JP2014140076A - Light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a reduction in luminance unevenness and an improvement in luminous efficiency.SOLUTION: An electrode wiring pattern (102) has anode-side wiring extending from an anode electrode land (103) to a lower part of a dam resin (108) and cathode-side wiring extending from a cathode electrode land (104) to the lower part of the dam resin (108) so as to electrically connect a plurality of LED chips (105) to the anode electrode land (103) and the cathode electrode land (104). The dam resin (108) comprises a resin having light reflectivity.

Description

  The present invention relates to a light-emitting device including a plurality of light-emitting elements connected in series and parallel and a protection element electrically connected to the plurality of light-emitting elements, and more particularly to a technique for improving luminance unevenness and light emission efficiency. Is.

  With recent improvements in efficiency, LEDs (Light Emitting Diodes) have come to be widely used in backlights and lighting fixtures of display devices as energy-saving light sources rather than light bulbs or fluorescent lamps. In such applications, energy efficiency is very important.

  Here, LEDs, particularly gallium nitride-based LEDs, are likely to fail due to electrostatic discharge. That is, the reverse breakdown voltage is small. For this reason, as a countermeasure, a technique in which Zener diodes are arranged in antiparallel to LEDs has been disclosed (for example, see Patent Document 1).

  In the configuration using the Zener diode, an overcurrent is bypassed by a Zener breakdown for a forward overvoltage, and an overcurrent is bypassed as a normal forward diode for a reverse overvoltage. Is protected from overvoltage in either direction. Further, since the forward voltage of the LED is smaller than the Zener breakdown voltage of the Zener diode, no current is flown through the Zener diode even when the forward voltage is applied to the LED, and no energy loss occurs.

  On the other hand, as another countermeasure, a technique in which a resistor is connected in parallel to an LED is disclosed (for example, see Patent Documents 2 and 3).

  FIG. 13 is a circuit configuration diagram of the LED collective lamp 1000 described in Patent Document 2. In the LED collective lamp 1000, a resistor (Rb) 1200 is connected in parallel to each of a plurality of LEDs 1100 connected in series. Thereby, even when a certain LED 1100 is disconnected, it is possible to prevent other LEDs 1100 from being extinguished by each resistor 1200 acting as a bypass resistor. Further, the deterioration of the LED 1100 can be prevented.

  However, in order for the bypass resistor to fulfill its purpose, it is necessary to pass a current sufficient to turn on another LED 1100 that is not disconnected to the bypass resistor, so that the resistance value of the resistor 1200 to be used must be lowered. For this reason, there is a problem that the current flowing through the bypass resistor causes a large energy loss.

  Patent Document 3 describes a semiconductor light emitting device in which a variable resistor is connected in parallel or in series to each of a plurality of LEDs in order to adjust the current flowing through the LEDs. This semiconductor light emitting device also has a problem that a large energy loss occurs because the resistance value of the variable resistor must be lowered.

  As an example of forming a resistor connected to an LED, Patent Document 4 describes an LED array in which a thick film resistive element is connected in series to each of a plurality of LEDs.

Japanese Patent Laid-Open No. 11-298041 (released on October 29, 1999) Japanese Patent Laid-Open No. 11-307815 (published on November 5, 1999) JP 2007-294547 A (published on November 8, 2007) Japanese Utility Model Publication No. 63-180957 (published on November 22, 1988)

  By the way, when the present inventor mounts a plurality of LEDs connected in series and parallel on a substrate in order to obtain light emission with high luminance and high output, an electrode wiring pattern for electrical connection is arranged between the LEDs. For this reason, it has been found that there is a problem that luminance unevenness occurs or that the light emission efficiency is lowered by the electrode wiring pattern absorbing light.

  However, Patent Documents 1 to 4 do not describe any of the above problems and means for solving the above problems.

  Further, the configuration using the Zener diode or the resistor described in Patent Documents 1 to 3 has the following problems.

  In the case of a configuration using Zener diodes, as many Zener diodes as possible must be connected in order to minimize the influence of disconnection in a package in which a plurality of LEDs connected in series are mounted. Therefore, there are problems such as an increase in package size and addition of a Zener diode mounting process.

  In addition, in order to wire bond the Zener diode, it is necessary to arrange the Zener diode in the vicinity of the LED and within the range of the sealing resin that seals the LED. This is not preferable because luminance (light output) is reduced due to absorption. Moreover, when a Zener diode is mounted within the range of the sealing resin, there arises a problem that the LED cannot be arranged in the center.

  As described above, the Zener diode has a large burden in mounting on the LED. Further, the Zener diode is not easy to manufacture as compared with the resistor, and further, there is a problem that reliability over a long period is inferior to the resistor.

  However, even in the case of a configuration using a resistor, light absorption by the resistor occurs. Further, if the resistor is disposed outside the sealing resin so as to avoid light absorption due to the resistor, problems such as an increase in package size occur. Furthermore, there are limitations on the arrangement area for relatively large resistors and thick film resistors.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to improve luminance unevenness and light emission efficiency in a configuration in which a plurality of LEDs connected in series and parallel are mounted on a substrate. It is an object of the present invention to provide a light emitting device capable of achieving the above. A further object of the present invention is to provide a light emitting device capable of further improving the light emission efficiency by installing a protective element at a location where light absorption is minimized.

  In order to solve the above problems, a light-emitting device according to one embodiment of the present invention includes a substrate having a rectangular outer shape in a top view and a plurality of LEDs arranged near the center of the main surface of the substrate. A chip, a resin frame that is annularly provided on the main surface of the substrate so as to surround a mounting region on which the plurality of LED chips are mounted, and an electrode that is connected to an external power source of the light emitting device. An anode electrode land and a cathode electrode land provided on the outside of the frame and in the vicinity of a corner of the main surface of the substrate, and an electrode wiring pattern formed on the main surface of the substrate, and the electrode wiring The pattern extends from the anode electrode land to the lower part of the resin frame so as to electrically connect the plurality of LED chips to the anode electrode land and the cathode electrode land. And a cathode side wiring extending from the cathode electrode land to a lower portion of the resin frame, and the resin frame is made of a resin having light reflectivity. .

  In order to solve the above-described problem, a light-emitting device according to one embodiment of the present invention is disposed near a center of a main surface of a substrate having a rectangular outer shape in a top view, A plurality of light-emitting elements that are LED chips, an electrode wiring pattern having a first light-emitting element connection electrode that is an anode electrode and a second light-emitting element connection electrode that is a cathode electrode, and the plurality of light-emitting elements An electrode land for the anode and a cathode provided in the vicinity of a corner of the main surface of the substrate, which are electrodes connected to at least one of the protective element and the Zener diode connected in parallel with the external power source of the light emitting device And the electrode wiring pattern is configured to electrically connect the plurality of light emitting elements, the anode electrode land, and the cathode electrode land. Is characterized in that a wiring pattern provided between the anode electrode land and the cathode electrode lands.

  In order to solve the above-described problem, a light-emitting device according to one embodiment of the present invention is an anode that is a substrate and an electrode for connecting to an external power source of the light-emitting device, and is formed on a main surface of the substrate. An electrode land for the cathode and an electrode land for the cathode, and an anode side wiring extending from the anode electrode land and a cathode side wiring extending from the cathode electrode land. The electrode wiring pattern is disposed in the vicinity of the center of the main surface of the substrate, and is electrically connected in series between the anode-side wiring and the cathode-side wiring. A plurality of LED chips having an anode shape and a cathode electrode, and a plurality of wires electrically connecting the plurality of LED chips to each other A plurality of LED chips and a phosphor-containing resin layer covering the plurality of wires, and the plurality of LED chips include a first LED chip and a second LED chip, and a long side of the second LED chip. Is adjacent to the long side of the first LED chip, the anode electrode of the first LED chip and the anode electrode of the second LED chip face each other, and the cathode electrode of the first LED chip and the cathode electrode of the second LED chip Are opposed to each other, and the plurality of wires directly connect the cathode electrode of the first LED chip and the anode electrode of the second LED chip, and are different from directions along the long sides of the first LED chip and the second LED chip. It is characterized by having a wire extending in the direction.

  In order to solve the above problems, a light-emitting device according to one embodiment of the present invention includes a substrate having a rectangular outer shape in a top view and a plurality of substrates disposed near the center of the main surface of the substrate. An LED chip, a resin frame provided in an annular shape on the main surface of the substrate so as to surround a mounting area on which the plurality of LED chips are mounted, and an electrode for connecting to an external power source, An anode electrode land and a cathode electrode land electrically connected to the LED chip, wherein the anode electrode land and the cathode electrode land are located outside the resin frame and the main substrate substrate. It is provided near the corner of the surface, and the resin frame is made of a resin having light reflectivity.

  According to one embodiment of the present invention, in a configuration in which a plurality of LEDs connected in series and parallel are mounted on a substrate, improvement in luminance unevenness and improvement in light emission efficiency can be achieved. Furthermore, the luminous efficiency can be further improved by installing the protective element at a location where light absorption is minimized.

It is a top view which shows 1st Embodiment (no sealing resin) of the light-emitting device in this invention. It is a top view which shows 1st Embodiment (completed product) of the light-emitting device in this invention. FIG. 3 is a cross-sectional view of the light emitting device of FIG. 2 taken along the line X-X ′. (A) is an equivalent circuit diagram which shows the circuit structure of the light-emitting device of FIG. 1, (b) is an equivalent circuit diagram which shows the comparative example of (a). It is a top view which shows 2nd Embodiment of the light-emitting device in this invention. It is a top view which shows 3rd Embodiment of the light-emitting device in this invention. It is a top view which shows 4th Embodiment of the light-emitting device in this invention. It is a top view which shows 5th Embodiment of the light-emitting device in this invention. It is a top view which shows 6th Embodiment of the light-emitting device in this invention. It is a top view which shows 7th Embodiment of the light-emitting device in this invention. It is a top view which shows 8th Embodiment of the light-emitting device in this invention. It is a figure which shows one Embodiment of an LED bulb provided with the light-emitting device of this invention, (a) shows the external appearance when it sees from a side surface, (b) shows the mounting surface in which this light-emitting device was mounted. It is an equivalent circuit diagram which shows the circuit structure of the conventional light-emitting device.

[Embodiment 1]
An embodiment of the present invention will be described below with reference to the drawings. In the following, the overall configuration will be briefly described first, and then the characteristic configuration and manufacturing method will be described in order.

(overall structure)
FIG. 1 is a top view showing a configuration example of the light emitting device 100 according to the present embodiment, and shows a state before the LED chip 105 mounted on the main surface of the ceramic substrate 101 is resin-molded. FIG. 2 is a top view showing a configuration example of the light emitting device 100 according to the present embodiment, and shows a state where the LED chip 105 and the like mounted on the main surface of the ceramic substrate 101 are resin-molded to form a completed package. . However, since the phosphor is contained in the resin mold (phosphor-containing resin layer 109 described later) and is colored and absorbs light, it is difficult to transmit light and the mounting surface of the LED chip 105 cannot be seen. Further, since the dam resin 108 (resin frame) described later has low light transmittance, the lower surface of the dam resin 108 cannot be seen from above. In FIG. 2, in order to explain the mounting surface of the LED chip 105, these opaque members are seen through. The same applies to the drawings (FIGS. 5 to 10) of other embodiments described later. FIG. 3 is a cross-sectional view of the light emitting device 100 of FIG. 2 taken along the line XX ′.

  In the following, the vertical direction and the horizontal direction in FIGS. 1 and 2 are defined as the vertical direction (first direction) and the horizontal direction (second direction) of the main surface. Further, the upper side and the lower side in FIG. 3 are the upper side and the lower side of the light emitting device 100. Furthermore, when viewed from a direction perpendicular to the main surface of the ceramic substrate 101, that is, the planar view shown in FIGS.

  As shown in FIGS. 1 to 3, the light emitting device 100 of the present embodiment includes a ceramic substrate 101 (substrate), an LED chip 105 (light emitting element), a wire 106 (metal wire), a printing resistor 107 (protective element), A dam resin 108 (resin frame) and a phosphor-containing resin layer 109 are provided.

  The ceramic substrate 101 is a substrate made of ceramic. The ceramic substrate 101 has a rectangular outer shape when viewed from above. On the main surface of the ceramic substrate 101, an LED chip 105, a wire 106, a printing resistor 107, a dam resin 108, and a phosphor-containing resin layer 109 are provided. An electrode wiring pattern 102, an anode electrode land 103, and a cathode electrode land 104 are formed on the main surface of the ceramic substrate 101.

  The LED chip 105 is a blue LED having an emission peak wavelength of 450 nm, but is not limited thereto. As the LED chip 105, for example, an ultraviolet (near ultraviolet) LED chip having an emission peak wavelength of 390 nm to 420 nm may be used, thereby further improving the light emission efficiency. A plurality (44 in this embodiment) of LED chips 105 are fixed to the main surface of the ceramic substrate 101 with a silicone resin adhesive. The LED chip 105 has a rectangular outer shape when viewed from above. On the upper surface of the LED chip 105, an anode electrode and a cathode electrode (hereinafter collectively referred to as a chip electrode) are provided so as to face each other in the longitudinal direction. The electrical connection of the LED chip 105 is performed by wire bonding using the wire 106. The wire 106 is made of, for example, gold.

The printing resistor 107 is a thin film resistive element having a printed paste-like resistance component fixed by firing, and is thinner than the LED chip 105. The printing resistor 107 is made of ruthenium oxide RuO ₂ . The printing resistor 107 is partially formed on the main surface of the ceramic substrate 101 (three places in this embodiment: printing resistors 107a to 107c) so as to be connected to the LED chip 105 in parallel.

The dam resin 108 is made of a white silicone resin (having a translucent silicone resin as a base material and containing titanium oxide TiO ₂ as a light diffusion filler), and has low light transmittance or light reflectivity. It is a resin frame. The dam resin 108 is provided in an annular shape so as to surround the mounting region of the LED chip 105. The dam resin 108 has a rectangular shape with four corners rounded when viewed from above. Note that the material of the dam resin 108 is not limited to the above materials, and may be acrylic, urethane, epoxy, polyester, acrylonitrile butadiene styrene (ABS), or polycarbonate (PC) resin. The color of the dam resin 108 is not limited to white, and may be milky white, for example. By coloring the resin white or milky white, the light transmittance of the resin can be set low, or the resin can have light reflectivity.

The phosphor-containing resin layer 109 is a sealing resin layer obtained by curing a dispersion of a particulate phosphor in a liquid silicone resin. In this example, red phosphor SrCaAlSiN ₃ : Eu and green phosphor Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce are used as the particulate phosphor. The phosphor-containing resin layer 109 is provided adjacent to the inside of the dam resin 108 so as to cover the LED chip 105 and the wire 106. According to the shape of the dam resin 108, the phosphor-containing resin layer 109 has a rectangular shape with four corners rounded when viewed from above. The vertical direction of the main surface of the ceramic substrate 101 is the short direction of the phosphor-containing resin layer 109, and the left-right direction of the main surface is the longitudinal direction of the phosphor-containing resin layer 109.

Note that the particulate phosphor is not limited to this, and for example, BOSE (Ba, O, Sr, Si, Eu) or the like can be suitably used. In addition to BOSE, SOSE (Sr, Ba, Si, O, Eu), YAG (Ce activated yttrium, aluminum, garnet), CaAlSiN ₃ : Eu, α sialon ((Ca), Si, Al, O, N) , Eu), β sialon (Si, Al, O, N, Eu) and the like can be preferably used. A phosphor that obtains light emission of a predetermined color (chromaticity) from the light emitting device 100 in combination with the light emission color of the LED chip 105 is used.

(Electric circuit configuration)
FIG. 4A shows an equivalent circuit diagram of the LED chip 105 and the printing resistor 107 in the light emitting device 100.

  As shown in FIG. 4A, in the light emitting device 100, the 44 LED chips 105 have a circuit configuration in which four series circuit units each having 11 LED chips 105 connected in series are connected in parallel. have. The chip wirings in the series circuit section are divided into three groups: A: 3 serial portions, B: 5 serial portions, and C: 3 serial portions. That is, a group circuit A having a circuit configuration in which three LED chips 105 are connected in series, a circuit configuration in which four LED chips 105 are connected in parallel, and a series circuit in which five LED chips 105 are connected in series. A group C having a circuit configuration in which four units are connected in parallel; a group C having a circuit configuration in which a series circuit unit in which three LED chips 105 are connected in series is connected in parallel; , Can be said to be connected in series.

  The printing resistor 107 is provided for each divided group. A printing resistor 107a is connected in parallel to the group A series circuit section. A printing resistor 107b is connected in parallel to the group B series circuit section. A printing resistor 107c is connected in parallel to the group C series circuit section.

  The three printing resistors 107 a to 107 c connected in parallel to the series circuit portions of the groups A to C have a resistance value ratio equal to the number of the LED chips 105 so that voltages are equally applied to the LED chips 105. It is set to be equal to the ratio of.

Here, assuming that the resistance value of the printing resistors 107a and 107c is R and the resistance value of the printing resistor 107b is R ′,
R: R ′ = 3: 5
The resistance values R and R ′ are adjusted so that The resistance values R and R ′ are set to 1 MΩ to 10 GΩ in order to minimize the reactive current when the LED chips 105 emit light.

  In order to achieve an effect such as prevention of surge destruction on the LED chip 105, the resistance value of the printed resistor 107 is preferably smaller than the resistance component of the impedance of the LED chip 105 in the reverse bias direction, and is 10 GΩ or less. It is desirable. Further, when the leakage current flowing through the printing resistor 107 is suppressed to the extent that it can be distinguished from a true defective product in a defect selection inspection process in which a forward voltage of a micro area is measured after the light emitting device is completed, 1 MΩ or more is required. It is desirable to make it. Therefore, the resistance values R and R 'of the printing resistors 107a to 107c are preferably 1 MΩ to 10 GΩ.

  As described above, the LED chips 105 are arranged in groups, and the printing resistors 107 are provided for each group, so that one printing resistor 107 is connected in parallel to the series circuit unit in which 11 LED chips 105 are connected in series. Rather than connecting to, there is an effect of minimizing the decrease in light output when the series circuit section is disconnected.

  This effect will be described with reference to FIG. 4B as a comparative example. FIG. 4B is an equivalent circuit diagram when eleven LED chips 105 are connected in series, four of them are connected in parallel, and one printed resistor 107 is connected in parallel. As shown in FIG. 4B, when 11 LED chips 105 are connected in series without being grouped, even if one LED chip 105 becomes open failure, no current flows through all 11 chips. All of them will not emit light.

  On the other hand, as shown in FIG. 4 (a), when 11 LED chips 105 are connected in groups (grouped) by dividing three, five, and three LED chips 105, one open defect occurs in the series. Even in the case of three, no current flows, but eight in another group emit light. Also, even if one open failure occurs in series, the current does not flow in five, but six in another group emit light. Therefore, the configuration shown in FIG. 4A has a remarkable effect that none of the eleven light emitting elements does not emit light as in the case of FIG. 4B.

  Further, since the printing resistors 107a to 107c are connected in parallel to the LED chip 105, it is possible to prevent the LED chip 105 from being deteriorated, and it is possible to extend the life and ensure the reliability. . Therefore, it is possible to provide the light emitting device 100 with excellent reliability.

(Configuration of ceramic substrate 101)
Next, the configuration of the main surface of the ceramic substrate 101 will be specifically described. As described above, the electrode wiring pattern 102, the anode electrode land 103, and the cathode electrode land 104 are formed on the main surface of the ceramic substrate 101.

  The electrode wiring pattern 102 is for electrically connecting the LED chip 105, the anode electrode land 103, and the cathode electrode land 104 directly or via relays between the anode electrode land 103 and the cathode electrode land 104. This is a wiring pattern. The electrode wiring pattern 102 is made of gold (Au) and is arranged (formed) according to the circuit configuration. In this embodiment, the electrode wiring pattern 102 includes connection wirings 102a, 102d, 102g, and 102j, anode electrodes 102b, 102e, and 102h (first light emitting element connection electrodes), and cathode electrodes 102c, 102f, and 102i. (Second light emitting element connection electrode).

  The anode electrode 102b and the cathode electrode 102c are electrodes corresponding to the connection of the LED chips 105 of the group A shown in FIG. The anode electrode 102 b and the cathode electrode 102 c are electrically connected to each LED chip 105 by a wire 106. The anode electrode 102b and the cathode electrode 102c are arranged so as to sandwich the group A LED chips 105 and face each other along the short side direction of the phosphor-containing resin layer 109. The anode electrode 102b, the cathode electrode 102c, and the LED chip 105 of group A constitute one group L1.

  The anode electrode 102e and the cathode electrode 102f are electrodes provided corresponding to the connection of the group B LED chips 105 shown in FIG. The anode electrode 102e and the cathode electrode 102f are electrically connected to each LED chip 105 by a wire 106. The anode electrode 102e and the cathode electrode 102f are arranged so as to sandwich the group B LED chips 105 and face each other along the short direction of the phosphor-containing resin layer 109. The anode electrode 102e, the cathode electrode 102f, and the group B LED chips 105 constitute one group L2.

  The anode electrode 102h and the cathode electrode 102i are electrodes corresponding to the connection of the group C LED chips 105 shown in FIG. The anode electrode 102 h and the cathode electrode 102 i are electrically connected to each LED chip 105 by a wire 106. The anode electrode 102 h and the cathode electrode 102 i are arranged so as to correspond to each other along the short direction of the phosphor-containing resin layer 109 with the group C LED chips 105 interposed therebetween. The anode electrode 102h, the cathode electrode 102i, and the group C LED chips 105 constitute one group L3.

  The groups L1 to L3 are arranged along the longitudinal direction of the phosphor-containing resin layer 109. The anode electrodes 102b, 102e, and 102h are arranged on the upper side in FIG. The cathode electrodes 102c, 102f, and 102i are arranged below the mounting region of the LED chip 105 in FIG.

  The connection wirings 102a, 102d, 102g, and 102j are relay wirings for connecting the groups L1 to L3 in series between the anode electrode land 103 and the cathode electrode land 104. The connection wiring 102a electrically connects the anode electrode land 103 and the anode electrode 102b. The connection wiring 102d electrically connects the cathode electrode 102c and the anode electrode 102e. The connection wiring 102g electrically connects the cathode electrode 102f and the anode electrode 102h. The connection wiring 102j electrically connects between the cathode electrode 102i and the cathode electrode land 104. The connection wirings 102a, 102d, 102g, and 102j are arranged along the short direction of the phosphor-containing resin layer 109 and around the mounting regions of the groups L1 to L3.

  The anode electrode land 103 and the cathode electrode land 104 are electrodes that can be connected to an external power source of the light emitting device 100. The anode electrode land 103 and the cathode electrode land 104 are made of silver (Ag) -platinum (Pt). The anode electrode land 103 is arranged near the corner of the main surface of the ceramic substrate 101 (upper right in FIG. 1). The cathode electrode land 104 is disposed near a corner (lower left in FIG. 1) of the main surface of the ceramic substrate 101 facing the anode electrode land 103. That is, the anode electrode land 103 and the cathode electrode land 104 are arranged on the diagonal of the main surface of the ceramic substrate 101 so as to face each other.

  Note that the connection wirings 102 a and 102 j are extended so as to be connected to the anode electrode land 103 and the cathode electrode land 104, so that a part thereof is not covered with the dam resin 108 or the phosphor-containing resin layer 109. For this reason, it is desirable to form the insulating protective film 110 in the connection wirings 102a and 102j in the portions exposed without being covered with the dam resin 108 or the phosphor-containing resin layer 109.

  As described above, on the main surface of the ceramic substrate 101, the anode electrodes 102b, 102e, and 102h and the cathode electrodes 102c, 102f, and 102i are disposed so as to sandwich the corresponding LED chip 105 mounting region. Further, in the mounting region of the LED chips 105 of the groups L1 to L3 (groups A to C), as described later, the LED chips 105 are electrically connected by direct connection by wire bonding, which is conventionally used. The existing electrode wiring pattern becomes unnecessary. The connection wirings 102a, 102d, 102g, and 102j are arranged around the LED chip 105 group of the groups L1 to L3 (groups A to C), respectively, and do not cross the arrangement of the LED chip 105 group.

  Therefore, it is possible to reduce the distance between the LED chips 105 and increase the mounting density of the LED chips 105. Therefore, it is possible to reduce the light emission of each LED chip 105 from appearing as a bright spot, and to improve luminance unevenness in the plane of the light emitting device 100. Further, it becomes possible to reduce the size.

  Further, part of the anode electrode 102e and the cathode electrode 102f is disposed below the dam resin 108. Therefore, light absorption by the anode electrode 102e and the cathode electrode 102f can be suppressed. In this way, by arranging the electrode wiring pattern 102 as much as possible in the lower part of the resin frame, it is possible to suppress light absorption by these. In addition, connection wiring is reduced as much as possible. Therefore, it is possible to improve the light emission efficiency.

  Note that the connection wiring (particularly, the connection wirings 102d and 102g) is preferably narrower and smaller in area than the anode electrodes 102b, 102e, and 102h and the cathode electrodes 102c, 102f, and 102i. . As a result, thermal loads such as thermal cycles during light emission and non-light emission at the interface between the phosphor-containing resin layer 109 and the ceramic substrate 101 and at the interface between the phosphor-containing resin layer 109 and the connection wiring. It is possible to reduce peeling of the phosphor-containing resin layer 109 due to a difference in adhesion characteristics and a difference in thermal expansion coefficient. Also, with this configuration, it is possible to reduce light loss due to connection wiring arranged across the mounting surface and in-plane luminance unevenness as a light emitting device.

  In addition, by arranging the anode electrodes 102b, 102e, and 102h and the cathode electrodes 102c, 102f, and 102i on the same side, the polarity direction of the chip electrode when the LED chip 105 is mounted is made the same. It becomes possible to do. Accordingly, die bonding can be performed without changing the polarity direction of the chip electrode, that is, without changing the direction of the LED chip 105, and the die bonding apparatus / process of the LED chip 105 can be simplified.

  Furthermore, the anode electrodes 102b and 102h are located inside the anode electrode 102e, and the cathode electrodes 102c and 102i are located inside the cathode electrode 102f. Thus, by making the distance between the anode electrode 102b and the cathode electrode 102c, and the distance between the anode electrode 102h and the cathode electrode 102i smaller than the distance between the anode electrode 102e and the cathode electrode 102f, The likelihood of the wire bonding areas of the anode electrodes 102b and 102h and the cathode electrodes 102c and 102i is increased, and the wire bonding workability can be improved. However, this is not the case when priority is given to the reduction of light absorption by the electrode wiring pattern 102.

(Arrangement of LED chip 105)
Next, the arrangement of the LED chip 105 will be specifically described. The 44 LED chips 105 are divided into three groups L1 to L3 in consideration of the circuit configuration and mounting area described above.

  In the group L1, four series circuit portions are arranged in parallel along the longitudinal direction of the phosphor-containing resin layer 109 between the anode electrode 102b and the cathode electrode 102c, and are electrically connected in parallel. Are listed. Three LED chips 105 in the series circuit portion are arranged in series along the short side direction of the phosphor-containing resin layer 109, and are electrically connected in series.

  In the group L2, four series circuit portions are arranged in parallel along the longitudinal direction of the phosphor-containing resin layer 109 between the anode electrode 102e and the cathode electrode 102f, and are electrically connected in parallel. Are listed. Five LED chips 105 in the series circuit portion are arranged in series along the short direction of the phosphor-containing resin layer 109, and are electrically connected in series.

  In the group L3, four series circuit portions are arranged in parallel along the longitudinal direction of the phosphor-containing resin layer 109 between the anode electrode 102h and the cathode electrode 102i so as to be electrically connected in parallel. Are listed. Three LED chips 105 in the series circuit portion are arranged in series along the short side direction of the phosphor-containing resin layer 109, and are electrically connected in series.

  The three groups L <b> 1 to L <b> 3 are arranged so that the number of LED chips 105 is reduced in the vicinity of the corner of the phosphor-containing resin layer 109 so that the overall mounting area is reduced. That is, the group L2 is arranged near the center of the main surface of the ceramic substrate 101, and the groups L1 and L3 are arranged on both sides along the longitudinal direction of the phosphor-containing resin layer 109, respectively. Since the groups L1 and L3 have fewer LED chips 105 than the group L2, the groups L1 and L3 have an appropriate size so as to match the shape of the phosphor-containing resin layer 109 and to secure an electrode wiring pattern area having a wire bond area. Arranged with a degree.

  As described above, by arranging the plurality of LED chips 105 in three groups L1 to L3, it is possible to fit the mounting area of the LED chips 105 in a rectangle as small as possible. Accordingly, the layout arrangement on the ceramic substrate 101 including the anode electrode land 103 and the cathode electrode land 104 can be reduced, and a smaller light emitting device 100 can be realized.

  Further, in each of the groups L1 to L3, between the adjacent LED chips 105 in the series circuit portion, the cathode electrode of one LED chip 105 and the anode electrode of the other LED chip 105 are directly connected by a wire 106 by wire bonding. Has been. Therefore, since the electrode wiring pattern 102 that relays between the LED chips 105 is not provided in each of the groups L1 to L3, the distance between the LED chips 105 is reduced and the mounting density of the LED chips 105 is increased. It becomes possible.

  Further, all the LED chips 105 are arranged in the same direction and in such a direction that the facing direction of the cathode electrode and the anode electrode is along the short direction of the phosphor-containing resin layer 109. That is, all the LED chips 105 are arranged so that the direction of the chip electrodes is uniform, and the longitudinal direction of the upper surface is along the short direction of the phosphor-containing resin layer 109. In this embodiment, the anode electrode is positioned on the upper side in FIG. Thereby, die bonding can be performed without changing the polarity direction of the chip electrode, that is, without changing the direction of the LED chip 105.

(Arrangement of printing resistor 107)
Next, the arrangement of the printing resistors 107 will be specifically described. The printing resistors 107a to 107c are arranged for each of the divided groups (L1, L2, L3).

  The printing resistor 107a is formed so as to be electrically connected to the connection wiring 102a and the anode electrode 102e. The printing resistor 107a is arranged in a straight line with the anode electrode 102e. The printing resistor 107b is formed so as to be electrically connected to the cathode electrode 102c and the cathode electrode 102f. The printing resistor 107b is arranged in a straight line with the connection wiring 102d. The printing resistor 107c is formed so as to be electrically connected to the cathode electrode 102f and the connection wiring 102j. The printing resistor 107c is arranged so as to be aligned with the cathode electrode 102f.

  Further, the printing resistors 107 a to 107 c are arranged around the mounting area of the LED chip 105. Further, most of the printing resistors 107a and 107c and a part of the printing resistor 107b are disposed below the dam resin 108 having a low light transmittance.

  As described above, the printing resistors 107a to 107c are disposed as much as possible below the dam resin 108 and covered with the dam resin 108, so that light absorption by the printing resistors 107a to 107c can be suppressed to a minimum. Therefore, it is possible to prevent the light output of the light emitting device 100 from decreasing.

(Configuration of dam resin 108)
Next, the configuration of the dam resin 108 will be specifically described.

  As shown in FIG. 3, the cross-sectional shape of the dam resin 108 is an upwardly convex dome shape (upper side <lower side). Due to this cross-sectional shape, light emitted from the LED chip 105 in the lateral direction, particularly in the direction of the dam resin 108, is reflected by the dam resin 108. Therefore, there is an effect of facilitating extraction of light toward the front surface of the substrate.

  The cross-sectional shape of the dam resin 108 is not limited to this. In order to minimize the formation region of the phosphor-containing resin layer 109, the dam resin 108 is desirably formed so as to cover part of the electrode wiring pattern 102 and part of the wire 106.

(Configuration of phosphor-containing resin layer 109)
Next, the configuration of the phosphor-containing resin layer 109 will be specifically described.

  As shown in FIG. 3, the cross-sectional shape of the phosphor-containing resin layer 109 is an upwardly convex dome shape (upper side <lower side). That is, the phosphor-containing resin layer 109 is formed in a shape obtained by cutting out a part of an elliptical sphere when viewed from the exterior. In the light emitting device 100, the dome-shaped surface (spherical surface) of the phosphor-containing resin layer 109 is a light emitting surface of the light emitting device 100. Therefore, by using the light emission surface having the above shape, it is possible to efficiently extract the light from the LED chip 105 and the light from the phosphor, and as a result, it is possible to obtain the effect of improving the light emission efficiency. Become.

  In addition, the surface of the phosphor-containing resin layer 109 is not limited to the dome shape described above, and the degree of convexity can be adjusted by adjusting the viscosity of the phosphor-containing resin layer. Alternatively, it may be a slightly curved surface with a smooth curved surface.

(Production method)
Next, a method for manufacturing the light emitting device 100 having the above configuration will be briefly described.

  In addition, the light emitting device 100 is formed on a single large ceramic substrate as an integrated body composed of a plurality of light emitting device groups, and the periphery (four sides) of each light emitting device is divided by dicing at the end of the manufacturing process. Each light emitting device 100 is formed.

  First, the electrode wiring pattern 102, the anode electrode land 103, and the cathode electrode land 104 are formed on the main surface of the ceramic substrate 101. A printing resistor 107 is formed on the main surface of the ceramic substrate 101 by, for example, printing. Then, after the LED chip 105 is die-bonded to the main surface of the ceramic substrate 101, wire bonding is performed using the wire 106.

Subsequently, a dam resin 108 is formed on the main surface of the ceramic substrate 101. Specifically, it is formed by drawing a liquid white silicone resin (containing light diffusion filler TiO ₂ ) with a dispenser. This dam resin is cured at 120 ° C. for 60 minutes.

  Subsequently, a dome-shaped phosphor-containing resin layer 109 as shown in FIG. 3 is formed on the main surface of the ceramic substrate 101. Specifically, the phosphor-containing resin layer 109 is filled in a region surrounded by the dam resin 108 with a dispenser. Finally, the ceramic substrate 101 is divided into individual light emitting devices 100. Thereby, the light emitting device 100 can be manufactured. According to this manufacturing method, the light emitting device 100 can be manufactured easily and inexpensively.

  The dam resin 108 may be formed by sticking a molded sheet produced in accordance with the shape of the dam resin 108 to the main surface of the ceramic substrate 101 instead of the dam resin 108. The molded sheet is obtained by molding fluorine rubber, silicone rubber, or the like into a sheet shape, and may include an adhesive sheet on the surface side to be attached to the main surface.

  Furthermore, in this embodiment, the dam resin 108 is formed so as to be surely incorporated in the light emitting device 100. However, in the case of a method in which a formed sheet is attached to the main surface of the ceramic substrate 101, the light emitting device 100 is used. Depending on the desired light distribution characteristics, the molded sheet may be finally removed.

  Further, the phosphor-containing resin layer 109 is not limited to the method of filling the phosphor-containing resin layer 109 with a dispenser in the region surrounded by the dam resin 108 as described above. For example, the phosphor-containing resin layer 109 does not use the dam resin 108, but uses a mold or the like to compress the LED chip 105, the electrode wiring pattern 102, or the like through a phosphor-containing transparent material. It may be formed so as to be collectively sealed with a light-sensitive resin.

  In the method for manufacturing the light emitting device 100, the dam resin 108 and the phosphor-containing resin layer 109 can be easily formed on the printed resistor 107. Therefore, the degree of freedom of the arrangement region of the printing resistor 107 is increased, and the printing resistor 107 can be arranged in the vicinity of the LED chip 105 or below the dam resin 108 and the phosphor-containing resin layer 109.

  In the above manufacturing method, after the LED chip 105 is mounted, wire bonding is performed, and then the dam resin 108 is formed. However, not limited to this, the dam resin 108 is formed first, and then the LED chip 105 is mounted. It may be mounted and wire bonding may be performed.

Here, an example of the dimension of the light-emitting device 100 having the above configuration will be given.
Ceramic substrate 101: External size 12 mm × 15 mm, thickness 1 mm
Electrode wiring pattern 102: width 300 μm, thickness 10 μm
Electrode land 103 for anode and electrode land 104 for cathode: diameter 1.4 mm, straight portion 2 mm, thickness 20 μm
LED chip 105: width 240 μm, length 400 μm, height 80 μm
Dam resin 108: Ring width 0.7 mm, external size 6.9 × 7.9 mm, corner R = 2 mm
These dimensions are merely examples.

(Modification)
In the light emitting device 100 described above, the ceramic substrate 101 is used. However, the present invention is not limited thereto. For example, a metal core substrate in which an insulating layer is formed on the surface of the metal substrate may be used instead of the ceramic substrate 101. In this case, the insulating layer can be formed only in an area where the printing resistor 107 and the electrode wiring pattern 102 are formed, and a plurality of LED chips 105 can be directly mounted on the surface of the metal substrate.

  Further, the outer shape of the ceramic substrate 101 is not limited to a rectangle. Furthermore, the vertical direction (first direction) and the horizontal direction (second direction) of the main surface are determined by the relative positional relationship of the electrode wiring pattern 102, the LED chip 105, and the like. It is not determined as a standard.

  Further, the LED chip 105 is rectangular in a top view, but may be square. As the LED chip 105, for example, a 300 μm square and a height of 100 μm can be used. Furthermore, the mounting method of the LED chip 105 is not limited to wire bonding, and, for example, flip chip bonding may be used (not shown).

  Further, the number, grouping, and circuit configuration of the LED chips 105 are not limited to those described above. For example, even if the 44 LED chips 105 are grouped as “A: 4 in series, B: 4 in series, C: 4 in series”, etc., the same effect can be obtained. In other words, the plurality of LED chips 105 only need to have a circuit configuration in which two or more series circuit portions in which two or more LED chips 105 are connected in series are connected in parallel.

  Furthermore, although the degree of freedom of the mounting area is reduced, a Zener diode may be used instead of the printing resistor 107. In this case, a plurality of Zener diodes can be used according to the number of LED chips 105 connected in series in the serial connection portion.

  Next, another embodiment of the present invention will be described with reference to the drawings. Configurations other than those described in each embodiment are the same as those in the first embodiment. Further, for convenience of explanation, in each embodiment, members having the same functions as those shown in the drawings of Embodiment 1 are given the same reference numerals, and descriptions thereof are omitted.

[Embodiment 2]
FIG. 5 is a top view illustrating a configuration example of the light emitting device 200 according to the present embodiment.

  The light emitting device 200 of the present embodiment is different from the light emitting device 100 of the first embodiment in the configuration of the electric circuit. Other than that, it has the same configuration as the light emitting device 100 of the first embodiment.

  As shown in FIG. 5, in the light emitting device 200, seven LED chips 105 are arranged in a straight line, and 14 series circuit units in which the seven LED chips 105 are connected in series are arranged in parallel. It has a circuit configuration connected in parallel. That is, a total of 98 LED chips 105 connected in series and parallel, 7 in series and 14 in parallel, are mounted on the main surface of the ceramic substrate 101.

  The electrode wiring pattern 102 includes an anode electrode 102k and a cathode electrode 102l. The anode electrode 102k and the cathode electrode 102l are electrically connected to each LED chip 105 by a wire 106. The anode electrode 102k and the cathode electrode 102l sandwich the LED chip 105 group and face each other along the short direction of the phosphor-containing resin layer 109 (the direction in which the LED chips 105 are linearly arranged). Has been placed.

  One printing resistor 107 is provided so as to be connected in parallel to the series circuit portion. That is, the printing resistor 107 is formed so as to be connected to the anode electrode 102k and the cathode electrode 102l. The printing resistor 107 is arranged in a direction orthogonal to the anode electrode 102k and the cathode electrode 102l in a top view.

  In the light emitting device 200, as in the light emitting device 100 of the first embodiment, the effect of suppressing the disconnection failure of the series circuit unit including the LED chip 105 by the printed resistor 107 and the series circuit unit including the LED chip 105 are provided. It is possible to obtain an effect of minimizing a decrease in light output when the wire is disconnected.

[Embodiment 3]
FIG. 6 is a top view illustrating a configuration example of the light emitting device 300 according to the present embodiment.

  The light emitting device 300 of the present embodiment is different from the light emitting device 100 of the first embodiment in the mounting direction (polarity direction) of the LED chip 105 and the wiring direction of the wire 106 corresponding thereto. Other than that, it has the same configuration as the light emitting device 100 of the first embodiment.

  As shown in FIG. 6, in the light emitting device 300, the group L1 includes two series circuit units formed by connecting four LED chips 105 in series, and the group L2 includes eight LED chips 105. Are connected in series, and in the group L3, two series circuit units each having four LED chips 105 connected in series are connected in parallel. That is, a total of 40 LED chips 105 connected in series and parallel are mounted on the main surface of the ceramic substrate 101.

  In addition, each LED chip 105 is arranged in such a direction that the longitudinal direction coincides with the longitudinal direction of the phosphor-containing resin layer 109. That is, the LED chip 105 of the light emitting device 300 is rotated 90 degrees from the arrangement direction of the LED chip 105 of the light emitting device 100. Depending on the arrangement of the LED chips 105, the wires 106 are wired obliquely.

  In the light emitting device 300, in addition to the same effect as the light emitting device 100 of the first embodiment, it is possible to reduce the size of the dam resin 108, and to be closer to a point light source. Further, in the light emitting device 300, since the space between the anode electrode land 103 and the cathode electrode land 104 and the LED chip 105 mounting area can be widened, the LED chip 105 can be easily bonded. There is.

  However, in the light emitting device 300, as compared with the light emitting device 100, the wire usage increases due to the length of the wire 106. For this reason, as a whole, the mounting method of the light emitting device 100 is preferable to the mounting method of the light emitting device 300.

[Embodiment 4]
FIG. 7 is a top view illustrating a configuration example of the light-emitting device 400 of the present embodiment.

  The light emitting device 400 of the present embodiment is different from the light emitting device 100 of the first embodiment in the configuration of the LED chip 105 and the wire 106 of the group L2. Other than that, it has the same configuration as the light emitting device 100 of the first embodiment.

  As shown in FIG. 7, in the light emitting device 400, in the group L2, three series circuit units formed by connecting eight LED chips 105 in series are connected in parallel. Therefore, in the light emitting device 400, a total of 48 LED chips 105 connected in series and parallel are mounted on the main surface of the ceramic substrate 101. The LED chips 105 of the group L2 are arranged so that the longitudinal direction thereof coincides with the longitudinal direction of the phosphor-containing resin layer 109. Depending on the arrangement of the LED chips 105, the wires 106 are wired obliquely.

  In the light emitting device 400, more LED chips 105 can be mounted in the frame of the dam resin 108 having the same size as the dam resin 108 of the light emitting device 300 of the third embodiment. In this manner, the mounting direction of the LED chips 105 may be changed for each group so that a desired number of LED chips 105 are mounted.

[Embodiment 5]
FIG. 8 is a top view illustrating a configuration example of the light emitting device 500 of the present embodiment.

  Compared with the light emitting device 100 of the first embodiment, the light emitting device 500 of the present embodiment has 44 LED chips 105 mounted on the light emitting device 100, but the light emitting device 500 has 40 LED chips. The difference is that 105 and four LED chips 105 'are mounted. Other than that, it has the same configuration as the light emitting device 100 of the first embodiment.

  The LED chip 105 ′ has a smaller chip size than the LED chip 105 (for example, a square of 0.3 × 0.3 mm when viewed from above). As shown in FIG. 8, the LED chip 105 ′ is disposed at the four corners of the mounting area of the LED chip 105 as a whole. In other words, the LED chips 105 ′ are arranged at the four corners close to the dam resin 108 in the phosphor-containing resin layer 109 region.

  In the light emitting device 500, the LED chip 105 ′ at the four corners close to the dam resin 108 in the phosphor-containing resin layer 109 region is made smaller in size than the other mounted LED chips 105, so that the frame of the dam resin 108 is obtained. Can be reduced, and the light emitting area can be reduced.

[Embodiment 6]
FIG. 9 is a top view illustrating a configuration example of the light-emitting device 600 of the present embodiment.

  The light emitting device 600 of the present embodiment is different from the light emitting device 100 of the first embodiment in the shapes of the dam resin 108 and the phosphor-containing resin layer 109. Other than that, it has the same configuration as the light emitting device 100 of the first embodiment.

  As shown in FIG. 9, in the light emitting device 600, the dam resin 108 has an annular shape in a top view. Most of the dam resin 108 is formed on the printing resistor 107. The phosphor-containing resin layer 109 has a circular shape in top view along the shape of the dam resin 108.

  In the light emitting device 600, since the phosphor-containing resin layer 109 is formed in a circular shape, light emitted from the LED chip 105 is easily emitted uniformly in all directions. This also facilitates application and design of the light emitting device 600 to a general-purpose lighting fixture.

[Embodiment 7]
FIG. 10 is a top view illustrating a configuration example of the light emitting device 700 of this embodiment.

  The light emitting device 700 of the present embodiment is different from the light emitting device 100 of the first embodiment in the installation area of the printing resistor 107b and the installation area of the dam resin 108. Other than that, it has the same configuration as the light emitting device 100 of the first embodiment.

  As shown in FIG. 10, in the light emitting device 700, the printing resistor 107 b has a shape along the curve of the dam resin 108 and is disposed below the dam resin 108. The dam resin 108 is formed thick so as to cover all the printing resistors 107a to 107c.

  In the light emitting device 700, since all the printing resistors 107a to 107c are covered with the dam resin 108 and disposed at a position that does not impair other optical characteristics, the light emitting efficiency loss due to light absorption of the printing resistors 107a to 107c is minimized. It becomes possible to.

[Embodiment 8]
FIG. 11 is a top view illustrating a configuration example of the light-emitting device 800 of the present embodiment.

  The light emitting device 800 of the present embodiment differs from the light emitting device 100 of the first embodiment in the mounting direction of the LED chips 105 of the group L2. Other than that, it has the same configuration as the light emitting device 100 of the first embodiment. In FIG. 11, the dam resin 108 and the phosphor-containing resin layer 109 are omitted, but these members are formed in the same manner as in FIG.

  As shown in FIG. 11, in the light emitting device 800, the LED chips 105 of the group L2 are arranged in such an orientation that the cathode electrode is positioned on the upper side. That is, the LED chips 105 of the group L2 of the light emitting device 800 are rotated 180 degrees from the mounting direction of the LED chips 105 of the group L2 of the light emitting device 100. Accordingly, in the electrode wiring pattern 102, the arrangement of the anode electrode 102e and the cathode electrode 102f is reversed. In addition, the printed resistor 107 has the same electrical circuit configuration as the light emitting device 100, and only the formation region is changed.

  In the light emitting device 800, it is necessary to dispose the connection wiring 102d for connecting the group L1 and the group L2 and the connection wiring 102g for connecting the group L2 and the group L3 so as to cross between the groups. Therefore, the light absorption loss due to these wirings can be reduced.

  In the above-described first to eighth embodiments, the example in which the printing resistor 107 is always provided has been described. However, the use in which the electrostatic withstand voltage is not so much required or the case where the electrostatic withstand voltage of each LED chip 105 is large. However, the printing resistor 107 may not be included.

[Embodiment 9]
In this embodiment, an electronic device including the light-emitting device described in any of Embodiments 1 to 8 will be described.

  For example, there is an illumination device in which the light-emitting device is mounted on a mounting substrate that has a power supply circuit on the back surface and is integrated with a heat sink. The anode electrode land 103 and the cathode electrode land 104 of the light emitting device are electrically connected to the anode electrode land and the cathode electrode land of the mounting substrate by external wiring or the like. The upper surface of the light emitting device is covered with a case having a light diffusion function or a transparent case.

  Further, the light emitting device is mounted not only in one but in a plurality so that one side of the rectangular ceramic substrate 101 is parallel or the diagonal direction of the rectangular ceramic substrate 101 is in a straight line, A fluorescent lamp type lighting device may be used. In addition, it is good also as a light bulb type illuminating device by mounting only one.

  Here, as a specific example of the lighting device, a configuration of an LED bulb including the light-emitting device described in Embodiments 1 to 8 will be described. FIGS. 12A and 12B are diagrams showing an example of the configuration of the LED bulb 900. FIG. 12A shows an appearance when viewed from the side, and FIG.

  As shown in FIG. 12, in the LED bulb 900, the mounting plate 904 is fixed to the radiating fin 902 fixed to the base 901 with a fastening screw 905, and the scattering material-containing lens dome 903 is provided so as to cover the mounting plate 904. It has the structure provided. The base 901 is a metal part for screwing into a socket in a light bulb. As the size of the base 901, E26, E17 or the like can be suitably used. In particular, since the light emitting devices described in Embodiments 1 to 8 can have a surface area as small as 15 mm × 12 mm, the E17 base is suitable.

  A light emitting device 909 is mounted on the mounting plate 904. The light emitting device 909 is fixed by a pressing pin 906. As the light-emitting device 909, any of the light-emitting devices described in Embodiment Modes 1 to 8 may be used. The anode electrode land 103 and the cathode electrode land 104 of the light emitting device 909 are electrically connected to external wiring (anode connection 907 and cathode connection 908).

  Since the LED light bulb 900 includes the light emitting device 909, luminance unevenness is improved and the light emission efficiency is improved, so that the LED light bulb 900 is a very excellent lighting device.

  Furthermore, a plurality of the light emitting devices may be arranged in a matrix on the housing substrate to constitute a planar light source. In this planar light source, each of the light emitting devices is provided with an external lens for adjusting the light distribution characteristics, or the phosphor-containing resin layer 109 is made convex as shown in FIG. By providing a lens function, it is possible to have photo-alignment characteristics. A liquid crystal display device using such a planar light source as a BL (backlight) light source can be configured.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

[Summary]
An LED bulb according to aspect 1 of the present invention includes a base positioned at one end of a radiator, a mounting plate positioned at the other end of the radiator, and a light emitting device mounted on the mounting plate, The light emitting device includes a ceramic substrate, an anode electrode land formed on the ceramic substrate, an anode electrode formed on the ceramic substrate and connected to the anode electrode land, and formed on the ceramic substrate. And connecting wires arranged so as to face the anode electrode along the first direction, and arranged on the ceramic substrate, between the anode electrode and the connecting wires by wire bonding. A plurality of columns having a plurality of LED (Light Emitting Diode) chips connected in series along the first direction are arranged in parallel along a second direction orthogonal to the first direction. The first group is disposed on the ceramic substrate, connected in series to the connection wiring by wire bonding, and the LED chip included in the first group along the first direction has a mounting direction of 180 degrees. A second group including a plurality of LED chips arranged in a rotated state in parallel along the second direction, and a cathode formed on the ceramic substrate and relay-connected to the second group And an electrode land.

  The LED bulb according to aspect 2 of the present invention is the LED light bulb according to aspect 1, wherein the LED chip is a blue LED, and further includes a YAG (Ce activated yttrium / aluminum / garnet) phosphor-containing resin on the LED chip. May be.

  The LED bulb according to aspect 3 of the present invention is the LED light bulb according to aspect 1, in which the ceramic substrate has a rectangular outer shape, and the anode electrode land and the cathode electrode land are along opposite sides. May be.

  In the LED bulb according to Aspect 4 of the present invention, in the above Aspect 1, the connection wiring may include gold.

[Others]
The present invention can also be described as follows.

  In order to solve the above problems, a light emitting device of the present invention includes a substrate, a plurality of light emitting elements mounted on the main surface of the substrate, and a protection element connected in parallel to the plurality of light emitting elements. A resin frame made of a resin having a low light transmittance, which is annularly provided on the main surface of the substrate so as to surround a mounting region on which the plurality of light emitting elements are mounted, and the plurality of light emitting elements. And a phosphor-containing resin layer made of a resin containing a phosphor, which is provided adjacent to the inside of the resin frame so as to cover the resin frame, and the main surface of the substrate has a first layer in the main surface. A first light emitting element connection electrode and a second light emitting element connection electrode are formed so as to face each other along one direction, and the plurality of light emitting elements are formed by connecting two or more light emitting elements in series. A series circuit portion includes the first light emitting element connecting electrode and Two or more circuit configurations are connected in parallel with the second light emitting element connecting electrode, and each series circuit portion includes the first light emitting element connecting electrode and the second light emitting element connecting electrode. Are arranged along a second direction that is in the main surface and orthogonal to the first direction, and the light emitting elements in the series circuit units are arranged along the first direction, and the first The electrode for connecting a light emitting element and the electrode for connecting the second light emitting element are arranged below the resin frame, the phosphor-containing resin layer, or both.

  According to said structure, the 1st light emitting element connection electrode and the 2nd light emitting element connection electrode are arrange | positioned so that the mounting area | region of a light emitting element may be pinched | interposed. Further, the light emitting elements in the series circuit portion are electrically connected by direct connection, for example, by wire bonding, so that the conventionally used electrode wiring pattern becomes unnecessary. Therefore, it is possible to reduce the distance between the light emitting elements and increase the mounting density of the light emitting elements. Accordingly, it is possible to reduce the light emission of each light emitting element from appearing as a bright spot, to improve luminance unevenness in a plane as a light emitting device, and to reduce the size.

  Further, by arranging the first light emitting element connecting electrode and the second light emitting element connecting electrode as low as possible in the resin frame, it is possible to suppress light absorption by these. Furthermore, light absorption by the electrode wiring pattern is also reduced. Therefore, it is possible to improve the light emission efficiency. In addition, since the protective element is connected in parallel to the light emitting element, the light emitting element can be prevented from being deteriorated, and the lifetime can be extended to ensure reliability. Therefore, it is possible to provide a light emitting device with high light emission efficiency and excellent reliability.

  In the light emitting device of the present invention, a plurality of groups each including the plurality of light emitting elements, the first light emitting element connecting electrode, and the second light emitting element connecting electrode are arranged along the second direction, It is preferable that connection wires arranged to connect adjacent groups in series are formed on the main surface, and the protection element is provided for each group.

  According to the above configuration, the light emitting element mounting area can be minimized by arranging the light emitting elements in groups according to the number of light emitting elements and the circuit configuration. This also makes it possible to reduce the arrangement area of the first light emitting element connection electrode, the second light emitting element connection electrode, the resin frame, and the like. Therefore, it is possible to reduce the size. In addition, since the protective element is provided for each group, it is possible to minimize a decrease in light output when the series circuit section is disconnected.

  In the light emitting device of the present invention, the resin forming the resin frame is preferably colored white or milky white. Thereby, the light transmittance of the resin forming the resin frame can be set low, or the resin forming the resin frame can have light reflectivity.

  In the light emitting device of the present invention, between the adjacent light emitting elements in each of the series circuit portions, the cathode electrode of one light emitting element and the anode electrode of the other light emitting element are directly connected by a metal wire by wire bonding. Is preferred. Thereby, the distance between the light emitting elements can be shortened, and the mounting density of the light emitting elements can be increased.

  In the light emitting device of the present invention, the protective element is a thin film printing resistor partially formed on the main surface of the substrate, and the protective element is connected to the first light emitting element connection electrode and the second light emitting element connection. It is preferable that the resin frame body, the phosphor-containing resin layer, or both of them are disposed around the mounting region so as to be electrically connected to the electrode for use. .

  In the light emitting device of the present invention, each of the protection elements is a thin film printing resistor partially formed on the main surface of the substrate, and each of the protection elements is connected to the first light emitting element connection electrode in a corresponding group. Arranged around the mounting region and below the resin frame, the phosphor-containing resin layer, or both so as to be electrically connected to the second light emitting element connection electrode It is preferable that

  According to each configuration described above, it is possible to easily create the resin frame, the phosphor-containing resin layer, and the like on the protective element. Therefore, the degree of freedom of the arrangement area of the protection element is increased, and the protection element can be arranged in the vicinity of the light emitting element or below the resin frame and the phosphor-containing resin layer. Moreover, it is possible to suppress light absorption by the protective element to a minimum by disposing the protective element as much as possible below the resin frame and covering it with the resin frame.

  In the light emitting device of the present invention, the substrate is preferably a ceramic substrate made of ceramic.

  In the light-emitting device of the present invention, the cathode electrode and the anode electrode of each of the light-emitting elements are arranged to face each other, and the plurality of light-emitting elements are all in the same direction, and the cathode electrode and the anode electrode It is preferable that the facing direction is arranged in a direction along the first direction.

  In the light-emitting device of the present invention, the cathode electrode and the anode electrode of each of the light-emitting elements are arranged to face each other, and the plurality of light-emitting elements are all in the same direction, and the cathode electrode and the anode electrode It is preferable that the facing direction is arranged in a direction along the second direction.

  According to each of the above configurations, since all the light emitting elements are arranged in the same direction, each light emitting element can be die-bonded without changing the direction of the light emitting element, and the die bonding apparatus / process can be simplified. Is possible. In addition, by selecting the direction of the facing direction according to the shape of the light emitting element, the distance between the light emitting elements can be suitably reduced, and the mounting density of the light emitting elements can be maximized.

  In the light emitting device of the present invention, the resistance value of the thin film printing resistor is preferably 1 MΩ to 10 GΩ.

  In the light emitting device of the present invention, it is preferable that the resin frame has an annular shape in plan view. As a result, since the phosphor-containing resin layer has a circular shape in plan view, light emitted from the light-emitting element is easily emitted uniformly in all directions, and the light-emitting device can be applied to general-purpose lighting fixtures and can be easily designed. It becomes.

[Additional Notes]
The LED bulb includes a base positioned at one end of a heat radiator, a mounting plate positioned at the other end of the heat radiator, and a light emitting device mounted on the mounting plate, the light emitting device including a ceramic substrate, An anode electrode land formed on the ceramic substrate, an anode electrode formed on the ceramic substrate and connected to the anode electrode land, an anode electrode formed on the ceramic substrate, and A connection wiring arranged so as to face each other along the first direction, and a wiring bonding between the anode electrode and the connection wiring arranged along the first direction between the anode electrode and the connection wiring. A first group including a plurality of columns each having a plurality of LED (Light Emitting Diode) chips connected in series along a second direction orthogonal to the first direction; Arranged on the ceramic substrate, connected in series to the connection wiring by wire bonding, and arranged with the LED chip included in the first group along the first direction rotated 180 degrees. A second group including a plurality of columns each having a plurality of LED chips arranged in parallel along the second direction, and a cathode electrode land formed on the ceramic substrate and relay-connected to the second group. May be.

  According to the above configuration, it is possible to improve luminance unevenness and to reduce the size. In addition, since deterioration of the light-emitting element can be prevented and reliability can be ensured by extending the lifetime, it is possible to provide a light-emitting device with high light emission efficiency and excellent reliability. There is an effect that can be done.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

  The present invention can be suitably used not only in a field related to a light emitting device in which a plurality of LEDs connected in series and parallel are mounted on a substrate, but also in a field related to a method of manufacturing a light emitting device, The present invention can also be widely used in the field of electronic devices including light emitting devices such as LED bulbs.

100, 200, 300, 400, 500, 600, 700, 800 Light-emitting device 101 Ceramic substrate (substrate)
102 electrode wiring pattern 102a, 102d, 102g, 102j wiring for connection 102b, 102e, 102h electrode for anode (first light emitting element connection electrode)
102c, 102f, 102i Cathode electrode (second light emitting element connection electrode)
103 Electrode land for anode 104 Electrode land for cathode 105, 105 ′ LED chip (light emitting element)
106 wire (metal wire)
107, 107a to 107c Printing resistance (protective element)
108 Dam resin (resin frame)
109 Phosphor-Containing Resin Layer 900 LED Bulb 909 Light Emitting Device

Claims (17)

A substrate having a rectangular outer shape in top view;
A plurality of LED chips arranged near the center of the main surface of the substrate;
A resin frame provided in an annular shape on the main surface of the substrate so as to surround a mounting region in which the plurality of LED chips are mounted;
An electrode for connecting to an external power source of the light emitting device, provided on the outer side of the resin frame and in the vicinity of the corner of the main surface of the substrate, an anode electrode land and a cathode electrode land,
An electrode wiring pattern formed on the main surface of the substrate,
The electrode wiring pattern includes an anode-side electrode extending from the anode electrode land to a lower portion of the resin frame so as to electrically connect the plurality of LED chips to the anode electrode land and the cathode electrode land. Wiring and cathode side wiring extending from the cathode electrode land to the lower part of the resin frame,
The light emitting device, wherein the resin frame is made of a resin having light reflectivity.   2. The cathode electrode land according to claim 1, wherein the cathode electrode land is provided in the vicinity of the corner on the main surface of the substrate where the anode electrode land is provided and diagonally opposed to the corner. Light emitting device.   2. The light emitting device according to claim 1, wherein the anode electrode land and the cathode electrode land are arranged diagonally on the main surface of the substrate. A plurality of wires that electrically connect the plurality of LED chips to each other;
The phosphor-containing resin layer provided so as to be in contact with the inside of the resin frame and to cover the plurality of LED chips and the plurality of wires is further provided. Light emitting device.   The light emitting device according to claim 4, wherein the phosphor-containing resin layer has a circular shape in a top view along the shape of the resin frame. A substrate having a rectangular outer shape in top view;
A plurality of light emitting elements, which are a plurality of LED chips, disposed near the center of the main surface of the substrate;
An electrode wiring pattern having a first light-emitting element connection electrode as an anode electrode and a second light-emitting element connection electrode as a cathode electrode;
At least one of a protective element and a Zener diode connected in parallel with the plurality of light emitting elements;
It is an electrode for connecting to an external power source of the light emitting device, and includes an anode electrode land and a cathode electrode land provided near the corner of the main surface of the substrate,
The electrode wiring pattern is provided between the anode electrode land and the cathode electrode land so as to electrically connect the plurality of light emitting elements to the anode electrode land and the cathode electrode land. A light emitting device characterized by having a wiring pattern.   2. The light emitting device according to claim 1, wherein the width of the anode electrode land and the width of the cathode electrode land are larger than the width of the electrode wiring pattern. The substrate includes ceramic,
The light emitting device according to claim 1, wherein the plurality of LED chips are attached to a main surface of the substrate via a silicone resin adhesive.   The light-emitting device according to claim 1, further comprising a protective film provided on the anode-side wiring and the cathode-side wiring. A substrate,
An electrode for connecting to an external power source of the light-emitting device, an anode electrode land and a cathode electrode land formed on the main surface of the substrate,
An electrode wiring pattern formed on the main surface of the substrate and having an anode-side wiring extending from the anode electrode land and a cathode-side wiring extending from the cathode electrode land;
It is disposed near the center of the main surface of the substrate, and is electrically connected in series between the anode-side wiring and the cathode-side wiring, and each has a rectangular outer shape when viewed from above. A plurality of LED chips having an anode electrode and a cathode electrode; and
A plurality of wires that electrically connect the plurality of LED chips to each other;
The phosphor-containing resin layer covering the plurality of LED chips and the plurality of wires,
The plurality of LED chips have a first LED chip and a second LED chip,
The long side of the second LED chip is adjacent to the long side of the first LED chip,
The anode electrode of the first LED chip and the anode electrode of the second LED chip face each other,
The cathode electrode of the first LED chip and the cathode electrode of the second LED chip face each other,
The plurality of wires are wires that directly connect the cathode electrode of the first LED chip and the anode electrode of the second LED chip, and extend in a direction different from the direction along the long sides of the first LED chip and the second LED chip. A light-emitting device including the light-emitting device. The substrate includes ceramic,
The light emitting device according to claim 10, wherein the plurality of LED chips are attached to a main surface of the substrate via a silicone resin adhesive.   The light-emitting device according to claim 10, further comprising a Zener diode electrically connected between the anode-side wiring and the cathode-side wiring.   11. The light emitting device according to claim 10, further comprising a protective film provided on the anode side wiring and the cathode side wiring. A substrate having a rectangular outer shape in top view;
A plurality of LED chips arranged near the center of the main surface of the substrate;
A resin frame provided in an annular shape on the main surface of the substrate so as to surround a mounting region in which the plurality of LED chips are mounted;
It is an electrode for connecting to an external power source, and includes an anode electrode land and a cathode electrode land electrically connected to the plurality of LED chips,
The anode electrode land and the cathode electrode land are provided outside the resin frame and near the corner of the main surface of the substrate,
The light emitting device, wherein the resin frame is made of a resin having light reflectivity.   The light-emitting device according to claim 1, wherein the wiring on the anode side further extends to the mounting region.   The light emitting device according to claim 1, wherein the wiring on the cathode side further extends to the mounting region.   The anode electrode land and the cathode electrode land are formed on a main surface of the substrate, and electrically connect the plurality of LED chips to the anode electrode land and the cathode electrode land. The light-emitting device according to claim 14, further comprising an electrode wiring pattern provided between the electrodes.

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