JP2018041897A - Light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting device in which deterioration of Ag is reduced. SOLUTION: A substrate having a metal member containing Ag on its surface and an insulating substrate, a light emitting element mounted on the substrate, at least a part of the metal member, and a seal covering the light emitting element. A light emitting device comprising a member, and the sealing member includes a dimethyl silicone resin covering a light emitting element, a silicon oxide film covering the dimethyl silicone resin, and a phenyl silicone resin covering the silicon oxide film. [Selection diagram] Fig. 1

Description

  The present invention relates to a light emitting device.

  In a light-emitting device using a semiconductor light-emitting element (hereinafter also simply referred to as “light-emitting element”), a package including a metal member having silver (Ag) having a high reflectivity with respect to light from the light-emitting element as an outermost surface is provided. Are known. Ag is easily altered (sulfurized) in an atmosphere in which a corrosive gas such as a sulfur-containing gas exists. As a result, discoloration and corrosion occur, and the reflectance is lowered, and the characteristics of the light emitting device are significantly lowered. Therefore, it is known to use a material having a high gas barrier property as the sealing resin that covers Ag (for example, Patent Document 1) or to laminate a sealing resin (for example, Patent Documents 2 and 3). It is also known that the surface of Ag is covered with a protective film using an inorganic material such as glass (for example, Patent Documents 4 and 3).

JP 2012-138425 A JP 2014-216329 A JP 2008-216329 A JP 2007-324256 A JP 2009-224536 A

  There is a need for a light emitting device with reduced Ag alteration.

Embodiments of the present invention include the following configurations.
A substrate comprising a metal member containing Ag on the surface, an insulating base, a light emitting element placed on the substrate, at least a part of the metal member, and a sealing member that covers the light emitting element. And a sealing member comprising: a dimethyl silicone resin that covers the light emitting element; a silicon oxide film that covers the dimethyl silicone resin; and a phenyl silicone resin that covers the silicon oxide film.

  As described above, a light-emitting device in which alteration of Ag is reduced can be obtained.

FIG. 1 is a schematic cross-sectional view illustrating a light emitting device according to an embodiment. FIG. 2 is a schematic cross-sectional view illustrating the light emitting device according to the embodiment. FIG. 3 is a schematic cross-sectional view illustrating the light emitting device according to the embodiment.

  A mode for carrying out the present invention will be described below with reference to the drawings. However, the form shown below illustrates the light-emitting device for embodying the technical idea of the present invention, and the present invention does not limit the light-emitting device to the following.

  Further, the present specification by no means specifies the member shown in the claims as the member of the embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the embodiments are not intended to limit the scope of the present disclosure to that unless otherwise specified. It should be noted that the size and positional relationship of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate.

  The light emitting device according to the embodiment includes a substrate, a light emitting element placed on the substrate, and a sealing member that covers the light emitting element. The substrate includes a metal member containing Ag (silver) on the surface and an insulating base. The sealing member includes a dimethyl silicone resin that covers the light emitting element, a silicon oxide film that covers the dimethyl silicone resin, and a phenyl silicone resin that covers the silicon oxide film.

  By using a sealing member having a three-layer structure as described above, Ag deterioration of the metal member can be reduced.

(substrate)
The substrate includes a metal member and an insulating base. The board | substrate may be provided with flat form or the recessed part. When a board | substrate is provided with a recessed part, the metal member containing Ag on the surface can be arrange | positioned at the bottom face of a recessed part and / or the side surface of a recessed part.

  The metal member contains Ag in at least a part of its surface. For example, a metal member comprising only an Ag-containing layer or a metal member provided with a base material and an Ag-containing layer containing Ag on the surface thereof can be given.

  Examples of the metal member include a plate-like metal member in which a plating containing Ag is formed on the surface of a base material such as a metal plate. Examples of such a conductive base material include metal plates such as Cu, Al, Ag, and Au. In addition, a metal member such as a conductive wiring provided on an insulating base such as ceramic or resin can be used. Examples of the base material for such a metal member include Mo and W.

  The metal member is used as a light reflecting member that exhibits a high reflectance with respect to light from the light emitting element. The surface of the metal member containing Ag should just be arrange | positioned in the position where the light from a light emitting element is irradiated. For example, a metal member such as a lower side, a side, or an upper side of the light emitting element can be placed.

  The metal member can be a metal member that functions as an electrode of the light-emitting device and / or a metal member that does not contribute to energization. The metal member and the light emitting element can be bonded by a conductive or insulating bonding member. The metal member and the light emitting element can be electrically connected to each other using a wire or the like.

  Further, at least a part of the surface of the metal member containing Ag is sealed with dimethyl silicone resin together with the light emitting element.

  Examples of the insulating substrate include resin, ceramics, and glass. As the resin, specifically, as the thermosetting resin, an epoxy resin composition, a modified epoxy resin composition, a silicone resin composition, a modified silicone resin composition, a silicone modified epoxy resin, an epoxy modified silicone resin composition, Examples of the resin include polyimide resin compositions, modified polyimide resin compositions, and unsaturated polyesters. Thermoplastic resins include polyamide, polyphthalamide (PPA), polycarbonate resin, polyphenylene sulfide (PPS), and liquid crystal polymer (LCP). , ABS resin, phenol resin, acrylic resin, PBT resin and the like, and a resin containing at least one of them can be used. In addition, the substrate preferably has a reflectance with respect to light from the light emitting element of 60% or more, more preferably 70%, 80% or 90% or more.

  Further, the substrate may contain a light reflecting material such as titanium oxide, silicon dioxide, zirconium dioxide, potassium titanate, alumina, aluminum nitride, zinc oxide, boron nitride, mullite. Thereby, the light from a light emitting element can be reflected efficiently. For example, when titanium oxide is used, it is preferably contained in an amount of 10 to 60% by weight, more preferably 15 to 50% by weight, based on the total weight of the molding resin.

  In addition to the substrate, a frame may be provided. The frame can be formed, for example, by drawing a resin including a light reflecting material such as titanium oxide in a frame shape while discharging the resin from the tip of a nozzle disposed above the substrate.

(Light emitting element)
A light emitting element is comprised from the semiconductor layer containing the light emitting layer laminated | stacked on the element substrate. The p layer, light emitting layer, and n layer constituting the semiconductor layer are not particularly limited. For example, In _X Al _Y Ga _1- XYN (0 ≦ X, 0 ≦ Y, X + Y ≦ 1). Nitride-based compound semiconductors such as are preferably used. Each of these nitride semiconductor layers may have a single layer structure, but may have a laminated structure of layers having different compositions and film thicknesses, a superlattice structure, or the like. In particular, the light emitting layer preferably has a single quantum well or multiple quantum well structure in which thin films that produce quantum effects are stacked.

  A pair of electrodes included in the light-emitting element is disposed on the same surface of the semiconductor layer or on both surfaces with the semiconductor layer interposed therebetween. The pair of electrodes may have a single-layer structure or a stacked structure as long as they are ohmic-connected to the semiconductor layer so that the current-voltage characteristics are linear or substantially linear. Such an electrode can be formed with an arbitrary thickness using materials and configurations known in the art.

(Sealing member)
The sealing member is a member that protects the light emitting element and the like from dust, moisture, external force, and the like, and covers at least a part of the metal member and the light emitting element. Specifically, the sealing member includes a dimethyl silicone resin that covers the light emitting element, a silicon oxide film that covers the dimethyl silicone resin, and a phenyl silicone resin that covers the silicon oxide film.

  The dimethyl silicone resin integrally or separately covers the metal member containing Ag on the surface and the light emitting element. Although dimethyl silicone resin has lower gas barrier properties than phenyl silicone resin, it has excellent thermal shock resistance. Therefore, when using a wire to energize the light emitting element, covering all or most of the wire with dimethyl silicone resin can make it difficult to disconnect. The thickness of the dimethyl silicone resin is preferably 150 μm to 600 μm.

  The silicon oxide film covers the dimethyl silicone resin. Specifically, the silicon oxide film is formed between a dimethyl silicone resin and a phenyl silicone resin described later. The silicon oxide film is an inorganic film that can be formed by a sputtering method, a vapor deposition method, or the like, and is a light-transmitting film.

The silicon oxide film formed by the above-described method has a density of 2.2 to 2.5 g / cm ³ , and exhibits excellent gas barrier properties even with a thin film thickness. The thickness of the silicon oxide film is preferably 30 nm to 300 nm. By setting it as the film thickness of such a range, when a dimethyl silicone resin expands-contracts with a heat | fever, it can make it difficult to produce problems, such as a crack. Furthermore, with the above-described film thickness, light from the light-emitting element can be hardly absorbed.

  The silicon oxide film may cover only the dimethyl silicone resin, or may cover the dimethyl silicone resin and other members. For example, when a substrate on which the light-emitting element is placed is provided, a silicon oxide film may be formed so as to cover both the surface of the substrate and the dimethyl silicone resin.

  The phenyl silicone resin covers the silicon oxide film. Phenyl silicone resin is inferior in thermal shock resistance to dimethyl silicone resin but has high gas barrier properties. Moreover, it is excellent in crack resistance compared to a silicon oxide film. Therefore, crack resistance can be improved by forming the phenyl silicone resin so as to cover the silicon oxide film on the dimethyl silicone resin. Moreover, when a recessed part is shallow, a wire may be arrange | positioned in phenyl silicone resin. That is, since a part of the wire can be covered with the phenyl silicone resin, the wire can be protected. The thickness of the phenyl silicone resin is preferably 150 μm to 600 μm.

  By using a sealing member having a three-layer structure as described above, Ag deterioration of the metal member can be reduced.

The sealing member can cover a wire, a protective element, and the like in addition to the metal containing Ag and the light emitting element. Further, the sealing member may contain a phosphor. The phosphor converts light from the light emitting element into light having a different wavelength. Examples of the phosphor include oxide-based, sulfide-based, and nitride-based phosphors. For example, when a gallium nitride-based light emitting device that emits blue light is used as the light emitting device, a YAG system that absorbs blue light to emit yellow to green light, a LAG system, a SiAlON system that emits green light (β sialon), a SCASN that emits red light, Examples of the phosphor include CASN, KSF phosphor (K ₂ SiF ₆ : Mn), and sulfide phosphor. The phosphor may be contained in both the dimethyl silicone resin and the phenyl silicone resin, or may be contained in either one. Preferably, the dimethyl silicone resin contains a phosphor. In addition, the sealing member can contain a colorant, a light diffusing agent, a light reflecting material, various fillers, and the like as desired.

(Embodiment 1)
FIG. 1 is a schematic cross-sectional view of a light emitting device 100 according to the first embodiment. The light emitting device 100 includes a substrate 110 having a recess R <b> 1, a light emitting element 160 placed on the substrate 110, and a sealing member 170 that covers the light emitting element 160. The substrate 110 includes two metal members 120 that function as a pair of electrodes, and a base body 130 that holds them. The metal member 120 is plate-shaped and includes a conductive base material 120b and an Ag-containing layer 120a on the surface thereof. A part of the Ag-containing layer 120a is exposed on the bottom surface of the recess R1 of the substrate 110. The first bottom surface R1ax is also the top surface of the substrate 110. In the first embodiment, the light emitting element 260 is placed on the metal member 120 that is an electrode.

  In the base body 130, a portion constituting the side wall of the recess R1 and a portion constituting a part of the bottom surface of the recess are integrally formed. In the first embodiment, the substrate recess R1 includes a lower recess R1a having a first bottom surface R1ax and a first side surface R1ay, and an upper recess R1b above it.

  The upper recess R1b includes a second bottom surface R1bx located above the first bottom surface R1ax and outside the first bottom surface R1ax. The upper recess R1b includes a second side surface R1by located above the first side surface R1ay and outside the first side surface R1ay. The second bottom surface R1bx is located below the top surface R1c of the side wall of the substrate.

  The light emitting element 160 placed on the first bottom surface R1ax is bonded to the Ag-containing layer 120a via a bonding member. The light emitting element and the metal member 120 including the Ag-containing layer 120 a are joined by a conductive wire 150.

  In the first embodiment, the dimethyl silicone resin 172 is disposed in the lower recess R1a. The silicon oxide film 174 is formed so as to cover the dimethyl silicone resin 172 and also cover the bottom surface R1bx of the upper recess R1b. The phenyl silicone resin 176 covers the silicon oxide film 174 and is disposed in the upper recess R1b.

  The silicon oxide film 174 may be disposed on the side surface of the upper recess R1b that is the second side surface R1by of the recess. Furthermore, the silicon oxide film 174 may be formed on the upper surface R1c of the sidewall of the recess.

  By setting it as the light-emitting device of such a structure, the quality change of Ag containing layer 120a can be suppressed.

(Embodiment 2)
FIG. 2 is a schematic cross-sectional view of the light emitting device 200 according to the second embodiment. The light emitting device 200 is different from the first embodiment in that it includes three metal members 220. The substrate 210 includes a concave portion R2 including a lower concave portion R2a and an upper concave portion R2b as in the first embodiment. The metal member 220 includes two first metal members 221 that function as a pair of electrodes, and one second metal member 222 that does not contribute to energization. The three metal members 220 are the same member, and are each provided with conductive bases 221b and 222b and Ag-containing layers 221a and 222a on the surfaces thereof. The second metal member 222 has the light emitting element 260 mounted on the upper surface thereof, and is exposed to the outside on the lower surface immediately below the second metal member 222. Thereby, when the light emitting device 200 is mounted on the wiring board, the second metal member 222 can function as a heat radiating member capable of efficiently releasing the heat from the light emitting element 260 to the outside.

  The first metal member 221 and the second metal member 222 are integrally held by the base body 230 to constitute the substrate 210. The first metal member 221 and the second metal member 222 are respectively exposed on the bottom surface of the recess of the substrate 210. The light emitting element 260 is placed on the second metal member 222 that does not contribute to energization. The light emitting element 260 and the second metal member 222 are electrically connected by a conductive wire 250.

  In the second embodiment, the dimethyl silicone resin 272 is disposed in the lower recess R <b> 2 a and covers the light emitting element 260. The silicon oxide film 274 is formed so as to cover the dimethyl silicone resin 272 and also cover the bottom surface of the upper recess R2b. The phenyl silicone resin 276 covers the silicon oxide film 274 and is disposed in the upper recess R2b.

  By using the light emitting device having such a structure, it is possible to suppress deterioration of both the Ag-containing layer 221a of the first metal member 221 that contributes to energization and the Ag-containing layer 222b of the second metal member 222 that does not contribute to energization. Can do.

(Embodiment 3)
FIG. 3 is a schematic cross-sectional view of the light emitting device 300 according to the third embodiment. In the light emitting device 300, the flat substrate 330 is insulative, and the light emitting element 360 is placed on the metal member 320 formed on the upper surface of the insulating substrate 330. The metal member 320 includes a first metal member 321 that contributes to energization and a second metal member 322 that does not contribute to energization. The light emitting element 360 is placed on the second metal member 322 that does not contribute to energization. The first metal member 321 and the light emitting element 360 are electrically connected by a wire 350. A connecting portion between the first metal member 321 and the second metal member 322 and between the first metal member 321 and the wire 350 is covered with a frame body 340. The second metal member 322 is disposed in the region surrounded by the frame body 340, and the first metal member 321 is not disposed in the region surrounded by the frame body 340. The first metal member 321 is partly embedded in the frame body 340 and partly disposed outside the frame body 340. The first metal member 321 disposed outside the frame body 340 functions as an external connection terminal.

  In the third embodiment, the light emitting element 360 is disposed in a recess formed by the frame body 340 and the upper surface of the substrate 310. The dimethyl silicone resin 372 covers the light emitting element 360. The silicon oxide film 374 covers the dimethyl silicone resin 372. The phenyl silicone resin 376 covers the silicon oxide film 374.

  In the third embodiment, the first metal member 321 and the second metal member 322 are thin metal layers provided on one insulating base 330, and Ag containing layers 321a and 322a each including at least a surface thereof are Ag. It is. Here, a thin metal such as a base plating or a metal foil can be used as the base material.

  In the third embodiment, the Ag-containing layer 321a of the first metal member 321 that contributes to energization is not covered with the sealing member. Only the Ag-containing layer 322 a of the metal member 322 that does not contribute to energization is covered with the sealing member 370. The sealing member 370 includes a dimethyl silicone resin 372 that covers the light emitting element 360, a silicon oxide film 374 that covers the dimethyl silicone resin 372, and a phenyl silicone resin 376 that covers the silicon oxide film 374. These three-layer sealing members 370 are formed in one frame 340.

  By setting it as the light-emitting device of such a structure, the quality change of Ag containing layer 322a of the metal member 322 which does not contribute to electricity supply can be suppressed.

  The lead, package, and light emitting device according to the present disclosure are used for various light emitting devices such as an illumination light source, various indicator light sources, an in-vehicle light source, a display light source, a liquid crystal backlight light source, a sensor light source, and a traffic light. be able to. Further, the present invention can be applied to all light emitting devices using leads, such as a so-called side view type light emitting device.

DESCRIPTION OF SYMBOLS 100, 200, 300 ... Light-emitting device 110, 210, 310 ... Board | substrate 120, 220, 320 ... Metal member 221, 321 ... 1st metal member 222, 322 ... 2nd metal member 120a, 221a, 222a, 321a, 322a ... Ag Containing layer 120b, 220b ... Base material 130, 230, 330 ... Base R1, R2 ... Substrate recess R1a, R2a ... Lower recess
R1ax: first bottom surface of recess (upper surface of substrate)
R1ay: first side surface of the recess R1b, R2b: upper recess
R1bx: second bottom surface of the recess
R1by: second side surface of the recess R1c: upper surface of the side wall of the recess 340: frame 150, 250, 350 ... wire 160, 260, 360 ... light emitting element 170, 270, 370 ... sealing member 172, 272, 372 ... dimethyl silicone Resin 174, 274, 374 ... Silicon oxide film 176, 276, 376 ... Phenyl silicone resin

Claims (5)

A substrate comprising a metal member containing Ag on the surface and an insulating base;
A light-emitting element placed on the substrate;
At least a part of the metal member, and a sealing member covering the light emitting element;
Have
The sealing member is
Dimethyl silicone resin covering the light emitting element;
A silicon oxide film covering the dimethyl silicone resin;
A phenyl silicone resin covering the silicon oxide film;
A light emitting device comprising:   The light-emitting device according to claim 1, further comprising a wire that electrically connects the metal member and the light-emitting element, wherein all or most of the wire is covered with the dimethyl silicone resin.   The light-emitting device according to claim 1, wherein the dimethyl silicone resin has a thickness of 150 μm to 600 μm.   The light emitting device according to any one of claims 1 to 3, wherein the silicon oxide film has a thickness of 30 nm to 300 nm.   The light emitting device according to claim 1, wherein the phenyl silicone resin has a thickness of 150 μm to 600 μm.

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