JP2007149896A - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device having improved optical output and uniformity. <P>SOLUTION: This light emitting device 1 comprises a package body 2 having a recess 2a for receiving an LED chip, a pair of electrodes 3a and 3b provided on the external surface of the package body 2, two LED chips 4a and 4b mounted on the bottom surface of the recess 2a in the state wherein they are connected in parallel between the pair of electrodes 3a and 3b and in the forward direction, and current adjusters 5a and 5b individually interposed between the electrodes 3a and 3b and the LED chips 4a and 4b. The resistance values of the current adjusters 5a and 5b are set so that the values of the currents flowing through the respective LED chips 4a and 4b are nearly equal to each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light emitting device using an LED chip as a light source.

  Conventionally, a light emitting device using an LED chip as a light source has been provided. In particular, as a wavelength conversion material that emits light of a different emission color from the LED chip when excited by the light emitted from the LED chip and the LED chip. Research and development of light-emitting devices that emit light having a color different from the emission color of LED chips by combining phosphors (fluorescent pigments, fluorescent dyes, etc.) are being conducted in various places. In recent years, LED chips that emit blue light or ultraviolet light have been developed using gallium nitride (GaN) -based compound semiconductors, and white light is produced by combining LED chips that emit blue light or ultraviolet light and phosphors. White light emitting devices (generally called white LEDs) that obtain (emission spectrum of white light) have been commercialized.

  As this type of light emitting device, for example, as shown in FIGS. 7A and 7B, a substantially rectangular parallelepiped package body 100 having a recess 100 a for storing an LED chip, and an outer surface of the package body 100 are provided. An LED chip 102 provided with a pair of electrodes 101a and 101b and an LED chip 102 mounted on the bottom surface of the recess 100a while being connected between the pair of electrodes 101a and 101b is provided. A phosphor (not shown) is provided for converting light emitted from the light into light of different emission colors.

  A light emitting device using such an LED chip as a light source has advantages such as small size, light weight, and power saving, and is currently widely used for lighting applications such as a display light source, an alternative light source for a small light bulb, and a light source for a liquid crystal panel. ing. Here, when such a light-emitting device is used for an application that requires a relatively large light output such as lighting, a single light-emitting device often cannot obtain a desired light output. Generally, an LED unit is configured by mounting a light emitting device on a single circuit board so that a desired light output is ensured by the entire LED unit.

  However, if a plurality of light-emitting devices as shown in FIGS. 7A and 7B are mounted on a single circuit board, the circuit board naturally increases in size according to the number of light-emitting devices. However, this has hindered miniaturization of the LED unit.

In order to solve such a problem, the light output per light emitting device is improved by mounting LED chips on the package body of the light emitting device with high density (for example, Patent Document 1). As such a light emitting device, as shown in FIGS. 8A and 8B, a substantially rectangular parallelepiped package body 200 having a recess 200a for housing an LED chip, and a pair of electrodes provided on the outer surface of the package body 200 Some include 201a, 201b and two LED chips 202a, 202b mounted on the bottom surface of the recess 200a in a state where the pair of electrodes 201a, 201b are connected in parallel in the forward direction.
Japanese Patent Laying-Open No. 2003-8083 (FIG. 18)

  By the way, when using a plurality of LED chips, if a plurality of LED chips are connected in series, the voltage required to cause the LED chips to emit light becomes very high. Therefore, the plurality of LED chips should be connected in parallel to each other. Is preferred.

  However, since the LED chip has a variation in electrical characteristics (a variation in forward voltage) for each product, when a plurality of LED chips are connected in parallel, the current that flows for each LED chip differs, which There is a problem in that the brightness varies among LED chips and uniform light cannot be emitted, that is, the uniformity is deteriorated.

  On the other hand, as long as one LED chip 102 is provided in one package body 100 as in the light emitting device shown in FIGS. 7A and 7B, the circuit board corresponds to each light emitting device. By mounting the current adjusting means, the above problem could be solved although the light output was low.

  On the other hand, if the light emitting device shown in FIGS. 8A and 8B is provided with LED chips 202a and 202b connected in parallel to one package body 200, current adjusting means is provided on the circuit board. Incidentally, the currents flowing through the LED chips 202a and 202b in the package body 200 cannot be made equal, and the above problem cannot be solved although the light output is high.

  That is, in the conventional light emitting device, it has been impossible to achieve both improvement in light output and improvement in uniformity.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a light emitting device capable of improving light output and uniformity.

  In order to solve the above problems, in the invention of the light emitting device according to claim 1, the package body, the pair of electrodes provided on the package body, and the pair of electrodes connected in parallel in the forward direction to each other. A plurality of LED chips mounted on the LED chip, and a current adjustment unit individually connected in series to each LED chip between a pair of electrodes, and the current adjustment unit has a current value flowing through each LED chip substantially equal to each other. Each resistance value is set so that

  In the invention of the light emitting device according to claim 2, in addition to the configuration of claim 1, the current adjusting unit includes a series circuit including a plurality of resistors connected in series between one electrode and the LED chip, and the series circuit. And a resistance value adjusting means for adjusting a resistance value by selecting a resistor to be short-circuited.

  In the invention of the light emitting device according to claim 3, in addition to the configuration of claim 1, the current adjusting unit is composed of a plurality of resistors connected in series, and one end is connected to one of the electrode and the LED chip. It is characterized by comprising a series circuit and resistance value adjusting means for adjusting the resistance value by selecting a resistor connecting the other one of the plurality of resistors.

  In the invention of the light emitting device according to claim 4, in addition to the configuration of claim 1, the current adjusting unit includes a parallel circuit including a plurality of resistors connected in parallel between one electrode and the LED chip, and the parallel circuit. And a resistance value adjusting means for adjusting a resistance value by selecting a resistance for interrupting energization.

  In the invention of the light-emitting device according to claim 5, in addition to the configuration of claim 1, the current adjustment unit includes a plurality of resistors having one end connected to one of the one electrode and the LED chip, and the plurality of resistors. And a resistance value adjusting means for adjusting a resistance value by selecting a resistor that connects the other remaining side to the other end side.

  In the invention of the light emitting device of claim 6, in addition to the configuration of claim 2 or 3, the plurality of resistors are embedded in the package body so as to be located at different positions in the thickness direction of the package body, and terminal portions of the respective resistors Is characterized by being exposed in the package body.

  In the invention of the light emitting device according to claim 7, in addition to the configuration of claim 1, the current adjusting portion is composed of wiring for connecting one electrode and the LED chip, and the resistance value is set by the path length of the wiring. It is characterized by.

  According to an eighth aspect of the present invention, in addition to the configuration of the seventh aspect, the package body is formed using a ceramic material, and the current adjusting portion is mixed with ceramic powder.

  In the invention of the light-emitting device according to the first aspect, since the plurality of LED chips are mounted on the package body in a state in which the pair of electrodes are connected in parallel to each other in the forward direction, a voltage necessary for lighting the light-emitting device is obtained. While lowering, the optical output can be improved. In addition, since the current values flowing through the LED chips are made to be substantially equal to each other by the current adjustment unit, the current and temperature of each LED chip are stabilized, and thereby the brightness of each LED chip becomes substantially equal. There is an effect that the uniformity can be improved.

  The invention of the light emitting device according to the second to fifth aspects has an effect that the current flowing through each LED chip can be easily adjusted.

  The invention of the light emitting device according to claim 6 has an effect that the mounting density of the light emitting device can be improved (miniaturized).

  The invention of the light-emitting device according to claim 7 eliminates the need for using a chip resistor or the like as the current adjusting section, and thus has the effect of reducing the number of components and reducing the manufacturing cost and providing an inexpensive light-emitting device.

  The invention of the light emitting device according to claim 8 has an effect that the path length of the wiring used as the current adjusting portion can be shortened because the resistance of the current adjusting portion is increased by the ceramic powder. In addition, since the thermal conductivity between the package body made of ceramic material can be improved, the heat generated in the current adjustment section can be efficiently dissipated through the package body, so that the heat does not stay in the current adjustment section, There is an effect that an increase in the package temperature can be suppressed.

  Embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1)
As shown in FIG. 1B, the light emitting device 1 of the present embodiment includes a package body 2 having a recess 2a for housing an LED chip, a pair of external electrodes 3a and 3b provided on the outer surface of the package body 2, A plurality (two in this embodiment) of LED chips 4a and 4b mounted on the bottom surface of the recess 2a in a state of being connected in parallel in the forward direction between the pair of external electrodes 3a and 3b, and one external electrode 3a Current adjustment units 5a and 5b individually interposed between the LED chips 4a and 4b are provided, and the current adjustment units 5a and 5b are configured such that the current values flowing through the LED chips 4a and 4b are substantially equal to each other. Each resistance value is set in.

  As the LED chips 4a and 4b, for example, InGaN-based, InAlGaN-based, GaAs-based, GaP-based or the like that emits red light to ultraviolet light is used. In this embodiment, GaN-based that emits blue light is used. Yes. In the present embodiment, two LED chips are used, but more LED chips may be provided. In particular, it is preferable to arrange the LED chips in an n × n matrix (for example, four LED chips in a matrix of 2 rows and 2 columns) because light can be emitted substantially isotropically.

  The package body 2 is formed in a substantially rectangular parallelepiped shape using ceramics, synthetic resin, or the like, and a substantially cylindrical LED chip housing recess 2a having a diameter that decreases from the front to the rear is provided on the front surface thereof. Yes. A pair of external electrodes 3a and 3b for electrically connecting a circuit board (not shown) and the LED chips 4a and 4b are provided on both outer side surfaces of the package body 2 which are parallel to each other.

  A pair of cathode electrodes (not shown) electrically connected to the cathode terminals of the LED chips 4a and 4b are provided on the bottom surface of the recess 2a. The pair of cathode electrodes is made of Ni, Au, or the like. The wirings L1 and L2 are electrically connected to the external electrode 3b provided on the outer surface of the package body 2. Furthermore, a pair of anode electrodes (not shown) that are electrically connected to the anode terminals of the LED chips 4a and 4b are provided on the bottom surface of the recess 2a. The pair of anode electrodes are electrically connected to an external electrode 3a provided on the outer surface of the package body 2 using wirings L3 and L4 made of Ni, Au, etc., and currents are respectively connected to the wirings L3 and L4. Adjustment parts 5a and 5b are interposed. Therefore, the external electrode 3a is on the anode side, and the external electrode 3b is on the cathode side.

  The current adjustment units 5a and 5b are, for example, chip resistors, and their resistance values are set so that the current values flowing through the LED chips 4a and 4b are substantially equal to each other. Here, the resistance value of each current adjusting part 5a, 5b is determined by the potential difference between the external electrodes 3a, 3b and the forward voltage of each LED chip 4a, 4b measured in advance. For example, if the potential difference between the external electrodes 3a and 3b is V, the forward currents of the LED chips 4a and 4b are Va and Vb, and the resistance values of the current adjusters 5a and 5b are Ra and Rb, Ra: Rb = V The resistance values Ra and Rb may be set so that −Va: V−Vb.

  In the package body 2 described above, the LED chips 4a and 4b and the current adjusting portions 5a and 5b, each having a resistance value selected in accordance with the forward voltage of each LED chip 4a and 4b, are flip-chip mounted, wire By mounting by bonding mounting or the like, as shown in FIG. 1A, a series circuit composed of the current adjustment unit 5a and the LED chip 4a and a series circuit composed of the current adjustment unit 5b and the LED chip 4b are paired. The light emitting device 1 connected in parallel between the external electrodes 3a and 3b is obtained.

  In the light emitting device 1, the resistance values of the current adjusting units 5a and 5b are set so that the current values flowing through the LED chips 4a and 4b are substantially equal to each other. In this case, even if the forward voltage is different between the LED chips 4a and 4b, it is possible to pass a current having a substantially equal value to the LED chips 4a and 4b.

  According to the light emitting device 1 of the present embodiment described above, the two LED chips 4a and 4b are formed on the bottom surface of the recess 2a of the package body 2 while being connected in parallel in the forward direction between the pair of external electrodes 3a and 3b. Since it is mounted, the light output of the light emitting device 1 can be improved while lowering the voltage required for lighting the light emitting device 1. In addition, since the current values flowing through the LED chips 4a and 4b are substantially equal to each other by the current adjusting units 5a and 5b, the current and temperature of the LED chips 4a and 4b are stabilized. The brightness | luminance of LED chip 4a, 4b becomes substantially equal, and there exists an effect that the uniformity of the light-emitting device 1 can be improved.

  By the way, in the above example, the LED chips 4a and 4b and the current adjusting portions 5a and 5b, each having a resistance value selected according to the forward voltage of each LED chip 4a and 4b, are mounted on the package body 2. However, the LED chips 4a and 4b may be mounted on the package body 2 on which the current adjustment units 5a and 5b are mounted in advance. In this case, a plurality of types of package bodies 2 having different resistance values of the mounted current adjustment portions 5a and 5b are prepared, and the optimum one for the LED chips 4a and 4b is selected from such package bodies 2. Thus, it is possible to pass a current having a substantially equal value to each of the LED chips 4a and 4b.

  In this embodiment, the current adjusting portions 5a and 5b are individually provided between the external electrode 3a on the anode side and the LED chips 4a and 4b. However, the external electrode 3b on the cathode side and each LED are provided. The current adjustment units 5a and 5b may be individually provided between the chips 4a and 4b. Furthermore, the current adjustment unit 5a is provided between the external electrode 3a on the anode side and the LED chip 4a, and the cathode side. A current adjusting portion 5b may be provided between the external electrode 3b and the LED chip 4b. In short, it is only necessary that the current adjusting portions 5a and 5b are individually interposed between the external electrodes 3a and 3b and the LED chips 4a and 4b. This also applies to Embodiments 2 to 7 described later.

  In addition, a reflector (not shown) that reflects the light of the LED chips 4a and 4b may be provided on the inner peripheral surface of the recess 2a of the package body 2, and in addition, in the recess 2a of the package body 2, A light diffusing member (not shown) that diffuses the light from the LED chips 4a and 4b, a wavelength conversion member (not shown) that converts the light from the LED chips 4a and 4b into light of a predetermined wavelength, and the LED chips 4a and 4b You may provide the sealing material (not shown) etc. which seal. Furthermore, an optical member such as a condensing lens that condenses the light of the LED chips 4a and 4b or a wide-angle lens may be provided on the front surface of the package body 2. This also applies to Embodiments 2 to 7 described later.

(Embodiment 2)
The light emitting device 10 of the present embodiment is characterized by the configuration of the package body 20, particularly the current adjusting units 50a and 50b, and the other configurations are the same as those of the first embodiment. A description thereof will be omitted.

  As shown in FIG. 2B, the light emitting device 10 of the present embodiment includes a package body 20 having a recess 20a for housing an LED chip, a pair of electrodes 3a and 3b provided on the outer surface of the package body 20, and a pair. A plurality of (two in this embodiment) LED chips 4a and 4b mounted on the bottom surface of the recess 20a in a state where the electrodes 3a and 3b are connected in parallel in the forward direction, and one electrode 3a and the LED chip 4a. , 4b and current adjusting units 50a, 50b that can adjust the resistance value.

  The current adjusting unit 50a individually short-circuits the series circuit 60a including three resistors R1 to R3 connected in series between the external electrode 3a and the anode terminal of the LED chip 4a, and the resistors R1 to R3 of the series circuit 60a. A resistance value adjusting unit 70a. Here, the resistance value adjusting unit 70a includes a terminal part P1 connected between the external electrode 3a and the resistor R1, a terminal part P2 connected between the resistor R1 and the resistor R2, a resistor R2 and a resistor R3. And a terminal portion P4 connected between the resistor R3 and the anode terminal of the LED chip 4a. In the resistance adjusting unit 70a, the resistors R1 to R3 can be individually short-circuited by connecting the terminal portions P1 to P4 with the bonding wires W, whereby the resistance value of the series circuit 60a (that is, the resistance of the current adjusting unit 50a). Value) can be adjusted. On the other hand, the current adjustment unit 50b is similar to the current adjustment unit 50a, and includes a series circuit 60b including three resistors R4 to R6 connected in series between the external electrode 3a and the anode terminal of the LED chip 4b. And a resistance value adjusting unit 70b for individually short-circuiting the resistors R4 to R6 of the series circuit 60b. Here, the resistance value adjusting unit 70b includes a terminal part P5 connected between the external electrode 3a and the resistor R4, a terminal part P6 connected between the resistor R4 and the resistor R5, a resistor R5, and a resistor R6. And a terminal portion P8 connected between the resistor R6 and the anode terminal of the LED chip 4b. In the resistance value adjusting unit 70b, the resistance value of the current adjusting unit 50b can be adjusted by connecting the terminal portions P4 to P8 with the bonding wires W, similarly to the resistance value adjusting unit 70a.

  As shown in FIG. 2B, the package body 20 has a multilayer structure in which seven ceramic sheets (hereinafter abbreviated as “sheets”) S1 to S7 are stacked to form a substantially rectangular parallelepiped shape. The front surface is provided with a substantially cylindrical recess 20a for accommodating an LED chip, the diameter of which decreases from the front to the rear. On the bottom surface of the recess 20a (front surface of the sheet S3), a pair of cathode electrodes (not shown) electrically connected to the cathode terminals of the LED chips 4a and 4b, respectively, and anode terminals of the LED chips 4a and 4b, A pair of anode electrodes (not shown) that are electrically connected to each other are provided. A pair of external electrodes 3a and 3b are provided on both outer side surfaces of the package body 20 parallel to each other.

  Furthermore, the sheet S2 of the package body 20 is provided with resistors R1 and R4, the sheet S4 is provided with resistors R2 and R5, and the sheet S6 is provided with resistors R3 and R6. Accordingly, the resistors R1, R4, the resistors R2, R5, and the resistors R3, R6 are located in different positions in the thickness direction of the package body 20, and are embedded in the package body 20 so as not to overlap in the thickness direction of the package body 20. Has been. On the other hand, the sheets S2 to S7 are provided with a pair of through holes 20b and 20b for the resistors R1 and R4, and the sheets S4 to S7 are provided with a pair of through holes 20c and 20c for the resistors R2 and R4. The sheets S6 and S7 are provided with a pair of through holes 20d and 20d for the resistors R3 and R6. These through holes 20b to 20d are filled with a conductive resin or the like, respectively, whereby the terminal portions P1 to P8 of the resistors R1 to R6 are exposed on the front surface of the package body 20. In this way, the resistors R1 to R6 and the terminal portions P1 to P8 are embedded in the package body 20.

  In addition, although not shown in FIG. 2 (b), these sheets S1 to S7 are individually provided with current adjusting portions 50a and 50b between the external electrode 3a and a pair of cathode electrodes (not shown). And wiring for connecting the external electrode 3b and a pair of anode electrodes (not shown).

  By mounting the LED chips 4a and 4b on the package body 20 described above by flip chip mounting, wire bonding mounting, or the like, as shown in FIG. 2A, the current adjusting unit 50a and the LED chip 4a are formed. The light emitting device 10 in which the series circuit and the series circuit including the current adjustment unit 50b and the LED chip 4b are connected in parallel between the pair of electrodes 3a and 3b is obtained.

  In the light emitting device 10 thus obtained, the resistors R1 to R3 of the series circuit 60a are connected in series to the LED chip 4a, and the resistors R4 to R6 of the series circuit 60b are connected in series to the LED chip 4b. At this time, the series circuit 60a Is the total value of the resistors R1 to R3, and the resistance value of the series circuit 60b is the total value of the resistors R4 to R6.

  Next, a method for adjusting the resistance value in the current adjusting units 50a and 50b will be described. First, operating power is supplied to the light emitting device 10, and the current values flowing through the LED chips 4a and 4b are measured using a probe (probe) not shown. Here, if the current values flowing through the LED chips 4a and 4b are substantially equal to each other, the operation is finished without performing the next adjustment. On the other hand, if the current values flowing through the LED chips 4a and 4b are not substantially equal to each other, based on the measurement results, the terminal portions P1 to P4 of the resistance value adjusting unit 70a and the terminal portions P5 to P5 of the resistance value adjusting unit 70b are used. P8 is selectively connected by a bonding wire W to short-circuit desired resistors R1 to R6, whereby each of the series circuits 60a and 60b so that the current values flowing through the LED chips 4a and 4b are substantially equal to each other. Adjust the resistance value. For example, by connecting the terminal portions P5 and P6 with the bonding wire W, the resistance value of the series circuit 60b of the current adjusting unit 50b becomes the total value of the resistors R5 and R6, thereby increasing the current flowing through the LED chip 4b. It becomes possible to do.

  Thus, by adjusting the resistance values of the current adjusting units 50a and 50b by the resistance value adjusting units 70a and 70b, the forward voltage differs between the LED chips 4a and 4b when operating power is supplied to the light emitting device 10. Even so, it is possible to pass a current having a substantially equal value to each of the LED chips 4a and 4b.

  Therefore, according to the light emitting device 10 of the present embodiment described above, in addition to the same effect as that of the first embodiment, there is an effect that the current flowing through the LED chips 4a and 4b can be easily adjusted. .

  Further, since the resistors R1 to R6 of the current adjusting units 50a and 50b are embedded in the package body 20 so as to be located at different positions in the thickness direction of the package body 20, the mounting density of the light emitting device 10 is improved (small size). The effect that it can aim at () is achieved. In addition, since the terminal portions P1 to P8 of the resistors R1 to R6 are exposed on the front surface of the package body 20, the effect of facilitating connection by the bonding wires W is achieved.

  Incidentally, the package body is not limited to the example shown in FIG. 2B, and for example, a package body 21 as shown in FIG. 3A may be used.

  As shown in FIG. 3A, the package main body 21 has a multilayer structure formed by stacking seven sheets S1 to S7 in a substantially rectangular parallelepiped shape, like the package main body 20, and has a front surface. Is provided with a recess 21a having the same shape as the recess 20a. The bottom surface of the recess 21a (the front surface of the sheet S3) is provided with the pair of cathode electrodes (not shown) and the pair of anode electrodes (not shown). A pair of external electrodes 3a and 3b are provided on the side surfaces.

  Further, resistors R1 to R3 are embedded in the sheets S6 and S7 of the package main body 21, and resistors R4 to R6 are embedded in the sheets S3 and S4, whereby the resistors R1 to R3 and the resistors R4 to R6 are embedded in the package main body 21. It is located in a different position in the thickness direction. In addition, one through hole 21b to 21d is provided on each side surface of the sheets S6 and S7 where the external electrodes 3a and 3b are not provided. In addition, one through hole 21b to 21d is provided on each side surface of the sheets S3 and S4 where the external electrodes 3a and 3b are not provided. These through holes 21b to 21d are filled with conductive resin or the like, respectively, whereby the terminal portions P1 to P8 of the resistors R1 to R6 are exposed on the front surface of the package body 21. In this way, the resistors R1 to R6 and the terminal portions P1 to P8 are embedded in the package body 21.

  In addition, although not shown in FIG. 3A, the sheets S1 to S7 are individually provided with current adjusting portions 50a and 50b between the external electrode 3a and a pair of cathode electrodes (not shown). And wiring for connecting the external electrode 3b and a pair of anode electrodes (not shown).

  When the package body 21 described above is employed, unlike the package body 20 described above, the bonding wires W and the terminal portions P1 to P8 are difficult to see from the front side of the package body, and the aesthetics of the light emitting device 10 are improved. Is possible.

  Furthermore, the package body is not limited to the example shown in FIGS. 2B and 3A, and for example, a package body 22 as shown in FIG. 3B may be used.

  As shown in FIG. 3 (b), the package body 22 has a multilayer structure formed by stacking seven sheets S1 to S7 into a substantially rectangular parallelepiped shape, like the package body 20, and has a front surface. Is provided with a recess 22a having the same shape as the recess 20a. The bottom surface of the recess 22a (the front surface of the sheet S3) is provided with the pair of cathode electrodes (not shown) and the pair of anode electrodes (not shown). A pair of external electrodes 3a and 3b are provided on the side surfaces.

  Furthermore, resistors R1 to R3 and resistors R4 to R6 are embedded in the sheets S6 and S7 of the package body 22 so as to face each other with the recess 22a interposed therebetween. In addition, through holes 22b to 22d are provided in portions corresponding to the sheets S6 and S7 in the recess 22a. These through holes 22b to 22d are filled with a conductive resin or the like, respectively, whereby the terminal portions P1 to P8 of the resistors R1 to R6 are exposed on the inner peripheral surface of the recess 22a. In this way, the resistors R1 to R6 and the terminal portions P1 to P8 are embedded in the package body 20.

  In addition, although not shown in FIG. 3 (b), these sheets S1 to S7 are individually provided with current adjusting portions 50a and 50b between the external electrode 3a and a pair of cathode electrodes (not shown). And wiring for connecting the external electrode 3b and a pair of anode electrodes (not shown).

  If the package body 22 described above is employed, the bonding wire W is not positioned on the outer surface of the package body, unlike the package bodies 20 and 21 described above, and therefore the bonding wire W is disconnected due to an external factor. Can be prevented, and the bonding wire can be protected. In this case, it becomes possible to further protect the bonding wire by filling the recess 22a with a resin or arranging an optical member such as a lens or a wavelength conversion member having a phosphor so as to close the recess 22a. .

  The resistance values of the resistors R1 to R6 may be the same value or different values, and if the resistance values of the resistors R1 to R6 are appropriately changed according to the LED chips 4a and 4b to be used. Good. In addition, the number of resistors constituting the series circuit of the current adjusting unit is not limited to three as described above, and more resistors may be connected in series, or conversely, two resistors are connected in series. A suitable one may be used depending on the situation. This also applies to Embodiments 3 to 5 described later.

(Embodiment 3)
The light emitting device 11 of the present embodiment is characterized by the configuration of the package body 23, in particular, the current adjusting units 51a and 51b, and the other configurations are the same as those of the second embodiment. A description thereof will be omitted.

  As shown in FIG. 4A, the current adjusting unit 51a according to the present embodiment includes three resistors R1 to R3 connected in series, and one end (resistor R1) is connected to one of the external electrodes 3a. 61a and a resistance value adjusting unit 71a. Here, the resistance value adjusting unit 71a includes a terminal unit P1 connected between the resistors R1 and R2, a terminal unit P2 connected between the resistors R2 and R3, and an end of the series circuit 61a. The terminal portion P3 connected to the end portion of the resistor R3 (the end portion not connected to the resistor R2) and the terminal portion P4 connected to the anode terminal of the LED chip 4a. In the resistance value adjusting unit 71a, by selecting a terminal portion connected to the terminal portion P4 and the bonding wire W from the terminal portions P1 to P3 (from the resistors R1 to R3 of the series circuit 61a, the LED chip 4a The resistance value of the series circuit 61a (that is, the resistance value of the current adjusting unit 51a) can be adjusted by selecting a resistance connected to the anode terminal of the current adjusting unit 51a. The current adjustment unit 51b is similar to the current adjustment unit 51a, and includes a series circuit 61b including three resistors R4 to R6 connected in series, and one end (resistance R4) connected to one of the external electrodes 3a. And a resistance value adjusting unit 71b. Here, the resistance value adjusting unit 71b includes a terminal unit P5 connected between the resistors R4 and R5, a terminal unit P6 connected between the resistors R5 and R6, and a terminal of the series circuit 61b. The terminal portion P7 connected to the end portion of the resistor R6 (the end portion not connected to the resistor R5) and the terminal portion P8 connected to the anode terminal of the LED chip 4b. And in this resistance value adjustment part 71b, like the said resistance value adjustment part 71a, by selecting the terminal part connected with the terminal part P8 and the bonding wire W from the terminal parts P5-P7, the current adjustment part 61 The resistance value can be adjusted.

  The package body 23 has a configuration similar to that of the package body 20, and differs from the second embodiment in that current adjustment units 51a and 51b are provided instead of the current adjustment units 50a and 50b. In addition, the package body 23 may have the same configuration as the package bodies 21 and 22.

  By mounting the LED chips 4a and 4b on the package body 23 described above by flip chip mounting, wire bonding mounting, or the like, as shown in FIG. 4A, the current adjusting unit 51a and the LED chip 4a are formed. The light emitting device 11 in which the series circuit and the series circuit including the current adjusting unit 51b and the LED chip 4b are connected in parallel between the pair of external electrodes 3a and 3b is obtained.

  Next, a method for adjusting the resistance value in the current adjusting units 51a and 51b will be described. First, while operating power is supplied to the light emitting device 11, any one of the terminal portions P1 to P3 and the terminal portion P4 and any of the terminal portions P5 to P7 and the terminal portion using a probe (probe) not shown. P8 is connected to each other, and in this state, the current value flowing through each LED chip 4a, 4b is measured.

  Here, if the current values flowing through the LED chips 4a and 4b are substantially equal to each other, the operation is finished without performing the next adjustment. On the other hand, if the current values flowing through the LED chips 4a and 4b are not substantially equal to each other, the terminal portions P1 to P3 and P5 to P7 connected to the terminal portions P4 and P8 are changed based on the measurement result, A search is made for a combination that provides resistance values at which the values of currents flowing through the LED chips 4a and 4b are substantially equal to each other. After finding a combination in which the current values flowing through the LED chips 4a and 4b are substantially equal to each other in this way, the terminal portions are connected using the bonding wires W. For example, by connecting the terminal portions P2 and P4 in the current adjusting portion 51a and the terminal portions P6 and P8 in the current adjusting portion 51b with bonding wires W, the resistance value of the current adjusting portion 51a is the resistance R1 or R2. The total value and the resistance value of the current adjusting unit 51b become the total value of the resistors R4 and R5.

  As described above, according to the light emitting device 11 of the present embodiment, when the operating power is supplied to the light emitting device 11 by adjusting the resistance values of the current adjusting units 51a and 51b by the resistance value adjusting units 71a and 71b. Even if the forward voltages are different between the LED chips 4a and 4b, it is possible to pass a current having a substantially equal value to the LED chips 4a and 4b.

  In the example shown in FIG. 4A, the series circuits 61a and 61b of the current adjusting units 51a and 51b are connected to the external electrode 3a, and the LEDs are selected from the resistors R1 to R3 and R4 to R6 of the series circuits 61a and 61b. The resistors connected to the anode terminals of the chips 4a and 4b are selected, but the series circuits 61a and 61b of the current adjusting units 51a and 51b are connected to the anode terminals of the LED chips 4a and 4b, and the series circuits 61a and 61b. The resistors connected to the external electrode 3a may be selected from the resistors R1 to R3 and R4 to R6.

(Embodiment 4)
The light emitting device 12 of the present embodiment is characterized by the configuration of the package body 24, in particular, the current adjustment units 52a and 52b, and the other configurations are the same as those of the second embodiment. A description thereof will be omitted.

  As shown in FIG. 4B, the current adjustment unit 52a of the present embodiment includes a parallel circuit 62a including three resistors R1 to R3 each having one end connected to the anode terminal of the LED chip 4a, and a resistance value adjustment unit. 72a. Here, the resistance value adjustment unit 72a includes terminal portions P1 to P3 connected to the other ends of the resistors R1 to R3, and a terminal portion P4 connected to the external electrode 3a. In the resistance value adjusting unit 72a, by selecting a terminal portion connected to the terminal portion P4 and the bonding wire W from the terminal portions P1 to P3 (from the resistors R1 to R3 of the series circuit 62a, the external electrode 3a The resistance value of the series circuit 62a (that is, the resistance value of the current adjusting unit 52a) can be adjusted. The current adjustment unit 52b is similar to the current adjustment unit 52a, and includes a parallel circuit 62b composed of three resistors R4 to R6 each having one end connected to the anode terminal of the LED chip 4b, and a resistance value adjustment unit 72b. And. Here, the resistance value adjusting unit 72b includes terminal portions P5 to P7 connected to the other ends of the resistors R4 to R6, and a terminal portion P8 connected to the external electrode 3a. And in this resistance value adjustment part 72b, like the said resistance adjustment part 72a, by selecting the terminal part connected with the terminal part P8 and the bonding wire W from the terminal parts P5-P7, the current adjustment part 52b. The resistance value can be adjusted.

  The package body 24 has a configuration similar to that of the package body 20, and differs from the second embodiment in that current adjustment units 52a and 52b are provided instead of the current adjustment units 50a and 50b. In addition, the package body 23 may have the same configuration as the package bodies 21 and 22.

  By mounting the LED chips 4a and 4b on the package body 24 described above by flip chip mounting, wire bonding mounting, or the like, as shown in FIG. 4B, the current adjusting unit 52a and the LED chip 4a are formed. The light emitting device 12 in which the series circuit and the series circuit including the current adjusting unit 52b and the LED chip 4b are connected in parallel between the pair of external electrodes 3a and 3b is obtained.

  Next, a method for adjusting the resistance value in the current adjusting units 52a and 52b will be described. First, while operating power is supplied to the light emitting device 12, any one of the terminal portions P1 to P3, the terminal portion P4, and any one of the terminal portions P5 to P7 and a terminal portion using a probe (probe) not shown. P8 is connected to each other, and in this state, the current value flowing through each LED chip 4a, 4b is measured.

  Here, if the current values flowing through the LED chips 4a and 4b are substantially equal to each other, the operation is finished without performing the next adjustment. On the other hand, if the current values flowing through the LED chips 4a and 4b are not substantially equal to each other, the terminal portions P1 to P3 and P5 to P7 connected to the terminal portions P4 and P8 are changed based on the measurement result, A search is made for a combination that provides resistance values at which the values of currents flowing through the LED chips 4a and 4b are substantially equal to each other. After finding a combination in which the current values flowing through the LED chips 4a and 4b are substantially equal to each other in this way, the terminal portions are connected using the bonding wires W. For example, by connecting the terminal parts P2 and P4 in the current adjustment part 52a and the terminal parts P6 and P8 in the current adjustment part 52b by bonding wires W, the resistance value of the current adjustment part 52a is the resistance value of the resistor R2. The resistance value of the current adjusting unit 51b becomes the resistance value of the resistor R5.

  As described above, according to the light emitting device 12 of the present embodiment, when the operating power is supplied to the light emitting device 12 by adjusting the resistance values of the current adjusting units 52a and 52b by the resistance value adjusting units 72a and 72b. Even if the forward voltages are different between the LED chips 4a and 4b, it is possible to pass a current having a substantially equal value to the LED chips 4a and 4b.

  In the example shown in FIG. 4B, one ends of the resistors R1 to R3 and R4 to R6 of the current adjusting units 52a and 52b are connected to the anode terminals of the LED chips 4a and 4b, respectively, and these resistors R1 to R3 and R4 are connected. The resistor connected to the external electrode 3a is selected from among R6, but one end of each of the resistors R1 to R3 and R4 to R6 of the current adjusting parts 52a and 52b is connected to the external electrode 3a, and the resistors R1 to R1 are connected. You may make it select the resistance connected to the anode terminal of LED chip 4a, 4b from R3, R4-R6.

(Embodiment 5)
The light emitting device 13 of the present embodiment is characterized by the configuration of the package body 25, in particular, the current adjustment units 53a and 53b, and the other configurations are the same as those of the second embodiment. A description thereof will be omitted.

  As shown in FIG. 5A, the current adjustment unit 53a of the present embodiment includes a parallel circuit 63a including three resistors R1 to R3 each having one end connected to the anode terminal of the LED chip 4a, and a resistance value adjustment unit. 73a. Here, the resistance value adjusting unit 73a includes terminal portions P1a to P3a connected to the other ends of the resistors R1 to R3, and terminal portions P1b to P3b connected to the external electrode 3a, respectively. The terminal portion P1a , P1b, terminal portions P2a, P2b, and terminal portions P3a, P3b are connected by bonding wires W, respectively. In the resistance value adjusting unit 73a, the bonding wire W is cut (by cutting off the energization to the parallel circuit 63a by selecting the resistors R1 to R3 that cut off the energization). The resistance value (that is, the resistance value of the current adjusting unit 53a) can be adjusted. The current adjustment unit 53b includes a parallel circuit 63b composed of three resistors R4 to R6, one end of which is connected to the anode terminal of the LED chip 4b, and a resistance value adjustment unit 73b. Here, the resistance value adjusting unit 73b includes terminal portions P4a to P6a connected to the other ends of the resistors R4 to R6, and terminal portions P4b to P6b connected to the external electrode 3a, respectively. The terminal portion P4a , P4b, terminal portions P5a, P5b, and terminal portions P6a, P6b are connected by bonding wires W, respectively. In the resistance value adjusting unit 73b, the resistance value of the current adjusting unit 53b can be adjusted by cutting the bonding wire W in the same manner as the resistance value adjusting unit 73a.

  The package body 25 has the same configuration as that of the package body 20, and differs from the second embodiment in that current adjustment units 53a and 53b are provided instead of the current adjustment units 50a and 50b. In addition, the package body 23 may have the same configuration as the package bodies 21 and 22.

  By mounting the LED chips 4a and 4b on the package body 25 described above by flip chip mounting, wire bonding mounting, or the like, as shown in FIG. 5A, the current adjusting unit 53a and the LED chip 4a are formed. The light emitting device 13 in which the series circuit and the series circuit including the current adjusting unit 53b and the LED chip 4b are connected in parallel between the pair of external electrodes 3a and 3b is obtained.

  Next, a method for adjusting the resistance value in the current adjusting units 53a and 53b will be described. First, an operating power is supplied to the light emitting device 13 and a current value flowing through each LED chip 4a, 4b is measured using a probe (probe) not shown. Here, if the current values flowing through the LED chips 4a and 4b are substantially equal to each other, the operation is finished without performing the next adjustment. On the other hand, if the current values flowing through the LED chips 4a and 4b are not substantially equal to each other, the bonding wires W of the resistance value adjusting unit 73a and the resistance value adjusting unit 70b are selectively cut based on the measurement result. The energization of the desired resistors R1 to R6 is cut off, and thereby the resistance values of the series circuits 63a and 63b are adjusted so that the current values flowing through the LED chips 4a and 4b are substantially equal to each other. In the example shown in FIG. 5A, the bonding wire W is not cut.

  As described above, according to the light emitting device 13 of the present embodiment, when the operation power is supplied to the light emitting device 13 by adjusting the resistance values of the current adjusting units 53a and 53b by the resistance value adjusting units 73a and 73b. Even if the forward voltages are different between the LED chips 4a and 4b, it is possible to pass a current having a substantially equal value to the LED chips 4a and 4b.

  In the example shown in FIG. 5A, one ends of the resistors R1 to R3 and R4 to R6 of the current adjusting units 53a and 53b are connected to the anode terminals of the LED chips 4a and 4b, respectively, and these resistors R1 to R3 and R4 are connected. ~ R6 is connected to the external electrode 3a in advance by the bonding wire W, but one end of each of the resistors R1 to R3 and R4 to R6 of the current adjusting portions 53a and 53b is connected to the external electrode 3a, and the resistors R1 to R1 are connected. R3, R4 to R6 may be connected in advance to the anode terminals of the LED chips 4a and 4b with bonding wires W.

  In the example shown in FIG. 5A, the bonding wire W is cut. For example, as shown in FIG. 5B, resistors R1 to R4 provided on the package body 26 are blades (see FIG. 5). You may make it cut | disconnect by not shown.

  The circuit configuration of the light-emitting device 14 shown in FIG. 5B has the same circuit configuration as that of the light-emitting device 13 shown in FIG. 5A. However, each current adjusting unit has an external electrode 3a and each LED chip 4a. , 4b is different from the light emitting device 13 in that it includes four resistors connected in parallel with the anode terminals of 4b.

  As shown in FIG. 5B, the package body 26 of the light-emitting device 14 has a multilayer structure formed by stacking seven sheets S1 to S7 into a substantially rectangular parallelepiped shape, similar to the package body 20. The front surface is provided with a recess 26a having the same shape as the recess 20a. The bottom surface of the recess 26a (the front surface of the sheet S3) is provided with the pair of cathode electrodes (not shown) and the pair of anode electrodes (not shown). A pair of external electrodes 3a and 3b are provided on the side surfaces.

  Furthermore, each sheet | seat S4-S7 of this package main body 26 is provided so that each resistance R1-R4 of the electric current adjustment part for LED chip 4a may overlap in the thickness direction. The package body 26 is provided with slits 26b in the thickness direction of the package body 26 for exposing portions of the resistors R1 to R4. Since this point is the same in the current adjustment unit for the LED chip 4b, the description thereof is omitted. Although not shown in FIG. 5B, each of the current adjusting portions is individually connected to the sheets S1 to S7 between the external electrode 3a and a pair of cathode electrodes (not shown). Wiring for connecting the external electrode 3b and a pair of anode electrodes (not shown) is provided.

  And in this light-emitting device 14, the resistance value of each electric current adjustment part is adjusted with the method similar to the light-emitting device 13, However In the light-emitting device 13, the bonding wire W is cut | disconnected and the resistance value is adjusted. On the other hand, the light emitting device 14 differs in that the resistance value is adjusted by inserting a blade or the like into the slit 26b and cutting the resistance. FIG. 5B shows an example in which the resistors R1 and R2 are cut with a blade.

  Therefore, according to the light emitting device 14, the same effect as that of the light emitting device 13 can be obtained, and it is possible to cut off the power supply to the resistor simply by inserting a blade or the like into the slit 26 b. Compared with the case where the bonding wires W are sequentially cut, the workability of the adjustment work can be improved. Moreover, since the cut bonding wire W does not remain, the aesthetics of the light emitting device can be improved.

  In the example shown in FIG. 5B, the resistor is cut directly, but instead of the resistor, a wire electrically connected to the resistor is exposed to the slit 26b, and such a wire is exposed by a blade. You may make it cut | disconnect.

(Embodiment 6)
As shown in FIG. 6A, the light emitting device 15 of the present embodiment includes a package body 27 having a recess (not shown) for housing the LED chip, and a pair of external electrodes 3 a provided on the outer surface of the package body 27. , 3b, two LED chips 4a, 4b mounted on the bottom surface of the recess while being connected in parallel in the forward direction between the pair of external electrodes 3a, 3b, and one external electrode 3a and the LED chips 4a, 4b. Current adjusting units 8a and 8b individually interposed between the current adjusting units 8a and 8b, and the current adjusting units 8a and 8b have resistance values so that the current values flowing through the LED chips 4a and 4b are substantially equal to each other. Is set. In addition, about the structure similar to the said Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The package body 27 is formed in a substantially rectangular parallelepiped shape using a ceramic material or a synthetic resin material, and a substantially cylindrical recess (not shown) is provided on the front surface thereof. In addition, a pair of external electrodes 3a and 3b for electrically connecting a circuit board (not shown) and the LED chips 4a and 4b are provided on both outer side surfaces of the package body 27 parallel to each other. 3a is used as the anode side, and the external electrode 3b is used as the cathode side.

  A pair of cathode electrodes (not shown) electrically connected to the cathode terminals of the LED chips 4a and 4b are provided on the bottom surfaces of the recesses. The pair of cathode electrodes (not shown) includes Ni, Au, and the like. Are electrically connected to the external electrode 3b provided on the outer surface of the package body 27. Furthermore, a pair of anode electrodes (not shown) that are electrically connected to the anode terminals of the LED chips 4a and 4b are provided on the bottom surface of the recess. The pair of anode electrodes (not shown) are electrically connected to the external electrode 3a provided on the outer surface of the package body 27 using wirings L3 and L4 made of Ni, Au, etc., and are connected to the wirings L3 and L4. Are respectively provided with current adjusting portions 8a and 8b.

  The current adjusting units 8a and 8b are so-called trimmable chip resistors whose resistance values can be adjusted by laser trimming, and the resistance values are such that the current values flowing through the LED chips 4a and 4b are substantially equal to each other. Adjusted to

  By mounting the LED chips 4a and 4b on the package body 27 described above by flip chip mounting, wire bonding mounting, or the like, as shown in FIG. 6A, the current adjusting unit 8a and the LED chip 4a are formed. The light emitting device 15 in which the series circuit and the series circuit including the current adjusting unit 8b and the LED chip 4b are connected in parallel between the pair of external electrodes 3a and 3b is obtained.

  Next, a method for adjusting the resistance value in the current adjusting units 8a and 8b will be described. First, operating power is supplied to the light emitting device 15, and the value of current flowing through each LED chip 4a, 4b is measured using a probe (probe) not shown. Here, if the current values flowing through the LED chips 4a and 4b are substantially equal to each other, the operation is finished without performing the next adjustment. On the other hand, if the current values flowing through the LED chips 4a and 4b are not substantially equal to each other, the current adjusting units 8a and 8b are laser-trimmed on the basis of the measurement results, thereby causing the currents flowing through the LED chips 4a and 4b. The resistance values of the current adjusting units 8a and 8b are adjusted so that the values are substantially equal to each other.

  Thus, by adjusting the resistance values of the current adjusting units 8a and 8b by laser trimming, even if the forward voltages are different between the LED chips 4a and 4b, the currents having substantially the same value as the LED chips 4a and 4b. It becomes possible to flow.

  Therefore, according to the light emitting device 15 of the present embodiment described above, in addition to the same effects as those of the first embodiment, there is an effect that the current flowing through the LED chips 4a and 4b can be easily adjusted. .

(Embodiment 7)
The light emitting device 16 of the present embodiment is characterized by the configuration of the package body 28, particularly the current adjusting units 9a and 9b, and the other configurations are the same as those of the first embodiment. A description thereof will be omitted.

  As shown in FIG. 6B, the light emitting device 16 of the present embodiment includes a package body 28 having a recess 28a for housing the LED chip, a pair of electrodes 3a and 3b provided on the outer surface of the package body 28, and a pair. The two LED chips 4a and 4b are mounted on the bottom surface of the recess 28a while being connected in parallel in the forward direction between the electrodes 3a and 3b, and wiring for connecting the one electrode 3a and the LED chip 4a. A current adjusting unit 9a, and a current adjusting unit 9b made of wiring for connecting one of the electrodes 3a and the LED chip 4b. The current adjusting units 9a and 9b have different current values flowing through the LED chips 4a and 4b. Each resistance value is set so as to be approximately equal. In addition, about the structure similar to the said Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted. In FIG. 6B, only a part of the current adjusting portions 9a and 9b is shown for the sake of simplification of the drawing.

  As shown in FIG. 6B, the package main body 28 has a multilayer structure formed by stacking seven sheets S1 to S7 into a substantially rectangular parallelepiped shape, like the package main body 20. Is provided with a recess 28a having the same shape as the recess 20a. On the bottom surface of the recess 28a (the front surface of the sheet S3), a pair of cathode electrodes (not shown) electrically connected to the cathode terminals of the LED chips 4a and 4b, respectively, and anode terminals of the LED chips 4a and 4b, A pair of anode electrodes (not shown) that are electrically connected to each other are provided. A pair of external electrodes 3a and 3b are provided on both outer side surfaces of the package body 28 parallel to each other.

  Further, the sheets S1 to S7 are provided with current adjusting portions 9a and 9b made of wiring for connecting the external electrode 3a and a pair of cathode electrodes (not shown), and the external electrodes 3b and a pair of anode electrodes ( Wiring (not shown) for connecting to a not-shown is provided. Here, the current adjusting portions 9a and 9b and the wiring (not shown) are formed using a metal material such as Ni or Au, but the same ceramic powder as the sheets S1 to S7 constituting the package body 28 is mixed. Has been.

  As described above, the current adjusting portions 9a and 9b are wiring for connecting the external electrode 3a and a pair of cathode electrodes (not shown), and in this embodiment, the current adjusting portions 9a and 9b are routed so as to meander three-dimensionally. Thus, the path length is lengthened, thereby adjusting the resistance values of the current adjusting portions 9a and 9b so that the current values flowing through the LED chips 4a and 4b are substantially equal to each other.

  By mounting the LED chips 4a and 4b on the package body 28 described above by flip-chip mounting, wire bonding mounting, or the like, as shown in FIG. 6B, a series composed of the current adjusting unit 9a and the LED chip 4a is formed. The light emitting device 16 in which the circuit and the series circuit including the current adjusting unit 9b and the LED chip 4b are connected in parallel between the pair of external electrodes 3a and 3b is obtained. Here, in the present embodiment, a plurality of types of package bodies 28 having different resistance values of the current adjusting portions 9a and 9b are prepared in advance, and the most suitable LED chip 4a and 4b is selected from such package bodies 28. By selecting, the current values of the LED chips 4a and 4b are set to be substantially equal.

  As described above, in the light emitting device 16, the resistance values of the current adjusting units 9a and 9b are set so that the current values flowing through the LED chips 4a and 4b are substantially equal to each other. When a forward voltage is different between the LED chips 4a and 4b, it is possible to pass a current having a substantially equal value to the LED chips 4a and 4b.

  According to the light emitting device 16 of the present embodiment described above, in addition to the same effects as those of the first embodiment, since it is not necessary to use a chip resistor or the like as the current adjusting units 9a and 9b, the number of components can be reduced. The manufacturing cost can be reduced and an inexpensive light emitting device can be provided.

  Further, since the same ceramic powder as the sheets S1 to S7 constituting the package main body 28 is mixed in the current adjusting portions 9a and 9b, the resistance of the current adjusting portions 9a and 9b is increased by the ceramic powder, thereby the current adjusting portion. There is an effect that the path length of the wirings used as 9a and 9b can be shortened. Moreover, since the ceramic powder is mixed, the thermal conductivity between the current adjusting portions 9a and 9b and the package body 28 is improved, so that the heat generated in the current adjusting portions 9a and 9b is efficiently transmitted through the package body 28. The heat is well radiated, so that heat does not stay in the current adjusting portions 9a and 9b, and an increase in the package temperature can be suppressed.

(A) is a schematic explanatory drawing of the light-emitting device of Embodiment 1, (b) is a perspective view. (A) is a schematic explanatory drawing of the light-emitting device of Embodiment 2, (b) is a perspective view. (A) is a perspective view of another light-emitting device, (b) is a perspective view of another light-emitting device. (A) is a schematic explanatory drawing of the light-emitting device of Embodiment 3, (b) is a schematic explanatory drawing of the light-emitting device of Embodiment 4. (A) is a schematic explanatory drawing of the light-emitting device of Embodiment 5, (b) is a perspective view of another light-emitting device. (A) is a schematic explanatory drawing of the light-emitting device of Embodiment 6, (b) is a perspective view of the light-emitting device of Embodiment 7. FIG. (A) is a schematic explanatory drawing of the light-emitting device of a prior art example, (b) is a perspective view. (A) is a schematic explanatory drawing of the other light-emitting device of a prior art example, (b) is a perspective view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 Package main body 2a Recessed part 3a, 3b Electrode 4a, 4b LED chip 5a, 5b Current adjustment part

Claims (8)

  A package body, a pair of electrodes provided on the package body, a plurality of LED chips mounted on the package body in a state of being connected in parallel in the forward direction between the pair of electrodes, and each LED chip between the pair of electrodes. And a current adjusting unit individually connected in series, and each of the current adjusting units has a resistance value set so that current values flowing through the LED chips are substantially equal to each other. .   The current adjusting unit includes a series circuit composed of a plurality of resistors connected in series between one electrode and the LED chip, and a resistance value adjusting unit that adjusts a resistance value by selecting a resistor that is short-circuited in the series circuit. The light emitting device according to claim 1, comprising:   The current adjustment unit selects a series circuit having a plurality of resistors connected in series and one end connected to one of the electrode and the LED chip, and a resistor connecting the remaining one of the plurality of resistors. The light emitting device according to claim 1, further comprising: a resistance value adjusting unit that adjusts the resistance value by adjusting the resistance value.   The current adjustment unit adjusts the resistance value by selecting a parallel circuit composed of a plurality of resistors connected in parallel between one electrode and the LED chip, and a resistor that cuts off current in the parallel circuit. The light emitting device according to claim 1, further comprising: means.   The current adjustment unit is configured to select a plurality of resistors having one end connected to either one of the electrodes and the LED chip and a resistor connecting the other of the plurality of resistors to the other end. The light emitting device according to claim 1, further comprising a resistance value adjusting unit that adjusts the value.   The plurality of resistors are embedded in the package body so as to be located at different positions in the thickness direction of the package body, and terminal portions of the resistors are exposed on the package body. The light-emitting device of description.   2. The light emitting device according to claim 1, wherein the current adjusting unit includes a wiring for connecting one of the electrodes and the LED chip, and a resistance value is set according to a path length of the wiring.   The light emitting device according to claim 7, wherein the package body is formed using a ceramic material, and ceramic powder is mixed in the current adjusting unit.

Images