JP2013062500A - Reflection substrate for led light-emitting element and led package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection substrate for an LED light-emitting element, excellent in both specular reflectance and diffuse reflectance and capable of achieving high luminous efficiency, and to provide an LED package.SOLUTION: The reflection substrate for an LED light-emitting element has a surface for mounting an LED light-emitting element. Within the surface, a surface at least other than a portion where the LED light-emitting element is mounted has an arithmetic mean roughness Ra of 0.50 to 1.00 μm and an average interval Psm of irregularity of 10 to 20 μm.

Description

  The present invention relates to a reflective substrate for an LED light emitting element used in a light emitting diode (hereinafter referred to as “LED”) package.

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 “at least a light reflecting substrate having an insulating layer and a metal layer provided in contact with the insulating layer has a wavelength of more than 320 nm to 700 nm. The light reflecting substrate is characterized in that the reflectance is 50% or more and the total reflectance of light having a wavelength of 300 nm to 320 nm is 60% or more. (Claim 12]), an embodiment is also described in which the surface of the light reflecting substrate is uneven with an average wavelength of 0.01 to 100 μm ([Claim 2]).

  Patent Document 2 states that “an insulating substrate having an aluminum substrate and an insulating layer provided on the surface of the aluminum substrate, wherein the insulating layer is an anodized film of aluminum and constitutes the insulating layer. Among elements, the content of elements other than aluminum and oxygen is 20 atomic% or less, and the surface of the aluminum substrate has a large wave structure with an average wavelength of 5 to 100 μm and / or a medium wave with an average opening diameter of 0.7 to 5 μm. An insulating substrate having a structure shape ”is described ([claim 1] [claim 3]).

International Publication No. 2010/150810 JP 2011-132590 A

  As a result of studying the substrates described in Patent Documents 1 and 2, the present inventor clearly shows that, depending on the surface shape of the substrate, although the high regular reflectance is maintained, the diffuse reflectance may decrease. It was clarified that there is room for improvement in luminous efficiency.

  Therefore, an object of the present invention is to provide a reflective substrate for an LED light emitting element and an LED package that are excellent in both regular reflectance and diffuse reflectance and can achieve high luminous efficiency.

As a result of intensive studies to achieve the above object, the inventor of the present invention uses a reflective substrate having a surface in which the arithmetic average roughness Ra and the average interval Psm of the unevenness are within a specific range. The present invention was completed by finding out that it was excellent in any of the rates and that high luminous efficiency could be achieved.
That is, the present invention provides the following (1) to (5).

(1) A LED light emitting element reflective substrate having a surface on which the LED light emitting element is mounted,
Among the surfaces, at least the surface other than the portion where the LED light emitting element is mounted has an arithmetic average roughness Ra of 0.50 to 1.00 μm, and an average unevenness interval Psm of 10 to 20 μm. Reflective substrate.

(2) The surface is the surface of the reflective layer provided on the metal substrate,
The reflective substrate for an LED light-emitting element according to (1), wherein the reflective layer is formed using inorganic particles having an average particle diameter of 0.1 to 5 μm.

  (3) The LED light-emitting element according to (2), wherein the reflective layer is further formed using at least one inorganic binder selected from the group consisting of aluminum phosphate, sodium silicate, and aluminum chloride. Reflective substrate.

  (4) The reflective layer is further formed using at least one thermosetting resin selected from the group consisting of epoxy resin, phenol resin, urea resin, melamine resin, unsaturated polyester resin, and silicon resin ( The reflective substrate for LED light emitting elements as described in 2).

  (5) An LED package having the reflective substrate for an LED light-emitting element according to any one of (1) to (4) and an LED light-emitting element mounted on the surface.

As will be described below, according to the present invention, it is possible to provide a reflective substrate for an LED light emitting element and an LED package which are excellent in both regular reflectance and diffuse reflectance and can achieve high luminous efficiency. .
Moreover, since the LED package of this invention has a high diffuse reflectance, it can be used suitably for a fluorescent lamp alternative LED lamp, and is useful.

1A and 1B are schematic cross-sectional views showing examples of preferred embodiments of the reflective substrate for an LED light emitting device of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of another preferred embodiment of the reflective substrate for an LED light emitting device of the present invention. FIG. 3 is a schematic cross-sectional view showing an example of a preferred embodiment of the LED package of the present invention.

[Reflective substrate for LED light emitting element]
The reflective substrate for an LED light-emitting element of the present invention (hereinafter simply referred to as “the reflective substrate of the present invention”) is a reflective substrate for an LED light-emitting element having a surface on which the LED light-emitting element is mounted. The surface other than the portion on which the LED light emitting element is mounted has an arithmetic average roughness Ra (hereinafter also simply referred to as “Ra”) of 0.50 to 1.00 μm, and an average interval Psm (hereinafter referred to as unevenness). , Simply referred to as “Psm”) is a reflective substrate having a thickness of 10 to 20 μm.
Here, the “surface on which the LED light emitting element is mounted” means the surface of the part where the LED light emitting element is mounted (hereinafter also referred to as “surface (mounting region)”) and the part other than the part where the LED light emitting element is mounted. A surface including a surface (hereinafter also referred to as “surface (non-mounting region)”).
“Ra” and “Psm” refer to surface property parameters described in JIS B0601: 2001, respectively. In the present invention, both are stylus type surface roughness meters (for example, SURFCOM 480A, ACCRETECH). (Manufactured by Tokyo Seimitsu Co., Ltd.).

[Surface shape]
In the present invention, Ra of the surface (non-mounting region) is 0.50 to 1.00 μm, preferably 0.65 to 0.90 μm.
When the Ra of the surface (non-mounting region) is within this range, the regular reflectance and the diffuse reflectance are good.

Moreover, in this invention, Psm of the said surface (non-mounting area | region) is 10-20 micrometers, and it is preferable that it is 10-15 micrometers.
When the Psm of the surface (non-mounting region) is within this range, the diffuse reflectance is better, and the ratio of diffuse reflectance to regular reflectance (diffuse reflectance / regular reflectance) is greater than 95%.

  For the reason that the regular reflectance and the diffuse reflectance are further improved, a frame body joined so as to surround the surface (mounting region) and the LED light emitting element (for example, reference numeral 2 in JP 2004-207678 A). Also, Ra and Psm on the surface (hereinafter also referred to as “frame surface”) are preferably in the numerical ranges described above.

[First embodiment]
In the present invention, as shown in FIG. 1, the surface (non-mounting region) and the surface (mounting region) of the reflective substrate 1 of the present invention are constituted by the surface of the reflective layer 3 provided on the metal substrate 2. Also good.
In FIG. 1, reference numeral 4 indicates inorganic particles described later, reference numeral 5 indicates an inorganic binder described later, and reference numeral 6 indicates a thermosetting resin described later.

<Metal substrate>
The metal that is the material of the metal substrate is not particularly limited, and specific examples thereof include aluminum, tantalum, niobium, titanium, hafnium, zirconium, zinc, tungsten, bismuth, antimony, and the like.
The metal substrate is preferably an aluminum substrate, which will be described in detail below, because it is excellent in workability and strength.

(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 a trace amount of foreign elements; high purity aluminum is used for low purity aluminum (for example, recycled material). It is also possible to use a vapor-deposited substrate; a substrate in which a surface of silicon wafer, quartz, glass or the like is coated with high-purity aluminum by a method such as vapor deposition or sputtering; a resin substrate laminated with aluminum;
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 is described in paragraphs [0031] to [0051] of Patent Document 1 (International Publication No. 2010/150810). The composition, preparation method, and the like can be appropriately employed.

  In the present invention, the aluminum substrate has a thickness of about 0.1 to 2.0 mm, preferably 0.15 to 1.5 mm, and more preferably 0.2 to 1.0 mm. This thickness can be appropriately changed according to the user's wishes or the like.

<Reflective layer>
On the other hand, the reflective layer is made of inorganic particles having an average particle diameter of 0.1 to 5 μm, preferably 0.5 to 2 μm, from the viewpoint of setting Ra and Psm on the surface (non-mounting region) to the numerical ranges described above. It is formed using.
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.

(Inorganic particles)
The kind of the inorganic particles is not particularly limited. For example, conventionally known metal oxides, metal hydroxides, carbonates, sulfates, and the like can be used, and among these, metal oxides are preferably used.
Specific examples of the inorganic particles include metal oxides such as aluminum oxide (alumina), magnesium oxide, yttrium oxide, titanium oxide, zinc oxide, silicon dioxide, and zirconium oxide; aluminum hydroxide, calcium hydroxide, Hydroxides such as magnesium hydroxide; calcium carbonate (light calcium carbonate, heavy calcium carbonate, ultrafine calcium carbonate, etc.), carbonates such as barium carbonate, magnesium carbonate, strontium carbonate; sulfates such as calcium sulfate and barium sulfate Other examples include calcium carbonate, calcite, marble, gypsum, kaolin clay, calcined clay, talc, sericite, optical glass, glass beads, and the like.
Among these, aluminum oxide, silicon dioxide, and aluminum hydroxide are preferable because the affinity with the thermosetting resin and inorganic binder described later is good.

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

Furthermore, in the present invention, it is preferable to use inorganic particles having a refractive index of 1.5 to 1.8 because the regular reflectance and the diffuse reflectance are improved.
Examples of inorganic particles satisfying the refractive index include aluminum oxide (alumina), magnesium oxide, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium sulfate, and barium sulfate. , Marble, plaster, kaolin clay, talc, sericite, optical glass, glass beads and the like.

(Inorganic binder)
The reflective layer is selected from the group consisting of aluminum phosphate, sodium silicate, and aluminum chloride because the strength of the reflective layer is improved and the adhesion strength between the reflective layer and the metal substrate is also improved. It is preferably formed using at least one inorganic binder.

(Thermosetting resin)
The reflective layer further improves the strength of the reflective layer, and also improves the adhesion strength between the reflective layer and the metal substrate, and further, epoxy resin, phenol resin, urea resin, melamine resin, unsaturated polyester. It is preferably formed using at least one thermosetting resin selected from the group consisting of a resin and a silicon resin.

The reflective layer may contain other compounds in addition to the inorganic particles, the inorganic binder, and the thermosetting resin described above.
Examples of the other compound include a dispersant (water, organic solvent), a photopolymerizable monomer, a photopolymerization initiator, a crosslinking agent, a crosslinking accelerator, and a surfactant.

(Formation method)
In the present invention, the method for forming the reflective layer is not particularly limited. For example, a coating liquid (composition) containing the inorganic particles and the inorganic binder or the thermosetting resin on the metal substrate. ) By screen printing or the like and dried.

[Second embodiment]
In the present invention, as shown in FIG. 2, the surface (non-mounting region) and the surface (mounting region) of the reflective substrate 1 of the present invention may be constituted by the surface of an insulating substrate 7 made of alumina ceramics.
Specific examples of the alumina ceramic include sintered bodies such as an aluminum oxide (Al ₂ O ₃ ) sintered body and an aluminum nitride (AlN) sintered body.

<Etching>
In the present invention, the insulating substrate is obtained by performing desired etching on the surface of the sintered body made of alumina ceramic from the viewpoint of setting Ra and Psm of the surface (non-mounting region) to the above numerical ranges. It is done.
Here, as the etching, for example, the following alkali etching treatment is preferably exemplified.

(Alkaline etching treatment)
In the alkali etching treatment, the insulating substrate is brought into contact with an alkaline solution to dissolve the surface layer, dissolve the edge portion of the grain boundary of the sintered body existing on the surface, and change the surface to have a smooth unevenness (swell). It is done for the purpose.

In the present invention, the etching amount of the alkali etching treatment, the Psm for the surface (non-mounting region) from the viewpoint of a 10 to 20 [mu] m, preferably at 1 g / m ² or more, is 5 to 20 g / m ² Is more preferable.

  Examples of the alkali used in the alkaline solution include caustic alkali and alkali metal salts. Specifically, examples of caustic alkali include caustic soda and caustic potash. Examples of alkali metal salts include alkali metal silicates such as sodium silicate, sodium silicate, potassium metasilicate, and potassium silicate; alkali metal carbonates such as sodium carbonate and potassium carbonate; sodium aluminate and alumina. Alkali metal aluminates such as potassium acid; alkali metal aldones such as sodium gluconate and potassium gluconate; dibasic sodium phosphate, dibasic potassium phosphate, tribasic sodium phosphate, tertiary potassium phosphate, etc. An alkali metal hydrogen phosphate is mentioned. Among these, a caustic alkali solution and a solution containing both a caustic alkali and an alkali metal aluminate are preferable from the viewpoint of high etching rate and low cost. In particular, an aqueous solution of caustic soda is preferable.

  Moreover, although the density | concentration of the said alkaline solution can be determined according to the etching amount, it is preferable that it is 1-50 mass%, and it is more preferable that it is 10-35 mass%. When aluminum ions are dissolved in the alkaline solution, the concentration of aluminum ions is preferably 0.01 to 10% by mass, and more preferably 3 to 8% by mass. The temperature of the alkaline solution is preferably 20 to 90 ° C. The treatment time is preferably 1 to 120 seconds.

  Examples of the method of bringing the insulating substrate into contact with the alkaline solution include, for example, a method of passing the insulating substrate in a bath containing an alkaline solution, a method of immersing the insulating substrate in a bath containing an alkaline solution, The method of spraying a solution on the surface of an aluminum substrate is mentioned.

<Reflective layer (silver deposited film)>
In the present invention, the insulating substrate may have a reflective layer made of a silver (Ag) vapor deposition film on the insulating substrate for the reason that the regular reflectance and the diffuse reflectance are better.
Here, from the viewpoint of maintaining the surface shape of the surface (non-mounting region), the thickness of the Ag vapor deposition film is preferably 0.1 to 10 μm, and more preferably 0.5 to 1 μm. . The film thickness is adjusted by changing the mass of the Ag wire used in the vapor deposition apparatus. The film thickness is maintained by using a non-contact interference film thickness meter to maintain the film thickness formed on a smooth glass substrate by changing the line mass. It is possible to calculate from a calibration curve created by measuring using.

(Formation method)
The formation method of the said Ag vapor deposition film is not specifically limited, It can form using a conventionally well-known metal vapor deposition apparatus.

[Common mode]
<Wiring layer>
The reflective substrate of the present invention may have a wiring layer (metal wiring layer) when mounting the LED light emitting element.
In the present invention, the wiring layer may be provided on a part of the surface on which the LED light emitting element is mounted, or the surface on which the LED light emitting element is mounted (hereinafter referred to as “mounting surface” in this paragraph). ”) And may be electrically connected to the mounting surface of the LED light emitting element via a through hole.

The material of the wiring layer 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 layer made of Cu from the viewpoint of improving the ease of wire bonding.

  The thickness of the wiring layer 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 of forming the wiring layer, in addition to various plating processes such as an electrolytic plating process, an electroless plating process, and a displacement plating process, a sputtering process, a vapor deposition process, a vacuum bonding process for metal foil, and an adhesion process with an adhesive layer provided. Etc.
Among these, from the viewpoint of high heat resistance, the metal-only layer formation is preferable, and from the viewpoint of thick film / uniform formation and high adhesion, layer formation by plating is particularly preferable.

Since the plating process is a plating process for an inorganic material, it is preferable to use a technique in which a reduced metal layer called a seed layer is provided and then a thick metal layer is formed using the metal layer.
In addition, it is preferable to use electroless plating for the formation of the seed layer. The plating solution includes a main component (for example, a metal salt and a reducing agent) and an auxiliary component (for example, a pH adjusting agent, a buffering agent, a complex). It is preferable to use a solution composed of an agent, accelerator, stabilizer, improver, etc. In addition, as a plating solution, SE-650 * 666 * 680, SEK-670 * 797, SFK-63 (all manufactured by Nippon Kanisen Co., Ltd.), Melplate NI-4128, Enplate NI-433, Enplate NI-411 Commercial products such as those manufactured by Meltex can be used as appropriate.
Further, when copper is used as the material for the wiring layer, various electrolytic solutions containing sulfuric acid, copper sulfate, hydrochloric acid, polyethylene glycol and a surfactant as main components and other various additives can be used.

The wiring layer formed in this way is patterned by a known method according to the mounting design of the LED light emitting element. In addition, a metal layer (including solder) is provided again at a location where the LED is actually mounted, and can be appropriately processed so as to be easily connected by thermocompression bonding, flip chip, wire bonding, or the like.
As a suitable metal layer, a metal material such as solder or gold (Au), silver (Ag), copper (Cu), aluminum (Al), magnesium (Mg), nickel (Ni) is preferable. From the viewpoint of mounting reliability, a method of providing Au or Ag via solder or Ni is preferable from the viewpoint of connection reliability.

  If a pattern is formed by an inkjet printing method or a screen printing method using a metal ink described below as a method for forming a wiring layer, a wiring layer having a pattern can be easily formed without requiring many steps on an uneven surface. Can be formed.

(Inkjet printing method)
A wiring layer can be formed on a desired portion of the surface of the reflective substrate by ink jet printing using a metal ink containing a conductive metal. Specifically, a wiring pattern is formed with metal ink, and then fired to form a wiring.
Examples of the metal ink include those obtained by uniformly dispersing fine particles of a conductive metal in a solvent containing a binder, a surfactant, and the like. In this case, the solvent needs to have both affinity for the conductive metal and volatility.

Conductive metals contained in the metal ink include fine particles of metals such as silver, copper, gold, platinum, nickel, aluminum, iron, palladium, chromium, molybdenum, tungsten; silver oxide, cobalt oxide, iron oxide, ruthenium oxide, etc. Metal oxide fine particles; Cr—Co—Mn—Fe, Cr—Cu, Cr—Cu—Mn, Mn—Fe—Cu, Cr—Co—Fe, Co—Mn—Fe, Co—Ni—Cr—Fe, etc. Fine particles of a composite alloy of the above; fine particles of a plating composite such as silver plating and copper; and the like. These may be used alone or in combination of two or more.
Among these, metal fine particles are preferable, silver, copper, and gold are more preferable, oxidation resistance is excellent, it is difficult to form a high-insulation oxide, and the cost is low, and the conductivity after firing the wiring pattern is improved. For this reason, silver is particularly preferable.

The shape of the conductive metal that is a fine particle is not particularly limited, and examples thereof include a spherical shape, a granular shape, and a scaly shape. From the viewpoint of increasing the contact area between the fine particles and improving the conductivity, the scaly shape is preferable. preferable.
The average size of the conductor metal contained in the metal ink is preferably 1 to 20 nm and more preferably 5 to 10 nm from the viewpoint of increasing the filling rate in the wiring pattern formed with the metal ink and improving the conductivity.

(Screen printing method)
A wiring pattern is formed on a desired portion of the surface of the reflective substrate by screen printing using a metal ink containing a conductive metal, and then fired to form a wiring.
The supply of the metallic ink by the screen printing method can be performed by providing a transmissive portion according to the wiring pattern on the screen and squeezing the metallic ink from the transmissive portion.
As a metal ink containing a conductor metal, what was used by the inkjet printing method mentioned above can be used.

[LED package]
Below, the LED package of this invention is demonstrated in detail.
The LED package of the present invention is an LED package having the above-described reflective substrate of the present invention and an LED light emitting element mounted on the surface thereof.
Next, the configuration of the LED package of the present invention will be described with reference to FIG.

  As shown in FIG. 3, the LED package 20 includes an LED 9 mounted on the surface of the reflective substrate 1 (reflective layer 3). The LED 9 is molded with a transparent resin 11 mixed with fluorescent particles 10 and is wire-bonded to the reflective substrate 1 of the present invention having a metal wiring layer 8 that also serves as an electrode for external connection.

In the present invention, the LED light emitting element is formed by forming a semiconductor such as GaAlN, ZnS, ZnSe, SiC, GaP, GaAlAs, AlN, InN, AlInGaP, InGaN, GaN, AlInGaN on the substrate as the light emitting layer. It is done.
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.

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.
[Production of reflective substrate]
<Comparative Example 1>
After kneading 100 g of alumina particles (AL-160SG-3, average particle size: 0.52 μm, manufactured by Showa Denko KK), 0.5 g of polyvinyl alcohol (PVA) binder and 20 g of water, firing was performed at 300 ° C. for 2 hours. .
Next, it was molded into a size of 2 mm in thickness of 3 cm × 3 cm by a press, heated at a heating rate of 400 ° C./hour, held at 1800 ° C. for 8 hours, sintered, and alumina. A reflective substrate made of a ceramic sintered body was produced.

<Comparative example 2>
The alumina ceramic sintered body produced in Comparative Example 1 was subjected to an etching treatment by spraying for 30 minutes using an aqueous solution having a caustic soda concentration of 5.0 mass% and a temperature of 40 ° C., and the surface was dissolved at 25 g / m ^2. A substrate was produced.

<Example 1>
The alumina ceramic sintered body produced in Comparative Example 1 was subjected to an etching process by spraying for 10 minutes using an aqueous solution having a caustic soda concentration of 5.0 mass% and a temperature of 40 ° C., and the surface was dissolved at 8 g / m ^2. A substrate was produced.

<Comparative Example 3>
Using a metal vapor deposition device (JEE-4X, manufactured by JEOL) on the surface of the alumina ceramic sintered body produced in Comparative Example 1, Ag vapor was used so that the film thickness was 0.7 μm using Ag wire as the radiation source. A reflective substrate on which a film was formed was produced.

<Comparative example 4>
A metal deposition apparatus (JEE-4X, manufactured by JEOL) is used on the surface of the reflective substrate (etched alumina ceramic sintered body) produced in Example 1, and Ag wire is used as the radiation source, and the film thickness is 15 μm. A reflective substrate on which an Ag vapor deposition film was formed was prepared.

<Example 2>
A metal vapor deposition apparatus (JEE-4X, manufactured by JEOL) is used on the surface of the reflective substrate (etched alumina ceramic sintered body) produced in Example 1, the Ag wire is used as the radiation source, and the film thickness is 0. A reflective substrate on which an Ag vapor deposition film was formed so as to be 0.7 μm was produced.

<Comparative Example 5>
(Preparation of aluminum substrate)
Si: 0.06 mass%, Fe: 0.30 mass%, Cu: 0.005 mass%, Mn: 0.001 mass%, Mg: 0.001 mass%, Zn: 0.001 mass%, Ti: Containing 0.03% by mass, the balance is prepared using Al and an inevitable impurity aluminum alloy, and after performing the molten metal treatment and filtration, an ingot having a thickness of 500 mm and a width of 1200 mm is obtained by a DC casting method. Produced.
Next, the surface was shaved with a chamfering machine with an average thickness of 10 mm, soaked at 550 ° C. for about 5 hours, and when the temperature dropped to 400 ° C., the thickness was 2.7 mm using a hot rolling mill. A rolled plate was used.
Furthermore, after performing heat processing at 500 degreeC using a continuous annealing machine, it finished by cold rolling to thickness 1.0mm, and obtained the aluminum substrate of JIS1050 material.

(Preparation of reflective layer forming material)
190 g of alumina particles (Admafine, average particle size: 45 nm, manufactured by Admatechs), 225 g of bisphenol A epoxy resin (Japan Epoxy Resin), 20 g of photopolymerization initiator (IRGACURE907, manufactured by Ciba Specialty Chemicals), , 15g of monomer component (dipentaerythritol hexaacrylate), 3g of silicone oil (KS-66, manufactured by Shin-Etsu Silicone) and 20g of solvent (carbitol acetate) are kneaded to form a reflective layer. A functional resin composition was prepared.

(Formation of reflective layer)
The said thermosetting resin composition was apply | coated with the screen printing method with respect to the said aluminum substrate, and the reflective board | substrate which has a reflection layer was produced by making it dry.
Specifically, using a 100-mesh polyester bias plate, solid printing was performed to a film thickness of 40 μm, and then the film was dried at 80 ° C. for 10 minutes in a hot air circulation drying furnace.

<Comparative Example 6>
A reflective substrate was produced in the same manner as in Comparative Example 5, except that an embossed aluminum substrate (embossed sheet SE6, manufactured by Sumitomo Light Metal Co., Ltd.) was used instead of the aluminum substrate.

<Comparative Example 7>
First, Comparative Example 5 except that alumina particles (AO509-1, average particle size: 10 μm, manufactured by Admatex) were used instead of alumina particles (Admafine, average particle size: 45 nm, manufactured by Admatex). A thermosetting resin composition was prepared by the same method as the reflective layer forming material prepared in 1.
Next, the above thermosetting resin was further applied to the reflective substrate having the reflective layer produced in Comparative Example 5 so as to have a film thickness of 40 μm, and then at 80 ° C. for 10 minutes in a hot air circulation drying oven. A reflective substrate was produced by drying.

<Example 3>
Except for using alumina particles (AL-160SG-3, average particle size: 0.52 μm, Showa Denko) instead of alumina particles (AO509-1, average particle size: 10 μm, manufactured by Admatex), A reflective substrate was produced in the same manner as in Comparative Example 7.

<Example 4>
(Preparation of aluminum substrate)
An aluminum substrate similar to that in Comparative Example 5 was produced.
(Preparation of reflective layer forming material)
190 k of alumina particles (AL-160SG-3, average particle size: 0.52 μm, manufactured by Showa Denko KK) and 20 g of a modified polydimethylsiloxane-containing material prepared by the method described below, heat for forming a reflective layer A curable resin composition was prepared.
(Preparation of modified polydimethylsiloxane)
Into a reaction vessel equipped with a stirrer, a thermometer, and a dropping line, 1.0 g of ethyl silicate (silicate 40, n = 4 to 6, manufactured by Tama Chemical Industry Co., Ltd.) was put, and polydimethyl having ethyl silicate alkoxy-modified at both ends. 32.0 g of siloxane (HBSIL039, mass average molecular weight; equivalent to 32,000, manufactured by Arakawa Chemical Co., Ltd.) was mixed with stirring in the atmosphere (room temperature) for about 30 minutes to obtain a raw material liquid A as a hybrid. Here, silicates having the same type and the same characteristics were used as silicates used in ethyl silicate and polydimethylsiloxane obtained by alkoxy-modifying ethyl silicate at both ends.
Then, the raw material liquid A was added dropwise over a period of about 1 hour with 0.93 g of a required amount of water in the hydrolysis step and the condensation step, and mixed with stirring. Then, it naturally cooled to room temperature over about 30 minutes, stirring, and obtained the modified polydimethylsiloxane containing material.
(Formation of reflective layer)
The said thermosetting resin composition was apply | coated with the screen printing method with respect to the said aluminum substrate, and the reflective board | substrate which has a reflection layer was produced by making it dry.
Specifically, using a 100-mesh polyester bias plate, solid printing was performed to a film thickness of 40 μm, and then the film was dried at 80 ° C. for 10 minutes in a hot air circulation drying furnace.

<Example 5>
(Preparation of aluminum substrate)
An aluminum substrate similar to that in Comparative Example 5 was produced.
(Preparation of reflective layer forming material)
A thermosetting resin composition for kneading 190 g of alumina particles (AL-160SG-3, average particle size: 0.52 μm, manufactured by Showa Denko KK) and 20 g of a phenol resin composition having the following composition to form a reflective layer. A product was prepared.
(Phenolic resin composition)
Novolak resin (m-cresol / p-cresol = 60/40, weight average molecular weight 7,000, containing 0.5% by mass of unreacted cresol) 0.90 g
・ Ethyl methacrylate / isobutyl methacrylate / methacrylic acid copolymer (molar ratio 35/35/30) 0.10 g
・ Fluorosurfactant (Megafac F-780F, manufactured by Dainippon Ink and Chemicals, solid content: 30% by mass) 0.0045 g (solid content conversion)
・ Methyl ethyl ketone 12g
(Formation of reflective layer)
The said thermosetting resin composition was apply | coated with the screen printing method with respect to the said aluminum substrate, and the reflective board | substrate which has a reflection layer was produced by making it dry.
Specifically, using a 100-mesh polyester bias plate, solid printing was performed to a film thickness of 40 μm, and then the film was dried at 80 ° C. for 10 minutes in a hot air circulation drying furnace.

<Comparative Example 8>
(Preparation of aluminum substrate)
An aluminum substrate similar to that in Comparative Example 5 was produced.
(Preparation of reflective layer forming material)
A binder liquid A in which 90 g of water, 55 g of phosphoric acid 85% (Wako Pure Chemical Industries) and 25 g of aluminum hydroxide (Wako Pure Chemical Industries) are mixed, and alumina particles (Admafine, average particle diameter: 45 nm, manufactured by Admatex Co., Ltd.) as inorganic particles. ) Was added and stirred to prepare an inorganic composition forming a reflective layer.
(Formation of reflective layer)
The said inorganic composition was apply | coated with the screen printing method with respect to the said aluminum substrate, and the reflective board | substrate which has a reflection layer was produced by making it dry.
Specifically, solid printing was performed using a 100-mesh polyester bias plate to a film thickness of 70 μm, and then the film was dried at 250 ° C. for 30 minutes in a hot air circulation type drying furnace.
The presence of aluminum phosphate (inorganic binder) in the reflective layer was confirmed by infrared spectroscopy (IR).

<Comparative Example 9>
First, Comparative Example 8 except that alumina particles (AO509-1, average particle size: 10 μm, manufactured by Admatex) were used instead of alumina particles (Admafine, average particle size: 45 nm, manufactured by Admatex). An inorganic composition was prepared in the same manner as the reflective layer forming material prepared in 1.
Next, the inorganic composition was further applied to the reflective substrate having the reflective layer produced in Comparative Example 8 so as to have a film thickness of 40 μm, and then dried at 80 ° C. for 10 minutes in a hot air circulation drying oven. Thus, a reflective substrate was produced. In addition, about the particle size of the inorganic particle which forms the following Table 1 and a reflective layer, the particle size of the inorganic particle (alumina particle, AO509-1) which forms the reflective layer of a reflective substrate surface is described.

<Example 6>
A comparison was made except that alumina particles (AL-160SG-3, average particle size: 0.52 μm, Showa Denko) were used instead of alumina particles (Admafine, average particle size: 45 nm, manufactured by Admatechs). A reflective substrate was produced in the same manner as in Example 8.

<Example 7>
A reflective substrate was produced in the same manner as in Comparative Example 8, except that the following inorganic composition was used as the reflective layer forming material.
(Reflective layer forming material)
By using 100 g of the binder liquid B having the composition shown below, and adding 250 g of alumina particles (AL-160SG-3, average particle size: 0.52 μm, manufactured by Showa Denko KK) as inorganic particles, and stirring them, An inorganic composition for forming a reflective layer was prepared.
<Composition of binder liquid B>
・ 85% hydrochloric acid (Wako Pure Chemical) 46.9g
・ Aluminum hydroxide (Wako Pure Chemical) 11g
・ Water 90g

<Example 8>
A reflective substrate was produced in the same manner as in Comparative Example 8, except that the following inorganic composition was used as the reflective layer forming material.
(Preparation of reflective layer forming material)
No. 3 sodium silicate stock solution (specific gravity 1.4) manufactured by Toyama Chemical Co., Ltd. and water mixed in a mass ratio of 1: 1 were mixed with alumina particles (AL-160SG-3, average) as inorganic particles. 250 g of a particle size of 0.52 μm (manufactured by Showa Denko KK) was added and stirred to prepare an inorganic composition forming a reflective layer.

<Example 9>
First, alumina particles (AL-160SG-3, average particle size: 0.52 μm, Showa Denko) were used instead of alumina particles (Admafine, average particle size: 45 nm, manufactured by Admatechs). An inorganic composition was prepared in the same manner as the reflective layer forming material prepared in Comparative Example 8.
Next, the inorganic composition was further applied to the reflective substrate having the reflective layer produced in Comparative Example 8 so as to have a film thickness of 40 μm, and then dried at 80 ° C. for 10 minutes in a hot air circulation drying oven. Thus, a reflective substrate was produced. In addition, about the particle size of the inorganic particle which forms the following Table 1 and a reflective layer, the particle size of the inorganic particle (alumina particle, AL-160SG-3) which forms the reflective layer of a reflective substrate surface is described.

<Example 10>
As the inorganic particles of the reflective layer forming material, aluminum hydroxide (BF013, average particle size: 1.2 μm, manufactured by Nippon Light Metal Co., Ltd.) was used instead of alumina particles (Admafine, average particle size: 45 nm, manufactured by Admatex). A reflective substrate was produced in the same manner as in Comparative Example 8 except that it was used.

<Example 11>
As inorganic particles of the reflective layer forming material, barium sulfate (W-1, average particle size: 1.5 μm, manufactured by Takehara Chemical Industry Co., Ltd.) was used instead of alumina particles (Admafine, average particle size: 45 nm, manufactured by Admatechs). A reflective substrate was produced in the same manner as in Comparative Example 8, except that

<Example 12>
(Preparation of aluminum substrate)
An aluminum substrate similar to that in Comparative Example 5 was produced.
(Production of reflective layer)
After kneading 100 g of alumina particles (AL-160SG-3, average particle size: 0.52 μm, manufactured by Showa Denko KK), 0.5 g of polyvinyl alcohol (PVA) binder and 20 g of water, firing was performed at 300 ° C. for 2 hours. .
Next, it was molded into a size of 2 mm in thickness of 3 cm × 3 cm by a press, heated at a heating rate of 400 ° C./hour, held at 1800 ° C. for 8 hours, sintered, and alumina. A ceramic sintered body was produced.
Next, the produced alumina ceramic sintered body was subjected to an etching process by spraying using an aqueous solution having a caustic soda concentration of 5.0 mass% and a temperature of 40 ° C. for 15 minutes, and a reflective layer having a surface dissolved of 12 g / m ^{2 was} obtained. Produced.
(Production of reflective substrate)
An inorganic adhesive (Sumiceram S-17, manufactured by Asahi Chemical Industry Co., Ltd.) is applied to the surface of the aluminum substrate using a brush, and the reflective layer (sintered body) is quickly pressed and dried at 80 ° C. for 30 minutes. Then, by further curing at 150 ° C. for 1 hour, a reflective substrate in which the aluminum substrate and the reflective layer were adhered was produced.

<Example 13>
(Preparation of aluminum substrate)
An aluminum substrate similar to that in Comparative Example 5 was produced.
(Production of reflective layer)
After kneading 100 g of titanium oxide particles (PT-301, average particle size: 0.24 μm, manufactured by Ishihara Sangyo Co., Ltd.), 0.5 g of polyvinyl alcohol (PVA) binder and 20 g of water, the mixture was baked at 300 ° C. for 2 hours.
Next, it was molded into a size of 2 mm in thickness of 3 cm × 3 cm by a press, heated at a heating rate of 400 ° C./hour, held at 1500 ° C. for 8 hours, sintered, and oxidized. A titanium ceramic sintered body was prepared.
Next, the produced titanium oxide ceramic sintered body was immersed in 1% hydrofluoric acid at a liquid temperature of 30 ° C. for 10 minutes to produce a reflective layer having a surface dissolved by 4 g / m ² .
(Production of reflective substrate)
A reflective substrate in which the reflective layer was adhered to the surface of the aluminum substrate was produced in the same manner as in Example 12.

<Comparative Example 10>
The insulating substrate of Example 1 described in paragraphs [0095] to [0106], [0114] and [0119] of Patent Document 2 (Japanese Patent Laid-Open No. 2011-132590) was used as a reflective substrate.

[Surface shape measurement]
About the surface shape of each light reflection board produced above, Ra and Psm were measured using a stylus type surface roughness meter (SURFCOM 480A, ACCRETECH (Tokyo Seimitsu) company make). These results are shown in Table 1 below.

[Reflectance]
Using the SP-60 type integrating sphere photometer manufactured by X-Rite, the specular reflectance (total average of SPIN mode) and diffuse reflectance (total average of SPEX mode) of 400 to 700 nm were measured for the produced insulating reflective substrate. It was measured. Along with these results, the reflectance ratio (diffuse reflectance / regular reflectance) is shown in Table 1 below.

[Luminescence efficiency]
A blue LED light emitting element was mounted on the surface of each of the produced reflective substrates by a wire bonding method, and the Cu wiring layer and the blue LED light emitting element were connected.
After mounting the blue LED light emitting element, a pseudo white LED package was produced by providing a sealing material containing a yellow phosphor on the surface.
About each produced pseudo white type LED package, the electric current (A) at the time of driving with the voltage of 10V and the light beam quantity (lm) in chromaticity X value = 0.33 are measured, and luminous efficiency ( lm / W) was calculated. The results are shown in Table 1 below.
Luminous efficiency (lm / W) = light flux (lm) / (current (A) × 10 (V))

From the results shown in Table 1, the reflection substrate having a surface shape in which one or both of Ra and Psm are outside the predetermined numerical range has a diffuse reflectance value of regular reflectance except for Comparative Examples 7 and 10. It was found that the ratio (diffuse reflectance / regular reflectance) was 95% or less.
Moreover, it turned out that the reflective substrate produced in the comparative example 7 has low luminous efficiency.
Similarly, it was found that the reflective substrate produced in Comparative Example 10 had a small Psm and reduced luminous efficiency.
In contrast, a reflective substrate having a surface shape in which Ra and Psm are both within a predetermined numerical range has a high regular reflectance and a diffuse reflectance, and their ratio (diffuse reflectance / regular reflectance) is also high. It became larger than 95%, and it turned out that high luminous efficiency can be achieved, and it turned out that all are useful as a fluorescent lamp alternative LED lamp (Examples 1-13).
In particular, comparison between Example 1 and Examples 2 to 13 reveals that the light emission efficiency tends to be higher when the surface shape is the surface shape of the reflective layer.

DESCRIPTION OF SYMBOLS 1 Reflective substrate 2 Metal substrate 3 Reflective layer 4 Inorganic particle 5 Inorganic binder 6 Thermosetting resin 7 Insulating substrate (alumina ceramics)
8 Metal wiring layer 9 LED light emitting element 10 Fluorescent particle 11 Transparent resin 20 LED package

Claims (5)

A LED light emitting element reflective substrate having a surface on which the LED light emitting element is mounted,
Among the surfaces, at least the surface other than the portion on which the LED light emitting element is mounted has an arithmetic average roughness Ra of 0.50 to 1.00 μm, and an unevenness average interval Psm of 10 to 20 μm. Reflective substrate for light emitting element. The surface is a surface of a reflective layer provided on a metal substrate;
The reflective board | substrate for LED light emitting elements of Claim 1 in which the said reflection layer is formed using an inorganic particle with an average particle diameter of 0.1-5 micrometers.   The reflection for LED light emitting elements according to claim 2, wherein the reflection layer is further formed using at least one inorganic binder selected from the group consisting of aluminum phosphate, sodium silicate and aluminum chloride. substrate.   The reflective layer is further formed using at least one thermosetting resin selected from the group consisting of an epoxy resin, a phenol resin, a urea resin, a melamine resin, an unsaturated polyester resin, and a silicon resin. The reflective board | substrate for LED light emitting elements of description.   The LED package which has the reflecting substrate for LED light emitting elements of any one of Claims 1-4, and the LED light emitting element mounted in the said surface.