JP7441140B2

JP7441140B2 - Wavelength conversion member, wavelength conversion device, and light source device

Info

Publication number: JP7441140B2
Application number: JP2020131691A
Authority: JP
Inventors: 洋介八谷; 利之桜井; 翔平高久; 智雄田中; 裕貴竹内
Original assignee: NGK Spark Plug Co Ltd
Current assignee: Niterra Co Ltd
Priority date: 2020-08-03
Filing date: 2020-08-03
Publication date: 2024-02-29
Anticipated expiration: 2040-08-03
Also published as: JP2022028346A

Description

本発明は、波長変換部材、波長変換装置、および、光源装置に関する。 The present invention relates to a wavelength conversion member, a wavelength conversion device, and a light source device.

従来から、光源が発した光の波長を変換する波長変換部材が知られている。一般的に、波長変換部材は、入射する光の波長を変換する蛍光体と、蛍光体の裏面に配置され、蛍光体に入射した光を反射する反射膜と、を有する。例えば、特許文献１には、反射膜を覆う封止膜によって、反射膜と外気との接触を抑制する技術が開示されている。また、特許文献２には、反射膜の外側に、放熱部材と波長変換部材との接合力を高めるための接合補助膜を備える技術が開示されている。 2. Description of the Related Art Wavelength conversion members that convert the wavelength of light emitted from a light source have been known. Generally, a wavelength conversion member includes a phosphor that converts the wavelength of incident light, and a reflective film that is placed on the back surface of the phosphor and reflects the light that has entered the phosphor. For example, Patent Document 1 discloses a technique for suppressing contact between the reflective film and the outside air by using a sealing film that covers the reflective film. Further, Patent Document 2 discloses a technique in which a bonding auxiliary film is provided on the outside of the reflective film to increase the bonding force between the heat dissipation member and the wavelength conversion member.

特許６０９４６１７号公報Patent No. 6094617 特開２０１９－１０５７６３号公報JP 2019-105763 Publication

しかしながら、上記先行技術によっても、波長変換部材において、反射膜の劣化を防止することで発光強度の低下を抑制するには、なお改善の余地があった。例えば、特許文献１に記載の技術では、封止膜は、蛍光体より小さい反射膜を覆いつつ、端部がセラミック蛍光体に接合される。これにより、封止膜において、反射膜を覆う部分のセラミック蛍光体からの距離と、セラミック蛍光体に接合する部分のセラミック蛍光体からの距離と、が異なるため、封止膜は、折れ曲がる形状となる。このような形状の封止膜は、応力が作用するとクラックが入りやすいため、クラックを通る外気と反射膜とが接触し、反射膜が酸化などするおそれがある。反射膜が酸化などによって劣化すると、波長変換部材の発光強度が低下する。また、特許文献２に記載の技術では、接合補助膜は、反射膜全体を覆いつつ、外縁部が蛍光体に接合される。このため、接合補助膜は、折れ曲がる形状となるため、クラックが入りやすく、クラックを通る外気と反射膜とが接触しやすくなる。これにより、反射膜が劣化し、波長変換部材の発光強度が低下するおそれがある。 However, even with the above-mentioned prior art, there is still room for improvement in suppressing the decrease in emission intensity by preventing deterioration of the reflective film in the wavelength conversion member. For example, in the technique described in Patent Document 1, the end portion of the sealing film is bonded to the ceramic phosphor while covering a reflective film smaller than the phosphor. As a result, in the sealing film, the distance from the ceramic phosphor in the part that covers the reflective film is different from the distance from the ceramic phosphor in the part bonded to the ceramic phosphor, so the sealing film has a bendable shape. Become. Since a sealing film having such a shape is likely to crack when stress is applied, there is a risk that the reflective film will come into contact with the outside air that passes through the cracks, causing oxidation of the reflective film. When the reflective film deteriorates due to oxidation or the like, the emission intensity of the wavelength conversion member decreases. Furthermore, in the technique described in Patent Document 2, the outer edge portion of the bonding auxiliary film is bonded to the phosphor while covering the entire reflective film. Therefore, since the bonding auxiliary film has a bent shape, cracks are likely to occur, and the reflective film is likely to come into contact with the outside air passing through the cracks. This may cause the reflective film to deteriorate and the light emission intensity of the wavelength conversion member to decrease.

本発明は、波長変換部材において、発光強度の低下を抑制する技術を提供することを目的とする。 An object of the present invention is to provide a technique for suppressing a decrease in emission intensity in a wavelength conversion member.

本発明は、上述の課題の少なくとも一部を解決するためになされたものであり、以下の形態として実現することが可能である。 The present invention has been made to solve at least part of the above-mentioned problems, and can be realized as the following forms.

（１）本発明の一形態によれば、波長変換部材が提供される。この波長変換部材は、光が入射する入射面と、前記入射面の反対側に位置する裏面と、を有し、前記入射面から入射する光の波長を変換するセラミック蛍光体と、前記セラミック蛍光体の前記裏面の一部に接合され、前記セラミック蛍光体に入射した光を反射する反射面を有する反射膜と、前記反射膜を封止する封止膜であって、前記反射膜を覆い、前記封止膜の端部が前記反射膜の端部を超えて前記セラミック蛍光体の前記裏面に接合される封止膜と、を備え、前記セラミック蛍光体と前記反射膜と前記封止膜との積層方向に沿った前記波長変換部材の断面において、前記セラミック蛍光体と前記反射膜との接合線の一方の端部の位置を第１位置とし、前記第１位置から、前記接合線に沿って、前記反射膜の前記積層方向における厚みの１０倍に相当する距離だけ前記接合線の他方の端部側に向かった位置を第２位置とし、前記第２位置から前記積層方向に沿った第１仮想線と、前記反射膜と前記封止膜との境界線との交点の位置を第３位置とし、前記第１位置と前記第３位置とを結ぶ仮想線を第２仮想線とすると、前記反射膜の断面のうち、前記第２仮想線よりも前記封止膜側に位置する領域の面積Ａは、前記第１仮想線、前記第２仮想線、および、前記接合線で囲まれる領域の面積Ｂよりも小さい。 (1) According to one embodiment of the present invention, a wavelength conversion member is provided. This wavelength conversion member has an entrance surface on which light enters, and a back surface located on the opposite side of the entrance surface, and includes a ceramic phosphor that converts the wavelength of light that enters from the entrance surface, and a ceramic phosphor that converts the wavelength of light that enters from the entrance surface. a reflective film bonded to a part of the back surface of the body and having a reflective surface that reflects light incident on the ceramic phosphor; and a sealing film that seals the reflective film, covering the reflective film; a sealing film in which an end of the sealing film is bonded to the back surface of the ceramic phosphor beyond an end of the reflective film, the ceramic phosphor, the reflective film, and the sealing film In the cross section of the wavelength conversion member along the lamination direction, the position of one end of the bonding line between the ceramic phosphor and the reflective film is defined as a first position, and from the first position, along the bonding line, A second position is defined as a distance corresponding to 10 times the thickness of the reflective film in the stacking direction toward the other end of the bonding line, and a second position is defined as a second position along the stacking direction from the second position. The position of the intersection of the first virtual line and the boundary line between the reflective film and the sealing film is defined as a third position, and the virtual line connecting the first position and the third position is defined as a second virtual line, In the cross section of the reflective film, an area A of a region located closer to the sealing film than the second imaginary line is an area surrounded by the first imaginary line, the second imaginary line, and the bonding line. is smaller than the area B.

この構成によれば、積層方向に沿った波長変換部材の断面において、反射膜の断面形状では、面積Ａは、面積Ｂより小さいため、反射膜のセラミック蛍光体側とセラミック蛍光体の反対側とは、緩やかに接続される。これにより、反射膜を覆いつつ端部が反射膜の端部を超えてセラミック蛍光体の裏面に接合される封止膜では、反射膜のセラミック蛍光体の反対側に配置される部分と、セラミック蛍光体の裏面に接合する接合部とが緩やかに接続される。封止膜において、この２つの部分が緩やかに接続されることで、封止膜の形状は、緩やかに曲がる形状になるため、封止膜に応力が作用しても、封止膜にクラックは発生しにくくなる。クラックは、反射膜を酸化などさせる外気が反射膜に接触するときの侵入経路となるが、上述した構成によれば、クラックの発生が抑制されるため、クラックを介した外気と反射膜との接触が抑制される。これにより、反射膜の劣化が抑制されるため、発光強度の低下を抑制することができる。 According to this configuration, in the cross-section of the wavelength conversion member along the lamination direction, in the cross-sectional shape of the reflective film, area A is smaller than area B, so the ceramic phosphor side of the reflective film and the opposite side of the ceramic phosphor are different. , loosely connected. As a result, in the sealing film, which covers the reflective film and whose end goes beyond the end of the reflective film and is bonded to the back surface of the ceramic phosphor, the part of the reflective film disposed on the opposite side of the ceramic phosphor and the ceramic A loose connection is made to the bonding portion bonded to the back surface of the phosphor. In the sealing film, these two parts are connected gently, so that the shape of the sealing film is gently curved, so even if stress is applied to the sealing film, there will be no cracks in the sealing film. It becomes less likely to occur. Cracks serve as an intrusion route when outside air comes into contact with the reflective film, which can cause oxidation of the reflective film. However, according to the above-mentioned configuration, since the generation of cracks is suppressed, the interaction between outside air and the reflective film through the cracks is suppressed. Contact is suppressed. This suppresses deterioration of the reflective film, thereby suppressing a decrease in emission intensity.

（２）上記形態の波長変換部材において、前記面積Ａは、前記面積Ｂの９０％以下であってもよい。この構成によれば、反射膜の断面において、封止膜側の面積Ａは、反射膜側の面積Ｂの９０％以下となっている。これにより、反射膜の端部は、セラミック蛍光体側の幅より外側に突出しない形状となりやすいため、封止膜の形状は、さらに緩やかに曲がる形状となる。したがって、クラックを介した外気と反射膜との接触がさらに抑制されるため、反射膜の劣化が抑制され、発光強度の低下をさらに抑制することができる。 (2) In the wavelength conversion member of the above embodiment, the area A may be 90% or less of the area B. According to this configuration, in the cross section of the reflective film, the area A on the sealing film side is 90% or less of the area B on the reflective film side. As a result, the ends of the reflective film tend to have a shape that does not protrude outward beyond the width of the ceramic phosphor side, so that the sealing film has a shape that is more gently curved. Therefore, since contact between the outside air and the reflective film through the cracks is further suppressed, deterioration of the reflective film is suppressed, and a decrease in emission intensity can be further suppressed.

（３）上記形態の波長変換部材において、前記積層方向に沿った前記波長変換部材の断面において、前記第１位置から前記積層方向に沿った仮想線を第３仮想線とすると、前記反射膜の断面は、前記第３仮想線の一方の側に位置し、前記第３仮想線にまたがって前記第３仮想線の両側に位置していなくてもよい。この構成によれば、反射膜の断面は、第３仮想線の一方の側に位置し、第３仮想線にまたがって第３仮想線の両側に位置していない。すなわち、反射膜において、セラミック蛍光体側の部分と、セラミック蛍光体の反対側の部分とは、比較的なだらかに接続される。これにより、封止膜の形状は、さらに緩やかに曲がる形状になるため、応力による封止膜でのクラックの発生がさらに抑制される。また、反射膜において、セラミック蛍光体側の部分と、セラミック蛍光体の反対側の部分とが比較的なだらかに接続されるため、反射膜上に形成される封止膜と反射膜との間に隙間が形成されにくくなる。これによっても、応力による封止膜でのクラックの発生がさらに抑制される。したがって、クラックを介した外気と反射膜との接触がさらに抑制されるため、反射膜の劣化が抑制され、発光強度の低下をさらに抑制することができる。 (3) In the wavelength conversion member of the above embodiment, in the cross section of the wavelength conversion member along the lamination direction, if an imaginary line from the first position along the lamination direction is a third imaginary line, The cross section may be located on one side of the third imaginary line, and may not straddle the third imaginary line and be located on both sides of the third imaginary line. According to this configuration, the cross section of the reflective film is located on one side of the third imaginary line, straddles the third imaginary line, and is not located on either side of the third imaginary line. That is, in the reflective film, the portion on the ceramic phosphor side and the portion on the opposite side of the ceramic phosphor are connected relatively smoothly. As a result, the shape of the sealing film becomes more gently curved, so that the generation of cracks in the sealing film due to stress is further suppressed. In addition, in the reflective film, since the part on the ceramic phosphor side and the part on the opposite side of the ceramic phosphor are connected relatively gently, there is a gap between the sealing film formed on the reflective film and the reflective film. is less likely to form. This also further suppresses the occurrence of cracks in the sealing film due to stress. Therefore, since contact between the outside air and the reflective film through the cracks is further suppressed, deterioration of the reflective film is suppressed, and a decrease in emission intensity can be further suppressed.

（４）上記形態の波長変換部材において、前記封止膜の端部は、前記第２仮想線に沿った方向に延伸してもよい。この構成によれば、封止膜の端部は、第２仮想線に沿った方向に延伸している。これにより、封止膜は、セラミック蛍光体に向かって広がっているため、はんだを用いて、波長変換部材の封止膜側と、他の部材とを接合するとき、はんだ内に発生するボイドが封止膜の形状に沿って波長変換部材の外側に向かって移動する。はんだ内のボイドは、セラミック蛍光体において光の波長を変換するときに発生する熱の伝熱を妨げるため、特に、波長変換部材の中央部分にはないことが望ましい。上述した構成によれば、はんだ内のボイドは、波長変換部材の外側に移動するため、熱的に厳しい波長変換部材の中心部分の放熱を良好に行うことができる。したがって、温度消光による発光強度の低下を抑制することができる。 (4) In the wavelength conversion member of the above embodiment, the end portion of the sealing film may extend in a direction along the second imaginary line. According to this configuration, the end portion of the sealing film extends in the direction along the second imaginary line. As a result, the sealing film spreads toward the ceramic phosphor, so when solder is used to bond the sealing film side of the wavelength conversion member to another member, voids that occur in the solder are eliminated. It moves toward the outside of the wavelength conversion member along the shape of the sealing film. Since voids in the solder impede the transfer of heat generated when converting the wavelength of light in the ceramic phosphor, it is particularly desirable that there be no voids in the central portion of the wavelength conversion member. According to the above-described configuration, the voids in the solder move to the outside of the wavelength conversion member, so that heat can be effectively dissipated from the central portion of the wavelength conversion member, which is thermally severe. Therefore, reduction in luminescence intensity due to temperature quenching can be suppressed.

（５）本発明の別の形態によれば、波長変換装置が提供される。この波長変換装置は、上記形態の波長変換部材と、前記波長変換部材の熱を外部に放出する放熱部材と、前記波長変換部材と前記放熱部材を接合する接合層と、を備える。この構成によれば、封止膜の形状は、緩やかに曲がる形状になるため、封止膜にクラックが発生しにくくなり、反射膜の酸化などを抑制することができる。また、波長変換部材で発生する熱を放熱部材によって外部に放出することができる。これにより、反射膜の劣化による発光強度の低下を抑制しつつ、熱による波長変換装置の発光強度の低下を抑制することができる。 (5) According to another aspect of the present invention, a wavelength conversion device is provided. This wavelength conversion device includes the wavelength conversion member of the above embodiment, a heat radiation member that emits heat of the wavelength conversion member to the outside, and a bonding layer that joins the wavelength conversion member and the heat radiation member. According to this configuration, since the sealing film has a gently curved shape, cracks are less likely to occur in the sealing film, and oxidation of the reflective film can be suppressed. Furthermore, the heat generated by the wavelength conversion member can be radiated to the outside by the heat radiating member. Thereby, it is possible to suppress a decrease in the emission intensity of the wavelength conversion device due to heat while suppressing a decrease in the emission intensity due to deterioration of the reflective film.

（６）本発明のさらに別の形態によれば、光源装置が提供される。この光源装置は、上記の波長変換装置と、前記セラミック蛍光体に光を照射する光源と、を備える。この構成によれば、波長変換装置では、緩やかに曲がる形状となっている封止膜にクラックが発生しにくいため、反射膜の劣化が抑制される。これにより、セラミック蛍光体で波長が変換された光の一部や、セラミック蛍光体を素通りする光などセラミック蛍光体内の光を、劣化しにくい反射膜で反射することができるため、光源装置の発光強度の低下を抑制することができる。 (6) According to yet another aspect of the present invention, a light source device is provided. This light source device includes the wavelength conversion device described above and a light source that irradiates the ceramic phosphor with light. According to this configuration, in the wavelength conversion device, cracks are less likely to occur in the gently curved sealing film, so deterioration of the reflective film is suppressed. This makes it possible to reflect light inside the ceramic phosphor, such as part of the light whose wavelength has been converted by the ceramic phosphor and light that passes through the ceramic phosphor, with a reflective film that does not easily deteriorate, allowing the light source device to emit light. Decrease in strength can be suppressed.

なお、本発明は、種々の態様で実現することが可能であり、例えば、波長変換部材や波長変換装置などを含む各種装置、これらの装置を製造する製造方法等の形態で実現することができる。 Note that the present invention can be realized in various forms, for example, in the form of various devices including wavelength conversion members and wavelength conversion devices, manufacturing methods for manufacturing these devices, etc. .

第１実施形態の波長変換装置を備える光源装置の断面図である。FIG. 1 is a cross-sectional view of a light source device including a wavelength conversion device according to a first embodiment. 第１実施形態の波長変換部材の断面図である。It is a sectional view of the wavelength conversion member of a 1st embodiment. 図２のＳ部拡大図である。3 is an enlarged view of part S in FIG. 2. FIG. 製造時の波長変換装置の断面図である。FIG. 3 is a cross-sectional view of the wavelength conversion device during manufacture.

＜第１実施形態＞
図１は、本実施形態の波長変換装置１を備える光源装置５の断面図である。図２は、第１実施形態の波長変換部材２の断面図である。本実施形態の光源装置５では、発光ダイオード（ＬＥＤ：ＬｉｇｈｔＥｍｉｔｔｉｎｇＤｉｏｄｅ）や半導体レーザー（ＬＤ：ＬａｓｅｒＤｉｏｄｅ）などの光源６が発した光Ｌ１を波長変換装置１に照射する。光Ｌ１が照射された波長変換装置１は、光Ｌ１とは異なる波長の光Ｌ２を発生し、光源装置５の外部に放出する。このような波長変換装置１は、例えば、ヘッドランプ、照明、プロジェクタなどの各種光学機器において使用される。波長変換装置１は、セラミック蛍光体１０と、反射膜２０と、封止膜３０と、接合膜４０と、放熱部材６０と、接合層７０と、を備えている。波長変換装置１は、セラミック蛍光体１０と、反射膜２０と、封止膜３０と、接合膜４０と、酸化防止膜５０と、を備える波長変換部材２（図２参照）と、放熱部材６０とを接合層７０によって接合することで製造される。なお、図１および図２における、セラミック蛍光体１０と、反射膜２０と、封止膜３０と、接合膜４０と、酸化防止膜５０と、放熱部材６０と、接合層７０とのそれぞれの大きさおよび厚みの関係は、説明の便宜上、実際の大きさまたは厚みの関係とは異なるように図示されている。 <First embodiment>
FIG. 1 is a sectional view of a light source device 5 including a wavelength conversion device 1 of this embodiment. FIG. 2 is a cross-sectional view of the wavelength conversion member 2 of the first embodiment. In the light source device 5 of this embodiment, the wavelength conversion device 1 is irradiated with light L1 emitted by a light source 6 such as a light emitting diode (LED) or a semiconductor laser (LD). The wavelength conversion device 1 irradiated with the light L1 generates the light L2 having a different wavelength from the light L1, and emits it to the outside of the light source device 5. Such a wavelength conversion device 1 is used, for example, in various optical devices such as headlamps, lighting, and projectors. The wavelength conversion device 1 includes a ceramic phosphor 10, a reflective film 20, a sealing film 30, a bonding film 40, a heat dissipation member 60, and a bonding layer 70. The wavelength conversion device 1 includes a wavelength conversion member 2 (see FIG. 2) including a ceramic phosphor 10, a reflective film 20, a sealing film 30, a bonding film 40, and an antioxidant film 50, and a heat dissipation member 60. It is manufactured by bonding the two using the bonding layer 70. Note that the respective sizes of the ceramic phosphor 10, the reflective film 20, the sealing film 30, the bonding film 40, the antioxidant film 50, the heat dissipation member 60, and the bonding layer 70 in FIGS. 1 and 2 are For convenience of explanation, the relationship between size and thickness is illustrated to be different from the actual size or thickness relationship.

波長変換部材２では、セラミック蛍光体１０において、波長変換装置１に照射される光の波長が変換される。セラミック蛍光体１０において波長が変換された光は、反射膜２０によって反射された光とともに、波長変換装置１の外部に放出される。波長変換部材２の詳細な構成は、後述する。 In the wavelength conversion member 2, the wavelength of the light irradiated onto the wavelength conversion device 1 is converted in the ceramic phosphor 10. The light whose wavelength has been converted by the ceramic phosphor 10 is emitted to the outside of the wavelength conversion device 1 together with the light reflected by the reflective film 20. The detailed configuration of the wavelength conversion member 2 will be described later.

放熱部材６０は、例えば、銅、銅モリブデン合金、銅タングステン合金、アルミニウム、窒化アルミニウムなど、セラミック蛍光体１０よりも高い熱伝導性を有する材料から形成されている平板部材である。放熱部材６０は、接合層７０を通して伝わるセラミック蛍光体１０の熱を外部に放出する。なお、放熱部材６０は、上述した材料からなる単層構造の部材であってもよいし、同種または異なる材料から形成されている多層構造の部材であってもよい。また、放熱部材６０のセラミック蛍光体１０側の面には、接合層７０との密着性を高めるめっきが配置されていてもよい。 The heat dissipation member 60 is a flat plate member made of a material having higher thermal conductivity than the ceramic phosphor 10, such as copper, copper-molybdenum alloy, copper-tungsten alloy, aluminum, and aluminum nitride. The heat radiating member 60 radiates the heat of the ceramic phosphor 10 transmitted through the bonding layer 70 to the outside. Note that the heat dissipation member 60 may be a member with a single layer structure made of the above-mentioned materials, or may be a member with a multilayer structure made of the same or different materials. Further, plating may be disposed on the surface of the heat dissipation member 60 on the ceramic phosphor 10 side to improve adhesion to the bonding layer 70.

接合層７０は、セラミック蛍光体１０と放熱部材６０の間に配置され、金と錫とからなる。接合層７０は、セラミック蛍光体１０と放熱部材６０とを接合し、セラミック蛍光体１０と放熱部材６０との間での熱のやり取りを行う。 The bonding layer 70 is arranged between the ceramic phosphor 10 and the heat dissipating member 60, and is made of gold and tin. The bonding layer 70 bonds the ceramic phosphor 10 and the heat radiating member 60 and exchanges heat between the ceramic phosphor 10 and the heat radiating member 60.

波長変換部材２は、セラミック蛍光体１０と、反射膜２０と、封止膜３０と、接合膜４０と、酸化防止膜５０と、を備える。 The wavelength conversion member 2 includes a ceramic phosphor 10, a reflective film 20, a sealing film 30, a bonding film 40, and an antioxidant film 50.

セラミック蛍光体１０は、平板状部材であって、本実施形態では、４ｍｍ×４ｍｍの矩形状をなす。セラミック蛍光体１０は、光が入射する入射面１１と、入射面１１の反対側に位置する裏面１２とを有する。セラミック蛍光体１０は、入射面１１から入射する光Ｌ１の波長を変換する。セラミック蛍光体１０は、蛍光性を有する結晶粒子を主体とする蛍光相と、透光性を有する結晶粒子を主体とする透光相を有するセラミック焼結体から構成されている。透光相の結晶粒子は、化学式Ａｌ₂Ｏ₃で表される組成を有し、蛍光相の結晶粒子は、化学式Ａ₃Ｂ₅Ｏ₁₂：Ｃｅで表される組成（いわゆる、ガーネット構造）を有することが好ましい。「Ａ₃Ｂ₅Ｏ₁₂：Ｃｅ」とは、Ａ₃Ｂ₅Ｏ₁₂の中にＣｅが固溶し、元素Ａの一部がＣｅに置換されていることを示す。 The ceramic phosphor 10 is a flat member, and in this embodiment, has a rectangular shape of 4 mm x 4 mm. The ceramic phosphor 10 has an entrance surface 11 on which light enters, and a back surface 12 located on the opposite side of the entrance surface 11. The ceramic phosphor 10 converts the wavelength of the light L1 entering from the entrance surface 11. The ceramic phosphor 10 is composed of a ceramic sintered body having a fluorescent phase mainly composed of crystal grains having fluorescence and a transparent phase mainly composed of crystal grains having translucency. The crystal particles in the transparent phase have a composition represented by the chemical formula Al ₂ O ₃ , and the crystal particles in the fluorescent phase have a composition represented by the chemical formula A ₃ B ₅ O ₁₂ :Ce (so-called garnet structure). It is preferable to have. "A ₃ B ₅ O ₁₂ :Ce" indicates that Ce is dissolved in A ₃ B ₅ O ₁₂ and a part of element A is replaced with Ce.

化学式Ａ₃Ｂ₅Ｏ₁₂：Ｃｅ中の元素Ａおよび元素Ｂは、それぞれ下記の元素群から選択される少なくとも１種類の元素から構成されている。
元素Ａ：Ｓｃ、Ｙ、Ｃｅを除くランタノイド（ただし、元素ＡとしてさらにＧｄを含んでいてもよい）
元素Ｂ：Ａｌ（ただし、元素ＢとしてさらにＧａを含んでいてもよい）
セラミック蛍光体１０として、セラミック焼結体を使用することで、蛍光相と透光相との界面で光が散乱し、光の色の角度依存性を減らすことができる。これにより、色の均質性を向上することができる。なお、セラミック蛍光体１０の材料は、上述の材料に限定されない。 Chemical formula A ₃ B ₅ O ₁₂ : Element A and element B in Ce are each composed of at least one type of element selected from the following element group.
Element A: Lanthanoids excluding Sc, Y, and Ce (however, element A may further contain Gd)
Element B: Al (however, it may further contain Ga as element B)
By using a ceramic sintered body as the ceramic phosphor 10, light is scattered at the interface between the fluorescent phase and the transparent phase, and the angular dependence of the color of the light can be reduced. Thereby, color uniformity can be improved. Note that the material of the ceramic phosphor 10 is not limited to the above-mentioned materials.

反射膜２０は、銀（Ａｇ）からなる矩形形状の薄膜であって、セラミック蛍光体１０の裏面１２の一部に接合されている。反射膜２０は、セラミック蛍光体１０の裏面１２に対向する反射面２１と、反射面２１の反対側に位置する裏面２２と、反射膜２０の外縁において反射面２１と裏面２２とを接続する側面２３と、を有する。反射面２１は、セラミック蛍光体１０に入射した光を反射する。裏面２２は、反射膜２０において反射面２１に対して略平行な面であって、裏面２２の幅は、反射面２１の幅に比べ狭い。本実施形態では、反射面２１の幅Ｗ２１は、３．７００ｍｍ×３．７００ｍｍとなっており、裏面２２の幅Ｗ２２は、３．６９９ｍｍ×３．６９９ｍｍとなっている。側面２３は、セラミック蛍光体１０と反射膜２０と封止膜３０との積層方向Ｄｓに沿って、裏面２２から反射面２１に向かって波長変換部材２の外側に広がるように形成される。反射膜２０の詳細な構成は、後述する。なお、反射膜２０は、アルミニウムなど光の反射率が高い材料から形成されていてもよい。 The reflective film 20 is a rectangular thin film made of silver (Ag), and is bonded to a part of the back surface 12 of the ceramic phosphor 10 . The reflective film 20 includes a reflective surface 21 facing the back surface 12 of the ceramic phosphor 10, a back surface 22 located on the opposite side of the reflective surface 21, and a side surface connecting the reflective surface 21 and the back surface 22 at the outer edge of the reflective film 20. 23. The reflective surface 21 reflects the light incident on the ceramic phosphor 10. The back surface 22 is a surface of the reflective film 20 that is substantially parallel to the reflective surface 21 , and the width of the back surface 22 is narrower than the width of the reflective surface 21 . In this embodiment, the width W21 of the reflective surface 21 is 3.700 mm x 3.700 mm, and the width W22 of the back surface 22 is 3.699 mm x 3.699 mm. The side surface 23 is formed so as to extend outward from the wavelength conversion member 2 from the back surface 22 toward the reflective surface 21 along the stacking direction Ds of the ceramic phosphor 10, the reflective film 20, and the sealing film 30. The detailed configuration of the reflective film 20 will be described later. Note that the reflective film 20 may be made of a material with high light reflectance, such as aluminum.

封止膜３０は、チタン（Ｔｉ）からなる薄膜であって、反射膜２０を覆い、反射膜２０を封止する。封止膜３０は、被覆部３１と、接合部３２と、接続部３３と、を有する。被覆部３１は、反射膜２０の裏面２２上に配置されており、厚みが１５０ｎｍである。被覆部３１のセラミック蛍光体１０側の対向面３１ａは、反射膜２０の裏面２２に対向する。接合部３２は、厚みが１５０ｎｍであり、反射膜２０の端部２０ａを超えてセラミック蛍光体１０の裏面１２に接合される。接合部３２は、セラミック蛍光体１０の裏面１２に接合される接合面３２ａを有する。接続部３３は、被覆部３１と接合部３２とを接続する。接続部３３は、セラミック蛍光体１０側に、対向面３１ａと接合面３２ａとを接続する接続面３３ａを有する。接続面３３ａは、反射膜２０の側面２３に沿っている。接合部３２は、特許請求の範囲の「封止膜の端部」に相当する。封止膜３０の詳細な構成は、後述する。 The sealing film 30 is a thin film made of titanium (Ti), and covers and seals the reflective film 20 . The sealing film 30 includes a covering portion 31 , a bonding portion 32 , and a connecting portion 33 . The covering portion 31 is disposed on the back surface 22 of the reflective film 20 and has a thickness of 150 nm. A facing surface 31 a of the covering portion 31 on the ceramic phosphor 10 side faces the back surface 22 of the reflective film 20 . The bonding portion 32 has a thickness of 150 nm, and is bonded to the back surface 12 of the ceramic phosphor 10 beyond the end portion 20a of the reflective film 20. The bonding portion 32 has a bonding surface 32 a that is bonded to the back surface 12 of the ceramic phosphor 10 . The connecting portion 33 connects the covering portion 31 and the joint portion 32. The connecting portion 33 has a connecting surface 33a on the ceramic phosphor 10 side that connects the opposing surface 31a and the bonding surface 32a. The connecting surface 33 a is along the side surface 23 of the reflective film 20 . The joint portion 32 corresponds to the “end portion of the sealing film” in the claims. The detailed structure of the sealing film 30 will be described later.

接合膜４０は、ニッケル（Ｎｉ）からなる薄膜であって、封止膜３０のセラミック蛍光体１０の反対側の表面３１ｂ、３２ｂ、３３ｂに配置されている。本実施形態では、接合膜４０の厚みは、２００ｎｍであり、封止膜３０の表面３１ｂ、３２ｂ、３３ｂの形状に沿って形成されている。これにより、接合膜４０の封止膜３０の反対側の表面４１の形状は、封止膜３０の表面３１ｂ、３２ｂ、３３ｂの形状と同じように、セラミック蛍光体１０側に向かって外縁部分が広がるように形成される。 The bonding film 40 is a thin film made of nickel (Ni), and is disposed on the surfaces 31b, 32b, and 33b of the sealing film 30 on the side opposite to the ceramic phosphor 10. In this embodiment, the thickness of the bonding film 40 is 200 nm, and is formed along the shape of the surfaces 31b, 32b, and 33b of the sealing film 30. As a result, the shape of the surface 41 of the bonding film 40 on the opposite side of the sealing film 30 is the same as the shape of the surfaces 31b, 32b, and 33b of the sealing film 30, with the outer edge portion toward the ceramic phosphor 10 side. Formed to spread.

酸化防止膜５０は、接合膜４０のセラミック蛍光体１０の反対側に配置されており、厚みが、１０～５００ｎｍ程度の金からなる薄膜である。酸化防止膜５０は、ニッケルからなる接合膜４０の表面の酸化を防止するとともに、後述する放熱部材６０と波長変換部材２とを接合層７０によって接合するとき、接合層７０に拡散し、セラミック蛍光体１０と放熱部材６０との接合力を向上する。 The antioxidation film 50 is disposed on the opposite side of the bonding film 40 from the ceramic phosphor 10, and is a thin film made of gold with a thickness of about 10 to 500 nm. The anti-oxidation film 50 prevents oxidation of the surface of the bonding film 40 made of nickel, and when a heat dissipation member 60 and a wavelength conversion member 2 (described later) are bonded by the bonding layer 70, it diffuses into the bonding layer 70 and prevents ceramic fluorescence. The bonding force between the body 10 and the heat dissipating member 60 is improved.

図３は、図２のＳ部拡大図である。図３は、波長変換部材２における反射膜２０の端部２０ａを含む周辺の断面図である。なお、図３における、セラミック蛍光体１０と、反射膜２０と、封止膜３０と、接合膜４０とのそれぞれの大きさおよび厚みの関係は、説明の便宜上、実際の大きさまたは厚みの関係とは異なるように図示されている。 FIG. 3 is an enlarged view of the S section in FIG. 2. FIG. 3 is a sectional view of the vicinity of the wavelength conversion member 2 including the end portion 20a of the reflective film 20. Note that, for convenience of explanation, the relationship in size and thickness of the ceramic phosphor 10, reflective film 20, sealing film 30, and bonding film 40 in FIG. 3 is based on the actual size or thickness relationship. It is illustrated differently.

図３に示す積層方向Ｄｓに沿った波長変換部材２の断面において、セラミック蛍光体１０と反射膜２０との接合線ＪＬ２１の一方の端部の位置を第１位置Ｐ１とする。第１位置Ｐ１から、接合線ＪＬ２１に沿って、反射膜２０の積層方向Ｄｓにおける厚みＤ２０の１０倍に相当する距離（図３に示す距離Ｄ１）だけ接合線ＪＬ２１の他方の端部側（図３の二点鎖線矢印Ｄｐが示す方向側）に向かった位置を第２位置Ｐ２とする。第２位置Ｐ２から積層方向Ｄｓに沿った第１仮想線ＶＬ１と、反射膜２０と封止膜３０との境界線ＢＬ２３との交点の位置を第３位置Ｐ３とする。第１位置Ｐ１と第３位置Ｐ３とを結ぶ仮想線を第２仮想線ＶＬ２とする。この場合、反射膜２０の断面のうち、第２仮想線ＶＬ２よりも封止膜３０側に位置する領域の面積Ａは、第１仮想線ＶＬ１、第２仮想線ＶＬ２、および、接合線ＪＬ２１で囲まれる領域の面積Ｂよりも小さい。具体的には、図３において、比較的密なドットハッチングが付されている部分の面積Ａは、面積Ａの部分に比べて比較的疎なドットハッチングが付されている部分の面積Ｂよりも小さい。これにより、封止膜３０の形状は、緩やかに曲がる形状になるため、波長変換部材２に応力が作用しても封止膜３０にクラックが発生しにくくなり、クラックを介した外気と反射膜２０との接触が抑制することができる。 In the cross section of the wavelength conversion member 2 along the stacking direction Ds shown in FIG. 3, the position of one end of the joining line JL21 between the ceramic phosphor 10 and the reflective film 20 is defined as a first position P1. From the first position P1, along the bonding line JL21, move a distance corresponding to 10 times the thickness D20 of the reflective film 20 in the stacking direction Ds (distance D1 shown in FIG. 3) to the other end side of the bonding line JL21 (see FIG. 3) is defined as a second position P2. The position of the intersection of the first virtual line VL1 along the stacking direction Ds from the second position P2 and the boundary line BL23 between the reflective film 20 and the sealing film 30 is defined as a third position P3. A virtual line connecting the first position P1 and the third position P3 is defined as a second virtual line VL2. In this case, the area A of the region located closer to the sealing film 30 than the second imaginary line VL2 in the cross section of the reflective film 20 is defined by the first imaginary line VL1, the second imaginary line VL2, and the bonding line JL21. It is smaller than the area B of the enclosed region. Specifically, in FIG. 3, the area A of the part with relatively dense dot hatching is larger than the area B of the part with relatively sparse dot hatching. small. As a result, the shape of the sealing film 30 becomes a gently curved shape, which makes it difficult for cracks to occur in the sealing film 30 even if stress is applied to the wavelength conversion member 2. Contact with 20 can be suppressed.

また、本実施形態では、面積Ａは、面積Ｂの９０％以下となっている。これにより、反射膜２０の側面２３は、セラミック蛍光体１０側の幅Ｗ２１より外側に突出しない形状となりやすいため、封止膜３０の形状は、比較的緩やかに曲がる形状となる。これにより、封止膜３０に応力が作用しても封止膜３０にクラックは発生しにくくなるため、クラックを介した外気と反射膜２０との接触が抑制することができる。 Furthermore, in this embodiment, the area A is 90% or less of the area B. As a result, the side surface 23 of the reflective film 20 tends to have a shape that does not protrude outward beyond the width W21 on the ceramic phosphor 10 side, so the shape of the sealing film 30 becomes a relatively gently curved shape. This makes it difficult for cracks to occur in the sealing film 30 even when stress is applied to the sealing film 30, so that contact between the outside air and the reflective film 20 through the cracks can be suppressed.

さらに、積層方向Ｄｓに沿った波長変換部材２の断面において、第１位置Ｐ１から積層方向Ｄｓに沿った仮想線を第３仮想線ＶＬ３とすると、反射膜２０の断面は、第３仮想線ＶＬ３の一方の側に位置し、第３仮想線ＶＬ３にまたがって第３仮想線ＶＬ３の両側に位置しない。具体的には、図３に示す波長変換部材２の断面において、反射膜２０の断面は、第３仮想線ＶＬ３より第２仮想線ＶＬ２側にのみ存在しており、第３仮想線ＶＬ３より第２仮想線ＶＬ２の反対側には存在していない。これにより、後述するように反射膜２０上に形成される封止膜３０の形状は、さらに緩やかな形状となるため、応力による封止膜３０のクラックの発生がさらに抑制される。また、反射膜２０上に形成される封止膜３０と反射膜２０との間には隙間が形成されにくくなるため、波長変換部材２に応力が作用しても隙間を起点としたクラックが封止膜３０に発生しにくくなる。したがって、クラックを介した外気と反射膜２０との接触がさらに抑制することができる。 Further, in the cross section of the wavelength conversion member 2 along the stacking direction Ds, if a virtual line from the first position P1 along the stacking direction Ds is a third virtual line VL3, then the cross section of the reflective film 20 is the third virtual line VL3. is located on one side of the third virtual line VL3, and is not located on either side of the third virtual line VL3. Specifically, in the cross section of the wavelength conversion member 2 shown in FIG. 2 does not exist on the opposite side of the virtual line VL2. As a result, as will be described later, the shape of the sealing film 30 formed on the reflective film 20 becomes more gentle, so that cracks in the sealing film 30 due to stress are further suppressed. Furthermore, since a gap is less likely to be formed between the sealing film 30 formed on the reflective film 20 and the reflective film 20, even if stress is applied to the wavelength conversion member 2, cracks originating from the gap will not occur in the sealing. This is less likely to occur on the stop film 30. Therefore, contact between the outside air and the reflective film 20 through the cracks can be further suppressed.

本実施形態では、封止膜３０は、図３に示すように、第２仮想線ＶＬ２に沿った方向に延伸してしている。具体的には、封止膜３０のセラミック蛍光体１０の反対側の表面３１ｂ、３２ｂ、３３ｂのそれぞれは、対向面３１ａ、接合面３２ａ、および、接続面３３ａとほぼ同じ形状になっている。これにより、被覆部３１のセラミック蛍光体１０とは反対側の表面３１ｂにおけるセラミック蛍光体１０の裏面１２からの距離は、接合部３２のセラミック蛍光体１０とは反対側の表面３２ｂにおけるセラミック蛍光体１０の裏面１２からの距離より長い。本実施形態では、表面３１ｂと表面３２ｂとを接続する接続部３３のセラミック蛍光体１０の反対側の表面３３ｂは、波長変換部材２の外側に向かうにしたがって、セラミック蛍光体１０の裏面１２に近づく。すなわち、封止膜３０は、セラミック蛍光体１０側に向かって広がるように形成される。 In this embodiment, the sealing film 30 extends in the direction along the second virtual line VL2, as shown in FIG. Specifically, each of the surfaces 31b, 32b, and 33b of the sealing film 30 on the side opposite to the ceramic phosphor 10 has substantially the same shape as the opposing surface 31a, the bonding surface 32a, and the connecting surface 33a. As a result, the distance from the back surface 12 of the ceramic phosphor 10 on the surface 31b of the covering portion 31 opposite to the ceramic phosphor 10 is the same as the distance from the ceramic phosphor 10 on the surface 32b of the joint portion 32 on the opposite side to the ceramic phosphor 10. It is longer than the distance from the back surface 12 of 10. In this embodiment, the surface 33b on the opposite side of the ceramic phosphor 10 of the connecting portion 33 that connects the surface 31b and the surface 32b approaches the back surface 12 of the ceramic phosphor 10 as it goes toward the outside of the wavelength conversion member 2. . That is, the sealing film 30 is formed so as to spread toward the ceramic phosphor 10 side.

次に、波長変換部材２の製造方法について説明する。最初に、セラミック蛍光体１０の裏面１２にレジスト膜を形成する。このとき、レジスト膜の厚みを調整することで、レジスト膜の開口部分の大きさを、セラミック蛍光体１０の裏面１２から離れるにしたがって小さくする。次に、レジスト膜が裏面１２に形成されているセラミック蛍光体１０に対して、銀を蒸着またはスパッタリングし、反射膜２０を成膜する。その後、レジスト膜を除去し、反射膜２０の裏面２２および側面２３、ならびに、セラミック蛍光体１０の裏面１２上に封止膜３０を製膜する。さらに、封止膜３０の表面３１ｂ、３２ｂ、３３ｂ上に、接合膜４０と酸化防止膜５０とを、この順番で製膜し、波長変換部材２を製造する。 Next, a method for manufacturing the wavelength conversion member 2 will be explained. First, a resist film is formed on the back surface 12 of the ceramic phosphor 10. At this time, by adjusting the thickness of the resist film, the size of the opening portion of the resist film is made smaller as the distance from the back surface 12 of the ceramic phosphor 10 increases. Next, silver is vapor-deposited or sputtered onto the ceramic phosphor 10 on which the resist film is formed on the back surface 12 to form the reflective film 20 . Thereafter, the resist film is removed, and a sealing film 30 is formed on the back surface 22 and side surfaces 23 of the reflective film 20 and the back surface 12 of the ceramic phosphor 10. Further, a bonding film 40 and an antioxidant film 50 are formed in this order on the surfaces 31b, 32b, and 33b of the sealing film 30, thereby manufacturing the wavelength conversion member 2.

さらに、波長変換部材２を用いて波長変換装置１を製造する場合、波長変換部材２と放熱部材６０との間に金錫半田箔を挟みこんだ状態で、窒素雰囲気中または水素雰囲気中のリフロー炉において加熱する。これにより、セラミック蛍光体１０と放熱部材６０とが接合層７０によって接合され、波長変換装置１が完成する。また、金錫半田箔を使用する代わりに、金錫半田ペーストを塗布して波長変換部材２と放熱部材６０とを接合してもよい。 Furthermore, when manufacturing the wavelength conversion device 1 using the wavelength conversion member 2, reflowing in a nitrogen atmosphere or a hydrogen atmosphere is performed with gold-tin solder foil sandwiched between the wavelength conversion member 2 and the heat dissipation member 60. Heat in a furnace. Thereby, the ceramic phosphor 10 and the heat dissipating member 60 are bonded by the bonding layer 70, and the wavelength conversion device 1 is completed. Further, instead of using gold-tin solder foil, the wavelength conversion member 2 and the heat dissipation member 60 may be joined by applying a gold-tin solder paste.

図４は、製造時の波長変換装置１の断面図である。金錫半田箔を用いて波長変換部材２と放熱部材６０とを接合するとき、放熱部材６０の表面に形成されるめっきに含まれるガス成分や、波長変換部材２と金錫半田箔との間の隙間に由来するボイドが、波長変換部材２と放熱部材６０との間に発生する（図４のＶ１参照）。本実施形態の波長変換装置１の製造方法では、波長変換部材２と放熱部材６０とを接合するとき、図４に示すように、セラミック蛍光体１０が波長変換部材２において最も鉛直方向上側に位置するように配置する。波長変換装置１の中心軸ＣＡ１付近で発生するボイドＶ１は、溶融状態の接合層７０の内部において、接合膜４０の表面４１に沿って、波長変換装置１の中心軸ＣＡ１から離れ、波長変換装置１の外側に移動する（図４に示す白抜き矢印Ｆ１）。これにより、本実施形態の波長変換装置１の製造方法では、波長変換装置１の中心軸ＣＡ１付近におけるボイドＶ１の密度を小さくすることができる。なお、図４における、セラミック蛍光体１０と、反射膜２０と、封止膜３０と、接合膜４０と、放熱部材６０と、接合層７０とのそれぞれの大きさおよび厚みの関係は、説明の便宜上、実際の大きさまたは厚みの関係とは異なるように図示されている。 FIG. 4 is a cross-sectional view of the wavelength conversion device 1 during manufacture. When the wavelength conversion member 2 and the heat dissipation member 60 are bonded using gold-tin solder foil, gas components contained in the plating formed on the surface of the heat dissipation member 60 and between the wavelength conversion member 2 and the gold-tin solder foil A void resulting from the gap is generated between the wavelength conversion member 2 and the heat dissipation member 60 (see V1 in FIG. 4). In the method for manufacturing the wavelength conversion device 1 of the present embodiment, when the wavelength conversion member 2 and the heat dissipation member 60 are bonded, the ceramic phosphor 10 is located at the uppermost position in the vertical direction in the wavelength conversion member 2, as shown in FIG. Place it so that A void V1 generated near the central axis CA1 of the wavelength converting device 1 moves away from the central axis CA1 of the wavelength converting device 1 along the surface 41 of the bonding film 40 inside the bonding layer 70 in a molten state, and the void V1 occurs near the central axis CA1 of the wavelength converting device 1. 1 (outline arrow F1 shown in FIG. 4). Thereby, in the method for manufacturing the wavelength conversion device 1 of this embodiment, the density of the voids V1 near the central axis CA1 of the wavelength conversion device 1 can be reduced. The size and thickness relationships among the ceramic phosphor 10, the reflective film 20, the sealing film 30, the bonding film 40, the heat dissipation member 60, and the bonding layer 70 in FIG. 4 are as explained in the description. For convenience, the relationship in size or thickness is shown to be different from the actual size or thickness.

以上説明した、本実施形態の波長変換部材２によれば、積層方向Ｄｓに沿った波長変換部材２の断面において、反射膜２０の断面形状では、面積Ａは、面積Ｂより小さい。すなわち、反射膜２０のセラミック蛍光体１０側の部分とセラミック蛍光体１０の反対側の部分とは、緩やかに接続される。これにより、反射膜２０を覆いつつセラミック蛍光体１０の裏面１２に接合される封止膜３０では、反射膜２０のセラミック蛍光体１０の反対側に配置される被覆部３１と、セラミック蛍光体１０の裏面１２に接合する接合部３２とが、緩やかな形状の接続部３３によって接続される。封止膜３０において、被覆部３１と接合部３２とが緩やかに接続されることで、封止膜３０の形状は、緩やかに曲がる形状になるため、封止膜３０に応力が作用しても、封止膜３０にクラックは発生しにくくなる。クラックは、反射膜を酸化などさせる外気が反射膜に接触するときの侵入経路となるが、上述した構成によれば、クラックの発生が抑制されるため、クラックを介した外気と反射膜２０との接触が抑制される。これにより、反射膜２０の劣化が抑制されるため、波長変換部材２の発光強度の低下を抑制することができる。 According to the wavelength conversion member 2 of the present embodiment described above, in the cross section of the wavelength conversion member 2 along the stacking direction Ds, the area A is smaller than the area B in the cross-sectional shape of the reflective film 20. That is, the portion of the reflective film 20 on the ceramic phosphor 10 side and the portion on the opposite side of the ceramic phosphor 10 are loosely connected. As a result, in the sealing film 30 that is bonded to the back surface 12 of the ceramic phosphor 10 while covering the reflective film 20, the coating portion 31 disposed on the opposite side of the ceramic phosphor 10 of the reflective film 20 and the ceramic phosphor 10 A connecting portion 32 that is joined to the back surface 12 of the connector is connected by a connecting portion 33 having a gentle shape. In the sealing film 30, the covering part 31 and the joint part 32 are loosely connected, so that the shape of the sealing film 30 is gently curved, so even if stress is applied to the sealing film 30, , cracks are less likely to occur in the sealing film 30. Cracks serve as an intrusion route for external air that oxidizes the reflective film when it comes into contact with the reflective film. However, according to the above-mentioned configuration, since the generation of cracks is suppressed, the external air and the reflective film 20 through the cracks are prevented from coming into contact with each other. contact is suppressed. Thereby, deterioration of the reflective film 20 is suppressed, so that a decrease in the emission intensity of the wavelength conversion member 2 can be suppressed.

また、例えば、積層方向に沿った反射膜の断面形状が矩形形状である場合、反射膜を覆う封止膜は、折れ曲がる形状となるため、クラックが発生しやすくなる。この場合、クラックの発生を抑制するために封止膜の厚みを厚くすると封止膜とセラミック蛍光体との接合面積が増えるおそれがあり、反射膜の反射面の面積が小さくなる。反射面の面積が小さくなると、波長変換部材の発光強度が低下する。本実施形態の波長変換部材２によれば、積層方向Ｄｓに沿った反射膜２０の断面において、面積Ａを面積Ｂより小さくすることで、封止膜３０でのクラックの発生を抑制する。このことによって、反射膜２０において、セラミック蛍光体１０に入射した光を反射する反射面２１の面積は、上述したような断面形状が矩形形状の反射膜における反射面の面積と変わらない。したがって、波長変換部材２の発光強度を低下させることなく、封止膜３０にクラックが発生することを抑制することができる。 Further, for example, when the cross-sectional shape of the reflective film along the stacking direction is rectangular, the sealing film covering the reflective film has a bent shape, which makes cracks more likely to occur. In this case, if the thickness of the sealing film is increased to suppress the occurrence of cracks, there is a risk that the bonding area between the sealing film and the ceramic phosphor will increase, and the area of the reflective surface of the reflective film will become smaller. When the area of the reflective surface becomes smaller, the emission intensity of the wavelength conversion member decreases. According to the wavelength conversion member 2 of this embodiment, by making the area A smaller than the area B in the cross section of the reflective film 20 along the stacking direction Ds, generation of cracks in the sealing film 30 is suppressed. As a result, in the reflective film 20, the area of the reflective surface 21 that reflects the light incident on the ceramic phosphor 10 is the same as the area of the reflective surface in the reflective film having a rectangular cross-sectional shape as described above. Therefore, generation of cracks in the sealing film 30 can be suppressed without reducing the emission intensity of the wavelength conversion member 2.

また、本実施形態の波長変換部材２によれば、反射膜２０の断面において、封止膜３０側の面積Ａは、反射膜２０側の面積Ｂの９０％以下となっている。これにより、反射膜２０の側面２３は、セラミック蛍光体１０側の幅Ｗ２１より外側に突出しない形状となりやすい。反射膜の側面がセラミック蛍光体側の幅より外側に突出していると、封止膜は反射膜に沿って形成されるため、封止膜も外側に突出した形状となり、大きく折れ曲がる場合がある。このため、封止膜に応力が作用するとクラックが発生しやすい。一方、波長変換部材２の封止膜３０の形状は、緩やかに曲がる形状になるため、応力が作用してもクラックは発生しにくい。したがって、クラックを介した外気と反射膜２０との接触がさらに抑制されるため、反射膜２０の劣化が抑制され、波長変換部材２の発光強度の低下をさらに抑制することができる。 Further, according to the wavelength conversion member 2 of this embodiment, in the cross section of the reflective film 20, the area A on the sealing film 30 side is 90% or less of the area B on the reflective film 20 side. Thereby, the side surface 23 of the reflective film 20 tends to have a shape that does not protrude outward beyond the width W21 on the ceramic phosphor 10 side. If the side surface of the reflective film protrudes outward beyond the width of the ceramic phosphor side, the sealing film is formed along the reflective film, so the sealing film also protrudes outward and may be bent significantly. Therefore, cracks are likely to occur when stress is applied to the sealing film. On the other hand, since the sealing film 30 of the wavelength conversion member 2 has a gently curved shape, cracks are unlikely to occur even if stress is applied. Therefore, since contact between the outside air and the reflective film 20 through the cracks is further suppressed, deterioration of the reflective film 20 is suppressed, and a decrease in the emission intensity of the wavelength conversion member 2 can be further suppressed.

また、本実施形態の波長変換部材２によれば、反射膜２０の断面は、図３に示すように、第３仮想線ＶＬ３の一方の側に位置し、第３仮想線ＶＬ３にまたがって第３仮想線ＶＬ３の両側に位置していない。すなわち、反射膜２０において、セラミック蛍光体１０側の部分と、セラミック蛍光体１０の反対側の部分とは、比較的なだらかに接続される。これにより、封止膜３０の形状は、さらに緩やかな形状になるため、応力による封止膜３０のクラックの発生がさらに抑制される。また、一般的に、反射膜上に形成される封止膜と反射膜との間に隙間が形成されると、応力のかかり具合によっては隙間を起点としたクラックが封止膜に発生しやすくなる。波長変換部材２によれば、反射膜２０において、セラミック蛍光体１０側の部分と、セラミック蛍光体１０の反対側の部分とが比較的なだらかに接続されるため、反射膜２０上に形成される封止膜３０と反射膜２０との間に隙間が形成されにくくなる。これによっても、応力による封止膜でのクラックの発生がさらに抑制される。したがって、クラックを介した外気と反射膜２０との接触がさらに抑制されるため、反射膜２０の劣化が抑制され、発光強度の低下をさらに抑制することができる。 Further, according to the wavelength conversion member 2 of the present embodiment, the cross section of the reflective film 20 is located on one side of the third imaginary line VL3, and extends across the third imaginary line VL3, as shown in FIG. 3 are not located on either side of virtual line VL3. That is, in the reflective film 20, the portion on the ceramic phosphor 10 side and the portion on the opposite side of the ceramic phosphor 10 are connected relatively smoothly. As a result, the shape of the sealing film 30 becomes even more gentle, so that cracks in the sealing film 30 due to stress are further suppressed. Additionally, in general, if a gap is formed between the sealing film formed on the reflective film and the reflective film, cracks may easily occur in the sealing film, starting from the gap, depending on the degree of stress applied. Become. According to the wavelength conversion member 2, in the reflective film 20, the part on the ceramic phosphor 10 side and the part on the opposite side of the ceramic phosphor 10 are connected relatively gently, so that the wavelength conversion member 2 is formed on the reflective film 20. A gap is less likely to be formed between the sealing film 30 and the reflective film 20. This also further suppresses the occurrence of cracks in the sealing film due to stress. Therefore, since contact between the outside air and the reflective film 20 through the cracks is further suppressed, deterioration of the reflective film 20 is suppressed, and a decrease in emission intensity can be further suppressed.

また、本実施形態の波長変換部材２によれば、封止膜３０の接合部３２と接続部３３とは、第２仮想線ＶＬ２に沿った方向に延伸している。これにより、封止膜３０は、セラミック蛍光体１０に向かって広がっている。金と錫から形成されている接合層７０を用いて、波長変換部材２と、放熱部材６０とを接合するとき、図４に示すように、接合層７０内に発生するボイドＶ１が、封止膜３０とほぼ同じ形状を有する接合膜４０の形状に沿って波長変換部材２の外側に向かって移動する。接合層７０内のボイドは、セラミック蛍光体１０において光の波長を変換するときに発生する熱の伝熱を妨げるため、特に、波長変換部材２の中央部分にはないことが望ましい。本実施形態の波長変換部材２によれば、接合層７０内のボイドＶ１は、波長変換部材２の外側に移動するため（図４参照）、熱的に厳しい波長変換部材２の中心部分の放熱を良好に行うことができる。したがって、波長変換部材２において、温度消光による発光強度の低下を抑制することができる。 Moreover, according to the wavelength conversion member 2 of this embodiment, the joint part 32 and the connection part 33 of the sealing film 30 extend in the direction along the second imaginary line VL2. Thereby, the sealing film 30 spreads toward the ceramic phosphor 10. When the wavelength conversion member 2 and the heat dissipation member 60 are bonded using the bonding layer 70 made of gold and tin, as shown in FIG. It moves toward the outside of the wavelength conversion member 2 along the shape of the bonding film 40, which has almost the same shape as the film 30. It is particularly desirable that voids in the bonding layer 70 are not present in the central portion of the wavelength conversion member 2 because they hinder the transfer of heat generated when the wavelength of light is converted in the ceramic phosphor 10. According to the wavelength conversion member 2 of this embodiment, since the void V1 in the bonding layer 70 moves to the outside of the wavelength conversion member 2 (see FIG. 4), heat dissipation from the central portion of the wavelength conversion member 2 which is thermally severe can be performed well. Therefore, in the wavelength conversion member 2, a decrease in emission intensity due to temperature quenching can be suppressed.

また、本実施形態の波長変換装置１によれば、封止膜３０の形状は、緩やかに曲がる形状になるため、封止膜３０にクラックが発生しにくくなり、反射膜２０の酸化などを抑制することができる。また、波長変換部材２で発生する熱を放熱部材６０によって外部に放出することができる。これにより、反射膜２０の劣化による発光強度の低下を抑制しつつ、熱による波長変換装置１の発光強度の低下を抑制することができる。 Further, according to the wavelength conversion device 1 of the present embodiment, the shape of the sealing film 30 is a gently curved shape, so that cracks are less likely to occur in the sealing film 30, and oxidation of the reflective film 20 is suppressed. can do. Further, the heat generated by the wavelength conversion member 2 can be radiated to the outside by the heat radiating member 60. Thereby, it is possible to suppress a decrease in the emission intensity of the wavelength conversion device 1 due to heat while suppressing a decrease in the emission intensity due to deterioration of the reflective film 20.

また、本実施形態の光源装置５によれば、波長変換装置１では、緩やかに曲がる形状となっている封止膜３０にクラックが発生しにくいため、反射膜２０の劣化が抑制される。これにより、セラミック蛍光体１０で波長が変換される光の一部や、セラミック蛍光体１０を素通りする光などセラミック蛍光体１０内の光を、劣化しにくい反射膜２０で反射することができるため、光源装置５の発光強度の低下を抑制することができる。 Furthermore, according to the light source device 5 of the present embodiment, in the wavelength conversion device 1, cracks are less likely to occur in the sealing film 30, which has a gently curved shape, so that deterioration of the reflective film 20 is suppressed. This allows light inside the ceramic phosphor 10, such as part of the light whose wavelength is converted by the ceramic phosphor 10 and light that passes through the ceramic phosphor 10, to be reflected by the reflective film 20, which does not easily deteriorate. , a decrease in the light emission intensity of the light source device 5 can be suppressed.

＜本実施形態の変形例＞
本発明は上記の実施形態に限られるものではなく、その要旨を逸脱しない範囲において種々の態様において実施することが可能であり、例えば次のような変形も可能である。 <Modification of this embodiment>
The present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit thereof. For example, the following modifications are also possible.

［変形例１］
上述の実施形態では、波長変換部材２は、セラミック蛍光体１０と反射膜２０と封止膜３０の他に、接合膜４０と酸化防止膜５０とを備えるとした。これらの膜はなくてもよい。 [Modification 1]
In the embodiment described above, the wavelength conversion member 2 includes the bonding film 40 and the anti-oxidation film 50 in addition to the ceramic phosphor 10, the reflective film 20, and the sealing film 30. These films may be omitted.

［変形例２］
上述の実施形態では、反射膜２０の断面において、面積Ａは、面積Ｂの９０％以下であるとした。しかしながら、面積Ａと面積Ｂとの関係は、これに限定されない。面積Ａが面積Ｂより小さければよい。面積Ａが面積Ｂの５０％以下となることで、封止膜３０の形状は、さらに緩やかに曲がる形状になるため、クラックがさらに発生しにくくなり、反射膜の劣化がさらに抑制される。 [Modification 2]
In the above embodiment, the area A is 90% or less of the area B in the cross section of the reflective film 20. However, the relationship between area A and area B is not limited to this. It is sufficient that area A is smaller than area B. Since the area A is 50% or less of the area B, the shape of the sealing film 30 becomes more gently curved, so that cracks are even less likely to occur, and deterioration of the reflective film is further suppressed.

［変形例３］
上述の実施形態では、積層方向Ｄｓに沿った波長変換部材２の断面において、反射膜２０の断面は、第３仮想線ＶＬ３より第２仮想線ＶＬ２側にのみ存在しており、反射膜２０と封止膜３０との境界線ＢＬ２３が第３仮想線ＶＬ３より第２仮想線ＶＬ２の反対側には存在していないとした。しかしながら、反射膜２０の断面の形状はこれに限定されない。反射膜２０の断面が第３仮想線ＶＬ３より第２仮想線ＶＬ２側にのみ存在することで、反射膜２０の側面２３の形状が緩やかになるため、封止膜３０の形状は、さらに緩やかに曲がる形状となる。 [Modification 3]
In the embodiment described above, in the cross section of the wavelength conversion member 2 along the stacking direction Ds, the cross section of the reflective film 20 exists only on the second virtual line VL2 side from the third virtual line VL3, and the cross section of the reflective film 20 It is assumed that the boundary line BL23 with the sealing film 30 does not exist on the opposite side of the second imaginary line VL2 from the third imaginary line VL3. However, the cross-sectional shape of the reflective film 20 is not limited to this. Since the cross section of the reflective film 20 exists only on the side of the second imaginary line VL2 from the third imaginary line VL3, the shape of the side surface 23 of the reflective film 20 becomes gentler, so that the shape of the sealing film 30 becomes even more gentle. It has a bendable shape.

［変形例４］
上述の実施形態では、封止膜３０は、図３に示すように、第２仮想線ＶＬ２に沿った方向に延伸しており、封止膜３０の表面３１ｂ、３２ｂ、３３ｂは、対向面３１ａ、接合面３２ａ、および、接続面３３ａとほぼ同じ形状になっているとした。しかしながら、封止膜３０の表面３１ｂ、３２ｂ、３３ｂの形状は、これに限定されていない。例えば、表面３１ｂ、３２ｂ、３３ｂは、平面形状であってもよい。 [Modification 4]
In the above-described embodiment, the sealing film 30 extends in the direction along the second virtual line VL2, as shown in FIG. , the joint surface 32a, and the connection surface 33a have substantially the same shape. However, the shapes of the surfaces 31b, 32b, and 33b of the sealing film 30 are not limited to this. For example, surfaces 31b, 32b, and 33b may have a planar shape.

以上、実施形態、変形例に基づき本態様について説明してきたが、上記した態様の実施の形態は、本態様の理解を容易にするためのものであり、本態様を限定するものではない。本態様は、その趣旨並びに特許請求の範囲を逸脱することなく、変更、改良され得るとともに、本態様にはその等価物が含まれる。また、その技術的特徴が本明細書中に必須なものとして説明されていなければ、適宜、削除することができる。 Although the present aspect has been described above based on the embodiments and modified examples, the embodiments of the above-described aspect are for facilitating understanding of the present aspect, and do not limit the present aspect. This aspect may be modified and improved without departing from the spirit and scope of the claims, and this aspect includes equivalents thereof. Furthermore, if the technical feature is not described as essential in this specification, it can be deleted as appropriate.

１…波長変換装置
２…波長変換部材
５…光源装置
６…光源
１０…セラミック蛍光体
１１…入射面
１２…裏面
２０…反射膜
２０ａ…端部
２１…反射面
３０…封止膜
３２…接合部
６０…放熱部材
７０…接合層
Ａ，Ｂ…面積
ＢＬ２３…境界線
Ｄｓ…積層方向
ＪＬ２１…接合線
Ｐ１…第１位置
Ｐ２…第２位置
Ｐ３…第３位置
ＶＬ１…第１仮想線
ＶＬ２…第２仮想線
ＶＬ３…第３仮想線 DESCRIPTION OF SYMBOLS 1...Wavelength conversion device 2...Wavelength conversion member 5...Light source device 6...Light source 10...Ceramic phosphor 11...Incidence surface 12...Back surface 20...Reflection film 20a...End part 21...Reflection surface 30...Sealing film 32...Joint part 60... Heat radiation member 70... Bonding layer A, B... Area BL23... Boundary line Ds... Lamination direction JL21... Bonding line P1... First position P2... Second position P3... Third position VL1... First imaginary line VL2... Second Virtual line VL3...Third virtual line

Claims

A wavelength conversion member,
a ceramic phosphor that has an incident surface on which light enters and a back surface located on the opposite side of the incident surface, and converts the wavelength of light incident from the incident surface;
a reflective film bonded to a part of the back surface of the ceramic phosphor and having a reflective surface that reflects light incident on the ceramic phosphor;
A sealing film that seals the reflective film, the sealing film covering the reflective film and having an end of the sealing film beyond the end of the reflective film and bonded to the back surface of the ceramic phosphor. comprising a membrane;
In a cross section of the wavelength conversion member along the lamination direction of the ceramic phosphor, the reflective film, and the sealing film,
a position of one end of the bonding line between the ceramic phosphor and the reflective film is a first position;
A second position is a position along the bonding line from the first position toward the other end of the bonding line by a distance equivalent to 10 times the thickness of the reflective film in the stacking direction,
A third position is a position of an intersection between a first virtual line extending from the second position along the stacking direction and a boundary line between the reflective film and the sealing film,
If a virtual line connecting the first position and the third position is a second virtual line,
Of the cross section of the reflective film,
The area A of the region located closer to the sealing film than the second virtual line is:
A wavelength conversion member characterized in that the area is smaller than an area B of a region surrounded by the first imaginary line, the second imaginary line, and the joining line.

The wavelength conversion member according to claim 1,
A wavelength conversion member characterized in that the area A is 90% or less of the area B.

The wavelength conversion member according to claim 1 or 2,
In the cross section of the wavelength conversion member along the lamination direction,
If a virtual line from the first position along the stacking direction is a third virtual line,
A wavelength conversion member characterized in that a cross section of the reflective film is located on one side of the third imaginary line, and does not straddle the third imaginary line and is located on both sides of the third imaginary line.

The wavelength conversion member according to any one of claims 1 to 3,
The wavelength conversion member, wherein an end portion of the sealing film extends in a direction along the second imaginary line.

A wavelength conversion device,
The wavelength conversion member according to any one of claims 1 to 4,
a heat dissipation member that radiates heat from the ceramic phosphor to the outside;
A wavelength conversion device comprising: a bonding layer bonding the wavelength conversion member and the heat dissipation member.

A light source device,
A wavelength conversion device according to claim 5,
and a light source that irradiates the ceramic phosphor with light.
Light source device.