JP2012054383A - Semiconductor light-emitting device and manufacturing method of the same - Google Patents

Abstract

In an LED device provided with a dam material, a photolithography method or a printing method with high positional accuracy must be applied when a reflective member such as a white resist or silicone resin is arranged in a region surrounded by the dam material. Disappear.
A reflective silicone resin is fluidly applied to the bottom of an area surrounded by a dam material. The upper surface of the reflective silicone resin 21 is lower than the upper surface of the LED 22. The thickness of the reflective silicone resin 21 is preferably about 30 to 50 μm.
[Selection] Figure 2

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device having a semiconductor light emitting element mounted on a circuit board and a manufacturing method thereof. Specifically, the semiconductor light emitting element is surrounded on the circuit board by a dam material, The present invention relates to a semiconductor light emitting device for sealing a semiconductor light emitting element and a method for manufacturing the same.

  In a semiconductor light emitting device (hereinafter referred to as an LED device unless otherwise specified) in which a semiconductor light emitting element (hereinafter referred to as an LED element) is mounted on a circuit board and packaged, the surface of the circuit board is improved in order to improve luminous efficiency. An LED device having a white reflecting member is known.

  For example, FIG. 1 of Patent Document 1 shows a light source device 10 (LED device) including a white resist layer 6 (reflecting member). In the light source device 10, a pair of electrodes 2 and 3 are formed on a substrate 1 (circuit board), and a light emitting diode chip 4 (LED element) connected to the electrodes 2 and 3 is sealed with a transparent resin 7. ing. The light emitting diode chip 4 is disposed on one electrode 2 and is electrically connected to the electrode 2. The chip 4 and the other electrode 3 are electrically connected by a wire 5. The transparent resin 7 has a dome shape whose upper surface is a spherical surface. A white resist layer 6 (reflection member) is formed on the substrate 1. The white resist layer 6 has an opening near the terminal of the electrode 3 to which the chip 4 of the light emitting diode 4 and the wire 5 are connected, and covers the electrodes 2 and 3 in the portion other than the opening. The opening has a rectangular shape, and the wall surface 6 </ b> A of the opening is located near the chip 4 and the terminal of the electrode 3.

  LED devices take various forms depending on the shape of components such as a circuit board, a sealing member, and a reflective structure. Among these, a plurality of LED elements are arranged on a circuit board mainly for a lighting device, a dam material surrounding the LED elements is provided, and a resin is filled in a region surrounded by the dam material to seal the LED elements. LED devices are known. For example, the semiconductor light emitting device 100 shown in FIG. 1 of Patent Document 2 includes a wiring board 1 (circuit board) and four light emitting units 2 each including a weir 22 (dam material). The weir 22 surrounds a plurality of semiconductor light emitting elements 21 arranged in each light emitting unit 2, and the semiconductor light emitting element 21 is sealed in a region surrounded by the weir 22.

Japanese Patent Laying-Open No. 2007-201171 (FIG. 1) JP 2009-135485 A (FIG. 1)

  In FIG. 4 of Patent Document 2, a reflection member (white coating layer) is provided outside the dam material (weir 22). However, in order to greatly improve the luminous efficiency, it is desirable to arrange a reflecting member inside the dam material. In this case, the white reflecting member before curing is first arranged at a desired position on the circuit board. When the reflecting member is a white resist, the outline and the opening are formed by photolithography. When the reflecting member is a white paint (ink), a printing method is applied. Next, the reflecting member is cured and the LED element is mounted. Finally, the dam material is formed and the sealing resin is filled. However, in order not to significantly reduce the light emission efficiency in the opening region of the reflecting member such as the LED element mounting portion, there arises a problem that high positional accuracy is required in the photolithography method and the printing method.

  Accordingly, the present invention has been made in view of this problem, and an object of the present invention is to provide a semiconductor light emitting device and a method for manufacturing the same, in which a reflecting member can be easily arranged in a circuit board region surrounded by a dam material.

The semiconductor light-emitting device of the present invention includes a dam material surrounding the semiconductor light-emitting element on a circuit board on which the semiconductor light-emitting element is mounted, filling a region surrounded by the dam material with the sealing resin, In a semiconductor light emitting device for sealing a semiconductor light emitting element,
A reflective member fluidly applied to the bottom of the region surrounded by the dam material;
The upper surface of the reflecting member is lower than the upper surface of the semiconductor light emitting element.

  It is preferable that the thickness of the reflecting member is approximately 30 to 50 μm.

  The reflective member may be a silicone resin in which reflective particles are kneaded.

  The reflective member may be a ceramic ink in which reflective particles are kneaded.

The method for manufacturing a semiconductor light emitting device of the present invention includes a dam material surrounding the semiconductor light emitting element on a circuit board on which the semiconductor light emitting element is mounted, and a sealing resin is filled in a region surrounded by the dam material. In a method for manufacturing a semiconductor light emitting device for sealing the semiconductor light emitting element with a resin,
Mounting the semiconductor light emitting element on the circuit board and forming the dam material;
Pouring the reflective member before curing into a region inside the dam material and excluding the region occupied by the semiconductor light emitting element, and curing the reflective member;
And filling the region inside the dam material with the sealing resin before curing, and curing the sealing resin.

  In the semiconductor light emitting device of the present invention, the reflection member is spread over the bottom of the region surrounded by the dam material while avoiding the semiconductor light emitting element. The reflecting member can be easily formed by applying a fluid reflecting member to the region and curing the reflecting member. As described above, the semiconductor light emitting device of the present invention has a structure in which the reflecting member can be easily arranged in the region surrounded by the dam material.

  Similarly, in the method for manufacturing a semiconductor light emitting device of the present invention, the reflective member can be easily formed by applying and curing a reflective member having fluidity between the dam material and the semiconductor light emitting element.

The perspective view of the LED device in the embodiment of the present invention. FIG. 2 is a perspective view of the LED device excluding the phosphor resin (sealing resin) from FIG. 1. FIG. 3 is a perspective view of an LED device excluding a reflective silicone resin (reflective member) from FIG. 2. Explanatory drawing of the manufacturing method of the LED apparatus shown in FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. In the description of the drawings, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted. For the sake of explanation, the scale of the members is changed as appropriate.

The appearance of the LED device 10 of this embodiment will be described with reference to FIG. FIG. 1 is a perspective view of the LED device 10 as viewed from above. A + electrode 14, a − electrode 15, and an alignment mark 16 are formed on the circuit board 13, and a frame-shaped dam material 11 is disposed. The inside of the dam material 11 is filled with a phosphor resin 12 (sealing resin).

  The + and-electrodes 14 and 15 and the alignment mark 16 are metal patterns obtained by plating nickel and gold on a copper foil. The dam material 11 is made of a silicone resin in which reflective particles such as titanium dioxide are dispersed, and the light directed to the side surface (direction parallel to the circuit board) together with the flow stop of the fluorescent resin 12 is directed to the front (perpendicular to the circuit board) It also functions as a reflector directed in the direction. The phosphor resin 12 is obtained by dispersing a phosphor such as YAG in a silicone resin and whitens the blue light emitted from the LED element 22 (shown in FIG. 2).

  The arrangement relationship of the reflecting members will be described with reference to FIG. FIG. 2 is a perspective view of the LED device 10 with the phosphor resin 12 removed from FIG. Four LED elements 22 are arranged inside the dam material 11. The reflective silicone resin 21 (reflective member) is present in the region not occupied by the LED element 22 in the inner region of the dam material without any gap. The reflective silicone resin 21 is obtained by kneading titanium dioxide as a reflective particle together with a solvent into a silicone resin, fluidly applying the silicone resin to the gap between the dam material 11 and the LED element 22 and sintering.

  The reflective silicone resin 21 fluidly applied to the inner bottom of the dam material 11 has an upper surface lower than the upper surface of the LED 22 so as not to obstruct light emitted from the side surface of the LED 22. The reflective silicone resin 21 has a thickness of approximately 30 to 50 μm. When this thickness is smaller than 30 μm, the reflection characteristics of the reflective silicone resin 21 are greatly affected by the surface of the circuit board 13. When the thickness is 30 μm or more, it becomes a practical level, and when it is 50 μm, it is almost completely unaffected by the circuit board 13.

  The lower part of the reflective silicone resin 21 will be described with reference to FIG. FIG. 3 is a perspective view of the LED device 10 with the reflective silicone resin 21 removed from FIG. When the reflective silicone resin 21 is removed, the connection electrodes 31, 32, and 33 appear in addition to the + electrode 14 and the − electrode 15 inside the dam material 11. The LED element 22 is flip-chip mounted, and these electrodes 14, 15, 31, 32, 33 and the anode and cathode of the LED element 22 are connected via bumps. These LED elements 22 are connected in series.

  Since the electrodes 14, 15, 31, 32, and 33 are covered with the reflective silicone resin 21, it is not necessary to use the reflective electrodes. That is, the surfaces of the electrodes 14, 15, 31, 32, and 33 are not silver layers that have high reflectivity but need countermeasures against sulfidation and migration, but are colored and have a stable gold layer that is not so high in reflectivity. Yes.

  A method of manufacturing the LED device 10 will be described with reference to FIG. FIG. 4 is an explanatory diagram of a method for manufacturing the LED device 10. In general, when the LED device 10 is manufactured, the LED device 10 is often formed on a collective substrate in which a plurality of circuit boards 13 are connected, and finally the collective substrate is cut into individual pieces. However, in this embodiment, the manufacturing process is described using a single circuit board 13 for the sake of simplicity. The number of LED elements 22 mounted on the circuit board 13 is also one.

(A) has shown the process of forming the dam material 11 after mounting the LED element 22 on the circuit board 13. First, the LED element 22 is flip-chip mounted on the circuit board 13. The electrode of the circuit board 13 and the electrode of the LED element 22 are joined by gold tin eutectic. This gold-tin eutectic bonding is characterized in that the bonding temperature is about 300 ° C., and when the circuit board 13 is reflowed to the mother substrate (the temperature is about 260 ° C.), the bonding portion remains solid. Next, when the LED element 22 is mounted, the dam material 11 before curing is arranged by a dispenser. The dam material 11 is cured at about 150 ° C. In order to control the emission color of the LED device 10 with high accuracy, the thickness of the phosphor resin 12 also needs to be controlled with high accuracy. Since the phosphor resin 12 is defined by the coating amount, the shape of the dam material 11 needs to be highly accurate in order to increase the thickness.

  (B) is a process of disposing the reflective silicone resin 21. The reflective silicone resin 21 before curing is applied to the region between the dam material 11 and the LED element 22 with a dispenser so that the upper surface of the LED element 22 is not exceeded in the region inside the dam material 11. Although not shown, the reflective silicone resin 21 is also passed through the gap between the LED elements 22. The sintering temperature is about 150 ° C., and when the thickness of the reflective silicone resin 21 after sintering becomes about 50 μm, the surface of the circuit board 13 becomes completely invisible.

  (C) is a step of sealing the LED element 10 with the phosphor resin 12 in the region inside the dam material 11. An accurate amount of the phosphor resin 12 is filled into a region inside the dam material 11 by a dispenser, and the phosphor resin 12 is cured at 150 ° C.

  The present invention uses the dam material originally provided, and simply realizes accurate arrangement of the reflecting member by coating. In this embodiment, after the LED element 10 is mounted on the circuit board, the reflective member is fluidly applied. Therefore, the reflective member is not affected by the high temperature when the LED element is joined. Can be used. The reflective member is not limited to a resin, and may be a reflective ceramic ink obtained by kneading reflective particles such as titanium dioxide particles together with a solvent in a binder such as organopolysiloxane. Although this ceramic ink is glassy, it can be sintered at a relatively low temperature of about 150 ° C. with a catalyst. Moreover, since it is inorganic, there is also a feature that it can contribute to a long life without being deteriorated by light emission of the LED element 22.

  In the present embodiment, the phosphor resin 12 is used as the sealing resin. However, the sealing resin does not necessarily contain a phosphor, and is a sealing resin in which a transparent sealing resin or a scattering material is kneaded. Also good. Further, it is not necessary to limit the phosphor to kneading in the sealing resin. Even if the phosphor layer is formed on the top of the resin or the phosphor layer is localized only on the periphery of the LED element 22 good.

  In this embodiment, the LED element 22 is flip-chip mounted. However, the LED element mounting method is not limited to flip-chip mounting, and may be a face-up mounting method in which a semiconductor layer of the LED element is directed to the upper surface side of the LED device and power is supplied by a wire. Note that the bumps for flip chip mounting employed in this embodiment can be plated bumps or stud bumps formed by electrolytic plating or the like. At this time, the plating bump has a thickness of about 20 to 30 μm, and the stud bump has a thickness of about 100 μm. Therefore, when the reflection member is fluidly applied, the reflection member 21 enters the gap between the circuit board 13 and the LED element 22. When it is not desired to dispose the reflecting member under the LED element 22, an underfill material may be disposed in advance in a region under the LED element 22.

10 ... LED device (semiconductor light-emitting device),
11 ... Dam materials,
12 ... phosphor resin (sealing resin),
13 ... Circuit board,
14 ... + electrodes,
15 ...- electrodes,
16 ... Alignment mark,
21 ... Reflective silicone resin (reflective member),
22 ... LED element (semiconductor light emitting element),
31, 32, 33 ... electrodes.

Claims (5)

A semiconductor comprising a dam material surrounding the semiconductor light emitting element on a circuit board on which the semiconductor light emitting element is mounted, filling a region surrounded by the dam material with a sealing resin, and sealing the semiconductor light emitting element with the sealing resin In the light emitting device,
A reflective member fluidly applied to the bottom of the region surrounded by the dam material;
A semiconductor light emitting device, wherein an upper surface of the reflecting member is lower than an upper surface of the semiconductor light emitting element.   2. The semiconductor light emitting device according to claim 1, wherein the thickness of the reflecting member is approximately 30 to 50 [mu] m.   The semiconductor light emitting device according to claim 1, wherein the reflective member is a silicone resin in which reflective particles are kneaded.   The semiconductor light emitting device according to claim 1, wherein the reflecting member is a ceramic ink kneaded with reflective particles. The method for manufacturing a semiconductor light emitting device of the present invention includes a dam material surrounding the semiconductor light emitting element on a circuit board on which the semiconductor light emitting element is mounted, and a sealing resin is filled in a region surrounded by the dam material. In a method for manufacturing a semiconductor light emitting device for sealing the semiconductor light emitting element with a resin,
Mounting the semiconductor light emitting element on the circuit board and forming the dam material;
Pouring the reflective member before curing into a region inside the dam material and excluding the region occupied by the semiconductor light emitting element, and curing the reflective member;
Filling a region inside the dam material with the sealing resin before curing, and curing the sealing resin.

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