METHOD FOR MANUFACTURING LIGHT EMITTING APPARATUS, LIGHT EMITTING APPARATUS, AND MOUNTING BASE THEREOF
The present invention provides a method for manufacturing a light emitting apparatus which can be separated by splitting, even though a mounting plate made of metal is employed. A metal plate is prepared, on which at least one joint slit made up of a joint and an opening is formed in a predetermined direction for integrating multiple mounting plates of the light emitting apparatuses. Multiple light emitting elements set in array are mounted on the metal plate. An aperture is provided at a position corresponding to a position for mounting the light emitting element on the metal plate, and a plate-like reflector made of resin, on which a first reflector splitting groove is formed at a position coinciding with the joint slit of the metal plate, is mounted and fixed on the metal plate in such a manner as superimposed thereon. The metal plate and the plate-like reflector being superimposed and fixed one on another are broken along the joint slit of the metal plate and the first reflector splitting groove of the plate-like reflector. The metal plate and the resinous reflector are superimposed one on another and broken together, whereby the metal plate can be split successfully.
This application claims the priority benefit under 35 U.S.C. §119 of Japanese Patent Application No. 2009-147905 filed on Jun. 22, 2009, which is hereby incorporated in the entirety by reference.
FIELD OF THE INVENTIONThe present invention relates to a method for manufacturing a light emitting apparatus on which a light emitting diode (LED) is mounted, and more particularly, it relates to a method for manufacturing a light emitting apparatus on which multiple LEDs are mounted in the form of line.
DESCRIPTION OF THE RELATED ARTJapanese Unexamined Patent Application Publication No. 2000-58924 (hereinafter, referred to as “patent document 1”) discloses that a thin sheet metal is employed as a mounting plate in order to enhance a heat radiation effect of the mounting plate on which the LED is mounted. The thin sheet metal is separated into two electrode areas according to a slit which is created by a press work, and one of the electrode areas is processed into a concave, being a mortar shape, which serves as a reflector. An LED is die-bonded at the center of the concave portion. The other electrode area is connected to a topside electrode of the LED via a bonding wire. At the time of manufacturing, a heat-resistant film is affixed to the back of the mounting plate having the slit thereon, and after the die-bonding and wire-bonding of the LED, all over the top surface is sealed by an epoxy resin. Accordingly, the slit is also filled with the epoxy resin. Subsequently, dicing is performed to separate the mounting plate to individual LEDs. Since the insulating heat-resistant film and the epoxy resin establish a joint at the slit, even when dicing is performed for separation, it is possible to maintain the coupling between the two electrode areas.
On the other hand, Japanese Unexamined Patent Application Publication No. 2006-108341 (hereinafter, referred to as “patent document 2”) discloses a method for manufacturing a semiconductor device and dicing is not performed in this method. In other words, perforation-like grooves are provided in length and breadth on the wiring mounting plate in advance, semiconductor substrates are respectively mounted on the areas partitioned by the perforation-like grooves, and a layer of encapsulation resin is provided on the top. According to this method, both the wiring mounting plate and the layer of encapsulation resin are broken along the perforation, so as to divide the wiring mounting plate.
As for the light emitting apparatus which uses the thin sheet metal as the mounting plate as described in the patent document 1, it is necessary to cut off and divide the metallic mounting plate by a dicing blade to obtain an individual light emitting apparatus. When the mounting plate is cut off by dicing, there is a problem that cuttings are generated and it may adhere to a light emitting surface of the LED.
On the other hand, when the technique of the patent document 2 is applied to the light emitting element, i.e., the perforation-like grooves are provided on the wiring mounting plate and the wiring mounting plate is broken and separated, stress on the mounting plate upon breaking may be added to the LED and bonding wire, and there is a possibility of problem occurrence, such as failing in illuminating. If the mounting plate is made of metal, it is difficult to break the mounting plate due to ductility of metal, even though the perforation-like grooves are provided.
An aspect of the present invention is to provide a method for manufacturing a light emitting apparatus in which the mounting plate can be separated by breaking (being forced apart), even in the case where a metallic mounting plate is employed.
SUMMARY OF THE INVENTIONThe present invention provides a method for manufacturing a light emitting apparatus as described below.
In other words, the method for manufacturing the light emitting apparatus has a step of preparing a metal plate on which at least one joint slit made up of a joint and an opening is provided in a predetermined direction, the joint integrating multiple mounting plates of the light emitting apparatuses, a step of mounting multiple light emitting elements on the metal plate in such a manner as set in array, a step of mounting and fixing a plate-like reflector made of resin on the metal plate in a superimposed manner, the plate-like reflector being provided with an aperture at a position corresponding to a position for mounting the light emitting element on the metal plate, and having a first reflector splitting groove formed on a position coinciding with the joint slit of the metal plate, and a step of breaking the metal plate and the plate-like reflector being superimposed and fixed one on another, along the joint slit of the metal plate and along the first reflector splitting groove of the plate-like reflector.
As thus described, since the metal plate and the plate-like reflector made of resin are superimposed and fixed one on another, so as to be broken together, it is possible to facilitate breaking of the metal plate.
It is further possible to configure such that a plate splitting groove orthogonal to the joint slit is formed on the metal plate, and a second reflector splitting groove is formed on the plate-like reflector at a position coinciding with the plate splitting groove. With this configuration, it is further possible to break along the plate splitting groove and the second reflector splitting groove.
Preferably, the first reflector splitting groove and/or the second reflector splitting groove are formed from both faces of the reflector, each being a V-shape groove.
It is possible to perform a step of forming an insulating slit on the metal plate, in addition to the joint slit, in order to electrically separate the metal plate into two areas after being split, and filling insulating resin into the insulating slit before the step of mounting the light emitting elements, or after the mounting step and before the step of fixing the plate-like reflector.
It is further possible to perform a step of establishing connection via a bonding wire, between a topside electrode of the light emitting element which is mounted in the mounting step and a bonding pad which is provided in the area on the side opposed to the light emitting element, placing the insulating slit therebetween.
Preferably, by extending a region where the light emitting element and the bonding wire are positioned on the metal plate in a direction virtually perpendicular to the longitudinal direction of the joint slit, the region being a band-like shape defined on the metal plate, so that the joint described above is arranged at a position deviated from the band-like region. This configuration aims to avoid application of stress on the light emitting element and the bonding wire when the breaking is performed.
A V-shaped notch may be provided from at least one side of the joint, and a cross section of the first reflector splitting groove may be formed also in the V-shape. Therefore, it is desirable that the plate-like reflector and the metal plate are fixed in such a manner that the notch coincides with the first reflector splitting groove.
In the breaking process, any of the plate splitting groove and the joint slit may be selected for the breaking.
According to another aspect of the present invention, a light emitting apparatus is provided as described below. In other words, this light emitting apparatus includes a metallic mounting plate having an insulating slit filled with insulating resin, a light emitting element mounted on the mounting plate, and a reflector made of resin arranged on the mounting plate and provided with an aperture at the position corresponding to the position for mounting the light emitting element, the light emitting apparatus being provided with a protrusion on the side surface orthogonal to the insulating slit of the mounting plate, and an inclined plane is formed on the end of the protrusion.
It is possible to configure such that the light emitting element is mounted on any one of a first area and a second area of the mounting plate being electrically separated by the insulating slit, one electrode of the light emitting element is electrically connected via the bonding wire to any one of the first area and the second area of the mounting plate, where the light emitting element is not mounted, and the protrusion is formed on each of the first area and the second area of the mounting plate.
According to a further alternative aspect of the present invention, a mounting base for multiple light emitting apparatuses is provided as described below. In other words, the present invention is also directed to the mounting base for multiple light emitting apparatuses, having at least one joint slit made up of a joint and an opening for integrating multiple metallic mounting bases of the light emitting apparatuses, where the joint is provided with a notch from at least one face thereof.
Preferred embodiments of the present invention will be explained with reference to the accompanying drawings.
First EmbodimentIn the first embodiment, a method for manufacturing a line-shaped light emitting apparatus will be explained.
As illustrated by the sectional view of
As illustrated by the top view of the mounting plate 10 in
In the line-shaped light emitting apparatus according to the present embodiment, there are arranged between the insulating slit 11 and the LED element 12, splitting V-shaped grooves 14 respectively on both faces of the mounting plate 10, and splitting V-shaped grooves 22 respectively on both faces of the reflector 20, in order that the light emitting apparatus arranging the four LED elements in the form of line is allowed to be separated one by one, into four apparatuses. The direction of the splitting V-shaped grooves 14 and 22 are parallel to the insulating slit 11. The splitting groove 14 and the splitting groove 22 are provided at the positions coinciding with each other.
Next, with reference to
As shown in
On the metal plate 30, as shown in
As shown in
The splitting V-shaped groove 14 is formed in parallel to each of the multiple insulating slits 11 with a certain spacing therebetween. As shown in
The V-shaped notch 33 of the joint 32 and the splitting V-shaped groove 14 may be formed by notching by a dicing blade from both faces of the metal plate 30, as an alternative way to the press process or the etching process.
Furthermore, the V-shaped notch 33 and the splitting V-shaped groove 14 are not necessarily formed on both faces, and they may be formed only on the underside or only on the upper side.
Next, in the step as shown in
Next, in the process as shown in
In the meantime, in the step as shown in
An adhesive agent (e.g., silicone-based adhesive) is applied to the surface of the metal plate 30 on which the reflector 20 is bonded. Accordingly, a laminated body is formed, in which the position of the joint slit 31 of the mounting plate 10 coincides with the position of the V-shaped groove 41 of the reflector 20. The splitting V-shaped groove 14 of the metal plate 30 and the splitting V-shaped groove 22 of the reflector 20 also coincide in position.
Thereafter, in the step as shown in
Finally, as shown in
As thus described, the resinous plate-like reflector 20 with small ductibility is bonded on the metal plate 30, and the reflector 20 and the metal plate 30 are simultaneously broken. Therefore, even though the metal plate 30 is made of a metal having ductibility, it is easily split to obtain the line-shaped mounting plate 10. Instead of splitting by hand, it is possible to split by punching.
When the metal plate 30 is broken, it is desirable that the joint slit 31 and the joint 32 are arranged at the position that does not overlap the region 35 where the wire bonding pad and the LED element 12, and the bonding wire 13 are arranged, as shown in
Since the notch 33 is provided in V-shape on the joint 32, a force applied to the metal plate 30 can be reduced when the breaking is performed, and there is further an effect that the stress is uniformly dispersed, whereby it becomes more difficult to apply stress on the LED element and the wire.
As shown in
As thus described, in the manufacturing method according to the first embodiment, even though the mounting plate 10 is made of metal, the light emitting apparatus can be obtained just by splitting the metal plate 30 and the reflector without dicing, and the line-shaped light emitting apparatus as shown in
The line-shaped light emitting apparatus as shown in
As shown in
As shown in
In the present embodiment, there has been explained an example that the metal plate 30 and the reflector 20 are provided with the joint slit 31, the splitting V-shaped grooves 14 and 22, the V-shaped groove 41 in two directions being orthogonal, in order to increase flexibility in selecting the direction of splitting. However, if it is determined in advance to manufacture a line-shaped light emitting apparatus in a predetermined direction, it is sufficient to provide the joint slit 31, the splitting V-shaped grooves 14 and 22, and the V-shaped groove 41 only for the direction of the determined line.
As described above, the method for manufacturing the LED light emitting apparatus of the present embodiment can be achieved by forming a simple slit or V-shaped groove on the metal plate 30 and the reflector 20, and injecting insulating resin in simple manner by a dispensing method. In addition, the metal plate 30 and the reflector 20 can be split by hand or the like, without using the dicing process. Therefore, an LED light emitting apparatus having a desired array such as a line shape can be easily manufactured at low cost, together with an effect that both reliability and versatility are high.
Second EmbodimentNext, the second embodiment of the present invention will be explained.
The first embodiment is directed to a procedure that the insulating adhesive is injected into the insulating slit 11 by the dispensing method in the step shown in
Specifically, as shown in
In the dispensing step, the injecting work is performed in such a manner that the dispenser does not come into contact with the bonding wire 13. By way of example, the insulating adhesive agent may be injected from the backside of the metal plate 30.
Since other steps shown in
In the first embodiment, the LED element 12 is die-bonded by using the adhesive resin, but the method of die bonding is not limited to such usage of the adhesive agent. In the third embodiment, there will be explained a case where die bonding is performed by eutectic bonding.
When eutectic solder (e.g., AuSn alloy) is used for the die bonding, it is necessary to heat the solder up to 180° C. or higher so as to melt the solder. Therefore, if the die bonding is performed after injecting the insulating adhesive agent into the insulating slit 11, there is a possibility that the heat may cause deterioration (e.g., discoloration or exfoliation of resin). In the third embodiment, die bonding of the LED element 12 is performed before the dispensing step. Firstly, in the step as shown in
According the steps as described above, it is possible to use solder for the die-bonding of the LED element 12.
It is to be noted that in the third embodiment, since the steps as shown in
The LED light emitting apparatus of the present invention described above may substitute for a fluorescent lamp to be used as an illuminating device. This apparatus may be applicable as a vehicle-equipped light source, such as ahead lamp, rear combination lamp, indoor lighting, and turn lamp, and also as a light source for reading used in a copy machine.
Claims
1. A method for manufacturing a light emitting apparatus, comprising the steps of:
- preparing a metal plate on which at least one joint slit made up of a joint and an opening is provided in a predetermined direction, the joint integrating multiple mounting plates of the light emitting apparatuses,
- mounting multiple light emitting elements on the metal plate in such a manner as set in array,
- fixing a plate-like reflector made of resin to be mounted on the metal plate in a superimposed manner, the plate-like reflector being provided with an aperture at a position corresponding to a position for mounting the light emitting element on the metal plate, and having a first reflector splitting groove formed on a position coinciding with the joint slit of the metal plate, and
- breaking the metal plate and the plate-like reflector being superimposed and fixed one on another, along the joint slit of the metal plate and the first reflector splitting groove of the plate-like reflector.
2. The method for manufacturing the light emitting apparatus according to claim 1, wherein,
- a plate splitting groove is formed on the metal plate in a direction orthogonal to the joint slit, and
- a second reflector splitting groove is formed on the plate-like reflector at a position coinciding with the plate splitting groove, and
- the method further comprises a step of splitting along the plate splitting groove and the second reflector splitting groove.
3. The method for manufacturing the light emitting apparatus according to claim 2, wherein,
- the first reflector splitting groove and/or the second reflector splitting groove are formed from both faces of the plate-like reflector, each being a V-shape groove.
4. The method for manufacturing the light emitting apparatus according to claim 1, wherein,
- an insulating slit is formed on the metal plate to electrically separate the metal plate into two areas, and
- the method further comprises a step of filling the insulating slit with insulating resin before the step of mounting the light emitting elements, or after the mounting step and before the step of fixing the plate-like reflector.
5. The method for manufacturing the light emitting apparatus according to claim 4, further comprising a step of establishing connection via a bonding wire, between a topside electrode of the light emitting element which is mounted in the mounting step and a bonding pad which is provided in the area on the side opposed to the light emitting element, placing the insulating slit therebetween.
6. The method for manufacturing the light emitting apparatus according to claim 5, wherein,
- a region where the light emitting element and the bonding wire are arranged on the metal plate is virtually extended in the direction perpendicular to the longitudinal direction of the joint slit, so that the joint is arranged at a position that is deviated from the region being a band-like shape defined on the metal plate.
7. The method for manufacturing the light emitting apparatus according to claim 1, wherein,
- the joint is provided with a V-shaped notch at least from one face thereof, the first reflector splitting groove is formed to have a V-shape cross-section, and the plate-like reflector and the metal plate are superimposed one on another in such a manner that the notch coincides with the first reflector splitting groove.
8. The method for manufacturing the light emitting apparatus according to claim 2, wherein,
- in the step of breaking, any one of the plate splitting groove and the joint slit is selected for the breaking.
9. A light emitting apparatus comprising,
- a mounting plate made of metal having an insulating slit which is filled with insulating resin,
- a light emitting element mounted on the mounting plate, and,
- a reflector made of resin arranged on the mounting plate, having an aperture at a position corresponding to a position for mounting the light emitting element, wherein,
- a protrusion is provided on the side surface orthogonal to the insulating slit of the mounting plate, and an inclined plane is formed on the end of the protrusion.
10. The light emitting apparatus according to claim 9, wherein,
- the light emitting element is mounted on any one of a first area and a second area of the mounting plate, the first area and the second area being obtained by electrically separated by the insulating slit,
- one electrode of the light emitting element is electrically connected via a bonding wire to any one of the first area and the second area on which the light emitting element is not mounted, and
- the protrusion is formed on each of the first area and second area of the mounting plate.
11. A mounting base for multiples light emitting apparatuses, comprising at least one joint slit made up of a joint and an opening, the joint integrating multiple metallic mounting bases of the light emitting apparatuses, wherein,
- the joint is provided with a notch from at least one face thereof.
Type: Application
Filed: Jun 17, 2010
Publication Date: Dec 23, 2010
Inventors: Takaaki Sakai (Tokyo), Shinichi Katano (Tokyo)
Application Number: 12/817,939
International Classification: F21V 7/00 (20060101); F21V 21/005 (20060101); B23P 11/00 (20060101);