JP2008258233A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently perform heat removal from a light-emitting element in order to attain the high output of a side surface light emission type light-emitting device to be mounted on the surface of a wiring substrate, and also to inexpensively manufacture the device. <P>SOLUTION: The side surface light emission type light-emitting device to be mounted on the surface of the wiring substrate includes: a base body part formed by integrally molding a reflection case with a terminal holding part in the rear part of the reflection case; and a lead member to be inserted to the base body part. A part to be drawn out from the base body part in the lead member is bent along the terminal holding part, so as to be a pair of connection parts to be connected to a wiring substrate pattern. Embedding parts embedded into the base body part in the lead member include projections in the thickness direction of the lead member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a side-emitting type light emitting device that is surface-mounted on a wiring board.

An example of the light emitting device of the above type is shown in Patent Document 1. This light emitting device has an opening at the front, lead members are exposed from both ends of the reflection case having a flat bottom, and a terminal holding portion is integrally provided at the rear of the light emission case, and the lead member is pulled out from the reflection case. The bent portion is bent along the terminal holding portion from the side of the reflection case, and is further folded to the back surface of the terminal holding portion.
In addition, refer to those described in Patent Documents 2 to 4 as side light emitting devices.
Reference should be made to Patent Document 5 as a light emitting device related to the present invention. In the light emitting device described in Patent Document 5, the lead member is bent in the sealing resin. The sealing resin is made of a transparent material, and the bent lead member serves as a reflection portion that reflects light from the light emitting element within the sealing resin.

JP 2004-363537 A JP 2006-253551 A JP 2006-19313 A Japanese Patent Laid-Open No. 2002-280616 Japanese Patent Laid-Open No. 6-204569

Recent light emitting devices are required to have high output. Therefore, the light emitting device tends to be mounted with a high output light emitting element. A high-power light-emitting element is accompanied by large heat generation. If the light emitting element itself becomes high temperature and the state continues for a long time, the durability of the light emitting element is lowered, which is not preferable. Therefore, it is necessary to efficiently perform heat removal from the light emitting element.
Note that the side-emitting type light-emitting device is exclusively used for illumination of a display of a mobile phone. Therefore, the light emitting device itself is small. Since the resin base portion needs to have a predetermined thickness from the viewpoint of preventing cracks and the like, the lead member embedded in the base portion is also limited in terms of its thickness and width.

The present invention has been made to achieve the above object, and its configuration is defined as follows.
A side-emitting type light emitting device that is surface-mounted on a wiring board,
A base portion formed by integrally molding a reflective case made of white resin and a terminal holding portion at the rear of the reflective case;
A lead member inserted into the base portion,
In the light emitting device in which the portion of the lead member that is pulled out from the base portion is bent along the terminal holding portion to be a pair of connection portions that are connected to the pattern of the wiring board.
In the lead member, a buried portion embedded in the base portion includes a convex portion in a thickness direction of the lead member.

According to the light emitting device according to the first aspect of the present invention configured as described above, since the convex portion is provided in the embedded portion of the lead member, the volume of the lead member embedded in the base portion is increased, and thus Its heat capacity increases. In other words, the convex portion becomes a heat sink, and the efficiency of heat extraction from the light emitting element is improved. Thereby, durability of a light emitting element improves. More specifically, the deterioration of the light emitting element itself can be prevented, and the deterioration of the paste material for fixing the light emitting element and the deterioration of the light emitting element surrounding material (sealing material and reflective case material) can be suppressed.
Further, since the lead member drawn out from the base portion is only the connecting portion, it is easier to mold compared to a configuration in which a part of the lead member is drawn out to the outside as a heat sink. For example, the configuration of the mold for forming the base portion is simplified, and deburring processing after the base portion is released from the mold is facilitated.

Since this convex part is formed in the thickness direction of the lead member, the width of the lead member can be reduced. Since the metal lead member is inferior in light reflectance as compared with the white resin constituting the reflection case, it is preferable to reduce the width of the lead member to increase the area occupied by the white resin at the bottom of the reflection case.
A part of the embedded portion of the lead member is exposed to the bottom of the reflection case, and the light emitting element is mounted there. Therefore, the embedded portion of the lead member is disposed between the reflective case and the terminal holding portion with one surface thereof being parallel or flush with the bottom surface of the reflective case. When this is viewed from the lead member, a reflection case is erected in the thickness direction on the first surface of the lead member, and a terminal holding portion is erected in the thickness direction on the second surface of the lead member. It becomes. Therefore, the convex portion formed in the thickness direction of the lead member is formed in the wide direction in the base portion. Therefore, even if the convex portion is formed in the wide direction of the base portion, the base portion has a sufficient thickness. Can be secured. Therefore, even if the convex portion is formed, the mechanical rigidity of the base portion does not decrease at all.

  Convex portions are formed in the thickness direction of the lead member. Here, the thickness direction of the lead member is not limited to a direction perpendicular to the planar direction of the lead member. What is necessary is just to accommodate in the terminal holding part erected from the 2nd surface of a lead member.

The second aspect of the present invention is defined as follows. That is,
In the light emitting device according to the first aspect, a base portion for mounting the light emitting element in the embedded portion of the lead member is flat on the side surface of the reflecting case, and the convex portion is formed from the base portion to the terminal holding portion side. Yes.
According to the light emitting device of the second aspect defined in this way, the side surface of the reflection case is formed flat at the base, so that the light emitted from the light emitting element can be efficiently reflected by the flat surface. . This increases the output of the light emitting device.

The third aspect of the present invention is defined as follows. That is,
In the light emitting device defined in the second aspect, the convex portion is obtained by partially thickening the lead member.
According to the light emitting device of the third aspect defined in this way, the lead member is partially thickened to form the convex portion. In other words, since the portion other than the base portion is relatively thin, less force is required when the lead member is bent. Therefore, it is possible to prevent damage (cracking, cracking, peeling, etc.) from entering the base portion when the lead member is bent.
Further, forming the thick portion on the lead member made of a metal plate can be easily performed by a method such as profile rolling. Therefore, it is possible to prevent an increase in the manufacturing cost of the lead member and consequently the manufacturing cost of the light emitting device.

The fourth aspect of the present invention is defined as follows. That is,
In the light emitting device according to the second aspect, the lead members have the same thickness as a whole, and the convex portion is a bent portion formed by bending the lead member in the thickness direction.
According to the light emitting device of the fourth aspect defined in this way, the convex portion can be formed by an inexpensive bending process. Therefore, an increase in the manufacturing cost of the lead member, and hence the manufacturing cost of the light emitting device can be suppressed.

The fifth aspect of the present invention is defined as follows. That is,
In the light emitting device defined in the first aspect, the convex portion is a portion in which the embedded portion of the lead member is partially thickened, and the light emitting element is mounted on the thick portion.
According to the light emitting device of the fifth aspect defined in this way, the lead member is partially thickened to form the convex portion at the base. In other words, since the portion other than the base portion is relatively thin, less force is required when the lead member is bent. Therefore, it is possible to prevent damage (cracking, cracking, peeling, etc.) from entering the base portion when the lead member is bent.
In addition, forming the thick portion on the lead member made of a metal plate can be easily performed by a method such as different diameter rolling. Therefore, it is possible to prevent an increase in the manufacturing cost of the lead member and consequently the manufacturing cost of the light emitting device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front perspective view of the light emitting device 1 of the embodiment, and FIG. 2 is a rear perspective view of the same. 3 also shows the light emitting device 1, FIG. 3A is a front view, FIG. 3B is a side view, FIG. 3C is a bottom view, and FIG. 3D is D in FIG. FIG.
The light emitting device 1 of the embodiment includes a base portion 10, a lead member 30 and a light emitting element 50.

The base unit 10 includes a reflection case 11 and a terminal holding unit 13. The base portion 10 is made of a white resin material having a high light reflectance, and a reflection case 11 and a terminal holding portion 13 are integrally formed. As such a white resin material, a material obtained by adding a white pigment such as titanium to a synthetic resin such as a liquid crystal polymer or polyimide can be used.
A concave portion 15 is formed in the reflection case 11, and the surface of a part of the first lead member 30 and the second lead member 40 (the first embedded portion 31 and the second embedded portion 41) is exposed at the bottom thereof. Yes. The peripheral surface of the recess 15 is a reflection surface 17.
The recess 15 is filled with a light-transmitting sealing material (such as an epoxy resin or a silicone resin). This sealing material can be filled with a fluorescent material, a diffusion material, or the like.

  A part of the first lead member 30 and the second lead member 40 (the first connection portion 33 and the second connection portion 43) is pulled out from the lower surface of the base portion 10, bent along the lower surface, Further, it is bent along the side surface of the base portion 10. The first connection portion 33 and the second connection portion 43 are electrically connected to a circuit board (not shown).

FIG. 4 shows the first lead member 30 and the second lead member 40, FIG. 4 (A) is a front view thereof, and FIG. 4 (B) is a side view thereof. FIG. 5 is a perspective view of the same.
The first lead member 30 includes a first embedded portion 31 embedded in the base portion 10 and a first connecting portion 33 drawn out from the base portion 10, and the whole is made of a single metal plate (copper plate). . The first embedded portion 31 includes a base portion 34 for mounting the light emitting element 50, and a first upper bent portion 35 and a first lower bent portion 36 formed on both edges of the base portion 34. The first lower bent portion 36 and the first connecting portion 33 are separated by a first notch 38.
The second lead member 40 includes a second embedded portion 41 embedded in the base portion 10 and a second connection portion 43 drawn from the base portion 10, and is entirely made of a single metal plate (copper plate). . The second embedded portion 41 is provided with a second upper bent portion 45 and a second lower bent portion 46 formed on both edges thereof. The second lower bent portion 46 and the second connecting portion 43 are separated by a second notch 48.

In the first lead substrate 30 and the second lead substrate 40 of the embodiment, as shown in FIG. 3D, the first embedded portion 31 and the second embedded portion 41 are embedded in the base portion 10. A part of the bottom surface of the recess 15 is exposed.
The first embedded portion 31 and the second embedded portion 41 are provided with upper bent portions 35 and 45 and lower bent portions 36 and 46, respectively, and these bent portions 35, 45, 36, and 46 are provided. Are embedded in the base portion 10 and are not exposed.
If these bent parts are exposed, the heat dissipation is improved. However, in this case, the shape of the mold when the base portion is molded using the first and second lead substrates as inserts becomes complicated, and the moldability is poor. Moreover, it takes time and effort to deburr after release.
Compared with the case where the bent portions 35, 45, 36, 46 are not provided, the lead members 31 and 41 of the embodiment have a large volume and thus a large heat capacity, and a large surface area increases heat dissipation. improves. Therefore, heat can be efficiently extracted from the light emitting element 50.

The light emitting device 1 of this embodiment is manufactured as follows (see FIG. 6). In FIG. 6, the same elements as those in FIGS. 4 and 5 are denoted by the same reference numerals, and the description thereof is omitted.
First, as shown in FIG. 6A, a flat metal plate is punched out. In FIG. 6 (A), the part which will be bent in the future is indicated by a dotted line.
Next, as shown in FIG. 6B, the light emitting element 50 is mounted on the base 34 of the first lead member, and the bonding wires 51 and 53 are suspended. Subsequently, the bent portions 35, 36, 45, and 46 are bent to a state shown in FIG.
Using the workpiece of FIG. 6C as an insert, the base portion 10 is molded as shown in FIG. 6D.

FIG. 7 shows lead members (first lead member 130 and second lead member 40) used in the light emitting device of another embodiment. In FIG. 7, the same elements as those of FIG.
In the first lead member 130 of this embodiment, notches 131 and 132 are provided in the first upper bent portion 35 and the first lower bent portion 36. The notches 131 and 132 facilitate the flow of the resin material when the resin material is molded, thereby improving the moldability.

FIG. 8 shows lead members (first lead member 230 and second lead member 240) used in the light emitting device of another embodiment. In FIG. 8, the same elements as those in FIG.
In this embodiment, the first lead member 230 has the bent portion 35 only on the upper side, and the second lead member 240 also has the bent portion 45 only on the upper side. By adopting such a configuration, the configuration of the lead member is simplified. As a result, the lead member can be provided at a low cost.

FIG. 9 shows lead members (first lead member 30 and second lead member 340) used in the light emitting device of another embodiment. In FIG. 9, the same elements as those in FIG.
In this embodiment, the bent portion is omitted from the second lead member 340. Since the light emitting element is not mounted on the second lead member 340 and the heat of the light emitting element is transmitted only through the bonding wire, the configuration of the second lead member 340 is simplified. As a result, the lead member can be provided at low cost.
In FIG. 9, the first lead member 130 shown in FIG. 7 or the first lead member 230 shown in FIG. 8 can be employed.

FIG. 10 shows lead members (first lead member 430 and second lead member 340) used in the light emitting device of another embodiment. In FIG. 10, the same elements as those in FIG.
In the first lead member 430 of this embodiment, a portion (base portion 34) where the light emitting element is to be mounted in the embedded portion 41 is a thick portion 435. The surface on which the light emitting element is mounted in the thick portion 435 is a flat surface (which maintains the light reflection efficiency), and a convex portion is formed on the back surface side (terminal holding portion side of the base portion).

Since the heat capacity of the first lead member 430 provided with the thick portion 435 is larger than that of the first lead member 430 without the thick portion, the heat extraction effect from the light emitting element is large. Even when the width of the base 34 made of metal having a low reflection efficiency is made as narrow as possible in order to improve the reflection efficiency (as a result, the area of the white material constituting the base portion increases), the first A sufficient heat capacity can be secured for the lead member.
In this embodiment, since there is no bent portion, the bending work is not necessary. Therefore, the manufacturing process of the lead member is simplified, and as a result, an inexpensive light emitting element can be provided.
The thick portion 435 is formed on the first lead member 430 by rolling the metal plate with a roll when the first lead member 430 is in a flat plate state (see FIG. 6A).

FIG. 11 shows lead members (first lead member 530 and second lead member 340) used in the light emitting device of another embodiment. In FIG. 11, the same elements as those of FIG. 9 are denoted by the same reference numerals, and the description thereof is omitted.
In this embodiment, the thick part 535 bulges on both surfaces of the embedded part 31. Thereby, the volume of the thick part 535 is increased, and heat extraction from the light emitting element is improved. As a result, the width of the base 34 on which the light emitting element is to be mounted in the first lead member 530 can be reduced.
Further, the lead member can be easily manufactured as compared with the embodiment having the bent portion.

FIG. 12 shows lead members (first lead member 630 and second lead member 340) used in the light emitting device of another embodiment. In FIG. 12, the same elements as those of FIG. 9 are denoted by the same reference numerals, and the description thereof is omitted.
In this embodiment, the thick portion 635 bulges to the front side (light emitting element mount side) of the embedded portion 31. By securing a sufficient volume in the thick portion, the width of the base portion 34 on which the light emitting element should be mounted in the first lead member 530 can be reduced.
Further, the lead member can be easily manufactured as compared with the embodiment having the bent portion.

  The present invention is not limited to the description of the embodiments and examples of the invention described above. Various modifications may be included in the present invention as long as those skilled in the art can easily conceive without departing from the description of the scope of claims.

FIG. 1 is a front perspective view of a light emitting device according to an embodiment of the present invention. FIG. 2 is a rear perspective view of the light emitting element. 3 shows the structure of the light emitting element, FIG. 3A is a front view, FIG. 3B is a right side view, FIG. 3C is a bottom view, and FIG. 3D is FIG. It is a partially cutaway DD sectional view taken on the line. 4A and 4B show the lead member of the embodiment, FIG. 4A is a plan view, and FIG. 4B is a right side view. FIG. 5 is a perspective view of the lead member. FIG. 6 is a diagram showing a manufacturing process of the light emitting device of the embodiment. FIG. 7 is a perspective view showing a lead member of another embodiment. FIG. 8 is a perspective view showing a lead member of another embodiment. FIG. 9 is a perspective view showing a lead member of another embodiment. FIG. 10 is a perspective view showing a lead member of another embodiment. FIG. 11 is a perspective view showing a lead member of another embodiment. FIG. 12 is a perspective view showing a lead member of another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-emitting device 10 Base | substrate part 11 Reflective case 13 Terminal holding | maintenance part 30,130,230,430,530,630 1st lead member 31,41 Embedded part 33,43 Connection part 34 Base 40,240,340 2nd lead Member 35, 36, 45, 46 Bending part 50 Light emitting element 435, 535, 635 Thick part

Claims (5)

A side-emitting type light emitting device that is surface-mounted on a wiring board,
A base portion formed by integrally molding a reflective case made of white resin and a terminal holding portion at the rear of the reflective case;
A lead member inserted into the base portion,
In the light emitting device in which the portion of the lead member that is pulled out from the base portion is bent along the terminal holding portion to be an integral connection portion that is connected to the pattern of the wiring board.
In the lead member, a buried portion embedded in the base portion includes a convex portion in a thickness direction of the lead member. The base part for mounting the light emitting element in the embedded part of the lead member is flat on the side surface of the reflecting case, and the convex part is formed from the base part to the terminal holding part side. The light-emitting device of description. The light emitting device according to claim 2, wherein the convex part is a part of the lead member made thick. The light emitting device according to claim 2, wherein the lead member has the same thickness as a whole, and the convex portion is a bent portion formed by bending the lead member to the thickness. The light emitting device according to claim 1, wherein the convex portion is a portion in which a buried portion of the lead member is partially thickened, and a light emitting element is mounted on the thick portion.

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