JP2023175214A - Method for producing joined body, joined body, method for producing semiconductor apparatus and semiconductor apparatus - Google Patents

Abstract

To provide a method for producing a joined body in which the joining strength of a boundary between a joining layer and members to be joined is improved.SOLUTION: A method for producing a joined body includes the steps of: forming an oxide film on the joining face of at lest either in two members to be joined; forming a fluorine compound layer on the surface of the oxide film; applying a conductive joining material comprising silver grains and a dispersant on the surface of the fluorine compound layer to form a conductive joining layer; and mounting the other member to be joined on the surface of the conductive joining layer so as to execute heating and compression.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a method for manufacturing a bonded body, a method for manufacturing a bonded body, a semiconductor device, and a semiconductor device.

When bonding heat dissipating members used in semiconductor devices and the like, it is necessary to use a bonding material that has heat dissipating properties. As a bonding material having heat dissipation properties, a conductive bonding material containing an organic substance as a dispersant in silver particles or silver compound particles such as silver oxide is generally known. An example of a bonding method using such a conductive bonding material is to apply the conductive bonding material to the bonding surface of one member to be bonded, and then place the other member to be bonded via the conductive bonding material. . Then, by heating and pressurizing one member to be joined with the other member to be joined, the silver oxide contained in the conductive joining material is reduced, silver nanoparticles are generated, and finally, A bonded body is formed by bonding via a bonding layer containing metallic silver.
Here, considering the case of a semiconductor device in which a heat dissipation member is bonded as a member to be bonded, the heat dissipation member and the bonding member that joins the heat dissipation member are made of different materials, and thus have different coefficients of linear expansion. Furthermore, since the heat dissipation member is repeatedly heated and cooled, stress is generated at the joint due to the difference in linear expansion coefficient between the members, and a load is applied to the member and the joint interface between the members. In Patent Document 1, in order to improve the strength of a bonding layer using a conductive bonding material as a bonding member, the porosity of the bonding layer is reduced by adjusting the weight ratio of silver compound particles and silver particles to a specific range. , a technique aimed at achieving both strength and heat dissipation of the bonding layer has been disclosed.

International Publication WO2018/101471 Publication

However, the method described in Patent Document 1 is a technique for improving the strength of the bonding layer, which is a bonding member, and has a problem in that it cannot achieve the effect of improving the bonding strength at the interface between the bonding layer and the member to be bonded. It is.

The present disclosure has been made to solve the above-mentioned problems, and aims to provide a method for manufacturing a bonded body that improves the bonding strength at the interface between a bonding layer and a member to be bonded.

A method for manufacturing a bonded body according to the present disclosure includes a step of forming an oxide film on the joint surface of at least one of two members to be joined, and a step of forming a fluorine compound layer on the surface of the oxide film. , applying a conductive bonding material containing silver-based particles and a dispersant to the surface of the fluorine compound layer to form a conductive bonding layer; and applying the conductive bonding material on the bonding surface of the one member to be bonded. The method is characterized by comprising a step of placing the other member to be joined with the layer interposed therebetween, and heating and pressurizing the member.

According to the present disclosure, an oxide film is formed on the bonding surface of at least one of the two members to be joined, and the bonding interface between the member to be joined and the conductive bonding layer is bonded via the oxide film. Fluorine is introduced. Therefore, it is possible to obtain a bonded body in which the bonding strength at the interface between the members to be bonded and the conductive bonding layer is further improved.

1 is a process diagram of a method for manufacturing a joined body according to Embodiment 1. FIG. FIG. 3 is a schematic cross-sectional view after an oxide film forming step according to Embodiment 1; FIG. 3 is a schematic cross-sectional view after a step of forming a fluorine compound layer according to Embodiment 1. FIG. FIG. 3 is a schematic cross-sectional view after the process of applying the conductive bonding material according to the first embodiment. FIG. 7 is a schematic cross-sectional view after the other member to be joined is placed and before the heating/pressing process in the heating/pressing process according to the first embodiment. FIG. 3 is a schematic cross-sectional view after heating and pressurizing according to the first embodiment. FIG. 2 is a schematic diagram of a bonded body obtained in an example. It is a cross-sectional SEM photograph of the bonded interface of the bonded body obtained in the example. This is a cross-sectional SEM photograph of the SEM-EDX analysis of the interface between the A6063 piece and the conductive bonding layer. This is an EDX analysis result of SEM-EDX analysis at the interface between the A6063 piece and the conductive bonding layer. FIG. 2 is a comparison diagram of shear strength between a bonded body produced in an example and a bonded body to which the technology of the present disclosure is not applied. FIG. 7 is a process diagram of a method for manufacturing a bonded body according to a second embodiment. FIG. 2 is a schematic cross-sectional view of a bonding interface between a member to be bonded and a conductive bonding layer, showing measurement points for measuring the proportions of elements. FIG. 7 is a process diagram of the method for manufacturing a bonded body shown in Embodiment 3; FIG. 7 is a schematic cross-sectional view of a joined body according to Embodiment 3. FIG. 7 is a schematic cross-sectional view of a semiconductor device according to a fourth embodiment.

Hereinafter, one example of a preferred form of the method for manufacturing a bonded body according to the present disclosure will be described, but the present disclosure is not limited to the following embodiments, and may be freely modified without departing from the gist of the present disclosure. It can be modified and implemented.

Embodiment 1.
FIG. 1 is a process diagram showing a preferred embodiment of the method for manufacturing a bonded body according to the first embodiment. FIG. 2 is a schematic cross-sectional view after the step of forming a fluorine compound layer according to the first embodiment. FIG. 3 is a schematic cross-sectional view after the process of applying the conductive bonding material according to the first embodiment. FIG. 4 is a schematic cross-sectional view after placing the other member to be joined and before the heating/pressing process in the heating/pressing process according to the first embodiment. FIG. 5 is a schematic cross-sectional view after heating and pressurizing according to the first embodiment. FIG. 6 is a schematic cross-sectional view of the joined body according to the first embodiment.

First, as shown in FIG. 1, the processing steps according to the first embodiment include a cleaning step using an organic solvent, an oxide film forming step, a fluorine compound layer forming step, a conductive bonding material coating step, a drying step, and a heating step.・Equipped with a pressurization process.

Although not shown, the cleaning process using an organic solvent is a process of cleaning the joining surface of at least one of the members to be joined, for the purpose of removing contaminants. As the organic solvent, acetone, ethanol, isopropyl alcohol, etc. are used. As a cleaning method, the members to be joined to be cleaned are immersed in an organic solvent such as acetone, ethanol, or isopropyl alcohol, and then subjected to ultrasonic cleaning to remove contaminants on the joining surfaces.

In the oxide film forming step, as shown in FIG. 2, an oxide film 2 is formed on the joining surface of at least one of the members 1 to be joined. The method for forming the oxide film 2 is not particularly limited, and can be formed by any known method. For example, in addition to a thermal oxidation method using a heating furnace or a laser, a vapor deposition method is also applicable. Incidentally, since the oxide film 2 may be a natural oxide film, the case where a natural oxide film is formed is also included in the oxide film forming process.
The oxide film 2 can be formed in an air atmosphere as a processing atmosphere when forming the oxide film 2 by a thermal oxidation method using a heating furnace or a laser. Furthermore, the oxide film 2 can be formed more efficiently by supplying oxygen or an assist gas containing oxygen into the processing furnace to create a processing atmosphere with a higher oxygen concentration than the air atmosphere. Further, the temperature of the member to be joined 1 when forming the oxide film 2 by heating is preferably 500° C. or more and 600° C. or less, for example, when the member to be joined 1 is an aluminum alloy.
The thickness of the oxide film 2 to be formed may be the same as that of the natural oxide film, but is preferably 200 nm or more. By forming the oxide film 2 of 200 nm or more, the bonding strength at the interface between the bonding layer and the members 1 to be bonded can be increased. It is easier to obtain a more improved bonded product. The thickness of the oxide film 2 can be determined by observing the cross section of the member 1 to be joined, evaluating the difference in the thickness of the member 1 before and after forming the oxide film 2, or measuring oxygen in the depth direction using XPS (X-ray Photoelectron Spectroscopy). It can be measured by distribution evaluation, etc. Further, it is preferable that the components of the oxide film 2 contain at least one element included in the member to be joined 1.

As shown in FIG. 3, the fluorine compound layer forming step is a step of forming a fluorine compound layer 3 on the surface of the oxide film 2 formed in the oxide film forming step. The fluorine compound layer 3 plays the role of supplying fluorine to the bonding interface between the bonding layer and the members 1 to be bonded, and as described in the examples below, the fluorine compound layer 3 plays the role of supplying fluorine to the bonding interface between the bonding layer and the members 1 to be bonded. It is considered that inclusion of is one of the important factors for obtaining the effects of the present disclosure. On the other hand, fluorine compounds may have water repellency and oil repellency, and as common technical knowledge, there is usually no active motivation to apply fluorine compounds to the bonding interface. That is, in order to obtain the effects of the present disclosure, it is preferable that the fluorine compound layer 3 stably exist on the oxide film 2, and for example, the fluorine-based polymer compound and formation method described below may be applied. Accordingly, the fluorine compound layer 3 can be formed.
Examples of fluorine-based polymer compounds include polychlorotrifluoroethylene, polyvinyl fluoride, ethylene-chlorotrifluoroethylene copolymer, polyvinylidene fluoride, perfluoroethylene propene copolymer, ethylene-tetrafluoroethylene copolymer, polytetrafluoroethylene, A material containing ethyl perfluoroisobutyne, ethyl perfluorobutyne, etc. can be used.
In addition, as a method for forming the fluorine compound layer 3, a method using a solvent in which a fluorine-based polymer compound is dissolved, a method of electrostatically applying a powdered fluorine-based polymer compound, etc. can be applied. be. As a specific example of a method using a solvent in which a fluorine-based polymer compound is dissolved, first, a method using a brush or the like impregnated with a solvent in which a fluorine-based polymer compound is dissolved; A solvent in which a fluorine-based polymer compound is dissolved is applied to the surface of the oxide film 2 formed in the oxide film forming step by immersing the members 1 to be joined in a solvent in which the compound is dissolved. The members to be joined 1 coated with a solvent in which a fluorine-based polymer compound is dissolved are evaporated in the atmosphere at room temperature or in a furnace heated from 100° C. to 150° C. to form a fluorine compound layer 3. I can do it.
Note that the fluorine-based polymer compound layer may contain not only one type of fluorine-based polymer compound but also multiple types of fluorine-based polymer compounds. The thickness of the fluorine compound layer 3 is preferably about 100 nm. The thickness of the fluorine compound layer 3 can be measured by observing the cross section of the member to be joined 1 or by evaluating the difference in the thickness of the member to be joined 1 before and after the formation of the fluorine compound layer 3.

In the process of applying the conductive bonding material, as shown in FIG. 4, the conductive bonding material 4 is coated on the fluorine compound layer.
The conductive bonding material 4 includes silver-based particles and a dispersant. Silver-based particles refer to silver particles, silver compound particles, or both. The content ratios of silver-based particles and dispersant contained in the conductive bonding material 4 can be arbitrarily selected within a range that does not impair the effects of the present disclosure.
The shape of the silver particles is not particularly limited, and any shape such as a flake shape or a true spherical shape can be used, and a combination of a plurality of shapes may also be used. The particle size of the silver particles is preferably about 1 μm or more and 100 μm or less. An example of silver compound particles is silver oxide particles. The particle size of the silver oxide particles is preferably about 1 μm or more and 100 μm or less. The particle size of the silver-based particles can be confirmed by measurement using a particle counter or a microscope.
As the dispersant, any organic solvent can be used as long as it does not impair the effects of the present disclosure. Examples of organic solvents include terpene solvents, ketone solvents, alcohol solvents, ester solvents, ether solvents, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, cellosolve solvents, and carbitol solvents. Examples include solvents. More specifically, terpineol, methyl ethyl ketone, acetone, isopropanol, butyl carbitol, decane, undecane, tetradecane, benzene, toluene, hexane, diethyl ether, kerosene, etc. can be used.
Furthermore, in order to improve the adhesion, fluidity, or printability of the conductive bonding material 4, a thickener, a surface tension regulator, or the like may be optionally added.
As mentioned above, the conductive bonding material 4 contains silver-based particles and a dispersant, and can be obtained by arbitrarily mixing other additives using various known methods, if necessary. .
The term "coating" as used in the process of applying the conductive bonding material is a concept that includes not only the case where the conductive bonding material 4 is applied in a planar manner to the members 1 to be joined, but also the case where the conductive bonding material 4 is applied in a linear manner. Further, the planar and linear conductive bonding material 4 applied to the members 1 to be bonded may include continuous portions, discontinuous portions, or both, and can be applied as desired. be.
The thickness of the conductive bonding material 4 to be applied is not particularly limited as long as the effects of the present disclosure can be obtained, and can be arbitrarily set depending on the material and size of the members to be bonded. As an example, when an aluminum alloy plate with a thickness of 2 mm is placed and bonded on copper coated with the conductive bonding material 4, it is preferable that the thickness of the conductive bonding material 4 is approximately 50 μm or more and 100 μm or less. .
The method of applying the conductive bonding material 4 is not particularly limited and any method can be used, such as dipping, screen printing, spraying, bar coating, spin coating, inkjet, dispenser, etc. Any method can be used, such as a pin transfer method, a brush coating method, a casting method, a flexographic method, a gravure method, or a syringe method.

In the drying step, although not shown, the conductive bonding material 4 applied in the conductive bonding material application step is dried, and the amount of dispersant contained in the conductive bonding material 4 is adjusted. If the other member to be joined is placed and heated and pressurized while the organic solvent used as a dispersant is excessively contained in the conductive joining material 4, the organic solvent not used for the reaction will decompose and Because of the evaporation, voids may be generated in the conductive bonding layer formed by heating and pressurizing the conductive bonding material 4. For this reason, it is preferable to adjust the amount of dispersant contained in the conductive bonding material 4 to an appropriate amount by drying the conductive bonding material 4 applied in the process of applying the conductive bonding material.
As for the processing conditions of the drying step, it is preferable to dry the members 1 coated with the conductive bonding material 4 in a drying oven at a temperature of about 40° C. or higher and 60° C. or lower. For example, when drying is performed in a drying oven maintained at 60° C., the amount of dispersant can be adjusted to an appropriate amount by drying for a period of approximately 15 minutes or more and 35 minutes or less.
Note that if there is no need to adjust the dispersant contained in the conductive bonding material 4, the drying step can be omitted.

In the heating and pressurizing process, as shown in FIG. 5, the other member to be joined 5 is placed on the joining surface of one member to be joined 1 coated with the conductive joining material 4, and heating and pressurizing are performed simultaneously. conduct. As shown in FIG. 6, one member to be joined 1 and the other member to be joined 5 are joined through the oxide film 2 and the conductive bonding layer 6 through the heating and pressurizing treatments. You can get body 7. The method of heating and pressurizing is not particularly limited, and can be performed using, for example, a general-purpose heat press machine. As for the processing conditions, for example, the heating temperature is preferably about 100° C. or more and 400° C. or less, and the pressing force is preferably about 5 MPa or more and 30 MPa or less. However, the combination of heating temperature and pressing force can be freely set according to the type of members to be joined, within a range that does not impair the effects of the present disclosure. Furthermore, the heating temperature and the pressing force can be increased or decreased in steps. Furthermore, the heating and pressure treatment can be performed in the air, in an inert gas atmosphere, or any other atmosphere as long as the effects of the present disclosure are not impaired.
Through the heating and pressurizing process, the conductive bonding material 4 forms a conductive bonding layer 6 while fluorine is introduced from the fluorine compound layer 3, and one member to be joined 1 and the other member to be joined 5 are bonded. A bonded body 7 bonded via the conductive bonding layer 6 can be obtained.

By applying the method for manufacturing a bonded body configured in this way, one member to be bonded has an oxide film formed on the bonding surface, and a conductive bonding layer formed on the oxide film and containing silver particles. , one member to be joined and the other member to be joined via the conductive joining layer, and a joined body containing fluorine at the interface between the one member to be joined and the conductive joining layer can be manufactured.

Next, as an example, processing conditions and joining results of each process in which A6063, which is an aluminum alloy, and C1020, which is an oxygen-free copper, are joined as members to be joined will be shown.

First, as a cleaning step using an organic solvent, a disc-shaped A6063 piece with a diameter of 5 mm and a thickness of 2 mm was immersed in acetone and subjected to ultrasonic cleaning.
Next, as an oxide film forming step, the A6063 piece was subjected to heat treatment at 500° C. for 6 hours in a heating furnace in an air atmosphere to form an oxide film with a thickness of 1 μm or more on the surface of the A6063 piece.
Next, as a step of forming a fluorine-based polymer compound layer, the A6063 piece after the oxide film was formed was immersed for 15 seconds in a solution containing a fluororesin using ethyl perfluoroisobutyl ether as a solvent. After dipping, it was dried in the air at room temperature.
Next, in the process of applying the conductive bonding material, the conductive bonding material was coated to a thickness of 50 μm on a C1020 plate measuring 30 mm×30 mm and having a thickness of 3 mm. As the conductive bonding material, a mixture of silver oxide particles with a purity of 99.9%, flaky pure silver particles, and diethylene glycol was used.
Next, in the heating and pressurizing process, an A6063 piece with an oxide film formed on the surface was placed on a C1020 plate coated with a conductive bonding material, and heated and applied for 5 minutes at a temperature of 400°C and a pressure of 20 MPa. The C1020 plate and the A6063 piece were joined together by pressing. FIG. 7 is a schematic diagram of a bonded body obtained in an example.

Next, the analysis results of the bonding interface and the evaluation results of the bonding strength will be shown for the bonded bodies obtained in the examples. FIG. 8 is a cross-sectional SEM photograph of the bonded interface of the bonded body obtained in the example. FIG. 9 is a cross-sectional SEM photograph of the SEM-EDX analysis of the interface between the A6063 piece and the conductive bonding layer. FIG. 10 shows the EDX analysis results of the SEM-EDX analysis at the interface between the A6063 piece and the conductive bonding layer. FIG. 11 is a comparison diagram of shear strength between the bonded body produced in the example and the bonded body to which the technology of the present disclosure is not applied.

First, as shown in FIG. 8, it can be confirmed that the A6063 piece and the C1020 plate are bonded via a conductive bonding layer containing metallic silver as the bonded body produced in the example. Furthermore, it can be seen that the interface between the A6063 piece and the conductive bonding layer has more irregularities than the interface between the C1020 plate and the conductive bonding layer. This is presumed to be caused by the formation of an oxide film on the bonding surface of the A6063 piece.

Next, the results of SEM-EDX analysis at the interface between the A6063 piece and the conductive bonding layer are shown. The pie chart in FIG. 10 shows the element ratios detected by EDX analysis at the location of spectrum 3 at the interface between the A6063 piece and the conductive bonding layer shown in the cross-sectional SEM photograph in FIG. 9. As shown in FIG. 10, it can be confirmed that about 15% fluorine is contained at the interface between the A6063 piece and the conductive bonding layer.

Next, FIG. 11 shows the results of a shear test conducted on the bonded body produced in the example and the bonded body in which only the cleaning process with an organic solvent was performed on an A6063 piece as a comparative example. The shear test was conducted at a shear rate of 100 μm/s. As shown in FIG. 11, it can be seen that the shear strength of the joined body produced as an example based on the present disclosure is higher than that of the joined body of the comparative example.

The above results show that one member to be joined has an oxide film formed on the joining surface, a conductive bonding layer formed on the oxide film and containing silver particles, and one member to be joined through the conductive bonding layer. and another member to be joined to the other member, and the interface between the one member to be joined and the conductive bonding layer contains fluorine, the interface between at least one member to be joined and the conductive bonding layer. This shows that the bonding strength has further improved.

In addition, from the above results, the mechanism by which the bonding strength at the interface between the A6063 and the conductive bonding layer was improved is not necessarily clear, but the conductive It is presumed that one of the factors is that fluorine is introduced into the bonding interface with the adhesive layer. Specifically, in the bonded body of the example, it is thought that the oxide film formed on the surface of the A6063 piece and the conductive bonding layer mainly composed of silver particles are bonded by Coulomb force, and the bonding It is thought that differences in the electrical properties of the interface may cause differences in bonding strength. In the present disclosure, since fluorine with high electronegativity is actively introduced into the bonding interface, changes in electrical characteristics at the bonding interface occur, resulting in a difference in bonding strength between the bonded members and the conductive bonding layer. It is estimated that this occurred. In other words, by introducing fluorine, which has a high electronegativity, into the bonding interface between the members to be joined and the conductive bonding layer, which are joined by Coulomb force, the bonding strength at the interface between the members to be joined and the conductive bonding layer increases. It is estimated that an even more improved zygote was obtained.

Therefore, by applying the method for manufacturing a joined body described in Embodiment 1, it is possible to provide a method for manufacturing a joined body in which the bonding strength at the interface between at least one of the members to be joined and the conductive bonding layer is further improved. I can do it.

Modification 1 of Embodiment 1.
In Embodiment 1, the processes shown in the cleaning process using an organic solvent, the process of forming an oxide film, and the process of forming a fluorine compound layer were applied only to one of the members to be joined. The processes shown in the film forming process and the fluorine compound layer forming process are applied to one of the members to be joined 1, and the cleaning process with an organic solvent, the process of forming an oxide film, and the fluorine compound layer are applied to the other member to be joined 5. The process shown in the process of applying the conductive bonding material and the drying process is applied without applying the process shown in the forming process of , and the process shown in the process of forming the conductive bonding material and the process shown in the drying process are applied, and the other member to be joined 5 is placed on one member to be joined 1 . The treatments shown in the heating and pressurizing steps may also be applied.

By applying the method for manufacturing a bonded body configured in this manner, as in the first embodiment, one member to be bonded with an oxide film formed on the bonding surface and a silver-based bonded member formed on the oxide film. A conductive bonding layer containing particles, and another bonded member bonded to one bonded member via the conductive bonding layer, the interface between the one bonded member and the conductive bonding layer A bonded body containing fluorine can be manufactured.

Therefore, by applying the method for manufacturing a bonded body shown in Modification 1 of Embodiment 1, the bonding strength at the interface between at least one of the members to be bonded and the conductive bonding layer can be increased as in Embodiment 1. A further improved method for manufacturing a joined body can be provided.

Modification 2 of Embodiment 1.
In the first embodiment, the processes shown in the organic solvent cleaning step, the oxide film formation step, and the fluorine compound layer formation step were applied only to one of the members to be joined 1, but to the other member to be joined 5. Similar processing may also be applied to

By applying the manufacturing method of the bonded body configured in this way, one of the members to be bonded with an oxide film formed on the bonding surface, the other member to be bonded with the oxide film formed on the bonding surface, and the silver It is possible to manufacture a bonded body that includes a conductive bonding layer containing system particles and bonding two members to be bonded via an oxide film, and containing fluorine at the interface between the two members to be bonded and the conductive bonding layer.

Therefore, by applying the method for manufacturing a bonded body shown in Modification 2 of Embodiment 1, it is possible to increase not only the bonding strength at the interface between one bonded member and the conductive bonding layer but also the bonding strength at the interface between one bonded member and the conductive bonding layer. It is possible to provide a method for manufacturing a bonded body in which the bonding strength at the interface with the conductive bonding layer is further improved.

Embodiment 2.
FIG. 12 is a process diagram of the method for manufacturing a bonded body according to the second embodiment. FIG. 13 is a schematic cross-sectional view of the bonding interface between the member to be bonded 1 and the conductive bonding layer 6, showing measurement points 8 for measuring the proportions of elements. Note that in the following description, descriptions regarding parts that overlap with those in Embodiment 1 will be omitted as appropriate.

In the second embodiment, a fluorine-based inorganic compound layer forming step is applied after the organic solvent cleaning step, and the fluorine-based inorganic compound layer is formed on the joining surface of at least one of the members to be joined. Although omitted in FIG. 12, a natural oxide film is formed on the bonding surface of at least one of the members to be bonded before the step of forming the fluorine-based inorganic compound layer, which is similar to that shown in Embodiment 1. The second embodiment also includes the step of forming an oxide film.
As a method for forming the fluorine-based inorganic compound layer, there are a method of heating at least one of the members to be joined in an atmosphere containing fluorine or a fluorine compound, a method of vapor-depositing a fluorine-based inorganic compound, and the like. In the method of heating in an atmosphere containing fluorine or a fluorine compound, for example, when the members to be joined are aluminum alloys, it is preferable to heat at a temperature of about 500°C.
As the fluorine-based inorganic compound, it is preferable to form a layer of aluminum fluoride or magnesium fluoride in consideration of the components of the members to be joined, for example, when aluminum alloy A6063 is used as the member to be joined. However, the component as a fluorine-based inorganic compound is not particularly limited, and any fluorine-based inorganic compound containing the elements contained in the members to be joined is preferable, and even fluorine-based inorganic compounds containing multiple elements are preferable. good.

In addition, in the bonded body to which the manufacturing method according to the present disclosure is applied, the proportion of elements detected at any interface between the bonded member and the conductive bonding layer that constitute the bonded body is such that the atomic weight % of fluorine is 5%. It is preferable that it is 20% or less. Examples of methods for measuring the proportions of elements include SEM-EDX. For example, at the measurement point 8 shown in FIG. 13, the ratio of elements is measured at the interface between the member to be joined 1 and the conductive bonding layer 6. Note that as long as the interface between the member to be joined 1 and the conductive bonding layer 6 can be measured, the locations of the measurement points and the number of measurement points may be set freely.

Further, the conductive bonding material used in Embodiment 1 and Embodiment 2 may contain fluorine, and for example, a fluorine compound may be added to the conductive bonding material. The fluorine compound to be added is preferably hydrophilic or lipophilic, and includes, for example, aluminum fluoride, sodium fluoride, magnesium fluoride, calcium fluoride, potassium fluorosilicide, potassium borofluoride, cryolite, or calycryol. Examples include light.
As a method for adding a fluorine compound to the conductive bonding material, it is preferable to mix a solution of the fluorine compound, a powder obtained by crushing a solid fluorine compound, or both into the conductive bonding material.

By applying the method for manufacturing a bonded body configured in this way, a fluorine-based inorganic compound layer is formed on the bonding surface of at least one of the two bonded members, and the bonding surface of at least one of the two bonded members is bonded. A bonded body containing fluorine at the bonding interface with the conductive bonding layer can be manufactured.

Therefore, by applying the method for manufacturing a joined body shown in Embodiment 2, it is possible to provide a method for manufacturing a joined body in which the bonding strength at the interface between at least one of the members to be joined and the conductive bonding layer is further improved. I can do it.

Embodiment 3.
FIG. 14 is a process diagram of a method for manufacturing a bonded body assuming a heat dissipation member according to the third embodiment. Note that each step corresponds to the processing step in FIG. 1, and descriptions of common descriptions are omitted as appropriate. FIG. 15 is a schematic cross-sectional view of the joined body 9 assuming a heat dissipation member according to the third embodiment.

First, the processing steps of the manufacturing method are shown along FIG. 14. Similar to the treatment process in FIG. 1, as a cleaning process using an organic solvent, the bonding surface of the aluminum alloy heat sink 10 and the bonding surface of the insulating substrate 13 are immersed in acetone, and ultrasonic cleaning is performed for the purpose of removing contaminants. conduct.

Next, as an oxide film forming step, the bonding surface of the heat sink 10 is irradiated with a laser and heated to form the oxide film 11.

Next, as a fluorine compound layer forming step, a solvent containing a fluorine-based polymer compound is applied with a brush onto the oxide film 11 formed in the oxide film forming step and dried at room temperature to form a fluorine compound layer. It is formed on the oxide film 11.

Next, in the process of applying the conductive bonding material, the conductive bonding material is applied using a dispenser onto the heat sink 10 on which the oxide film 11 and the fluorine compound layer have been formed.

Next, as a drying step, the heat sink 10 coated with the conductive bonding material is dried in a drying oven, and the amount of dispersant in the conductive bonding material is adjusted.
Note that the drying step can be omitted if there is no need to adjust the amount of dispersant in the conductive bonding material.

Finally, in a heating and pressurizing step, the insulating substrate 13 is placed on the heat sink 10 coated with a conductive bonding material, and bonded by heating and pressurizing.

In order to remove gas generated from the conductive bonding material, holes and grooves may be formed in the heat sink 10 and the insulating substrate 13, which are the members to be bonded, as necessary. By forming pores and grooves, for example, the organic solvent contained in the conductive bonding material and the organic components constituting the fluorine-based polymer compound layer can be decomposed and evaporated by heating and pressurizing processes. Since the gas generated by this can be removed, it is possible to suppress the generation of voids or the like in the conductive bonding layer 12.

Further, the bonded body 9 shown as a heat dissipation member in the third embodiment is an example, and the materials, shape, number, arrangement, etc. of the conductive bonding material and the bonded members can be changed arbitrarily.

By applying the manufacturing method of the bonded body configured in this way, a heat sink with an oxide film formed on the bonding surface, a conductive bonding layer formed on the oxide film and containing silver particles, and a conductive bond An insulating substrate bonded to a heat sink via a layer, and a bonded body containing fluorine at the interface between the heat sink and the conductive bonding layer can be manufactured.

Therefore, by applying the method for manufacturing a joined body shown in Embodiment 3, it is possible to provide a method for manufacturing a joined body in which the bonding strength at the interface between at least one of the members to be joined and the conductive bonding layer is further improved. I can do it.

FIG. 15 is a schematic cross-sectional view of the joined body 9 according to the third embodiment, which is obtained by applying the manufacturing method shown in FIG. 14. The bonded body 9 shown in FIG. 15 has a structure in which a heat sink 10 made of an aluminum alloy with an oxide film 11 formed on the bonding surface and an insulating substrate 13 are bonded via a conductive bonding layer 12, and is intended as a heat dissipation member. There is. The insulating substrate 13 has a structure in which the ceramic plate 133 is sandwiched and bonded between the copper plates 131 and 132, so more specifically, the heat sink 10 with the oxide film 11 formed on the bonding surface and the copper plate 132 , has a structure in which they are bonded via a conductive bonding layer 12. The heat sink 10 and the conductive bonding layer 12 are bonded by the bonded body manufacturing method described in the first embodiment. Furthermore, a coolant flow path is formed in the heat sink 10 on the opposite side of the surface that is bonded to the conductive bonding layer 12 . Since the linear expansion coefficients of the heat sink 10, the copper plate 132, and the conductive bonding layer 12 are different from each other, stress is generated at the bond between the heat sink 10 and the copper plate 132 via the conductive bonding layer 12 due to temperature changes. .

In a bonded body configured in this way, there is a heat sink with an oxide film formed on the bonding surface, a conductive bonding layer formed on the oxide film and containing silver particles, and a conductive bonding layer that connects the heat sink to the heat sink through the conductive bonding layer. A bonded body including a bonded insulating substrate and containing fluorine at the interface between the heat sink and the conductive bonding layer can be obtained.

Therefore, according to the configuration shown in Embodiment 3, it is possible to provide a bonded body in which the bonding strength at the interface between at least one of the members to be bonded and the conductive bonding layer is further improved.

Embodiment 4.
FIG. 16 is a schematic cross-sectional view of the semiconductor device 14 according to the fourth embodiment.
Embodiment 4 shows a method for manufacturing a semiconductor device to which the method for manufacturing a bonded body shown in Embodiment 3 is applied, and a semiconductor device to be constructed.

First, in the semiconductor device according to the fourth embodiment, when comparing the configuration of the semiconductor device 14 in FIG. 16 and the bonded body 9 in FIG. 15, the aluminum alloy heat sink 15 corresponds to the heat sink 10 shown in the third embodiment. In this semiconductor device, an insulating substrate 18 corresponds to the insulating substrate 13 shown in the third embodiment, and a semiconductor element 20 is mounted on the insulating substrate 18 via a solder 19. An oxide film 16 is formed on the bonding surface of the heat sink 15, and the heat sink 15 and the insulating substrate 18 are bonded via the oxide film 16 and the conductive bonding layer 17. In addition, the method for manufacturing a semiconductor device according to Embodiment 4 includes the cleaning step using an organic solvent shown in Embodiment 3, the step of forming an oxide film, the step of forming a fluorine-based polymer compound layer, and the step of forming a conductive This method applies a bonding material application process, a drying process, and a heating/pressure process. Furthermore, the same processing as in Embodiment 3 can be applied to the processing method in each step, and the details will be omitted since the explanation will be redundant.

By applying the method for manufacturing a semiconductor device configured in this way, a heat sink with an oxide film formed on the bonding surface, a conductive bonding layer formed on the oxide film and containing silver particles, and a conductive bond A semiconductor device including an insulating substrate bonded to a heat sink via a layer and containing fluorine at the interface between the heat sink and the conductive bonding layer can be manufactured.

Therefore, by applying the method for manufacturing a semiconductor device described in Embodiment 4, it is possible to provide a method for manufacturing a semiconductor device in which the bonding strength at least at the interface between the heat sink and the conductive bonding layer is further improved.

FIG. 16 is a schematic cross-sectional view of a semiconductor device according to a fourth embodiment, which is constructed by applying the above-described semiconductor device manufacturing method.
A semiconductor device 14 shown in FIG. 16 includes the bonded body 9 shown in Embodiment 3 as a heat dissipation section, and includes an aluminum alloy heat sink 15 with an oxide film 16 formed on the bonded surface and an insulating substrate 18. , are bonded via a conductive bonding layer 17. Note that the insulating substrate 18 has a structure in which a ceramic plate 183 is sandwiched and bonded between a copper plate 181 and a copper plate 182, and the heat sink 15 and the copper plate 182 are bonded to each other via the conductive bonding layer 17, as in the third embodiment. It has a bonded structure.
A semiconductor element 20 is mounted on a copper plate 181 constituting an insulating substrate 18 via a solder 19. Heat generated by the semiconductor element 20 when the semiconductor device is driven is transmitted to the heat sink 15 via the insulating substrate 18 and radiated. Since the linear expansion coefficients of the heat sink 15, the copper plate 182, and the conductive bonding layer 17 are different from each other, as the heat propagates from the semiconductor element 20, the heat sink 15 and the copper plate 182 bond together through the conductive bonding layer 17. causes stress.
Note that the semiconductor device shown in FIG. 16 is an example, and the materials, shapes, numbers, arrangement, etc. of the conductive bonding material and the members to be bonded can be arbitrarily changed.

In a semiconductor device configured in this way, there is a heat sink with an oxide film formed on the bonding surface, a conductive bonding layer formed on the oxide film and containing silver particles, and a conductive bonding layer that is connected to the heat sink through the conductive bonding layer. A semiconductor device including a bonded insulating substrate and containing fluorine at the interface between the heat sink and the conductive bonding layer can be obtained.

Therefore, according to the configuration shown in Embodiment 4, it is possible to provide a semiconductor device in which the bonding strength at the interface between at least one of the members to be bonded and the conductive bonding layer is further improved.

1 One member to be joined 2 Oxide film 3 Fluorine compound layer 4 Conductive bonding material 5 Other member to be joined 6 Conductive bonding layer 7 Bonded body 8 Measurement point 9 Bonded body 10 Heat sink 11 Oxide film 12 Conductive bonding layer 13 Insulation Substrate 131 Copper plate 132 Copper plate 133 Ceramic plate 14 Semiconductor device 15 Heat sink 16 Oxide film 17 Conductive bonding layer 18 Insulating substrate 181 Copper plate 182 Copper plate 183 Ceramic plate 19 Solder 20 Semiconductor element

Claims (9)

forming an oxide film on the joint surface of at least one of the two members to be joined;
forming a fluorine compound layer on the surface of the oxide film;
a step of applying a conductive bonding material containing silver-based particles and a dispersant to the surface of the fluorine compound layer or the bonding surface of the other bonded member;
placing the other member to be joined or the one member to be joined on the surface of the applied conductive joining material, and heating and pressurizing it;
A method for manufacturing a joined body comprising: 2. The method of manufacturing a bonded body according to claim 1, wherein the oxide film is formed thicker than a natural oxide film. The method for manufacturing a bonded body according to claim 1 or 2, wherein the conductive bonding material contains fluorine. One member to be joined has an oxide film formed on its joining surface;
a conductive bonding layer formed on the oxide film and containing silver-based particles;
another member to be joined to the one member to be joined via the conductive bonding layer;
Equipped with
A bonded body containing fluorine at an interface between the one member to be bonded and the conductive bonding layer. The joined body according to claim 4, wherein the thickness of the oxide film is thicker than the thickness of the natural oxide film. The joined body according to claim 4, wherein the conductive bonding layer contains fluorine. The ratio of fluorine contained in the interface between the one member to be joined and the conductive bonding layer is 5% or more and 20% or less in atomic weight %, according to any one of claims 4 to 6. zygote. A method for manufacturing a semiconductor device comprising the step of manufacturing a bonded body using the method for manufacturing a bonded body according to claim 1 or claim 2,
The method for manufacturing a semiconductor device, wherein the two bonding members are a heat dissipating member and an insulating substrate. The joined body according to claim 4, wherein the two members to be joined are a heat dissipation member and an insulating substrate,
A semiconductor device comprising a semiconductor element on the insulating substrate.

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