Multilayer board, module board, and electronic device

Abstract

To provide a multilayer substrate that can maintain a predetermined distance between conductor patterns on different layers with a limited number of laminated resin layers with conductor layers, or that reduces the maximum number of laminated layers required for circuit configuration, and also provides a module substrate including the multilayer substrate, and an electronic device including the module substrate.SOLUTION: A multilayer substrate 101 includes a plurality of resin layers, conductor layers, and interlayer connection conductors, and a laminate is formed by laminating the plurality of resin layers and conductor layers. An opening AP is formed in some of the resin layers, thereby forming a recess CA that exposes a portion of the resin layer below the resin layer. For example, Cu foils 25c and 25d are attached to the lower surface of the underlying resin layer 15, and Cu foils 26c and 26d are attached to the upper surface of the resin layer 16 that is the uppermost surface of the laminate, such that the interlayer connection conductors 35c and 35d formed on the resin layer 15 and the interlayer connection conductors 36c and 36d formed on the resin layer 16 are directly connected.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a multilayer substrate, a module substrate including the multilayer substrate, and an electronic device including the module substrate. [Background technology]

[0002] Patent Document 1 discloses a multilayer substrate including multiple 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 multilayer substrate in which regions with different thicknesses in the stacking direction are formed by varying the number of stacked resin layers. [Prior art documents] [Patent documents]

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

[0004] If the number of layers of the conductor-layer-attached resin layer, which has a conductor layer attached thereto, is varied to form regions with different thicknesses in the stacking direction, the thicker layers can provide the desired electronic component-like functionality. However, the maximum number of layers required for the circuit configuration of the multilayer board increases, making manufacturing difficult in terms of lamination accuracy and the number of processes. Furthermore, if the number of layers of the conductor-layer-attached resin layer is minimized, the spacing between the conductor patterns formed on the inner layers of the multilayer board and the conductor patterns formed on the outer layers of the multilayer board will inevitably be narrow. This makes it difficult to achieve the desired electrical characteristics.

[0005] Therefore, the object of the present invention is to provide a multilayer board in which conductor patterns between different layers can be maintained at a predetermined distance with a limited number of layers of resin layers with conductor layers, to provide a multilayer board in which the maximum number of layers required for circuit configuration is reduced, to provide a module board including this multilayer board, and further to provide an electronic device including this module board. [Means for solving the problem]

[0006] (1) An example of a multilayer substrate according to the present disclosure includes: A plurality of resin layers; a conductor layer attached to one surface of all or some of the resin layers among the plurality of resin layers; an interlayer connection conductor formed inside all or some of the resin layers among the plurality of resin layers; Equipped with a laminated body is formed by laminating the plurality of resin layers and the conductor layers, some of the resin layers have openings that expose parts of the resin layers below the resin layers to form recesses (cavities) on the surface of the laminate; the conductor layer is attached to the lower surface of the resin layer present in the lower layer, the conductor layer is attached to the upper surface of the resin layer, which is the uppermost surface (outer layer) of the laminate, The interlayer connection conductor formed in the resin layer present in the lower layer and the interlayer connection conductor formed in the resin layer positioned at the top layer of the laminate are electrically conductive.

[0007] (2) A module substrate as an example of the present disclosure includes: The device comprises an electronic component having terminal electrodes and the multilayer substrate, and the terminal electrodes of the electronic component are electrically connected to the exposed portions of the conductor layers of the multilayer substrate via a conductive adhesive material.

[0008] (3) An electronic device as an example of the present disclosure includes: The device includes the module substrate and a housing that houses the module substrate. [Effects of the Invention]

[0009] According to the present invention, a multilayer substrate can be obtained in which the conductor patterns between different layers can be maintained at a predetermined distance with a limited number of layers of resin layers with conductor layers, a multilayer substrate can be obtained in which the maximum number of layers required for circuit configuration is reduced, a module substrate including this multilayer substrate can be obtained, and an electronic device can be obtained which includes this module substrate. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view of a multilayer substrate 101 according to the first preferred embodiment. [Figure 2] FIG. 2 is an exploded cross-sectional view of the multilayer substrate 101 according to the first preferred embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing the configuration of a module substrate 301 including the multilayer substrate 101 shown in FIG. [Figure 4] FIG. 4 is a plan view of module substrate 301. [Figure 5] FIG. 5 is a cross-sectional view of a multilayer substrate 102 according to the second embodiment. [Figure 6] FIG. 6 is an exploded cross-sectional view of a multilayer substrate 102 according to the second embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing the configuration of a module substrate 302 including the multilayer substrate 102 shown in FIG. [Figure 8] FIG. 8 is a cross-sectional view of a multilayer substrate 103 according to the third embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing the configuration of module substrate 303 including multilayer substrate 103 shown in FIG. [Figure 10] FIG. 10 is a cross-sectional view of a multilayer substrate 104 according to the fourth embodiment. [Figure 11] FIG. 11 is a cross-sectional view showing the configuration of a module substrate 304 including the multilayer substrate 104 shown in FIG. [Figure 12] FIG. 12 is a cross-sectional view of a module substrate 305 according to the fifth embodiment. [Figure 13]FIG. 13 is a cross-sectional view of a module substrate 306 according to the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several specific examples will be given with reference to the drawings to illustrate several embodiments for carrying out the present invention. The same reference numerals are used for the same parts in each drawing. For the sake of convenience, the embodiments are shown divided into several embodiments, taking into account ease of explanation and understanding of the main points. However, 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.

[0012] First Embodiment In the first embodiment, a module substrate including a patch antenna and a multilayer substrate including this module substrate will be exemplified.

[0013] FIG. 1 is a cross-sectional view of a multilayer substrate 101 according to a first embodiment. FIG. 2 is an exploded cross-sectional view of the multilayer substrate 101 according to the first embodiment. Note that 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. Also, although a single multilayer substrate is shown in FIGS. 1 and 2, in the intermediate stage of manufacturing such a single multilayer substrate, the substrate is a continuum of multiple multilayer substrates, and the continuum is cut into single substrates at the final stage of the manufacturing process or immediately before the final stage. This relationship between the continuum and single substrates is similar in other figures.

[0014] Multilayer substrate 101 includes a plurality of resin layers 11, 12, 13, 14, 15, and 16, Cu foil attached to one side of these resin layers 11, 12, 13, 14, 15, and 16, and interlayer connection conductors formed inside resin layers 11, 12, 13, 15, and 16. These interlayer connection conductors are made of Cu and Ag, and are each formed by plating, for example.

[0015] The conductor layer has already been patterned to form a predetermined conductor pattern in Figures 1 and 2. These Cu foils are an example of the "conductor layer" according to the present invention.

[0016] 2, a Cu foil 21 is attached to the lower surface of the resin layer 11. In addition, interlayer connection conductors 31a and 31b are formed inside the resin layer 11 so as to penetrate the resin layer 11 and be electrically connected to the Cu foil 21.

[0017] Cu foils 22a, 22b, and 22c are attached to the lower surface of the resin layer 12. Interlayer connection conductors 32b and 32c are formed inside the resin layer 12, penetrating the resin layer 12 and electrically connecting to the Cu foils 22b and 22c, respectively.

[0018] Cu foils 23a, 23b, and 23c are attached to the lower surface of the resin layer 13. An interlayer connection conductor 33a is formed inside the resin layer 13, penetrating the resin layer 13 and electrically connecting to the Cu foil 23a.

[0019] The resin layer 14 has a Cu foil 24 attached to its lower surface.

[0020] Cu foils 25a, 25b, 25c, and 25d are attached to the lower surface of the resin layer 15. Interlayer connection conductors 35c and 35d are formed inside the resin layer 15, penetrating the resin layer 15 and electrically connecting to the Cu foils 25c and 25d, respectively.

[0021] Cu foils 26c and 26d are attached to the upper surface of the resin layer 16. Furthermore, interlayer connection conductors 36c and 36d are formed inside the resin layer 16, penetrating the resin layer 16 and electrically connecting to the Cu foils 26c and 26d, respectively.

[0022] Interlayer connection conductor 35c and interlayer connection conductor 36c are directly joined and electrically connected, and interlayer connection conductor 35d and interlayer connection conductor 36d are directly joined and electrically connected.

[0023] In this example, the resin layers 11, 12, 13, 14, 15, and 16 are made of, for example, a thermoplastic resin, and are laminated by bonding adjacent resin layers together in the lamination direction and bonding adjacent resin layers to Cu foil in the lamination direction. The resin layers 11, 12, 13, 14, 15, and 16 are made of, for example, a liquid crystal polymer resin (LCP). By using a resin material with low water absorption, such as a liquid crystal polymer resin, a multilayer substrate with high electrical properties and various reliability can be obtained.

[0024] The resin layers 11, 12, 13, 14, 15, and 16 and the Cu foils attached to these resin layers constitute a "laminate."

[0025] The Cu foils 26c and 26d attached to the resin layer 16, which is the uppermost surface (outer layer) of the laminate, are formed on the upper surface of this resin layer 16.

[0026] 1 and 2, the resin layer 16 has an opening AP, which exposes a portion of the underlying resin layer 15. As shown in Fig. 1, the opening AP in the resin layer 16 forms a recess (cavity) CA in a portion of the surface of the laminate.

[0027] Cu foils 25c and 25d are attached to the lower surface of the resin layer 15, which is located below the resin layer 16 in which the opening AP is formed, and Cu foils 26c and 26d are attached to the upper surface of the resin layer 16, which is the uppermost surface (outer layer) of the laminate.

[0028] The interlayer connection conductors 35c, 35d formed on the resin layer 15 below the resin layer 16 are electrically connected to the interlayer connection conductors 36c, 36d formed on the resin layer 16 positioned at the topmost layer of the laminate. That is, the interlayer connection conductors are directly bonded to each other. This allows for a larger distance (distance in the stacking direction) between the Cu foils 26c, 26d formed on the upper surface of the resin layer 16, which is the topmost (outer) layer of the laminate, and the Cu foil 24 attached to the lower surface of the resin layer 14.

[0029] The resin layer 15 below the resin layer 16 has Cu foil exposed portions EXa, EXb that expose parts of the Cu foils 25a, 25b attached to the resin layer 15 on the surface of the laminate within the recessed portions CA (within the openings AP). In other words, the Cu foil exposed portions EXa, EXb are openings that are partially formed in the resin layer 15. The Cu foil exposed portions EXa, EXb are examples of the "conductor layer exposed portions" according to the present invention.

[0030] As shown in FIG. 1, the Cu foil exposed portions EXa and EXb are formed by laser beam processing after the laminate is constructed, for example.

[0031] 1, the entire lower surface of the laminate is coated with an electrically insulating protective film 41. In addition, the outer surfaces of the Cu foils 26c and 26d on the upper surface of the laminate are coated with an electrically insulating protective film 42. These protective films 41 and 42 are made of a polymer compound such as polyimide.

[0032] 1 and 2, the Cu foils 26c and 26d attached to the upper surface of the resin layer 16, which is located at the position that will be the uppermost layer of the laminate, are ground conductor layers, and the pattern of the Cu foil 24 attached to the lower surface of the resin layer 14 that is located below the resin layer 16 is a signal conductor pattern. Also, the Cu foil 21 attached to the lower surface of the resin layer 11 is a ground conductor layer. With this structure, a strip line is formed by the Cu foil 24 as the signal conductor pattern, the Cu foils 21, 26c, and 26d as ground conductor layers, and the resin layers 11, 12, 13, 14, 15, and 16 between the Cu foil 24 and the Cu foils 21, 26c, and 26d.

[0033] If the Cu foil 21 is not present, or if the Cu foil 21 is present but is not a ground conductor layer, the microstrip line is formed by the Cu foil 24 as a signal conductor pattern, the Cu foils 26c and 26d as ground conductor layers, and the resin layers 14, 15, and 16 between the Cu foil 24 and the Cu foils 26c and 26d.

[0034] As described above, the distance between the Cu foils 26c, 26d and the Cu foil 24 can be easily increased, so that even with a thin multilayer board, it is possible to suppress the capacitance generated between the Cu foils 26c, 26d and the Cu foil 24. This allows the line width of the Cu foil 24, which is the signal conductor pattern, to be increased, thereby reducing the transmission loss of the strip line or microstrip line.

[0035] Fig. 3 is a cross-sectional view showing the configuration of a module substrate 301 including the multilayer substrate 101 shown in Fig. 1. The lower part of Fig. 3 is a cross-sectional view of module substrate 301 according to this embodiment, and the upper part of Fig. 3 is a cross-sectional view for explaining the process of manufacturing the module substrate 301.

[0036] The module substrate 301 includes a multi-layer substrate 101 and an electronic component 200 mounted thereon.

[0037] 3, electronic component 200 has terminal electrodes 6a and 6b on its bottom surface. In this example, electronic component 200 has a rectangular parallelepiped shape, has a radiation electrode 7 on its top surface, and functions as a patch antenna.

[0038] 3, the terminal electrodes 6a and 6b of the electronic component 200 are electrically connected to the Cu foils 25a and 25b exposed in the Cu foil exposed portions EXa and EXb via conductive bonding materials BMa and BMb. In other words, the electronic component 200 is mounted in the recessed portion CA. The conductive bonding materials BMa and BMb are, for example, a heat-melting metal such as solder or a conductive adhesive.

[0039] 3 shows an example in which the bottom surface of electronic component 200 is not directly bonded to the resin layer of multilayer substrate 101, but the portions other than those in contact with conductive bonding materials BMa and BMb may be directly bonded to the resin layer. This increases the bonding strength of electronic component 200 to multilayer substrate 101.

[0040] As shown in the lower part of Figure 3, electronic component 200 does not cause part of the multilayer substrate to function as an electronic component by increasing the number of layers in multilayer substrate 101, so a module substrate having a multilayer substrate with a reduced maximum number of layers required for circuit configuration can be obtained.

[0041] 4 is a plan view of module substrate 301. In this example, a recess CA also having a rectangular planar shape is formed in multilayer substrate 101 having a rectangular planar shape, and a single electronic component 200 is mounted in this recess CA.

[0042] A radiation electrode 7 is formed on the upper surface of the electronic component 200, and functions as a patch antenna with a ground conductor layer formed near the lower surface of the electronic component 200 or the Cu foil 21 of the multilayer substrate 101 as the ground conductor layer.

[0043] In the example shown in Figure 4, the planar shape of the recessed portion CA is similar to the planar shape of the electronic component 200, and a single electronic component 200 is mounted in the recessed portion CA, but multiple electronic components may also be mounted in the recessed portion CA.

[0044] According to this embodiment, by providing the recessed portions CA, it is possible to increase the spacing between the conductor patterns on different layers even though the number of laminated resin layers and conductor layers is small.

[0045] Furthermore, according to this embodiment, a multilayer substrate is used that reduces the maximum number of layers required for the circuit configuration, which facilitates manufacturing in terms of lamination accuracy and the number of processes.

[0046] Furthermore, according to this embodiment, electronic component 200 is mounted in recessed portion CA of multilayer substrate 101, so that module substrate 301 having a thin (low height) overall can be obtained.

[0047] Furthermore, since the resin layer is made of a thermoplastic resin, it is easy to laminate the layers together, and a separate bonding step using an adhesive layer is not required, which reduces the manufacturing cost.

[0048] Second Embodiment In the second embodiment, a multilayer substrate having interlayer connection conductors exposed on the surface of the laminate in the recessed portion, and a module substrate having the same will be exemplified.

[0049] Fig. 5 is a cross-sectional view of the multilayer substrate 102 according to the second embodiment. Fig. 6 is an exploded cross-sectional view of the multilayer substrate 102 according to the second embodiment.

[0050] The multilayer substrate 102 includes a plurality of resin layers 11, 12, 13, 14, 15, and 16, Cu foils attached to one side of the resin layers 11, 12, 13, 14, 15, and 16, and interlayer connection conductors formed inside the resin layers 11, 12, 13, 15, and 16.

[0051] 6, a Cu foil 21 is attached to the lower surface of the resin layer 11. In addition, interlayer connection conductors 31a and 31b that penetrate the resin layer 11 and are electrically connected to the Cu foil 21 are formed inside the resin layer 11.

[0052] Cu foils 22a, 22b, and 22c are attached to the lower surface of the resin layer 12. Interlayer connection conductors 32b and 32c are formed inside the resin layer 12, penetrating the resin layer 12 and electrically connecting to the Cu foils 22b and 22c, respectively.

[0053] Cu foils 23a, 23b, and 23c are attached to the lower surface of the resin layer 13. An interlayer connection conductor 33a is formed inside the resin layer 13, penetrating the resin layer 13 and electrically connecting to the Cu foil 23a.

[0054] The resin layer 14 has a Cu foil 24 attached to its lower surface.

[0055] Cu foils 25a, 25b, 25c, and 25d are attached to the lower surface of the resin layer 15. Interlayer connection conductors 35a, 35b, 35c, and 35d are formed inside the resin layer 15 and penetrate the resin layer 15 to be electrically connected to the Cu foils 25a, 25b, 25c, and 25d, respectively.

[0056] Cu foils 26c and 26d are attached to the upper surface of the resin layer 16. Furthermore, interlayer connection conductors 36c and 36d are formed inside the resin layer 16, penetrating the resin layer 16 and electrically connecting to the Cu foils 26c and 26d, respectively.

[0057] Interlayer connection conductor 35c and interlayer connection conductor 36c are directly joined and electrically connected, and interlayer connection conductor 35d and interlayer connection conductor 36d are directly joined and electrically connected.

[0058] The resin layers 11, 12, 13, 14, 15, and 16 and the Cu foils attached to these resin layers constitute a laminate.

[0059] 5 and 6, the resin layer 16 has an opening AP, which exposes a portion of the underlying resin layer 15. As shown in Fig. 5, the opening AP in the resin layer 16 forms a recess (cavity) CA in a portion of the surface of the laminate.

[0060] The resin layer 15 below the resin layer 16 includes interlayer connection conductors 35a and 35b that are electrically connected to the Cu foils 25a and 25b, respectively, attached to the resin layer 15. That is, the interlayer connection conductors 35a and 35b are exposed on the surface of the laminate in the recesses (openings).

[0061] Fig. 7 is a cross-sectional view showing the configuration of module substrate 302 including multilayer substrate 102 shown in Fig. 5. The lower part of Fig. 7 is a cross-sectional view of module substrate 302 according to this embodiment, and the upper part of Fig. 7 is a cross-sectional view for explaining the process of manufacturing the module substrate 302.

[0062] The module substrate 302 includes the multi-layer substrate 102 and the electronic component 200 mounted thereon.

[0063] As shown in the upper part of Figure 7, the interlayer connection conductors 35a and 35b are exposed on the surface of the laminate in the recessed portion CA. The terminal electrodes 6a and 6b of the electronic component 200 are directly bonded to the interlayer connection conductors 35a and 35b. For example, the terminal electrodes 6a and 6b of the electronic component 200 are made of Cu and are electrically connected to the interlayer connection conductors 35a and 35b made of Cu or Ag. This allows the electronic component 200 to be mounted in the recessed portion CA.

[0064] The configuration of the other components is the same as that shown in the first embodiment.

[0065] According to this embodiment, electrical continuity is established between the terminal electrodes 6a, 6b of the electronic component 200 and the interlayer connection conductors 35a, 35b by Cu or Ag, i.e., by the interlayer connection conductors partially containing a conductor containing elemental Cu or Ag. This allows for lower impedance than when continuity is established solely through solder, improving electrical characteristics. Furthermore, the distance between the terminal electrodes 6a, 6b of the electronic component 200 and the Cu foils 25a, 25b of the multilayer substrate 102 can be shortened, thereby reducing electrical resistance and improving electrical characteristics.

[0066] In FIG. 7, almost the entire bottom surface of electronic component 200 is directly bonded to the resin layer of multilayer substrate 102, except for the portions bonded to interlayer connection conductors 35a and 35b, so the bonding strength of electronic component 200 to multilayer substrate 102 is high.

[0067] Other effects are the same as those of the multilayer substrate and module substrate shown in the first embodiment.

[0068] Third Embodiment In the third embodiment, a multilayer substrate including a plurality of resin sheets each having an opening formed therein to form a recessed portion, and a module substrate including the multilayer substrate will be exemplified.

[0069] FIG. 8 is a cross-sectional view of a multilayer substrate 103 according to the third embodiment.

[0070] The multilayer substrate 103 includes a plurality of resin layers 11, 12, 13, 14, 15, and 16, Cu foils attached to one side of the resin layers 11, 12, 13, 14, 15, and 16, and interlayer connection conductors formed inside the resin layers 11, 12, 13, 15, and 16.

[0071] A Cu foil 21 is attached to the lower surface of the resin layer 11. In addition, interlayer connection conductors 31a and 31b that penetrate the resin layer 11 and are electrically connected to the Cu foil 21 are formed inside the resin layer 11.

[0072] Cu foils 22a, 22b, and 22c are attached to the lower surface of the resin layer 12. An interlayer connection conductor 32b is formed inside the resin layer 12, penetrating the resin layer 12 and electrically connecting to the Cu foil 22b.

[0073] Cu foils 23a and 23b are attached to the lower surface of the resin layer 13. In addition, an interlayer connection conductor 33a penetrating the resin layer 13 and electrically connected to the Cu foil 23a, and an interlayer connection conductor 33b electrically connected to the Cu foil 23b are formed inside the resin layer 13.

[0074] The resin layer 14 has Cu foils 24a, 24b, 24c, and 24d attached to its lower surface.

[0075] Cu foils 25c and 25d are attached to the lower surface of the resin layer 15. Furthermore, interlayer connection conductors 35c and 35d are formed inside the resin layer 15, penetrating the resin layer 15 and electrically connecting to the Cu foils 25c and 25d, respectively.

[0076] Cu foils 26c and 26d are attached to the upper surface of the resin layer 16. Furthermore, interlayer connection conductors 36c and 36d are formed inside the resin layer 16, penetrating the resin layer 16 and electrically connecting to the Cu foils 26c and 26d, respectively.

[0077] Interlayer connection conductor 35c and interlayer connection conductor 36c are directly joined and electrically connected, and interlayer connection conductor 35d and interlayer connection conductor 36d are directly joined and electrically connected.

[0078] Resin layer 16 has an opening AP1. Resin layer 15 has an opening AP2. This allows resin layers 15 and 16 to expose a portion of underlying resin layer 14. As shown in Figure 8, openings AP2 and AP1 in resin layers 15 and 16 form a recess (cavity) CA in a portion of the surface of the laminate.

[0079] The resin layer 14 has Cu foil exposed portions EXa, EXb that expose parts of the Cu foils 24a, 24b attached to the resin layer 14 on the surface of the laminate in the recessed portions CA (in the openings AP). In other words, the Cu foil exposed portions EXa, EXb are openings that are partially formed in the resin layer 14.

[0080] Fig. 9 is a cross-sectional view showing the configuration of module substrate 303 including multilayer substrate 103 shown in Fig. 8. The lower part of Fig. 9 is a cross-sectional view of module substrate 303 according to this embodiment, and the upper part of Fig. 9 is a cross-sectional view for explaining the process of manufacturing the module substrate 303.

[0081] 9, the terminal electrodes 6a, 6b of the electronic component 200 are electrically connected to the Cu foils 24a, 24b exposed in the Cu foil exposed portions EXa, EXb via conductive bonding materials BMa, BMb. In other words, the electronic component 200 is mounted in the recessed portion CA. The conductive bonding materials BMa, BMb are, for example, a heat-melting metal such as solder or a conductive adhesive.

[0082] According to this embodiment, electronic component 200 is mounted in deeper recessed portion CA, i.e., electronic component 200 is mounted in a multilayer substrate portion with a small number of layers, so the positional accuracy of the mounting electrodes is high. This makes it easier to mount electronic component 200. In addition, this also improves the mounting positional accuracy of the mounted component.

[0083] Furthermore, since electronic component 200 is mounted in deeper recessed portion CA, it is possible to obtain an overall thinner module substrate 303. Other advantages are the same as those described in the first embodiment.

[0084] Fourth Embodiment In the fourth embodiment, a multilayer substrate having a different configuration from that of the third embodiment and including a plurality of resin sheets with openings formed therein to form recesses, and a module substrate including the multilayer substrate will be exemplified.

[0085] FIG. 10 is a cross-sectional view of a multilayer substrate 104 according to the fourth embodiment.

[0086] The multilayer substrate 104 includes a plurality of resin layers 11, 12, 13, 14, 15, and 16, Cu foils attached to one side of the resin layers 11, 12, 13, 14, 15, and 16, and interlayer connection conductors formed inside the resin layers 11, 12, 13, 15, and 16.

[0087] A Cu foil 21 is attached to the lower surface of the resin layer 11. In addition, interlayer connection conductors 31a and 31b that penetrate the resin layer 11 and are electrically connected to the Cu foil 21 are formed inside the resin layer 11.

[0088] Cu foils 22a, 22b, and 22c are attached to the lower surface of the resin layer 12. Interlayer connection conductors 32b and 32c are formed inside the resin layer 12, penetrating the resin layer 12 and electrically connecting to the Cu foils 22b and 22c, respectively.

[0089] Cu foils 23a and 23b are attached to the lower surface of the resin layer 13. In addition, an interlayer connection conductor 33a penetrating the resin layer 13 and electrically connected to the Cu foil 23a, and an interlayer connection conductor 33b electrically connected to the Cu foil 23b are formed inside the resin layer 13.

[0090] Cu foils 24a, 24b, 24c, and 24d are attached to the lower surface of the resin layer 14. Furthermore, interlayer connection conductors 34a and 34b are formed inside the resin layer 14, penetrating the resin layer 14 and electrically connecting to the Cu foils 24a and 24b, respectively.

[0091] Cu foils 25c and 25d are attached to the lower surface of the resin layer 15. Furthermore, interlayer connection conductors 35c and 35d are formed inside the resin layer 15, penetrating the resin layer 15 and electrically connecting to the Cu foils 25c and 25d, respectively.

[0092] Cu foils 26c and 26d are attached to the upper surface of the resin layer 16. Furthermore, interlayer connection conductors 36c and 36d are formed inside the resin layer 16, penetrating the resin layer 16 and electrically connecting to the Cu foils 26c and 26d, respectively.

[0093] Interlayer connection conductor 35c and interlayer connection conductor 36c are directly joined and electrically connected, and interlayer connection conductor 35d and interlayer connection conductor 36d are directly joined and electrically connected.

[0094] The resin layer 16 has an opening AP1. The resin layer 15 has an opening AP2. This exposes the interlayer connection conductors 34a and 34b. As shown in Fig. 10, the openings AP2 and AP1 in the resin layers 15 and 16 form a recess (cavity) CA in part of the surface of the laminate.

[0095] Fig. 11 is a cross-sectional view showing the configuration of a module substrate 304 including the multilayer substrate 104 shown in Fig. 10. The lower part of Fig. 11 is a cross-sectional view of module substrate 304 according to this embodiment, and the upper part of Fig. 11 is a cross-sectional view for explaining the process of manufacturing the module substrate 304.

[0096] 11, the interlayer connection conductors 34a and 34b are exposed on the surface of the laminate in the recessed portion CA. The terminal electrodes 6a and 6b of the electronic component 200 are directly bonded to the interlayer connection conductors 34a and 34b, respectively. This allows the electronic component 200 to be mounted in the recessed portion CA.

[0097] According to this embodiment, electronic component 200 is mounted in deeper recessed portion CA, resulting in a thinner module substrate 304 overall. The configuration of each of the other components is the same as that shown in the second embodiment. Furthermore, the effects of this configuration are also the same as those of the multilayer substrate and module substrate shown in the second embodiment.

[0098] Fifth Embodiment In the fifth embodiment, a multilayer substrate having a different protective film configuration from those of the embodiments shown so far and a module substrate including the multilayer substrate will be illustrated.

[0099] 12 is a cross-sectional view of a module substrate 305 according to the fifth embodiment. This module substrate 305 includes a multilayer substrate 101 and an electronic component 200. The multilayer substrate 101 is the same as the multilayer substrate 101 described in the first embodiment. The basic configuration of the electronic component 200 is similar to that of the electronic component 200 described in the first embodiment.

[0100] In this embodiment, an electrically insulating protective film 43 is formed on the upper surface of the electronic component 200. The radiating electrode 7 is protected by this protective film 43. In this manner, the electronic component 200 may be coated with the protective film.

[0101] 12, protective film 42 is not formed inside recessed portion CA, but it may also be formed inside recessed portion CA. Furthermore, a protective film may be formed on the entire outer surface of electronic component 200.

[0102] Sixth Embodiment In the sixth embodiment, a multilayer substrate in which a plurality of resin layers and conductor layers are laminated via adhesive layers and a module substrate including the multilayer substrate will be exemplified.

[0103] FIG. 13 is a cross-sectional view of a module substrate 306 according to the sixth embodiment.

[0104] Module substrate 306 includes multilayer substrate 106 and electronic component 200 mounted thereon. Multilayer substrate 106 includes a plurality of resin layers 11, 12, 13, 14, 15, and 16, Cu foil attached to one side of these resin layers 11, 12, 13, 14, 15, and 16, and interlayer connection conductors formed inside resin layers 11, 12, 13, 15, and 16.

[0105] The resin layers 11, 12, 13, 14, 15, and 16 are, for example, thermosetting resin, and in this example, the resin layers adjacent to each other in the stacking direction and the resin layers adjacent to each other in the stacking direction and the Cu foil are bonded together via adhesive layer 8 to form a laminate.

[0106] As shown in this embodiment, the multilayer substrate may have multiple resin layers and conductor layers laminated together with adhesive layers interposed therebetween. Also, electronic component 200 may be adhered to recessed portion CA of multilayer substrate 106 with adhesive layer 8 interposed therebetween.

[0107] Seventh Embodiment In the seventh embodiment, an electronic device according to the present invention will be illustrated.

[0108] An electronic device according to the present invention includes any one of the module boards shown in the first to sixth embodiments, and a housing that houses the module board.

[0109] The electronic components included in the module board include, for example, a patch antenna, a chip capacitor for matching the impedance of the signal transmission line connected to the patch antenna, a power amplifier IC that outputs a transmission signal to the patch antenna, and a signal amplifier IC that amplifies the signal received by the patch antenna.

[0110] The housing that houses the module board is of a size and shape that allows the module board to be built in. Furthermore, if the electronic component communicates with an external device or is electromagnetically coupled, at least that part is made of a non-conductive or non-magnetic material.

[0111] 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.

[0112] For example, the substrate of electronic component 200 shown in Figures 3, 7, 9, 11, 12, and 13 may be made of a material different from the resin material of multilayer substrates 101, 102, 103, 104, and 106, as long as it is suitable for the electrical characteristics of the electronic component, but is not limited to this. That is, the substrate and resin layer of the electronic component may be made of different materials, or the substrate of electronic component 200 may be made of the same material as the resin material of multilayer substrates 101, 102, 103, 104, and 106. This allows for strong adhesion between the multilayer substrate and the electronic component. For example, both the resin materials of multilayer substrates 101, 102, 103, 104, and 106 and the substrate of electronic component 200 may be made of liquid crystal polymer resin.

[0113] Whether or not the resin materials are the same can be confirmed using a Fourier transform infrared spectrophotometer (FT-IR). That is, spectra are obtained using a Fourier transform infrared spectrophotometer (FT-IR), and if the peaks of the spectra are the same for electronic component 200 and the multilayer board, it can be confirmed that they are the same type of resin materials.

[0114] In the case of thermoplastic resins, the difference in melting points between resin materials of the same type is small. Whether the resin portion of the multilayer board and the resin portion of electronic component 200 are made of the same type of resin can be confirmed by the endothermic peak of differential scanning calorimetry (DSC). Specifically, using a Rigaku DSC8230, the two resins are heated at a rate of 10°C / min, melted, cooled, and then heated again at 10°C / min. If the difference in melting points between the two resins is within 5°C, they can be considered to be the same type of resin.

[0115] In each embodiment, a signal line conductor pattern and a ground conductor layer are formed to configure a microstrip line or a triplate type strip line, but the present invention is not limited to those having such a transmission line portion.

[0116] Furthermore, in each embodiment, an example has been shown in which an electronic component equipped with a patch antenna is used, but the present invention can also be applied to various other electronic components.

[0117] The multilayer substrate, module substrate, and electronic device of the present invention may be provided in the following aspects.

[0118] <1> A plurality of resin layers; a conductor layer attached to one surface of all or some of the resin layers among the plurality of resin layers; an interlayer connection conductor formed inside all or some of the resin layers among the plurality of resin layers; Equipped with a laminated body is formed by laminating the plurality of resin layers and the conductor layers, some of the resin layers have openings that expose parts of the resin layers below the resin layers to form recesses (cavities) on the surface of the laminate; the conductor layer is attached to the lower surface of the resin layer present in the lower layer, the conductor layer is attached to the upper surface of the resin layer, which is the uppermost surface (outer layer) of the laminate, the interlayer connection conductor formed in the resin layer present in the lower layer and the interlayer connection conductor formed in the resin layer disposed at a position that is the uppermost layer of the laminate are electrically conductive; Multilayer board.

[0119] <2> The plurality of resin layers and the conductor layers are laminated by bonding the resin layers together and bonding the resin layers to the conductor layers. <1> The multilayer substrate according to claim 1.

[0120] <3> The plurality of resin layers and the conductor layer are laminated via an adhesive layer. <1> The multilayer substrate according to claim 1.

[0121] <4> a conductor layer exposure portion that exposes a part of the conductor layer attached to a resin layer located on the bottom surface of the recess among the plurality of resin layers to the surface of the laminate within the recess (within the opening); <1> from <3> 10. The multilayer substrate according to claim 9, wherein

[0122] <5> Among the plurality of resin layers, a resin layer located on the bottom surface of the recessed portion includes the interlayer connection conductor exposed on the surface of the laminate within the recessed portion (within the opening). <1> from <3> 10. The multilayer substrate according to claim 9, wherein

[0123] <6> the conductor layer attached to the upper surface of the resin layer arranged at a position that will be the uppermost layer of the laminate is a ground conductor layer, the pattern of the conductor layer attached to the lower surface of the resin layer present in the inner layer of the laminate is a signal conductor pattern; <1> from <5> 10. The multilayer substrate according to claim 9, wherein

[0124] <7> an electronic component having terminal electrodes; <4> and the multilayer substrate according to A module substrate in which the terminal electrodes of the electronic components are electrically connected to the exposed conductor layer portions via a conductive bonding material (i.e., the electronic components are mounted in the recessed portions).

[0125] <8> an electronic component having terminal electrodes; <5> and the multilayer substrate according to A module substrate in which the terminal electrodes of the electronic component are directly bonded to the interlayer connection conductors exposed on the surface of the laminate within the recess (i.e., the electronic component is mounted in the recess).

[0126] <9> The substrate of the electronic component and the resin layer are made of the same material. <7> or <8> The module substrate according to claim 1.

[0127] <10> The substrate of the electronic component and the resin layer are made of different materials. <7> or <8> The module substrate according to claim 1.

[0128] <11> The material of the resin layer is a thermoplastic resin. <7> or <8> The module substrate according to claim 1.

[0129] <12> The material of the resin layer is a liquid crystal polymer resin. <7> or <8> The module substrate according to claim 1.

[0130] <13> <7> from <12> and a housing that houses the module substrate. [Explanation of symbols]

[0131] AP, AP1, AP2…Aperture BMa,BMb…Conductive bonding material CA…Recessed portion EXa, EXb…Cu foil exposed part 6a,6b…Terminal electrode 7...Radiation electrode 8...Adhesive layer 11, 12, 13, 14, 15, 16...Resin layers 21, 26c, 26d...Cu foil (conductor layer) 22a, 22b, 22c...Cu foil (conductor layer) 23a, 23b, 23c...Cu foil (conductor layer) 24, 24a, 24b, 24c, 24d...Cu foil (conductor layer) 25a, 25b, 25c, 25d...Cu foil (conductor layer) 31a, 31b...Interlayer connecting conductors 32b, 32c...Interlayer connecting conductor 33a, 33b...Interlayer connection conductors 34a, 34b...Interlayer connection conductors 35a, 35b, 35c, 35d...Interlayer connection conductors 36c, 36d...Interlayer connecting conductor 41,42,43...Protective film 101,102,103,104,106...Multilayer board 200...Electronic components 301, 302, 303, 304, 305, 306...Module board

Claims

1. A plurality of resin layers; a conductor layer attached to one surface of all or some of the resin layers among the plurality of resin layers; an interlayer connection conductor formed inside all or some of the resin layers among the plurality of resin layers; Equipped with a laminated body is formed by laminating the plurality of resin layers and the conductor layers, some of the resin layers have openings that expose parts of the resin layers present below the resin layers to form recesses on the surface of the laminate; the conductor layer is attached to the lower surface of the resin layer present in the lower layer, the conductor layer is attached to an upper surface of the resin layer, which is the uppermost surface of the laminate; the interlayer connection conductor formed in the resin layer present in the lower layer and the interlayer connection conductor formed in the resin layer disposed at a position that is the uppermost layer of the laminate are electrically conductive; Multilayer board.

2. The plurality of resin layers and the conductor layers are laminated by bonding the resin layers together and bonding the resin layers to the conductor layers. The multilayer substrate according to claim 1 .

3. The plurality of resin layers are laminated via adhesive layers. The multilayer substrate according to claim 1 .

4. a conductor layer exposure portion that exposes a part of the conductor layer attached to a resin layer located on a bottom surface of the recess among the plurality of resin layers on the surface of the laminate within the recess; The multilayer substrate according to any one of claims 1 to 3.

5. a resin layer located on a bottom surface of the recessed portion among the plurality of resin layers includes the interlayer connection conductor exposed on a surface of the laminate within the recessed portion; The multilayer substrate according to any one of claims 1 to 3.

6. the conductor layer attached to the upper surface of the resin layer arranged at a position that will be the uppermost layer of the laminate is a ground conductor layer, the pattern of the conductor layer attached to the lower surface of the resin layer present in the inner layer of the laminate is a signal conductor pattern; The multilayer substrate according to any one of claims 1 to 3.

7. An electronic component having terminal electrodes and the multilayer substrate according to claim 4, The terminal electrodes of the electronic components are electrically connected to the exposed conductor layer portions via a conductive adhesive material.

8. An electronic component having terminal electrodes and the multilayer substrate according to claim 5, a module substrate in which the terminal electrodes of the electronic components are directly bonded to the interlayer connection conductors exposed on the surface of the laminate within the recesses;

9. The substrate of the electronic component and the resin layer are made of the same material. The module substrate according to claim 7 .

10. The substrate of the electronic component and the resin layer are made of the same material. The module substrate according to claim 8 .

11. The substrate of the electronic component and the resin layer are made of different materials. The module substrate according to claim 7 .

12. The substrate of the electronic component and the resin layer are made of different materials. The module substrate according to claim 8 .

13. The material of the resin layer is a thermoplastic resin. The module substrate according to claim 7 .

14. The material of the resin layer is a thermoplastic resin. The module substrate according to claim 8 .

15. The material of the resin layer is a liquid crystal polymer resin. The module substrate according to claim 7 .

16. The material of the resin layer is a liquid crystal polymer resin. The module substrate according to claim 8 .

17. An electronic device comprising: the module board according to claim 7; and a housing that houses the module board.

18. An electronic device comprising: the module board according to claim 8; and a housing that houses the module board.

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