JP5186930B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device in which an LED element is accommodated in a resin case.

Conventionally, a light emitting device in which an LED element is housed in a resin case and the LED element is sealed with a resin such as silicone or epoxy is known. In particular, the side light emission type light-emitting device used as a light source for liquid crystal display or the like is formed thin, so that the distance between the LED element and the wall of the case is shortened, and the wall is emitted from the LED element. Degraded easily by light and heat. In order to solve the problems caused by the resin case, a light emitting device having a metal case has been proposed (see Patent Document 1).
JP 2007-194518 A

  However, if the case is made of metal, processing is troublesome as compared to the case of using resin, and the number of manufacturing steps, manufacturing cost, and the like increase.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to accurately suppress deterioration of a case even in a thin light-emitting device using a resin case.

In order to achieve the object, in the present invention, an LED element having a light emitting layer, plate-like metal first and second leads on which the LED element is mounted, and predetermined ones of the first and second leads . A pair of first wall portions that are opposed to each other and extend in the first direction, and a pair of LED elements that have a greater distance from the LED element than the first wall portion and that extend in the second direction. a second wall portion, a concave portion is formed and a resin case formed, integrally with the first or the second light emitting layer higher than said first lead to the lead mounting a pre Symbol LED element by, A pair of projecting portions provided in parallel with the first wall portion between the pair of first wall portions and the LED element, and the case includes the pair of first wall portions and the bottom portion. A pair of first slopes each having a first slope distance formed between A pair of second slopes having a slope and a second slope distance greater than the first slope distance formed between the pair of second wall portions and the bottom portion, respectively, and the pair of protrusions parts are light emitting devices are provided that have a first and a second inclined surface and the spacing of the pair.

  In the light-emitting device, it is preferable that a convex shape is not formed in the region exposed in the concave portion of the lead in addition to the protruding portion.

  In the light emitting device, the LED element side surfaces of the pair of protrusions are preferably inclined so as to expand from the bottom side of the recess toward the opening.

  In the light-emitting device, at least one of the pair of first wall portions includes a separation portion that is separated from the LED element in the second direction in the vicinity of the LED element, and the protruding portion is provided with the separation portion and the LED. It is preferable to be provided between the elements.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a thin light-emitting device using the resin-made cases, deterioration of a case can be suppressed exactly.

  1 to 3 show an embodiment of the present invention, and FIG. 1 is an external perspective view of a light emitting device.

  As shown in FIG. 1, the light-emitting device 1 is a side-view type LED device, and includes a case 4 in which a recess 3 that accommodates an LED chip 2 as an LED element is formed, and a lower surface and a side surface of the case 4. A pair of formed leads 5 is provided. The light emitting device 1 is used for a planar light emitting device used for, for example, a liquid crystal backlight, a panel meter, an indicator lamp, a surface emitting switch, and the like. The planar light emitting device includes a light guide plate on which light from the light emitting device 1 is incident on an end surface, and emits light in a planar shape from the light emitting surface of the light guide plate. The light-emitting device 1 is configured to be thin in the vertical direction corresponding to the thickness dimension of the light guide plate, and light is extracted from the opening 6 of the recess 3 substantially parallel to the substrate when mounted on the substrate. The opening 6 has a substantially rectangular shape that is long in the horizontal direction when viewed from the front. The recess 3 is filled with a sealing resin 7 as a sealing material, and the LED chip 2 is sealed with the sealing resin 7.

FIG. 2 is a front view of the light emitting device.
As shown in FIG. 2, the case 4 is made of, for example, nylon resin, epoxy resin, and the like, and includes a bottom portion 41 on which the LED chip 2 is disposed via leads 5 and a pair of first wall portions that face each other and extend in the horizontal direction. And a left wall 44 and a right wall 45 as a pair of second walls that are thicker than the upper wall 42 and the lower wall 43 and face each other and extend in the vertical direction. The horizontal dimension of the upper wall 42 and the lower wall 43 is longer than the vertical dimension of the left side wall 44 and the right side wall 45. Further, the upper wall 42 and the lower wall 43 are smaller in distance from the LED chip 2 than the left side wall 44 and the right side wall 45. The recess 3 is formed by a bottom surface 31, an upper surface 32, a lower surface 33, a left side surface 34, and a right side surface 35 which are the surfaces of the bottom portion 41, the upper wall 42, the lower wall 43, the left side wall 44 and the right side wall 45. The recess 3 is formed so as to expand from the bottom surface 31 side toward the opening 6, and the upper surface 32, the lower surface 33, the left side surface 34 and the right side surface 35 are inclined with respect to the bottom surface 31.

  A pair of leads 5 are arranged on the bottom surface 31 with a space therebetween, and the LED chip 2 is mounted on one lead 5. Each lead 5 is made of, for example, a copper (Cu) alloy whose surface is coated with silver (Ag). Each lead 5 extends from the bottom surface 31 of the recess 3 to the outside of the case 4 through the inside of the case 4 and is connected to the wiring portion of the board when the board is mounted.

  The LED chip 2 is a face-up type having a GaN-based light emitting layer that emits blue light. The LED chip 2 is mounted at the left and right center of the recess 3 and has a long rectangular shape in a direction parallel to the upper wall 42 and the lower wall 43 in a front view. The electrodes of the LED chip 2 and the leads 5 are electrically connected by wires 21 made of Au, for example. Each wire 21 is formed to extend from the LED chip 2 to the left side wall 44 or the right side wall 45. Note that the emission color, material, type, and the like of the LED chip 2 are not particularly limited. For example, the LED chip 2 may emit red light and have an AlGaInP-based light emitting layer, or may be a flip chip type. It can change suitably according to etc.

  The light emitting device 1 is formed on the mounting surface of the LED chip 2 in the lead 5, and is provided between the upper wall 42 and the lower wall 43 and the LED chip 2, and is provided in parallel with the upper wall 42 and the lower wall 43. A protrusion 8 is provided. Each protrusion 8 is formed so as to partition the space on the bottom surface 31 side of the recess 3 in the width direction. Each protrusion 8 is not formed over the longitudinal direction of the recess 3 but is formed only in a predetermined section in the longitudinal direction including the vicinity of the LED chip 2. In the present embodiment, no convex shape is formed in addition to the protrusions 8 in the regions exposed in the recesses 3 of the leads 5. The lower wall 43 has a separation portion 43 a that is separated from the LED chip 2 in the vertical direction in the vicinity of the LED chip 2, and one protruding portion 8 is provided between the separation portion 43 a and the LED chip 2.

  The sealing resin 7 is a transparent resin containing a phosphor. In this embodiment, silicone is used as the transparent resin. As the phosphor, for example, a yellow phosphor such as YAG (Yttrium Aluminum Garnet) or BOS (Barium ortho-Silicate) is used. When the phosphor is excited by receiving blue light emitted from the LED chip 2, the phosphor emits yellow wavelength-converted light. As a result, light is extracted from the opening 6 in a white state in which blue light and yellow light are mixed.

FIG. 3 is a longitudinal sectional view of the light emitting device.
As shown in FIG. 3, the LED chip 2 is mounted on one lead 5 via a die bond paste 22. Each protrusion 8 formed on the lead 5 is formed integrally with the lead 5. The height of each protrusion 8 from the bottom surface 31 is higher than the light emitting layer of the LED chip 2. Each protrusion 8 is formed so as to become thinner from the bottom surface 31 side toward the opening 6 side. In the present embodiment, the surface of each protruding portion 8 on the LED chip 2 side is formed so as to be inclined toward the opening 6.

  In manufacturing the light emitting device 1, first, the case 4 is molded using a predetermined mold in a state where the leads 5 formed with the protruding portions 8 and the like are inserted. Therefore, the case 4 can be manufactured more easily and easily than when the case is made of metal. Then, after the LED chip 2 is mounted on one lead 5 using the die bond paste 22, the LED chip 2 and each lead 5 are connected by the wire 21. At this time, each protrusion 8 is formed between the upper wall 42 and the lower wall 43 and the LED chip 2 and is not formed between the left side wall 44 and the right side wall 45. There is no hindrance to formation. Next, the sealing resin 7 is filled into the recess 3 of the case 4 by potting or the like, and the sealing resin 7 is cured to complete the light emitting device 1. At this time, since each protruding portion 8 is formed at a distance from the left side surface 34 and the right side surface 35, a corner portion or the like where the sealing resin 7 does not easily flow into the recess 3 is formed by each protruding portion 8. In addition, bubbles and the like are not generated in the sealing resin 7 due to the formation of the protrusions 8.

  In the light emitting device 1 configured as described above, when a voltage is applied to the LED chip 2 through each electrode lead 5, blue light is emitted from the LED chip 2, and part of the blue light is converted into yellow light by a phosphor. Is done. The phosphor of the sealing resin 7 has a light diffusing function in addition to a wavelength converting function, and uniform white light is emitted from the opening 6 to the outside.

  Here, since the protruding portion 8 is provided between the upper wall 42 and the lower wall 43 and the LED chip 2, direct light from the light emitting layer to the upper wall 42 and the lower wall 43 in the vicinity of the LED chip 2. Incidence can be prevented and deterioration of the upper wall 42 and the lower wall 43 can be suppressed. Here, since the deterioration of the resin of the case 4 is easily accelerated by short-wavelength light such as purple or blue, the effect of suppressing deterioration is remarkable when the blue LED chip 2 is used. According to the light emitting device 1 of the present embodiment, since the top and bottom walls are thin, the problems inherent to the side view type light emitting device in which the upper and lower wall portions are closer to the light emitting elements than the left and right wall portions can be solved. . And in this embodiment, by providing the protrusion part 8 between the separation part 43a of the lower wall 43 and the LED chip 2, it is possible to further reduce the thickness of the device while providing the protrusion part 8.

  In addition, since each protrusion 8 is formed in advance on the lead 5, the number of manufacturing steps does not increase as in the conventional case in which a metal ring is separately installed around the LED chip, and the LED chip 2 and the upper wall Even if the distance between the 42 and the lower wall 43 is relatively narrow, the light emitting device 1 can be manufactured without difficulty.

  In addition, by providing each protrusion 8 on the lead 5, the rigidity of the entire apparatus is improved, and deformation of the case 4 can be suppressed. Therefore, for example, the expansion and contraction of the sealing resin 7 due to heat and the external load can be accurately resisted, and the reliability of the device 1 can be improved.

  In the above embodiment, the protrusion 8 is formed only in a predetermined section in the vicinity of the LED chip 2 in the lead 5. However, for example, as shown in FIG. 4, the protrusion 8 is formed in the longitudinal direction. May be. In this case, it is preferable that the longitudinal ends of the protrusions 8 are separated from the left side surface 34 and the right side surface 35. Thus, by forming the protrusion part 8 over a longitudinal direction, since the cross-sectional area of the lead | read | reed 5 used as a thermal radiation path | route increases, thermal radiation efficiency can be improved. Moreover, in the said embodiment, although what formed each protrusion part 8 only in the lead 5 in which the LED chip 2 is mounted was shown, for example, as shown in FIG. 4, the lead 5 in which the LED chip 2 is not mounted. You may form the protrusion part 8 in this.

  Moreover, in the said embodiment, although each protrusion part 8 showed what was formed apart from the upper wall 42 and lower wall 43 of case 4, as shown, for example in FIG.5, FIG.6 and FIG.7, The protrusions 108, 208, and 308 may be formed in contact with the upper wall 42 or the lower wall 43.

FIG. 5 to FIG. 7 are longitudinal sectional views of light emitting devices showing modifications.
As shown in FIG. 5, in the light emitting device 101, the surface on the opposite side of the LED chip 2 in each protrusion 108 is buried in the upper wall 42 and the lower wall 43. The surface on the LED chip 2 side of each protrusion 108 is exposed in the recess 3 and is inclined so as to expand toward the opening 6. Each protrusion 108 is formed so as to become narrower from the bottom 31 side toward the opening 6 side. In this way, the case 4 can be made thinner by bringing a part of each protrusion 108 into contact with the upper wall 42 and the lower wall 43.

Further, as shown in FIG. 6, the protrusions 208 may be formed by folding back the width direction outer side of the lead 5 to the opening 6 side. Thereby, the lead 5 can be produced by bending a flat metal plate. In the light emitting device 201 of FIG. 6, the upper end surface of the protrusion 208 is formed flat.
Further, as shown in FIG. 7, each protrusion 308 may be formed with a constant width from the bottom surface 31 side toward the opening 6 side. In the light emitting device 301 of FIG. 7, protrusions 308 having a rectangular cross section are formed at both ends of the lead 5 in the width direction. Thereby, the cross-sectional area of the lead 5 increases, and the heat dissipation performance through the lead 5 of the heat generated in the LED chip 2 is improved.

  Moreover, in the said embodiment, although the upper surface 32 and the lower surface 33 showed what inclines at the same angle with respect to the bottom surface 31, for example, as shown in FIG.8 and FIG.9, you may make it incline at different angles. Good. FIG. 8 and FIG. 9 are longitudinal sectional views of a light emitting device showing modifications.

  In the light emitting device 401 of FIG. 8, the upper surface 432 is inclined more gently with respect to the bottom surface 31 than the lower surface 33. In the light emitting device 401, each protrusion 408 is formed to be separated from the upper surface 432 and the lower surface 33. Further, the lead 5 has a folded portion 409 that is folded back into the upper wall 442 at the upper end. Further, as illustrated in FIG. 9, the protruding portion 508 on the lower surface 33 side of the light emitting device 501 may be formed to be separated from the lower surface 33, and the protruding portion 509 on the upper surface 532 side may be formed in contact with the upper wall 542. .

  In the embodiment, the light emitting device 1 is shown in which the opening 6 is oriented in a direction parallel to the substrate when the substrate is mounted. For example, when the light emitting device 1 is mounted on the substrate, the opening 6 is perpendicular to the substrate. It may be oriented. That is, the light emitting device 1 is a pair of first wall portions facing each other and extending in the first direction, and a pair of second walls extending in the second direction facing each other and having a larger distance from the LED element than the first wall portion. If the wall is provided with a case in which a recess is formed, and the lead is provided with a pair of protrusions in parallel with the first wall between the pair of first wall and the LED element, Even if it is not a side view type, the deterioration suppression effect of case 4 etc. can be acquired.

  Moreover, in the said embodiment, although the upper wall 42 and the lower wall 43 as a 1st wall part and the left side wall 44 and the right side wall 45 as a 2nd wall part showed orthogonally, the 1st wall part and It is not always necessary to be orthogonal to the second wall portion. Moreover, although what used resin as a sealing material was shown, of course, inorganic materials, such as glass, may be used, and it is needless to say that a concrete detailed structure etc. can be changed suitably.

FIG. 1 is an external perspective view of a light emitting device showing an embodiment of the present invention. FIG. 2 is a front view of the light emitting device. FIG. 3 is a longitudinal sectional view of the light emitting device. FIG. 4 is a front view of a light emitting device showing a modification. FIG. 5 is a longitudinal sectional view of a light emitting device showing a modification. FIG. 6 is a longitudinal sectional view of a light emitting device showing a modification. FIG. 7 is a longitudinal sectional view of a light emitting device showing a modification. FIG. 8 is a longitudinal sectional view of a light emitting device showing a modification. FIG. 9 is a longitudinal sectional view of a light emitting device showing a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light-emitting device, 2 ... LED chip, 3 ... Recessed part, 4 ... Case, 5 ... Lead, 6 ... Opening, 7 ... Sealing resin, 8 ... Projection part, 21 ... Wire, 22 ... Die-bonding paste, 31 ... Bottom surface 32 ... Upper surface, 33 ... Lower surface, 34 ... Left side, 35 ... Right side, 41 ... Bottom, 42 ... Upper wall, 43 ... Lower wall, 44 ... Left side wall, 45 ... Right side wall, 101 ... Light emitting device, 108 ... Projection 201: light emitting device, 208: projecting portion, 301 ... light emitting device, 308 ... projecting portion, 401 ... light emitting device, 408 ... projecting portion, 409 ... folded portion, 442 ... upper wall, 501 ... light emitting device, 508 ... projecting Part, 509 ... projecting part, 542 ... upper wall.

Claims (4)

An LED element having a light emitting layer;
Plate-like metal first and second leads on which the LED elements are mounted;
A distance between the bottom portion where the predetermined portions of the first and second leads are disposed, a pair of first wall portions facing each other and extending in the first direction, and the LED element larger than the first wall portion. A resin case in which a recess is formed by a pair of second wall portions facing each other and extending in the second direction;
Formed prior Symbol the first or second high the first lead integrally from the light emitting layer to the lead mounting the LED element, the first between the LED element and the pair of first wall portions A pair of protrusions each provided in parallel with the wall ,
The case includes a pair of first slopes each having a first slope distance formed between the pair of first wall portions and the bottom portion, and the pair of second wall portions and the bottom portion. Each of the pair of second slopes has a second slope distance greater than the first slope distance formed, and the pair of protrusions are spaced from the pair of first and second slopes. be that the light-emitting device.   2. The light emitting device according to claim 1, wherein a convex shape is not formed in the region exposed in the concave portion of the lead in addition to the protruding portion.   The light emitting device according to claim 2, wherein the LED element side surfaces of the pair of projecting portions are inclined so as to expand from the bottom side of the recess toward the opening.   At least one of the pair of first wall portions has a separation portion that is separated from the LED element in the second direction in the vicinity of the LED element, and the protruding portion is provided between the separation portion and the LED element. The light-emitting device according to claim 3.

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