JP5034723B2 - Surge absorbing element and light emitting device - Google Patents

Description

  The present invention relates to a surge absorbing element and a light emitting device including the surge absorbing element.

As a surge absorption element, there is a so-called gap-type surge absorption element that includes electrodes arranged with a predetermined gap and absorbs a surge by discharging between the electrodes (see, for example, Patent Document 1).
Special table 2001-523040 gazette

  By the way, the surge absorbing element can be protected from an ESD (Electrostatic Discharge) surge by being connected in parallel to an electronic element such as a semiconductor light emitting element or an FET (Field Effect Transistor). it can. Some of these electronic elements generate heat during operation. When the electronic element becomes high temperature, the characteristic of the element itself is deteriorated and the operation is affected. For this reason, it is necessary to efficiently dissipate the generated heat.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a surge absorbing element and a light emitting device that can dissipate heat efficiently.

  The surge absorbing element according to the present invention includes first and second surfaces, an element body made of an electrically insulating material, and at least two elements disposed on the first surface of the element body with a predetermined gap. And a heat dissipating part disposed so as to be thermally connected to the second surface of the region, the heat dissipating part being made of metal and metal oxide. It is characterized by comprising a composite material.

  In the surge absorbing element according to the present invention, an ESD surge can be absorbed by a discharge between at least two electrodes disposed on the first surface of the element body with a predetermined gap. In the present invention, the heat radiating portion is made of a composite material of metal and metal oxide, and has a higher thermal conductivity than the element body and is disposed so as to be thermally connected to the second surface of the element body. The heat transmitted to the surge absorbing element can be efficiently dissipated from the heat radiating portion.

  Preferably, the heat radiating portion is disposed so as to contact the second surface of the element body. In this case, the heat transmitted to the surge absorbing element can be efficiently transmitted to the heat radiating portion.

  Preferably, the electrically insulating material is a glass substance. Preferably, the electrically insulating material is a glass substance and ceramics. In these cases, the electrical insulation of the element body can be reliably ensured.

  Preferably, the element body and the heat dissipation part are formed by simultaneous firing. In this case, the manufacturing process can be simplified.

  Preferably, the element body is formed by baking a paste containing an electrically insulating material. In this case, the formation of the element body becomes simple.

  Preferably, the heat dissipation part includes Ag as a main component of the metal. Ag has a relatively high thermal conductivity and can increase the efficiency of heat transfer in the heat radiating section and heat dissipation from the heat radiating section.

  Preferably, the heat radiating portion contains ZnO as a metal oxide.

  Preferably, the predetermined gap is covered with a resin material. Preferably, at least one of a conductor material and a semiconductor material is dispersed in the resin material. In these cases, the discharge voltage can be controlled.

  A light emitting device according to the present invention is a light emitting device including a surge absorbing element and a light emitting element, the surge absorbing element including first and second surfaces, and an element body made of an electrically insulating material; At least two electrodes disposed on the first surface of the element body with a predetermined gap and higher thermal conductivity than the region of the element body and thermally connected to the second surface of the region The heat dissipation part is made of a composite material of metal and metal oxide, and the light emitting element is electrically and physically connected to at least two electrodes so as to be connected in parallel to the surge absorbing element. It is characterized by being connected.

  In the light emitting device according to the present invention, an ESD surge can be absorbed by a discharge between at least two electrodes disposed on the first surface of the element body with a predetermined gap. In the present invention, since the light emitting element and at least two electrodes of the surge absorbing element are physically connected, heat generated in the light emitting element is transmitted to the surge absorbing element via the at least two electrodes. The heat dissipation part is made of a composite material of metal and metal oxide, and has a higher thermal conductivity than the element body and is disposed so as to be thermally connected to the second surface of the element body. The heat transmitted to the element can be efficiently dissipated from the heat radiating section.

  According to the surge absorbing element and the light emitting device according to the present invention, it is possible to efficiently dissipate heat.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  First, with reference to FIG.1 and FIG.2, the structure of surge absorber SA1 which concerns on this embodiment is demonstrated. FIG. 1 is a schematic perspective view showing a surge absorbing element according to this embodiment. FIG. 2 is a schematic cross-sectional view showing the surge absorbing element according to the present embodiment. As shown in FIGS. 1 and 2, the surge absorbing element SA <b> 1 includes an element body 10, a pair of first and second electrodes 20 and 30, and a heat radiating unit 40.

The element body 10 is layered and includes first and second main surfaces 11 and 12 facing each other. The element body 10 is made of an electrically insulating material, and in this embodiment is made of a glass material. Examples of the electrical insulating material include ceramics having an electrical insulation property (for example, Al ₂ O ₃ , ZrO ₂ , AlN, or TiO ₂ ) in addition to the glass substance. The element body 10 may be made of a glass material, may be made of ceramics, or may be made of a glass material and ceramics.

  The first electrode 20 and the second electrode 30 are disposed on the first main surface 11 of the element body 10. The first electrode 20 and the second electrode 30 have a rectangular shape when viewed from a direction perpendicular to the first main surface 11 and are arranged symmetrically with a predetermined gap. The first electrode 20 is not exposed on the three side surfaces of the element body 10 and extends from the edge of the first main surface 11 to a position inside by a predetermined distance. The second electrode 30 is not exposed on the three side surfaces of the element body 10 and extends from the edge of the first main surface 11 to a position inside by a predetermined distance.

  The first electrode 20 and the second electrode 30 serve as connection ends of an electronic element such as the semiconductor light emitting element 61 (see FIG. 6), and function as pad electrodes on which the electronic element is mounted. The first electrode 20 and the second electrode 30 also function as input / output terminals of the surge absorbing element SA1.

  The first electrode 20 and the second electrode 30 contain a metal (for example, Ag, Ag—Pd alloy, or Au) as a main component. The first electrode 20 and the second electrode 30 are formed by firing a conductive paste containing conductive metal powder (for example, Ag powder, Ag—Pd alloy powder, Au powder, or the like). The first electrode 20 and the second electrode 30 may be formed by a plating method such as a sputtering method.

  The heat radiating portion 40 has a substantially rectangular parallelepiped shape, and includes first and second main surfaces 41 and 42, first and second end surfaces 43 and 44, and first and second side surfaces 45 and 46. Yes. The first and second main surfaces 41 and 42 have a rectangular shape and face each other. The first and second end surfaces 43 and 44 extend in the short side direction of the first and second main surfaces 41 and 42 so as to connect the first and second main surfaces 41 and 42 and face each other. ing. The first and second side surfaces 45 and 46 extend in the long side direction of the first and second main surfaces 41 and 42 so as to connect the first and second main surfaces 41 and 42 and face each other. ing.

  The heat radiation part 40 is a sintered body made of a composite material of a metal and a metal oxide, and is configured as a laminated body in which a plurality of layers are laminated. In the actual surge absorbing element SA1, the plurality of layers constituting the heat radiation part 40 are integrated to such an extent that the boundary between them cannot be visually recognized.

The heat radiating part 40 contains a metal and has a higher thermal conductivity than the thermal conductivity of the element body 10 (in this embodiment, the thermal conductivity of a glass material, ceramics, or the like constituting the element body 10). In the present embodiment, for example, Ag is used as the metal and ZnO is used as the metal oxide. Instead of Ag, an Ag—Pd alloy or Pd may be included, or a plurality of these metals may be included. However, Ag is preferably used from the viewpoint of thermal conductivity. Instead of ZnO, Al ₂ O ₃ , SiO ₂ or ZrO ₂ may be included, and a plurality of these metal oxides may be included.

  The heat radiating portion 40 is joined to the element body 10 in a state where the first main surface 41 of the heat radiating portion 40 is in contact with the second main surface 12 of the element body 10. Thereby, the heat radiating part 40 is thermally connected to the second main surface 12 of the element body 10.

  The inside of the heat radiating portion 40 is in contact with the second main surface 12 of the element body 10 from the first main surface 41 that is in contact with and faces the second main surface 12 of the element body 10 by Ag which is a metal. There is conduction across the non-exposed surfaces 42-46. The second main surface 42, the first and second end surfaces 43 and 44, and the first and second side surfaces 45 and 46 of the heat radiating unit 40 are exposed.

  Subsequently, a manufacturing process of the surge absorbing element SA1 described above will be described.

  First, Ag and ZnO, which are main components constituting each layer of the heat radiating section 40, are weighed so as to have a predetermined ratio, and then the components are mixed to adjust the material. At this time, the adjusted material may contain a trace additive (for example, Pr, Co, Cr, Ca, Si, K, and Al metal or oxide). Then, an organic binder, an organic solvent, an organic plasticizer, etc. are added to this material, and it mixes and grinds for about 20 hours using a ball mill etc., and obtains a slurry.

  The slurry is applied onto a film made of, for example, polyethylene terephthalate by a known method such as a doctor blade method, and then dried to form a film having a thickness of about 30 μm. The film thus obtained is peeled from the film to obtain a green sheet for the heat radiating part.

  Next, a predetermined number of green sheets for the heat radiating portion are stacked to form a sheet laminate. And the obtained sheet | seat laminated body is cut | disconnected per chip | tip, and the some divided | segmented green body is obtained.

  Next, the green body is subjected to heat treatment at 180 to 400 ° C. for about 0.5 to 24 hours to remove the binder, and further baked at 850 to 1400 ° C. for about 0.5 to 8 hours. Do. Thereby, the thermal radiation part 40 will be obtained.

  Next, the glass paste which mixed glass powder, the organic binder, and the organic solvent is prepared, the said glass paste is printed on the 1st main surface 41 of the thermal radiation part 40, and is dried. Thereby, a glass paste layer is formed on the heat radiating portion 40.

And the electrode pattern corresponding to the 1st electrode 20 and the 2nd electrode 30 is formed on the glass paste layer formed in the thermal radiation part 40. FIG. This electrode pattern is formed by printing on a glass paste layer a conductive paste obtained by mixing an organic binder and an organic solvent on a metal powder containing Au particles or Ag particles as a main component, and drying the paste. The glass paste layer and the electrode pattern are baked at a temperature of 800 ° C. or higher in an O ₂ atmosphere, whereby the layered element body 10, the first electrode 20, and the second electrode 30 are formed. The Rukoto. Through the above process, the surge absorbing element SA1 shown in FIGS. 1 and 2 is completed.

  In addition, you may form the element | base_body 10 and the thermal radiation part 40 by baking simultaneously. For example, a glass paste layer is formed on the above-described sheet laminate, and then the sheet laminate and the glass paste layer are baked to obtain a sintered laminate including the element body 10 and the heat dissipation portion 40. Also, instead of glass paste, prepare ceramic paste that is a mixture of glass powder, ceramic powder, organic binder, and organic solvent, and print the ceramic paste on the sheet laminate and dry it to form the ceramic paste layer After that, it may be fired. Furthermore, when the above-described ceramic green sheet is prepared and a sheet laminate is formed, it may be laminated on the green sheet for the heat radiating portion and fired.

  As described above, in the present embodiment, there is a gap between the first electrode 20 and the second electrode 30 arranged on the first main surface 11 of the element body 10 of the element body 10 with a predetermined gap. The ESD surge can be absorbed by the discharge.

  In this embodiment, the heat radiating part 40 is made of a composite material of metal (Ag in this embodiment) and metal oxide (ZnO in this embodiment), and has a higher thermal conductivity than the element body 10 and the element body 10. Therefore, the heat transmitted to the surge absorbing element SA1 can be efficiently dissipated from the heat radiating portion 40.

  In the present embodiment, the heat radiating portion 40 is disposed so as to contact the second main surface 12 of the element body 10. Thereby, the heat transmitted to the surge absorbing element SA1 can be efficiently transmitted to the heat radiating unit 40.

  In this embodiment, the element body 10 is made of a glass material. Thereby, the electrical insulation of the element body 10 can be reliably ensured. Further, even when the element body 10 is made of the above-described ceramic, glass material, or ceramic, the electric insulation of the element body 10 can be reliably ensured.

  In this embodiment, the element body 10 is formed by baking a glass paste containing glass powder. Thereby, formation of the element | base_body 10 becomes easy.

  Preferably, the heat dissipation part includes Ag as a main component of the metal. Ag has a relatively high thermal conductivity and can increase the efficiency of heat transfer in the heat radiating section and heat dissipation from the heat radiating section.

  In the present embodiment, in the heat radiating portion 40, the metal (Ag) is conducted from the first main surface 41 of the heat radiating portion 40 to the plurality of surfaces 42 to 46. Thereby, in the heat radiating part 40, a heat radiating path by metal is easily formed, and the efficiency of heat transfer in the heat radiating part 40 and heat dissipation from the heat radiating part 40 can be enhanced.

  In this embodiment, the heat radiating part 40 contains Ag as a main component of the metal. Ag has a relatively high thermal conductivity, and it is possible to increase the efficiency of heat transfer in the heat radiating part 40 and heat dissipation from the heat radiating part 40.

When forming the heat radiation part 40, metal oxide particles coated with a metal coating may be used. As the particles, for example, _Al 2 _{O 3} particles having been subjected to Ag coated by electroless plating and the like. Thus, by using metal oxide particles that have been previously coated with a metal coating, it is possible to reliably form a heat dissipation path using metal.

  Next, with reference to FIG.3 and FIG.5, the 1st-3rd modification of surge absorber SA1 which concerns on this embodiment is demonstrated. 3 and 5 are schematic cross-sectional views showing modifications of the surge absorbing element according to the present embodiment.

  In the surge absorbing element SA <b> 2 according to the first modification shown in FIG. 3, the heat radiating portion 40 is thermally connected to the second main surface 12 of the element body 10 via the adhesive layer 50. The surge absorbing element SA2 can be obtained by bonding the element body 10 and the heat radiating portion 40, which are separately formed, with an adhesive layer 50. Also in the surge absorbing element SA2, the second main surface 12 of the element body 10 and the first main surface 41 of the heat radiating portion 40 face each other with the adhesive layer 50 interposed therebetween.

  The adhesive layer 50 is made of a resin material such as an epoxy resin or a silicone resin. When the element body 10 is made of ceramic, a glass substance can also be used as the adhesive layer 50. The thickness of the adhesive layer 50 is set in a range that does not hinder the thermal connection between the element body 10 and the heat radiating portion 40 and can secure the bonding strength between the element body 10 and the heat radiating portion 40.

  As described above, also in the first modification, the heat radiating portion 40 is thermally connected to the element body 10, and therefore, the heat transmitted to the surge absorbing element SA2 can be efficiently dissipated from the heat radiating portion 40. .

  In the surge absorbing element SA3 according to the second modification shown in FIG. 4, a predetermined gap between the first electrode 20 and the second electrode 30 is covered with a resin material 52. Further, in the surge absorbing element SA4 according to the third modified example shown in FIG. 5, the conductor material and the semiconductor material are added to the resin material 52 covering the predetermined gap between the first electrode 20 and the second electrode 30. At least one of the materials 54 is dispersed.

Examples of the resin material 52 include polyimide resin and silicone resin. Examples of the material 54 include metal particles (for example, nickel, copper, silver, gold, tungsten, molybdenum, or alloys thereof) and semiconductor ceramics (for example, a varistor material mainly composed of ZnO, and mainly composed of SrTiO _3. , Composite perovskite varistor materials obtained by substituting a part of Sr with Ca, Ba or the like, or SiC varistor materials).

  In the second and third modified examples, the predetermined gap between the first electrode 20 and the second electrode 30 is covered with the resin material 52 or the resin material 52 in which the material 54 is dispersed. Since it is covered, the discharge voltage can be controlled. Also,

  Of course, also in the second and third modified examples, the heat radiating portion 40 is thermally connected to the element body 10, so that the heat transferred to the surge absorbing elements SA3 and SA4 can be efficiently dissipated from the heat radiating portion 40. Can do.

  Next, the light emitting device LE according to the present embodiment will be described with reference to FIG. FIG. 6 is a schematic cross-sectional view showing the light emitting device according to this embodiment. The light emitting device LE includes, for example, the above-described surge absorbing element SA1 and a semiconductor light emitting element 61 electrically connected to the surge absorbing element SA1. The light emitting device LE may include surge absorbing elements SA2 to SA4 instead of the surge absorbing element SA1.

  The semiconductor light emitting element 61 is a light emitting diode (LED) of a GaN (gallium nitride) semiconductor, and includes a substrate 62 and a layer structure LS formed on the substrate 62. GaN-based semiconductor LEDs are well known and will be described briefly. The substrate 62 is an optically transparent and electrically insulating substrate made of sapphire. The layer structure LS includes an n-type (first conductivity type) semiconductor region 63, a light emitting layer 64, and a p-type (second conductivity type) semiconductor region 65, which are stacked. The semiconductor light emitting element 61 emits light according to a voltage applied between the n-type semiconductor region 63 and the p-type semiconductor region 65.

  The n-type semiconductor region 63 includes an n-type nitride semiconductor. In the present embodiment, the n-type semiconductor region 63 is formed by epitaxially growing GaN on the substrate 62, and has an n-type conductivity by adding an n-type dopant such as Si. Further, the n-type semiconductor region 63 may have a composition that has a refractive index smaller than that of the light emitting layer 64 and a larger band gap. In this case, the n-type semiconductor region 63 serves as a lower cladding for the light emitting layer 64.

  The light-emitting layer 64 is formed on the n-type semiconductor region 63, and the carriers (electrons and holes) supplied from the n-type semiconductor region 63 and the p-type semiconductor region 65 are recombined to emit light in the light-emitting region. Is generated. The light emitting layer 64 can have, for example, a multiple quantum well (MQW) structure in which barrier layers and well layers are alternately stacked over a plurality of periods. In this case, the barrier layer and the well layer are made of InGaN, and the band gap of the barrier layer is configured to be larger than the band gap of the well layer by appropriately selecting the composition of In (indium). The light emitting region is generated in a region where carriers are injected in the light emitting layer 64.

  The p-type semiconductor region 65 includes a p-type nitride semiconductor. In the present embodiment, the p-type semiconductor region 65 is formed by epitaxially growing AlGaN on the light emitting layer 64, and has p-type conductivity by adding a p-type dopant such as Mg. The p-type semiconductor region 65 may have a composition that has a refractive index smaller than that of the light emitting layer 64 and a larger band gap. In this case, the p-type semiconductor region 65 serves as an upper cladding for the light emitting layer 64.

  A cathode electrode 66 is formed on the n-type semiconductor region 63. The cathode electrode 66 is made of a conductive material, and an ohmic contact with the n-type semiconductor region 63 is realized. An anode electrode 67 is formed on the p-type semiconductor region 65. The anode electrode 67 is made of a conductive material and realizes ohmic contact with the p-type semiconductor region 65. Bump electrodes 68 are formed on the cathode electrode 66 and the anode electrode 67. In the semiconductor light emitting device 61 having the above-described configuration, when a predetermined voltage is applied between the anode electrode 67 (bump electrode 68) and the cathode electrode 66 (bump electrode 68) and a current flows, the light emitting region 64 emits light. Luminescence will occur.

  The semiconductor light emitting element 61 is bump-connected to the first electrode 20 and the second electrode 30. That is, the cathode electrode 66 is electrically and physically connected to the first electrode 20 via the bump electrode 68. The anode electrode 67 is electrically and physically connected to the second electrode 30 via the bump electrode 68. As a result, the surge absorbing element SA1 is connected in parallel to the semiconductor light emitting element 61. Therefore, the semiconductor light emitting element 61 is protected from the ESD surge by the surge absorbing element SA1.

  In the light emitting device LE, since the semiconductor light emitting element 61 and the first electrode 20 and the second electrode 30 of the surge absorbing element SA1 are physically connected, the heat generated in the semiconductor light emitting element 61 is generated by the first electrode. 20 and the second electrode 30 are transmitted to the surge absorbing element SA1. Since the element body 10 and the heat radiating part 40 are thermally connected, the heat transmitted to the surge absorbing element SA1 can be efficiently dissipated from the heat radiating part 40 as described above.

  The preferred embodiments of the present invention have been described above. However, the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  In the surge absorbing element SA1 according to the present embodiment, the heat radiating portion 40 is disposed so as to be thermally connected to the second main surface 12 of the element body 10, but is not limited thereto. For example, the heat radiating unit 40 may be thermally connected to any one of the surfaces other than the second main surface 12 of the element body 10.

  In the present embodiment, an example in which a semiconductor light emitting element is used as an electronic element is shown, but the present invention is not limited to this. The present invention can be applied to electronic elements (for example, FETs, bipolar transistors, etc.) that generate heat during operation in addition to semiconductor light emitting elements.

  In the present embodiment, a light-emitting diode of a GaN-based semiconductor LED is used as the semiconductor light-emitting element 61, but is not limited thereto. As the semiconductor light emitting element 61, for example, a nitride semiconductor LED other than GaN-based (for example, InGaNAs-based semiconductor LED), a compound semiconductor LED other than nitride-based, or a laser diode (LD: Laser Diode) may be used. .

It is a schematic perspective view which shows the surge absorption element which concerns on this embodiment. It is a schematic sectional drawing which shows the surge absorption element which concerns on this embodiment. It is a schematic sectional drawing which shows the 1st modification of the surge absorption element which concerns on this embodiment. It is a schematic sectional drawing which shows the 2nd modification of the surge absorption element which concerns on this embodiment. It is a schematic plan view which shows the 3rd modification of the surge absorption element which concerns on this embodiment. It is a schematic sectional drawing which shows the light-emitting device concerning this embodiment.

Explanation of symbols

  SA1 to SA4 ... surge absorbing element, 10 ... element body, 11, 12 ... first and second main surfaces, 20 ... first electrode, 30 ... second electrode, 40 ... heat dissipation part, 41, 42 ... first DESCRIPTION OF SYMBOLS 1 and 2nd main surface, 43,44 ... 1st and 2nd end surface, 45,46 ... 1st and 2nd side surface, 52 ... Resin material, 54 ... Metal particle, 61 ... Semiconductor light-emitting device, LE ... Light emitting device.

Claims (20)

An element body including the first and second surfaces and made of an electrically insulating material;
At least two electrodes disposed on the first surface of the element body with a predetermined gap;
A heat dissipating part disposed so as to have a higher thermal conductivity than the element body and to be thermally connected to the second surface of the element body,
The surge absorber according to claim 1, wherein the heat dissipating part is made of a composite material of metal and metal oxide.   The surge absorbing element according to claim 1, wherein the heat radiating portion is disposed so as to contact the second surface of the element body.   The surge absorbing element according to claim 1, wherein the electrically insulating material is a glass substance.   The surge absorbing element according to claim 1, wherein the electrically insulating material is a glass substance and ceramics.   The surge absorber according to any one of claims 1 to 4, wherein the element body and the heat radiating portion are formed by simultaneous firing.   The surge absorber according to any one of claims 1 to 3, wherein the element body is formed by baking a paste containing the electrically insulating material.   The surge absorber according to any one of claims 1 to 6, wherein the heat radiating portion contains Ag as a main component of the metal.   The surge absorber according to any one of claims 1 to 7, wherein the heat radiating portion contains ZnO as the metal oxide.   The surge absorbing element according to any one of claims 1 to 8, wherein the predetermined gap is covered with a resin material.   The surge absorbing element according to claim 9, wherein at least one of a conductor material and a semiconductor material is dispersed in the resin material. A light emitting device including a surge absorbing element and a light emitting element,
The surge absorbing element is
An element body including the first and second surfaces and made of an electrically insulating material;
At least two electrodes disposed on the first surface of the element body with a predetermined gap;
A heat dissipating part disposed so as to have a higher thermal conductivity than the element body and to be thermally connected to the second surface of the element body,
The heat dissipation part is made of a composite material of metal and metal oxide,
The light emitting device is electrically and physically connected to at least two of the electrodes so as to be connected in parallel to the surge absorbing element.   The light-emitting device according to claim 11, wherein the heat dissipating part is disposed so as to contact the second surface of the element body.   The light emitting device according to claim 11, wherein the electrically insulating material is a glass substance.   The light emitting device according to claim 11 or 12, wherein the electrically insulating material is a glass substance and ceramics.   The light emitting device according to claim 11, wherein the element body and the heat dissipation portion are formed by simultaneous firing.   The light emitting device according to any one of claims 11 to 13, wherein the element body is formed by baking a paste containing the electrically insulating material.   The light-emitting device according to claim 11, wherein the heat radiating portion includes Ag as a main component of the metal.   The light-emitting device according to claim 11, wherein the heat radiating portion contains ZnO as the metal oxide.   The light emitting device according to claim 11, wherein the predetermined gap is covered with a resin material.   The light-emitting device according to claim 19, wherein at least one of a conductor material and a semiconductor material is dispersed in the resin material.

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