Laser transfer film

Abstract

Disclosed is a laser-transferred film, which comprises a base layer, a thermally expandable light-absorbing layer, and an adhesive layer in this order, and which comprises one or more types of inorganic particles and organic particles on at least one surface of the base film. When a laser having a wavelength of 1,064 nm is irradiated onto the upper portion of the base film at a laser output range of 0.5 W to 10 W for a time period of 1 second or less, the thermally expandable light-absorbing layer and the adhesive layer expand to form a thermal expansion dome, and the thermal expansion dome has a height-to-diameter ratio of 0.1 to 1.

Description

[Technical field]

[0001] The present invention relates to a laser transfer film. [Background technology]

[0002] The laser transfer film includes a substrate film that maintains the film shape, a thermally expandable light absorbing layer that absorbs laser and expands, and an adhesive layer.

[0003] The transfer of a transfer object using a laser transfer film is a method in which, while maintaining the distance between the laser transfer film and the receiver, the heat-expandable light-absorbing layer is selectively expanded by irradiating it with a laser positioned above the base film, and the transfer object attached to the surface of the adhesive layer is transferred to the receiver.

[0004] The thermally expandable light absorbing layer forms an expansion structure in an expanded form by irradiation with a laser. In order to efficiently transfer the transfer body to a desired position on the receiver, the laser transfer film requires not only high transmittance of the base film during laser irradiation but also uniform size of the expansion structure over a wide range of laser output.

[0005] Therefore, in order to efficiently transfer the transfer material to the desired location on the receiver, it is necessary to find a laser transfer film that has a high transmittance of the base film and has expansion structures of uniform size over a wide laser output range. Summary of the Invention [Problem to be solved by the invention]

[0006] One aspect is to provide a laser transfer film having expansion structures of uniform size over a wide laser output range while having high transmittance through the base film to efficiently transfer the transfer material to a desired location on a receiver. [Means for solving the problem]

[0007] According to one aspect, A base film; A thermally expandable light absorbing layer; an adhesive layer, At least one surface of the base film contains one or more types of particles selected from inorganic particles and organic particles, When a laser having a wavelength of 1,064 nm is irradiated onto the upper portion of the base film at a laser output range of 0.5 W to 10 W for a time period of 1 second or less, the thermally expandable light absorbing layer and the adhesive layer expand to form a thermal expansion dome, The thermal expansion dome has a height to diameter ratio of 0.1 to 1. A laser transfer film is provided.

[0008] When a picosecond laser or a nanosecond laser is used to irradiate the area of ​​the thermally expandable light absorbing layer and the adhesive layer where 100 thermal expansion domes are to be formed, with a laser output range of 0.5 W to 10 W, 70 or more thermal expansion domes can be formed.

[0009] The substrate film has a light transmittance of 85% or more at a wavelength of 550 nm.

[0010] The surface of the base film has a 10-point average roughness (Rz) of 0.5 μm to 8 μm.

[0011] The particles are inorganic particles containing at least one selected from the group consisting of silica, calcium carbonate, titanium carbide, and zirconia, or The resin composition may also include organic particles containing one or more types selected from styrene-based, acrylic-based, olefin-based resins, and copolymer resins thereof.

[0012] The particles also have a thermal conductivity of 1.4 W / m·K or more.

[0013] The base film is A polyester resin core layer; a polyester-based resin skin layer on at least one surface of the polyester-based resin core layer, the skin layer including one or more types of particles selected from inorganic particles and organic particles; The content of the particles is 0.01 to 1.0% by weight based on 100% by weight of the total polyester resin contained in the polyester resin core layer and the polyester resin skin layer.

[0014] The thermally expandable light absorbing layer includes a binder and a light absorbing agent, The light absorbing agent also includes a near infrared absorbing dye having a maximum absorption wavelength of 900 nm to 1,200 nm.

[0015] The content of the light absorbing agent is 0.1 to 30 parts by weight based on 100 parts by weight of the thermally expandable light absorbing layer.

[0016] The coating amount of the heat-expandable light absorbing layer after drying is 0.5 g / m 2 or 9g / m 2 It is also.

[0017] The thickness of the thermally expandable light absorbing layer is also 0.4 μm to 10 μm.

[0018] The thermally expandable light absorbing layer and the adhesive layer are expanded to form a plurality of thermal expansion domes spaced apart from each other, The deviation of the diameter of the plurality of thermal expansion domes according to the following formula 1 is 10% or less: [Formula 1] Diameter deviation (%) = {(average diameter)-(measured diameter)} / (average diameter) x 100

[0019] The height deviation of the plurality of thermal expansion domes according to the following Equation 2 is 10% or less: [Formula 2] Height deviation (%) = {(average height)-(measured height)} / (average height) x 100

[0020] The thickness of the adhesive layer is 0.5 to 6 times the thickness of the thermally expandable light absorbing layer.

[0021] The present invention further includes a transfer body attached to the surface of the adhesive layer.

[0022] The transfer body also includes a semiconductor chip. Effect of the Invention

[0023] The laser transfer film according to one embodiment has a uniform expansion structure size over a wide range of laser output while having a high transmittance of the substrate film, and therefore can be efficiently transferred to a desired position on a receiver. [Brief description of the drawings]

[0024] [Figure 1] 1 is a cross-sectional view of a laser-transferred film according to an embodiment. [Diagram 2] 1 is a three-dimensional optical microscope photograph of the substrate film surface of the laser-transferred film produced in Example 1. [Diagram 3] 1 is a three-dimensional optical microscope photograph of the substrate film surface of the laser-transferred film produced according to Comparative Example 1. [Figure 4] 1A to 1C are diagrams for explaining the action and effect of the laser transfer film. [Diagram 5] 1 is a scanning electron microscope (SEM) image of the laser-transferred film manufactured according to Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The laser transfer film will be described in detail with reference to the embodiments and drawings of the present invention. It will be obvious to those skilled in the art that the embodiments are merely presented for the purpose of explaining the present invention in more detail, and the scope of the present invention is not limited by the embodiments.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

[0027] Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

[0028] In this specification, the phrase "at least one side" before a component means either "one side" or "both sides" of the component. In this specification, the phrase "at least one type," "one or more types," or "one or more" before a component complements the list of the entire components, but is not meant to complement the individual components described above.

[0029] As used herein, the term "and / or" is meant to include any and all combinations of one or more of the associated listed items. As used herein, the term "or" means "and / or."

[0030] In this specification, the term "comprise" is used to indicate that other components are not excluded, but that other components may be added and / or intervened, unless specifically stated to the contrary. In this specification, the term "combination thereof" is used to indicate a mixture or alloy of two or more components described above. In this specification, the term "based resin" is used to indicate a broad concept including "resin" and / or "derivative of resin".

[0031] In this specification, unless otherwise specified, the unit "parts by weight" refers to the weight ratio between each component.

[0032] In this specification, when an element is referred to as being disposed "on" another element, the element may be disposed directly on the other element, or there may be intervening elements between the elements, whereas when an element is referred to as being disposed "directly on" another element, there are no intervening elements.

[0033] In this specification, "laser transfer film" means a film that generates heat when irradiated with a laser, expands due to the heat so generated, and transfers a transfer object attached to the laser transfer film to a receiver film.

[0034] As used herein, "transfer" refers to the article that is transferred from the laser transfer film to the receiver film.

[0035] In this specification, the term "thermal expandability" refers to the property of expanding due to heat.

[0036] In this specification, the term "thermally expandable dome" refers to a convex structure formed by the expansion of a thermally expandable light-absorbing layer and an adhesive layer, and includes any structure having a geometrically perfect hemisphere or a similar convex structure.

[0037] According to one embodiment, the laser-transferred film includes a base film, a thermally expandable light absorbing layer, and an adhesive layer in this order. At least one surface of the base film includes at least one type of inorganic particles and organic particles. When a laser having a wavelength of 1,064 nm is irradiated onto the upper portion of the base film at a laser output range of 0.5 W to 10 W for a time period of 1 second or less, the thermally expandable light absorbing layer and the adhesive layer expand to form a thermal expansion dome, and the thermal expansion dome has a height to diameter ratio of 0.1 to 1.

[0038] The laser transfer film can efficiently transfer the transfer material to a desired location on a receiver to form a thermal expansion dome on the surface layer with a height to diameter ratio of 0.1 to 1 in a wide laser power range of 0.5 W to 10 W.

[0039] FIG. 1 is a cross-sectional view of a laser-transferred film according to an embodiment.

[0040] Referring to FIG. 1, a laser transfer film 10 according to an embodiment includes a base film 11, a thermally expandable light absorbing layer 12, and an adhesive layer 13 in this order.

[0041] In a series of processes such as (i) manufacturing the laser transfer film, (ii) laminating the laser transfer film with the receiver film, and (iii) removing the laser transfer film from the receiver film after the transfer is completed, the base film 11 plays a role of supporting other layers having functionality, such as the other layers constituting the laser transfer film, the thermally expandable light absorbing layer 12, the adhesive layer 13, and optionally a transfer body (e.g., an LED (light-emitting diode) chip) attached on the adhesive layer.

[0042] The base film 11 is generally also a polymer film.

[0043] The polymer film also has both optical transparency and thermal stability.

[0044] The polymer film may include a polycarbonate-based resin, a polyolefin-based resin, a polyvinyl-based resin, a polyester-based resin, or a combination thereof. For example, the polymer film may be a polyester-based resin. The polyester-based resin may include a linear polyester. For example, the polyester-based resin may be polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, or polyethylene-2,6-naphthalenedicarboxylate (PEN).

[0045] The polyester-based base material is also a polyester resin obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol. Examples of the aromatic dicarboxylic acid include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid. Examples of the aliphatic glycol include ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, and neopentyl glycol. The polyester resin may be a copolymer containing a third component by using two or more of the examples of the aromatic dicarboxylic acid and the aliphatic glycol.

[0046] The polyester-based substrate may be a uniaxially oriented film or a biaxially oriented film, which has high transparency and is excellent in productivity and processability.

[0047] The light transmittance of the base film 11 at a wavelength of 550 nm is 85% or more. The base film 11 has high light transmittance, and the position of the transfer body attached to the surface layer of the laser transfer film 10 can be accurately confirmed by using the vision of a laser device.

[0048] The base film 11 also contains one or more types of particles selected from inorganic particles and organic particles. At least one surface of the base film 11 also contains one or more types of particles selected from inorganic particles and organic particles.

[0049] The 10-point average roughness (Rz) of the surface of the base film 11 is 0.5 μm to 8 μm. If the 10-point average roughness (Rz) of the surface of the base film 11 is smaller than 0.5 μm, the expansion effect by the laser is small, whereas if the 10-point average roughness (Rz) of the surface of the base film 11 is larger than 8 μm, problems such as increased haze and reduced transmittance may occur.

[0050] The particles are also inorganic particles containing one or more selected from silica, calcium carbonate, titanium carbide, and zirconia. The shape of the inorganic particles may be any shape such as a sphere, a block, a rod, or a plate, but is not limited thereto. In addition, the hardness, ratio, and color of the inorganic particles are not limited. If necessary, two or more types of the inorganic particles may be used in parallel. For example, the inorganic particles are silica particles.

[0051] Alternatively, the particles may include organic particles containing at least one selected from styrene resin, acrylic resin, olefin resin, and copolymer resins thereof. Examples of acrylic resins include polymers or copolymers (co)polymerized with acrylic acid monomers or methacrylic acid monomers, such as acrylate, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, normal butyl methacrylate, and normal butyl methyl methacrylate. Examples of olefin resins include polymers or copolymers (co)polymerized with monomers such as ethylene or polypropylene. The organic particles may be homopolymers or may include multi-layered multicomponent (co)polymers in which other monomers are coated on a homopolymer. For example, the organic particles may be polymethyl methacrylate particles.

[0052] The thermal conductivity of the particles is 1.4 W / m K or more. If the thermal conductivity of the particles is high as described above, the heat generated in the light-to-heat conversion layer can be effectively transferred to the surface of the base film, and a thermal expansion dome with a height-to-diameter ratio of 0.1 to 1 can be easily formed on the surface layer of the laser transfer film 13. In addition, when forming a primer layer on the surface of the base film 11, a resin containing particles can be used to increase the particle content on the surface of the base film 11.

[0053] The base film 11 includes a polyester-based resin core layer and a polyester-based resin skin layer on at least one surface of the polyester-based resin core layer, the polyester-based resin skin layer including one or more inorganic particles and organic particles, and the content of the particles is 0.01 to 1.0 wt % based on 100 wt % of the total polyester resin included in the polyester-based resin core layer and the polyester-based resin skin layer.

[0054] If the content of the particles is less than 0.01 wt % based on 100 wt % of the total polyester resin contained in the polyester resin core layer and the polyester resin skin layer, the running properties and coatability of the base film 11 will be poor, and if the content of the particles is more than 1.0 wt %, the surface smoothness of the base film 11 will be poor.

[0055] The thickness of the base film 11 is 50 μm to 500 μm, for example, 50 μm to 150 μm. If the thickness of the base film 11 is less than 50 μm, there is a concern that the film may be deformed by heat during the drying process, and if the thickness of the base film 11 is more than 500 μm, there is a concern that the heat may not be sufficiently transferred and the film may not be cured.

[0056] The base film 11 may be subjected to a primer treatment to improve adhesion to the heat-expandable light-absorbing layer 12, may be subjected to stretching, heat treatment or water-repellent treatment to improve thermal stability, and may contain a small amount of fine particles or filler or be subjected to water-repellent treatment to adjust light transmittance.

[0057] A thermal expansion dome may be formed on the thermally expandable light absorbing layer 12 and the adhesive layer 13 when a laser having a wavelength of 1,064 nm is irradiated on the upper surface of the base film 11 at a laser output range of 0.5 W to 10 W for a time of 1 second or less. The thermal expansion dome has a ratio of height to diameter of 0.1 to 1. If the ratio of height to diameter of the thermal expansion dome is less than 0.1, the thermally expandable light absorbing layer 12 and the adhesive layer 13 are difficult to expand and a thermal expansion dome is not formed, whereas if the ratio of height to diameter of the thermal expansion dome exceeds 1, the light-to-heat conversion layer and the adhesive layer may be torn.

[0058] When the thermally expandable light absorbing layer 12 and the adhesive layer 13 are irradiated in an area where 100 thermal expansion domes are to be formed using a picosecond laser or a nanosecond laser at a laser output range of 0.5 W to 10 W, 60 or more thermal expansion domes can be formed. When the thermally expandable light absorbing layer 12 and the adhesive layer 13 are irradiated in an area where 100 thermal expansion domes are to be formed using a picosecond laser or a nanosecond laser at a laser output range of 0.5 W to 10 W at a speed of several mm / s, 60 or more thermal expansion domes can be stably formed.

[0059] The thermally expandable light absorbing layer 12 includes a binder and a light absorbing agent.

[0060] During the transfer of a transfer object to a receiver film using a laser transfer film, the thermally expandable light absorbing layer 12 absorbs light (laser) with the light absorbent contained in the thermally expandable light absorbing layer 12 and converts it into heat, thereby providing the force for transferring the transfer object to the receiver film.

[0061] The binder has good compatibility with the light absorbing agent, and allows the heat-expandable light absorbing layer 12 to contain a larger amount of the light absorbing agent without significantly reducing the adhesion of the heat-expandable light absorbing layer 12 to the base film 11.

[0062] The binder also includes a thermosetting resin.

[0063] The binder may include a polyester resin, an acrylic resin, a polyurethane resin, a melamine resin, or a combination thereof. For example, the binder may be an acrylic resin. The acrylic resin may include polyacrylate, polymethacrylate, polyacrylic acid, a copolymer of each of the above materials with polyolefin, or a combination thereof.

[0064] The light absorbent absorbs light in the infrared, visible and / or ultraviolet regions of the electromagnetic spectrum and converts the absorbed light into heat. The light absorbent is one that highly absorbs light in the wavelength region or specific wavelength used for transfer, but transmits or reflects light in other wavelength regions or wavelengths other than the specific wavelength, and absorbs the light to a much lesser extent.

[0065] The light absorbing agent also includes a near infrared absorbing dye having a maximum absorption wavelength of 900 nm to 1,200 nm.

[0066] For example, the near infrared absorbing dye having a maximum absorption wavelength of 900 nm to 1,200 nm includes a diimmonium salt dye represented by the following Chemical Formula 1:

[0067] [ka]

[0068] In the above Chemical Formula 1, n is 1 or 2; R 1 Or R 8 are each independently a substituted or unsubstituted C 1 -C 10 R is a straight or branched alkyl 1 Or R 8 When substituted, the substituents are cyano, nitro, carboxyl, sulfoxy, halogen, hydroxyl, C 1 -C 8an alkoxy group, an alkoxyalkoxy group, an aryloxy group, or an alkylamino group; X - is a fluoroalkyl phosphate anion represented by the following chemical formula 2.

[0069] [ka]

[0070] In the above Chemical Formula 2, x is 0 or 1, y is 1, 2 or 3; z is 6-y; R 9 Or R 13 are each independently hydrogen or fluorine.

[0071] The content of the light absorbent is 0.1 to 30 parts by weight based on 100 parts by weight of the thermally expandable light absorbing layer 12. For example, the content of the light absorbent is 0.5 to 30 parts by weight based on 100 parts by weight of the thermally expandable light absorbing layer 12. When the content of the light absorbent is within the above range, the light having a laser wavelength is absorbed to expand, and a laser transfer film having excellent transfer properties can be provided.

[0072] The coating amount of the thermally expandable light absorbing layer 12 after drying is 0.5 g / m 2 or 9g / m 2 For example, the thermally expandable light absorbing layer 12 has a coating amount of 1 g / m 2 or 9g / m 2 But maybe 2g / m 2 or 9g / m 2 Or 3g / m 2 or 9g / m 2 When the coating amount of the thermally expandable light absorbing layer 12 after drying is within the above range, a uniform coating layer is formed, and a laser transfer film having excellent transfer properties can be provided.

[0073] The thermally expandable light absorbing layer 12 is as thin as possible because localized heat absorption is advantageous for transfer. For example, the thermally expandable light absorbing layer 12 may have a thickness of 0.4 μm to 10 μm.

[0074] The thermally expandable light absorbing layer 12 and the adhesive layer 13 expand to form a plurality of thermal expansion domes spaced apart from each other, and the deviation of the diameters of the thermal expansion domes according to Equation 1 is 10% or less:

[0075] [Formula 1] Diameter deviation (%) = {(average diameter)-(measured diameter)} / (average diameter) x 100

[0076] The height deviation of the plurality of thermal expansion domes according to the following Equation 2 is 10% or less:

[0077] [Formula 2] Height deviation (%) = {(average height)-(measured height)} / (average height) x 100

[0078] The laser transfer film 10 further includes a transfer body attached to the surface of the adhesive layer 13 .

[0079] The adhesive layer 13 serves to attach the transfer body to the laser transfer film 10 .

[0080] If the adhesive strength of the laser transfer film 10 (specifically, the adhesive strength of the adhesive layer) is weaker than that of the receiver film, a problem occurs in which the transfer body is transferred to the receiver film side when the two films are laminated. Conversely, if the adhesive strength of the laser transfer film 10 is excessively stronger than that of the receiver film, a problem occurs in which transfer does not occur even when laser is irradiated.

[0081] The adhesive strength of the laser thermal transfer film 10 is from 5 gf / in (gram-force / inch) to 500 gf / in, and can be adjusted according to the adhesive strength of the receiver film.

[0082] The adhesive layer 13 may contain a polyacrylate-based resin, a polymethacrylate-based resin, an epoxy-based resin, a polystyrene-based resin, a polyurethane-based resin, a polysulfone-based resin, a polyester-based resin, a polyimide-based resin, a polysilicon-based resin, or a combination thereof.

[0083] The thickness of the adhesive layer 13 is 0.5 to 6 times the thickness of the thermally expandable light absorbing layer 12 .

[0084] The decal may be organic, inorganic, organometallic, or a combination thereof.

[0085] Examples of materials that may be selectively patterned into the transfer body include colorants (including pigments and / or dyes dispersed in a binder), polarizers, liquid crystal materials, particles (including spacers for liquid crystal displays, magnetic particles, insulating particles and / or conductive particles), light emitting materials (including phosphors and / or organic electroluminescent materials), light receiving materials that may be incorporated into light emitting elements (e.g., electroluminescent elements), hydrophobic materials (including partition banks for inkjet receptors), hydrophilic materials, multilayer stacks (e.g., multilayer element structures such as organic electroluminescent elements), microstructured layers, nanostructured layers, photoresists, metals, polymers, adhesives, binders, biological materials, or combinations thereof.

[0086] The transfer may also include one or more materials useful for display applications, particularly color filter fabrication.

[0087] The transfer body may also include a semiconductor chip such as an LED chip.

[0088] FIG. 4 is a diagram for explaining the action and effect of the laser transfer film 10. As shown in FIG.

[0089] 4, the laser transfer film 10 and the receiver film 20 are laminated together. The LED chip 30 is attached to the adhesive layer 13 of the laser transfer film 10.

[0090] In addition, a laser is locally irradiated onto the laser transfer film 10. At this time, the thermally expandable light absorbing layer 12 of the laser transfer film 10 generates heat and expands, forming a cavity C between the thermally expandable light absorbing layer 12 and the base film 11, and the thermally expandable light absorbing layer 12 and the adhesive layer 13 expand to form a thermal expansion dome.

[0091] Thereafter, the LED chip 30 attached to the adhesive layer 13 on the thermally expandable light absorbing layer 12 moves toward the receiver film 20 due to the expansion of the thermally expandable light absorbing layer 12, and is then adhered to the adhesive layer 23 of the receiver film 20 (which is disposed on the electrode layer 22 disposed on the base layer 21 of the receiver film 20).

[0092] Thereafter, the LED chip 30 is separated from the adhesive layer 13 of the laser transfer film 10 and then attached to the adhesive layer 23 of the receiver film 20 .

[0093] As a result, the LED chips 30 are transferred from the laser transfer film 10 to the receiver film 20 .

[0094] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to such examples. EXAMPLES

[0095] Example 1: Manufacturing of laser transfer film Sequentially, a polyethylene terephthalate resin core layer containing no particles and a polyethylene terephthalate resin skin layer containing silica particles (average particle size: 2 μm, thermal conductivity: 1.4 W / m·K) were formed on both sides of the core layer by biaxial stretching to produce a polyethylene terephthalate base film having a thickness of about 100 μm. At this time, the content of the silica particles was 0.01 wt % based on 100 wt % of the total polyethylene terephthalate resin contained in the core layer and the skin layer. The thickness of the core layer was about 90 μm, and the thickness of the skin layers on both sides was about 5 μm. The 10-point average roughness (Rz) of the skin layer was about 0.5 μm.

[0096] Separately, a composition for forming a thermally expandable light absorbing layer having a solid content of 20 wt% was prepared by mixing a thermosetting melamine resin (Cymel 303 (Cytec)) as a binder, a diimonium salt dye (NIR1000A (Kyung In Industrial)) as a light absorbing agent, and a solvent (a mixture of cyclohexanone and methyl ethyl ketone in a weight ratio of 40:100). At this time, the content of the diimonium salt dye was 2 parts by weight based on 100 parts by weight of the thermally expandable light absorbing layer.

[0097] Separately, a thermosetting acrylic resin (SA3000 (Sanwa Paint Co., Ltd.)) and a solvent (a mixture of cyclohexanone and methyl ethyl ketone in a weight ratio of 40:100) were mixed to prepare a composition for forming an adhesive layer having a solid content of 35 wt%.

[0098] The composition for forming a thermally expandable light absorbing layer was applied to the polyethylene terephthalate base film using a Meyer bar, and then thermally dried at a temperature of 130° C. for 1 minute. The coating amount after drying was 3 g / m 2 A thermally expandable light absorbing layer having an average thickness of 2.3 μm was formed. Then, the adhesive layer forming composition was applied onto the thermally expandable light absorbing layer with an applicator, and then thermally dried at a temperature of 110° C. for 2 minutes to form an adhesive layer having an average thickness of 2 μm, thereby producing a laser transfer film. At this time, the adhesive strength of the adhesive layer was 15 gf / inch.

[0099] Example 2: Manufacturing of laser transfer film A laser transfer film was manufactured in the same manner as in Example 1, except that the content of silica particles was 0.02 wt% based on 100 wt% of the total polyethylene terephthalate resin contained in the core layer and the skin layer. At this time, the 10-point average roughness (Rz) of the skin layer was about 2.1 μm.

[0100] Example 3: Manufacturing of laser transfer film A laser transfer film was manufactured in the same manner as in Example 1, except that the content of silica particles was 0.1 wt% based on 100 wt% of the total polyethylene terephthalate resin contained in the core layer and the skin layer. At this time, the 10-point average roughness (Rz) of the skin layer was about 3.0 μm.

[0101] Example 4: Manufacturing of laser transfer film A laser transfer film was manufactured in the same manner as in Example 1, except that the content of silica particles was 0.5 wt% based on 100 wt% of the total polyethylene terephthalate resin contained in the core layer and the skin layer. At this time, the 10-point average roughness (Rz) of the skin layer was about 5.2 μm.

[0102] Example 5: Manufacturing of laser transfer film A laser transfer film was manufactured in the same manner as in Example 1, except that the content of silica particles was 1.0 wt% based on 100 wt% of the total polyethylene terephthalate resin contained in the core layer and the skin layer. At this time, the 10-point average roughness (Rz) of the skin layer was about 7.8 μm.

[0103] Example 6: Manufacturing of laser transfer film A laser-transferred film was manufactured in the same manner as in Example 1, except that a polyethylene terephthalate resin skin layer containing polystyrene (PS) particles (average particle size: 2 μm, thermal conductivity: 0.1 W / m K) was formed on both sides of a polyethylene terephthalate resin core layer, and the content of polymethyl methacrylate (PMMA) particles was 0.01 wt% based on 100 wt% of the total polyethylene terephthalate resin contained in the core layer and skin layer. At this time, the 10-point average roughness (Rz) of the skin layer was about 0.7 μm.

[0104] Example 7: Manufacturing of laser transfer film A laser transfer film was manufactured in the same manner as in Example 6, except that the particle content was 0.5 wt% based on 100 wt% of the total polyethylene terephthalate resin contained in the core layer and skin layer. At this time, the 10-point average roughness (Rz) of the skin layer was about 5.5 μm.

[0105] Example 8: Manufacturing of laser transfer film A laser transfer film was manufactured in the same manner as in Example 6, except that the content of PMMA particles was 1.0 wt% based on 100 wt% of the total polyethylene terephthalate resin contained in the core layer and skin layer. At this time, the 10-point average roughness (Rz) of the skin layer was about 7.6 μm.

[0106] Comparative Example 1: Production of laser transfer film A laser-transferred film was produced in the same manner as in Example 1, except that a polyethylene terephthalate resin core layer not containing particles and a polyethylene terephthalate resin skin layer not containing particles were formed on both sides of the core layer to produce a polyethylene terephthalate base film having a thickness of about 100 μm. At this time, the 10-point average roughness (Rz) of the skin layer was about 0.2 μm.

[0107] Comparative Example 2: Production of laser transfer film A laser transfer film was manufactured in the same manner as in Example 1, except that the content of silica particles was 2.0 wt% based on 100 wt% of the total polyethylene terephthalate resin contained in the core layer and the skin layer. At this time, the 10-point average roughness (Rz) of the skin layer was about 12 μm.

[0108] Comparative Example 3: Production of laser transfer film A laser transfer film was manufactured in the same manner as in Example 6, except that the content of PMMA particles was 2.0 wt% based on 100 wt% of the total polyethylene terephthalate resin contained in the core layer and skin layer. At this time, the 10-point average roughness (Rz) of the skin layer was about 10 μm.

[0109] Evaluation example 1: Evaluation of physical properties of laser transfer film The physical properties of the laser-transferred films produced in Examples 1 to 8 and Comparative Examples 1 to 3 were measured by the following methods, and the results are shown in Table 1, FIG. 2, FIG. 3, and FIG. (1) Base film transmittance (%(@550nm)) For each substrate film of the laser transfer film, the transmittance was measured in the range of 300 nm to 1,200 nm using a Shimadzu UV-VIS-NIR spectrophotometer (Model UV-3600), and the light transmittance at a wavelength of 550 nm was recorded. The results are shown in Table 1. (2) Whether or not particles are present on the surface of the base film The substrate films of the laser-transferred films prepared in Example 1 and Comparative Example 1 were observed using a three-dimensional optical microscope to see whether particles were present on the surface. The results are shown in Figures 2 and 3, respectively. (3) Thermal expansion dome characteristics of the thermal expansion light absorbing layer and adhesive layer For the thermally expandable light absorbing layer 12 region and adhesive layer 13 region where 100 thermal expansion domes were to be formed in each laser transfer film 10, a Nd:YAG 1,064 nm picosecond laser device was used to irradiate the upper part of the base film 11 with laser energy ranging from 0.1 W to 10 W for several milliseconds (ms). A laser scanner device (SUPERSCAN V-15 (RAYLSE)) was used for the laser irradiation, and the laser irradiation position was created using a marking program (welMark 3), and a program was created and adjusted so that the laser was irradiated at 10 x 10 positions with a constant pitch (500 μm).

[0110] As can be seen from Fig. 4, the thermally expandable light absorbing layer 12 and the adhesive layer 13 expanded to form a thermal expansion dome ("TD"). The side surface of the formed thermal expansion dome ("TD") was photographed using a scanning electron microscope (SEM).

[0111] 5 is a SEM image of the laser-transferred film manufactured according to Example 1. Referring to FIG. 5, it can be seen that a plurality of thermal expansion domes are formed on the surface layer of each laser-transferred film 10.

[0112] Similarly to Example 1, the number of thermal expansion domes ("TD") formed on the surface of the laser-transferred films manufactured by Examples 2 to 8 and Comparative Examples 1 to 3 was counted, and the diameter ("d") and height ("t") were measured. Specifically, the diameter ("d") and height ("t") of each thermal expansion dome ("TD") formed on a 3 cm x 3 cm area on the surface of each laser-transferred film where 100 thermal expansion domes (spacing between "TD": 300 μm) were to be formed were measured, and the ratio of height to diameter ("t / d") was calculated. In addition, the average diameter and average height were calculated from the measured diameter ("d") and height ("t") of each thermal expansion dome ("TD"), and the deviation between the diameter and height of each thermal expansion dome was calculated by the following formula 1 and formula 2, respectively. The results are shown in Table 1.

[0113] [Formula 1] Diameter deviation (%) = {(average diameter)-(measured diameter)} / (average diameter) x 100

[0114] [Formula 2] Height deviation (%) = {(average height)-(measured height)} / (average height) x 100

[0115] [Table 1]

[0116] Referring to Table 1, in the region of the laser-transferred film manufactured in Examples 1 to 8 where 100 thermal expansion domes were to be formed, when a laser having a wavelength of 1,064 nm was irradiated for several milliseconds (ms) on the upper part of the base film at a laser output range of 0.5 W to 10 W, about 90 thermal expansion domes with a height to diameter ratio of 0.1 to 0.9 were formed. The deviations of the diameter and height of each thermal expansion dome were 5% or less and 6% or less, respectively.

[0117] In comparison, in Comparative Example 1, in which a polyethylene terephthalate (PET) substrate without particles was used in the skin layer, about 60 thermal expansion domes with a height to diameter ratio of 0.2 to 0.3 were formed in the thermal expansion light absorbing layer 12 region of the manufactured laser transfer film in which 100 thermal expansion domes were to be formed, when a laser with a wavelength of 1,064 nm was irradiated for several milliseconds (ms) at a laser output range of 3 W to 9 W on the upper part of the substrate film. The deviations of the diameter and height of each thermal expansion dome were 12% and 15%, respectively.

[0118] In Comparative Examples 2 and 3, in which a PET substrate with a particle content of 2.0% by weight was used for the skin layer, when a laser having a wavelength of 1,064 nm was irradiated for several milliseconds (ms) on the upper part of the substrate film in the region of the thermally expandable light absorbing layer 12 where 100 thermal expansion domes were to be formed in the manufactured laser transfer film, about 60 thermal expansion domes with a height to diameter ratio of 0.7 to 0.9 were formed. The deviations of the diameter and height of each thermal expansion dome were 11% or more and 13% or more, respectively.

[0119] Compared with the laser-transferred films produced in Examples 1 to 8, the laser-transferred films produced in Comparative Examples 1 to 3 had higher lower or upper laser output limits at which thermal expansion domes were formed, the laser output range was narrower, and fewer thermal expansion domes were formed.

[0120] As a result, when the laser-transferred films produced in Examples 1 to 8 were irradiated with a 1,064 nm wavelength laser over a wider laser output range for several milliseconds (ms), compared to the laser-transferred films produced in Comparative Examples 1 to 3, it was confirmed that many thermal expansion domes with height-to-diameter ratios of 0.1 to 0.9 were formed, and that the deviation in diameter and height of each thermal expansion dome formed was small, and that the diameter and height of each thermal expansion dome was uniform.

Claims

1. A base film; A thermally expandable light absorbing layer; an adhesive layer, At least one surface of the base film contains one or more types of particles selected from inorganic particles and organic particles, When a laser having a wavelength of 1,064 nm is irradiated onto the upper portion of the base film at a laser output range of 0.5 W to 10 W for a time period of 1 second or less, the thermally expandable light absorbing layer and the adhesive layer expand to form a thermal expansion dome, The thermal expansion dome has a height to diameter ratio of 0.1 to 1.

2. 2. The laser transfer film of claim 1, wherein when a picosecond or nanosecond laser is used to irradiate an area of ​​the thermally expandable light absorbing layer and the adhesive layer in which 100 thermal expansion domes are to be formed, with a laser output range of 0.5 W to 10 W, 70 or more of the thermal expansion domes are formed.

3. The laser transfer film according to claim 1 , wherein the base film has a light transmittance of 85% or more at a wavelength of 550 nm.

4. 2. The laser transfer film according to claim 1, wherein the surface of the base film has a 10-point average roughness (Rz) of 0.5 μm to 8 μm.

5. the particles are inorganic particles containing at least one selected from the group consisting of silica, calcium carbonate, titanium carbide, and zirconia; or The laser transfer film according to claim 1 , comprising organic particles containing at least one selected from the group consisting of styrene-based resins, acrylic-based resins, olefin-based resins, and copolymer resins thereof.

6. The laser transfer film according to claim 1 , wherein the particles have a thermal conductivity of 1.4 W / m·K or more.

7. The base film is A polyester resin core layer; a polyester-based resin skin layer on at least one surface of the polyester-based resin core layer, the polyester-based resin skin layer including one or more types of particles selected from inorganic particles and organic particles; 2. The laser transfer film of claim 1, wherein the content of the particles is 0.01 to 1.0% by weight based on 100% by weight of the total polyester resin contained in the polyester resin core layer and the polyester resin skin layer.

8. The thermally expandable light absorbing layer includes a binder and a light absorbing agent, The laser transfer film according to claim 1 , wherein the light absorber comprises a near-infrared absorbing dye having a maximum absorption wavelength of 900 nm to 1,200 nm.

9. The laser transfer film according to claim 8, wherein the content of the light absorbing agent is 0.1 to 30 parts by weight based on 100 parts by weight of the thermally expandable light absorbing layer.

10. The coating amount of the thermally expandable light absorbing layer after drying is 0.5 g / m ２ or 9 g / m ２ The laser transfer film according to claim 1 ,

11. The laser transfer film according to claim 1 , wherein the thermally expandable light absorbing layer has a thickness of 0.4 μm to 10 μm.

12. The thermally expandable light absorbing layer and the adhesive layer are expanded to form a plurality of thermal expansion domes spaced apart from each other, 2. The laser transfer film according to claim 1, wherein the deviation of the diameter of the thermal expansion domes according to the following formula 1 is 10% or less: [Formula 1] Diameter deviation (%)={(average diameter)-(measured diameter)} / (average diameter)×100.

13. 13. The laser transfer film according to claim 12, wherein the deviation in height of the thermal expansion domes according to the following formula 2 is 10% or less: [Formula 2] Height deviation (%) = {(average height) - (measured height)} / (average height) x 100.

14. The laser transfer film according to claim 12 , wherein the thickness of the adhesive layer is 0.5 to 6 times the thickness of the heat-expandable light absorbing layer.

15. The laser transfer film according to claim 1 , further comprising a transfer body attached to the surface of the adhesive layer.

16. The laser transfer film according to claim 15 , wherein the transfer body includes a semiconductor chip.

Images