JP2012209389A - Wiring board for mounting light-emitting element, light-emitting device and method for manufacturing wiring board for mounting light-emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide excellent reflection characteristics by enhancing the reflected amount of light from the light-emitting element-mounting surface side of an insulating substrate.SOLUTION: A wiring substrate for mounting a light-emitting element includes: the insulating substrate 10 in which a first main surface 10a side serves as a light reflection surface 12a; a conductive part 20v which is formed so as to penetrate the insulating substrate 10 therethrough and electrically connects the first main surface 10a and a second surface 10b of the insulating substrate 10; and a conductor pattern 31p for the conductive part which is formed on the second main surface 10b of the insulating substrate 10 and connected to the conductive part 20v. A part exposed to the first main surface 10a side of the conductive part 20v is capable of wire bonding connection with a light-emitting element which is mounted so as to emit the light from the first main surface 10a of the insulating substrate 10 toward the outside.

Description

  The present invention relates to a light emitting element mounting wiring board, a light emitting device, and a method for manufacturing a light emitting element mounting wiring board.

In recent years, for the purpose of saving energy and reducing CO ₂ emissions, such as portable devices using liquid crystal displays such as mobile phones and notebook personal computers, liquid crystal televisions using LED backlights, and LED bulbs. As a result, products using light emitting elements such as LED chips as light sources are increasing. The light emitting element is incorporated in the above product as a light emitting device such as an LED module or an LED package in which the light emitting element is mounted on a wiring substrate such as a glass epoxy substrate, an aluminum base substrate, or a ceramic substrate. Alternatively, a light emitting device in which a light emitting element is mounted on a lead frame and molded with a white mold resin may be used.

  As a light emitting element mounted on these light emitting devices, for example, a GaN blue LED chip or the like is used. For example, the blue LED chip is sealed with a sealing material mixed with a phosphor capable of converting blue light into white light and configured to emit white light. At that time, in order to suppress variation in the light emission characteristics, it is often used in a small size such as 0.25 mm × 0.35 mm square.

  For example, in Patent Document 1, as a light emitting device using a wiring board, an LED chip is mounted on a metal thin plate on the bottom surface in a through hole formed in an insulating substrate, and the LED chip and a metal layer formed on the surface of the insulating substrate are disclosed. And a chip component type LED (light emitting device) which is connected with a thin metal wire and sealed with a transparent resin. The metal layer on the front surface and the thin metal plate on the back surface are connected by a wiring pattern formed on the front surface, the back surface, and the side surface of the insulating substrate. For example, silver (Ag) or the like is laminated on the wiring pattern or the metal layer.

  In such a light-emitting device, in order to make maximum use of light emitted from the light-emitting element, it is effective to reflect light from the surface of the insulating substrate, that is, the surface on which the light-emitting element is mounted. As in Patent Document 1, it is also one of commonly used techniques to cover a wiring pattern or the like formed on the mounting surface of the light emitting element with silver (Ag) plating or the like.

Japanese Patent Application Laid-Open No. 07-235696

  However, Ag plating as described above is difficult to manage the appearance such as unevenness and color tone at the time of plating, and also changes color due to sulfuration after the light emitting device is manufactured, and light is reflected from the light emitting element mounting surface side. There is a drawback that the amount tends to decrease.

  An object of the present invention is to provide a light emitting element mounting wiring board, a light emitting device, and a method for manufacturing the light emitting element mounting wiring board having a good reflection characteristic by increasing the amount of light reflected from the light emitting element mounting surface side of the insulating substrate. There is to do.

  According to the first aspect of the present invention, the first main surface side and the second main surface of the insulating substrate are formed so as to penetrate the insulating substrate, the first main surface side being a light reflecting surface, and the insulating substrate. A conductive portion that conducts to a main surface; and a conductive pattern for a conductive portion that is formed on the second main surface of the insulating substrate and is connected to the conductive portion, and the first main surface of the conductive portion. Provided is a light emitting element mounting wiring board configured such that a portion exposed to the side is connected to a light emitting element mounted so as to emit light from the first main surface side of the insulating substrate toward the outside. Is done.

  According to the second aspect of the present invention, the light emitting element can be accommodated through the insulating substrate so that the inner diameter decreases from the first main surface side to the second main surface side of the insulating substrate. A housing hole formed on the second main surface of the insulating substrate so that a part of the housing hole is exposed from the housing hole toward the first main surface, and the light emitting element is mounted on the exposed portion. There is provided a wiring board for mounting a light emitting element according to the first aspect, including a mounting conductor pattern that can be configured.

  According to the third aspect of the present invention, the total reflectance of light on the light reflecting surface is 80% or more for light having a wavelength of 450 nm, for mounting the light emitting element according to the first or second aspect. A wiring board is provided.

  According to a fourth aspect of the present invention, there is provided the light emitting element mounting wiring board according to any one of the first to third aspects, wherein the light reflecting surface is substantially white.

  According to a fifth aspect of the present invention, the insulating substrate is disposed on the second main surface side of the insulating substrate, on the first main surface side of the insulating substrate, and on the insulating substrate. A wiring board for mounting a light-emitting element according to any one of the first to fourth aspects, comprising: a white insulating material that constitutes the light reflecting surface of the substrate.

  According to the sixth aspect of the present invention, the base material is made of any resin of polyimide, polyamideimide, polyethylene naphthalate, epoxy, and aramid having a thickness of 4 μm or more and 75 μm or less. The wiring board for mounting a light emitting element according to the fifth aspect, in which a curvature radius can be bent to 50 mm or less, is provided.

  According to a seventh aspect of the present invention, there is provided the wiring board for mounting a light emitting element according to any one of the second to sixth aspects, wherein a reflective coating film is formed on a side wall surface of the accommodation hole. The

  According to the eighth aspect of the present invention, the portion exposed from the accommodation hole of the mounting conductor pattern and the portion exposed to the first main surface side of the conductive portion include gold, silver, palladium, nickel, The wiring board for light emitting element mounting in any one of the 2nd-7th aspect with which the plating containing any element of tin is given is provided.

  According to the ninth aspect of the present invention, an insulating substrate having a light reflecting surface on the first main surface side, the first main surface and the second surface of the insulating substrate are formed so as to penetrate the insulating substrate. A light-emitting element mounting wiring board, comprising: a conductive portion that conducts to a main surface; and a conductive pattern for a conductive portion that is formed on the second main surface of the insulating substrate and is connected to the conductive portion. A light emitting device in which a light emitting element mounted so as to emit light from the first main surface side of the insulating substrate to the outside is wire-bonded to a portion exposed to the first main surface side of the portion; Provided.

According to a tenth aspect of the present invention, the wiring board for mounting a light emitting element has the insulating substrate so that the inner diameter decreases from the first main surface side to the second main surface side of the insulating substrate. An exposed portion that penetrates and is formed on the second main surface of the insulating substrate so as to be partially exposed from the receiving hole toward the first main surface side. And a mounting conductor pattern on which the light emitting element is mounted. The light emitting device according to the ninth aspect, wherein the light emitting element is sealed in the housing hole by a sealing material.

  According to an eleventh aspect of the present invention, the light-emitting element mounted on the mounting conductor pattern is wire-bonded to the conductive portion and die-bonded to the mounting conductor pattern. The light-emitting device according to the aspect is provided.

  According to a twelfth aspect of the present invention, the wiring board for mounting a light emitting element is formed so as to penetrate the insulating substrate, and electrically connects the first main surface and the second main surface of the insulating substrate. Another conductive part and another conductive part conductive pattern formed on the second main surface of the insulating substrate and connected to the other conductive part, and mounted on the mounting conductive pattern The light-emitting device according to the tenth aspect, wherein the light-emitting element is wire-bonded to the conductive portion and wire-bonded to a portion exposed to the first main surface side of the other conductive portion. Provided.

  According to the thirteenth aspect of the present invention, on the insulating substrate whose first main surface side is a light reflecting surface, a through hole forming step of forming a through hole, and on the second main surface of the insulating substrate, A conductor layer forming step of forming a conductor layer so as to cover the through-hole, and filling the through-hole with a conductive material from the first main surface side of the insulating substrate, and the first main surface of the insulating substrate and the A conductive portion forming step of forming a conductive portion that conducts with the second main surface; and a conductive portion conductor that is connected to the conductive portion by etching the conductive layer formed on the second main surface of the insulating substrate. An etching step of forming a pattern, and in the conductive portion forming step, a portion exposed to the first main surface side of the conductive portion is directed from the first main surface side of the insulating substrate to the outside. It is configured so that it can be wire-bonded to a light-emitting element mounted to emit light. Method for manufacturing a light-emitting element mounting wiring substrate is provided.

  According to the fourteenth aspect of the present invention, the insulating substrate can be penetrated so that the inner diameter decreases from the first main surface side to the second main surface side of the insulating substrate, and the light emitting element can be accommodated. A housing hole forming step for forming a housing hole formed in the insulating substrate, and in the etching step, the conductor layer formed on the second main surface of the insulating substrate is etched to form the housing hole. A part of the conductive pattern for mounting is formed so that the light emitting element can be mounted on the exposed part, and the accommodating hole forming step is at least from the conductive part forming step. A method for manufacturing a wiring board for mounting a light emitting element according to a thirteenth aspect is also provided.

  According to the present invention, it is possible to increase the amount of reflection of light from the light emitting element mounting surface side of the insulating substrate and to achieve good reflection characteristics.

It is a figure which shows a part of wiring board for light emitting element mounting which concerns on 1st Embodiment of this invention, (a) is a top view by the side of the 1st main surface of the wiring board for light emitting element mounting, (b) FIG. 3 is a top view of the second main surface side of the light emitting element mounting wiring board, and FIG. 3C is a cross-sectional view taken along line AA of FIG. It is a figure which shows a part of light-emitting device which concerns on 1st Embodiment of this invention, Comprising: It is sectional drawing of the same direction side as the AA cross section of Fig.1 (a). It is process drawing which shows each process of the manufacturing method of the wiring board for light emitting element mounting concerning 1st Embodiment of this invention with sectional drawing of the same direction side as the AA cross section of Fig.1 (a). It is sectional drawing which shows a part of light-emitting device which concerns on 2nd Embodiment of this invention.

<First Embodiment of the Present Invention>

(1) Structure of Light Emitting Element Mounting Wiring Board First, the structure of the light emitting element mounting wiring board according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a view showing a part of a wiring board for mounting a light emitting element according to the present embodiment, in which (a) is a top view on the first main surface side of the wiring board for mounting a light emitting element. FIG. 3 is a top view of the second main surface side of the light emitting element mounting wiring board, and FIG. 3C is a cross-sectional view taken along line AA of FIG.

  As shown in FIG. 1A, the light emitting element mounting wiring board can mount, for example, a blue LED chip 100 as a light emitting element having a peak wavelength in the vicinity of 450 nm on the first main surface 10a side of the insulating substrate 10. It is configured.

  Specifically, as shown in FIG. 1C, the light emitting element mounting wiring board includes an insulating substrate 10 having a light reflecting surface 12a on the first main surface 10a side. That is, the insulating substrate 10 includes, for example, a base material 11 arranged on the second main surface 10b side and a white insulating material 12 arranged on the first main surface 10a side and constituting the light reflecting surface 12a of the insulating substrate 10. Have. The insulating substrate 10 has an adhesive 13 on the second main surface 10b side, that is, on the surface of the base 11 opposite to the white insulating material 12.

  The substrate 11 is made of a flexible resin, for example, any resin such as polyimide (PI), polyamideimide (PAI), polyethylene naphthalate (PEN), epoxy, or aramid having a thickness of 4 μm to 75 μm. Thus, the insulating substrate 10 is configured to be bendable to a radius of curvature of 50 mm or less, for example. The white insulating material 12 is, for example, a white-based reflective coating film having a total reflectance of 80% or more with respect to light having a wavelength of 450 nm, which is substantially the same as the peak wavelength of the blue LED chip 100 to be mounted later. Here, the total reflectance is the sum of regular reflectance (specular reflectance) and diffuse reflectance (reflectance of light reflected in various directions). The adhesive 13 is, for example, a thermosetting epoxy adhesive or the like, and an adhesive for a TAB (Tape Automated Bonding) tape or a flexible wiring board, an adhesive for a coverlay, or the like can be used.

  As described above, since the light reflecting surface 12a is provided on the first main surface 10a side on which the blue LED chip 100 is mounted, the light that is emitted from the blue LED chip 100 and irregularly reflected is efficiently reflected on the first main surface 10a side. Can be reflected from the outside.

  Further, the light emitting element mounting wiring board is formed so as to penetrate the insulating substrate 10 and has a conductive portion 20v that conducts the first main surface 10a and the second main surface 10b of the insulating substrate 10. The conductive portion 20v is made of a conductive material such as copper (Cu) plating formed by, for example, electroplating. As shown in FIG. 1C, a portion of the conductive portion 20v exposed on the first main surface 10a side of the insulating substrate 10 is formed to have the same height as the first main surface 10a of the insulating substrate 10, for example. Yes. The portion exposed to the first main surface 10a side of the conductive portion 20v is configured to be wire-bonded by a wire 110 and a surface electrode (not shown) included in the blue LED chip 100 to be mounted later.

Further, the light emitting element mounting wiring board can pass through the insulating substrate 10 so that the inner diameter decreases from the first main surface 10 a side to the second main surface 10 b side of the insulating substrate 10, and can accommodate the blue LED chip 100. The housing hole 50h is configured as follows. That is, the accommodation hole 50h has a tapered shape, for example, and is configured to accommodate the blue LED chip 100 connected to the conductive portion 20v by wire bonding in the accommodation hole 50h. The taper angle of the accommodation hole 50h, that is, the angle between the second main surface 10b of the insulating substrate 10 and the side wall surface 50w of the accommodation hole 50h is, for example, less than 90 °. In addition, a reflective coating 52 is formed on the side wall surface 50w of the accommodation hole 50h. The reflective coating 52 is a white resin or the like, and for example, a thermosetting white solder resist or the like containing any resin such as epoxy, acrylic, or silicone can be used.

  In this way, the accommodation hole 50h configured to accommodate the blue LED chip 100 is tapered, and the reflective coating film 52 is formed on the side wall surface 50w composed of the base material 11 and the adhesive 13 with a small amount of light reflection. Therefore, the light etc. emitted from the blue LED chip 100 in the lateral direction or downward can be more efficiently reflected from the first main surface 10a side to the outside.

  Further, the light emitting element mounting wiring board has a conductive part conductive pattern 31p formed on the second main surface 10b of the insulating substrate 10 and connected to the conductive part 20v. The light emitting element mounting wiring board is formed on the second main surface 10b of the insulating substrate 10 so that a part thereof is exposed from the accommodation hole 50h toward the first main surface 10a, and the blue LED chip is formed on the exposed portion. The mounting conductor pattern 32p is configured so that 100 can be mounted.

  Specifically, the conductive portion conductor pattern 31p and the mounting conductor pattern 32p are formed on the second main surface 10b of the insulating substrate 10 with a thickness of, for example, 18 μm or more and 70 μm or less. The conductive part conductor pattern 31p is connected to the conductive part 20b and is configured as a wiring for supplying power to, for example, a blue LED chip 100 to be mounted later. The mounting conductor pattern 32p is configured as a wiring in which the blue LED chip 100 is mounted on a portion exposed from the accommodation hole 50h and can be die-bonded to a back electrode or the like (not shown) of the blue LED chip 100. The mounting conductor pattern 32p has a function of radiating heat generated when the blue LED chip 100 is driven. Thereby, it can be set as the wiring board for light emitting element mounting excellent in the thermal radiation characteristic.

  In FIG. 1B, the connection position of the conductive part 20b with the conductive part conductor pattern 31p and the mounting position of the blue LED chip 100 on the mounting conductive pattern 32p are indicated by broken lines.

  Further, at least a portion exposed from the accommodation hole 50h of the mounting conductor pattern 32p and a top surface of the conductive portion 20v, that is, a portion exposed on the first main surface 10a side, for example, gold (Au), silver (Ag), Plating (not shown) containing any element such as palladium (Pd), nickel (Ni), tin (Sn) is applied. Preferably, the plating is also applied to substantially the entire exposed surface of the conductive portion conductor pattern 31p and the mounting conductor pattern 32p other than those described above.

  As described above, in the present embodiment, only the upper surface of the conductive portion 20v is mainly exposed on the first main surface 10a side on which the blue LED chip 100 is mounted, and is opposite to the mounting surface of the blue LED chip 100. Conductive patterns 31p and 32p are provided on the second main surface 10b. Thereby, it can suppress that reflection of the light in the light reflection surface 12a is prevented by the conductor patterns 31p and 32p. Further, the exposed area of the conductive portion 20v can be reduced by adjusting the diameter of the conductive portion 20v exposed to the first main surface 10a side to such an extent that it can be connected to the blue LED chip 100 by wire bonding. Therefore, the exposed area of the light reflecting surface 12a provided on the mounting surface can be increased. As described above, the reflection amount of light from the first main surface 10a side, which is the mounting surface of the blue LED chip 100, can be increased, and favorable reflection characteristics can be obtained.

  In addition, the light emission according to the present embodiment is compared with the case where the light emitting element mounting wiring board is a double-sided wiring board as in the above-described conventional light emitting device in which wiring patterns are formed on the front and back surfaces of the insulating board. The element mounting wiring board is configured as a single-sided wiring board, which is advantageous for cost reduction.

In the present embodiment, the mounting conductor pattern 32p and the conductive portion 20v exposed at least on the first main surface 10a side are suppressed while suppressing the exposed area of the conductor patterns 31p and 32p and the conductive portion 20v on the first main surface 10a side. Has been plated to further increase the amount of reflection. In particular, by plating the exposed portion of the mounting conductor pattern 32p, it is possible to more efficiently reflect the light emitted downward from the blue LED chip 100 toward the outside from the first main surface 10a side. it can.

(2) Structure of Light Emitting Device Next, the structure of the light emitting device according to the first embodiment of the present invention will be described with reference to FIG. FIG. 2 is a view showing a part of the light emitting device according to the first embodiment of the present invention, and is a cross-sectional view on the same direction side as the AA cross section of FIG.

  As shown in FIG. 2, the light-emitting device is configured as an LED module in which a blue LED chip 100 as a light-emitting element having a peak wavelength near 450 nm, for example, is mounted on the light-emitting element mounting wiring board of FIG. Specifically, a surface electrode or the like (not shown) of the blue LED chip 100 is wire-bonded and connected by a wire 110 to a portion of the conductive portion 20v exposed on the first main surface 10a side of the insulating substrate 10. The blue LED chip 100 connected to the conductive portion 20v and accommodated in the accommodation hole 50h is mounted on the exposed portion of the mounting conductor pattern 32p, and is sealed in the accommodation hole 50h by the sealing material 120.

  Further, a back electrode or the like (not shown) of the blue LED chip 100 mounted on the mounting conductor pattern 32p is die-bonded to the mounting conductor pattern 32p via, for example, silver (Ag) paste 105 as a conductive material. Yes.

  The sealing material 120 is composed of, for example, a phosphor resin 121 and a package sealing resin 122. The phosphor resin 121 is mixed with a phosphor that converts the blue light emitted from the blue LED chip 100 having a peak wavelength near 450 nm into white light. Thereby, the blue LED chip 100 is configured to emit white light outward from the first main surface 10a side of the insulating substrate 10 which is the mounting surface. In addition, the sealing material 120 may be provided for every one accommodation hole 50h, and may be provided for each of the plurality of accommodation holes 50h. It is also possible to use a sealing material that combines the phosphor resin and the package sealing resin.

  Note that the light emitting device according to the present embodiment may be an LED package in which the light emitting element mounting wiring substrate is separated into pieces so as to include one or a plurality of receiving holes 50h in which the blue LED chip 100 is mounted. is there.

(3) Manufacturing Method of Light Emitting Element Mounting Wiring Substrate Next, a manufacturing method of the light emitting element mounting wiring substrate according to the first embodiment of the present invention will be described with reference to FIG. FIG. 3 is a process diagram showing each process of the method for manufacturing the light emitting element mounting wiring board according to the present embodiment in a cross-sectional view on the same direction side as the AA cross section of FIG. For example, a manufacturing process for a TAB tape is applied to the manufacturing process of the wiring board for mounting a light emitting element described below.

(Through hole forming process)
First, as shown in FIG. 3A, the base material 11 disposed on the second main surface 10b side and the white insulation that is disposed on the first main surface 10a side and constitutes the light reflecting surface 12a of the insulating substrate 10. An insulating substrate 10 having a material 12 is prepared. The insulating substrate 10 has an adhesive 13 on the second main surface 10b side, that is, on the surface of the base 11 opposite to the white insulating material 12. Such an insulating substrate 10 can be manufactured by coating a base material 11 with a white insulating material 12 such as a white reflective coating film and laminating or coating an adhesive material 13.

More specifically, a white coated polyimide film manufactured by Mitsui Chemicals or Toyobo can be used as the insulating substrate 10. Such a commercially available product can be used after being cut (slit) into a width capable of working in a roll form so that, for example, the manufacturing process of the TAB tape can be used. Moreover, as the adhesive material 13, you may use the product of each manufacturer, such as the Yodogawa paper mill, Toray, and Arisawa mill.

  Next, as shown in FIG. 3B, a through hole 20h is formed in the insulating substrate 10 having the light reflecting surface 12a on the first main surface 10a side. The through hole 20h is later filled with a conductive material to form a conductive portion 20v. The through hole 20h can be formed by, for example, press working, and by adjusting the opening diameter of the through hole 20h at that time, the exposed area on the first main surface 10a side of the conductive portion 20v to be formed later is adjusted. Can be adjusted. When forming the through hole 20h, a sprocket hole for transporting the insulating substrate 10 and an alignment hole (both not shown) may be formed together.

(Conductor layer forming process)
Next, as shown in FIG. 3C, a copper foil 30 as a conductor layer is formed on the second main surface 10b of the insulating substrate 10 so as to cover the through hole 20h. At this time, for example, a copper foil 30 having a thickness of 18 μm or more and 70 μm or less can be used and bonded to the insulating substrate 10 by, for example, laminating using a roll laminator under a normal pressure or reduced pressure environment. After the lamination is completed, the adhesive 13 is post-cured at a temperature of 150 ° C. or higher, for example. Lamination and post-cure conditions can be selected based on the recommended values of the adhesive manufacturer.

  Note that the conductor layer may be formed by bonding the copper foil 30 by thermocompression bonding without using an adhesive, or by directly forming a conductive material on the insulating substrate.

(Conductive part formation process)
3D, the through hole 20h is filled with a conductive material such as copper (Cu) from the first main surface 10a side of the insulating substrate 10, and the first main surface 10a of the insulating substrate 10 and A conductive portion 20v is formed that is electrically connected to the second major surface 10b. The conductive material constituting the conductive portion 20v is embedded and plated in the through hole 20h by, for example, electrolytic copper plating. At this time, the surface of the copper foil 30 on the second main surface 10b side is masked with a masking tape for plating (not shown).

  The height of the conductive portion 20v on the first main surface 10a side of the insulating substrate 10 can be adjusted by, for example, plating conditions such as plating time. For example, as shown in FIG. The main surface 10a and the height can be aligned. Thereby, the part exposed to the 1st main surface 10a side of the electroconductive part 20v is comprised so that wire bonding connection can be carried out with the blue LED chip 100 (refer Fig.1 (a)) mounted later.

  As a specific technique for the embedded plating, for example, a technique disclosed in Japanese Patent Application Laid-Open No. 2003-124264 can be used. In addition, for example, Ebara Eugelite or Atotech copper plating solution can be used for the electrolytic copper plating, and the method of using the copper plating solution can also be based on the recommended value from the manufacturer.

  After the completion of the electrolytic copper plating, a masking tape (not shown) is peeled off from the copper foil 30.

(Etching process)
Next, as shown in FIG. 3E, for example, a resist for etching is applied on the conductor layer 30 formed on the second main surface 10b of the insulating substrate 10, and then exposed and developed to form a resist pattern 40p. Form. At this time, a dry film or the like may be used instead of the etching resist.

  Subsequently, as shown in FIG. 3F, the conductive layer 30 formed on the second main surface 10b of the insulating substrate 10 is etched using the resist pattern 40p as a mask to connect the conductive portion 20v. Conductive pattern 31p is formed. Further, the mounting conductor pattern 32p is formed at a position where a part is exposed from the accommodation hole 50h formed later toward the first main surface 10a side. At this time, a masking tape or the like (not shown) is pasted on the first main surface 10a to mask the upper surface of the conductive portion 20v on the first main surface 10a side. Alternatively, a backing material may be applied to the upper surface of the conductive portion 20v.

  After the etching is completed, the resist pattern 40p and the masking tape are peeled off.

(Housing hole forming process)
Next, as shown in FIG. 3G, the insulating substrate 10 is penetrated so that the inner diameter decreases from the first main surface 10a side to the second main surface 10b side of the insulating substrate 10, and the blue LED chip 100 is inserted. The insulating substrate 10 is formed with a receiving hole 50h configured so as to be able to receive the substrate. Such a tapered shape of the accommodation hole 50h can be obtained by, for example, penetrating the insulating substrate 10 by laser processing. By using laser processing, it is easy to control the taper shape, for example, the taper angle of the accommodation hole 50h is less than 90 °, for example. Moreover, it is preferable to remove smear after laser processing.

  By forming the accommodation hole 50h in this manner, a part of the mounting conductor pattern 32p is exposed from the accommodation hole 50h toward the first main surface 10a, and the blue LED chip 100 can be mounted on the exposed portion.

  Further, by performing the accommodation hole forming step at least after the conductive portion forming step, the formed accommodation hole 50h is not filled with the conductive material.

(Reflection coating formation process)
Next, as shown in FIG. 3 (h), a reflective coating 52 is formed on the side wall surface 50 w of the accommodation hole 50. That is, the reflective coating film 52 composed of a thermosetting white solder resist or the like is applied by, for example, screen printing or the like so as to surround the vicinity of the opening above the side wall surface 50w of the accommodation hole 50h in a donut shape. The reflective coating 52 applied to the upper side of the side wall surface 50w is applied to the side wall surface 50h by flowing toward the bottom of the accommodation hole 50h along the side wall surface 50h by its own weight. At this time, the coating amount of the reflective coating 52 is adjusted so that the hole bottom of the accommodation hole 50 h is not blocked by the reflective coating 52. Thereafter, the reflective coating film 52 is heated and cured by heat.

(Plating formation process)
Next, plating is performed on at least a portion exposed from the accommodation hole 50h of the mounting conductor pattern 32p and a portion exposed to the first main surface 10a side of the conductive portion 20v (not shown). Preferably, the plating is also applied to substantially the entire exposed surface of the conductive pattern 31p for the conductive portion and the mounting conductive pattern 32p other than the above. In addition, you may implement a plating formation process before a reflective coating film formation process.

  Thus, the light emitting element mounting wiring board according to the present embodiment is formed.

(4) Method for Manufacturing Light-Emitting Device Next, a method for manufacturing a light-emitting device according to the first embodiment of the present invention will be described with reference to FIG.

(Die bonding process)
First, for example, a blue LED chip 100 as a light emitting element having a peak wavelength near 450 nm is prepared in a state after wafer dicing mounted on a wafer ring or a wafer tray. This blue LED chip 100 is die-bonded to an exposed portion of the mounting conductor pattern 32p using, for example, a silver (Ag) paste 105 or the like using an LED die bonder or the like. Thereafter, a die bonding material such as silver (Ag) paste 105 is heated and cured at 150 ° C. for about one hour in accordance with a value recommended by the die bonding material manufacturer, for example.

(Cleaning process)
As described above, when the die bonding material is cured by heating, the generated degas may contaminate bonding pads such as surface electrodes (not shown) included in the blue LED chip 100. Therefore, for example, under a reduced pressure environment, plasma cleaning of a contaminated bonding pad or the like is performed using a mixed gas such as argon (Ar) gas and oxygen (O ₂ ) gas.

(Wire bonding process)
Next, using a wire bonder for LED or the like, the blue LED chip 100 is wire-bonded and connected to a portion of the conductive portion 20v exposed on the first main surface 10a side of the insulating substrate 10. Specifically, bumps are formed on the surface electrodes (not shown) included in the blue LED chip 100 with wires. Next, first bonding is performed on the conductive portion 20v of the light emitting element mounting wiring board. Further, second bonding is performed on the bumps of the blue LED chip 100. Thereby, the wire bonding connection with high tolerance of a temperature cycle test can be obtained.

(Sealing process)
Subsequently, the blue LED chip 100 is sealed in the accommodation hole 50 h by the sealing material 120. That is, first, the phosphor resin 121 is applied in the accommodation hole 50h. By applying the phosphor resin 121 in the accommodation hole 50h, the flow-out of the phosphor resin 121 can be suppressed, and the coating film thickness can be easily controlled.

  Next, the package sealing resin 122 is applied onto the accommodation hole 50h and the first main surface 10a of the insulating substrate 10 around the accommodation hole 50h. At this time, in order to prevent the package sealing resin 122 from flowing out, for example, a white resin (not shown) may be applied in advance so as to surround the coating region of the package sealing resin 122. Specifically, white silicone resin or the like is discharged using a dispenser or the like so as to draw a frame around the accommodation hole 50h. By applying the package sealing resin 122 in the frame, the package sealing resin 122 can be prevented from flowing out. In addition, by providing a white resin having a predetermined reflectance in a predetermined shape, the white resin can also function as a white-based reflective coating film that reflects light emitted from the blue LED chip 100.

  As described above, the light emitting device according to this embodiment configured as an LED module is formed.

  In addition, the light emitting element mounting wiring board provided in the light emitting device is separated into pieces by using a dicer or a big blade so as to include one or a plurality of accommodation holes 50h in which the blue LED chip 100 is accommodated. A package is obtained.

<Second Embodiment of the Present Invention>
Next, a light emitting device and a light emitting element mounting wiring board included in the light emitting device according to a second embodiment of the present invention will be described. The light emitting device according to this embodiment is different from the above-described embodiment in that a light emitting element in which two electrodes are formed on one side is mounted. In FIG. 4 used for the following description, the same components having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and the following description is omitted. FIG. 4 is a cross-sectional view showing a part of the light emitting device according to this embodiment.

(1) Structure of Light-Emitting Element Mounting Wiring Substrate As shown in FIG. 4, the light-emitting element mounting wiring board included in the light-emitting device according to this embodiment is formed so as to penetrate through the insulating substrate 10. The first main surface 10a and the second main surface 10b are provided with a conductive portion 221v and another conductive portion 222v. The first main surface 10a side of the conductive portions 221v and 222v is connected by wire bonding by two electrodes (not shown) included in the blue LED chip 200 as a light emitting element having a peak wavelength near 450 nm, for example, and wires 211 and 212, respectively. It is configured to be possible.

  Further, the light emitting element mounting wiring board is formed on the second main surface 10b of the insulating substrate 10 and has a conductive part conductor pattern 231p and another conductive part conductive pattern 233p connected to the conductive parts 221v and 222v, respectively. . The conductive portion conductor patterns 231p and 233p are configured as wirings for applying a voltage between the two electrodes of the blue LED chip 200 via the conductive portions 221v and 222v.

  The light emitting element mounting wiring board is formed on the second main surface 10b of the insulating substrate 10 so that a part thereof is exposed from the accommodation hole 50h toward the first main surface 10a, and the blue LED chip is formed on the exposed portion. 200 has a mounting conductor pattern 232p configured to be capable of mounting 200. The mounting conductor pattern 232p does not need to have electrical continuity with the blue LED chip 200, and is mounted exclusively with the blue LED chip 200, and Ag plating or the like (not shown) applied to the exposed portion. Therefore, the light from the blue LED chip 200 is reflected.

  The above-described wiring board for mounting a light emitting element uses the same manufacturing method as that of the above-described embodiment, forms the conductive portions 221v and 222v in the conductive portion forming step, and forms conductive patterns 231p and 233p for the conductive portion in the etching step. Can be manufactured together.

(2) Structure of Light-Emitting Device As shown in FIG. 4, the light-emitting device according to the present embodiment is configured as an LED module in which a blue LED chip 200 is mounted on the light-emitting element mounting wiring board. Specifically, one of the two electrodes (not shown) of the blue LED chip 200 housed in the housing hole 50h and mounted on the mounting conductor pattern 232p is connected to the first main surface 10a side of the conductive portion 221v and the wire. 211, and another electrode of the blue LED chip 200 is wire-bonded and connected to a portion of the other conductive portion 222 v exposed to the first main surface 10 a side of the insulating substrate 10 by a wire 212. ing.

  The light-emitting device can be manufactured by wire-bonding the conductive portions 221v and 222v to the blue LED chip 200 in the same wire bonding step as in the above-described embodiment.

<Other Embodiments of the Present Invention>
As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, It can change variously in the range which does not deviate from the summary.

  For example, in the above-described embodiment, the insulating substrate 10 has the base material 11 and the white insulating material 12, but the insulating substrate has a white base material that constitutes the light reflection surface of the insulating substrate. It is good. In this case, since the base material itself has a function of reflecting light, it is not necessary to separately provide a white insulating material. In this case, the reflective coating provided on the side wall surface 50w of the accommodation hole 50h may be discarded. As a specific example of such an insulating substrate having a high reflectance, there is a white coverlay made by Arisawa Seisakusho coated with an adhesive.

  In the above-described embodiment, a thermosetting white solder resist is used for the reflective coating film 52 formed on the side wall surface 50w of the accommodation hole 50h. For example, a photoreactive white solder is used. A resist or the like can also be used. In this case, a reflective coating applied to a predetermined position, that is, the side wall surface 50w can be formed by, for example, a photolithography method.

  In the above-described embodiment, the white material is provided on the first main surface 10a of the insulating substrate 10 and the side wall surface 50w of the accommodation hole 50h. However, the material is not limited to this. When a white material is used, deterioration due to light or heat occurs regardless of whether it is organic or inorganic, and there is a possibility that the amount of reflection gradually decreases. Depending on the required specifications for the light emitting device, such as being very severe with respect to changes in light emission efficiency over time, for example, a black material may be used as the material, and the reflection amount may be reduced from the beginning. Thereby, although the initial light emission efficiency of the light emitting device is low, it is possible to suppress the temporal change of the light emission efficiency due to the use environment.

  In the above-described embodiment, the heights of the conductive portions 20v, 221v, and 222v on the first main surface 10a side of the insulating substrate 10 are aligned with the height of the first main surface 10a of the insulating substrate 10. The embedding plating time or the like may be adjusted so as to be recessed or protruded from the first main surface 10a within a range in which the blue LED chips 100 and 200 can be connected by wire bonding. Further, when the conductive portion is protruded from the first main surface, the conductive portion may protrude with a diameter larger than the opening diameter of the through hole 20h.

  In the above-described embodiment, the conductive portions 20v, 221v, and 222v are made of a conductive material such as copper (Cu) plating. However, other conductive materials such as a conductive paste may be used.

  In the above-described embodiment, the light emitting device is configured such that one blue LED chip 100 is accommodated in one accommodation hole 50h. However, a plurality of blue LED chips are accommodated in one accommodation hole 50h. A configuration may be adopted. In this case, when the LED package is made into individual pieces, a configuration having one accommodation hole in which a plurality of blue LED chips are accommodated, or a plurality of accommodation holes in which a plurality of blue LED chips are accommodated. It is good also as a structure to have.

  In the above-described embodiment, the accommodation hole 50h is formed by laser processing. However, the accommodation hole may be formed by, for example, polyimide etching using a photolithography method. In the case of polyimide etching, the shape of the accommodation hole largely depends on the material of the insulating substrate, and the controllability of the taper angle of the accommodation hole is reduced compared to laser processing, but by adjusting the etching conditions etc., the predetermined taper shape Can be obtained.

  Further, in the above-described embodiment, the light emitting element mounting wiring board is manufactured by applying the manufacturing process for the TAB tape. However, depending on the insulating substrate used, the manufacturing process for the rigid wiring board and the flexible wiring board is used. It is also possible to apply.

DESCRIPTION OF SYMBOLS 10 Insulation board | substrate 10a 1st main surface 10b 2nd main surface 12a Light reflection surface 20v, 221v, 222v Conductive part 31p, 231p, 233p Conductive part conductive pattern 32p, 232p Mounting conductive pattern 50h Housing hole 100,200 Blue LED chip (Light emitting element)
120 Sealing material

Claims (14)

An insulating substrate having a light reflecting surface on the first main surface side;
A conductive portion formed so as to penetrate the insulating substrate and electrically connecting the first main surface and the second main surface of the insulating substrate;
A conductive pattern for a conductive part formed on the second main surface of the insulating substrate and connected to the conductive part;
A portion exposed to the first main surface side of the conductive portion is configured to be capable of wire bonding connection with a light emitting element mounted so as to emit light from the first main surface side of the insulating substrate toward the outside. A wiring board for mounting a light-emitting element. A housing hole configured to penetrate the insulating substrate so that the inner diameter decreases from the first main surface side of the insulating substrate toward the second main surface side, and to accommodate the light emitting element;
A mounting conductor formed on the second main surface of the insulating substrate so as to be partially exposed from the housing hole toward the first main surface, and configured to mount the light emitting element on the exposed portion. The light-emitting element mounting wiring board according to claim 1, further comprising: a pattern. The total light reflectance of the light reflecting surface is
The wiring board for mounting a light emitting element according to claim 1 or 2, wherein the wavelength is 80% or more with respect to light having a wavelength of 450 nm. The light-emitting element mounting wiring board according to claim 1, wherein the light reflecting surface is substantially white. The insulating substrate is
A base material disposed on the second main surface side of the insulating substrate;
The light-emitting element according to claim 1, further comprising: a white insulating material disposed on the first main surface side of the insulating substrate and constituting the light reflecting surface of the insulating substrate. Wiring board for mounting. The substrate is
It is made of any resin of polyimide, polyamideimide, polyethylene naphthalate, epoxy, aramid having a thickness of 4 μm to 75 μm,
The insulating substrate is
6. The wiring board for mounting a light emitting element according to claim 5, wherein the radius of curvature is bendable to 50 mm or less. The wiring board for mounting a light-emitting element according to claim 2, wherein a reflective coating film is formed on a side wall surface of the accommodation hole. The portion of the mounting conductor pattern exposed from the accommodation hole and the portion of the conductive portion exposed to the first main surface are plated with one of gold, silver, palladium, nickel, and tin. The wiring board for mounting a light emitting element according to claim 2, wherein the wiring board is mounted. An insulating substrate having a light reflecting surface on the first main surface side;
A conductive portion formed so as to penetrate the insulating substrate and electrically connecting the first main surface and the second main surface of the insulating substrate;
A light emitting element mounting wiring board having a conductive pattern for a conductive portion formed on the second main surface of the insulating substrate and connected to the conductive portion;
A light emitting element mounted so as to emit light from the first main surface side of the insulating substrate to the outside is wire-bonded to a portion exposed to the first main surface side of the conductive portion. A light emitting device characterized by the above. The light emitting element mounting wiring board is:
An accommodation hole in which the light emitting element is accommodated, penetrating through the insulation substrate so that the inner diameter decreases from the first principal surface side of the insulation substrate toward the second principal surface side;
A mounting conductor pattern formed on the second main surface of the insulating substrate so as to be partially exposed from the housing hole toward the first main surface side, and the light emitting element mounted on the exposed portion; Have
The light emitting element is
The light emitting device according to claim 9, wherein the light emitting device is sealed in the accommodation hole by a sealing material. The light emitting element mounted on the mounting conductor pattern is:
While being connected to the conductive portion by wire bonding,
The light emitting device according to claim 10, wherein the light emitting device is die-bonded to the mounting conductor pattern. The light emitting element mounting wiring board is:
Another conductive part formed so as to penetrate the insulating substrate and electrically connecting the first main surface and the second main surface of the insulating substrate;
A conductive pattern for another conductive portion formed on the second main surface of the insulating substrate and connected to the other conductive portion;
The light emitting element mounted on the mounting conductor pattern is:
While being connected to the conductive portion by wire bonding,
The light emitting device according to claim 10, wherein a wire bonding connection is made to a portion of the other conductive portion exposed to the first main surface side. A through-hole forming step of forming a through-hole in the insulating substrate whose first main surface side is a light reflecting surface;
A conductor layer forming step of forming a conductor layer on the second main surface of the insulating substrate so as to cover the through hole;
A conductive portion forming step of forming a conductive portion that fills the through-hole with a conductive material from the first main surface side of the insulating substrate and electrically connects the first main surface and the second main surface of the insulating substrate. When,
Etching the conductor layer formed on the second main surface of the insulating substrate to form a conductive pattern for a conductive portion connected to the conductive portion, and
In the conductive part forming step,
A portion exposed to the first main surface side of the conductive portion is configured to be wire bonding connectable to a light emitting element mounted so as to emit light from the first main surface side of the insulating substrate toward the outside. A method for manufacturing a wiring board for mounting a light emitting element. The insulating substrate is provided with a receiving hole configured to penetrate the insulating substrate so that the inner diameter decreases from the first main surface side to the second main surface side of the insulating substrate, and to accommodate the light emitting element. A housing hole forming step to be formed;
In the etching step,
The conductor layer formed on the second main surface of the insulating substrate is etched so that a part is exposed from the accommodation hole toward the first main surface, and the light emitting element can be mounted on the exposed portion. To form a mounting conductor pattern,
14. The method for manufacturing a wiring board for mounting a light emitting element according to claim 13, wherein the housing hole forming step is performed at least after the conductive portion forming step.

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