JP2012069645A - Semiconductor light-emitting device and manufacturing method therefor - Google Patents

Abstract

Provided is an LED device that is easy to manufacture and has excellent luminous efficiency even if the side surface of the LED element is filled with a white member.
An LED element is flip-chip mounted on a circuit board. The LED element 21 is surrounded by a white member 11 on the side surface. The white member 11 contains a binder made of reflective fine particles and silicone resin. At this time, the upper surface of the LED element 21 and the upper surface of the white member 11 substantially coincide with each other, and the phosphor layer 15 is present on the upper surfaces of the LED element 21 and the white member 11.
[Selection] Figure 1

Description

  The present invention relates to a semiconductor light-emitting device in which a semiconductor light-emitting element is flip-chip mounted on a circuit board and a manufacturing method thereof.

  2. Description of the Related Art Among semiconductor light emitting devices (hereinafter referred to as LED devices unless otherwise specified) in which a semiconductor light emitting element (hereinafter referred to as an LED device) is mounted on a circuit board, an LED device provided with a reflective member on the side surface of the LED element Is known (for example, Patent Document 1).

  FIG. 4 of Patent Document 1 is shown in FIG. FIG. 4 is a cross-sectional view of the LED device in which the first sealing resin 6 containing the reflective agent fills the periphery of the LED chip 4 (LED element). The LED chip 4 is disposed in the center of a reflector case 1 made of a ceramic material, and the reflector case 1 includes a square pyramid-shaped opening 2. The LED chip 4 is die-bonded to the lead frame 3 a, and the upper surface electrode of the LED chip 4 is connected to the lead frame 3 b by a bonding wire 5.

  The LED chip 4 emits blue light from the epitaxial light emitting layer and emits yellow light from the ZnSe substrate. Of the yellow light and blue light, the light directed to the side is reflected by the reflective material of the first sealing resin 6 and returned to the LED chip 4. The downward light is reflected by a reflective layer (not shown) formed on the bottom surface of the LED chip 4. In this way, all of blue light and yellow light are finally emitted from the upper surface of the LED chip 4. As a result, two-color mixing is effectively performed, and high brightness white light is obtained.

JP 2002-43625 A (FIG. 1)

  In the LED device of Patent Document 1, the upper surface of the LED chip 4 and the upper surface of the sealing resin 6 coincide. Although there is no description in Patent Document 1 regarding a method for matching the upper surfaces, in order to dispose the sealing resin 6 so as not to damage the bonding wire 5, an accurate amount of the sealing resin 6 is usually dropped with a dispenser. Presumed. However, high-precision coating is not only troublesome, but is not common because it requires a member surrounding the LED chip 4 as in the case 1. In addition, this LED device has a low luminous efficiency due to the bonding wire 5. Furthermore, it is not an LED device including a blue (or near-ultraviolet) light emitting diode and a phosphor that have become mainstream in recent years.

  Therefore, in order to solve these problems, the present invention aims to provide an LED device that is easy to manufacture and has excellent luminous efficiency even when the side surface of the LED element is filled with white resin or white ink, and a method for manufacturing the LED device. And

In order to solve the above problems, a semiconductor light emitting device of the present invention is a semiconductor light emitting device in which a semiconductor light emitting element is mounted on a circuit board.
The semiconductor light emitting element is flip-chip mounted on the circuit board,
A white member surrounding a side surface of the semiconductor light emitting element;
The white member contains reflective fine particles and a binder,
The upper surface of the semiconductor light emitting element and the upper surface of the white member are substantially coincident with each other.

  A phosphor layer may be provided on the top surface of the semiconductor light emitting element and the white member.

  An inorganic binder that becomes vitreous when the binder of the white member is sintered may be used.

  The binder of the white member may be a silicone resin.

  It is preferable that the white member is filled in a gap between the semiconductor light emitting element and the circuit board.

In order to solve the above problems, a method for manufacturing a semiconductor light emitting device of the present invention is a method for manufacturing a semiconductor light emitting device in which a semiconductor light emitting element is mounted on a circuit board.
A preparation step of preparing a collective substrate connected to the circuit board;
A mounting step of flip-chip mounting the semiconductor light emitting element on the collective substrate;
An application step of applying a white member containing reflective fine particles to the entire surface of the aggregate substrate;
A polishing step of polishing the white member;
And a singulation process for separating the semiconductor light emitting device into a single piece.

  A fluorescent resin application step of applying a fluorescent resin containing a phosphor after the polishing step may be provided.

  A fluorescent resin polishing step for polishing the fluorescent resin may be provided after the fluorescent resin coating step.

  You may provide the transparent resin application | coating process which apply | coats transparent resin before the said singulation process.

  An inorganic binder that becomes glassy when the binder of the white member is sintered may be used.

  The binder of the white member may be a silicone resin.

  In the semiconductor light emitting layer device of the present invention, the periphery of the semiconductor light emitting element flip-chip mounted on the circuit board is filled with the white member containing the reflective fine particles, and the upper surfaces of the semiconductor light emitting element and the white member are substantially matched. In the flip-chip mounted semiconductor light emitting device, the upper side (outgoing side) is a transparent substrate and the lower side (mounting side) is a semiconductor layer. As a result, not only is the bonding wire for connection unnecessary, but even if the white member is arranged by a simple coating method, the upper surface of the white member and the upper surface of the transparent substrate can be easily matched by polishing. Furthermore, there is no loss of light due to the bonding wire. As described above, the semiconductor light emitting device of the present invention is easy to manufacture and has high luminous efficiency even when the side surface of the semiconductor light emitting element is filled with the white member.

  In the method for manufacturing a semiconductor light emitting device of the present invention, a semiconductor light emitting element is flip-chip mounted on a collective substrate to which circuit boards are connected, and a white member containing reflective fine particles is applied to the entire surface of the collective substrate. The upper surface is polished to expose the upper surface of the semiconductor light emitting device. As described above, the semiconductor light-emitting device of the present invention is easy to manufacture because it coats and polishes the collective substrate when the side surface of the semiconductor light-emitting element is filled with a white member. There is no loss of efficiency.

Sectional drawing of the LED apparatus in embodiment of this invention. The elements on larger scale of FIG. Explanatory drawing of the manufacturing method of the LED apparatus shown in FIG. Sectional drawing of the conventional LED device.

  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.

  FIG. 1 is a cross-sectional view of the LED device (semiconductor light emitting device) of this embodiment. In the LED device 10 (semiconductor light emitting device), an LED element 21 (semiconductor light emitting element) is flip-chip mounted on a circuit board 22. The electrode 17 formed on the upper surface of the plate material 20 in the circuit board 22 is connected to the electrode 19 formed on the lower surface of the plate material 20 through the through hole 18. In the LED element 21, a semiconductor layer 13 is formed on the lower surface of the sapphire substrate 12, and two bumps 14 are attached to the semiconductor layer 13. The semiconductor layer 13 is a diode provided with a light emitting layer, and each bump 14 corresponds to an anode and a cathode. The bumps 14 are connected to the electrodes 17 by metal eutectic bonding.

  A white silicone resin 11 (white member) obtained by kneading titanium oxide (reflective fine particles) with a silicone resin (binder) and heat-curing surrounds the side surface of the LED element 21. The white silicone resin 11 is also filled in the gap between the LED element 21 and the circuit board 22. The upper surface of the LED element 21 and the upper surface of the white silicone resin 11 coincide. There is a phosphor layer 15 on the upper surface of the LED element 21 and the white silicone resin 11. A transparent resin layer 16 is laminated on the phosphor layer 15.

  The plate member 20 has a thickness of several hundred μm and is selected from resin, ceramic, and metal in consideration of thermal conductivity. The electrodes 17 and 19 are formed by laminating a nickel layer and a gold layer on a copper foil of about 20 μm, for example. When the plate material 20 is resin, the through hole 18 is preferably filled with a metal paste to improve thermal conductivity. The sapphire substrate 12 has a thickness of 80 to 120 μm, the semiconductor layer 13 has a thickness of about 7 μm, and the bump 14 has a thickness of about 10 to 30 μm if formed by electrolytic plating. In order to efficiently direct light emitted downward from the LED element 21 upward, the white silicone resin 11 filled between the LED element 21 and the circuit board 22 preferably has a thickness of 30 μm or more. The phosphor layer 15 has a thickness of about 100 μm, and the transparent resin layer 16 has a thickness of several tens of μm.

The state of light emitted from the LED device 10 will be described with reference to FIG. FIG. 2 is obtained by adding blue light beams L1 and L2 emitted from the semiconductor layer 13 to the enlarged view of the region surrounded by A in FIG. Of the blue light emitted from the semiconductor layer 13, the light ray L <b> 1 is emitted from the LED device 10 through the sapphire substrate 12, the phosphor layer 15, and the transparent resin layer 16. The light beam L2 passes through the side surface of the sapphire substrate 12 and enters the white silicone resin 11, where it is reflected by the reflective fine particles, returns to the sapphire substrate 12 again, passes through the phosphor layer 15 and the transparent resin layer 16, and is emitted from the LED device 10. . A downward light beam (not shown) is reflected on the lower white silicone resin 11, the bump 14, or the LED chip 21 for flip chip mounting (not shown, the LED chip for flip chip mounting includes a reflecting layer). ) And reflect upwards. As described above, the light beams L1, L2 and the like emitted from the semiconductor layer 13 of the LED element 21 are emitted from the LED device 10 through the upper surface of the sapphire substrate except for losses such as absorption. In the phosphor layer 15, part of the blue light is wavelength-converted by the phosphor, and whitened by additive mixing of the wavelength-converted light and the blue light. The light emitted from the phosphor layer 15 is isotropic, but the downward light beam is directed upward in the same manner as the blue light described above.

  A method of manufacturing the LED device 10 of this embodiment will be described with reference to FIG. FIG. 3 is an explanatory diagram of a method for manufacturing the LED device 10. (A) is a preparatory process for preparing a collective board 23 connected with a circuit board 22 (numbers not shown). The collective substrate 23 is provided with a large number of circuit board regions on a large plate member 20, and an electrode 17, a through hole 18 (not shown), and an electrode 19 (not shown) are formed in each circuit board region.

  (B) is a mounting process in which the LED elements 21 are flip-chip mounted on the collective substrate 23. The LED elements 21 may be arranged one by one on the collective substrate 23, or the LED elements 21 are arranged on the adhesive sheet in advance according to the electrode pitch of the circuit board 23, and this adhesive sheet is stacked on the collective substrate 23. The LED elements 21 may be collectively arranged on the collective substrate 23. When the arrangement of the LED 21 is completed, the LED element 21 is pressurized and heated to be joined to the electrode 17.

  (C) is an application process in which the white silicone resin 11 containing reflective fine particles is applied to the entire surface of the collective substrate 23. Since the white silicone resin 11 may cover the LED element 21, the white silicone resin 11 may be disposed on the collective substrate 23 using a squeegee. Finally, the white silicone resin is heated to about 150 ° C. and cured.

  (D) is a polishing step for polishing the white silicone resin 11. Polishing is performed until the white silicone resin 11 coincides with the upper surface of the LED element 21. At this time, the upper surface of the LED element 21 may be slightly polished.

  (E) is a fluorescent resin coating process in which a fluorescent resin containing a phosphor is applied to form the phosphor layer 15. The phosphor is a yellow phosphor such as YAG, or a combination of a silicate green phosphor and a nitride red phosphor, and the binder may be silicone. The fluorescent resin is cured at about 150 ° C. after application.

  (F) is a fluorescent resin polishing step for polishing the phosphor layer 15. Since the emission color (white color coordinate) of the LED device 10 is greatly influenced by the amount of the phosphor, the thickness is adjusted by polishing the phosphor layer 15. Further, when a silicate green phosphor and a nitride red phosphor are combined as the phosphor, it is necessary to consider the influence of the peak wavelength of the LED element 21.

  (G) is a transparent resin coating process in which a transparent resin is applied to form the transparent resin layer 16. The transparent resin layer 16 functions as a gas barrier as well as mechanical protection of the phosphor layer 15. The transparent resin may be silicone and is cured after application.

  (H) is a singulation process for separating the LED device 10 into a single piece from the collective substrate 20. The collective substrate 23 formed up to the transparent resin layer 16 is cut by a dicing device to divide the LED device 10 into individual pieces.

  In this embodiment, the white silicone resin 11 polishing step (d) is provided after the white corn resin 11 coating step (c). The polishing step (d) can be omitted if the application amount is controlled with a high-precision dispenser and the upper surface of the white silicone resin 11 and the upper surface of the LED element 21 are substantially matched. Similarly, in this embodiment, the fluorescent resin polishing step (f) after the fluorescent resin coating step (e) can be omitted if a highly accurate dispenser is used. However, in the manufacturing method of the LED device using the collective substrate as in this embodiment, a large number of LED elements can be processed at once, so that the polishing process does not become a heavy load. The transparent resin layer 16 and the transparent resin coating step (g) can also be omitted when the strength of the phosphor layer 15 is sufficient and the environment resistance (particularly moisture) of the phosphor is high.

  In this embodiment, the binder is a silicone resin as the white member. The white member may be a white ceramic ink obtained by kneading and solidifying an inorganic binder that becomes glassy when sintered, such as organopolysiloxane, and reflective fine particles. This white ceramic ink is cured at about 150 ° C. by a catalyst. The white ceramic ink is also characterized by little light degradation because the binder is inorganic.

  In the present embodiment, the LED element 21 emits blue light, but the LED element 21 may emit near ultraviolet light. In this case, the phosphor layer 15 is kneaded with a blue phosphor, a green phosphor and a red phosphor. At this time, not only the color rendering property of visible light is improved, but also the color emission due to the azimuth angle is reduced because the light emitting portion is only the upper surface of the LED element 21. Further, when white is not required, the phosphor layer 15 may be omitted.

10 ... LED device (semiconductor light-emitting device),
11 ... White silicone resin (white member),
12 ... sapphire substrate,
13 ... semiconductor layer,
14 ... Bump,
15 ... phosphor layer,
16 ... Transparent resin layer,
17, 19 ... electrodes,
18 ... Through hole,
20 ... plate material,
21 ... LED element (semiconductor light emitting element),
22 ... circuit board,
23 ... Collective board,
L1, L2 ... rays.

Claims (11)

In a semiconductor light emitting device in which a semiconductor light emitting element is mounted on a circuit board,
The semiconductor light emitting element is flip-chip mounted on the circuit board,
A white member surrounding a side surface of the semiconductor light emitting element;
The white member contains reflective fine particles and a binder,
A semiconductor light-emitting device, wherein an upper surface of the semiconductor light-emitting element and an upper surface of the white member substantially coincide with each other.   The semiconductor light emitting device according to claim 1, further comprising a phosphor layer on top surfaces of the semiconductor light emitting element and the white member.   The semiconductor light-emitting device according to claim 1, wherein the white light-emitting member is an inorganic binder that becomes glassy when sintered.   The semiconductor light emitting device according to claim 1, wherein the binder of the white member is a silicone resin.   The semiconductor light emitting device according to claim 1, wherein the white member is filled in a gap between the semiconductor light emitting element and the circuit board. In order to solve the above problems, a method for manufacturing a semiconductor light emitting device of the present invention is a method for manufacturing a semiconductor light emitting device in which a semiconductor light emitting element is mounted on a circuit board.
A preparation step of preparing a collective substrate connected to the circuit board;
A mounting step of flip-chip mounting the semiconductor light emitting element on the collective substrate;
An application step of applying a white member containing reflective fine particles to the entire surface of the aggregate substrate;
A polishing step of polishing the white member;
A method for manufacturing a semiconductor light emitting device, comprising: a step of separating the semiconductor light emitting device into a single piece.   The method for manufacturing a semiconductor light emitting device according to claim 6, further comprising a fluorescent resin application step of applying a fluorescent resin containing a phosphor after the polishing step.   The method for manufacturing a semiconductor light emitting device according to claim 7, further comprising a fluorescent resin polishing step of polishing the fluorescent resin after the fluorescent resin application step.   The method for manufacturing a semiconductor light-emitting device according to claim 6, further comprising a transparent resin application step of applying a transparent resin before the individualization step.   10. The method for manufacturing a semiconductor light emitting device according to claim 6, wherein the binder of the white member is an inorganic binder that becomes vitreous when sintered. 10. The method for manufacturing a semiconductor light-emitting device according to claim 6, wherein the binder of the white member is a silicone resin.

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