JP2010046700A - Bonded structure and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel bonded structure manufactured by bonding various kinds of carbon films and metal materials by soldering, and a method for manufacturing the same. <P>SOLUTION: The bonded structure is composed of a first member 1 and a second member 2, and has a bonding portion 3. The first member 1 includes a substrate 1s and a carbon film 1f which coats at least a part of the surface of the substrate 1s. At least a part of the second member 2 includes a metal material 2. The bond portion 3 is formed by bonding the carbon film 1f and the metal material 2 by soldering. The carbon film 1f contains oxygen in at least the bonded interface 1j. Tin solder 3j of the bond portion 3 contains tin as a main component and one or more selected from a group of zinc and rare-earth elements. The tin solder 3j of the bond portion 3 is chemically bonded to the oxygen contained in the carbon film 1f and also is diffusion-bonded to the metal material 2 or is chemically bonded to oxygen in an oxide formed on the surface of the metal material 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a joined body in which various carbon films and a metal material are soldered.

  Carbon is an extremely excellent material from the viewpoint of resource problems and environmental problems because the amount of burying is almost infinite and harmless. Carbon materials having various crystal structures such as diamond, diamond-like carbon, graphite, glassy carbon, fullerene, and carbon nanotube are known depending on the bonding form between atoms. Among them, amorphous carbon (diamond-like carbon: DLC) having an amorphous structure has excellent mechanical properties such as wear resistance and solid lubricity, corrosion resistance, insulation, and visible / infrared light transmittance. And oxygen barrier properties. Therefore, the amorphous carbon film is often used by being coated on the surface of various base materials. For example, in electrical equipment, a semiconductor element may be mounted on a heat sink (heat radiating plate) covered with an insulating amorphous carbon film.

  For example, Patent Document 1 discloses a heat sink, an insulating amorphous carbon film covering the heat sink, a multilayer metal body as a three-layer electrode provided on the insulating amorphous carbon film, and a multilayer A semiconductor device including a semiconductor element soldered and mounted on a metal body is disclosed. Of the multilayer metal body, the first layer on the insulating amorphous carbon film is made of a metal having high adhesion to the insulating amorphous carbon film, and the second layer is a junction between the first layer and the third layer. The third layer is made of a metal having conductivity and high adhesion to the solder. In other words, in Patent Document 1, since the electrode is a multilayer metal body, the bondability between the insulating amorphous carbon film and the electrode is ensured.

In order to use an amorphous carbon film for an electric device or the like, a technique for joining various metal materials and an amorphous carbon film as in Patent Document 1 is required. For joining, practical strength is required, and joining conditions according to the purpose of use, such as thermal and electrical contact being obtained and characteristics of the constituent materials not being impaired, are essential.
JP 2006-245235 A

  As a method for joining the amorphous carbon film and the metal material, there is brazing. In the joining by brazing, the joining temperature becomes a high temperature exceeding 400 ° C. Therefore, brazing may not be possible if the heat resistance of either the amorphous carbon film or the metal material is low. Furthermore, since many alloys used for brazing have poor wettability with an amorphous carbon film, they often cannot be joined together.

  There is also a method of joining an amorphous carbon film and a metal material with an organic adhesive. However, the organic adhesive has a problem that it has low thermal conductivity and low electrical conductivity and has a low strength in a high-humidity environment. There are organic adhesives that contain silver or copper in the organic adhesive for the purpose of supplementing thermal conductivity and conductivity, but the properties are insufficient compared to bonding materials made of alloys such as solder. is there.

  In view of the above problems, an object of the present invention is to provide a novel joined body in which various carbon films and a metal material are joined by solder, and a method for manufacturing the same.

  The present inventors have paid attention to a solder for ceramics capable of joining ceramics. However, even if a ceramic solder is simply used for joining the carbon film and the metal material, practical joint strength cannot be obtained. Therefore, the present inventors have conceived that the carbon film and the metal material can be firmly soldered by setting the carbon film to a specific composition.

That is, the joined body of the present invention comprises a first member comprising a base material and a carbon film coated on at least a part of the surface of the base material, and a second member comprising at least a part of a metal material. A joined body having a joint portion to which the carbon film and the metal material are soldered,
The carbon film contains oxygen at least on the bonded surface,
The joint includes at least one selected from the group consisting of tin and zinc and rare earth elements as a main component, and is chemically bonded to oxygen of the carbon film and is formed on the surface of the metal material by diffusion bonding with the metal material. It is characterized in that it is joined with tin solder that chemically bonds with oxygen of the formed oxide.

  In the joined body of the present invention, the joint between the carbon film and the metal material is soldered with tin solder containing tin as a main component and at least one selected from the group consisting of zinc and rare earth elements. This tin solder contains one or more selected from the group consisting of zinc and rare earth elements, which are elements having an extremely high oxygen affinity and a strong binding force with oxygen. In the joined body of the present invention, since the carbon film contains oxygen at least on the surface to be joined, the oxygen is chemically bonded to an element having a high oxygen affinity, so that tin solder is joined to the carbon film. Moreover, with respect to a metal material, the tin solder is joined to the metal material by diffusing the tin solder component into the metal material to form an alloy. Alternatively, when an oxide (passive film) is formed on the surface of a metal material such as stainless steel or an aluminum alloy, this oxygen is chemically bonded to an element having a high oxygen affinity, so that tin solder is added to the metal material. Be joined. As a result, in the joined body of the present invention, even when the surface of the first member is covered with the carbon film, the first member and the second member are firmly joined by soldering with tin solder.

  In particular, the carbon film desirably contains silicon at least on the surface to be bonded. Since silicon has a high oxygen affinity, not only is it easy to introduce oxygen into the bonded surface of the carbon film, but if the carbon film is an amorphous carbon film, it contains silicon to provide high adhesion, high hardness, and high wear resistance. The properties such as the property, the low friction coefficient, and the high insulation are imparted, which is preferable in terms of the bonding strength and the improvement of the characteristics of the carbon film.

In addition, the method for producing a joined body of the present invention includes a first member in which at least a part of a base material is coated with a carbon film, and a second member in which at least a part is made of a metal material. A method of manufacturing a joined body having a joint portion to which the metal material is soldered,
An oxygen-containing carbon film forming step of imparting oxygen to at least the bonded surface of the carbon film;
A soldering step of soldering the carbon film and the metal material with a tin solder containing at least one selected from the group consisting of zinc and rare earth elements mainly composed of tin;
It is characterized by including.

  The best mode for carrying out the joined body and the method for producing the same according to the present invention will be described below.

[Joint]
The joined body of the present invention includes a first member in which at least a part of a base material is coated with a carbon film, and a second member in which at least a part is made of a metal material, and the carbon film and the metal material are tin solders. With a soldered joint.

  The first member includes a base material and a carbon film coated on at least a part of the surface of the base material. The shape and material of the base material are not particularly limited, but the surface of the base material on which the carbon film is coated preferably has high adhesion to the carbon film. This is because if the adhesion between the substrate and the carbon film is low, even if the bonding strength at the bonded portion is high, peeling may occur between the substrate and the carbon film and the bonded body may be destroyed. The base material is preferably made of a metal such as iron, aluminum, titanium, or silicon, or an alloy mainly composed thereof, or a ceramic such as a carbide or nitride, because of excellent adhesion to the carbon film.

  The carbon film is a film made of a carbon material containing carbon as a main component. Examples of the carbon material constituting the carbon film include diamond, diamond-like carbon, graphite, glassy carbon, fullerene, and carbon nanotube. However, it is amorphous because it can easily form a smooth surface and easily add oxygen. An amorphous carbon (diamond-like carbon: DLC) film having a structure is preferable. The composition of the carbon film is not particularly limited as long as oxygen is contained in at least a bonding surface, and may contain silicon, hydrogen, a metal element, nitrogen, or the like in addition to oxygen. As will be described later, oxygen chemically bonds with tin solder at the joint. Therefore, oxygen should just be contained in the to-be-joined surface of a carbon film, but may be contained in the whole carbon film. At this time, the surface layer having a thickness of 0.5 to 500 nm from the outermost surface of the carbon film is preferably a high oxygen content layer having a high oxygen content. The high oxygen-containing layer is preferably a layer containing 50 to 70 atomic% or even 55 to 65 atomic% of oxygen when the high oxygen containing layer is 100 atomic% (excluding hydrogen when hydrogen is included).

  Moreover, in the joined body of the present invention, it is preferable that at least a surface to be joined of the carbon film, particularly the DLC film, contains silicon. Since silicon is an element having a high oxygen affinity, at least silicon is present on the bonded surface of the carbon film, so that oxygen is easily introduced into the bonded surface. Silicon may be contained in the bonded surface of the carbon film, but may be contained in the entire carbon film. The carbon film preferably contains 2 to 40 atomic% of silicon when the whole is 100 atomic%. In particular, when the total carbon film is 100 atomic%, it is preferable that silicon is contained in an amount of 4 atomic% or more, 6 atomic% or more, and further 9 atomic% or more because the bonding strength of the bonding portion is improved.

  The carbon film may have a single-layer structure as long as oxygen is contained in at least the bonding surface. However, in order to achieve various characteristics required for the carbon film such as insulation and adhesion at a high level. Furthermore, it may be composed of a multilayer structure or an inclined structure having two or more layers having different hydrogen and silicon contents in the film thickness direction.

  The film thickness of the carbon film may be appropriately selected according to the use of the joined body and the required properties, but is 0.1 to 100 μm, more preferably 0.5 to 50 μm from the viewpoint of adhesion to the base material. Is good.

  The shape and material of the second member are not particularly limited as long as at least a part of the second member is made of a metal material. For example, a member in which a metal film is coated on at least a part of the surface of a base material made of a material other than a metal material may be used in addition to a bulk material or a thin film made of a metal material. The type of the metal material is not particularly limited, and may be a metal material or alloy having a passive film formed on the surface, such as stainless steel and aluminum, in addition to iron, copper, nickel, molybdenum, tungsten and the like.

  Here, FIG. 1 is a cross-sectional view schematically showing the joined body of the present invention. In the joint part 3, the first member 1 and the second member 2 are joined. Specifically, the carbon film 1f covered with the substrate 1s and the metal material (that is, the second member 2) are soldered and joined with the tin solder 3j. The tin solder contains one or more selected from the group consisting of zinc and rare earth elements mainly composed of tin. The additive element selected from the group consisting of zinc and rare earth elements has a high oxygen affinity. Therefore, the additive element chemically bonds with oxygen present on the bonded surface 1j of the carbon film 1f, and the tin solder 3j is directly bonded to the carbon film 1f. Further, the tin solder 3j is diffusion-bonded to the metal material 2 from the joined surface 2j to the metal material in the same manner as normal soldering, and the tin solder 3j is directly bonded to the metal material 2. Even in the case of the metal material 2 made of a metal having an oxide (passive film) on the surface, the additive element is combined with oxygen of the oxide present on the bonded surface 2j, and the tin solder 3j is bonded to the metal material 2. Directly joined.

  When the additive element is contained in an amount of 0.5 to 7.5% by mass and further 2 to 4% by mass when tin solder is 100% by mass, sufficient bonding strength can be obtained. Among the zinc and rare earth elements, zinc and / or ruthenium is particularly preferable as the additive element. The tin solder may contain at least one or more elements included in ordinary solder such as copper, silver, lead, bismuth, indium, antimony, and nickel. The tin solder should not contain lead.

  The joined body of the present invention having the above configuration has high joint shear strength. Specifically, the joint shear strength of the joint is preferably 5 MPa or more, more preferably 6 MPa or more. In this specification, the joint shear strength of the joint is measured by the method specified in Japanese Industrial Standard JISZ3198-5 “Lead-free solder test method—Part 5: Tensile and shear test method of solder joint”. Value.

[Use of joined body]
The joined body of the present invention described above can be suitably used for a semiconductor element heat radiating member for radiating and cooling heat generated in a semiconductor element. The semiconductor element heat dissipation member is a member that mounts the semiconductor element and dissipates and / or cools the heat generated in the semiconductor element. Specifically, the semiconductor element heat dissipation member is called a heat sink, a heat spreader, a heat dissipation plate, a cooling plate, or the like. It means a heat dissipating member involved in the dissipation and cooling of heat generated in the semiconductor element. The semiconductor element heat dissipation member will be described below with reference to FIG.

  FIG. 2 is a cross-sectional view schematically showing a semiconductor element heat dissipation member. The semiconductor element heat dissipating member is provided with an insulating DLC film 12 on the metal base 11 so as to electrically insulate at least the metal base 11 and the semiconductor element 41. The insulating DLC film A semiconductor element 41 is mounted on 12 via an electrode 21. At this time, the DLC film 12 and the electrode 21 are soldered with tin solder 31 at the joint 30. The semiconductor element 41 is fixed to the electrode 21 with a general solder 43. That is, the metal substrate 11 and the DLC film 12 correspond to the first member of the joined body of the present invention, and the electrode 21 (or the electrode 21, the solder 43, and the semiconductor element 41) correspond to the second member of the joined body of the present invention.

  The metal substrate is not particularly limited as long as it is made of a known metal material having thermal conductivity. For example, the thermal conductivity of the metal substrate is preferably 8 W / m · K or more, more preferably 10 W / m · K or more, and 100 W / m · K or more. When used as a semiconductor element heat radiating member such as a heat sink, the metal substrate serves as a heat radiating plate. In order to dissipate the heat of the semiconductor element efficiently, the higher the thermal conductivity of the metal substrate, the better. From such a viewpoint, the metal substrate is preferably made of a metal or alloy containing at least one selected from Al, Cu, Mo, W, Si, and Fe. Further, the shape and dimensions of the metal substrate may be appropriately determined according to the purpose of use.

  The insulating DLC film preferably contains carbon as a main component and contains hydrogen. The insulating DLC film containing hydrogen has a high strength and does not easily peel from the surface of the metal substrate. The content of hydrogen contained in the insulating DLC film is not particularly limited, but from the viewpoint of preventing peeling, it is 20 atomic% or more, further 25 atomic% or more when the insulating DLC film is 100 atomic%. preferable. The higher the hydrogen content, the more flexible the insulating DLC film, which is preferable for preventing peeling. However, when the hydrogen content is too high, the DLC film has an organic structure, and the strength is high. On the contrary, peeling may easily occur due to a significant decrease. Therefore, the content of hydrogen when the insulating DLC film is 100 atomic% is preferably 40 atomic% or less, and more preferably 35 atomic% or less.

  When the insulating DLC film further contains silicon, not only oxygen can be easily introduced into the DLC film, but also the adhesion to the metal substrate is improved. In addition, the inclusion of silicon can reduce the difference in thermal expansion coefficient between the semiconductor element mainly composed of silicon and the insulating DLC film, and can reduce the stress caused by the difference in thermal expansion coefficient between the two. it can. The content of silicon contained in the insulating DLC film is not particularly limited, but is preferably 1 to 30 atomic%, more preferably 5 to 20 atomic%. If the silicon content is 1 atomic% or more, even if the semiconductor element heat dissipation member is exposed to a large temperature change, the stress caused by the difference in thermal expansion coefficient between the semiconductor element and the insulating DLC film can be relieved, and peeling occurs. Is prevented. Further, if the silicon content is 30 atomic% or less, further 20 atomic% or less, it is possible to prevent the conductivity of the insulating DLC film from increasing, and sufficiently ensure the insulation between the semiconductor element and the metal substrate. it can.

  In addition, the thickness of the insulating DLC film in the semiconductor element heat dissipation member is preferably 0.1 μm or more, and more preferably 0.5 μm or more, from the viewpoint of sufficiently ensuring the insulation between the semiconductor element and the metal substrate. Moreover, in order to efficiently dissipate the heat generated in the semiconductor element to the metal substrate, the thickness is preferably several tens of μm or less.

  The semiconductor element heat dissipating member comprising the joined body of the present invention described above is excellent in heat dissipation characteristics of heat generated in the semiconductor element and excellent in adhesion to the semiconductor element and other members.

  The structure of the present invention can be used for a substrate or a housing for mounting an electronic component (such as a resistor or a capacitor) in addition to the above-described semiconductor element heat dissipation member.

[Method of manufacturing joined body]
The joined body of the present invention can be produced by the method for producing the joined body of the present invention described below (hereinafter referred to as “the joining method of the present invention”). That is, the manufacturing method of the present invention includes a first member in which at least a part of a base material is coated with a carbon film, and a second member in which at least a part is made of a metal material, and the carbon film and the metal material Is a method for manufacturing a joined body having a soldered joint, and mainly includes an oxygen-containing carbon film forming step and a soldering step.

  Here, the first member is obtained by forming a carbon film on the surface of the base material by a known CVD method or PVD method such as plasma CVD method, ion plating method, sputtering method or the like. Prior to the formation of the carbon film, the substrate may be subjected to a surface treatment in order to improve the adhesion with the substrate surface. For example, fine irregularities may be formed on the surface of the base material to increase the adhesion by the anchor effect, or an intermediate layer to improve the adhesion may be formed.

  The oxygen-containing carbon film forming step is a step of imparting oxygen to at least the bonded surface of the carbon film. In order to provide oxygen to at least the bonded surface of the carbon film, a carbon film containing oxygen may be formed in advance when the carbon film is formed, or at least the carbon film may be formed after the carbon film is formed. You may perform the process which provides oxygen to a to-be-joined surface. For example, the carbon film is exposed to ultraviolet rays in an atmosphere containing oxygen (UV treatment), or the carbon film is exposed to plasma containing oxygen (plasma treatment), so that even a carbon film after film formation is covered. Oxygen can be applied to the bonding surface. In UV treatment or plasma treatment, an oxygen-containing functional group represented by —O, ═O, —OH or the like is preferably added. Forms of C—O, C—OH, C═O, Si—O, Si—OH, etc. on the bonded surface by bonding oxygen-containing functional groups to carbon or silicon contained in at least the bonded surface of the carbon film Exists.

  The oxygen-containing carbon film forming step is preferably a step in which the oxygen content excluding hydrogen on the bonded surface of the carbon film is 50 to 70 atomic%, more preferably 55 to 65 atomic%. By setting the oxygen content of the bonded surface of the carbon film to 50 atomic% or more, a bonded body having a high bonding shear strength at the bonded portion can be obtained. As the oxygen content increases, the joining shear strength tends to increase. However, even if the oxygen content of the bonded surface of the carbon film exceeds 70 atomic%, no significant improvement is observed. The oxygen content of the bonded surface of the carbon film can be set to a desired content by changing the film forming conditions of the carbon film and the processing conditions of the UV treatment and the plasma treatment. In this specification, the oxygen content on the surface of the carbon film is a value obtained by surface analysis by X-ray photoelectron spectroscopy (XPS). In XPS, elemental analysis of the outermost surface from the surface of a carbon film to about 3 nm is possible.

  The oxygen-containing carbon film forming step is preferably a step in which the silicon content excluding hydrogen on the bonded surface of the carbon film is 20 to 40 atomic%, further 25 to 40 atomic%. In the case of a carbon film containing silicon, the surface carbon of the carbon film is oxidized and vaporized by performing UV treatment or plasma treatment, so that the silicon content of the surface layer of the carbon film can be increased. By setting the silicon content of the bonded surface of the carbon film to 20 to 40 atomic%, a bonded body having a high bonding shear strength at the bonded portion can be obtained. The silicon content of the bonded surface of the carbon film can be set to a desired content by changing the film forming conditions of the carbon film and the processing conditions of the UV treatment and the plasma treatment. In this specification, the silicon content on the surface of the carbon film is a value obtained by surface analysis by X-ray photoelectron spectroscopy (XPS).

  The soldering step is a step of soldering the carbon film and the metal material with tin solder containing at least one selected from the group consisting of tin and zinc and rare earth elements. In the soldering step, tin solder having the above composition may be used, and soldering may be performed by a normal procedure. When soldering is performed by ultrasonic bonding, it is preferable that the molten tin solder is bonded to the bonded surface by the cavitation effect by applying ultrasonic waves, and oxygen of the bonded surface is easily trapped. At this time, since soldering can be performed at 100 to 400 ° C., deterioration of the carbon film or the metal material due to heat is prevented.

  As mentioned above, although embodiment of the joined_body | zygote of this invention and its manufacturing method was demonstrated, this invention is not limited to the said embodiment. The present invention can be implemented in various forms without departing from the gist of the present invention, with modifications and improvements that can be made by those skilled in the art.

  Hereinafter, the present invention will be specifically described with reference to examples of the joined body and the method for producing the same according to the present invention.

  A pair of test pieces was prepared from two pure aluminum plate materials, a DLC film was formed on one, and both were soldered to obtain a joined body. In addition, the shape of the joined body was the same as the No. 1 shear test piece test material defined in JISZ3198-5. The production procedure will be described below.

[DLC film formation]
A DLC film was formed on the entire surface of the aluminum test piece by DC plasma CVD. When forming a DLC film containing argon, hydrogen as a dilution gas, and methane and silicon as source gases, tetramethylsilane is further used to form a plasma by applying a DC voltage, DLC films containing hydrogen and different silicon contents were formed. The silicon content was adjusted by changing the amount of tetramethylsilane.

[Oxygen-containing carbon film formation process]
The DLC film formed on the test piece was subjected to UV treatment or plasma treatment to give oxygen to the surface of the DLC film. The UV treatment uses a UV ozone cleaner (UV42 manufactured by Philgen Co., Ltd.), and the treatment time is in the range of 1 to 120 minutes under the conditions of wavelengths: 184.9 nm and 253.7 nm, ultraviolet intensity: 28 mW / cm ^2. I changed it. The plasma treatment was performed using a hydrophilic treatment apparatus for an electron microscope (HDT-400 manufactured by JEOL Ltd.) with a plasma output of 500 W and a treatment time in the range of 10 to 120 seconds.

[Analysis of DLC film]
The silicon content in the DLC film was quantified by electron probe microanalysis (EPMA) and X-ray photoelectron spectroscopy (XPS). The hydrogen content in the film was quantified by elastic recoil particle detection (ERDA). ERDA is a method of measuring the hydrogen concentration in the film by irradiating the surface of the film with a 2 MeV helium ion beam, detecting hydrogen ejected from the film with a semiconductor detector.

  Further, the carbon, oxygen and silicon contents on the surface of the DLC film were measured by XPS. For this surface analysis, an XPS analyzer manufactured by ULVAC-PHI Co., Ltd. was used. X-ray source: monochromatic AlKα, photoelectron extraction angle: 5 °, analysis region: about 200 μmφ, C1s, O1s and Si2p about 3 nm from the outermost surface From the spectrum, the content of each element contained on the surface of the DLC film was determined.

  The XPS analysis results of each DLC film after the oxygen-containing amorphous carbon film forming step are shown in FIGS. FIG. 3 shows the surface element content with respect to the time of the plasma treatment performed on the DLC film that does not contain silicon and has a hydrogen content of 20 atomic% when the DLC film is 100 atomic%. FIG. 4 shows the surface element content with respect to the time of UV treatment performed on the DLC film having no hydrogen and 20 atomic% when the DLC film is 100 atomic%. FIG. 5 shows the surface element content with respect to the time of plasma treatment performed on the DLC film having a silicon content of 5 atomic% and a hydrogen content of 34 atomic% when the DLC film is 100 atomic%. FIG. 6 shows the surface element content with respect to the time of UV treatment performed on a DLC film having a silicon content of 6 atomic% and a hydrogen content of 30 atomic% when the DLC film is 100 atomic%. FIG. 7 shows the surface element content with respect to the time of UV treatment performed on a DLC film having a silicon content of 10 atomic% and a hydrogen content of 31 atomic% when the DLC film is 100 atomic%.

  In the DLC film not containing silicon (FIGS. 3 and 4), the oxygen amount was not greatly increased, but the oxygen amount was increased as compared with the untreated film (processing time 0). This is because the C—C bond and the C—H bond are changed to the C—O bond and the C═O bond by the UV treatment and the plasma treatment. However, even when the treatment time was extended, the amount of oxygen was almost constant, and there was no significant difference in the treatment method. The reason why the amount of oxygen did not increase greatly is presumed that the amount of oxygen that can be imparted is limited because carbon is oxidized and vaporized during the treatment. On the other hand, in the DLC film containing silicon (FIGS. 5 to 7), the amount of oxygen on the surface tends to increase as the treatment time becomes longer. Further, since carbon is oxidized and vaporized during the treatment, silicon on the surface is concentrated, so that it can be said that oxygen is easily provided.

[Soldering process]
Next, the test piece that had been subjected to UV treatment or plasma treatment after the DLC film was formed and the test piece that did not have the DLC film were soldered with a solder for ceramics (Cerasolzer Eco # 217 manufactured by Eishin Industry Co., Ltd.). In addition, this solder for ceramics is Sn-3.8Zn-1.24Sb-0.03Al (a numerical value is mass%). For soldering, an ultrasonic soldering device (special sun bonder SO-6 manufactured by Eishin Industry Co., Ltd.) was used, and each test piece was placed on a heater held at 290 ° C. or higher, and each soldered portion (covered part) After preliminarily soldering the ceramic solder to the bonding surface) while applying ultrasonic waves, the bonded surfaces were overlapped and bonded on the bonding jig.

[Evaluation]
The joining strength (joining shear strength) of the joined body obtained by soldering each test piece shown in FIGS. 4, 6 and 7 by the above procedure was measured by the method defined in JISZ3198-5. The measurement results are shown in FIGS. FIG. 8 is a graph showing the bonding shear strength with respect to the surface oxygen content of the DLC film, and FIG. 9 is a graph showing the bonding shear strength with respect to the surface silicon content. In addition, the joined body using the test piece with the UV treatment time of 0 hour is a comparative example (indicated as “untreated” in FIGS. 8 and 9).

  According to FIG. 8, in the DLC film not containing silicon, each bonded body having the DLC film whose surface oxygen content is about 30 at% after UV treatment is compared with the untreated (oxygen 15 at%) bonded shear. Strength improved. Further, in the DLC film containing silicon, the higher the surface oxygen content, the better the joint shear strength. In particular, in each joined body having a DLC film having a surface oxygen content of 54 to 63 at%, the joint shear exceeding 4.9 MPa. Intensity was shown.

  Moreover, from FIG. 9, each joined body having a DLC film having a surface silicon content of 25 at% or more showed a joining shear strength exceeding 4.9 MPa.

[Comparative example]
A bonded body was prepared using Sn—Cu solder on a DLC film (each test piece in FIG. 7) subjected to UV treatment containing 10 atomic% of silicon. Soldering was performed at 230 ° C. or higher.

  In the soldering, the DLC film and the Sn—Cu solder were not wet at all in any of the test pieces. In other words, it was not possible to join even with or without UV treatment.

It is sectional drawing which shows the conjugate | zygote of this invention typically. It is sectional drawing which shows typically the semiconductor element heat radiating member consisting of the conjugate | zygote of this invention. The surface element content with respect to the time of the plasma treatment performed on the DLC film not containing silicon is shown. The surface element content with respect to the time of UV treatment performed on the DLC film not containing silicon is shown. The surface element content with respect to the time of the plasma treatment performed on the DLC film having a silicon content of 5 atomic% is shown. The surface element content with respect to the time of UV treatment performed on a DLC film having a silicon content of 6 atomic% is shown. The surface element content with respect to the time of UV treatment performed on a DLC film having a silicon content of 10 atomic% is shown. It is a graph which shows the joining shear strength with respect to the surface oxygen content of a DLC film. It is a graph which shows the joining shear strength with respect to the surface silicon content of a DLC film.

Explanation of symbols

1: First member 1s: Base material 1f: Carbon film 1j: Surface to be bonded 11: Metal substrate 12: Insulating amorphous carbon film 2: Second member (metal material) 2j: Surface to be bonded 21: Electrode 3 30: Junction 3j, 31: Tin solder

Claims (15)

A first member comprising a base material and a carbon film coated on at least a part of the surface of the base material; and a second member comprising at least a part of a metal material, the carbon film and the metal material comprising A joined body having a soldered joint,
The carbon film contains oxygen at least on the bonded surface,
The joint includes at least one selected from the group consisting of tin and zinc and rare earth elements as a main component, and is chemically bonded to oxygen of the carbon film and is formed on the surface of the metal material by diffusion bonding with the metal material. A bonded body characterized in that it is bonded with tin solder that chemically bonds to oxygen of the oxidized oxide.   The joined body according to claim 1, wherein the carbon film is an amorphous carbon film.   The joined body according to claim 1, wherein the carbon film contains silicon at least on a surface to be joined.   The said carbon film is a joined body in any one of Claims 1-3 which contains 2-40 atomic% of silicon, when the whole is 100 atomic%.   The joined body according to any one of claims 1 to 4, wherein a joining shear strength of the joined portion is 5 MPa or more. A first member in which at least a part of a base material is coated with a carbon film; and a second member at least part of which is made of a metal material; and a joining portion in which the carbon film and the metal material are soldered A method for manufacturing a joined body having:
An oxygen-containing carbon film forming step of imparting oxygen to at least the bonded surface of the carbon film;
A soldering step of soldering the carbon film and the metal material with a tin solder containing at least one selected from the group consisting of zinc and rare earth elements mainly composed of tin;
The manufacturing method of the conjugate | zygote characterized by including.   The method of manufacturing a joined body according to claim 6, wherein the carbon film is an amorphous carbon film. The carbon film includes silicon at least on a bonded surface,
The method for manufacturing a joined body according to claim 6 or 7, wherein the oxygen-containing carbon film forming step is a step of adding oxygen to at least silicon.   The method for producing a joined body according to any one of claims 6 to 8, wherein the oxygen-containing carbon film forming step is a step of irradiating the carbon film of the first member with ultraviolet rays in an atmosphere containing oxygen.   The said oxygen-containing carbon film formation process is a process of exposing the said carbon film of said 1st member to the plasma containing oxygen, The manufacturing method of the conjugate | zygote in any one of Claims 6-8.   The said oxygen-containing carbon film formation process is a process which makes oxygen content except hydrogen of the to-be-joined surface of the said carbon film 50-70 atomic%, The manufacturing method of the joined body in any one of Claims 6-10. .   The method for producing a joined body according to claim 9 or 10, wherein the oxygen-containing carbon film forming step is a step of setting a silicon content excluding hydrogen on a bonded surface of the carbon film to 20 to 40 atomic%.   A joined body produced by the production method according to claim 6.   14. The joined body according to claim 13, wherein the carbon film contains 2 to 40 atomic% of silicon when the whole is 100 atomic%.   The joined body according to claim 13 or 14, wherein a joining shear strength of the joined portion is 5 MPa or more.

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