JP2010251666A - Light emitting device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device which has good light extraction efficiency by preventing a light leak to below a mounting substrate while reducing the cost of the light emitting device by downsizing the mounting substrate. <P>SOLUTION: The light emitting device 1 reflects light emitted downward from a light emitting element 10 by a flat portion 30c of a bottom surface 30a of a sealing member 30 provided to be positioned below an upper surface 20a of the mounting substrate 20. Further, the light emitting device 1 is configured to make the light emitted by the light emitting element 10 not incident on a droop portion 30b by positioning the bottom surface 30a of the sealing member 30 below the upper surface 20a of the mounting substrate 20 so that the droop pertion 30b is behind the mounting substrate 20 when the bottom surface 30a of the sealing member 30 includes the droop portion 30b drooping continuously from the flat portion 30c to below the flat portion 30c along a side face 20b of the mounting substrate 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light emitting device in which a sealing member is integrally formed on a mounting substrate on which a light emitting element is mounted, and a method for manufacturing the same.

  Conventionally, a light-emitting device in which a sealing member that functions as a lens is integrally formed on a mounting substrate has been invented in order to increase the light extraction efficiency from a light-emitting element (LED) and to give a desired directivity in the light emission direction. Has been. In such a light emitting device, in addition to further increasing the efficiency of light extraction and ensuring heat dissipation, cost reduction is one of the important issues, and miniaturization of components is being studied.

For example, Patent Document 1 (see paragraphs 0014 to 0020 and FIG. 1) describes a light emitting diode in which a semiconductor chip is mounted on an intermediate substrate, and the upper surface of the semiconductor chip and the intermediate substrate is sealed with a sealing portion. .
Patent Document 2 (paragraph 0025, FIG. 2) describes an LED module in which an LED chip is mounted on a substrate, and the LED chip and the upper surface of the substrate to a part of the edge of the substrate are sealed with optical elements. Yes.
Furthermore, Patent Document 3 (paragraphs 0021 to 0028, FIG. 1) describes an LED in which a lead frame on which an LED chip is mounted is sealed with a mold resin.

JP 2007-273964 A JP 2008-504711 A JP 2006-165410 A

As described above, the conventional light emitting device using a mounting substrate such as a mounting substrate or a lead frame smaller than the size of the sealing member has the following problems, and the above-described Patent Documents 1 to 3 are also shown below. There was a problem like this.
It is possible to reduce the price by reducing the size of the entire device in parts other than the light emitting element. However, if the size of the light emitting element and the size of the sealing member are relatively close to each other, Thus, the component exceeding the critical angle of total reflection on the inner surface of the sealing member increases, and the light extracted to the outside decreases.
On the other hand, if the sealing member that is sufficiently larger than the light emitting element is formed by reducing the size of only the mounting substrate while keeping the size of the sealing member as it is, a part of the above problems can be solved. However, there is a problem in that light emitted from the light emitting element cannot be used effectively because light leaks downward (back side) of the mounting substrate.
In addition, a part of the light incident on the mounting substrate surface directly from the light emitting element or through reflection on the inner surface of the sealing member is absorbed by the constituent member of the mounting substrate, so that the light extraction efficiency decreases.

Moreover, in the structure which seals the said mounting base | substrate with a sealing member larger than the above mounting base | substrates, depending on the molding method of a sealing member, a sealing member may be in a junction part of a sealing member and a mounting base | substrate. There may be a drooping part due to the sagging of.
When such a hanging part is formed on the bottom surface of the sealing member, the light emitted from the light emitting element and incident on the hanging part leaks from the hanging part, and the use efficiency of light as a light emitting device is reduced. .

In the light emitting diode described in Patent Document 1, when the above-described drooping portion occurs in the vicinity of the side surface of the intermediate substrate at the bottom surface of the sealing portion, the light enters the drooping portion of the light emitted from the semiconductor chip. The light leaks downward and reduces the light use efficiency from the light emitting diode.
Moreover, when the sealing part is formed by casting (pouring) into a mother die as in the light emitting diode of Patent Document 1, the bottom surface of the sealing part has low flatness. Therefore, even if the light incident on the bottom surface of the sealing portion has an apparent incident angle that exceeds the critical angle of total reflection, there are many components that leak downward from the bottom surface of the sealing portion.

  The LED module described in Patent Document 2 has a configuration in which the optical element extends to the edge of the substrate, but this means that side light from the LED chip leaks from the fixing point of the sealing / adhesive layer. This is to prevent the light emitted from the LED chip from being reflected by the bottom surface of the optical element. For this reason, the light emitted downward from the LED chip is incident on the mounting substrate surface composed of the substrate surface, the metal pattern layer provided on the substrate surface, and the dielectric layer. Although a part of the light incident on the mounting substrate surface is reflected upward, many components are absorbed by the mounting substrate, and the light extraction efficiency from the LED module is lowered.

  The LED described in Patent Document 3 is a bullet-type LED, and the bottom surface of the lens portion which is a sealing member is coupled to two terminal portions extending below the lead frame, and from the surface on which the LED chip is mounted. It is far below. For this reason, the light that has traveled below the LED chip mounting surface of the lead frame is reflected off the bottom surface of the lens portion and is not effectively extracted upward. Therefore, regardless of the presence or absence of the fillet, the light component that has traveled downward reduces the light use efficiency from the LED.

  The present invention has been made in view of the above problems, and an object of the present invention is to reduce the cost of the light-emitting device by downsizing the mounting substrate, and prevent light leakage downward from the mounting substrate, thereby reducing the light extraction efficiency. It is providing the light-emitting device of good.

  In order to achieve the above object, a light emitting device according to claim 1, a mounting substrate having an upper surface and a side surface continuous from the upper surface, a light emitting element provided on a part of the upper surface of the mounting substrate, A sealing member including a light emitting element and having a bottom surface extending outside the mounting substrate, the bottom surface of the sealing member being located below the top surface of the mounting substrate and emitted from the light emitting element. A flat portion that reflects the light to be reflected, and a hanging portion that hangs downward from the flat portion along the side surface of the mounting substrate continuously from the flat portion.

According to such a configuration, the light emitting device reflects light emitted downward from the light emitting element by the flat portion of the bottom surface of the sealing member provided so as to be positioned below the upper surface of the mounting substrate. In addition, the light emitting device has a hanging portion that hangs downward from the flat portion that is provided along the side surface of the mounting substrate continuously from the flat portion on the bottom surface of the sealing member. Here, in the light emitting device, the bottom surface of the sealing member is positioned below the top surface of the mounting substrate, and the hanging portion is behind the mounting substrate, so that light emitted from the light emitting element is incident on the hanging portion. It is difficult to do.
Thereby, the light emitting device deflects the light emitted downward from the light emitting element upward and prevents the light from leaking out from the hanging portion, and takes it out to the outside.

The light emitting device according to claim 2 is the light emitting device according to claim 1, wherein the light emitting element has a top surface and a side surface continuous from the top surface, and the bottom surface of the sealing member from the top surface of the mounting substrate. The depth of the flat portion is H _OFF , the maximum height of the top surface of the light emitting element from the top surface of the mounting substrate is H _EM , the minimum horizontal distance from the side surface of the mounting substrate to the side surface of the light emitting device is a, and the side surface of the mounting substrate is sealed When the horizontal distance to the flat portion of the bottom surface of the stop member is b,
H _OFF ≧ (b / a) × H _EM
It was set as the structure which satisfy | fills.

According to such a configuration, since the entire bottom hanging part of the bottom surface of the sealing member is behind the mounting substrate when viewed from the light emitting element, light emitted downward from the light emitting element does not directly enter the hanging part.
Thus, the light emitting device prevents light leakage from the hanging part.

The light emitting device according to claim 3 is the light emitting device according to claim 2, wherein the refractive index of the sealing member is n.
a ≧ H _EM × tan {(sin ⁻¹ (1 / n))}
It was set as the structure which satisfy | fills.

According to such a configuration, the incident angle of light emitted downward from the light emitting element and directly incident on the bottom surface of the sealing member is equal to or greater than the critical angle of total reflection. For this reason, the light emitting device totally reflects and deflects the light emitted downward from the light emitting element and directly incident on the bottom surface of the sealing member by the bottom surface of the sealing member.
Thereby, the light emitting device efficiently deflects the light emitted downward from the light emitting element upward and takes it out.

  A light-emitting device according to a fourth aspect is the light-emitting device according to any one of the first to third aspects, wherein the surface facing the bottom surface of the sealing member is a hemispherical surface.

  According to such a configuration, the light emitting device is reflected upward by the light emitted upward from the light emitting element and the bottom surface of the sealing member, etc., by the sealing member in which the light extraction surface facing the bottom surface is configured as a hemispherical surface. Light is extracted outside while reducing the total reflection on the inner surface of the hemispherical surface.

  The light-emitting device according to claim 5 is the light-emitting device according to any one of claims 1 to 4, wherein the top surface of the mounting substrate is a rectangular shape that is long in one direction, and the mounting substrate is The upper surface of at least one end in the direction has an exposed portion exposed from the sealing member.

  According to such a configuration, the light emitting device extends the mounting substrate in one direction, minimizes the width in the direction perpendicular to the mounting substrate, and does not reduce the area of the flat portion on the bottom surface of the sealing member serving as the reflecting surface. , Improve the heat dissipation of the mounting board.

  The light-emitting device according to claim 6 is the light-emitting device according to claim 5, further comprising a metal film electrically connected to the light-emitting element on the upper surface of the mounting substrate, the metal film being exposed on the upper surface of the mounting substrate. The portion has a pair of external connection electrode terminals.

  According to such a configuration, the light emitting device electrically connects the light emitting element and the external connection electrode terminal provided on the exposed portion by the metal film provided on the upper surface of the mounting substrate, and emits light by the metal film. The light emitted from the element is reflected, deflected upward, and taken out to the outside.

  The light-emitting device according to claim 7 is the light-emitting device according to claim 6, wherein the exposed portions are provided at both ends in the longitudinal direction of the mounting substrate, and a pair of external connections are provided at the exposed portions at both ends. An electrode terminal is provided.

  According to such a configuration, the light-emitting device is electrically connected to the external power supply means such as the drive circuit by the positive and negative external connection electrode terminals provided at both ends of the mounting substrate that are separated in the longitudinal direction. Connect.

  The manufacturing method according to claim 8 includes a light emitting element mounting step and a sealing member molding step, and in the sealing member molding step, the side surface of the mounting substrate is sandwiched between jigs having a smooth upper surface, and The mounting substrate and the jig are arranged so that the upper surface of the jig is positioned below the upper surface of the mounting substrate, and the sealing member is compression-molded, thereby forming the bottom surface of the sealing member on the upper surface of the jig. It was decided.

According to this procedure, in the light emitting element mounting step, the light emitting element is mounted on the upper surface of the mounting substrate having the upper surface and the side surface continuous from the upper surface. Then, after the light emitting element mounting step, the sealing member including the light emitting element is compression-molded. In this compression molding, the mounting substrate and the jig are arranged so that the side surface of the mounting substrate is sandwiched between jigs having a smooth upper surface, and the upper surface of the jig is positioned below the upper surface of the mounting substrate. Then, the sealing member is compression molded. Thus, the bottom surface of the sealing member is formed on the upper surface of the jig.
For this reason, the flat part of the bottom face of the sealing member which was excellent in the light reflectivity compared with the casting method, for example is formed. In addition, since the flat portion of the bottom surface of the sealing member is formed below the upper surface of the mounting substrate, a light emitting device that suppresses light emitted from the light emitting element from directly entering the hanging portion is manufactured. .

According to the first aspect of the present invention, the light emitted downward from the light emitting element is efficiently reflected at the bottom surface of the sealing member, so that the mounting substrate is downsized and the light extraction efficiency to the outside is improved. Can be achieved.
According to the second aspect of the present invention, light leakage from the hanging part formed on the bottom surface of the sealing member and absorption of light to the side surface of the mounting substrate to which the hanging part is bonded can be prevented. The light extraction efficiency to the outside can be further improved.
According to the third aspect of the present invention, the light emitted from the light emitting element and directly incident on the bottom surface of the sealing member is totally reflected on the bottom surface of the sealing member and efficiently deflected upward. The efficiency of taking out to the outside is further improved.
According to the fourth aspect of the present invention, since the light extraction surface of the light emitting device is a hemispherical surface, the incident angle of light incident on the inner surface of the light extraction surface can be reduced. For this reason, total reflection of light on the inner surface of the light extraction surface is reduced, and the light extraction efficiency to the outside of the light emitting device can be improved.
According to the fifth aspect of the present invention, the heat dissipation of the mounting substrate can be improved without reducing the reflection area of the light emitted from the light emitting element by the bottom surface of the sealing member. For this reason, it is possible to emit light stably without reducing the light extraction efficiency to the outside of the light emitting device.
According to the sixth aspect of the present invention, the light incident on the upper surface of the mounting substrate is reflected by the metal film that also serves as the wiring pattern, so that the reflectance of the upper surface of the mounting substrate can be improved. In addition, since the external connection electrode terminal for electrical connection with the external drive circuit is provided on the top surface of the mounting substrate, the entire back surface of the mounting substrate can be used as a thermal connection surface, improving heat dissipation. It can be easily achieved.
According to the seventh aspect of the present invention, since the interval between the positive and negative external connection electrode terminals can be separated, the mounting substrate can be reduced in size, and in the electrical connection with the external drive circuit, a defect such as a short circuit can be prevented. Generation | occurrence | production can be prevented and a favorable electrical connection can be performed easily.
According to the invention described in claim 8, since the bottom surface of the sealing member can be formed so as to be flat and located below the top surface of the mounting substrate, a light emitting device with high light extraction efficiency is manufactured. be able to.

It is sectional drawing of the light-emitting device in embodiment which concerns on this invention. It is the top view which looked at the light-emitting device in embodiment which concerns on this invention from the upper side. It is a schematic diagram which shows the structure of the mounting substrate in embodiment which concerns on this invention, (a) is the top view seen from the top, (b) is sectional drawing in line BB of (a). It is sectional drawing of the other structural example of the light emitting element in embodiment which concerns on this invention. It is sectional drawing of the light-emitting device in the modification of embodiment which concerns on this invention. It is the top view which looked at the light-emitting device in the modification of embodiment which concerns on this invention from the upper side. It is an expanded sectional view showing some light emitting devices in an embodiment concerning the present invention. It is an expanded sectional view showing some light emitting devices in an embodiment concerning the present invention. It is typical sectional drawing for demonstrating the positional relationship of the member which comprises the light-emitting device in embodiment which concerns on this invention. It is a top view which shows the process of mounting a light emitting element in a mounting substrate in the manufacturing process of the light-emitting device in embodiment which concerns on this invention. It is a top view which shows the formation process of sealing resin in the manufacturing process of the light-emitting device in embodiment which concerns on this invention. FIG. 5B is a cross-sectional view showing the step of FIG. 5B in the manufacturing process of the light emitting device according to the embodiment of the present invention. FIG. 5B is a cross-sectional view showing a step subsequent to FIG. 5B in the manufacturing process of the light emitting device according to the embodiment of the present invention. FIG. 5D is a cross-sectional view showing a step subsequent to FIG. 5D in the manufacturing process of the light emitting device according to the embodiment of the present invention. FIG. 5E is a cross-sectional view showing the next process of FIG. 5E in the manufacturing process of the light emitting device according to the embodiment of the present invention. It is sectional drawing which shows the structure of the light-emitting device of a comparative example. It is the top view which looked at the light-emitting device of the comparative example from the upper side.

Embodiments of the present invention will be described below with reference to the drawings as appropriate.
<Configuration>
With reference to FIG. 1A thru | or FIG. 4, the structure of the light-emitting device 1 of embodiment of this invention is demonstrated. 1A is a cross-sectional view taken along line AA in FIG. 1B.
As shown in FIGS. 1A to 1C, in the light emitting device 1 according to the embodiment, the light emitting element 10 is mounted on a mounting substrate 20 having a flat upper surface 20a, and the light emitting element 10, the upper surface 20a of the mounting substrate 20, and the mounting substrate 20 are mounted. A part of the side surface 20 b is covered with a hemispherical sealing member 30.

The light emitting element 10 is an LED chip that is flip-chip mounted on a mounting portion 22 b provided on the upper surface 20 a of the mounting substrate 20. The light emitting element 10 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 on a substrate. It has a semiconductor light emitting element structure provided with an electrode for supplying current. As a specific example of the semiconductor light-emitting element structure, an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer are stacked in this order from the substrate side. For example, a GaN-based compound semiconductor which is a nitride semiconductor is used, and an n-type semiconductor layer having a thickness of about 1 to 2 μm, 50 to 150 nm on a sapphire substrate through a base layer such as a buffer layer, a mask layer, and an intermediate layer. A light emitting layer having a thickness of about 100 nm and a p-type semiconductor layer having a thickness of about 100 to 300 nm are formed.
Note that the light-emitting element 10 is not limited to these configurations, and may be configured using other semiconductor materials, or may be configured to include a protective layer, a reflective layer, and the like as appropriate.

For example, when the light emitting element 10 is a white light emitting element, as shown in FIG. 2A, a phosphor layer 12 made of phosphor or a resin containing phosphor is disposed outside the semiconductor light emitting element structure 11 that emits blue light. It is good also as a structure covered with. For example, the semiconductor light-emitting element structure 11 that emits blue light has a cerium-activated YAG (yttrium, aluminum, garnet) -based phosphor that emits yellow light, or a silicate-based fluorescence such as (Sr, Ba) ₂ SiO ₄ : Eu. It can be set as the white light emitting element 10 combining with a body.
Further, in the light emitting element 10, a plurality of semiconductor light emitting element structures 11 are spaced apart from each other, for example, arranged in a matrix of 2 × 2, and the plurality of semiconductor light emitting element structures 11 are covered with a phosphor layer 12. You may comprise.
Thus, if it is the structure which coat | covers the semiconductor light-emitting element structure 11 with the fluorescent substance layer 12, it will convert into white light in the vicinity of the semiconductor light-emitting element structure 11, and the sealing member 30 inner surface resulting from the scattering by a fluorescent substance Therefore, high light extraction efficiency can be realized. In addition, phosphors can be mixed in the sealing member 30 and provided.

The mounting substrate 20 is configured by laminating a metal film 22 and an insulating protective film 23 on a substrate 21 having a rectangular planar shape. The mounting substrate 20 has a mounting portion 22b for mounting the light emitting element 10 on the upper surface 20a and an external connection electrode terminal 22a for electrical connection with an external drive circuit, and is a wiring pattern. Electric power is supplied to the light emitting element 10 via the two electrically insulated metal films 22. Further, the upper surface 20 a of the mounting substrate 20 is covered with the insulating protective film 23 except for the opening, with the external connection electrode terminal 22 a and the mounting portion 22 b being the opening of the insulating protective film 23.
In addition, the mounting substrate 20 is covered with the light emitting element 10 mounted on the upper surface 20a and the upper surface 20a by the sealing member 30, and up to a part of the lateral side surface (side surface constituting the long side) 20b of the mounting substrate 20. The sealing member 30 extends. The bottom surface 30 a of the sealing member 30 is provided at a position lower than the top surface 20 a of the mounting substrate 20.
A detailed positional relationship among the light emitting element 10, the mounting substrate 20, and the sealing member 30 will be described later.

  The substrate 21 is a base of the mounting substrate 20, and for example, ceramics such as aluminum nitride ceramics, metal, resin, or the like can be used.

The metal film 22 has an external connection electrode terminal 22 a exposed from the insulating protective film 23 and a mounting portion 22 b, and is a wiring pattern that electrically connects an external drive circuit and the light emitting element 10. The metal film 22 also functions as a reflective film that reflects light emitted downward from the light emitting element 10.
The metal film 22 is preferably made of a material having good conductivity and high reflectance of light having a wavelength emitted from the light emitting element 10. For example, a wiring layer is formed using Ti / Pt / Au or the like in order to ensure conductivity, and a single layer film or a multilayer film further including Ag, Al, Rh, etc. on the surface layer in order to improve reflectivity May be provided.

The external connection electrode terminal 22a is an electrode pad for connecting a wiring from an external power source such as an external drive circuit in order to supply power to the light emitting element 10 from the outside. Moreover, the mounting part 22b is an electrode pattern provided according to the electrode of the light emitting element 10 mounted.
The pair of external connection electrode terminals 22 a are provided on the exposed portions 20 c of the upper surface 20 a exposed from the sealing member 30 at both ends in the longitudinal direction (the direction along the long side) of the mounting substrate 20. The pair of external connection electrode terminals 22a are electrically connected to the positive electrode and the negative electrode of the light emitting element 10 in the mounting portion 22b through the metal film 22 as a wiring pattern, respectively.
Thus, by providing the pair of external connection electrode terminals 22a composed of the positive electrode and the negative electrode at both ends in the longitudinal direction of the mounting substrate 20, the light emitting device 1 is connected to an external drive circuit. At this time, regardless of the downsizing of the mounting substrate 20, it is possible to prevent the occurrence of defects such as a short circuit and easily perform a good electrical connection. In addition, as shown in FIGS. 2B and 2C, which will be described later, compared to the case where a pair of external connection electrodes 20a is provided at one end in the longitudinal direction of the mounting substrate 20, there is less area where the pair of wiring patterns are adjacent to each other. It is possible to prevent the wiring patterns from being short-circuited.

The insulating protective film 23 is a protective film that covers the upper surface of the metal film 22 that is a wiring pattern, excluding the external connection electrode terminal 22a and the mounting portion 22b. The insulating protective film 23 also functions as a reflective film that reflects light emitted downward from the light emitting element 10. Therefore, almost the entire upper surface 20a of the mounting substrate 20 is covered, including the upper surface of the metal film 22 described above.
As the insulating protective film 23, an insulating reflective film made of a dielectric multilayer film made of a translucent dielectric such as SiO ₂ / Nb ₂ O ₅ can be used.

  Note that a reflective film made of a metal having a high reflectance may be laminated instead of the insulating protective film 23 or under the insulating protective film 23. In this case, the reflective film is not laminated between the two metal films 22 so as not to be electrically connected between the two metal films 22 which are wiring patterns. As such a metal reflection film, a single-layer film or a multilayer film containing Ag, Al, Rh, or the like can be used as in the surface layer material of the metal film 22 described above. For example, the metal film 22 which is a wiring pattern can be formed using Ti / Pt / Au or the like, and the reflective film can be formed thereon using Ti / Al or the like.

  Further, the mounting substrate 20 is not limited to a configuration in which both ends of the upper surface 20a in the longitudinal direction are exposed from the sealing member 30 as illustrated in FIG. 1B. A modification of the mounting substrate 20 will be described with reference to FIGS. 2B and 2C. 2B is a cross-sectional view taken along line CC in FIG. 2C.

  As shown in FIG. 2B and FIG. 2C, an exposed portion 20c in which the upper surface 20a at one end in the longitudinal direction of the mounting substrate 20 is exposed from the sealing member 30 is provided, and a positive electrode and a positive electrode are formed on the exposed portion 20c of the upper surface 20a. A pair of external connection electrode terminals 22a made of a negative electrode may be provided. In this case, the upper surface 20a of the other end of the mounting substrate 20 does not need to be exposed, and the length of the mounting substrate 20 can be shortened. As a result, the mounting substrate 20 can be reduced in size, and the area of the flat portion 30c of the bottom surface 30a of the sealing member 30 that reflects light emitted downward from the light emitting element 10 can be increased. The light extraction efficiency can be improved.

Such a mounting substrate 20, if one end of the longitudinal direction are covered by the sealing member 30, in addition to the side surface 20b ₁ of the end portion in the transverse direction of the mounting substrate 20, a sealing member 30 Also on the side surface 20 b ₂ at the end portion in the longitudinal direction to be covered, the hanging portion 30 b is formed on the bottom surface 30 a of the sealing member 30.
The light emitting device 1 of the present invention, even for hanging portion 30b which is formed on the side surface 20b ₂ in the longitudinal direction of the end portion of such a mounting substrate 20, so that light emitted from the light emitting element 10 is not incident, The positional relationship among the light emitting element 10, the mounting substrate 20, and the bottom surface 30a of the sealing member 30 is determined.

Furthermore, both end portions in the longitudinal direction of the mounting substrate 20 may be covered with the sealing member 30. In this case, the upper portions of all side surfaces of the mounting substrate 20 are covered with the sealing member 30. The light emitting element 10, the mounting board 20, and the sealing member 20 are sealed so that the light emitted from the light emitting element 10 does not enter the hanging portions 30 b formed on all the side surfaces 20 b ₁ and 20 b ₂ of the mounting board 20. The positional relationship with the bottom surface 30a of the stop member 30 is determined.

As a result, the mounting substrate 20 can be further reduced in size, and the area of the flat portion 30c of the bottom surface 30a of the sealing member 30 that reflects light emitted downward from the light emitting element 10 can be further increased. The light extraction efficiency as 1 can be further improved.
In the case of such a configuration, the external connection electrode terminal 22a is provided on the back surface side of the mounting substrate 20, and is electrically connected to the mounting portion 22b of the light emitting element 10 through, for example, a via. be able to.

The sealing member 30 has a bottom surface 30a having a flat surface, reflects light emitted downward from the light emitting element 10 and deflects it upward. The sealing member 30 seals the entire light emitting element 10 and the upper part of the mounting substrate 20 (a part of the upper surface 20a and the side surface 20b), and the upper surface 20a side (on the bottom surface 30a) that is the light extraction direction of the light emitting device 1. A light extraction surface 30e is provided on the opposite side. Accordingly, the sealing member 30 prevents the light emitting element 10 from being deteriorated by the outside air. Further, when the light emitting element 10 is arranged at substantially the center (outer shape) of the sealing member 30 in a plan view, light can be uniformly irradiated from the light emitting element 10 to the light extraction surface 30e. Further, the light extraction surface 30e of the sealing member 30 is a hemispherical surface, and the light emitting element 10 is arranged at the substantially center of the hemispherical surface in a plan view, so that the incident angle of light incident on the hemispherical surface is the critical point of total reflection. It can suppress becoming a corner or more. Thus, the incident light component totally reflected by the inner surface of the hemispheric surface that is the light extraction surface 30e can be reduced, and light can be efficiently extracted to the outside. Moreover, in the cross-sectional view, the light emitting element 10 should just be arrange | positioned on the planar view central axis of the light extraction surface 30e. For example, the light extraction surface 30e may be a hemispherical surface, and the center of curvature thereof may be located below a predetermined height (for example, H _OFF ) from the center of the light emitting element 10. Preferably, the light extraction surface 30e is formed of a spherical surface having the light emitting element 10 as the center, so that good light extraction efficiency can be obtained. In this case, the light extraction surface 30e has a part of a spherical surface continuous to the hemispherical surface and the bottom surface 30a below the upper surface 20a of the mounting substrate 20 in addition to the hemispherical surface having the light emitting element 10 as the center.
In addition, the light extraction surface 30e of the sealing member 30 has a desired shape such as a hemispherical surface, a convex curved surface flattened from a spherical surface, a shell shape, or a concave curved surface, and functions as a lens that collects and diffuses light. You can also. Hereinafter, in this specification, the sealing member 30 may be described as a lens.
The sealing member 30 is made of transparent resin, glass, or the like. As the resin, for example, a hard silicone resin or an epoxy resin can be used.

  The sealing member 30 has a diameter larger than the width (length in the short direction) of the mounting substrate 20, and a part of the sealing member 30 extends to the outside in the short direction of the mounting substrate 20. To do. Further, the bottom surface 30 a of the sealing member 30 is positioned (offset) below the upper surface 20 a that is the mounting surface of the mounting substrate 20. In other words, the sealing member 30 has a recess on the bottom surface side, and the mounting substrate 20 is provided such that its upper surface 20a coincides with the bottom surface of the recess of the sealing member 30, and the lower surface of the mounting substrate 20 protrudes outside the recess. ing.

The bottom surface 30 a of the sealing member 30 is formed with a drooping portion 30 b at a joint portion with the side surface 20 b of the mounting substrate 20. The drooping portion 30 b is generated in the process of molding the sealing member 30.
The drooping portion 30b is, for example, a resin dripping (climbing) as shown in FIG. 3A or a resin layer as shown in FIG. 3B at the joint between the side surface 20b of the mounting substrate 20 and the sealing member 30. It is formed as a fillet.

A region of the bottom surface 30a of the sealing member 30 that does not cover the mounting substrate 20 is a flat portion 30c that is a flat surface except for the hanging portion 30b.
If the width of the hanging part 30b shown in FIGS. 3A and 3B is b, the width b is the horizontal distance from the side face 20b of the mounting substrate 20 to the end part 30d of the flat part 30c on the bottom face 30a of the sealing member 30. It is. In the present invention, the positional relationship between the light emitting element 10, the mounting substrate 20, and the bottom surface 30 a of the sealing member 30 is determined so that light emitted downward from the light emitting element 10 does not enter the hanging part 30 b of the width b. It has been.

Next, referring to FIG. 4, the light emitting element 10 for preventing the light emitted from the light emitting element 10 from entering the hanging part 30 b, the mounting substrate 20, and the sealing member 30 extending to the outside of the mounting substrate 20. The positional relationship with the bottom surface 30a will be described.
As shown in FIG. 4, the position of the upper surface 20a of the mounting substrate 20, the position to the height of the upper surface 10a of the light emitting element 10 and _{H EM.} Further, the depth from the position of the upper surface 20a to the position of the flat portion of the bottom surface 30a of the sealing member 30 is H _OFF .
As described above, the width of the hanging part 30b is b, and the horizontal distance from the point P1 at the end of the upper surface 10a of the light emitting element 10 to the point P2 at the end of the upper surface 20a of the mounting substrate 20 is a. Further, when the position where the light emitted from the point P1 passes through the point P2 and enters the flat portion 30c of the bottom surface 30a of the sealing member 30 is the point P3, the horizontal direction from the side surface 20b of the mounting substrate 20 at the point P3. Let c be the distance.

At this time, the distance closest to the side surface 20b of the mounting substrate 20 among the light emitted downward from the light emitting element 10 and directly incident on the bottom surface 30a of the sealing member 30 is c.
Here, c can be expressed as in equation (1).
c = (H _OFF / H _EM ) × a (1)

The condition for preventing the light emitted from the light emitting element 10 from entering the hanging portion 30b is to satisfy the expression (2).
c ≧ b (2)

Substituting equation (1) into equation (2) yields equation (3).
H _OFF ≧ (b / a) × H _EM (3)

By defining H _OFF , _HEM and a so as to satisfy the expression (3) with respect to the width b of the hanging part 30b expected to be formed, the light emitted from the light emitting element 10 to the hanging part 30b Incident can be prevented. Accordingly, light leakage from the hanging part 30b and light absorption on the side surface 20b of the mounting substrate 20 on which the hanging part 30b is formed can be prevented, and a decrease in light extraction efficiency from the light emitting device 1 can be prevented.

In the present invention, the bottom surface 30a of the sealing member 30 extending to the outside of the mounting substrate 20 totally reflects the light emitted downward from the light emitting element 10 and deflects it upward in the light extraction direction.
With reference to FIG. 4, the conditions under which the light emitted downward from the light emitting element 10 and directly incident on the bottom surface 30a of the sealing member 30 is totally reflected by the bottom surface 30a (flat portion 30c) will be described.

  An incident angle θ is an angle between the incident direction of light directly incident on the bottom surface 30a of the sealing member 30 from the end point P1 on the upper surface 10a of the light emitting element 10 and the normal line of the bottom surface 30a of the sealing member 30. At this time, when the light emitted from the point P1 passes through the point P2 at the end of the top surface 20a of the mounting substrate 20 and enters the point P3 on the bottom surface 30a of the sealing member 30, the incident angle θ is the smallest. .

When the refractive index of the sealing member 30 is n and the outside of the sealing member 30 is air (refractive index = 1), the critical angle θ _m of total reflection at the bottom surface 30a of the sealing member 30 is expressed by the equation (4). It is expressed as follows.
θ _m = sin ⁻¹ (1 / n) (4)

Further, the incident angle θ at the point P3 is expressed as in Expression (5).
θ = tan ⁻¹ (a / H _EM ) (5)

The condition for totally reflecting all the light emitted from the light emitting element 10 and incident on the bottom surface 30a of the sealing member 30 is to satisfy Expression (6).
θ ≧ θ _m (6)

When Expression (4) and Expression (5) are substituted into Expression (6), Expression (7) is obtained.
a ≧ H _EM × tan {sin ⁻¹ (1 / n)} (7)

By defining _HEM and a so as to satisfy Expression (7), the bottom surface 30a of the sealing member 30 can function as a reflection surface that totally reflects the light emitted from the light emitting element 10.

Here, a design example of the mounting substrate 20 will be described.
When the outer dimensions of the light emitting element 10 are 1.1 mm × 1.1 mm, the height (H _EM ) is 0.5 mm, and the refractive index (n) of the sealing member 30 is 1.5, the formula (7 ), A ≧ 0.45 mm. That is, the light incident on the bottom surface 30 a of the sealing member 30 can be totally reflected by providing a distance from the end of the light emitting element 10 to the end of the mounting substrate 20 of 0.45 mm or more. Accordingly, it is desirable that the width of the mounting substrate 20 is designed to be 0.45 + 1.1 + 0.45 = 2.0 mm or more.

Further, if the width (thickness) b of the hanging part 30b can be suppressed to 0.1 mm or less, for example, when the light emitting element 10 and the mounting board 20 having the above-described design values are used, the upper surface of the mounting board 20 is used. The depth (H _OFF ) of the flat portion 30c of the bottom surface 30a of the sealing member 30 from 20a is H _OFF ≧ 0.11 mm from Equation (3). That is, if the flat portion 30c of the bottom surface 30a of the sealing member 30 is provided 0.11 mm or more below the upper surface 20a of the mounting substrate 20, it is possible to avoid the incidence of light from the light emitting element 10 to the hanging portion 30b. it can. For this reason, if the H _{OFF is set} to 0.2 mm with a margin, for example, good light extraction efficiency can be obtained.

  Therefore, the thickness of the mounting substrate 20 is such that the bottom surface 30a of the sealing member 30 positioned below the upper surface 20a of the mounting substrate 20 when the light emitting device 1 is mounted on a device that uses the light emitting device 1 or the like. It can be determined from the viewpoint of functioning favorably as the reflecting surface and the heat dissipation property of the light emitting device 1, for example, 0.4 to 2.0 mm.

In addition, although the above description demonstrated the case where the cross section of the light emitting element 10 was a rectangle, it is not limited to this. For example, when the cross section is not rectangular like the light emitting element 10A shown by a broken line in FIG. 4, for example, the shape is rounded, a and H _EM that are the attributes of the reference point P1 in the light emitting element 10A are: The height (maximum height) of the light emitting element 10A from the upper surface 20a of the mounting substrate 20 to the farthest point is _HEM, and the horizontal distance (minimum distance) from the side surface 20b of the mounting substrate 20 to the closest point is defined as HEM. As a, it can apply to above-mentioned Formula (3) and Formula (7).

<Operation>
Next, with reference to FIG. 1A thru | or FIG. 1C, operation | movement of the light-emitting device 1 in embodiment which concerns on this invention is demonstrated.
The light emitting device 1 is connected to an external drive circuit (not shown) at the external connection electrode terminal 22a, and is mounted on the mounting portion 22b via the metal film 22 that is a wiring pattern disposed on the upper surface 20a side of the mounting substrate 20. Power is supplied to the electrically connected light emitting elements 10. The light emitting element 10 emits light upon receiving power supply, and emits light to the outside of the light emitting element 10.
In addition, when the light emitting element 10 has the phosphor layer 12 as illustrated in FIG. 2A, the wavelength of all or part of the light emitted from the semiconductor light emitting element structure 11 is converted by the phosphor layer 12, The light is emitted to the outside of the light emitting element 10.

The light emitted upward from the light emitting element 10 is preferably extracted outside the light emitting device 1 from the light extraction surface 30e of the sealing member 30 formed in a hemispherical shape.
A part of the light emitted downward from the light emitting element 10 is reflected by the insulating protective film 23 and the metal film 22 provided on the upper surface 20a side of the mounting substrate 20, and is deflected upward.
The light emitted downward from the light emitting element 10 and incident on the bottom surface 30a of the sealing member 30 is totally reflected by the bottom surface 30a of the sealing member 30 and deflected upward. At this time, the light emitted downward from the light emitting element 10 does not enter the hanging portion 30 b of the sealing member 30.
The light reflected by the upper surface 20 a of the mounting substrate 20 or the bottom surface 30 a of the sealing member 30 and deflected upward is extracted from the light extraction surface 30 e of the sealing member 30 to the outside of the light emitting device 1.

<Manufacturing method>
Next, with reference to FIGS. 5A to 5F (refer to FIGS. 1A, 1C, and 2A as appropriate), a method for manufacturing the light-emitting device 1 in the embodiment according to the present invention will be described.
In the method for manufacturing the light emitting device 1 according to the present embodiment, a light emitting element mounting step for mounting the light emitting element 10 on the mounting substrate 20 and a sealing member 30 on the mounting substrate 20 on which the light emitting element 10 is mounted are formed by a compression molding method. And a sealing member forming step.

(Light emitting element mounting process)
The light emitting element mounting process is a process of mounting the light emitting element 10 on the mounting substrate 20 and includes a die bonding process of a semiconductor light emitting element structure, a phosphor layer forming process, and a mounting substrate dividing process.
In addition, the light emitting element mounting process in this invention should just include the process of die-bonding the light emitting element 10 to the mounting board | substrate 20 separated at least regardless of the presence or absence of the fluorescent substance layer 12. FIG. The step further including the phosphor layer forming step and the mounting substrate dividing step described below shows one of preferable steps of the light emitting element mounting step.

(Die bonding process of semiconductor light emitting device structure)
As shown in FIG. 5A, an integrated substrate 60 in which a plurality of mounting substrates 20 are integrated is used until the phosphor layer 12 is formed.
In the integrated substrate 60, the mounting portions 22b of the semiconductor light emitting element structure (LED chip) 11 are arranged in a matrix on a sheet-shaped mounting substrate 61 having a large area. In addition, the mounting portion 22b of each semiconductor light emitting element structure 11 is provided with an electrode pattern composed of a negative electrode and a positive electrode so as to match the electrode configuration pattern of the semiconductor light emitting element structure 11. For example, the semiconductor light emitting element structure 11 and the mounting substrate 20 are joined electrically and mechanically by flip chip mounting using eutectic bonding. The mounting substrate 20 is made of, for example, aluminum nitride ceramics having a thickness of 0.4 to 2.0 mm, and an electrical wiring pattern to the mounting portion 22b that is a joint portion with the semiconductor light emitting element structure 11 on the upper surface 20a side. And a reflective layer made of a highly reflective metal or dielectric multilayer film.

(Phosphor layer formation process)
A phosphor layer 12 is formed on the surface of each semiconductor light emitting element structure 11 mounted on the integrated substrate 60. For example, when the screen printing method is used, a mask for screen printing designed to obtain a phosphor layer 12 having a desired thickness is used, and a thermosetting silicone resin or the like is used as a binder to be uniform with the phosphor. An appropriate amount of the kneaded material is applied to the surface of the semiconductor light emitting element structure 11 and formed so as to cover the semiconductor light emitting element structure 11 with a squeegee. At this time, it is desirable that the phosphor layers 12 covering the upper surface and the side surface of the semiconductor light emitting element structure 11 have the same thickness.

Thereafter, the phosphor layer 12 is heated and cured at a necessary temperature to obtain an integrated substrate 60 in which the light emitting elements 10 with the phosphor layer are arranged in an array.
The phosphor layer 12 is obtained by cutting a ceramic plate (plate-like sintered body) containing a phosphor into a desired size and pasting it on the surface of the semiconductor light emitting element structure 11 using a thermosetting resin such as a silicone resin. Then, the thermosetting resin may be heated and cured at a necessary temperature and then bonded.

(Mounting board dividing process)
Next, the integrated substrate 60 is diced along a predetermined division line (dicing line) 62a in the longitudinal direction of the mounting substrate 20, and the bar-shaped integrated substrate 60 is cut out. Thereafter, each bar-shaped integrated substrate 60 cut out is further diced along a dividing line 62b in the short direction of the mounting substrate 20 to cut out the individual mounting substrates 20.

  In addition, the dividing line 62b in the short direction of the mounting substrate 20 is not cut, and the compression molding of the sealing member 30 corresponding to each mounting substrate 20 is performed in a bar shape in which the plurality of mounting substrates 20 are continuous in the longitudinal direction. May be performed simultaneously. Then, by cutting along the planned dividing line 62b in the short longitudinal direction of the mounting substrate 20, it is possible to obtain the mounting substrate 20, that is, the light emitting device 1, in which the individual sealing members 30 are formed.

(Sealing member molding process)
The sealing member molding step is a step of compression molding the sealing member 30 on the mounting substrate 20 on which the light emitting element 10 is mounted, and includes a potting step of the sealing member, a primary curing step of the sealing member, Secondary curing step of the sealing member.

(Potting process of sealing member (sealing resin))

Next, as shown in FIGS. 5B and 5C, the mounting substrate 20 on which the light emitting element 10 is mounted is placed on the lower mold 51 heated to a predetermined temperature. A mold jig (jig) 52 is installed so as to sandwich 20b from both sides. At this time, the height of the upper surface 52a of the mold jig 52 is lower than the upper surface 20a of the mounting substrate 20 by a predetermined height (H _OFF ). The upper surface 52a of the mold jig 52 that forms the bottom surface 30a of the sealing member 30 is a smooth surface.
Here, a mold release agent is applied to the upper surface 52a of the mold jig 52 in order to form a flat bottom surface 30a of the sealing member 30 and to facilitate removal from the mold. Further, on the external connection electrode terminal 22a (see FIG. 1B) of the mounting substrate 20, after the sealing member 30 is molded, the coating with the sealing resin 31 used as the material of the sealing member 30 can be removed. You may mask by sticking a heat release sheet.

Thereafter, the temperature is heated to the primary curing temperature of the thermosetting resin that is the sealing resin 31 that becomes the sealing member 30, and the liquid sealing resin 31 is mounted on the mounting substrate 20 by a dispenser 54 or the like as shown in FIG. 5D. And an appropriate amount of potting (dropping) is performed on the mold jig 52.
The sealing resin 31 that has entered the gap between the side surface 20b of the mounting substrate 20 and the mold jig 52 becomes the hanging portion 30b.

(Primary curing process of sealing member)
Next, as shown in FIGS. 5E and 5F, the upper mold 53 is closed from above the potted sealing resin 31, and a predetermined pressure is applied to compress the sealing resin 31. The upper mold 53 is formed with a hemispherical lens mold. And it hold | maintains for the predetermined time in the state compressed with the upper side metal mold | die 53, and hardens the sealing resin 31 primarily.

  It is preferable that the heating temperature and the heating time by the lower mold 51 and the upper mold 53 are set so as to reach a hardness sufficient for the sealing resin 31 to maintain a predetermined shape. For example, when a hard silicone resin or an epoxy resin is used, the primary curing temperature is preferably 100 to 170 ° C, more preferably 120 to 150 ° C. The primary curing time is preferably 180 to 900 seconds, more preferably 250 to 600 seconds.

  By using such a mold jig 52, a desired bottom shape and joint shape can be obtained on the sealing member 30 by molding the sealing resin 31 once. Further, the upper die 53 can form a light extraction surface and a lens surface having a desired diameter and a radius of curvature on the sealing member 30.

(Secondary curing process of sealing member)
Next, the mounting substrate 20 formed with the sealing resin 31 having a desired shape is taken out from the lower mold 51 and the upper mold 53 and heated under predetermined conditions to secondary cure the sealing resin 31. Let The secondary curing conditions are set such that the secondary curing temperature is equal to or higher than the primary curing temperature, for example, and the secondary curing time is set longer than the primary curing time so that the sealing resin 31 is sufficiently cured. It is preferable to do. In the case of a hard silicone resin or an epoxy resin, the secondary curing time can be about 3 to 5 hours. By sufficiently performing the secondary curing in this way, it is possible to prevent an unreacted resin component from remaining in the sealing resin 31 and adversely affecting the reliability of the light emitting element 10. Further, after a short time primary curing in the lower mold 51 and the upper mold 53, the light emitting device 1 is taken out from the lower mold 51 and the upper mold 53, and the sealing resin 31 is removed for a long time. By performing secondary curing, the throughput of the process can be increased.
Through the above steps, the light emitting device 1 including the light emitting element 10, the mounting substrate 20, and the sealing member 30 is completed.

The mold jig 52 shown in FIGS. 5B and 5C is not limited to the configuration in which the side surface 20b of the mounting substrate 20 is sandwiched from both sides by the plurality of mold jigs 52 as described above. For example, one plate-shaped mold jig 52 having a thickness that is thinner than the thickness of the mounting substrate 20 by a predetermined height (H _OFF ) and provided with a through hole in the shape of the mounting substrate 20 in plan view is used. You can also. In this case, a mold jig 52 provided with a through hole is installed on the lower mold 51, and the mounting substrate 20 is installed in the through hole. At this time, the side surface of the mounting substrate 20 is sandwiched between the side surfaces of the through holes of the mold jig 52. Further, the bottom surface of the mounting substrate 20 is in contact with the upper surface of the lower mold 51, and the upper surface 20 a of the mounting substrate 20 protrudes from the through hole of the jig mold 52. For this reason, the height of the upper surface 52 a of the mold jig 52 is lower than the upper surface 20 a of the mounting substrate 20 by a predetermined height (H _OFF ). The upper surface 52a of the mold jig 52 that forms the bottom surface 30a of the sealing member 30 is a smooth surface.

Furthermore, the jig mold 52 is not a through-hole, but has a depth shallower than the thickness of the mounting substrate 20 by a predetermined height (H _OFF ), and is provided with a recess in the shape of the mounting substrate 20 in plan view. One plate-shaped mold jig 52 can also be used. In this case, a mold jig 52 having a recess is provided on the lower mold 51, and the mounting substrate 20 is installed in the recess. At this time, the side surface of the mounting substrate 20 is sandwiched between the side surfaces of the recesses of the mold jig 52. Further, the bottom surface of the mounting substrate 20 is in contact with the bottom surface of the concave portion of the jig die 52, and the upper surface 20 a of the mounting substrate 20 protrudes from the concave portion of the jig die 52. For this reason, the height of the upper surface 52 a of the mold jig 52 is lower than the upper surface 20 a of the mounting substrate 20 by a predetermined height (H _OFF ). The upper surface 52a of the mold jig 52 that forms the bottom surface 30a of the sealing member 30 is a smooth surface.

Further, the jig mold 52 provided with such a through hole or recess and the lower mold 51 may be integrated. In other words, the lower mold 51 may be provided with a recess that is shallower than the thickness of the mounting substrate 20 by a predetermined height (H _OFF ) and has the shape of the mounting substrate 20 in plan view. In this case, since the bottom surface 30a of the sealing member 30 is formed on the upper surface of the lower mold 51, the upper surface of the lower mold 51 may be a smooth surface. The mounting substrate 20 is installed in each through-hole or recess using the jig mold 52 or the lower mold 51 provided with a plurality of such through-holes or recesses, and corresponds to each mounting substrate 20. You may make it perform the compression molding of the sealing member 30 simultaneously.
The light emitting device 1 can be manufactured by the above-described manufacturing method using the mold jig 52 or the lower mold 51 provided with the through holes or the recesses as described above.

Next, examples and comparative examples for confirming the effects of the present invention will be described.
(Example)
In this embodiment, the light-emitting device having the structure shown in FIGS. 1A to 1C and 2A is manufactured by the following method.

First, a plurality of positive electrode and negative electrode patterns (metal film 22) made of Ti / Pt / Au are formed on a sheet-like mounting substrate 61 (mounting substrate 20) made of aluminum nitride ceramics and having a thickness of about 1.0 mm. To do. Further, in a region other than the mounting portion 22b of the LED chip (semiconductor light emitting element structure 11), a metal reflective layer made of Ti / Al and a reflective layer of a dielectric multilayer film made of SiO ₂ / Nb ₂ O ₅ (insulation protection) A film 23) is sequentially provided.

  Next, an InGaN-based blue LED chip (semiconductor light emitting element structure 11) having an emission wavelength of 450 nm is flip-chip mounted on the electrode pattern which is the mounting portion 22b. The LED chip and the electrode pattern are bonded by eutectic bonding using paste-like Au—Sn, and bonded at a maximum temperature of 320 ° C. by a reflow apparatus in a nitrogen atmosphere.

  Next, an appropriate amount of thermosetting silicone resin is applied to the side surface and upper surface of the LED chips (semiconductor light emitting element structure 11) arranged on the sheet-like mounting substrate 61, and the YAG phosphor-containing ceramic plate cut out to a predetermined size. (Phosphor layer 12) is affixed and heated at 150 ° C. for 600 seconds to cure the silicone resin. Thereby, an LED chip (light emitting element 10) with the phosphor layer 12 is formed.

  Thereafter, the sheet-like mounting substrate 61 on which LED chips (light emitting elements 10) with phosphor layers are arranged is diced to cut out the mounting substrate 20 having a size of about 14.0 mm × 2.0 mm.

The mounting substrate 20 that has been diced into individual pieces is placed on the lower mold 51, and a mold jig 52 for forming the bottom surface is installed so as to sandwich the side surface 20b of the mounting substrate 20. At this time, the upper surface 52 b of the mold jig 52 is positioned about 0.2 mm below the upper surface 20 a of the mounting substrate 20. Then, a liquid silicone resin is dropped on the mounting substrate 20 and the mold jig 52, and the silicone resin is placed in the mold (lower mold 51 and upper mold 53) of the compression molding machine at 150 ° C. for 180 seconds. Harden. The mounting substrate 20 is taken out from the mold (the lower mold 51 and the upper mold 53), and the silicone resin is further cured at 150 ° C. for 4 hours.
Thus, the light emitting device 1 having the hemispherical sealing member 30 having a diameter of about 8 mm as shown in FIGS. 1A to 1C and 2A is obtained.

(Comparative example)
As a comparative example of the light emitting device 1, the length in the short direction (short side) of the mounting substrate in the example is about 10 mm, and the substrate (mounting substrate 120) is also in the short direction as shown in FIGS. 6A and 6B. ) Is made larger than the diameter of the sealing member (lens) 130. 6A is a cross-sectional view taken along line DD in FIG. 6B.
As shown in FIGS. 6A and 6B, in the light emitting device 101 in the comparative example, the sealing member 130 is all provided on the upper surface 120 a of the mounting substrate 120.
The manufacturing method of the comparative example is the same as the manufacturing method of the above-described embodiment, except that the mold jig 52 that sandwiches the separated mounting substrate 120 is not used.

(Comparison of light output)
The light emitting device of the example emits light with an optical output of 504 mW at a forward current of 350 mA, an optical output of 941 mW at a forward current of 700 mA, and an optical output of 1273 mW at a forward current of 1000 mA.
The light emitting device of the comparative example emits light with an optical output of 498 mW at a forward current of 350 mA, an optical output of 918 mW at a forward current of 700 mA, and an optical output of 1228 mW at a forward current of 1000 mA.

  It can be seen that the light emitting device of the example according to the present invention has a higher light output than the light emitting device of the comparative example. In the light emitting device of the comparative example, all light components emitted downward from the LED chip (light emitting element) are incident on the mounting substrate, reflected by the mounting substrate, and part of the light component is absorbed by the mounting substrate. Become. On the other hand, in the light emitting device of the example, among the light components emitted downward from the LED chip, a part of the light component incident on the mounting substrate is absorbed by the mounting substrate, as in the comparative example. However, all the light components emitted farther than the width of the mounting substrate are incident on the bottom surface of the sealing member at a critical angle of total reflection or more and are totally reflected. As a result, other light components emitted downward from the LED chip are totally reflected on the bottom surface of the sealing member while minimizing absorption due to reflection on the mounting substrate, and are transmitted downward from the bottom surface and leak out. There is nothing. For this reason, light can be efficiently extracted from the light emitting device.

  In addition, the bottom surface of the sealing member outside the mounting substrate has a flat portion and a hanging portion, and the flat portion is positioned closer to the upper surface side of the mounting substrate than in this embodiment, and directly from the LED chip to the hanging portion. If the light emitting device is such that light is incident and light is absorbed on the side surface of the mounting substrate, the light output is higher than that of the light emitting device of the comparative example, but the light output is lower than that of the light emitting device of the example.

  When a part of the width of the mounting substrate is made smaller than the diameter of the sealing member, a hanging portion is formed on the bottom surface of the sealing member on the side surface of the narrow width portion of the mounting substrate. The light emitting device of the embodiment has a structure in which light does not enter such a hanging portion, can avoid unintentional absorption of light on the side surface of the mounting substrate, etc., and improves the light extraction efficiency of the light emitting device. It contributes.

  The light emitting device of the present invention can be suitably used for backlight light sources such as illumination light sources, LED displays, liquid crystal display devices, traffic lights, illumination switches, various sensors, various indicators, and the like.

DESCRIPTION OF SYMBOLS 1 Light emitting device 10 Light emitting element 10a Upper surface 11 Semiconductor light emitting element structure 12 Phosphor layer 20 Mounting board 20a Upper surface 20b, 20b ₁ , 20b ₂ Side surface 20c Exposed part 22 Metal film 22a External connection electrode terminal 22b Mounting part 23 Insulating protective film 30 Sealing member 30a Bottom surface 30b Hanging part 30c Flat part 30d End part 30e Light extraction surface 31 Sealing resin 51 Lower mold 52 Mold jig (jig)
52a Upper surface 53 Upper mold 54 Dispenser 60 Integrated substrate 61 Sheet-like mounting substrate 62a, 62b Scheduled dividing line

Claims (8)

A mounting substrate having an upper surface and a side surface continuous from the upper surface;
A light emitting element provided on a part of the upper surface of the mounting substrate;
A sealing member enclosing the light emitting element and having a bottom surface extending outside the mounting substrate;
The bottom surface of the sealing member is located below the top surface of the mounting substrate, and a flat portion that reflects light emitted from the light emitting element, and a side surface of the mounting substrate that is continuous from the flat portion. A drooping portion that hangs downward from the flat portion along the
A light emitting device comprising: The light emitting element has an upper surface and a side surface continuous from the upper surface,
The depth of the flat portion of the bottom surface of the sealing member from the top surface of the mounting substrate is H _OFF ,
H _EM is the maximum height of the upper surface of the light emitting element from the upper surface of the mounting substrate.
The minimum horizontal distance from the side surface of the mounting substrate to the side surface of the light emitting element is a,
When the horizontal distance from the side surface of the mounting substrate to the flat portion of the bottom surface of the sealing member is b,
H _OFF ≧ (b / a) × H _EM
The light emitting device according to claim 1, wherein: When the refractive index of the sealing member is n,
a ≧ H _EM × tan {(sin ⁻¹ (1 / n))}
The light emitting device according to claim 2, wherein:   4. The light emitting device according to claim 1, wherein a surface facing the bottom surface of the sealing member is a hemispherical surface. 5. The upper surface of the mounting substrate is a rectangular shape that is long in one direction,
5. The light emitting device according to claim 1, wherein the mounting substrate has an exposed portion where the upper surface of at least one end portion in the longitudinal direction is exposed from the sealing member. apparatus. Provided on the upper surface of the mounting substrate, a metal film electrically connected to the light emitting element,
The light emitting device according to claim 5, wherein the metal film has a pair of external connection electrode terminals on the exposed portion of the upper surface of the mounting substrate. The exposed portion is provided at both ends in the longitudinal direction of the mounting substrate,
The light emitting device according to claim 6, further comprising a pair of electrode terminals for external connection at the exposed portions at both ends. A light emitting element mounting step of mounting a light emitting element on the upper surface of the mounting substrate having an upper surface and a side surface continuous from the upper surface;
After the light emitting element mounting step, including a sealing member molding step of compression molding a sealing member containing the light emitting element,
In the sealing member molding step, the mounting substrate is arranged such that a side surface of the mounting substrate is sandwiched between jigs having a smooth upper surface, and the upper surface of the jig is positioned below the upper surface of the mounting substrate. And the jig, and the sealing member is compression-molded to form the bottom surface of the sealing member on the upper surface of the jig.

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