JP2006186196A - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device which is compact enough to arrange a plurality of light emitting elements closely. <P>SOLUTION: The light emitting device is provided with a lead frame which secures light emitting elements and supplies an electric power to the light emitting elements, a pair of terminals connected electrically with the lead frame and a resin part to support the lead frame. The lead frame is provided with a wiring part to lead an electric power from the terminals to the light emitting elements. A part of the wiring part is exposed over the outside of the resin part, and it is bent at a right angle along the side surface of the resin part, so that the resin part can be made small in size and the light emitting device be also made compact as a result. The bent wiring part is located inside the projection of the outline of the resin part, so that, even if a plurality of light emitting devices are arranged adjacent to each other, electrical insulation can be maintained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light emitting device using a light emitting element such as an LED, and more particularly to a light emitting device suitable for an application in which a plurality of devices are arranged adjacent to each other.

  Conventionally, in order to further reduce the size of a small illuminating device constituted by a combination of a light source such as a lamp and a reflecting member, an illuminating device in which light emitting elements such as LEDs are arranged in a line or a plane as a light source has been proposed. ing. For example, in Patent Document 1, a plurality of light-emitting elements are arranged in a line, and are linearly moved or rotated at high speed by a drive mechanism unit, whereby a light beam that has a large amount of light and can be collected efficiently is efficiently Disclosed is a small lighting device that is well produced. It is also possible to obtain an illumination device having a desired emission color by arranging a plurality of light emitting elements arranged in a row in combination with elements having a desired wavelength. By using such a small illumination device, the strobe of the imaging device and the illumination unit of the image projection display device can be realized using a light emitting element such as an LED.

  In general, a pair of electrode terminals for supplying power to the light emitting element is a type that is drawn out from both ends of the resin part that packages the whole as described in Patent Document 2, and Patent Document 3 There is a type that pulls out both from one end of the resin part.

Further, there is a disclosure in Patent Documents 2, 4, and 5 regarding bending of the end portion of the lead frame, and particularly in Patent Document 4, the light emitting diode devices are closely arranged by bending the end portion of the lead frame.
JP 2003-346503 A JP 2000-223738 A Japanese Patent No. 3261280 JP-A-8-162678 JP 2004-214436 A

  In a light-emitting device using a light-emitting element, it is desired to arrange a plurality of light-emitting elements as close as possible in order to obtain a bright light beam. Therefore, it is desirable to reduce the size of the package resin portion as much as possible. In addition, it is desirable that the electrode terminal has a configuration in which both of the electrode terminals are drawn from one side portion of the package resin portion because the degree of freedom in arranging the light emitting device is high.

  However, Patent Documents 1, 2, 3, and 5 do not disclose means for solving the problem of reducing the size of the package resin portion as much as possible and arranging a plurality of light emitting elements as close as possible. Patent Document 4 only discloses that the light emitting diodes are densely arranged by bending the end portion of the lead frame, and does not consider the bending related to the lead frame in the internal circuit of the light emitting device. Further, in Patent Document 3, although the terminals are drawn out in the same direction, the header lead portions are exposed to the outside of the package at the same height, and when arranged closely, adjacent devices are electrically short-circuited. Therefore, it cannot be arranged closely adjacent.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a light-emitting device suitable not only for downsizing of a package but also for applications in which the devices are arranged adjacent to each other.

  In order to achieve the above object, a light emitting device of the present invention includes a light emitting element, a lead frame that fixes the light emitting element and supplies power to the light emitting element, and a resin portion that holds at least the lead frame. The lead frame includes a pair of terminal portions functioning as electrical terminals and a wiring portion for guiding power from the terminal portions to the light emitting elements. A part of the wiring portion is arranged outside the resin portion and is bent at a substantially right angle with respect to the lead frame surface with which the light emitting element is in contact, and the resin portion is parallel to the lead frame surface with which the light emitting element is in contact. Is bent so that the projection of the bent wiring portion is inside the straight line or curve that is each side of the shadow projected. Thus, by exposing a part of the wiring part to the outside of the resin part and bending it along the side surface of the resin part, the size of the resin part can be reduced and the light emitting device can be made small. In addition, since the bent wiring portion is located inside the outer shape of the resin portion, electrical insulation can be maintained even when a plurality of light emitting devices are arranged adjacent to each other.

  In the above light-emitting device, the number of light-emitting elements may be plural, and the lead frame may have a plurality of mounting portions arranged in a row for mounting the plurality of light-emitting elements. In this case, the pair of terminal portions are both pulled out from one end of the resin portion, and the first terminal portion is directly connected to the mounting portion located at one end portion among the plurality of mounting portions arranged in a row. The second terminal portion can be connected by a wiring portion bent to the mounting portion located at the other end portion. Thereby, even if it is a light-emitting device with which the light emitting element is arrange | positioned at row | line | column, a small resin part with a narrow width | variety is realizable.

Further, according to the present invention, the following method for manufacturing a light emitting device is provided. That is, a method of manufacturing a light emitting device having at least one light emitting element,
The lead frame is molded using resin so that a terminal portion functioning as an electrical terminal in the lead frame and a part of the wiring portion for guiding power from the terminal portion to the light emitting element are exposed to the outside. 1 step,
The wiring part that is outside the resin part formed in the first step so that the projection enters the inside of the straight line or curve that is each side of the shadow projected from the resin part on a plane parallel to the lead frame surface. A second step in which a part is bent at a substantially right angle with respect to the lead frame surface formed of the resin;
And a third step of electrically connecting and fixing the light emitting element to the lead frame so that power can be supplied from the lead frame.

An embodiment of the present invention will be described with reference to the drawings.
First, FIG. 1 is a side view, FIG. 2 is a top view, FIG. 3 is an AA sectional view, and FIG. 4 is a BB sectional view for the structure of the semiconductor light emitting device of the first embodiment. It explains using. The semiconductor light emitting device includes an LED (light emitting diode) chip 11, a metal lead frame 17 that fixes the LED chip to the upper surface and supplies power to the LED chip 11, and a heat sink disposed adjacent to the lower surface of the lead frame 17. 14, a resin portion 13 that integrally holds the lead frame 17, the electrode terminal 16, and the heat sink 14, and a light guide portion 15 that guides the light emitted from the LED chip 11 to form a light beam having a desired diffusion angle. I have.

  As shown in FIGS. 5 (a) and 5 (b), the shape of the resin portion 13 is as shown in FIGS. 5 (a) and 5 (b). LED openings 51a and 51b for exposing the LED chip 11 are formed on the upper surface side. And an electric circuit component opening 54 for mounting an electric circuit component 53 such as a rectifying element or a resistor on the base portion of the pair of electrode terminals 16. As shown in FIG. 4, an opening 41 having the same shape as the outer periphery of the heat sink 13 is provided on the lower surface side of the resin portion 13, and the heat sink 13 protrudes outward from the opening 41. Further, the resin part 13 is provided with two through holes 52. The base of the light guide 15 is inserted and fixed in the through hole 52.

  The structure of the lead frame 17 will be described with reference to FIG. FIG. 6 shows a part of a metal frame in which a plurality of lead frames 17 are mechanically connected by an outer frame 67 during the manufacturing process. The lead frame 17 is separated from the outer frame 67 at the final stage of the manufacturing process.

  The lead frame 17 includes a pair of electrode terminals 16 that function as electrical terminals, an LED mounting area 12 on which the LED chip 11 is mounted, and a wiring portion 65 for guiding power from the electrode terminal 16 to the LED mounting area 12. I have. The shape of the LED mounting area 12 is such that a plurality of (four in this case) LED chips 11 are mounted in series in a row as shown in FIG. 6, and a plurality of LED mounting portions 61, 62, 63, 64. The LED mounting portions 61 and 62 are exposed from the opening 51a of the resin portion 13, and the LED mounting portions 63 and 64 are exposed from the opening 51b. As shown in FIG. 5B, the LED chip 11 is fixed to the LED mounting portions 61, 62, 63, and 64, and the lower surface electrodes are electrically connected. The upper surface electrode of the LED chip 11 is electrically connected to the adjacent mounting portions 62 to 64 or the terminal portion 68 in the LED mounting region 12 by a bonding wire 69. Accordingly, the LED chips 11 are connected in series as shown in FIG. 7 (a) or (b). By connecting in series, power consumption can be reduced. Further, depending on the characteristics of the LED chip 11, the surface of the surface of the first and second electrode terminals 16 such as a resistor and a rectifying element as shown in FIGS. The electric circuit element 53 is mounted so as to straddle the first and second electrode terminals 16a and 16b, and the electrodes of the electric circuit element 53 are electrically connected to the first and second electrode terminals 16a and 16b. . As a result, an electric circuit configuration as shown in FIG. In addition, when using the LED chip 11 having a shape in which two electrodes are provided on the upper surface, the two electrodes on the upper surface are both connected to the mounting portions 61 to 64 and the terminal portion 68 by bonding wires. To achieve serial connection.

  The pair of electrode terminals 16 includes two electrode terminals 16 a and 16 b arranged in parallel, and both are led out in the same direction from one end of the resin portion 13. The first electrode terminal 16 a is configured integrally with the mounting portion 61. The second electrode terminal 16b is connected by an exposed wiring portion 65 to a terminal portion 68 located at the end opposite to the end from which the second electrode terminal 16b is drawn. In the present embodiment, in order to reduce the size of the resin part 13, the wiring part 65 is exposed to the outside of the resin part 13 as shown in FIG. As shown in FIG. 5, the exposed wiring portion 65 is bent substantially perpendicularly to the LED mounting region 12 so as to be along the side surface of the resin portion 13, and in the notch 31 provided in the lower portion of the side surface of the resin portion 13, the exposed wiring portion. 65 is accommodated. Thereby, as shown in FIG. 3, when the resin part 13 and the exposed wiring part 65 are projected on the main plane of the LED mounting area 12, the inside of the projected outer position 36 of the resin part 13 (on the LED chip 11 side). ) Is a positional relationship in which the projection of the exposed wiring portion 65 enters. For this reason, the exposed wiring portion 65 does not protrude outward from the outer shape of the resin portion 13, although the exposed wiring portion 65 is routed around one side surface in the short direction of the resin portion 13. The cut end surface of the lead frame 17 is exposed on the other side surface side.

  As described above, the exposed wiring portion 65 is routed around one side surface of the resin portion 13 but is folded and accommodated inside the outer shape of the resin portion, so that the exposed wiring portion 65 is not bent. Thus, the size of the resin portion 13 can be reduced by the area of the exposed wiring portion 65. As a result, a device having a line shape with a narrow outer shape can be realized as a semiconductor light emitting device, and therefore, a plurality of semiconductor light emitting devices can be arranged adjacent to each other at a high density. Further, since the exposed wiring portion 65 is accommodated inside the outer shape of the resin portion, electrical insulation between the cut end surface of the lead frame 17 exposed on the side surface of the adjacent semiconductor light emitting device can be ensured.

  The heat sink 14 is a block-like member made of a metal material (for example, copper) having good thermal conductivity, and is disposed adjacent to the lower surface of the LED mounting region 12 of the lead frame 17 as shown in FIGS. ing. The upper surface of the heat sink 14 and the lower surface of the lead frame 17 are formed as flat surfaces, and the heat of the LED chip 11 is efficiently conducted to the heat sink 14 via the lead frame 17 by improving the adhesion between them. However, since the heat sink 13 is made of a metal material having good thermal conductivity, there arises a problem that the heat sink 13 is electrically connected to the lead frame 17. Therefore, in the present embodiment, an insulating film 90 that is electrically insulative and has good thermal conductivity is sandwiched between the upper surface of the heat sink 17 and the lower surface of the lead frame 17 as shown in FIG. Thereby, insulation is ensured while improving the adhesion between the heat sink 14 and the lead frame 17. As the insulating film 90, for example, a resin film such as polyimide, a silicone film in which a ceramic filler is dispersed, or the like can be used. Thereby, high thermal conductivity can be realized while maintaining electrical insulation.

  The length in the longitudinal direction of the upper surface of the heat sink 14 is longer than the length from the end in the same direction of the LED chips 11 arranged in a row, and the length (width) in the short direction is the resin portion. It is 0.4 to 0.6 times the width of 13 (short direction) and larger than the width of the LED chip 11. In addition, the heat sink 13 is disposed so that the LED chip 11 is positioned at approximately the center of the upper surface of the heat sink 14 in the width direction. The height of the heat sink 14 is 3 to 10 times the depth of the LED openings 51 a and 51 b of the resin portion 13, and protrudes greatly from the resin portion 13. Thereby, it is comprised so that the heat | fever of the LED chip 11 may be thermally radiated efficiently. Further, as shown in FIG. 4, a groove 42 is formed on the side surface of the heat sink 14 in a portion located inside the opening 41 of the resin portion 13 in parallel with the upper surface. Filling the groove 42 with the resin that forms the resin portion 13 prevents the heat sink 13 from coming off from the opening 41.

  Next, a method for manufacturing the semiconductor light emitting device of this embodiment will be described. First, a metal frame shown in FIG. 6 is formed by pressing a plate-like metal plate. In this metal frame, a plurality of lead frames 17 are mechanically connected by an outer frame 67. On the other hand, a metal heat sink 13 having the shape described above and an insulating film 90 having a shape that matches the shape of the upper surface thereof are prepared. An insulating film 90 is mounted on the upper surface of the heat sink 13, and the lead frame 17 and the heat sink 13 are integrated by supplying and molding a resin material in the peripheral space in a state where the insulating film 90 is pressed and adhered to the lower surface of the lead frame 17. To form the resin portion 13. Thus, the two LED chip openings 51a and 51b are provided on the upper surface, the opening 41 is provided with the heat sink 13 integrated and protruded on the lower surface, and the resin portion 13 having the through hole 52 and the notch 31 is molded. . The resin material may be supplied to the peripheral space of the lead frame 17 in a state where the resin constituting the resin portion 13 is dissolved or softened, or the precursor of the resin constituting the resin portion 13 or unreacted It is also possible to form the resin part 13 by supplying it to the peripheral space in the state of a mixture of two or more resin materials and then reacting it by heating or irradiation with radiation such as light or electromagnetic waves.

  Next, the exposed wiring portion 65 protruding from the side surface of the resin portion 13 is bent at a right angle to the side opposite to the opening 51 of the resin portion 13, that is, the lower surface side so as to be along the side surface of the resin portion 13. The exposed wiring portion 65 is accommodated in the notch 31.

  When the LED chip 11 is mounted on the LED mounting portions 61 to 64 exposed in the openings 51a and 51b of the resin portion 13, and one of the LED chips 11 has an electrode on the lower surface, it is electrically connected to the mounting portions 61 and 64. Connect to. The upper surface electrode of the LED chip 11 is wire-connected to the opposing LED mounting portions 61 to 64 by bonding or the like. Thereby, the electric circuit of FIG.7 (b) by which the four LED chips 11 were connected in series is comprised. Further, if necessary, a surface-mount type electric circuit element 53 such as a resistor or a rectifying element is mounted on the bases of the first and second electrode terminals 16 so as to straddle the electrode terminals 16, and FIG. The electrical circuit is realized.

  Furthermore, the portion of the broken line area 66 of the metal frame in FIG. 6 is cut and separated into individual semiconductor light emitting devices. After the silicone resin 32 having a predetermined refractive index is filled in the opening 41, the light guide portion 15 is mounted, and the end portion is inserted into the through hole 52 of the resin portion 13 and fixed. Thereby, the semiconductor light emitting device of the present embodiment is completed.

  In the semiconductor light emitting device of the present embodiment, by supplying current between the electrode terminals 16, the four LED chips 11 connected in series emit light, and the emitted light is guided through the silicone resin 32. The light enters the portion 15, is formed into a predetermined diffused light beam by the light guide portion 15, and is emitted.

  Since this semiconductor light emitting device is equipped with four LED chips 11, the amount of emitted light is large, and the power consumption is small because of the series connection. In addition, since the LED chips 11 are arranged in a row on the narrow resin portion 13, a plurality of semiconductor light emitting devices can be arranged adjacent to each other in the width direction, and the surface light source can be easily configured. Can do.

  Although this semiconductor light emitting device is a device having a narrow line-shaped outer shape, in the present embodiment, the heat sink 14 is disposed immediately below the LED mounting region 12 of the lead frame 17, thereby providing sufficient heat dissipation characteristics. Can be secured. Thereby, since it can prevent that the junction part of LED chip 11 becomes high temperature, the fall of the emitted light amount by a temperature rise can be prevented, and the stable light emission characteristic can be maintained.

  Further, since the exposed wiring portion 65 is bent along the side surface of the resin portion 13 and stored in the notch 31, the width of the semiconductor light emitting device can be reduced by the width of the exposed wiring portion 65. Since the exposed wiring portion 65 does not protrude to the outside, there is no possibility that adjacent semiconductor light emitting devices are electrically connected to each other.

Next, a second embodiment of the present invention will be described with reference to FIG.
The semiconductor light emitting device according to the second embodiment is different from the semiconductor light emitting device according to the first embodiment in that the entire surface of the heat sink 14 is coated with an electrical insulating film 101 having good thermal conductivity. Yes. As the electrical insulating film 101, a resin film, a silicone film, or the like can be used in the same manner as the insulating film 90 of the first embodiment. Note that the insulating film 90 used in the first embodiment is not disposed. Other configurations are the same as those in the first embodiment, and thus the description thereof is omitted.

  In the manufacturing process of the semiconductor light emitting device of the second embodiment, the metal heat sink 14 is previously covered with the insulating film 101 with the insulating film 90 and the resin portion 13 is formed in close contact with the lower surface of the lead frame 17. To do. The insulating film 90 is not disposed. Other steps are the same as those in the first embodiment.

  In the second embodiment, since the heat sink 14 is covered with the insulating film 101 having good thermal conductivity, the lead frame 17 and the heat sink 14 can be electrically insulated, and the lead frame 17 can be electrically insulated. Heat can be conducted well to the heat sink 14. Therefore, an effect equivalent to that of the first embodiment can be obtained.

  In the first and second embodiments described above, the description has been given of the case where the four LED chips 11 are used. However, the number of the LED chips 11 is not limited to four, preferably two or more, preferably The desired number can be 3 or more. Further, the arrangement of the LED chips 11 is not limited to one row, but may be two or more rows. Furthermore, it is also possible to use light emitting elements other than the LED chip 11.

The side view of the semiconductor light-emitting device of 1st Embodiment. FIG. 2 is a top view of the semiconductor light emitting device of FIG. 1. FIG. 2 is a cross-sectional view of the semiconductor light emitting device of FIG. 1 taken along the line AA. BB sectional drawing of the semiconductor light-emitting device of FIG. (A) The perspective view of the state which removed the light guide part 15 from the light emitting element of FIG. 1, (b) The top view of the state which removed the light guide part 15 from the light emitting element of FIG. FIG. 3 is a top view of a metal frame used in the manufacturing process of the semiconductor light emitting device of FIG. 1. (A) And (b) The electric circuit diagram which shows the connection of the LED chip 11 of the semiconductor light-emitting device of 1st Embodiment. (A) The perspective view and side view which show the state which cut | disconnected the lead frame 17, the exposed wiring part 65, and the electrode terminal 16 from the metal frame in the manufacturing process of the semiconductor light-emitting device of FIG. The perspective view and side view which show the state bent along the side surface of the part 13 at substantially right angle, and accommodated in the notch. FIG. 2 is a cutaway perspective view showing an insulating film 90 of the semiconductor light emitting device of FIG. 1. FIG. 6 is a cutaway perspective view showing an insulating film 101 that covers a heat sink of the semiconductor light emitting device of the second embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... LED chip, 12 ... LED mounting area, 13 ... Resin part, 14 ... Heat sink, 15 ... Light guide part, 16 ... Terminal part, 16a ... 1st Terminal part, 16b ... 2nd terminal part, 17 ... Lead frame, 31 ... Notch, 32 ... Silicone resin, 35 ... Main plane of lead frame 17, 36 ... Resin Projection outline position of part 13, 41 ... opening for heat sink, 42 ... groove, 51a, 51b ... opening for LED chip, 52 ... through hole, 53 ... electric circuit element, 54. ..Electric circuit element openings, 61, 62, 63, 64 ... mounting portion, 65 ... exposed wiring portion, 67 ... outer frame portion, 68 ... terminal portion, 69 ... wire, 90 ... insulating film, 101 ... insulating film.

Claims (3)

A light emitting element, a lead frame that fixes the light emitting element and supplies power to the light emitting element, and a resin portion that holds at least the lead frame,
The lead frame includes a pair of terminal portions functioning as electrical terminals, and a wiring portion for guiding power from the terminal portions to the light emitting elements,
A part of the wiring part is
Arranged outside the resin portion and bent at a substantially right angle to the lead frame surface with which the light emitting element is in contact; and
The light-emitting device is bent so that the projection of the bent wiring portion is inside the outer shape of a shadow obtained by projecting the resin portion on a surface parallel to the lead frame surface with which the light-emitting element is in contact . 2. The light emitting device according to claim 1, wherein the light emitting elements are plural, and the lead frame has a plurality of mounting portions arranged in a row for mounting the plurality of light emitting elements,
The pair of terminal portions are both pulled out from one end of the resin portion, and the first terminal portion is directly on the mounting portion located at one end portion among the plurality of mounting portions arranged in a row. The light emitting device is characterized in that the connected second terminal portion is connected to the mounting portion located at the other end by the bent wiring portion. A method of manufacturing a light emitting device having at least one light emitting element,
The lead frame is molded using resin so that a terminal portion functioning as an electrical terminal in the lead frame and a part of the wiring portion for guiding power from the terminal portion to the light emitting element are exposed to the outside. A first step to:
A part of the wiring part that is exposed to the outside of the resin part formed in the first step so that the projection enters the inside of the outline of the shadow obtained by projecting the resin part on a surface parallel to the lead frame surface, A second step of bending at a substantially right angle with respect to the lead frame surface formed of the resin;
And a third step of electrically connecting and fixing the light emitting element to the lead frame so that power can be supplied from the lead frame.

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