JP4303550B2 - Light emitting device - Google Patents

Description

The present invention relates to a light emitting device, and in particular, due to a thermal influence during sealing of a sealing member, bonding wires and bumps are crushed and an electrical short circuit occurs. The present invention relates to a light emitting device capable of preventing the occurrence of cracks in the vicinity of a light emitting element of a sealing member caused by a difference in thermal expansion coefficient between the light emitting element and the sealing member due to a temperature change.

  As a typical structure of a light-emitting device using an LED (light-emitting diode) as a light source, there is one that covers a predetermined range of an LED element and a lead portion with a light-transmitting sealing material. As this sealing material, there are resins such as epoxy and silicon, and glass, but resins are generally used in terms of moldability, mass productivity, and cost.

  By sealing the LED element with a sealing resin, the design freedom and productivity of the light emitting device are excellent, but the optical and chemical characteristics of the sealing resin are deteriorated by the light emitted from the LED element, As a result, reducing the luminous efficiency of the light emitting device has been regarded as a problem.

  It is known that a sealing resin material (for example, an epoxy resin) gradually turns yellow by receiving strong light emitted from an LED element, and the resin material is colored. When such coloring occurs, there is a problem that light emitted from the LED element is absorbed to reduce the light output of the light emitting device, and the influence of coloring appears on the output light.

  As a solution to such a problem, there is a light emitting device in which an LED element is sealed with a glass layer having moisture resistance, and other portions are sealed with a resin (for example, see Patent Document 1).

  FIG. 6 is a cross-sectional view showing the light emitting device disclosed in Patent Document 1. As shown in FIG. The light emitting device 200 includes wiring conductors 201 and 202, a cup part 203 formed on the wiring conductor 202, an LED element 204 bonded to a bottom part 203A in the cup part 203, and an electrode part (not shown) of the LED element 204. ) And a predetermined portion of the wiring conductors 201 and 202, a glass layer 206 for sealing the LED element 204 provided in the cup portion 203, and a fluorescent material contained in the glass layer 206 206A, and a sealing resin 207 which is molded into a shell shape and seals the whole, and has optical transparency. The fluorescent material 206A is mixed in the glass layer 206 for wavelength conversion, and the light emitted from the LED element 204 is wavelength-converted by the fluorescent material 206A.

  According to such a configuration, since the LED element 204 is surrounded by the glass layer 206 injected into the cup portion 203, attenuation of light due to yellowing or coloring can be reduced. Further, moisture permeation can be prevented and deterioration of the phosphor can be prevented.

In recent years, high-power LEDs have been developed, and a high-power type of several watts has already been commercialized. LEDs are characterized by low heat generation, but high power (high brightness) type LED elements generate a large amount of current, and therefore generate heat that cannot be ignored. For this reason, it is necessary to replace the sealing member with a conventional resin material and to use a sealing material excellent in heat resistance, for example, a glass material.
Japanese Patent Laid-Open No. 11-204838 (FIG. 1)

However, according to the conventional light emitting device, when a glass material is selected as a sealing member in consideration of heat resistance, generally, glass softened by heating is sealed by pressing, or molten glass is supplied. Therefore, there is a case where heat damage may occur during the sealing process. As a method for reducing the thermal burden during the sealing process, for example, there is a method using a low melting glass, but the low melting glass tends to be highly expanded, and between the wiring conductor contacting the sealing member, etc. Physical stress due to the difference in thermal expansion occurs. For example, while the LED element has a thermal expansion coefficient of about 5 × 10 ⁻⁶ / ° C., the low-melting glass has a thermal expansion coefficient of about 15 × 10 ⁻⁶ / ° C. Peeling and cracking easily occur between the two.

  In addition, when heat-press sealing a flip-chip bonded LED element using a glass material, the bump is easily softened by heat, and further, a load is applied to the bump through the glass having a high viscosity. There is also a problem that a short circuit occurs between the electrodes due to crushing.

  Accordingly, an object of the present invention is to provide a light emitting device capable of preventing cracks and short circuits between electrodes caused by the thermal stress even when glass is used as a sealing material.

In order to achieve the above-described object, the present invention provides a light emitting element having unevenness on a side surface, a wiring layer on which the light emitting element is mounted and supplying power to the light emitting element, and the wiring layer formed on the upper surface. A ceramic part, a wire connecting the light emitting element and the wiring layer of the substrate part, and a buffer made of porous ceramic covering the whole of the light emitting element and the whole part of the wire a layer, the buffer layer surface and is formed so as to cover the upper surface of the substrate portion of the Ri emitting element and sealing the light emitting element and the thermal expansion coefficient Do different transparent glass, the light emitting element A sealing member in which stress due to thermal contraction is generated after sealing processing , and the buffer layer is interposed between the light emitting element and the sealing member and is generated by thermal contraction stress absorbs, of the sealing member To prevent the generation of cracks in the vicinity of the light emitting element of the sealing member where the sealing time and sealing process after the temperature change in the by Ri said light emitting elements caused by the difference in the coefficient of thermal expansion between the sealing member A light emitting device is provided.

The buffer layer may be SiO ₂ meet.

  The buffer layer may be mixed with a phosphor.

According to the light emitting device of the present invention, by providing a porous ceramic buffer layer between the light emitting element and the sealing member, the sealing member damages the light emitting element when the sealing member is sealed. There is no occurrence of cracks in the vicinity of the light emitting element in the sealing member due to thermal contraction .

  FIG. 1 is a cross-sectional view showing a configuration of a light emitting device according to a first embodiment of the present invention. The light emitting device 10 includes a substrate portion 11 as a power supply member, an LED element 12 mounted on the upper surface of the substrate portion 11, and a buffer layer 13 sealed on the upper surface of the substrate portion 11 so as to cover the LED element 12. And a sealing member 14 formed so as to cover the buffer layer 13 and the upper surface of the substrate portion 11.

  The substrate portion 11 includes a high expansion ceramic substrate 11a (insulating substrate), wiring layers 11b, 11c, 11d, and 11e formed in a predetermined pattern on the upper surface of the ceramic substrate 11a, and a lower surface of the ceramic substrate 11a. The wiring layers 11f and 11g formed in a predetermined pattern, the Au plating film 11h coated on the surface of the wiring layer 11c, the Au plating film 11i coated on the surface of the wiring layer 11d, and the surface of the wiring layer 11f The coated Au plating film 11j, the Au plating film 11k coated on the surface of the wiring layer 11g, the through hole 11l connecting the wiring layer 11b and the wiring layer 11f, and the through connecting the wiring layer 11d and the wiring layer 11g. And a hole 11m.

For the ceramic substrate 11a, for example, a glass-containing Al ₂ O ₃ material (thermal expansion coefficient: 13.2 × 10 ⁻⁶ / ° C.) can be used. Wiring layers 11 c, 11d, 11 f, 11g functions as an electrode for supplying power. Further, the Au plating films 11h, 11i, 11j, and 11k are provided in order to improve connectivity, conductivity, and corrosion resistance. In addition, before the LED element 12 is mounted on the substrate unit 11, the wiring layers 11b to 11g, the Au plating films 11h to 11k, and the through holes 11l and 11m need to be formed in the ceramic substrate 11a in advance.

The LED element 12 is configured by using a semiconductor such as GaN or AlInGaP, and the chip size is 0.3 × 0.3 mm (standard size), 1 × 1 mm (large size), or the like. For the buffer layer 13, SiO _{2 in} which the chemical bond of the silicon resin is broken by heat is used. The sealing member 14 includes, for example, “PSK100” (thermal expansion coefficient: 11.4 × 10 ⁻⁶ / ° C.) manufactured by Sumita Optical Glass Co., Ltd.

  The sealing member 14 is made of a glass material having translucency and a low melting point. The LED element 12 has power supply electrodes 12 a and 12 b on the lower surface, and the electrodes 12 a and 12 b are soldered onto a predetermined wiring layer of the substrate portion 11.

  Hereinafter, assembly of the light emitting device 10 will be described.

  First, the LED element 12 is positioned so that the electrodes 12a and 12b are placed on the wiring layers 11c and 11d of the substrate part 11, and the wiring layer 11c and the electrode 12a and the wiring layer 11d and the electrode 12b are soldered, respectively. .

  Next, a liquid silicone resin material is dropped from directly above the central portion of the LED element 12, and the buffer layer 13 is formed by coating the entire upper surface and side surfaces of the LED element 12 in layers.

Next, with the buffer layer 13 formed, the substrate unit 11 and the LED element 12 are placed in a temperature atmosphere of about 150 ° C., and the buffer layer 13 is primarily cured.

Next, the sealing member 14 made of a glass material is sealed on the surface of the buffer layer 13 and the surface of the substrate unit 11. A mold is used for sealing the sealing member 14, and it is formed into a semicircular shape as shown in FIG. Thus, the light emitting device 10 is completed. Note that silicon resin breaks chemical bonds by heat and becomes SiO _{2 at} the time of glass sealing, but does not cause blackening and does not cause light absorption.

In the light emitting device 10 having the above configuration, for example, if the wiring layer 11f is on the anode side of the LED element 12, the plus side of a DC power source (not shown) is connected to the wiring layer 11f, and the minus side is connected to the wiring layer 11g. Is done. The LED element 12, the electrodes 12a, when applying a forward voltage via an electrically connected Bang-flop 12b, holes and electrons in the carrier recombination occurs in the light emitting layer of the LED element 12 to emit light, the output light is emitted to the outside of the LED element 12 through the sapphire board. Most of this light is transmitted through the sealing member 14 and exits from the sealing member 14, and part of the light is reflected from the inner surface and exits from the sealing member 14.

According to the first embodiment described above, the following effects are obtained.
(1) By sealing the whole with the sealing member 14 made of a glass material, it is possible to reduce attenuation of light due to yellowing or coloring, which is a problem in resin sealing.
(2) By providing the buffer layer 13 around the LED element 12, the external force applied to the LED element 12 through the glass material having a high viscosity when the sealing member 14 is sealed is reduced. That is, since the LED element 12 and the sealing member 14 are not in direct contact with each other due to the buffer layer 13, the buffer layer 13 can absorb the stress caused by thermal expansion and thermal contraction.
(3) By sealing the LED element 12 with the glass via the buffer layer 13, it is possible to prevent the occurrence of cracks that have occurred in the vicinity of the LED element 12 of the sealing member 14 . Such a configuration in which the buffer layer 13 is provided is particularly effective in the large size (1 mm × 1 mm) LED element 12 in which the contact area with the sealing member 14 is widened.
(4) by surrounding the LED element 12 with a buffer layer 13, it is possible to prevent a short circuit between electrodes due to crushing of the bun flop. Moreover, since the buffer layer 13 suppresses the collapse of the bump shape, the optical axis of the LED element 12 can be prevented from being tilted by glass sealing.
(5) When the LED element 12 is formed by scribing the wafer, fine irregularities are generated on the side surface of the scribed LED element 12. This unevenness forms an unbalanced portion of the stress at the interface between the LED element 12 and the sealing member 14 for the glass-sealed light emitting device 10 and thus causes micro cracks.
Such relative problems, than the buffer layer 13 in the scribe surface and further aspect of the LED element 12 is provided, prevent the occurrence of microcracks during the heat shrinkage of the sealing member 14.

FIG. 2 is a cross-sectional view showing a modification of the light emitting device according to the first embodiment. In the light emitting device 20, the configuration in which the buffer layer 21 is provided only on the side surface of the LED element 12 is different. Such also prevents a short circuit between electrodes due to collapse of the van-flop as a constituent, it is possible to relieve the stress caused by the thermal contraction of the sealing member 14. Further, since the buffer layer is not provided on the substrate side of the LED element 12, extraction of light emitted from the LED element 12 is not hindered.

  FIG. 3 is a cross-sectional view showing a light emitting device according to the second embodiment of the present invention. The light-emitting device 30 of FIG. 3 is a face-up type, and is sealed so as to cover the substrate part 31 as a power supply member, the LED element 32 mounted on the upper surface of the substrate part 31, and the LED element 32 as a whole. The buffer layer 33, the sealing member 34 formed so as to cover the upper surface of the buffer layer 33 and the substrate part 31, and the wires 35a and 35b for connecting the electrode of the LED element 32 and the wiring layer on the substrate part 31. And is configured.

  The substrate unit 31 includes a ceramic substrate 31a as an insulating substrate using the same material as the substrate unit 11 of FIG. 1, wiring layers 31b and 31c formed in a predetermined pattern on the upper surface of the ceramic substrate 31a, and the ceramic substrate 31a. Wiring layers 31d and 31e formed in a predetermined pattern on the lower surface, through holes 31f connecting the wiring layers 31b and 31d, and through holes 31g connecting the wiring layers 31c and 31e. . The wiring layers 31b to 31e are provided with an Au plating film on the surface, but are not shown here.

For example, a glass-containing Al ₂ O ₃ material can be used for the ceramic substrate 31a. The wiring layers 31b to 31e function as electrodes for supplying power. In addition, the board | substrate part 31 needs to form the wiring layers 31b-31e and the through holes 31f and 31g in the ceramic board | substrate 31a previously before mounting of the LED element 32. FIG. As the sealing member 34, a glass material having translucency and a low melting point is used.

  The LED element 32 is fixed on the wiring layer 31c with an adhesive or the like. One electrode (not shown) on the upper surface of the LED element 32 and the wiring layer 31b are connected by a wire 35a, and the other upper surface of the LED element 32 is connected. The electrode (not shown) and the wiring layer 31c are connected by a wire 35b.

  The buffer layer 33 covers the exposed surface of the LED element 32 and the wires 35a and 35b.

  The sealing member 34 is formed in a hemispherical shape so as to cover the surface of the buffer layer 33 and the wiring layer exposed on the upper surface of the substrate portion 31 and a part of the exposed portion of the substrate portion 31.

  Hereinafter, the assembly of the light emitting device 30 will be described.

  First, the substrate part 31 in which the wiring layers 31b to 31e and the through holes 31f and 31g are formed on the ceramic substrate 31a is prepared, and the LED element 32 is mounted at a predetermined position on the wiring layer 31c.

  Next, the LED element 32 and the wiring layers 31b and 31c are connected by bonding using the wires 35a and 35b.

  Next, a liquid silicon material is dropped to a predetermined thickness so as to cover the exposed surface of the LED element 32 and the wires 35a and 35b.

Next, after placing the LED element 32 and the wires 35a and 35b in a temperature atmosphere of about 150 ° C. and performing primary curing of the buffer layer 33, a sealing member 34 based on the molding of a glass material is formed around the buffer layer 33. Form. Thus, the light emitting device 30 is completed.

  In the light emitting device 30, for example, if the wiring layer 31d is the anode side of the LED element 32, the plus side of a DC power source (not shown) is connected to the wiring layer 31d, and the minus side is connected to the wiring layer 31e. The LED element 32 emits light by this energization. The light is emitted from the upper surface of the LED element 32 in the figure, most of the light is emitted to the outside through the sealing member 34, and the other part is internally reflected in the sealing member 34, and then the sealing member 34. I go out.

According to the second embodiment described above, since the buffer layer 33 is provided around the LED element 32 of the light emitting device 30 in which the LED element 32 is mounted face up, the wires 35a and 35b are deformed when the glass material is sealed. In addition to being able to prevent the short circuit between the electrodes due to crushing, the sealing member 34 was generated near the LED element 32 due to the high thermal expansion of the sealing member 34 as in the first embodiment. It becomes possible to prevent the occurrence of cracks.

  For example, when the buffer layer 33 is not provided, if the temperature after glass sealing is set high, the LED element is damaged, so there is a temperature restriction, and the glass sealing is performed in a state where the glass has a high viscosity. It is inevitable that an external force is applied to the wires 35a and 35b, and it is difficult to maintain the wires 35a and 35b in a desired posture. For example, when the wire 35a is crushed by a pressure press made of a glass material, there is a problem that the wiring layers 31b and 31c are short-circuited. In this case, not only light emission but also a power supply side (not shown) is affected. Incidentally, such a problem does not occur in the resin material.

  In the face-up type LED element, the presence of a wire that is a metal member on the upper surface itself becomes a buffer material. However, the problem is that it collapses and causes an electrical short. For this reason, it is important that there is an electrical short-circuit preventing element for preventing crushing or the like even without a cushioning element.

  FIG. 4 is a cross-sectional view showing a light emitting device according to the third embodiment of the present invention. In the light emitting device 40, a submount 43 on which the LED element 41 is mounted is mounted on the lead portions 44a and 44b. In FIG. 4, the submount is illustrated in a non-cross-sectional state.

  The light emitting device 40 includes an LED element 41 having a bump 42 on the mounting surface, a submount 43 on which the LED element 41 is mounted, lead portions 44a and 44b as power supply members on which the submount 43 is mounted, It has the buffer layer 45 provided so that the exposed surface of the LED element 41 may be covered, and the sealing member 46 by the translucent glass which seals the buffer layer 45 and its circumference | surroundings.

  The submount 43 is made of, for example, high thermal conductivity AlN (aluminum nitride), and electrodes 43a connected to the bumps 42 are formed on the mounting surface side of the LED element 41, and the opposite surface (on the lead frame side). The electrode 43b for connecting to the pair of lead portions 44a and 44b is formed on the surface). A through hole 43c is provided in the submount 43 in order to connect the electrode 43a and the electrode 43b.

  The lead portions 44a and 44b are formed as a part of the lead frame so as to face each other with a predetermined gap inside the belt-like portions on both sides, and a pair is assigned to one LED element. A part of the tip portion of each of the lead portions 44a and 44b is made thin so that a step is generated, and the submount 43 is placed on the step portion.

  The buffer layer 45 is provided based on the same material and processing as the buffer layers 13, 21, and 33 shown in the other embodiments described above.

  As in the other embodiments described above, the sealing member 46 is made of a glass material having translucency and a low melting point.

  In the light emitting device 40, assuming that the lead portion 44a is a positive (+) power supply terminal, the current supplied to the lead portion 44a is such that one of the lead portion 44a and the electrode 43b, one of the through holes 43c, and the electrode 43a. On the other hand, the current that flows to the anode of the LED element 41 through one of the bumps 42 and the cathode of the LED element 41 further flows to the other of the bumps 42, the other of the electrodes 43a, the other of the through holes 43c, and the electrodes 43b. The LED element 41 emits light by flowing to the lead portion 44b through the other side.

  Hereinafter, the assembly of the light emitting device 40 will be described.

  First, the submount 43 in which the electrodes 43a and 43b and the through holes 43c are formed in advance is prepared, and the LED element 41 is mounted at a predetermined position on the submount 43 via the bumps 42. As a result, the LED element 41 is electrically connected and mechanically fixed.

  Next, the LED elements 41 mounted on the submount 43 are arranged in the recesses at the tips of the lead portions 44a and 44b so that the energization directions are matched.

  Next, a liquid silicon material is dropped to a predetermined thickness so as to cover the periphery of the LED element 41.

Next, the LED element 41 , the submount 43, and the lead portions 44 a and 44 b are placed in a temperature atmosphere of about 150 ° C., and primary curing is performed to form the buffer layer 45 around the LED element 41 .

Next, a glass sheet for forming the sealing member 46 is disposed above and below the LED element 41, and a mold is disposed above and below the LED element 41.

  Next, the glass sheet is formed into a predetermined shape by performing pressure pressing with a mold in a predetermined temperature atmosphere. Thereby, the light emitting device 40 is completed. Eventually, the other ends of the lead portions 44a and 44b are separated from the lead frame, and individualized into individual light emitting devices 40.

According to the third embodiment described above, the LED elements 41 mounted on the high thermal conductivity of the sub-mount 43 when sealed with glass material, thermal expansion of the LED element 41 and the glass material Ri by the buffer layer 45 It is possible to prevent cracks and peeling from occurring around the LED element 41 and the submount 43 in the sealing member 46 due to the difference in rate.

  In the light emitting device 40, a phosphor may be mixed in the buffer layer 45. In this case, wavelength conversion based on a mixture of excitation light emitted from the phosphor excited by the emitted light of the LED element 41 and emitted light of the LED element 41 is performed. As the phosphor, for example, Ce (cerium): YAG (yttrium, aluminum, garnet) that is excited by blue light emitted from the LED element 41 to emit yellow light can be used.

  FIG. 5 is a sectional view showing a light emitting device according to the fourth embodiment of the present invention. The light emitting device 50 has a configuration in which a heat radiating member is attached to the light emitting device 40 of FIG. That is, the heat-dissipating member 51 using a metal material having excellent thermal conductivity such as copper is attached to the lower part of the submount 52 made of AlN or the like.

  The light emitting device 50 includes a heat dissipating member 51 functioning as a heat dissipator, a submount 52 mounted on the heat dissipating member 51, and lead portions 53a and 53b on which tip portions are placed on stepped portions at both ends of the submount 52. The LED element 41 mounted on the submount 52, the buffer layer 54 provided to cover the exposed surface of the LED element 41, the buffer layer 54, and the And a sealing member 55 made of transparent glass having a low melting point for sealing the periphery.

  The submount 52 is processed to be thin so that a predetermined range at both ends generates a step, and the tip portions of the lead portions 53a and 53b are placed on the thin portion, and the tips are the side surfaces of the wiring patterns 52a and 52b. Connected by soldering or the like. Furthermore, the submount 52 is provided with wiring patterns 52a and 52b that contact the pair of bumps 42 from the upper surface to the side surface.

The buffer layer 54 is made of a porous phosphor-containing SiO _{2 in} which a phosphor 54a is mixed with Si-based alkoxide, and has a function of wavelength conversion as well as stress buffering.

As described in the third embodiment, Ce (cerium): YAG (yttrium, aluminum, garnet) or the like can be used for the phosphor 54a .

  Since the assembly of the light emitting device 50 in the fourth embodiment is in accordance with the third embodiment, the overlapping description is omitted here, but the portion above the submount 52 in FIG. Thereafter, the heat radiating member 51 may be attached to the lower surface by bonding or the like.

According to the fourth embodiment described above, the following effects are obtained.
(1) Since the heat dissipating member 51 that promotes heat dissipating is provided in the lower part of the submount 52, the heat generated by the lighting of the LED element 41 can be efficiently dissipated to the outside, and the thermal expansion accompanying the temperature rise of the sealing member 55 and the like by the glass material -The occurrence of cracks can be prevented by suppressing the occurrence of thermal shrinkage.
(2) By mixing the phosphor 54a with the buffer layer 54, wavelength conversion can be performed and light extraction efficiency can be improved.

  In each of the above-described embodiments, a reflecting surface may be formed on the surface of the substrate portions 11 and 31 and the lead portions 44a, 44b, 53a, and 53b to increase the light emission efficiency.

  In addition, the phosphor may be partially mixed on the LED elements 12 and 32 in the sealing members 14 and 34, or the wavelength converting phosphor may be mixed in the buffer layers 13 and 33.

Further, when a TiO ₂ ceramic material is used for the buffer layer 54, the refractive index has a large value of 2.4, so that the light extraction efficiency from the LED element 41 can be increased.

  Further, in each of the above-described embodiments, the number of LED elements disposed in one sealing member is one, but a multi-light-emitting type light emitting device having two or more LED elements is provided. You can also. The plurality of LED elements to be mounted may have a configuration in which a plurality of LED elements having different emission colors are provided or a configuration in which a plurality of LED elements having the same emission color are provided. Furthermore, as a drive form of the LED element, all of the plurality of LED elements may be connected in parallel or in parallel in units of groups, may be connected in series in a plurality of units, or all may be connected in series.

  Further, the sealing member 14 has been described as “PSK100” manufactured by Sumita Optical Glass Co., Ltd. However, the present invention is not limited thereto, and any other glass may be used as long as it is softened at a temperature at which sealing processing can be performed without causing thermal damage to the light emitting element. It doesn't matter.

  Moreover, although the hemispherical structure was shown as the shape of the sealing members 14, 34, 46, and 55, the present invention is not limited to the illustrated shape, and a shape that does not have a lens portion, a polygon, and a cylinder. It can be in any shape such as shape.

  Further, the molding of the sealing members 14, 34, 46, 55 is not limited to a molding method using a pressure press using a glass sheet. For example, molten glass is supplied to the vicinity of the LED element to form a gold Other sealing methods such as heat molding with a mold may be used.

It is sectional drawing which shows the structure of the light-emitting device which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the modification of the light-emitting device which concerns on 1st Embodiment. It is sectional drawing which shows the light-emitting device which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the light-emitting device which concerns on the 3rd Embodiment of this invention. It is sectional drawing which shows the structure of the light-emitting device which concerns on the 4th Embodiment of this invention. It is sectional drawing which shows the structure of the conventional light-emitting device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Light-emitting device 11 Substrate part 11a Ceramic substrate 11b, 11c, 11d, 11e, 11f, 11g Wiring layer 11h, 11i, 11j, 11k Au plating film 11l, 11m Through hole 12 LED element 12a, 12b Electrode 13 Buffer layer 14 Sealing member 20 light emitting device 21 buffer layer 30 emitting device 31 substrate portion 31a ceramic substrate
31b, 31c, 31d, 31e Wiring layers 31f, 31g Through hole 32 LED element 33 Buffer layer 34 Sealing member 35a, 35b Wire (bonding wire)
40 Light-Emitting Device 41 LED Element 42 Bump 43 Submount 43a, 43b Electrode 43c Through Hole 44a, 44b Lead Part 45 Buffer Layer 46 Sealing Member 50 Light-Emitting Device 51 Heat Dissipation Member 52 Submount 52a, 52b Wiring Pattern 53a, 53b Lead Part 54 Buffer layer 55 Sealing member 200 Light emitting device 201, 202 Wiring conductor 203 Cup part 203A Bottom 204 LED element 205 Wire 206 Glass layer 206A Fluorescent material 207 Sealing resin

Claims (3)

A light emitting device with unevenness on the side surface;
A substrate part having a wiring layer on which the light emitting element is mounted and supplying power to the light emitting element ; and a ceramic substrate on which the wiring layer is formed;
A wire connecting the light emitting element and the wiring layer of the substrate portion;
A buffer layer made of porous ceramic covering the whole of the light emitting element and the whole part of the wire;
The surface of the buffer layer and is formed so as to cover the upper surface of the substrate portion, Ri Do the light emitting element from the sealing to the light emitting element and the thermal expansion coefficient different from transparent glass, sealing processing of the light emitting element A sealing member in which stress due to heat shrinkage is generated later ,
The buffer layer is interposed between the light emitting element and the sealing member to absorb the stress of the sealing member caused by thermal shrinkage, and when the sealing member is sealed and after the sealing process the light emitting device characterized in that to prevent the occurrence of cracks in the vicinity of the light emitting element of the sealing member resulting from an I Ri said light emitting element to a temperature change in the difference in thermal expansion coefficient between the sealing member. The buffer layer, light-emitting device according to claim 1, characterized in that the SiO _2. The buffer layer, light-emitting device according to claim 1 or 2, characterized in that the phosphor is mixed.

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