laser |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20090119 |
|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20091110 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20100722 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20110406 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20110621 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20110706 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140715 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 Ref document number: 4781941 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |