JP4480407B2 - Light emitting element storage package and light emitting device - Google Patents

Description

  The present invention relates to a light emitting element housing package for housing a light emitting element, and a light emitting device using the same.

  A light-emitting device for housing a light-emitting element 14 such as a conventional light-emitting diode (LED) is shown in FIG. As shown in FIG. 2, the light emitting device has a light emitting element 14 mounted at the center of the upper surface, and leads that electrically connect the inside and outside of the light emitting element 14 and the light emitting element storage package (hereinafter also simply referred to as a package). A base 11 made of an insulator on which a wiring conductor (not shown) made of a terminal, a metallized wiring layer, or the like is formed, and a through-hole that is bonded and fixed to the upper surface of the base 11 and accommodates the light emitting element 14 at the center. It is mainly composed of the formed frame body 12 made of metal, resin, ceramics or the like.

  The substrate 11 is made of an aluminum oxide sintered body (alumina ceramic), an aluminum nitride sintered body, a mullite sintered body, ceramics such as glass ceramics, or a resin such as an epoxy resin. When the substrate 11 is made of ceramics, the metallized wiring layer is formed on the upper surface by baking a metal paste made of tungsten (W), molybdenum (Mo) -manganese (Mn), or the like at a high temperature. When the base 11 is made of resin, when the base 11 is molded, a lead terminal made of copper (Cu), iron (Fe) -nickel (Ni) alloy or the like protrudes at one end into the base 11. To be fixed.

  The frame 12 is made of a metal such as aluminum (Al) or Fe-Ni-cobalt (Co) alloy, a ceramic such as an alumina sintered body, or a resin such as an epoxy resin. It is formed by a molding technique such as molding. Furthermore, a through hole is formed in the central portion of the frame body 12 so as to spread outward as it goes upward. To improve the light reflectance of the inner peripheral surface of the through hole, Al or the like is formed on the inner peripheral surface. The metal is deposited by vapor deposition or plating. The frame body 12 is joined to the upper surface of the base 11 with a brazing material such as solder, silver brazing, or a resin adhesive.

Then, a wiring conductor (not shown) formed on the surface of the substrate 11 and the electrode of the light emitting element 14 are electrically connected via a bonding wire (not shown), and then the phosphor is applied to the surface of the light emitting element 14. After the layer 16 is formed, the inside of the frame 12 is filled with a transparent resin 15 and thermally cured, so that the light emitted from the light-emitting element 14 can be converted by the phosphor layer 16 to extract light having a desired wavelength spectrum. Can be made with equipment.
JP 2003-110146 A

  In recent years, light emitting devices that obtain white by mixing red and blue and green phosphors with near ultraviolet light as an excitation source to obtain white color have attracted attention for their high color rendering properties. Since ultraviolet rays are used as an excitation source, deterioration of the light-emitting device housing package and the resin member in the light-emitting device is regarded as a problem. Therefore, a light emitting device in which all members are made of an inorganic material is desired.

  Therefore, a metal 12 such as an Al material having a high reflection efficiency with respect to visible light is machined with high surface accuracy to obtain a frame 12 with a high reflection efficiency with respect to visible light. Attempts have been made to join the substrate 11 with an inorganic adhesive such as a metal adhesive or glass.

  However, when the base 11 made of ceramics and the frame 12 made of Al are joined with a metal adhesive in the structure as shown in FIG. 2, Al as the frame 12 forms a strong non-moving body on the surface. There is a problem in that the wettability with the metal adhesive is poor and poor bonding between the frame 12 and the substrate 11 occurs.

  Therefore, it has been proposed to remove the non-conductor on the surface of Al, which is the frame body 12, with a flux or the like, and in this case, the flux component replaces the Al surface, so the reflectivity of the Al surface with respect to visible light is reduced. There is a problem that the frame 12 having a good reflectance cannot be obtained.

  Further, when glass is used as the inorganic adhesive, the frame 12 is easily peeled off from the base 11 due to the difference in thermal expansion between the frame 12 made of Al and the base 11 made of inorganic adhesive made of glass and ceramics. There was a problem.

  In addition, when Cu is used as the frame body 12, it can be easily joined to the base 11 with an inorganic adhesive. Also, since Cu has low hardness, it is possible to easily and inexpensively obtain a mirror-like surface with a high light reflectance of Ra 0.01 or less by machining or pressing, and applying an Al vapor deposition film on the surface. Thus, the frame body 12 having high light reflection efficiency can be obtained at low cost.

  However, a material with low hardness generally has a large thermal expansion, and the coefficient of thermal expansion is significantly different from that of the base 11 made of ceramics or glass. There is a problem that the reflection surface of the frame 12 is distorted by the stress and the light reflection efficiency is deteriorated.

  Further, when a low thermal expansion metal typified by Fe-Ni-Co alloy or Fe-Ni alloy is used as the frame body 12, the frame body 12 is easily and firmly bonded to the substrate 11 such as ceramics or glass with an inorganic adhesive. In addition, the difference in thermal expansion between the frame body 12 and the base body 11 can be reduced.

  However, the low thermal expansion metal represented by Fe—Ni—Co alloy and Fe—Ni alloy has a problem that it is difficult to process to finish the surface in a mirror state, and costs are high.

  Further, silver (Ag) can be used as the frame body 12 as a metal having a high light reflection efficiency. However, Ag easily changes with time in light reflection efficiency due to surface oxidation, and therefore the frame body 12 for this application. Not suitable for. Further, it is possible to use a metal such as Cu, Fe, or Ni and an alloy using the same by forming an Ag film by plating, vapor deposition or the like as the frame 12, but for the same reason as above, Not suitable for.

  In addition, when the frame 12 is made of glass, the glass material can be pressed to obtain a mirror surface with a high light reflectivity with an arithmetic average roughness Ra of 0.01 or less at a low cost. By applying the Al vapor deposition film, it is possible to obtain the frame 12 having good light reflection efficiency at low cost.

  However, when joining the frame body 12 having the Al vapor deposition film on the surface of the glass material pressed to the base 11, using a metal adhesive such as solder, the Al vapor deposition film was applied to the metal adhesive and the glass material. Since the wettability with the frame 12 is poor, there is a problem that poor bonding is likely to occur.

  In addition, when the base body 11 and the frame body 12 are joined with an inorganic adhesive such as glass, the base body 11 and the frame body 12 can be firmly joined, but in joining with an inorganic adhesive such as glass, In order to melt inorganic adhesives made of glass, it is generally necessary to apply a temperature of 350 ° C or higher, and the reflectivity of the Al deposited film on the glass material tends to deteriorate due to an atmosphere of 350 ° C or higher. Had a point.

  In addition, by using an adhesive that can be bonded at a bonding operation temperature of 350 ° C. or lower, such as a hydrolysis product of metal alkoxide (sol-gel glass), low-melting glass, or water glass, the frame body 12 and the substrate 11 can be bonded. Although it was possible to join, there was a problem that the joining strength was very weak and there was no impact resistance that could withstand practical use.

  The present invention has been made in view of the above problems, and its purpose is to efficiently emit light emitted from a light emitting element to the outside of the light emitting device, and to emit light excellent in impact resistance and ultraviolet resistance. An object is to provide a device package and a light emitting device.

According to one aspect of the present invention, a light emitting device includes a base, a frame provided on the base, a reflection member provided on the inside of the frame and having a light reflection surface, and a reflection member. And a light emitting element mounted on the substrate. The light emitting element emits light having a wavelength included in a range from 300 nm to 400 nm. The reflecting member is bonded to the upper surface of the base and is attached to the inner peripheral surface of the frame. The substrate includes a ceramic material or a glass material. Frame and the reflecting member is made of glass.

According to another aspect of the present invention, a light emitting element storage package includes a base having a light emitting element mounting area, a frame provided on the base and surrounding the light emitting element mounting area, and a frame. And a reflection member provided inside the body. The reflecting member has a light reflecting surface surrounding the light emitting element mounting region. The reflecting member is bonded to the upper surface of the base and is attached to the inner peripheral surface of the frame. The substrate includes a ceramic material or a glass material. Frame and the reflecting member is made of glass.

  The light emitting element storage package of the present invention has a base having a mounting portion for mounting the light emitting element on the upper surface, and an inner peripheral surface attached to the upper surface of the base so as to surround the mounting portion. A reflecting member made of frame-shaped glass that is a reflecting surface for reflecting light, and an inner peripheral surface attached to the outer peripheral surface of the reflecting member while being joined to the upper surface of the base so as to surround the reflecting member Since the reflective member is fitted inside the frame firmly bonded to the base, the frame is crimped, or the reflective member is attached to the base or the frame. By bonding with an inorganic adhesive having a melting point of not higher than ° C., the reflecting member can be provided on the substrate at a very low temperature. As a result, it is possible to effectively prevent the reflecting surface of the reflecting member from being distorted by heat, reflect light very efficiently, and obtain a light emitting device with high radiated light intensity.

  In addition, since it is not necessary to use a material that easily deteriorates ultraviolet rays, such as a resin adhesive, as an adhesive for joining the reflecting member and the substrate, the adhesive is deteriorated by light such as near ultraviolet light emitted from the light emitting element. Can be effectively prevented from breaking down and can be made excellent in UV resistance.

  Furthermore, the frame body bonded to the base body very firmly maintains the airtightness inside the frame body, and effectively suppresses the distortion and thermal expansion of the base body inside the frame body, and stress is applied to the reflecting member. It can be effectively prevented from joining. As a result, the reflecting member bonded to the substrate with a relatively weak bonding force can be reinforced and fixed, the light reflecting characteristics of the reflecting member can be maintained well, and the light emitting element can be maintained over a long period of time. It can be operated well.

  In addition, since the reflecting member is made of glass, the glass is easily flattened by press molding alone, compared to metal whose surface needs to be formed by mechanical processing such as electrolytic polishing after press molding. The reflective surface can be obtained, the manufacturing process can be shortened, and the manufacturing cost can be reduced.

  In the light emitting element storage package of the present invention, preferably, the reflective member has an arithmetic average roughness of the inner peripheral surface of 0.01 μm or less and a metal film is deposited on the surface thereof. The light reflectance of the surface can be further improved, and the light emitting element storage package capable of efficiently radiating the light emitted from the light emitting element to the outside.

  In the light emitting element storage package of the present invention, preferably, the reflecting member is attached to the substrate by a metal alkoxide hydrolysis product or a bonding material made of glass having a melting point of 350 ° C. or lower. The reflecting member can be stably fixed to the base body without being deteriorated by emitted light, and the light reflection characteristics can be maintained better.

  Since the light-emitting device of the present invention includes the light-emitting element storage package of the present invention, a light-emitting element mounted on the mounting portion, and a transparent member that covers the light-emitting element, light emitted from the light-emitting element. Can be efficiently radiated to the outside of the light emitting device, and a light emitting device excellent in impact resistance and ultraviolet resistance can be provided.

  The light emitting device of the present invention will be described in detail below. FIG. 1 is a cross-sectional view showing an example of an embodiment of a light emitting device according to the present invention, wherein 1 is a base, 2 is a frame, 3 is a reflecting member, 4 is a light emitting element, and 5 is a transparent material such as silicone resin or glass. A member, 6 is a phosphor layer, and 8 is a lid, which mainly constitute a light emitting device.

  The substrate 1 in the present invention is an aluminum oxide sintered body (alumina ceramic), an aluminum nitride sintered body, a mullite sintered body, a ceramic such as glass ceramic, or a glass insulator such as silica. It is a support member which supports.

  A metallized wiring layer made of a metal powder such as W, Mo, Mn or the like is formed on the surface of the substrate 1, and a frame 2 made of glass is formed on the surface of the substrate 1 by using an adhesive such as solder, brazing material, glass, or resin adhesive. Are joined together. Preferably, the bonding material for bonding the frame 2 and the substrate 1 is an inorganic adhesive such as solder, brazing material, or glass. Thereby, even when light such as near-ultraviolet light emitted from the light emitting element 4 leaks through the reflecting member 3 or the base 1 or passes through the interface between the reflecting member 3 and the base 1, It is possible to effectively prevent the bonding material for bonding the base body 1 and the frame body 2 from deteriorating, and the bonding strength between the base body 1 and the frame body 2 can be maintained extremely firmly.

  Preferably, the reflecting member 3 has an arithmetic average roughness of the inner peripheral surface of 0.01 μm or less and a metal film on the surface. As a result, the light reflectance of the reflecting surface of the reflecting member 3 can be further improved, and a light emitting element storage package that can efficiently radiate light emitted from the light emitting element 4 to the outside is obtained.

  The reflective member 3 is inserted into the inside of the frame 2 firmly joined to the base 1 and then the frame 2 is caulked, or the reflective member 3 is attached to the base 1 or the frame 2 at 350 ° C. or lower. By joining with an inorganic adhesive having a melting point, the reflecting member 3 can be provided on the substrate 1 at a very low temperature. As a result, it is possible to effectively prevent the reflecting surface of the reflecting member 3 from being distorted by heat, reflect light very efficiently, and obtain a light emitting device with high radiated light intensity.

  Preferably, the reflecting member 3 is attached to the substrate 1 with a bonding material made of a hydrolysis product of a metal alkoxide or glass having a melting point of 350 ° C. or less. Thereby, the reflecting member 3 can be stably fixed to the base 1 without being deteriorated by the light emitted from the light emitting element 4, and the light reflection characteristics can be maintained better. The bonding strength between the base body 1 and the frame body 2 made of a metal alkoxide hydrolysis product or glass having a melting point of 350 ° C. or lower is relatively weak, but the frame body 2 firmly bonded to the base body 1 is reinforced. The reflecting member 3 can be kept better fixed by a synergistic effect with the effect. Therefore, the metal alkoxide hydrolyzate or the glass having a melting point of 350 ° C. or less has sufficient impact resistance to withstand practical use.

  In addition, an inexpensive material such as Cu that can be easily joined with an inorganic adhesive such as soldering or brazing can be used as the frame 2. When the frame 2 is made of Cu, the base 1 is made of an aluminum oxide sintered body (alumina ceramic), an aluminum nitride sintered body, a mullite sintered body, a ceramic such as glass ceramic, or a glass insulator such as silica. Therefore, thermal stress is likely to occur at the joint between the frame 2 and the base 1, and in the conventional configuration in which the inner peripheral surface of the frame 2 is a reflective surface, the reflective surface is thermally stressed. Whereas the distorted light reflectance has been reduced, in the light emitting element storage package of the present invention, the reflective member 3 having the reflective surface and the frame 2 are separate, so that the reflective surface is effectively distorted. Can be prevented.

  Further, a metallized wiring layer made of a metal powder such as W, Mo, or Mn is formed on the surface or inside of the substrate 1 to electrically connect the inside and outside of the light emitting device. A lead terminal made of a metal such as Cu or Fe—Ni alloy is joined to the metallized wiring layer on the surface exposed to the outside. And the light emitting element 4 is joined to the base | substrate 1 with joining materials, such as Au-Sn eutectic solder. Then, the electrode of the light emitting element 4 is electrically connected to the metallized wiring layer of the substrate 1 via a bonding wire (not shown).

  It should be noted that a metal having excellent corrosion resistance, such as Ni or gold (Au), should be deposited on the exposed surface of the metallized wiring layer in a thickness of about 1 to 20 μm. In addition to preventing this, the connection between the metallized wiring layer and the light emitting element 4 and the connection between the metallized wiring layer and the bonding wire can be strengthened. Therefore, an Ni plating layer having a thickness of about 1 to 10 μm and an Au plating layer having a thickness of about 0.1 to 3 μm are sequentially deposited on the exposed surface of the metallized wiring layer by an electrolytic plating method or an electroless plating method. Is more preferable.

  Further, the upper surface of the substrate 1 is not electrically short-circuited to the metallized wiring layer in order to effectively suppress the transmission of light to the lower surface side of the substrate 1 and efficiently reflect the light to the upper side of the substrate 1. Thus, it is preferable to form a metal such as Al, Ag, Au, platinum (Pt), or Cu as the reflective layer by vapor deposition or plating. Moreover, it is good also as a reflection layer by enlarging the area of a metallization wiring layer.

  And the light emitting element 4 is mounted on the mounting part of the light emitting element storage package of the present invention, and the light emitting element 4 is covered with the transparent member 5, so that the light emitting device of the present invention is obtained.

  The transparent member 5 may be a cured product of a translucent gel-like substance provided so as to cover the surface of the light emitting element 4, and the upper surface of the reflecting member 3 or the upper surface of the frame 2 so as to cover the light emitting element 4. It may be a translucent lid that is joined to.

  Preferably, the surface of the light-emitting element 4 is covered with a transparent member 5 such as silicone resin, sol-gel glass, silicone-modified glass, fluororesin, or low-melting glass. If the upper surface of the light emitting element 4 is in contact with air, the light emitting element 4 generally has a higher refractive index than air (approximately 2.7 for gallium nitride relative to air 1), so the inside and outside of the light emitting element 4 (in this case, air) The critical angle of reflection generated at the interface of is small. As a result, the total reflection is likely to occur, and the probability that the light generated in the light emitting element 4 is emitted to the outside (external quantum efficiency) is low. Therefore, in order to increase the critical reflection angle, it has a refractive index approximate to the refractive index of the light emitting element 4, is transparent to the light emitted from the light emitting element 4, and is transparent to the light emitted from the light emitting element 4. It is effective to cover the light emitting element 4 with a material that does not deteriorate. The refractive index of the transparent member 5 such as silicone resin, sol-gel glass, silicone-modified glass, or low-melting glass has a value larger than air and close to the refractive index of the light-emitting element 4. As a result, the external quantum efficiency of the light-emitting element 4 is increased, and a light-emitting element storage package and a light-emitting device with high light emission efficiency can be obtained.

  Further, a phosphor made of a transparent member mixed with phosphor particles for converting part or all of the transmitted light into light having a desired wavelength (for example, visible light of 420 to 780 nm) on the transparent member 5. Layer 6 may be applied and formed. Thereby, the light of the light emitting element 4 can be converted into a desired color.

Various known phosphor particles can be used in the phosphor layer 6. For example, La ₂ O ₂ S: Eu that emits red (about 580 to 780 nm) fluorescence, ZnS: Cu, Al, blue (420 to 550 nm) that emits green (about 450 to 650 nm) fluorescence (BaMgAl) ₁₀ O ₁₂ : Eu or the like can be used.

  Since the phosphor converts the light of the light emitting element 4 into fluorescence on the surface thereof, it is more efficient to use particles having a particle size that does not cause a problem of the existence of defects in crystals constituting the phosphor. However, since it is difficult to mount only phosphor particles directly on the surface of the transparent member 5 in the form of particles, the phosphor particles are mixed in the transparent member and applied to the surface of the transparent member 5 to form the phosphor layer 6. . Examples of the transparent member for containing such phosphor particles include an epoxy resin, a silicone resin, an acrylic resin, or glass.

  For example, the light emitting element 4 having an emission wavelength of 300 to 400 nm generates light in a wavelength band mainly including an ultraviolet region, and the phosphor particles efficiently convert light in this wavelength band into fluorescence. can do.

  Moreover, you may attach the cover body 8 to the upper surface of the frame 2 using a joining material, as shown in FIG. The lid 8 is made of a transparent member such as glass, sapphire, quartz, or a resin (plastic) such as epoxy resin, silicone resin, acrylic resin, etc., and the bonding material is a resin adhesive such as epoxy resin or silicone resin, solder, or brazing material. Inorganic adhesives such as low melting point glass can be used. Accordingly, the light emitting element 4, the phosphor layer 6, the metallized wiring layer, and the bonding wire installed inside the frame body 2 are well protected, and the inside of the light emitting element storage package is hermetically sealed to light emitting the element. 4 can be operated stably.

Moreover, it is preferable to use a highly airtight material such as glass or sapphire as the lid 8 and an inorganic adhesive such as solder, brazing material or low melting point glass as the bonding material. As a result, the inside of the frame 2 can be sealed in an airtight state with a helium leak amount of less than 10 ⁻⁹ Pa · m ³ / s. As a result, it is possible to protect the light emitting element 4, the phosphor layer 6, the metallized wiring layer, and the bonding wire installed inside the frame body 2 from deterioration due to oxygen or water vapor, thereby extending the life of the light emitting device. Become.

  Further, by forming the lid 8 in a lens shape and adding the function of an optical lens, the light emitted from the light emitting device is condensed or dispersed, and the light is extracted outside at a desired radiation angle and intensity distribution. Can do.

  A transparent member 7 such as a silicone resin, an epoxy resin, a fluorine resin, or glass, or an inert transparent gas 7 such as nitrogen, argon, or helium is installed between the lid 8 and the phosphor layer 6.

  Since the refractive index of the phosphor layer 6 is expressed by the combination of the refractive index of the phosphor particles and the refractive index of the transparent member covering the phosphor particles, it is larger than the refractive index of air. Therefore, the critical reflection angle generated at the interface between the phosphor layer 6 and the outside becomes small, and the probability that the light generated at the phosphor layer 6 is totally reflected at the interface between the phosphor layer 6 and the outside and goes out is low. In order to increase the critical reflection angle, it has a refractive index approximate to that of the phosphor layer 6, is transparent to the light emitted from the phosphor layer 6, and is transparent to the light emitted from the phosphor layer 6. It is effective to coat the phosphor layer 6 with a material that does not deteriorate.

  The refractive index of the transparent member 7 such as silicone resin, sol-gel glass, silicone-modified glass, fluororesin, or low-melting glass has a value larger than air and close to the refractive index of the phosphor layer 6. As a result, when a transparent member 7 such as silicone resin, sol-gel glass, silicone-modified glass, fluororesin, or low-melting glass is installed between the phosphor layer 6 and the lid 8, light generated in the phosphor layer 6 is emitted to the outside. Thus, a light emitting element housing package and a light emitting device with high luminous efficiency can be obtained.

  If an inert transparent gas 7 such as nitrogen, helium, or argon is placed between the phosphor layer 6 and the lid 8, the critical reflection angle is increased and the probability of taking out the light generated from the phosphor layer 6 is reduced. However, it is possible to protect the light emitting element 4, the phosphor layer 6, the metallized wiring layer, and the bonding wire installed inside the frame body 2 from deterioration due to oxygen or water vapor, thereby extending the life of the light emitting device. .

  It should be noted that the present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the scope of the present invention. For example, the transparent member 5 may contain phosphor particles, and the transparent member 5 may be a phosphor layer.

It is sectional drawing which shows an example of embodiment of the light-emitting device of this invention. It is sectional drawing which shows the conventional light-emitting device.

Explanation of symbols

1: Base body 2: Frame body 3: Reflecting member 4: Light emitting element 5: Transparent member

Claims (3)

A substrate;
A frame provided on the substrate;
A reflection member provided on the inner side of the frame, and having a light reflection surface;
A light emitting element that is provided on the inner side of the reflecting member and is mounted on the base, and that emits light having a wavelength included in a range from 300 nm to 400 nm;
The reflective member is bonded to the upper surface of the base body, and is attached to the inner peripheral surface of the frame,
Emitting device wherein the substrate together comprise a ceramic material or glass material, the frame body and the reflection member is characterized in that it consists of glass.   The light emitting device according to claim 1, wherein the reflecting member is bonded to the base body or the frame body with an inorganic adhesive. A substrate having a light emitting element mounting region;
A frame provided on the substrate and surrounding the light emitting element mounting region;
A reflection member that is provided inside the frame and has a light reflection surface that surrounds the light emitting element mounting region;
The reflective member is bonded to the upper surface of the base body, and is attached to the inner peripheral surface of the frame,
Together with the substrate contains a ceramic material or glass material, the light emitting device package for housing the frame body and the reflection member is characterized in that it consists of glass.

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