JP2007317811A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device for preventing emission characteristics from deteriorating due to the sagging or crawling of resin. <P>SOLUTION: The light-emitting device has a package 1 having a recess 11 that is open in a rectangular shape on a surface, wherein an LED chip 2 is mounted into the recess 11 and a phosphor sheet 3 is provided so that the recess 11 is covered. In the light-emitting device, a step part 12 is provided at the open edge of the recess 11, the peripheral part of the phosphor sheet 3 is placed on the bottom surface of the step part 12 and is stuck via resin, and a reservoir 13 for accumulating the surplus of resin is provided at the corner of the rectangular section while the step part 12 is expanded outward. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light emitting device in which an LED chip and a phosphor are mounted on a package.

  Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 2005-244075 (Patent Document 1), a light emitting device in which an LED chip and a phosphor sheet are mounted on a package is known. As shown in FIG. 4, the LED 91 is mounted on the bottom surface of the recess 93 of the package 91, and a step 94 is provided on the periphery of the recess 93. A phosphor sheet 95 is fixed to the stepped portion 94 via a fixing resin.

Therefore, since the phosphor sheet 95 is held on the side surface of the step portion 94 while being placed on the step portion 94, the phosphor sheet 95 is fixed to the step portion 94 without being displaced.
JP-A-2005-244075

  On the other hand, the LED chip 92 has recently been increased in size with the increase in luminance, and it is necessary to use a sealing resin having a relatively low viscosity in order to relieve stress on the enlarged chip. However, also in the fixing resin, when a resin having the same viscosity as that of the sealing resin is used, the fixing force is not sufficient, so that it is necessary to increase the application amount of the fixing resin.

  However, in the conventional light emitting device, in particular, when a large amount of resin having a low viscosity is applied to the stepped portion, the phosphor sheet 95 is placed so that the fixing applied to the stepped portion 94 is performed. The resin hangs down from the step portion 94 to the bottom surface side of the recess 93, or rises from the step portion 94 to the outside of the recess portion 93 or the upper surface of the phosphor sheet 95, causing a problem that the light emission characteristics of the light emitting device deteriorate.

  The present invention has been invented in view of the above-described background art, and an object thereof is to provide a light-emitting device that prevents deterioration of light-emitting characteristics due to dripping or creeping up of a resin.

  In order to solve the above-mentioned problems, the invention according to claim 1 of the present application includes a package having a concave portion opened in a rectangular shape on the surface, an LED chip is mounted in the concave portion, and a phosphor sheet is provided so as to cover the concave portion. A step portion is provided at the opening edge of the concave portion, and the phosphor sheet has its peripheral portion placed on and fixed to the bottom surface of the step portion via resin, The corner portion of the rectangle is characterized in that a reservoir portion is provided in which the step portion swells outward and the excess of the resin is accumulated.

  Further, in the invention according to claim 2 of the present application, in the detector according to claim 1, the bottom surface of the step portion on which the peripheral portion of the phosphor sheet is placed has a step portion outward from the center side of the recess. It is characterized by being inclined to become deeper.

  In the light emitting device according to the first aspect of the present invention, the reservoir portion is provided at the corner portion where the resin is most likely to accumulate at the periphery of the rectangular recess. Therefore, because the excess resin applied to the stepped part escapes to the pooled part, it hangs down from the stepped part to the bottom of the concave part, or crawls up from the stepped part to the outside of the concave part or the top surface of the phosphor sheet, It is possible to prevent the light emission characteristics of the light emitting device from deteriorating. In addition, the reservoir portion is provided at the corner of the rectangle, and the phosphor sheet is mounted and fixed on the bottom surface of the stepped portion, so that the phosphor sheet is held by restricting the side surface of the stepped portion, It can be fixed without shifting.

  In the light emitting device according to claim 2, since the bottom surface of the step portion is inclined so that the step portion becomes deeper outward from the center side of the recess portion, the resin applied to the step portion is the step portion. It will be easier to gather on the outside side of. Therefore, the excess resin is more difficult to sag from the stepped portion and can be easily released to the pooled portion.

  1 and 2 show a light emitting device according to an embodiment corresponding to claims 1 and 2 of the present application. This light-emitting device is a light-emitting device including a package 1 having a concave portion 11 having a rectangular opening on the surface, an LED chip 2 mounted in the concave portion 11, and a phosphor sheet 3 provided so as to cover the concave portion 11. A step portion 12 is provided at the opening edge of the concave portion 11, and the phosphor sheet 3 has its peripheral portion mounted on and fixed to the bottom surface of the step portion 12 via the fixing resin 5. The corner portion 11 is provided with a reservoir portion 13 in which the stepped portion 12 bulges outward and the excess of the fixing resin 5 is accumulated. Further, the bottom surface of the step portion 12 on which the peripheral portion of the phosphor sheet 3 is placed is inclined so that the step portion 12 becomes deeper outward from the center side of the concave portion 11.

  Hereinafter, the light-emitting device of this embodiment will be described in more detail. As shown in FIGS. 1 and 2, the package 1 of the light emitting device has a rectangular parallelepiped shape of about 5 to 8 mm square made of ceramics or the like, and has a concave portion 11 opened in a rectangular shape. Steps 12 are formed at the peripheral edge of the recess 11, and reservoirs 13 are provided at the four corners of the recess 11 in which the step 12 is swelled outward and where excess resin is stored. . Further, the bottom surface of the step portion 12 is inclined so that the step portion 12 becomes deeper outward from the center side. 2 is a cross-sectional view taken along the line AA of FIG. 1 and does not show a cross-sectional view of the pool portion, but the bottom surface of the pool portion may be inclined so as to become deeper outward. Moreover, the center side of the recessed part 11 is opened in a circular shape deeper than the step part 12, and this opening becomes narrower as it goes downward.

  The bottom surface of the recess 11 is a mounting surface 14 provided with chip connection electrodes and the like, and the LED chip 2 is mounted on the mounting surface 14. The LED chip 2 is formed of, for example, a gallium nitride-based semiconductor compound material (GaN, InGaN) that emits blue light, and a plurality of such LED chips 2 may be provided on the mounting surface 14. The LED chip 2 to be mounted is sealed with a low-viscosity transparent sealing resin 4 such as an epoxy resin or a silicone resin.

  The light emitting device also includes a phosphor sheet 3 formed of a resin mixed with phosphor particles, a glass substrate, or the like. For example, a part of blue light emitted from the LED chip 2 is phosphor sheet. By being converted into yellow light by 3, white light is emitted from the light emitting device. The back surface 31 of the phosphor sheet 3 is processed to be uneven, and the peripheral portion of the back surface 31 is fixed so as to be placed on the bottom surface of the step portion 12 to which the fixing resin 5 has been applied in advance. Moreover, although the thickness of the fluorescent substance sheet 3 used here is about 0.5 mm, it is not specifically limited to this thickness. The fixing resin 5 is a low-viscosity resin made of the same material as the sealing resin 4.

  Next, the manufacturing process of this light emitting device will be described. First, the LED chip 2 is mounted on the mounting surface 14 by being connected to a chip connection electrode or the like provided on the mounting surface 14. Then, the mounted LED chip 2 is sealed with the sealing resin 4, and the fixing resin 5 is applied to the bottom surface of the stepped portion 12. Since the fixing resin 5 is a low-viscosity resin made of the same material as the sealing resin 4, it is applied in a large amount to supplement the fixing force. Finally, the phosphor sheet 3 is placed on the step portion 12 to which the fixing resin 5 is applied, and the fixing resin 5 and the sealing resin 4 are thermally cured. When the phosphor sheet 3 is placed, the surplus of the fixing resin 5 is pushed out by the phosphor sheet 3 and accumulated in the reservoir portion 13 provided at the corner portion of the recess 11.

  Therefore, in the light emitting device of this embodiment, the reservoir portion 13 is provided at the corner portion where the fixing resin 5 is most likely to accumulate at the periphery of the concave portion 11 opened in a rectangular shape. Therefore, even if a large amount of the fixing resin 5 is applied to the step portion 12, the surplus fixing resin 5 escapes to the pool portion 13, so that it drops from the step portion 12 toward the bottom surface of the recess 11, or from the step portion 12. It is possible to prevent the light emission characteristics of the light emitting device from being deteriorated by climbing to the outside of the recess 11 or the upper surface of the phosphor sheet 3.

  Further, since the bottom surface of the step portion 12 is inclined so that the step portion 12 becomes deeper outward from the center side of the concave portion 11, the fixing resin 5 applied to the step portion 12 is on the outer side of the step portion 12. It's easy to get together. Therefore, the excess fixing resin 5 is more difficult to drip from the stepped portion 12 and can be easily released to the pool portion 13.

  Further, the reservoir portion 13 is provided at the corner of the rectangle, and the phosphor sheet 3 is placed and fixed on the bottom surface of the step portion 12, so that the phosphor sheet 3 is restricted to the side surface of the step portion 12. And can be fixed without shifting. Moreover, since the uneven | corrugated process is given to the back surface 31 of the fluorescent substance sheet 3, the adhesion area of the fluorescent substance sheet 3 increases and it can adhere to the step part 12 more strongly.

  Moreover, since the sealing resin 4 uses a low-viscosity resin, the influence of stress on the LED chip 2 can be suppressed. Therefore, even when a relatively large LED chip 2 is sealed, the LED chip 2 can be effectively sealed without causing a problem that the LED chip 2 is peeled off. Furthermore, since the fixing resin 5 is made of the same material as that of the sealing resin 4, it can be applied in the same process as the sealing resin 4, and the production process can be shortened.

  In addition, the light-emitting device which is another embodiment shown in FIG. 3 is provided with the condensing lens 6 between the LED chip 2 and the phosphor sheet 3 instead of the sealing resin.

The top view which shows the light-emitting device which is 1st embodiment of this invention. Sectional drawing which shows the light-emitting device. Sectional drawing which shows the light-emitting device which is another embodiment. Sectional drawing which shows the light-emitting device which is a prior art example.

Explanation of symbols

1 Package, Recess, Step, Reservoir 2 LED chip 3 Phosphor sheet

Claims (2)

  A light-emitting device that includes a package having a rectangular opening on the surface, in which an LED chip is mounted and a phosphor sheet is provided so as to cover the depression, and a step is provided at the opening edge of the depression The phosphor sheet has a peripheral portion placed on and fixed to the bottom surface of the step portion via resin, and the rectangular corner portion has a shape in which the step portion bulges outward. A light emitting device characterized in that a reservoir for storing an excess of the resin is provided.   The light emitting device according to claim 1, wherein the bottom surface of the step portion on which the peripheral portion of the phosphor sheet is placed is inclined so that the step portion becomes deeper outward from the center side of the recess.

Images