JP5257144B2 - Light emitting device and manufacturing method thereof - Google Patents

Description

  The present invention relates to an improvement in a light-emitting device using a surface-mounted light-emitting element.

  2. Description of the Related Art Conventionally, a light emitting device including a surface mount type light emitting element, a connector, and a housing is configured by soldering a light emitting element and other elements and terminals to a circuit on a substrate. Patent Document 1 discloses a light emitting device in which a light emitting element and a terminal are mounted on a substrate by soldering, and the substrate is attached to a case. Patent Document 2 discloses a light-emitting device in which a circuit and terminals are formed of a metal plate, and a surface-mounted light-emitting element is attached to the metal plate by soldering. Patent Document 3 discloses a light emitting device in which a bullet-type light emitting element is attached to a substrate formed integrally with a resin case.

Special table 2008-517832 gazette JP 2008-98343 A JP 2003-258314 A

In the light emitting device of Patent Document 1, since it is necessary to solder the terminals to the substrate, it is not possible to mount the surface mount component and the terminals at once by reflow soldering. Therefore, it is necessary to mount by hand soldering or so-called robot soldering, which leads to a decrease in yield. Further, since the substrate and the housing are separate, there is room for reducing the number of parts.
In the light emitting device of Patent Document 2, since a light emitting element is soldered to a metal plate, it cannot be mounted by reflow soldering.
In the light emitting device of Patent Document 3, since it is not considered to use a surface mount type light emitting element, various components cannot be mounted on the substrate by reflow soldering. Further, since the substrate and the housing are separate, there is room for reducing the number of parts.
Accordingly, an object of the present invention is to provide a light-emitting device that can mount a surface-mount type element by reflow soldering in a light-emitting device including a surface-mount type element.

In order to achieve the above object, the present invention has the following configuration. That is,
A surface mount type LED lamp, a resin mounting board, and a conductive member inserted into the mounting board,
The mounting surface of the mounting substrate is a flat surface, and the LED lamp is mounted on the mounting surface.
The conductive member has an electrode pad that is exposed on the mounting surface and connected to the LED lamp, a connection terminal that is drawn out of the mounting substrate, and a circuit portion embedded in the mounting substrate. A light emitting device characterized by the above.

  According to the light emitting device of the present invention, the mounting surface of the mounting substrate is flat, and a part of the conductive member to be inserted becomes a terminal. Therefore, the surface mounting elements such as LED lamps are bundled together by reflow soldering. Can be mounted on the mounting surface. This improves the yield and is advantageous in terms of cost. In addition, since the circuit portion of the conductive member is inserted into the mounting substrate, the contact area between the conductive member and the mounting substrate is increased in the circuit portion. As a result, the heat of the heat generating member such as the LED lamp can be propagated to the mounting substrate through the circuit portion and released to the outside, and the heat dissipation is improved.

1 is an exploded perspective view of a light emitting device 1. FIG. 3 is a top view of the housing 2. FIG. It is the sectional view on the AA line in FIG. 6 is a diagram illustrating a method for manufacturing the light emitting device 1. FIG. 6 is a diagram illustrating a method for manufacturing the light emitting device 1. FIG. 6 is a top view of a modification of the light emitting device 1. FIG. 7A is a front side exploded perspective view of the light emitting device 100, and FIG. 7B is a back side exploded perspective view. 2 is a perspective view of a pallet 120. FIG.

(LED lamp)
In the light emitting device of the present invention, a surface mount type LED lamp is used. Since the surface mount type LED lamp is small, it contributes to miniaturization of the device. The surface mount type LED lamp has a connection portion for connecting to an electrode pad of a mounting substrate. The connection portion may be drawn out from the LED lamp, or may be formed on a part of the lower surface or side surface of the LED lamp.

(Mounting board)
In the present invention, a resin mounting board is used. The material of the mounting substrate is not particularly limited, but is preferably a high heat transfer resin. This is because the heat dissipation of the device is improved. Examples of the high heat transfer resin include a liquid crystal polymer added with a metal filler and the like, PBT, and PPS. The material of the mounting board is preferably a material having a small expansion coefficient. This is because peeling of elements mounted on the mounting substrate is reduced. The mounting substrate is formed by injection molding using a conductive member described later as an insert, and the mounting surface of the mounting substrate is formed into a flat surface. The mounting substrate has a thickness that allows the conductive member to be inserted in a predetermined arrangement. The mounting substrate is preferably formed integrally with a connection terminal storage portion that stores a connection terminal described later. This is because the number of parts is reduced, which is advantageous in terms of cost.

(Conductive member)
In the present invention, the conductive member is inserted into a resin mounting board. Although the material of a conductive member is not specifically limited, Metals, such as copper, steel, and aluminum, are preferable. The conductive member includes an electrode pad that is exposed on the mounting surface of the mounting substrate and connected to a surface mounting element such as an LED lamp, a connection terminal that is drawn out of the mounting substrate, and a circuit portion embedded in the mounting substrate. Prepare. In addition to the LED lamp, the electrode pad is provided for each element mounted on the mounting substrate, such as a resistor, a diode, or a Zener diode. The electrode pad is preferably formed so as to have as large an area as possible. This is because misalignment when mounting the element is prevented. In addition, the contact area between the mounted element and the conductive member is ensured, so that heat is drawn through the conductive member, and heat dissipation is improved. The conductive member is formed by punching and molding a metal plate to form a convex part to be an electrode pad exposed on the mounting surface and to form a concave part to be a circuit part embedded in the mounting substrate. can do. The connection terminal can be drawn out in parallel to the mounting substrate from the side surface of the mounting substrate. It is preferable to provide a connection terminal storage portion that stores the connection terminal on the side opposite to the mounting surface of the mounting substrate, and bend the drawn connection terminal to the side opposite to the mounting surface of the mounting substrate and store it in the connection terminal storage portion. . This is because it contributes to a reduction in the number of parts and a reduction in size.
In addition to the electrode pads, the conductive member may include a heat radiating member connecting portion that is exposed on the mounting surface of the mounting substrate. Thereby, heat dissipation of heat generating members, such as an LED lamp, can be promoted and heat dissipation can be enhanced. It is preferable to connect a member having a large heat capacity such as a known heat sink to the heat radiating member connecting portion. This is because heat dissipation is further improved.

A method for manufacturing a light-emitting device in one embodiment of the present invention is as follows. That is, a surface mounting type LED lamp, a resin mounting board, and a conductive member inserted into the mounting board are provided, the mounting surface of the mounting board is flat, and the LED lamp is mounted on the mounting surface. The conductive member has an electrode pad that is exposed on the mounting surface and on which the LED lamp is mounted, a connection terminal that is drawn out of the mounting substrate, and a circuit unit that is embedded in the mounting substrate. A method for manufacturing a light-emitting device, comprising a mounting step of mounting an LED lamp on an electrode pad by reflow soldering. According to the manufacturing method, since the mounting surface of the mounting substrate is flat, the surface mounting type LED lamp can be mounted by reflow soldering, and the connection terminal can be provided on the mounting substrate. As a result, there is no need to provide a separate mounting process for the connection terminals, and the manufacturing process can be simplified and the manufacturing cost can be reduced. The member to be mounted by reflow soldering is not particularly limited as long as it is a member to which reflow soldering can be applied. In addition to surface mount type LED lamps, surface mount type elements such as surface mount type Zener diodes and resistance elements, Examples include diodes and transistors.
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an exploded perspective view of a light emitting device 1 that is an embodiment of the present invention. The light emitting device 1 includes a housing 2. The housing 2 is made of a liquid crystal polymer having high heat conductivity, and has a hollow, substantially rectangular parallelepiped shape. The upper surface 21a of the upper portion 21 (upper side of the drawing) of the housing 2 is a flat surface, on which the LED lamp 3, the Zener diode 4, the rectifier diode 5, and the resistance element 6 are mounted. The front surface of the housing 2 is open, and the hollow portion of the housing 2 becomes the connection terminal storage portion 22 and stores the connection terminal 7. Engaging protrusions 8 are provided on both side surfaces of the housing 2. A cover 9 is provided on the upper portion 21 side of the housing 2. The cover 9 includes a lens 91 and an engagement hole 92. The cover 9 covers the upper surface 21 a of the housing 2, and the cover 9 is attached to the housing 2 by the engagement protrusion 8 engaging with the engagement hole 92.

A top view of the housing 2 is shown in FIG. A metal plate 10 is inserted on the upper surface side of the housing 2. The metal plate 10 is a copper conductive thin plate, and includes an LED lamp electrode pad 31, a Zener diode electrode pad 41, a rectifier diode electrode pad 51, a resistor element electrode pad 61, and a predetermined circuit together with these. A circuit portion 11 to be formed is provided. As shown in FIG. 2, each electrode pad is exposed on the upper surface 21 a of the housing 2, and the circuit portion 11 is embedded in the housing 2. The LED lamp 3 is mounted on the electrode pad 31 for the LED lamp. The LED lamp 3 is a surface mount type LED lamp, and includes an electrode on a lower surface (a surface opposite to the light emitting surface). The Zener diode 4 is mounted on the Zener diode electrode pad 41, and the resistor element 6 is mounted on the resistor element electrode pad 61, respectively. Each of the Zener diode 4 and the resistance element 6 is a surface-mount type element, and includes an electrode on the lower surface.
A sectional view taken along line AA in FIG. 2 is shown in FIG. 3, and an installation mode of the metal plate 10 and a mounting mode of each element will be described. As shown in FIG. 3, in the metal plate 10, the electrode pads 31 and 61 (not shown, but 41 and 51 are the same) are formed to be more convex than the circuit portion 11. Thereby, the circuit part 11 is embedded in the upper part 21 of the housing 2, and each electrode pad 31, 41, 51, 61 is exposed on the upper surface 21a. Further, a part (indicated by reference numeral 11a) of the circuit portion 11 is bent and embedded along the side portion 23 of the housing 2, and further bent toward the hollow portion (connection terminal accommodating portion 22) side of the housing 2. The connection terminal 7 is formed so as to protrude from the inner wall of the side portion 23. The LED lamp 3 is mounted on the electrode pad 31 exposed on the upper surface 21 by soldering via the solder layer 12. Thus, the upper part 21 of the housing 2 functions as a mounting substrate on which each element including the LED lamp 3 is mounted. In other words, the housing 2 is one in which the mounting substrate (upper part 21) and the connection terminal accommodating part 22 are integrally formed.

Next, FIGS. 4 and 5 are diagrams illustrating a method for manufacturing the light emitting device 1. As shown in FIG. 4A, regions corresponding to the electrode pads 31, 41, 51, 61, the circuit unit 11, and the connection terminals 7 are formed on the metal plate 10 by punching. At this time, the respective regions are connected by the connecting portion 13 and maintained in a predetermined arrangement. Next, as shown in FIG. 4B, each electrode pad 31, 41, 51, 61 is formed in a convex shape on the upper surface side (upper side of the paper) by next molding. Further, the first bent portion 71 of the connection terminal 7 is bent to the back surface side (the side opposite to the side where each electrode pad 31, 41, 51, 61 protrudes), and the metal plate 10 is bent to the first bent portion 72 of the connection terminal 7. The metal plate 10 is bent in a parallel direction so as to face the back surface. Next, the housing 2 is formed by injection molding as shown in FIG. The injection direction at the time of injection molding is the direction from the one electrode of the resistance element electrode pad 61 toward the other electrode (the direction indicated by the symbol P in FIG. 4C). That is, the emission direction is an arrangement direction of the electrode pads 61 and is a direction parallel to the longitudinal direction of the resistance element 6 mounted on the electrode pads 61. The shape of the housing 2 is a elevational side body shape of the hollow which one is open, the upper portion 21 of the housing 2 is inserted the metal plate 10. The upper surface 21a of the upper portion 21 is a flat surface, and the electrode pads 31, 41, 51, 61 are exposed from the upper surface 21a. The circuit portion 11 is embedded in the upper portion 21, and the hollow portion of the housing 2 (connection terminal) The connecting terminal 7 is accommodated in the accommodating portion 22).
Next, as shown in FIG. 5D, the connecting portion 13 is removed and a solder paste is printed on the upper surface 21a of the upper portion 21 of the housing 2 by silk printing to form a solder layer having a predetermined thickness. Thereafter, heating is performed in a reflow furnace, and as shown in FIG. 5E, the LED lamp 3 is placed on the LED lamp electrode pad 31, the Zener diode 4 is placed on the Zener diode electrode pad 41, and the resistance element electrode pad 61 is placed on the electrode pad 61. The resistance elements 6 are mounted by reflow soldering. In this way, each element is mounted on the upper surface 21 a of the housing 2. Thereafter, the cover 9 is attached to the upper surface 21 a side of the housing 2 to manufacture the light emitting device 1.

  According to the light emitting device 1 of the present invention, since the upper surface 21a (mounting surface) of the housing 2 is a flat surface as described above, each element can be mounted by reflow soldering, and the connection terminal 7 is connected to the housing 2. Therefore, it is not necessary to separately attach the connection terminal by soldering. This simplifies the manufacturing process and is advantageous in terms of cost. In addition, the housing 2 includes a connection terminal housing portion 22 that serves as a connector to the outside while the upper surface 21a is a mounting surface. That is, the housing 2 integrally includes a mounting substrate and a connector. Thereby, compared with the case where a mounting board and a connector are comprised separately, a number of parts is reduced and an assembly operation is simplified. Further, it is advantageous in terms of cost. Furthermore, since the connection terminal 7 is bent and stored in the connection terminal storage portion 22 on the back surface of the upper portion 21 serving as a mounting substrate, the light-emitting device 1 is configured to be compact. Will improve. Moreover, since the circuit part 11 is inserted in the upper part 21 of the housing 2, the contact area of the circuit part 11 and the housing 2 increases. Thereby, the heat of the heat generating member such as the LED lamp 3 can be propagated to the housing 2 through the circuit portion 11 and released to the outside, and the heat dissipation is improved.

  Usually, when the mounting substrate expands and contracts, there is a possibility that an element mounted on the mounting substrate is peeled off. In particular, if the amount of expansion / contraction in the arrangement direction of the electrode pads on which the elements are mounted is large, the elements are easily peeled off. When the element has a connection terminal (lead) protruding outside the element, the influence of expansion / contraction of the mounting substrate is absorbed by the deformation of the lead, so that the element is hardly peeled off. In the light emitting device 1 of the present embodiment, the resistance element 6 is a surface-mount type element having an electrode on the lower surface, and does not have a protruding connection terminal (lead). However, since the injection direction when the housing 2 is injection-molded is the direction in which the resistive element electrode pads 61 are arranged and parallel to the longitudinal direction of the resistive element 6, the housing 2 in the longitudinal direction of the resistive element 6. The amount of expansion / contraction is small compared to other directions. Thereby, peeling of the resistance element 6 resulting from expansion / contraction of the housing 2 is prevented. As a result, even when each element generates heat when the light emitting device 1 is used, the resistance element 6 does not peel off, and the reliability of the device is high. In the light emitting device 1 according to the present embodiment, the resistance element 6 is longer than other elements such as the LED lamp 3, and therefore the injection molding is performed in the arrangement direction of the resistance element electrode pads 61. Although peeling was prevented, it is not limited to this, For example, it is good also as preventing the peeling of the LED lamp 3 by injection molding in the arrangement direction of the electrode pad 31 for LED lamps.

  A top view of a housing 2 of a modification of the light emitting device 1 of the present invention is shown in FIG. As shown in FIG. 6, the heat radiation portion 14 is provided on the upper surface 21 a of the housing 2. The heat radiating part 14 is formed from the metal plate 10 inserted in the upper part 21 of the housing 2 so as to be continuous with the LED lamp electrode pad 31 through the continuous part 14a. The heat radiating part 14 is exposed on the upper surface 21 a in the same manner as the electrode pads 31, 41, 51, 61. The continuous portion 14 is embedded in the upper portion 21 of the housing 2 similarly to the circuit portion 11. With such a heat radiating part 14, the heat of the LED lamp 3 is drawn to the outside, and the heat dissipation of the device is improved. Further, a member having a large heat capacity such as a heat sink can be connected to the heat radiating portion 14. Normally, when a heat sink is provided on the mounting board, a heat transfer sheet is provided between the mounting board and the heat sink so that an air layer is not formed between the mounting board and the heat sink. Since it forms from the metal plate 10, it can connect with a heat sink directly, without forming an air layer. For example, the heat sink can be attached to the heat radiating portion 14 by reflow soldering simultaneously with the mounting of the LED lamp 3. According to this, it is not necessary to provide a separate heat sink attachment process, and the manufacturing process can be simplified. Further, since it is not necessary to provide a heat transfer sheet when attaching the heat sink, the number of parts can be reduced, and the manufacturing cost can be reduced. In addition, although the thermal radiation part 14 of the present Example was exposed on the upper surface 21a (mounting surface), it is not limited to this, A part of metal plate 10 is exposed on the surface different from a mounting surface, and the thermal radiation part 14 and You can also By providing the heat radiating portion 14 on a surface different from the mounting surface, the degree of freedom of the heat sink mounting mode is improved.

In the light emitting device 1, the housing 2 is integrally provided with the mounting substrate and the connector. However, the present invention is not limited to this, and these may be configured separately. FIG. 7 (a) shows a front side exploded perspective view of a light emitting device 100 which is another embodiment provided separately from a mounting board and a connector, and FIG. 7 (b) shows a rear side exploded perspective view. In addition, the same code | symbol is attached | subjected to the member equivalent to the light-emitting device 1, and the description is abbreviate | omitted.
As shown in FIG. 7A, the light emitting device 100 includes a mounting substrate 101 made of a liquid crystal polymer having high heat conductivity and a housing 2 made of a transparent resin. Similar to the housing 2 of the light emitting device 1, a metal plate 109 is inserted into the mounting substrate 101. An upper surface (mounting surface) 101a of the mounting substrate 101 is a flat surface, and electrode pads (not shown) for each element such as the LED lamp 3 are formed. An LED lamp 3, a Zener diode 4, a rectifier diode 5, and a resistance element 6 are connected to the electrode pads for each element. Further, the connection terminal 7 is drawn out from the side surface of the mounting substrate 101. The housing 102 is made of a transparent resin and includes a mounting board holding unit 103 and a connection terminal storage unit 114. As shown in FIG. 7B, the back surface of the housing 102 is open, and the mounting board 101 is stored in the mounting board holding part 103. An engagement hole 110 is provided on the side surface of the mounting board holding portion 103, and the engagement protrusion 8 provided on the side of the mounting board 101 is engaged to fix the mounting board 101. The light of the LED lamp 3 is emitted to the outside from the upper surface 103 a of the mounting substrate holding part 103. The connection terminal 7 is stored in the connection terminal storage unit 104. The connection terminal storage unit 104 has an opening 104a and is connected to the outside through the opening 104a. That is, the connection terminal storage unit 104 functions as a connector.

  Each element such as the LED lamp 3 is mounted by reflow soldering using a pallet 120 having a predetermined shape. FIG. 8 shows a perspective view of the pallet 120. In the pallet 120, a plurality of grooves 120a are formed along the outer shape of the mounting substrate 101 into which the metal plate 109 is inserted. (In FIG. 8, 15 grooves 120a are formed.) The depth of the grooves 120a is substantially the same as the thickness of the mounting substrate 101. The mounting substrate 101 with the metal plate 109 inserted is installed in the groove 120a so that the mounting surface 101a is exposed. Thereafter, a solder layer is formed on the top surface of the pallet 120 with a solder paste. And it passes through a reflow furnace and each element is mounted by reflow soldering. By using such a pallet 120, it is possible to simultaneously mount surface-mounted elements on a large number of mounting boards 101 by reflow soldering (so-called a large number can be obtained), so that the manufacturing cost can be reduced. The light emitting device 100 manufactured in this way also has the same effect as the light emitting device 1. Prior to the step of mounting each element on the mounting substrate 101, a resist layer is provided in a region other than the electrode pads for each element on the mounting surface 101a of the mounting substrate 101, and a solder layer is provided only in the electrode pad region. It is good as well.

  The light emitting device of the present invention can be used as a light source of various devices.

DESCRIPTION OF SYMBOLS 1,100 Light-emitting device 101 Mounting board 10,109 Metal plate 11 Circuit part 12 Solder layer 13 Connection part 2,102 Housing 21 Upper part 21a Upper surface 22,104 Connection terminal storage part 3 LED lamp 31 LED lamp electrode pad 4 Zener diode 41 Zener diode electrode pad 5 Rectifier diode 51 Rectifier diode electrode pad 6 Resistive element 61 Resistive element electrode pad 7 Connection terminal 8 Engaging protrusion 9 Cover 120 Pallet

Claims (6)

A surface mount type LED lamp, a resin mounting board, a conductive member inserted into the mounting board, and a connection terminal housing portion integrally formed with the mounting board by the resin ;
The mounting surface of the mounting substrate is a flat surface, and the LED lamp is mounted on the mounting surface.
The conductive member, possess an electrode pad connected to the LED lamp and exposed on the mounting surface, and a connection terminal led out to the outside of the mounting substrate, and a circuit portion which is embedded in the mounting board, the ,
The light emitting device according to claim 1, wherein the connection terminal storage unit is provided on a side opposite to the mounting surface of the mounting substrate and stores the connection terminal . The mounting substrate is formed by injection molding,
The light emitting device according to claim 1, wherein the electrode pads are arranged along an emission direction of the mounting substrate. The light emitting device according to claim 1, wherein the circuit portion is bent and embedded along a side portion of the mounting substrate and further bent toward the connection terminal storage portion. Claim before Symbol connection terminals are both drawn from the side surface of the mounting substrate, which is bent on a surface thereof opposite to the mounting surface of the mounting board, is housed in the connecting terminal accommodating portion, it is characterized by 3. The light emitting device according to 1 or 2 .   The light emitting device according to claim 1, wherein the conductive member includes a heat radiating portion that is exposed on a mounting surface of the mounting substrate. A surface mount type LED lamp, a resin mounting board, a conductive member inserted into the mounting board, and a connection terminal housing portion integrally formed with the mounting board by the resin ;
The mounting surface of the mounting substrate is a flat surface, and the LED lamp is mounted on the mounting surface.
The conductive member, possess an electrode pad connected to said LED lamp exposed to the mounting surface, and a connection terminal led out to the outside of the mounting substrate, and a circuit portion which is embedded in the mounting board, the ,
The connection terminal storage part is provided on the opposite side of the mounting surface of the mounting substrate, and is a method of manufacturing a light emitting device that stores the connection terminal ,
The manufacturing method of the light-emitting device characterized by including the mounting process which mounts the said LED lamp on the said mounting surface by reflow soldering.

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