Wiring board and electronic module

Abstract

This wiring board comprises a first element, a first insulating base material, and a second insulating base material. An element mounting region has therein an element mounting region in which the first element is disposed, and contains a first resin material and silica. The second insulating base material is positioned in contact with the first element in the element mounting region, surrounds the first element, and contains a second resin material and silica. The weight percentage of the second resin material in the second insulating base material is higher than the weight percentage of the first resin material in the first insulating base material.

Description

Wiring Substrate and Electronic Module

[0001] The present disclosure relates to a wiring substrate and an electronic module.

[0002] There has been known a wiring substrate in which an opening is filled with an insulating base material to cover an element located in the opening (see Patent Document 1).

[0003] Japanese Unexamined Patent Publication No. 2016-207958

[0004] The wiring substrate of the present disclosure includes a first element, a first insulating base material, and a second insulating base material. The first insulating base material internally has an element mounting region where the first element is arranged, and contains a first resin material and silica. The second insulating base material is positioned in contact with the first element in the element mounting region, surrounds the first element, and contains a second resin material and silica. The weight percentage of the second resin material in the second insulating base material is higher than the weight percentage of the first resin material in the first insulating base material.

[0005] Fig. 1 is a perspective view showing the wiring substrate according to an embodiment. Fig. 2 is a cross-sectional view taken along line A-A shown in Fig. 1. Fig. 3 is a cross-sectional view showing a wiring substrate according to a modification of the embodiment. Fig. 4 is a cross-sectional view showing the electronic module according to an embodiment.

[0006] Hereinafter, modes for implementing the wiring substrate and the electronic module according to the present disclosure (hereinafter referred to as "embodiments") will be described in detail with reference to the drawings. The present disclosure is not limited by these embodiments. Furthermore, each embodiment can be appropriately combined within a range that does not cause inconsistency in processing contents. In the following embodiments, the same parts are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0007] Furthermore, in the embodiments described below, expressions such as "orthogonal" or "perpendicular" may be used, but these expressions do not require strict "orthogonality" or "perpendicularity". That is, each of the above expressions allows for deviations such as those resulting from manufacturing accuracy and installation accuracy, for example.

[0008] Furthermore, in the drawings referenced below, for the sake of clarity, mutually orthogonal X-axis, Y-axis, and Z-axis directions are sometimes defined, and a Cartesian coordinate system is shown in which the Z-axis direction is the thickness direction of the wiring board.

[0009] In the conventional technology described above, there is a need to reduce the possibility of air gaps occurring between the insulating substrate and the element.

[0010] This disclosure provides a technology that can reduce the possibility of air gaps occurring between an insulating substrate and an element.

[0011] <Embodiment> Figure 1 is a perspective view showing a wiring board according to an embodiment. Figure 2 is a cross-sectional view taken along the line A-A shown in Figure 1.

[0012] As shown in Figures 1 and 2, the wiring board 100 according to the embodiment comprises a first element 200, a first insulating substrate 10, and a second insulating substrate 20. The wiring board 100 may further comprise a conductor 30 and a third insulating substrate 40. The wiring board 100 may also be a laminate of the first insulating substrate 10 and the third insulating substrate 40. The wiring board 100 may also comprise wiring 50 and electrodes 60.

[0013] <First Element> The first element 200 is an element mounted on the wiring board 100. The first element 200 may be embedded in the first insulating substrate 10. The first element 200 may be, for example, a capacitor, an inductor, a drive IC, or a power supply capacitor. That is, the wiring board 100 can use a capacitor, an inductor, a drive IC, or a power supply capacitor as the first element 200. The first element 200 may have a plurality of conductive parts 201 that connect to the conductor 30. For example, the conductive parts 201 may be solder.

[0014] <First insulating substrate> The first insulating substrate 10 contains a first resin material and silica. The first resin material may be an organic resin. The organic resin may be, for example, any of epoxy resin, phenolic resin, acrylic resin, polycarbonate resin, polyimide resin, olefin resin, and polyphenylene resin. Alternatively, the organic resin may be, for example, polytetrafluoroethylene (PTFE), other fluororesins, or polyphenylene ether resin. The first insulating substrate 10 may also contain components other than organic resins. The first insulating substrate 10 may contain multiple types of organic resins.

[0015] In the first insulating substrate 10, the content of inorganic materials such as silica may be higher than the content of organic resin. More specifically, the content of inorganic materials in the first insulating substrate 10 may be 50% by mass or more of the first insulating substrate 10. Also, the content of organic resin in the first insulating substrate 10 may be 50% by mass or less of the first insulating substrate 10.

[0016] The first insulating substrate 10 has an element mounting region R inside on which the first element 200 is placed. In addition to the first element 200, the second insulating substrate 20 may also be located in the element mounting region R. In other words, the element mounting region R may be the region on which the first element 200 and the second insulating substrate 20 are located. Furthermore, at least a portion of the conductor 30 may be located in the element mounting region R. In other words, the element mounting region R may be the region on which at least a portion of the conductor 30 is located.

[0017] The element mounting region R may be rectangular in shape when viewed from above. The upper end of the element mounting region R may be at the same height as the upper end of the first element 200. The lower end of the element mounting region R may be at the same height as the lower end of the conductor 30.

[0018] The first insulating substrate 10 may contain maleimide resin (an example of a third resin material). Maleimide resin is a thermosetting resin with excellent heat resistance. A wiring board 100 having the first insulating substrate 10 containing maleimide resin has high heat resistance.

[0019] The first insulating substrate 10 may contain a rubber material. For example, the first insulating substrate 10 may contain both nitrile rubber (NBR) and silicone rubber as the rubber material. The first insulating substrate 10 may contain either nitrile rubber or silicone rubber. Nitrile rubber and silicone rubber reduce the Young's modulus of the first insulating substrate 10. Therefore, a wiring board 100 having a first insulating substrate 10 containing at least one of nitrile rubber and silicone rubber can relieve the stress on the first element 200.

[0020] The first insulating substrate 10 may have a first surface 101 and a second surface 102 located opposite the first surface 101. The first insulating substrate 10 may be a plate-like body with the first surface 101 and the second surface 102 as its main surfaces. The first insulating substrate 10 may have a plurality of via conductors 51 located inside the first insulating substrate 10 and extending in the direction from the first surface 101 toward the second surface 102.

[0021] The first insulating substrate 10 may have an organic resin layer 11. In the example shown in Figure 2, the first insulating substrate 10 has a multilayer structure in which multiple organic resin layers 11 are laminated, but the first insulating substrate 10 may have a single-layer structure. That is, the first insulating substrate 10 may have a structure in which only one organic resin layer 11 is present. The multiple organic resin layers 11 are laminated along the thickness direction of the first insulating substrate 10, which in this embodiment is along the Z-axis direction.

[0022] The organic resin layer 11 refers to a layer containing organic resin, and includes not only layers composed solely of organic resin, but also layers containing inorganic materials such as silica in addition to the organic resin. Furthermore, the mass percentage of organic resin in the organic resin layer 11 may be less than the mass percentage of inorganic materials in the organic resin layer 11.

[0023] A wiring board 100 having such a first insulating substrate 10 offers a high degree of design freedom. Furthermore, by constructing the first insulating substrate 10 using multiple organic resin layers 11, the first insulating substrate 10 can be manufactured while checking layer by layer whether the wiring 50 described later is properly formed, thereby improving the yield of the first insulating substrate 10.

[0024] Furthermore, the first insulating substrate 10 containing organic components is more suitable for forming fine wiring patterns compared to an inorganic substrate. Also, as will be described later, the first insulating substrate 10 containing resin material has a lower density than the third insulating substrate 40 containing ceramic, thus enabling weight reduction.

[0025] <Second insulating substrate> The second insulating substrate 20 contains a second resin material and silica. The second resin material may be an organic resin. The organic resin may be, for example, any of epoxy resin, phenolic resin, acrylic resin, polycarbonate resin, polyimide resin, olefin resin, and polyphenylene resin. Alternatively, the organic resin may be, for example, polytetrafluoroethylene (PTFE), other fluororesins, or polyphenylene ether resin. The second insulating substrate 20 may also contain components other than organic resins. The second insulating substrate 20 may contain multiple types of organic resins.

[0026] In the second insulating substrate 20, the content of inorganic materials such as silica may be higher than the content of organic resin. More specifically, the content of inorganic materials in the second insulating substrate 20 may be 50% by mass or more of the second insulating substrate 20. Also, the content of organic resin in the second insulating substrate 20 may be 50% by mass or less of the second insulating substrate 20.

[0027] The second insulating substrate 20 may have a fifth surface 105 and a sixth surface 106 located on the opposite side of the fifth surface 105. The second insulating substrate 20 may have a side surface 107 connecting the fifth surface 105 and the sixth surface 106. The second insulating substrate 20 may be located in contact with the first element 200 within the element mounting region R. The second insulating substrate 20 may cover the side surface 202 of the first element 200. The second insulating substrate 20 may be located surrounding the first element 200. For example, the second insulating substrate 20 may be an underfill filling the space between the first element 200 and the first insulating substrate 10 in the element mounting region R.

[0028] A portion 202A of the side surface 202 of the first element 200 located on the side opposite to the third insulating substrate 40 may be exposed from the second insulating substrate 20. In other words, the top surface and a portion 202A, which is part of the side surface 202 continuous with the top surface, may be exposed from the second insulating substrate 20. The top surface and portion 202A of the first element 200 exposed from the second insulating substrate 20 may be in contact with the first insulating substrate 10. The organic resin layer 11 in contact with the first element 200 may flow around the first element 200 toward the third insulating substrate 40.

[0029] The side surface 107 of the second insulating substrate 20 may be curved toward the first element 200. The side surface 107 of the second insulating substrate 20 may be curved so that it gradually approaches the first element 200 as it moves from the first surface 101 toward the central part between the first surface 101 and the second surface 102. The side surface 107 of the second insulating substrate 20 may be curved so that it gradually approaches the first element 200 as it moves from the second surface 102 toward the central part between the first surface 101 and the second surface 102. The second insulating substrate 20 may be configured such that its thickness is thinnest in the central part between the first surface 101 and the second surface 102.

[0030] As a result, the first element 200 is less likely to move in the areas where the thickness of the second insulating substrate 20 is reduced. Therefore, the wiring board 100 can reduce the possibility that the first element 200 will move significantly within the second insulating substrate 20 when vibration is transmitted to the first element 200.

[0031] <Conductor> At least a portion of the conductor 30 is located in the element mounting region R and is electrically connected to the first element 200. For example, the portion of the conductor 30 that contacts the second insulating substrate 20 may be located in the element mounting region R. The conductor 30 is a junction conductor located on the first surface 101 of the first insulating substrate 10. The conductor 30 may contain silica components. The conductor 30 may be located between the first insulating substrate 10 and the second insulating substrate 20 and the third insulating substrate 40 and electrically connect the first element 200 and the wiring 50. A wiring board 100 having such a conductor 30 offers a high degree of design freedom.

[0032] <Third insulating substrate> The third insulating substrate 40 may contain ceramic, or ceramic may be the main component. The third insulating substrate 40 may be formed using a ceramic composite material containing silica components such as glass, so-called glass ceramic. Glass ceramic can be any of the following: a composite of a glass phase and ceramic particles, a composite of a glass phase and a crystalline phase formed by the crystallization of a part of the glass phase, a form in which ceramic particles exist in the glass phase, or a form in which the glass phase exists at the grain boundaries between ceramic particles. In this disclosure, the main component is, for example, a material that accounts for 50% or more by mass of the material.

[0033] For example, the third insulating substrate 40 may be LTCC (Low Temperature Co-fired Ceramics). The third insulating substrate 40 may also be HTCC (High Temperature Co-Fired Ceramic). When LTCC is used as the third insulating substrate 40, it is possible to use low-melting-point metals such as copper or silver, which have relatively low electrical resistance, as wiring.

[0034] The third insulating substrate 40 may contain ceramic fillers as ceramic particles. Examples of ceramic fillers include alumina (aluminum oxide), calcium titanate, or magnesium titanate. The third insulating substrate 40 containing alumina has high rigidity.

[0035] The third insulating substrate 40 may have a third surface 103 and a fourth surface 104 located opposite the third surface 103. The third insulating substrate 40 may be a plate-like body with the third surface 103 and the fourth surface 104 as its main surfaces. The third insulating substrate 40 may be located in contact with the first surface 101. That is, the third insulating substrate 40 may be directly bonded to the first insulating substrate 10 without an adhesive layer. The third insulating substrate 40 may have via conductors (not shown) located inside the third insulating substrate 40 that extend in the direction from the third surface 103 toward the fourth surface 104.

[0036] The third insulating substrate 40 may have a ceramic layer 41. In the example shown in Figure 2, the third insulating substrate 40 is shown as a single-layer structure composed of one ceramic layer 41, but the third insulating substrate 40 may also have a multilayer structure. That is, the third insulating substrate 40 may have a structure having multiple ceramic layers 41. The multiple ceramic layers 41 are stacked along the Z-axis direction shown in Figure 2, which is the thickness direction of the third insulating substrate 40. By constructing the third insulating substrate 40 using multiple ceramic layers 41 in this way, a third insulating substrate 40 having wiring (not shown) such as via conductors and land conductors inside can be obtained.

[0037] A wiring board 100 having such a third insulating substrate 40 offers a high degree of design flexibility. Furthermore, by constructing the third insulating substrate 40 using multiple ceramic layers 41, the third insulating substrate 40 can be manufactured while checking whether the wiring is properly formed layer by layer, thereby improving the yield of the third insulating substrate 40.

[0038] The wiring board 100 is not limited to a configuration in which the third insulating substrate 40 is in contact with the first surface 101, but may also be configured in which a fourth insulating substrate (not shown) containing a resin material and silica is in contact with the first surface 101. The wiring board 100 may also be configured in which the third insulating substrate 40 is in contact with the lower surface of the fourth insulating substrate.

[0039] <Wiring> The wiring 50 is located on the first insulating substrate 10 and extends from one of the first surface 101 and the second surface 102 to the other. Note that "extending" here does not necessarily mean extending along the shortest distance. The wiring 50 may be electrically connected to the conductor 30 on the first surface 101. The wiring 50 may be electrically connected to the electrode 60 on the second surface 102. The wiring 50 may have a land conductor 52 in the middle that extends along the first surface 101 or the second surface 102.

[0040] The wiring 50 may include a plurality of via conductors 51 and one or more land conductors 52. The via conductors 51 and the land conductors 52 are located inside the first insulating base material 10. The via conductors 51 penetrate through one or more organic resin layers 11. When there are a plurality of organic resin layers 11, the land conductors 52 are located, for example, between adjacent organic resin layers 11, and electrically connect the plurality of via conductors 51 to each other.

[0041] Here, in a cross-sectional view, the land conductor 52 may have a trapezoidal shape (see land conductor 52A). More specifically, the width of the land conductor 52 may decrease as it approaches the third insulating base material 40. With this configuration, when laminating the first insulating base material 10 onto the third insulating base material 40, it is possible to easily control the pressure applied to the land conductor 52 in the direction where the third insulating base material 40 exists, and the contact between the via conductors 51 and the land conductors 52 can be achieved more reliably. Note that the wiring 50 does not necessarily need to include the land conductors 52.

[0042] An interval L2 between adjacent via conductors 51 may be smaller than an interval L1 between the via conductor 51 adjacent to the first element 200 and the first element 200. This increases the interval L1 between the via conductor 51 and the first element 200. Therefore, the wiring substrate 100 can reduce the possibility that the via conductor 51 is distorted during manufacturing, comes into contact with the first element 200, and causes a short circuit.

[0043] The wiring 50 may be a conductor mainly composed of copper and a metal other than copper such as silver. The wiring 50 may contain a silica component. In this case, the wiring 50 is firmly bonded via the silica component to the first insulating base material 10 which also contains a silica component. Therefore, the rigidity of the first insulating base material 10 can be increased.

[0044] Note that the first insulating base material 10 may include a plurality of via conductors 61. The via conductors 61 may be electrically connected to the electrode 60 on the second surface 102. The via conductors 61 may be electrically connected to the first element 200 on the upper surface of the first element 200.

[0045] <Electrode> The electrode 60 may be located on the first insulating base material 10. For example, the electrode 60 may be located on the second surface 102. The electrode 60 may be electrically connected to the wiring 50. For example, the electrode 60 may be electrically connected to the via conductor 51. Further, the electrode 60 may be electrically connected to the via conductor 61. Furthermore, the electrode 60 may be electrically connected to a second element 210 described later. In this way, the electrode 60 may electrically connect the wiring 50, the first element 200, and the second element 210.

[0046] <First Insulating Base Material, Second Insulating Base Material and Third Insulating Base Material> In the wiring substrate 100 configured as described above, the weight percentage of the second resin material in the second insulating base material 20 is higher than the weight percentage of the first resin material in the first insulating base material 10. Accordingly, since the resin content in the peripheral portion of the first element 200 is high, the fluidity of the peripheral portion of the first element 200 is increased. Therefore, the wiring substrate 100 can reduce the possibility that a void is formed between the insulating base material and the first element 200.

[0047] Also, since the resin content in the peripheral portion of the first element 200 is high, the Young's modulus of the peripheral portion of the first element 200 is lowered. Therefore, the wiring substrate 100 can mitigate vibration and stress applied to the first element 200.

[0048] The weight percentage of silica in the first insulating base material 10 may be higher than the weight percentage of silica in the second insulating base material 20. Accordingly, by containing a large amount of silica in the first insulating base material 10 surrounding the second insulating base material 20, the coefficient of thermal expansion of the entire wiring substrate 100 can be reduced. Further, since silica is relatively less deformed by heat, the possibility that the wiring substrate 100 is deformed by heat from the first element 200 or other electronic components mounted on the wiring substrate 100 can be reduced.

[0049] As described above, the wiring substrate 100 may include a conductor 30 at least partially located in the element mounting region R and electrically connected to the first element 200. Accordingly, since the conductive portion 201 of the first element 200 is positioned connected to the conductor 30, the heat dissipation performance of the first element 200 can be improved.

[0050] As described above, the wiring board 100 may include a third insulating substrate 40. The third insulating substrate 40 may be positioned in contact with the first surface 101 of the first insulating substrate 10. This improves the rigidity of the wiring board 100. Therefore, warping of the wiring board 100 can be reduced.

[0051] Of the first insulating substrate 10 and the second insulating substrate 20, only the second insulating substrate 20 may be located between the first element 200 and the third insulating substrate 40. The element mounting region R may be located in contact with the third surface 103 of the third insulating substrate 40. In other words, the first insulating substrate 10 does not have to be located between the first element 200 and the third insulating substrate 40.

[0052] Generally, the third insulating substrate 40 containing ceramic has a higher thermal conductivity than the substrate containing resin material. Therefore, with the above configuration, since the first insulating substrate 10 is not located between the first element 200 and the third insulating substrate 40, it is possible to reduce the physical distance between the first element 200 and the third insulating substrate 40, which has a higher thermal conductivity than the first insulating substrate 10. This makes it easier to dissipate the heat generated in the first element 200 to the third insulating substrate 40.

[0053] Furthermore, the third insulating substrate 40 containing ceramic generally has higher rigidity than the insulating substrate containing resin material. Therefore, with the above configuration, the first element 200 can be mounted on the third insulating substrate 40 containing ceramic during manufacturing, thus reducing the possibility of the wiring board 100 bending when mounting the first element 200 compared to when the first element 200 is mounted on an insulating substrate containing resin material.

[0054] The Young's modulus of the first insulating substrate 10 may be higher than that of the second insulating substrate 20. The first insulating substrate 10 may cover the portion 202A of the side surface 202 of the first element 200 that is exposed from the second insulating substrate 20.

[0055] As a result, the rigidity of the first insulating substrate 10 is higher than that of the second insulating substrate 20, and the first insulating substrate 10 covers the portion 202A of the side surface 107 of the first element 200 that is located on the opposite side of the third insulating substrate 40. Therefore, the possibility of the first element 200 shifting during manufacturing or before the insulating substrate hardens can be reduced in the wiring board 100.

[0056] The first and second resin materials may be thermosetting resins. Thermosetting resins tend to cure more uniformly than photocuring resins. This makes it easier to manufacture the wiring board 100. In addition, the wiring board 100 can be cured in a single batch.

[0057] The curing temperature of the first insulating substrate 10 may be higher than the curing temperature of the second insulating substrate 20. For example, the curing temperature of the first insulating substrate 10 may be 150 to 250°C. The effective temperature of the second insulating substrate 20 may be 150 to 200°C.

[0058] <Modification> In the above embodiment, the wiring board 100 was described in an example in which one first element 200 is arranged in one element mounting area R. The wiring board 100 is not limited to this, and may be configured in which multiple first elements 200 are arranged in one element mounting area R.

[0059] Figure 3 is a cross-sectional view showing a modified wiring board according to an embodiment. As shown in Figure 3, the configuration may be such that two first elements 200 are arranged in one element mounting area R. The two first elements 200 may have different heights. Arranging multiple first elements 200 in one element mounting area R makes it easier to manufacture the wiring board 100 compared to the case where multiple first elements 200 are located in separate element mounting areas R. Furthermore, by combining multiple types of elements as the first elements 200, it is possible to provide a wiring board 100 that has multiple functions. Note that the wiring board 100 may be configured to have multiple element mounting areas R, with one or more first elements 200 arranged in each element mounting area R.

[0060] Furthermore, the wiring board 100 may have a configuration in which the third insulating substrate 40 has a recess 42 (see Figure 2). The recess 42 is recessed on the fourth surface 104 side of the third surface 103. At least a part of the first element 200 may be located in the recess 42. Specifically, the lower part of the first element 200 or the conductive portion 201 may be located in the recess 42. This allows the position of the first element 200 to be determined.

[0061] <Electronic Module> Figure 4 is a cross-sectional view showing an electronic module according to the embodiment. As shown in Figure 4, the electronic module 300 comprises a wiring board 100 and a second element 210. The second element 210 may be mounted on the second surface 102, which is the surface of the wiring board 100. This provides the above-mentioned effects to the wiring board 100 of the electronic module 300.

[0062] Although the present disclosure has been described in detail above, this disclosure is not limited to the embodiments described above, and various modifications and improvements are possible without departing from the gist of this disclosure.

[0063] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. Indeed, the above embodiments can be embodied in a variety of forms. Furthermore, the above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0064] Furthermore, this technology can also take the following configurations. <Note> (1) A wiring board comprising: a first element; a first insulating substrate having an element mounting region on which the first element is arranged, and containing a first resin material and silica; and a second insulating substrate located in contact with the first element within the element mounting region, surrounding the first element, and containing a second resin material and silica, wherein the weight % of the second resin material in the second insulating substrate is higher than the weight % of the first resin material in the first insulating substrate. (2) The wiring board according to (1), wherein the weight % of the silica in the first insulating substrate is higher than the weight % of the silica in the second insulating substrate. (3) The wiring board according to (1) or (2), further comprising a conductor, at least a portion of which is located in the element mounting region and electrically connected to the first element. (4) The wiring board according to any one of (1) to (3), further comprising a third insulating substrate containing ceramic, wherein the first insulating substrate has a first surface and a second surface located opposite to the first surface, and the third insulating substrate is located in contact with the first surface. (5) The wiring board according to (4), wherein of the first insulating substrate and the second insulating substrate, only the second insulating substrate is located between the first element and the third insulating substrate. (6) The wiring board according to (4) or (5), wherein the Young's modulus of the first insulating substrate is higher than that of the second insulating substrate, the second insulating substrate covers the side surface of the first element, the portion of the side surface of the first element located opposite to the third insulating substrate is exposed from the second insulating substrate, and the first insulating substrate covers the portion of the side surface of the first element exposed from the second insulating substrate. (7) The wiring board according to any one of (1) to (6), wherein the first resin material and the second resin material are thermosetting resins. (8) The wiring board according to any one of (1) to (7), wherein the first insulating substrate contains maleimide resin as the third resin material. (9) The wiring board according to any one of (1) to (8), wherein the first insulating substrate contains rubber material.(10) The wiring board according to any one of (1) to (3), wherein the first insulating substrate has a first surface, a second surface located opposite to the first surface, and a plurality of via conductors located inside the first insulating substrate and extending in the direction from the first surface toward the second surface, and the spacing between adjacent via conductors is smaller than the spacing between a via conductor adjacent to the first element and the first element. (11) The wiring board according to any one of (1) to (10), wherein the side surface of the second insulating substrate is curved toward the first element. (12) The wiring board according to any one of (1) to (11), wherein the first element is one of a capacitor, an inductor, a drive IC, and a power supply capacitor. (13) The wiring board according to any one of (1) to (12), wherein it has a plurality of first elements, and the plurality of first elements are arranged in one element mounting area. (14) The wiring board according to any one of (4) to (6), wherein the third insulating substrate has a third surface in contact with the first surface, a fourth surface located opposite the third surface, and a recess that is recessed toward the fourth surface than the third surface, and at least a portion of the first element is located in the recess. (15) An electronic module comprising the wiring board according to any one of (1) to (14), and a second element mounted on the surface of the wiring board.

[0065] 10 First insulating substrate 11 Organic resin layer 20 Second insulating substrate 30 Conductor 40 Third insulating substrate 41 Ceramic layer 42 Recess 50 Wiring 51 Via conductor 52 Land conductor 52A Land conductor 60 Electrode 61 Via conductor 100 Wiring board 101 First surface 102 Second surface 103 Third surface 104 Fourth surface 105 Fifth surface 106 Sixth surface 107 Side surface 200 First element 201 Conductive area 202 Side surface 202A Area 210 Second element 300 Electronic module R Element mounting area

Claims

1. A wiring board comprising: a first element; a first insulating substrate having an element mounting region on which the first element is arranged, and containing a first resin material and silica; and a second insulating substrate located in contact with the first element within the element mounting region, surrounding the first element, and containing a second resin material and silica, wherein the weight percentage of the second resin material in the second insulating substrate is higher than the weight percentage of the first resin material in the first insulating substrate.

2. The wiring board according to claim 1, wherein the weight percentage of silica in the first insulating substrate is higher than the weight percentage of silica in the second insulating substrate.

3. The wiring board according to claim 1 or 2, further comprising a conductor, at least a portion of which is located in the element mounting area and electrically connected to the first element.

4. A wiring board according to any one of claims 1 to 3, further comprising a third insulating substrate containing ceramic, wherein the first insulating substrate has a first surface and a second surface located opposite to the first surface, and the third insulating substrate is located in contact with the first surface.

5. The wiring board according to claim 4, wherein of the first insulating substrate and the second insulating substrate, only the second insulating substrate is located between the first element and the third insulating substrate.

6. The wiring board according to claim 4 or 5, wherein the Young's modulus of the first insulating substrate is higher than that of the second insulating substrate, the second insulating substrate covers the side surface of the first element, the portion of the side surface of the first element located on the side opposite to the third insulating substrate is exposed from the second insulating substrate, and the first insulating substrate covers the portion of the side surface of the first element exposed from the second insulating substrate.

7. The wiring board according to any one of claims 1 to 6, wherein the first resin material and the second resin material are thermosetting resins.

8. The wiring board according to any one of claims 1 to 7, wherein the first insulating substrate contains maleimide resin as the third resin material.

9. The wiring board according to any one of claims 1 to 8, wherein the first insulating substrate contains a rubber material.

10. The wiring board according to any one of claims 1 to 3, wherein the first insulating substrate has a first surface, a second surface located opposite the first surface, and a plurality of via conductors located inside the first insulating substrate and extending in the direction from the first surface toward the second surface, and the spacing between adjacent via conductors is smaller than the spacing between adjacent via conductors and the first element.

11. The wiring board according to any one of claims 1 to 10, wherein the side surface of the second insulating substrate is curved toward the first element.

12. The wiring board according to any one of claims 1 to 11, wherein the first element is a capacitor, an inductor, a drive IC, and a power supply capacitor.

13. A wiring board according to any one of claims 1 to 12, wherein it has a plurality of the first elements, and the plurality of the first elements are arranged in one element mounting region.

14. The wiring board according to any one of claims 4 to 6, wherein the third insulating substrate has a third surface in contact with the first surface, a fourth surface located opposite the third surface, and a recess that is recessed toward the fourth surface than the third surface, and at least a portion of the first element is located in the recess.

15. An electronic module comprising a wiring board according to any one of claims 1 to 14, and a second element mounted on the surface of the wiring board.

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