JP2020198353A - Junction structure and optical device - Google Patents

Abstract

To provide a junction structure and optical device including the same, capable of high adhesion reliability.SOLUTION: A junction structure 2A includes a base part 6 and an optical component 8 joined to the base part. The base part includes a substrate 14 and a base component 16 provided on the substrate. The base component includes an oxidation region on at least a surface 161 on the opposite side to the substrate, and the optical component is bonded to the oxidation region with adhesive agent 12.SELECTED DRAWING: Figure 1

Description

The present invention relates to junction structures and optical devices.

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

JP 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 components such as a lens and a filter are fixed to the substrate by an adhesive (for example, an ultraviolet curable resin adhesive). The bond between the optical component and the adhesive is relatively strong. On the other hand, the surface of the substrate may be gold-plated. When the surface of the substrate is gold-plated in this way, 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 (board) and the optical component, the interface between the adhesive and the base is likely to be broken. Therefore, the adhesive reliability of the bonded structure is lowered.

Therefore, an object of the present invention is to provide a bonding structure capable of achieving high adhesive reliability and an optical device including the bonding structure.

The joining structure according to one embodiment of the present invention includes a base portion and an optical component joined to the base portion. The base portion has a substrate and a base member provided on the substrate. The base member has an oxidation region at least on the surface opposite to the substrate. The optical component is adhered to the oxidized region with an adhesive.

According to the present invention, it is possible to provide a bonding structure capable of achieving high adhesive reliability and an optical device including the bonding structure.

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

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

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

In the bonding structure, the optical component is bonded to the base portion by being bonded to the oxidation region with an adhesive. The adhesive is in contact with the oxidized region of the underlying member. Therefore, the bonding between the adhesive and the base member is stable. As a result, high adhesive reliability can be realized in the bonded structure.

The base member may contain a material to be oxidized. Examples of the material include aluminum, copper, nickel or silicon, or an alloy of aluminum, copper, nickel and silicon. These oxidized regions tend to provide strong bonding. In particular, aluminum or silicon tends to form a dense oxidized region at low cost.

The substrate may be arranged on a temperature control element that regulates temperature. In this case, the temperature of the substrate and the configuration on the substrate can be adjusted even if the ambient temperature of the bonded structure rises, for example. As a result, the thermal stress generated in the base member, the adhesive, etc. can be reduced, so that the joint structure is not easily broken. Therefore, the bonded structure can easily realize high adhesive reliability.

An example of the substrate material is ceramic. The portion of the temperature control element in contact with the substrate is usually ceramic. Therefore, if the material of the substrate is ceramic, the difference in linear expansion coefficient between the temperature control element and the portion of the substrate in contact with each other is small. As a result, for example, even if the ambient temperature of the bonded structure rises, the substrate, the temperature control element, and the bonding thereof are unlikely to be destroyed.

The thickness of the base member may be 50 nm or less. When the thickness of the base member is thin as described above, the thermal stress caused by the difference in the coefficient of linear expansion between the substrate and the base member is reduced, and for example, the warp of the substrate can be reduced.

The base member and the substrate may be joined via a base film containing titanium or nickel. In this case, the bond between the base member and the substrate becomes strong.

The base member may be provided on the entire surface of the substrate. In this configuration, for example, when the base member is formed by a vapor deposition method, 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 the vapor deposition method (for example, a plating method). Therefore, the options for forming the base member are expanded.

The base member is 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 the processing cost. If the thickness is within the above range, the base member can be easily handled.

An example of the shape of the base member is a rectangular parallelepiped or a cylinder. When the shape of the base member is a rectangular parallelepiped, the processing cost for preparing the base member can be reduced. When the shape of the base member is a cylinder, the uniformity of the thermal stress generated in the adhesive is improved, so that the deformation of the adhesive can be prevented.

The optical device according to the other aspect of the present disclosure includes the above-mentioned junction structure. As described above, the above-mentioned bonding structure can realize high adhesive reliability. Therefore, an optical device having the above-mentioned bonding structure can also realize high adhesive reliability, and as a result, the reliability of the optical device is improved.

[Details of Embodiments of the present disclosure]
Specific examples of the 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 claims and is intended to include all modifications within the meaning and scope equivalent to the scope of claims. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted. In the explanation, the words indicating the directions such as "up" and "down" are convenient words based on the state shown in the drawing. The dimensional ratios in the drawings do not always match those described.

The optical device 4 shown in FIG. 1 includes a junction 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 an in-vehicle device mounted on, for example, a vehicle.

[Joint structure]
The bonding structure 2A has a base portion 6 and a lens 8, and the base portion 6 and the lens 8 are bonded with an adhesive. Therefore, the bonding structure 2A has an adhesive layer 12 formed of the above-mentioned adhesive between the base portion 6 and the lens 8. The base portion 6 includes a substrate 14 and a base member 16.

<Board>
The substrate 14 is a member that supports the lens 8 and the LD 10. An example of the material of the substrate 14 is ceramic or metal. Examples of the above 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 the substrate 14 is selected from materials different from the base member 16. An example of the thickness of the substrate 14 is 0.6 mm.

<Electronic cooling module (temperature control element)>
The substrate 14 may be provided on the electronic cooling module 18 which is a temperature control element for adjusting the temperature. The electronic cooling module 18 may be a part of the base 6. As shown in FIG. 1, the electronic cooling module 18 has a first ceramic plate 20, a second ceramic plate 22, and a plurality of n-type semiconductor columns 24 and p-type semiconductor columns 26. 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. The 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 column 24 and the p-type semiconductor column 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, for example, silver (Ag) paste.

<Base member>
The base member 16 is provided on the surface 14a of the substrate 14 in the mounting area A on which the lens 8 is mounted. 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 the purpose of explaining the base member 16.

The base member 16 has an oxidation region on the surface 161 at least on the side opposite to the substrate 14 (lens 8 side). The base member 16 may have an oxide film (oxidation region) on the lens 8 side, or the entire base member 16 may have an oxidation region. The base member 16 contains a material that is oxidized in air. Hereinafter, for convenience of explanation, the "material to be oxidized" will be referred to as a material α. An example of the material α is a simple substance of aluminum (Al), copper (Cu), nickel (Ni) or silicon (Si), or an alloy thereof.

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

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

The base member 16 can be formed, for example, by vapor deposition (for example, electron beam 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, treating it with UV ozone, baking it in an oxygen-containing atmosphere, or leaving it in the air for a certain period of time. As a result, an oxide film 16a is formed on the surface of the thin film, and as a result, the base member 16 is obtained.

The lens 8 is optically coupled to the LD 10. The lens 8 converts the laser beam L from the LD 10 into, for example, convergent light, divergent light, parallel light, or the like. 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 (glass or resin) of the lens 8.

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

[LD]
The LD10 outputs the laser beam L. The LD10 may be a chip type, a CAN type, or a surface mount package type. The wavelength band of the laser beam L may be any one suitable for the application of the optical device 4. For example, the wavelength band of the laser beam L is a red wavelength band, a green wavelength band, or a blue wavelength band. In the present embodiment, the LD 10 is arranged so that its optical axis and the optical axis of the lens 8 coincide with each other.

The LD 10 is mounted on the substrate 14 via the support base 30 and the intermediate plate 32. Specifically, the LD 10 is fixed to the intermediate plate 32 with, for example, a conductive adhesive. Examples of conductive adhesives are silver (Ag) pastes or solders (the same applies hereinafter). The thickness of the support base 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 the present embodiment, for example, the support base 30 and the intermediate plate 32 have a thickness in which the optical axis of the lens 8 and the optical axis of the LD 10 coincide with each other.

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 with, for example, a conductive adhesive. As shown in FIG. 1, when the base member 16 is formed on the entire surface 14a of the substrate 14, the support base 30 may be fixed to the base member 16.

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 LD10 (for example, AlN, silicon carbide (SiC), silicon (Si), diamond, etc.). The material of the intermediate plate 32 may be the same as that of the support base 30. The intermediate plate 32 is fixed to the support base 30 with, for example, a conductive adhesive.

The optical device 4 does not have to have the intermediate plate 32. In this case, the LD 10 is fixed to the support base 30. The support base 30 may be a part of the 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 is incident on the lens 8. The laser beam 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 bonding structure 2A of the optical device 4, the base member 16 has an oxide film (oxidation region) 16a on the lens 8 side, and the lens 8 is formed on the oxide film 16a of the base member 16 via the adhesive layer 12. It is glued. As a result, the lens 8 is joined to the base portion 6. In the bonding 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 material of the lens 8 is 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 fracture test of the joint structure 2A is performed, it tends to be agglomerated fracture rather than interfacial fracture. For example, when a load is applied to a joint structure in which a first member and a second member are bonded with an adhesive and the joint between the first and second members breaks, the variation in the load is the cohesive failure. Is smaller than the interface fracture. Therefore, in the bonding structure 2A, high adhesive reliability (or adhesive stability) can be realized, and as a result, the reliability of the optical device 4 is improved. Further, in the optical device 4 having an optical component such as the lens 8, it is important to maintain an appropriate spatial arrangement of the optical component (lens 8 in this embodiment) with respect to the LD 10 in order to maintain the performance of the optical system. However, in the junction structure 2A, since the reliability is improved as described above, it is easy to maintain the performance of the optical system even under various environments.

In the cohesive fracture, the variation in the load is smaller than that in the interfacial fracture, so that the minimum load when the joint between the lens 8 and the base portion 6 by the adhesive layer 12 is broken is larger than that in the interfacial fracture. Therefore, in the joint structure 2A, the adhesive strength is high and the fracture itself is unlikely to occur.

In cohesive fracture, fracture occurs inside the adhesive layer 12. Therefore, the adhesive strength between the lens 8 and the base portion 6 can be adjusted by the characteristics of the adhesive forming the adhesive layer 12. Therefore, in the joint structure 2A, high adhesive reliability can be easily realized.

When the material α contained in the base member 16 is an alloy of aluminum, copper, nickel or 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. it can. As a result, the manufacturing cost of the bonding structure 2A and the optical device 4 including the bonding structure 2A can be reduced. In particular, aluminum or silicon tends to form a dense oxide film at low cost. When the material α is aluminum, copper, nickel or silicon, or an alloy of any of them, the oxide film thereof easily realizes a strong bond with the adhesive layer 12. When the material α is a metal that forms a passivation film as the oxide film 16a (for example, aluminum, aluminum alloy, etc.), it is easy to realize a stronger bond between the base member 16 and the adhesive layer 12.

When the junction structure 2A or the optical device 4 includes the electronic cooling module 18, the temperature of the LD 10 can be adjusted. Therefore, by driving the LD10, even if the LD10 generates heat, the laser beam L in a desired wavelength band can be stably output from the LD10. The temperature of the junction 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 bonding structure 2A (specifically, the substrate 14 and the configuration on the substrate 14) can be adjusted to a desired temperature. As a result, the thermal stress generated in the adhesive layer 12 can be reduced, so that the adhesive layer 12 is less likely to be broken.

When the material of the substrate 14 is ceramic (for example, AlN having a coefficient of linear expansion of 5 ppm / K), the substrate 14 is the first ceramic plate 20 (for example, linear expansion) of the electronic cooling module 18 as shown in FIG. It is advantageous when it is arranged on a plate) made of alumina having a coefficient of 7 ppm / K. This is due to the following reasons.

That is, when the material of the substrate 14 is ceramic, the difference in the coefficient of linear expansion of the substrate 14 from that of the first ceramic plate 20 is small. Therefore, even if the temperature of the ambient environment of the bonding structure 2A rises or the temperature of the bonding 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 not easily destroyed.

When the base member 16 is, for example, a thin film having a thickness t1 of 50 nm or less, the thermal stress due to the difference in linear expansion coefficient between the substrate 14 and the base member 16 tends to be small. As a result, the warp of the substrate 14 can be reduced. In the form in which the base member 16 is formed on 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 step 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 the vapor deposition method (for example, a plating method). Therefore, the options for the method of forming the base member 16 are expanded.

Next, various modifications of the bonding structure 2A and the optical device 4 will be described. The modified example of the joint structure 2A described below has the same effect as that of the joint structure 2A unless otherwise specified. The modification is applicable to the optical device 4 instead of the junction structure 2A. The optical device obtained by applying the modified example to the optical device 4 also has the same effect as that of the optical device 4 unless otherwise specified. In various modifications, the base member may be an oxidized region as a whole, but a form having an oxide film as an oxidized region will be described.

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

The base film 34 is a film containing titanium or nickel. An example of the base film 34 is 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 by thin film deposition in the same manner as the base member 16, for example. By providing the base member 16 on the substrate 14 via the base film 34, the base member 16 and the substrate 14 are more firmly bonded to each other. As a result, the reliability of the joint portion between the base member 16 and the substrate 14 is also improved, and as a result, the reliability of the joint structure 2A is improved. The base film 34 may be a part of the base member 16 (a film provided on the substrate 14 side of the base member 16) or a part of the substrate 14.

The base member 16 is also a thin film in the present modification 1, and the example of the thickness of the base member 16 is the same as in the case of the joint structure 2A. As shown in FIG. 2, the base member 16 may be provided substantially only in the mounting area A. In this case, the material cost of the base member 16 can be reduced as compared with the provision on the entire surface 14a.

(Modification 2)
The bonding structure according to the present disclosure may be the bonding structure 2C shown in FIG. 3, in that the bonding structure 2C also has a base member 36 formed on the back surface 14b (the surface opposite to the surface surface 14a) of the substrate 14. , Different from the joint structure 2A. The joint structure 2C will be described with a focus on this difference.

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

(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 case of the joint structure 2A in that the base member 38 is provided instead of the base member 16. The joint structure 2D will be described focusing 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, for example, instead of the entire surface 14a. The example of the material of the base member 38 is the same as that of the base member 16. An oxide film 38a is formed on the surface 381 of the base member 38. Therefore, the base member 38 has a main body portion 38b formed of the material α and an oxide film 38a. In this case, the surface of the oxide film 38a (the surface on the lens 8 side) is also the surface 381 of the base member 38. Examples of the shape of the base member 38 include a rectangular parallelepiped and a cylinder. 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. The base member 36 is fixed to the substrate 14 with, for example, an adhesive layer 40. An example of an adhesive forming the adhesive layer 40 is a highly heat-dissipating adhesive.

When the base member 38 is a block body, it is easier to form the base member than when the base member 38 is formed into a thin film by a vapor deposition method, a plating method, 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. When 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, thermal stress is likely to be uniformly generated in the adhesive layer 12, so that deformation of the adhesive layer 12 can be suppressed. Therefore, the adhesive layer 12 itself is not easily destroyed, and the reliability of the bonded structure 2D is improved.

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 above. The present disclosure is not limited to the experimental examples described below. In the experimental example, four substrates 14 were prepared. The material of the substrate 14 was AlN.

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

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

Shear strength tests were performed using Sample S1 and Sample S2, respectively. The test method was the same except that sample S1 and sample S2 were used. Therefore, the sample S1 and the sample S2 are referred to as a sample S, and the test method will be described with reference to FIG.

Sample S was subjected to UV ozone cleaning treatment. Then, as shown in FIG. 6, a metal washer 42 was placed on the sample S. 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. The cured product 44 is an experimental model of the adhesive layer 12. The UV curable resin used was an epoxy-based UV curable resin.

Then, a load was applied to the metal washer 42 along the direction parallel to the surface of the sample S (along the direction orthogonal to the axis of the metal washer 42). The load was applied by a force gauge (ZTS-50N) manufactured by Imada Co., Ltd. While increasing the load, the load when the cured product 44 was destroyed and the cured product 44 was peeled from the sample S was obtained. In addition, an image of the surface state (peeling mode) of the sample S of the peeling mark of the cured product 44 was acquired.

The above shear test was performed using each of the two samples S1 and each of the two samples S2 as a sample S. Table 1 shows the load when the cured product 44 obtained from the test results was peeled from the sample S. In Table 1, No. 1 and No. 2 is a number for distinguishing shear tests using two samples S1 (or two samples S2).

(However, 1kgf = 9.8N)

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 than when the sample S2 is used as the base. It can be understood that there is.

After the shear test, the adhesion marks on the surfaces of the samples S1 and S2 were observed at a magnification of 150 times using a digital microscope (KEYENCE VHX-6000 Co., Ltd.). The images of the captured samples S1 and S2 are shown in FIGS. 7 and 8. The inside of the annular portion 46 in FIGS. 7 and 8 is the region where the cured product 44 was present. When sample S1 was used, a large amount of cured product 44 remained on the surface, whereas when sample S2 was used, almost no cured product 44 remained on the surface. That is, regarding the fracture mode during the shear test, cohesive fracture was dominant when sample S1 was used, while interfacial fracture was dominant when sample S2 was used.

Sample S1 has a base member 16. As described in the above test method, before the metal washer 42 is arranged 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 is subjected to UV ozone treatment. An oxide film was formed. Therefore, based on the difference in the test results when the sample S1 and the sample S2 are used, when the base member 16 including the material α to be oxidized (Al in this experimental example) is provided in the base portion, the adhesive layer 12 and the base portion interface It was found that the cohesive fracture rate was improved by improving the adhesive strength of the aluminum. Since cohesive fracture is more reliable than interfacial fracture, in the form where the base member 16 contains the material α (Al in this experimental example) to be oxidized, the base portion and the adhesive layer have high adhesion reliability. realizable.

The various embodiments and modifications of the present disclosure have been described above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made 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 form of arranging the base member on the optical component side is effective, for example, when the material of the surface of the optical component on the adhesive side is other than glass and resin.

The base member in the present disclosure may be an oxidized region in which the entire base member is 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 are exhibited. Whether the base member has an oxide region in a part thereof (for example, when it has an oxide film) or the whole base member has an oxide region is determined, for example, with respect to a thin film, a block body, etc. formed of the material of the base member. It can be adjusted by the conditions of the oxidation treatment to be carried out (for example, UV ozone treatment, baking treatment in an oxygen-containing atmosphere, leaving in the air for a certain period of time, etc.).

The joint structure may include a plurality of 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 (for example, a wavelength selective filter). The filter is, for example, an optical component in which a dielectric film (or a dielectric multilayer film) having a predetermined function is formed on a substrate made of glass or resin.

The optical device may include a plurality of LDs arranged on the base. The plurality of LDs may output light in different wavelength bands. For example, the optical device may include a red LD that outputs a laser beam in a red wavelength band, a green LD that outputs a laser beam in a green wavelength band, and a blue LD that outputs a laser beam in a blue wavelength band. As described above, when the optical device includes a plurality of LDs, the optical device may include a plurality of 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 junction structure.

When the optical device includes a plurality of LDs and a plurality of lenses, the optical device may further include a combined wave optical system provided on the base and combining a plurality of laser beams from the plurality of LDs. In this case, the plurality of lenses and the plurality of LDs have a one-to-one correspondence, and the combined wave 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 the laser light from the corresponding LD into parallel light. The combined wave optical system may have, for example, a plurality of wavelength selective filters. As described above, in the form in which the optical device has a plurality of lenses and a plurality of wavelength selective filters, each of the plurality of lenses and the plurality of wavelength selective filters corresponds to an optical component having a junction structure. In the combined wave optical system using adhesive bonding, for example, it is important to maintain the arrangement relationship between the LD, lens, etc. and the combined wave optical system. However, since the bonding structure according to the present disclosure is highly reliable, there are various types. It is easy to maintain combined wave performance even in an environment.

The optical device has a cover to protect the configuration (LD, optical components, etc.) on the substrate from moisture, dust, etc. in the outside air, protect the bonding structure from moisture, and easily maintain the reliability of the bonding. May be good. In order to reduce the penetration rate of moisture, the cover may be hermetically sealed to the substrate by welding or the like. In such a form in which the optical device has a cover, the cover has a window portion that outputs the laser beam output from the LD to the outside of the cover. The optical device may have a substrate or a support member that supports the temperature control element on which the substrate is arranged. In this case, the cover may be welded to the support member and the configuration on the support member may be hermetic.

The optical device may include another light emitting element 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 spirit of the present disclosure.

2A to 2D ... Bonding structure 4 ... Optical device 6 ... Base 8 ... Lens (optical component)
10 ... Laser diode 12 ... Adhesive layer (adhesive)
14 ... Substrate 14a ... Front surface 14b ... Back surface 16 ... Base member 16a ... Oxidized film (oxidized region)
16b ... Main body 18 ... Electronic cooling module (temperature control element)
20 ... 1st ceramic plate 22 ... 2nd ceramic plate 24 ... n-type semiconductor pillar 26 ... p-type semiconductor pillar 28 ... Electrode 30 ... Support base 32 ... Intermediate plate 34 ... Base film 36, 38 ... Base member 38a ... Oxidation film ( Oxidation region)
38b ... Main body 40 ... Adhesive layer 42 ... Metal washer 44 ... Hardened material 46 ... Ring portion 161, 361, 381 ... Surface A on the side opposite to the substrate of the base member ... Mounting area L ... Laser light t1 ... Thickness ( Base member thickness)
t2 ... Thickness (thickness of base member)
S, S1, S2 ... Sample T ... Height of metal washer φ ... Inner diameter of metal washer

Claims (10)

With the base
Optical components joined to the base and
With
The base is
With the board
The base member provided on the substrate and
Have,
The base member has an oxidation region at least on the surface opposite to the substrate.
The optical component is adhered to the oxidized region with an adhesive.
Joint structure. The base member contains a material to be oxidized and contains
The material is aluminum, copper, nickel or silicon, or an alloy of any of aluminum, copper, nickel and silicon.
The joining structure according to claim 1. The substrate is arranged on a temperature control element that regulates temperature.
The joining structure according to claim 1 or 2. The material of the substrate is ceramic.
Have,
The joining structure according to claim 3. The thickness of the base member is 50 nm or less.
The joining structure according to any one of claims 1 to 4. The base member and the substrate are joined via a base film containing titanium or nickel.
The joining structure according to claim 5. The base member is provided on the entire surface of the substrate.
The joining structure according to any one of claims 1 to 6. The base member is a block body and
The thickness of the block body is 100 μm or more and 500 μm or less.
The joining structure according to any one of claims 1 to 4. The shape of the base member is a rectangular parallelepiped or a cylinder.
The joining structure according to claim 8. The joining structure according to any one of claims 1 to 9 is provided.
Optical device.