The present invention relates to a phosphor board, a light-emitting substrate, and a lighting apparatus.
Patent Document 1 discloses a light-emitting diode (LED) lighting fixture provided with a substrate on which a light-emitting element (LED element) is mounted. This LED lighting fixture is provided with a reflective material on the surface of the substrate to improve the light-emitting efficiency.
[Patent Document 1] Chinese Patent Publication No. 106163113
However, in the case of the configuration disclosed in Patent Document 1, it was not possible to adjust the light emitted by the LED lighting fixture using a reflective material to be light emitted with a color different from the light emitted by the light-emitting element and the glare counter-measures were insufficient.
The present invention has an object of providing a phosphor board capable of reducing the glare of light emitted by a light-emitting element in a case where the light-emitting element is mounted thereon.
A phosphor board of a first aspect of the present invention is a phosphor board over which at least one light-emitting element is mounted, the phosphor board including an insulating substrate, a circuit pattern layer which is disposed over one surface of the insulating substrate and which is to be bonded to the at least one light-emitting element, a phosphor layer which is disposed over the one surface side of the insulating substrate and which includes phosphor for which a light emission peak wavelength is in a visible light region when emitted light of the at least one light-emitting element is used as excitation light, and a support layer which is disposed between the insulating substrate and the phosphor layer, which is a layer that does not include the phosphor, and which supports the phosphor layer.
The phosphor board of a second aspect of the present invention is the phosphor board described above in which the support layer has a monolayer structure including a white pigment.
The phosphor board of a third aspect of the present invention is the phosphor board described above in which the support layer is also disposed between a portion of the circuit pattern layer other than a portion to be bonded to the at least one light-emitting element, and the phosphor layer.
The phosphor board of a fourth aspect of the present invention is the phosphor board described above in which the support layer has a multilayer structure in which an adjacent layer that is adjacent to the phosphor layer includes a white pigment.
The phosphor board of a fifth aspect of the present invention is the phosphor board described above in which the support layer is formed of the adjacent layer and a base layer which is disposed between the insulating substrate and the adjacent layer and which does not include a white pigment, and a thickness of the adjacent layer is thinner than a thickness of the base layer.
The phosphor board of a sixth aspect of the present invention is the phosphor board described above in which the adjacent layer is also disposed between a portion of the circuit pattern layer other than a portion to be bonded to the at least one light-emitting element, and the phosphor layer.
The phosphor board of a seventh aspect of the present invention is the phosphor board described above in which the phosphor is formed of a plurality of phosphor particles, the white pigment is formed of a plurality of white particles, and D150, which is a volume-based median diameter (D50) of the plurality of phosphor particles measured by a laser diffraction scattering method, and D250, which is a volume-based median diameter (D50) of the plurality of white particles measured by the laser diffraction scattering method, have a relationship as in (Equation 1) below.
The phosphor board of an eighth aspect of the present invention is the phosphor board described above in which a thickness of the phosphor layer is thinner than a thickness of the support layer.
The phosphor board of a ninth aspect of the present invention is the phosphor board described above in which an outer surface of the phosphor layer is positioned outside of an outer surface of the circuit pattern layer, in a thickness direction of the insulating substrate.
The phosphor board of a tenth aspect of the present invention is the phosphor board described above in which the at least one light-emitting element is a plurality of light-emitting elements.
A light-emitting substrate of a first aspect of the present invention includes the phosphor board described above, and the at least one light-emitting element.
A lighting apparatus of a first aspect of the present invention includes the light-emitting substrate described above, and a power supply for supplying power to emit light from the at least one light-emitting element.
A description will be given of the first to fifth embodiments, which are examples of the present invention, in the described order. Next, a description will be given of modifications of these embodiments. In all drawings referred to in the following description, the same constituent components will be marked with the same reference numerals and not be repeated.
A description will be given below of the first embodiment with reference to
Since a phosphor board 30 of the present embodiment is a constituent component of the light-emitting substrate 10 of the present embodiment, description thereof will be given in the description of the configuration and function of the light-emitting substrate 10 of the present embodiment.
The light-emitting substrate 10 of the present embodiment is rectangular when viewed from the surface 31A side and the rear surface 33A side, as an example. In addition, the light-emitting substrate 10 of the present embodiment is provided with a plurality of the light-emitting elements 20, the phosphor board 30, and electronic components (not shown) such as connectors and driver ICs. That is, in the light-emitting substrate 10 of the present embodiment, the plurality of the light-emitting elements 20 and the electronic components described above are mounted on the phosphor board 30.
The light-emitting substrate 10 of the present embodiment has the function of emitting light when power is supplied from an external power source (not shown) through a connector. Therefore, the light-emitting substrate 10 of the present embodiment is used as a main optical component in, for example, a lighting device (not shown) or the like.
A detailed description will be given in the following description, but the basic configurations of the phosphor board 30 and the light-emitting substrate 10 of the present embodiment are as follows, respectively.
The phosphor board 30 of the present embodiment is the phosphor board 30 on which at least one light-emitting element 20 is mounted and which is provided with an insulating layer 32 (an example of an insulating substrate), a circuit pattern layer 34 disposed on a surface 31 (an example of a surface) of the insulating layer 32 and bonded to the at least one light-emitting element 20, a phosphor layer 36 that is disposed on the surface 31 side of the insulating layer 32 and that includes a phosphor for which the emission peak wavelength is in the visible light region when the emitted light of the at least one light-emitting element 20 is used as excitation light, and a support layer 35 which is a layer that does not include the phosphor, which supports the phosphor layer 36, and which is disposed between the insulating layer 32 and the phosphor layer 36.
In addition, the light-emitting substrate 10 of the present embodiment is provided with the phosphor board 30 having the basic configuration described above and the at least one light-emitting element 20.
The plurality of the light-emitting elements 20 are each a Chip Scale Package (CSP) in which a flip chip LED 22 (referred to below as LED 22) is incorporated (refer to
In addition, a junction level JL of the LED 22 is set to a position higher than the level of the surface of the phosphor layer 36. Here, to further explain the meaning of “to” used for numerical value ranges in the present specification, for example, “50° C. to 100° C.” means “50° C. or higher and 100° C. or lower”. That is, “to” as used for numerical value ranges in the present specification means “the portion described before ‘to’ or more and the portion described after ‘to’ or less”.
Although the range of a plurality of electrode pairs 34A, which will be described below, and wiring portions 34B, which are portions other than the plurality of the electrode pairs 34A, are illustrated in
The phosphor board 30 of the present embodiment is provided with the insulating layer 32, the circuit pattern layer 34, the support layer 35, the phosphor layer 36, and a rear surface pattern layer 38 (refer to
In addition, through holes 39 are formed in the phosphor board 30 in a total of six locations, four near the four corners and two near the center, as shown in
A description will be given below of the main features of the insulating layer 32 of the present embodiment. As described above, the shape is rectangular as viewed from the surface 31 side and a rear surface 33 side, as an example.
The material is an insulating material including bismaleimide resin and glass cloth, as an example.
The thickness is 100 µm, as an example.
The coefficients of thermal expansion (CTE) in the longitudinal direction and transverse direction are each 10 ppm/°C or less in a range of 50° C. to 100° C., as an example. In addition, from another viewpoint, the coefficients of thermal expansion (CTE) in the longitudinal direction and transverse direction are each 6 ppm/K, as an example. This value is almost equivalent (90% to 110%, that is, within ±10%) to that in the case of the light-emitting element 20 of the present embodiment.
The glass transition temperature is higher than 300° C., as an example.
The storage modulus is greater than 1.0 × 1010 Pa and less than 1.0 × 1011 Pa in a range of 100° C. to 300° C., as an example.
As an example, the flexural moduli in the longitudinal direction and transverse direction are, 35 GPa and 34 GPa, respectively, under normal conditions.
The hot flexural moduli in the longitudinal direction and transverse direction are 19 GPa at 250° C., as an example. As an example, the water absorption is 0.13% in a case of being left for 24 hours in an environment at a temperature of 23° C. The dielectric constant is 4.6 at 1 MHz under normal conditions, as an example. The dielectric loss tangent is 0.010 at 1 MHz under normal conditions, as an example.
The circuit pattern layer 34 of the present embodiment is a metal layer provided on the surface 31 of the insulating layer 32, as an example, a copper foil layer (a layer made of Cu), and is conductive with terminals 37 bonded to a connector (not shown). The circuit pattern layer 34 supplies power supplied from an external power source (not shown) through the connector to the plurality of the light-emitting elements 20 in the state of forming the light-emitting substrate 10. Therefore, a part of the circuit pattern layer 34 is a plurality of the electrode pairs 34A to which the plurality of the light-emitting elements 20 are respectively bonded. That is, the circuit pattern layer 34 is disposed on the surface 31 of the insulating layer 32 and connected to each of the light-emitting elements 20. In addition, from another view, the circuit pattern layer 34 is disposed on the surface 31 of the insulating layer 32 and is connected to each of the light-emitting elements 20 at bonding surfaces 34A1, which are the outer surfaces of each of the electrode pairs 34A.
In addition, as described above, since the plurality of the light-emitting elements 20 are regularly lined up over the entire surface 31 side of the insulating layer 32 (refer to
Viewed from the surface 31 side, the ratio (the exclusive area of the circuit pattern layer 34) of the circuit pattern layer 34 with respect to the surface 31 of the insulating layer 32, is 60% or more of the surface 31 of the insulating layer 32, as an example (refer to
The support layer 35 of the present embodiment, as described above, is disposed on a portion of the surface 31 of the insulating layer 32 other than the portion where the circuit pattern layer 34 is disposed and supports a part of the phosphor layer 36 (refer to
The support layer 35 of the present embodiment, unlike the phosphor layer 36 described below, does not include a phosphor (an aggregate of a plurality of phosphor particles), but is an insulating layer that, as an example, includes a white pigment (an aggregate of a plurality of white particles) and a binder, in which the plurality of white particles are dispersed in the binder. In addition, the support layer 35 in the present embodiment is a monolayer structure, as an example. Here, as an example, the plurality of white particles are titanium oxide, but may also be calcium oxide or other white particles. In addition, the binder may be, for example, an epoxy-based binder, an acrylate-based binder, a silicone-based binder, or the like, as long as the binder has insulating properties equivalent to those of a binder included in a solder resist.
As described above, the support layer 35 is disposed between the insulating layer 32 and the phosphor layer 36 (refer to
The phosphor layer 36 of the present embodiment is disposed on the surface (the upper side surface in the figure) of the support layer 35 on the opposite side to the insulating layer 32 and on the non-bonding surface 34B1 of the circuit pattern layer 34, as shown in
The outer side surface (outer surface) of the phosphor layer 36 in the thickness direction of the insulating layer 32 is positioned outside, in the thickness direction, of the outer side surface (outer surface) of the circuit pattern layer 34 in the thickness direction of the insulating layer 32 (refer to
The phosphor layer 36 in the present embodiment is, for example, an insulating layer that includes a phosphor (an aggregate of a plurality of phosphor particles) and a binder, as described below, in which the plurality of phosphor particles are dispersed in the binder. The phosphor included in the phosphor layer 36 has the property of exciting the emitted light of each of the light-emitting elements 20 to be used as excitation light. Specifically, the phosphor of the present embodiment has a property in which the light emission peak wavelength is in the visible light region when the light emission of the light-emitting elements 20 is used as excitation light. The binder may be, for example, an epoxy-based binder, an acrylate-based binder, a silicone-based binder, or the like that has insulating properties equivalent to those of a binder included in a solder resist.
Here, in the present specification, the volume-based median diameter (D50), as measured by a laser diffraction scattering method, of the plurality of phosphor particles included in the phosphor layer 36 is denoted as D150. In addition, the volume-based median diameter (D50), as measured by a laser diffraction scattering method, of the plurality of white particles included in the support layer 35 is denoted as D250. Then, in the phosphor board 30 of the present embodiment, D150 and D250 have the relationship in (Equation 1), as an example.
That is, in the present embodiment, the median diameter (D50) of the plurality of white particles forming the white pigment is set to be in a range of 80% or more and 120% or less with respect to the median diameter (D50) of the plurality of phosphor particles forming the phosphor.
Here, the phosphor included in the phosphor layer 36 of the present embodiment is, as an example, at least one type of phosphor selected from the group consisting of α-type sialon phosphors containing Eu, β-type sialon phosphors containing Eu, CASN phosphors containing Eu, and SCASN phosphors containing Eu. The phosphors described above are examples in the present embodiment and phosphors other than the phosphors described above may also be used, such as YAG, LuAG, BOS, and other phosphors with visible light excitation.
The α-type sialon phosphors containing Eu are represented by general formula MxEuySil2-(m+n)Al(m+n)OnN16n. In the general formula described above, M is one type of element or more, including at least Ca, selected from the group consisting of Li, Mg, Ca, Y, and lanthanide elements (excluding La and Ce) and, when the valence of M is a, ax + 2y = m, where x is 0 < x ≤ 1.5, 0.3 ≤ m < 4.5, and 0 < n < 2.25.
The β-type sialon phosphor containing Eu is a phosphor in which divalent europium (Eu2+) is solid-dissolved as the light-emitting center in a β-type sialon represented by general formula: Si6-zAlzOzN8-z (z = 0.005 to 1).
In addition, examples of nitride phosphors include CASN phosphors containing Eu, SCASN phosphors containing Eu, and the like.
CASN phosphors containing Eu refer to, for example, a red phosphor represented by the formula CaAlSiN3:Eu2+, in which Eu2+ is used as an activator, and a crystal formed of alkaline earth silicon nitride is set as the matrix. In the definition of CASN phosphors containing Eu in the present specification, SCASN phosphors containing Eu are excluded.
SCASN phosphors containing Eu refer to, for example, a red phosphor represented by formula (Sr,Ca)AlSiN3:Eu2+, in which Eu2+ is used as an activator, and a crystal formed of alkaline earth silicon nitride is set as the matrix.
The rear surface pattern layer 38 of the present embodiment is a metal layer provided on the rear surface 33 of the insulating layer 32, as an example, a copper foil layer (a layer made of Cu) .
As shown in
As an example, the rear surface pattern layer 38 overlaps 80% or more of the region of the circuit pattern layer 34 disposed on the surface 31 as viewed from the thickness direction of the insulating layer 32.
The foregoing was a description of the configuration of the light-emitting substrate 10 and the phosphor board 30 of the present embodiment.
Next, a description will be given of the method for manufacturing the light-emitting substrate 10 of the present embodiment with reference to
A detailed description will be given in the following description, but the basic configurations of the method for manufacturing the phosphor board 30 and the method for manufacturing the light-emitting substrate 10 of the present embodiment, are as follows, respectively.
The method for manufacturing the phosphor board 30 of the present embodiment includes a first step (circuit pattern layer forming step) of forming the circuit pattern layer 34 to be bonded to at least one of the light-emitting elements 20 on the surface 31 (an example of one surface) of the insulating layer 32 (an example of an insulating substrate), a third step (phosphor layer forming step) of forming, on the surface 31 side of the insulating layer 32, the phosphor layer 36 including a phosphor in which the emission peak wavelength is in the visible light region when the emitted light of the at least one light-emitting element 20 is used as excitation light, and a second step (support layer forming step) of forming the support layer 35, which is a layer that does not include the phosphor and which supports the phosphor layer 36, between the insulating layer 32 and the phosphor layer 36, in which, in the phosphor layer forming step, the phosphor layer 36 is laminated on the support layer 35.
The method for manufacturing the light-emitting substrate 10 of the present embodiment includes the method for manufacturing the phosphor board 30 of the present embodiment described above and a fifth step (bonding step) of bonding at least one of the light-emitting elements 20 to the circuit pattern layer 34.
The support layer 35 formed by this step may be formed by coating the white paint once or a plurality of times in the thickness direction of the insulating layer 32.
In addition to the method described above, this step may be performed by, for example, the following method. In a case where the phosphor paint binder is, for example, a UV curable resin (photosensitive resin), a mask pattern is applied to the portion (paint opening portion) overlapping each of the bonding surfaces 34A1 and exposed to UV light, the portions other than the mask pattern are UV cured, and the unexposed portions (uncured portions) are removed with a resin removal solution to expose each of the bonding surfaces 34A1. Thereafter, generally, after-curing is performed by the application of heat (photo-developing method). In addition, instead of the third step and fourth step, the phosphor layer 36 may be formed by screen-printing using a screen mask (not shown) in which opening portions are set in advance (screen-printing method). In such a case, the phosphor paint opening portions in the portions overlapping the bonding surfaces 34A1 in the screen mask may be root-clogged.
When this step is completed, the phosphor board 30 is manufactured.
When this step is completed, the light-emitting substrate 10 is manufactured.
The foregoing was a description of the method for manufacturing the light-emitting substrate 10 of the present embodiment.
Next, a description will be given of the light-emitting operation of the light-emitting substrate 10 of the present embodiment with reference to
First, when an activation switch (not shown) that activates the plurality of the light-emitting elements 20 is turned on, power supply is started from an external power source (not shown) through a connector (not shown) to the circuit pattern layer 34, the plurality of the light-emitting elements 20 scatter and emit light L in a radial manner and a part of the light L reaches the surface 31A of the phosphor board 30. More specifically, the light emission in the LEDs 22 of the light-emitting elements 20 is carried out at the junction level JL of the LEDs 22 (that is, the PN bonding surface) (refer to
A description will be given below of the behavior of the light L, separated into the travel directions of the emitted light L.
A part of the light L emitted from each of the light-emitting elements 20 is emitted outside without being incident to the phosphor layer 36. In such a case, the wavelength of the light L remains the same as the wavelength of the light L when emitted from each of the light-emitting elements 20.
In addition, the light of the LED 22 itself in a part of the light L emitted from each of the light-emitting elements 20 is incident to the phosphor layer 36. Here, the “light of the LED 22 itself in a part of the light L” means the light in the emitted light L that is not color-converted by the phosphor of each of the light-emitting elements 20 (the CSP itself), that is, the light of the LED 22 itself (as an example, blue light (with a wavelength in the vicinity of 470 nm)).
When the light L of the LED 22 itself hits the phosphor dispersed in the phosphor layer 36, the phosphor is excited and emits excitation light. Here, the reason why the phosphors are excited is because phosphors (visible light excitation phosphors) having an excitation peak in blue light are used for the phosphors dispersed in the phosphor layer 36.
Accordingly, some of the energy of the light L is used to excite the phosphors and the light L loses some 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, in a case where red CASN is used as the phosphor), the wavelength of the light L becomes longer (for example, 650 nm or the like).
In addition, the excitation light in the phosphor layer 36 may be emitted from the phosphor layer 36 as it is, but a part of the excitation light is directed to the circuit pattern layer 34 on the lower side and a part of the excitation light is directed to the support layer 35 on the lower side.
The excitation light directed to the circuit pattern layer 34 is then emitted to the outside due to reflection from the circuit pattern layer 34. As above, in a case where the wavelength of the excitation light by the phosphor is 600 nm or longer, a reflection effect is expected even when the circuit pattern layer 34 is Cu. Depending on the type of phosphor in the phosphor layer 36, the wavelength of the light L may differ from the example described above, but in any case, the light L is subjected to wavelength conversion. For example, in a case where the wavelength of the excitation light is less than 600 nm, a reflection effect is expected when the circuit pattern layer 34 or the surface thereof is, for example, Ag (plated) . In contrast, the excitation light directed to the support layer 35 is emitted to the outside due to reflection from the white pigment of the support layer 35. In such a case, it is possible to improve the reflection effect in the entire wavelength range of visible light.
As described above, the light L emitted by each of the light-emitting elements 20 (the light L emitted in a radial manner by each of the light-emitting elements 20) is respectively irradiated to the outside together with the excitation light described above through a plurality of optical paths as described above. Therefore, in a case where the light emission wavelength of the phosphor included in the phosphor layer 36 and the light emission wavelength of the phosphor sealing (or covering) the LED 22 in the light-emitting element 20 (CSP) are different, the light-emitting substrate 10 of the present embodiment irradiates, together with the excitation light described above, a bundle of the light L when each of the light-emitting elements 20 carries out emission, as a bundle of the light L including the light L of a wavelength different from the wavelength of the light L emitted by each of the light-emitting elements 20. For example, the light-emitting substrate 10 of the present embodiment irradiates a composite light of the light (wavelength) emitted by the light-emitting element 20 and the light (wavelength) emitted from the phosphor layer 36.
In contrast, in a case where the light emission wavelength of the phosphor included in the phosphor layer 36 and the light emission wavelength of the phosphor sealing (or covering) the LED 22 in the light-emitting element 20 (CSP) are the same (in a case of the same correlated color temperature), the light-emitting substrate 10 of the present embodiment irradiates, together with the excitation light described above, a bundle of the light L when each of the light-emitting elements 20 carries out emission as a bundle of the light L including the light L of the same wavelength as the wavelength of the light L when each of the light-emitting elements 20 carries out emission.
The foregoing was a description of the light-emitting operation of the light-emitting substrate 10 of the present embodiment.
Next, a description will be given below of the effects of the present embodiment with reference to the drawings.
A description will be given of the first effect by comparing the present embodiment with a comparative form (refer to
In the case of the light-emitting substrate 10a of the comparative form, the light L emitted from each of the light-emitting elements 20 and incident to the surface 31A of the substrate 30a is reflected or scattered without wavelength conversion. Therefore, in the case of the substrate 30a of the comparative form, it is not possible to adjust the light to an emitted light color different from the light emitted by the light-emitting elements 20 in a case where the light-emitting elements 20 are mounted thereon. That is, in the case of the light-emitting substrate 10a of the comparative form, it is not possible to adjust the light to an emitted light color different from the light emitted by the light-emitting elements 20.
In contrast, in the case of the present embodiment, 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 at the periphery of each of the bonding surfaces 34A1 with each of the light-emitting elements 20. Therefore, a part of the light L emitted in a radial manner from each of the light-emitting elements 20 is incident to the phosphor layer 36 to be wavelength-converted by the phosphor layer 36 and irradiated to the outside. In such a case, a part of the light L emitted in a radial manner from each of the light-emitting elements 20 is incident to the phosphor layer 36 to excite the phosphor included in the phosphor layer 36 and generate excitation light.
Accordingly, according to the phosphor board 30 of the present embodiment, in a case where the light-emitting elements 20 are mounted, it is possible to adjust the light L emitted from the phosphor board 30 to be light emitted with a color different from the light L emitted by the light-emitting elements 20. Accordingly, according to the light-emitting substrate 10 of the present embodiment, it is possible to adjust the light L emitted from the phosphor board 30 to light L with an emitted light color different from the light L emitted by the light-emitting element 20. From another viewpoint, according to the light-emitting substrate 10 of the present embodiment, it is possible to emit the light L with an emitted light color different from the light L emitted by the light-emitting elements 20 to the outside.
A description will be given of the second effect by comparing the present embodiment with the comparative form (refer to
In contrast, as shown in
Accordingly, according to the present embodiment, it is possible to reduce glare compared to the comparative form.
This effect is more effective in a case where the phosphor layer 36 is provided over the entire surface of the insulating layer 32, specifically, in a case where the ratio of the phosphor layer 36 with respect to the surface 31 of the insulating layer 32 is 80% or more of the surface 31, viewed from the surface 31 side.
In the case of the present embodiment, a part of the phosphor layer 36 is supported by the support layer 35 (refer to
Accordingly, the phosphor board 30 of the present embodiment is cheaper than in a case where the support layer 35 is formed by the phosphor layer 36. Accordingly, in the method for manufacturing the phosphor board 30 of the present embodiment, the cost of manufacturing the phosphor board 30 is cheaper than in a method for manufacturing a phosphor board in which the support layer 35 is formed by the phosphor layer 36.
In the case of the light-emitting substrate 10 of the present embodiment, considering the influence of the heat generated when the plurality of LEDs 22 emit light and the heat generated by the phosphor layer 36 that undergoes excitation, for example, the thickness of the circuit pattern layer 34 is set to be thicker than a normal circuit board (as an example, 175 µm). On top of that, in the case of the present embodiment, the outer surface of the phosphor layer 36 is set outside the outer surface of the circuit pattern layer 34 in the thickness direction of the insulating layer 32. This effect is noticeable in the case of the above configuration as in the present embodiment.
In addition, in the case of the present embodiment, the thickness of the phosphor layer 36 is thinner than the thickness of the support layer 35, as described above.
Accordingly, the phosphor board 30 of the present embodiment is cheaper than in a case where the thickness of the phosphor layer 36 is the thickness of the support layer 35 or less. Accordingly, in the method for manufacturing the phosphor board 30 of the present embodiment, the manufacturing cost of the phosphor board 30 is cheaper than in a method for manufacturing a phosphor board in which the thickness of the phosphor layer 36 is the thickness of the support layer 35 or less.
In the case of the present embodiment, as described above, the support layer 35 includes a white pigment. Therefore, according to the present embodiment, it is possible to increase the reflective effect of the entire wavelength range of excitation light, which is set to be visible light.
In the case of the present embodiment, D150 and D250 have the relationship in (Equation 1).
With the above configuration, the difference in median diameters of the fine particles (plurality of phosphor particles and plurality of white particles) in each layer is set to be comparatively small.
Accordingly, the phosphor board 30 of the present embodiment has a smaller difference in the coefficient of thermal expansion (CTE) between the support layer 35 and the phosphor layer 36, resulting in reduced stress being generated at the interface thereof.
The foregoing was a description of the effects of the present embodiment.
In addition, the foregoing was a description of the first embodiment.
Next, a description will be given of the second embodiment with reference to
A phosphor board 30A (refer to
Next, a description will be given of a method for manufacturing the phosphor board 30A of the present embodiment with reference to
This step is the same as in the case of the first embodiment (refer to
The foregoing was a description of the method for manufacturing the light-emitting substrate 10A of the present embodiment.
Next, a description will be given of a light-emitting operation of the light-emitting substrate 10A of the present embodiment. The light-emitting operation of the light-emitting substrate 10A of the present embodiment is basically the same as the case of the first embodiment. However, unlike the case of the first embodiment, in the light-emitting substrate 10A of the present embodiment, the non-bonding surface 34B1 of the circuit pattern layer 34 is covered with the support layer 35. Therefore, in the excitation light in the phosphor layer 36, the excitation light directed toward the circuit pattern layer 34 is reflected by the support layer 35.
The foregoing was a description of the light-emitting operation of the light-emitting substrate 10A of the present embodiment.
In the case of the present embodiment, unlike the case of the first embodiment, the entire region of the phosphor layer 36 is supported by the support layer 35 including a white pigment. Therefore, according to the present embodiment, in the entire region of the phosphor layer 36, the reflection effect of the entire wavelength region of the excitation light, which is set to be visible light, may be improved.
Other effects of the present embodiment are the same as those of the case of the first embodiment.
The foregoing was a description of the effects of the present embodiment.
In addition, the foregoing was a description of the second embodiment.
Next, a description will be given of the third embodiment with reference to
A phosphor board 30B (refer to
Next, a description will be given of a method for manufacturing the phosphor board 30B of the present embodiment with reference to
This step is the same as in the case of the first embodiment (refer to
In the first half of the step, paint (not shown), which is the base of the first layer 35B1, is coated on the portion of the surface 31 of the insulating layer 32 other than the portion where the circuit pattern layer 34 is disposed and the first layer 35B1 is formed (refer to
Next, in the second half of the step, white paint (not shown, the same as in the case of the first embodiment), which is the base of the second layer 35B2, is coated on the entire outer surface of the first layer 35B1 formed in the first half of the step and the non-bonding surface 34B1 of the circuit pattern layer 34 and the second layer 35B2 with an entirely flat outer surface is formed (refer to
When this step is completed, the support layer 35B (the first layer 35B1 and the second layer 35B2), which is a multilayer structure, is formed on the surface 31 of the insulating layer 32 at portions other than the portions where the circuit pattern layer 34 is disposed.
The foregoing was a description of the method for manufacturing the light-emitting substrate 10B of the present embodiment.
A light-emitting operation of the light-emitting substrate 10B of the present embodiment is basically the same as in the case of the second embodiment.
The foregoing was a description of the light-emitting operation of the light-emitting substrate 10B of the present embodiment.
In the phosphor board 30B of the present embodiment, in the same manner as in the phosphor board 30A of the second embodiment (refer to
In addition, unlike the phosphor board 30A of the second embodiment (refer to
Other effects of the present embodiment are the same as in the cases of the first embodiment and second embodiment.
The foregoing was a description of the effects of the present embodiment.
The foregoing was a description of the third embodiment.
Next, a description will be given of the fourth embodiment with reference to
A phosphor board 30C of the present embodiment (refer to
Next, a description will be given of a method for manufacturing the phosphor board 30C of the present embodiment with reference to
In a case of forming the circuit pattern layer 34 in this step, first, a pattern of the same shape as the circuit pattern layer 34 viewed from the thickness direction is formed on the surface 31A side of the motherboard MB by etching using a mask pattern (not shown), for example. Next, a part (a portion corresponding to the wiring portion 34B) of the pattern is half-hatched (etched to the middle in the thickness direction) by etching using, for example, a mask pattern (not shown).
When this step is completed, the phosphor board 30C is manufactured.
The foregoing was a description of the method for manufacturing the light-emitting substrate 10C of the present embodiment.
A light-emitting operation of the light-emitting substrate 10C of the present embodiment is basically the same as that of the case of the second embodiment.
The foregoing was a description of the light-emitting operation of the light-emitting substrate 10C of the present embodiment.
The effects of the present embodiment are the same as those of the case of the first embodiment, the second embodiment, and the third embodiment.
The foregoing was a description of the effects of the present embodiment.
The foregoing was a description of the fourth embodiment.
Next, a description will be given of the fifth embodiment with reference to
A phosphor board 30D of the present embodiment (refer to
Next, a description will be given of a method for manufacturing the phosphor board 30D of the present embodiment with reference to
This step is the same as in the case of fourth embodiment (refer to
In the first half of the step, paint (not shown), which is the base of the first layer 35D1, is coated on the surface 31 of the insulating layer 32 at portions other than the portions where the circuit pattern layer 34 is disposed and the first layer 35D1 (refer to
Next, in the second half of the step, a white paint (not shown, the same as in the case of the first embodiment), which is the base of the second layer 35D2, is coated on the first layer 35D1 formed in the first half of the step and on all of the outer surface of the non-bonding surfaces 34B1 of the circuit pattern layer 34 and the second layer 35D2 is formed (refer to
When this step is completed, the phosphor board 30D is manufactured.
When this step is completed, the light-emitting substrate 10D is manufactured.
The foregoing was a description of the method for manufacturing the light-emitting substrate 10D of the present embodiment.
A light-emitting operation of the light-emitting substrate 10D of the present embodiment is basically the same as in the case of the second embodiment.
The foregoing was a description of the light-emitting operation of the light-emitting substrate 10D of the present embodiment.
Unlike the phosphor board 30C of the fourth embodiment (refer to
Other effects of the present embodiment are the same as in the cases of the first embodiment, second embodiment, third embodiment, and fourth embodiment.
The foregoing was a description of the effects of the present embodiment.
The foregoing was a description of the fifth embodiment.
Although each of the aforementioned embodiments is described above as examples of the present invention, the present invention is not limited to each of the aforementioned embodiments. The technical scope of the present invention includes, for example, the following forms (modifications).
For example, in the description of each of the embodiments, an example of the light-emitting element 20 was a CSP. However, an example of the light-emitting element 20 may be other than a CSP. For example, the light-emitting element 20 may simply be a flip chip. In addition, application to the substrate of a Chip On Board (COB) device itself is also possible.
In addition, in the description of each embodiment, the plurality of the light-emitting elements 20 were mounted on the phosphor board 30 and the light-emitting substrate 10 was provided with a plurality of the light-emitting elements 20. However, considering the mechanism of the description of the aforementioned first effect, it is clear that the first effect is achieved even if there is only one light-emitting element 20. Therefore, the number of light-emitting elements 20 mounted on the phosphor board 30 is at least one. In addition, there is at least one light-emitting element 20 mounted on the light-emitting substrate 10.
In addition, in the description of each embodiment, the outer side surface of the phosphor layer 36 in the thickness direction of the insulating layer 32 was positioned outside the circuit pattern layer 34 in the thickness direction (refer to
In addition, in the description of each embodiment, the rear surface pattern layer 38 was provided on the rear surface 33A side of the phosphor board 30 (refer to
In addition, in the description of the present embodiment, the phosphor layer 36 was disposed on the surface 31A side of the insulating layer 32 and the circuit pattern layer 34 at portions other than the plurality of electrode pairs 34A (refer to
In addition, in the description of each embodiment, it was described that, when manufacturing the phosphor board 30 and the light-emitting substrate 10, the CS-3305A manufactured by Risho Kogyo Co., Ltd., was used as the motherboard MB. However, this is an example and a different motherboard MB may be used. For example, the present invention is not limited to the standard specifications such as insulating layer thickness and copper foil thickness of the CS-3305A manufactured by Risho Kogyo Co., Ltd., and in particular, an even thicker copper foil may be used.
It is possible to combine the light-emitting substrate 10 of each of the embodiments (also including modifications thereof) with other constituent components for application to a lighting device. The other constituent components in this case are a power supply that supplies power to make the light-emitting elements 20 of the light-emitting substrate 10 emit light, and the like.
In addition, in the third embodiment, the support layer 35B was described as a two-layer structure formed of the first layer 35B1 and the second layer 35B2 as a multilayer structure. However, as long as the support layer 35B includes a layer including a white pigment, the multilayer structure support layer 35B may be a structure with three or more layers. This point is the same for the case of the fifth embodiment.
This application claims priority based on Japanese Application No. 2020-144279 filed on Aug. 28, 2020, the entire disclosure of which is hereby incorporated herein.
Number | Date | Country | Kind |
---|---|---|---|
2020-144279 | Aug 2020 | JP | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2021/030626 | 8/20/2021 | WO |