JP7063583B2 - 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 plurality of LED (light emitting diode) elements are mounted as light emitting elements on a general-purpose substrate such as a ceramic substrate or a metal substrate is known. In such a light emitting device, the LED element is sealed with a translucent resin containing a phosphor, and the light from the LED element and the light obtained by exciting the phosphor by the light from the LED element are mixed. By doing so, white light or the like can be obtained depending on the application.

For example, in Patent Document 1, double partition walls are provided concentrically, a plurality of light emitting elements and a first phosphor-containing layer for sealing them are provided inside the inner partition wall, and the inner and outer partition walls are provided. A light emitting device provided with a plurality of light emitting elements and a second phosphor-containing layer for sealing them is described. That is, Patent Document 1 describes a light emitting device in which a region is divided by a partition wall formed concentrically.

Patent Document 2 describes a light emitting device in which a second resin having a partition portion for further partitioning an inner region of the first resin formed in a circle into four regions is arranged in a cross shape. In the light emitting device described in Patent Document 2, since the second resin is formed on the first resin after the formation of the first resin, the heights of the first resin and the second resin are formed to be uniform. not.

Japanese Unexamined Patent Publication No. 2014-179653 Japanese Unexamined Patent Publication No. 2014-36063

In a light emitting device in which a plurality of light emitting regions are formed on a substrate, if there is a height in the height of the annular white frame resin that defines the periphery of the light emitting region and the cross-shaped white resin that partitions the light emitting region, each light emission is performed. Light from the area is not emitted uniformly. When a light emitting device is used as a ceiling light for indoor lighting, a floodlight, or a lighting fixture for illumination, it is difficult to design an appropriate lighting if the light emitted from each light emitting region is non-uniform. In particular, when an optical element such as a lens is arranged in the vicinity of the light emitting region, the above-mentioned problem may become remarkable.

Therefore, an object of the present invention is to provide a light emitting device having a uniform height of a partition member for forming a plurality of light emitting regions.

The light emitting device according to the present invention includes a substrate, a first dam material arranged in a substantially circular shape on the substrate, a second dam material arranged in a cross shape inside the first dam material on the substrate, and a first. The first region, the second region, the third region and the fourth region partitioned by the dam material and the second dam material, the first light emitting element group mounted on the substrate in the first region, and the second region. The second light emitting element group mounted on the substrate, the third light emitting element group mounted on the substrate in the third region, and the fourth light emitting element group mounted on the substrate in the fourth region. A first sealing resin arranged in the first region so as to seal the first light emitting element group, and a second sealing resin arranged in the second region so as to seal the second light emitting element group. And the third sealing resin arranged in the third region so as to seal the third light emitting element group, and the fourth seal arranged in the fourth region so as to seal the fourth light emitting element group. It has a waterproof resin, and is characterized in that the height of the first dam material on the substrate is equal to the height of the second dam material on the substrate.

According to the above light emitting device, it is possible to ensure the uniformity of the light emitted from the plurality of light emitting regions as compared with the case where the present configuration is not provided, whereby the color of the light emitted from the plurality of light emitting regions is mixed. The color rendering property of the emission color of the entire device is improved.

(A) is a plan view of the light emitting device 1, (B) is a cross-sectional view of AA'in FIG. 1 (A), and (C) is a cross-sectional view of BB'in FIG. 1 (A). (A) is a plan view showing a circuit board and a wiring pattern arranged on a metal substrate, (B) is a sectional view taken along the line AA'of FIG. 2 (A), and (C) is a sectional view of FIG. 2 (A). BB'is a cross-sectional view. (A) is a plan view showing a state in which a light emitting element is arranged in FIG. 2 (A), (B) is a cross-sectional view taken along the line AA'of FIG. 3 (A), and (C) is a cross-sectional view of FIG. 3 (A). It is a cross-sectional view of BB'. (A) is a plan view showing a state in which a resist is applied to FIG. 3 (A), (B) is a cross-sectional view taken along the line AA'of FIG. 4 (A), and (C) is a sectional view of FIG. 4 (A). BB'is a cross-sectional view. (A) is a diagram showing a method for forming a first frame resin, (B) is a diagram showing a method for forming a second frame resin, and (C) is a diagram showing a method for forming a third frame resin. (D) is a diagram for explaining a method of adjusting the height of the frame resin. It is a figure which shows the manufacturing method of a light emitting device 1.

Hereinafter, the light emitting device will be described in detail with reference to the drawings. However, it should be understood that the invention is not limited to the drawings or embodiments described below.

1 (A) is a plan view of the light emitting device 1, FIG. 1 (B) is a cross-sectional view taken along the line AA'of FIG. 1 (A), and FIG. 1 (C) is a cross-sectional view taken along the line BB'of FIG. 1 (A). Is.

The light emitting device 1 includes a metal substrate 10, a circuit board 11, a resist 12, a first dam material 20, a second dam material 21, a first LED element 31 to a fourth LED element 34, and a first sealing resin 41 to a fourth sealing resin. It has 44, wiring patterns 51 to 58 arranged on the circuit board 10, electrode pads 61 to 68, and the like. Further, as will be described later, the LED elements are electrically connected to each other and the LED element and the electrode are electrically connected by the bonding wire W.

The metal substrate 10 is a flat substrate made of aluminum having excellent heat resistance and heat dissipation and having a mounting region of LED elements 31 to 34. The metal substrate 10 has a substantially rectangular shape, and four notches 13 to 16 for attaching the light emitting device 1 to a lighting fixture or the like are provided around the metal substrate 10. The metal substrate 10 also functions as a heat dissipation substrate that dissipates heat generated by the first LED element 31 to the fourth LED element 34 and the particles of the phosphor described later. The material of the metal substrate 10 may be another metal such as copper as long as it has excellent heat resistance and heat dissipation, and the shape is not limited to a rectangle but may be a square, a polygon, or the like. The shape and number of notches are also not limited to those shown in FIG. 1 (A).

The circuit board 11 is an insulating substrate made of a glass epoxy substrate, and has a substantially rectangular shape having the same size as the metal substrate 10. The circuit board 11 may be made of another material such as ceramic as long as it is insulating, and the shape may not necessarily be the same as that of the metal substrate 10. Similar to the metal substrate 10, four notches are provided around the circuit board 11.

The resist 12 is an insulating white paint and is applied to the surface of the circuit board 11. The resist 12 is provided to prevent a short circuit between wiring patterns arranged on the circuit board 11 or to prevent a short circuit between the wiring pattern and the bonding wire.

2A is a plan view showing the circuit board 11 arranged on the metal substrate 10 and the wiring pattern, FIG. 2B is a cross-sectional view taken along the line AA'of FIG. 2A, and FIG. 2C is a cross-sectional view taken along the line AA'. ) Is a cross-sectional view taken along the line BB'in FIG. 2 (A).

As shown in FIG. 2, the circuit board 11 has four openings 11A to 11D, and the surface of the metal substrate 10 is exposed from each opening. The surfaces of the metal substrate 10 exposed by the four openings 11A to 11D each serve as a mounting area for an LED element described later.

As shown in FIG. 2, conductive wiring patterns 51 to 58 are formed on the upper surface of the circuit board 11 around the four openings 11A to 11D. The wiring patterns 51 to 58 are formed by gold plating, but may be formed of another metal thin film.

3 (A) is a plan view showing a state in which a light emitting element is arranged in FIG. 2 (A), FIG. 3 (B) is a sectional view taken along the line AA'of FIG. 3 (A), and FIG. 3 (C) is a view. 3 (A) is a cross-sectional view taken along the line BB'.

In the opening 11A of the circuit board 11, 25 first LED elements 31 are mounted on the surface of the metal circuit 10. Five sets of first LED elements 31 connected in series by five are electrically connected in parallel between the wiring patterns 53 and 54 by a bonding wire W. In the opening 11B of the circuit board 11, 25 second LED elements 32 are mounted on the surface of the metal circuit 10. Five sets of second LED elements 32, five of which are connected in series, are electrically connected in parallel between the wiring patterns 55 and 56 by a bonding wire W.

In the opening 11C of the circuit board 11, 25 third LED elements 33 are mounted on the surface of the metal circuit 10. Five sets of third LED elements 33, five of which are connected in series, are electrically connected in parallel between the wiring patterns 57 and 58 by a wire W. In the opening 11D of the circuit board 11, 25 fourth LED elements 34 are mounted on the surface of the metal circuit 10. Five sets of fourth LED elements 34, five of which are connected in series, are electrically connected in parallel between the wiring patterns 51 and 52 by a bonding wire W.

A Zener diode 71 for preventing backflow is connected between the wiring patterns 53 and 54. A Zener diode 72 for preventing backflow is connected between the wiring patterns 55 and 56. A Zener diode 73 for preventing backflow is connected between the wiring patterns 57 and 58. A Zener diode 74 for preventing backflow is connected between the wiring patterns 51 and 52. The Zener diodes 71 to 74 for preventing backflow are arranged so that a current does not flow directly from the anode electrode side to the cathode electrode side, which will be described later.

In the light emitting device 1, all of the first LED element 31 to the fourth LED element 34 are blue LED dies of the same type that emit blue light having a light emitting wavelength band of about 450 to 460 nm. The first LED element 31 to the fourth LED element 34 are not limited to the blue LED die, and may be, for example, a purple LED die or a near-ultraviolet LED die, and the emission wavelength band thereof is within the range of about 200 to 460 nm including the ultraviolet region. May be. Each of the first LED element 31 to the fourth LED element 34 is fixed to the metal substrate 10 side with the light emitting surface facing the side opposite to the metal substrate 10 by an insulating adhesive (die bond).

In each of the openings 11A to 11D of the circuit board 11 shown in FIG. 3, the total number of LED elements mounted on the metal substrate 10, the number of LED elements connected in series, and the number of sets of LED elements connected in parallel. Are examples, and may be other numbers.

The eight points shown by the dotted lines in FIG. 3 indicate the portions exposed on the surface as the electrode pads 61 to 68 after the resist 12 is applied.

4 (A) is a plan view showing a state in which the resist 12 is applied to FIG. 3 (A), FIG. 4 (B) is a cross-sectional view taken along the line AA'of FIG. 4 (A), and FIG. 4 (C) is taken. Is a cross-sectional view taken along the line BB'in FIG. 4 (A).

The resist 12 is applied so as to cover the circuit board 11 leaving the periphery of the four openings 11A to 11D and the portion exposed on the surface as the electrode pads 61 to 68 on the wiring patterns 51 to 58. In FIG. 4A, for the sake of explanation, the portion to which the resist 12 is applied is shown by diagonal lines. Further, the resist 12 is further applied so as to cover the tip portions of the wiring patterns 51, 53, 55 and 57 formed in a part of the cross shape formed inside the four openings 11A to 11D in the circuit board 11. You may.

One of the electrode pads 63 and 64 is an anode electrode and the other is a cathode electrode, and when these are connected to an external power source and a predetermined voltage is applied, one of the wiring patterns 53 and 54 is connected to the other via the LED element. A current flows through the light, and the plurality of first LED elements 31 emit light at the same time. Similarly, a predetermined voltage is applied between the electrode pads 65 and 66 to cause the plurality of second LED elements 32 to emit light at the same time, and a predetermined voltage is applied between the electrode pads 67 and 68 to cause the plurality of third LED elements 33 to simultaneously emit light. Light is emitted, a predetermined voltage is applied between the electrode pads 61 and 62, and the plurality of fourth LED elements 34 simultaneously emit light.

For example, assuming that the forward voltage of one LED element 31 is Vf ₁ (about 3V), when a voltage of 5 × Vf ₁ (about 15V) or more is applied between the electrode pads 53 and 54, all the LEDs The element 31 will emit light. The same applies to the other LED elements 32 to 34.

FIG. 5A is a diagram showing a method for forming the first frame resin, FIG. 5B is a diagram showing a method for forming the second frame resin, and FIG. 5C is a diagram showing a method for forming the third frame resin. 5 (D) is a diagram for explaining a method of adjusting the height of the frame resin.

In FIG. 5A, the uncured first frame resin 81 is placed from the hopper (not shown) on the substrate in the state of FIG. 4A so as to surround the first LED element 31 to the fourth LED element 34. , A plan view showing a state of application in the direction of arrow C, and a cross-sectional view taken along the line AA'in the plan view are shown. The substrate 13 in the cross-sectional view is a general term for an aggregate formed of a metal substrate 10, a circuit board 11, and a resist 12. Let H be the height of the uncured first frame resin 81 from the substrate 13.

FIG. 5B shows a state in which the uncured second frame resin 82 is applied from a hopper (not shown) from the top to the bottom of the first frame resin 81 coated in a substantially circular shape in the direction of the arrow D. A plan view showing the above and a cross-sectional view of AA'in the plan view are shown. The coating amount is defined by the hopper so that the height from the substrate 13 in the central portion of the uncured second frame resin 82 is also the same height (H) as the height of the uncured first frame resin 81.

FIG. 5C shows a state in which the uncured third frame resin 83 is applied from the hopper (not shown) in the direction orthogonal to the second frame resin 82 from left to right in the figure in the direction of arrow E. A plan view and a cross-sectional view of AA'in the plan view are shown. From the top of the first frame resin 81 and the second frame resin 82 to the portion where the third frame resin 83 is applied, from the substrate 13 to the upper part of the third frame resin 83 as shown in the cross-sectional view of FIG. 5C. The height (H) will fluctuate.

In FIG. 5D, after the third frame resin 83 is applied, a scraper (not shown) is used to perform a flattening treatment such as removing the frame resin at the raised portion or leveling it from above, and the height from the substrate 13 is high. Is shown in a uniform state (height H). After the flattening treatment is completed, the frame resin is cured to form a substantially circular first dam 20 and a cross-shaped second dam material 21. The height (H) from the substrate may be slightly reduced due to shrinkage due to curing, but this point is not taken into consideration in FIG. 5 (D).

In the flattening process, if the resin once applied is leveled without being removed, the initially raised resin will spread to the left and right, so the width of the applied frame resin will increase. In such a case, it is necessary to adjust the coating amount of the frame resin in advance so that the resin does not flow into the mounting area of the LED element.

By the flattening treatment as described above, as shown in FIG. 1 (B), the inner edge portion of the first dam material 20 does not enter inside from the outer edge portions of the first openings 11A to 11D of the circuit board 11. Is formed in. Similarly, the outer edge portion of the first dam material 20 is formed on the upper portion of the resist 21, and is formed so as to cover the wiring pattern exposed to the outside from the resist 12. Further, as shown in FIG. 1B, the second frame resin 21 is a part of the cross shape formed inside the four openings 11A to 11D in the circuit board 11 by the flattening treatment as described above. It is formed so that it does not enter from the top to the inside. As a result, the second frame resin 21 covers the tip portions of the wiring patterns 51, 53, 55 and 57 formed in a part of the cross shape formed inside the four openings 11A to 11D in the circuit board 11. ing.

The first frame resin 81 to the third frame resin 83 are obtained by mixing a white paint with a thermosetting silicone resin, and have light reflectivity after curing. Therefore, the light emitted from the LED elements arranged in each of the regions divided into four by the first dam material 20 and the second dam material 21 is configured so as not to be mixed with each other. As a result, the light emitted laterally from the first LED element 31 to the fourth LED element 34 is directed toward the front surface of the light emitting device 1 (the side opposite to the metal substrate 10 when viewed from the first LED element 31 to the fourth LED element 34). Since it is reflected, the light emission intensity in front of the light emitting device 1 becomes high. When it is desired to mix the color of the light emitted from the LED element, a scattering agent or the like is mixed with the first frame resin 81 to the third frame resin 83 instead of the white paint, and the resin is cured while maintaining the transparency. Is also possible.

In the example shown in FIG. 5A, the first frame resin 81 was applied in a circular shape. However, the first frame resin 81 may be applied in an elliptical shape. That is, it is preferable that the first dam material 20 is formed in a substantially circular shape including a circular shape and an elliptical shape. The second frame resin 82 and the third frame resin 82 are formed in a cross shape inside the first frame resin even when the first frame resin 81 is applied in an elliptical shape.

FIG. 6 is a diagram showing a manufacturing method of the light emitting device 1.

First, the circuit board 11 on which the wiring patterns 51 to 58 and the openings 11A to 11D are formed in advance is fixed to the upper surface of the metal substrate 10 prepared in advance by an adhesive sheet (not shown) (S1). This state is the state shown in FIG.

Next, the LED elements 31 to 34 are mounted on the surface of the metal substrate 10 in the openings 11A to 11D of the circuit board 11, and the mounted LED elements 31 to 34 and the wiring patterns 51 to 58 are electrically connected by the bonding wire W. Connect to (S2). This state is the state shown in FIG.

Next, the resist 12 is applied so as to cover a predetermined portion of the wiring patterns 51 to 58 (S3). This state is the state shown in FIG.

Next, the first frame resin 81 to the third frame resin 82 are applied from above the resist 12 (S4). This state is the state shown in FIG. 5 (C).

Next, a flattening treatment is performed so that the heights of the applied first frame resin 81 to third frame resin 83 become uniform (S5). After that, the substrate 13 coated with the frame resin is stored in a temperature-adjustable place for a predetermined time, and further heated to cure the frame resin to form the first dam material 20 and the second dam material 21 (S6). This state is the state shown in FIG. 5 (D).

Next, the uncured sealing resin is applied to the regions divided into four by the first dam material 20 and the second dam material 21 (S7). After that, the substrate 13 coated with the sealing resin is stored in a temperature-adjustable place for a predetermined time, and further heated and cured as the first sealing resin 41 to the fourth sealing resin 44 (S8), and the light emitting device. Complete 1 This state is the state shown in FIG.

In the light emitting device 1, the four regions on the fan, which are separated by the first dam material 20 and the second dam material 21 and are sealed by the first sealing resin 41 to the fourth sealing resin 44, are the first to the first, respectively. It corresponds to the fourth light emitting region. The first light emitting region (the part where the first sealing resin 41 is arranged) is amber, the second light emitting region (the part where the second sealing resin 42 is arranged) is blue, and the third light emitting region (the third). The portion where the sealing resin 43 is arranged) emits green light, and the fourth light emitting region (the portion where the fourth sealing resin 44 is arranged) emits red light.

The first sealing resin 41 absorbs blue light from the first LED element 31 and emits light in amber color (580 to 640 nm) (Y, Gd) ₃ Al ₅ O ₁₂ : Ce YAG-based phosphor and boron. It is a thermosetting silicone resin containing a mixture of added Ca ₂ Si ₅ N ₈ : Eu nitrogen-based phosphor and the like. A filler may be mixed in the first sealing resin 41 as a scattering agent, or a colorless and transparent epoxy resin or the like may be used instead of the silicone resin.

The second sealing resin 42 is a colorless and transparent thermosetting silicone resin that outputs blue light from the second LED element 32 as it is, does not contain a phosphor. A filler may be mixed in the second sealing resin 42 as a scattering agent, or a colorless and transparent epoxy resin or the like may be used instead of the silicone resin. When the second LED element 32 is an element that emits ultraviolet light, it may contain a phosphor such as BaMgAl ₁₀ O ₁₇ : Eu ²⁺ that absorbs ultraviolet light and emits blue light.

The third sealing resin 43 is a thermosetting silicone resin containing a phosphor such as (BaSr) ₂ SiO ₄ : Eu ²⁺ , which absorbs blue light from the third LED element 33 and emits green light. A filler may be mixed in the third sealing resin 43 as a scattering agent, or a colorless and transparent epoxy resin or the like may be used instead of the silicone resin.

The fourth sealing resin 44 is a thermosetting silicone resin containing a phosphor such as CaAlSiN ₃ : Eu ²⁺ that absorbs blue light from the fourth LED element 34 and emits red light. A filler may be mixed in the fourth sealing resin 44 as a scattering agent, or a colorless and transparent epoxy resin or the like may be used instead of the silicone resin.

As described above, the light emitting device 1 is provided with four systems of electrode pads 61 to 68 corresponding to the first to fourth light emitting regions, and each light emitting region can independently emit light. Therefore, in the light emitting device 1, it is possible to emit light for each color, and if all four colors are emitted, white light can be obtained. Further, by adjusting the current in each light emitting region, it is possible to adjust the overall light emitting color. That is, the light emitting device 1 is a full-color COB lighting package in which four LED light emitting modules are integrated into one unit to realize a toning function of white light.

Therefore, the light emitting device 1 can be used as an LED light source device such as a floodlight, high ceiling lighting, stadium lighting, and illumination. Further, in order to control the light emitted from the light emitting device 1, an optical member such as a condensing lens may be arranged directly above the light emitting device 1.

In the light emitting device 1, as described above, the first dam material 20 and the second dam material 21 are formed so that their heights from the substrate are uniform. Therefore, it is suitable for arranging an optical member such as a condensing lens directly above the light emitting device 1. Further, when four light emitting regions are individually emitted, all the regions are surrounded by dam materials having the same shape and the same height, so that it is easy to control the amount of light in each region.

Further, the light emitting device 1 is configured to have four light emitting regions that emit light in amber, blue, green, and red, but the color combination is not limited to the above. For example, it may be a combination of other colors such as four colors of blue, green, red and cyan, four colors of blue, green, red and white, and two places of blue and two places of red. Regardless of the color combination, it is important that the outer shapes of the four light emitting regions have the same shape and that the surroundings are surrounded by dam material of the same height.

Further, in the light emitting device 1, since the first LED element 31 to the fourth LED element 34 are directly mounted on the upper surface of the metal substrate 10 exposed in each of the openings 11A to 11D of the circuit board 11, the heat dissipation is good. , It is possible to extend the product life.

Further, in the light emitting device 1, in order to facilitate manufacturing, LED dies having the same emission wavelength are used as the first LED element 31 to the fourth LED element 34, and different types of phosphors are dispersed and mixed in each sealing resin ( Alternatively, a different emission color is obtained for each light emitting region by allowing the phosphor to be mixed). However, as the first LED element 31 to the fourth LED element 34, LED dies having different emission wavelengths may be used. In this case, it is not always necessary to mix the fluorescent substance in the sealing resin in order to obtain a desired emission color.

1 Light emitting device 10 Metal substrate 11 Circuit board 11A, 11B, 11C, 11D Opening 12 Resist 20 1st dam material 21 2nd dam material 31, 32, 33, 34 LED element 41, 42, 43, 44 Sealing resin 51 , 52, 53, 54, 55, 56, 57, 58 Wiring pattern 61, 62, 63, 64, 65, 66, 67, 68 Electrode pads 71, 72, 73, 74 Zener diode 81, 82, 83 Frame resin W Bonding wire

Claims (1)

By forming the first dam material in a substantially circular shape on the substrate and forming the second dam material in a cross shape inside the first dam material on the substrate, the first region and the second are formed on the substrate. Forming a region, a third region and a fourth region,
The first light emitting element group is mounted in the first region, and the first light emitting element group is mounted.
A second light emitting element group is mounted in the second region, and the second light emitting element group is mounted.
A third light emitting element group is mounted in the third region, and the third light emitting element group is mounted.
A fourth light emitting element group is mounted in the fourth region, and the fourth light emitting element group is mounted.
The first light emitting element group mounted in the first region is sealed with the first sealing resin.
The second light emitting element group mounted in the second region is sealed with a second sealing resin.
The third light emitting element group mounted in the third region is sealed with a third sealing resin.
The fourth light emitting element group mounted in the fourth region is sealed with the fourth sealing resin.
Including that
Forming the first dam material and the second dam material is
The first frame resin corresponding to the first dam material and the second frame resin corresponding to the second dam material are applied onto the substrate, respectively.
After applying the first frame resin and the second frame resin, the first frame resin and the second frame resin are leveled to increase the height of the first frame resin and the second frame resin on the substrate. Uniformly
After making the heights of the first frame resin and the second frame resin uniform on the substrate, the first frame resin and the second frame resin are cured.
Including that
In each of the light emitting element groups of the first light emitting element group to the fourth light emitting element group, they are all light emitting elements having the same light emitting color.
The at least one sealing resin of the first sealing resin to the fourth sealing resin contains a fluorescent substance.
When the second dam material is applied, the amount of the resin to be applied is adjusted so that the resin to be applied does not flow into the first region, the second region, the third region and the fourth region.
A method for manufacturing a light emitting device.

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