JP6537410B2 - Method of manufacturing light emitting device - Google Patents

Description

  The present invention relates to a method of manufacturing a light emitting device.

  There is known 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. In such a light emitting device, for example, an LED element that emits blue light is sealed with a resin containing a phosphor, and light obtained by exciting the phosphor with light from the LED element is mixed, depending on the application. I get white light and so on.

  For example, Patent Document 1 discloses a highly thermally conductive heat dissipation base having a mounting surface for die bonding, a hole which is mounted on the heat dissipation base and exposes a part of the mounting surface, and the outside of the heat dissipation base. A circuit board having a projecting portion extending outward from the peripheral edge, a light emitting element mounted on the mounting surface through the hole, and a translucent resin body sealing the upper side of the light emitting element; The light emitting diode which formed the through hole electrically connected with a light emitting element in the outer periphery of a protrusion part, and provided the external connection electrode in the upper surface and lower surface of this through hole is described.

  Further, in Patent Document 2, a cavity in which a recess is formed, a convex heat slug (base portion) attached to the cavity in a state of penetrating the bottom of the recess, and a submount substrate mounted on the heat slug A plurality of LED chips disposed on the submount substrate, a lead frame electrically connected to each of the LED chips, a phosphor layer including each of the LED chips, and a silicone resin encapsulated in the recess. And an LED package having a lens.

  Moreover, the illuminating device which increased the light quantity is known by arrange | positioning and arrange | positioning several LED. For example, Patent Document 3 discloses a lens array in which a plurality of LEDs 3, a substrate 4 on which the LEDs 3 are mounted, and a plurality of lens elements for condensing or diverging irradiation light emitted from the LEDs are integrated. An LED lighting device is described having two.

JP, 2006-005290, A Unexamined-Japanese-Patent No. 2010-170945 JP 2012-042670 A

  A plurality of light emitting units are formed on one common substrate in order to obtain parallel light with high light quantity, and a light emitting device is manufactured in which light emitted from each light emitting unit is collected by a lens corresponding to the light emitting unit and emitted. Think about what to do. In particular, when a plurality of light emitting elements are mounted on each light emitting portion, the number of elements included in the entire light emitting device increases and the amount of heat generated at the time of driving also increases, so expansion of the common substrate or lens due to the heat can not be ignored. .

  Therefore, an object of the present invention is to improve the emission efficiency from a plurality of light emitting portions through a plurality of lenses when thermal expansion occurs in a common substrate or a lens by driving a light emitting device.

  A process of mounting a plurality of light emitting elements on a substrate to form a plurality of light emitting units, and a lens array including a plurality of lenses disposed in alignment with the arrangement positions of the plurality of light emitting units are disposed on the plurality of light emitting units. According to the thermal expansion coefficients of the substrate and the lens array so that the relative positions of the plurality of light emitting units and the plurality of lenses match when the plurality of light emitting units are turned on and the substrate and the lens array thermally expand. And a step of positioning the substrate and the lens array by shifting the plurality of light emitting portions and the plurality of lenses from each other by a distance of a predetermined size.

In the above manufacturing method, the substrate is rectangular, and in the disposing step, the relative positions of the plurality of light emitting portions and the plurality of lenses can be changed according to the thermal expansion and the thermal contraction. In the step of fixing the ends to the same housing and positioning, the substrate and the lens array are made to abut on the housing by contacting two adjacent sides of the substrate and the ends of the lens array corresponding to the two sides. Positioning is preferred.
In the above forming step, for each of the plurality of light emitting parts, a plurality of LED elements as light emitting elements are mounted on a substrate, the plurality of LED elements are electrically connected to each other by wires, and sealing is performed containing a phosphor It is preferable to fill the resin on the substrate to seal a plurality of LED elements.
In the above forming step, for each of the plurality of light emitting parts, a plurality of LED packages configured by covering the upper surface and the side surface of the LED element with the resin layer containing the phosphor is flip chip on the substrate as the light emitting element It is preferable to implement.

  According to the present invention, it is possible to improve the emission efficiency from the plurality of light emitting portions through the plurality of lenses when thermal expansion occurs in the common substrate or the lens by driving the light emitting device.

It is the front view and rear view of the illuminating device 1. FIG. FIG. 5A is a top view and a side view of the light emitting device 2. FIG. 6 is a top view of a lens array 40. FIG. 5A is a top view and a vertical cross-sectional view of the light emitting unit 20. FIG. 2 is a circuit diagram of the entire light emitting device 2; It is a top view of the light emitting portion 20 _3. FIG. 6 schematically shows the arrangement of the LED elements 30 in the light emitting device 2. 5 is a flowchart illustrating an example of a manufacturing process of the light emitting device 2. FIG. 7 is a view showing an example of a method of fixing the lens array 40 to the substrate 10; FIG. 7 is a diagram showing 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 which shows typically arrangement | positioning of the LED element 30 in the light-emitting device 2B. It is a top view of 2 C of light emitting devices, and the light emission part 20C in 2 C of light emitting devices. It is a figure which shows typically arrangement | positioning of the LED element 30 in light-emitting device 2D. It is a figure which shows typically arrangement | positioning of the LED element 30 in the light-emitting device 2E. It is the top view and side view of the light-emitting device 2F. They are the top view and longitudinal cross-sectional view of 20 G of light emission parts.

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

  FIG. 1A and FIG. 1B are a front view and a back view of the lighting device 1. The lighting device 1 is a device that can be used, for example, as a light projector for lighting, and includes, as an example, a total of six light emitting devices 2 arranged in two rows and three columns as shown in FIG. 1 (A). The lighting device 1 is configured as one device by arranging the cases (casings) 3 of the respective light emitting devices 2 close to each other. As the number of light emitting devices 2 included in one lighting device, there are various examples such as two, four, or eight or more other than the illustrated one. 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 the heat generated in the light emitting device 2.

  2A and 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 is disposed on the substrate 10, a plurality of light emitting units 20 formed on the substrate 10, and a plurality of light emitting units 20. And a lens array 40. Further, as shown in FIG. 1B and FIG. 2B, each light emitting device 2 has, on the back surface of the substrate 10, a radiation fin 4 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 at its 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 the circuit substrate 12 on the 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 releasing substrate for releasing the heat generated by the light emitting unit 20, and is made of, for example, aluminum excellent in heat resistance and heat dissipation. However, as long as the material of the metal substrate 11 is excellent in heat resistance and heat dissipation, another metal such as copper may be used.

  The circuit substrate 12 is an insulating substrate such as a glass epoxy substrate, a BT resin substrate, a ceramic substrate or a metal core substrate. A wiring pattern 14 for electrically connecting the plurality of light emitting units 20 to each other is formed on the top surface of the circuit board 12. At 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, and the plurality of light emitting units 20 of the light emitting device 2 emit light when these are connected to an external power supply and a voltage is applied.

  The light emitting units 20 are a plurality of independent light emitting units formed on the substrate 10 which is one common substrate, and are evenly disposed 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 later, each light emitting unit 20 includes 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 distance (pitch) between the light emitting units 20 be 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. FIG. The lens array 40 is an assembly of lenses in which a plurality of lenses 41 are integrally formed. In the illustrated example, the lens array 40 has 22 lenses 41 disposed in proximity except for the center thereof. 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 condenses the light emitted from the corresponding light emitting unit 20, respectively. 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 a light projector, it is required to configure the light emitting device 2 as small as possible so that the resistance received by the wind during use is reduced. For this reason, it is preferable to make adjacent lenses 41 contact with each other without leaving a space, and to increase the density of the lens 41 portion with respect to the entire lens array 40. Since the light emitting units 20 and the lenses 41 correspond one to one, the diameter of the lenses 41 determines the pitch of the light emitting units 20.

  As described above, the substrate 10 has the opening 13 at the center. The opening 13 is formed at the same position of the metal substrate 11 and the circuit substrate 12. In addition, 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, and 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 in terms 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 in which the metal substrate 11 is in contact with the air increases. As a result, part of the heat transferred from the light emitting unit 20 (light emitting element) to the metal substrate 11 is also released from the edge of the opening 13 to the outside of the device. Further, in the light emitting device 2, since the heat dissipating fins 4 on the back side of the substrate 10 are also in contact with the outside air on the front side of the substrate 10 through the opening 13, the area where the heat dissipating fins 4 touch the outside air is also expanded. Thus, part of the heat transferred from the metal substrate 11 to the heat dissipating 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 openings 13 can promote the release of heat generated in each light emitting unit 20 (light emitting element) 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 openings 13 is preferably at least larger than the diameter d2 of the individual light emitting units 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.

  Moreover, as shown to FIG. 2A, the terminal 16 for a test | inspection for confirming the operation | movement (lighting) of the light emission part 20 is provided in the upper surface of the circuit board 12 for every light emission part 20. As shown in FIG. The inspection terminals 16 are disposed so as to sandwich the corresponding light emitting unit 20, with each two terminals as one set. The inspection terminal 16 is disposed outside the light emitting unit 20, but since there is also a wiring pattern 14 for lighting the plural light emitting units 20 simultaneously on the circuit board 12, the arrangement position of the inspection terminal 16 emits light If it is too far from the part 20, routing of wiring becomes difficult. Therefore, as shown in FIG. 2A, the inspection terminals 16 of each set are formed on the circuit board 12 at positions within the diameter of the main surface of the lens 41 corresponding to the light emitting unit 20 of interest. .

  Moreover, in order to prevent an erroneous measurement, two terminals which comprise the terminal 16 for a test | inspection of each set are equally arrange | positioned with the common space | interval d among several light emission parts 20. FIG. Furthermore, if possible in relation to the wiring pattern 14, it is preferable that the two terminals constituting the inspection terminals 16 of each set be arranged at a common angle to the side of the substrate 10. As described above, when the arrangement of the plurality of inspection terminals 16 is aligned, the operation check of each light emitting unit 20 becomes easy when checking the operation of the light emitting unit 20 in order, and the occurrence frequency of the erroneous measurement It is possible to lower it.

  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 line IVB-IVB in FIG. 4A, and FIG. 4C is FIG. A cross-sectional view taken along the line IVC-IVC). The light emitting unit 20 includes 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 for example, is a blue LED that emits blue light having an emission wavelength band of about 450 to 460 nm. In each light emitting unit 20, the circuit board 12 has the 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. Thus, the LED element 30 is directly mounted on the metal substrate 11, thereby promoting the heat radiation of the heat generated by the LED element 30 and the particles of the phosphor to be described later.

  Further, the LED elements 30 are mounted in a grid shape and mounted in, for example, a rectangular mounting area 22 in the opening 21. FIG. 4A particularly shows an example where 16 LED elements 30 in 4 rows and 4 columns are mounted. In this case, four LED elements 30 are connected in series, and the four sets are further connected in parallel. Thus, in each light emitting unit 20, the LED elements 30 are connected in series and in parallel with each other in the number of series and the number of parallel setting for the light emitting unit 20.

Hereinafter, in particular, when the number of LED elements 30 connected in series indicates four light emitting units, the light emitting unit 20 ₄ is described as “light emitting unit 20 ₄ ”. When the light emitting units are not distinguished by the number of series connected LED elements 30, 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. Further, the LED element 30 has a pair of element electrodes on the top surface, and as shown in FIG. 4A, the element electrodes of the adjacent LED elements 30 are electrically connected to each other by the wire 31. The wires 31 emitted from the LED elements 30 located on the outer peripheral side of the opening 21 are finally connected to the wiring pattern 14 of the circuit board 12. Thereby, current is supplied to each LED element 30 through 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 the circuit board is configured to surround the LED elements 30 in the light emitting unit 20. It is fixed to the outer peripheral portion of the opening 21 on the upper surface of the cover 12. The sealing frame 23 is a dam material for preventing the sealing resin 24 from flowing out. In addition, for example, the sealing frame 23 is provided with a reflective coating on its surface to allow light emitted laterally from the LED element 30 to be located above the light emitting unit 20 (when viewed from the LED element 30, metal The light is reflected toward 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 and integrally covers and protects (seals) the entire LED element 30 of the light emitting unit 20 and the wire 31. As the sealing resin 24, for example, it is preferable to use a colorless and transparent resin such as an epoxy resin or a silicone resin, and in particular, a heat-resistant resin of about 250.degree.

  In addition, phosphors (not shown) such as yellow phosphors are 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 to yellow light. The light emitting unit 20 emits white light obtained by mixing the blue light from the LED element 30 which is a blue LED and the yellow light obtained by exciting the yellow phosphor thereby.

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

FIGS. 5A and 5B are circuit diagrams of the entire 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 top surface of the circuit board 12. By changing the connection method of the switching terminals 17 according to 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, series-parallel connection of the light emitting units 20 can be performed. It is possible to switch. For example, 22 light emitting units 20 are connected in series to the driver 50 as shown in FIG. 5 (A) according to the connection method of the switching terminals 17 or as shown in FIG. 5 (B). The 22 light emitting units 20 are divided into two groups connected in parallel to the driver 50, and the 11 light emitting units 20 included in each set are connected in series with each other.

  As described above, each light emitting unit 20 includes a plurality of LED elements 30 divided into a plurality of rows connected in parallel with each other and connected in series with each other in each of the plurality of rows. The light emitting device 2 is connected in series in each light emitting unit 20 such that the sum of forward voltages (Vf) of the LED elements 30 connected in series in the entire device falls within the range of voltages drivable by the driver 50. The number of LED elements 30 is set. For this reason, in the light emitting device 2, all the light emitting units 20 do not necessarily have the same number of LED elements 30. Generally, the number of the LED elements 30 included in one light emitting unit 20 differs 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. Moreover, when using LED element (1) which is the LED element 30, it is assumed that Vf of one light emission part 20 whose number of series is four is 10.5-11.7V. 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, and falls within a drivable range by the driver 50. On the other hand, when another LED element (2) is used as the LED element 30, it is assumed that 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 in the entire light emitting device 2 is 255.0 to 299.4 V, which exceeds the maximum voltage that can be driven by the driver 50.

For this reason, when the latter LED element (2) is used, the number of series connected in a part of the light emitting units 20 is three, and the number of series where the 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, 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 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. As a result, the sum of the forward voltages of the LED elements 30 connected in series in the entire device is adjusted to fall within the range of voltages that can be driven by the target driver 50. Therefore, even if the type of LED element 30 to be used is changed, the light emitting device 2 can be driven by the common driver 50 regardless 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 are connected in series three by three, and the four sets are further connected in parallel. In each of the light emitting units 20 ₄ and 20 ₃ , the mounting area 22 is a rectangular area having the same shape and size, and the LED element 30 is always mounted at least at four corners of the mounting area 22. 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 density of the LED elements 30 is different from each other because both of the mounting areas 22 have the same size and the inter-element pitch 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 view schematically showing 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 unit 20” without distinction. However, in the light emitting device 2, as described above, the forward voltage of the entire device is adjusted. 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 to be used, the number of LED elements 30 connected in series may be the same in all the light emitting units 20, or the number of light emitting units 20 may be two or less or five or more.

  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 number of series and the number of parallel setting for the light emitting units 20. Implemented in density. Thereby, since the light emission diameter becomes the same among the plurality of light emitting units 20, a lens array including the 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 It becomes possible to use 40.

  In the light emitting unit 20 in which the number of LED elements 30 is relatively reduced, the amount of emitted light decreases. Therefore, when the light emitting units 20 having different series numbers and / or parallel numbers are combined, unevenness in the amount of emitted light as the entire light emitting device 2 Can occur. Therefore, as the light emitting unit 20 has a smaller number of LED elements 30 in series and in parallel, an LED element with a higher forward voltage may be used as the LED element 30. If the LED element has a high forward voltage, the emitted light will be brighter, so by selecting the 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, and unevenness is caused. It is possible to emit no light.

  However, since the lighting device 1 is installed at a place far away from human eyes because of the nature 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 may not necessarily be evenly arranged in the light emitting device 2. Moreover, you may use the LED element with same forward voltage in all the light emission parts 20. FIG.

  FIG. 8 is a flowchart showing an example of a manufacturing process of the light emitting device 2. At the time of manufacturing the light emitting device 2, first, the 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 of the light emitting units 20. At that time, 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 substrate 12 (S1). Next, the LED elements 30 are connected in series and parallel to each other by the wire 31 (S2). In addition, the sealing frame 23 is fixed to the outer peripheral portion of the opening 21 (S3). Furthermore, the sealing resin 24 containing a phosphor is filled in the 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, on the diagonal of the upper surface of the circuit board 12, two positioning holes 18a and 18b are formed as an example, and the circuit board 12 corresponding to each light emitting unit 20 is provided. 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, the 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 disposed on the light emitting units 20 by roughly aligning the relative positions of the light emitting units 20 and the corresponding lenses 41 (S5). At that time, for example, the lens array 40 is fixed to the substrate 10 by holding the substrate 10 and the end of the lens array 40 by the case 3. Alternatively, the lens array 40 may be fixed to the substrate 10 by the method described below.

  FIGS. 9A to 9C are diagrams showing an example of a method of fixing the lens array 40 to the substrate 10. 9A to 9C respectively 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 the diagonal L. In FIG. 9A to FIG. 9C, the number of light emitting units 20 and the number of 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, on the diagonal L of the lower surface (surface facing the substrate 10) of the lens array 40, two support portions 43a and 43b are provided in advance in accordance with the positions of the positioning holes 18a and 18b. The support portions 43 a and 43 b are columnar members formed integrally with the lens array 40 or bonded 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 aligned with the center of each light emitting unit 20, the process of adjusting the relative position between the plurality of light emitting units 20 and the plurality of lenses 41 is simplified.

  The positioning holes 18a and 18b have larger diameters along the diagonal L as the distance from the one end P of the diagonal L increases. For example, as shown in FIGS. 2A and 9A, both the positioning holes 18a and 18b are circular, and the diameter of the positioning hole 18b farther from the one end P than the positioning hole 18a is the diameter. large. Alternatively, the positioning holes 18a and 18b may be oval (long holes) whose major axis is the direction of the diagonal L. In this case, the positioning hole 18b has a larger major axis than the positioning hole 18a. Further, the diameter of the portion of the lower end of the support portions 43a and 43b to be fitted with 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 L can be changed, so that even when the substrate 10 and the lens array 40 thermally expand or shrink at different rates, the relative positions Fine adjustment of the becomes possible.

  Thus, 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 on and the thermal contraction when the light emitting device 2 is off. The lens array 40 is fixed to each other. Then, the substrate 10 and the lens array 40 are accurately positioned by the method described below (S6).

  Positioning of the substrate 10 and the lens array 40 in S6 is performed in accordance with the following concept. The heat generated at the time of lighting of the light emitting device 2 causes the aluminum metal substrate 11 and the resin circuit substrate 12 constituting the substrate 10 and the glass lens array 40 to expand with different thermal expansion coefficients. For example, assuming that the temperature of the substrate 10 and the lens array 40 increases by about 100 ° C. by lighting, in the case of the substrate 10 having a side of about 10 cm, an elongation amount of about 1 mm between the substrate 10 and the lens array 40 A difference can occur. Therefore, the relative position between each light emitting unit 20 and each lens 41 is shifted in advance in the reverse direction by Δd in consideration of the difference Δd in the expansion amount. Thereby, when thermal expansion occurs by driving the light emitting device 2 (turning on the plurality of light emitting parts 20), the difference between the offset amount set in advance and the expansion amount due to the thermal expansion cancels each other, and each light emitting part 20 And the optical axis of each lens 41 coincide. Therefore, when the light emitting device 2 is driven and thermal expansion occurs in the substrate 10 and the lens array 40, it is possible to improve the emission efficiency from each light emitting unit 20 through each lens 41.

  FIGS. 10A and 10B are diagrams showing an example of a method of positioning the substrate 10 and the lens array 40. FIG. When positioning the substrate 10 and the lens array 40, for example, as shown in FIG. 10A, using two adjacent sides of the substrate 10 and the end of the lens array 40 corresponding to the two sides as a reference plane, Abut the wall of the case 3. Then, the lens array 40 having a smaller coefficient of thermal expansion is shifted away from the reference plane by a length corresponding to the difference Δd in the amount of expansion due to the thermal expansion of the substrate 10 and the lens array 40. The thermal expansion causes the substrate 10 and the lens array 40 to expand uniformly, and the whole is expanded. Therefore, when the plurality of light emitting units 20 are turned on and the substrate 10 and the lens array 40 thermally expand in the above process, as shown in FIG. 10B, the light emitting units 20 and the lenses 41 It becomes possible to adjust relative position.

  Thus, the manufacturing process of the light emitting device 2 is completed. Below, the modification of the light emission part 20 is demonstrated.

  11A and 11B are a top view and a side view of the light emitting device 2A. The light emitting device 2 shown in FIGS. 2A and 2B and the light emitting device 2A shown in FIGS. 11A and 11B differ in the shape of the light emitting unit 20 and the arrangement of the inspection terminals 16. , Otherwise the same configuration. While the light emitting unit 20 of the light emitting device 2 is substantially rectangular, 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, and may be a circle or another shape. Further, the inspection terminal 16 of the light emitting device 2A is different from that of the light emitting device 2 in the distance between the two terminals of 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 disposed on the substrate 10 at an interval d and an angle θ according to the shape of the light emitting unit.

FIG. 12A and FIG. 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. Thus, in the light emitting device 2A as well, the LED elements 30 of each light emitting unit 20A are set in series and in parallel for the light emitting units 20A in a circular mounting area 22A of a size common to the plurality of light emitting units 20A. It is mounted with the mounting density according to. In this case, the number of LED elements 30 connected in series, the number connected in parallel, or both may be different for each light emitting unit 20A.

FIG. 13 is a view schematically showing the 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 2 B shown in FIG. 13 are different only in the number of series and the number of parallel LED elements 30 in each light emitting portion, and have the same configuration in other points. In the light emitting device 2, the number of light emitting units 20 arranged in parallel is four, but the number of the light emitting units 20 may be different from the number in parallel. 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 changing both the number of series and the number of parallel for each light emitting unit 20, the LED elements 30 of each light emitting unit 20B may be mounted within the mounting area 22 having a common shape and size among 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 are different only in the arrangement of the inspection terminals 16 of the light emitting portions, and have the same configuration in other points. In the light emitting device 2, the inspection terminals 16 of each set are disposed so as to sandwich the light emitting unit 20, but as shown in FIGS. 14A and 14B, the inspection terminals 16 of each set are The light emitting unit 20C may be disposed on one side of the light emitting unit 20C without sandwiching the light emitting unit 20C. Even in this case, the two terminals constituting each set of inspection terminals 16 are equally spaced apart by a common distance d between the plurality of light emitting units 20C.

  FIG. 15: is a figure which shows typically arrangement | positioning of the LED element 30 in light-emitting device 2D. The light emitting device 2D shown in FIG. 15 has the same size as the light emitting device 2 shown in FIG. 7 in the other points, although the size of the LED element 30 is different for each light emitting unit 20D. In the light emitting device 2D, the areas of the light emitting regions 22D of the light emitting units 20D are equal to one another, and the size of the LED elements 30 included in the light emitting units 20D is smaller for the light emitting units 20D having more LED elements 30 in series. Thus, even if the number of elements is changed for each light emitting unit 20D, it is possible to use a lens array including a plurality of lenses having the same outer shape. In addition, if the size of the element is reduced, the number of series in the light emitting region 22D of 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. It is also possible to set the voltage within a drivable range by the driver for the light emitting device 2D. In addition, among the light emitting devices 2A to 2C described so far, LED elements 30 having different sizes may be used for light emitting units having different numbers of series as described above.

  FIG. 16 is a view schematically showing the arrangement of the LED elements 30 in the light emitting device 2E. In the light emitting device 2E shown in FIG. 16, the size of each lens 41E in the lens array 40E is different for each light emitting unit 20E, but has the same configuration as the light emitting device 2 shown in FIG. 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 unit 20E of the light emitting device 2E includes four light emitting units 20E ₄ (one example of a first light emitting unit) including 16 LED elements 30 connected in series and parallel with each other in fours and fours in parallel; A light emitting unit 20E ₃ (an example of a second light emitting unit) including nine LED elements 30 connected in series and in parallel with each other by three in series and three in parallel. In the light emitting device 2E, the mounting density of the LED elements 30 is the same for 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 It can be arranged. Therefore, in the light emitting device 2E, it is possible to form many light emitting units 20E with a higher density on the surface of the substrate 10, and the amount of emitted light increases.

  17 (A) and 17 (B) are a top view and a side view of the light emitting device 2F. Unlike the light emitting device 2A shown in FIG. 11A, the light emitting device 2F shown in FIG. 17A does not have an opening at the center of the substrate 10F. 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 light emitting units 20F of the light emitting device 2F is smaller than the number of light emitting units 20A of the light emitting device 2A. Otherwise, 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 and 20B to 20E described above, and in this case, the opening may not be provided at the center of the substrate 10F.

  FIG. 18A and FIG. 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. FIG. 18A shows an example in which nine LED packages 30G are mounted in a 3 × 3 grid. The light emitting units 20 and 20A to 20F of the above-described light emitting devices 2 and 2A to 2F are not limited to those in which the LED elements 30 are connected by the wire 31 and the whole is sealed by the sealing resin 24. The LED package 30G as shown in FIG. 18B may be flip chip mounted.

  The LED package 30 </ b> G includes an LED element 30 ′ in which two element electrodes 32 are formed on the lower surface, and a phosphor layer 33. The LED package 30 </ b> G is a bump type light emitting element in which bumps 34 for flip chip bonding are formed on the element electrodes 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, for example, by dispersing and mixing phosphor particles (not shown) in a colorless and transparent resin such as an epoxy resin or a silicone resin, and the upper surface and the side surfaces of the LED element 30 ′ are uniformly formed. To coat. For example, the phosphor layer 33 contains a yellow phosphor such as YAG, absorbs blue light emitted from the LED element 30 ', and converts the wavelength into yellow light. In this case, the LED package 30G 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 thereby. In addition, the kind of fluorescent substance which the fluorescent substance layer 33 contains may be a thing other than this, and may differ for every LED package 30G.

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

Claims (4)

Mounting a plurality of light emitting elements on a substrate to form a plurality of light emitting units;
Arranging a lens array including a plurality of lenses arranged in accordance with the arrangement position of the plurality of light emitting units on the plurality of light emitting units;
Thermal expansion coefficients of the substrate and the lens array so that the relative positions of the plurality of light emitting units and the plurality of lenses match when the plurality of light emitting units are turned on and the substrate and the lens array are thermally expanded. Positioning the substrate and the lens array by shifting the plurality of light emitting units and the plurality of lenses from each other by a distance corresponding to a size of
A method of manufacturing a light emitting device, comprising: The substrate is rectangular,
In the disposing step, the end portions of the substrate and the lens array are provided in the same housing so that relative positions of the plurality of light emitting units and the plurality of lenses can be changed according to thermal expansion and thermal contraction. Fixed
In the positioning step, the substrate and the lens array are positioned by bringing two adjacent sides of the substrate and an end of the lens array corresponding to the two sides into contact with the casing. The manufacturing method according to Item 1. In the forming step, for each of the plurality of light emitting units,
Mounting a plurality of LED elements as the light emitting element on the substrate;
Electrically connecting the plurality of LED elements with each other by wire;
The manufacturing method according to claim 1, wherein a sealing resin containing a phosphor is filled on the substrate to seal the plurality of LED elements.   In the forming step, for each of the plurality of light emitting parts, a plurality of LED packages configured by covering the upper surface and the side surface of the LED element with a resin layer containing a phosphor is used as the light emitting element on the substrate. The manufacturing method according to claim 1, wherein flip chip mounting is performed.

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