JP6004795B2 - LED light source device and light reflective substrate - Google Patents

Description

  The present invention relates to an LED light source device in which an LED element is mounted on a light reflective substrate, and a light reflective substrate used therefor. Here, “LED” is a light emitting diode, ie, “light emitting diode”.

  The LED element is an extremely small light source element that consumes very little power, has a long service life and generates little heat, and is used as a light source for various displays including backlights for liquid crystal display panels, decorations, and lighting for instruments. It was used a lot. Furthermore, recently, attention has been focused on its power saving effect, long life, and high safety, and LED elements have been mounted on general lighting and vehicle headlamps instead of incandescent bulbs and fluorescent lamps. Lighting devices equipped with the required number of LED light source devices have been commercialized and have been widely used.

  Therefore, in recent years, the light emission luminance of LED elements has been increasing. However, in the case of an illumination light source, soft white light that is natural and has good color rendering properties as well as brightness is preferred. It was difficult to satisfy the requirement directly with the LED as a light source element.

  Therefore, an LED element is mounted on a substrate on which electrodes are formed, and sealed with a sealing body in which a phosphor is dispersed to form an LED package, and light in a narrow wavelength band emitted by the LED element is applied to the phosphor. Various LED light source devices have been developed that emit white light or pseudo-white light with good color rendering properties by being once absorbed and converted into light of a wide wavelength band.

  In that case, a highly reflective film or layer other than the portion where the electrode is formed on the substrate surface is used so that the light emitted from the LED element can be efficiently applied to the phosphor without being absorbed by the substrate and used without loss. The covering technique is also known.

  For example, in Patent Document 1, an electrode and a white ink layer containing fine particles of titanium oxide are formed on the upper surface of a circuit board, LED elements are flip-chip mounted on the circuit board, and the entire surface contains a phosphor. A semiconductor light emitting device (LED device) covered with a resin layer is disclosed.

  In Patent Document 2, an electrode is formed on the upper surface of a substrate having insulation and heat resistance, a white inorganic resist layer is formed in a region excluding the electrode, and an LED element is bonded on the electrode. An LED light source device is disclosed in which wire bonding is mounted and the entire surface is sealed with a transparent resin mixed with a phosphor so as to cover the LED element.

  The white inorganic resist layer is formed of a white inorganic resist, also called ceramic ink, in which, for example, silica sol that functions as an inorganic binder, organopolysiloxane, or the like is dispersed or mixed with a filler such as titanium oxide that is white inorganic fine particles. . The white ink used in Patent Document 1 is the same. According to such an LED light source device, bright white light can be obtained by efficiently using the light emitted from the LED element.

JP 2012-15437 A (FIG. 14, FIG. 15, paragraphs 0035 to 0039) International Publication No. 2012/002580 Pamphlet (Figure 1, pages 7-10)

In such a conventional LED light source device, the white ink layer and the white inorganic resist layer formed on the substrate generally use titanium oxide (TiO ₂ ) as the white inorganic fine particles (pigments), and the wavelength is 420 nm. It has high reflection characteristics with respect to light in the visible light range up to a certain extent. Therefore, if the light emission center wavelength of the LED element is blue light of about 450 nm, high reflectivity can be obtained. However, in recent years, high-efficiency LED elements (elements called NUV-LEDs or near-ultraviolet LEDs) that emit near-ultraviolet light having a light emission center wavelength of 380 nm to 420 nm or shorter wavelengths have been developed. By combining the element with a red, green, and blue three-wavelength phosphor, an LED light source device capable of obtaining white light with higher color rendering can be realized.

  However, in the conventional white ink layer or white inorganic resist layer using titanium oxide or the like as a pigment, the reflectance decreases sharply when the wavelength of light becomes shorter than about 420 nm, and the light emitted from the near-ultraviolet LED described above is emitted. There was a problem that it could not be reflected and used efficiently.

  The present invention has been made to solve the above problem, and even when a near-ultraviolet LED element having an emission center wavelength of 380 nm to 420 nm is mounted, the emitted light is efficiently used to increase the amount of output light. It is an object of the present invention to provide an LED light source device and a light reflective substrate that can be used.

The present invention provides a light reflective substrate in which an electrode and a white inorganic resist layer are formed on one surface of a substrate, and at least the electrode and at least a surface of the light reflective substrate on which the white inorganic resist layer is formed. In an LED light source device having LED elements that are electrically connected and mounted,
In order to achieve the above object, the white inorganic resist layer is formed by dispersing or mixing a white inorganic pigment in an inorganic binder, and is composed of a first layer and a second layer from the surface side of the substrate. .

  The white inorganic pigment of the first layer has a larger refractive index for light in the entire visible light region than the white inorganic pigment of the second layer, and the second layer is compared with the first layer. The total reflectivity for at least near ultraviolet light is high, and the total reflectivity is uniform over the entire region from the visible light region to the near ultraviolet light region.

The white inorganic pigment of the first layer and titanium acid Barium, the white inorganic pigment of the second layer, alumina, talc, aluminum hydroxide, boehmite, barium sulfate, one or more of calcined kaolin A combination of

  The white inorganic resist layer may be formed on the entire surface of the substrate, and the electrode may be disposed on the upper surface of the white inorganic resist layer.

  Alternatively, the electrode may be directly disposed on one surface of the base material, and the white inorganic resist layer may be formed in a region where the electrode is not disposed on the surface of the base material.

The LED element is a near-ultraviolet LED element, and a sealing body that covers the near-ultraviolet LED element is provided on the light-reflective substrate on which the near-ultraviolet LED element is mounted, and the phosphor is dispersed in the sealing body. It is good to form with the resin material which has translucency.

  The present invention also provides a light reflective substrate for use in the LED light source device.

  That is, in a light-reflective substrate having a white inorganic resist layer formed on one surface of a base material, the white inorganic resist layer is dispersed or mixed with a white inorganic pigment in an inorganic binder in order to achieve the above-described purpose. And is constituted by a first layer and a second layer from the surface side of the substrate. The white inorganic pigment of the first layer has a higher refractive index for light in the entire visible light region than the white inorganic pigment of the second layer, and the second layer is at least near-ultraviolet compared to the first layer. The total reflectance with respect to light is high, and the total reflectance is uniform over the entire region from the visible light region to the near ultraviolet light region.

  The white inorganic pigments of the first layer and the second layer may be selected in the same manner as in the case of the white inorganic resist layer in the LED light source device described above.

  Also, the arrangement of the white inorganic resist layer and the electrode on one surface of the substrate may be the same as in the case of the LED light source device described above.

  In the LED light source device and the light reflective substrate according to the present invention, since the white inorganic resist layer on the base material has a substantially uniform high reflectance from the visible light region to the near ultraviolet light region, the emission center wavelength is 380 nm to 420 nm. Even when a near-ultraviolet LED element is mounted, the amount of output light can be increased by efficiently using the emitted light. Thereby, it is possible to efficiently obtain bright white light rich in color rendering.

It is a schematic sectional drawing which shows fundamental embodiment of the light reflective board | substrate by this invention. An example of luminance distribution characteristics of light emitted from a general blue LED element and light obtained by converting the wavelength of the emitted light by a phosphor, and an example of total reflectance characteristics of a single white inorganic resist layer using titanium oxide as a conventional white inorganic pigment. FIG. Example of luminance distribution characteristics of light emitted from a general near-ultraviolet LED element and light obtained by converting the wavelength of the light by a phosphor, and an example of total reflectance characteristics of a white inorganic resist layer using titanium oxide as a conventional white inorganic pigment FIG. It is a diagram which shows the example of a total reflectance characteristic in the wavelength range 360nm-740nm at the time of forming the one layer white inorganic resist layer by the base-material surface and the conventional various white inorganic pigment in it. It is the diagram which similarly shows the example of the total reflectance characteristic in the wavelength range 380 nm-450 nm, expanding the wavelength scale. Wavelength range of 360 nm to 740 nm when a substrate surface and two layers (invention) in which titanium oxide and barium titanate are separately used for the white inorganic pigment and a single white inorganic resist layer mixed and used are formed. It is a diagram which shows the example of a total reflectance characteristic. It is the diagram which similarly shows the example of the total reflectance characteristic in the wavelength range 380 nm-450 nm, expanding the wavelength scale. It is a schematic sectional drawing which shows 1st Embodiment of the LED light source device by this invention. It is a schematic sectional drawing which shows an example of the internal structure of an LED element. It is a schematic sectional drawing which shows 2nd Embodiment of the LED light source device by this invention. It is a schematic sectional drawing which shows 3rd Embodiment of the LED light source device by this invention. It is a schematic sectional drawing which shows 4th Embodiment of the LED light source device by this invention. It is a schematic sectional drawing which shows 5th Embodiment of the LED light source device by this invention. It is a schematic sectional drawing which shows 6th Embodiment of the LED light source device by this invention. It is a schematic sectional drawing which shows 7th Embodiment of the LED light source device by this invention.

  Hereinafter, embodiments for carrying out the present invention will be specifically described with reference to the drawings.

[Basic Embodiment of Light Reflective Substrate]
First, a basic embodiment of a light reflective substrate according to the present invention will be described. FIG. 1 is a schematic cross-sectional view along the thickness direction of the base material of the light-reflective substrate.

  The light reflective substrate 1 shown in FIG. 1 is obtained by forming a white inorganic resist layer 11 on the entire surface of one surface (upper surface in the figure) of a plate-like substrate 10.

  The white inorganic resist layer 11 is formed of a white inorganic resist in which a white inorganic pigment is dispersed or mixed in an inorganic binder, and is composed of a first layer 11 a and a second layer 11 b from the surface side of the substrate 10. For the convenience of illustration, the thickness of the white inorganic resist layer 11 is greatly enlarged, but the thickness of the substrate 10 is about several hundred μm to 1 mm, whereas the white inorganic resist layer 11 The thickness of 11 is 100 μm or less, preferably about 30 to 40 μm in two layers.

  The white inorganic pigment of the first layer 11a has a higher refractive index than the white inorganic pigment of the second layer 11b with respect to the light in the entire visible light range, and the second layer 11b is compared with the first layer 11a. At least the total reflectivity for near-ultraviolet light is high, and the total reflectivity is uniform over the entire region from the visible light region to the near-ultraviolet light region.

  Here, uniform means that a change in total reflectance of about ± several percent is included as an error range.

  Also, the total reflectance (%) is the sum of the regular reflectance (%), which is the ratio of specularly reflected light with the incident angle = reflection angle, and the diffuse reflectance (%), which is the ratio of other reflected light. That's it. In general, this total reflectance is referred to as reflectance.

  For the substrate 10, for example, an epoxy resin (glass epoxy resin) whose thermal stability and dimensional stability are enhanced by glass cloth and an inorganic filler may be used. However, other materials having insulating properties and heat resistance, such as bakelite, which is generally used as a substrate for wiring boards, BT resin substrate, silicone substrate, ceramic substrate, which have better heat resistance than ordinary epoxy resin A material such as alumina or aluminum nitride may be used. Furthermore, you may use the metal base material which was excellent in heat dissipation, aluminum, copper, etc. as a base material.

  Further, since the white inorganic resist layer 11 having high concealability and high reflectance is formed on the entire surface on the LED element mounting side, a colored epoxy resin, silicone, aluminum nitride (reflectance 40 %) And transparent glass can also be used.

  Each of the first layer 11a and the second layer 11b of the white inorganic resist layer 11 is a white inorganic resist (“white”) in which a filler of fine particles of a white inorganic pigment is dispersed or mixed in silica sol or organopolysiloxane functioning as an inorganic binder. (Also called “ceramic ink”).

  That is, the white inorganic resist is disposed on one surface of the substrate 10 by screen printing or the like, and then cured in an atmosphere of about 150 ° C. to form the first layer 11a, and the entire surface of the first layer 11a is white again. After arranging the inorganic resist by screen printing or the like, the second layer 11b is formed by curing in an atmosphere of about 150 ° C.

  The white inorganic pigment of the first layer 11a needs to have a larger refractive index than the white inorganic pigment of the second layer 11b with respect to light in the entire visible light region. The larger the refractive index of the white inorganic pigment, the larger the refractive index difference from the binder, and the higher the reflectance. As a result, the concealability is also improved, and when the substrate 10 is colored, the color of the surface (base) of the substrate becomes invisible. When the base material 10 is translucent, the penetration | invasion of the light to the inside of a base material can be prevented.

  As the white inorganic pigment of the first layer 11a, a pigment having a refractive index of 2.0 or more with respect to light in the visible light region is desirable, and barium titanate (2.4) and / or titanium oxide (2.7) is used. can do. The numerical value in the parenthesis indicates a typical refractive index of each substance with respect to light in the visible light range.

  Further, as the white inorganic pigment of the second layer 11b, a pigment having a refractive index of less than 2.0 with respect to light in the visible light region is desirable, and alumina (1.76), talc (1.62), aluminum hydroxide (1 .57), boehmite (1.65), barium sulfate (1.64), calcined kaolin (1.62), or a combination thereof may be used. The numerical value in the parenthesis shows the refractive index for light in the visible light region.

  The visible light region usually means a light region having a wavelength from violet light to red light of about 380 nm to about 770 nm, and the near ultraviolet light region is a wavelength region close to visible light (purple light) in the ultraviolet light. In general, the light range is about 315 nm to about 380 nm. The visible light region and near-ultraviolet light region in this specification also conform to this.

  However, near-ultraviolet LED (NUV-LED) elements developed in recent years have an emission center wavelength of 380 nm to 420 nm, and many of them emit violet light that is closest to ultraviolet light among visible light. The emission center wavelength is shorter than that of the device. However, it does not necessarily have an emission center wavelength in the generally defined near-ultraviolet light region.

  Here, an example of luminance distribution characteristics of light emitted from a general blue LED element and light obtained by converting the wavelength of the light by a phosphor, and the total reflectance characteristics of a white inorganic resist layer using titanium oxide as a conventional white inorganic pigment. An example is shown in FIG.

  In FIG. 2, a curve having two peaks indicates the luminance distribution characteristic of the output light of the LED light source device, the unit of the luminance is arbitrary, and indicates the relative luminance for each wavelength of the output light.

  A peak curve a having a peak at a wavelength of about 450 nm is a luminance distribution of the emitted light of the blue LED element, and it can be seen that the light is a blue light in a narrow wavelength band having a sharp peak at about 450 nm of the emission center wavelength. A peak curve b having a peak at a wavelength of about 550 nm is a luminance distribution of light wavelength-converted by the phosphor, and is pseudo white light composed of blue light of the LED element and yellow light converted by the phosphor. I understand.

  On the other hand, a solid curve e plotted with x marks shows an example of the total reflectance characteristic of one white inorganic resist layer in which the white inorganic pigment is titanium oxide. This shows a constant high value with a total reflectance of about 90% from a wavelength of 750 nm to about 430 nm, and has a sufficiently high total reflectance even in the emission region of the blue LED element. Therefore, in the case of an LED light source device mounted with a blue LED element, the light emitted from the blue LED element and the fluorescent light can be emitted by simply forming a white inorganic resist layer with a white inorganic pigment as titanium oxide on the surface of the substrate. Light in the entire wavelength range of the output light wavelength-converted by the body is almost reflected and can be used efficiently.

  In contrast, FIG. 3 shows an example of luminance distribution characteristics of light emitted from a general near-ultraviolet LED element and light obtained by converting the wavelength of the light by a phosphor, and a white inorganic resist having titanium oxide as a conventional white inorganic pigment. The example of the total reflectance characteristic of a layer is shown.

  In FIG. 3, a peak curve c having a peak at a wavelength of about 415 nm is a luminance distribution of emitted light of the near-ultraviolet LED element, has a high and sharp peak at an emission center wavelength of about 415 nm, and is higher than that of a blue LED element. It turns out that it is violet light of a narrow wavelength band. Further, the peak curve d having a peak at a wavelength of about 625 nm is a luminance distribution of the light that has been wavelength-converted by the phosphor, and it can be seen that the light has been converted into light in a wider wavelength range from red to blue.

  On the other hand, a solid curve e plotted with x marks shows an example of the total reflectance characteristic of a single white inorganic resist layer in which the same white inorganic pigment as in FIG. 2 is made of titanium oxide. This shows that the total reflectivity is about 90% from a wavelength of 750 nm to about 430 nm, and shows a constant high value. However, in the shorter wavelength range, the total reflectivity rapidly decreases, and the emission center of this near ultraviolet LED element. It decreases to about 70% at a wavelength of about 415 nm. When the emission center wavelength of the near-ultraviolet LED element is even shorter, the total reflectivity is further reduced.

  Therefore, in the case of an LED light source device mounted with a near-ultraviolet LED element, the light emitted from the near-ultraviolet LED element is wasted simply by forming a white inorganic resist layer made of titanium oxide as a white inorganic pigment on the surface of the substrate. It is clear that it cannot be reflected and used efficiently.

  Here, FIG. 4 shows an example of the total reflectance characteristics in the wavelength range of 360 nm to 740 nm when a substrate surface and one white inorganic resist layer made of various conventional white inorganic pigments are formed. FIG. 5 shows an example of total reflectance characteristics in the wavelength range of 380 nm to 450 nm with the wavelength scale enlarged.

  As is clear from these figures, the characteristics of the substrate surface indicated by the solid line f have a total reflectance of 70% or more for light having a wavelength of about 700 nm (red light), but the light wavelength is short. The total reflectivity decreases, and the total reflectivity is only about 30% for light having a wavelength of 400 nm (purple light).

When a white inorganic resist layer in which the white inorganic pigment is titanium oxide (TiO ₂ ) is formed on the surface of the base material (shown by a broken line g), a single white inorganic resist layer in which the white inorganic pigment is barium titanate. The total reflectivity characteristics when the sapphire is formed (indicated by a two-dot chain line h) are almost uniform and nearly 90% high from 750 nm (red light) to 420 nm (blue light) in the visible light region. Have However, in the former shown by the broken line g, the total reflectance is drastically decreased in the short wavelength region where the wavelength is shorter than about 420 nm, and in the latter case shown by the two-dot chain line h, the wavelength is shorter than about 400 nm.

  On the other hand, the total reflectance characteristics when a white inorganic resist layer in which the white inorganic pigment is alumina is formed (indicated by a dotted line i) is from the above-described white inorganic range from 750 nm to 400 nm in the visible light region. Although the total reflectivity is somewhat lower than when the pigment is titanium oxide or barium titanate, it is still nearly uniform at a high value of 80% or more. Furthermore, the total reflectivity hardly decreases even in the light range of violet light or near ultraviolet light whose wavelength is shorter than about 400 nm, and maintains about 80%.

Therefore, a wavelength range of 360 nm when a substrate surface and two layers of the white inorganic pigment separately using titanium oxide and barium titanate (the present invention) and one white inorganic resist layer mixed and used are formed. An example of the total reflectance characteristic at ˜740 nm is shown in FIG. FIG. 7 shows an example of total reflectance characteristics in the same wavelength range of 380 nm to 450 nm, with the wavelength scale enlarged.

  The total reflectance characteristic (indicated by the solid line f) of the substrate surface is the same as the example shown in FIGS. On the other hand, a white inorganic resist layer is formed by laminating a lower layer (first layer) using barium titanate as a white inorganic pigment and an upper layer (second layer) using alumina as a white inorganic pigment on the substrate surface. The total reflectivity characteristics (indicated by a two-dot chain line j) in the case where the total reflectivity is maintained at a constant value of almost 90% from the visible light range of 750 nm to 400 nm, and the total reflectivity is shorter than 400 nm. Although the rate gradually decreases, it has a high total reflectance of about 85% even for light with a wavelength of 380 nm.

  When a white inorganic resist layer is formed by laminating a white inorganic pigment lower layer (first layer) using titanium oxide and a white inorganic pigment upper layer (second layer) using alumina (indicated by a dotted line k). The total reflectivity characteristic is substantially the same as the above-described case indicated by the two-dot chain line j from the 750 nm to 420 nm in the visible light region, and the total reflectivity is maintained at a constant value of approximately 90% and is shorter than 420 nm. Although the total reflectance gradually decreases in the region, it has a high total reflectance of about 80% even for light having a wavelength of 390 nm.

  Therefore, if these two white inorganic resist layers are formed on the substrate surface, even when a near-ultraviolet LED element having an emission center wavelength of about 415 nm as shown in FIG. Almost 90% of the light incident on the layer (film) can be reflected and made available.

  On the other hand, the total reflectance characteristics when a white inorganic resist layer formed by mixing alumina and barium titanate as a white inorganic pigment (shown by a broken line m) is also 750 nm to 420 nm in the visible light region. Up to about 85%, the total reflectance increases slightly as the wavelength decreases from 550 nm to 420 nm, but in the wavelength range shorter than 420 nm, the total reflectance increases. It begins to decrease, and the total reflectance rapidly decreases in the wavelength region of 400 nm or less.

  Therefore, when a near-ultraviolet LED element having an emission center wavelength of about 415 nm is mounted, it is possible to reflect and use about 85% of the light incident on these layers (films) out of the emitted light. However, the reflectance is low as compared with the case where the two white inorganic resist layers are formed. Further, when a near-ultraviolet LED element having a light emission center wavelength of 400 nm or less is mounted, the reflectance with respect to the emitted light is considerably lowered, so that the emitted light cannot be used efficiently.

  Therefore, in the light reflective board | substrate 1 shown in FIG. 1, the white of the 1st layer 11a and the 2nd layer 11b from the surface side of the base material 10 on the one surface (surface on the side which mounts an LED element) of the base material 10 is carried out. A white inorganic resist layer 11 in which an inorganic resist layer is laminated is formed of a white inorganic resist in which the following white inorganic pigment is dispersed or mixed in an inorganic binder.

  Barium titanate (refractive index 2.4) having a large refractive index is used for the white inorganic pigment of the first layer 11a, and the white inorganic pigment of the second layer 11b has an absorption region from the visible light region to the ultraviolet light region. Alumina (refractive index: 1.76) having a refractive index smaller than that for the light in the entire visible light region without using it is used. As a result, as shown in FIGS. 4 and 5, the second layer 11b (white inorganic pigment is alumina) is at least completely resistant to near-ultraviolet light compared to the first layer 11a (white inorganic pigment is barium titanate). The reflectivity is high, the total reflectivity is uniform over the entire region from the visible light region to the near ultraviolet light region, and the height is about 80%.

  The total reflectance characteristics of the white inorganic resist layer 11 as a whole are approximately 90% in total reflectance from 750 nm to 400 nm in the visible light region, as indicated by a two-dot chain line j in FIGS. While maintaining a constant value, the total reflectance gradually decreases in a wavelength region shorter than 400 nm, but has a total reflectance of about 85% even for light having a wavelength of 380 nm.

  Therefore, if a near-ultraviolet LED element is mounted on the light-reflecting substrate 1 to constitute an LED light source device, the incident component of the emitted light is approximately 90% when the emission center wavelength of the near-ultraviolet LED element is about 415 nm. Even when the emission center wavelength is about 380 nm, the incident component of the emitted light can be reflected and used for about 85%.

  However, even if titanium oxide is used for the white inorganic pigment of the first layer 11a, as shown by the dotted line k in FIGS. 6 and 7, a high total reflectance of 85% or more is obtained up to the violet light region of the visible light region. Therefore, even when a near-ultraviolet LED element is mounted, most of the incident components of the emitted light can be reflected and used.

  Further, as the white inorganic pigment of the first layer 11a, barium titanate and titanium oxide are mixed and used, or as the white inorganic pigment of the second layer 11b, instead of alumina, talc, aluminum hydroxide and boehmite described above are used. , Barium sulfate, calcined kaolin, or a combination of these and a plurality of alumina can be used to obtain almost the same total reflectance characteristics as the above-described example, A light reflective substrate suitable for mounting the element can be manufactured.

[Embodiment of LED light source device]
Hereinafter, various embodiments of the LED light source device according to the present invention will be described with reference to FIGS. 8 to 15. In these drawings, portions corresponding to those in FIG. Is omitted. Also, in FIGS. 8 to 15, even if the shapes are slightly different, the corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

In the description of the various embodiments of the LED light source device, various embodiments of the light reflective substrate used for the LED light source device will also be described.
(1) Flip-chip double-sided mounting type There are various types of LED light source devices in which LED elements are mounted on a light-reflective substrate. First, the first and second embodiments are flip-chip double-sided mounting type LED light source devices. Will be described with reference to FIGS.

  FIG. 8 is a schematic cross-sectional view showing the configuration of the first embodiment. In this LED light source device, an LED element 2 is mounted on a light-reflective substrate 1 ′ provided with electrodes 12 and 13 and is also referred to as an LED package. The LED element is also referred to as an LED chip. The same applies to the following embodiments.

  On the light reflective substrate 1 ′, a pair of electrodes 12 and 13 are directly disposed on one surface of the base material 10 (an upper surface which is a surface on which the LED element 2 is mounted). The portions of the electrodes 12 and 13 arranged on the surface of the base material 10 have a thickness of 30 to 50 μm, and the post portions 12a and 13a filled in the through holes formed in the base material 10 are used. The thin bottom electrode portions 12b and 13b formed on the bottom surface of the substrate 10 are integrated. Such an electrode may be referred to as a wiring layer.

The electrodes 12 and 13 are made of a highly conductive metal, for example, copper (Cu) by a copper plating method. In this embodiment, the electrodes 12 and 13 are electrically conductive, such as a Ni-Ag plating layer in which a silver (Ag) plating layer is superimposed on a nickel (Ni) plating layer on the upper surface of the portion on the surface of the substrate 10. Plated layers 12c and 13c having good and high reflectivity are formed. However, the plating layers 12c and 13c are not essential.

  The white inorganic resist layer 11 in which the first layer 11a and the second layer 11b described above with reference to FIG. 1 are laminated from the substrate 10 side over the entire region where the electrodes 12 and 13 on the upper surface of the substrate 10 are not disposed. However, it is formed in the thickness substantially the same as the thickness of the part arrange | positioned on the surface of the base material 10 of the electrodes 12 and 13. FIG. Therefore, the thickness of the first layer 11a and the second layer 11b is 15 to 25 μm, respectively, and the total thickness of the white inorganic resist layer 11 is 30 to 50 μm.

  The first bump 23 and the second bump 24 of the LED element 2 are aligned and arranged on the electrodes 12 and 13 on the light-reflecting substrate 1 ′ configured as described above, and the first bump 23 and the second bump 24 are arranged. The bumps 24 are bonded to the electrodes 12 and 13 by metal eutectic bonding or solder reflow bonding, respectively, and are electrically connected to each other, and the LED element 2 is mechanically fixed on the light reflective substrate 1 ′.

  The LED element 2 is configured as shown in a schematic sectional view of an example of the internal structure in FIG. That is, the n-type semiconductor layer 21 is provided on the lower surface of the sapphire substrate 25, and the p-type semiconductor layer 22 is further provided on the lower surface, and the pn junction between the n-type semiconductor layer 21 and the p-type semiconductor layer 22 emits light. It is a layer. A first bump 23 is provided as an n-side electrode on a part of the lower surface of the n-type semiconductor layer 21, and a second bump 24 is provided as a p-side electrode on a part of the lower surface of the p-type semiconductor layer 22. .

  The LED element 2 is mounted on the light-reflecting substrate 1 'as described above, and the first bump 23 and the second bump 24 are joined to the electrodes 12 and 13, respectively, and are electrically connected to each other and machine. It sticks.

  A sealing body 3 is provided on the light-reflective substrate 1 ′ on the side where the LED element 2 is mounted so as to cover the LED element 2. In this embodiment, the sealing body 3 is filled with a light-transmitting resin material in which phosphors are dispersed without gaps, and is formed into a predetermined outer shape. In the figure, the outer periphery is schematically square, but it can be formed in an arbitrary shape such as a spherical shape.

  As the phosphor, a yellow phosphor is used in combination with a blue LED element, or a red, green, and blue three-wavelength phosphor is used in combination with a near-ultraviolet LED element, so that the blue light and purple light are used. Can be converted into white light and output. However, the phosphor is not limited to this, and may be selected from any color, or may be used by appropriately mixing them, whereby a light emission output of any color according to the application can be obtained. Further, the light emitted from the LED element 2 may be diffused and wavelength-converted and output by repeating internal reflection in the transparent sealing body without using the phosphor.

  In the LED light source device of this embodiment, a white inorganic resist layer 11 composed of two layers is formed in a region where the electrodes 12 and 13 are not disposed on the surface of the light reflective substrate 1 ′ on which the LED element 2 is mounted. Has been. Since the white inorganic resist layer 11 has a high total reflectance from the visible light region to the violet light region as described above, a near-ultraviolet LED device having an emission center wavelength of about 415 nm or less is mounted as the LED device 2. Also, most of the incident component of the emitted light to the white inorganic resist layer 11 can be reflected and used.

  Therefore, it is possible to output white light having high color rendering properties with high luminance through the sealing body 3 made of a translucent resin material in which red, green, and blue three-wavelength phosphors are dispersed. Further, even when combined with a sealing body in which other phosphors are dispersed or a sealing body that does not use a phosphor, it is possible to obtain bright output light of a color corresponding to the application.

  In addition, if the plating layers 12c and 13c having high reflectivity are also formed on the upper surfaces of the electrodes 12 and 13, since the incident light to the plating layers 12c and 13c in the emitted light of the LED element 2 is almost reflected. The utilization efficiency can be further increased.

  When this LED light source device is mounted on a circuit board on the device side (not shown), the lower surface electrode portions 12b and 13b of the electrodes 12 and 13 are directly joined to a wiring pattern such as a power feeding circuit on the circuit board to Connection and mechanical fixation.

  Since the electrodes 12 and 13 have not only good conductivity but also high thermal conductivity, the heat generated by the LED element 2 during light emission can be efficiently conducted and radiated to the circuit board side. Moreover, since the white inorganic resist layer 11 also has high thermal conductivity, the heat generated by the LED elements 2 can be efficiently dispersed throughout the base material 10 and can be dissipated from the heat to the circuit board side.

  Therefore, even if the LED element 2 emits light with high luminance for a long time, it can be prevented from being deteriorated by heat.

  Next, a second embodiment will be described with reference to FIG. FIG. 10 is a schematic cross-sectional view showing the configuration of the LED light source device.

  The second embodiment differs from the first embodiment described above only in the shape of the electrodes 14 and 15. In the electrodes 14 and 15 in this embodiment, the portions arranged on the surface of the base material 10 are formed in the same planar shape as the post portions 12a and 13a of the electrodes 12 and 13 in FIG. This corresponds to one formed so as to protrude by 30 to 50 μm from the surface of the material 10. The top surfaces of the electrodes 14 and 15 are the same as the bottom surfaces of the first bump 23 and the second bump 24 of the LED element 2. Lower electrode portions 14b and 15b are integrally formed on the lower surface side of the substrate 10.

  On the upper surfaces of the electrodes 14 and 15, plated layers 14 c and 15 c such as a Ni—Ag plated layer having good conductivity and high reflectance may be formed.

  The white inorganic resist layer 11 in which the first layer 11a and the second layer 11b described above are laminated from the substrate 10 side over the entire region where the electrodes 14 and 15 on the upper surface of the substrate 10 are not disposed is an electrode. 14 and 15 are formed to have a thickness (30 to 450 μm) that is substantially the same as the height of the portion of the base material 10 that protrudes from the surface.

  Therefore, according to this embodiment, the area ratio of the white inorganic resist layer 11 having a high total reflectivity on the surface of the base material 10 is increased by an amount corresponding to the reduction of the planar shape of the electrodes 14 and 15 to the minimum necessary. The light emitted from the LED element 2 can be used more effectively.

  The LED element 2 is mounted on the light-reflective substrate 1 ′, and the first bump 23 and the second bump 24 are bonded to the electrodes 14 and 15 by metal eutectic bonding, solder reflow bonding, etc. It is the same as in the first embodiment described above that the LED element 2 is mechanically fixed on the light-reflective substrate 1 ′ while being connected. However, the upper surface shape of the electrodes 14 and 15 and the lower surface shapes of the first bump 23 and the second bump 24 of the LED element 2 are the same and the area is the same. Therefore, in order to secure a necessary bonding area, alignment accuracy is ensured. I need to do it well.

The sealing body 3 is provided on the light-reflective substrate 1 'on the side where the LED element 2 is mounted so as to cover the LED element 2, as in the first embodiment.
(2) Wire bond double-sided mounting type Next, the third and fourth embodiments of the LED light source device of the wire bond double-sided mounting type according to the present invention will be described with reference to FIGS.

  FIG. 11 is a schematic sectional view showing the configuration of the third embodiment.

  In this LED light source device, an electrode 16 having an area and a planar shape larger than the entire lower surface of the LED element 2 ′ is arranged at the center of the upper surface of the light reflective substrate 1 ′, and is relatively large formed on the base material 10. It is integrated with the lower surface electrode portion 16b formed on the lower surface of the base material 10 via the post portion 16a filled in the through hole. On the upper surface of the electrode 16, plated layers 14 c and 16 c such as a Ni—Ag plated layer having good conductivity and high reflectance may be formed.

  An electrode 14 similar to the electrode 14 in the second embodiment shown in FIG. 10 is arranged at a distance from the electrode 16 on the right side in FIG.

  These electrodes 14 and 16 are also formed of copper (Cu) by a copper plating method, for example.

  The white inorganic resist layer 11 in which the first layer 11a and the second layer 11b described above are laminated from the substrate 10 side over the entire region where the electrodes 14 and 16 on the upper surface of the substrate 10 are not disposed is an electrode. 14 and 16 are formed to have substantially the same thickness (30 to 50 μm) as the portions on the surface of the substrate 10.

  The LED element 2 ′ mounted on the light reflective substrate 1 ′ is like the LED element 2 shown in FIG. 9 turned upside down, and an n-side electrode that replaces the first bump 23 and the second bump 24 is formed on the upper surface. A p-side electrode is provided.

  An adhesive is applied to the lower surface of the LED element 2 ', and is placed on the electrode 16 of the light-reflective substrate 1' and adhered thereto, and the LED element 2 'is mechanically fixed to the light-reflective substrate 1'. .

  Thereafter, the n-side electrode is connected to the electrode 14 by the bonding wire 4, and the p-side electrode is connected to the electrode 16 by the bonding wire 5. In this way, the LED element 2 'and the electrodes 14 and 16 of the light reflective substrate 1' are electrically connected by wire bonding.

  The sealing body 3 is provided on the light-reflective substrate 1 'on the side where the LED element 2' is mounted so as to cover the LED element 2 ', as in the above-described embodiments.

  The effect by this 3rd Embodiment is the same as that of 1st Embodiment.

  FIG. 12 is a schematic cross-sectional view showing the configuration of the fourth embodiment.

  This LED light source device is disposed on the upper surface of the base material 10 in the same manner as the electrodes 14 and 15 in the second embodiment shown in FIG. The electrodes 14 and 15 having a small planar shape are arranged.

  The white inorganic resist layer 11 in which the first layer 11a and the second layer 11b described above are laminated from the substrate 10 side over the entire region where the electrodes 14 and 15 on the upper surface of the substrate 10 are not disposed is an electrode. 14 and 15 are formed to have substantially the same thickness (30 to 50 μm) as the portions on the surface of the substrate 10.

Thereafter, an adhesive is applied to the lower surface of the LED element 2 ′, and is placed on and adhered to the white inorganic resist layer 11 of the light reflective substrate 1 ′. Fixed.

  The n-side electrode is connected to the electrode 14 by the bonding wire 4, and the p-side electrode is connected to the electrode 15 by the bonding wire 5. In this way, the LED element 2 'and the electrodes 14 and 15 of the light reflective substrate 1' are electrically connected by wire bonding.

  The sealing body 3 is provided on the light-reflective substrate 1 'on the side where the LED element 2' is mounted so as to cover the LED element 2 ', as in the above-described embodiments.

  The effect by this 4th Embodiment is the same as that of 2nd Embodiment.

  When the LED light source devices of the third and fourth embodiments are also mounted on a circuit board on the device side (not shown), the lower electrode portions 14b and 16b or 15b of the electrodes 14 and 16 or 15 are connected to the circuit. Electrical connection and mechanical fixation can be performed by directly joining to a wiring pattern such as a power supply circuit on the substrate.

However, in the case of the fourth embodiment shown in FIG. 12, the heat generated by the LED element 2 ′ during light emission cannot be conducted and dissipated through the electrodes 14 and 15 to the circuit board side. However, since the entire lower surface of the LED element 2 ′ is bonded to the white inorganic resist layer 11 having a high thermal conductivity, the heat generated by the LED element 2 ′ is efficiently dispersed throughout the base material 10. Heat can be radiated to the circuit board side through the lower surface or the electrodes 14 and 15.
(3) Flip chip top surface mounting type Next, a fifth embodiment of a flip chip top surface mounting type LED light source device according to the present invention will be described with reference to FIG. FIG. 13 is a schematic cross-sectional view showing the configuration of the fifth embodiment.

  In the LED light source device of the fifth embodiment, as shown in FIG. 1, the first layer 11 a and the second layer 11 b are on the base 10 side over the entire upper surface of the base 10 like the light reflective substrate 1. A white inorganic resist layer 11 laminated from above is formed, and a pair of electrodes 17 and 18 are formed on the surface of the second layer 11b with copper (Cu) to a thickness of about 10 μm by a copper plating method or the like to reflect light. Constituting the conductive substrate 1 ″.

  The electrodes 17 and 18 are arranged not only at positions corresponding to the first bumps 23 and the second bumps 24 of the LED element 2 but also as a wiring pattern (for example, on the paper surface of FIG. 13) to be connected to the outside. (Extending in the vertical direction) is also integrally formed.

  Also, plating layers 17c and 18c such as Ni-Ag plating layer and having high conductivity and high reflectivity may be formed on the upper surfaces of the electrodes 17 and 18, respectively.

  On the light-reflecting substrate 1 ″ thus configured, the LED element 2 is arranged with the first bump 23 and the second bump 24 aligned with the electrodes 17 and 18, respectively. The two bumps 24 are bonded to the electrodes 17 and 18 by metal eutectic bonding or solder reflow bonding, respectively, and are electrically connected to each other, and the LED element 2 is mechanically fixed on the light reflective substrate 1 ″.

  The sealing body 3 is provided on the light-reflective substrate 1 ″ on the side where the LED element 2 is mounted so as to cover the LED element 2, as in the above-described embodiments.

Since this LED light source device can increase the area ratio of the white inorganic resist layer 11 on the upper surface of the light reflective substrate 1 ″, the light emitted from the LED element 2 can be used more efficiently.

  When the LED light source device is mounted on a circuit board on the device side (not shown), the lower surface of the light reflective substrate 1 ″ is fixed to the circuit substrate by bonding or the like, and the electrodes 17, It is necessary to electrically connect the wiring pattern formed integrally with the wiring pattern 18 and the wiring pattern such as a power feeding circuit on the circuit board by wire bonding, a dedicated connector, or the like.

Further, the heat generated when the LED element 2 emits light is conducted and diffused through the electrodes 17 and 18 and the white inorganic resist layer 11 to the base material 10 and further radiated to the bonded circuit board side. (4) Wire Bond Top Mount Type Next, the sixth and seventh embodiments of the LED light source device of the wire bond top mount type according to the present invention will be described with reference to FIGS.

  FIG. 14 is a schematic cross-sectional view showing the configuration of the sixth embodiment.

  The LED light source device of the sixth embodiment uses a light-reflective substrate 1 ″ similar to that of the fifth embodiment described above, but at the center of the surface of the second layer 11b of the white inorganic resist layer 11, An electrode 19 having a larger area and shape than the lower surface of the LED element 2 'is formed, and the electrode 17 is formed smaller than the electrode 17 in FIG.

  These electrodes 17 and 19 also integrally form a wiring pattern (for example, extending in a direction perpendicular to the paper surface of FIG. 14) to be a lead wire for connection to the outside.

  Also, plated layers 17c and 19c such as a Ni-Ag plated layer and having high conductivity and high reflectance may be formed on the upper surfaces of the electrodes 17 and 19, respectively.

  Thereafter, an adhesive is applied to the lower surface of the LED element 2 ′, placed on the electrode 19 and bonded, and the LED element 2 ′ is mechanically fixed to the light reflective substrate 1 ″.

  Then, the n-side electrode of the LED element 2 ′ is connected to the electrode 17 by the bonding wire 4, and the p-side electrode is connected to the electrode 19 by the bonding wire 5. In this way, the LED element 2 ′ and the electrodes 17 and 19 of the light reflective substrate 1 ″ are electrically connected to each other by wire bonding.

  The sealing body 3 is provided on the light-reflective substrate 1 ″ on the side on which the LED element 2 ′ is mounted so as to cover the LED element 2 ′, as in the above-described embodiments.

  The operational effects of the sixth embodiment are substantially the same as those of the fourth embodiment.

  When the LED light source device is mounted on a circuit board on the device side (not shown), the lower surface of the light reflective substrate 1 ″ is fixed to the circuit substrate by bonding or the like, and the electrodes 17, It is necessary to electrically connect the wiring pattern formed integrally with 19 and the wiring pattern such as a power feeding circuit on the circuit board by wire bonding or the like.

  Further, the heat generated when the LED element 2 ′ emits light is conducted and diffused to the base material 10 through the electrode 19 and the white inorganic resist layer 11, and further radiated to the bonded circuit board side.

  FIG. 15 is a schematic cross-sectional view showing the configuration of the seventh embodiment.

In the seventh embodiment, the second layer 11b of the white inorganic resist layer 11 of the light reflective substrate 1 ″.
Small electrodes 17 and 18 similar to the electrode 17 in the sixth embodiment described above are arranged on the surface of the surface with a large gap.

  Thereafter, an adhesive is applied to the lower surface of the LED element 2 ′, and is placed on and adhered to the white inorganic resist layer 11 of the light reflective substrate 1 ″ to mechanically attach the LED element 2 ′ to the light reflective substrate 1 ″. Secure to.

  The n-side electrode of the LED element 2 ′ is connected to the electrode 17 through the bonding wire 4, and the p-side electrode is connected to the electrode 18 through the bonding wire 5. In this way, the LED element 2 'and the electrodes 17 and 18 of the light reflective substrate 1 "are electrically connected to each other by wire bonding.

  The sealing body 3 is provided on the light-reflective substrate 1 ″ on the side on which the LED element 2 ′ is mounted so as to cover the LED element 2 ′, as in the above-described embodiments.

  The operational effects of the seventh embodiment are almost the same as those of the fifth and sixth embodiments, but the area of the white inorganic resist layer 11 exposed on the light-reflective substrate 1 ″ can be increased. The light emitted from the element 2 'can be used more efficiently.

  When the LED light source device is mounted on a circuit board on the device side (not shown), the lower surface of the light reflective substrate 1 ″ is fixed to the circuit substrate by bonding or the like, and the electrodes 17, It is necessary to electrically connect the wiring pattern formed integrally with the wiring pattern 18 and the wiring pattern such as a power feeding circuit on the circuit board by wire bonding, a dedicated connector, or the like.

  Further, the heat generated when the LED element 2 ′ emits light is conducted and diffused through the white inorganic resist layer 11 to the base material 10 and further radiated to the bonded circuit board side.

  As described above, various embodiments of the present invention have been described. However, these configurations can be appropriately changed, added, or combined within a range that satisfies the matters stipulated in the claims. is there. For example, the present invention can naturally be used when a plurality of LED elements are mounted on a light reflective substrate or a Zener diode is mounted together as a protective element.

  The present invention is particularly effective when a near-ultraviolet LED is mounted as the LED element, but other LED elements such as a blue LED element may be mounted. And it can utilize widely for LED light source devices, such as for various illuminations, a display, and a decoration.

1, 1 ', 1 ": Light reflective substrate 2, 2': LED element 3: Sealed body
4, 5: Bonding wire 10: Base material 11: White inorganic resist layer
11a: 1st layer 11b: 2nd layer 12-19: Electrode
12a, 13a, 16a: Post part 12b-16b: Lower surface electrode part
12c to 19c: Plating layer 21: n-type semiconductor layer 22: p-type semiconductor layer
23: First bump (n-side electrode) 24: Second bump (p-side electrode)
25: Sapphire substrate

Claims (9)

A light reflective substrate in which an electrode and a white inorganic resist layer are formed on one surface of a substrate;
In the LED light source device having the LED element mounted at least electrically connected to the electrode on the surface side of the light reflective substrate on which the white inorganic resist layer is formed,
The white inorganic resist layer is formed by dispersing or mixing a white inorganic pigment in an inorganic binder, and is composed of a first layer and a second layer from the surface side of the base material,
The white inorganic pigment of the first layer has a higher refractive index than the white inorganic pigment of the second layer with respect to light in the entire visible light region,
And the second layer, the total reflectivity is high for at least the near-ultraviolet light as compared with the first layer, Ri total reflectance uniform der over the entire region from the visible light range to the near-ultraviolet light range,
The LED light source device, wherein the white inorganic pigment of the first layer is barium titanate . Before SL white inorganic pigments alumina of the second layer, talc, aluminum hydroxide, boehmite, LED light source according to claim 1, wherein the barium sulfate is any or a plurality of combinations of calcined kaolin apparatus. A light reflective substrate in which an electrode and a white inorganic resist layer are formed on one surface of a substrate;
In the LED light source device having the LED element mounted at least electrically connected to the electrode on the surface side of the light reflective substrate on which the white inorganic resist layer is formed,
The white inorganic resist layer is formed by dispersing or mixing a white inorganic pigment in an inorganic binder, and is composed of a first layer and a second layer from the surface side of the base material,
The white inorganic pigment of the first layer has a higher refractive index than the white inorganic pigment of the second layer with respect to light in the entire visible light region,
The second layer has a high total reflectivity for at least near-ultraviolet light as compared to the first layer, and the total reflectivity is uniform over the entire region from the visible light region to the near-ultraviolet light region,
The white inorganic resist layer is formed, L ED light source device you wherein the electrode is disposed on the upper surface of the white inorganic resist layer on the entire one surface of the substrate. A light reflective substrate in which an electrode and a white inorganic resist layer are formed on one surface of a substrate;
In the LED light source device having the LED element mounted at least electrically connected to the electrode on the surface side of the light reflective substrate on which the white inorganic resist layer is formed,
The white inorganic resist layer is formed by dispersing or mixing a white inorganic pigment in an inorganic binder, and is composed of a first layer and a second layer from the surface side of the base material,
The white inorganic pigment of the first layer has a higher refractive index than the white inorganic pigment of the second layer with respect to light in the entire visible light region,
The second layer has a high total reflectivity for at least near-ultraviolet light as compared to the first layer, and the total reflectivity is uniform over the entire region from the visible light region to the near-ultraviolet light region,
The electrode is arranged directly on one surface of the substrate, wherein the white inorganic resist layer, L ED light source you wherein the electrode in one surface of the substrate is formed in a region which is not located apparatus. The LED element is a near-ultraviolet LED element;
A sealing body that covers the near-ultraviolet LED element is provided on the light-reflective substrate on the side on which the near-ultraviolet LED element is mounted, and the sealing body is formed of a translucent resin material in which phosphors are dispersed. The LED light source device according to any one of claims 1 to 4 , wherein the LED light source device is provided. In the light reflective substrate having a white inorganic resist layer formed on one surface of the substrate,
The white inorganic resist layer is formed by dispersing or mixing a white inorganic pigment in an inorganic binder, and is composed of a first layer and a second layer from the surface side of the base material,
The white inorganic pigment of the first layer has a higher refractive index than the white inorganic pigment of the second layer with respect to light in the entire visible light region,
And the second layer, the total reflectivity is high for at least the near-ultraviolet light as compared with the first layer, Ri total reflectance uniform der over the entire region from the visible light range to the near-ultraviolet light range,
The light reflective substrate according to claim 1, wherein the white inorganic pigment of the first layer is barium titanate . Before SL white inorganic pigment of the second layer of alumina, talc, aluminum hydroxide, boehmite, light reflection of claim 6, characterized in that the one or more of a combination of barium sulfate, calcined kaolin Substrate. In the light reflective substrate having a white inorganic resist layer formed on one surface of the substrate,
The white inorganic resist layer is formed by dispersing or mixing a white inorganic pigment in an inorganic binder, and is composed of a first layer and a second layer from the surface side of the base material,
The white inorganic pigment of the first layer has a higher refractive index than the white inorganic pigment of the second layer with respect to light in the entire visible light region,
The second layer has a high total reflectivity for at least near-ultraviolet light as compared to the first layer, and the total reflectivity is uniform over the entire region from the visible light region to the near-ultraviolet light region,
The white inorganic resist layer is formed, the light reflective substrate, characterized in that the electrodes on the upper surface of the white inorganic resist layer is disposed on the entire one surface of the substrate. In the light reflective substrate having a white inorganic resist layer formed on one surface of the substrate,
The white inorganic resist layer is formed by dispersing or mixing a white inorganic pigment in an inorganic binder, and is composed of a first layer and a second layer from the surface side of the base material,
The white inorganic pigment of the first layer has a higher refractive index than the white inorganic pigment of the second layer with respect to light in the entire visible light region,
The second layer has a high total reflectivity for at least near-ultraviolet light as compared to the first layer, and the total reflectivity is uniform over the entire region from the visible light region to the near-ultraviolet light region,
Electrodes are disposed directly on one surface of the substrate, wherein the white inorganic resist layer, a light reflective substrate you wherein the electrode in one surface of the substrate is formed in a region which is not located .

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