JP2017201731A - Light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device superior in quality and reliability which enables the suppression of delamination between members owing to an impact from outside.SOLUTION: A light-emitting device 100 according to the present invention comprises: a support base 2 having external electrodes 7; a light-emitting element 5 provided on at least part of a top face of the support base 2; and an encapsulation member 1 enveloping the light-emitting element 5 and having a maximum outer periphery larger than that of the support base 2 in plan view. The support base 2 has at least one notch 3 on a surface thereof. The encapsulation member 1 is embedded in at least part of the at least one notch 3. The light-emitting device is formed so that electrode faces of the external electrodes 7 are exposed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light emitting device including a light emitting element.

  Conventionally, semiconductor light emitting devices such as LEDs and LDs have been used as various light sources because of their small size and high power efficiency, and research is being conducted to efficiently extract light from the light emitting devices. Among them, a light-emitting device in which a light-transmitting sealing member functioning as a lens is integrally formed has been devised in order to give a desired directivity in the light emission direction. In such a light emitting device, further studies on the efficiency of light extraction and the lens shape are underway.

  When the size of the light emitting element and the size of the sealing member that becomes the lens are relatively close to each other, the critical angle of total reflection on the inner surface of the sealing member in the light emitted from the light emitting element. It has been found that there is a problem that the amount of the component exceeding the value increases and the light extracted to the outside decreases.

  On the other hand, when the size of the supporting substrate and the sealing member on which the light emitting element is placed is increased without changing the size of the light emitting element, a part of the light emitted from the light emitting element or a part of the reflected light Is absorbed by the upper surface of the support substrate, and the light extraction efficiency is reduced.

  Therefore, in order to reduce the total reflection component on the inner surface of the sealing member and reduce the light absorbed on the upper surface of the supporting base material, a light emitting device having a sealing member sufficiently larger than the supporting base material has been devised. (See Patent Document 1 and Patent Document 2).

JP 2007-273964 A JP 2009-88235 A

  However, in a light-emitting device including a sealing member that is sufficiently larger than the support base material, an impact from the outside is easily applied to the extending portion of the sealing member that extends outward from the support base material. There is a high possibility that the joint surface between the member and the supporting base material is peeled off.

  Such a peeling problem becomes a factor that threatens the deterioration of the light extraction efficiency, the lifetime of the product, and the quality and reliability of the product itself.

  The present invention has been made in view of the above problems, and an object thereof is to provide a light-emitting device that suppresses peeling.

In order to achieve the above object, a light-emitting device according to the present invention includes a support base including a plurality of external electrodes, a light-emitting element provided on at least a part of the upper surface of the support base, and the light-emitting element. And a sealing member having a maximum outer periphery larger than that of the plurality of external electrodes in a plan view.The support base has at least one notch on the surface, and the sealing member It is embedded in at least a part of the notch and is formed so as to expose the electrode surface of the external electrode.

  According to the present invention, it is possible to realize a light-emitting device that suppresses peeling between the support base and the sealing member.

1A is a schematic top view of a light emitting device according to an embodiment of the present invention, and FIG. It is a schematic bottom view of the light-emitting device which concerns on one embodiment of this invention. It is a bottom perspective view of a light emitting device according to an embodiment of the present invention. It is a fragmentary sectional view which shows a part of light-emitting device which concerns on one embodiment of this invention. It is a general | schematic fragmentary sectional view of the light-emitting device which concerns on one embodiment of this invention. It is a fragmentary sectional view which shows a part of light-emitting device which concerns on one embodiment of this invention. It is a general | schematic fragmentary sectional view of the light-emitting device which concerns on one embodiment of this invention. 1A is a schematic top view of a light emitting device according to an embodiment of the present invention, and FIG. It is a figure explaining the outline of the total reflection which concerns on one embodiment of this invention. 1A is a schematic top view of a light emitting device according to an embodiment of the present invention, and FIG. It is a fragmentary sectional view which shows a part of light-emitting device which concerns on one embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings as appropriate. However, the form shown below illustrates the light-emitting device for embodying the technical idea of the present invention, and the present invention is not limited to the following.

(First embodiment)
[Outline of configuration of light emitting device]
As shown in FIGS. 1 to 3, the light emitting device 100 according to the first embodiment of the present invention mainly includes a semiconductor light emitting element (hereinafter simply referred to as “light emitting element 5”), a support base 2, and a plan view. The sealing member 1 has a maximum outer periphery larger than that of the support base 2. 1A shows the light emitting device 100 in plan view, and FIG. 1B shows a cross-sectional view of the light emitting device 100 taken along the line AA ′ in FIG. 2 shows the light emitting device 100 in a bottom view, and FIG. 3 is a bottom perspective view of the light emitting device 100.

(Light emitting element)
The light emitting element 5 emits blue light, for example. The light emitting element 5 is mounted by being electrically connected to the upper surface of the support base 2 and is preferably connected by flip chip bonding or wire bonding. The light emitting element 5 can be provided directly on the upper surface of the support substrate 2 or indirectly on a submount or the like placed on the upper surface of the support substrate 2. The light-emitting element 5 includes at least a light-emitting layer, and more preferably includes a semiconductor stacked structure in which a first conductive semiconductor, a light-emitting layer, and a second conductive semiconductor are formed in this order, and supplies current to the semiconductor stacked structure. The semiconductor light emitting device structure is provided with the electrode to be operated. For example, using a GaN-based compound semiconductor that is a nitride semiconductor, an n-type semiconductor layer having a thickness of about 1 to 2 μm, a light emitting layer having a thickness of about 50 to 150 nm, and a thickness of about 100 to 300 nm on a sapphire substrate. The p-type semiconductor layer can be made into a semiconductor light emitting device structure. In order to efficiently extract light, the sapphire substrate may be peeled off from the semiconductor layer by lift-off or the like.
In addition, the light emitting element 5 is not limited to these structures, You may comprise using another semiconductor material.

The light emitting element 5 may include a color conversion member that is excited by light emitted from the light emitting element 5 and emits light having a longer wavelength than the light emitting element 5. For example, as shown in FIG. 4, in the case of the white light emitting element 9, the outside of the light emitting element 5 that emits blue light may be covered with a phosphor layer 8 made of phosphor or a resin containing phosphor. For example, the light-emitting element 5 that emits blue light includes a YAG (yttrium, aluminum, garnet) -based phosphor that emits yellow light, a silicate-based phosphor such as (Sr, Ba) ₂ SiO ₄ : Eu, and the like. The white light emitting element 9 can be obtained by combining. Further, in the light emitting element 5, the plurality of light emitting elements 5 are separated from each other, for example, arranged in a matrix of 2 × 2, and the plurality of light emitting elements 5 are collectively covered with the phosphor layer 8. It may be configured. Thus, if it is the structure which coat | covers the light emitting element 5 with the fluorescent substance layer 8, it will reflect in the sealing member 1 inner surface resulting from scattering by a fluorescent substance by converting into white light in the vicinity of the light emitting element 5. Suppressing and realizing high light extraction efficiency. In addition to this, the phosphors can be mixed and provided in the sealing member 1, or the phosphor layer 8 can be disposed away from the light emitting element 5. As a specific forming method, for example, it can be formed by electrophoretic deposition, printing, spraying, brushing, flow coating, dipping, potting and the like.

(Supporting substrate)
As shown in FIGS. 1 and 2, the support base 2 is provided with a light emitting element 5 on at least a part of its upper surface, and includes an external electrode 7 and at least one notch 3 on the surface. As shown in FIG. 5 (a), the supporting base 2 is made of an insulating substrate provided with wiring, or a lead frame provided with a package resin as shown in FIGS. 5 (b) and 5 (c). I can do it. In the case of using a lead frame, the support substrate 2 refers to the package resin, and the notch 3 is provided in the package resin. The external electrode 7 in this case refers to the outer lead portion of the lead frame, and the sealing member 1 is formed so as to expose at least a part of the outer lead portion of the lead frame. The supporting base material 2 may have any shape as long as it can support the sealing member 1 and has a stable center of gravity so that it can be stably mounted on a secondary substrate or the like. It may be a shape such as.

As the insulating substrate, for example, a ceramic substrate such as Al ₂ O ₃ , AlN, Si ₃ N ₄ , and SiC can be used, and even if the inner layer has a wiring pattern made of a conductor containing Cu, Ag, or the like. good. Further, a resin substrate, a glass epoxy substrate in which an inorganic substance is contained in an organic substance, or the like may be used. Furthermore, in the case of forming a light emitting device that requires high contrast, a dark-colored insulating substrate is formed by adding Cr ₂ O ₃ , MnO ₂ , Fe ₂ O ₃ or the like to the base material itself of the insulating substrate. It is preferable to do.

  The lead frame is electrically connected to the light emitting element 5 and functions as an external connection terminal, and it is preferable to use a material having a relatively large thermal conductivity as the material of the lead frame. By forming with such a material, the heat generated in the light emitting element 5 can be efficiently released. For example, those having a thermal conductivity of about 200 W / (m · K) or more are preferable. Furthermore, a material having a relatively large mechanical strength or a material that can be easily punched or etched or etched is preferable. Specific examples include metals such as copper, aluminum, gold, silver, tungsten, iron, nickel, iron-nickel alloys, phosphor bronze, iron-containing copper, and the like. Further, a clad material in which two or more kinds of metals are bonded together may be used.

(External electrode)
The external electrode 7 provided on the support base 2 is electrically connected to a secondary substrate or the like via solder or the like, and at least the external electrode 7 has a region exposed from the sealing member 1. This region is the electrode surface of the external electrode 7. The electrode surface of the external electrode 7 may be entirely exposed from the sealing member 1 or may be partially exposed. As shown in FIG. 5, the external electrode 7 is provided on the side surface or the bottom surface of the support base 2, for example. The external electrode 7 may have any shape as long as it has at least a surface by providing an electrode surface.

(Notch)
The notch 3 is provided on the surface of the support base 2, the sealing member 1 is embedded in at least a part of the notch 3, and an anchor that enhances the bonding property between the sealing member 1 and the support base 2. Has an effect. The surface of the support substrate 2 includes all of the upper surface, side surface, and bottom surface of the support substrate 2. It is more preferable that the notch 3 is formed on the side surface or the bottom surface of the support base 2 and a high anchor effect can be obtained. According to this embodiment, the sealing member 1 embedded in the cutout 3 on the side surface or the bottom surface generates a stress that supports the support base material 2, and can suppress peeling against an external impact. Specifically, it is possible to prevent disconnection of a wire or the like that joins the support substrate 2 and the light emitting element 5 and a problem that a gap is generated between the sealing member 1 and the light emitting element 5.

  As shown in FIG. 1B, the notch 3 is not limited to the continuous formation of the notch 3 having a uniform width and depth, and the width and depth of the notch 3 are arbitrarily determined. The notch 3 may be formed on the surface of the support base 2 with an uneven width and depth. Further, the notch 3 is not limited to one, and a plurality of notches may be provided. As the total surface area of the notch 3 increases, not only the anchor effect increases, but also the contact area between the sealing member 1 and the support base 2 increases and the heat of the sealing member 1 is easily released to the support base 2. Have In addition, it is preferable that the notch 3 is provided in the support base material 2 substantially symmetrically, and according to this form, the bias of the stress which the sealing member 1 supports the support base material 2 can be reduced.

  Further, the sealing member 1 may be embedded in all of the notches 3 or may be embedded in a part thereof. When the sealing member 1 is filled in all of the notches 3, the adhesion between the sealing member 1 and the support base material 2 is good, and a high anchor effect can be obtained. When the sealing member 1 is embedded only in a part of the notch 3, for example, even if the sealing member 1 expands at a high temperature, a part of the sealing member 1 that expands in the gap of the notch 3 is used. I can escape.

  As described above, the notch 3 can be provided only on the side surface or the bottom surface of the support base material 2 without being provided on the top surface of the support base material 2. This form contributes that the sealing member 1 is sufficiently larger than the support base 2 and can easily cover the outer periphery of the support base 2. When the notch 3 is provided on the upper surface of the support base 2, the light closes in the notch 3 on the upper surface and the light extraction efficiency is lowered. According to this embodiment, such a problem can be prevented. Moreover, the notch 3 provided in the side surface or the bottom face does not ask | require penetration and non-penetration.

  FIG. 6 is a view of the support substrate 2 of FIG. 1 (b) as viewed from the R direction. The shape of the notch 3 is a continuous rectangular section as shown in FIG. 1 (b). Not limited to this, as shown in FIG. 6, the cross section may be a substantially circular shape or an n-gonal shape (n is 3 or more). Further, a plurality of layers may be laminated on the inner wall of the notch 3, and different shapes may be provided for each layer. By laminating a plurality of layers, the surface area with which the sealing member 1 comes into contact can be increased, a higher anchor effect can be obtained, and the heat accumulated in the sealing member 1 can be released to the support base 2. So heat dissipation is also improved.

In another form of the notch 3, the notch 3 can be provided at a corner or side of the support base 2 or a portion corresponding thereto. As shown in FIG. 7 (a), for example, the supporting base material 2 is an n-faced body (n is 4 or more) or a truncated cone provided with a notch 3 so as to taper from the top surface to the bottom surface in a front view. It can be made into the shape. In this embodiment, the inclined portion on the side surface of the support base material 2 serves as an anchor between the sealing member 1 and the support base material 2, and has an effect of improving the bonding property between the sealing member 1 and the support base material 2. Moreover, the notch 3 can be provided in the corner | angular part or side of the upper surface of the support base material 2, or a part equivalent to it, as shown in FIG.7 (b). In this embodiment, the light emitted from the light-emitting element 5 is not easily absorbed by the upper surface of the support base material 2, and the light is directly emitted to the outside, so that the light extraction efficiency is increased. Further, in this embodiment, by providing the anchor notch 3 separately at the inclined portion of the side surface of the support base 2, the bonding property between the sealing member 1 and the support base 2 can be improved.
Furthermore, the notch 3 may be provided so that the upper surface of the support base material 2 may be inclined as shown in FIG.7 (c). According to this embodiment, the optical axis of the light emitted from the light emitting element 5 can be determined in an arbitrary direction.

(Cut-out manufacturing process)
As a manufacturing process of the cutout 3, for example, a method of physically providing the cutout 3 by dicing cut or the like, and a method of forming the cutout 3 in advance on a plurality of sheets with a ceramic substrate or the like and stacking them. There is. In the method of physically providing the notch 3 by dicing cut or the like, when a plurality of packages are provided on a single insulating substrate or lead frame, it is possible to manufacture a large amount at a time with less man-hours. High nature. Further, when the cutout 3 is provided on a multilayer substrate such as a ceramic substrate, the shape and position of the cutout 3 can be arbitrarily determined. Therefore, the cutout 3 is more suitably formed by stacking a plurality of layers. ing.

(Sealing member)
A sealing member 1 shown in FIG. 1 has a maximum outer periphery larger than that of the support base material 2 in a plan view. And a hanging part 4 extending downward. The lens unit 6 refers to the surface of the lens. The drooping portion 4 has a role of improving the bondability and heat dissipation because the bonding area between the sealing member 1 and the support base 2 is increased. The shape and length of the hanging part 4 are arbitrary, and may be any shape and length that is at least embedded in the notch 3. Furthermore, the drooping portion 4 can take a form in which the bottom surface of the drooping portion 4 is positioned below the bottom surface of the support base material 2. According to this form, when the drooping portion 4 is mounted on a secondary substrate or the like, The bottom surface can prevent the solder from creeping up. Further, as shown in FIG. 2, the sealing member 1 is formed so that at least the electrode surface of the external electrode 7 is exposed. The sealing member 1 only needs to cover at least the upper surface of the support substrate 2 on which the light emitting element 5 is placed so as to include the light emitting element 5. It is preferable to be positioned below the upper surface of the support base 2. When the bottom surface of the sealing member 1 is at the same position as the top surface of the support base material 2, the sealing member 1 is embedded only in the notch 3 on the top surface of the support base material 2. The sealing member 1 can be embedded in the cutout 3 on the side surface or the bottom surface of the support base 2, and a higher effect can be obtained as an effect of the present invention. In this specification, the bottom surface of the sealing member 1 faces the lens unit 6, and the sealing member 1 covers the outer periphery of the support base 2 in the height direction when the light emitting device is viewed from the front. This means the lowest surface of the portion, and does not include the sealing member 1 embedded in the notch 3. In the case of the light emitting device 100 of FIG. 1, the bottom surface of the sealing member 1 is the bottom surface of the hanging portion 4 and faces the lens portion 6 that emits light upward. The material of the sealing member 1 has a light-transmitting property capable of transmitting light from the light-emitting element 5, and specific materials include silicon resin, epoxy resin, urea resin, and the like. Moreover, the sealing member 1 can also contain a coloring material, a light-diffusion material, a filler, a fluorescent material, etc. in addition to such a material.

(Lens part of the sealing member)
The shape of the lens portion 6 of the sealing member 1 is not only a substantially circular shape as shown in FIG. 1A in plan view, but also an n-order polynomial curve (n is 1 or more), or a combination thereof. For example, the shape of the lens portion 6 can be an n-gon (n is 3 or more) or a flower shape in plan view. In front view, the shape may be not only a substantially circular shape as shown in FIG. 1B but also an n-order polynomial curve (n is 1 or more) or a combination thereof. Specifically, there are fan-shaped and dome-shaped convex lens shapes, wing-shaped concave lens shapes, and lens shapes such as a Fresnel lens and a Futakov lens, but these are only examples and the lens shapes are limited to these. It is not a thing.

(Second embodiment)
[Outline of configuration of light emitting device]
As shown in FIGS. 8A and 8B, the light emitting device 200 according to the second embodiment of the present invention is mainly larger than the light emitting element 5, the support base 2, and the support base 2 in plan view. It is comprised with the sealing member 1 which has the largest outer periphery and has the reflection part 12. FIG. Since the configuration other than the configuration of the sealing member 1 is the same as that of the first embodiment, other details are omitted. FIG. 8A shows the light emitting device 200 in a plan view, and FIG. 8B shows a cross-sectional view of the light emitting device 200 taken along the line AA ′ in FIG. 8A.

  The light emitting device 200 according to the second embodiment of the present invention has a notch 3 that is continuous on the side surface and the bottom surface of the support base 2, and the sealing member 1 is embedded in the notch 3. In addition, the sealing member 1 is formed by the lens portion 6, the reflection portion 12, and the hanging portion 4, and is formed so as to expose the electrode surface of the external electrode 7 of the support base 2 although not shown.

(Sealing member)
As shown in FIG. 8 (b), the sealing member 1 has an upper lens portion 6, a reflection portion 12 formed continuously from the lens portion 6, and a support substrate 2 continuously from the reflection portion 12. And a hanging part 4 extending downward. Other forms, materials, and the like of the sealing member 1 are the same as those in the first embodiment.

(Reflection part of sealing member)
The reflection unit 12 has a role of causing a part of the light emitted from the light emitting element 5 to be laterally or downward is totally reflected upward by the reflection unit 12 and increasing the component of the light emitted upward. In order to totally reflect the light emitted from the light emitting element 5 to the side or downward by the reflecting portion 12, as shown in FIG. 9, as long as the refractive index n of the sealing member 1 is larger than the refractive index 1 of air. The higher the refractive index n, the more the light component totally reflected by the reflecting portion 12 and the higher the light extraction efficiency. The shape of the reflecting portion 12 is not limited to a straight line when viewed from the front as shown in FIG. 8B, but may be an n-order polynomial curve (n is 1 or more) or a combination thereof. In addition, a reflection film that causes reflection may be separately provided on the surface of the reflection unit 12 that is in contact with the air layer. According to this embodiment, a part of light incident at a deep angle in a range where total reflection does not occur at the reflection portion 12 can be reflected by the reflection film, and the light is emitted not only by the refractive index of the sealing member 1. The light from the element 5 can be reflected efficiently.

(Third embodiment)
[Outline of configuration of light emitting device]
As shown in FIGS. 10A and 10B, the light emitting device 300 according to the third embodiment of the present invention is mainly larger than the light emitting element 5, the support base 2, and the support base 2 in plan view. It is comprised with the sealing member 1 which has the reflection part 12 which has the largest outer periphery and inclines upwards in a horizontal direction. Since other than the form of the reflecting portion 12 is the same as the first embodiment and the second embodiment, other details are omitted. 10A shows the light-emitting device 300 in plan view, and FIG. 10B shows a cross-sectional view of the light-emitting device 300 taken along the line AA ′ in FIG. 10A. .

  The light emitting device 300 according to the third embodiment of the present invention has a notch 3 that is continuous on the side surface and the bottom surface of the support base 2, and the sealing member 1 is embedded in the notch 3. Further, the sealing member 1 is formed by the lens portion 6, the reflecting portion 12 inclined in the horizontal direction, and the hanging portion 4, and is formed so as to expose the electrode surface of the external electrode 7 of the support base 2 although not shown. ing.

(Sealing member)
As shown in FIG. 10 (b), the sealing member 1 is continuously formed from the lens portion 6, the reflecting portion 12 formed continuously from the lens portion 6 and inclined upward in the horizontal direction, and the reflecting portion 12. And the drooping part 4 extended below along the support base material 2 is provided. Other forms, materials, and the like of the sealing member 1 are the same as those in the first embodiment and the second embodiment.

(Reflection part of sealing member)
As shown in FIG. 10B, the reflection portion 12 is formed so as to be inclined upward (0 <θ <90 °) with respect to the horizontal direction. By adopting this form, light that leaks to the outside from the end of the extended sealing member 1, that is, the intersection of the reflecting portion 12 and the lens portion 6, among the light emitted from the light emitting element 5 to the side or below. Can be reduced. Preferably, as shown in FIG. 11, the intersection of the reflecting portion 12 and the lens portion 6 is preferably formed above the light emitting element 5. As a result, the light reflected by the reflecting portion 12 can be efficiently extracted from above without being absorbed downward by the secondary substrate or the like without being lost downward.

DESCRIPTION OF SYMBOLS 1 ... Sealing member 2 ... Support base material 3 ... Notch 4 ... Hanging part 5 ... Light emitting element 6 ... Lens part 7 ... External electrode 8 ... Phosphor layer 9 ... White light emitting element 12 ... Reflection part 100,200,300 ... Light emitting device

Claims (10)

A support substrate comprising a plurality of external electrodes;
A light emitting device provided on at least a part of the upper surface of the support substrate;
A sealing member including the light emitting element and having a maximum outer periphery larger than the plurality of external electrodes in plan view,
The support substrate has at least one notch on the surface;
The sealing member is
A light emitting device embedded in at least a part of the cutout and formed to expose an electrode surface of the external electrode.   The light emitting device according to claim 1, wherein a bottom surface of the sealing member is positioned below a top surface of the support base material.   The light emitting device according to claim 1, wherein the notch is provided only on a side surface or a bottom surface of the support base material. The light-emitting device according to claim 1, wherein the notch is provided between the external electrodes. The sealing member is
A lens part formed on the top;
A reflecting portion that is formed continuously from the lens portion and reflects upwardly the light emitted from the light emitting element to the side or below;
The light emitting device according to claim 1, further comprising: a hanging portion that extends downward along the support base material continuously from the reflecting portion. The light-emitting device according to claim 5 , wherein the reflection portion is inclined upward with respect to a horizontal direction in a front view. The light emitting device according to claim 1, wherein the supporting base material is an insulating substrate provided with wiring. The insulating substrate is Al. ₂ O ₃ , AlN, Si ₃ N ₄ The light-emitting device according to claim 7, which is a ceramic substrate made of SiC. The light-emitting device according to claim 7, wherein the insulating substrate is a glass epoxy substrate in which an inorganic material is contained in a resin substrate or an organic material. Is excited by light emitted from the light emitting element, according to any one of claims 1 to 9 and further comprising a color conversion member to emit light with a longer wavelength than the light emitting element Light-emitting device.

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