Implementation structure

Abstract

To provide an electronic component that can effectively suppress diffusion of metal atoms from an external electrode to a solder or a solder joint, even when the electronic component is exposed to a high-temperature environment after implementation.SOLUTION: An electronic component includes a component body and an external electrode provided on a surface of the component body, and the external electrode has a layered structure of Ni / Cu / Sn.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an electronic component and a mounting structure including the electronic component. [Background technology]

[0002] Generally, an electronic component includes a component body and an external electrode provided on its surface. When the electronic component is mounted on a substrate, the external electrode can be soldered to an electrode portion (e.g., a land) formed on the substrate (in this specification, a joint formed by soldering is also referred to as a "solder joint"). For example, Patent Document 1 describes that in a multilayer ceramic capacitor having a terminal electrode (external electrode) at an end of a laminate (component body) formed of an internal electrode layer and a dielectric layer, the terminal electrode is formed of an Ag-based conductor film (base film), a Ni-plated intermediate layer, and an external plating layer (Sn-plated layer). Patent Document 1 discloses that by setting the thickness of the Ni-plated intermediate layer to a predetermined thickness or more and reducing the variation therein, it is possible to effectively prevent solder erosion of the Ag-based conductor film that may occur during soldering, and to form a terminal electrode with excellent heat resistance (e.g., 10 seconds at 270°C). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-196351 Summary of the Invention [Problem to be solved by the invention]

[0004] Mounting structures in which electronic components are mounted on a substrate are required to withstand use in even harsher temperature environments, such as when used in a circuit section for electronic fuel injection control in an automobile engine room. When a mounting structure is used in such a harsh high-temperature environment, in a configuration such as that of Patent Document 1, Ni contained in the Ni-plated intermediate layer may diffuse (thermally diffuse) into the solder joint at a relatively high speed, which may cause Ag to diffuse from the Ag-based conductor film (base film) into the solder joint. "Solder erosion," in which Ag is lost from the Ag-based conductor film due to diffusion into the solder joint, may occur even during use of the mounting structure, resulting in insufficient connection between the component body of the electronic component and the Ag-based conductor film, which may reduce the connection reliability of the electronic component.

[0005] The present disclosure aims to provide an electronic component that can effectively suppress diffusion of metal atoms from an external electrode to a solder or a solder joint even when exposed to a high-temperature environment after mounting the electronic component, and further aims to provide a mounting structure on which such an electronic component is mounted. [Means for solving the problem]

[0006] The present disclosure includes the following aspects. [1] A component body; an external electrode provided on a surface of the component body; An electronic component comprising: The external electrodes are 1 / Cu / anti-oxidation film laminate structure, Said M 1 is a metal of Groups 9 to 11, or an alloy containing a metal of Groups 9 to 11; Electronic components. [2] Said M 1 The electronic component according to the above [1], wherein the metal is Ni or an alloy containing Ni. [3] Said M 1 The electronic component according to the above [1] or [2], wherein is Ni. [4] The electronic component according to any one of the above [1] to [3], wherein the antioxidant film is a layer of Sn, Ag, Au, or OSP. [5] The electronic component according to any one of the above [1] to [4], wherein the anti-oxidation film is a Sn layer. [6] The electronic component according to any one of the above [1] to [5], wherein the Cu layer has a thickness of 0.1 μm or more and 10 μm or less. [7] The electronic component according to any one of the above [1] to [6], wherein the Cu layer has a thickness of 0.3 μm or more and 5 μm or less. [8] An electronic component including a component body and an external electrode provided on a surface of the component body; Solder joints and A mounting structure comprising: the electronic component is joined to another electronic component by a solder joint; The external electrodes are provided with (Cu,M 2 ) x Sn y or Cu x Sn y The intermetallic compound layer represented by Said M 2 is a metal of groups 9 to 11, The x is 5 or more and 7 or less, The y is 4 or more and 6 or less. Structural implementation. [9] The external electrodes are 1 / (Cu,M 2 ) x Sn y Or M 1 / Cu x Sn y The laminated structure includes Said M 1 is a metal of Groups 9 to 11, or an alloy containing a metal of Groups 9 to 11, Said M 2 is a metal of groups 9 to 11, The x is 5 or more and 7 or less, The y is 4 or more and 6 or less. The mounting structure according to [8] above.

[10] The external electrodes are 1 / Cu / (Cu,M 2 ) x Sn yOr M 1 / Cu / Cu x Sn y The laminated structure includes Said M 1 is a metal of Groups 9 to 11, or an alloy containing a metal of Groups 9 to 11, Said M 2 is a metal of groups 9 to 11, The x is 5 or more and 7 or less, The y is 4 or more and 6 or less. The mounting structure according to [8] above.

[11] Said M 1 / Cu / (Cu,M 2 ) x Sn y Or M 1 / Cu / Cu x Sn y The mounting structure according to the above

[10] , wherein the thickness of the Cu layer in the laminated structure is 0.1 μm or more and 5 μm or less.

[12] Said M 1 is Ni or an alloy containing Ni, and said M 2 The mounting structure according to any one of the above [9] to

[11] , wherein is Ni.

[13] The above (Cu,M 2 ) x Sn y Layer or Cu x Sn y The mounting structure according to any one of the above items [8] to

[12] , wherein the coverage of the layer with respect to the layer below is 50% or more and 100% or less.

[14] The above (Cu,M 2 ) x Sn y Layer or Cu x Sn y The mounting structure according to any one of the above items [8] to

[13] , wherein the layer has a thickness of 0.1 μm or more.

[15] The mounting structure according to any one of the above [8] to

[14] , wherein x+y is 10 or greater and 12 or less.

[16] The mounting structure according to any one of the above [8] to

[15] , wherein x is 6 and y is 5. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide an electronic component that can effectively suppress the diffusion of metal atoms from external electrodes to solder joints, even when the electronic component is exposed to a high-temperature environment after mounting. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view of a multilayer ceramic capacitor 1a according to one embodiment of the present disclosure. [Diagram 2] FIG. 2 is a schematic cross-sectional view of a mounting structure 21 according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The electronic components and mounting structures of the present disclosure will be described in detail below with reference to the drawings. However, the shapes and arrangements of the electronic components and mounting structures of the respective embodiments are not limited to the examples shown in the drawings.

[0010] The electronic component of the present disclosure comprises: A part body, an external electrode provided on the surface of the component body; An electronic component comprising: The external electrodes are 1 / Cu / anti-oxidation film. 1 is a metal of Groups 9 to 11, or an alloy containing a metal of Groups 9 to 11.

[0011] In this embodiment, the electronic component of the present disclosure may be a multilayer ceramic capacitor 1a shown in Fig. 1. The multilayer ceramic capacitor 1a has a component body 2 and external electrodes 3a and 3b provided on the surface of the component body. The component body 2 has internal electrodes 5a and 5b and a dielectric portion (dielectric layer) 6. The external electrodes 3a and 3b are respectively provided with underlayers 11a and 11b and M 1 The insulating film 10 is made up of layers 12a and 12b, Cu layers 13a and 13b, and oxidation prevention films 14a and 14b.

[0012] The electronic component of the present disclosure has an external electrode, 1 With such a laminated structure, when the electronic component of the present disclosure is mounted on another electronic component by soldering, the above-mentioned M 1 An intermetallic compound layer is formed due to the laminated structure of the anti-oxidation film, Cu, and the like. This intermetallic compound layer can function as a barrier film against solder erosion, and can function as a barrier film for a long period of time even when used at high temperatures, resulting in high reliability.

[0013] In this embodiment, the component body 2 is the body of a capacitor, but is not limited to this as long as an external electrode is provided on the surface of the component body. For example, the component body can be the body of an electronic component that can be used as an inductor, resistor, LC composite component, etc.

[0014] The component body is not particularly limited and may be constructed using a commonly used method.

[0015] The material of the component body is not particularly limited, and may be any commonly used material, such as ceramic, resin, metal, or a composite material thereof, and specifically, ceramic.

[0016] Although the multilayer ceramic capacitor 1a shown in FIG. 1 has two external electrodes, the electronic device of the present disclosure is not limited to this embodiment and may be provided with three or more external electrodes.

[0017] As shown in FIG. 1, the external electrodes 3a and 3b are formed on the underlayers 11a and 11b, respectively. 1 The external electrodes are made up of the underlayer, the copper layers 12a and 12b, the copper layers 13a and 13b, and the oxidation prevention films 14a and 14b. 1 / Cu / anti-oxidation film laminate structure.

[0018] The underlayer is not particularly limited, but may be a layer of Cu, Ag, Ni, or Pd, or an alloy thereof. The underlayer is preferably a layer of Cu or Ag, more preferably a layer of Cu. The underlayer may be a single layer or two or more layers.

[0019] The underlayer may also include other materials, such as glass.

[0020] The underlayer is provided on the surface of the component body, and preferably in contact with the component body.

[0021] The thickness of the underlayer is not particularly limited and may be, for example, 1 μm or more and 500 μm or less, preferably 3 μm or more and 300 μm or less, more preferably 5 μm or more and 100 μm or less, for example, 5 μm or more and 50 μm or less, or 10 μm or more and 30 μm or less.

[0022] The method for forming the underlayer is not particularly limited, and examples thereof include plating (for example, electrolytic plating or electroless plating), sputtering, applying a paste and curing or baking it, and the like.

[0023] The above M 1 The layer is disposed on the underlayer.

[0024] The above M 1 is a metal of Groups 9 to 11, or an alloy containing a metal of Groups 9 to 11.

[0025] In one embodiment, M 1 is Ni or an alloy containing Ni.

[0026] The alloy is preferably an alloy of Ni with one or more metals selected from the group consisting of Zn, W, Re, Os, Mo, Nb, Ir, Ru, Rh, Cr, Pt, Ti, Lu, Pd, Fe, Cu and Co.

[0027] In a preferred embodiment, M 1 is Ni.

[0028] The above M 1 The thickness of the layer is not particularly limited and may be, for example, 0.01 μm to 100 μm, preferably 0.1 μm to 50 μm, more preferably 0.3 μm to 10 μm, for example, 0.3 μm to 3 μm or 1 μm to 5 μm.

[0029] The above M 1 The method for forming the layer is not particularly limited, but examples thereof include plating (eg, electrolytic plating or electroless plating), sputtering, and the like.

[0030] The thickness of the Cu layer may be preferably 0.1 μm to 10 μm, more preferably 0.2 μm to 8 μm, and further preferably 0.3 μm to 5.0 μm. By making the thickness of the Cu layer 0.3 μm or more, when the Cu layer is mounted on another electronic component, the following (Cu,M) can be obtained over a wider range, preferably over the entire surface of the electrode. 2 ) x Sn y or Cu x Sn y A layer of Cu is formed, which can more reliably suppress solder erosion. In addition, by making the thickness of the Cu layer 10 μm or less, miniaturization becomes easier. By making the thickness of the Cu layer 0.1 μm or more, (Cu,M 2 ) x Sn y or Cu x Sn y This makes it easier to form a uniform layer of Cu, which increases the effect of suppressing solder erosion. This is thought to be because if the thickness of the Cu layer is 0.1 μm or more, the Cu in the solder is also supplied to the interface.

[0031] The method for forming the Cu layer is not particularly limited, but examples thereof include plating (for example, electrolytic plating or electroless plating) and sputtering.

[0032] The oxidation prevention film is preferably a layer of Sn, Ag, Au, or OSP (Organic Solderability Preservative, ie, water-soluble preflux).

[0033] The oxidation-preventing film is preferably a layer of Sn, Ag or Au, and more preferably a Sn layer.

[0034] The thickness of the antioxidant film is not particularly limited and may be, for example, 0.01 μm or more and 100 μm or less, preferably 0.1 μm or more and 50 μm or less, more preferably 0.3 μm or more and 10 μm or less, for example, 0.3 μm or more and 3 μm or less, or 1 μm or more and 5 μm or less.

[0035] The method for forming the oxidation-preventing film is not particularly limited, but examples thereof include plating (for example, electrolytic plating or electroless plating), sputtering, and the like.

[0036] The above M 1 The thickness of the laminated structure of / Cu / antioxidation film may be preferably 1.0 μm or more and 300 μm or less, and more preferably 5.0 μm or more and 100 μm or less.

[0037] The above M 1 The layer, the Cu layer, and the oxidation prevention film may each contain other trace substances, such as trace atoms that may be unavoidably mixed in.

[0038] The above M 1 The / Cu / antioxidation film is preferably Ni / Cu / Sn.

[0039] The electronic component of the present disclosure described above can be mounted on another electronic component by using solder, thereby obtaining a mounting structure. The present disclosure also provides a mounting structure including the electronic component of the present disclosure and a solder joint.

[0040] The mounting structure of the present disclosure includes: an electronic component including a component body and an external electrode provided on a surface of the component body; Solder joints and A mounting structure comprising: The electronic component is joined to another electronic component by a solder joint, The external electrodes have a (Cu,M 2 ) x Sn y or Cu x Sn y In this case, the above-mentioned M 2 is a metal of Groups 9 to 11, x is 5 or more and 7 or less, and y is 4 or more and 6 or less.

[0041] In this embodiment, the mounting structure of the present disclosure may be a mounting structure 21 shown in Fig. 2. The mounting structure 21 includes a multilayer ceramic capacitor 1b and solder joints 22a, 22b. The multilayer ceramic capacitor 1b of the mounting structure 21 is joined to a substrate 23, which is another electronic component, by a solder joint. The multilayer ceramic capacitor 1b is obtained by joining the above-mentioned multilayer ceramic capacitor 1a to the substrate 23 by solder, and has the same configuration as the above-mentioned electronic component, except that the external electrodes 3a, 3b are changed to external electrodes 3c, 3d.

[0042] In this embodiment, the other electronic component is a substrate 23, but is not limited thereto and is not particularly limited as long as it is an electronic component that can be connected to the electronic component of the present disclosure by soldering.

[0043] The solder joints 22a, 22b join the substrate 23 and the multilayer ceramic capacitor 1, and more specifically, join electrode portions 24a, 24b provided on the surface of the substrate 23 to external electrodes 3c, 3d of the multilayer ceramic capacitor 1b.

[0044] The electrodes 24a and 24b provided on the surface of the substrate are not particularly limited, and may be any commonly used material. The electrodes may be made of, for example, a conductive material such as Ni, Cu, Ag, Sn, Au, or Pd, and, in some cases, a preflux.

[0045] The solder joints can be formed by a common method, for example, by using a solder paste and reflowing it.

[0046] In this embodiment, the solder is not particularly limited, and any commonly used solder can be used. For example, Sn-Ag-Cu alloy (SAC), Sn-Zn-Bi alloy, Sn-Cu alloy, Sn-Ag-In-Bi alloy, Sn-Zn-Al alloy, Sn-Sb alloy, etc. can be used as the solder.

[0047] In a preferred embodiment, the solder is SAC.

[0048] The external electrodes 3c and 3d are provided with (Cu, M 2 ) x Sn y or Cu x Sn y The presence of such an intermetallic compound layer can suppress the diffusion of metal atoms from the external electrodes to the solder joints, that is, the solder erosion.

[0049] The intermetallic compound layer is present over the entire interface between the external electrode and the solder joint. By having the intermetallic compound layer present over the entire interface between the external electrode and the solder joint, it is possible to more reliably suppress the diffusion of metal atoms from the external electrode to the solder joint.

[0050] The external electrodes in the above mounting structure are 1 / (Cu,M 2 ) x Sn y Or Cu x Sn y , or M 1 / Cu / (Cu,M 2 ) x Sn y Or Cu x Sn y The laminated structure includes:

[0051] The above M 1has the same meaning as above and is a metal of Groups 9 to 11, or an alloy containing a metal of Groups 9 to 11.

[0052] The above M 2 is a metal of Groups 9 to 11.

[0053] In a preferred embodiment, M 2 is Ni.

[0054] The above x is 5 or more and 7 or less, and the above y is 4 or more and 6 or less.

[0055] In one embodiment, x is greater than or equal to 5.5 and less than or equal to 6.5, and y is greater than or equal to 4.5 and less than or equal to 5.5.

[0056] x+y is preferably 10 or more and 12 or less, and more preferably 10.5 or more and 11.5 or less.

[0057] In a preferred embodiment, x is 6 and y is 5.

[0058] The above M 1 / (Cu,M 2 ) x Sn y or Cu x Sn y and M. 1 / Cu / (Cu,M 2 ) x Sn y or Cu x Sn y The laminated structure is such that, when the laminated ceramic capacitor 1a is joined to the substrate 23 by soldering, M 1 / Cu / This is formed when Sn in the oxidation prevention film and Sn in the solder form an intermetallic compound.

[0059] The above (Cu,M 2 ) x Sn y M in 2 The content may be preferably 0.01 at % or more and 25 at % or less, and more preferably 0.1 at % or more and 20 at % or less.

[0060] The above M 1 The thickness of the layer may be preferably 0.1 μm to 10 μm, more preferably 0.5 μm to 8 μm.

[0061] The thickness of the Cu layer, if present, may preferably be 0.1 μm to 5 μm, more preferably 0.3 μm to 3 μm.

[0062] The above (Cu,M 2 ) x Sn y or Cu x Sn y The thickness of the layer may preferably be 0.01 μm or more and 20 μm or less. (Cu,M 2 ) x Sn y or Cu x Sn y By making the thickness of the layer 0.01 μm or more, it is possible to more reliably suppress the diffusion of metal atoms from the external electrodes to the solder joints. (Cu,M 2 ) x Sn y or Cu x Sn y By setting the layer thickness to 20 μm or less, the mounting structure can be made smaller. EXAMPLES

[0063] Hereinafter, the electronic component and mounting structure of the present disclosure will be specifically described using examples, but the electronic component and mounting structure of the present disclosure are not limited to these examples.

[0064] Examples 1 to 3 (Electronic component manufacturing) The chip-shaped ceramic laminate was immersed in a paste containing Cu powder and glass, and then pulled out to adhere the paste. It was then fired at 800°C to form a composite layer containing Cu and glass as a base layer on the surface of the ceramic laminate. Next, a Ni layer, a Cu layer, and a Sn layer were formed on the base layer by sputtering to obtain samples of Examples 1 to 3. The thickness of each layer is shown in Table 1.

[0065] Comparative Example 1 A sample of Comparative Example 1 was obtained in the same manner as in Examples 1 to 3 above, except that the Cu layer between the Ni layer and the Sn layer was not formed.

[0066] [Table 1]

[0067] Examples 4 to 6 (Creating mounting structure) The samples of Examples 1 to 3 were reflow-mounted on a printed circuit board using SAC solder to obtain the mounting structures of Examples 4 to 6. Reflow was performed at a preheat temperature of 150° C., which was kept for 60 seconds, and then at a maximum temperature of 250° C. for 100 seconds.

[0068] Comparative Example 2 The sample of Comparative Example 1 was reflow-mounted on a printed circuit board using SAC solder to obtain a mounting structure of Comparative Example 2.

[0069] Test Example 1 For the mounting structures of Examples 4 to 6 and 2, the cross sections of the external electrodes were observed with a scanning electron microscope (FE-SEM / EDX) (manufactured by Hitachi High-Technologies Corporation, FE-SEM: SU8230 / EDX: 5060FQ).

[0070] It was confirmed that, for the mounting structures of Examples 4 to 6, the external electrodes had a Ni / (Cu,Ni)6Sn5 layer formed on the underlayer, whereas, for the sample of Comparative Example 2, it was confirmed that a Ni / Ni3Sn4 / (Cu,Ni)6Sn5 layer was formed on the underlayer.

[0071] Test example 2 (heat resistance test) The mounting structures obtained in Examples 4 to 6 and Comparative Example 2 were left to stand in an environment at a temperature of 175°C, and observed for the presence or absence of solder erosion. The presence or absence of solder erosion was determined by observing the cross section of the external electrodes with a scanning electron microscope (FE-SEM / EDX) (manufactured by Hitachi High-Technologies Corporation, FE-SEM: SU8230 / EDX: 5060FQ). In addition, the reaction rate constant for solder erosion was calculated from the difference between the initial film thickness and the film thickness after standing at 175°C. The results are shown in the table below.

[0072] [Table 2]

[0073] No solder erosion was observed even after 500 hours in the mounting structures of Examples 4 to 6. On the other hand, in the mounting structure of Comparative Example 2, localized solder erosion was observed. [Industrial Applicability]

[0074] The electronic components of the present disclosure are suitable for use in applications requiring use at high temperatures. [Explanation of symbols]

[0075] 1a, 1b...Multilayer ceramic capacitor 2…Part body 3a,3b…External electrode 3c,3d…External electrode 5a,5b…Internal electrode 6...Dielectric part (dielectric layer) 11a,11b...base layer 12a, 12b…M 1 layer 13a,13b…Cu layer 14a, 14b...Anti-oxidation film 21...Mounting structure 22a, 22b...Solder joint 23...Substrate 24a, 24b...electrode part

Claims

1. A part body, an external electrode provided on a surface of the component body; An electronic component comprising: The external electrodes are １ / Cu / antioxidation film laminate structure, Said M １ is a metal of Groups 9 to 11 or an alloy containing a metal of Groups 9 to 11; Electronic components.

2. Said M １ The electronic component according to claim 1 , wherein is Ni or an alloy containing Ni.

3. Said M １ The electronic component according to claim 1 or 2, wherein is Ni.

4. 4. The electronic component according to claim 1, wherein the oxidation prevention film is a layer of Sn, Ag, Au, or OSP.

5. 5. The electronic component according to claim 1, wherein the anti-oxidation film is a Sn layer.

6. The electronic component according to any one of claims 1 to 5, wherein the Cu layer has a thickness of 0.1 µm or more and 10 µm or less.

7. The electronic component according to any one of claims 1 to 6, wherein the Cu layer has a thickness of 0.3 µm or more and 5 µm or less.

8. an electronic component including a component body and an external electrode provided on a surface of the component body; Solder joints and A mounting structure comprising: the electronic component is joined to another electronic component by a solder joint; The external electrodes are provided with (Cu, M ２ ) ｘ Sn ｙ Or Cu ｘ Sn ｙ The intermetallic compound layer represented by Said M ２ is a metal of Groups 9 to 11, The x is 5 or more and 7 or less, The y is 4 or more and 6 or less. Structural implementation.

9. The external electrodes are １ / (Cu, M ２ ) ｘ Sn ｙ Or M １ / Cu ｘ Sn ｙ The laminated structure includes Said M １ is a metal of Groups 9 to 11 or an alloy containing a metal of Groups 9 to 11; Said M ２ is a metal of Groups 9 to 11, The x is 5 or more and 7 or less, The y is 4 or more and 6 or less. The mounting structure according to claim 8 .

10. The external electrodes are １ / Cu / (Cu,M ２ ) ｘ Sn ｙ Or M １ / Cu / Cu ｘ Sn ｙ The laminated structure includes Said M １ is a metal of Groups 9 to 11 or an alloy containing a metal of Groups 9 to 11; Said M ２ is a metal of Groups 9 to 11, The x is 5 or more and 7 or less, The y is 4 or more and 6 or less. The mounting structure according to claim 8 .

11. Said M １ / Cu / (Cu,M ２ ) ｘ Sn ｙ Or M １ / Cu / Cu ｘ Sn ｙ 11. The mounting structure according to claim 10, wherein the thickness of the Cu layer in the laminated structure is 0.1 μm or more and 5 μm or less.

12. Said M １ is Ni or an alloy containing Ni, and the M ２ The mounting structure according to any one of claims 8 to 11, wherein is Ni.

13. The (Cu, M ２ ) ｘ Sn ｙ Layer or Cu ｘ Sn ｙ 13. The mounting structure according to claim 8, wherein the coverage of the layer with respect to the underlying layer is 50% or more and 100% or less.

14. The (Cu, M ２ ) ｘ Sn ｙ Layer or Cu ｘ Sn ｙ The mounting structure according to any one of claims 8 to 13, wherein the layer has a thickness of 0.1 µm or more.

15. The mounting structure according to any one of claims 8 to 14, wherein x+y is 10 or more and 12 or less.

16. The mounting structure according to any one of claims 8 to 15, wherein x is 6 and y is 5.

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