JP2011066302A - Semiconductor light emitting device, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor light emitting device that can be improved in light extraction efficiency, and to provide a method of manufacturing the same. <P>SOLUTION: The semiconductor light emitting device 10 includes: a container portion 20 including a recessed portion 21 having a bottom surface 22 and a wall surface 23 raised from a circumferential edge of the bottom surface 22 and spreading with the distance away from the bottom surface 22; a semiconductor light emitting element 70 disposed inside the recessed portion 21; and a sealing portion 50 bonded to the bottom surface 22 of the recessed portion 21 so as to seal the semiconductor light emitting element 70 so that a second surface 52 opposed to the spreading wall surface 23 of the recessed portion 21 may form a gap with a substantially equal interval with the wall surface 23. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a semiconductor light emitting device and a manufacturing method thereof.

In recent years, semiconductor light-emitting devices using semiconductor light-emitting elements called LEDs (Light Emitting Diodes), which are expected to have high efficiency and long life, are used for lighting fixtures and backlights of liquid crystal displays in place of light bulbs and fluorescent lamps. It has become like this.
As a prior art described in the publication, a reflector that reflects light emitted from the semiconductor light emitting element is disposed around the semiconductor light emitting element, and a light-transmitting resin that seals the semiconductor light emitting element is provided so as not to contact the reflector. Semiconductor light emitting devices exist (see Patent Documents 1 and 2).

JP 2008-205395 A JP-A-8-264840

In such a semiconductor light emitting device, it is required to allow more light output from the semiconductor light emitting element to be extracted outside, that is, to improve the light extraction efficiency in the semiconductor light emitting device.
Accordingly, an object of the present invention is to provide a semiconductor light emitting device capable of improving the light extraction efficiency. It is another object of the present invention to provide a method for manufacturing a semiconductor light emitting device that can improve light extraction efficiency.

  For this purpose, the semiconductor light-emitting device of the present invention includes a container portion having a recess having a bottom surface and a wall surface that rises from the periphery of the bottom surface and expands away from the bottom surface, and a semiconductor disposed inside the recess. A sealing portion bonded to the light emitting element and the bottom surface of the recess so as to seal the semiconductor light emitting element, and a surface opposite to the wall surface where the recess expands forms a substantially equal gap with the wall surface And have.

  The gap is formed by contraction of the liquid sealing agent when the liquid sealing agent supplied to the recess is solidified to form a sealing portion.

  Furthermore, the bottom surface of the recess is rougher than the wall surface of the recess.

  The method of manufacturing a semiconductor light emitting device according to the present invention includes a step of disposing a semiconductor light emitting element inside a concave portion with respect to a container portion having a concave portion having a bottom surface and a wall surface rising from a peripheral edge of the bottom surface. Supplying the liquid sealant to the disposed recess, and shrinking the liquid sealant as the liquid sealant supplied to the recess is solidified, thereby Forming a gap between the wall surface and the liquid sealant and forming a sealing portion for sealing the semiconductor light emitting element.

  In addition, the method further includes a step of providing the wall surface with a release agent that reduces the adhesion between the wall surface and the liquid sealing agent before the step of supplying the liquid sealing agent.

  Furthermore, the wall surface of the container used in the step of disposing the semiconductor light emitting element expands as it gets away from the bottom surface, and has reflectivity with respect to light output from the semiconductor light emitting element. Features.

  Furthermore, the bottom surface of the container portion used in the step of disposing the semiconductor light emitting element is subjected to storm treatment, and in the step of forming the sealing portion, the bottom surface and the sealing portion are It is characterized by being in contact.

  According to the semiconductor light emitting device of the present invention, a semiconductor light emitting device with improved light extraction efficiency can be provided. Furthermore, according to the method for manufacturing a semiconductor light emitting device of the present invention, it is possible to provide a method for manufacturing a semiconductor light emitting device with improved light extraction efficiency.

It is a top view of an example of a semiconductor light emitting device manufactured by the manufacturing method of the present invention. It is sectional drawing of II-II in FIG. It is a figure for demonstrating the process of the manufacturing method of the semiconductor light-emitting device of this invention.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a top view of an example of a semiconductor light emitting device 10 manufactured by the manufacturing method of the present invention, and FIG. 2 is a cross-sectional view taken along line II-II in FIG.

  The semiconductor light emitting device 10 includes a container portion 20 in which a recess 21 is formed, a semiconductor light emitting element 70 disposed inside the recess 21 of the main body portion, and the semiconductor light emitting element 70 covered with the recess 21 of the container portion 20. The provided sealing part 50 is provided. The concave portion 21 provided in the container portion 20 includes a circular bottom surface 22 and a wall surface 23 that rises from the periphery of the bottom surface 22 and expands away from the bottom surface 22.

  The sealing portion 50 is in contact with the bottom surface 22 provided in the concave portion 21 of the container portion 20, while forming a gap with the wall surface 23. That is, a gap is formed between the expanding wall surface 23 provided in the concave portion 21 of the container portion 20 and the surface of the sealing portion 50 (second surface 52 described later) facing the wall surface 23. . The gaps are substantially equidistant, and the liquid sealing agent 55 described later contracts when the liquid sealing agent 55 (see FIG. 3) supplied to the recess 21 is solidified to form the sealing portion 50. Formed by. In the present embodiment, this gap is the gas layer 60.

  In addition, the upper surface in this specification refers to the surface on the side from which the light emitted from the semiconductor light emitting element 70 is extracted from the semiconductor light emitting device 10, and the lower surface in this specification refers to the upper surface. The opposite surface, that is, the surface opposite to the surface from which the light of the semiconductor light emitting element 70 is extracted from the semiconductor light emitting device 10 is meant.

  Hereinafter, each configuration of the semiconductor light emitting device 10 will be described.

<Container part>
The container part 20 includes a container 30 and a lead part 40, and the lead part 40 has an anode lead part 41 and a cathode lead part 42.

The container 30 is made of, for example, a thermoplastic resin containing a white pigment. Examples of the thermoplastic resin constituting the container 30 include 9T-nylon (registered trademark), silicone resin, and liquid crystal polymer (aromatic polyester). In addition, about the container 30, you may comprise using a ceramic etc. other than the thermoplastic resin mentioned above, for example.
In addition, it is preferable that the angle which the wall surface 23 of the recessed part 21 and the bottom face 22 of the recessed part 21 form is 105 degrees-175 degrees in the cross section of the container part 20 which passes along the center of the bottom face 22 as shown in FIG. .

  Next, the anode lead portion 41 and the cathode lead portion 42 are held by being partially sandwiched between the containers 30. In addition, the anode lead portion 41 and the cathode lead portion 42 are configured such that one end side thereof is exposed on the bottom surface 22 of the recess 21 and the other end side thereof is exposed to the outside of the container 30. The other end sides of the anode lead portion 41 and the cathode lead portion 42 are bent to the back side of the container 30 (the side opposite to the concave portion 21).

  The anode lead part 41 and the cathode lead part 42 constituting the lead part 40 are formed of a metal plate having a thickness of about 0.1 to 0.5 mm. The material of the lead part 40 is preferably a metal excellent in workability and thermal conductivity. As the lead part 40, for example, an iron / copper alloy is used as a base, and nickel, titanium, gold, silver or the like is laminated thereon as a plating layer. In this embodiment, the anode lead part 41 and the cathode lead part 42 having a silver plating layer formed on the surface are used.

  Further, as described above, the anode lead portion 41 and the cathode lead portion 42 are exposed on the bottom surface 22 constituting the concave portion 21 of the container portion 20, and a material (for example, a material constituting the container 30 (for example, The thermoplastic resin is exposed. In the present embodiment, the anode lead portion 41 is formed to extend to the central portion of the bottom surface 22.

  On the other hand, the material (for example, the thermoplastic resin containing a white pigment) which comprises the container 30 is exposed to the wall surface 23 which comprises the recessed part 21 of the container part 20 with the bottom face 22. FIG. Here, the wall surface 23 preferably has reflectivity for the light output from the semiconductor light emitting element 70. However, the wall surface 23 may be formed of other materials instead of the material constituting the container 30. For example, the wall surface 23 may be made of metal.

<Semiconductor light emitting device>
The semiconductor light emitting device 70 is mounted on a cathode lead portion 42 provided at the center of the bottom surface 22 of the recess 21 of the container 30. The anode electrode provided on the semiconductor light emitting element 70 is an anode lead 41 exposed on the bottom surface 22, and the cathode electrode provided on the semiconductor light emitting element 70 is a cathode lead 42 exposed on the bottom 22. They are electrically connected using wires.

The semiconductor light emitting device 70 emits blue light having a main emission peak in a wavelength region of 430 nm or more and 500 nm or less, and includes a seed layer made of AlN formed on a sapphire substrate, and a bottom layer formed on the seed layer. It includes at least a base layer and a laminated semiconductor layer mainly composed of GaN. The laminated semiconductor layer is configured by laminating a base layer, an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer in this order from the substrate side. In the present embodiment, the forward voltage V _f of the semiconductor light emitting element 70 is + 3.2V.

<Sealing part>
The sealing unit 50 is bonded to the bottom surface 22 of the recess 21 so as to seal the semiconductor light emitting element 70. The sealing unit 50 includes a first surface 51 that contacts the bottom surface 22 provided in the recess 21 of the container unit 20, and a second surface 52 that faces the wall surface 23 provided in the recess 21 via the gas layer 60. And a third surface 53 provided on the opening side of the recess 21.
Here, the first surface 51 is composed of the anode lead portion 41, the cathode lead portion 42, and the thermoplastic resin existing between them, which constitute the bottom surface 22 of the recess 21, and the semiconductor light emission provided on the bottom surface 22. The element 70 is in contact with each other.

  The sealing portion 50 is formed of a transparent material having a high light transmittance and a high refractive index at wavelengths in the visible region. In particular, a material having a high light transmittance with respect to the emission wavelength of the semiconductor light emitting element 70 sealed by the sealing portion 50 is preferable. As a material constituting the sealing portion 50, a material satisfying characteristics of high heat resistance, light resistance, and mechanical strength is used. For example, silicon resin, epoxy resin, acrylic resin, sol-gel glass and the like are preferable. These raw materials have a characteristic that the volume is reduced by shrinking as the solidification occurs. Of the above-mentioned raw materials, a silicon resin is more preferable, and a silicon resin not containing a coupling agent is particularly preferable. Here, the coupling agent is added in order to improve adhesion to other members, for example, an organically modified silicon component having an epoxy group, an acrylic group, a vinyl group or the like as a functional group. . In addition, it is preferable that the sealing part 50 is formed from a silicon resin, and the container 30 is also preferably formed from a silicon resin, and more preferably, the sealing part 50 is formed from a silicon resin that does not include a coupling agent. 30 is formed of silicon resin.

In addition, you may make the sealing part 50 contain a fluorescent substance as needed. The phosphor converts part of the light emitted from the semiconductor light emitting element 70 into light having a longer wavelength.
In the example shown in FIG. 2, the third surface 53 of the sealing portion 50 is shown as a convex surface, but the shape is not limited to this, and the third surface 53 may be a flat surface, a concave surface, or a collection surface. It may be a surface having grooves or protrusions in order to enhance the light property.
Further, although not limited, the semiconductor light emitting device 70 of the present embodiment has a width of 0.35 mm, and the sealing part 50 has an upper surface diameter of 2.4 mm and a lower surface diameter of 1: 0.9 mm and the height of the sealing portion 50: 0.85 mm, the refractive index of the sealing portion 50 is 1.41 to 1.42, and the gap between the sealing portion 50 and the wall surface 23 is 0.00. 01 mm. In addition, it is preferable that the clearance gap between the sealing part 50 and the wall surface 23 is 0.01 mm-0.1 mm.

Next, the light emitting operation of the semiconductor light emitting device 70 described above will be described.
When a forward voltage V _f is applied between the anode lead 41 and the cathode lead 42, a forward current flows from the anode lead 41 to the cathode lead 42 via the semiconductor light emitting element 70. As a result, the semiconductor light emitting element 70 emits light. Then, after the light emitted from the semiconductor light emitting device 70 travels through the sealing portion 50 and is reflected directly or by the first surface 51 facing the bottom surface 22 and the second surface 52 facing the wall surface 23. The light is emitted from the third surface 53 to the outside. However, a part of the light traveling toward the third surface 53 of the sealing unit 50 is reflected by the third surface 53 and travels through the sealing unit 50 again. Here, when the sealing unit 50 includes a phosphor, a part of the light traveling through the sealing unit 50 is converted into light having a longer wavelength, and the light is emitted from the semiconductor light emitting element 70 together with the light having the wavelength. Is emitted.

  During this time, out of the light traveling in the sealing portion 50, the light traveling toward the first surface 51 facing the bottom surface 22 is reflected at the interface between the first surface 51 and the bottom surface 22 of the sealing portion 50. Become. Here, in the present embodiment, since the silver plating layer is formed on the surfaces of the anode lead portion 41 and the cathode lead portion 42 exposed on the bottom surface 22, the surface faces the first surface 51 of the sealing portion 50. Light is reflected by this silver plating layer.

  Of the light traveling in the sealing portion 50, the light traveling toward the second surface 52 facing the wall surface 23 is reflected at the interface between the second surface 52 of the sealing portion 50 and the gas layer 60. become. Here, when the gas layer 60 is provided outside the second surface 52 of the sealing portion 50 as in the present embodiment, the second surface 52 of the sealing portion 50 is not provided without providing the gas layer 60. The difference in refractive index at the interface is larger than when a configuration in which the wall 23 and the wall surface 23 are in direct contact is employed. For this reason, when the former configuration is adopted, the amount of light jumping out from the second surface 52 of the sealing portion 50 is reduced compared to the case where the latter configuration is adopted. The amount of light returning from the second surface 52 of the stopper 50 into the sealing portion 50 increases.

  A part of the light jumping out from the second surface 52 of the sealing portion 50 is reflected by the wall surface 23, but a part of the light is absorbed by the wall surface 23. On the other hand, light absorption is less likely to occur in the sealing portion 50 than the wall surface 23. Therefore, by making the sealing portion 50 and the wall surface 23 face each other via the gas layer 60, the amount of light that jumps out from the second surface 52 of the sealing portion 50 can be reduced, resulting in semiconductor light emission. The extraction efficiency of light emitted from the device 10 can be increased.

In the present embodiment, the second surface 52 and the wall surface 23 of the sealing unit 50 are arranged to face each other with the gas layer 60 interposed therebetween. Therefore, a part of the light that jumps out from the second surface 52 toward the gas layer 60 is reflected by the surface of the wall surface 23 that expands away from the bottom surface 22 to be emitted to the outside of the semiconductor light emitting device 10. Can be made. This is because the wall surface 23 functions as a reflector. Here, it is preferable that the wall surface 23 has reflectivity with respect to the light output from the semiconductor light emitting element 70 because the light extraction efficiency can be further increased.
As a result, the efficiency of extracting light emitted from the semiconductor light emitting device 10 can be further increased by reflecting the light on the surface of the wall surface 23. In addition, if the wall surface 23 is comprised with the thermoplastic resin or metal containing a white pigment, reflectivity will increase.

  In the present embodiment, it has been confirmed that the light extraction efficiency of the semiconductor light emitting device 10 is improved by 10% to 20% compared to the conventional semiconductor light emitting device.

<Method for Manufacturing Semiconductor Light Emitting Device>
Next, a method for manufacturing the semiconductor light emitting device 10 of the present invention will be described with reference to FIG. FIG. 3 is a sectional view of the periphery of the recess 21 of the semiconductor light emitting device 10 manufactured according to the embodiment of the present invention for each process.

<Container formation process>
First, the container part 20 having the lead part 40 and the container 30 is manufactured. The container part 20 is manufactured, for example, by injection molding, for example, white thermoplastic resin on a frame sheet metal that is a raw material of the lead part 40. At this time, the recess portion 21 is formed in the container portion 20. In addition, about the container part formation process, it does not necessarily need to perform as a series of processes, and you may make it manufacture the container part 20 by a prior manufacturing process.

<Light emitting element connection process>
Next, in the light emitting element connection step, which is a step of arranging the semiconductor light emitting elements, as shown in FIG. 3A, the center portion of the bottom surface 22 provided in the concave portion 21 of the container portion 20, that is, the cathode lead portion. Die bonding is performed to attach the semiconductor light emitting element 70 using an adhesive or the like to the portion where the 42 is exposed. Subsequently, the anode electrode 41 of the semiconductor light emitting device 70 and the anode lead 41 exposed on the bottom surface 22 are electrically connected using a gold wire, and the cathode electrode of the semiconductor light emitting device 70 and the cathode exposed on the bottom surface 22 are connected. Wire bonding is performed to electrically connect the lead portion 42 for use with a gold wire.

<Releasing agent application process>
And as shown in FIG.3 (b), the mold release agent 80 is apply | coated to the wall surface 23 provided in the recessed part 21 of the container part 20. As shown in FIG. At this time, it is desirable not to apply the release agent 80 to the bottom surface 22. The mold release agent 80 used in the present embodiment has a function of reducing the adhesion between the wall surface 23 and a liquid sealant 55 (see FIG. 3C described later) that is a raw material of the sealing portion 50. I just need it. The release agent application step is not an essential step in the present invention.

<Sealing agent supply process>
Furthermore, in the sealing agent supply step, which is a step of supplying the liquid sealing agent to the recess, the liquid sealing agent 55 is supplied to the recess 21 of the container portion 20 as shown in FIG. At this time, the liquid sealant 55 is in contact with both the bottom surface 22 and the wall surface 23 of the recess 21. In addition, you may make it make the liquid sealing agent 55 contain a fluorescent substance as needed.

<Solidification process>
And about the solidification process which is a process of forming a sealing part, as shown in FIG.3 (d), the liquid sealing agent 55 supplied to the recessed part 21 of the container part 20 is solidified and sealed. Part 50 is formed. In order to solidify the liquid sealant 55, the liquid sealant 55 is subjected to heat treatment or light irradiation.
By performing the heat treatment or the like, the liquid sealing agent 55 contracts when the liquid sealing agent 55 is solidified to form the sealing portion 50. On the other hand, the container portion 20 is not greatly changed in shape by the above processing, and the wall surface 23 of the recess 21 does not move greatly. Therefore, the 2nd surface 52 of the sealing part 50 obtained forms a clearance gap between the wall surfaces 23 of the recessed part 21 (refer arrow in the figure). In addition, when the liquid sealant 55 contracts to solidify, the liquid sealant 55 maintains contact with the bottom surface 22 of the recess 21, so that the first surface 51 of the obtained seal part 50 is It remains in contact with the bottom surface 22 of the recess 21.
Thus, since the liquid sealing agent 55 is solidified to form the sealing portion 50, there is a gap between the second surface 52 of the sealing portion 50 and the wall surface 23 provided in the recess 21 of the container portion 20. A gap is formed. For example, in the atmosphere, the gas layer 60 is formed by air entering the gap. In addition, if the liquid sealing agent 55 is contracted in a state where the opening of the concave portion 21 of the container portion 20 is directed vertically upward, the sealing portion 50 having the above-described state can be easily obtained.
Thus, the semiconductor light emitting device 10 shown in FIG. 1 is obtained.

In the semiconductor light emitting device 10 obtained in this way, the sealing portion 50 is bonded to the container portion 20 via the bottom surface 22 of the concave portion 21, and the sealing portion 50 and the concave portion 21 are maintained in order to maintain the bonding. It is desirable that the adhesiveness with the bottom surface 22 is high. On the other hand, the sealing part 50 forms a gap between the wall surface 23 of the recess 21 and the liquid sealing agent 55 as a raw material is separated from the wall surface 23 so that the liquid sealing agent 55 and the recess 21 It is desirable that the adhesion with the wall surface 23 is low. As a configuration that satisfies these requirements, for example, the bottom surface 22 of the recess 21 is made rougher than the wall surface 23 of the recess 21. By having this structure, since the adhesiveness between the bottom surface 22 which is a rougher surface and the first surface 51 of the sealing portion 50 is high, the sealing portion 50 is less likely to be detached from the bottom surface 22. In addition, since the adhesion with the smoother wall surface 23 is low, a gap between the wall surface 23 and the sealing portion 50 is easily formed.
Here, as a means for making the bottom surface 22 of the concave portion 21 rougher than the wall surface 23 of the concave portion 21, for example, an unevenness is formed on the bottom surface 22 in advance in the container portion forming step. When solidified in a state where the liquid sealing agent 55 enters the unevenness, a so-called anchor effect is exhibited, and the adhesion between the bottom surface 22 of the recess 21 and the sealing portion 50 is enhanced.

  Then, as a method for forming irregularities on the bottom surface 22 of the container portion 20, for example, a surface treatment is performed on the surfaces of the anode lead portion 41 and the cathode lead portion 42 that are provided exposed on the bottom surface 22. It is done. As an example of such a storm treatment, for example, a plating layer formed by dendrite growth may be formed on the surfaces of the anode lead portion 41 and the cathode lead portion 42. Moreover, you may make it perform a storm processing previously about the site | part exposed to the bottom face 22 among the containers 30. FIG.

  As described above, in the present embodiment, in the manufacture of the semiconductor light emitting device 10, the shrinkage at the time of forming the sealing portion 50 by solidifying the liquid sealing agent 55 is used. A gap is formed between the second surface 52 and the wall surface 23 of the container portion 20. For this reason, the light extraction efficiency of the semiconductor light emitting device 10 can be improved, and the formation of the sealing portion 50 and the formation of the gap can be performed in one step, and the manufacturing process of the semiconductor light emitting device 10 is simplified. Can be.

In the present embodiment, the concave portion 21 provided in the container portion 20 of the semiconductor light emitting device 10 has a shape in which the wall surface 23 is expanded as the distance from the bottom surface 22 increases. You can select it.
Moreover, in this Embodiment, although the bottom face 22 was made circular shape, it is not restricted to this, For example, a polygonal shape etc. may be employ | adopted.
In the present embodiment, the semiconductor light emitting device 70 includes a group III nitride semiconductor such as GaN. However, the present invention is not limited to this. For example, the semiconductor light emitting element 70 includes a device including GaP, GaAs, or the like. It doesn't matter.

DESCRIPTION OF SYMBOLS 10 ... Semiconductor light-emitting device, 20 ... Container part, 21 ... Recessed part, 22 ... Bottom surface, 23 ... Wall surface, 30 ... Container, 40 ... Lead part, 41 ... Lead part for anode, 42 ... Lead part for cathode, 50 ... Sealing Part 51: first surface 52: second surface 53: third surface 55 ... liquid sealant 60 ... gas layer 70 ... semiconductor light emitting element 80 ... mold release agent

Claims (7)

A container portion having a recess having a bottom surface and a wall surface that rises from the periphery of the bottom surface and expands away from the bottom surface;
A semiconductor light emitting device disposed inside the recess,
A semiconductor having a sealing portion bonded to the bottom surface of the concave portion so as to seal the semiconductor light emitting element, and a surface opposite to the wall surface that expands the concave portion forms a gap that is substantially equidistant from the wall surface. Light emitting device.   2. The gap is formed by contraction of the liquid sealing agent when the liquid sealing agent supplied to the recess is solidified to form a sealing portion. Semiconductor light emitting device.   The semiconductor light emitting device according to claim 1, wherein the bottom surface of the recess is rougher than the wall surface of the recess. A step of disposing a semiconductor light emitting element inside the concave portion with respect to a container portion having a concave portion having a bottom surface and a wall surface rising from the peripheral edge of the bottom surface,
Supplying a liquid sealant to the recess in which the semiconductor light emitting element is disposed;
By shrinking the liquid sealant as the liquid sealant supplied to the recess is solidified, a gap is formed between the wall surface of the recess and the liquid sealant, and Forming a sealing portion for sealing the semiconductor light emitting element.   5. The semiconductor light emitting device according to claim 4, further comprising a step of providing, on the wall surface, a release agent that reduces adhesion between the wall surface and the liquid sealing agent before the step of supplying the liquid sealing agent. Production method.   The wall surface of the container part used in the step of disposing the semiconductor light emitting element is widened away from the bottom surface and has reflectivity for light output from the semiconductor light emitting element. A method of manufacturing a semiconductor light emitting device according to claim 4 or 5. The bottom surface of the container part used in the step of arranging the semiconductor light emitting element is subjected to a storm treatment,
The method for manufacturing a semiconductor light emitting device according to claim 4, wherein in the step of forming the sealing portion, the bottom surface and the sealing portion are in contact with each other.

Images