JP2015041664A - Insulation reflecting substrate and led package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulation reflecting substrate having high chemical resistance, capable of preventing decrease in strength of an inorganic reflecting layer, and excellent in reflectance, and to provide an LED package.SOLUTION: The insulation reflecting substrate has a metal substrate, and the inorganic reflecting layer provided on at least a part of the surface of the metal substrate. The inorganic reflecting layer contains inorganic particles and an inorganic binder. The inorganic binder contains silica.

Description

  The present invention relates to an insulating reflective substrate used for a light emitting element, and more particularly to an insulating reflective substrate that can be used for a light emitting diode (hereinafter referred to as “LED”).

In general, LEDs are said to have a power consumption of 1/100 and a lifespan of 40 times (40000 hours) compared to fluorescent lamps. Such a feature of power saving and long life is an important factor in adopting LEDs in an environment-oriented flow.
In particular, white LEDs are excellent in color rendering properties and have a merit that a power supply circuit is simpler than fluorescent lamps, and therefore, expectations for light sources for illumination are increasing.
In recent years, white LEDs (30 to 150 Lm / W) with high luminous efficiency, which are required as a light source for illumination, have appeared one after another, and the fluorescent lamp (20 to 110 Lm / W) has been reversed in terms of light use efficiency in practical use. doing.
As a result, the flow of practical use of white LEDs instead of fluorescent lamps has increased rapidly, and the number of cases in which white LEDs are employed as backlights or illumination light sources for liquid crystal display devices is increasing.

  As a substrate that can be used for such a white LED, Patent Document 1 discloses that “an inorganic reflective layer is provided on at least a part of a valve metal substrate, and the inorganic reflective layer is made of aluminum phosphate, aluminum chloride, and sodium silicate. For light-emitting elements, comprising at least one inorganic binder selected from the group consisting of and inorganic particles having a refractive index of 1.5 to 1.8 and an average particle size of 0.1 to 5 μm Reflective substrate "is described.

International Publication No. 2012/133173

As a result of studying the substrate described in Patent Document 1, the present inventor has low chemical resistance such as aluminum phosphate used as a binder, and dissolves in an acid / alkali treatment solution during wiring formation. Thus, it has been clarified that the strength of the inorganic reflective layer may be lowered.
The inventor has studied to provide a chemical-resistant layer (hereinafter also referred to as “chemical-resistant layer”) on the surface of the inorganic reflective layer, but the chemical-resistant layer is provided on the surface of the inorganic reflective layer. It has been clarified that there is a problem that the reflectance, which is a characteristic of the inorganic reflective layer, is lowered when the layer is provided.

  Therefore, an object of the present invention is to provide an insulating reflective substrate and an LED package that have high chemical resistance, can prevent a decrease in strength of an inorganic reflective layer, and are excellent in reflectance.

As a result of intensive studies to achieve the above-mentioned problems, the inventors of the present invention have achieved high reflectivity because the inorganic binder contains silica in the inorganic reflective layer containing the inorganic particles and the inorganic binder. However, the present inventors have found that the chemical resistance is high and the strength of the inorganic reflective layer can be prevented from being lowered.
That is, the present invention provides an insulating reflection substrate and an LED package having the following configurations.

  (1) It has a metal substrate and an inorganic reflective layer provided on at least a part of the surface of the metal substrate, the inorganic reflective layer contains inorganic particles and an inorganic binder, and the inorganic binder is silica. Insulating reflective substrate that contains.

(2) The insulated reflective board | substrate as described in (1) whose ratio of the silica in an inorganic binder is 40 mass% or more.
(3) The insulated reflective board | substrate as described in (1) or (2) whose average particle diameter of an inorganic particle is 0.1 micrometer-5 micrometers.
(4) The insulated reflective board | substrate in any one of (1)-(3) whose average particle diameter of a silica is 0.004 micrometer-0.07 micrometer.
(5) The insulating reflective substrate according to any one of (1) to (4), wherein the inorganic binder is formed by firing a solution containing colloidal silica.

  (6) An LED package comprising the insulating reflective substrate according to any one of (1) to (5) and an LED light emitting element mounted on the surface of the insulating reflective substrate.

  According to the present invention, it is possible to provide an insulating reflective substrate and an LED package that have high reflectivity, high chemical resistance, and can prevent a decrease in strength of the inorganic reflective layer.

It is typical sectional drawing which shows an example of suitable embodiment of the insulated reflective board | substrate of this invention. It is typical sectional drawing which shows an example of the suitable embodiment of the LED package of this invention.

[Insulating reflective substrate]
The insulating reflective substrate (hereinafter also referred to as “reflective substrate”) of the present invention will be described in detail below.
The reflective substrate of the present invention has a metal base and an inorganic reflective layer provided on at least a part of the surface of the metal base, the inorganic reflective layer contains inorganic particles and an inorganic binder, and is inorganic. It is an insulating reflective substrate whose binder contains silica.
Next, the configuration of the insulating reflective substrate of the present invention will be described with reference to FIG.

FIG. 1 is a schematic cross-sectional view showing an example of a preferred embodiment of the insulating reflective substrate of the present invention.
As shown in FIG. 1, the insulating reflective substrate 1 of the present invention has a metal base 2 and an inorganic reflective layer 3 provided on at least a part of the surface of the metal base 2. A reflective substrate containing inorganic particles 4 and an inorganic binder 5.

[Metal base material]
The metal substrate that the reflective substrate of the present invention has is not particularly limited, and specific examples of the metal that is the material of the metal substrate include aluminum, gold, silver, copper, tantalum, niobium, titanium, and hafnium. , Zirconium, zinc, tungsten, bismuth, antimony and the like.
The metal substrate is preferably an aluminum substrate that will be described in detail below because of its excellent workability and strength.
In addition, for the reason that the heat dissipation property of the reflective substrate becomes better, it is preferably a metal substrate composed of at least one metal selected from the group consisting of gold, silver, and copper, among which workability is high. From the viewpoint of easy and high weather resistance, a copper base material is more preferable.

<Aluminum substrate>
As the aluminum substrate, a known aluminum substrate can be used. In addition to a pure aluminum substrate, an alloy plate containing aluminum as a main component and containing a small amount of foreign elements; low purity aluminum (for example, recycled material) and high purity aluminum It is also possible to use a substrate obtained by depositing high purity aluminum on the surface of a silicon wafer, quartz, glass or the like; a resin substrate laminated with aluminum; or the like.
Here, the foreign elements that may be included in the alloy plate include silicon, iron, copper, manganese, magnesium, chromium, zinc, bismuth, nickel, titanium, etc., and the content of the foreign elements in the alloy is It is preferably 10% by mass or less.
Such an aluminum substrate is not particularly limited in terms of composition, preparation method (for example, casting method, etc.), and the composition and preparation described in paragraphs [0031] to [0051] of International Publication No. 2010/150810. Methods and the like can be adopted as appropriate.

  In this invention, it is preferable that the thickness of a metal base material is 0.1-3 mm, it is preferable that it is 0.15-1.5 mm, and it is more preferable that it is 0.2-1.0 mm. This thickness can be appropriately changed according to the user's wishes or the like.

[Inorganic reflective layer]
The inorganic reflective layer which the reflective substrate of the present invention has is a reflective layer containing inorganic particles and an inorganic binder.

  In the present invention, the thickness of the inorganic reflective layer is preferably 10 μm to 200 μm, more preferably 40 μm to 170 μm, because the reflectance of the reflective substrate becomes higher and the strength of the inorganic reflective layer is improved. A thickness of 80 μm to 150 μm is particularly preferable.

  The inorganic reflective layer contains inorganic particles having a specific particle diameter, which will be described later, and silica particles as an inorganic binder, and is composed of a large number of inorganic particles partially bound together by the inorganic binder. It is an aggregate and is a porous body having a specific porosity in which minute voids are formed between a large number of inorganic particles.

By using such a porous layer as an inorganic reflective layer, both insulation and diffuse reflectance are improved.
This is because, as shown in FIG. 1, the surface of the porous layer has a moderately uneven shape due to inorganic particles, and the internal voids contribute to the reflection and scattering of light. it is conceivable that.

In the present invention, the porosity in the inorganic reflective layer is preferably 10% to 70%, more preferably 15% to 50%, and particularly preferably 20 to 40% from the viewpoints of strength and reflectance of the inorganic reflective layer. preferable.
When the porosity is in the above range, a moderately concavo-convex shape is formed on the surface of the inorganic reflective layer (mainly inorganic particles), flexibility is maintained, and the LED light emitting element is mounted. Handleability is improved.
Here, the porosity refers to the total porosity measured by the geometric method. In the present invention, the bulk density is calculated by the Archimedes method, and the true density is measured by the gas phase substitution method (Pycnometer method). The value obtained by substituting the obtained result into the following formula (1) is defined as the porosity.
Porosity (%) = {1- (bulk density / true density)} × 100 (1)

  Hereinafter, the inorganic particles and the inorganic binder contained in the inorganic reflective layer will be described in detail.

<Inorganic particles>
The kind of the inorganic particles contained in the inorganic reflective layer is not particularly limited, and conventionally known oxides (for example, metal oxides), hydroxides (for example, metal hydroxides), inorganic salts (for example, carbonic acid) Salt, sulfate, etc.) can be used.

In the present invention, the average particle size of the inorganic particles is preferably 0.1 μm to 5 μm, more preferably 0.2 μm to 3 μm, and particularly preferably 0.5 μm to 2 μm.
By using inorganic particles having such an average particle diameter, it is possible to ensure appropriate voids between the particles when binding with an inorganic binder described later.
Here, the average particle diameter means an average value of the particle diameters of the inorganic particles, and in the present invention, it means a 50% volume cumulative diameter (D50) measured using a laser diffraction particle size distribution measuring device.

The refractive index of the inorganic particles is preferably 1.5 or more and 3.0 or less, and more preferably 1.5 or more and 1.8 or less.
By using inorganic particles satisfying such a refractive index, the reflectance of the reflective substrate of the present invention becomes higher.
Here, the refractive index means a value measured at 25 ° C. according to “5. Measuring method of solid sample” of JIS K 0062: 1992.

Specific examples of the inorganic particles include aluminum oxide (alumina) (refractive index n = 1.65 to 1.76, hereinafter, the numbers in parentheses in this paragraph indicate the refractive index), hydroxide. Aluminum (1.58-1.65 to 1.76), calcium hydroxide (1.57 to 1.6), calcium carbonate (1.58), calcite (1.61), calcium carbonate (1.61) , Light calcium carbonate (1.59), heavy calcium carbonate (1.56), ultrafine calcium carbonate (1.57), gypsum (1.55), calcium sulfate (1.59), marble (1.57 ), Barium sulfate (1.64), barium carbonate (1.6), magnesium oxide (1.72), magnesium carbonate (1.52), magnesium hydroxide (1.58), strontium carbonate (1.52) , Orinkley (1.56), calcined clay (1.62), talc (1.57), sericite (1.57), optical glass (1.51-1.64), glass beads (1.51), etc. These may be used alone or in combination of two or more.
Among these, aluminum oxide, calcium hydroxide, and barium sulfate are preferable because the inorganic particles themselves have high whiteness and are advantageous in reflection characteristics.

In the present invention, two or more kinds of particles or two or more kinds of particles having an average particle diameter may be used in combination as the inorganic particles.
By using particles having different types and average particle diameters in combination, it is possible to improve the strength of the inorganic reflective layer and further improve the adhesion between the inorganic reflective layer and the metal substrate.

In the present invention, the shape of the inorganic particles is not particularly limited. For example, the shape is spherical, polyhedral (for example, icosahedron, dodecahedron, etc.), cubic, tetrahedral, or uneven on the surface. It may be any shape having a plurality of convex protrusions (hereinafter also referred to as “compete shape”), a plate shape, a needle shape, or the like.
Among these, spherical, polyhedral, cubic, tetrahedral, and complex shapes are preferred for the reason of excellent heat insulation, and spherical is more preferred for reasons of easy availability and excellent heat insulation.

<Inorganic binder>
As described above, in the present invention, the inorganic binder contains silica.
Since the inorganic binder contains silica, the chemical resistance of the inorganic reflective layer is increased, so it does not melt into the processing liquid such as acid and alkali during wiring formation, and the strength of the inorganic reflective layer is reduced. Can be prevented.
Moreover, since it is not necessary to provide a chemical resistant layer on the surface of the inorganic reflective layer, a high reflectance can be maintained.

Here, the inorganic binder is preferably formed by firing a solution containing colloidal silica, and the silica in the inorganic binder is preferably silica derived from colloidal silica. .
Silica as an inorganic binder acts as a binder by melting the surface and bonding the silica together to form a film.

  In the present invention, the inorganic binder preferably includes 30% by mass or more of silica, more preferably 50% by mass or more, further preferably 80% by mass or more, and 100% by mass, ie, the above It is particularly preferable to use only silica as the inorganic binder.

Moreover, it is preferable that the average particle diameter of a silica particle is 0.004 micrometer-0.07 micrometer, It is more preferable that it is 0.01 micrometer-0.06 micrometer, It is especially preferable that it is 0.02 micrometer-0.05 micrometer.
By using silica having such an average particle diameter, the strength of the inorganic reflective layer can be further improved, and appropriate voids can be secured between the particles of the inorganic particles in the inorganic reflective layer. The rate can be further improved.
Here, the average particle diameter refers to an average value of the particle diameter of the silica, and in the present invention, refers to a 50% volume cumulative diameter (D50) measured using a laser diffraction particle size distribution measuring apparatus.

The ratio of the average particle diameter of silica of the inorganic binder to the average particle diameter of the inorganic particles is preferably 0.7 or less, more preferably 0.003 to 0.3, and It is especially preferable that it is 01-0.1.
By setting the ratio of the average particle diameter of silica and the average particle diameter of inorganic particles within this range, the strength of the inorganic reflective layer can be further improved, and between the inorganic particles in the inorganic reflective layer. Appropriate voids can be secured.

(Colloidal silica)
The colloidal silica used in the present invention is not particularly limited, but the average particle size of the silica particles in the colloidal silica is preferably 0.004 μm to 0.07 μm, more preferably 0.01 μm to 0.06 μm. Preferably, it is 0.02 μm to 0.05 μm.

  The ratio of the average particle diameter of the colloidal silica to the average particle diameter of the inorganic particles is preferably 0.7 or less, more preferably 0.003 to 0.3, and 0.01 to 0.1. It is particularly preferred.

The colloidal silica used in the present invention preferably has a silica concentration of 10% to 50%.
By using colloidal silica having such a silica concentration, the dispersibility of silica in the coating liquid is improved, and a uniform coating film can be formed.

  As such colloidal silica, commercially available products can be used. For example, Fuso Chemical Industries, Ltd .: PL-1, PL-3, Nissan Chemical Industries, Ltd .: ST-O, ST-O-40, ST -OL, ST-XS, ST-30, ST-50, ST-N, ST-OXS, ST-C, ST-CM, ST-AK, manufactured by AZ ELECTRONIC MATERIALS: Klebosol 20H12, 30CAL25, 30L12E, 30R940R12C, 40R25 or the like can be used.

  In the present invention, as the inorganic binder, for example, at least one selected from the group consisting of phosphoric acid and / or metal phosphate, sodium silicate, and aluminum chloride may be used in combination with the silica described above. .

(Metal phosphate)
The phosphoric acid metal salt is not particularly limited, and examples of the phosphoric acid in the phosphoric acid metal salt include phosphoric acid, metaphosphoric acid, orthophosphoric acid, polyphosphoric acid, sesquiphosphoric acid, and the like. As the metal in the phosphoric acid metal salt, For example, gold, silver, copper, aluminum, zirconium, titanium, zinc, cerium, and the like can be given. As the metal phosphate, a combination of these can be used as appropriate. Moreover, such a metal phosphate may be used individually by 1 type, and may use 2 or more types together.
Here, the phosphoric acid metal salt is the above-described phosphoric acid and an oxide or hydroxide containing the above-described metal (for example, gold hydroxide, silver oxide, copper hydroxide, aluminum hydroxide) in the presence of water. It can be obtained by reaction.

  Of these, the metal phosphate is preferably gold phosphate, silver phosphate, copper phosphate, or aluminum phosphate. Among these, gold phosphate, silver phosphate, and copper phosphate are preferable because the adhesion between the inorganic reflective layer and the metal substrate is improved, and the adhesion to the wiring is unexpectedly improved. More preferably.

  In the present invention, the metal constituting the metal base and the metal constituting the phosphate metal salt are the same type of metal because the adhesion between the inorganic reflective layer and the metal base is better. Is preferred. Among these, an embodiment in which an aluminum substrate is used as the metal substrate and aluminum phosphate is used as the inorganic binder (phosphate metal salt) is more preferable because of easy workability and high weather resistance. For the same reason, a mode in which a copper base is used as the metal base and copper phosphate is used as the inorganic binder (metal phosphate) is more preferable.

(Sodium silicate)
Sodium silicate is also called sodium silicate or water glass, and is generally Na ₂ SiO _3, which is a sodium salt of metasilicate, but Na ₄ SiO ₄ , Na ₂ Si ₂ O ₅ , Na ₂ Si ₄ O ₉ or the like can also be used.
The sodium salt of metasilicic acid can be obtained by melting silicon dioxide with sodium carbonate or sodium hydroxide.

(Aluminum chloride)
Aluminum chloride may be any of anhydrous aluminum chloride, aluminum chloride hexahydrate, and polyaluminum chloride (a polymer of basic aluminum chloride formed by dissolving aluminum hydroxide in hydrochloric acid).

Inorganic reflective layer containing the above-mentioned inorganic binder and inorganic particles, the surface of the metal substrate, that the mass after drying by heating is provided in an amount of 20g / m ² ~500g / m ² preferred.
Further, regarding the content ratio of the inorganic binder and the inorganic particles in the inorganic reflective layer, it is preferable that the inorganic binder is contained in an amount of 5 to 100 parts by mass with respect to 100 parts by mass of the inorganic particles, and 10 to 50 parts by mass. Is more preferable.
Further, the inorganic reflective layer may contain other compounds in addition to the inorganic binder and the inorganic particles. Examples of other compounds include a dispersant and a reaction accelerator.

<Method for forming inorganic reflection layer>
In the present invention, the method for forming the inorganic reflective layer is not particularly limited. For example, a coating liquid (composition) containing the inorganic particles and colloidal silica is screen-printed on the surface of the metal substrate. It can form by the method of apply | coating and drying etc., For example, the method etc. which were described in [0021]-[0023] of patent document 1 (International publication 2012/133173) are mentioned.

Here, in the present invention, when forming the inorganic reflective layer, after forming a coating liquid containing the inorganic particles and colloidal silica on the surface of the metal substrate, first, dry air is blown at a low temperature. It is preferably formed by a method of removing (evaporating) a part of moisture in the coating film and concentrating, then heating to a predetermined temperature and baking.
Thus, before forming an inorganic reflection layer by baking etc., the ratio of the space | gap in the inorganic reflection layer after baking can be adjusted by removing a part of the water | moisture content in a coating film.

[Insulating layer]
The reflective substrate of the present invention is not essential because the insulating properties can be ensured by the inorganic reflective layer, but it is preferable to provide an arbitrary insulating layer on the front surface and / or the back surface of the metal substrate.

  The insulating layer may be, for example, a resin layer formed of a thermosetting resin such as an epoxy resin or a phenol resin. However, for the reasons such as high thermal conductivity and high thermal radiation, inorganic oxidation It is preferable that it is a thing and an anodic oxide film. In particular, an embodiment in which the metal substrate is an aluminum substrate and the insulating layer is an anodized aluminum film is preferable.

The anodic oxide film may be an anodic oxide film of an aluminum base material different from the aluminum base material. However, from the viewpoint of preventing formation defects of the insulating layer, the surface of the aluminum base material has a depth direction. It is preferable that the part is an anodized film formed on the part that has not been anodized (that is, on the aluminum substrate) by anodizing the part.
The thickness of the anodic oxide film is preferably 1 to 200 μm. When the thickness is 1 μm or more, sufficient insulation is provided and the withstand voltage is improved. On the other hand, when the thickness is 200 μm or less, it can be manufactured with a small amount of power, and the manufacturing cost can be kept low. The thickness of the anodic oxide film is preferably 20 μm or more, and more preferably 40 μm or more.
Examples of the anodizing treatment for forming such an anodized film include the methods described in [0038] to [0043] of Patent Document 1 (International Publication No. 2012/133173).

[LED package]
Below, the LED package of this invention is demonstrated in detail.
FIG. 2 is a schematic sectional view showing an example of an LED package using the insulating reflective substrate of the present invention.
As shown in FIG. 2, the LED package 20 of the present invention includes a reflective substrate 1 of the present invention, a wiring 8 provided on the inorganic reflective layer 3 included in the reflective substrate 1 of the present invention, LED package 20 having LED light emitting element 9 bonded together.
In FIG. 2, the reflective substrate 1 is as described above.

〔wiring〕
The wiring which the LED package of this invention has is a metal wiring layer electrically joined with the LED light emitting element mentioned later.
The wiring material is not particularly limited as long as it is a material that conducts electricity. Specific examples thereof include gold (Au), silver (Ag), copper (Cu), aluminum (Al), magnesium (Mg), nickel. (Ni) etc. are mentioned, These may be used individually by 1 type and may use 2 or more types together.
Of these, Cu is preferably used because of its low electrical resistance. Note that an Au layer or a Ni / Au layer may be provided on the surface layer of the wiring made of Cu from the viewpoint of improving the ease of wire bonding.

  In addition, the thickness of the wiring is preferably 0.5 to 1000 μm, more preferably 1 to 500 μm, and particularly preferably 5 to 250 μm, from the viewpoint of conduction reliability and package compactness.

  As a method for forming the wiring, for example, paragraphs [0045] to [0052] of JP2013-62500A can be cited.

[LED light emitting element]
The LED light emitting element of the LED package of the present invention is obtained by forming a semiconductor such as GaAlN, ZnS, ZnSe, SiC, GaP, GaAlAs, AlN, InN, AlInGaP, InGaN, GaN, AlInGaN on a substrate as a light emitting layer. Can be used.
Examples of the semiconductor structure include a homostructure, a heterostructure, or a double heterostructure having a MIS junction, a PIN junction, or a PN junction. Various emission wavelengths can be selected from ultraviolet light to infrared light depending on the material of the semiconductor layer and the degree of mixed crystal.

Although not shown, the LED package 20 may have the wiring 8 and the LED light emitting element 9 molded with a transparent resin mixed with fluorescent particles.
The material of the transparent resin is preferably a thermosetting resin.
The thermosetting resin is preferably formed of at least one selected from the group consisting of epoxy resins, modified epoxy resins, silicone resins, modified silicone resins, acrylate resins, urethane resins, and polyimide resins. , Modified epoxy resin, silicone resin, and modified silicone resin are preferable.
Further, the transparent resin is preferably hard to protect the blue LED.
Moreover, it is preferable to use resin excellent in heat resistance, a weather resistance, and light resistance for transparent resin.
The transparent resin may be mixed with at least one selected from the group consisting of a filler, a diffusing agent, a pigment, a fluorescent material, a reflective material, an ultraviolet absorber, and an antioxidant so as to have a predetermined function. it can.

Furthermore, the said fluorescent particle should just absorb the light from blue LED and wavelength-convert it into the light of a different wavelength.
Specific examples of the fluorescent particles include nitride-based phosphors, oxynitride-based phosphors, sialon-based phosphors, and β-sialon-based phosphors that are mainly activated by lanthanoid elements such as Eu and Ce. An alkaline earth halogen apatite phosphor, an alkaline earth metal borate phosphor, an alkaline earth metal aluminate phosphor mainly activated by a lanthanoid group such as Eu, or a transition metal group element such as Mn; Alkaline earth silicate phosphor, alkaline earth sulfide phosphor, alkaline earth thiogallate phosphor, alkaline earth silicon nitride phosphor, germanate phosphor; mainly activated by lanthanoid elements such as Ce Rare earth aluminate phosphors, rare earth silicate phosphors, organic complexes mainly activated by lanthanoid elements such as Eu, etc., and these may be used alone, It may be used in combination with more species.

On the other hand, the LED package of the present invention can also be used as a phosphor mixed color white LED package using an ultraviolet to blue LED and a fluorescent light emitter that absorbs the LED and emits fluorescence in the visible light region.
These fluorescent light emitters absorb blue light from the blue LED to generate fluorescence (yellowish fluorescent light), and white light is emitted from the light emitting element by the fluorescent light and the afterglow of the blue LED.
The above-described method is a so-called “pseudo white light emission type” in which a blue LED light source chip and one kind of yellow phosphor are combined. In addition, for example, an ultraviolet to near-ultraviolet LED light source chip and red / green / blue fluorescence. LED of the present invention as a light-emitting unit using a known light-emitting method such as “ultraviolet to near-ultraviolet light source type” in which several types of bodies are combined, and “RGB light source type” that emits white light with three red / green / blue light sources Package can be used.

In the LED package of the present invention, the method of mounting the LED light emitting element on the reflective substrate of the present invention involves mounting by heating, but the thermocompression bonding including solder reflow and the mounting method by flip chip provide uniform and reliable mounting. From the viewpoint of applying, the maximum attainable temperature is preferably 220 to 350 ° C, more preferably 240 to 320 ° C, and particularly preferably 260 to 300 ° C.
The time for maintaining these maximum temperatures is preferably from 2 seconds to 10 minutes, more preferably from 5 seconds to 5 minutes, and particularly preferably from 10 seconds to 3 minutes.

  Moreover, as temperature at the time of mounting by wire bonding, from a viewpoint of performing reliable mounting, 80-300 degreeC is preferable, 90-250 degreeC is more preferable, and 100-200 degreeC is especially preferable. The heating time is preferably 2 seconds to 10 minutes, more preferably 5 seconds to 5 minutes, and particularly preferably 10 seconds to 3 minutes.

  The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these.

[Example 1]
[Production of insulating reflective substrate]
<Metal substrate>
As the metal substrate, a base material having an anodized film formed on the surface of an aluminum plate was used.
An aluminum plate (1050 material, thickness 0.8 mm, manufactured by Nippon Light Metal Co., Ltd.) was sprayed with an aqueous solution having a sodium hydroxide concentration of 27 mass% and an aluminum ion concentration of 6.5 mass% at a temperature of 70 ° C. Sprayed for 20 seconds. Thereafter, the liquid was drained with a nip roller, and further, a water washing treatment described later was performed, and then the liquid was drained with a nip roller.
The water washing treatment was carried out using an apparatus for washing with a free-fall curtain-like liquid film, and further washed with water for 5 seconds using a spray tube having a structure having spray tips spread in a fan shape at intervals of 80 mm. .
After the water washing treatment, desmut treatment was performed. The acidic aqueous solution used for the desmut treatment was a 1% sulfuric acid aqueous solution, which was sprayed from a spray tube at a liquid temperature of 35 ° C. for 5 seconds. Then, the liquid was drained with a nip roller.
Next, the substrate after these treatments was used as an anode, and anodization treatment was performed using an anodizing apparatus. As the electrolytic solution, an electrolytic solution (temperature 20 ° C.) in which aluminum sulfate was dissolved in a 70 g / L sulfuric acid aqueous solution to make the aluminum ion concentration 5 g / L was used. In addition, the anodizing treatment is performed under constant-voltage electrolysis conditions so that the voltage during the anodic reaction of the substrate is 25 V, and the final anodic oxide film thickness is 60 μm to insulate the aluminum anodic oxide film. An aluminum substrate (hereinafter also referred to as “anodized aluminum substrate”) having a surface as a layer was manufactured.
Thereafter, the liquid was drained by a nip roller, and further, the water was washed using a spray tube having the same structure as that used in the water washing process, and then the liquid was drained by a nip roller.

<Inorganic reflective layer>
(Preparation of inorganic reflection layer forming coating solution A)
Colloidal silica PL-3 (silica concentration 20%, average particle size 0.035 μm, manufactured by Fuso Chemical Industry Co., Ltd.) 100 g, AL-160SG-3 (average particle size: 0.52 μm, manufactured by Showa Denko Co., Ltd.) as inorganic particles ) Was added and stirred to prepare an inorganic reflective layer forming coating solution A.
(Formation of inorganic reflective layer)
After coating the prepared inorganic reflective layer forming coating liquid A on a metal substrate using a screen plate having a resist thickness of 80 μm by a screen printing method to form a coating film, dry air is applied at room temperature in an oven, After removing and concentrating 80% by mass of water contained in the coating film, the insulating reflective substrate having an inorganic reflective layer formed on the substrate was prepared by baking at 200 ° C. for 20 minutes.
The formed inorganic reflective layer had a porosity of 10% and a thickness of 80 μm.

[Example 2]
An insulating reflective substrate was produced in the same manner as in Example 1 except that 30% by mass of water contained in the coating film was removed and concentrated during drying after the coating film was formed.
The porosity of the formed inorganic reflective layer was 30%.

[Example 3]
An insulating reflective substrate was produced in the same manner as in Example 1 except that water was not removed and concentrated after the coating film was formed.
The porosity of the formed inorganic reflective layer was 40%.

[Example 4]
An insulating reflective substrate was produced in the same manner as in Example 2 except that the resist thickness of the screen plate during the coating film formation was 40 μm.
The thickness of the formed inorganic reflective layer was 40 μm.

[Example 5]
An insulating reflective substrate was produced in the same manner as in Example 2 except that the resist thickness of the screen plate at the time of forming the coating film was 150 μm.
The thickness of the formed inorganic reflective layer was 150 μm.

[Example 6]
Instead of the inorganic reflective layer forming coating liquid A, the following inorganic reflective layer forming coating liquid B is used, and 30% by mass of water contained in the coating film is removed during drying after the coating film is formed. An insulating reflective substrate was produced in the same manner as in Example 1 except that it was concentrated.
The porosity of the formed inorganic reflective layer was 10%.

(Preparation of inorganic reflection layer forming coating solution B)
Colloidal silica PL-3 (silica concentration 20%, average particle size 0.035 μm, manufactured by Fuso Chemical Industry Co., Ltd.) 30 g, aluminum phosphate (Wako Pure Chemical Industries, Ltd.) 14 g, and inorganic particles AL-160SG-3 ( 100 g of an average particle size: 0.52 μm (manufactured by Showa Denko KK) was added and stirred to prepare an inorganic reflective layer forming coating solution B.

[Example 7]
In place of the inorganic reflective layer forming coating liquid A, the following inorganic reflective layer forming coating liquid C is used, and 60% by mass of water contained in the coating film is removed during drying after the coating film is formed. An insulating reflective substrate was produced in the same manner as in Example 1 except that it was concentrated.
The porosity of the formed inorganic reflective layer was 10%.

(Preparation of inorganic reflection layer forming coating solution C)
Colloidal silica PL-3 (silica concentration 20%, average particle size 0.035 μm, manufactured by Fuso Chemical Industry Co., Ltd.) 50 g, aluminum phosphate (Wako Pure Chemical Industries, Ltd.) 10 g, AL-160SG-3 (inorganic particles) 100 g of average particle diameter: 0.52 μm, manufactured by Showa Denko KK was added and stirred to prepare an inorganic reflective layer forming coating solution C.

[Comparative Example 1]
Implemented except that instead of the inorganic reflective layer forming coating liquid A, the following inorganic reflective layer forming coating liquid D was used, and after forming the coating film, the inorganic reflective layer was formed by drying at 180 ° C. for 5 minutes. An insulating reflective substrate was produced in the same manner as in Example 1.
The porosity of the formed inorganic reflective layer was 10%.

(Preparation of inorganic reflection layer forming coating solution D)
By adding 100 g of AL-160SG-3 (average particle size: 0.52 μm, manufactured by Showa Denko KK) as inorganic particles to 76 g of the binder liquid having the composition shown below, the inorganic reflective layer forming coating liquid D is stirred. Was prepared.
<Binder liquid composition>
・ Phosphoric acid 85% (Wako Pure Chemical Industries, Ltd.) 48g
・ Aluminum hydroxide (Wako Pure Chemical Industries, Ltd.) 11g
・ Water 17g

[Comparative Example 2]
Furthermore, an insulating reflective substrate was produced in the same manner as in Comparative Example 1 except that a chemical resistant layer was formed on the inorganic reflective layer by the following method.

(Formation of chemical resistant layer)
A chemical-resistant layer forming solution was prepared by adding 20 g of butyl acetate to 80 g of SWR-PK-01 manufactured by Asahi Rubber Co., Ltd. and stirring.
The prepared chemical-resistant layer forming solution is applied on the inorganic reflective layer by a screen printing method using a screen plate having a resist thickness of 3 μm to form a coating film, and then dried at 200 ° C. for 15 minutes, whereby inorganic reflection is achieved. A chemical resistant layer was formed on the layer.

[Evaluation]
<Chemical resistance>
Each of the produced insulating reflective substrates was immersed in 1% by weight sulfuric acid at room temperature for 20 minutes, washed with water, then immersed in 1% by weight sodium hydroxide solution at room temperature for 20 minutes, washed with water, and insulated reflection before and after evaluation. The mass change of the inorganic reflective layer in the substrate was measured.
A: The mass change of the inorganic reflective layer was 0.1% or less.
B: The mass change of the inorganic reflective layer was more than 0.1% and less than 1%.
C: The mass change of the inorganic reflective layer was 1% or more.

<Inorganic reflective layer strength>
About each produced insulating reflective board | substrate, after performing said chemical-resistant evaluation, the board | substrate was cut with the guillotine cutter, and the test which confirms whether peeling was seen in the inorganic reflection layer when cut was performed 10 times.
AA: No peeling at all.
A: Peeled once.
B: Peeled twice or three times.
C: Peeling was observed 4 times or more.

<Reflectance>
About each produced insulation reflective board | substrate, 400-700 nm total reflectance (all average of a SPIN mode) and diffuse reflectance were measured and averaged using the reflection densitometer (CM2600D, Konica Minolta Co., Ltd. make). The reflectance was evaluated with this average value.
AA: The average value was over 93%.
A: The average value was more than 90% and 93 or less.
B: The average value was more than 85% and 90 or less.
C: The average value was 85% or less.

  The results of each evaluation are shown in Table 1 below.

From the results shown in Table 1, Examples 1 to 7 of the present invention in which the inorganic reflective layer contains inorganic particles and an inorganic binder and the inorganic binder contains silica include silica in the inorganic binder. It can be seen that the chemical resistance and film strength are higher than those of Comparative Examples 1 and 2, which are not present. Moreover, when a chemical-resistant layer is formed on the inorganic reflective layer, the chemical resistance and film strength are improved, but the reflectance is low (Comparative Example 2), whereas Examples 1 to 7 are: It can be seen that the chemical resistance and the film strength are improved while maintaining the reflectance.
Further, from the comparison between Example 1 and Examples 6 and 7, it can be seen that the chemical resistance improves as the silica content in the inorganic binder increases.
The effects of the present invention are clear from the above results.

DESCRIPTION OF SYMBOLS 1 Reflective substrate 2 Metal base material 3 Inorganic reflective layer 4 Insulating layer 5 Inorganic binder 8 Wiring (metal wiring layer)
9 LED light emitting device 20 LED package

Claims (6)

A metal substrate;
An inorganic reflective layer provided on at least a part of the surface of the metal substrate,
The inorganic reflection layer contains inorganic particles and an inorganic binder,
An insulating reflective substrate, wherein the inorganic binder contains silica.   The insulating reflective substrate according to claim 1, wherein a ratio of silica in the inorganic binder is 40% by mass or more.   The insulating reflective substrate according to claim 1 or 2, wherein an average particle diameter of the inorganic particles is 0.1 µm to 5 µm.   The insulating reflective substrate according to any one of claims 1 to 3, wherein an average particle diameter of the silica is 0.004 µm to 0.07 µm.   The insulating reflective substrate according to claim 1, wherein the inorganic binder is formed using a solution containing colloidal silica.   An LED package comprising the insulating reflective substrate according to claim 1, and an LED light emitting element mounted on a surface of the insulating reflective substrate.

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