Phosphor substrate, light-emitting substrate, and lighting device

Abstract

The present invention relates to a phosphor substrate, a light-emitting substrate and a lighting device. The phosphor substrate (30) of the present invention has a plurality of light-emitting elements (20) mounted on one side. The phosphor substrate (30) comprises: an insulating substrate (32); a first electrode group (34) arranged on one side of the insulating substrate (32) and having a plurality of electrodes connected to the plurality of light-emitting elements (20); a phosphor layer (36) arranged on one side of the insulating substrate (32) and comprising a phosphor whose peak wavelength of light emission when the light emission of the light-emitting element (20) is used as excitation light is in the visible light region; and a second electrode group (38) arranged on the other side of the insulating substrate (32) and having a plurality of electrodes.

Description

Technical Field

[0001] The present invention relates to a fluorescent substrate, a light-emitting substrate and a lighting device. Background Art

[0002] Patent Document 1 discloses an LED lighting fixture including a substrate on which a light emitting element (LED element) is mounted. In this LED lighting fixture, a reflective material is provided on the surface of the substrate to improve light emission efficiency.

[0003] Patent document 1: China Patent Publication No. 106163113

[0004] The LED lighting device disclosed in Patent Document 1 cannot adjust the light emitted by the LED lighting device to a light having a different color from the light emitted by the light emitting element by using a reflective material. In addition, Patent Document 1 does not clearly disclose the structure of the back surface of the substrate. Summary of the invention

[0005] An object of the present invention is to provide a phosphor substrate having a phosphor layer on one surface and having a plurality of light emitting elements mounted thereon, wherein the phosphor substrate is less likely to warp than when a second electrode group is not disposed on the other surface.

[0006] A first embodiment of the present invention provides a phosphor substrate having a plurality of light-emitting elements mounted on one side, the phosphor substrate comprising: an insulating substrate; a first electrode group, arranged on one side of the insulating substrate, having a plurality of electrodes joined to the plurality of light-emitting elements; a phosphor layer, arranged on one side of the insulating substrate, comprising a phosphor having a peak emission wavelength in the visible light region when the emission of the light-emitting elements is used as excitation light; and a second electrode group, arranged on the other side of the insulating substrate, having a plurality of electrodes.

[0007] The second type of phosphor substrate of the present invention is based on the first type of phosphor substrate, and at least a part of the first configuration area in the above-mentioned insulating substrate serving as the configuration area of ​​the above-mentioned first electrode group overlaps with the second configuration area in the above-mentioned insulating substrate serving as the configuration area of ​​the above-mentioned second electrode group in the thickness direction of the above-mentioned insulating substrate.

[0008] A phosphor substrate according to a third aspect of the present invention is the phosphor substrate according to the second aspect, wherein 80% or more of the first arrangement region overlaps with the second arrangement region in the thickness direction of the insulating substrate.

[0009] A phosphor substrate according to a fourth aspect of the present invention is the phosphor substrate according to the second or third aspect, wherein an area of ​​the second arrangement region is not less than 90% and not more than 110% of an area of ​​the first arrangement region.

[0010] A phosphor substrate according to a fifth aspect of the present invention is the phosphor substrate according to any one of the first to fourth aspects, wherein the first arrangement region is a region that is 60% or more of one surface of the insulating substrate.

[0011] A phosphor substrate according to a sixth aspect of the present invention is the phosphor substrate according to any one of the first to fifth aspects, wherein the plurality of electrodes included in the second electrode group are provided as dummy electrodes that are not electrically connected to the plurality of electrodes included in the first electrode group.

[0012] A phosphor substrate according to a seventh aspect of the present invention is the phosphor substrate according to any one of the first to sixth aspects, wherein the second electrode group is patterned.

[0013] A phosphor substrate according to an eighth aspect of the present invention is the phosphor substrate according to any one of the first to seventh aspects, wherein the light emitting element is formed as a chip-sized CSP in which an LED is incorporated and packaged.

[0014] A phosphor substrate according to a ninth aspect of the present invention is the phosphor substrate according to the eighth aspect, wherein the correlated color temperature of the phosphor is different from the correlated color temperature of the phosphor included in the CSP.

[0015] Here, the “correlated color temperature of a phosphor” means the correlated color temperature of the emission color of the phosphor (hereinafter the same).

[0016] A phosphor substrate according to a tenth aspect of the present invention is the phosphor substrate according to the eighth aspect, wherein the correlated color temperature of the phosphor is the same as the correlated color temperature of the phosphor included in the CSP.

[0017] The light emitting substrate of the present invention includes the phosphor substrate according to any one of the first to tenth aspects, and a plurality of light emitting elements bonded to the plurality of electrodes of the first electrode group, respectively.

[0018] The lighting device of the present invention includes the light-emitting substrate described above and a power source for supplying electric power for causing the light-emitting element to emit light.

[0019] The phosphor substrates of the first to tenth aspects of the present invention are phosphor substrates having a phosphor layer on one side and mounting a plurality of light-emitting elements, and can suppress the occurrence of warping caused by heat generated by the plurality of light-emitting elements, compared with a case where no second electrode group is arranged on the other side.

[0020] In addition, the light-emitting substrate of the present invention can suppress the occurrence of warping of the phosphor substrate, thereby stabilizing the light emission from the plurality of light-emitting elements and the phosphor layer.

[0021] The above-mentioned object and other objects, features and advantages will become more apparent from the preferred embodiments described below and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1A It is a top view of the light emitting substrate of this embodiment.

[0023] Figure 1B It is a bottom view of the light emitting substrate and the phosphor substrate of this embodiment.

[0024] Figure 1C Is Figure 1A A partial cross-sectional view of the light-emitting substrate cut along the 1C-1C cutting line.

[0025] Figure 2A It is a top view of the phosphor substrate (the phosphor layer is omitted) of this embodiment.

[0026] Figure 2B It is a top view of the phosphor substrate of this embodiment.

[0027] Figure 3A It is an explanatory diagram of the first step in the method for manufacturing the light emitting substrate of the present embodiment.

[0028] Figure 3B It is an explanatory diagram of the second step in the method for manufacturing the light emitting substrate according to the present embodiment.

[0029] Figure 3C It is an explanatory diagram of the third step in the method for manufacturing the light emitting substrate according to the present embodiment.

[0030] Figure 3D It is an explanatory diagram of the fourth step in the method for manufacturing the light emitting substrate according to the present embodiment.

[0031] Figure 3E It is an explanatory diagram of the fifth step in the method for manufacturing the light emitting substrate according to the present embodiment.

[0032] Figure 4 This is a diagram for explaining the light-emitting operation of the light-emitting substrate of this embodiment.

[0033] Figure 5 It is a diagram for explaining the light-emitting operation of the light-emitting substrate according to the first comparative example.

[0034] Figure 6 This is a graph showing the results of a first test of the correlated color temperature of the light-emitting substrate of the present embodiment.

[0035] Figure 7 This is a graph showing the results of a second test of the correlated color temperature of the light-emitting substrate of the present embodiment.

[0036] Fig. 8A It is a bottom view of a light emitting substrate and a fluorescent substrate of a modified example (first modified example).

[0037] Figure 8B It is a bottom view of a light emitting substrate and a fluorescent substrate of a modification (second modification).

[0038] Figure 8C It is a bottom view of a light-emitting substrate and a fluorescent substrate of a modified example (third modified example). DETAILED DESCRIPTION

[0039] "summary"

[0040] Below, refer to Figure 1A to Figure 1C , Figure 2A , Figure 2B The structure and function of the light emitting substrate 10 of this embodiment will be described. Figure 3A to Figure 3E A method for manufacturing the light emitting substrate 10 of this embodiment will be described. Figure 4 The light emitting operation of the light emitting substrate 10 of this embodiment will be described. Figures 4 to 7 The effects of the present embodiment will be described in the following. In all the drawings referred to in the following description, the same components are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

[0041] 《Structure and function of the light-emitting substrate of this embodiment》

[0042] Figure 1A 3 is a top view (viewed from the surface 31 ) of the light emitting substrate 10 of the present embodiment. Figure 1B It is a bottom view (viewed from the back surface 33 ) of the light emitting substrate 10 according to the present embodiment. Figure 1C Is Figure 1A A partial cross-sectional view of the light-emitting substrate 10 cut along the 1C-1C cutting line.

[0043] The light emitting substrate 10 of the present embodiment is rectangular as an example when viewed from the front surface 31 and the back surface 33. In addition, the light emitting substrate 10 of the present embodiment includes a plurality of light emitting elements 20, a phosphor substrate 30, and electronic components such as a connector and a driver IC (not shown). That is, the light emitting substrate 10 of the present embodiment is equipped with a plurality of light emitting elements 20 and the above-mentioned electronic components on the phosphor substrate 30.

[0044] The light emitting substrate 10 of this embodiment has a function of emitting light when powered by an external power source (not shown) through direct attachment of a wire or via a connector. Therefore, the light emitting substrate 10 of this embodiment is used as a main optical component in a lighting device (not shown) or the like.

[0045] <Multiple light-emitting elements>

[0046] As an example, each of the plurality of light emitting elements 20 is a CSP (Chip Scale Package) in which a flip chip LED 22 (hereinafter referred to as LED 22) is assembled (see Figure 1C ). As a CSP, Figure 1C As shown, the entire periphery (five surfaces) except the bottom surface of LED 22 is preferably covered by phosphor sealing layer 24. Phosphor sealing layer 24 contains phosphor, and the light of LED 22 is color-converted by the phosphor of phosphor sealing layer 24 and emitted to the outside. Figure 1A As shown, a plurality of light emitting elements 20 are mounted on the phosphor substrate 30 in a state where they are regularly arranged on the surface 31 (one side as an example) of the phosphor substrate 30 over the entire surface 31. In addition, the correlated color temperature of the light emitted by each light emitting element 20 of the present embodiment is 3,018K as an example. In addition, when the plurality of light emitting elements 20 are in light emitting operation, heat is dissipated (cooled) by using a heat sink (not shown) and a cooling fan (not shown) so that the phosphor substrate 30 is, as an example, dropped from room temperature to 50°C to 100°C. Here, the meaning of "to" used in the numerical range in this specification is supplemented, for example, "50°C to 100°C" means "50°C or more and 100°C or less". Moreover, "to" used in the numerical range in this specification means "above the recorded part before 'to' and below the recorded part after 'to'".

[0047] <Phosphor substrate>

[0048] Figure 2A This is a diagram of the phosphor substrate 30 according to the present embodiment, and is a plan view (a diagram viewed from the surface 31 ) in which the phosphor layer 36 is omitted. Figure 2B 31 is a top view of the fluorescent substrate 30 of the present embodiment (a view viewed from the surface 31). The bottom view of the fluorescent substrate 30 of the present embodiment is the same as the view of the light-emitting substrate 10 viewed from the back surface 33. Figure 1C The partial cross-sectional view of FIG. 3 is the same as the view without the light emitting element 20. That is, the phosphor substrate 30 of the present embodiment is rectangular as an example when viewed from the front surface 31 and the back surface 33.

[0049] The phosphor substrate 30 of the present embodiment includes an insulating layer 32 (an example of an insulating substrate), an electrode layer 34 (an example of a first electrode group), a phosphor layer 36, and a back pattern layer 38 (an example of a second electrode group) (see Figure 1B , Figure 1C , Figure 2A as well as Figure 2B ). In addition, Figure 2A The phosphor layer 36 is omitted, but Figure 2B As shown, as an example, the phosphor layer 36 is arranged on the surface 31 of the insulating layer 32 and the electrode layer 34 except for a plurality of electrode pairs 34A (an example of a plurality of electrodes) described later.

[0050] In addition, if Figure 1B and Figure 2A As shown, the phosphor substrate 30 is provided with through holes 39 at six locations, namely, four locations near the four corners and two locations near the center. The through holes 39 at the six locations are used as positioning holes when manufacturing the phosphor substrate 30 and the light-emitting substrate 10. Furthermore, the through holes 39 at the six locations are used as threaded holes for installation to ensure the heat dissipation effect to the (light-emitting) lamp housing (to prevent the substrate from warping and floating). In addition, as described later, the phosphor substrate 30 of the present embodiment is obtained by providing two panels (hereinafter referred to as motherboard MB) with copper foil layers on both sides of an insulating plate. Refer to Figure 3A ) is manufactured by processing (etching, etc.), and as an example, CS-3305A manufactured by Richang Industry Co., Ltd. is used.

[0051] 〔Insulation layer〕

[0052] Hereinafter, main features of the insulating layer 32 of this embodiment will be described.

[0053] As described above, the shape is, as an example, a rectangular shape when viewed from the front surface 31 and the back surface 33 .

[0054] As an example of the material, an insulating material including bismaleimide resin and glass cloth is used.

[0055] The thickness is 100 μm to 200 μm as an example.

[0056] As an example, the longitudinal and lateral thermal expansion coefficients (CTE) are respectively 10 ppm / °C or less in the range of 50°C to 100°C. In addition, from another point of view, as an example, the longitudinal and lateral thermal expansion coefficients (CTE) are respectively 6 ppm / K. This value is substantially the same as that of the light emitting element 20 of the present embodiment (90% to 110%, i.e., within ±10%).

[0057] The glass transition temperature, as an example, is above 300°C.

[0058] As an example, the storage modulus is greater than 1.0×10 10 Pa and less than 1.0×10 11 Pa.

[0059] 〔Electrode layer〕

[0060] The electrode layer 34 of this embodiment is a metal layer provided on the surface 31 side of the insulating layer 32. The electrode layer 34 of this embodiment is, for example, a copper foil layer (layer made of Cu). In other words, the electrode layer 34 of this embodiment is formed to contain copper at least on its surface.

[0061] The electrode layer 34 is formed as a pattern provided on the insulating layer 32, and is electrically connected to a terminal (not shown) connected to a connector (not shown). Furthermore, the electrode layer 34 supplies power supplied from an external power source (not shown) via the connector to the plurality of light-emitting elements 20 in the configuration of the light-emitting substrate 10. Therefore, a portion of the electrode layer 34 becomes a plurality of electrode pairs 34A to which the plurality of light-emitting elements 20 are respectively connected. That is, the electrode layer 34 of the light-emitting substrate 10 of the present embodiment is arranged on the insulating layer 32, and is connected to each light-emitting element 20.

[0062] As described above, the plurality of light emitting elements 20 in the light emitting substrate 10 of the present embodiment are regularly arranged over the entire surface 31, and therefore the plurality of electrode pairs 34A are also regularly arranged over the entire surface 31 (see Figure 2A ). The portion other than the plurality of electrode pairs 34A in the electrode layer 34 is referred to as a wiring portion 34B. Figure 1C As shown in FIG. 1 , as an example, the plurality of electrode pairs 34A protrude outward in the thickness direction of the insulating layer 32 (phosphor substrate 30) from the wiring portion 34B. In other words, among the surfaces of the electrode layer 34 facing outward in the thickness direction of the insulating layer 32, the surfaces (bonding surfaces 34A1) bonded to the light emitting elements 20 are located outward in the thickness direction of the insulating layer 32 from the surfaces other than the bonding surfaces 34A1 (non-bonding surfaces 34B1).

[0063] In addition, the region where the electrode layer 34 is arranged on the surface 31 of the insulating layer 32 (defined as the first arrangement region) is, as an example, a region (area) of 60% or more of the surface 31 of the insulating layer 32 (see Figure 2A ). In addition, more than 80% of the first arrangement region overlaps with the region (defined as the second arrangement region) in which the back pattern layer 38 is arranged in the insulation layer 32 in the thickness direction of the insulation layer 32 .

[0064] 〔Phosphor layer〕

[0065] like Figure 2BAs shown in FIG. 1 , as an example, the phosphor layer 36 of the present embodiment is arranged in the portion other than the plurality of electrode pairs 34A in the surface 31 of the insulating layer 32 and the electrode layer 34. That is, the phosphor layer 36 is arranged in the region other than the plurality of electrode pairs 34A in the electrode layer 34. In other words, at least a portion of the phosphor layer 36 is arranged to surround the periphery of each bonding surface 34A1 over the entire circumference when viewed from the surface 31 side (see FIG. 1 ). Figure 1C and Figure 2B ) In the present embodiment, the area on the surface 31 of the insulating layer 32 where the fluorescent layer 36 is arranged is, as an example, 80% or more of the area on the surface 31 of the insulating layer 32 .

[0066] The surface of the phosphor layer 36 on the outside in the thickness direction of the insulating layer 32 is located on the outside in the thickness direction relative to the bonding surface 34A1 of the electrode layer 34 (see Figure 1C ).

[0067] The phosphor layer 36 of the present embodiment is, as an example, an insulating layer including a phosphor and an adhesive described later. The phosphor included in the phosphor layer 36 is a microparticle maintained in a state of being dispersed in an adhesive, and has the property of exciting the light emitted by the LED 22 of each light emitting element 20 as excitation light. Specifically, the phosphor of the present embodiment has the property that the peak wavelength of light emission when the light emitted by the light emitting element 20 is used as excitation light is in the visible light region. In addition, the adhesive is, for example, epoxy, acrylate, silicone, etc., as long as it has the same insulating properties as the adhesive contained in the solder resist.

[0068] (Specific example of phosphor)

[0069] Here, the phosphor included in the phosphor layer 36 of the present embodiment is, as an example, selected from at least one of α-type Sialon phosphors containing Eu, β-type Sialon phosphors containing Eu, CASN phosphors containing Eu, and SCASN phosphors containing Eu. In addition, the above-mentioned phosphor is an example of the present embodiment, and may also be a phosphor other than the above-mentioned phosphors such as YAG, LuAG, BOS, and other visible light-excited phosphors.

[0070] The α-sialon phosphor containing Eu has the general formula: M x Eu y Si 12－(m+n) Al (m+n) O n N 16-nIn the above general formula, M is one or more elements selected from Li, Mg, Ca, Y and lanthanide elements (but excluding La and Ce) including at least Ca, and when the valence of M is a, ax+2y=m, x is 0<x≤1.5, 0.3≤m<4.5, 0<n<2.25.

[0071] The β-sialon phosphor containing Eu is composed of the general formula: Si 6-z Al z O z N 8-z (z = 0.005 ~ 1) represents the divalent europium (Eu 2+ ) is a phosphor in which the luminescent center is solid dissolved in β-sialon.

[0072] In addition, examples of the nitride phosphor include a CASN phosphor containing Eu and a SCASN phosphor containing Eu.

[0073] CASN phosphor containing Eu (an example of nitride phosphor) is, for example, a phosphor of the formula CaAlSiN3:Eu 2+ Expressed in Eu 2+ A red phosphor having a crystal composed of alkaline earth silicon nitride as a matrix and an activator. In addition, in the definition of CASN phosphor containing Eu in this specification, SCASN phosphor containing Eu is excluded.

[0074] The SCASN phosphor containing Eu (an example of a nitride phosphor) is, for example, a phosphor of the formula (Sr, Ca)AlSiN3:Eu 2 + Expressed in Eu 2+ A red phosphor with an activator as its matrix and a crystal composed of alkaline earth silicon nitride.

[0075] 〔Back pattern layer〕

[0076] The back pattern layer 38 of the present embodiment is a metal layer provided on the back surface 33 side of the insulating layer 32. The back pattern layer 38 of the present embodiment is, as an example, a copper foil layer (layer made of Cu).

[0077] like Figure 1B As shown, the back pattern layer 38 is a layer in which a plurality of rectangular portions 38A (an example of a plurality of electrodes, hereinafter referred to as a plurality of portions 38A) are arranged linearly along the long side direction of the insulating layer 32 and are adjacently arranged in a phase-shifted manner in the short side direction. That is, the back pattern layer 38 of this embodiment forms a pattern in which a plurality of portions 38A are arranged.

[0078] In addition, as an example, the back pattern layer 38 is an independent floating layer. That is, the back pattern layer 38 (the plurality of portions 38A constituting it) of this embodiment is a dummy electrode that is not electrically connected to the plurality of electrode pairs 34A of the electrode layer 34 on the surface 31 side. In addition, the area of ​​the second configuration region of this embodiment is set to be larger than the area of ​​the first configuration region (refer to Figure 1B and Figure 2A ), but is set to an area of ​​90% to 110% of the area of ​​the first configuration area.

[0079] The above is the description of the structures of the light emitting substrate 10 and the phosphor substrate 30 according to the present embodiment.

[0080] 《Method for manufacturing light-emitting substrate according to the present embodiment》

[0081] Next, refer to Figure 3A to Figure 3E The method for manufacturing the light emitting substrate 10 of the present embodiment will be described. The method for manufacturing the light emitting substrate 10 of the present embodiment includes a first step, a second step, a third step, a fourth step, and a fifth step, and each step is performed in the order in which it is described.

[0082] <First step>

[0083] Figure 3A 1 and 10 are diagrams showing the start and end of the first step. The first step is a step of forming a pattern 34C identical to the electrode layer 34 when viewed in the thickness direction on the surface 31 of the motherboard MB and forming a back pattern layer 38 on the back surface 33. This step is performed, for example, by etching using a mask pattern (not shown).

[0084] <Second step>

[0085] Figure 3B 34A and 34B are diagrams showing the start and end of the second process. The second process is a process of half-shading (etching to the middle of the thickness direction) a portion of the pattern 34C. After this process is completed, an electrode layer 34 having a plurality of electrode pairs 34A and a wiring portion 34B is formed. That is, after this process is completed, a plurality of bonding surfaces 34A1 and a plurality of non-bonding surfaces 34B1 are formed on the electrode layer 34. This process is performed, for example, by etching using a mask pattern (not shown).

[0086] <Third step>

[0087] Figure 3C3 is a diagram showing the start and end of the third step. The third step is a step of applying a fluorescent coating 36C to the entire surface 31 of the insulating layer 32, that is, the surface on which the electrode layer 34 is formed. In this step, the fluorescent coating 36C is applied, for example, by printing. In this case, the fluorescent coating 36C is applied thicker than all the electrode layers 34. In other words, in this case, the fluorescent coating 36C is applied in the thickness direction of the insulating layer 32 in a manner that covers each bonding surface 34A1 from the outside in the thickness direction (in a manner that each bonding surface 34A1 is shielded by the fluorescent coating 36C).

[0088] <Fourth step>

[0089] Figure 3D : is a diagram showing the start and end of the fourth step. The fourth step is a step of removing a portion of the phosphor layer 36 formed by curing the phosphor paint 36C to expose the bonding surfaces 34A1 of all the electrode pairs 34A. Here, when the binder of the phosphor paint 36C is, for example, a thermosetting resin, after curing the phosphor paint 36C by heating, a two-dimensional laser processing device (not shown) is used to selectively irradiate the portion on each bonding surface 34A1 of the phosphor layer 36 with laser. As a result, the portion on each bonding surface 34A1 of the phosphor layer 36 and the portion near each bonding surface 34A1 of the electrode pair 34A are abraded, and each bonding surface 34A1 is exposed. With the above results, the phosphor substrate 30 of the present embodiment is manufactured.

[0090] In addition to the above method, this step can also be performed by the following method, for example. When the binder of the fluorescent coating 36C is, for example, a UV curable resin (photosensitive resin), a mask pattern is applied to the portion (coating opening portion) overlapping with each bonding surface 34A1, UV light is exposed, and the portion other than the mask pattern is UV cured, and the non-exposed portion (uncured portion) is removed with a resin removing liquid, thereby exposing each bonding surface 34A1. Then, usually, post-curing is performed by heating (photo development method).

[0091] <Fifth step>

[0092] Figure 3E : is a diagram showing the start and end of the fifth process. The fifth process is a process of mounting a plurality of light-emitting elements 20 on a phosphor substrate 30. In this process, a solder paste SP is printed on each bonding surface 34A1 of a plurality of electrode pairs 34A of the phosphor substrate 30, and the solder paste SP is melted in an environment of 250°C as an example while each electrode of the plurality of light-emitting elements 20 is aligned with each bonding surface 34A1. Then, when the solder paste SP is cooled and solidified, each light-emitting element 20 is bonded to each electrode pair 34A. That is, this process is performed by a reflow process as an example.

[0093] The above is the description of the method for manufacturing the light emitting substrate 10 according to the present embodiment.

[0094] 《Light-emitting operation of the light-emitting substrate of the present embodiment》

[0095] Next, refer to Figure 4 The light emitting operation of the light emitting substrate 10 of this embodiment will be described. Figure 4 This is a diagram for explaining the light emitting operation of the light emitting substrate 10 according to the present embodiment.

[0096] First, when an operation switch (not shown) for operating the plurality of light emitting elements 20 is turned on, power is supplied from an external power source (not shown) to the electrode layer 34 via a connector (not shown), and the plurality of light emitting elements 20 radially scatter light L, and a portion of the light L reaches the surface 31 of the phosphor substrate 30. The following describes the path of the light L according to the traveling direction of the emitted light L.

[0097] Part of the light L emitted from each light emitting element 20 is emitted to the outside without entering the fluorescent layer 36. In this case, the wavelength of the light L remains the same as the wavelength of the light L emitted from each light emitting element 20.

[0098] In addition, the light of LED22 itself in a part of the light L emitted from each light emitting element 20 enters the phosphor layer 36. Here, the above-mentioned "light of LED22 itself in a part of the light L" refers to the light in the emitted light L that has not been color-converted by the phosphor (phosphor sealing layer 24) of each light emitting element 20 (CSP itself), that is, the light of LED22 itself (as an example, blue (wavelength of about 470nm) light). Moreover, when the light L of LED22 itself collides with the phosphor dispersed in the phosphor layer 36, the phosphor is excited to emit excitation light. Here, the reason for the excitation of the phosphor is that the phosphor dispersed in the phosphor layer 36 uses a phosphor having an excitation peak for blue light (visible light excitation phosphor). With this, part of the energy of the light L is used for the excitation of the phosphor, and thus the light L loses part of its energy. As a result, the wavelength of the light L is converted (wavelength conversion is performed). For example, depending on the type of phosphor in the phosphor layer 36 (for example, when the phosphor uses a red CASN), the wavelength of the light L becomes longer (for example, 650nm, etc.). In addition, the excitation light in the phosphor layer 36 is sometimes emitted from the phosphor layer 36 as it is, but a part of the excitation light is directed toward the electrode layer 34 on the lower side. Moreover, a part of the excitation light is emitted to the outside by reflection of the electrode layer 34. As described above, when the wavelength of the excitation light emitted by the phosphor of the phosphor layer 36 is greater than 600nm, a reflection effect can be expected even if the electrode layer 34 is Cu. In addition, depending on the type of phosphor of the phosphor layer 36, the wavelength of the light L is different from the above example, but the wavelength conversion of the light L is performed in any case. For example, when the wavelength of the excitation light is less than 600nm, if the electrode layer 34 or its surface is set to Ag (gold plating), a reflection effect can be expected. In addition, a white reflection layer can also be provided on the lower side (insulating layer 32 side) of the phosphor layer 36. The reflection layer is provided by, for example, a white coating such as titanium oxide filler.

[0099] As described above, the light L emitted by each light emitting element 20 (the light L emitted radially by each light emitting element 20) is irradiated to the outside together with the above-mentioned excitation light through the above-mentioned multiple optical paths. Therefore, when the emission wavelength of the phosphor contained in the phosphor layer 36 is different from the emission wavelength of the phosphor (phosphor sealing layer 24) of the LED 22 in the sealing (or covering) light emitting element 20 (CSP), the light emitting substrate 10 of the present embodiment irradiates the beam of light L emitted by each light emitting element 20 as a beam of light L containing light L having a wavelength different from the wavelength of the light L emitted by each light emitting element 20 together with the above-mentioned excitation light. For example, the light emitting substrate 10 of the present embodiment irradiates the synthesized light of the light (wavelength) emitted by the light emitting element 20 and the light (wavelength) emitted by the phosphor layer 36.

[0100] In contrast, when the emission wavelength of the phosphor contained in the phosphor layer 36 is the same as the emission wavelength of the phosphor (phosphor sealing layer 24) of the LED 22 in the sealed (or covered) light emitting element 20 (CSP) (the same correlated color temperature), the light emitting substrate 10 of the present embodiment irradiates the beam of light L emitted by each light emitting element 20 as a beam of light L containing the same wavelength as the wavelength of light L emitted by each light emitting element 20, together with the above-mentioned excitation light.

[0101] The above is the description of the light emitting operation of the light emitting substrate 10 according to the present embodiment.

[0102] <<Effects of the present embodiment>>

[0103] Next, the effects of this embodiment will be described with reference to the drawings.

[0104] <First Effect>

[0105] Regarding the first effect, the present embodiment is compared with the first comparative embodiment described below (see Figure 5 Here, in the description of the first comparison method (and the second comparison method described below), when the same structural elements as those in the present embodiment are used, the same names, figure marks, etc. as those in the present embodiment are used for the structural elements. Figure 5 The diagram is used to explain the light-emitting operation of the light-emitting substrate 10A of the first comparative embodiment. The light-emitting substrate 10A of the first comparative embodiment (substrate 30A on which a plurality of light-emitting elements 20 are mounted) has the same structure as the light-emitting substrate 10 (phosphor substrate 30) of the present embodiment, except that the phosphor layer 36 is not included.

[0106] In the case of the light emitting substrate 10A of the first comparative embodiment, the light L emitted from each light emitting element 20 and incident on the surface 31 of the substrate 30A is reflected or scattered without wavelength conversion. Therefore, in the case of the substrate 30A of the first comparative embodiment, when the light emitting element 20 is mounted, it is not possible to adjust the light to a light of a different light color from the light emitted by the light emitting element 20. That is, in the case of the light emitting substrate 10A of the first comparative embodiment, it is not possible to adjust the light to a light of a different light color from the light emitted by the light emitting element 20.

[0107] In contrast, in the present embodiment, when viewed from the thickness direction of the insulating layer 32, the phosphor layer 36 is disposed on the surface 31 of the insulating layer 32 and around each bonding surface 34A1 with each light emitting element 20. Therefore, a portion of the light L radially emitted from each light emitting element 20 is incident on the phosphor layer 36, and is wavelength-converted by the phosphor layer 36 and irradiated to the outside. In this case, a portion of the light L radially emitted from each light emitting element 20 is incident on the phosphor layer 36, exciting the phosphor contained in the phosphor layer 36 to generate excitation light.

[0108] here, Figure 6 : is a graph showing the results of the first test of the correlated color temperature of the light emitting substrate 10 of the present embodiment. Figure 7 : is a graph showing the results of the second test of the correlated color temperature of the light emitting substrate 10 according to the present embodiment.

[0109] The first test is a result obtained by investigating the relationship between current (mA) and correlated color temperature (K) for a plurality of light emitting elements 20 when power is supplied to a light emitting substrate 10 having a plurality of light emitting elements 20 having a correlated color temperature of 2200K to 2300K to cause the light emitting elements 20 to emit light. Here, HE (1) and HE (2) represent two examples in which the structure of the electrode layer 34 is the same as that of the present embodiment. Figure 6 As shown in the results, in any case, the correlated color temperature of the light L emitted by the light emitting substrate 10 is lower than the correlated color temperature of the plurality of light emitting elements 20. That is, in the case of this embodiment, by providing the phosphor layer 36, the correlated color temperature can be shifted.

[0110] In addition, the second test is the result of investigating the relationship between the current (mA) and the correlated color temperature (K) of the plurality of light-emitting elements 20 when power is supplied to the light-emitting substrate 10 having the plurality of light-emitting elements 20 having a correlated color temperature of 2900K to 3000K to make them emit light. Here, HE (1) indicates the case where the structure of the electrode layer 34 is the same as that of the present embodiment. Figure 7 As shown in the results, the correlated color temperature of the light L emitted by the light emitting substrate 10 is lower than the correlated color temperature of the plurality of light emitting elements 20. That is, in the case of the present embodiment, by providing the phosphor layer 36, the correlated color temperature can be shifted.

[0111] Therefore, according to the phosphor substrate 30 of the present embodiment, when the light emitting element 20 is mounted, the light L emitted from the phosphor substrate 30 can be adjusted to light of a different luminous color from the light L emitted by the light emitting element 20. Accordingly, according to the light emitting substrate 10 of the present embodiment, the light L emitted from the phosphor substrate 30 can be adjusted to light of a different luminous color from the light L emitted by the light emitting element 20. From another point of view, according to the light emitting substrate 10 of the present embodiment, light L of a different luminous color from the light L emitted by the light emitting element 20 can be irradiated to the outside.

[0112] <Second effect>

[0113] In the case of the first comparison method, such as Figure 5 As shown in FIG. 1 , a spot is generated in the light L irradiated to the outside due to the arrangement interval of each light emitting element 20. Here, the larger the spot of the light L is, the larger the glare is.

[0114] In contrast, in the case of this embodiment, if Figure 2B As shown, each bonding surface 34A1 is surrounded by the phosphor layer 36 (over the entire circumference), and the phosphor layer 36 is also provided between adjacent light emitting elements 20. Therefore, excitation light is also emitted from the periphery of each bonding surface 34A1 (the periphery of each light emitting element 20).

[0115] Therefore, according to the present embodiment, glare can be reduced compared to the first comparative example.

[0116] This effect is particularly effective when phosphor layer 36 is provided over the entire surface of insulating layer 32 , specifically, when the area where phosphor layer 36 is arranged on surface 31 of insulating layer 32 accounts for 80% or more of surface 31 .

[0117] <Third Effect>

[0118] As described above, when the plurality of light emitting elements 20 are in light emitting operation, heat is dissipated (cooled) by using a heat sink (not shown) and a cooling fan (not shown) so that the phosphor substrate 30 is cooled from room temperature to 50° C. to 100° C., for example.

[0119] Here, in the case of a mode (not shown, referred to as a second comparative mode) that is different from the present embodiment only in that the back surface 33 does not include the back surface pattern layer 38, due to the influence of the above-mentioned heat generation, when the electrode layer 34 and the insulating layer 32 are thermally expanded, the thermal expansion coefficients are different from each other, so warping occurs in the phosphor substrate 30. As a result, in the case of the second comparative mode, there is a concern that the traveling direction of the light L emitted from the plurality of light emitting elements 20 and the phosphor layer 36 is affected by the warping. In addition, in the case of the second comparative mode, there is a concern that cracks are generated in the phosphor layer 36 due to the warping.

[0120] On the other hand, the phosphor substrate 30 of the present embodiment includes a back pattern layer 38 disposed on the back surface 33 of the insulating layer 32 (see Figure 1B ). Therefore, by attaching components with the same thermal behavior (expansion, contraction) (i.e., components of the same shape) on the front and back sides via the insulating layer 32, warping can be suppressed. If the Cu pattern is laid only on the surface 31 side, stress and warping will occur at the interface of materials with different thermal behaviors, but by sandwiching it between the two sides, the warping can be forcibly eliminated. In other words, according to the phosphor substrate 30 of this embodiment, the occurrence of warping of the phosphor substrate 30 can be suppressed compared to the case of the second comparative embodiment. Along with this, the light-emitting substrate 10 of this embodiment can stabilize the light emission from multiple light-emitting elements 20 and the phosphor layer 36.

[0121] In the present embodiment, the ratio of the first arrangement region (the arrangement region of the electrode layer 34) to the surface 31 of the insulating layer 32 is 60% or more (see Figure 2A ). Therefore, the wiring portion 34B (see Figure 2A That is, in the case of this embodiment, the electrode layer 34 and the back pattern layer 38 cooperate to effectively dissipate the heat generated by the plurality of light emitting elements 20.

[0122] In addition, in this embodiment, at least a portion (80% or more) of the first configuration region overlaps with the back pattern layer 38 in the thickness direction of the insulating layer 32. Therefore, it can be said that this is effective in that the heat of the insulating layer 32 can be efficiently released (dissipated) from both sides in the thickness direction.

[0123] In addition, in the present embodiment, the area of ​​the second configuration region is 90% to 110% of the area of ​​the first configuration region. That is, the back pattern layer 38 is in contact with the electrode layer 34 in an almost equal area (about ±10%) in the insulating layer 32. Therefore, the heat of the insulating layer 32 can be efficiently dissipated from the surface 31 side and the back surface 33 side of the insulating layer 32.

[0124] The above is the description of the effects of the present embodiment.

[0125] As described above, the present invention has been described by taking the above-mentioned embodiment and examples as examples, but the present invention is not limited to the above-mentioned embodiment and examples. The technical scope of the present invention also includes the following aspects (modifications), for example.

[0126] For example, in the description of this embodiment, an example of the light emitting element 20 is set as CSP. However, an example of the light emitting element 20 may be other than CSP. For example, only a flip chip may be mounted. In addition, it can also be applied to the substrate itself of the COB device.

[0127] In the description of this embodiment, the surface of the fluorescent layer 36 on the outside in the thickness direction of the insulating layer 32 is located on the outside in the thickness direction relative to the bonding surface 34A1 of the electrode layer 34 (see Figure 1C ). However, considering the mechanism of the first effect described above, it is obvious that the first effect can be achieved even if the surface of the insulating layer 32 of the phosphor layer 36 on the outside in the thickness direction is located at the same thickness direction as the bonding surface 34A1 of the electrode layer 34 or on the inside in the thickness direction than the bonding surface 34A1.

[0128] In the description of this embodiment, the phosphor layer 36 is disposed on the surface 31 of the insulating layer 32 and the electrode layer 34 other than the plurality of electrode pairs 34A (see Figure 2B ). However, considering the mechanism of the first effect described above, it is obvious that the first effect can be achieved even if the arrangement is not arranged over the entire area of ​​the portion other than the plurality of electrode pairs 34A in the surface 31 of the phosphor substrate 30. Therefore, even if the method is different from the phosphor substrate 30 and the light-emitting substrate 10 of the present embodiment in that the phosphor layer 36 is arranged only in the range of the surface 31, which is different from the case of the present embodiment, it can be said that the method belongs to the technical scope of the present invention.

[0129] In the description of the present embodiment, CS-3305A manufactured by Richang Industry Co., Ltd. is used as the motherboard MB when manufacturing the phosphor substrate 30 and the light-emitting substrate 10. However, this is only an example, and a different motherboard MB may be used.

[0130] In addition, in the present embodiment, the back pattern layer 38 (the plurality of portions 38A constituting the back pattern layer 38) is described as a dummy electrode that is not electrically connected to the plurality of electrode pairs 34A of the electrode layer 34 on the surface 31 side. However, the back pattern layer 38 may be connected to the electrode layer 34 on the surface 31, for example, via a through hole (not shown), and the back pattern layer 38 may be configured as a part of an electrical path for supplying power to the electrode layer 34, or as a part of a heat dissipation path.

[0131] In addition, the back pattern layer 38 of this embodiment is arranged as an example. Figure 1B However, the second electrode group of the present invention may have a pattern different from that of the back surface pattern layer 38 of the present embodiment.

[0132] For example, Fig. 8A Like the back pattern layer 38B of the phosphor substrate 30B (light-emitting substrate 10B) of the first modified example, the second electrode group of the present invention may be a combination of elongated bodies (plurality of portions 38B1) arranged along the long side direction of the phosphor substrate 30B.

[0133] In addition, for example, Figure 8B Like the back pattern layer 38C of the second variant of the phosphor substrate 30C (light-emitting substrate 10C), the second electrode group of the present invention can also be a combination of elongated bodies (multiple parts 38C1) arranged from one end of the short side direction of the phosphor substrate 30C along the other end.

[0134] In addition, for example, Figure 8C Like the back pattern layer 38D of the phosphor substrate 30D (light-emitting substrate 10D) of the third variant example, the second electrode group of the present invention can also be a combination of a plurality of island-shaped blocks composed of a plurality of rectangular parts 38D1, and a part other than the plurality of island-shaped blocks (a mesh-shaped part 38D2 extending from one end to the other end in the long side direction of the phosphor substrate 30D and from one end to the other end in the short side direction).

[0135] As described above, the second electrode group of the present invention may be in any pattern. In this case, it is preferred that the second electrode group be in a pattern similar to that of the first electrode group.

[0136] The light emitting substrate 10 of this embodiment (including its modified examples) can be combined with other components and applied to a lighting device. In this case, the other components are a power supply for supplying power for causing the light emitting element 20 of the light emitting substrate 10 to emit light.

[0137] This application claims the benefit of priority based on Japanese patent application No. 2018-244545, filed on December 27, 2018, the disclosure of which is incorporated herein in its entirety.

Claims

1. A light-emitting substrate, wherein: have: a phosphor substrate; and A plurality of light emitting elements are mounted on the surface of the phosphor substrate. The fluorescent substrate comprises: Insulating substrate; A first electrode layer, disposed on a surface of the insulating substrate, having a plurality of electrode pairs bonded to the plurality of light-emitting elements; a phosphor layer disposed on the surface of the insulating substrate in such a manner as to form the surface of the phosphor substrate, and comprising a second phosphor having a peak emission wavelength in the visible light region when the emission of the light emitting element is used as excitation light; as well as The second electrode group is disposed on the back side of the insulating substrate and has a plurality of electrodes. The light emitting element is formed as a CSP having an LED covered by a phosphor sealing layer and packaged as a chip-sized, The phosphor sealing layer contains a first phosphor and covers the surface of the light emitting element other than the bottom surface. The phosphor layer is disposed on the surface of the insulating substrate and the first electrode layer at a portion other than the plurality of electrode pairs. The area on the surface of the insulating substrate where the fluorescent layer is arranged accounts for 80% or more of the area on the surface of the insulating substrate. The wavelength of the excitation light of the first phosphor is different from the wavelength of the excitation light of the second phosphor.

2. The light-emitting substrate according to claim 1, wherein: At least a portion of a first arrangement region of the insulating substrate as an arrangement region of the first electrode layer overlaps with a second arrangement region of the insulating substrate as an arrangement region of the second electrode group in the insulating substrate in the thickness direction of the insulating substrate.

3. The light-emitting substrate according to claim 2, wherein: More than 80% of the first arrangement region overlaps with the second arrangement region in the thickness direction of the insulating substrate.

4. The light-emitting substrate according to claim 2 or 3, wherein: The area of ​​the second arrangement region is not less than 90% and not more than 110% of the area of ​​the first arrangement region.

5. The light-emitting substrate according to claim 2 or 3, wherein: The first arrangement region is a region that is 60% or more of the surface of the insulating substrate.

6. The light emitting substrate according to any one of claims 1 to 3, wherein The plurality of electrodes included in the second electrode group are provided as dummy electrodes that are not electrically connected to the plurality of electrode pairs included in the first electrode layer.

7. The light-emitting substrate according to any one of claims 1 to 3, wherein The second electrode group is patterned.

8. The light emitting substrate according to any one of claims 1 to 3, wherein The correlated color temperature of the second phosphor included in the phosphor layer is different from the correlated color temperature of the first phosphor included in the CSP.

9. The light emitting substrate according to any one of claims 1 to 3, wherein The correlated color temperature of the second phosphor included in the phosphor layer is the same as the correlated color temperature of the first phosphor included in the CSP.

10. A lighting device, wherein: have: The light-emitting substrate according to any one of claims 1 to 9; and A power source supplies electric power for causing the light emitting element to emit light.

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