JP2020025089A - Led device, manufacturing method thereof, and laminate - Google Patents

Abstract

To provide an LED device capable of suppressing light deterioration of a sealing portion, a manufacturing method of an LED device capable of easily manufacturing the above-described LED device, and a laminate that is a component that enables easy manufacture of the above-described LED device.SOLUTION: An LED device includes a board, an LED element arranged on the board, and a sealing portion provided to cover the light emitting surface of the LED element. The sealing portion includes a first sealing portion and a second sealing portion. The first sealing portion is fused to the light emitting surface, and the second sealing portion surrounds the periphery of the LED element and the first sealing portion in a plan view. A formation material of a portion in which the light emitting surface is fused in the first sealing portion is a crystalline fluororesin.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an LED device, a method for manufacturing an LED device, and a laminate.

  As an LED device including an LED (Light Emitting Diode) element, a device having a structure in which an LED element is sealed with a resin sealing material is known. In the LED device having such a configuration, the sealing material protects the LED element from physical impact. Further, the sealing material shields a gas such as oxygen or water vapor that deteriorates the LED element or the electrode. Therefore, an LED device in which an LED element is sealed with a resin sealing material is a device which is hardly damaged and has high reliability.

  As such an LED device, for example, an LED element, a case accommodating the LED element, a sealing material filled in the case, and an inorganic glass lens placed on the case so as to cover the sealing material are used. A device including the same is known (for example, see Patent Document 1).

JP 2014-11364 A

  However, in an LED device that emits high-output light, the light emitted from the LED element may cause deterioration of the sealing material (light deterioration). In particular, in a UV-LED device provided with a UV-LED element that emits ultraviolet light, the photodegradation of the sealing material is apt to progress, and improvement has been demanded.

  The present invention has been made in view of such circumstances, and has as its object to provide an LED device capable of suppressing light deterioration of a sealing portion. Another object of the present invention is to provide a method for manufacturing an LED device that can easily manufacture the above-described LED device. Another object of the present invention is to provide a laminate that is a component that enables the above-described LED device to be easily manufactured.

  In order to solve the above problem, one embodiment of the present invention includes a substrate, an LED element provided over the substrate, and a sealing portion provided over a light exit surface of the LED element. The sealing portion has a first sealing portion and a second sealing portion, the first sealing portion is fused to the light emitting surface, and the second sealing portion is a plan view. The present invention provides an LED device which surrounds the periphery of the LED element and the first sealing portion, and a material for forming a portion of the first sealing portion fused to the light emitting surface is a crystalline fluororesin.

  In one aspect of the present invention, the second sealing portion may be formed using a condensation polymerization type silicone resin as a forming material.

  In one embodiment of the present invention, the first sealing portion is a laminate of a light-transmitting optical member and a resin layer formed of the crystalline fluororesin, and the resin layer is It may be configured to be fused to the emission surface.

  In one aspect of the present invention, the first sealing portion may be made of a crystalline fluororesin.

  In one embodiment of the present invention, the crystalline fluororesin may have a melting point of 100 ° C. or more and 278 ° C. or less.

  In one embodiment of the present invention, the crystalline fluororesin may have a structure containing a chlorine atom as a substituent.

  In one embodiment of the present invention, the crystalline fluororesin may have a refractive index of 1.36 or more.

  One embodiment of the present invention is a step of forming a laminate of a light-transmitting optical member and a resin layer using a fluororesin as a forming material; Provided is a method for manufacturing an LED device, comprising: a step of heating while being brought into contact with an emission surface to thermally fuse the resin layer to the LED element; and a step of sealing a side surface of the LED element with a sealing resin. .

  In one embodiment of the present invention, the manufacturing method may be such that the sealing resin is a silicone resin.

  One embodiment of the present invention is a laminate of an optical member having a light-transmitting property and a resin layer formed using a fluororesin, and the resin layer has a thickness of 10 μm or more and 100 μm or less. The lower temperature of the melting point and the glass transition point of the forming material is higher than the melting point of the fluororesin, and the total light transmittance of the laminate in the wavelength band of 250 nm or more and 700 nm or less is 70% or more in the entire range. Provide body.

  ADVANTAGE OF THE INVENTION According to this invention, the LED device which can suppress the optical degradation of a sealing part can be provided. Further, it is possible to provide an LED device manufacturing method capable of easily manufacturing the above-described LED device. In addition, it is possible to provide a laminate that is a component that can easily manufacture the above-described LED device.

It is a schematic sectional view showing LED device 1 of this embodiment. FIG. 4 is a process chart illustrating a method for manufacturing the LED device 1 of the embodiment. FIG. 4 is a process chart illustrating a method for manufacturing the LED device 1 of the embodiment. FIG. 4 is a process chart illustrating a method for manufacturing the LED device 1 of the embodiment. FIG. 4 is a process chart illustrating a method for manufacturing the LED device 1 of the embodiment. It is a schematic sectional drawing which shows the LED device 2 of a modification. 4 is a graph showing the results of Example 1. 9 is a graph showing the results of Example 2. 9 is a graph showing the results of Comparative Example 2. It is process drawing which shows the manufacturing method of the laminated body of a modification. It is process drawing which shows the manufacturing method of the laminated body of a modification.

  Hereinafter, the LED device according to the present embodiment will be described with reference to FIGS. In all of the following drawings, dimensions, ratios, and the like of the components are appropriately changed in order to make the drawings easy to see.

  FIG. 1 is a schematic sectional view showing an LED device 1 according to the present embodiment. As shown in the drawing, the LED device 1 of the present embodiment has a substrate 10, an LED element 20, and a sealing portion 30A.

(substrate)
The substrate 10 is a substrate having electrodes 11 and wiring (not shown). The electrodes 11 and the wires of the substrate 10 are used for being electrically connected to the LED elements 20 to be mounted.

  The substrate 10 is not particularly limited as long as it is generally used as a substrate of an LED device. Examples of the substrate 10 include a thermoplastic resin such as a nylon resin and a liquid crystal polymer (LCP), a thermosetting resin such as an epoxy resin and a polyimide resin, alumina, aluminum nitride, and LTCC (Low-Temperature Co-fired). Ceramics such as ceramics and low-temperature co-fired ceramics) are preferably used.

  The substrate 10 may have light reflectivity or may not have light reflectivity. The optical characteristics of the substrate 10 can be appropriately selected according to the design of the device.

(LED element)
The LED element 20 is disposed on the substrate 10 with the light exit surface 20a facing the opposite side of the substrate 10.

  The “light emitting surface 20 a” of the LED element 20 is a surface of the LED element 20 connected by the flip chip method on the opposite side to the surface on which the electrode 21 is provided. The LED element 20 has a basic structure in which an n-type semiconductor layer, a p-type semiconductor layer, and the like are sequentially stacked on a single crystal substrate. In the LED element 20, the surface of the single crystal substrate corresponds to the light emitting surface 20a.

The LED element 20 can be used without any particular limitation as long as it has a generally known structure. Examples of the LED element 20 include a blue LED, a red LED, a green LED, and an ultraviolet LED.
In this specification, the term “ultraviolet light” means light having a wavelength of 400 nm or less.

The LED element 20 is connected to the substrate 10 in a flip-chip manner. The LED element 20 is connected to the electrode 11 on the substrate 10 by solder.
One or more LED elements 20 are provided on one substrate 10.

(Sealing part)
The sealing portion 30A is provided so as to cover the light emitting surface 20a of the LED element 20. The sealing portion 30A seals the LED element 20 together with the substrate 10.

  In this specification, “sealing” refers to shielding the LED element 20 as an object from the outside air. That is, in the LED device 1, the sealing portion 30A shields the LED element 20 from the outside air together with the substrate 10.

  The sealing portion 30A has a first sealing portion 31 and a second sealing portion 32.

(First sealing part)
The first sealing portion 31 has a resin layer 38 and an optical member 39. The first sealing portion 31 is disposed on the light exit surface 20a.

(Resin layer)
The resin layer 38 is made of a crystalline fluororesin, and is thermally fused to the light emitting surface 20a at a surface 38a facing the light emitting surface 20a. The resin layer 38 is in contact with the light exit surface 20a without any gap. Whether the material for forming the resin layer 38 is a crystalline fluororesin can be confirmed by analysis using X-ray diffraction measurement (XRD).

  At the interface between the resin layer 38 and the light exit surface 20a, no bubbles can be seen when observed under magnification. The interface between the resin layer 38 and the light exit surface 20a is observed using an image magnified 50 times using a microscope.

  The thickness of the resin layer 38 is preferably 10 μm or more and 100 μm or less.

As a material for forming the resin layer 38, a crystalline fluororesin can be used. Such a crystalline fluororesin is preferably a resin having a low proportion of C—H bonds in the molecular structure. When the proportion of C—H bonds in the molecular structure is low, the light resistance of the resin layer 38 can be easily increased. For example, the proportion of the —CH ₂ — units in the molecular chain is preferably 30 mol% or less, more preferably 20 mol% or less, and still more preferably 10 mol%, based on the entire molecular main chain. Preferably, it is substantially 0 mol%.

  Further, the crystalline fluororesin is preferably a resin containing a chlorine atom as a substituent. When the crystalline fluororesin contains a chlorine atom, the refractive index tends to be higher than that of the fluororesin in which all the substituents are fluorine atoms.

  The refractive index of the crystalline fluororesin is preferably 1.36 or more, more preferably 1.42 or more. The refractive index of the crystalline fluororesin is preferably as high as possible without impairing the effects of the invention. Note that the refractive index of the above-mentioned crystalline fluororesin is a refractive index for light having a wavelength of 589 nm.

  The higher the refractive index of the crystalline fluororesin, the smaller the difference in the refractive index between the material forming the surface of the first sealing portion 31 that is in contact with the LED element 20 and the material forming the light exit surface 20a of the LED element 20. . Thereby, total reflection at the interface between the LED element 20 and the first sealing portion 31 can be suppressed, and the light extraction efficiency of the LED element 20 can be improved.

  The “light extraction efficiency” indicates the ratio of the intensity of light extracted from the LED element 20 to the intensity of light generated by the LED element 20. When the reflection of light on the light exit surface 20a of the LED element 20 is suppressed, and the amount of light extracted from the inside of the LED element 20 to the outside increases, the light extraction efficiency improves.

  Further, the substituent of the crystalline fluororesin is preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and further preferably a methyl group.

  Further, the substituent of the crystalline fluororesin is preferably a haloalkyl group in which a hydrogen atom of the alkyl group is independently substituted with a halogen atom, and a perfluoro group in which all of the hydrogen atoms of the alkyl group are substituted with a fluororesin. Alkyl groups are more preferred, and trifluoromethyl groups are even more preferred.

  When the crystalline fluororesin contains an alkyl group or a haloalkyl group, the transparency tends to be higher than a fluororesin in which all the substituents are fluorine atoms.

Examples of such crystalline fluororesins include ethylene tetrafluoride-perfluoroalkyl vinyl ether copolymer (PFA, melting point 310 ° C.), ethylene tetrafluoride-propylene hexafluoride copolymer (FEP, melting point 275 ° C.), Examples thereof include ethylene tetrafluoride-propylene hexafluoride-vinylidene fluoride copolymer (THV, melting point: 120 to 225 ° C) and ethylene trifluoride chloride polymer (PCTFE, melting point: 220 ° C).
The resin layer 38 made of such a crystalline fluororesin and having a thickness of 10 μm or more and 100 μm or less can achieve both light transmittance required for an LED device and durability of the resin layer 38.

  Above all, as the crystalline fluororesin, an ethylene tetrafluoride-propylene hexafluoride copolymer or an ethylene trifluoride chloride polymer is preferable, and an ethylene trifluoride chloride polymer is more preferable.

  In the present specification, literature values can be adopted for physical quantities such as “melting point”, “glass transition point”, and “refractive index”. When each physical quantity is unknown, a value measured according to a standard method can be adopted.

(Optical members)
The optical member 39 is a light-transmitting member that is disposed so as to overlap the resin layer 38 in a plan view.

  The lower one of the melting point and the glass transition point of the forming material of the optical member 39 is higher than the melting point of the crystalline fluororesin that is the forming material of the resin layer 38. Examples of a material for forming the optical member 39 include silica glass and borosilicate glass.

  Examples of the type of silica glass include fused silica glass produced by electric melting and flame fusion, and synthetic quartz glass produced by a gas phase method or a liquid phase method.

The borosilicate glass contains B ₂ O ₃ with SiO ₂ as a main component (that is, contains 50% or more of SiO ₂ ), and further contains Al ₂ O ₃ , MgO, CaO, an alkali metal oxide component (Li _{2 O, Na 2 O, K} 2 O) is a glass composed like. As borosilicate glass, those exhibiting good transmittance up to the ultraviolet region are known (for example, see Japanese Patent No. 3192013), and can be suitably used for the LED device of the present embodiment.

  The optical member 39 may have a flat surface 39a facing the LED element 20. When the surface 39a is a flat surface, scattering of light at the interface between the optical member 39 and the resin layer 38 is suppressed, and the light extraction efficiency of light emitted from the LED element 20 can be improved.

  The surface 39a of the optical member 39 may have irregularities as long as the surface 39a does not hinder the extraction of light emitted from the LED element 20. In this case, since the contact area between the optical member 39 and the resin layer 38 increases as compared with the case where the surface 39a is a flat surface, the separation between the optical member 39 and the resin layer 38 can be suppressed.

  The optical member 39 shown in the figure is a lens-shaped member, but is not limited thereto. The optical member 39 may be plate-shaped, and may have a shape such as a truncated cone, a column, a hemisphere, or a semi-ellipse. You may.

(2nd sealing part)
The second sealing portion 32 is disposed so as to surround the LED element 20 and the first sealing portion 31 in plan view. In this specification, “plan view” refers to a state in which the substrate 10 is viewed from the normal direction of the upper surface 10 a of the substrate 10.

  Specifically, the second sealing portion 32 is in contact with the upper surface 10a of the substrate 10, the side surface 20b of the LED element 20, the end portion 38b of the resin layer 38, and the side surface 39b of the optical member 39 without any gap.

  The second sealing portion 32 uses a cured product of the silicone resin composition as a forming material. As the silicone resin, an addition polymerization type silicone resin and a condensation polymerization type silicone resin can be used. Since the light resistance is high, the forming material of the second sealing portion 32 is preferably a condensation polymerization type silicone resin.

(Condensation polymerization type silicone resin)
Examples of the condensation polymerization type silicone resin include a resin containing a silicone resin obtained by hydrolysis and polycondensation of a monomer compound represented by the following formula (1) as a main component.
R ¹ _n Si (OR ² ) _(4-n) (1)

  Here, the term “main component” means that the above-mentioned silicone resin is, for example, 50% by mass or more, for example, 60% by mass or more, based on the total mass of the solid content of the condensation-polymerized silicone resin, in terms of solid content. 70% by mass or more, for example, 80% by mass or more, for example, 90% by mass or more, which means that it may be 100% by mass.

In Formula (1), R ¹ represents an alkyl group or an optionally substituted aryl group having 6 to 10 carbon atoms having 1 to 10 carbon atoms which may have a substituent, R ² is Each independently represents an alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 10 carbon atoms which may have a substituent, or a hydrogen atom; Represents an integer.

When R ¹ or R ² is an alkyl group, the alkyl group may be linear, branched, or have a cyclic structure. The number of carbon atoms of the alkyl group is not particularly limited, and may be, for example, 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms.

  In the alkyl group, one or more hydrogen atoms constituting the alkyl group may be substituted with another group. Examples of the substituent of the alkyl group include an aryl group having 6 to 10 carbon atoms such as a phenyl group and a naphthyl group, and a halogen atom such as a fluorine atom and a chlorine atom.

Specific examples of the alkyl group represented by R ¹ or R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, and an n-pentyl group. And an unsubstituted alkyl group such as a neopentyl group, a hexyl group, an octyl group, a nonyl group, and a decyl group, and an aralkyl group such as a phenylmethyl group, a phenylethyl group, and a phenylpropyl group.

When R ¹ or R ² is an aryl group, examples of the aryl group include an aryl group having 6 to 10 carbon atoms. In the aryl group, one or more hydrogen atoms constituting the aryl group may be substituted with another group. Examples of the substituent of the aryl group include an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, a propyl group, and a butyl group, and a halogen atom such as a fluorine atom and a chlorine atom.

Specific examples of the aryl group represented by R ¹ or R ² include an unsubstituted aryl group such as a phenyl group and a naphthyl group, and an alkylphenyl group such as a methylphenyl group, an ethylphenyl group, and a propylphenyl group. Alkylaryl group and the like.

When an LED element that emits light having a wavelength of 315 nm or less is used as the LED element 20, R ¹ and R ² are preferably alkyl groups. A silicone resin obtained from a monomer compound in which R ¹ and R ² are alkyl groups has a small amount of light absorption and can be expected to have high light resistance. A silicone resin obtained from a monomer compound in which R ¹ is a methyl group and R ² is a methyl group or an ethyl group is more preferred.

  Here, when n of the monomer compound represented by the above formula (1) is 1, a branched structure of three organopolysiloxane chains can be formed. A silicone resin obtained by hydrolyzing and polycondensing such a monomer compound can form a network structure. For this reason, a cured product obtained by curing the above resin has high hardness, excellent heat resistance, and has little deterioration even when irradiated with ultraviolet rays.

  On the other hand, when n of the monomer compound represented by the above formula (1) is 2, a cured product obtained by curing the above resin has excellent flexibility and is easily processed.

The silicone resin obtained by hydrolysis and polycondensation of the monomer compound represented by the above formula (1) is represented by the following formula (2).
(R ¹¹ R ¹² R ¹³ SiO _1/2 ) _M (R ¹⁴ R ¹⁵ SiO _2/2 ) _D (R ¹⁶ SiO _3/2 ) _T (SiO _4/2 ) _Q (2)

In the formula (2), R ^{11 to} R ¹⁶ are each independently an alkyl group, an aryl group, or a halogen atom.

The alkyl groups of R ^{11 to} R ¹⁶ are each independently preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and further preferably an alkyl group having 1 to 3 carbon atoms.

Examples of the alkyl group of R ^{11 to} R ¹⁶ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a neopentyl group, and a hexyl group. And an unsubstituted alkyl group such as octyl group, nonyl group and decyl group, and a substituted alkyl group such as phenylmethyl group, phenylethyl group and phenylpropyl group.
As the aryl group of R ^{11 to} R ^16, an aryl group having 6 to 10 carbon atoms is preferable independently.

Examples of the aryl group of R ^{11 to} R ¹⁶ include an unsubstituted aryl group such as a phenyl group and a naphthyl group, and a substituted aryl group such as a methylphenyl group, an ethylphenyl group, and a propylphenyl group.
As the halogen atoms for R ^{11 to} R ¹⁶ , each independently is preferably a fluorine atom or a chlorine atom.

In the formula (2), M, D, T, and Q represent constituent ratios, and are numbers from 0 to 1 and satisfy M + D + T + Q = 1. The repeating units constituting the polyorganosiloxane represented by the above formula (2) include monofunctional [R ³ SiO _0.5 ] (triorganosylhemioxane) and bifunctional [R ² SiO] (diorgano Siloxane), trifunctional [RSiO _1.5 ] (organosilsesquioxane), tetrafunctional [SiO ₂ ] (silicate) (however, for simplicity, R ^{11 to} R ¹⁶ are collectively referred to as R The composition of the silicone resin represented by the above formula (2) is determined by the composition ratio of these four types of repeating units.

Such a condensation polymerization type silicone resin can be produced by polymerizing a corresponding monomer compound. A commercially available product can also be used as the condensation-polymerized silicone resin.
Commercially available condensation polymerization type silicone resins include, for example, DMS-12, DMS-21, DMS-27, DMS-35 which are silanol type diorganosilicons manufactured by Gelest and XC96-723 manufactured by Momentive. YF-3800, YF-3057, resin-like silicone oligomers XC96-B0446, XR31-B2230, Shin-Etsu Chemical resin-like silicones KR-220L, KR-242A, KR-300, resin-like silicone oligomers X-40-9225, KR-500, KR-213, X-21-5841 which is a silanol type diorgano silicone at both ends, KF-9701, SILRES MK, SILRES MSE 100 of Asahi Kasei Wacker Inc., Silicate 48 of Colcoat Inc., EMS- 85, and the like.
These condensation polymerization type silicone resins may be used alone or in combination.

(Organic solvent)
The silicone resin as described above can be used by dissolving it in an appropriate organic solvent as needed. Further, the silicone resin as described above is dissolved in an appropriate organic solvent as needed, and further a phosphor, an inorganic particle, a silicone resin composition to which a curing catalyst or the like is added, and then, for example, by heating, etc. Can be cured.

  As the organic solvent, an organic solvent having a boiling point of 100 ° C. or higher is preferable. Examples of the organic solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monoethylhexyl ether, ethylene glycol monophenyl ether, and ethylene glycol monophenyl ether. Benzyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monoethylhexyl ether, diethylene glycol monophenyl ether, diethylene glycol Monobenzyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monoisopropyl ether, propylene glycol monobutyl ether, propylene glycol monohexyl ether, propylene glycol monoethylhexyl ether, propylene glycol monophenyl ether, propylene glycol monobenzyl ether, Dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoisopropyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monohexyl ether, dipropylene glycol monoethylhexyl ether, dipropylene glycol monophenyl Glycol ether solvents such as ether and dipropylene glycol monobenzyl ether; ethylene glycol monoethyl ether acetate, ethylene glycol monoisopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monohexyl ether acetate, ethylene glycol monoethylhexyl ether acetate, ethylene Glycol ester solvents in which an acetic acid group is added to the above-mentioned glycol ether solvents such as glycol monophenyl ether acetate and ethylene glycol monobenzyl ether acetate.

  The content of the condensation polymerization type silicone resin is preferably 50 to 100% by mass, more preferably 60 to 90% by mass, and more preferably 65 to 85% by mass based on the total mass of the silicone resin composition. It is more preferred that there be.

As a material for forming the second sealing portion 32, an epoxy resin or a fluororesin can be used in addition to the above-described silicone resin composition.
The LED device 1 of the present embodiment has the above configuration.

  In the LED device 1 as described above, the resin layer 38 in contact with the light emitting surface 20a of the LED element 20 is made of a crystalline fluororesin as a forming material. The fluororesin has higher light resistance than, for example, a cured product of a silicone resin that is a material for forming the second sealing portion 32. Further, crystalline fluororesin has relatively high adhesiveness among fluororesins. Therefore, in the LED device 1, the peeling of the sealing portion 30A can be suppressed.

  It is known that the deep ultraviolet LED including the deep ultraviolet LED element that emits the deep ultraviolet light from the LED element 20 easily deteriorates the sealing portion. Here, in the present specification, “deep ultraviolet light” refers to ultraviolet light having a wavelength of 190 nm or more and 315 nm or less. In the above-described LED device 1, even if a deep ultraviolet LED is employed as the LED element 20, light deterioration of the sealing portion 30A is suppressed, and the life of the device can be extended.

  In the LED device 1, the resin layer 38 is fused to the light exit surface 20a and is in contact with the light exit surface 20a without any gap. That is, since the light exit surface 20a does not come into contact with the air layer, total reflection at the interface between the light exit surface 20a and the air layer can be suppressed, and the light extraction efficiency of the LED element 20 can be improved. Therefore, in the LED device 1, high output can be achieved while suppressing light deterioration of the sealing portion 30A.

  That is, according to the LED device 1 configured as described above, the LED device can suppress the light deterioration of the sealing unit 30.

(Method of manufacturing LED device)
2 to 5 are process diagrams illustrating a method for manufacturing the LED device 1 of the present embodiment. The steps shown in FIGS. 2 and 3 correspond to the “step of forming a laminate” in the method for manufacturing an LED device of the present invention. The step shown in FIG. 4 corresponds to the “step of heat fusion” in the method for manufacturing an LED device of the present invention. The step shown in FIG. 5 corresponds to the “sealing step” in the method for manufacturing an LED device of the present invention.

  First, as shown in FIG. 2, a laminate of the optically transmissive optical member 39 and the film 380 using the above-mentioned crystalline fluororesin as a forming material is formed.

  In this step, the surface 39a of the optical member 39 is brought into contact with the first surface 380a of the film 380, and the film 380 is heated to a temperature equal to or higher than the melting point of the crystalline fluororesin constituting the film 380. At the time of heating, pressure may be appropriately applied from the optical member 39 side.

  The thickness of the film 380 is preferably 15 μm or more and 120 μm or less.

  By applying the heat H, the film 380 is melted or softened, and is thermally fused to the optical member 39.

  Next, as shown in FIG. 3, a portion 381x of the film 380 that does not overlap with the optical member 39 is cut out to obtain a laminate 300 of the fluororesin layer 381 and the optical member 39. The laminate 300 corresponds to the “laminate” of the present invention. The fluororesin layer 381 corresponds to the “resin layer using a fluororesin as a forming material” of the present invention.

  The laminate 300 is a laminate of a light-transmitting optical member 39 and a fluororesin layer 381 made of a fluororesin.

  The thickness of the fluororesin layer 381 is 10 μm or more and 100 μm or less.

  The lower one of the melting point and the glass transition point of the material for forming the optical member 39 is higher than the melting point of the fluororesin which is the material for forming the fluororesin layer 381.

  The laminate 300 has a total light transmittance of 70% or more in the stacking direction of the laminate 300 over the entire wavelength band of 250 nm or more and 700 nm or less. The total light transmittance of the laminated body 300 in the laminating direction is preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more.

  The total light transmittance of the laminated body 300 can be adjusted by controlling the material of the optical member 39, the thickness in the laminating direction, the material of the fluororesin layer 381, and the thickness in the laminating direction. In addition, by changing conditions such as extending the time for heat fusion between the optical member 39 and the film 380 and increasing the pressure applied during the heat fusion, the disturbance of the interface between the optical member 39 and the fluororesin layer 381 is reduced. However, the total light transmittance can be improved.

  Next, as shown in FIG. 4, the surface 381 a on the fluororesin layer 381 side of the laminate 300 is brought into contact with the light emission surface 20 a of the LED element 20 mounted on the substrate 10. In this state, the substrate 10, the LED element 20, and the laminate 300 are heated to a temperature equal to or higher than the melting point of the crystalline fluororesin constituting the fluororesin layer 381. At the time of heating, pressure may be appropriately applied from the optical member 39 side.

  By applying the heat H, the fluororesin layer 381 is melted or softened, and is thermally fused to the LED element 20. Thereby, the laminate 300 functions as the first sealing portion 31. The fluororesin layer 381 forms the resin layer 38.

  At this time, if the melting point of the fluororesin which is the material for forming the fluororesin layer 381 is 100 ° C. or more and 278 ° C. or less, it is easy to fuse at a heating temperature equal to or lower than the melting point of the solder used to connect the LED element 20 and the substrate 10 , Making it easier to manufacture. Examples of the solder used include an Au-20 mass% Sn alloy (melting point: 278 ° C.).

  The melting point of the fluororesin is preferably 150 ° C. or higher, more preferably 200 ° C. or higher. Further, the melting point of the fluororesin is preferably 250 ° C. or less.

  Next, as shown in FIG. 5, a liquid silicone resin composition L as a sealing resin is dropped so as to cover the side surface 20b of the LED element 20. As the silicone resin composition, those described above can be used. Next, the second sealing part 32 is formed by heating the silicone resin composition to cure the silicone resin composition.

  The heating temperature of the silicone resin composition is preferably from 120 to 200 ° C, more preferably from 140 to 200 ° C. The heating time is preferably 0.5 to 24 hours, more preferably 1 to 10 hours. By setting the heating temperature and the heating time within these ranges, a cured product having practically sufficient strength can be obtained.

The laminate 300 and the second sealing portion 32 are integrated to form a sealing portion 30A. In the sealing portion 30A, the fluororesin layer 381 of the first sealing portion 31 is in contact with the light emitting surface 20a of the LED element 20, and the second sealing portion 32 is in contact with the side surface 20b of the LED element 20, and the LED element 20 is Seal.
As described above, the LED device 1 can be manufactured.

  According to the above-described method for manufacturing an LED device, since the solid film 380 made of fluororesin is used as the material for forming the resin layer 38, bubbles caused by the solvent are less likely to be mixed into the first sealing portion 31.

  When a liquid material containing a fluororesin is used as the material for forming the resin layer 38, it is necessary to accurately control the supply amount and the supply position of the liquid material according to the size and position of the light emitting surface 20a of the LED element 20. And the work tends to be difficult. On the other hand, unlike the case of supplying the fluororesin as a liquid material by forming the fluororesin layer 381 by manufacturing a laminate of the fluororesin layer and the optical member in advance as in the above-described production method, It is easy to control the amount and the supply position.

  Furthermore, in the above-described manufacturing method, the laminate 300 in which the fluororesin layer 381 is laminated on the optical member 39 in advance is formed, and then the laminate 300 is fused to the light emitting surface 20a of the LED element 20. Therefore, as compared with the case where the optical member 39, the fluororesin layer 381, and the LED element 20 are heat-sealed at a time, mutual displacement between the members is less likely to occur, and the alignment is facilitated.

  Thus, according to the above-described LED device manufacturing method, the LED device 1 can be easily manufactured.

  Further, by using the above-described laminate 300, the above-described LED device 1 can be easily manufactured.

  In addition, in the LED device 1 of the present embodiment, the sealing portion 30A has the optical member 39, but is not limited thereto.

  FIG. 6 is a schematic cross-sectional view showing an LED device 2 of a modified example, and is a view corresponding to FIG. The sealing portion 30 </ b> B of the LED device 2 has a first sealing portion 35 and a second sealing portion 32. The sealing portion 30B is provided so as to cover the light emitting surface 20a of the LED element 20. The sealing portion 30B seals the LED element 20 together with the substrate 10.

  The first sealing portion 35 is disposed on the light exit surface 20a. The first sealing portion 35 is a plate-shaped member that is made of a crystalline fluororesin and is thermally fused to the light emitting surface 20a. The first sealing portion 35 in this modification is made of a crystalline fluororesin. As the crystalline fluororesin, the same resin as the material for forming the resin layer 38 described above can be used.

  The first sealing portion 35 and the light emitting surface 20a are fused together in a state where bubbles cannot be confirmed when the interface between the first sealing portion 35 and the light emitting surface 20a is enlarged and observed. After the first sealing portion 35 and the LED element 20 are disposed on the light emitting surface 20a of the LED element 20 mounted on the substrate 10, the first sealing portion 35 is formed as necessary. By heating in a state where the pressure is applied from the part 35 side, the fusion can be performed.

  The second sealing portion 32 is in contact with the upper surface 10a of the substrate 10, the side surface 20b of the LED element 20, the end 381b of the film 381, and the side surface 39b of the optical member 39 without any gap.

  Even in the LED device 2 configured as described above, since the first sealing portion 35 in contact with the light emission surface 20a is made of a fluororesin having high light resistance, the deterioration of the sealing portion 30 is suppressed. A possible LED device.

  Further, in the method for manufacturing an LED device of the present embodiment, in the step of forming the laminate, the fluororesin layer 381 is formed using the film 380, but is not limited thereto.

  10 and 11 are process diagrams showing modified examples of the process of forming a laminate.

  First, as shown in FIG. 10, the fluororesin solution M is dropped on the surface 39a of the light-transmitting optical member 39.

  Next, as shown in FIG. 11, the solvent S contained in the fluororesin solution M is volatilized to obtain a laminate 310 of the fluororesin layer 385 and the optical member 39. The fluororesin layer 385 corresponds to the “resin layer using a fluororesin as a forming material” of the present invention.

  As a method of volatilizing the solvent S from the fluororesin solution M, air blowing, heating and reduced pressure, and a combination thereof can be adopted.

  The thickness of the fluororesin layer 385 is 10 μm or more and 100 μm or less.

  In the step of forming the laminate, a method using a film is preferable because a fluororesin layer having a uniform thickness is easily formed on the surface 39a.

  When the modified example shown in FIGS. 10 and 11 is adopted as a process of forming a laminated body, when the unevenness of the surface 39a is large, the fluororesin layer 385 can be made to follow the surface 39a more easily than the method using a film. Cheap.

  An LED device can be manufactured by using the laminate 310 obtained by the above method in place of the laminate 300 in each step described with reference to FIGS. Thereby, the laminate 310 functions as the first sealing portion 31. The fluororesin layer 385 forms the resin layer 38.

  As described above, the preferred embodiments of the present invention have been described with reference to the accompanying drawings, but it is needless to say that the present invention is not limited to the embodiments. The shapes, combinations, and the like of the constituent members shown in the above-described examples are merely examples, and various changes can be made based on design requirements without departing from the spirit of the present invention.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

  In the following Examples and Comparative Examples, differences in results due to differences in the method of forming the resin layer were evaluated using model samples.

(Example 1)
Two quartz glass plates (25 mm × 25 mm × 1.1 mm, melting point 1650 ° C., refractive index 1.46) are prepared, and a film (20 mm × 20 mm × 0.075 mm) made of crystalline fluororesin, PCTFE, Toho Kasei Co., Ltd. (Made by the company, melting point: 220 ° C., refractive index: 1.42) was sandwiched between two quartz glass plates.

  Next, one of the pair of quartz glass plates sandwiching the film was placed in an aluminum cup with one of the quartz glass plates facing down. Further, an aluminum cup containing a stainless steel ball for load was placed on the other quartz glass plate. The total amount of the stainless steel balls was 100 g.

  Next, after heating at 260 ° C. for 1 hour, the sample was cooled to room temperature to produce a sample of Example 1.

  Observation was performed with an optical microscope at a magnification of 50 times, but no entrapment of bubbles was observed in the obtained sample.

(Comparative Example 1)
50 μg of an amorphous fluororesin solution (Cytop, S type, manufactured by Asahi Glass Co., Ltd.) having a concentration of 9% by mass was dropped on the surface of one quartz glass plate. The other quartz glass plate was overlaid on the amorphous fluororesin solution.

  Next, one of the pair of quartz glass plates sandwiching the amorphous fluororesin solution was placed in an aluminum cup with one of the quartz glass plates facing down. Further, an aluminum cup containing a stainless steel ball for load was placed on the other quartz glass plate. The total amount of the stainless steel balls was 100 g. After heating at 180 ° C. for 1 hour, the sample was cooled to room temperature to prepare a sample of Comparative Example 1.

  Observation at an magnification of 50 times using an optical microscope revealed that the obtained sample had a portion where the resin was present in the resin layer and a portion where no resin was present, and was observed as unevenness.

  FIG. 7 is a graph showing the results of measuring the light transmittance of the sample of Example 1. In FIG. 7, the horizontal axis indicates the measurement wavelength (unit: nm), and the vertical axis indicates the light transmittance (%).

The light transmittance of the sample was measured under the following conditions.
<Measurement conditions>
Apparatus: UV-3600 manufactured by Shimadzu Corporation
Attachment: Integrating sphere ISR-3100
Measurement wavelength: 220-800 nm
Background measurement: Atmosphere Measurement speed: Medium speed

  FIG. 7 shows, as a reference example, a measurement result of a sample in which only two sheets of quartz glass used in the sample of Example 1 are overlapped.

  As shown in the figure, it was found that the sample of Example 1 exhibited higher transmittance than the sample of the reference example in almost all measurement wavelength ranges. Further, it was found that the sample of Example 1 exhibited a sufficiently high transmittance from the visible light region to the ultraviolet region.

In addition, interference fringes were observed in the sample of the reference example, suggesting that an air layer was present between the two glass plates.
In contrast, no interference fringes were observed in the sample of Example 1. It was suggested that the sample of Example 1 did not have an air layer between the two glasses enough to form interference fringes.

  In the LED device employing the configuration of the present invention, similarly to the sample of the first embodiment, there is no air layer between the light emitting surface of the LED element and the optical member made of glass such that interference fringes are formed. It can be configured. In the LED device having such a configuration, light emitted from the LED element is less likely to be totally reflected by the surface on the light emitting surface side of the optical member as compared to the LED device including an air layer therein, and the light extraction efficiency is improved. It is thought that it is possible.

(Example 2)
A quartz glass plate (1.5 mm × 1.5 mm × 0.5 mm) is placed on a film (75 μm thick, manufactured by Toho Kasei Co., Ltd.) made of PCTFE, which is a crystalline fluororesin, and a load of 12.5 g is applied. Then, the film was heated at 230 ° C. for 3 hours to fuse the film to a quartz glass plate.

  Next, except for the portion of the film fused to the quartz glass plate, the surrounding surplus portion was cut and removed, thereby producing a laminate of a PCTFE film and the quartz glass plate.

  Then, a deep ultraviolet LED element (1.0 mm × 1.0 mm, peak wavelength 280 nm, manufactured by DOWA Electronics Co., Ltd.) was used as a substrate (manufactured by Yokowo Co., Ltd.) made of LTCC (Low-Temperature Co-fired Ceramics, low-temperature co-fired ceramics). Then, a deep ultraviolet LED package was manufactured by bonding using a flip chip method using solder.

  Next, the film side of the laminated body was placed in contact with the light emitting surface of the deep ultraviolet LED package and was placed in an overlapping manner. The laminate was heated at 230 ° C. for 3 hours while applying a load of 17.5 g to fuse the laminate to the LED package, thereby producing a sample of Example 2.

(Comparative Example 2)
In the same manner as in Example 2, a laminate of a PCTFE film and a quartz glass plate was produced. The laminate was superimposed on the light emitting surface of the deep ultraviolet LED package, and a sample of Comparative Example 2 was produced. The film of the laminate is not fused to the light exit surface of the LED package.

  FIG. 8 is a graph (radiant flux spectrum) showing the intensity of light emitted from the sample of Example 2. FIG. 9 is a graph (radiant flux spectrum) showing the intensity of light emitted from the sample of Comparative Example 2. 8 and 9, the horizontal axis indicates the wavelength of emitted light (unit: nm), and the vertical axis indicates light intensity (spectral radiant flux) (unit: μW / nm).

The light intensity of the sample was measured under the following conditions.
<Measurement conditions>
Apparatus: OP-RADIANT-UV Integrating sphere system for ultraviolet LED measurement (Ocean Photonics)
Current value: 40 mA

  8 and 9 show, as reference examples, measurement results of the deep ultraviolet LED package itself used in the sample of Example 2.

  As shown in FIG. 8, in the sample of Example 2, it was found that the light intensity was higher than that of the LED package itself, and the light extraction efficiency was increased.

  On the other hand, as shown in FIG. 9, the sample of Comparative Example 2 was found to have lower light intensity and lower light extraction efficiency than the LED package itself.

  By pouring and curing an addition-polymerizable silicone resin (for example, OE-6351, manufactured by Dow Corning Toray Co., Ltd.) around the LED element of the sample prepared in Example 2 and the laminate fused to the element, the first element was cured. , And the LED device covered with the second sealing portion.

(Example 3)
Two slide glasses (manufactured by Matsunami Glass Industry Co., Ltd., product number: S1111) were prepared.
A 25 mm × 25 mm × 75 μm PCTFE film was placed at one longitudinal end of one slide glass. PCTFE is a crystalline fluororesin.

  Next, the other end of the other slide glass in the longitudinal direction was placed on the PCTFE film, and heated and fused at 200 ° C. for 3 hours while applying a load of 100 g to produce a sample of Example 3. did. The obtained sample was a laminate in which one end of one slide glass and the other end of the other slide glass were connected by a layer of PCTFE film.

One slide glass is a model of the “light transmitting optical member” in the LED device manufacturing method of the present invention.
The PCTFE film layer is a model of the “resin layer using a fluororesin as a forming material” in the LED device manufacturing method of the present invention.
The other slide glass is a model of the “LED element” in the LED device manufacturing method of the present invention.
That is, it was found that in the method of Example 3, the “step of forming a laminate” and the “step of heat-sealing” in the method of manufacturing an LED device of the present invention can be favorably performed.

  In addition, when one of the slide glasses and the other slide glass was gripped on the obtained sample and the tensile strength was measured, the tensile strength was 58.7 MPa. In the sample after the measurement of the tensile strength, the layer of the PCTFE film remained on one of the slide glasses, and did not remain on the other. It was confirmed that the sample after the measurement was peeled off at the interface between the PCTFE film and the slide glass.

  In addition, the tensile strength is the strength when two identical samples were prepared, and each sample was broken using a Shimadzu "Small table test machine EZ-L" under the conditions of a load cell 500N and a tensile speed of 5 mm / min. Was measured. The average value of the two measurements was taken as the tensile strength of the sample.

(Example 4)
Two slide glasses identical to the slide glasses used in Example 3 were prepared.
Using a heat-resistant tape, an area of 26 mm × 25 mm surrounded by the heat-resistant tape was formed at one end on the slide glass. Next, 200 μL of an amorphous fluororesin solution (Cytop (trademark), manufactured by AGC Co., Ltd., concentration: 9% by mass) was applied to a 26 × 25 mm region surrounded by a heat-resistant tape. The slide glass coated with the amorphous fluororesin solution was dried at 200 ° C. for 3 hours to form a fluororesin layer on one end of the slide glass.

  Subsequently, the other end in the longitudinal direction of the other slide glass was placed on the fluororesin layer, and heated and fused at 200 ° C. for 3 hours while applying a load of 100 g to obtain a sample of Example 4. Produced. The obtained sample was a laminate in which one end of one slide glass and the other end of the other slide glass were connected by a fluororesin layer.

One slide glass is a model of the “light transmitting optical member” in the LED device manufacturing method of the present invention.
The fluororesin layer is a model of the “resin layer using fluororesin as a forming material” in the LED device manufacturing method of the present invention.
The other slide glass is a model of the “LED element” in the LED device manufacturing method of the present invention.
That is, it was found that in the method of Example 4, the “step of forming a laminate” and “the step of heat-sealing” in the method of manufacturing an LED device of the present invention can be favorably performed.

  When the tensile strength of the obtained sample was measured in the same manner as in Example 3, the tensile strength was 14.3 MPa. In the sample after the measurement of the tensile strength, the fluororesin layer remained on one slide glass and the other did not. It was confirmed that the sample after measurement was peeled off at the interface between the fluororesin layer and the slide glass.

  From a comparison between the tensile strength of the sample of Example 3 and the tensile strength of the sample of Example 4, the sample of Example 3 shows that the slide glass and the resin layer using the fluororesin as the forming material are more firmly adhered. I knew it was there.

  From the above, it was found that the present invention was useful.

  1, 2, LED device, 10 board, 10a top surface, 20 LED element, 20a light emitting surface, 20b, 39b side surface, 30, 30A, 30B sealing part, 31, 35 first sealing Part, 38 ... resin layer, 38b ... end part, 32 ... second sealing part, 39 ... optical member, 38a, 39a ... surface, 300 ... laminate, 310 ... film, 381 ... fluororesin layer, H ... heat, M: Fluororesin solution

Claims (10)

Board and
An LED element disposed on the substrate,
A sealing portion provided to cover the light exit surface of the LED element,
The sealing unit has a first sealing unit and a second sealing unit,
The first sealing portion is fused to the light exit surface,
The second sealing portion surrounds the periphery of the LED element and the first sealing portion in a plan view,
An LED device in which a material for forming a portion to be fused to the light emitting surface in the first sealing portion is a crystalline fluororesin.   The LED device according to claim 1, wherein the second sealing portion is formed of a condensation polymerization type silicone resin. The first sealing portion is a laminate of a light-transmitting optical member and a resin layer using the crystalline fluororesin as a forming material,
The LED device according to claim 1, wherein the resin layer is fused to the light exit surface.   The LED device according to claim 1, wherein the first sealing portion is made of a crystalline fluororesin.   5. The LED device according to claim 1, wherein a melting point of the crystalline fluororesin is 100 ° C. or more and 278 ° C. or less. 6.   The LED device according to claim 1, wherein the crystalline fluororesin contains a chlorine atom as a substituent.   The LED device according to any one of claims 1 to 6, wherein the crystalline fluororesin has a refractive index of 1.36 or more. A step of forming a laminate of a light-transmitting optical member and a resin layer using a fluororesin as a forming material,
A step of heating the surface of the laminate on the resin layer side in contact with the light emitting surface of the LED element, and thermally fusing the resin layer to the LED element;
Sealing the side surface of the LED element with a sealing resin.   The method according to claim 8, wherein the sealing resin is a silicone resin. An optical member having a light transmitting property, a laminate of a resin layer using a fluororesin as a forming material,
The thickness of the resin layer is 10 μm or more and 100 μm or less,
The lower temperature of the melting point and the glass transition point of the material for forming the optical member is higher than the melting point of the fluororesin,
A laminate wherein the total light transmittance of the laminate in a wavelength band of 250 nm or more and 700 nm or less is 70% or more in the entire range.

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