Lid and method for manufacturing the same, and optical semiconductor

Abstract

To provide a lid and a manufacturing method for the same that can reduce costs of materials and can reduce complexity when encapsulating a light-emitting element and to provide an optical semiconductor.SOLUTION: A lid 10 for an optical semiconductor includes a base material 11 that is configured of quartz or glass, a Cr / Ni or Ti / Cu stacked film 12 formed in a ring shape on the surface of the base material 11 along an edge portion of a surface of the base material 11 to be bonded to a base part for the optical semiconductor, and a sealing member 13 welded on a Ni or Cu layer that is an upper layer of the stacked film 12. The sealing member 13 is welded on the surface of the Ni or Cu layer of the stacked film 12 in a reducing atmosphere. An optical semiconductor 50 includes a base 30 on which a light-emitting element 20 is mounted and the lid 10 connected to the base 30 and used to encapsulate the light-emitting element 20.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a lid that can suppress material costs and reduce the complexity during sealing, a method for manufacturing the same, and an optical semiconductor.

Background Art

[0002] As a type of optical semiconductor, in recent years, research on light-emitting diodes that have the potential to replace mercury lamps and can output deep ultraviolet light has been actively conducted. An optical semiconductor mounts a light-emitting element in the space within a package and provides a sealing structure in the package to protect the light-emitting element. These packages are composed of a base for mounting the light-emitting element and a lid that serves as a cover for sealing the light-emitting element. As one method for sealing the base and the lid, there is a method that uses a sealing member, such as a solder.

[0003] For example, Patent Document 1 discloses an optical semiconductor package having a sealing structure composed of a package substrate (base), a window member (lid), and a metal bonding material (solder). In this package substrate and window member, a metal layer is provided in a joining planned region for welding to the metal bonding material. The metal layer provided on the window member is a multilayer film in which titanium (Ti), platinum (Pt), and gold (Au) are laminated in this order. Note that chromium (Cr) may be used instead of titanium, and copper (Cu) and nickel may be used instead of platinum (paragraphs 0032 to 0035 of Patent Document 1). In addition, it is described that the metal bonding material is a gold-tin preform having a shape corresponding to the joining planned region, and the metal bonding material may be temporarily fixed in advance on the base side or the lid side (paragraph 0041 of Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] Conventional technology has the problem of increasing material costs because it uses gold (Au) for the metal layer used to weld the brazing material to the lid. In recent years, the price of Au has soared, so it is important to reduce the amount of Au used in order to lower costs. Although it is stated that the metal bonding material may be temporarily fixed to the base or lid, if the brazing material is welded to the lid beforehand, compared to the case where it is not, the sealing of the semiconductor element mounted on the base only requires the alignment of two elements, the lid and the base, thus reducing the complexity of the sealing process. This invention has been made in view of these points, and therefore the object of this application is to provide a lid having a novel structure, a method for manufacturing the same, and an optical semiconductor that can reduce material costs and the complexity of sealing compared to conventional methods. [Means for solving the problem]

[0006] To achieve this objective, the invention of the lid of this application is characterized by comprising a substrate made of quartz or glass, a Cr / Ni or Ti / Cu laminated film formed on the surface of the substrate along the edge of the surface of the substrate that is to be joined to the base, and a sealing member welded to the Ni layer or Cu layer which is the upper layer of the laminated film.

[0007] Furthermore, according to the optical semiconductor invention of this application, the invention comprises a substrate made of quartz or glass, a lid having a Cr / Ni or Ti / Cu laminated film formed on the surface of the substrate along the edge of the surface of the substrate that is to be joined to a base for optical semiconductors, and a sealing member welded to the Ni layer or Cu layer which is the upper layer of the laminated film, a base connected to the lid via the sealing member, and a light-emitting element mounted in a container formed by the lid and the base.

[0008] Furthermore, in a method for manufacturing a lid comprising a substrate made of quartz or glass and used in conjunction with a base, the method for welding a sealing member along the edge of the surface to be joined to the base is characterized by comprising the steps of forming a Cr / Ni or Ti / Cu laminated film on the surface of the substrate along the edge of the surface to be joined to the base, and welding the sealing member onto the surface of the Ni layer or Cu layer which is the upper layer of the laminated film under a reducing atmosphere. [Effects of the Invention]

[0009] According to the lid of this invention, there is no need to provide an Au layer on the surface of the Ni layer or Cu layer, which is the upper layer of the Cr / Ni or Ti / Cu laminated film formed on the substrate, thus reducing material costs. Furthermore, since the sealing member is welded to the lid in advance, when sealing the electronic components mounted on the base, only the alignment of the base and the lid is required, thus reducing the complexity of the sealing process. Furthermore, according to the optical semiconductor of this invention, a lid is used for sealing the light-emitting element that comprises a substrate, a Cr / Ni or Ti / Cu laminated film formed on the substrate, and a sealing member welded to the upper layer of the laminated film, i.e., a lid without an Au layer, thus reducing material costs. Furthermore, the lid manufacturing method involves forming a Cr / Ni or Ti / Cu laminated film on the surface of the substrate and welding a sealing member to the Ni layer or Cu layer, which is the upper layer of the laminated film, under a reducing atmosphere. As a result, the oxide film on the surface of the Ni layer or Cu layer is removed under the reducing atmosphere, making it possible to weld the sealing member to the Ni layer or Cu layer. Therefore, there is no need to provide an Au layer on the Ni layer or Cu layer, and a lid with the sealing member welded to the Ni layer or Cu layer can be manufactured. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1(A) is a perspective view showing an overview of the lid according to an embodiment of the present invention. Figure 1(B) is a cross-sectional view showing an overview of the lid according to an embodiment of the present invention. [Figure 2] Figure 2(A) is a perspective view showing an overview of the optical semiconductor according to an embodiment of the present invention. Figure 2(B) is a cross-sectional view showing an overview of the optical semiconductor according to an embodiment of the present invention. [Figure 3] This is an explanatory diagram illustrating an embodiment of the manufacturing method for the lid of the present invention. [Figure 4] Figure 3 is an explanatory diagram of the manufacturing process example. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments of the lid, its manufacturing method, and the optical semiconductor invention of this application will be described with reference to the drawings. The figures used in this explanation are merely schematic representations to the extent necessary to understand these inventions. Furthermore, in the figures used in this explanation, similar components are indicated with the same number, and their explanations may be omitted. Also, the shapes, materials, etc., described below are merely preferred examples within the scope of this invention. Therefore, the present invention is not limited to the following embodiments.

[0012] 1. Lid configuration Figure 1(A) is a perspective view showing an overview of the lid of an embodiment of the present invention. Figure 1(B) is a cross-sectional view along line AA in Figure (A). The lid 10 of the present invention comprises a base material 11 made of quartz or glass, for example, formed in a rectangular shape in a plan view; a ring-shaped laminated film 12 of Cr / Ni or Ti / Cu formed on the surface of the base material 11 along the edge of the surface of the base material 11 that is to be joined to a base for optical semiconductors, for example, a laminated film of Cr / Ni or Ti / Cu, and a sealing member 13 that is welded to the Ni layer or Cu layer which is the upper layer of the laminated film 12 in order to join the base material to the base for optical semiconductors. In this case, when the lid of the present invention is used as a lid for an optical semiconductor that emits ultraviolet light such as UVA, UVB, and UBC, quartz is preferred because it has excellent transmittance to deep ultraviolet light. Furthermore, when glass is used as the substrate for the lid, and the lid is used as a lid for an optical semiconductor that emits deep ultraviolet light such as UVA, UVB, and UBC, the glass is preferably one with high transmittance to deep ultraviolet light, such as borosilicate glass or quartz glass.

[0013] According to the lid 10 of the present invention, there is no need to provide an Au layer on the surface of the Ni layer or Cu layer, which is the upper layer of the Cr / Ni or Ti / Cu laminated film 12 formed on the substrate, thus reducing material costs. Moreover, since the sealing member is pre-welded to the lid, when sealing the light-emitting element mounted on the base, only the alignment of the base and the lid is required, thus reducing the complexity of the sealing process.

[0014] Furthermore, the sealing member 13 should be selected from a material that not only has excellent corrosion resistance but also meets the requirements for heat resistance. In other words, it is best to select a material with a melting point higher than the solder (melting point 180°C to 230°C) used when mounting the electronic component completed using this lid, such as an optoelectronic semiconductor, into various electronic devices, and that can maintain the airtightness of the package without being remelted during soldering. For example, AuSn (melting point 280°C to 300°C) is a good choice.

[0015] 2. Configuration of the optical semiconductor The lid of the present invention can be used as a lid material, which is a component of the package of an optical semiconductor. Below, an example of an optical semiconductor constructed using the lid of the present invention as a lid material for the package of the optical semiconductor will be described. Figure 2 is a diagram for explanation, and Figure (A) is a perspective view of an optical semiconductor using a base for mounting an light-emitting element, a light-emitting element mounted on the base, and the lid of the present invention for sealing the light-emitting element. Figure (B) is a cross-sectional view of the optical semiconductor along the line BB in Figure (A). However, both Figures (A) and (B) are perspective views or cross-sectional views in an exploded state.

[0016] Prepare a lid 10 of the present invention, a light-emitting element 20 of an arbitrary shape, which is rectangular in plan view in this example, and a base 30 made of, for example, well-known AlN as a base. The base 30 in this case is rectangular in plan view, and as shown in FIGS. 2(A) and 2(B), has a recess 30a for housing the light-emitting element 20, a bank portion 30b along the edge of the base 30, wiring terminals 30c and 30d connected to the light-emitting element provided on the bottom surface of the recess 30a, and a mounting terminal 30e provided on the back surface of the base 30. The wiring terminal 30c and the wiring terminal 30d are electrically connected to the mounting terminal 30e by via wiring (not shown). Further, a metallized film (not shown) corresponding to the sealing member of the lid 10 is provided on the top surface of the bank portion 30b. Here, a base made of AlN has high thermal conductivity, and excessive heat causes various problems related to the performance and reliability of the optical semiconductor, so it is often used for optical semiconductors for the purpose of removing heat as much as possible.

[0017] Fix the light-emitting element 20 on the wiring terminal 30c with, for example, a conductive adhesive (not shown), and then connect the light-emitting element 20 and the wiring terminal 30d with, for example, a gold wire 40 by a well-known wire bonding technique. Next, in order to protect the light-emitting element 20 and the gold wire 40, fill the recess 30a with a sealing resin and cure it. Next, stack the lid 10 according to the present invention on the base 30, apply a predetermined heat to them, melt the sealing member of the lid 10, and join the lid 10 and the base 30. In this way, an optical semiconductor 50 having a structure in which the light-emitting element 20 is housed in the lid 10 and the base 30 is obtained.

[0018] 3. Method for manufacturing the lid FIG. 3 is an explanatory diagram for explaining an embodiment of a method for manufacturing a lid of the present invention. First, a substrate 61 made of crystal or glass, for example, rectangular in plan view, is prepared. Next, a laminated film 62 of Cr / Ni or Ti / Cu is formed on the surface of the surface of the substrate 61 to be joined to the base for the optical semiconductor by a well-known sputtering technique. Next, the laminated film 62 is patterned by a photolithography technique or the like so as to have a ring shape along the edge of the surface to be joined to the base.

[0019] Next, the substrate 61 on which the laminated film 62 is formed is carried into the processing chamber 70 as shown in FIG. 4. After the substrate 61 is carried into the processing chamber 70, a reducing gas is injected into the processing chamber 70 to make the atmosphere in the processing chamber 70 a reducing atmosphere state. After the atmosphere in the processing chamber 70 becomes a reducing atmosphere state, in the processing chamber 70, a sealing member 64 preformed along the edge of the substrate 61 into the shape of the joining planned area between the base and the substrate 61 is superposed on the laminated film 62 formed on the substrate 61. Here, the reason for making it a reducing atmosphere state is as follows. Usually, the Ni or Cu layer, which is the upper layer of the laminated film 62, forms an oxide film on the surface, and since the oxide film has low wettability, the sealing member 63 cannot be welded to the substrate 61. However, by placing the substrate 61 in a reducing atmosphere, the oxide film on the surface of the Ni or Cu layer can be removed. Thereby, the sealing member 63 can be welded to the substrate 61.

[0020] Here, examples of the reducing gas to be used include hydrogen or formic acid. Also, considering the risk of explosion, the concentration of the reducing gas is preferably 5 vol% or less in terms of volume ratio.

[0021] Next, the temperature of the reducing gas atmosphere in the processing chamber 70 is raised until it reaches the melting point of the sealing member 63. Thereby, the sealing member 63 melts and is welded to the substrate 61. At this time, the temperature of the reducing gas atmosphere needs to be rapidly lowered after the temperature is raised to the melting point and the sealing member 63 melts. This is because if the state of raising the temperature is continued, the sealing member 63 will continue to melt and the preformed shape will collapse. In this way, by welding the sealing member 63 under a reducing gas atmosphere, it is not necessary to provide an Au layer, and since the sealing member is welded in advance, a lid can be obtained that reduces the complexity of alignment when sealing the light-emitting element.

[0022] Here, assuming that AuSn is used as the sealing material, the temperature of the reducing gas atmosphere is preferably 280°C to 300°C, which is the melting point of AuSn.

[0023] In the above embodiment, a rectangular substrate in plan view was used, and an example of forming a rectangular optical semiconductor in plan view was described. However, the shape of the substrate and optical semiconductor can be selected as any shape depending on the application, such as a circular shape in plan view. Furthermore, in the above embodiment, the lid of the present invention was used as a lid material which is a component of the optical semiconductor package. However, the lid of the present invention is not limited to optical semiconductors and may be used in packages for other electronic devices. [Explanation of Symbols]

[0024] 10: Lid of an embodiment of the present invention 11: Substrate 12: Multilayer film 13: Sealing material 20: Light-emitting element 30: Base 30a: recess 30b: embankment 30c, 30d: Wiring terminals; 30e: Mounting terminals 40: Gold wire 50: Optical semiconductor according to the embodiment of the present invention 60: Lid of an embodiment of the present invention 61: Substrate 62: Multilayer film 63: Sealing material 70: Processing Room

Claims

1. In a lid that uses a substrate made of quartz or glass and is joined to a base, Along the edge of the surface of the substrate that is to be joined to the base, a laminated film is laid on the surface of the substrate in the order of a Cr layer and a Ni layer from the substrate side, or a laminated film is laid in the order of a Ti layer and a Cu layer from the substrate side. A sealing member welded to the Ni layer or Cu layer which is the upper layer of the laminated film, A lid characterized by having the following features.

2. The lid according to claim 1, characterized in that the sealing member is made of AuSn.

3. A lid comprising a substrate made of quartz or glass, a Cr / Ni or Ti / Cu laminated film formed on the surface of the substrate along the edge of the surface of the substrate that is to be bonded to a base for an optical semiconductor, and a sealing member welded to the Ni layer or Cu layer which is the upper layer of the laminated film, The base is connected to the lid via the sealing member, A light-emitting element mounted inside a container formed by the lid and the base, A photosemiconductor that possesses the following characteristics.

4. In a method for manufacturing a lid that comprises a substrate made of quartz or glass and is used in conjunction with a base, When welding a sealing member along the edge of the surface of the substrate that is to be joined to the base, A step of forming a laminated film by laminating layers on the surface of the substrate along the edge of the surface of the substrate that is to be joined to the base, in the order of a Cr layer and a Ni layer from the substrate side, or in the order of a Ti layer and a Cu layer from the substrate side, A step of welding the sealing member to the Ni layer or Cu layer which is the upper layer of the laminated film in a reducing gas atmosphere, A method for producing a lid, characterized by including the following:

5. The method for producing a lid according to claim 4, characterized in that the reducing gas atmosphere is a reducing gas atmosphere of hydrogen or formic acid.

6. The method for producing a lid according to claim 4 or 5, characterized in that the reducing gas atmosphere has a reducing agent concentration of 5 vol% or less by volume.

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