JP6643831B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device.

  A COB (Chip On Board) light emitting device in which a light emitting element such as an LED (light emitting diode) element is mounted on a general-purpose substrate such as a ceramic substrate or a metal substrate is known. In such a light emitting device, an LED element that emits blue light, for example, is sealed with a resin containing a fluorescent substance, and light obtained by exciting the fluorescent substance with light from the LED element is mixed. Obtain white light and so on.

  For example, Patent Literature 1 discloses a heat-dissipating base having high heat conductivity having a mounting surface for die bonding, a hole placed on the heat-dissipating base and exposing a part of the mounting surface, and an outer portion of the heat-dissipating base. A circuit board having a projecting portion projecting outward from the periphery, a light emitting element mounted on the mounting surface through the hole, and a light transmitting resin body sealing above the light emitting element; A light emitting diode is described in which a through hole is formed on the outer peripheral edge of the protruding portion and is electrically connected to the light emitting element, and external connection electrodes are provided on the upper and lower surfaces of the through hole.

  Patent Document 2 discloses a cavity having a concave portion, a convex heat slug (pedestal portion) attached to the cavity so as to penetrate the bottom of the concave portion, and a submount substrate mounted on the heat slug. And a plurality of LED chips arranged on the submount substrate, a lead frame electrically connected to each LED chip, a phosphor layer enclosing each LED chip, and a silicone resin sealed in the recess. An LED package is described having a lens.

  There is also known an illumination device in which a plurality of LEDs are integrated and arranged to increase the amount of light. For example, Patent Literature 3 discloses a lens array in which a plurality of LEDs 3, a substrate 4 on which these LEDs 3 are mounted, and a plurality of lens elements for condensing or diverging irradiation light emitted from the LEDs are integrated. 2 is described.

JP 2006-005290 A JP 2010-170945 A JP 2012-042670 A

  In order to obtain a high amount of parallel light, a plurality of light emitting units each including a light emitting element such as a plurality of LED elements are formed on one common substrate, and light emitted from each light emitting unit corresponds to the light emitting unit. Consider manufacturing a light emitting device that collects and emits light with a lens. In such a light emitting device, the number of LED elements included in one light emitting unit can be changed for each light emitting unit so that the forward voltage of the LED device as a whole falls within a range that can be driven by the driver used. is there. However, if the number of elements is changed for each light emitting unit, the light emitting diameter also changes. Therefore, in order to optimize the light collection efficiency, the size of the lens needs to be adjusted for each light emitting unit in accordance with the light emitting diameter. In this case, it is necessary to prepare a plurality of types of lens arrays when manufacturing the light emitting device, which causes an increase in manufacturing cost.

  Therefore, an object of the present invention is to make it possible to use a lens array including a plurality of common lenses as a lens array for condensing light from each light emitting unit regardless of the number of light emitting elements included in each of the plurality of light emitting units. That is, the manufacturing cost of the light emitting device is reduced.

  A substrate, a plurality of light-emitting units disposed on the substrate, and a plurality of lenses provided corresponding to each of the plurality of light-emitting units to collect light emitted from the light-emitting units; Each of the plurality of light emitting units is divided into a plurality of columns connected in parallel to each other, and the number of light emitting units set in each of the plurality of columns is connected in series to each other. A plurality of light emitting elements, and the size of the plurality of light emitting elements is smaller as the number of light emitting elements connected in series is larger.

In the above light emitting device, it is preferable that the areas of the light emitting regions of the plurality of light emitting units are equal to each other.
The light emitting device further includes a driver for driving the plurality of light emitting units, the light emitting element is an LED element, and the sum of the forward voltages of the LED elements connected in series among the plurality of light emitting units is driven by the driver. It is preferable that the number of LED elements connected in series in each of the plurality of light emitting units is set so as to fall within the range of possible voltages.

  According to the present invention, regardless of the number of light emitting elements included in each of the plurality of light emitting units, it is possible to use a lens array including a plurality of common lenses as a lens array that collects light from each light emitting unit, The manufacturing cost of the light emitting device can be reduced.

It is the front view and back view of the lighting device 1. FIG. It is a top view and a side view of the light emitting device 2. FIG. 3 is a top view of the lens array 40. 3A and 3B are a top view and a vertical cross-sectional view of the light emitting unit 20. FIG. 3 is an overall circuit diagram of the light emitting device 2. FIG. _{3 is} a top view of the light emitting unit 203. FIG. 3 is a diagram schematically illustrating an arrangement of LED elements 30 in the light emitting device 2. 6 is a flowchart illustrating an example of a manufacturing process of the light emitting device 2. FIG. 3 is a diagram illustrating an example of a method of fixing a lens array 40 to a substrate 10. FIG. 4 is a diagram illustrating an example of a method of positioning the substrate 10 and the lens array 40. It is the top view and side view of light emitting device 2A. It is a top view of 20 A of light emission parts. It is a figure showing typically arrangement of LED element 30 in light emitting device 2B. It is a top view of the light emitting device 2C and the light emitting part 20C in the light emitting device 2C. It is a figure showing typically arrangement of LED element 30 in light emitting device 2D. It is a figure showing typically arrangement of LED element 30 in light emitting device 2E. It is the top view and side view of light emitting device 2F. It is the top view and longitudinal section of light emitting part 20G.

  Hereinafter, a light emitting device and a manufacturing method thereof will be described with reference to the drawings. However, it should be understood that the invention is not limited to the drawings or the embodiments described below.

  FIG. 1A and FIG. 1B are a front view and a rear view of the lighting device 1. The lighting device 1 is a device that can be used, for example, as a floodlight for lighting, and has, as an example, a total of six light emitting devices 2 arranged in two rows and three columns as shown in FIG. The lighting device 1 is configured as one device by disposing the cases (casings) 3 of the respective light emitting devices 2 in close proximity. The number of the light emitting devices 2 included in one lighting device includes various examples other than those illustrated, for example, two, four, or eight or more. As shown in FIG. 1B, the lighting device 1 has a radiation fin (heat sink) 4 on the back surface of the case 3 of each light emitting device 2 for promoting the release of heat generated in the light emitting device 2.

  FIG. 2A and FIG. 2B are a top view and a side view of the light emitting device 2. As shown in FIGS. 2A and 2B, the light emitting device 2 includes a substrate 10, a plurality of light emitting units 20 formed on the substrate 10, and a plurality of light emitting units 20. A lens array 40. Further, as shown in FIGS. 1B and 2B, each light emitting device 2 has a radiation fin 4 on the back surface of the substrate 10 for radiating heat generated by the plurality of light emitting units 20.

  The substrate 10 is a substantially rectangular substrate having a circular opening 13 in the center. For example, the vertical and horizontal lengths of the substrate 10 are each about 10 cm, and the thickness of the substrate 10 is about 1 to 2 mm. The substrate 10 is configured by, for example, bonding a circuit substrate 12 on a metal substrate 11 with an adhesive sheet. The end of the substrate 10 is fixed to the case 3 of the light emitting device 2 shown in FIG.

  The metal substrate 11 functions as a mounting substrate for mounting the light emitting unit 20 and a heat radiating substrate for radiating heat generated in the light emitting unit 20, and thus is made of, for example, aluminum having excellent heat resistance and heat radiation. However, the material of the metal substrate 11 may be another metal such as copper as long as it is excellent in heat resistance and heat dissipation.

  The circuit board 12 is an insulating substrate such as a glass epoxy substrate, a BT resin substrate, a ceramic substrate, or a metal core substrate. On the upper surface of the circuit board 12, a wiring pattern 14 for electrically connecting the plurality of light emitting units 20 to each other is formed. On the right end of the circuit board 12 shown in FIG. 2A, two connection electrodes 15 for connecting the light emitting device 2 to an external power supply are formed. One of the connection electrodes 15 is a positive electrode and the other is a negative electrode. When these are connected to an external power supply and a voltage is applied, the plurality of light emitting units 20 of the light emitting device 2 emit light.

  The light emitting units 20 are a plurality of independent light emitting units formed on the substrate 10 as one common substrate, and are evenly arranged on the substrate 10 so as to surround the opening 13. In the illustrated example, the light emitting device 2 has 22 light emitting units 20. As described below, each light emitting unit 20 has a plurality of LED elements (an example of a light emitting element). In order to make the light emitted from the light emitting device 2 uniform, it is preferable that the interval (pitch) between the light emitting units 20 is a fixed size. However, the pitch of the light emitting units 20 may be different between the vertical direction and the horizontal direction of the substrate 10.

  FIG. 3 is a top view of the lens array 40. The lens array 40 is an assembly of lenses in which a plurality of lenses 41 are formed integrally. In the illustrated example, the lens array 40 has 22 lenses 41 arranged close to each other except for the center. The central portion 42 of the lens array 40 is preferably an opening. As shown in FIG. 2B, the optical axis X of each lens 41 coincides with the normal direction of the substrate 10. Each lens 41 is provided in the same arrangement as the light emitting unit 20 on the substrate 10 corresponding to each light emitting unit 20, and collects light emitted from the corresponding light emitting unit 20. Each lens 41 has, for example, the same shape and size. The end of the lens array 40 is fixed to the case 3 of the light emitting device 2 shown in FIG. In particular, in the application of the floodlight, it is required that the light emitting device 2 be configured as small as possible so that the resistance received by the wind during use is small. For this reason, it is preferable that the adjacent lenses 41 be in contact with each other without an interval so as to increase the density of the lens 41 portion with respect to the entire lens array 40. Since the light emitting unit 20 and the lens 41 have a one-to-one correspondence, the pitch of the light emitting unit 20 is determined by the diameter of the lens 41.

  As described above, the substrate 10 has the opening 13 at the center. The opening 13 is formed at the same position on the metal board 11 and the circuit board 12. It is preferable that the lens 41 is not disposed above the opening 13 and the lens array 40 is open above the opening 13. The shape of the opening 13 is not limited to a circle, but may be another shape such as a rectangle, and the position of the opening 13 may not be strictly at the center of the substrate 10. In the light emitting device 2, the presence of the opening 13 in the substrate 10 is advantageous from the viewpoint of heat dissipation as described below.

  First, in the light emitting device 2, since the metal substrate 11 is exposed at the edge of the opening 13, the area where the metal substrate 11 is in contact with the outside air is increased. As a result, part of the heat transmitted from the light emitting unit 20 (light emitting element) to the metal substrate 11 is also radiated outside the device from the edge of the opening 13. Further, in the light emitting device 2, the radiation fins 4 on the back side of the substrate 10 come into contact with the outside air even on the front side of the substrate 10 through the opening 13, so that the area where the radiation fins 4 come into contact with the outside air also increases. As a result, part of the heat transmitted from the metal substrate 11 to the radiation fins 4 is also released to the front side of the substrate 10 through the opening 13. Therefore, in the light emitting device 2, the opening 13 allows the heat generated in each light emitting unit 20 (light emitting element) to be released to the outside of the device.

  From the viewpoint of heat dissipation, the diameter of the opening 13 needs to have a certain size. For example, the diameter d1 of the opening 13 is preferably larger than at least the diameter d2 of each light emitting unit 20, and more preferably larger than the arrangement interval (pitch) d3 of the plurality of light emitting units 20. In the illustrated example, the pitch d3 of the light emitting units 20 is larger than the diameter d2 of the light emitting units 20.

  In addition, as shown in FIG. 2A, an inspection terminal 16 for checking the operation (lighting) of the light emitting unit 20 is provided on the upper surface of the circuit board 12 for each light emitting unit 20. The inspection terminals 16 are arranged so as to sandwich the corresponding light emitting unit 20 with two terminals as one set. Although the inspection terminals 16 are arranged outside the light emitting units 20, the wiring pattern 14 for simultaneously lighting the plurality of light emitting units 20 is provided on the circuit board 12. If the distance from the part 20 is too great, it is difficult to route the wiring. Therefore, as shown in FIG. 2A, each set of the inspection terminals 16 is formed on the circuit board 12 at a position within the diameter of the main surface of the lens 41 corresponding to the target light emitting unit 20. .

  In addition, in order to prevent erroneous measurement, the two terminals constituting each set of the inspection terminals 16 are uniformly arranged with a common interval d between the plurality of light emitting units 20. Furthermore, if possible in relation to the wiring pattern 14, it is preferable that the two terminals constituting each set of the inspection terminals 16 be arranged at a common angle with respect to the side of the substrate 10. In this way, if the arrangement of the plurality of sets of the inspection terminals 16 is aligned, it is easy to confirm the operation of each light emitting unit 20 when confirming the operation of the light emitting unit 20 in order, and to reduce the frequency of occurrence of erroneous measurement. It becomes possible to lower.

  4A to 4C are a top view and a longitudinal sectional view of the light emitting unit 20. FIG. More specifically, FIG. 4A is a top view of the light emitting unit 20, FIG. 4B is a cross-sectional view taken along the line IVB-IVB of FIG. 4A, and FIG. 4) is a sectional view taken along the line IVC-IVC. The light emitting section 20 has a plurality of LED elements 30, a sealing frame 23, and a sealing resin 24 as main components.

  The LED element 30 is an example of a light emitting element, and is, for example, a blue LED that emits blue light having an emission wavelength band of about 450 to 460 nm. In each of the light emitting units 20, the circuit board 12 has an opening 21, and the metal substrate 11 is exposed through the opening 21. The LED element 30 is mounted on the metal substrate 11 exposed through the opening 21. As described above, since the LED element 30 is directly mounted on the metal substrate 11, heat radiation of heat generated by the LED element 30 and phosphor particles described below is promoted.

  In addition, the LED elements 30 are mounted in a grid-like manner in, for example, a rectangular mounting area 22 in the opening 21. FIG. 4A particularly shows an example in which 16 LED elements 30 in 4 rows and 4 columns are mounted. In this case, four LED elements 30 are connected in series, and four sets of the LED elements 30 are further connected in parallel. In this manner, the LED elements 30 are connected in series and parallel to each other in the respective light emitting units 20 in the number of series and parallel numbers set for the light emitting units 20.

In the following, particularly when the serial number of the LED elements 30 indicates four light emitting units, the light emitting units are described as “light emitting units 20 ₄ ”. When the light emitting units are not distinguished by the number of LED elements 30 connected in series, they are simply referred to as “light emitting units 20”.

  The lower surface of the LED element 30 is fixed to the upper surface of the metal substrate 11 by, for example, a transparent insulating adhesive. In addition, the LED element 30 has a pair of element electrodes on the upper surface, and the element electrodes of the adjacent LED elements 30 are electrically connected to each other by wires 31 as shown in FIG. The wire 31 coming out of the LED element 30 located on the outer peripheral side of the opening 21 is finally connected to the wiring pattern 14 of the circuit board 12. Thus, a current is supplied to each LED element 30 via the wire 31.

  The sealing frame 23 is a substantially rectangular resin frame made of, for example, a white resin according to the size of the opening 21 of the circuit board 12, and surrounds the LED element 30 in the light emitting section 20. 12 is fixed to the outer peripheral part of the opening 21 on the upper surface. The sealing frame 23 is a dam member for preventing the sealing resin 24 from flowing out. Further, the sealing frame 23 is, for example, provided with a reflective coating on its surface, so that light emitted to the side from the LED element 30 is disposed above the light emitting unit 20 (metallic when viewed from the LED element 30). (The side opposite to the substrate 11). In FIG. 4A, the sealing frame 23 is illustrated as being transparent.

  The sealing resin 24 is filled in a region surrounded by the sealing frame 23 on the metal substrate 11 to integrally cover and protect (sealing) the entire LED element 30 and the wire 31 of the light emitting unit 20. As the sealing resin 24, for example, a colorless and transparent resin such as an epoxy resin or a silicone resin, particularly a resin having heat resistance of about 250 ° C. may be used.

  Further, a phosphor (not shown) such as a yellow phosphor is dispersed and mixed in the sealing resin 24. The yellow phosphor is a particulate phosphor material such as YAG (yttrium aluminum garnet) that absorbs blue light emitted from the LED element 30 and converts the wavelength into yellow light. The light emitting section 20 emits white light obtained by mixing the blue light from the LED element 30, which is a blue LED, with the yellow light obtained by exciting the yellow phosphor.

Alternatively, the sealing resin 24 may contain a plurality of types of phosphors such as a green phosphor and a red phosphor. The green phosphor is a particulate phosphor material such as (BaSr) ₂ SiO ₄ : Eu ²⁺ which absorbs blue light emitted from the LED element 30 and converts the wavelength into green light. The red phosphor is a particulate phosphor material such as CaAlSiN ₃ : Eu ²⁺ which absorbs blue light emitted by the LED element 30 and converts the wavelength into red light. In this case, the light emitting unit 20 is configured to mix white light obtained by mixing blue light from the LED element 30, which is a blue LED, with green light and red light obtained by exciting the green phosphor and the red phosphor. Emit light.

FIGS. 5A and 5B are overall circuit diagrams of the light emitting device 2. Reference numeral 50 refers to a driver for driving the 22 light emitting units 20 of the light emitting device 2, reference numeral 20 _3, serial number of the LED elements 30 refers to three light-emitting portion. In the light emitting device 2, as shown in FIG. 2A, a total of five switching terminals 17 are provided on the upper surface of the circuit board 12. By changing the way of connecting the switching terminals 17 in accordance with the relationship between the number of light emitting devices 2 included in the lighting device 1 and the maximum voltage that can be supplied by the driver 50 used, the serial connection of the light emitting units 20 can be realized. It is possible to switch. For example, depending on how the switching terminals 17 are connected to each other, as shown in FIG. 5A, 22 light emitting units 20 are connected in series to the driver 50, or as shown in FIG. The 22 light emitting units 20 are divided into two sets connected in parallel to the driver 50, and the 11 light emitting units 20 included in each set are connected in series.

  As described above, each light emitting unit 20 has a plurality of LED elements 30 that are divided into a plurality of columns connected in parallel to each other and are connected in series to each other in each of the plurality of columns. In the light emitting device 2, the LED elements 30 connected in series in the entire device are connected in series in the individual light emitting units 20 so that the sum of the forward voltages (Vf) falls within the range of the voltage that can be driven by the driver 50. The number of LED elements 30 is set. For this reason, in the light emitting device 2, not all the light emitting units 20 necessarily have the same number of LED elements 30. Generally, the number of the LED elements 30 included in one light emitting unit 20 is different for each light emitting unit 20.

  For example, it is assumed that the maximum voltage that can be supplied by the driver 50 is 264V. Further, it is assumed that when one LED element (1) is used as the LED element 30, the Vf of one light emitting unit 20 having four in series is 10.5 to 11.7V. In this case, even if 22 light emitting units 20 are connected in series, Vf of the entire light emitting device 2 is 231.0 to 257.4 V, which is within a range that can be driven by the driver 50. On the other hand, it is assumed that when another LED element (2) is used as the LED element 30, the Vf of one light emitting unit 20 having four in series becomes 11.6 to 13.6V. In this case, when 22 light emitting units 20 are connected in series, Vf of the entire light emitting device 2 becomes 255.0 to 299.4 V, which exceeds the maximum voltage that can be driven by the driver 50.

Therefore, when the latter LED element (2) is used, the number of series in some light emitting units 20 is set to three, and the number of series in which Vf is 11.6 to 13.6 V is four. a light emitting portion 20 _4, Vf combines a number of series and three light-emitting portion 20 ₃ is 8.69～10.21V. Then, out of a total of 22 light emitting units 20, if at least 11 in the light emitting portion 20 _3, Vf across the light emitting device 2 becomes less 264V, it falls within the scope that can be driven by a driver 50. Therefore, the light emitting device 2, when using the LED elements (1), the 22 light emitting units 20 is the series number of the four light-emitting portion 20 _4, when using the LED elements (2) among the 22 pieces of the light emitting portion 20, for example, the eleven serial number and four light emitting portion 20 _4, the remaining 11 pieces of the series number and three light-emitting portion 20 _3.

  As described above, in the light emitting device 2, the number of the LED elements 30 connected in series in each light emitting unit 20 is different, such as m in one light emitting unit 20 and n in another light emitting unit 20. Thereby, the total sum of the forward voltages of the LED elements 30 connected in series in the entire device is adjusted so as to be within the range of the voltage that can be driven by the target driver 50. Therefore, even if the type of the LED element 30 to be used is changed, the light emitting device 2 can be driven by the common driver 50 irrespective of the forward voltage of each LED element 30.

Figure 6 is a top view of the light emitting portion 20 _3. Figure 4 (A) light emitting section 20 _third light emitting portion 20 (the light emitting portion 20 ₄₎ shown in FIG 6 shown in differs only the number of the LED elements 30, but otherwise have the same configuration. A light-emitting portion 20 ₄ 16 LED element 30, they are connected by four in series, whereas the four pairs are further connected in parallel, the light emitting portion 20 _3, 12 LED elements 30, three of which are connected in series, three of which are further connected in parallel. Both of the light emitting portion ₂₀ 4, 20 _3, mounting region 22 is a rectangular region of the same shape and size, the four corners of at least the mounting region 22, LED elements 30 always are mounted. On top of that, both of the light emitting portion ₂₀ 4, 20 _3, in the inside of the mounting region 22, LED elements 30 are mounted for example evenly. In the light emitting units 20 ₄ and 20 ₃ , the mounting densities of the LED elements 30 are different from each other because the size of the mounting area 22 is the same and the pitch between the elements is different. Further, the light emitting portion 20 _4, 20 _3, emission density when viewed emitting portion one light emitter or different from each other.

FIG. 7 is a diagram schematically illustrating the arrangement of the LED elements 30 in the light emitting device 2. In FIGS. 2A and 2B, the plurality of light emitting units are simply referred to as “light emitting units 20” without distinction, but in the light emitting device 2, the forward voltage of the entire device is adjusted as described above. Therefore, for example, the number of series is four light-emitting portion 20 ₄ and the number of series is combined with three light-emitting portion 20 _3. FIG. 7 shows an example in which the light emitting portion 20 ₄ and the light emitting portion 20 ₃ are connected alternately. However, depending on the driver 50 used, all the light emitting units 20 may have the same number of LED elements 30 in series, or may have two or less or five or more serial light emitting units 20.

  As described above, the LED elements 30 of each light emitting unit 20 are mounted in the mounting area 22 having a shape and size common to the plurality of light emitting units 20 according to the serial number and the parallel number set for the light emitting unit 20. Implemented in density. As a result, the light emitting diameters of the plurality of light emitting units 20 are the same, so that a lens array including a plurality of lenses 41 having the same shape and size regardless of the number of LED elements 30 included in each light emitting unit 20 40 can be used.

  In the light emitting unit 20 in which the number of the LED elements 30 is relatively reduced, the emitted light amount is reduced. Therefore, when the light emitting units 20 having different serial numbers and / or parallel numbers are combined, the emitted light amount becomes uneven as a whole of the light emitting device 2. Can occur. Therefore, an LED element having a higher forward voltage may be used as the LED element 30 as the light emitting unit 20 has a smaller number of series and parallel LED elements 30. If the LED element has a high forward voltage, the emitted light becomes brighter. Therefore, by selecting an LED element to be used for each light emitting unit 20, the emitted light amount is made uniform among the plurality of light emitting units 20 to reduce unevenness. It is possible to emit no light.

  However, since the lighting device 1 is installed far away from human eyes due to the property of being used as a light projector, unevenness in brightness on the light emitting device 2 does not cause much problem. For this reason, the light emitting units 20 having different serial numbers and / or parallel numbers do not necessarily have to be evenly arranged in the light emitting device 2. Further, LED elements having the same forward voltage may be used in all the light emitting units 20.

  FIG. 8 is a flowchart illustrating an example of a manufacturing process of the light emitting device 2. When the light emitting device 2 is manufactured, first, a plurality of light emitting units 20 are collectively formed on the substrate 10, and a plurality of sets of LED elements 30 are mounted on each light emitting unit 20. In this case, for each light emitting unit 20, a plurality of LED elements 30 are mounted on the metal substrate 11 in the opening 21 of the circuit board 12 (S1). Next, the LED elements 30 are connected to each other in series and parallel by the wires 31 (S2). Further, the sealing frame 23 is fixed to the outer peripheral portion of the opening 21 (S3). Further, the sealing resin 24 containing the phosphor is filled in a region surrounded by the sealing frame 23 on the metal substrate 11, and the plurality of LED elements 30 are sealed (S4).

  As shown in FIG. 2A, two positioning holes 18 a and 18 b are formed on the diagonal line of the upper surface of the circuit board 12 as an example, and the circuit board 12 corresponding to each light emitting unit 20 is formed. The position of the opening 21 is determined with reference to the positions of the positioning holes 18a and 18b. That is, the mounting position of the LED element 30 of each light emitting unit 20 and the arrangement position of the sealing frame 23 are determined based on the positions of the positioning holes 18a and 18b. Thereby, variation in the formation position of the light emitting unit 20 is reduced.

  Subsequently, the lens array 40 including the plurality of lenses 41 is arranged on the light emitting units 20 while roughly adjusting the relative position between each light emitting unit 20 and the corresponding lens 41 (S5). At this time, for example, the lens array 40 is fixed to the substrate 10 by holding the substrate 10 and the ends of the lens array 40 with the case 3. Alternatively, the lens array 40 may be fixed to the substrate 10 by a method described below.

  FIGS. 9A to 9C are diagrams illustrating an example of a method of fixing the lens array 40 to the substrate 10. 9A to 9C show a top view of the substrate 10, a top view of the lens array 40, and a longitudinal sectional view of the light emitting device 2 along a diagonal line L, respectively. 9A to 9C, the number of the light emitting units 20 and the number of the lenses 41 are shown as eight for simplicity.

  In the illustrated example, the substrate 10 and the lens array 40 are positioned using the positioning holes 18a and 18b. In this case, two support portions 43a and 43b are provided in advance on the diagonal line L of the lower surface (the surface facing the substrate 10) of the lens array 40 in accordance with the positions of the positioning holes 18a and 18b. The support portions 43a and 43b are formed integrally with the lens array 40 or are columnar members adhered to the lens array 40. The substrate 10 and the lens array 40 are positioned by fitting the support portions 43a and 43b into the positioning holes 18a and 18b, respectively. Thereby, since the optical axis of each lens 41 can be easily adjusted to the center of each light emitting unit 20, the process of adjusting the relative positions of the plurality of light emitting units 20 and the plurality of lenses 41 is simplified.

  The diameter of the positioning holes 18a and 18b along the diagonal line L increases as the distance from the one end P of the diagonal line L increases. For example, as shown in FIGS. 2A and 9A, the positioning holes 18a and 18b are both circular, and the diameter of the positioning hole 18b farther from the one end P than the positioning hole 18a has. large. Alternatively, the positioning holes 18a and 18b may have an elliptical shape (a long hole) whose major axis is the direction of the diagonal line L. In this case, the positioning hole 18b has a longer diameter than the positioning hole 18a. The diameter of the lower end of each of the support portions 43a and 43b that fits into the positioning holes 18a and 18b is slightly smaller than that of the positioning holes 18a and 18b. Thereby, the relative positions of the plurality of light emitting units 20 and the plurality of lenses 41 along the diagonal line L can be changed. Therefore, even when the substrate 10 and the lens array 40 thermally expand or contract at different rates, the relative positions can be changed. Can be fine-tuned.

  In this way, the relative positions of the plurality of light emitting units 20 and the plurality of lenses 41 can be changed according to the thermal expansion when the light emitting device 2 is turned on and the thermal contraction when the light emitting device 2 is turned off. The lens array 40 is fixed to each other. Then, accurate positioning between the substrate 10 and the lens array 40 is performed by the method described below (S6).

  The positioning between the substrate 10 and the lens array 40 in S6 is performed according to the following concept. Due to the heat generated when the light emitting device 2 is turned on, the aluminum metal substrate 11 and the resin circuit board 12 constituting the substrate 10 and the glass lens array 40 expand at different coefficients of thermal expansion. For example, assuming that the temperature of the substrate 10 and the lens array 40 rises by about 100 ° C. due to lighting, in the case of the substrate 10 having a side of about 10 cm, the extension amount of about 1 mm between the substrate 10 and the lens array 40. Differences can occur. Therefore, in consideration of the difference Δd in the amount of elongation, the relative position between each light emitting unit 20 and each lens 41 is shifted in the opposite direction by Δd in advance. Thus, when the light emitting device 2 is driven (the plurality of light emitting units 20 are turned on) and thermal expansion occurs, the difference between the preset displacement amount and the expansion amount due to the thermal expansion cancel each other, and each light emitting unit 20 And the optical axis of each lens 41 coincides. For this reason, when the light emitting device 2 is driven and the substrate 10 and the lens array 40 undergo thermal expansion, it is possible to improve the efficiency of emission from each light emitting unit 20 through each lens 41.

  FIGS. 10A and 10B are diagrams illustrating an example of a method of positioning the substrate 10 and the lens array 40. FIG. When the substrate 10 and the lens array 40 are positioned, for example, as shown in FIG. 10A, two adjacent sides of the substrate 10 and an end of the lens array 40 corresponding to the two sides are used as reference planes. The case 3 is brought into contact with the wall. Then, the lens array 40 having a smaller coefficient of thermal expansion is shifted farther from the reference plane by a length corresponding to the difference Δd in the amount of expansion between the substrate 10 and the lens array 40 due to thermal expansion. Due to thermal expansion, the substrate 10 and the lens array 40 expand evenly, and the whole is enlarged. Therefore, when the plurality of light emitting units 20 are turned on and the substrate 10 and the lens array 40 are thermally expanded by the above-described process, as shown in FIG. The relative positions can be adjusted.

  Thus, the manufacturing process of the light emitting device 2 is completed. Hereinafter, a modified example of the light emitting unit 20 will be described.

  FIGS. 11A and 11B are a top view and a side view of the light emitting device 2A. The light emitting device 2 illustrated in FIGS. 2A and 2B is different from the light emitting device 2A illustrated in FIGS. 11A and 11B in the shape of the light emitting unit 20 and the arrangement of the inspection terminals 16. In other respects, it has the same configuration. The light emitting unit 20 of the light emitting device 2 is substantially rectangular while the light emitting unit 20A of the light emitting device 2A is slightly larger than the light emitting unit 20 and is circular. As described above, the shape of each light emitting unit in the light emitting device is not limited to a rectangle, but may be a circle or another shape. The inspection terminal 16 of the light emitting device 2A is different from the light emitting device 2 in the distance between the two terminals for each light emitting unit 20A and the size of the angle with respect to the side of the substrate 10; It has the same configuration as the device 2. The inspection terminals 16 are arranged on the substrate 10 at an interval d and an angle θ according to the shape of the light emitting unit.

FIGS. 12A and 12B are top views of the light emitting unit 20A. 12 (A) shows serial number of the LED elements 30 is four, the number of parallel shows four light emitting portion 20A _4. Further, FIG. 12 (B) series number of the LED elements 30 is four, the number of parallel shows three light emitting portion 20A _3. As described above, also in the light emitting device 2A, the LED elements 30 of each light emitting unit 20A are provided in the circular mounting area 22A having a size common to the plurality of light emitting units 20A, in the series number and the parallel number set for the light emitting unit 20A. Is mounted at a mounting density according to. In this case, the number of LED elements 30 in series, the number in parallel, or both may be different for each light emitting unit 20A.

FIG. 13 is a diagram schematically illustrating an arrangement of the LED elements 30 in the light emitting device 2B. The light emitting device 2 shown in FIG. 7 and the light emitting device 2B shown in FIG. 13 differ from each other only in the number of series and parallel numbers of LED elements 30 in each light emitting unit, and have the same configuration in other respects. In the light emitting device 2, the number of parallel light emitting units 20 is all the same four, but for each light emitting unit 20, both the serial number and the parallel number may be different. Emitting device 2B shown in FIG. 13, the number of series with the parallel number of four and even four light emitting section 20B _4, and a parallel number of three in series number five light emitting portion 20B _3. FIG. 13 shows an example in which the light-emitting portion 20B ₄ and the light emitting portion 20B ₃ are connected alternately. Even when both the serial number and the parallel number are changed for each light emitting unit 20, the LED element 30 of each light emitting unit 20B may be mounted in the mounting area 22 having a common shape and size by the plurality of light emitting units 20B. preferable.

  FIGS. 14A and 14B are top views of the light emitting device 2C and the light emitting unit 20C in the light emitting device 2C. The light emitting device 2 shown in FIG. 2A and the light emitting device 2C shown in FIG. 14A differ only in the arrangement of the inspection terminals 16 of each light emitting unit, and have the same configuration in other respects. In the light emitting device 2, the test terminals 16 of each set are arranged so as to sandwich the light emitting unit 20, but as shown in FIGS. 14A and 14B, the test terminals 16 of each set are The light emitting unit 20C may be arranged on one side without sandwiching the light emitting unit 20C. Even in this case, the two terminals constituting each set of the inspection terminals 16 are equally arranged with a common interval d between the plurality of light emitting units 20C.

  FIG. 15 is a diagram schematically illustrating an arrangement of the LED elements 30 in the light emitting device 2D. The light emitting device 2D shown in FIG. 15 has the same configuration as the light emitting device 2 shown in FIG. 7, although the size of the LED element 30 differs for each light emitting unit 20D. In the light emitting device 2D, the area of the light emitting region 22D of each light emitting unit 20D is equal to each other, and the size of the LED element 30 included in each light emitting unit 20D is smaller as the number of serially arranged LED elements 30 is larger. Thus, even if the number of elements is changed for each light emitting unit 20D, a lens array including a plurality of lenses having the same outer shape can be used. In addition, if the size of the element is reduced, the number of series in the light emitting region 22D having the same area can be increased, and the forward voltage of each light emitting unit 20D can be adjusted according to the number of series. The voltage can be set within a range that can be driven by the driver for the light emitting device 2D. In addition, among the light emitting devices 2A to 2C described above, the LED elements 30 having different sizes may be used for the light emitting portions having different numbers in series.

  FIG. 16 is a diagram schematically illustrating an arrangement of the LED elements 30 in the light emitting device 2E. The light emitting device 2E shown in FIG. 16 has the same configuration as the light emitting device 2 shown in FIG. 7, except that the size of each lens 41E in the lens array 40E is different for each light emitting unit 20E. The size of each lens 41E increases as the number of LED elements 30 included in the light emitting unit 20E corresponding to the lens 41E increases.

For example, the light emitting portion 20E of the light emitting device. 2E, the light-emitting portion 20E 4 with 16 LED element 30 connected in series-parallel to each other in series several four and parallel number of 4 or _(an example of the first light emitting portion), A light emitting unit 20E ₃ (an example of a second light emitting unit) having nine LED elements 30 connected in series and parallel with each other with three in series and three in parallel. In the light emitting device 2E, the mounting density of the LED elements 30 is the same in each light emitting unit 20E, and as a result, the size of the light emitting region 22E is different for each light emitting unit 20E. The lens 41E of the light emitting device 2E is composed of a lens 41E ₄ corresponding to the light-emitting portion 20E _4, and corresponds to the light-emitting portion 20E ₃ lens 41E ₄ smaller lens 41E _3. In Figure 16, the light emitting portion 20E ₄ and the light emitting portion 20E ₃ is shows an example of a case that is staggered on the substrate 10. Thus, the number of LED elements 30 in each light-emitting portion 20E, that is, changing the size of the lens 41E according to the size of the light emitting region 22E, a small light-emitting portion 20E ₃ between the large emitting portion 20E ₄ Can be arranged. Therefore, in the light emitting device 2E, many light emitting portions 20E can be formed at a higher density on the surface of the substrate 10, and the amount of emitted light increases.

  FIGS. 17A and 17B are a top view and a side view of the light emitting device 2F. In the light emitting device 2F shown in FIG. 17A, unlike the light emitting device 2A shown in FIG. 11A, an opening is not provided at the center of the substrate 10F. Further, the substrate 10F and the lens array 40F of the light emitting device 2F are smaller than the substrate 10 of the light emitting device 2A, and the number of the light emitting units 20F of the light emitting device 2F is smaller than the number of the light emitting units 20A of the light emitting device 2A. In other respects, the light emitting device 2F has the same configuration as the light emitting device 2A. The light emitting unit 20F may have the same configuration as the light emitting units 20, 20B to 20E described above, and in that case, the opening may not be provided at the center of the substrate 10F.

  FIGS. 18A and 18B are a top view and a vertical cross-sectional view of the light emitting unit 20G. More specifically, FIG. 18A is a top view of the light emitting unit 20G, and FIG. 18B is a cross-sectional view taken along line XVIIIB-XVIIIB in FIG. 18A. FIG. 18A shows an example in which nine LED packages 30G are mounted in a 3 × 3 lattice shape. The light emitting units 20 and 20A to 20F of the light emitting devices 2 and 2A to 2F are not limited to those in which the LED elements 30 are connected to each other by wires 31 and the whole is sealed with the sealing resin 24, and FIG. Alternatively, an LED package 30G as shown in FIG. 18B may be flip-chip mounted.

  The LED package 30 </ b> G includes an LED element 30 ′ having two element electrodes 32 formed on the lower surface, and a phosphor layer 33. The LED package 30G is a bump-type light emitting element in which a bump 34 for flip chip bonding is formed on an element electrode 32 on the lower surface of the LED element 30. The LED element 30 ′ is, for example, a blue semiconductor light emitting element (blue LED) that emits blue light having an emission wavelength band of about 450 to 460 nm.

  The phosphor layer 33 is formed by dispersing and mixing phosphor particles (not shown) in a colorless and transparent resin such as an epoxy resin or a silicone resin, and uniformly arranges the upper surface and side surfaces of the LED element 30 ′. Cover. For example, the phosphor layer 33 contains a yellow phosphor such as YAG, and absorbs blue light emitted by the LED element 30 'and converts the wavelength into yellow light. In this case, the LED package 30G emits white light obtained by mixing blue light from the LED element 30 ', which is a blue LED, with yellow light obtained by exciting the yellow phosphor. The type of the phosphor contained in the phosphor layer 33 may be other than this, and may be different for each LED package 30G.

DESCRIPTION OF SYMBOLS 1 Illumination device 2, 2A, 2B, 2C, 2D, 2E, 2F Light emitting device 10, 10F board 11 Metal substrate 12 Circuit board 13 Opening 16 Inspection terminal 18a, 18b Positioning hole 20, 20A, 20B, 20C, 20D , 20E, 20F, 20G Light emitting section 22 Mounting area 23 Sealing frame 24 Sealing resin 30, 30 'LED element 30G LED package 40, 40E, 40F Lens array 41, 41E Lens 43a, 43b Supporting section 50 Driver

Claims (2)

Board and
A plurality of light emitting units arranged on the substrate,
Including a plurality of lenses provided corresponding to each of the plurality of light emitting units and condensing light emitted from the light emitting units, and a lens array arranged on the plurality of light emitting units,
Each of the plurality of light emitting units has a plurality of light emitting elements which are divided into a plurality of columns connected in parallel to each other and which are connected in series to each other by the number set for the light emitting units in each of the plurality of columns,
The sizes of a plurality of light emitting elements, rather smaller than the more light-emitting unit number is large in light emitting devices connected in series,
The area of each of the light emitting region of the plurality of light emitting portions have equal each other,
A light-emitting device characterized by the above-mentioned. A driver that drives the plurality of light emitting units;
The light emitting element is an LED element,
LED elements connected in series with each of the plurality of light emitting units such that the sum of the forward voltages of the LED elements connected in series across the plurality of light emitting units falls within the range of the voltage that can be driven by the driver. The light emitting device according to claim 1 , wherein the number is set.

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