JP7302299B2 - Junction structure and optical device - Google Patents

Description

The present invention relates to junction structures and optical devices.

As an optical device, for example, there is an LED light source device disclosed in Patent Document 1. The LED light source device has a plurality of LED elements (LEDs) that emit light of respective primary colors, and a plurality of collimator lens groups (lenses) as optical components.

Japanese Unexamined Patent Application Publication No. 2012-141483

In an optical device, LEDs and other optical components (eg, lenses, filters, etc.) are mounted on a substrate, which is an example of a base. At this time, optical parts such as lenses and filters are fixed to the substrate with an adhesive (for example, an ultraviolet curing resin adhesive). The bond between the optical component and the adhesive is relatively strong. On the other hand, the substrate surface may be plated with gold. Thus, when the substrate surface is plated with gold, the adhesive comes into contact with the gold plating. Since the bond between the gold plating and the adhesive is relatively weak, when a certain load is applied to the joint structure between the base (substrate) and the optical component, the interface between the adhesive and the base tends to break. As a result, the adhesion reliability of the above joint structure is degraded.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a joint structure capable of realizing high adhesion reliability and an optical device including the same.

A joint structure according to an aspect of the present invention includes a base and an optical component joined to the base. The pedestal has a substrate and a base member provided on the substrate. The base member has an oxidized region at least on the surface opposite to the substrate. The optical component is adhered to the oxidized region with an adhesive.

ADVANTAGE OF THE INVENTION According to this invention, the joint structure which can implement|achieve high adhesion reliability and an optical device containing the same can be provided.

FIG. 1 is a schematic diagram showing an example of an optical device including a junction structure according to one embodiment. FIG. 2 is a schematic diagram for explaining a modification of the joining structure. FIG. 3 is a schematic diagram for explaining another modification of the joint structure. FIG. 4 is a schematic diagram for explaining still another modification of the joint structure. FIG. 5 is a schematic diagram of a sample of the platform used in the experimental examples. FIG. 6 is a drawing for explaining an experimental method in an experimental example. FIG. 7 is a drawing showing experimental results when using a sample of the base portion having no base member. FIG. 8 is a drawing showing experimental results when using a base member sample having an Al film as a base member.

[Description of Embodiments of the Present Disclosure]
First, the contents of the embodiments of the present disclosure will be listed and described.

A joint structure according to one aspect of the present disclosure includes a base and an optical component joined to the base. The pedestal has a substrate and a base member provided on the substrate. The base member has an oxidized region on the surface opposite the substrate. The optical component is adhered to the oxidized region with an adhesive.

In the bonded structure, the optical component is bonded to the base by being glued to the oxidized region with an adhesive. The adhesive contacts the oxidized regions of the underlying member. Therefore, the bonding between the adhesive and the base member is stabilized. As a result, the joint structure can achieve high adhesion reliability.

The underlying member may include a material that is oxidized. Examples of the material include aluminum, copper, nickel, silicon, or any alloy of aluminum, copper, nickel, and silicon. These oxidized regions tend to provide a strong bond. In particular, aluminum or silicon facilitates the formation of dense oxidized regions at low cost.

The substrate may be placed on a temperature control element that controls temperature. In this case, it is possible to regulate the temperature of the substrate and the structure on the substrate, even if for example the ambient temperature of the junction structure rises. As a result, the thermal stress generated in the underlying member, the adhesive, etc. can be reduced, so that the joint structure is less likely to be destroyed. Therefore, the joint structure can easily achieve high bonding reliability.

An example of the material of the substrate is ceramic. The portion of the temperature control element that contacts the substrate is usually made of ceramic. Therefore, if the material of the substrate is ceramic, the difference in coefficient of linear expansion between the portions of the temperature control element and the substrate that are in contact with each other is small. As a result, for example, even if the ambient temperature of the junction structure rises, the substrate, the temperature control element, and the junction therebetween are less likely to be destroyed.

The base member may have a thickness of 50 nm or less. When the base member is thin in this way, the thermal stress caused by the difference in the coefficient of linear expansion between the substrate and the base member is reduced, and warping of the substrate, for example, can be reduced.

The base member and the substrate may be bonded via a base film containing titanium or nickel. In this case, the bonding between the base member and the substrate is strengthened.

The base member may be provided over the entire surface of the substrate. With this configuration, for example, when the base member is formed by vapor deposition, the processing cost of the vapor deposition process can be reduced. When the base member is provided on the entire surface of the substrate, the base member can be formed by a method other than vapor deposition (for example, plating method). Therefore, options for forming the base member are widened.

The base member may be a block body, and the thickness of the block body may be 100 μm or more and 500 μm or less. When the base member is a block body, for example, it is easy to prepare the base member while reducing processing costs. If the thickness is within the above range, the base member can be easily handled.

Examples of the shape of the underlying member are a rectangular parallelepiped and a cylinder. When the base member has a rectangular parallelepiped shape, the processing cost for preparing the base member can be reduced. When the shape of the base member is cylindrical, the uniformity of the thermal stress generated in the adhesive is improved, so deformation of the adhesive can be prevented.

An optical device according to another aspect of the present disclosure includes the junction structure described above. As described above, the above joint structure can achieve high adhesion reliability. Therefore, an optical device having the bonding structure described above can also achieve high bonding reliability, and as a result, the reliability of the optical device is improved.

[Details of the embodiment of the present disclosure]
Specific examples of embodiments of the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all modifications within the meaning and scope of equivalents of the scope of the claims. In the description of the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted. In the description, directional terms such as "up" and "down" are terms of convenience based on the states shown in the drawings. The dimensional proportions of the drawings do not necessarily match those of the description.

The optical device 4 shown in FIG. 1 includes a joint structure 2A of a base portion 6 and a lens (optical component) 8 and a laser diode (LD) 10 . An example of the optical device 4 is a light source device. The optical device 4 is, for example, an in-vehicle device mounted in a vehicle.

[Joint structure]
The joint structure 2A has a pedestal 6 and a lens 8, and the pedestal 6 and the lens 8 are joined with an adhesive. Therefore, the joint structure 2A has an adhesive layer 12 formed of the adhesive between the base portion 6 and the lens 8. As shown in FIG. The pedestal 6 includes a substrate 14 and a base member 16 .

<Substrate>
A substrate 14 is a member that supports the lens 8 and the LD 10 . Examples of materials for substrate 14 are ceramics or metals. Examples of such ceramics are aluminum nitride (AlN) or aluminum oxide (alumina). Examples of metals are copper, copper alloys, iron, iron alloys, nickel, or nickel alloys (eg, Kovar), and the material of substrate 14 is selected from a different material than underlying member 16 . An example thickness of substrate 14 is 0.6 mm.

<Electronic cooling module (temperature control element)>
The substrate 14 may be provided on an electronic cooling module 18, which is a temperature control element for controlling temperature. The electronic cooling module 18 may be part of the pedestal 6 . The electronic cooling module 18 has a first ceramic plate 20, a second ceramic plate 22, and a plurality of n-type semiconductor pillars 24 and p-type semiconductor pillars 26, as shown in FIG. An example of the electronic cooling module 18 is a Peltier element.

The first ceramic plate 20 and the second ceramic plate 22 sandwich a plurality of n-type semiconductor columns 24 and p-type semiconductor columns 26 . The material of the first ceramic plate 20 and the second ceramic plate 22 is alumina. A plurality of n-type semiconductor columns 24 and p-type semiconductor columns 26 are connected to electrodes 28 provided on the first ceramic plate 20 and the second ceramic plate 22, respectively. The n-type semiconductor pillars 24 and the p-type semiconductor pillars 26 may be arranged so as to realize the function of the electronic cooling module 18 .

The substrate 14 is mounted on the first ceramic plate 20 . The substrate 14 is bonded to the first ceramic plate 20 with silver (Ag) paste, for example.

<Backing material>
The base member 16 is provided in a mounting area A on which the lens 8 is mounted on the surface 14 a of the substrate 14 . As shown in FIG. 1, the base member 16 may be provided on the entire surface 14a (the surface on the lens 8 side). In FIG. 1 , a part of the base member 16 is cut out for explanation of the base member 16 .

The base member 16 has an oxidized region at least on the surface 161 opposite to the substrate 14 (lens 8 side). The base member 16 may have an oxide film (oxidized region) on the lens 8 side, or the entire base member 16 may be an oxidized region. Underlying member 16 includes a material that is oxidized in air. Hereinafter, for convenience of explanation, the “material to be oxidized” will be referred to as material α. Examples of the material α are aluminum (Al), copper (Cu), nickel (Ni) or silicon (Si) alone, or any alloy thereof.

In this embodiment, the underlying member 16 having the oxide film 16a as the oxidized region will be described. The oxide film 16a is a film formed by oxidizing the material α. In this case, the base member 16 can have a main body portion 16b made of material α and an oxide film 16a covering the main body portion 16b. In this case, the surface of the oxide film 16 a (the surface on the lens 8 side) is also the surface 161 of the base member 16 .

The underlying member 16 is a thin film. The thickness t1 of the underlying member 16 is, for example, 50 nm or less. Typically, the thickness t1 is 20 nm or more.

The base member 16 can be formed, for example, by vapor deposition (eg, electron beam vapor deposition). Specifically, a thin film of the material α is formed on the substrate 14 by vapor deposition in a vacuum apparatus. The surface of the thin film is oxidized by taking out the vapor-deposited substrate 14 from the vacuum apparatus, UV ozone treatment, baking in an oxygen-containing atmosphere, or leaving it in the air for a certain period of time. Thereby, an oxide film 16a is formed on the surface of the thin film, and as a result, the underlying member 16 is obtained.

Lens 8 is optically coupled with LD 10 . The lens 8 converts the laser light L from the LD 10 into, for example, convergent light, divergent light, or parallel light. In this embodiment, the material of the lens 8 includes glass and resin. The lens 8 can be formed, for example, by molding the material of the lens 8 (glass or resin).

The adhesive layer 12 is a layer formed of an adhesive that bonds the lens 8 and the base member 16 together. Examples of adhesives are resin-based adhesives. Examples of resin adhesives are epoxy adhesives or acrylic adhesives. The adhesive may be an energy ray curable resin adhesive (eg, an ultraviolet (UV) curable resin adhesive). With an energy ray curing adhesive, the lens 8 can be bonded to the base 6 by curing the adhesive after adjusting the position of the lens 8 with respect to the LD 10, for example. An example thickness of the adhesive layer 12 is 20 μm to 80 μm, for example 50 μm.

[LD]
The LD 10 outputs laser light L. The LD 10 may be of chip type, CAN type or surface mount package type. The wavelength band of the laser light L may be any one according to the application of the optical device 4 . For example, the wavelength band of the laser light L is red wavelength band, green wavelength band or blue wavelength band. In this embodiment, the LD 10 is arranged so that its optical axis and the optical axis of the lens 8 are aligned.

The LD 10 is mounted on the substrate 14 via the support base 30 and intermediate plate 32 . Specifically, the LD 10 is fixed to the intermediate plate 32 by, for example, a conductive adhesive. An example of a conductive adhesive is silver (Ag) paste or solder (the same applies hereinafter). The thickness of the support table 30 and the intermediate plate 32 may be such that the optical axis of the LD 10 with respect to the surface 14a of the substrate 14 has a desired height. In this embodiment, for example, the support base 30 and the intermediate plate 32 have thicknesses that allow the optical axis of the lens 8 and the optical axis of the LD 10 to coincide.

The material of the support base 30 is the same as that of the substrate 14, for example. The support base 30 is fixed to the substrate 14 by, for example, a conductive adhesive. As shown in FIG. 1, when the underlying member 16 is formed on the entire surface 14a of the substrate 14, the supporting base 30 may be fixed to the underlying member 16. As shown in FIG.

An example of the material of the intermediate plate 32 is a material having a coefficient of thermal expansion close to that of the semiconductor material of the LD 10 (eg, AlN, silicon carbide (SiC), silicon (Si), diamond, etc.). The material of the intermediate plate 32 may be the same as the material of the support base 30 . The intermediate plate 32 is fixed to the support base 30 by, for example, a conductive adhesive.

The optical device 4 may not have the intermediate plate 32 . In this case, the LD 10 is fixed to the support base 30 . Support 30 may be part of substrate 14 . In this case, the base member 16 may be formed on the surface of the support base 30 . The material of the support base 30 may be the material exemplified in the description of the intermediate plate 32 .

In the optical device 4 , when the LD 10 outputs the laser light L, the laser light L enters the lens 8 . The laser light L incident on the lens 8 is output from the lens 8 as convergent light, parallel light, or diffused light depending on the function of the lens 8 .

In the joint structure 2A of the optical device 4, the base member 16 has an oxide film (oxidized region) 16a on the lens 8 side, and the lens 8 is attached to the oxide film 16a of the base member 16 via the adhesive layer 12. Glued. The lens 8 is thereby joined to the base portion 6 . In the joint structure 2A, the oxide film 16a and the adhesive layer 12 are in contact with each other. Therefore, the bonding strength between the base member 16 and the adhesive layer 12 is increased. On the other hand, since the lens 8 is made of glass or resin, the bonding strength between the lens 8 and the adhesive layer 12 is also high.

In such a joint structure 2A, when the joint structure 2A is subjected to a destructive test, cohesive failure rather than interfacial failure tends to occur. For example, when a load is applied to a joint structure in which a first member and a second member are adhered with an adhesive, and the joint between the first and second members breaks, the variation in the load is considered to be in the direction of cohesive failure. is smaller than interfacial failure. Therefore, the bonding structure 2A can achieve high bonding reliability (or bonding stability), and as a result, the reliability of the optical device 4 is improved. Furthermore, in the optical device 4 having an optical component such as the lens 8, maintaining the proper spatial arrangement of the optical component (the lens 8 in this embodiment) with respect to the LD 10 is important for maintaining the performance of the optical system. However, in the joint structure 2A, the reliability is improved as described above, so that the performance of the optical system can be easily maintained even under various environments.

In cohesive failure, the variation in the load is smaller than in interfacial failure, so the minimum load required to break the bond between the lens 8 and the base portion 6 by the adhesive layer 12 is larger than in the interfacial failure. Therefore, in the joint structure 2A, the bonding strength is high and the destruction itself is less likely to occur.

In cohesive failure, failure occurs inside the adhesive layer 12 . Therefore, the adhesive strength between the lens 8 and the base portion 6 can be adjusted by the properties of the adhesive that forms the adhesive layer 12 . Therefore, in the joint structure 2A, it is easy to achieve high bonding reliability.

When the material α of the base member 16 is aluminum, copper, nickel, silicon, or an alloy of aluminum, copper, nickel, and silicon, the material cost of the base member 16 having the oxide film 16a is reduced. can. As a result, the manufacturing cost of the junction structure 2A and the optical device 4 including it can be reduced. In particular, aluminum or silicon easily forms a dense oxide film at low cost. If the material α is aluminum, copper, nickel or silicon, or any alloy, their oxide films are likely to achieve strong bonding with the adhesive layer 12 . If the material α is a metal that forms a passive film as the oxide film 16a (for example, aluminum, aluminum alloy, etc.), stronger bonding between the base member 16 and the adhesive layer 12 can be easily achieved.

If the junction structure 2A or the optical device 4 has an electronic cooling module 18, the temperature of the LD 10 can be adjusted. Therefore, by driving the LD 10, even if the LD 10 generates heat, the LD 10 can stably output the laser light L in the desired wavelength band. The temperature of the joint structure 2A can also be adjusted by the electronic cooling module 18 . Therefore, even if the LD 10 generates heat or the ambient temperature rises, the temperature of the junction structure 2A (specifically, the substrate 14 and the structure on the substrate 14) can be adjusted to a desired temperature. As a result, thermal stress or the like generated in the adhesive layer 12 can be reduced, so that the adhesive layer 12 is less likely to break.

When the material of the substrate 14 is ceramic (eg, AlN with a linear expansion coefficient of 5 ppm/K), the substrate 14 is the first ceramic plate 20 (eg, linear expansion coefficient) of the electronic cooling module 18 as shown in FIG. plate made of alumina with a modulus of 7 ppm/K). This is for the following reasons.

That is, when the material of the substrate 14 is ceramic, the difference in coefficient of linear expansion between the substrate 14 and the first ceramic plate 20 is small. Therefore, even if the temperature of the surrounding environment of the joint structure 2A rises or the temperature of the joint structure 2A rises due to the driving of the optical device 4, the thermal stress generated in the substrate 14 or the first ceramic plate 20 is small, and the substrate 14, The first ceramic plate 20 or the adhesive layer 12 is less likely to break.

If the base member 16 is a thin film having a thickness t1 of 50 nm or less, for example, the thermal stress caused by the difference in linear expansion coefficient between the substrate 14 and the base member 16 tends to be small. As a result, warping of the substrate 14 can be reduced. In the form in which the base member 16 is formed over the entire surface 14a, for example, when the base member 16 is formed by a vapor deposition method, the processing cost of the vapor deposition process can be reduced. When the base member 16 is provided on the entire surface 14a, the base member 16 can be formed by a method other than vapor deposition (for example, plating method). Therefore, options for forming the base member 16 are increased.

Next, various modifications of the junction structure 2A and the optical device 4 will be described. Modified examples of the joint structure 2A described below have the same effects as those of the joint structure 2A unless otherwise specified. A modification is applicable to the optical device 4 instead of the junction structure 2A. An optical device obtained by applying the modification to the optical device 4 also has the same effects as the optical device 4 unless otherwise specified. In various modifications, the base member may be entirely an oxidized region, but will be described as having an oxide film as the oxidized region.

(Modification 1)
The joint structure according to the present disclosure may be the joint structure 2B shown in FIG. The junction structure 2B is mainly different in that an underlying film 34 is provided between the underlying member 16 and the substrate 14 . The junction structure 2B will be described with a focus on this difference.

The underlying film 34 is a film containing titanium or nickel. Examples of the underlying film 34 are a titanium film or a nickel film. The thickness of the base film 34 is, for example, 30 nm or less, and usually 5 nm or more. The base film 34 is formed, for example, by vapor deposition in the same manner as the base member 16 . By providing the base member 16 on the substrate 14 with the base film 34 interposed therebetween, the base member 16 and the substrate 14 are bonded more firmly. As a result, the reliability of the bonding portion between the base member 16 and the substrate 14 is also improved, and as a result, the reliability of the bonding structure 2A is improved. The base film 34 may be a part of the base member 16 (a film provided on the base member 16 on the substrate 14 side) or a part of the substrate 14 .

The underlying member 16 is a thin film also in Modification 1, and the example of the thickness of the underlying member 16 is the same as in the case of the joint structure 2A. The base member 16 may be substantially provided only in the mounting area A, as shown in FIG. In this case, the material cost of the underlying member 16 can be reduced by providing it over the entire surface 14a.

(Modification 2)
The bonding structure according to the present disclosure may be the bonding structure 2C shown in FIG. , is different from the joint structure 2A. The junction structure 2C will be described with a focus on this difference.

The material and thickness of liner member 36 may be the same as liner member 16 . Therefore, an oxide film (oxidized region) is formed on the surface 361 of the base member 36 . When viewed from the thickness direction of the substrate 14 , the underlying member 36 can be formed at a position overlapping the underlying member 16 . When the base member 16 is formed over the entire surface 14a, the base member 36 may be formed over the entire back surface 14b. As shown in FIG. 3, the size of the base member 16 may be slightly smaller than the back surface 14b. In the bonding structure 2C, the structures of the front surface 14a and the rear surface 14b of the substrate 14 are substantially the same, so the base portion 6 is less likely to warp even if thermal stress occurs in the substrate 14. FIG.

(Modification 3)
The joint structure according to the present disclosure may be the joint structure 2D shown in FIG. The joint structure 2D is different from the joint structure 2A in that a base member 38 is provided instead of the base member 16 . The junction structure 2D will be described with a focus on this difference. In FIG. 4 , a part of the base member 38 is cut out in order to explain the base member 38 .

The base member 38 is a block body. The base member 38 may be selectively provided on the mounting area A rather than on the entire surface 14a, for example. Examples of materials for the base member 38 are the same as those for the base member 16 . An oxide film 38 a is formed on the surface 381 of the base member 38 . Therefore, the base member 38 has a main body portion 38b made of the material α and an oxide film 38a. In this case, the surface of the oxide film 38 a (the surface on the lens 8 side) is also the surface 381 of the base member 38 . Examples of the shape of the underlying member 38 include rectangular parallelepipeds and cylinders. The thickness t2 of the base member 38 is 100 μm or more and 500 μm or less. The upper limit of the thickness t2 can be set, for example, according to the height of the optical axis of the lens 8 with respect to the surface 14a. Base member 36 is secured to substrate 14 by, for example, adhesive layer 40 . An example of the adhesive that forms the adhesive layer 40 is a high heat dissipation adhesive.

When the base member 38 is a block body, the base is easier to form than when a thin-film base member is formed by vapor deposition, plating, or the like. When the thickness t2 is 100 μm or more and 500 μm or less, the base member 38 is easy to handle. If the base member 38 is a rectangular parallelepiped, the processing cost can be reduced. When the base member 38 is a cylinder, even when the temperature of the joint structure 2D rises, uniform thermal stress is likely to occur in the adhesive layer 12, so deformation of the adhesive layer 12 can be suppressed. Therefore, the adhesive layer 12 itself is less likely to be destroyed, improving the reliability of the joint structure 2D.

Next, an experimental example will be described. For convenience of explanation, the same reference numerals are given to the elements corresponding to the elements of the embodiments and modifications described so far. The present disclosure is not limited to the experimental examples described below. In the experimental example, four substrates 14 were prepared. The material of substrate 14 was AlN.

On two of the four substrates 14, as shown in FIG. 5, the base film 34 and the base member 16 were laminated to obtain two samples S1 as base samples. The material of the underlying film 34 was titanium, and the underlying film 34 was a titanium film. The thickness of the underlying film 34 was approximately 50 nm. The material of the base member 16 was Al. The thickness of the underlying member 16 was approximately 100 nm. Each sample S1 was manufactured by sequentially forming the base film 34 and the base member 16 on the substrate 14 by electron beam vapor deposition.

The remaining two substrates 14 themselves among the four substrates 14 were used as sample S2 (see FIG. 5) of the base portion. That is, each sample S2 was an AlN substrate.

A shear strength test was performed using each of sample S1 and sample S2. The test method was the same except that samples S1 and S2 were utilized. Therefore, the sample S1 and the sample S2 will be referred to as sample S, and the test method will be described with reference to FIG.

Sample S was subjected to UV ozone cleaning treatment. After that, a metal washer 42 was placed on the sample S as shown in FIG. The height T of the metal washer 42 was 0.2 mm. The inner diameter φ of the metal washer 42 was 1.05 mm. Next, after filling the inside of the metal washer 42 with an ultraviolet curable resin, the ultraviolet curable resin was irradiated with ultraviolet rays to obtain a cured product 44 . A cured product 44 is an experimental model of the adhesive layer 12 . The UV curable resin used was an epoxy UV curable resin.

After that, a load was applied to the metal washer 42 along the direction parallel to the surface of the sample S (along the direction perpendicular to the axis of the metal washer 42). A force gauge (ZTS-50N) manufactured by Imada Co., Ltd. was used to apply the load. While increasing the load, the load at which the cured product 44 was broken and the cured product 44 was separated from the sample S was obtained. Further, an image of the surface state (peeling mode) of the sample S of the peeling trace of the cured product 44 was acquired.

Two samples S1 and two samples S2 were used as samples S in the shear test. Table 1 shows the load at which the cured product 44 was peeled from the sample S obtained from the test results. In Table 1, No. 1 and no. 2 is a number for distinguishing shear tests using two samples S1 (or two samples S2).

（ただし、１ｋｇｆ＝９．８Ｎ）

(However, 1 kgf = 9.8 N)

From the results in Table 1, the adhesive strength between the base and the cured product 44 (corresponding to the adhesive layer 12) is improved when the sample S1 is used as the base compared to when the sample S2 is used as the base. It can be understood that

After the shear test, adhesion marks on the surfaces of samples S1 and S2 were observed at a magnification of 150 using a digital microscope (Keyence Corporation VHX-6000). Images of sample S1 and sample S2 taken are shown in FIGS. 7 and 8. FIG. The inner side of the annular portion 46 in FIGS. 7 and 8 is the area where the cured product 44 was present. When sample S1 was used, a large amount of cured product 44 remained on the surface, while when sample S2 was used, almost no cured product 44 remained on the surface. That is, regarding the failure mode during the shear test, cohesive failure was dominant when sample S1 was used, while interfacial failure was dominant when sample S2 was used.

Sample S1 has base member 16 . As described in the above test method, before the metal washer 42 is placed on the sample S to form the cured product 44, the sample S is subjected to UV ozone treatment, so that the surface of the base member 16 of the sample S1 had an oxide film. Therefore, from the difference in the test results when using the sample S1 and the sample S2, when the base member 16 including the oxidized material α (Al in this experimental example) is included in the base member, the adhesive layer 12 and the base interface It was found that the cohesive failure rate improved due to the improvement in the adhesive strength of Cohesive failure is more reliable than interfacial failure. Therefore, in a configuration in which the base has a base member 16 containing a material to be oxidized α (Al in this experimental example), high adhesion reliability between the base and the adhesive layer can be obtained. realizable.

Various embodiments and modifications of the present disclosure have been described above. However, the present invention is not limited to the above embodiments, and various modifications are possible without changing the gist of the present disclosure.

The base member may also be provided between the optical component and the adhesive (adhesive layer 12 in FIG. 1). In this case, the degree of freedom in selecting the adhesive is increased. The configuration in which the base member is arranged on the optical component side is effective, for example, when the material of the adhesive side surface of the optical component is other than glass and resin.

The underlying member in the present disclosure may be an oxidized region that is entirely oxidized. Even in this case, since the oxidized region is in contact with the adhesive, the effects described in the various embodiments and modifications of the present disclosure can be achieved. Whether the base member has an oxidized region in part (for example, when it has an oxide film) or whether the entire region is an oxidized region depends on, for example, a thin film, a block body, or the like formed of the material of the base member. The conditions of the oxidation treatment to be performed (for example, UV ozone treatment, baking treatment in an oxygen-containing atmosphere, leaving in the air for a certain period of time, etc.) can be adjusted.

The junction structure may comprise multiple optical components. In this case, a base member may be interposed between each optical component and the substrate. The optical component may be a filter (eg, wavelength selective filter). A filter is an optical component in which a dielectric film (or dielectric multilayer film) having a predetermined function is formed on a substrate made of, for example, glass or resin.

The optical device may comprise multiple LDs arranged on a pedestal. A plurality of LDs may output light in different wavelength bands. For example, the optical device may include a red LD that outputs laser light in the red wavelength band, a green LD that outputs laser light in the green wavelength band, and a blue LD that outputs laser light in the blue wavelength band. Thus, if the optical device comprises multiple LDs, the optical device may comprise multiple lenses. In the form in which the optical device has a plurality of lenses, each of the plurality of lenses corresponds to an optical component of the cemented structure.

When the optical device includes a plurality of LDs and a plurality of lenses, the optical device may further include a multiplexing optical system that is provided on the base and multiplexes the multiple laser beams from the multiple LDs. In this case, the plurality of lenses and the plurality of LDs correspond one-to-one, and the combining optical system combines the plurality of laser beams that have passed through the plurality of lenses. Each of the plurality of lenses may have a function of converting laser light from the corresponding LD into parallel light. The combining optics may, for example, have multiple wavelength selective filters. Thus, in a form in which the optical device has a plurality of lenses and a plurality of wavelength selective filters, the plurality of lenses and the plurality of wavelength selective filters respectively correspond to the optical components of the cemented structure. In a multiplexing optical system using adhesive bonding, for example, it is important to maintain the arrangement relationship between an LD, a lens, etc. and the multiplexing optical system. It is easy to maintain the multiplexing performance even in the environment.

An optical device has a cover to protect the structure (LD, optical parts, etc.) on the substrate from moisture, dust, etc. in the outside air, and to protect the bonding structure from moisture and to easily maintain the reliability of bonding. good too. The cover may be hermetically sealed to the substrate, such as by welding, to reduce the rate of moisture intrusion. In the form in which the optical device has a cover in this way, the cover has a window through which the laser light output from the LD is output to the outside of the cover. The optical device may have a support member that supports the substrate or the temperature control element on which the substrate is arranged. In this case, the cover may be welded to the support member and the arrangement on the support member hermetically sealed.

The optical device may have other light-emitting elements instead of the LD, which is a semiconductor laser element.

The various embodiments and modifications described so far may be appropriately combined without departing from the scope of the present disclosure.

2A to 2D... Joining structure 4... Optical device 6... Base part 8... Lens (optical component)
10... Laser diode 12... Adhesive layer (adhesive)
DESCRIPTION OF SYMBOLS 14... Substrate 14a... Front surface 14b... Back surface 16... Underlying member 16a... Oxide film (oxidized region)
16b...Main body part 18...Electronic cooling module (temperature control element)
20... First ceramic plate 22... Second ceramic plate 24... N-type semiconductor column 26... P-type semiconductor column 28... Electrode 30... Support base 32... Intermediate plate 34... Base films 36, 38... Base member 38a... Oxide film ( oxidation area)
38b Body portion 40 Adhesive layer 42 Metal washer 44 Cured material 46 Annular portions 161, 361, 381 Surface of base member opposite to substrate A Mounting area L Laser beam t1 Thickness ( thickness of base material)
t2 ... thickness (thickness of base member)
S, S1, S2...Sample T...Height of metal washer φ...Inner diameter of metal washer

Claims (12)

base and
an optical component bonded to the base;
with
The platform is
a substrate;
a base member provided on the substrate;
has
The base member has an oxidized region at least on the surface opposite to the substrate,
the optical component is adhered to the oxidized region with an adhesive;
The base member is a block body,
The thickness of the block is 100 μm or more and 500 μm or less.
junction structure. base and
an optical component bonded to the base;
with
The platform is
a substrate;
a base member provided on the entire surface of the substrate;
has
The base member has an oxidized region on the entire surface opposite to the substrate,
the optical component is adhered to the oxidized region with an adhesive;
The base member has a thickness of 50 nm or less.
junction structure. base and
an optical component bonded to the base;
with
The platform is
a substrate;
a base member provided on the entire surface of the substrate;
has
The base member has an oxidized region on the entire surface opposite to the substrate,
the optical component is adhered to the oxidized region with an adhesive;
The substrate is arranged on a temperature control element that adjusts temperature,
The material of the substrate is ceramic or metal,
junction structure. base and
an optical component bonded to the base;
with
The platform is
a substrate;
a base member provided on the entire surface of the substrate;
a back surface side base member provided on the entire back surface of the substrate;
has
The base member has an oxidized region at least on the surface opposite to the substrate,
the optical component is adhered to the oxidized region with an adhesive;
The material and thickness of the back side base member are the same as those of the base member,
The base member has a thickness of 50 nm or less.
junction structure. base and
an optical component bonded to the base;
with
The platform is
a substrate;
a base member provided on the entire surface of the substrate;
a back surface side base member provided on the entire back surface of the substrate;
has
The base member has an oxidized region at least on the surface opposite to the substrate,
the optical component is adhered to the oxidized region with an adhesive;
The material and thickness of the back side base member are the same as those of the base member,
The substrate is arranged on a temperature control element that adjusts temperature,
The material of the substrate is ceramic or metal,
junction structure. The shape of the base member is a rectangular parallelepiped or a cylinder,
The joining structure according to claim 1. The base member has a thickness of 50 nm or less.
The joining structure according to claim 3 or 5 . wherein the base member and the substrate are bonded via a base film containing titanium or nickel;
The joining structure according to any one of claims 2, 4 and 7 . the base member includes a material to be oxidized,
the material is aluminum, copper, nickel or silicon, or an alloy of any of aluminum, copper, nickel and silicon;
The joining structure according to any one of claims 1 to 8 . The substrate is placed on a temperature control element that adjusts temperature,
The joining structure according to any one of claims 1, 2, 4 and 6 . The material of the substrate is ceramic or metal ,
having
The joining structure according to claim 10 . Equipped with the joint structure according to any one of claims 1 to 11 ,
optical device.

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