JP2012174979A - Substrate for loading light emitting element and light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate for loading a light emitting element, for not lowering luminance even when electronic components such as a Zener diode are loaded together with the light emitting element, and a light emitting device.SOLUTION: The substrate for loading a light emitting element of this invention includes a substrate 1, a first loading part 1a for loading a light emitting element 5 on an upper surface of the substrate 1, a recessed part 2 formed on at least a part around the first loading part 1a, and a second loading part 2a for loading an electronic component 6 on a bottom surface of the recessed part 2. Thus, even when the light emitting device is loaded with the light emitting element 5 at the first loading part 1a and is loaded with the electronic component 6 such as a Zener diode at the second loading part 2a, since there is not electronic component 6 that interrupts light emitted from the light emitting element 5 on the same surface as the light emitting element 5, reduction of the light emitted from the light emitting device is reduced and decline of the luminance of the light of the light emitting device is suppressed. Also, dispersion of the luminance of the light emitted from the light emitting device is suppressed.

Description

  The present invention relates to a light emitting element mounting substrate and a light emitting device for mounting a light emitting element such as an LED.

  Conventionally, a light emitting element mounting substrate for mounting a light emitting element such as an LED (Light Emitting Diode) is electrically connected to an insulating substrate, a mounting portion provided on the upper surface of the insulating substrate, and the mounting portion and its periphery to the lower surface. Wiring conductors. Then, the light emitting element is fixed to one wiring conductor of such a light emitting element mounting substrate with a conductive bonding material, and the electrode of the light emitting element and the other wiring conductor are electrically connected via a connecting means such as a bonding wire. And the light emitting device is sealed with a transparent sealing resin to obtain a light emitting device.

  In a light-emitting device using an LED as a light-emitting element, since the withstand voltage against the static electricity of the LED is low, the charged static electricity is discharged to the electrode pad of the LED and the wiring pattern between the LEDs, resulting in voltage fluctuation and overvoltage. There is a case where an adverse effect such as breakage of the LED is caused. Therefore, a measure has been taken to prevent an overvoltage from being applied to the LED, for example, by connecting a Zener diode. (For example, see Patent Document 1).

JP 2005-19942

  However, when an electronic component such as a Zener diode is arranged on the same surface as the surface on which the light emitting element is mounted, the light emitted from the light emitting element is blocked by the Zener diode. Therefore, the light emitted from the side where the Zener diode of the light emitting device is emitted is reduced, and the luminance of the light emitting device is lowered. In addition, there is a problem in that the brightness of light emitted from the light emitting device varies and light of uniform brightness cannot be emitted.

  The present invention has been devised in view of the above-described problems of the prior art, and an object of the present invention is to provide a light emitting element mounting substrate and a light emitting device that do not reduce luminance even when an electronic component is mounted together with the light emitting element. It is to provide.

  The light emitting element mounting substrate of the present invention includes a substrate, a first mounting portion for mounting the light emitting element on the upper surface of the substrate, a recess formed in at least a part of the periphery of the first mounting portion, And a second mounting portion for mounting an electronic component on the bottom surface of the recess.

  The light emitting element mounting substrate of the present invention is characterized in that, in the above configuration, the concave portion is gradually enlarged from the opening portion toward the bottom surface.

  Moreover, the light emitting element mounting substrate of the present invention has the electronic component mounted on the second mounting portion in the above configuration, and is disposed above the electronic component so as to cover the bottom surface of the concave portion in plan view. And a reflective layer.

The light emitting element mounting substrate of the present invention is characterized in that, in the above configuration, the recess is filled with a sealing material, and the reflective layer is disposed on the surface of the sealing material.

  The light emitting element mounting substrate of the present invention is characterized in that, in each of the above structures, the reflective layer is located closer to the bottom surface than the first mounting portion in the thickness direction of the substrate. It is.

  In the light emitting element mounting substrate of the present invention, in each of the above configurations, a deformation prevention layer is disposed on the lower surface of the substrate in a region overlapping the boundary between the first mounting portion and the concave portion in plan view. It is characterized by.

  The light-emitting device of the present invention includes the light-emitting element mounting substrate having the above-described configuration, the light-emitting element mounted on the first mounting portion, and a transparent sealing material that covers the light-emitting element. It is characterized by.

  According to the light emitting element mounting substrate of the present invention, the substrate, the first mounting portion for mounting the light emitting element on the upper surface of the substrate, the concave portion formed in at least a part of the periphery of the first mounting portion, and the concave portion Since the second mounting portion for mounting the electronic component on the bottom surface of the light emitting device is provided, the light emitting device is mounted on the first mounting portion and the electronic component such as a Zener diode is mounted on the second mounting portion. However, since there is no electronic component that blocks light emitted from the light emitting element on the same surface as the light emitting element, the decrease in the light emitted from the light emitting device is reduced, and the luminance of the light emitted from the light emitting device is reduced. It can suppress that it falls. In addition, variations in luminance of light emitted from the light emitting device can be suppressed.

  Further, in the light emitting element mounting substrate of the present invention, in the above structure, since the concave portion is gradually enlarged from the opening portion toward the bottom surface, the electronic component is mounted in the concave portion and the electronic component is sealed. When the sealing material for filling is filled, the sealing material is locked. Since the sealing material is arranged in this way, the upper surface side easily expands even if the substrate expands due to the heat generated by the light emitting element, so that the sealing material can be prevented from coming out of the recess.

  Further, according to the light emitting element mounting substrate of the present invention, in the above configuration, the electronic component mounted on the second mounting portion and the reflection disposed above the electronic component so as to cover the bottom surface of the recess in plan view. Since the light emitted from the light emitting element toward the light emitting element mounting substrate is reflected by the reflective layer, it is effective in increasing the luminance of the emitted light when the light emitting device is used. .

  Further, the light emitting element mounting substrate of the present invention has a structure in which the concave portion is filled with the sealing material and the reflective layer is disposed on the surface of the sealing material. Can be bonded on a wider surface, which is effective in increasing the bonding strength between the reflective layer and the substrate.

  Further, according to the light emitting element mounting substrate of the present invention, in the above configuration, the reflective layer is positioned on the bottom surface side of the first mounting portion in the thickness direction of the substrate. Is spaced apart in the thickness direction of the substrate and is electrically insulated, so that the reflective layer and the first mounting portion can be arranged in contact with each other or overlap in a plan view, and thus emitted from the light emitting element. It is more effective in reflecting the reflected light.

  Further, according to the light emitting element mounting substrate of the present invention, in the above configuration, the deformation preventing layer is disposed on the lower surface of the substrate in a region overlapping with the boundary between the first mounting portion and the concave portion in plan view. It can suppress that a crack arises from the corner | angular part by the side of the insulated substrate of a recessed part toward a lower surface.

Moreover, according to the light emitting device of the present invention, it is possible to suppress a decrease in luminance of light emitted from the light emitting element.

(A) is a top view which shows an example of embodiment of the light emitting element mounting substrate of this invention, (b) is sectional drawing which shows the AA cross section of (a). (A) is a top view which shows the other example of embodiment of the light emitting element mounting substrate of this invention, (b) is sectional drawing which shows the AA cross section of (a). (A) is a top view which shows the other example of embodiment of the light emitting element mounting substrate of this invention, (b) is sectional drawing which shows the AA cross section of (a). (A) is a top view which shows the other example of embodiment of the light emitting element mounting substrate of this invention, (b) is sectional drawing which shows the AA line cross section of (a), (c) [FIG. 3] is a sectional view showing a section taken along line BB of (a). (A) is a top view which shows the other example of embodiment of the light emitting element mounting substrate of this invention, (b) is sectional drawing which shows the AA line cross section of (a), (c) [FIG. 3] is a sectional view showing a section taken along line BB of (a). (A) is a top view which shows the other example of embodiment of the light emitting element mounting substrate of this invention, (b) is sectional drawing which shows the AA cross section of (a). (A) is a top view which shows the other example of embodiment of the light emitting element mounting substrate of this invention, (b) is sectional drawing which shows the AA cross section of (a). (A) is a top view which shows an example of embodiment of the light-emitting device of this invention, (b) is sectional drawing which shows the AA sectional view of (a). It is a top view which shows an example of embodiment of the light emitting element mounting substrate of this invention.

  A light-emitting element mounting substrate and a light-emitting device of the present invention will be described with reference to the accompanying drawings. 1 to 9, 1 is a substrate, 1a is a first mounting portion, 2 is a recess, 2a is a second mounting portion, 3 is a reflective layer, 3a is a second reflective layer, 4 is a wiring conductor, and 5 is a light emitting element. , 6 is an electronic component, 7 is a sealing material, 8 is a side wall, 10 is a deformation preventing layer, and 11 is a translucent member.

  The light emitting element mounting substrate of the present invention includes a substrate 1, a first mounting portion 1a for mounting the light emitting element 5 on the upper surface of the substrate 1, and a first mounting portion, as in the examples shown in FIGS. A recess 2 formed in at least a part of the periphery of 1a and a second mounting portion 2a for mounting the electronic component 6 on the bottom surface of the recess 2 are provided.

  In the example shown in FIG. 1, a recess 2 is formed in a part of the periphery of the first mounting portion 1a. In the example shown in FIGS. 2 to 7, an annular recess 2 is formed in a plan view so as to surround the first mounting portion 1 a around the first mounting portion 1 a. In the example shown in FIG. 7, the upper surface of the side wall portion 8 of the substrate 1 is located above the upper surface of the light emitting element 5 when the light emitting element 5 is mounted in a sectional view. In the example shown in FIG. 7, the second reflective layer 3 a is disposed on the inner surface of the side wall portion 8.

  Since the light emitting element mounting substrate of the present invention has the above-described configuration, the light emitting element 5 is mounted on the first mounting portion 1a, and the electronic component 6 such as a Zener diode is mounted on the second mounting portion 2a. When the apparatus is used, there is no electronic component 6 that blocks light emitted from the light emitting element 5 on the same surface as the light emitting element 5. Therefore, it can suppress that the light radiated | emitted from a light-emitting device reduces, and can suppress that the brightness | luminance of the light radiated | emitted from a light-emitting device falls. In addition, variations in luminance of light emitted from the light emitting device can be suppressed.

Further, in the light emitting element mounting substrate of the present invention, as shown in the example shown in FIG. 3, when the concave portion 2 is gradually increased from the opening portion toward the bottom surface, the electronic component 6 is mounted in the concave portion 2. When the sealing material 7 for sealing the electronic component 6 is filled, the sealing material 7 is locked. Furthermore, even if the substrate 1 expands due to the heat generated by the light emitting element 5, the upper surface side easily expands, so that the sealing material 7 can be prevented from coming out of the recess 2.

  Moreover, according to the light emitting element mounting substrate of this invention, like the example shown in FIGS. 1-7, the electronic component 6 mounted in the 2nd mounting part 2a and the electronic component 6 above the electronic component 6 by planar view. When the reflective layer 3 covering the bottom surface of the recess 2 is provided, the light emitted from the light emitting element 5 toward the light emitting element mounting substrate side is reflected by the reflective layer 3. This is effective for increasing the brightness of the light to be emitted. In addition, when the reflective layer 3 is formed so as to surround the first mounting portion 1a in a plan view, light emitted from the light emitting element 5 is reduced from being transmitted through the substrate 1 or absorbed by the substrate 1 to emit light. This is effective for increasing the luminance of light emitted from the apparatus and suppressing variations in the luminance of light.

  Moreover, as for the light emitting element mounting substrate of this invention, the recessed part 2 is filled with the sealing material 7, and the reflection layer 3 is arrange | positioned on the surface of the sealing material 7 like the example shown in FIGS. In some cases, the reflective layer 3 and the substrate 1 can be bonded to each other on a wider surface by the sealing material 7, which is effective in increasing the bonding strength between the reflective layer 3 and the substrate 1.

  Moreover, according to the light emitting element mounting substrate of the present invention, as shown in the example shown in FIG. 3, when the reflective layer 3 is positioned on the bottom side of the first mounting portion 1 a in the thickness direction of the substrate 1. Since the reflective layer 3 and the first mounting portion 1a are spaced apart in the thickness direction of the substrate 1 and are electrically insulated, the reflective layer 3 and the first mounting portion 1a are in contact with each other in plan view. Since it can arrange | position so that it may overlap, the reflective layer 3 can be formed in a wider area | region, and it is more effective to reflect the light radiated | emitted from the light emitting element 5. FIG.

  Further, according to the light emitting element mounting substrate of the present invention, as in the example shown in FIGS. 6 and 7, on the lower surface of the substrate 1, the region overlapping the boundary between the first mounting portion 1 a and the recess 2 in plan view. When the deformation preventing layer 10 is disposed, it is possible to suppress the generation of cracks from the corners of the bottom surface of the recess 2 toward the bottom surface. In the example shown in FIG. 6, the wiring conductor 4 disposed on the lower surface of the substrate 1 also serves as the deformation prevention layer 10.

  The substrate 1 is made of a ceramic such as an aluminum oxide sintered body (alumina ceramic), an aluminum nitride sintered body, a mullite sintered body, a glass ceramic sintered body, or the like.

  If the substrate 1 is made of, for example, an aluminum oxide sintered body, a suitable organic binder and solvent are added to and mixed with raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide to form a slurry. Then, the ceramic green sheet is obtained by forming it into a sheet shape by a conventionally known doctor blade method or calendar roll method, etc., and thereafter, the ceramic green sheet is subjected to appropriate punching processing and a plurality of layers are laminated to obtain a high temperature. It is manufactured by firing at (about 1600 ℃).

  The concave portion 2 is laminated with a ceramic green sheet in which through holes whose inner surface is the inner wall surface of the concave portion 2 are formed in the ceramic green sheet by laser processing or punching with a mold, and other through holes are not formed. It is formed by keeping. An electronic component 6 such as a Zener diode or a varistor is mounted on the bottom surface of the recess 2.

  The thickness of the electronic component 6 is smaller than the depth of the concave portion 2 as in the examples shown in FIGS. 1 to 9, and the electronic component 6 is placed in the concave portion 2, and the opening of the concave portion 2 is the electronic component. If it is located above the upper surface of 6, it is possible to suppress the light emitted from the light emitting element 5 from the side from being blocked by the electronic component 6.

  As in the example shown in FIG. 1, when the recess 2 is formed in a part of the periphery of the first mounting portion 1 a, there are few portions where the substrate 1 becomes thin by forming the recess 2. It is effective to increase In such a configuration, when the reflective layer 3 covers the opening of the recess 2 and is disposed so as to surround the first mounting portion 1a, the brightness of the reflected light can be made high and uniform. Therefore, it is preferable. The reflective layer 3 may be formed by disposing a plate-like member, or may be formed by applying a resin material described later.

  As shown in FIGS. 2 to 9, when the recess 2 is formed so as to surround the first mounting portion 1 a and the opening of the recess 2 is covered with the reflective layer 3, the first mounting is performed. Compared with the case where the concave portion 2 is formed in a part of the periphery of the portion 1a, the reflective layer 3 is easily formed of the same material, which is effective in making the luminance of reflected light uniform. In addition, when a plurality of electronic components 6 are arranged around the light emitting element 5, it is easy to secure a region for arranging the electronic components 6.

  In the example shown in FIG. 4, a plurality of concave portions 2 are arranged at equal intervals so as to surround the first mounting portion 1 a, and the sealing material 7 and the reflective layer 3 are formed in each of the concave portions 2. ing. With such a configuration, since there is a wall between the plurality of recesses 2, there is little reduction in the strength of the substrate 1 due to the formation of the recesses 2. Moreover, each recessed part 2 may be enlarged, square shape, and circular shape may be increased in planar view, and the number of the recessed parts 2 may be increased further. Further, thinning the wall between the recesses 2 is effective for improving the uniformity of reflection.

  In the example shown in FIG. 5, the sealing material 7 and the reflective film 3 are also formed on the wall by making the upper surface of the wall between the recesses 2 in the example shown in FIG. 4 lower than the upper surface of the substrate 1. . With such a configuration, since one reflection layer 3 can be formed so as to surround the first mounting portion 1a, compared to the example shown in FIG. 4, the brightness of reflected light is made uniform. It is valid.

  In the example shown in FIGS. 2, 3, 6, and 7, one concave portion 2 is arranged so as to surround the first mounting portion 1 a, and the sealing material 7 and the reflective layer 3 are disposed in the concave portion 2. Is arranged so as to surround the first mounting portion 1a. With such a configuration, it is easy to form the reflective layer 3 with the same material and at the same height, which is effective for making the brightness of the reflected light uniform. When the reflective layer 3 is formed of a resin material as will be described later, since the reflective layer 3 can be formed by arranging the resin material only in the recess 2, it is possible to suppress the resin material from flowing out to the first mounting portion 1a. It is valid. When the reflective layer 3 is formed of a plate-like member, it is effective to suppress the position of the reflective layer 3 from shifting by using a plate-like member that fits into the recess 2 in plan view.

  The substrate 1 on which the concave portion 2 is formed so as to surround the first mounting portion 1a can be manufactured as follows. First, a ceramic green sheet for the substrate 1 is prepared, and a first through-hole whose outer edge is the same size as the outer edge of the recess 2 is formed by punching with a mold or the like. Next, a resin sheet is embedded in the first through hole. Thereafter, a second through hole having an outer edge located outside the first mounting portion 1a is formed in the resin sheet portion, and a ceramic green sheet is embedded in the second through hole to form a composite sheet. When the composite sheet thus obtained is laminated with another ceramic green sheet and then fired, the resin sheet is burned out, and the substrate 1 in which the recesses 2 are disposed so as to surround the first mounting portion 1a can be produced.

  In addition, a second through hole whose outer edge is located outside the first mounting portion 1a is formed in the resin sheet, and after the ceramic green sheet is embedded in the second through hole, the second through hole is embedded in the first through hole. It is also possible to form a composite sheet by embedding it.

The concave portion 2 gradually increases from the opening toward the bottom surface. When the inner surface on the outer peripheral side of the substrate 1 is inclined in addition to the inner surface on the first mounting portion 1a side, the concave portion 2 is filled. It is possible to more effectively suppress the sealing material 7 from coming out of the recess 2.

  The recess 2 may have a bottom surface larger than the opening, and may have a stepped portion on the inner surface on the first mounting portion 1a side. In such a case, since the filled sealing material 7 is caught by the stepped portion, it is possible to suppress the sealing material 7 from coming out of the recess 2.

  In addition, when the inner surface of the recess 2 is inclined, when the sealing material 7 is filled in the recess 2, the sealing material 7 is less likely to be filled than when there is a step portion on the inner surface of the recess 2. Since there are few corner | angular parts, it can reduce that the clearance gap which is not filled with the sealing material 7 is made.

  The sealing material 7 is made of a resin material such as an acrylic resin, an epoxy resin, a phenol resin, a cresol resin, a silicone resin, or a polyether amide resin, such as thermosetting or photocurable, or a glass material. Can do.

  The reflective layer 3 is formed so as to cover the opening of the recess 2 after the electronic component 6 is mounted on the bottom surface of the recess 2 as in the examples shown in FIGS. 1, 2 and 4 to 7. As such a reflective layer 3, a white resin film or metal film having a high reflectance, a resin film to which particles having a high reflectance are added, a plate member having a high reflectance, or the like can be used.

  For example, when a metal film is disposed as the reflective layer 3, the reflective layer 3 is formed as a thin film such as vapor deposition or plating using a highly reflective material such as aluminum, silver, palladium, or platinum. It can be formed by being deposited on the upper surface of the sealing material 7 by a method. In the case of using a resin film to which particles having high reflectivity are added, the reflective layer 3 is made of epoxy particles such as titanium dioxide, barium sulfate, barium carbonate, magnesium oxide, silicon dioxide, or silver that are made of epoxy. It can be formed by adding and mixing with resin, silicon resin, phenol resin or the like, and applying and curing on the upper surface of the sealing material 7. When a plate member having a high reflectance is used, a metal plate material using the above-described highly reflective metal, a resin plate material to which the above-described highly reflective particles are added, or the above-described reflectance It is possible to use a plate-like member having a high metal deposited on its surface, a plate-like member having a resin film to which the above-described highly reflective particles are added, and the like.

  When the reflective layer 3 is a white resin film or metal film having a high reflectance, or a resin film to which particles having a high reflectance are added, a sealing material 7 is provided so as to cover the electronic component 6 in the recess 2. The reflective layer 3 may be formed so as to cover the sealing material 7 after filling.

  Further, as in the example shown in FIG. 3, when the reflective layer 3 is disposed in the recess 2 that gradually increases from the opening toward the bottom, the electronic component 6 is mounted on the bottom of the recess 2, and the sealing material 7 is disposed, and the reflective layer 3 is arranged in the thickness direction of the substrate 1 by disposing a resin to which the above-described highly reflective metal particles are added or a white resin having a high reflectance on the sealing material 7. The first mounting portion 1a can be positioned on the bottom side.

  Further, when a plate-like member having a high reflectance is used as the reflective layer 3, the sealing material 7 is filled in the recess 2 so as to cover the electronic component 6, and the plate-like material is placed on the sealing material 7. What is necessary is just to form the reflection layer 3 by arrange | positioning a member. Further, as in the example shown in FIG. 1, a step is formed on the inner wall of the recess 2 above the electronic component 6, and a reflection layer 3 is formed by arranging and bonding a plate-like member on the upper surface of the step. It doesn't matter.

If the upper surface of the reflective layer 3 is positioned below the first mounting portion 1a in the thickness direction of the substrate 1 as in the example shown in FIGS. Compared with the case where it is located above 1 mounting part 1a, when reflecting the light radiated | emitted below from the light emitting element 3, it can be diffused and reflected in the wide area | region above the board | substrate 1. FIG. Further, when the reflective layer 3 is formed using a metal film or a resin film, the reflective layer 3 can be prevented from being formed on the first mounting portion 1a side, and the light emitting element 5 is mounted on the first mounting portion 1a. In doing so, the light emitting element 5 can be prevented from tilting. Moreover, since the upper surface of the reflective layer 3 does not protrude above the first mounting portion 1a in the thickness direction of the substrate 1, the light emitting device 5 reflects when the light emitting device 5 is mounted on the first mounting portion 1a. It is possible to suppress hitting the layer 3.

  A wiring conductor 4 is formed on the first mounting portion 1 a for mounting the light emitting element 5 of the substrate 1 in order to mount the light emitting element 5 or to electrically connect to the electrode of the light emitting element 5. When the flip chip type light emitting element 5 is mounted on the light emitting element mounting substrate, the wiring conductor 4 joins the light emitting element 5 and is electrically connected to the light emitting element 5.

  Further, the wiring conductor 4 is formed so as to pass through the inside of the substrate 1 and be exposed on the surface of the substrate 1. In the example shown in FIGS. 1 to 7, the wiring conductor 4 is formed so as to be exposed on the lower surface of the substrate 1, but may be formed on the side surface of the substrate 1 or formed from the side surface to the lower surface of the substrate 1. May be.

  Furthermore, when the wiring conductor 4 is formed on the inner wall surface of the recess 2 on the first mounting portion 1a side as in the example shown in FIG. 7, when the light emitting element 5 is mounted on the first mounting portion 1a, Since it is not mounted on the through conductor, the light emitting element 5 is not inclined when the light emitting element 5 is mounted with the through conductor protruding from the upper surface of the substrate 1, and the light emitting element 5 is satisfactorily placed on the first mounting portion 1a. Can be installed. When the wiring conductor 4 is formed on the inner wall surface of the recess 2 as described above, the reflective layer 3 is formed of an insulating material so that the wiring conductors 4 are not short-circuited via the reflective layer 3. To do. Such a wiring conductor 4 can be formed by providing a penetrating conductor at the boundary between the ceramic green sheet and the resin sheet serving as the first mounting portion 1a of the composite sheet.

  The wiring conductor 4 is made of metal powder metallization such as tungsten (W), molybdenum (Mo), manganese (Mn), silver (Ag), or copper (Cu). A metallized paste for wiring conductor 4 obtained by adding and mixing an appropriate organic binder and solvent to the above metal powder is printed on a ceramic green sheet for substrate 1 in a predetermined shape by screen printing or the like, and used for substrate 1 It is formed at a predetermined position of the substrate 1 by firing at the same time as the ceramic green sheet.

  The wiring conductor 4 includes a wiring conductor disposed between the surface of the substrate 1 and the insulating layer, and a through conductor that electrically connects the wiring conductors 4 that are positioned above and below the insulating layer. For the wiring conductors arranged between the surface and the insulating layer, the metallized paste for the wiring conductor 4 is printed on the ceramic green sheet for the substrate 1 by printing means such as a screen printing method, and fired together with the generated shape for the substrate 1. Formed by. In addition, the through conductor is penetrated for the through conductor by a processing method such as punching by die or punching or laser processing on the ceramic green sheet for the substrate 1 prior to the printing application of the metallized paste for forming the wiring conductor 4. A hole is formed, and a metallized paste for a through conductor is filled in the through hole by a printing means such as a screen printing method, and is fired together with a generated shape to be the substrate 1. The metallized paste is prepared by adding an organic binder and an organic solvent to the main component metal powder and, if necessary, a dispersing agent and the like, and mixing and kneading by a kneading means such as a ball mill, a three-roll mill or a planetary mixer. Further, glass or ceramic powder may be added to match the sintering behavior of the ceramic green sheet or to increase the bonding strength with the substrate 1 after firing. The metallized paste for the through conductor is adjusted to have a higher viscosity than the metallized paste for the wiring conductor 4, which is suitable for filling, depending on the type and amount of the organic binder or organic solvent. The metallized paste may contain glass or ceramics in order to increase the bonding strength with the substrate 1.

The exposed surface of the wiring conductor 4 is coated with a metal plating having excellent corrosion resistance, such as nickel or gold, to become a connection electrode or an external terminal electrode. Thus, corrosion of the wiring conductor 4 can be effectively suppressed, the bonding between the wiring conductor 4 and the electronic component 6, the bonding between the wiring conductor 4 and the bonding wire, and the wiring conductor 4 and the wiring conductor of the external circuit board. Can be firmly joined. Further, for example, a nickel plating layer having a thickness of about 1 to 10 μm and a gold plating layer having a thickness of about 0.1 to 3 μm are sequentially deposited on the exposed surface of the wiring conductor 4 by an electrolytic plating method or an electroless plating method. Is done. In order to improve the bonding between the light emitting element 5 or the electronic component 6 and the wiring conductor 4, it is preferable to form a gold plating layer.

  Further, the substrate 1 may include a side wall portion 8 which is disposed along the outer periphery of the substrate 1 and whose upper surface is located above the upper surface of the light emitting element 5 as in the example illustrated in FIG. 7. The concave portion surrounded by the side wall portion 8 is formed by the same method as that for the concave portion 2 described above.

  Further, as in the example shown in FIG. 7, a second reflective layer 3 a for reflecting light emitted from the light emitting element 5 may be provided on the inner surface of the side wall portion 8. The second reflective layer 3a is formed, for example, by forming a metallized layer on the inner surface of the side wall 8 and depositing a plating layer on the metallized layer. Moreover, you may form with the above-mentioned resin film or metal film.

  The metallized metal layer to be the second reflective layer 3a is, for example, printed by applying a metallized paste produced using the same material as the wiring conductor 4 to the inner surface of the green sheet to be the side wall portion 8 by a conventionally known screen printing method. In addition, it is deposited on the inner surface of the side wall portion 8 by firing simultaneously with the green sheet. Thereby, the 2nd reflective layer 3a can be formed in the inner surface of the side wall part 8. FIG. In addition, the metallized paste may change the kind and amount of the organic binder and the solvent in consideration of printability.

Further, similarly to the wiring conductor 4, a metal having excellent corrosion resistance such as nickel, gold, and silver is deposited on the exposed surface of the second reflective layer 3 a. For example, a nickel plating layer having a thickness of 1 to 10 μm and a gold plating layer having a thickness of about 0.1 to 3 μm or a silver plating layer having a thickness of about 1 to 5 μm are sequentially deposited on the exposed surface of the reflective layer 3. Thereby, the light emitted from the light emitting element 5 can be reflected more efficiently. In addition, when a silver plating layer is deposited on the outermost surface, the emitted light is close to white in a light emitting device that emits white light as compared to the case where a gold plating layer is deposited on the outermost surface. Therefore, it is preferable. Moreover, the silver plating layer has less light absorption than the gold plating layer, and can reflect light efficiently. In particular, when the light is short-wavelength light such as blue light, the difference in reflectance tends to increase, and therefore it is preferable to form a silver plating layer on the surface of the second reflective layer 3a. Note that a silver plating layer may be formed on the surface of the reflective layer 3 as necessary.

  Further, when the concave portion 2 is formed in a part of the periphery of the first mounting portion 1a, the second reflective layer 3a is insulated from the wiring conductor 4 disposed in the first mounting portion 1a, and is seen in a plan view. It is preferable to cover the opening of the recess 2 and surround the first mounting portion 1a. With this configuration, when the surface of the second reflective layer 3a is formed by electrolytic plating, it is insulated from the wiring conductor 4 in the first mounting region 1a. can do. That is, a gold plating layer having excellent corrosion resistance is formed on the surface of the wiring conductor 4 in the first mounting region 1a, and the surface of the second reflective layer 3a is a silver plating layer that absorbs less light than the gold plating layer. And a reflective layer capable of efficiently reflecting light can be formed.

  When the angle θ between the inner surface of the side wall 8 and the upper surface of the substrate 1 or the reflective layer 3 is set to 35 ° to 70 °, it becomes easy to stably and efficiently form the inner surface of the through hole by punching. At the same time, the substrate 1 can be easily miniaturized. Further, the light emitted from the light emitting element 5 can be reflected to a wider outside.

  The first mounting portion 1a may be located above the lower end of the second reflective layer 3a formed on the inner surface of the side wall portion 8. In this case, the light emitted downward from the light emitting element 5 around the light emitting element 5 is reflected by the second reflective layer 3a and emitted to the outside.

  When the wiring conductor 4 is disposed on the lower surface of the substrate 1 as a deformation preventing layer 10 in a region overlapping the boundary between the first mounting portion 1a and the recess 2 in plan view, as shown in the example shown in FIG. It is only necessary that the wiring conductor 4 disposed on the lower surface of the substrate is disposed from a region overlapping the first mounting portion 1a to a region overlapping the recess 2 in plan view.

  Further, as in the example shown in FIG. 7, the deformation prevention layer 10 is formed on the lower surface of the substrate 1 from a region overlapping the first mounting portion 1 a in a plan view to a region serving as a boundary between the first mounting portion 1 a and the recess 2. It may be formed. Since the deformation preventing layer 10 is disposed so as to overlap the first mounting region 1a, it is effective for releasing the heat generated in the light emitting element 5 to the external circuit board. The deformation prevention layer 10 may be formed of the same material as that of the wiring conductor 4, but a material having a higher thermal conductivity than the substrate 1, for example, a metal material such as copper or copper-tungsten, A ceramic material having a higher thermal conductivity than 1b is preferred. With such a configuration, when the light emitting element 5 that generates a large amount of heat is mounted to form a light emitting device, it is possible to suppress a decrease in light emission efficiency due to heat.

  Further, when the light emitting element mounting substrate and the external circuit substrate are electrically connected by the wiring conductor 4 provided on the lower surface side of the light emitting element mounting substrate, as shown in the example shown in FIG. If the thickness of the prevention layer 10 is made larger than the thickness of the wiring conductor 4 provided on the lower surface of the substrate 1, the deformation prevention layer 10 can be in good contact with the external circuit board.

  As shown in the example shown in FIG. 8, the light-emitting device of the present invention includes a light-emitting element mounting substrate having the above configuration, a light-emitting element 5 mounted on the first mounting portion 1 a, and a light-transmissive member 11 that covers the light-emitting element 5. It is equipped with. With the above structure, a light-emitting device with excellent luminance can be obtained.

  The light emitting element 5 is a light emitting diode (LED) or a semiconductor laser (LD). For example, the first mounting portion is made of a conductive bonding material such as a brazing material made of an Au-silicon (Si) alloy or an epoxy resin containing silver (Ag). 1a is fixed on one wiring conductor 4 on the bottom surface, and the electrode of the light emitting element 5 and the other wiring conductor 4 are electrically connected to each other through a connecting member such as a bonding wire mainly composed of Au. Is done. In the case of the flip-chip type light emitting element 5, the bumps made of metal such as solder or gold connected to the electrodes of the light emitting element 5 are heated and melted or ultrasonic vibration is applied. Alternatively, it is connected to the wiring conductor 4 via solder or a conductive adhesive.

  And by providing the translucent member 11 so that the light emitting element 5 may be covered, it can be set as the light-emitting device excellent in light-emitting luminance. The translucent member 11 is transparent (having translucency) made of silicon resin, epoxy resin, glass, or the like that seals the light emitting element 5. For example, after a liquid sealing resin is applied so as to cover the light emitting element 5, the sealing resin is cured, so that a light emitting device is provided in which the light emitting element 5 is covered with the sealing resin as the light transmissive member 11. . When the side wall portion 8 is provided along the outer periphery of the substrate 1 as in the example shown in FIG. 7, the sealing resin that is the translucent member 11 may be filled in the region surrounded by the side wall portion 8. Or you may mount the sealing material which is the translucent member 11 shape | molded by the box shape on the board | substrate 1 so that the light emitting element 5 may be covered, and you may fix it with an adhesive agent. When the board | substrate 1 is provided with the side wall part 8, you may make it block | close the space enclosed by the side wall part 8 with the translucent member 11 shape | molded by plate shape. When the translucent member 11 formed in a box shape or a plate shape is used, if a part of the light transmitting member 11 is formed in a lens shape, the light emitted from the light emitting element 5 is condensed by the lens shape portion. Therefore, a light emitting device with higher luminance can be obtained.

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, when a plate-like member having a high reflectance is used as the reflective layer 3, the sealing material 7 may be filled in the recess 2 in order to suppress the peeling of the plate-like member.

  In addition, the light emitting device may have a plurality of light emitting elements 5 and electronic components 6 mounted thereon. For example, a plurality of light emitting elements 5 may be mounted on one first mounting portion 1a, and the recesses 2 are formed around the plurality of first mounting portions 1a in plan view as in the example shown in FIG. It may be. When the light emitting element 5 is mounted on each of the plurality of first mounting portions 1a, the first mounting portion 1a is formed according to the size of the light emitting element 5 to be mounted, so that the reflective layer 3 is formed wider. Therefore, a light-emitting device with higher luminance can be obtained.

  Further, when the recess 2 is formed in a part of the periphery of the first mounting portion 1a, the first mounting portion 1a is made higher than the upper surface of the surrounding substrate 1, and the recess 2 and the first mounting portion are arranged. The reflective layer 3 may be formed so as to cover the upper surface of the substrate 1 around 1a.

DESCRIPTION OF SYMBOLS 1 ... Substrate 1a ... 1st mounting part 2 ... Recess 2a ... 2nd mounting part 3 ... Reflective layer 3a ... 2nd reflective layer 4 ... Wiring conductor 5 ... Light emitting element 6 ... Electronic component 7 ... Sealing material 8 ... Side wall
10 ... Deformation prevention layer
11 ... Translucent member

Claims (7)

  To mount a substrate, a first mounting portion for mounting the light emitting element on the upper surface of the substrate, a recess formed in at least a part of the periphery of the first mounting portion, and an electronic component on the bottom surface of the recess And a second mounting part. A light-emitting element mounting substrate.   The light-emitting element mounting substrate according to claim 1, wherein the concave portion gradually increases from the opening toward the bottom surface.   The electronic component mounted on the second mounting portion, and a reflective layer disposed above the electronic component so as to cover the bottom surface of the concave portion in plan view. Item 3. The light-emitting element mounting substrate according to Item 2.   The light-emitting element mounting substrate according to claim 3, wherein the recess is filled with a sealing material, and the reflective layer is disposed on a surface of the sealing material.   The light emitting element mounting substrate according to claim 3, wherein the reflective layer is positioned on the bottom surface side of the first mounting portion in the thickness direction of the substrate.   The deformation preventing layer is disposed on a lower surface of the substrate in a region overlapping with a boundary between the first mounting portion and the concave portion in plan view. Light-emitting element mounting substrate.   The light-emitting element mounting substrate according to claim 1, the light-emitting element mounted on the first mounting portion, and a transparent sealing material that covers the light-emitting element. A light emitting device characterized by the above.

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