JP4097462B2 - Method for supporting fine particles on substrate, substrate on which fine particles are supported by the method, optical element and circuit element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for introducing and supporting fine particles inside a substrate, a substrate on which fine particles are supported by the method, an optical element, and a circuit element.
[0002]
[Prior art]
Recent technological developments in the electronics industry have been remarkable, and products with new functions have been announced one after another. Along with this, materials having various functions have been developed as component materials for electronic devices, and in recent years, there has been an increasing demand for higher functionality on the surface and inside of plastic structures (components). Responding to such demands for high functionality, technical support on the material side of plastic structure or plasticizing itself, and processing that incorporates functional parts and controls the structure according to the requirements Efforts are being made in two aspects, technical support in terms of aspects. For example, in order to improve the functionality and performance of the surface of plastic structures, various technologies are used from both the material and processing sides to improve and modify the chemical, electrical, optical, and physical properties of the surface. Efforts are being made. In addition, with high functionality and high performance inside the plastic structure, electrical and light conductivity, light transmission or blocking properties, moisture and gas transmission or blocking properties, heat, light, and stress In response to various characteristics such as responsiveness to external stimuli or memory characteristics, various technical efforts have been made from both the material and processing surfaces.
[0003]
Therefore, for example, in order to impart different functions (new functions, etc.) to the surface of the substrate, chemical, electrical, optical, physical, etc. etching is performed directly from the surface side, or a resist is applied. Development methods such as development and similar etching are used.
[0004]
On the other hand, technological progress with respect to laser light sources is remarkable, and in particular, pulsed lasers have nanosecond (10^-9From a pulse width on the order of seconds, picoseconds (10^-12Ultra-short pulses are progressing to pulse widths on the order of seconds, and more recently, femtoseconds (10^-15A pulse laser having a pulse width on the order of seconds) has also been developed. Pulse width is 10^-12Ultra-short pulse lasers or systems that have subseconds (for example, the pulse width is on the order of femtoseconds) or the system has characteristics such as directivity, spatial and temporal coherence, etc. Since the width is extremely narrow, even with the same average output, the electric field strength per unit time and unit space is extremely high. Therefore, an attempt to form a new structure (induced structure) by irradiating a substance with an ultrashort pulse laser using this high electric field strength has been carried out mainly using an inorganic glass material.
[0005]
On the other hand, the polymer material has a feature of low thermal conductivity and tends to store heat easily. In other words, the thermal motion of polymer materials occurs more easily than that of inorganic glass materials, and the amount of heat required for motion and reaction can be reduced. Therefore, the structure can be changed even with relatively low irradiation energy compared to inorganic glass materials. Ablation occurs. However, the pulse width is 10^-12Because the electric field strength per unit time and unit space of ultrashort pulse lasers that are less than a second (for example, the pulse width is on the order of femtoseconds) is very high, damage to polymer materials due to laser irradiation is likely to occur. As a result, it is difficult to grasp the design of the polymer material necessary for the formation of the induced structure of the polymer material. To date, studies have not been performed as well as inorganic glass materials.
[0006]
[Problems to be solved by the invention]
Thus, in order to impart different functions to the substrate surface, etching is performed entirely from the surface side for imparting, or in order to impart partially, a resist is applied, developed, and etched. Since a forming method such as performing the method is used, workability is low. Further, in order to carry fine particles on the plastic, it is necessary to mix the plastic and the fine particles to form a film, and then perform fine processing by resist coating and etching as described above. Further, whether or not the dispersion is good when the plastic and the fine particles are mixed in advance is limited by the affinity between the plastic and the fine particles or the dispersion medium. Therefore, there is a demand for a method for imparting different functions to the substrate surface easily and with excellent workability.
[0007]
Accordingly, an object of the present invention is to provide a method for supporting fine particles on a substrate that can support fine particles easily and with excellent workability in the substrate, and a substrate on which fine particles are supported by the method. There is to do.
Another object of the present invention is to provide an optical element and a circuit element that have excellent functions and can be easily manufactured with excellent workability.
[0008]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that the pulse width is 10 after the fine particle layer is formed on the plastic substrate.^-12It has been found that when a laser of less than 1 second is irradiated from the surface of the fine particle layer side, the fine particles are carried inside the plastic base material. The present invention has been completed based on these findings.
[0009]
  That is, the present invention is a method for supporting fine particles on a substrate, and includes the following steps (A) to (B), and is a method for supporting fine particles on a substrate.
  Step (A): Step of forming a fine particle layer on the substrate
  Step (B): condensed from the fine particle layer sidePulse width is 10 ^-12 Less than a secondThe process of introducing fine particles into the substrate by laser irradiation
[0010]
Furthermore, it is preferable that the following step (C) is provided as a subsequent step of the step (B).
Step (C): Step of removing the remaining fine particle layer
[0011]
As the base material, a plastic base material can be suitably used. The fine particles are preferably inorganic fine particles, and the inorganic fine particles may contain at least one metal atom selected from gold, silver, copper, platinum and titanium, or a silicon atom.
[0013]
  The present invention also provides,in frontRecordDepending on how fine particles are supported on the substrateOptical element in which a substrate carrying fine particles is used as a constituent elementChildprovide.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings as necessary. In addition, about the same member, the same code | symbol may be attached | subjected.
[Method of supporting fine particles on substrate]
In the method for supporting fine particles on the substrate of the present invention, a fine particle layer (fine particle layer) is formed on the substrate when the fine particles are supported on the substrate, and a laser is irradiated from the fine particle layer side. It is characterized in that fine particles are introduced into the substrate from the outside. Specifically, it includes the following steps (A) to (B), and further includes the following step (C) as a subsequent step of the step (B) as necessary.
Step (A): Step of forming a fine particle layer on the substrate
Step (B): A step of introducing fine particles into the substrate by irradiation of a focused laser beam from the fine particle layer side.
Step (C): Step of removing the remaining fine particle layer
[0015]
(Process (A))
In the step (A), a fine particle layer is formed on the substrate. The surface of the substrate on which the fine particle layer is formed may be one surface of the substrate or a plurality of surfaces. In addition, the fine particle layer can be formed at least partially on one surface of the substrate, and thus may be formed entirely or only partially on a necessary site. Good.
[0016]
(Base material)
The substrate may be either an organic substrate or an inorganic substrate. As the base material, plastic base materials made of various polymer materials can be used. The substrate may have any form of a single layer or a laminate. The polymer material constituting the plastic base material includes various polymer components such as organic polymer and inorganic polymer. The polymer materials may be used alone or in combination of two or more. The organic polymer is not particularly limited, and various organic resins such as a thermoplastic resin, a thermosetting resin, and an ultraviolet curable resin can be used. A thermoplastic resin is preferable, and two or more of them are preferable. A thermoplastic resin material having a glass transition temperature (glass transition point) of 2 is preferred.
[0017]
Examples of organic polymers include polydienes such as polyisoprene and polybutadiene; polyalkenes such as polyisobutylene; polyacrylates such as polybutyl acrylate and polyethyl acrylate; polyvinyl esters such as polybutoxymethylene. Polyurethanes; Polysiloxanes; Polysulfides; Polyphosphazenes; Polytriazines; Polycarboranes; Polycarbonate (PC); Methacrylate resins such as polymethyl methacrylate (PMMA); Polyesters such as polyethylene terephthalate (PET) Polyethersulfone (PES) (Polyethersulfone); Polynorbornene; Epoxy resin; Polyaryl; Polyimide; Polyetherimide (PEI); Polyesterimide; Polyamide; Styrenic resin such as polystyrene, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin); Polyarylene ether such as polyphenylene ether; Polyarylate; Polyacetal; Polyphenylene sulfide; Polysulfone (polysulfone); Polyether ketones such as polyether ether ketone and polyether ketone ketone; Polyvinyl alcohol; Polyvinyl pyrrolidone; Fluorine such as vinylidene fluoride resin, hexafluoropropylene resin, hexafluoroacetone resin Based resins and the like.
[0018]
(Fine particles)
The fine particles are not particularly limited as long as they have a fine particle shape, and fine particles made of various materials (or materials) can be used, and examples thereof include inorganic fine particles and organic fine particles. The fine particles can be used alone or in combination of two or more. As fine particles, inorganic fine particles can be suitably used.
[0019]
As inorganic fine particles, periodic table group 1 elements such as lithium, sodium, potassium, rubidium and cesium; periodic table group 2 elements such as magnesium, calcium, strontium and barium; scandium, yttrium and lanthanoid elements (such as lanthanum and cerium), Periodic Table Group 3 elements such as actinoid elements (actinium, etc.); Periodic Table Group 4 elements such as titanium, zirconium, hafnium; Periodic Table Group 5 elements such as vanadium, niobium, tantalum; Periodic Table 6 such as chromium, molybdenum, tungsten, etc. Group elements: Periodic Table 7 elements such as manganese, technetium, rhenium; Periodic Table 8 elements such as iron, ruthenium, osmium; Periodic Table 9 elements such as cobalt, rhodium, iridium; Periods such as nickel, palladium, platinum, etc. Group 10 elements; Group 11 elements of the periodic table of copper, silver, gold, etc. ; Group 12 elements of the periodic table such as zinc, cadmium and mercury; Group 13 elements of the periodic table such as boron, aluminum, gallium, indium and thallium; Group 14 elements of the periodic table such as silicon, germanium, tin and lead; Antimony, bismuth and the like In particular, particulate inorganic compounds containing inorganic atoms (inorganic elements) such as Group 15 elements of the periodic table are included. The inorganic compound may contain one kind or two or more kinds of inorganic atoms.
[0020]
As long as it has the form of fine particles, the inorganic fine particles may be composed of simple inorganic elements, including inorganic element oxides (including complex oxides), hydroxides, halides (chlorides, etc.), Oxo acid salts (nitrate, sulfate, phosphate, carbonate, etc.) may be used.
[0021]
The inorganic fine particles preferably contain at least one metal atom selected from gold, silver, copper, platinum and titanium, or a silicon atom. That is, as the inorganic fine particles, metal fine particles containing various metal atoms and silicon fine particles containing silicon atoms can be suitably used.
[0022]
As the material (or material) of the metal fine particles, metal compounds containing various metal atoms can be used. Metal atoms related to the metal fine particles include titanium, zirconium, platinum, copper, silver, gold, aluminum and the like. As the metal fine particles, those containing at least one metal atom selected from gold, silver, copper, platinum and titanium are preferable. In particular, gold and platinum are less likely to be oxidized and are stable, and thus are optimal as metal atoms of metal fine particles.
[0023]
In addition, as the material (or material) of the silicon fine particles, various silicon-based compounds containing silicon atoms can be used.
[0024]
In addition, as a material (or raw material) of organic fine particles, the organic polymer illustrated by the term of the said base material is mentioned. Moreover, organic compounds such as organic acid salts (acetates, propionates, stearates, etc.) and complexes of the inorganic elements can also be used as the organic fine particles.
[0025]
The particle size (average particle size) of the fine particles is, for example, desirably 300 μm or less (preferably 5 nm to 100 μm, more preferably 10 nm to 1,000 nm).
[0026]
Various surface treatments may be applied to the surface of the fine particles. By subjecting the fine particles to surface treatment, for example, stability as colloidal particles in a solvent can be enhanced.
[0027]
The method of forming the fine particle layer is not particularly limited, and a method of applying and drying a fine particle dispersion (for example, a colloidal liquid of fine particles) is preferable because it is simple, but depending on the material of the fine particles, sputtering is preferable. A dry process such as a method, a vacuum deposition method, or an ion plating method, or a wet process such as a thermal decomposition method or a sol-gel method may be used.
[0028]
The thickness of the fine particle layer can be selected from a range of, for example, about 0.01 to 50 μm (preferably 0.05 to 30 μm, more preferably 0.1 to 10 μm). The fine particle layer is preferably a thin layer. When the thickness of the fine particle layer is less than 0.01 μm, it becomes difficult to obtain a planar continuous fine particle layer, and when it exceeds 50 μm, problems such as the generation of cracks in the fine particle layer may occur.
[0029]
The fine particle layer preferably has a flat upper surface, but may have an uneven shape. Further, the size (area) of the upper surface is not particularly limited.
[0030]
The fine particle layer may have either a single layer structure or a multilayer structure. Furthermore, the fine particle layer may contain other materials and additives as required.
[0031]
(Process (B))
In the step (B), fine particles are introduced into the base material by irradiating a laser beam focused on a predetermined portion from the fine particle layer side (upper surface of the fine particle layer) provided on the base material. Therefore, the fine particles can be carried inside the substrate.
[0032]
(Focused laser)
In the present invention, it is important to use a focused laser (sometimes referred to as a “collected laser”). By irradiating the focused laser beam from the outside of the fine particle layer on the base material, the microparticles enter the base material at the irradiated part and its peripheral part, and the focused laser beam on the base material irradiates. The structure of the irradiated part and its peripheral part can be changed, and a fine structure change part (induction structure part) can be formed. For example, if the wavelength of the irradiated laser is set to 800 nm, no change occurs in the base material or the fine particle layer when the unfocused laser is irradiated. Photon absorption (for example, two-photon absorption, three-photon absorption, four-photon absorption, five-photon absorption, etc.) occurs, and an induced structure can be formed in the substrate or the fine particle layer. Specifically, when the induced structure portion of the base material was observed after the focused laser irradiation, it was confirmed that fine particles that had been deagglomerated had entered the base material. This is because the dispersion of fine particles due to impact generated in the irradiation part of the focused laser, the pushing of the fine particles into the base material due to the dispersion, and the base material due to the thermal motion of the base material (particularly plastic base material) This is thought to be caused by the incorporation of fine particles inside. Note that the probability of such multiphoton absorption increases in proportion to the intensity of light, and the higher the intensity, the easier the multiphoton absorption occurs.
[0033]
In particular, in the present invention, by appropriately adjusting the intensity of the laser beam and the degree of condensing the laser beam, the degree of loading of fine particles in the base material (particularly the plastic base material) (amount, density, depth, etc.) Can be adjusted.
[0034]
As such a laser, 1 × 10^-12Seconds or less (1 x 10^-12Second to 1 × 10^-15Second) laser (sometimes referred to as "ultrashort pulse laser") is particularly preferred. A smaller pulse width is preferable in that a high light intensity can be easily obtained. It is also possible to form a much finer induction structure. Such an ultrashort pulse laser can be obtained, for example, by reproducing and amplifying a laser using a titanium / sapphire crystal or a dye laser.
[0035]
In the laser (particularly, an ultrashort pulse laser), the wavelength is preferably, for example, in the wavelength region of visible light (for example, 400 to 800 nm). Moreover, as repetition, it can select from the range of 1 Hz-80 MHz, for example, and is about 10 Hz-500 kHz normally.
[0036]
The average output or irradiation energy of the laser (particularly, ultrashort pulse laser) is not particularly limited, and can be appropriately selected according to the size of the target structural change portion, the degree of structural change, and the like. For example, it can be selected from a range of about 500 mW or less (for example, 1 to 500 mW), preferably 5 to 300 mW, and more preferably about 10 to 100 mW. Thus, in this invention, the irradiation energy of a laser (especially ultrashort pulse laser) may be low.
[0037]
The method for condensing the laser is not particularly limited, and for example, a method using a condensing lens can be suitably employed. Such a condensing lens is not particularly limited, and the material of the base material, the material of the fine particles, the size of the target structural change portion (fine particle carrying portion) and the degree of change in the structure (degree of fine particle carrying), etc. It can be selected as appropriate according to the conditions.
[0038]
The irradiation spot diameter of the condensing laser is not particularly limited, and can be appropriately selected according to the size of the target structural change portion, the degree of structural change, the size, numerical aperture, or magnification of the condensing lens. For example, it can select from the range of about 1.0-50 micrometers (preferably 10-30 micrometers).
[0039]
(Irradiation method)
The method of irradiating the focused laser is not particularly limited, and for example, a method of irradiating only one point (or a part) at any point or every point, or irradiating in a line while moving the focal position Can be adopted. The line shape at the time of irradiating the focused laser while moving the focal position of the focused laser is not particularly limited, and may be an arbitrary line, for example, a straight line or a curved line. . Further, the focal position of the focused laser can be moved continuously or intermittently. In addition, by irradiating the condensing laser by computer control, it is possible to irradiate any complicated line shape while moving the focal position of the condensing laser.
[0040]
FIG. 1 is a schematic bird's-eye view showing an example of a focused laser irradiation method of the present invention. In FIG. 1, reference numeral 1 denotes a substrate with a fine particle layer having a fine particle supporting portion (sometimes referred to as a “base material with fine particle supporting fine particle layer”), 2 denotes a fine particle layer (fine particle layer), and 21 denotes a fine particle layer 2. Irradiation part (structure change part), 22 is an unirradiated part in the fine particle layer 2, 3 is a base material, 41 is a fine particle support part (structure change part) in the base material 3, and 42 is no fine particle support in the base material 3 Part (structure unchanged part). 51 has a pulse width of 10^-12An ultrashort pulse laser (which may be simply referred to as “laser”) that is less than or equal to a second, 52 is a condenser lens, and 5 is a condenser laser. The base material 1 with a fine particle carrying fine particle layer is produced from a base material on which a fine particle layer 2 is formed. The irradiation part (structure change part) 21 in the fine particle layer 2 and the fine particle support part 41 in the base material 3 are parts (structure change part) whose structure is changed by the influence of the irradiation of the focused laser 5, Further, the non-irradiated part 22 in the fine particle layer 2 and the fine particle unsupported part 42 in the base material 3 are not affected by the irradiation of the focused laser 5, and retain the original film state. (Structure unchanged part).
[0041]
The fine particle layer 2 is formed on the base material 3, and the upper surface of the fine particle layer 2 is a plane, and is parallel to the XY plane or perpendicular to the Z axis.
[0042]
A predetermined portion of the fine particle layer 2 is irradiated with a focused laser 5 in focus. The condensing laser 5 is a laser in which the laser 51 is condensed by the condensing lens 52.
[0043]
6a is an initial position or a center position (when it is referred to as “irradiation start position”) when the focused laser 5 starts to be irradiated, and 6b is when the focused laser 5 has been irradiated. The final position or its center position (which may be referred to as “irradiation end position”), and 6c may be referred to as the focus of irradiation of the focused laser 5 or its center position (simply referred to as “focus position”). ) Is the moving direction from the irradiation start position 6a to the irradiation end position 6b. Reference numeral 6 denotes a trajectory (in some cases, referred to as “focal position trajectory”) in which the focal position or the central position of the focal point of the focused laser 5 is moved. That is, in FIG. 1, the focal position of the focused laser 5 is continuously moved linearly in the direction of the focal position moving direction 6c from the irradiation start position 6a to the irradiation end position 6b. The focal position locus is the focal position locus 6.
[0044]
Specifically, when the fine particle layer 2 is irradiated with the condensing laser 5, the structure of each focal position on the focal position locus 6 of the condensing laser 5 and its peripheral part (near part) changes (for example, the density is reduced). Due to this partial structural change, the fine particle-supporting fine particle layer-attached base material 1 has the line-shaped structure changing portions (21, 41), the original unirradiated portion 22 and the structure unchanged portion 42. And have. That is, by irradiating the fine particle layer 2 with the focused laser 5, it is possible to form the structure changing portion 41 in which the fine particles are introduced and supported in the base material 3, and to change the structure in the fine particle layer 2. A portion 21 is formed. The structure change portion 41 is formed directly below the structure change portion 21 and in contact with the structure change portion 21. Moreover, the structure change part 41 and the structure change part 21 are the changes of the structure which usually belongs to a different kind.
[0045]
Further, since the focal position is continuously moved during the irradiation of the condensing laser 5, the part of the fine particle layer 2 or the base material 3 where the structure is changed is continuously changed according to the movement of the focal position. The structure change part (21, 41) which consists of the site | part which extended to the moving direction and changed is formed. As shown in FIG. 1, when the focal position of the condensing laser 5 is moved in the direction of movement 6 from the irradiation start position 6a to the irradiation end position 6b, a structure formed along the direction of movement direction 6c. A change part (21, 41) can be formed. Therefore, the longitudinal direction of the structure changing portions (21, 41) is the direction of the moving direction 6c.
[0046]
The speed (moving speed) for moving the focal position of the focused laser 5 is not particularly limited, and is appropriately selected according to the material of the fine particle layer 2 and the base material 3, the magnitude of the irradiation energy of the focused laser 5, and the like. Can do. In addition, it is also possible to control the size or the like of the structure change portion (21, 41) by controlling the moving speed.
[0047]
The focal position of the condensing laser 5 can be moved by moving the relative positions of the laser 51 and the condensing lens 52, the fine particle layer 2 and the base material 3, for example, the laser 51 and the condensing lens 52, and / or Alternatively, it can be performed by moving the fine particle layer 2 and the substrate 3. Specifically, for example, a base material 3 (irradiation sample) on which a fine particle layer 2 is formed is placed on a stage that can be moved precisely in a two-dimensional or three-dimensional direction, and a laser generator and a light collecting device. The lens is fixed to the fine particle layer 2 so as to be in focus (may be at any part), and the stage is moved to move the focal position, so that the structure can be formed at any part of the fine particle layer 2 or the substrate 3. A change part can be produced.
[0048]
As described above, the substrate 1 with the fine particle-supporting fine particle layer is a condensing laser (in particular, a pulse width of 10^-12A structure in which fine particles are supported on an arbitrary part of the base material 3 by a simple operation of irradiating a laser of a super-short pulse laser of less than a second) and moving the focal position as necessary. It can be produced by forming a part (structure changing part or fine particle carrying part) where the change is made.
[0049]
In FIG. 1, the structure changing portions (21, 41) are continuously formed in the moving direction by moving the focal position of the focusing laser 5, and the moving direction of the focal position is the longitudinal direction. Yes. Therefore, the length of the structure change portion (21, 41) in the longitudinal direction can be adjusted in accordance with, for example, the moving distance by which the focal position of the focused laser 5 is moved. For example, when the focal position of the condensing laser 5 is moved linearly, the length of the structure changing portions (21, 41) in the focal movement direction is the moving distance obtained by moving the focal position of the condensing laser 5 It can be equivalent or nearly equivalent.
[0050]
The size of the structure change portion (21, 41) is not particularly limited, and is controlled precisely even if the diameter or the length of one side is 1 mm or less (preferably 500 μm or less). Can be formed. In particular, by using an ultrashort pulse laser as the laser, it is possible to control the structural change portion (particularly, the fine particle supporting portion in the base material) with higher precision.
[0051]
In the present invention, in one base material 1 with a fine particle-supporting fine particle layer, the number of the structure change portions (fine particle support portions) in the base material 3 is not particularly limited, and may be singular or plural. Good. When a plurality of structure change portions are provided, they can be formed at an appropriate interval. The interval between the structural change portions can be arbitrarily selected. The interval between the structural change portions is preferably 3 μm or more, for example. If the interval between the structural change portions is less than 3 μm, the structural change portions may be fused at the time of manufacturing the structural change portion, and it may not be possible to form a plurality of independent structural change portions.
[0052]
Note that the size, shape, and degree of structural change of the structure change part depend on the irradiation time of the focused laser, the moving direction and speed of the focused position of the focused laser, the type of base material, and the material of the fine particles. It can be appropriately adjusted depending on the type, the pulse width of the laser, the irradiation energy, the numerical aperture and magnification of the condenser lens, and the like.
[0053]
The structure changing portion 41 in the substrate 3 only needs to carry fine particles, and the structure may be changed in addition to the fine particles. In the structure changing unit 41, the state in which the fine particles are supported may be any state. Examples of the supported state of the fine particles include a dispersed state, an agglomerated state, a connected state, and a state in which these are combined.
[0054]
In addition, the structure unchanged part 42 in the base material 3 is a part which is not influenced by laser irradiation, and the part (unirradiated part) where the laser is not irradiated and the fine particle layer 2 are not formed on the upper surface. The region (the laser may be irradiated or may not be irradiated) is included.
[0055]
As described above, according to the method for supporting fine particles on the base material of the present invention, the fine particles can be introduced and supported from the surface of the base material to the inside even if the fine particles are not previously contained in the base material. it can. In addition, the fine particle carrying portion in the base material carrying the fine particles can be formed extremely finely and with good control. In addition, since the method of irradiating the focused laser after forming the fine particle layer on the base material, the fine particles can be easily supported on the base material with excellent workability.
[0056]
(Process (C))
In the step (C), the fine particle layer remaining on the base material is removed from the base material without moving into the base material. Thus, by removing the fine particle layer, a base material having a fine particle supporting portion (structure changing portion) on the surface portion is produced. In addition, this process (C) can be performed as needed. Step (C) can be employed as a subsequent step of step (B).
[0057]
When removing the fine particle layer, for example, a removal method by cleaning, an etching method by an etching solution, or the like can be used. For example, when the fine particle layer is a layer of metal fine particles, an acidic aqueous solution (for example, an aqueous solution of an inorganic acid such as a hydrochloric acid aqueous solution, a sulfuric acid aqueous solution, a nitric acid aqueous solution, an oxalic acid aqueous solution, or hydrofluoric acid) is used as an etching solution. It can be removed by etching. The etching method at this time is not particularly limited, and examples thereof include a method of immersing the whole substrate having the fine particle layer or only the fine particle layer in an etching solution.
[0058]
[Substrate carrying fine particles]
The base material on which the fine particles of the present invention are supported is formed by the method for supporting fine particles on the base material, that is, a fine particle layer is formed on the base material, and the fine particle layer or the fine particle layer is formed on the base material. It can be produced by irradiating a focused laser, introducing and supporting fine particles in the base material, and removing the fine particle layer remaining on the base material as necessary.
[0059]
When the fine particle layer on the substrate is irradiated with a focused laser, a structure change portion (induced structure portion) is formed in the fine particle layer due to a change in the structure of the fine particle layer in the focused laser irradiation portion. By introducing the fine particles of the fine particle layer into the base material, a structure change portion (inductive structure portion) in which the fine particles are supported is formed immediately below the structure change portion of the fine particle layer, and as shown in FIG. A substrate with a fine particle layer on which fine particles are supported (a substrate with a fine particle-supported fine particle layer) is produced. FIG. 2 is a schematic cross-sectional view showing an example of a substrate with a particulate-supporting particulate layer. In FIG. 2, 1, 2, 21, 22, 3, 41, and 42 are the same as described above, the substrate with the fine particle-supported fine particle layer, the fine particle layer, the structure change portion in the fine particle layer, and the unirradiated in the fine particle layer, respectively. Part, base material, structural change part in the base material, and structure unchanged part in the base material. The substrate 1 with the particulate-supporting particulate layer has the particulate layer 2 constituted by the structure changing portion 21 and the non-irradiated portion 22, and the substrate 3 constituted by the structure changing portion 41 and the structure unchanged portion 42. In addition, the structure change portion 41 is formed in contact with the structure change portion 21 directly below. That is, the structure change part 41 is formed from the interface between the base material 3 and the fine particle layer 2 to the inside of the base material 3, and the depth at which the structure change part 41 is formed (depth from the interface of the base material). Is not particularly limited. Moreover, in FIG. 2, the width of the structure change portion 41 is smaller than that of the structure change portion 21 and is an extremely fine induction structure portion.
[0060]
By removing the fine particle layer for the fine particle-supported fine particle layer-coated substrate 1, a substrate having a structure change portion (fine particle support portion) carrying fine particles on the surface can be obtained. Such a base material having a fine particle support portion on its surface has a structure as shown in FIG.
[0061]
A substrate on which such a fine particle supporting part is formed can be suitably used as an optical element such as a diffraction grating or a polarizing element. When the fine particles are metal fine particles, the fine particle supporting portion (for example, the fine particle dispersed portion in which the fine particles are dispersed) has electrical conductivity and can be suitably used as an electric circuit element.
[0062]
【The invention's effect】
According to the method for supporting fine particles on the base material of the present invention, the fine particles can be easily supported from the surface of the base material to the inside thereof with excellent workability. In addition, an optical element or a circuit element having an excellent function can be easily and efficiently manufactured.
[0063]
【Example】
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
Example 1
A commercially available polyethylene terephthalate film (PET film; thickness 75 μm) was subjected to ultraviolet ozone cleaning (UV ozone cleaning) for 3 minutes using a “650W low-pressure mercury lamp” manufactured by Oak Co. A PET film having a silver fine particle layer (Ag layer; thickness 250 nm) coated with 1% by weight (water / alcohol) dispersion of silver fine particles (average primary particle diameter 20 nm) on one surface of Irradiated sample A) was obtained.
[0064]
From the upper surface of the Ag layer of the irradiated sample A, focusing on the surface (upper surface) of the Ag layer or the vicinity thereof, using a titanium / sapphire / femtosecond pulse laser device and an objective lens (magnification: 10 ×). , Ultrashort pulse laser (irradiation wavelength: 800 nm, pulse width: 150 × 10^-15Second, repetition: 200 kHz), irradiation energy (average output): 20 mW, focal point: Ag layer surface, irradiation spot diameter: about 20 μm, moving speed of irradiation sample A in a direction perpendicular to the irradiation direction: about 500 μm / Irradiated while moving in a line in seconds. Further, 15 lines having a width of 20 μm and a length of 8 mm were formed in parallel with the lines at intervals of 15 μm. As a result, the Ag layer portion of the irradiation sample A is different from the original Ag layer from the focal position (irradiation start position) where the irradiation of the ultrashort pulse laser is started to the focal position (irradiation end position) where the irradiation is stopped. A structural change portion (induced structure portion) having a structure was formed. Further, when a cross section was observed using a TEM (transmission electron microscope), silver fine particles were dispersed in the PET film up to a width of 8 μm and a depth of 100 nm.
[0065]
When the Ag layer is removed, the Ag layer carried on the PET film becomes the surface, so that it can be used as an electric circuit element as it is, and the silver fine particles carried inside the PET film are connected to the Ag film. It was confirmed that an electric circuit element can be obtained by forming a conductive portion.
[0066]
Next, the sample having this Ag layer was immersed in a 1.8 wt% hydrofluoric acid aqueous solution for 10 seconds, then taken out and washed with distilled water. As a result, all the Ag layer on the PET film was dissolved and removed, and Silver fine particles dispersed and supported in the PET film remained, and a diffraction grating (diffraction grating A) as shown in FIG. 3 was obtained.
[0067]
Moreover, when this diffraction grating A was irradiated with a He-Ne (helium-neon) laser having a wavelength of 632.8 nm, the appearance of transmission diffraction spots was confirmed.
[0068]
(Comparative Example 1)
As in Example 1, when the sample was not irradiated with an ultrashort pulse laser, the silver fine particles did not penetrate into the PET film, and the silver fine particles inside the PET film were obtained simply by laminating the silver fine particle layer on the PET film. Could not be supported.
[0069]
(Example 2)
A commercially available polycarbonate film (PC film; thickness 0.5 mm) was subjected to UV ozone cleaning for 3 minutes using an Oak “650W low-pressure mercury lamp”, and then one side of the PC film was coated with silicon. PC having 1 wt% (water / alcohol) dispersion of fine particles (average particle size of primary particles: 30 nm; “Aerosil 90” manufactured by Nippon Aerosil Co., Ltd.), dried, and having a silicon fine particle layer (Si layer; thickness 500 nm) A film (irradiated sample B) was obtained.
[0070]
From the upper surface of the Si layer of this irradiated sample B, in the same manner as in Example 1, the irradiated sample B was irradiated with an ultrashort pulse laser under the same conditions as in Example 1, and the cross section was observed using a TEM. Silicon fine particles (silica fine particles) were dispersed in the PC film up to a width of 18 μm and a depth of 60 μm.
[Brief description of the drawings]
FIG. 1 is a schematic bird's-eye view showing an example of a focused laser irradiation method of the present invention.
FIG. 2 is a schematic cross-sectional view showing an example of a substrate with a fine particle-supporting fine particle layer.
3 is a schematic cross-sectional view showing an example of a state after the fine particle layer on the base material is removed from the fine particle-supported fine particle layer-attached base material shown in FIG.
[Explanation of symbols]
1 Substrate with a fine particle layer having a fine particle support (base material with a fine particle support fine particle layer)
2 Fine particle layer (fine particle layer)
21 Irradiation part (structure change part) in fine particle layer 2
22 Unirradiated part in fine particle layer 2
3 Base material
41 Particulate support part (structure change part) in the substrate 3
42 Part not carrying fine particles (structure unchanged part) in the substrate 3
5 Focused laser
51 Pulse width is 10^-12Ultrashort pulse laser that is less than a second
52 Condensing lens
6 Focus position locus of focused laser 5
6a Irradiation start position of the focused laser 5
6b Irradiation end position of focused laser 5
6c Movement direction of the focal position of the focused laser 5

Claims (6)

A method for supporting fine particles on a base material, comprising the following steps (A) to (B).
Step (A): A step of forming a fine particle layer on the base material Step (B): Fine particles in the base material by laser irradiation with a ^focused pulse width of 10 ⁻¹² seconds or less from the fine particle layer side The process of introducing Furthermore, the supporting method of the microparticles | fine-particles to the base material of Claim 1 which has comprised the following process (C) as a post process of a process (B).
Step (C): Step of removing the remaining fine particle layer   The method for supporting fine particles on a substrate according to claim 1 or 2, wherein the substrate is a plastic substrate.   The method for supporting fine particles on a substrate according to any one of claims 1 to 3, wherein the fine particles are inorganic fine particles.   The method for supporting fine particles on a substrate according to claim 4, wherein the inorganic fine particles contain at least one metal atom selected from gold, silver, copper, platinum and titanium, or a silicon atom. An optical element in which a substrate on which fine particles are supported by the method for supporting fine particles on a substrate according to any one of claims 1 to 5 is used as a constituent element.

Images