JP2005209763A - Light-emitting device and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device which shows an improved heat dissipation effect, maintains high reliability, and emits light at high brightness while consuming less power. <P>SOLUTION: The light-emitting device 10 comprises a board 5 having a recession on the top face thereof, and a light-emitting element 17 placed on the bottom of the recession. The board 5 has through-holes 6, 7 and 8 which are filled with conductive and/or heat dissipating materials 9, 18 and are formed on the bottom of the recession, and metal patterns 11 to 16 which are in contact with the conductive and/or heat dissipating materials 9, 18 filling the through holes 6, 7 and 8 and are formed on the upper surface, including the recession, and the lower surface of the board 5, respectively. The light-emitting element 17 is placed on the metal pattern 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a light emitting device and a method for manufacturing the light emitting device.

  In recent years, high-intensity, high-output semiconductor light-emitting elements and small, high-sensitivity light-emitting devices have been developed and used in various fields. Such a light emitting device is used in various fields such as a light source of an optical printer head, a liquid crystal backlight light source, a light source of various meters, a variety of reading sensors, etc. by utilizing characteristics such as small size, light weight, and low power consumption. ing.

  For example, as an example of such a light emitting device, there is a light emitting device 42 as shown in FIG. This light emitting device has a recess and uses a plastic package 40 in which a lead electrode 41 led out from the bottom surface of the recess is integrally formed. On the lead electrode 41 exposed from the bottom surface of the recess, a light emitting element is provided. LED chip 43 is die-bonded. In addition, the LED chip 43 is electrically connected to lead electrodes 41 provided on the package 40 by electrodes (not shown) formed on the surface of the LED chip 43 through gold wires 44 or the like. Thus, the LED chip 43 disposed in the recess is sealed with a translucent mold resin 45. As a result, LED chips, wires, and the like disposed inside the package are protected from the external environment such as moisture and external force, and a highly reliable light-emitting device can be obtained.

Usually, a light emitting element emits heat due to power consumption. The light emitting device 42 configured as described above releases heat generated from the light emitting element to the substrate side via the lead electrode 41.
However, if a large current is applied to the light emitting device 42 in order to improve the output of the light emitting element, the heat dissipation effect by the package 40 is not sufficient, so the temperature of the light emitting element rises, and the operating speed of the element and the resin present in the surroundings are increased. There is a problem that not only deterioration and the like are caused, but also light emission efficiency is lowered. Further, since the lead electrode 41 is bent and pulled out to the lower surface of the package 40, the stress associated with the processing of the lead electrode 41 is applied to the package 40 or the lead electrode 41 itself, leading to problems such as contact failure and disconnection. There is. Further, since the lead electrode 41 is bent, the package 40 needs to have a certain thickness, and it is difficult to further reduce the size and weight.

Further, as shown in FIG. 7, a substrate 50 having a concave portion on the upper surface is used, and the bottom surface of the concave portion is covered with a heat dissipating pad 52, and the LED chip 51 is mounted on the exposed heat dissipating pad 52. A light emitting device 53 is proposed (for example, Patent Document 1).
In such a light emitting device 50, since the LED chip 51 is directly mounted on the heat dissipating pad 52, the heat dissipating effect can be enhanced.
Japanese Patent Laid-Open No. 2003-31850

However, recently, in order to cope with high-density mounting, in addition to further miniaturization and thinning, a light emitting device having high performance and high reliability has been demanded. Therefore, it is required to ensure the performance and reliability of the light emitting device.
The present invention has been made in view of the above problems, and provides a light-emitting device capable of further improving the heat dissipation effect in the light-emitting device and capable of emitting light with high power consumption while maintaining high reliability. For the purpose.

  The light emitting device of the present invention is a light emitting device comprising a substrate having a recess on the upper surface and a light emitting element placed on the bottom surface of the recess, and the substrate has a conductive and / or heat dissipation material on the bottom surface of the recess. The upper surface and the lower surface including at least one embedded through-hole and including the concave portion are each provided with a metal pattern in contact with the conductive and / or heat-dissipating material embedded in the through-hole, The light emitting element is placed on the metal pattern.

In the light emitting device, it is preferable that the light emitting element is mounted directly on the metal pattern above the through hole.
A plurality of through holes may be formed.
Further, the metal patterns formed on the upper surface and the lower surface of the substrate are respectively formed as at least two electrically separated patterns, and the two electrically separated patterns serve as a pair of terminal electrodes of the light emitting element. It may function.
Further, the conductive and / or heat dissipation material may be solder, metal paste, conductive paste, or a combination material of a metal thin film and a resin, and the metal pattern is gold, copper, nickel, chromium, silver, or these It may be formed of a single layer film or a laminated film of a metal alloy.

The method for manufacturing a light emitting device of the present invention includes a step of forming a through hole in a first substrate having a metal thin film formed on an upper surface and a lower surface,
A step of embedding a conductive and / or heat dissipating material in the through hole;
Patterning metal thin films on the upper and lower surfaces of the first substrate;
Bonding a second substrate having a through-hole forming a recess to the first substrate to form a substrate having a recess on the upper surface;
Forming a metal thin film on the concave surface of the substrate having the concave portion on the upper surface;
It comprises a step of mounting a light emitting element on the obtained substrate.

  According to the light emitting device of the present invention, since the light emitting element is placed on the metal pattern formed on the upper surface of the substrate, the heat generated by the light emitting element is efficiently passed from the upper surface side of the substrate through the metal pattern. Can be diverged. In addition, the metal pattern is in contact with the conductive and / or heat-dissipating material embedded in the through hole, and the through hole is in contact with the metal pattern formed on the lower surface of the substrate. The heat generated by the element can be efficiently dissipated through the metal pattern on the lower surface of the substrate directly from the mounting portion of the light emitting element through the through hole. Moreover, since the conductive and / or heat-dissipating material is embedded in the through-hole, the mold resin does not leak from the through-hole even when molded in the recess, and the reliability is good. A light emitting device can be obtained.

In addition, when the light emitting element is mounted directly on the metal pattern on the through hole, the conductive and / or heat dissipating material in the through hole directly through the metal pattern at the place where the light emitting element is mounted. Therefore, heat can be transferred from the upper and lower surfaces of the substrate more efficiently.
Furthermore, when a plurality of through holes are formed, the heat generated in the light emitting element can be more effectively transmitted to the metal pattern on the lower surface of the substrate, and the heat dissipation effect can be exhibited more remarkably.
Further, when the metal patterns formed on the upper surface and the lower surface of the substrate are respectively at least two electrically separated patterns, the two electrically separated patterns are converted into a pair of terminals of the light emitting element. It is possible to function as an electrode, and it is not necessary to form a terminal electrode separately from a metal pattern formed for heat dissipation, and a light-emitting element with a simpler structure and a lower cost can be obtained. Moreover, unlike conventional lead electrodes, bending is not applied, so stress associated with lead electrode processing is not applied to the package or lead electrode itself, and the terminal electrode itself is protected by a through hole in the substrate. Therefore, problems such as poor contact and disconnection can be prevented.

Furthermore, when the conductive and / or heat-dissipating material is a metal or alloy, metal paste, conductive paste, or a combination material of a metal thin film and a resin, sufficiently exhibit heat dissipation while ensuring conductivity. Therefore, the light emission efficiency can be further improved, and the life of the light emitting device can be extended.
In addition, when the metal pattern is formed of a single layer film or a laminated film of gold, copper, nickel, chromium, silver, or an alloy of these metals, the heat dissipation efficiency is good and the conductivity is good. Therefore, power consumption can be further reduced, and a highly reliable and high-performance light-emitting device can be obtained.

  According to the method for manufacturing a light emitting device of the present invention, the heat generated by the light emitting element can be efficiently dissipated, and a high performance and highly reliable light emitting device can be realized by a simple manufacturing method. An increase in manufacturing cost can be suppressed and an inexpensive light emitting device can be manufactured.

The light emitting device of the present invention includes at least a substrate and a light emitting element.
As long as the substrate has a shape having a recess on the upper surface, the type and material of the substrate are not particularly limited, and all substrates that are usually used in the field can be used. For example, various materials such as glass; glass epoxy; ceramic, alumina; resin substrate such as polyester, polyimide, polyvinyl alcohol, and acrylic; metal substrate such as IMS substrate, metal core substrate, enamel substrate, and the like can be used. The concave portion on the upper surface may be formed by hollowing the upper surface of the flat substrate, or another flat plate in which a through hole or a hole is formed on the flat substrate. You may form by affixing a board | substrate and may form combining these.

The shape and size of the concave portion on the upper surface are not particularly limited. For example, the planar shape may be various shapes such as a circle, an ellipse, and a polygon. The cross-sectional shape can be various shapes such as a rectangular shape, a tapered shape having a top surface larger than the bottom surface, and a reverse tapered shape. Among these, in consideration of light extraction efficiency, an inverted truncated cone shape having a larger upper surface than the bottom surface is preferable. Moreover, the area in the upper surface of a recessed part is about 2-10 mm < ² >, and the depth is about 0.2-0.8 mm, for example. The substrate has a thickness of about 0.2 to 0.8 mm at the bottom surface of the recess, that is, the thinnest portion, and a thickness of about 0.4 to 1.6 mm at the top surface of the recess, that is, the thickest portion. Accordingly, sufficient strength as the light emitting device can be ensured during the process of forming the light emitting device, and light can be efficiently extracted from the light emitting element.

The substrate has at least one through hole on the bottom surface of the recess. Moreover, you may have two or more through-holes. The size of the through hole is not particularly limited, and is suitably smaller than the light emitting element placed on the substrate, for example, having an area of about 0.03 to 0.2 mm ^{2 on the} bottom surface of the recess. In addition, the shape of the through-hole can be various shapes such as a circular shape, an elliptical shape, and a polygonal shape, and a cross-sectional shape can be various shapes such as a rectangular shape, a tapered shape, and a reverse tapered shape. Can do. Among these, a rectangular shape is preferable in consideration of embedding a conductive and / or heat dissipating material in the through hole. When a plurality of through holes are formed, all the through holes may not have the same shape and size.

  The conductive and / or heat dissipation material embedded in the through hole is a material having at least either heat dissipation or conductivity, and preferably functions of both heat dissipation and conductivity. Means a material having Such a function is not necessarily exhibited by one type of material, but may be achieved by combining two or more types of materials in the through hole. As an index of the conductive and / or heat dissipating material, for example, a material having a thermal conductivity of about 10 to 500 W / m · k can be given. Examples of such a material include a metal or alloy, a metal paste, a conductive paste, or a combination material of a metal thin film and a resin. Specifically, a metal paste containing solder, aluminum, copper, silver, chromium, gold or the like alone or in combination, a single layer film or a laminated film of these metals is formed on the inner surface of the through hole, and an epoxy resin is formed in this film , Acrylic resin, silicone resin, urethane resin, polyimide resin, acrylate resin, polycarbonate resin, polynorbornene resin, modified silicone resin, amorphous polyamide resin, fluororesin and the like.

  Moreover, the metal pattern is formed in each of the upper surface and lower surface containing the recessed part of a board | substrate. The metal pattern is in contact with the conductive and / or heat dissipating material embedded in the through hole on both the upper surface and the lower surface, and is preferably electrically connected. The metal pattern is disposed so as to completely cover the through hole, and the contact between the two is preferably performed on the entire upper or lower surface of the conductive and / or heat dissipating material embedded in the through hole. Only part of the upper surface or the lower surface of the heat and / or heat dissipation material may be in contact with the metal pattern.

If a metal pattern is formed with a metal film, the kind will not be specifically limited. For example, a material having low resistance, gold, copper, nickel, chromium, silver, a single layer film or a laminated film of an alloy of these metals, and the like can be given. A film thickness is not specifically limited, For example, about 5-50 micrometers is mentioned. The planar shape of the pattern is not particularly limited, and it is preferably a shape that can appropriately exhibit both the heat radiation of the light emitting element and the terminal electrode of the light emitting element.
Specifically, on the upper surface including the concave portion of the substrate, one pattern covering the entire region (a part of the bottom surface of the concave portion, the side surface and the upper surface) other than a partial region of the concave bottom surface; Two patterns, a first pattern covering the entire area other than the area, and a second pattern electrically separated from the first pattern in a partial area of the bottom surface of the recess; other than a partial area of the bottom surface of the recess The first pattern that covers the entire area of the first pattern and the second pattern and the third pattern that are electrically separated from the first pattern within a partial area of the bottom surface of the recess (however, the second pattern and the second pattern And three patterns are electrically separated). By setting it as such a pattern, the heat dissipation of a light emitting element can be made especially favorable.

  In addition, on the lower surface of the substrate, one pattern covering almost the entire surface; two electrically separated patterns; three electrically separated patterns, and the like can be given. Note that the shape and size of the pattern can be changed as appropriate depending on the size of the substrate, the wiring pattern of the substrate for mounting the light emitting device, and the like. By setting it as such a pattern, the wiring pattern which can be surface-mounted especially as a terminal electrode can be obtained.

  The metal pattern on the upper or lower surface of the substrate is electrically connected to the pair of electrodes of the light emitting element placed on the bottom surface of the recess of the substrate, thereby functioning as a pair of terminal electrodes drawn out on the upper or lower surface of the substrate. be able to. For example, when the metal patterns formed on the upper surface and the lower surface of the substrate are respectively formed as two electrically separated patterns, and two through holes are formed, for example, the two electrically The separated patterns (first pattern on the upper surface, second pattern; first pattern on the lower surface, second pattern) are electrically connected to each other on the upper surface and the lower surface through the through holes. The second patterns are electrically connected to each other. Therefore, the first pattern on the upper surface or the lower surface can serve as the first terminal electrode, and the second pattern on the upper surface or the lower surface can serve as the second terminal electrode. The pair of terminal electrodes may be both on the upper surface, both on the lower surface, or one on each of the lower and upper surfaces.

A light emitting element is placed on the metal pattern and on the bottom surface of the recess on the top surface of the substrate. The light emitting element is preferably formed on the metal pattern above the through hole. As a result, heat generated by the light emitting element is efficiently applied not only to the metal pattern on the upper surface of the substrate but also to the conductive and / or heat-dissipating material directly embedded in the through hole, and subsequently to the metal pattern on the lower surface of the substrate. The heat dissipation efficiency is improved.
When only one through hole is formed in the bottom surface of the recess formed on the upper surface of the substrate, it is preferable that the light emitting element is placed above the through hole as described above. When two or more through holes are formed, it is preferable that one of the through holes is disposed below the light emitting element. However, in any case, the through hole may be disposed at least in the vicinity of the light emitting element, that is, at a position where heat generated by the light emitting element can be dissipated from the through hole.

  The light emitting elements in the light emitting device of the present invention include all those known in the art. For example, an LED chip, a laser diode, etc. are mentioned. These are produced by a method known in the art and need only have a known configuration.

Specific examples include those using various semiconductors such as ZnSe and GaN. Among them, preference is given to those short wavelength that can efficiently excite the fluorescent material is used capable of emitting nitride semiconductor _{(In X Al Y Ga 1-} X-Y N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) . Further, this nitride semiconductor may optionally contain boron or phosphorus. Note that the emission wavelength can be appropriately adjusted depending on the semiconductor material and the degree of mixed crystal. The semiconductor constituting the light emitting element may have a homo structure, a hetero structure, or a double hetero structure having a MIS junction, a pin junction, a pn junction, or the like. Moreover, it is good also as a single quantum well structure or multiple quantum well structure which formed the light emitting layer in the thin film which produces a quantum effect.

In the case of using a nitride semiconductor, materials for forming the light emitting element include materials such as sapphire, spinel, SiC, Si, ZnO, and GaN. In order to form a nitride semiconductor with good crystallinity with high productivity, it is preferable to use a sapphire substrate. A buffer layer such as GaN, AlN, or GaAlN may be formed on the sapphire substrate. A nitride semiconductor can be formed on the sapphire substrate by MOCVD or the like.
In particular, as an example of a light emitting device having a pn junction using a nitride semiconductor, a first contact layer formed of n-type gallium nitride and a first clad formed of n-type aluminum gallium nitride on a buffer layer A double hetero structure in which a layer, an active layer formed of indium gallium nitride, a second cladding layer formed of p-type aluminum nitride / gallium, and a second contact layer formed of p-type gallium nitride are sequentially stacked. Can be mentioned. After laminating the metal layer on the p-type layer, the semiconductor substrate may be removed.

  In the light emitting device of the present invention, only one light emitting element may be placed on the bottom surface of the recess of one substrate, but two or more light emitting elements may be placed. In addition, for example, protective elements such as a Zener diode and a capacitor may be combined. As these protective elements, all those known in the art can be used.

  In the method for manufacturing a light emitting device of the present invention, a step of forming a through hole in the first substrate having a metal thin film formed on the upper surface and the lower surface, a step of embedding a conductive and / or heat dissipation material in the through hole, A step of patterning a metal thin film on the upper and lower surfaces of one substrate, a step of forming a substrate having a recess on the upper surface by bonding a second substrate on which a through hole forming a recess is formed, and a recess on the upper surface The method includes a step of forming a metal thin film on the surface of the concave portion of the substrate having, and a step of mounting a light emitting element on the obtained substrate and wire bonding. These steps are not necessarily performed in this order, the order may be changed, and another step may be performed before and after each step.

The first substrate having the metal thin film formed on the upper surface and the lower surface can be obtained by forming the metal thin film on the upper surface and the lower surface of the substrate using various methods such as electrolytic plating, sputtering, and vacuum deposition. it can. Moreover, you may utilize a commercially available thing.
As a method for forming the through hole in the first substrate, a known method such as photolithography and etching, drilling with a drill, or the like can be used.
Also, when embedding a conductive and / or heat-dissipating material in the through hole, (i) First, a thin film made of metal or the like is formed inside the through hole, and then a metal paste or resin is filled. (Ii) By forming a metal film on the through hole, the through hole may be embedded with the metal film, and then the metal film formed in a region other than the through hole may be removed. ) The through-hole may be directly filled with a metal paste or a conductive paste. For forming the metal film and filling with the metal paste or the like, a method known in the art can be used.
As a method of patterning the metal thin film, a known method such as photolithography and an etching process can be used.

The bonding of the second substrate to the first substrate is not particularly limited, and can be performed using a known adhesive such as an epoxy resin or an acrylic resin.
The method for forming the metal thin film on the surface of the recess is not particularly limited, and examples thereof include an electrolytic plating method. In this plating method, a laminated film may be formed by changing the conditions and the type of plating solution. In the case of a laminated film, after the first layer is formed, patterning may be performed, and further the second layer may be formed. It is not necessary that all of the laminated films are formed in the same pattern. By forming the metal thin film on the surface of the recess in this way, the metal thin film can be integrated with the metal thin film that has been patterned into a predetermined shape on the bottom surface of the recess, thereby forming a metal pattern.

A method of mounting a light emitting element on a substrate and wire bonding can be performed using a method usually used in this field.
In the method for manufacturing a light emitting device of the present invention, it is preferable to fill the substrate with a sealing resin after performing all of the above steps. Thereby, the hue, luminous intensity, directivity, color rendering, etc. of the light from the light emitting element can be adjusted, the light extraction efficiency can be improved, and further deterioration of the light emitting element due to moisture or oxidation can be prevented. Can do.

  Below, the light-emitting device of this invention is demonstrated in detail based on drawing.

Embodiment 1
A light emitting device of this embodiment is shown in FIG. Further, FIG. 2A shows the shape of the metal pattern on the upper surface of the substrate constituting the light emitting device 10, and FIG. 2B shows the shape of the metal pattern on the lower surface of the substrate.
This light-emitting device 10 has a taper-shaped through-hole (tilt angle: about 45 °, bottom surface of a recess) by an adhesive layer 2 on a substrate 1 made of glass epoxy and having a thickness of about 0.3 to 0.5 mm. Formed by using a substrate 5 formed by laminating a substrate 4 made of glass epoxy having a thickness of about 0.3 to 0.5 mm and having a diameter of about 2 to 2.5 mm. ing.

  Three through holes 6, 7, 8 are formed in the bottom surface of the concave portion of the substrate 5 in the diameter direction of the bottom surface. The substantially central through-hole 7 on the bottom surface is formed slightly larger than the other two through-holes 6 and 8. The sizes of the through holes 7, 6, and 8 are, for example, about 0.4 to 0.6 mm in diameter and about 0.2 to 0.4 mm. Inside the through holes 6, 7, 8, a copper thin film 9 is formed by plating, and a metal paste 18 is embedded therein. For example, the thermal conductivity of silver paste is about 25 W / m · k. As the metal paste 18, a silver paste, a copper paste, or the like can be used.

As shown in FIG. 2A, three metal patterns 11, 12, and 13 are formed on the upper surface including the concave portion of the substrate 5. One metal pattern 11 is formed over substantially the entire upper surface except for a part of the bottom surface of the recess of the substrate 5. The other metal patterns 12 and 13 are electrically separated from each other by separating the metal pattern 11 from the metal pattern 11 at, for example, about 0.05 to 0.2 mm at a part of the bottom surface of the recess, and the through holes 6 and 8 are formed so as to cover each.
Each of the metal patterns 11, 12, and 13 is a laminated film in which a Ni-Ag film (Ni thickness of 3 μm or more, Ag thickness of 3 μm or more) by electrolytic plating is formed on a copper thin film by plating having a film thickness of about 10 to 15 μm. It is formed by.

On the lower surface of the substrate 5, three metal patterns 14, 15 and 16 are formed as shown in FIG. The metal patterns 14, 15, and 16 are disposed so as to be electrically separated from each other, and are electrically connected to the through holes 6, 7, and 8 on a one-to-one basis.
A light emitting element 17 is placed on the bottom surface of the concave portion of the substrate 5, and a pair of electrodes in the light emitting element 17 are bonded to the metal patterns 12 and 13 formed on the bottom surface of the concave portion by wires 19.
Further, the concave portion of the substrate 5 on which the light emitting element 17 is placed is sealed with a sealing resin 3 made of a silicone resin containing a phosphor.

Such a light emitting device 10 can be formed as follows.
First, a copper thin film is formed on the upper and lower surfaces of the flat substrate 1 by a standard plating technique.
Next, through holes 6, 7, 8 are formed in a predetermined region of the substrate 1 by photolithography and etching processes.
Further, the substrate 1 on which the through holes 6, 7, 8 are formed is plated by the standard plating technique described above, and the copper thin film 9 is formed in the through holes 6, 7, 8. Thereafter, the metal paste 18 is filled into the through holes 6, 7, 8 having the copper thin film 9 formed on the inner surface so that the surface of the through holes 6, 7, 8 is substantially flush with the bottom surface of the recess of the substrate 5. .
Subsequently, the copper thin film formed on the upper surface of the substrate 1 is patterned into a predetermined shape by, for example, photolithography and etching processes. Note that the copper thin film in the region where the substrate 4 is bonded to the substrate 1 is removed by patterning at this time. Further, on the lower surface of the substrate 1, the copper thin film is patterned into a predetermined shape by, for example, photolithography and etching processes.

Thereafter, the substrate 4 on which the predetermined through hole is formed is bonded onto the substrate 1 through the adhesive layer 2 to form the substrate 5 on which the light emitting element 17 is placed.
Next, a resist pattern having a predetermined shape is formed on the upper surface and the lower surface of the substrate 5, and a copper thin film is formed by the standard plating technique described above. Subsequently, a Ni-Ag thin film is laminated on the copper thin film, Metal patterns 11 to 16 are formed on the upper and lower surfaces of the substrate 5.

Separately from the above steps, a surface-mount (SMD) type light-emitting element 17 using a standard light-emitting element formation technique, for example, 475 nm In _0.2 Ga _0.8 having a monochromatic emission peak as visible light as an active layer. A nitride semiconductor light emitting device having an N semiconductor is formed.

First, TMG (trimethylgallium) gas, TMI (trimethylindium) gas, nitrogen gas and dopant gas are flowed together with a carrier gas on the cleaned sapphire substrate, and a nitride semiconductor film is formed by MOCVD. A layer to be an n-type nitride semiconductor or a p-type nitride semiconductor is formed by switching between SiH ₄ and Cp ₂ Mg as a dopant gas. Thereby, on the sapphire substrate, a GaN layer that is an undoped nitride semiconductor, an n-type GaN layer that becomes an Si-doped n-type contact layer, a GaN layer that is an undoped nitride semiconductor, an active layer having a multiple quantum well structure ( 5 pairs of GaN layers serving as barrier layers and InGaN layers serving as well layers are stacked, and finally a GaN layer serving as a barrier layer is stacked), an AlGaN layer serving as an Mg-doped p-type cladding layer, an Mg-doped p layer A p-type GaN layer which is a type contact layer is sequentially laminated.

Next, each surface of the p-type contact layer and the n-type contact layer is exposed on the same side as the nitride semiconductor on the sapphire substrate by etching. Next, sputtering using Rh and Zr as targets is performed on the p-type contact layer to provide a diffusion electrode.
Further, sputtering using W, Pt, and Au as targets is performed, and a p-side pedestal electrode and an n-side pedestal electrode are simultaneously formed by laminating the diffusion electrode and a part of the n-type contact layer in the order of W / Pt / Au, respectively. To do.
A scribe line is drawn on the obtained semiconductor wafer and then divided by an external force to form the light emitting element 17.

The light emitting element 17 is mounted by die bonding on the bottom surface of the concave portion of the substrate 5 on which the metal patterns 11 to 16 are formed, and the p-side pedestal electrode and the n-side pedestal electrode and the metal patterns 12 and 13 are respectively wire-bonded. Connect electrically.
Further, the sealing resin 3 made of a silicone resin containing a phosphor is injected into the recesses of the substrate 5 by potting, and the recesses are filled to a level so that the light emitting device 10 is completed.

In the light emitting device 10 according to this embodiment, the heat generated from the light emitting element 17 is transmitted to the metal pattern 11 directly below the light emitting element 17 due to the configuration as described above, and the upper surface of the light emitting device 10 is substantially aligned along the metal pattern 11. It can diverge from the entire surface, improving the heat dissipation efficiency. Further, the heat of the light emitting element 17 is transmitted through the through hole below the light emitting element 17 and is dissipated by the metal pattern 15 on the lower surface of the substrate 5, so that the heat radiation efficiency is further improved.
Furthermore, since the side surface of the concave portion on the upper surface of the substrate 5 is inclined and the metal pattern 11 having good reflection efficiency is formed on the concave surface, these function as a reflector, and the light extraction efficiency from the light emitting element 17 is improved. Will improve.

Further, a pair of electrodes in the light emitting element 17 is connected to metal patterns 13 and 12 formed in the vicinity of the light emitting element 17, and these metal patterns 13 and 12 pass through the through holes 6 and 8 and are formed on the lower surface of the substrate 5. Since the metal patterns 14 and 16 are electrically connected to each other, the metal patterns 14 and 16 function as terminal electrodes, and the light emitting device 10 can be surface-mounted on a mounting substrate.
Further, when the sealing resin 19 is sealed in the concave portion of the substrate, the through hole is completely closed by the metal paste 18 that is a conductive and / or heat-dissipating material. The manufacturing yield is improved without leaking to the lower surface of the substrate.

Moreover, since the terminal electrode is not processed by bending from the upper surface to the lower surface of the substrate 5 as in the prior art, the substrate 5 and the terminal electrode itself are not stressed, and a highly reliable light-emitting device is obtained. Can do. In addition, since the terminal electrode itself is protected by the through hole, problems such as disconnection can be prevented.
Furthermore, in the manufacturing method of the light emitting device, it is possible to realize the light emitting device having improved heat dissipation as described above and improved in reliability and performance by a simple method without causing an increase in manufacturing cost. it can.

Embodiment 2
In the light emitting device of this embodiment, as shown in FIGS. 3A and 3B, through holes 26 and 27 are formed in the vicinity of the light emitting element 17 instead of the through hole 7 below the light emitting element 17. Other than that, the light emitting device 10 is the same as the light emitting device 10 of the first embodiment.
Thus, even if it is not under the light emitting element 17, a heat dissipation effect can be made favorable by providing a through-hole in the vicinity and further increasing the number of through-holes.

Embodiment 3
As shown in FIGS. 4A and 4B, the light emitting device of this embodiment is configured such that the metal pattern 12 on the upper surface of the substrate 5 is combined with the metal pattern 11 to form the metal pattern 21, thereby forming the upper surface of the substrate 5. In addition, two electrically separated metal patterns 21 and 13 are arranged, the through hole 28 is slightly larger than the through hole 8, and the position is slightly moved. Except for the point that the hole 7 and the through hole 28 are electrically connected to the same metal pattern 35, it is substantially the same as the light emitting device 10 of the first embodiment.

Thus, in the pair of electrodes of the light emitting element 17, one is connected to the metal pattern 13 on the upper surface, the through hole 6 and the metal pattern 14 on the lower surface, one terminal electrode is the metal pattern 14, and the other is the metal on the upper surface. By being connected to the pattern 21 and having the other terminal electrode as the metal pattern 21, mounting can be performed freely not only on the surface but also on the top and bottom of the substrate.
Further, the heat dissipation effect can be further improved due to the large through hole 28.

Embodiment 4
In the light emitting device of this embodiment, as shown in FIGS. 5A and 5B, a through hole 29 is formed in the vicinity of the light emitting element 17 instead of the through hole 7 below the light emitting element 17. This is the same as the light-emitting device of Embodiment 3.

Thus, in the pair of electrodes of the light emitting element 17, one is connected to the metal pattern 13 on the upper surface, the through hole 6 and the metal pattern 14 on the lower surface, one terminal electrode is the metal pattern 14, and the other is the metal on the upper surface. By being connected to the pattern 21 and having the other terminal electrode as the metal pattern 21, mounting can be performed freely not only on the surface but also on the top and bottom of the substrate.
Even if the through hole is not formed below the light emitting element 17, the heat dissipation effect can be further improved due to the large through holes 28 and 29.

  The light emitting device and the manufacturing method thereof of the present invention can be used for various light sources such as a backlight light source, a display, illumination, and a vehicle lamp.

It is sectional drawing which shows embodiment of the light emitting element of Embodiment 1 in this invention. (A) is a top view which shows the metal pattern of the board | substrate upper surface in the light emitting element of FIG. 1, (b) is a top view which shows the metal pattern of the board | substrate lower surface. (A) is a top view which shows the metal pattern of the board | substrate upper surface in the light emitting element of Embodiment 2, (b) is a top view which shows the metal pattern of the board | substrate lower surface. (A) is a top view which shows the metal pattern of the board | substrate upper surface in the light emitting element of Embodiment 3, (b) is a top view which shows the metal pattern of the board | substrate lower surface. (A) is a top view which shows the metal pattern of the board | substrate upper surface in the light emitting element of Embodiment 4, (b) is a top view which shows the metal pattern of the board | substrate lower surface. It is sectional drawing which shows the conventional light emitting element. It is sectional drawing which shows another conventional light emitting element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Adhesive layer 3 Sealing resin 4 Substrate 5 Substrate 6, 7, 8, 26, 27, 28, 29 Through-hole 9 Copper thin film 10 Light emitting device 11, 12, 13, 14, 15, 16, 35, 36 Metal pattern 17 Light emitting element 18 Metal paste 19 Wire

Claims (7)

A light-emitting device comprising a substrate having a recess on the upper surface and a light-emitting element placed on the bottom surface of the recess,
The substrate has at least one through hole in which a conductive and / or heat-dissipating material is embedded in the bottom surface of the recess, and the conductive and embedded in the through hole on the upper surface and the lower surface including the recess, respectively. / Or has a metal pattern in contact with the heat dissipating material,
The light emitting device, wherein the light emitting element is placed on the metal pattern. The light emitting device according to claim 1, wherein the light emitting element is placed on a metal pattern above the through hole. The light emitting device according to claim 1, wherein a plurality of through holes are formed. The metal patterns formed on the upper surface and the lower surface of the substrate are respectively formed as at least two electrically separated patterns, and the two electrically separated patterns function as a pair of terminal electrodes of the light emitting element. The light emitting device according to claim 1. The light-emitting device according to claim 1, wherein the conductive and / or heat-dissipating material is a metal or an alloy, a metal paste, a conductive paste, or a combination material of a metal thin film and a resin. The light emitting device according to claim 1, wherein the metal pattern is formed of a single layer film or a laminated film of gold, copper, nickel, chromium, silver, or an alloy of these metals. Forming a through hole in a first substrate having a metal thin film formed on an upper surface and a lower surface;
A step of embedding a conductive and / or heat dissipating material in the through hole;
Patterning metal thin films on the upper and lower surfaces of the first substrate;
Bonding a second substrate having a through-hole forming a recess to the first substrate to form a substrate having a recess on the upper surface;
Forming a metal thin film on the concave surface of the substrate having the concave portion on the upper surface;
A method for manufacturing a light-emitting device, comprising the step of mounting a light-emitting element on the obtained substrate.

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