Module board and electronic device

Abstract

To provide a module substrate with excellent electrical and mechanical properties and an electronic device equipped with the same by making each outer surface of a multilayer substrate, or the outer surface of each part of a module substrate including a multilayer substrate and mounted components, into an appropriate surface.SOLUTION: A module substrate 301 includes a multilayer substrate 101 and a mounted component 201. The multilayer substrate 101 includes multiple resin layers and conductor layers attached to certain of the multiple resin layers, and has a first surface S1 and a second surface S2 that form a front and back surface relationship. The multilayer substrate 101 includes an external electrode 1 on the first surface S1. When the maximum height roughness of the mounting portion facing region of the multilayer substrate 101 is represented by Rz1, the maximum height roughness of the mounting portion on the second surface S2 of the multilayer substrate 101 is represented by Rz2, and the maximum height roughness of the radiating electrode forming region of the mounted component 201 is represented by Rz3, the relationship of Rz1<Rz2<Rz3 is satisfied.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a module substrate including a multilayer substrate formed by laminating resin layers and components mounted on the multilayer substrate, and to an electronic device including the module substrate. [Background technology]

[0002] Patent Document 1 discloses a multilayer substrate including a plurality of resin layers, conductor layers attached to one side of the resin layers, and interlayer connection conductors formed inside predetermined resin layers. It also discloses a module substrate in which a radiating electrode is laminated on a part of the multilayer substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 051649 Summary of the Invention [Problem to be solved by the invention]

[0004] The outer surfaces of the resin layers and conductor layers that make up the multilayer board in the lamination direction, as well as the mounting surfaces and outer surfaces of the components mounted on the multilayer board, were uniform and without distinction.

[0005] The inventors of the present application have discovered that it is important that each outer surface of a multilayer substrate, or each outer surface of a module substrate that includes a multilayer substrate and components mounted thereon, be an appropriate surface in terms of electrical and mechanical properties, a concept that has not been previously considered.

[0006] For example, when a mounted component functions as an antenna, either by itself or as a main part, the outer surface of the mounted component is important in terms of antenna characteristics. It is also important that the bonding surface between the multilayer substrate and the mounted component is an appropriate surface in terms of mechanical properties. Furthermore, the outer surface of a module substrate may be required as a mounting surface.

[0007] Therefore, an object of the present invention is to provide a module substrate having excellent electrical and mechanical characteristics, and an electronic device including the same, by making the outer surfaces of each of the multilayer substrates or the outer surfaces of each part of the module substrate including the multilayer substrate and the mounted components face the appropriate front surface.

Means for Solving the Problems

[0008] (1) A module substrate as an example of the present disclosure includes a multilayer substrate having a plurality of resin layers and a conductor layer attached to a predetermined resin layer among the plurality of resin layers, an insulator and a radiation electrode formed on the insulator, and a mounted component mounted on the multilayer substrate, and is provided with the multilayer substrate has a first surface and a second surface that form a front-back relationship, the multilayer substrate has an external electrode exposed on the first surface, the multilayer substrate has a mounting portion of the mounted component on a part of the second surface of the multilayer substrate, the mounted component has a mounting surface that contacts the mounting portion of the multilayer substrate, the radiation electrode is formed on a surface away from the mounting surface or in a region along the surface, the resin layer in the mounting portion of the multilayer substrate and the insulator on the mounting surface of the mounted component are directly joined, When the width of the mounting portion facing region, which is the region of the first surface of the multilayer substrate that faces the mounting portion, is defined as the reference length of the cross-sectional curve of the mounting portion facing region, the maximum height roughness of the mounting portion facing region is represented by Rz1, when the width of the mounting portion of the multilayer substrate on the second surface is defined as the reference length of the cross-sectional curve of the mounting portion, the maximum height roughness of the mounting portion is represented by Rz2, and when the width of the formation region of the radiation electrode is defined as the reference length of the cross-sectional curve of the insulator, and the maximum height roughness of the surface of the insulator is represented by Rz3, they are in the relationship of Rz1 < Rz2 < Rz3. This is a characteristic.

[0009] (2) An electronic device as an example of the present disclosure The device is characterized by comprising the module substrate and another substrate on which the module substrate is mounted.

[0010] (3) An electronic device as an example of the present disclosure includes: The module is characterized by comprising the module substrate and a housing that houses the module substrate. [Effects of the Invention]

[0011] According to the present invention, by making each outer surface of a multilayer substrate, or the outer surface of each part of a module substrate including a multilayer substrate and mounted components, into an appropriate surface, a module substrate with excellent electrical and mechanical properties and an electronic device equipped with the same can be obtained. [Brief explanation of the drawings]

[0012] [Figure 1] The lower part of FIG. 1 is a cross-sectional view of a module substrate 301 according to the first embodiment, and the upper part of FIG. 1 is a cross-sectional view of a state before mounting components 201 on a multilayer substrate 101. [Figure 2] The lower part of FIG. 2 is a cross-sectional view of a module substrate 302 according to the second embodiment, and the upper part of FIG. 2 is a cross-sectional view of a state before mounting components 202 on a multilayer substrate 102. [Figure 3] The lower part of FIG. 3 is a cross-sectional view of a module substrate 303 according to the third embodiment, and the upper part of FIG. 3 is a cross-sectional view of the multilayer substrate 103 before mounting components 203 thereon. [Figure 4] FIG. 4 is a cross-sectional view of a module substrate 304 according to the fourth embodiment. [Figure 5] FIG. 5 is a cross-sectional view of a module substrate 305 according to the fifth embodiment. [Figure 6] FIG. 6 is a cross-sectional view of a module substrate 306 according to the sixth embodiment. [Figure 7] FIG. 7 is a cross-sectional view of an electronic device 407 according to the seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, several specific examples will be given with reference to the drawings to illustrate multiple modes for carrying out the present invention. The same symbols are used for the same parts in each drawing. To facilitate explanation and understanding of the main points, the modes for carrying out the invention are shown divided into multiple embodiments, but partial omission, substitution, or combination of the configurations shown in different embodiments is possible. From the second embodiment onwards, descriptions of matters common to the first embodiment will be omitted, and only the differences will be described. In particular, similar effects resulting from similar configurations will not be mentioned in each embodiment.

[0014] First Embodiment In the first embodiment, an example of a module substrate configured by mounting components on a multilayer substrate will be described.

[0015] The lower part of Fig. 1 is a cross-sectional view of a module substrate 301 according to the first embodiment, and the upper part of Fig. 1 is a cross-sectional view of a multilayer substrate 101 in a state before a mounted component 201 is mounted thereon. In Fig. 1, even if the mounted component 201 has multiple insulator layers, the interface between two adjacent insulator layers in the layer direction is not shown. Also, in the cross-sectional view, lines that appear in the cross section (appearing due to cutting) are drawn, and lines that exist behind the cross section are not shown. This also applies to each embodiment described later.

[0016] Module substrate 301 includes multilayer substrate 101 and mounted component 201. Multilayer substrate 101 includes a plurality of resin layers 11, 12, 13, 14, and 15, and conductor layers and interlayer connection conductors attached to predetermined resin layers among the plurality of resin layers.

[0017] A connection conductor BM is applied to the opening of the resin layer 15. The connection conductor BM is, for example, a heat-melting metal such as solder. Multilayer substrate side pad electrodes 2a and 2b are formed below the connection conductor BM. In this example, the resin layers 11, 12, 13, 14, and 15 are laminates of thermoplastic resin sheets with Cu foil attached to one side.

[0018] As shown in the upper part of FIG. 1, the multilayer substrate 101 has a first surface S1 and a second surface S2 that form a front-back relationship. A resin surface RS is exposed on the second surface S2 of the multilayer substrate 101.

[0019] On the upper surface or in the vicinity of the upper surface of the mounted component 201, radiation electrodes 7a, 7b and other electrodes 8 are formed so that the mounted component 201 acts as a patch antenna or as part of a patch antenna. The radiation electrodes 7a, 7b and the electrode 8 are along the upper surface of the mounted component 201. In the upper part of FIG. 1, the width Wr indicates the width of the radiation electrode formation region.

[0020] Terminal electrodes 6a, 6b are formed on the mounting surface (lower surface) of the mounted component 201. A plated through hole 9 is formed between the terminal electrodes 6a, 6b and the radiation electrodes 7a, 7b. An insulating surface IS is exposed on the mounting surface (lower surface) of the mounted component 201. In the upper part of FIG. 1, the width Wm indicates the width of the mounting part of the mounted component 201.

[0021] Here, taking the width Wm of the mounting part facing region, which is the region of the first surface S1 of the multilayer substrate 101 that faces the mounting part of the mounted component 201, as the reference length of the cross-sectional curve of the mounting part facing region, the maximum height roughness of the mounting part facing region is represented by Rz1. Rz1 is, for example, 4 μm.

[0022] Also, taking the width Wm of the mounting part of the mounted component 201 as the reference length of the cross-sectional curve of the mounting part, the maximum height roughness of the mounting part is represented by Rz2. Rz2 is, for example, 50 μm.

[0023] Also, taking the width Wr of the formation region of the radiation electrodes 7a, 7b as the reference length of the cross-sectional curve of the insulator of the mounted component 201, the maximum height roughness of the surface of the insulator is represented by Rz3. Here, the "surface of the insulator" means the surface of the insulator that the radiation electrodes 7a, 7b contact.

[0024] The above maximum height roughnesses Rz1, Rz2, Rz3 are in the relationship of Rz1 < Rz2 < Rz3. Thus, the module substrate 301 has three surfaces with different roughnesses (concavities and convexities).

[0025] When manufacturing the multilayer substrate 101, the laminated resin layers are pressed against a smooth rigid body to determine the maximum height roughness Rz1 of the first surface S1 of the multilayer substrate 101. The second surface of the multilayer substrate 101 is pressed against an object with a small maximum height roughness to determine the maximum height roughness Rz2 of the second surface S2 of the multilayer substrate 101.

[0026] When mounting component 201 is manufactured, the maximum height roughness Rz3 of the upper surface of mounting component 201 is determined by pressing the upper surface of mounting component 201 with an object having a large maximum height roughness in contact with it.

[0027] The external electrodes 1 of the multilayer substrate 101 are connected to pad electrodes formed on another substrate as will be described later, thereby mounting the module substrate 301 on the other substrate. Alternatively, as will be described later, electronic components are mounted on the external electrodes 1, thereby forming a module substrate on which electronic components are mounted.

[0028] Signal line conductor patterns SL1 and SL2 and a ground conductor layer GL are formed inside the multilayer substrate 101. Two microstrip transmission lines are configured by the signal line conductor patterns SL1 and SL2, the ground conductor layer GL, and the resin layer between the signal line conductor patterns SL1 and SL2 and the ground conductor layer GL.

[0029] 1, a component 201 is placed at a predetermined position on a multilayer substrate 101, and the entire structure is heated to a predetermined temperature and pressurized with a predetermined pressure. This melts the connection conductor BM, electrically connecting pad electrodes 2a and 2b on the multilayer substrate to terminal electrodes 6a and 6b on the component 201. Furthermore, the insulator surface IS of the component 201 and the resin surface RS of the multilayer substrate 101 are directly bonded to each other.

[0030] For example, the insulating material of the mounted component 201 is the same material as the resin layers 11, 12, 13, 14, and 15 of the multilayer substrate 101. This makes it possible to obtain high adhesion between the mounted component 201 and the multilayer substrate 101. For example, the insulator of the mounted component 201 and the resin layers 11, 12, 13, 14, and 15 of the multilayer substrate 101 are made of a thermoplastic resin, such as a liquid crystal polymer resin (LCP).

[0031] Whether or not the resin materials are the same can be confirmed using a Fourier transform infrared spectrophotometer (FT-IR). That is, a spectrum is obtained using a Fourier transform infrared spectrophotometer (FT-IR), and if the peaks of the spectrum are the same for the mounted component and the multilayer board, it can be confirmed that they are the same type of resin materials.

[0032] Furthermore, with thermoplastic resins, the difference in melting points between resin materials of the same type is small. Whether the resin part of a multilayer board and the resin part of the mounted components are made of the same type of resin can be confirmed by looking at the endothermic peak in differential scanning calorimetry (DSC). Specifically, using a Rigaku DSC8230, the temperature is raised at a rate of 10°C / min, the melted material is cooled, and then the temperature is raised again at 10°C / min. If the difference in melting points between the two resin materials is within 5°C, they can be considered to be the same type of resin.

[0033] The same or different type determination as described above is also applicable to other embodiments described below.

[0034] In this way, if a thermoplastic resin is used, a stronger adhesive force can be obtained between the mounted component 201 and the multilayer substrate 101. Furthermore, if the resin layer of the multilayer substrate 101 is made of a thermoplastic resin, it is easy to stack resin sheets together and a separate bonding process is not required, so the total number of processes can be reduced and manufacturing can be done at low cost.

[0035] Furthermore, if the resin layer of multilayer substrate 101 is made of a liquid crystal polymer resin, multilayer substrate 101 has a low water absorption rate, so that fluctuations in electrical characteristics due to humid environments are suppressed, resulting in a highly reliable module substrate.

[0036] The insulating material of the mounted component 201 and the resin layers 11, 12, 13, 14, and 15 of the multilayer substrate 101 may be different materials. For example, one of the insulating materials of the resin layers 11, 12, 13, 14, and 15 of the multilayer substrate 101 and the mounted component 201 may be a thermoplastic resin and the other may be a thermosetting resin. Examples of thermosetting resins include polyimide resin and epoxy resin.

[0037] The insulator of the mounted component 201 may be ceramic. In this case, the insulator surface IS of the mounted component 201 and the resin surface RS of the multilayer substrate 101 can be directly bonded.

[0038] The resin layers of multilayer substrate 101 do not have to be of the same type, and layers of different materials may be mixed. However, if resin layer 15 forming second surface S2 is made of a thermoplastic resin, direct bonding between insulator surface IS of mounted component 201 and resin surface RS of multilayer substrate 101 becomes easy.

[0039] Alternatively, the resin layer 15 forming the second surface S2, or the entire resin layers 11 to 15, may be made of a thermosetting resin. In this case, a sheet of a pre-crosslinking reaction product may be used for at least the resin layer 15, and the resin may be thermoset by heating, during which the insulator surface IS of the mounted component 201 and the resin surface RS of the multilayer substrate 101 may be directly bonded.

[0040] Mounted component 201 is a component that meets the electrical characteristics required for an antenna, and therefore a material that can provide the required characteristics can be used as the insulating material for mounted component 201. For example, if it is important that the insulator for mounted component 201 has a high dielectric constant, a material with a higher dielectric constant than the resin layer of multilayer substrate 101 is used. This makes it possible to obtain module substrate 301 equipped with an antenna with excellent electrical characteristics.

[0041] As described above, the roughness in maximum height Rz1 of the first surface S1 of the multilayer substrate 101 is smaller than the roughness in maximum height Rz2 of the second surface S2 of the multilayer substrate 101.

[0042] The fact that the maximum height roughness of first surface S1 of multilayer substrate 101 is the smallest means that the mounting surface of module substrate 301 is highly smooth. As a result, when mounting module substrate 301 on another substrate, the module substrate can be easily mounted on the highly flat mounting surface of the other substrate. Furthermore, when mounting electronic components on external electrodes 1 of module substrate 301, the electronic components can be easily mounted on the highly flat bottom surface of module substrate 301 (first surface S1 of multilayer substrate 101).

[0043] As described above, the roughness in maximum height Rz2 of the second surface S2 of the multilayer substrate 101 is greater than the roughness in maximum height Rz1 of the first surface S1 of the multilayer substrate 101.

[0044] The predetermined maximum height roughness on the second surface S2 of the multilayer substrate 101 enhances the adhesion of the mounted component 201 to the second surface S2 of the multilayer substrate 101. In other words, the substantial contact area between the resin surface RS and the insulator surface IS is large, so that the adhesion of the mounted component 201 to the second surface S2 of the multilayer substrate 101 is high.

[0045] As already mentioned, the maximum height roughness Rz3 of the surface (top surface) of the mounted component 201 opposite the mounting surface on the multilayer substrate 101 is larger than the maximum height roughness Rz1 of the first surface S1 of the multilayer substrate 101 and the maximum height roughness Rz2 of the second surface S2 of the multilayer substrate 101.

[0046] Because the maximum height roughness of the top surface of the mounted component is large, the electrical characteristics of the mounted component as an antenna can be set to predetermined characteristics, compared to a mounted component having electrodes formed on or near a flat surface. In the first embodiment, the top surface of the mounted component 201 is provided with radiating electrodes 7a, 7b and other electrodes 8. A patch antenna is formed by these radiating electrodes 7a, 7b, the ground conductor layer GL of the multilayer substrate 101, and a resin layer between the radiating electrodes 7a, 7b and the ground conductor layer GL of the multilayer substrate 101. The antenna directivity and other characteristics can be set to predetermined characteristics depending on the maximum height roughness Rz3 of the top surface of the mounted component 201. In other words, a module substrate can be obtained that has excellent electrical characteristics of the mounted component or excellent electrical characteristics of the electronic circuit formed by the mounted component and the multilayer substrate.

[0047] Second Embodiment In the second embodiment, a module substrate in which the mounting structure of components on a multilayer substrate is different from that in the first embodiment will be exemplified.

[0048] The lower part of FIG. 2 is a cross-sectional view of a module substrate 302 according to the second embodiment, and the upper part of FIG. 2 is a cross-sectional view of a state before mounting components 202 on a multilayer substrate 102.

[0049] This module substrate 302 includes a multi-layer substrate 102 and a mounted component 202 .

[0050] The multilayer substrate 102 includes a plurality of resin layers 11, 12, 13, 14, and 15, and conductor layers and interlayer connection conductors attached to predetermined resin layers among the plurality of resin layers.

[0051] An opening is formed in the resin layer 15 of the multilayer substrate 102, and this opening forms a recess (cavity) CA in the surface of the laminate. The mounted component 202 is mounted in the recess CA of the multilayer substrate 102.

[0052] 2, a resin surface RS is exposed on the second surface S2 of the multilayer substrate 102. Also, an insulator surface IS is exposed on the lower surface of the mounted component 202.

[0053] The mounted component 202 includes a lamination direction conductor path formed by laminating resin sheets having interlayer connection conductors 4 and conductor foils 5 in contact with the interlayer connection conductors 4 .

[0054] Incidentally, by forming the stacking direction conductor paths, it is also possible to form uneven portions on the top surface of the mounted component 202.

[0055] Similar to the example shown in the first embodiment, the maximum height roughness of the mounting portion on the first surface S1 of the multilayer substrate 102 is represented by Rz1, and among the second surfaces S2 of the multilayer substrate 102, the maximum height roughness in the opposing region of the mounting portion is represented by Rz2. When the maximum height roughness of the surface of the insulator in the radiation electrode formation region of the mounted component 202 is represented by Rz3, they are in the relationship of Rz1 < Rz2 < Rz3.

[0056] A plurality of external electrodes 1 are exposed on the first surface S1 of the multilayer substrate 102. In the state shown at the upper part of FIG. 2, on the second surface (the surface within the recessed portion CA) of the multilayer substrate 102, connection conductors BM that are respectively conductive with the ends of the signal line conductor patterns SL1 and SL2 are formed.

[0057] The mounted component 202 is a laminated substrate with resin layers laminated thereon, and the resin materials of each resin layer of this mounted component 202 and the resin materials of each resin layer of the multilayer substrate 102 are of the same type. For example, a thermoplastic resin. An example of this thermoplastic resin is, for example, a liquid crystal polymer resin (LCP).

[0058] As shown in FIG. 2, the mounted component 202 is mounted within the recessed portion CA of the multilayer substrate 102, and the whole is pressurized and heated to a predetermined temperature, thereby adhesively mounting the mounted component 202 within the recessed portion CA of the multilayer substrate 102. That is, the ends of the signal line conductor patterns SL1 and SL2 on the multilayer substrate side are electrically connected to the terminal electrodes 6a and 6b on the mounted component 202 side via the connection conductors BM. Also, the insulating surface IS of the mounted component 202 and the resin surface RS of the multilayer substrate 102 are directly joined.

[0059] Note that the materials of each resin layer of the mounted component 202 are not limited to being of the same type, and layers of different materials may be mixed. Also, for each resin layer of the multilayer substrate 102, it is not limited to being of the same type, and layers of different materials may be mixed.

[0060] 《Third Embodiment》 In the third embodiment, examples are given particularly regarding the materials of the insulator of the mounted component and the material of the multilayer substrate, and further regarding the joining method.

[0061] The lower part of FIG. 3 is a cross-sectional view of the module substrate 303 according to the third embodiment, and the upper part of FIG. 3 is a cross-sectional view of the component 203 before being mounted on the multilayer substrate 101.

[0062] This module substrate 303 includes a multilayer substrate 101 and a component 203. The component 203 is mounted on the second surface S2 of the multilayer substrate 101.

[0063] The multilayer substrate 101 is the same as the multilayer substrate 101 shown in the first embodiment.

[0064] Similar to the example shown in the first embodiment, when the maximum height roughness of the mounting portion on the first surface S1 of the multilayer substrate 101 is represented by Rz1, the maximum height roughness in the opposing region of the mounting portion on the second surface S2 of the multilayer substrate 101 is represented by Rz2, and the maximum height roughness of the surface of the insulator in the radiation electrode formation region of the component 203 is represented by Rz3, there is a relationship of Rz1 < Rz2 < Rz3.

[0065] The component 203 is a laminated substrate with resin layers laminated thereon, and the resin materials of the resin layers of this component 203 and the resin materials of the resin layers of the multilayer substrate 101 are different materials. For example, the resin layer of the component 203 is a thermosetting resin such as polyimide resin or epoxy resin, and each resin layer of the multilayer substrate 101 is a thermoplastic resin such as liquid crystal polymer resin. Also, for example, the resin layer of the multilayer substrate 101 is a thermosetting resin such as polyimide resin or epoxy resin, and each resin layer of the component 203 is a thermoplastic resin such as liquid crystal polymer resin. [[ID=!18]]

[0066] As shown in FIG. 3, the component 203 is mounted on the upper surface of the multilayer substrate 101, and the whole is pressurized and heated to adhesively mount the component 203 on the upper surface of the multilayer substrate 101. That is, the pad electrodes 2a, 2b on the multilayer substrate side are electrically connected to the terminal electrodes 6a, 6b on the component 203 side. Also, the insulating surface IS of the component 203 and the resin surface RS of the multilayer substrate 101 are directly joined.

[0067] It seems there is an exclamation mark in the ID of line 18 which might be an error. I've translated it as it is but it should be checked if it's a correct ID.The resin layers of multilayer substrate 101 do not have to be of the same type, and layers of different materials may be mixed. Furthermore, the resin sheets of mounted component 203 do not have to be of the same type, and layers of different materials may be mixed. However, if resin layer 15 forming second surface S2 and / or the resin layer on the mounting surface of mounted component 203 is / are made of a thermoplastic resin, direct bonding between insulator surface IS of mounted component 201 and resin surface RS of multilayer substrate 101 is facilitated.

[0068] The resin layer 15 forming the second surface S2 and the resin layer on the mounting surface of the mounted component 203 may be made of a thermosetting resin. In this case, a sheet of a pre-crosslinking reaction product may be used for the resin layer 15 forming the second surface S2 and / or the resin layer on the mounting surface of the mounted component 203, and the resin layer may be thermally cured by heating, during which the insulator surface IS of the mounted component 203 and the resin surface RS of the multilayer substrate 101 may be directly bonded.

[0069] Fourth Embodiment In the fourth embodiment, a module substrate including electronic components will be exemplified.

[0070] 4 is a cross-sectional view of a module substrate 304 according to the fourth embodiment. This module substrate 304 includes a multilayer substrate 104, mounted components 201, and electronic components 24. Hatching of the electronic components 24 is omitted in the illustration.

[0071] The multilayer substrate 104 includes a plurality of resin layers 11, 12, 13, 14, and 15, and conductor layers and interlayer connection conductors attached to predetermined resin layers among the plurality of resin layers.

[0072] A connection conductor BM is applied to the opening of the resin layer 15. The connection conductor BM is, for example, a heat-melting metal such as solder. Multilayer substrate side pad electrodes 2a and 2b are formed below the connection conductor BM. In this example, the resin layers 11, 12, 13, and 14 are laminates of thermoplastic resin sheets with Cu foil attached to one side.

[0073] Signal line conductor patterns SL1, SL2 and a ground conductor layer GL are formed inside the multilayer substrate 104. Two microstrip transmission lines are configured by the signal line conductor patterns SL1, SL2, the ground conductor layer GL, and the resin layer between the signal line conductor patterns SL1, SL2 and the ground conductor layer GL.

[0074] 4, the mounted component 201 is placed at a predetermined position on the multilayer substrate 104, and the entire structure is heated to a predetermined temperature and pressurized with a predetermined pressure. This melts the connection conductor BM, electrically connecting the pad electrodes 2a and 2b on the multilayer substrate side to the terminal electrodes 6a and 6b on the mounted component 201 side. Also, the insulator surface IS of the mounted component 201 and the resin surface RS of the multilayer substrate 101 are directly bonded to each other.

[0075] The configuration of the mounted component 201 is the same as that of the mounted component 201 shown in the first embodiment.

[0076] External electrodes 1 are formed on the mounting surface (lower surface) of multilayer substrate 104. Component-side pad electrodes 42 are formed on the mounting surface (upper surface) of electronic component 24.

[0077] Component-side pad electrodes 42 are connected to external electrodes 1 of multilayer substrate 104 via connecting conductors BM. Connecting conductors BM are, for example, a heat-melting metal such as solder.

[0078] The electronic component 24 is, for example, an IC that amplifies the power of a transmission signal and supplies the power to an antenna, or an IC that amplifies a signal received by an antenna.

[0079] According to this embodiment, the electronic components 24 can be easily mounted on the multilayer substrate 104 because the electronic components 24 can be easily mounted on the multilayer substrate 104 .

[0080] Fifth Embodiment In the fifth embodiment, a module substrate including a curved multilayer substrate will be exemplified.

[0081] 5 is a cross-sectional view of a module substrate 305 according to the fifth embodiment. This module substrate 305 includes a multilayer substrate 105 and a connector 25 mounted thereon. Hatching of the connector 25 is omitted in the illustration.

[0082] The upper surface of the mounted component 205 has a relatively large maximum height roughness so that the mounted component 205 functions as a patch antenna or as a part of a patch antenna. In this example, the radiation electrode 7 is formed on or near the upper surface of the mounted component 205.

[0083] A terminal electrode 6 is formed on the mounting surface (lower surface) of the mounted component 205. A laminate of a plurality of conductor foils 5 and a plurality of interlayer connection conductors 4 is formed between this terminal electrode 6 and the radiating electrode 7. In this way, a lamination direction conductor path is formed in the mounted component 205 by laminating resin sheets having interlayer connection conductors 4 and conductor foils 5 in contact with these interlayer connection conductors 4. This lamination direction conductor path forms a recess on the surface (upper surface) opposite the mounting surface (lower surface) of the mounted component 205. The radiating electrode 7 is aligned with this recess.

[0084] Here, the maximum height roughness of the mounting portion facing region, which is the region of the first surface S1 of the multilayer substrate 105 that faces the mounting portion of the mounted component 205, is represented by Rz1, where the width Wm of the mounting portion facing region is the reference length of the cross-sectional curve of the mounting portion facing region.

[0085] Furthermore, the maximum height roughness of the mounting portion of the second surface S2 of the multilayer substrate 105, where the width Wm of the mounting portion of the mounted component 205 is taken as the reference length of the cross-sectional curve of the mounting portion, is represented by Rz2.

[0086] Furthermore, Rz3 represents the maximum height roughness of the surface of the insulator when the width Wr of the formation area of ​​the radiating electrode 7 is the reference length of the cross-sectional curve of the insulator of the mounted component 205. Here, the "surface of the insulator" refers to the surface of the insulator that is in contact with the upper or lower surface of the radiating electrode 7.

[0087] The maximum height roughnesses Rz1, Rz2, and Rz3 are in the relationship of Rz1 < Rz2 < Rz3. Thus, the module substrate 305 has three surfaces with different roughnesses (concavities and convexities).

[0088] Inside the multilayer substrate 105, conductor patterns SLa and SLb for signal lines and a ground conductor layer GL are formed. A microstrip type transmission line is formed by the conductor patterns SLa and SLb for signal lines, the ground conductor layer GL, and the resin layer between the conductor patterns SLa and SLb for signal lines and the ground conductor layer GL.

[0089] A plurality of external electrodes 1 are exposed on the first surface S1 of the multilayer substrate 105. A pad electrode 2 is formed on the second surface S2 of the multilayer substrate 105. The terminal electrode 6 of the mounted component 205 is joined to this pad electrode 2. Also, the resin surface of the mounted component 205 is joined to the resin layer of the multilayer substrate 105.

[0090] The component side pad electrode 42 is connected to the external electrode 1 of the multilayer substrate 105 via a connection conductor BM. The connection conductor BM is a heat-melted metal such as solder, for example.

[0091] In the example shown in FIG. 5, the multilayer substrate 105 is bent (refracted) by 90° in the mounting surface direction of the mounted component 205 along the X-Z plane.

[0092] The connector 25 is connected to a patch antenna formed by mounting the mounted component 205.

[0093] According to the present embodiment, since the multilayer substrate 105 is flexible, a module substrate 305 having a predetermined shape can be configured as a whole.

[0094] 《Sixth Embodiment》 In the sixth embodiment, an example is shown in which the structure of the boundary portion between the multilayer substrate and the mounted component is different from the module substrate shown so far.

[0095] FIG. 6 is a cross-sectional view of a module substrate 306 according to a sixth embodiment. The module substrate 306 includes a multilayer substrate 106 and a mounted component 206. The multilayer substrate 106 includes a plurality of resin layers 11, 12, 13, 14, 15, and a conductor layer and an interlayer connection conductor attached to a predetermined resin layer among these plurality of resin layers. A connection conductor BM is coated and formed in an opening of the resin layer 15. The connection conductor BM is a heat-melted metal such as solder, for example. A multilayer substrate side pad electrode 2 is formed below the connection conductor BM.

[0096] On the upper surface of the mounted component 206, a radiation electrode 7 is formed on the upper surface of the mounted component 206 or in the vicinity of the upper surface so that the mounted component 206 acts as a patch antenna or a part of a patch antenna. The radiation electrode 7 is along the upper surface of the mounted component 206.

[0097] Here, among the first surface S1 of the multilayer substrate 106, the maximum height roughness of the mounting part facing area, which is the area facing the mounting part of the mounted component 206, with the width Wm of the mounting part facing area as the reference length of the cross-sectional curve of the mounting part facing area, is represented by Rz1.

[0098] Also, among the second surface S2 of the multilayer substrate 106, the maximum height roughness of the mounting part with the width Wm of the mounting part of the mounted component 206 as the reference length of the cross-sectional curve of the mounting part is represented by Rz2.

[0099] Also, the maximum height roughness of the surface of the insulator with the width Wr of the formation area of the radiation electrode 7 as the reference length of the cross-sectional curve of the insulator of the mounted component 206 is represented by Rz3. Here, the surface of the insulator "surface of the insulator" is the surface of the insulator in contact with the upper surface or the lower surface of the radiation electrode 7.

[0100] The above maximum height roughnesses Rz1, Rz2, and Rz3 are in the relationship of Rz1 < Rz2 < Rz3.

[0101] The boundary between the mounted component 206 and the multilayer substrate 106 (the base of the mounted component 206) is covered with a resin material 10. Since this resin material 10 has a structure that covers the second surface S2 of the multilayer substrate 106, the root part of the mounted component 206 is pressed into the multilayer substrate 106.

[0102] The resin material 10 is, for example, an epoxy resin, and is applied to the multilayer substrate 106 in the state where the mounted components 206 are mounted. It is desirable that the resin material 10 has a higher Young's modulus than the material that constitutes the resin layer of the multilayer substrate 106.

[0103] Young's modulus can be determined by conducting a nanoindenter test in accordance with the standards of JIS Z 2255 and ISO 14577. For example, it can be determined from load-displacement data using a KLA Micro Nanoindenter device.

[0104] Since the mounting portion of the mounted component 206 is rigid and the other portions are flexible, when an external force that tends to bend the module substrate 306 is applied, stress tends to concentrate at the base of the mounted component 206 .

[0105] In module substrate 306 of this embodiment, the bonding strength between multilayer substrate 106 and mounted component 206 is strong, preventing cracks and chips at the interface between multilayer substrate 106 and mounted component 206. In addition, the rigidity of mounted component 206 relative to multilayer substrate 106 is high, suppressing deformation such as tilting of mounted component 206. This suppresses deviation in the radiation direction (directivity) of the antenna.

[0106] 6 shows an example in which resin material 10 is a separate member from multilayer substrate 106 and mounted component 206, but the shape of resin material 10 may be formed from multilayer substrate 106 or mounted component 206. That is, after mounted component 206 is placed on multilayer substrate 106, pressure is applied to press mounted component 206 into multilayer substrate 106, and heat is applied. This causes mounted component 206 to sink into multilayer substrate 106, and the resin layer on top of multilayer substrate 106 is raised toward the base of mounted component 206, and this raised portion is formed as resin material 10. Alternatively, resin material 10 is formed by melting the base of mounted component 206 using the pressure and heat.

[0107] Seventh Embodiment In the seventh embodiment, an electronic device including a module substrate and another substrate will be exemplified.

[0108] 7 is a cross-sectional view of an electronic device 407 according to a seventh embodiment. This electronic device 407 includes another substrate 27, and a multilayer substrate 101 and mounted components 201 mounted thereon. Hatching is omitted from the illustration of the other substrate 27.

[0109] The configuration of module substrate 301 including multilayer substrate 101 and mounted components 201 is the same as module substrate 301 shown in FIG. 1 in the first embodiment.

[0110] An external electrode 1 is formed on the mounting surface (lower surface) of module substrate 301. An other-substrate-side pad electrode 41 is formed on the mounting surface (upper surface) of other substrate 27.

[0111] The external electrodes 1 of the multilayer substrate 101 are connected to the pad electrodes 41 on the other substrate side via the connection conductors BM. The connection conductors BM are, for example, a heat-melting metal such as solder.

[0112] The other substrate 27 is, for example, a rigid glass epoxy resin substrate.

[0113] According to this embodiment, the mountability of multilayer substrate 101 to the highly flat mounting surface of other substrate 27 is high, and therefore module substrate 301 can be mounted with high precision on other substrate 27. For example, multilayer substrate 101 on which external electrodes 1 are distributed can be easily mounted on other substrate 27.

[0114] Eighth Embodiment In the eighth embodiment, an electronic device including a housing will be exemplified.

[0115] The electronic device according to this embodiment includes any one of the module substrates shown in the first to sixth embodiments, and a housing that houses the module substrate.

[0116] The housing that houses the module board has a size and shape that allows the module board to be housed (built-in).

[0117] In order not to impair the gain of the antenna, at least the area of ​​the housing near the antenna is made of a non-conductive or non-magnetic material.

[0118] Various embodiments of the present invention have been presented so far, but these are all examples and are not intended to limit the scope of the present invention. Various omissions, substitutions, and modifications can be made to the embodiments of the present invention without departing from the spirit of the invention. Embodiments with such omissions, substitutions, and modifications are included within the scope and spirit of the present invention, and are also included in the scope of the invention and its equivalents as set forth in the claims of this application.

[0119] For example, if it is important that the dielectric of the mounted component has a high dielectric constant because the mounted component is a component that meets the electrical characteristics required of the antenna, a material with a higher dielectric constant than the resin layer of the multilayer substrate may be used. For example, a ceramic material with a high dielectric constant may be used. This allows for a module substrate equipped with an antenna with excellent electrical characteristics.

[0120] Furthermore, although the embodiments do not show examples in which a protective film is formed on the multilayer substrate or mounted components, a protective film may be formed on a predetermined portion or the entire surface of the outer surface.

[0121] In addition, in each embodiment, a microstrip line is configured by forming a signal line conductor pattern SL and a ground conductor layer GL, but the configuration of the module substrate is not limited to one in which a transmission line is connected to a mounted component.

[0122] The multilayer substrate and electronic device of the present invention may be provided in the following aspects.

[0123] <1> a multilayer substrate having a plurality of resin layers and a conductor layer attached to a predetermined resin layer among the plurality of resin layers; An insulator and a radiation electrode formed on the insulator, and a mounted component mounted on the multilayer substrate comprising The multilayer substrate has a first surface and a second surface that form a front-back surface relationship The multilayer substrate has an external electrode exposed on the first surface The multilayer substrate has a mounting portion for the mounted component on a part of the second surface of the multilayer substrate The mounted component has a mounting surface that contacts the mounting portion of the multilayer substrate The radiation electrode is formed in a region away from or along the surface of the mounting surface 4 When the width of the mounting portion facing region, which is the region of the first surface of the multilayer substrate facing the mounting portion, is taken as the reference length of the cross-sectional curve of the mounting portion facing region, the maximum height roughness of the mounting portion facing region is represented by Rz1, and the width of the mounting portion of the multilayer substrate is taken as the reference length of the cross-sectional curve of the mounting portion, the maximum height roughness of the mounting portion is represented by Rz2, and the width of the formation region of the radiation electrode is taken as the reference length of the cross-sectional curve of the insulator, and the maximum height roughness of the surface of the insulator is represented by Rz3, there is a relationship of Rz 1 < Rz 2 < Rz 3 Module substrate

[0124] <2> The resin layer of the multilayer substrate and the material of the insulator of the mounted component are the same material The module substrate according to <1>

[0125] <00​​​​​​​​​​​​​​​ <5> The resin layer of the multilayer substrate is a liquid crystal polymer resin. <4> The module substrate according to claim 1.

[0128] <6> The mounted component has a terminal electrode, an interlayer connection conductor mainly composed of Cu or Ag is formed on the first surface of the multilayer substrate, and the terminal electrode of the mounted component is connected to the interlayer connection conductor. <1> from <5> 10. The module substrate according to claim 9, wherein

[0129] <7> a transmission line is formed on the multilayer substrate; <1> from <6> 10. The module substrate according to claim 9, wherein

[0130] <8> The multilayer substrate has a bent portion. <1> from <7> 10. The module substrate according to claim 9, wherein

[0131] <9> a component connected to the external electrode and mounted on the multilayer substrate; <1> from <8> 10. The module substrate according to claim 9, wherein

[0132] <10> A resin material is provided to cover the boundary between the mounted component and the multilayer substrate (the base of the mounted component). <1> from <9> 10. The module substrate according to claim 9, wherein

[0133] <11> <1> from <10> a module substrate according to any one of and another substrate on which the module substrate is mounted. electronic equipment.

[0134] <12> <1> from <10> and a housing that houses the module board. [Explanation of symbols]

[0135] BM...connecting conductor CA…Recessed portion GL: Ground conductor layer IS...insulating surface RS…Resin surface S1...Side 1 S2...Side 2 SL1, SL2, SLa, SLb...Signal line conductor patterns 1...External electrode 2, 2a, 2b... Multilayer board side pad electrodes 4...Interlayer connecting conductor 5...Conductor foil 6,6a,6b…Terminal electrode 7,7a,7b…Radiation electrode 8...Electrode 9...Plated through-hole 10...Resin material 11, 12, 13, 14, 15...Resin layers 24...Electronic components 25...Connector 27...Other boards 41...Pad electrode on other substrate 42...Component side pad electrode 101,102,104,105,106...Multilayer board 201, 202, 203, 205, 206...Installed parts 301, 302, 303, 304, 305, 306...Module board 407...Electronic equipment

Claims

1. a multilayer substrate having a plurality of resin layers and a conductor layer attached to a predetermined resin layer among the plurality of resin layers; a mounting component having an insulator and a radiation electrode formed on the insulator, the mounting component being mounted on the multilayer substrate; Equipped with the multilayer substrate has a first surface and a second surface that form a front and back surface relationship; the multilayer substrate has external electrodes exposed on the first surface, the multilayer substrate has a mounting portion for the mounted component on a part of the second surface of the multilayer substrate, the mounting component has a mounting surface that contacts the mounting portion of the multilayer substrate, the radiation electrode is formed on a surface away from the mounting surface or in an area along the surface, a resin layer in the mounting portion of the multilayer substrate and the insulator on the mounting surface of the mounted component are directly bonded to each other; where the width of a mounting portion facing region, which is a region of the first surface of the multilayer substrate that faces the mounting portion, is taken as a reference length of a cross-sectional curve of the mounting portion facing region and the maximum height roughness of the mounting portion facing region is represented by Rz1, the width of the mounting portion of the second surface of the multilayer substrate is taken as a reference length of a cross-sectional curve of the mounting portion and the maximum height roughness of the mounting portion is represented by Rz2, and the width of a region where the radiation electrode is formed is taken as a reference length of a cross-sectional curve of the insulator and the maximum height roughness of the surface of the insulator is represented by Rz3, there is a relationship of Rz1<Rz2<Rz3. Module board.

2. the resin layer of the multilayer substrate and the insulator material of the mounted component are made of the same material; The module substrate according to claim 1 .

3. the resin layer of the multilayer substrate and the insulating material of the mounted component are made of different materials; The module substrate according to claim 1 .

4. The resin layer of the multilayer substrate is a thermoplastic resin. The module substrate according to claim 1 .

5. The resin layer of the multilayer substrate is a liquid crystal polymer resin. The module substrate according to claim 4 .

6. The mounted component has a terminal electrode, an interlayer connection conductor mainly composed of Cu or Ag is formed on the first surface of the multilayer substrate, and the terminal electrode of the mounted component is connected to the interlayer connection conductor. The module substrate according to claim 1 .

7. a transmission line is formed on the multilayer substrate; The module substrate according to claim 1 .

8. The multilayer substrate has a bent portion. The module substrate according to claim 1 .

9. a component connected to the external electrode and mounted on the multilayer substrate; The module substrate according to claim 1 .

10. a resin material covering the boundary between the mounted component and the multilayer substrate; The module substrate according to claim 1 .

11. A module substrate according to any one of claims 1 to 3; and another substrate on which the module substrate is mounted. electronic equipment.

12. 4. An electronic device comprising: the module board according to claim 1; and a housing that houses the module board.

Images