WO2012067203A1 - Substrate for light-emitting element, and light-emitting device - Google Patents

Abstract

Provided are: a substrate for a light-emitting element, said substrate having an electrically insulating bottom surface while minimizing decreases in heat diffusion; and a high-brightness light-emitting device using such a substrate. Said substrate has: a substrate body that comprises an inorganic insulating material and has a mounting surface, which contains a mounting area in which a light-emitting element is mounted, and a non-mounting surface on the side opposite the mounting surface; and a heat dissipator provided inside the substrate body from the mounting surface to the non-mounting surface such that one end reaches the mounting area. Said heat dissipator has an insulating layer that comprises an inorganic material and is disposed, parallel to the surfaces of the substrate so as to cover the entire cross-section of the heat dissipator, at a position such that the thickness-direction distance between said insulating layer and the non-mounting surface is 60% or less of the thickness of the substrate body. The main body of the heat dissipator, said main body being the parts other than the aforementioned insulating layer, comprises a conductor.

Description

Light emitting element substrate and light emitting device

The present invention relates to a light emitting element substrate and a light emitting device using the same.

In recent years, with the increase in luminance of light emitting elements such as light emitting diodes (LEDs), light emitting devices using light emitting elements are used as backlights for mobile phones and large liquid crystal TVs. However, the amount of heat generation increases with the increase in luminance of the light emitting element, and in order to eliminate the decrease in luminance of the light emitting element, the substrate for the light emitting element having high heat dissipation property that quickly diffuses the heat generated from the light emitting element Is required.

Known as a substrate for a light-emitting element having high thermal diffusivity is a structure in which a penetrating metal body composed of a metal having a higher thermal conductivity than an insulating substrate is provided through an insulating substrate made of low-temperature fired ceramics. Yes. It is known that the penetrating metal body has, for example, Cu, Ag, Au or the like as a main component and is larger than the mounting area of the light emitting element (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2006-41230

However, in a high power type light emitting device, a substrate for a light emitting element with higher thermal diffusibility is required from the viewpoint of ensuring the lifetime. In the case of a high-power type light-emitting device, the light-emitting element is likely to be at a high temperature, so that characteristic deterioration such as a decrease in luminance is likely to occur, and the mold resin covering the light-emitting element and the phosphor contained therein are likely to deteriorate. .

In the light emitting device, the distance between the pair of external electrode terminals may be a problem on the back side opposite to the main surface on which the light emitting element is mounted. For example, in a structure in which a one-wire type light emitting element having a pair of element electrodes on the upper part and the lower part is mounted on a through metal body and the through metal body is used not only as a heat dissipation path but also as a conductive path, it is provided on the back side. In some cases, the distance between the pair of external electrode terminals is not sufficient. In particular, when the input power is large as in a high-power type light-emitting device, or when the cross-sectional area of the through metal body is increased to ensure thermal diffusivity, the distance between the external electrode terminals cannot be sufficient. The electrical insulation between them tends to be insufficient. In addition, since the conventional configuration using an external circuit for heat dissipation cannot provide sufficient heat dissipation, it is necessary to provide a heat dissipation fin that provides sufficient heat dissipation by electrically insulating the electric circuit and the heat dissipation structure. I came. For this reason, there is a demand for a light emitting element substrate that can sufficiently ensure electrical insulation on the back surface side while ensuring high thermal diffusivity.

The present invention has been made in order to solve the above-described problem, and in a light emitting element substrate having a heat dissipating body, the electrical insulation on the back side is ensured while suppressing a decrease in thermal diffusivity. It is intended to provide. Another object of the present invention is to provide a light-emitting device using such a light-emitting element substrate and having excellent thermal diffusibility and electrical reliability.

The substrate for a light emitting element of the present invention is made of an inorganic insulating material, and includes a mounting surface including a mounting portion on which the light emitting element is mounted, a substrate body having a non-mounting surface on the surface opposite to the mounting surface, The heat sink has a heat dissipating member provided so that one end reaches the mounting portion from the mounting surface to the non-mounting surface, and the heat dissipating member has a thickness direction distance from the non-mounting surface. The insulating body made of an inorganic material arranged in a surface direction so as to cover the entire cross section of the heat radiating body at a position that is 60% or less of the thickness of the substrate main body, and the main body of the heat radiating body The portion other than the insulating layer is made of a conductor.

In the substrate for a light emitting device of the present invention, the upper surface of the insulating layer is disposed at a position where the distance in the thickness direction from the non-mounting surface of the substrate body is 40% or less of the thickness of the substrate body. Preferably it is. The cross-sectional area of the heat radiating body in the direction orthogonal to the thickness direction of the substrate main body is preferably 0.2 to 16 times the area of the mounting portion of the light emitting element. The thickness of the insulating layer is preferably 10 to 200 μm, particularly preferably 10 to 100 μm.
Unless otherwise specified, “to” indicating the numerical range described above is used to mean that the numerical values described before and after it are used as a lower limit value and an upper limit value, and hereinafter “to” Used with meaning.
The insulating layer can be made of a material mainly composed of glass. The insulating layer can be composed of a sintered body of a glass ceramic composition containing glass powder and ceramic powder. The substrate body is preferably composed of a sintered body of a glass ceramic composition containing glass powder and ceramic powder. Furthermore, it is preferable that the conductor constituting the main body of the heat dissipating body has at least one of Cu, Ag, and Au as a main component. Furthermore, the frame body for accommodating a light emitting element can be provided in the peripheral part by the side of the mounting surface of the said board | substrate body.

Furthermore, the present invention provides a light emitting device comprising the light emitting element substrate of the present invention and a light emitting element mounted on the mounting portion of the light emitting element substrate.

In the light emitting device of the present invention, one electrode of the light emitting element is connected to the first wiring conductor layer formed on the mounting portion of the light emitting element substrate by a conductive adhesive material, and the other electrode is Preferably, the light emitting element substrate is connected to a second wiring conductor layer formed on the mounting surface of the light emitting element substrate so as to be insulated from the first wiring conductor layer by wire bonding.

In the substrate for a light emitting element of the present invention, the radiator provided from the mounting surface to the non-mounting surface of the substrate main body is an intermediate portion in the thickness direction of the main body of the radiator (hereinafter, referred to as a heat dissipation main body) made of a conductor. Since the insulating layer made of an inorganic material is inserted or arranged at the end portion on the non-mounting surface side, insulation between the electrode terminals on the back surface side is ensured. In addition, the distance of the insulating layer in the thickness direction from the non-mounting surface of the substrate body (hereinafter referred to as the distance from the non-mounting surface) is 60% or less of the thickness of the substrate body, and the radiator Since the insulating layer that forms part of the surface is not arranged on the side close to the mounting surface, the increase in thermal resistance due to the intervening insulating layer is suppressed, and the light emission has a sufficiently low thermal resistance and good heat dissipation An element substrate is obtained.

In addition, by using the light emitting element substrate having a high thermal diffusivity in this way, a light emitting device with high luminance can be obtained with less luminance deterioration of the light emitting element.

It is sectional drawing which shows one Embodiment of the board | substrate for light emitting elements of this invention. It is sectional drawing which shows one Embodiment of the light-emitting device of this invention. It is a graph which shows the result of having calculated | required the value of the thermal resistance of the board | substrate for light emitting elements by which the insulating layer which comprises a part of heat radiator is comprised from glass material by numerical analysis. It is sectional drawing which shows another embodiment of the board | substrate for light emitting elements of this invention. It is a graph which shows the result of having calculated | required the thermal resistance value by the numerical analysis about the board | substrate for light emitting elements comprised by changing the ratio of the distance from the non-mounting surface of the board | substrate body with respect to the thickness of a board | substrate body. It is a graph which shows the result of having calculated | required the thermal resistance value by the numerical analysis about the board | substrate for light emitting elements comprised changing the ratio of the cross-sectional area of the heat radiator with respect to the bottom area of a light emitting element.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto.

A substrate for a light emitting device of the present invention includes a mounting surface including a mounting portion on which the light emitting device is mounted, a substrate body made of an inorganic insulating material having a non-mounting surface on the surface opposite to the mounting surface, and the substrate body. And a heat dissipating body provided in a thickness direction from the mounting surface of the light emitting element to the non-mounting surface and with one end portion reaching the mounting portion.

And this heat radiator was arrange | positioned in the surface direction of the board | substrate body over the whole cross section of the said heat radiator in the position from which the distance from the non-mounting surface of a board | substrate body will be 60% or less of the thickness of a board | substrate body. It has an insulating layer, and the remaining part other than this insulating layer is a heat radiating body constituted by a conductor. That is, a heat radiating body is constituted by a heat radiating body made of a conductor and an insulating layer disposed at the predetermined position. In addition, the cross section of a heat radiator means a cross section perpendicular | vertical to the thickness direction of a board | substrate body, and the surface direction of a board | substrate body means a direction perpendicular | vertical to a thickness direction.

The standard of the distance from the non-mounting surface of the substrate body in the insulating layer is, for example, the lower surface of the insulating layer, but may be the upper surface of the insulating layer. The position of the upper surface of the insulating layer can be said to be the position of the lower surface of the heat radiating main body (hereinafter referred to as the mounting surface side heat radiating main body) whose end is in contact with the mounting portion. However, the length of the heat radiating body and the thickness of the insulating layer in contact with the lower surface of the heat radiating body are adjusted so that the thickness is 60% or less of the thickness of the substrate body.

When the reference of the distance from the non-mounting surface of the substrate body in the insulating layer is the lower surface of the insulating layer, the value of 60% or less includes 0%. In that case, the lower surface of the insulating layer is exposed to the non-mounting surface. Including this position, and as described above, the distance from the non-mounting surface is 60% or less of the thickness of the substrate body, including the case where the reference of the distance from the non-mounting surface is the upper surface of the insulating layer. The position of the insulating layer may be indicated as an intermediate portion in the thickness direction.
In the present invention, the distance of the insulating layer in the thickness direction from the non-mounting surface of the substrate body may be based on the lower surface of the insulating layer as described above, or may be the upper surface of the insulating layer. This case is also included.

In the light emitting element substrate of the present invention, the heat dissipation body made of a conductor is divided by an insulating layer made of an inorganic material having a lower thermal conductivity than the conductor, but this insulating layer is separated from the non-mounting surface of the substrate body. Is located at a position where the distance of the substrate body is 60% or less of the entire thickness of the substrate body, so that the increase in thermal resistance due to the interposition of the insulating layer is suppressed, and the heat radiator composed of the heat radiating body and the insulating layer is A light-emitting element substrate having sufficiently low thermal resistance and good heat dissipation is obtained.

熱 Thermal resistance is proportional to the length of the heat dissipation path through which heat is transmitted, and inversely proportional to the cross-sectional area and thermal conductivity. The temperature rise increases in proportion to the size of the heat flux concentrated on the thermal resistance. Therefore, in order to avoid the temperature rise of the semiconductor element, that is, to lower the thermal resistance of the entire system including the substrate, it has a high thermal resistance. It is necessary not to concentrate the heat flux on the part. In the structure assumed by the present invention, it is necessary not to concentrate the heat flux on the insulator layer having a low thermal conductivity and a high heat resistance as a heat dissipation path, so that the diffusion due to the heat conduction is insufficient and the heat flux is concentrated. Arranging the insulating layer further away from the region immediately below the semiconductor element is considered significant in terms of suppressing thermal resistance.

In the present invention, the insulating layer that forms part of the heat sink together with the heat dissipation body is disposed at a position where the distance from the non-mounting surface of the substrate body is 60% or less of the entire thickness of the substrate body. The heat from the element is first conducted to a heat radiating body made of a conductor arranged so as to be in contact with the mounting portion, and a heat radiating body having a certain length (more specifically, 40% of the thickness of the board main body) or more. Conducts and reaches the insulating layer. In the structure in which the insulating layer is disposed at such a position, heat is conducted not only in the thickness direction but also in the lateral direction (plane direction) in the process of heat propagation in the heat radiating body. The heat flux concentrated on the insulating layer having a low rate can be reduced, and an increase in thermal resistance due to the arrangement of the insulating layer can be sufficiently suppressed.

Hereinafter, an embodiment of a light emitting element substrate of the present invention will be described with reference to the drawings. Although this embodiment shows an example of a light emitting element substrate applied to mount a 1 wire type light emitting element, the present invention is not limited to this.

FIG. 1 is a cross-sectional view of a light-emitting element substrate of the present invention. The light emitting element substrate 10 has a substantially flat substrate body 1. In addition, in this specification, substantially flat form means flat form on a visual level. The substrate body 1 is made of an inorganic insulating material, and a frame 2 is formed on the peripheral edge of the upper surface. A cavity is formed by the frame body 2, and the bottom surface of the cavity is a mounting surface 1 a on which a light emitting element is mounted, and the surface opposite to the mounting surface 1 a of the substrate body 1 is a non-mounting surface 1 b. It has become.

Examples of the inorganic insulating material constituting the substrate body 1 include an aluminum oxide sintered body (alumina ceramic), an aluminum nitride sintered body, a mullite sintered body, and a glass ceramic composition containing glass powder and ceramic powder. Examples thereof include LTCC (Low Temperature Co-fired Ceramics). In the present invention, LTCC is preferable from the viewpoints of high reflectivity, ease of production, easy processability, economy, and the like.

In the present invention, the shape, thickness, size and the like of the substrate body 1 are not particularly limited, and can be changed according to the design of the light emitting device, such as the number of light emitting elements to be mounted and the arrangement method. Moreover, the raw material composition of LTCC which comprises the substrate main body 1, sintering conditions, etc. are demonstrated in the manufacturing method of the board | substrate 10 for light emitting elements mentioned later. The substrate body 1 preferably has a bending strength of, for example, 250 MPa or more from the viewpoint of suppressing damage or the like when the light emitting element is mounted or after use.

A wiring conductor layer 3 electrically connected to the light emitting element is provided on the mounting surface 1 a of the substrate body 1. The wiring conductor layer 3 includes an anode-side or cathode-side first wiring conductor layer 3a formed so as to be connected to the light-emitting element mounting portion and the vicinity thereof, and a first portion disposed on the periphery of the mounting surface 1a. And the second wiring conductor layer 3b opposite to the wiring conductor layer 3a.

In the present embodiment, the constituent material of the wiring conductor layer 3 is not particularly limited as long as it is the same as the wiring conductor layer used for a normal light emitting element substrate. Specifically, it will be described in the manufacturing method described later. The thickness of the wiring conductor layer 3 (that is, the thickness of each of the first wiring conductor layer 3a and the second wiring conductor layer 3b) is preferably 5 to 50 μm.

The other surface of the substrate body 1 is a non-mounting surface 1b on which no light emitting element is mounted, and external electrode terminals 4 on the anode side and the cathode side are provided on the non-mounting surface 1b. The external electrode terminal 4 has a first external electrode terminal 4a and a second external electrode terminal 4b. These external electrode terminals 4 are connected to the wiring conductor layers 3 formed on the mounting surface 1a of the substrate body 1 through the connection vias 5 formed inside the substrate body 1, respectively (corresponding first wiring conductor layers respectively). 3a and the second wiring conductor layer 3b).

The shape and constituent materials of the external electrode terminal 4 and the connection via 5 can be used without particular limitation as long as they are the same as those used for the substrate for a light emitting element. These will be specifically described in the substrate manufacturing method described later.

In the present embodiment, the radiator 6 is provided in the substrate body 1 along the thickness direction from the mounting surface 1a to the non-mounting surface 1b. The heat dissipating body 6 has an upper end in contact with the first wiring conductor layer 3 a formed on the mounting surface of the light emitting element, and a lower end reaching a predetermined position such as an intermediate portion in the thickness direction of the substrate body 1. A first heat dissipating body 7a disposed on the lower end of the first heat dissipating body 7a so as to cover the entire cross section, and the insulating layer 8 sandwiched between the first heat dissipating body 7a. It consists of the 2nd thermal radiation main body 7b arrange | positioned coaxially so that it may continue under the 1 thermal radiation main body 7a. In the embodiment of FIG. 1, the lower end portion of the second heat radiating body 7 b reaches the non-mounting surface 1 b of the substrate body 1. Hereinafter, the first heat radiating body 7a and the second heat radiating body 7b are collectively referred to as a heat radiating body 7.

The cross-sectional areas of the first heat radiating body 7a and the second heat radiating body 7b may be smaller, larger or equal to the area of the light emitting element mounting portion. It is preferably larger than the area of the part. The larger the cross-sectional area of these heat dissipating bodies 7a and 7b, the more effective it is to suppress the thermal resistance and enhance the heat dissipating property. There is a demerit that the cost increases when the value is increased. In view of the balance between required heat dissipation performance and cost, it is preferable that the cross-sectional area of the heat dissipating bodies 7a and 7b is 0.2 to 16 times the area of the light emitting element mounting portion, and 1.0 to 4 0.0 times is more preferable, and 1.4 to 4.0 times is particularly preferable. The cross-sectional area of the heat radiating bodies 7a and 7b refers to the area of a cross section perpendicular to the thickness direction of the substrate body. The area of the mounting portion on which the light emitting element is mounted corresponds to the bottom area of the light emitting element (the area of the mounting surface of the light emitting element mounted on the mounting surface).
Moreover, in the site | part of the thermal radiation main body 7, when the cross-sectional area is the same shape regarding thickness direction (for example, column shape, prismatic shape, etc.), the cross-sectional area of any site | part of the thickness direction of the thermal radiation main body 7 may be sufficient. However, when the cross-sectional area of the heat radiating body 7 defined in the horizontal direction in plan view changes in the thickness direction of the substrate (for example, a truncated cone shape or a truncated pyramid shape), The smallest cross-sectional area is the target.

Moreover, it is preferable that the first and second heat dissipating bodies 7a and 7b have the same cross-sectional area. As a constituent material of these heat radiating bodies 7a and 7b, any material can be used without particular limitation as long as it is the same as that used for a thermal via of a substrate for a light emitting element. This will be specifically described in the substrate manufacturing method described later.

The insulating layer 8 disposed in the middle portion in the thickness direction of the heat radiating body 6 has a distance L2 from the non-mounting surface 1b of the substrate body 1 on the lower surface thereof to 60% or less of the thickness L1 of the substrate body 1. It is provided in the position. More specifically, when the thickness L1 of the substrate body 1 is 500 μm, the insulating layer 8 is provided so that the lower surface is located at a position where the distance L2 from the non-mounting surface 1b is 0 to 300 μm. When the distance L2 of the lower surface of the insulating layer 8 from the non-mounting surface 1b of the substrate body exceeds 60% of the thickness L1 of the substrate body 1, the heat resistance of the entire radiator 6 is increased and sufficient heat dissipation is achieved. It becomes difficult to obtain. In addition, when the thickness L3 of the first heat radiating body 7a is at least 40% of the thickness L1 of the substrate body 1, the heat dissipation is further improved and sufficient heat dissipation is obtained. When L2 is 0% of L1, the insulating layer 8 is arranged in contact with the lower end of the first heat radiating body 7a, and the insulating layer 8 is flush with the non-mounting surface 1b. The second heat radiating body 7b does not exist. This is also an embodiment of the present invention. The thickness L1 of the substrate body 1 is not particularly limited, but is usually about 200 to 500 μm. The substrate body 1 preferably has a substantially uniform thickness, but may have a non-uniform thickness.

The thickness of the insulating layer 8 is 10 to 200 μm, particularly preferably 10 to 100 μm. If the thickness is less than 10 μm, the effect of ensuring insulation by providing the insulating layer 8 cannot be sufficiently obtained. When the thickness exceeds 100 μm, the heat resistance of the heat radiating body 6 becomes too large, and it becomes difficult to obtain sufficient heat dissipation. The insulating layer 8 preferably has a substantially uniform thickness, but may have a non-uniform thickness.

The insulating layer 8 can be made of a material mainly composed of glass (hereinafter referred to as a glass material). Moreover, the insulating layer 8 can also be comprised by the sintered compact (LTCC) of the glass-ceramics composition containing glass powder and ceramic powder similarly to the board | substrate body 1. FIG. The raw material composition, sintering conditions, and the like of LTCC constituting the insulating layer 8 will be described in a method for manufacturing a light emitting element substrate described later.

The glass material which comprises the insulating layer 8 is demonstrated below. Glass material constituting the insulating layer 8 are those containing glass be at least _{SiO 2,} B 2 _{O 3,} where and Na ₂ O and _K at least one kind of component selected from ₂ O.

Further, this glass material can contain ceramic powder in a proportion of 10% by mass or less. The content of the ceramic powder is preferably 3% by mass or more. By containing ceramic powder, the strength of the insulating layer 8 may be increased. Further, from the viewpoint of chemical resistance such as acid resistance, the glass material preferably contains silica powder or alumina powder as ceramic powder.

When the glass material contains at least one selected from silica powder, alumina powder, zirconia powder, and titania powder, the average particle size D ₅₀ (hereinafter, simply referred to as D ₅₀ may be described as the powder). .) Is 2.5 μm or less, more preferably 0.5 μm or less, it is possible to improve the printability and to flatten the end of the insulating layer 8 to suppress the undulation of the layer surface. Note that D ₅₀ is a value obtained by a particle size measuring apparatus using a laser diffraction / scattering method.

The content of the ceramic powder in the glass material can be set by the particle size. When D ₅₀ is 1 to 2.5 μm, the content is preferably 3 to 10% by mass. 8 mass% or less is preferable and 5 mass% or less is more preferable. When D ₅₀ is less than 1 μm, the content is preferably 3 to 5% by mass. When the ceramic powder is contained exceeding the above upper limit, the fluidity of the glass material is deteriorated, and not only the flatness of the insulating layer 8 is deteriorated but also the sintering is likely to be insufficient.

The glass constituting the insulating layer is expressed by mol% on the basis of oxide, SiO ₂ 62-84%, B ₂ O ₃ 10-25%, Al ₂ O ₃ 0-5%, Na ₂ O and K _At least one selected from ₂ O is contained in a total of 1 to 5%, the total content of SiO ₂ and Al ₂ O ₃ is 62 to 84%, MgO is selected from 0 to 10%, CaO, SrO, BaO In the case of containing at least one selected from the above, a product obtained by firing a borosilicate glass powder whose total content is 5% or less is preferable.

Each component of such glass will be described. In the following, unless otherwise specified, the composition is simply expressed as% in terms of mol% based on oxide.

SiO ₂ is a glass network former, a component that increases chemical durability, particularly acid resistance, and is essential. If it is less than 62%, the acid resistance may be insufficient. If it exceeds 84%, the glass melting temperature tends to be high, or the glass transition point (Tg) tends to be too high.

B ₂ O ₃ is a glass network former and is essential. If it is less than 10%, the glass melting temperature tends to be high, and the glass may become unstable. Preferably it is 12% or more. If it exceeds 25%, not only is it difficult to obtain stable glass, but chemical durability may be reduced.

Al ₂ O ₃ is not essential, but may be contained in a range of 5% or less in order to enhance the stability or chemical durability of the glass. If it exceeds 5%, the transparency of the glass may decrease.

The total content of SiO ₂ and Al ₂ O ₃ is 62 to 84%. If it is less than 62%, chemical durability may be insufficient. If it exceeds 84%, the glass melting temperature becomes high, or Tg becomes too high.

Na ₂ O and K ₂ O are components that lower Tg, and at least one of them is essential. It can contain up to 5% in total. If it exceeds 5%, chemical durability, particularly acid resistance, may deteriorate. Moreover, there exists a possibility that the electrical insulation of a sintered compact may fall. Na ₂ O, and containing any one or more of _{K 2 O,} Na 2 O, it is preferable that the total content of _{K 2} O is not less than 1%.

MgO is not essential, but may be contained up to 10% in order to lower Tg or stabilize the glass. Preferably it is 8% or less.

CaO, SrO, and BaO are not essential, but may be contained up to 5% in total in order to lower the melting temperature of the glass or stabilize the glass. If it exceeds 5%, the acid resistance may decrease.

The glass constituting the insulating layer of the present invention consists essentially of the above components, but may contain other components as long as the object of the present invention is not impaired. When such components are contained, the total content of these components is preferably 10% or less. However, lead oxide is not contained.

The insulating layer 8 of the present invention is preferably formed by firing a composition formed by mixing such a borosilicate glass powder composed of each component and, if necessary, the ceramic powder. A mixed powder of a borosilicate glass powder having a composition and the ceramic powder is formed into a paste, screen-printed, and fired. However, the method is not particularly limited as long as the insulating layer 8 having a predetermined thickness can be formed at a position within a predetermined range of the distance from the non-mounting surface 1b in the substrate body 1.

As mentioned above, although an example was given and demonstrated about embodiment of the light emitting element use substrate 1 of this invention, the light emitting element use substrate of this invention is not limited to this. As long as it is not contrary to the gist of the present invention, the configuration can be changed as necessary.

In the manufacture of the light emitting element substrate 10 of the present invention configured as described above, materials and manufacturing methods normally used for the LTCC substrate for mounting the light emitting element can be applied. Further, the light emitting device of the present invention to be described later can also be produced by an ordinary method using ordinary members except that the light emitting element substrate 10 of the present invention is used.

In the following, among the substrates shown in FIG. 1 for mounting a one-wire type light emitting element, the substrate body 1 is composed of LTCC, and the insulating layer 8 constituting a part of the radiator 6 is composed of a glass material. The method for manufacturing the substrate 10 for light emitting device of the present invention will be described by taking as an example the method for manufacturing the substrate to be manufactured.

1 can be manufactured by a manufacturing method including the following steps (A) to (E). More specifically, the following steps (A) to (E) are preferably carried out in this order to produce the light emitting element substrate according to the present invention. In the following description, the members used for the manufacture will be described with the same reference numerals as those of the finished product. For example, the heat dissipating body and the conductor paste layer for the heat dissipating body are represented by the same 7 (or 7a, 7b) code, and the insulating layer and the unfired insulating layer are represented by the same 8 code. The other is the same.

(A) Green sheet manufacturing process for main body A plurality of green sheets (hereinafter referred to as green for main body) for forming the substrate main body 1 of the substrate 10 for light emitting element using a glass ceramic composition containing glass powder and ceramic powder. (Also referred to as a sheet). The main body green sheet includes an upper layer green sheet, an inner layer green sheet, and a lower layer green sheet. In this step, a green sheet for a frame is also produced in order to form a frame.

(B) Conductive paste layer forming step A conductive paste layer is formed at a predetermined position of each main body green sheet, and the unfired wiring conductor layer 3, the unfired external electrode terminal 4, the unfired connection via 5, and the unfired heat dissipation body 7a. , 7b, etc., respectively.

(C) Glass paste layer formation process The glass paste layer which consists of glass materials is formed in the predetermined position of the green sheet for inner layers, and the unbaking insulating layer 8 is formed.

(D) Laminating Step A plurality of uncoated sheets obtained by forming a conductive paste layer (in this example, a glass paste layer is further formed in the inner layer green sheet) on the surface or inside of the main body green sheet. A fired main body member (hereinafter sometimes referred to as a green sheet with a conductive paste layer and a green sheet with a glass paste layer) and the like are stacked and integrated by thermocompression to obtain an unfired substrate.

(E) Firing step The unfired substrate is fired at 800 to 930 ° C.

Hereinafter, each process will be further described.

(A) Green sheet manufacturing process for main body The green sheet for main body is made of glass ceramic composition (for example, LTCC composition) containing glass powder and ceramic powder, binder, plasticizer, dispersant, solvent, etc. if necessary. Is added to the slurry to prepare a slurry, which is formed into a sheet by a doctor blade method or the like and dried. Moreover, the green sheet for a frame is produced by processing the green sheet thus produced into a predetermined shape.

Glass powder in a glass ceramic composition used for producing a green sheet for a main body (hereinafter, this glass powder is also referred to as glass powder for main body) having a glass transition point (Tg) of 550 ° C. or higher and 700 ° C. or lower. Is preferred. When Tg is less than 550 ° C., degreasing may be difficult, and when it exceeds 700 ° C., the shrinkage start temperature becomes high and the dimensional accuracy may be lowered.

Further, it is preferable that the glass powder is one in which crystals are precipitated when fired at 800 ° C. or higher and 930 ° C. or lower. In the case where crystals do not precipitate, there is a possibility that sufficient mechanical strength cannot be obtained. Furthermore, the thing whose crystallization peak temperature (Tc) measured by DTA (differential thermal analysis) is 880 degrees C or less is preferable. When Tc exceeds 880 ° C., the dimensional accuracy may be reduced.

As such glass powder for main body, SiO ₂ is 57 to 65%, B ₂ O ₃ is 13 to 18%, CaO is 9 to 23%, Al ₂ O ₃ is 3% in terms of mol% based on oxide. Those containing at least one selected from K ₂ O and Na ₂ O in a total of 0.5 to 6% are preferable. By using such a thing, it becomes easy to improve the surface flatness of the substrate body 1.

Here, SiO ₂ serves as a glass network former. When the content of SiO ₂ is less than 57%, it is difficult to obtain a stable glass and the chemical durability may be lowered. On the other hand, when the content of SiO ₂ exceeds 65%, the glass melting temperature and Tg may be excessively increased. The content of SiO ₂ is preferably 58% or more, more preferably 59% or more, and particularly preferably 60% or more. Further, the content of SiO ₂ is preferably 64% or less, more preferably 63% or less.

B ₂ O ₃ is a glass network former. If the content of B ₂ O ₃ is less than 13%, there is a possibility that the glass melting temperature or Tg may be too high. On the other hand, when the content of B ₂ O ₃ exceeds 18%, it is difficult to obtain a stable glass, and the chemical durability may be lowered. The content of B ₂ O ₃ is preferably 14% or more, more preferably 15% or more. Further, the content of B ₂ O ₃ is preferably 17% or less, more preferably 16% or less.

Al ₂ O ₃ is added to increase the stability, chemical durability, and strength of the glass. If the content of Al ₂ O ₃ is less than 3%, the glass may become unstable. On the other hand, when the content of Al ₂ O ₃ exceeds 8%, the glass melting temperature and Tg may be excessively high. The content of Al ₂ O ₃ is preferably 4% or more, more preferably 5% or more. Further, the content of Al ₂ O ₃ is preferably 7% or less, more preferably 6% or less.

CaO is added to increase glass stability and crystal precipitation, and to lower the glass melting temperature and Tg. When the content of CaO is less than 9%, the glass melting temperature may be excessively high. On the other hand, when the content of CaO exceeds 23%, the glass may become unstable. The content of CaO is preferably 12% or more, more preferably 13% or more, and particularly preferably 14% or more. Further, the content of CaO is preferably 22% or less, more preferably 21% or less, and particularly preferably 20% or less.

K ₂ O and Na ₂ O are added to lower Tg. When the total content of K ₂ O and Na ₂ O is less than 0.5%, the glass melting temperature and Tg may be excessively high. On the other hand, when the total content of K ₂ O and Na ₂ O exceeds 6%, chemical durability, particularly acid resistance may be lowered, and electrical insulation may be lowered. The total content of K ₂ O and Na ₂ O is preferably 0.8% or more and 5% or less.

In addition, the glass powder for main bodies is not necessarily limited to what consists only of the said component, Other components can be contained in the range with which various characteristics, such as Tg, are satisfy | filled. When other components are contained, the total content is preferably 10% or less.

The glass powder for main body is obtained by blending and mixing each glass raw material so as to become a glass having the above composition, producing by a melting method, and pulverizing by a dry pulverization method or a wet pulverization method. In the case of the wet pulverization method, it is preferable to use water or ethyl alcohol as a solvent. Examples of the pulverizer include a roll mill, a ball mill, and a jet mill.

The 50% particle size (D ₅₀ ) of the glass powder for main body is preferably 0.5 μm or more and 2 μm or less. If D ₅₀ of the glass powder is less than 0.5 [mu] m, handling the glass powder is likely to agglomerate are not only difficult, uniform dispersion becomes difficult. On the other hand, if the D ₅₀ of the glass powder exceeds 2μm, there is a possibility that increase and insufficient sintering of the glass softening temperature is generated. The particle diameter may be adjusted by classification as necessary after pulverization, for example.

As the ceramic powder, those conventionally used for the production of LTCC substrates can be used. For example, alumina powder, zirconia powder, or a mixture of alumina powder and zirconia powder can be suitably used. In particular, it is preferable to use a ceramic powder (hereinafter referred to as a high refractive index ceramic powder) having a higher refractive index than alumina together with the alumina powder.

The high refractive index ceramic powder is a component for improving the reflectance of the substrate that is a sintered body, and examples thereof include titania powder, zirconia powder, and stabilized zirconia powder. While the refractive index of alumina is about 1.8, the refractive index of titania is about 2.7 and the refractive index of zirconia is about 2.2, which is higher than that of alumina. . D ₅₀ of these ceramic powders is preferably 0.5 μm or more and 4 μm or less.

By mixing and mixing such glass powder and ceramic powder such that the glass powder is 30% by mass to 50% by mass and the ceramic powder is 50% by mass to 70% by mass, the glass ceramic composition is mixed. Things are obtained. In addition, a slurry can be obtained by adding a binder and, if necessary, a plasticizer, a dispersant, a solvent, and the like to the glass ceramic composition.

As the binder, for example, polyvinyl butyral, acrylic resin or the like can be suitably used. As the plasticizer, for example, dibutyl phthalate, dioctyl phthalate, butyl benzyl phthalate and the like can be used. As the solvent, organic solvents such as toluene, xylene, 2-propanol and 2-butanol can be preferably used.

The slurry thus obtained is formed into a sheet by a doctor blade method or the like and dried to produce a plurality of green sheets for the main body (upper layer green sheet, lower layer green sheet and inner layer green sheet). . In addition, a green sheet for a frame is manufactured by processing the green sheet manufactured in the same manner into a predetermined shape. Further, a small-diameter through hole for forming a connection via and a large-diameter through hole for forming a heat dissipating main body are formed at predetermined positions of the green sheet for main body using a punching machine or the like.

(B) Conductive paste layer formation process The conductive paste layer for forming the wiring conductor layer 3 and the external electrode terminal 4 is formed in the predetermined position on the green sheet for main bodies produced at the said process. Also, a conductor for filling the inside of the through hole for forming the connection via formed in the green sheet for the main body and the through hole for forming the heat radiating main body to form the connection via 5 and the heat radiating main bodies 7a and 7b A paste layer is formed.

Formation of conductor paste layers 3a and 3b for first and second wiring conductor layers, conductor paste layer 5 for connection vias, conductor paste layers 7a and 7b for heat radiation bodies, and conductor paste layer 4 for external electrode terminals Examples of the method include a method of applying and filling a conductive paste by screen printing. The film thicknesses of the conductor paste layers 3a and 3b for the first and second wiring conductor layers and the conductor paste layer 4 for the external electrode terminals are adjusted so that the finally obtained film thickness becomes a predetermined film thickness. It is preferable.

As the conductive paste, for example, a metal powder mainly composed of copper (Cu), silver (Ag), gold (Au) or the like is added to a vehicle such as ethyl cellulose, and a solvent or the like is added to make a paste. Things can be used. As the metal powder, silver powder, metal powder composed of silver and platinum, or metal powder composed of silver and palladium are preferably used.

(C) Glass paste layer forming step for insulating layer For insulating layer so that this layer is completely covered on either or both of conductor paste layers 7a and 7b for heat dissipation body of inner layer green sheet The glass paste layer 8 is formed by screen printing.

A glass paste for an insulating layer is a paste obtained by adding a vehicle such as ethyl cellulose and, if necessary, a solvent, etc. to a composition obtained by mixing the glass powder for an insulating layer and the ceramic powder as necessary. What was made into a shape can be used. The film thickness of the insulating layer glass paste layer 8 to be formed is adjusted so that the finally obtained insulating layer 8 has a thickness of 10 to 200 μm, more preferably 10 to 100 μm.

(D) Laminating step The green sheet with a conductive paste layer obtained in the step (B) and the green sheet with a glass paste layer obtained in the step (C) are superposed in a predetermined order, and this upper layer green sheet A green sheet for a frame body is further stacked on the substrate, and then integrated by thermocompression bonding. In this way, the unfired substrate 10 is obtained.

(E) Firing process About the unbaked board | substrate 10 obtained at the said process, after degreasing | defatting a binder etc. as needed, the baking for sintering a glass ceramic composition etc. is performed and it is set as the board | substrate 10 for light emitting elements.

Degreasing is performed, for example, under the condition of holding at a temperature of 500 ° C. to 600 ° C. for 1 hour to 10 hours. When the degreasing temperature is less than 500 ° C. or the degreasing time is less than 1 hour, the binder or the like may not be sufficiently removed. On the other hand, if the degreasing temperature is about 600 ° C. and the degreasing time is about 10 hours, the binder and the like can be sufficiently removed, and if it exceeds this, productivity and the like may be lowered.

Calcination is performed by appropriately adjusting the time in a temperature range of 800 ° C. to 930 ° C. in consideration of obtaining a dense structure of the base body 1 and productivity. Specifically, it is preferable to hold at a temperature of 850 ° C. or more and 900 ° C. or less for 20 minutes or more and 60 minutes or less, and a temperature of 860 ° C. or more and 880 ° C. or less is particularly preferable. If the firing temperature is less than 800 ° C., the base body 1 may not be obtained as a dense structure. On the other hand, if the firing temperature exceeds 930 ° C., the productivity may be lowered, for example, the base body 1 may be deformed. Further, when a metal paste containing a metal powder containing silver as a main component is used as the conductor paste, if the firing temperature exceeds 880 ° C., there is a risk that the predetermined shape cannot be maintained due to excessive softening. .

In this way, the light emitting element substrate 10 is obtained. After firing, Ni / gold plating (Ni) is applied so as to cover the surfaces of the wiring conductor layers 3a and 3b exposed on the mounting surface 1a of the substrate body 1 as necessary. It is also possible to dispose a conductive protective film used for conductor protection in the substrate 10 for a normal light emitting device, such as plating having a two-layer structure of plating and Au plating.

The manufacturing method of the light emitting element substrate 10 in which the insulating layer 8 that constitutes a part of the radiator 6 is made of a glass material has been described. However, when the substrate in which the insulating layer 8 is made of LTCC is manufactured. Uses a green sheet made of LTCC having no holes at the position where the insulating layer 8 is disposed, and (D) the laminating step and then (E) the firing step are performed in the same manner as described above.

In the manufacturing method of the light emitting element substrate 10 described above, the frame green sheet need not be a single green sheet, and may be a laminate of a plurality of green sheets. Further, the number of main body green sheets excluding the frame green sheet is not limited. Furthermore, the order of forming each part can be changed as appropriate as long as the light emitting element substrate 10 can be manufactured.

Next, a preferred embodiment of a light emitting device having the light emitting device substrate 10 of the present invention will be described with reference to the drawings. However, the light emitting device of the present invention is not limited to this. FIG. 2 is a cross-sectional view showing an embodiment of the light emitting device of the present invention.

The light-emitting device 20 of the present invention includes the above-described light-emitting element substrate 10 of the present invention and a one-wire type light-emitting element (for example, an LED element) 11 mounted on the mounting portion of the light-emitting element substrate 10. . The light emitting element 11 is fixed to the mounting portion of the substrate body 1 using a conductive die bond material 12 containing a conductive material such as silver, and the anode side of the lower surface of the light emitting element 11 or the The cathode-side first electrode 11a is electrically connected to the first wiring conductor layer 3a. The second electrode 11b on the upper surface of the light emitting element 11 on the cathode side or the anode side is connected to the second wiring conductor layer 3b by the bonding wire 13. Further, a sealing layer 14 made of mold resin is provided so as to cover these light emitting elements 11 and bonding wires 13. The sealing layer 14 can contain a phosphor.

According to the light-emitting device 20 of the present invention, since the light-emitting element substrate 10 having a sufficiently low thermal resistance and good heat dissipation is used, the luminance of the light-emitting element 11 is less deteriorated and high emission luminance is obtained. It is done. Such a light emitting device 20 can be suitably used as, for example, a backlight such as a mobile phone or a large liquid crystal display, illumination for automobiles or decoration, and other light sources.

Next, examples of the present invention will be described. The present invention is not limited to these examples.

A 1-wire type LED element (size length 0.6 mm, width 0.6 mm, thickness 0.1 mm) is mounted on the mounting portion of the light emitting element substrate 10 shown in FIG. Assuming an evaluation model fixed to the first wiring conductor layer 3a, the thermal resistance of this evaluation model was obtained by numerical analysis. As an analysis program, ANSYS ICEPAK Version 12.1.6 was used, and the input power was 1.0 W. The substrate body 1 was made of LTCC and had a thickness of 500 μm. Further, the insulating layer 8 constituting a part of the radiator 6 is a glass layer or LTCC layer shown below, and the thickness d of the insulating layer 8 and the lower surface of the insulating layer 8 from the non-mounting surface 1b of the substrate body 1 The analysis was performed by changing the distance L2 as shown in Table 1. The analysis results are shown in Tables 1 and 2. Moreover, the analysis result shown in Table 1 is shown with the graph of FIG.

In Tables 1 and 2, Examples 1 to 9 and Examples 13 and 14 are evaluation models corresponding to examples of the present invention, and Examples 10 to 12 and Example 15 are evaluation models corresponding to comparative examples. Relative thermal resistance value is a relative value when a thermal resistance value obtained by analyzing in a similar manner for a model constituted by only a conductor layer without providing the insulating layer 8 on the radiator 6 is a reference (1.00). It is. The relative thermal resistance value means that the smaller the numerical value, the better the thermal diffusivity. Table 3 shows physical property values (thermal conductivity) of each component of the evaluation model used for the analysis.

The thermal conductivity of “LTCC” constituting the substrate body and insulating layer of the evaluation model shown in Table 3 and “glass” constituting the insulating layer is a physical property value of the material produced as shown below. is there.

<Measurement of thermal conductivity of LTCC>
The green sheet for main body and the green sheet for insulating layer for manufacturing the substrate main body 1 are manufactured as follows. That is, as represented by mol% based on oxides, glass composition, SiO ₂ is _60.4%, B 2 _{O 3} is 15.6%, _Al 2 _{O 3} is 6%, CaO is 15%, _{K 2} O is The raw materials are blended and mixed so that 1% and Na ₂ O become 2%. The raw material mixture is put in a platinum crucible and melted at 1600 ° C. for 60 minutes, and then the molten glass is poured out and cooled. The glass is pulverized for 40 hours by an alumina ball mill to produce glass powder. In addition, ethyl alcohol is used as a solvent for pulverization.

Next, the glass powder was 38% by mass, the alumina filler (manufactured by Showa Denko KK, trade name: AL-45H) was 38% by mass, the zirconia filler (manufactured by Daiichi Rare Element Chemical Co., Ltd., trade name: HSY-3F-J). ) Is mixed so as to be 24% by mass, and mixed to produce a glass ceramic composition (LTCC composition) for a substrate body and an insulating layer. 50 g of this glass ceramic composition, 15 g of an organic solvent (mixed with toluene, xylene, 2-propanol, 2-butanol in a mass ratio of 4: 2: 2: 1), a plasticizer (di-2-ethylhexyl phthalate) 2.5 g, 5 g of polyvinyl butyral (made by Denka, trade name: PVK # 3000K) as a binder, and 0.5 g of a dispersant (trade name: BYK180, made by Big Chemie) are mixed and mixed to prepare a slurry. .

The slurry is applied onto a PET film by a doctor blade method, and the dried green sheets are laminated so that the thickness after firing becomes 0.5 mm, thereby producing a green sheet for a main body. In the case of the green sheet for an insulating layer, it is laminated so that the thickness after firing becomes 0.1 mm.

These green sheets are degreased by holding them at 550 ° C. for 5 hours, and further fired by holding them at 870 ° C. for 30 minutes, and then the thermal conductivity of the sintered body (substrate body, insulating layer) is measured. The value measured in this way is the thermal conductivity of LTCC shown in Table 3.

<Measurement of thermal conductivity of glass>
A glass powder for forming an insulating layer is prepared as shown below. First, the raw materials are blended and mixed so that the glass composition is 81.6% of SiO ₂ , 16.6% of B ₂ O ₃ , and 1.8% of K ₂ O in terms of mol% based on oxide. The raw material mixture was put in a platinum crucible and melted at 1600 ° C. for 60 minutes, and then the molten glass was poured out and cooled. This glass is pulverized by an alumina ball mill to produce glass powder for an insulating layer. In addition, ethyl alcohol is used as a solvent for pulverization.

The glass powder solidified with a press is fired to form a glass bulk body, and then the thermal conductivity is measured. The value measured in this way is the thermal conductivity of the glass shown in Table 3.

From the analysis results in Tables 1 and 2, the distance L2 from the lower surface of the insulating layer 8 to the non-mounting surface of the substrate body is 60% or less (300 μm or less) of the thickness L1 (500 μm) of the substrate body 1. In the evaluation models of Examples 1 to 9 and Examples 13 and 14 (Examples), the insulating layer 8 is disposed at a position close to the mounting surface 1a where the distance L2 exceeds 60%. As compared with the evaluation model of (Comparative Example), it can be seen that the thermal resistance is kept low, and the heat dissipation is good.

In addition to the calculation of the thermal resistance value by the numerical simulation using the analysis program as described above, the light-emitting element substrate 10 was actually manufactured, and the light-emitting element was mounted on the mounting portion to verify the heat dissipation effect. The sample substrate for actual measurement was manufactured according to the method for manufacturing a substrate for a light emitting element described above. Two types of sample substrates (Examples 16 and 17) were prepared, and the configurations of the sample substrates in each example were the same as those in Example 13 and Example 15, respectively. In addition, Example 16 is an Example and Example 17 is a comparative example.

Specifically, a sample substrate having the structure shown in FIG. 1 was prepared. The substrate body 1 is an LTCC substrate having a size of 5 mm × 5 mm, the thickness L1 of the substrate body 1 is 500 μm, and the insulating layer 8 disposed in the middle portion in the thickness direction of the radiator 6 is an LTCC layer. The distances L2 of the lower surface of the insulating layer 8 from the non-mounting surface of the substrate body were 0 μm and 400 μm, respectively, and the thickness d of the insulating layer 8 was 100 μm. Further, an LED element “ES-CEBLV45” (1.14 mm × 1.14 mm) manufactured by Epistar was used as the light emitting element, and the input power was 1 W. Table 4 shows the measured thermal resistance values. In Table 4, the relative thermal resistance value when the thermal resistance value measured in Example 16 is 1.00 is shown.

When the relative thermal resistance values of Example 13 and Example 15 shown in Table 2 are compared, the ratio between the relative thermal resistance value of Example 15 and the relative thermal resistance value of Example 13 (relative thermal resistance value of Example 15 / Example 13). (Relative thermal resistance value) was 1.45 (1.60 / 1.10), whereas the ratio of the actually measured relative thermal resistance value of Example 17 to the relative thermal resistance value of Example 16 was 1.41. It is. Therefore, it can be confirmed that the predicted value by the numerical simulation and the actually measured value on the sample substrate agree well. Further, since the measured thermal resistance value shows the same tendency as in Table 3, excellent heat dissipation can be obtained by disposing the insulating layer 8 closer to the non-mounting surface 1b of the substrate body 1. This can be confirmed.

Next, as shown in FIG. 4, the insulating layer 8 is disposed on the lower side of the heat radiating body 7 a disposed so that the upper end portion is in contact with the mounting surface 1 a of the substrate body 1. A light emitting element substrate 10 having a structure arranged so as to reach the surface 1b and changing the distance (the thickness d of the insulating layer 8) between the lower surface of the heat radiating body 7a and the non-mounting surface 1b of the substrate body 1 is assumed. . Further, assuming an evaluation model in which a 1-wire type LED element (size: 0.6 mm, width: 0.6 mm, thickness: 0.1 mm) is mounted on the mounting portion of the light emitting element substrate 10, The thermal resistance of the evaluation model was obtained by numerical analysis.

As the analysis program, ANSYS ICEPAK Version 12.1.6 was used as in the above analysis, and the input power was 1.0 W. The substrate body 1 was made of LTCC and had a thickness L1 of 500 μm. Further, the insulating layer 8 is made of LTCC as in the case of the substrate body 1. Further, the heat radiating body 7a is assumed to have a prismatic shape in which the cross section perpendicular to the thickness direction of the substrate is a square having a side length of 1.2 mm, and the physical property values (heat Conductivity) was used for analysis. The analysis results are shown in Table 5. Moreover, the analysis result shown in Table 5 is shown with the graph of FIG.

In Table 5, Examples 19 to 26 are evaluation models corresponding to examples of the present invention, and Examples 27 to 33 are evaluation models corresponding to comparative examples. The ratio (%) of the distance from the non-mounting surface of the lower surface of the insulating layer 8 to the thickness of the substrate body 1 in Table 5 is the lower surface of the heat radiating body 7a (or the upper surface of the insulating layer 8) and the substrate body in FIG. 1 represents a percentage of a value obtained by dividing the distance d from the non-mounting surface 1b by 1 by the thickness L1 of the substrate body 1. The relative thermal resistance value is based on the thermal resistance value obtained by analyzing the model of Example 18 in which the heat radiating body is configured only by the conductor layer without providing the insulating layer 8 below the heat radiating body 7a. Relative value when (1.00).

From the analysis results of Table 5 and FIG. 5, the ratio (d / L1) (%) of the distance from the lower surface of the insulating layer 8 to the thickness of the substrate body 1 from the non-mounting surface 1b of the substrate body 1 is 60% or less. It can be seen that in some cases, a sufficiently low thermal resistance is obtained, and when it is 40% or less, the thermal resistance is further reduced. That is, the heat dissipating body 7a has a sufficient length so that the distance d from the lower surface 1b of the substrate body 1 to the heat dissipating body 7a is 60% or less, preferably 40% or less of the thickness L1 of the substrate body. When it has, it turns out that a thermal resistance does not raise so much and shows favorable heat dissipation.

Furthermore, in the evaluation model of Example 20, the change in the thermal resistance value when the cross-sectional area of the heat radiating body 7a was changed was also analyzed. That is, in the light emitting element substrate 10 having the structure shown in FIG. 4 in which the substrate body 1 and the insulating layer 8 are made of LTCC, the thickness L1 of the substrate body 1 is 500 μm, the lower surface of the heat radiating body 7a and the substrate body 1 In the evaluation model in which the distance d from the non-mounting surface 1b is 100 μm, the evaluation model of Examples 34 to 41 in which the cross-sectional area of the cross section perpendicular to the thickness direction of the substrate of the heat radiating body 7a is changed using the above analysis program The thermal resistance value was analyzed. The LED element is a one-wire type having a square bottom of 0.6 mm in length and 0.6 mm in width and having a thickness of 0.1 mm. The analysis results are shown in Table 6. The analysis results shown in Table 6 are shown in the graph of FIG.

In Table 6, the ratio of the size of the heat radiating body 7a to the bottom area of the light emitting element represents a value obtained by dividing the cross-sectional area of the heat radiating body 7a by the bottom area of the light emitting element. The relative thermal resistance value is obtained by analyzing the evaluation model of Example 36 in which the cross-sectional area of the heat radiating body 7a has the same square bottom area as the light emitting element having the size of 0.6 mm in length and 0.6 mm in width. It is a relative value when the thermal resistance value is the reference (1.00). In the evaluation model of Example 20, the cross section of the heat radiating body 7a is a square with a side length of 1.2 mm, and the ratio of the size of the heat radiating body 7a to the bottom area of the light emitting element is 4.00 (400 times). %). Therefore, the evaluation model of Example 37 is also the evaluation model of Example 20.

From the analysis results of Table 6, it can be seen that the larger the ratio of the cross-sectional area of the heat radiating body 7a to the bottom area of the light emitting element, the lower the thermal resistance and the better the heat dissipation. However, if the cross-sectional area of the heat radiating body 7a is increased, there is a demerit that the material cost of the noble metal and the like constituting the heat radiating body 7a is increased. It can be seen that when the range is ˜16 times, the increase in material cost can be suppressed and sufficient heat radiation performance can be obtained. Further, from the viewpoint of the balance between the material cost and the heat dissipation performance, a more preferable range of the ratio of the cross-sectional area of the heat dissipation body 7a is 1.0 to 4.0 times the bottom area of the light emitting element.
As in the case of the heat radiating body 7a, the larger the ratio of the cross-sectional area of the heat radiating body 7b to the bottom area of the light emitting element, the lower the thermal resistance and the better the heat radiating property.

ADVANTAGE OF THE INVENTION According to this invention, the board | substrate for light emitting elements which has favorable thermal diffusibility and the electrical insulation of the back side was ensured is obtained. The light-emitting device of the present invention using such a light-emitting element substrate has low luminance deterioration and high light-emitting luminance. For example, backlights for mobile phones and large liquid crystal displays, automobiles, or decorations. It can be suitably used as an illumination or other light source.
The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2010-2559592 filed on November 19, 2010 are incorporated herein as the disclosure of the present invention. .

DESCRIPTION OF SYMBOLS 1 ... Board | substrate body, 2 ... Frame, 3 ... Wiring conductor layer (conductor paste layer for wiring conductor layers), 4 ... External electrode terminal (conductor paste layer for external electrode terminals), 5 ... Connection via (for connection via) Conductor paste layer), 6 ... radiator, 7 ... heat radiating body (conductor paste layer for heat radiating body), 8 ... insulating layer (unfired insulating layer), 10 ... substrate for light emitting element, 11 ... light emitting element, 12 ... Conductive die-bonding material, 13 ... bonding wire, 14 ... sealing layer, 20 ... light emitting device.

Claims (12)

A substrate body made of an inorganic insulating material, including a mounting surface including a mounting portion on which the light emitting element is mounted, and a non-mounting surface on the surface opposite to the mounting surface;
In the substrate body, from the mounting surface to the non-mounting surface, having a heat radiator provided so that one end reaches the mounting portion,
The heat radiator is an inorganic material arranged in the surface direction so as to cover the entire cross section of the heat radiator at a position where the distance in the thickness direction from the non-mounting surface is 60% or less of the thickness of the substrate body. An insulating layer made of
And the part other than the said insulating layer which is the main body of the said heat radiator is comprised with the conductor, The board | substrate for light emitting elements characterized by the above-mentioned. The light-emitting element substrate according to claim 1, wherein the insulating layer has an upper surface disposed at a position where a distance in a thickness direction from the non-mounting surface is 40% or less of a thickness of the substrate body. . 3. The light emitting device according to claim 1, wherein a cross-sectional area of the heat radiating body in a direction orthogonal to a thickness direction of the substrate body is 0.2 to 16 times an area of a mounting portion on which the light emitting element is mounted. Device substrate. 4. The light-emitting element substrate according to claim 1, wherein the insulating layer has a thickness of 10 to 200 μm. 4. The light-emitting element substrate according to claim 1, wherein the insulating layer has a thickness of 10 to 100 μm. The light emitting element substrate according to any one of claims 1 to 5, wherein the insulating layer is made of a material mainly composed of glass. The substrate for a light emitting device according to any one of claims 1 to 6, wherein the insulating layer is made of a sintered body of a glass ceramic composition containing glass powder and ceramic powder. The light-emitting element substrate according to any one of claims 1 to 7, wherein the substrate body is made of a sintered body of a glass ceramic composition containing glass powder and ceramic powder. The light emitting element substrate according to any one of claims 1 to 8, wherein the conductor constituting the main body of the heat dissipating body contains at least one of Cu, Ag, and Au as a main component. 10. The light-emitting element substrate according to claim 1, further comprising a frame for housing the light-emitting element on a mounting surface of the substrate body. A light-emitting element substrate according to any one of claims 1 to 10,
A light emitting device comprising: a light emitting element mounted on the mounting portion of the light emitting element substrate. One electrode of the light-emitting element is connected to a first wiring conductor layer formed on the mounting portion of the light-emitting element substrate by a conductive adhesive material, and the other electrode is the electrode of the light-emitting element substrate. The light-emitting device according to claim 11, wherein the light-emitting device is connected to a second wiring conductor layer formed on a mounting surface by being insulated from the first wiring conductor layer by wire bonding.

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