JP2011166035A - Light emitting device and lighting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device for suppressing the separation of a sealing resin layer without providing a special member such as a frame member, and to provide a lighting apparatus using the light emitting device. <P>SOLUTION: The light emitting device 1 includes a substrate 10 having an insulating property at least at a front surface side, a thermo-conductive pad 15a formed at the front surface side of the substrate 10, a light reflecting layer 45 that is formed on the thermo-conductive pad 15a at least except the element mounting part and laminated with the inclusion of a recess 45a extending in the front surface direction of the substrate 10 in a cross-sectional shape at a boundary with the element mounting part, a light emitting element 11 mounted to the element mounting part on the thermo-conductive pad 15a, and a sealing resin layer 12 covering the light emitting element 11 including the boundary of the light reflecting layer 45. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light emitting device and a lighting device using a light emitting element such as an LED.

  Recently, a lighting device has been developed in which a plurality of light emitting elements such as LEDs are mounted on a substrate as a light source to obtain a predetermined light amount. This illuminating device is used, for example, as a so-called direct attachment type base illumination that is directly attached to a ceiling surface or the like.

  By the way, in such an illuminating device, the sealing member (sealing resin layer) which covers and seals the light emitting element mounted in the board | substrate is provided. This sealing member is generally made of a material in which a phosphor is mixed into a transparent silicone resin or the like, and is injected into a region surrounded by a resin frame member (for example, a reflector) to be solidified (for example, , See Patent Document 1). In this case, the frame member has a function of preventing the sealing member from inadvertently flowing out, but the light emitted from the light emitting element is reflected on the inner surface of the frame member, and is further subjected to multiple reflection within the sealing member. Thus, there arises a problem that the light emission efficiency is lowered due to the reflection loss.

  For this reason, the viscosity of a sealing member is adjusted to the extent which does not flow out, and the method of sealing a light emitting element with a sealing member without providing a frame member can be considered. For example, Patent Document 2 discloses that a sealing member is formed without a frame member.

  In addition, a technique is disclosed in which a sealing member is dropped for each light emitting element in an uncured state, cured in a hemispherical shape after dropping, and sealed for each light emitting element (see, for example, Patent Document 3). ).

JP 2008-85302 A (paragraphs [0066] and [0067]) JP 2009-54989 A (paragraph [0022], FIGS. 1 to 3) JP 2008-166081 A (paragraph [0050]))

  However, when the frame member is not provided as described above, since the sealing member is bonded onto the substrate, for example, when a lateral force is applied, the sealing member may be peeled off from the substrate.

  This invention is made | formed in view of such a subject, and it aims at providing the light-emitting device and illuminating device which can suppress peeling of a sealing resin layer, without providing special members, such as a frame member.

The light-emitting device according to claim 1 is formed by excluding at least an element mounting portion on the heat conductive pad; a substrate having insulating properties at least on the surface side; a heat conductive pad formed on the surface side of the substrate; A light-reflecting layer laminated with a recess whose cross-sectional shape extends in the surface direction of the substrate at a boundary with the element mounting portion; a light-emitting element mounted on the element mounting portion on the thermal conduction pad; And a sealing resin layer covering the light emitting element including the boundary portion of the reflective layer.
In the present invention and the following inventions, the technical meaning and interpretation of terms are as follows unless otherwise specified.

  A glass epoxy resin, a ceramic material, or another synthetic resin material can be applied to the substrate material. Furthermore, the present invention provides a metal base substrate in which an insulating layer is laminated on one surface of a base plate having good thermal conductivity such as aluminum and excellent heat dissipation for improving the heat dissipation of each light emitting element. Does not preclude the application. In addition, a rectangular shape, a square shape, or a circular shape can be applied to the substrate. The special shape is not limited.

  The heat conductive pad is preferably used as, for example, a wiring pattern, but is not necessarily used as a wiring pattern. A function as a heat spreader that conducts and diffuses heat from a light emitting element or a function that reflects light may be sufficient.

The light reflecting layer is not particularly limited in its material and forming means as long as a concave portion capable of suppressing the peeling of the sealing resin layer can be formed. Preferably, a white resist layer is used as the light reflecting layer. In addition to being able to suppress the peeling of the sealing resin layer by using a white resist layer, in the case of a region covering the heat conductive pad, the heat conductive pad is prevented from being deteriorated, and the solder is used. Can function as a solder resist. In addition, although it is preferable to use a photoresist material for formation of a resist layer, it is not limited to this material.
A light emitting element is a solid light emitting element such as an LED. Further, the number of mounted light emitting elements is not particularly limited.
As the sealing resin layer, for example, a transparent silicone resin containing an appropriate amount of phosphor can be used.
The light emitting device according to claim 2 is the light emitting device according to claim 1, wherein the surface of the light reflecting layer is formed at a position lower than the height of the light emitting element.
With this configuration, it can be reduced that the light reflecting layer becomes an obstacle to light emitted from the light emitting element.
According to a third aspect of the present invention, there is provided an illumination device comprising: a device main body; and the light emitting device according to the first or second aspect disposed in the device main body.
The lighting device includes a light source, a lighting fixture used indoors or outdoors, a display device, and the like.

  According to invention of Claim 1, the light-emitting device which can suppress peeling of a sealing resin layer can be provided, without providing special members, such as a frame member.

According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, it can be reduced that the light reflection layer becomes an obstacle to the light emitted from the light emitting element, and the light emission efficiency is improved. can do.
According to the invention described in claim 3, it is possible to provide an illuminating device that exhibits the effects of the invention described in the above-mentioned claim.

It is a top view which shows the light-emitting device of the 1st Embodiment of this invention seeing from the surface side. It is a top view which shows the wiring pattern and connection pattern in the board | substrate. It is a top view which shows the state which removed the connection pattern in a board | substrate and mounted the light emitting element. It is a top view which shows the state which apply | coated the fluorescent substance layer to the state shown in FIG. It is a top view which shows the back surface side of a board | substrate. It is typical sectional drawing which follows the YY line in FIG. It is a connection diagram which shows the connection state of a light emitting element. It is a perspective view which shows the illuminating device of the ceiling direct attachment type which has arrange | positioned the light-emitting device. It is a top view which shows the light-emitting device of the 2nd Embodiment of this invention seeing from the surface side.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 7 show the light emitting device 1, and FIG. 8 shows an illumination device 20 using the light emitting device 1. In addition, the same code | symbol is attached | subjected to the same part in each figure, and the overlapping description is abbreviate | omitted.
As shown in FIG. 1, the light emitting device 1 includes a substrate 10, a plurality of light emitting elements 11, and a phosphor layer 12 as a sealing resin layer that covers each light emitting element 11.

  The substrate 10 is formed in an elongated rectangular shape using an insulating material such as glass epoxy resin. Therefore, the surface of the substrate has insulating properties, the length dimension is 230 mm, and the width dimension is 35 mm. The thickness dimension of the substrate 10 is preferably 0.5 mm or more and 1.8 mm or less, and in this embodiment, a thickness of 1 mm is applied.

  The shape of the substrate 10 is not limited to a rectangular shape. A square or circular shape can be applied. Moreover, a ceramic material or another synthetic resin material can be applied to the material of the substrate 10. Furthermore, the present invention is a metal base in which an insulating layer is laminated on one surface of a base plate having good thermal conductivity such as aluminum and excellent heat dissipation in order to enhance the heat dissipation of each light emitting element 11. It does not prevent the application of the substrate.

  A plurality of front and back through portions 40 for mounting the substrate 10 are formed on the outer edge portions of the opposing long sides of the substrate 10. The front and back through-holes 40 are arc-shaped cutouts that open to the outside, and are used when the light-emitting device 1 is attached to the main body of the lighting device. Specifically, the shaft portion of the mounting screw 41, which is a fixing means, passes through the notch portion and is screwed into the main body side of the lighting device, and the head portion is hooked on the upper edge of the notch portion and fixed. 1 is attached. Further, on the surface side of the substrate 10, a groove portion 141 is formed after removing a connection pattern 14 to be described in detail later.

  Furthermore, noise is superimposed on the power supply connector 42 connected to the power supply side, the connection connector 43 used when a plurality of the light emitting devices 1 are connected to form the lighting device, and the lighting circuit on the surface side of the substrate 10. A capacitor C for preventing erroneous lighting of the light emitting element 11 is mounted.

  As shown in FIGS. 2 to 4 and 6, a wiring pattern 15 is formed on the substrate 10. The wiring pattern 15 includes a heat conductive pad 15a in which a plurality of light emitting elements 11 are arranged and arranged in a plurality of longitudinal directions, a power supply conductor 15b that electrically connects the heat conductive pads 15a, and a power supply terminal 15c. ing.

  One heat conductive pad 15a basically has a substantially rectangular shape, and two narrow feed conductors 15b1 extend in the longitudinal direction from one side. The feeding conductor 15b1 is formed with a plurality of, specifically six, convex feeding electrons 15b2 in a direction orthogonal to the extending direction.

  On the other hand, the feeding conductor 15b1 of the adjacent thermal conductive pad 15a is inserted with an insulating interval in the long side and the central part of the thermal conductive pad 15a, and further, an insertion recess 15b3 into which the power supply 15b2 is inserted is formed. ing. Nine such heat conductive pads 15a are combined in a reversed order and arranged in the longitudinal direction to form a pattern.

  As shown in FIG. 6, the wiring pattern 15 and the connection pattern 14 have a three-layer structure. On the surface of the substrate 10, copper (Cu) as the first layer 151 and nickel (Ni) as the second layer 152 are electroplated. The third layer 153 is subjected to electrolytic plating with silver (Ag) having high reflectivity. The third layer 153 of the wiring pattern 15, that is, the surface layer, is all subjected to silver (Ag) plating to form a reflective layer, and the total light reflectance is as high as 90%.

  In this electrolytic plating treatment, the nickel (Ni) film thickness of the second layer 152 is preferably 5 μm or more, and the silver (Ag) film thickness of the third layer 153 is preferably 1 μm or more. By setting the film thickness, a uniform film thickness can be formed and the reflectance can be made uniform.

  As shown in FIGS. 1 and 6, a white resist layer 45 having a high reflectance is laminated on the entire surface of the substrate 10 as a light reflection layer on almost the entire surface except for the mounting region of the light emitting element 11 and the mounting portion of the components. Has been. Therefore, in FIGS. 2 to 4, the wiring pattern 15 and the like are shown for the sake of explanation. However, when the white resist layer 45 is formed, the wiring pattern 15 and the like are actually visually visible. It has become difficult.

  In FIG. 3, in order to easily explain the region where the resist layer 45 is not formed, the region S where the resist layer 45 is not formed is shown as a representative in the second thermal conduction pad 15a from the right in the drawing. Yes. Accordingly, the other eight heat conductive pads 15a similarly have regions S where the resist layer 45 is not formed. At least a portion to which the light emitting element 11 (LED bare chip) is bonded, that is, a mounting portion of the light emitting element 11 is a region S where the resist layer 45 is not formed.

  As shown in FIG. 6, a heat conductive pad 15a is formed on the surface of the substrate 10, and a resist layer 45 is laminated thereon. The resist layer 45 is formed having a recess 45 a whose cross-sectional shape extends in the surface direction of the substrate 10 at the boundary with the region S where the resist layer 45 is not formed. That is, in the range of the thickness dimension of the resist layer 45 laminated on the heat conductive pad 15a, the concave portion 45a is formed in the lateral direction with an inclined surface so as to spread downward in the drawing.

  This resist layer is made of a white photoresist material, and has a function of reflecting light traveling from the light emitting element 11 toward the front surface side of the substrate 10 to the front surface side, and corrosion of metal layers such as the heat conductive pad 15a and the power supply conductor 15b. It has a function to prevent the above.

  The plurality of light emitting elements 11 are LED bare chips. For example, an LED bare chip that emits blue light in order to cause white light to be emitted from the light emitting unit is used. As shown in FIG. 5, the bare chip of this LED is bonded onto the heat conductive pad 15 a using a silicone resin-based insulating adhesive 16. In this case, the height of the upper surface of the bare chip of the LED is higher than the height of the surface of the resist layer 45. In other words, the surface of the resist layer 45 is formed at a position lower than the height of the light emitting element 11.

  Incidentally, the thickness dimension of the heat conductive pad 15a is 35 μm, the thickness dimension of the resist layer 45 is 30 to 40 μm, and the height dimension of the light emitting element 11 is 80 μm.

  An LED bare chip is, for example, an InGaN-based element, in which a light-emitting layer is stacked on a light-transmitting sapphire element substrate, and the light-emitting layer includes an n-type nitride semiconductor layer, an InGaN light-emitting layer, and a p-type nitride layer. A physical semiconductor layer is sequentially stacked. And the electrode for sending an electric current through a light emitting layer was formed with the p-type electrode pad on the p-type nitride semiconductor layer, and the n-type electrode pad on the n-type nitride semiconductor layer. It consists of a negative electrode. These electrodes are electrically connected on the wiring pattern 15 by bonding wires 17. The bonding wires 17 are made of gold (Au) fine wires, and are connected via bumps mainly composed of gold (Au) in order to improve mounting strength and reduce damage to bare LED chips.

  As representatively shown in FIG. 3, the plurality of light emitting elements 11 are bonded onto the heat conductive pad 15a corresponding to the power supply 15b2 of the heat conductive pad 15a. In one thermal conductive pad 15a, six light emitting elements 11 are provided on the upper and lower sides in the drawing, and a total of twelve light emitting elements 11 are provided. These light emitting elements 11 are provided on a plurality of heat conductive pads 15a arranged in the longitudinal direction, and are arranged so as to form a plurality of rows to form a light emitting element row. Specifically, two light emitting element rows are formed in the longitudinal direction.

  Further, since the power supply 15b2 of the heat conductive pad 15a is inserted into the insertion recess 15b3 of the adjacent heat conductive pad 15a, the light emitting element 11 can be disposed at the center of the heat conductive pad 15a. The heat generated from the light emitting element 11 can be effectively dissipated through the heat conductive pad 15a.

  Each of the light emitting elements 11 arranged in this manner has, for example, a positive side power supply through a heat conduction pad 15a and a bonding wire 17 through a plus side electrode of the light emitting element 11 and a bonding wire 17 from the plus side electrode of the light emitting element 11. Are sequentially connected to the power supply 15b2 of the adjacent heat conduction pad 15a through which power is supplied to each light emitting element 11.

  The light emitting elements 11 connected as described above are connected as shown in FIG. That is, nine parallel circuits in which 12 light emitting elements 11 are connected in parallel are connected in series. A capacitor C for preventing erroneous lighting is connected to both ends of each parallel circuit and the series connection circuit.

  The phosphor layer 12 is made of a translucent synthetic resin, for example, a transparent silicone resin, and contains an appropriate amount of a phosphor such as YAG: Ce. The phosphor layer 12 has a chevron shape and a flat circular arc shape, and forms a plurality of rows along the light emitting element row as shown in FIGS. 1, 4 and 6, that is, two rows. Each light emitting element 11 and the bonding wire 17 are covered and sealed. As shown in FIG. 6, the phosphor layer 12 is formed so as to enter the recess 45 a at the boundary portion of the resist layer 45.

  The phosphor is excited by light emitted from the light emitting element 11 and emits light of a color different from the color of light emitted from the light emitting element 11. In the present embodiment in which the light emitting element 11 emits blue light, a yellow phosphor that emits yellow light having a complementary color relationship with blue light is used for the phosphor so that white light can be emitted. Has been.

  The phosphor layer 12 is adjusted to a predetermined viscosity and applied in correspondence with each light emitting element 11 and the bonding wire 17 in an uncured state while maintaining a flat arc shape without inadvertently flowing out. Into the recess 45a at the boundary portion of the resist layer 45, it is then heated and cured or left for a predetermined time to be cured.

  As shown in FIGS. 5 and 6, a pattern of a heat-dissipating copper foil 46 is formed on the entire back surface of the substrate 10. This pattern is divided into 18 blocks vertically and horizontally so as to correspond to the heat conductive pads 15a on the front side.

  With such a configuration, the temperature uniformity of the entire substrate 10 can be achieved and the heat dissipation performance can be improved, and in particular, the warpage and deformation due to the heat of the substrate 10 can be caused by the line-shaped dividing portion 46a orthogonal to the longitudinal direction of the substrate 10. Can be suppressed. Note that a resist layer is laminated on the copper foil 46 (see FIG. 6).

  Next, an outline of the manufacturing process of the light emitting device 1 configured as described above will be described with reference to FIGS. As shown in FIG. 2, a wiring pattern 15 and a connection pattern 14 are formed on the surface side of the substrate 10. The wiring pattern 15 and the connection pattern 14 have a three-layer configuration. The wiring pattern 15 functions as a power supply path for supplying power to each light emitting element 11. The connection pattern 14 is made of copper (Cu ) When electrolytically plating nickel (Ni) of the second layer 152 and silver (Ag) of the third layer 153 on the pattern, it functions as a connection path for making the portions of the respective heat conductive pads 15a have the same potential.

  In the process of forming the wiring pattern 15 and the connection pattern 14, a copper (Cu) pattern is formed on the surface of the substrate 10 as the first layer 151. Next, nickel (Ni) as the second layer 152 and silver (Ag) as the third layer 153 are subjected to electrolytic plating.

Next, as representatively shown in FIG. 6, the pattern of the resist layer 45 is formed on the wiring pattern 15 and the connection pattern 14. As described above, the pattern of the resist layer 45 is formed in a range excluding the mounting region of the light emitting element 11 and the mounting portion of the component. In this embodiment, a white photoresist material is used, and exposure is performed by irradiating ultraviolet rays to form a pattern. In this case, when the resist layer is irradiated with ultraviolet rays, a part of the irradiated light at the boundary portion of the resist layer 45 is transmitted through the resist layer and reflected by the surface of the heat conductive pad 15a and directed sideways or obliquely upward. In the range of the thickness dimension, exposure is performed in a hollow shape. As a result, a recess 45a at the boundary portion of the resist layer 45 is formed by a subsequent development process or the like. Formation by such exposure can be performed by adjusting and setting the irradiation intensity and time of ultraviolet rays.
The step of forming the pattern of the resist layer 45 can also be performed after the next step of removing the connection pattern 14.

  As shown in FIG. 3, the connection pattern 14 is removed from the substrate 10 on which the wiring pattern 15, the connection pattern 14, and the resist layer 45 are formed. For example, the connection pattern 14 on the surface of the substrate 10 is scraped off using a router, a trimmer, or the like. Therefore, the electrical connection between each heat conductive pad 15a and the connection pattern 14 is cut off. After the connection pattern 14 is scraped off, a groove 141 that is linear in the longitudinal direction and concave in cross section is formed as a trace.

  Subsequently, a plurality of light emitting elements 11 are mounted on the heat conductive pad 15a of the wiring pattern 15 so as to form a light emitting element row, and a row is formed on the phosphor layer 12 as shown in FIG. Cover and seal. In this case, since the phosphor layer 12 is adjusted to have a predetermined viscosity, the side surface is held in a flat arc shape, and enters the concave portion 45 a at the boundary portion of the resist layer 45 and is cured.

  Next, with reference to FIG. 8, the illuminating device 20 which has arrange | positioned the said light-emitting device 1 is demonstrated. In the figure, a direct ceiling-mounted illumination device 20 used by being installed on a ceiling surface is shown. The illuminating device 20 includes an elongated and substantially rectangular parallelepiped main body case 21. In the main body case 21, a plurality of the light emitting devices 1, specifically two, are connected in a straight line. ing. The power supply unit including the power supply circuit is built in the main body case 21. A diffusive front cover 22 is attached to the lower opening of the main body case 21.

  The operation of the light emitting device 1 having the above-described configuration will be described. When energized by the power supply circuit, the light emitting elements 11 are turned on all at once, the light emitted from the light emitting elements 11 is emitted through the phosphor layer 12, and the light emitting device 1 emits white light. Used as a planar light source.

  During the lighting, the heat conductive pad 15a functions as a heat spreader that diffuses the heat generated by each light emitting element 11. Further, during the light emission of the light emitting device 1, the light emitted from the light emitting element 11 toward the substrate 10 is reflected mainly in the light utilization direction by the reflection layer on the surface layer of the heat conductive pad 15a. Therefore, the light extraction efficiency can be improved.

  Moreover, since the phosphor layer 12 enters the concave portion 45a at the boundary portion of the resist layer 45 and is cured, the phosphor layer 12 can be prevented from peeling from the surface of the substrate 10.

  Furthermore, since the surface of the resist layer 45 is formed at a position lower than the height of the light emitting element 11, it can be reduced that the resist layer 45 becomes an obstacle to light emitted from the light emitting element 11.

As described above, according to this embodiment, peeling of the phosphor layer 12 can be suppressed without providing a special member such as a frame member. Moreover, it can reduce that the resist layer 45 becomes an obstacle of the light radiate | emitted from the light emitting element 11, and can make luminous efficiency favorable.
Next, a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part which is the same as that of 1st Embodiment, or an equivalent, and the overlapping description is abbreviate | omitted.
In this embodiment, the phosphor layer 12 covers the light emitting elements 11 individually for each light emitting element 11 and seals them to form a row.

  According to such a configuration, the amount of the phosphor layer 12 can be reduced, and similarly to the first embodiment, the peeling of the phosphor layer 12 can be suppressed, and the resist layer 45 is made of the light emitting element 11. It is possible to reduce the obstacle to the light emitted from the light source, and to improve the light emission efficiency.

The present invention is not limited to the configuration of each of the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, a photoresist material is preferably used for forming the resist layer as the light reflecting layer, but is not limited to this material. Other materials and other means may be applied as long as a concave portion capable of suppressing the peeling of the sealing resin layer can be formed.
Moreover, the recessed part formed in the boundary part of a resist layer does not need to be formed in the whole range of a boundary part. Even if it is partially formed, the desired effect may be obtained.

The thermal conductive pad is preferably used as a wiring pattern, but is not necessarily used as a wiring pattern. A function as a heat spreader that conducts and diffuses heat from a light emitting element or a function that reflects light may be sufficient.
For example, the sealing resin layer may be configured to emit red light, green light, and blue light directly from the light emitting element without using a phosphor.
The lighting device can be applied to a light source, a lighting fixture used indoors or outdoors, a display device, and the like.

DESCRIPTION OF SYMBOLS 1 ... Light-emitting device, 10 ... Board | substrate, 11 ... Light emitting element (LED chip),
12 ... Sealing resin layer (phosphor layer), 14 ... Connection pattern,
141 ... groove, 15 ... wiring pattern, 15a ... heat conduction pad,
17 ... bonding wire, 20 ... lighting device,
45... Light reflecting layer (resist layer), 45 a.

Claims (3)

A substrate having at least an insulating surface;
A thermally conductive pad formed on the surface side of the substrate;
A light reflecting layer which is formed excluding at least the element mounting portion on the heat conduction pad and is laminated with a concave portion whose cross-sectional shape extends in the surface direction of the substrate at the boundary with the element mounting portion;
A light emitting device mounted on a device mounting portion on the thermal conductive pad;
A sealing resin layer covering a light emitting element including a boundary portion of the light reflecting layer;
A light-emitting device comprising:   The light emitting device according to claim 1, wherein a surface of the light reflecting layer is formed at a position lower than a height of the light emitting element. The device body;
The light-emitting device according to claim 1 or 2 disposed in the device main body;
An illumination device comprising:

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