JP2013182857A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device of bulb type having a wide luminous intensity distribution irrespective of a simple structure inside a globe.SOLUTION: A circuit board 44 included in a lighting device has a surface mounted LED device 42 mounted in the central part and a side light-emitting LED device 43 mounted in a periphery part. This surface mounted LED device 42 has a strong luminous intensity distribution in a vertical direction of the circuit board 44, and the side light-emitting LED device 43 has a strong luminous intensity distribution in a horizontal direction of the circuit board 44. As a result, the bulb-type LED lamp 40 (lighting device) has a simple structure inside the globe 41 while having a wide luminous intensity distribution.

Description

  The present invention relates to a light bulb-type lighting device including a circuit board on which a light emitting diode (LED) is mounted.

  In recent years, as an alternative to incandescent lamps with high power consumption, light bulb-type LED lamps with low power consumption and similar in shape to incandescent lamps have become widespread. However, the light emitted from the bulb-type LED lamp has a strong directivity, so the base side is dark. As a countermeasure, for example, there is a lighting fixture (bulb-type lighting device) shown in FIG.

  FIG. 1 of Patent Document 1 is shown again in FIG. 9 and will be described in more detail. FIG. 9 is a front view showing a part of the entire configuration of a conventional light bulb type LED lamp in a longitudinal section. The lamp 1 includes a cover 2 that is a metal outer member, a light source device 11, a light source cover 21 (also referred to as a globe) that covers the light source device 11, a lighting circuit 25, and a base 31. The light source device 11 includes a light emitting unit 12 (LED) and a light guide body 17. There is a reflecting surface 20 on the top of the light guide 17 and an emitting portion 19 below.

  The light that has entered the light guide 17 from the light emitting unit 12 is guided to the reflecting surface 20, and a part of the light reflected by the reflecting surface 20 is emitted in the lateral direction. The light emitted in the lateral direction is reflected by the spherical surface on the top end side of the light source cover 21 and is projected to the light emitting unit 12 side. As a result, it is possible to project light to the base 31 side as well as the general lighting bulb.

JP 2009-289697 A (FIG. 1)

  9 can be said to have improved light distribution characteristics by adding the light guide 17 included in the light source device 11 inside the light source cover 21. However, the addition of the light guide 17 causes not only an increase in the number of parts but also an increase in the number of assembling steps, and a complicated structure becomes a problem. For example, since the mass of the light guide 17 is present at the upper part, the structure for fixing the light guide 17 to the light emitting unit substrate 13 must be strong. In addition, the light guide 17 has a complicated shape, and also has a two-body structure including a transparent resin portion and a reflection plate 20. The reflecting plate 20 is also preferably a semi-transmissive reflecting plate in order to emit light toward the apex side. As described above, when the inside of the glove has a three-dimensional structure, various problems often accompany it. In other words, it is desirable to make the circuit board on which the LED serving as the light source is mounted as flat as possible.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a light bulb-type lighting device in which the structure in the globe does not become three-dimensional even if the light distribution is widened in the direction of the base. .

In a bulb-type lighting device including a circuit board on which an LED serving as a light source is mounted,
Of the plurality of LEDs, the LED mounted on the center of the circuit board is a bare-chip LED die, or a surface-mounted LED device,
The LED mounted on the periphery of the circuit board is a side-emitting LED device.

  The lighting device of the present invention includes a circuit board on which a plurality of LEDs are mounted in a globe. LEDs are classified into at least two. One LED is mounted at the center of the circuit board and emits light mainly in the vertical direction of the circuit board, and the other LED is arranged around the circuit board and mainly emits light horizontally on the circuit board. It is LED which radiates. In this way, the LED mounted on the central portion of the circuit board and the LED mounted on the periphery of the circuit board share and emit light in the vertical and horizontal directions of the circuit board. As a result, the illumination device of the present invention has a wide light distribution, and the circuit board on which the LEDs are mounted is planar. The LED mounted on the center of the circuit board may be an LED die that is a bare chip or a surface-mounted LED device.

  The side-emitting LED device includes a submount substrate perpendicular to the circuit board, a frame-shaped reflective resin surrounding the bottom surface, the top surface, and the side surface, an LED die mounted on the submount substrate, and the LED die. You may provide the coating resin to coat | cover.

  The side-emitting LED device includes a submount substrate that is perpendicular to the circuit board, a reflective resin that covers an upper surface and a side surface, an LED die that is mounted on the submount substrate, and a coating resin that covers the LED die. May be provided.

  The circuit board may have a notch in the mounting portion of the side-emitting LED device.

  The coating resin may contain a phosphor.

  The LED die included in the side light emitting LED device includes an upper surface reflection layer and a side surface fluorescent member on the upper surface and the side surface, respectively, and a connection electrode is attached to the bottom surface, and the connection electrode is connected to the wiring electrode of the circuit board. You may do it.

  The LED die included in the surface-mounted LED device has an upper surface and side surfaces coated with an upper surface phosphor layer and a side surface reflecting member, a connection electrode is attached to the bottom surface, and the connection electrode is a wiring electrode of the circuit board You may connect with.

  As described above, the illumination device of the present invention can obtain a wide light distribution by emitting light in the vertical and horizontal directions of the circuit board with two types of LEDs. At this time, since the LED device in the package state or the LED die in the bare chip state is simply mounted on the circuit substrate, the circuit substrate becomes relatively flat. As a result, the illumination device of the present invention does not have a three-dimensional structure in the globe even if it has a light distribution that spreads in the direction of the base.

The front view which shows the whole structure of the illuminating device of 1st Embodiment of this invention in a partial longitudinal cross section. The top view of the circuit board contained in the illuminating device shown in FIG. Sectional drawing of LED mounted in the circuit board shown in this circuit board, and this circuit board. FIG. 4 is a side view of a side-emitting LED device among the LEDs shown in FIG. 3. Sectional drawing of the circuit board and LED contained in the illuminating device of 2nd Embodiment of this invention. FIG. 6 is a side view of a side-emitting LED device among the LEDs shown in FIG. 5. Sectional drawing of the circuit board and LED contained in the illuminating device of 3rd Embodiment of this invention. The top view of the state which peeled the uppermost layer from LED shown in FIG. The front view which shows a part of whole structure of the conventional light bulb type illuminating device in a longitudinal section.

  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. Furthermore, the relationship with the invention specific matter described in the claims is described in parentheses.

In general, a packaged LED and a bare chip LED are mounted on a circuit board incorporated in a lighting device. The packaged LED is a LED in which a submount substrate is attached to a bare chip LED element, or a bare chip LED element is covered with a resin or the like. Therefore, in this specification, packaged LEDs are referred to as LED devices, and bare-chip LEDs are referred to as LED dies. Furthermore, when mounted on a circuit board, an LED device in which the light distribution distribution appears strongly in the vertical direction with respect to the circuit board is called a surface-mounted LED device. This is called a light-emitting LED device. A bare-chip LED element included in the LED device is also called an LED die.
(First embodiment)

  1st Embodiment of this invention is described using FIGS. First, an overall configuration of a light bulb type LED lamp 40 which is an illumination device of the present embodiment will be described with reference to FIG. FIG. 1 is a front view showing a part of the entire configuration of the bulb-type LED lamp 40 in a longitudinal section. A circuit board 44 is mounted on the upper portion of the cover 46 that is an outer member. A surface-mounted LED device 42 (LED) is mounted on the center portion of the circuit board 44, and a side-emitting LED device 43 (LED) is mounted on the peripheral portion of the circuit board 44. The cover 46 has a cavity, and the lighting circuit 45 is accommodated in the cavity. Further, the globe 41 is fixed at the periphery of the cover 46, and the base 47 is connected at the lower part of the cover 46. The cover 46 not only supports these members but is also involved in the heat dissipation of the LEDs (the surface-mounted LED device 42 and the side-emitting LED device 43), and is made of resin or aluminum having good thermal conductivity. The upper end portion of the cover 46 has a trapezoidal cross section so that the light emitted from the side-emitting LED device 43 can easily go to the base 47 side.

  Next, the circuit board 44 included in the light bulb type LED lamp 40 will be described with reference to FIG. FIG. 2 is a plan view of the circuit board 44. The circuit board 44 is circular, the surface-mounted LED device 42 is mounted at the center, and the eight side-emitting LED devices 43 are mounted at the periphery. In the surface mount LED device 42, the submount substrate 42a, the dam material 42b, and the coating resin 42c are visible.

  Next, the LED mounted on the circuit board 44 will be described with reference to FIGS. 3 is a cross-sectional view of the circuit board 44 drawn along the line AA in FIG. 2, the surface-mounted LED device 42 and the side-emitting LED device 43 mounted on the circuit board 44, and FIG. FIG. Side-emitting LED devices 43 are mounted on both ends (the right end is not shown) of the circuit board 44, and a surface-mounted LED device 42 is mounted in the center. The circuit board 44 is an aluminum board provided with an insulating film on an aluminum base, and wiring electrodes 36 and 37 are formed thereon.

First, the side-emitting LED device 43 will be described. The side-emitting LED device 43 includes a submount substrate 43a that is perpendicular to the circuit board 44, a frame-like reflective resin 43b that surrounds the bottom surface, the top surface, and the side surface, an LED die 43e mounted on the submount substrate 43a, an LED It consists of a coating resin 43c that covers the die 43e. The LED die 43e is die-bonded to the submount substrate 43a and is electrically connected to an electrode (not shown) of the submount substrate 43a by a wire 43d. The coating resin 43c is a silicone resin and contains a phosphor. The side-emitting LED device 43 is connected to the wiring electrode 36 on the circuit board 44 by the solder 35. From the light emitting surface of the side-emitting LED device 43, as shown in FIG. 4, a frame-like reflective resin 43b and a coating resin 43c inside the frame-like reflective resin 43b can be seen.

  Next, the surface mount type LED device 42 will be described. As shown in FIG. 3, the surface mount LED device 42 includes a submount substrate 42a, a dam material 42b, a coating resin 42c, and a plurality of LED dies 42f and 42g. In the area inside the dam material 42b formed on the submount substrate 42a, the LED dies 42f and 42g are die-bonded to the submount substrate 42a and covered with a coating resin 42c containing a phosphor. In addition, although many LED dies are mounted in the area | region inside the dam material 42b, only LED dies 42f and 42g are shown for description. The LED die 42f and an electrode (not shown) on the submount substrate 42a are electrically connected by the wire 42d, and the LED die 42f and the LED die 42g are connected in series by the wire 42e. The surface mount type LED device 42 is mounted at the center of the circuit board 44.

The surface-mounted LED device 42 has a strong light distribution in the vertical direction with respect to the circuit board 44, and the side-emitting LED device 43 has a strong light distribution in the horizontal direction with respect to the circuit board 44. As a result, the light distribution of the light bulb-type lamp 40 (see FIG. 1) also extends in the direction of the cap 47 (see FIG. 1). At this time, since only the surface-mounted LED device 42 and the side-emitting LED device 43 are mounted on the circuit board 44, the inside of the globe 41 (see FIG. 1) has a planar structure. Although only one surface-mounted LED device 42 is mounted on the circuit board 44, a plurality of surface-mounted LED devices 42 may be mounted when the brightness needs to be increased.
(Second Embodiment)

  In the circuit board 44 included in the illumination device (bulb-type LED lamp 40) of the first embodiment, the LED responsible for the light distribution in the vertical direction of the circuit board 44 is the surface-mounted LED device 42. However, an LED die, which is a bare chip, may be used as the LED that handles light distribution in the vertical direction of the circuit board 44. Further, in the side-emitting LED device 43 mounted on the circuit board 44, the light distribution distribution below the horizontal direction may not be sufficient because the reflective resin 43b (see FIG. 3) has a frame shape. Therefore, referring to FIGS. 5 and 6, a second embodiment of the present invention will be described on the assumption that the LED die is directly mounted on the circuit board and the light distribution below the horizontal direction of the circuit board is improved. In addition, the external appearance of the illuminating device in this embodiment is equal to the light bulb type LED lamp 40 shown in FIG.

  FIG. 5 is a cross-sectional view of the circuit board 54, the LED dies 53f and 53g, and the side-emitting LED device 53 mounted on the circuit board 54 included in the lighting device of this embodiment, and FIG. 6 is a side-emitting LED. 4 is a side view of the device 53. FIG. Side emission type LED devices 53 are mounted on both ends (the right end is not shown) of the circuit board 54, and LED dies 52 f and 52 g are mounted on the center of the circuit board 54. Although a large number of LED dies are mounted in the center of the circuit board 54, only the LED dies 52f and 52g are shown for explanation. The circuit board 54 is an aluminum board provided with an insulating film on an aluminum base, and wiring electrodes 56, 57 and 58 are formed thereon. The planar shape of the circuit board 54 is a circular shape with a notch in part, and the dam material 52 b is concentric with the circuit board 54.

  First, the side-emitting LED device 53 and the peripheral circuit board 54 will be described. The side-emitting LED device 53 covers a submount substrate 53a that is perpendicular to the circuit board 54, a reflective resin 53b that covers the top and side surfaces, an LED die 53e that is mounted on the submount substrate 53a, and the LED die 53e. It consists of coating resin 53c. The LED die 53e is die-bonded to the submount substrate 53a and is electrically connected to an electrode (not shown) of the submount substrate 53a by a wire 53d. The coating resin 53c is a silicone resin and contains a phosphor. The side-emitting LED device 53 is connected to the wiring electrode 56 on the circuit board 54 with solder 55. From the light emitting surface of the side-emitting LED device 53, as shown in FIG. 6, a U-shaped reflective resin 53b having an open lower side and a coating resin 53c on the inside thereof can be seen.

  As described above, the circuit board 54 is basically circular like the circuit board 44 of FIG. 2, but the lower side of the side-emitting LED device 53 is notched. In FIG. 3, the notch 59 of the circuit board 54 is indicated by a dotted line. The side-emitting LED device 53 spreads the light distribution in the direction of the base 47 (see FIG. 1) due to the absence of reflective resin at the bottom and the notch 59 in the circuit board 54.

Next, the LED devices 52f and 52g will be described. As shown in FIG. 5, there is a region surrounded by a dam material 52b at the center of the circuit board 54. In this region, the LED devices 52f and 52g are die-bonded on the wiring electrode 58, and a coating resin containing a phosphor. 52c. The LED die 52f and the wiring electrode 57 are electrically connected by the wire 52d, and the LED die 52f and the LED die 52g are connected in series by the wire 52e.
(Third embodiment)

  The surface-mounted LED device 42 and the side-emitting LED devices 43 and 53 included in the first embodiment and the second embodiment were provided with submount substrates 42a, 43a, and 53a. On the other hand, the structure of the LED device may be simplified by omitting the submount substrate. Therefore, a third embodiment of the present invention will be described as an example using an LED device in which the submount substrate is omitted and the structure is simplified with reference to FIGS. In addition, the external appearance of the illuminating device in this embodiment is equal to the light bulb type LED lamp 40 shown in FIG.

  FIG. 7 is a cross-sectional view of the circuit board 74 included in the lighting device of the third embodiment, the side-emitting LED device 73 and the surface-mounted LED device 72 mounted on the circuit board 74, and FIG. FIG. 5A is a plan view of a state in which an upper surface reflective layer 73a is peeled off from a side-emitting LED device 73, and FIG. 5B is a plan view of a state in which the upper surface phosphor layer 72a of the surface mount LED device 72 is removed. A side-emitting LED device 73 is mounted on both ends of the circuit board 74 (the right end is not shown), and a surface-mounted LED device 72 is mounted on the center of the circuit board 74. In addition, although many surface mount type LED devices 72 are mounted in the center part of the circuit board 74, only two are shown for description. The circuit board 74 is an aluminum board provided with an insulating film on an aluminum base, and wiring electrodes 75 and 76 are formed thereon. The planar shape of the circuit board 74 is circular like the circuit board 44 of FIG. Comparing the circuit board 44 and the circuit board 74, the surface-mounted LED device 42 on the circuit board 44 is replaced with a number of surface-mounted LED devices 72 on the circuit board 74, and similarly, the side-emitting LED device 43 is replaced by the side-emitting LED device 43. Replaced by device 73.

  First, the side-emitting LED device 73 mounted on the left end of the circuit board 74 will be described. The LED die 73c included in the side light emitting LED device 73 includes an upper surface reflection layer 73a and a side surface fluorescent member 73b on the upper surface and the side surface, respectively, and two connection electrodes 73d are attached to the bottom surface. As shown in FIG. 8A, the side fluorescent member 73b surrounds the LED die 73c in a frame shape. The connection electrode 73d is connected to the wiring electrode 75 of the circuit board 74. The LED die 73c includes a semiconductor layer (not shown) having a thickness of less than 10 μm on the lower surface of a sapphire substrate (not shown) having a thickness of about 80 to 120 μm. The upper reflective layer 73a is obtained by kneading and curing reflective fine particles such as titanium oxide and alumina in a silicone resin.

  When the semiconductor layer included in the LED die 73c emits light in the side-emitting LED device 73, the light is incident on the sapphire substrate side (note that there is a metal reflective layer below the semiconductor layer). The light incident on the sapphire substrate is emitted from the side surface of the sapphire substrate by the upper surface reflection layer 73a of the LED die 73c. The light emitted from the side surface of the sapphire substrate is whitened by the side fluorescent member 73 b and radiates light around the horizontal direction of the circuit board 74.

Next, the surface mount type LED device 72 mounted on the center of the circuit board 74 will be described.
The LED die 72c included in the surface-mounted LED device 72 includes an upper surface phosphor layer 72a and a side surface reflecting member 72b on the upper surface and side surfaces, respectively, and two connection electrodes 72d are attached to the bottom surface. As shown in FIG. 8B, the side reflecting member 72b surrounds the LED die 72c in a frame shape. The connection electrode 72 d is connected to the wiring electrode 76 of the circuit board 74. The LED die 72c includes a semiconductor layer (not shown) having a thickness of less than 10 μm on the lower surface of a sapphire substrate (not shown) having a thickness of about 80 to 120 μm, like the LED die 73c. The side reflecting member 72b is obtained by kneading and curing reflective fine particles such as titanium oxide and alumina in a silicone resin.

  In the surface-mounted LED device 72, when the semiconductor layer included in the LED die 72c emits light, the light is incident on the sapphire substrate side (note that there is a metal reflective layer below the semiconductor layer). The light incident on the sapphire substrate is assisted by the side reflecting member 72b of the LED die 72c, and almost all is emitted from the upper surface of the sapphire substrate. The light emitted from the upper surface of the sapphire substrate is whitened by the upper surface phosphor layer 72 a and radiates light around the vertical direction of the circuit substrate 74.

  As described above, the illumination device of the present embodiment provides a wide light distribution because the side-emitting LED device 73 and the surface-mounted LED device 72 emit light in the horizontal and vertical directions of the circuit board 74, respectively. In this embodiment, the side-emitting LED device 73 and the surface-mounted LED device 72 are not only simple in structure, but can be packaged when mounted on the circuit board 74 and the process is simplified.

  For example, the process is as follows. First, the side-emitting LED device 73 and the surface-mounted LED device 72 are attached to the adhesive sheet. At this time, the arrangement pitch is matched with the mounting pitch of the circuit board 74. In parallel with this, the solder paste is printed on the mounting portion of the circuit board 74. The adhesive sheet on which the side-emitting LED device 73 and the surface-mounted LED device 72 are mounted and the circuit board 74 are overlapped and passed through a reflow furnace, whereby the side-emitting LED device 73 and the surface-mounted LED device 72 are connected to the circuit board 74. Connecting.

35, 55 ... solder,
36, 37, 56, 57, 58, 75, 76 ... wiring electrodes,
40 ... Light bulb type LED lamp (lighting device),
41 ... Glove,
42, 72 ... surface mount LED device (LED),
42a, 43a, 53a ... submount substrate,
42b, 52b ... dam materials,
42c, 43c, 52c, 53c ... coating resin,
42d, 42d, 43d, 52d, 52e, 53d ... wire,
42f, 42g, 43e, 53e, 72c, 73c ... LED die,
43, 53, 73 ... Side-emitting LED device (LED),
43b, 53b ... reflective resin,
44, 54, 74 ... circuit boards,
45 ... lighting circuit,
46 ... cover,
47 ...
52f, 52g ... LED die (LED),
59 ... notches,
72a ... upper surface phosphor layer,
72b ... side reflection member,
72d, 73d ... connection electrodes,
73a ... top reflective layer,
73b: Side fluorescent member.

Claims (7)

In a bulb-type lighting device including a circuit board on which an LED serving as a light source is mounted,
Of the plurality of LEDs, the LED mounted on the center of the circuit board is a bare-chip LED die, or a surface-mounted LED device,
The lighting device, wherein the LED mounted on the periphery of the circuit board is a side-emitting LED device.   The side-emitting LED device includes a submount substrate perpendicular to the circuit board, a frame-like reflective resin surrounding the bottom surface, the top surface, and the side surface, an LED die mounted on the submount substrate, and the LED die. The lighting device according to claim 1, further comprising a coating resin to be coated.   The side-emitting LED device includes a submount substrate that is perpendicular to the circuit board, a reflective resin that covers an upper surface and a side surface, an LED die that is mounted on the submount substrate, and a coating resin that covers the LED die. The illuminating device according to claim 1, comprising:   The lighting device according to any one of claims 1 to 3, wherein the circuit board has a notch in a mounting portion of the side-emitting LED device.   The lighting device according to claim 1, wherein the coating resin contains a phosphor.   The LED die included in the side-emitting LED device includes an upper surface reflection layer and a side surface fluorescent member on the upper surface and the side surface, and a connection electrode is attached to the bottom surface, and the connection electrode is connected to the wiring electrode of the circuit board. The lighting device according to any one of claims 1 to 5, wherein The LED die included in the surface-mounted LED device has an upper surface and side surfaces coated with an upper surface phosphor layer and a side surface reflecting member, a connection electrode is attached to the bottom surface, and the connection electrode is a wiring electrode of the circuit board The lighting device according to claim 1, wherein the lighting device is connected to the lighting device.

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