WO2006100917A1

WO2006100917A1 - Light emitting element reflector, manufacturing method thereof, and light emitting device using the reflector

Info

Publication number: WO2006100917A1
Application number: PCT/JP2006/304477
Authority: WO
Inventors: Kenitiro Tani; Kazuo Kigawa; Jiro Iijima; Yoshio Tsukiyama; Masashi Tezuka
Original assignee: Tanaka Kikinzoku Kogyo K.K.; Sumitomo Metal (Smi) Electronics Devices Inc.
Priority date: 2005-03-22
Filing date: 2006-03-08
Publication date: 2006-09-28
Also published as: JP4823214B2; JPWO2006100917A1

Abstract

A cylindrical reflector is arranged so as to surround a light emitting element arranged on a substrate and reflects the light from the light emitting element by its inner surface. At least a part of the outer wall has wax material on the entire surface and the wax material is melted when bonding with the substrate. The melted wax material goes down along the outer wall to the lowest portion in contact with the substrate. As for a specific shape, the outer wall has two-stage structure having a drum portion in contact with the substrate and a collar portion wider than the drum portion and wax material is arranged on the bottom of the drum portion and bottom of the collar portion in a block state. Alternatively, the outer wall and the inner wall are substantially parallel to each other to form a thin cylindrical body and wax material is arranged at least a part of the outer wall.

Description

Specification

REFRETATOR FOR LIGHT EMITTING ELEMENT, MANUFACTURING METHOD THEREOF, AND LIGHT EMITTING DEVICE HAVING THE REFRETATOR

Technical field

The present invention relates to a reflector for reflecting light emitted from a light emitting element, a method for manufacturing the same, and a light emitting device to which this reflector is applied, in a device including a light emitting element such as a light emitting diode.

Background art

[0002] Light-emitting elements such as light-emitting diodes (hereinafter referred to as LEDs) are small, have long life and low power consumption, and have excellent drive characteristics. Recently, it has been put to practical use in vehicle sign lights (stop lamps, turn indicators, etc.), signals, and outdoor lights.

FIG. 6 schematically shows an example of the configuration of a light emitting device including a light emitting element. In FIG. 6, the light emitting device includes a light emitting element and a substrate for fixing the light emitting element, and the light emitting element is driven and controlled through the substrate. In a light-emitting device using a light-emitting element, a reflector (reflector) is installed around the light-emitting element to effectively use the light from the light-emitting element so that the light of the light-emitting element force is reflected forward. It is common that

[0004] A conventionally used reflector for a light-emitting element is generally a block-shaped cylinder having an inclined inner surface as shown in FIG. Such a reflector is manufactured by forming a reflective film by attaching silver to a base material formed by molding a metal such as resin or copper into a predetermined shape.

Patent Document 1: JP-A-9 81055

Disclosure of the invention

[0005] Incidentally, as a method of fixing the reflector to the substrate, joining by brazing is generally used. In this case, first, a foil-like brazing material is fused to the bottom of the reflector, placed on the substrate, and heated to melt and join the brazing material. However, with conventional reflectors After bonding to the substrate in this way, the thickness distribution of the brazing material at the bonded portion may become uneven. There is also a problem that defects such as gaps and bubbles remain in the joint. These defects may make the reflector connection unstable and may cause peeling during use. In some cases, tilting may occur, and light from the light emitting element may not be reflected effectively.

[0006] Accordingly, an object of the present invention is to provide a reflector that can suppress the occurrence of bonding defects and can be stably bonded and fixed to a substrate.

[0007] The reason why the non-uniform thickness and defects occur in the brazing material of the joint is considered to be due to the fact that the molten brazing material does not necessarily spread uniformly. In particular, the molten brazing material tends to agglomerate into a ball shape due to its surface tension, and has a large joining area. In some cases, the brazing material is difficult to spread uniformly over the entire surface, and uneven thickness and defects are likely to occur. On the other hand, it is possible to suppress the generation of gaps by increasing the amount of brazing material in advance, but if the amount of brazing material used is too large, the bonding surface force will also protrude and the brazing material will protrude from the substrate and other members. There is a risk of damage. In addition, when a large amount of brazing material is agglomerated, there is a concern that the reflector will float on the brazing material and cannot be fixed in the correct position.

[0008] The present inventors consider that the behavior of the brazing material at the time of melting as described above is considered, and in order to obtain a stable joint portion, the inventors of the present invention consider that a brazing material on the side surface of the reflector is suitable. I thought.

That is, the present invention is a cylindrical reflector that is arranged so as to surround a light-emitting element installed on a substrate and reflects light from the light-emitting element by its inner surface. A brazing material is provided on the entire surface or the entire surface, and the brazing material is melted when bonded to the substrate, and the molten brazing material is lowered along the outer wall to the lower end contacting the substrate. It is a reflector.

[0010] In the reflector of the present invention, the brazing material on the side surface (outer wall) of the reflector is melted at the time of joining to the substrate, and this is lowered toward the substrate along the outer wall. Due to this lowering, the brazing material reaches the bottom surface of the reflector and the substrate in an energized state, thereby suppressing the occurrence of defects at the joint. And in this application, the thing of the following two specific modes is shown as a reflector using the fall of this brazing material. [0011] In the first form, the outer wall shape has a two-stage structure including a body part in contact with the substrate and a flange part wider than the body part, and the outer wall shape is formed on the bottom surface of the body part and the bottom surface of the flange part The brazing material of the flange part melts at the time of joining to the substrate, descends along the outer wall, and becomes integrated with the brazing material on the bottom surface of the trunk part! /.

[0012] The reflector according to the first embodiment improves the structure of the outer wall of a conventional block-shaped reflector having a relatively large bottom area. In the present invention, the shape is a two-stage structure (inverted L shape) of a body part and a flange part wider than the body part, and a brazing material is joined to the bottom surfaces of the copper part and the flange part. A schematic illustration of this structure is shown in Fig. 1 (a). When this reflector is brazed to the substrate, the joint is formed by melting the brazing material on the bottom of the body, and then the brazing material on the bottom of the buttock melts and is not urged along the outer wall of the reflector. And then it is integrated with the brazing material on the bottom of the torso (Fig. 1 (b)). Through this series of operations, even if bubbles or chips are generated in the brazing material on the bottom of the body, the brazing material is replenished with a buttock force, and a defect-free joint is formed.

[0013] The bottom shape of the collar may be horizontal, but is preferably provided with an inclination (FIG. 1 (c)). This is because the transition of the molten brazing material to the wall surface of the body portion becomes smoother.

[0014] The thickness of the brazing material is preferably 1 to 30% of the thickness of the substrate, or 10 to 60 μm. Further, it is preferable that the brazing material at the bottom of the trunk and the brazing material at the bottom of the buttock are equal in thickness.

[0015] The reflector according to the second embodiment of the present application includes a thin plate cylinder that is substantially parallel to the outer wall and the inner surface, and includes a brazing material in at least a part of the outer wall, and the outer wall is joined to the substrate. The brazing filler metal melts and descends to the lower end where it contacts the substrate.

[0016] The reflector differs from the first reflector in that the first reflector is in the form of a block, whereas the reflector is made of a thin plate having a small contact area with the substrate. And this shape and the above-mentioned action of the brazing material descending on the side surface will form a healthy joint! That is, when the reflector is placed on the substrate, there is a slight force gap between its lower end and the substrate, but the brazing material on the substrate tends to penetrate from the outer wall side to the inner surface side due to capillary action. is there. In the present invention, the lowered brazing material is energized, and more easily penetrates through the gap and surrounds the lower end portion from the inner and outer surfaces. In addition, this reflector is connected to the substrate. Since the contact area is small, even if the brazing material agglomerates, the entire bottom end is surrounded and fixed easily. This behavior of the brazing material occurs all around the lower end of the reflector. Therefore, the junction between the reflector and the substrate can be strengthened.

[0017] In the reflector according to the present invention, it is preferable that the edge is formed so that the tip portion in contact with the substrate is in substantially line contact with the substrate. The tip shape is made in this way in order to make the state (shape) of the brazing material after brazing suitable. In other words, when the edge is formed and the tip is in a line contact state, an appropriate gap is likely to be formed between the substrate and the outer wall-side force brazing material is easily penetrated, and a more suitable joint shape is formed. This is because it is easy to obtain.

[0018] The thickness of the brazing material here is preferably 1 to 30% of the thickness of the substrate, or 10 to 60 m, like the reflector of the first embodiment. In addition, about the area | region where a brazing material coat | covers an outer peripheral surface, the brazing material may be formed in the whole surface, and one part (lower half etc.) may be sufficient as it.

[0019] It should be noted that the reflector according to the second embodiment of the present invention is formed of a thin plate, so that the heat emitted from the light emitting element can also be efficiently dissipated, and the capacity of the light emitting element can be sufficiently exploited. It is also advantageous in that it can be released. From the viewpoint of heat dissipation efficiency, it is acceptable to form a plurality of protrusions on the outer wall of the reflector.

[0020] The reflector according to the present invention described above may be formed by integrally molding a reflective material such as silver in any form, but preferably includes a base material and a reflective layer, and has an inner peripheral surface. Preferably, a reflective layer is formed. A typical example of the reflective material constituting the reflective layer is silver. Although silver is excellent in reflectance, it has poor corrosion resistance and may be blackened (oxidized) during use. Therefore, it is preferable that the reflective material having excellent corrosion resistance (reflectance maintaining property) is provided with a silver-indium-tin alloy, a silver-gallium alloy, and a reflective layer having rhodium power. The reflective layer preferably has a thickness of 0.1 to LO / z m.

[0021] Also, as a base material for the reflector, it can be used with conventional reflectors such as Kovar (Fe—Ni—Co alloy) and 42 alloy (Fe—Ni alloy). . In the case of a block-shaped reflector with a large contact area, Kovar or the like is often applied as a material having a small difference in thermal expansion from the substrate (usually ceramics such as aluminum nitride). However, for the second reflector, which has a thin plate force, a wider range of materials can be selected. Base This is because there is little need to consider the difference in thermal expansion because the contact area with the plate is small. Therefore, in the second reflector, the base material can be formed of copper, a copper alloy (such as a copper-nickel alloy), aluminum, or the like, which is a material having better workability than Kovar.

Furthermore, as the brazing material, in addition to silver brazing made of a silver-copper alloy or the like, gold brazing (gold-tin, etc.), aluminum brazing, or tin brazing is preferable.

[0023] It should be noted that the shape of the cross section of the reflector according to the present invention is not limited, and may be any of a circular shape, an elliptical shape, and a polygonal shape as long as it surrounds the light emitting element and can reflect the emitted light. . Further, the inclination of the inner peripheral surface may be linear or curved as long as the light of the light emitting element force can be reflected. The tilt should be determined based on the reflection efficiency of light from the optical element.

[0024] The reflector 1 according to the present invention may be used alone (in a state in which the reflectors are formed one by one) at the time of bonding to the substrate, but a plurality of reflectors are arranged and connected in advance. It is okay. By applying such an array of reflectors, the reflector can be efficiently bonded to the substrate.

[0025] The reflector 1 according to the present invention can be manufactured by drawing and pressing the plate material.

The dimensional accuracy of the molded product by drawing and press carriage depends on the dimensional accuracy of processing tools such as punches and dies, but the accuracy of the molded product is maintained by strictly defining these dimensional accuracy. However, it can be repeatedly manufactured.

[0026] In the case of manufacturing a reflector having a base material and a reflective layer, the reflective layer is formed by forming the base material by the above-described drawing process and attaching a reflective material to this as in the conventional case. It ’s okay. Further, as a plate material to be processed, a clad material composed of a base material and a reflective layer may be applied and drawn. According to the latter method, the reflector can be manufactured efficiently. The reflector according to the present invention further includes a brazing material on the outer peripheral surface. The brazing material may also be formed after the reflector is molded, but it is processed in the state of a clad material. It is preferable to mold. In other words, efficient production is possible by processing three layers of the clad material: reflective layer, base material, and brazing material. Production of the clad material to be processed is not particularly limited, and a reflective layer may be formed on the plate material as a base material, or the reflective material may be rolled on the plate material and bonded by roll rolling. good. The cladding material is the above As described above, Kovar, 42 alloy (Fe Ni alloy), copper, copper alloy, aluminum, etc. can be selected as the base material. On the other hand, the reflective layer is preferably made of silver, silver indium tin alloy, silver-gallium alloy, or rhodium force. Further, the brazing material is preferably silver brazing, gold brazing, aluminum brazing, or tin brazing.

Brief Description of Drawings

FIG. 1 is a view showing an outer wall structure of a first reflector according to the present invention.

FIG. 2 is a diagram for explaining a reflector manufacturing process in the first embodiment.

FIG. 3 is a cross-sectional photograph of the reflector according to the first embodiment after the substrate is joined.

FIG. 4 is a cross-sectional photograph of the reflector according to the second embodiment after substrate bonding.

[Fig. 5] Cross-sectional photograph of a conventional reflector after substrate bonding.

FIG. 6 illustrates an example of a structure of a device including a light emitting element.

BEST MODE FOR CARRYING OUT THE INVENTION

[0028] Embodiments that are considered suitable for the present invention will be described below.

First embodiment 餱: Here, the reflector of the second embodiment of the present application was manufactured. FIG. 2 is a diagram schematically illustrating the manufacturing process of this reflector. First, a silver sheet serving as a reflective layer, a Kovar material serving as a base material, and a brazing material (72% Ag—28% Cu) sheet were clad by roll rolling to produce a thin three-layer clad plate material. Next, the clad plate material was drawn with a punch, and the center portion was punched to form a reflector.

Second Embodiment: Here, the reflector of the first embodiment of the present application was manufactured. A three-layer clad material produced in the same manner as in the first embodiment was formed into a block-shaped reflector having a two-stage outer wall structure having the same shape as that illustrated in FIG.

[0031] Bonding test to base plate: Then, a brazing test to a ceramic substrate was performed on the two manufactured reflectors. In this test, a reflector was positioned and placed on a ceramic substrate, heated in a furnace, then removed and cooled, and the state of the joint was observed. For comparison, the conventional reflector shown in Fig. 6 was also tested in the same way.

FIG. 3 and FIG. 4 show cross-sectional photographs after the substrate bonding of the reflector manufactured in each example. From these pictures, in the reflector according to this embodiment, However, the brazing material on the outer wall flows down, and sufficient brazing material is supplied and fixed to the lower end of the brazing material. Moreover, the generation | occurrence | production of the clearance gap was not seen in the junction part.

[0033] On the other hand, FIG. 5 is a cross-sectional photograph of the joining portion of the conventional reflector, but in the case of the conventional product, a gap is formed between the substrate and the substrate. This gap was observed in some places on the inner periphery of the joint. Therefore, although the reflector 1 according to this comparative example can be temporarily joined, it is considered that there is a risk of detachment during use.

Industrial applicability

[0034] The reflector 1 according to the present invention can maintain a stable bonded state in which there is no defect in the bonded portion after bonding to the substrate, and it is difficult for displacement and detachment from the substrate to occur during use. In the present invention, since the brazing material is provided in advance, the reflector joining process can be efficiently performed. In addition, a light emitting device including the reflector according to the present invention can maintain good light emission for a long period of time and can fully exhibit the characteristics of a light emitting element having a long lifetime.

Claims

The scope of the claims

[1] In a cylindrical reflector that is arranged so as to surround a light emitting element installed on a substrate and reflects light from the light emitting element by its inner surface,

A brazing material is provided on at least a part or the entire outer wall,

2. A reflector as set forth in claim 1, wherein the brazing material is melted when bonded to the substrate, and the molten brazing material is lowered along the outer wall to the lower end contacting the substrate.

[2] The outer wall has a two-stage structure in which the body portion is in contact with the substrate and the flange portion is wider than the body portion.

, A brazing material is provided on the bottom surface of the trunk portion and the bottom surface of the flange portion,

2. The brazing material in the flange portion melts when bonded to the substrate, and the molten brazing material descends along the outer wall so as to be integrated with the brazing material on the bottom surface of the moon portion. Reflector.

[3] The reflector according to claim 2, wherein the bottom surface of the buttocks is inclined!

[4] It is a thin plate cylindrical body force in which the outer wall and the inner surface are substantially parallel, and at least part of the outer wall is provided with a filter material.

2. The reflector as claimed in claim 1, wherein the brazing material is melted when bonded to the substrate, and the melted brazing material descends along the outer wall to a lower end portion contacting the substrate.

[5] The reflector as set forth in claim 4, wherein the lower end portion in contact with the substrate has an edge shape so as to be in substantially line contact with the substrate.

[6] The reflector according to any one of claims 1 to 5, wherein a reflective layer formed on the inner peripheral surface side of the base material and made of a reflective material is laminated.

7. The reflector according to claim 6, wherein the reflective material constituting the reflective layer is any one of silver, a silver-indium tin alloy, a silver-gallium alloy, and a mouthpiece.

[8] The reflector according to [6] or [7], wherein the base material is made of Kovar, copper, copper alloy, or aluminum!

[9] A reflector formed by connecting a plurality of reflectors according to any one of claims 1 to 8.

[10] The method of manufacturing a reflector according to any one of claims 1 to 9, comprising a clad material that also serves as a reflective material and a brazing material, or a base material, a reflective material, and a brazing material. A process of forming by pressing or punching a clad material to press a punch or die. How to have.

A light-emitting device comprising the reflector according to any one of claims 1 to 9.