Capacitor-embedded substrate

Abstract

A capacitor-embedded substrate (1) includes: an insulating substrate (10) provided with a cavity (15); a chip capacitor element (20) embedded in the cavity (15) of the insulating substrate (10); and a filling resin (30). The chip capacitor element (20) includes: a cavity core portion (40) having a first face (41) and a second face (42) opposite in a thickness direction; and a capacitor portion (50) disposed on at least one of the first face (41) and the second face (42) of the cavity core portion (40). The capacitor portion (50) is composed of an anode composed of an inorganic base, a dielectric, and a cathode. When a linear expansion coefficient of the insulating substrate (10) is set as CTE1, a linear expansion coefficient of the inorganic base of the capacitor portion (50) is set as CTE2, a linear expansion coefficient of the cavity core portion (40) is set as CTE3, and a linear expansion coefficient of the filling resin (30) is set as CTE4, |CTE3-CTE1|<|CTE4-CTE1| and |CTE3-CTE1|<|CTE2-CTE1| are satisfied.

Description

Technical Field

[0001] This invention relates to a capacitor-embedded substrate. Background Technology

[0002] Patent Document 1 discloses a multilayer wiring board, characterized in that it comprises: a core substrate having a first main surface and a second main surface; a multilayer having a structure in which conductor layers and resin insulating layers are alternately stacked, formed on the surface of at least one of the first main surface and the second main surface; and a metal reinforcement disposed on the outer edge of the core substrate.

[0003] Furthermore, Patent Document 1 states that, preferably, the aforementioned metal reinforcement is a dummy metallization layer disposed on the outer edge of the core substrate and in contact with the aforementioned laminate. Additionally, Patent Document 1 states that, preferably, the aforementioned metal reinforcement is a plurality of dummy through-hole conductors or a plurality of dummy via conductors disposed on the outer edge of the core substrate.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2005-191243 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] According to Patent Document 1, a metal reinforcing body is provided on the outer edge of the core substrate for reinforcement. Therefore, even if thermal stress is generated due to the difference in thermal expansion coefficients during thermal cycling, it is difficult for delamination, also known as peeling, to occur on the surface of the core substrate, thus providing a multilayer wiring board with excellent reliability.

[0009] However, in the multilayer wiring board described in Patent Document 1, it is necessary to configure metal reinforcements such as dummy metallization layers throughout the substrate layout, which imposes significant constraints on the layout and limits its practical application. Furthermore, when components made of dissimilar materials are embedded within the multilayer wiring board described in Patent Document 1, simply configuring metal reinforcements locally on the substrate is insufficient to adequately prevent delamination.

[0010] The present invention was made to solve the above-mentioned problems, and its purpose is to provide a capacitor-embedded substrate that is difficult to delaminate and has high reliability.

[0011] Solution for solving the problem

[0012] The capacitor-embedded substrate of the present invention includes: an insulating substrate having a first main surface and a second main surface opposite to each other in the thickness direction, and a cavity therein; a core capacitor element embedded in the cavity of the insulating substrate; and a filling resin filling the cavity between the insulating substrate and the core capacitor element. The core capacitor element includes: a cavity core having a first surface and a second surface opposite to each other in the thickness direction; and a capacitor portion disposed on at least one of the first surface and the second surface of the cavity core. The capacitor portion comprises an anode, a dielectric, and a cathode, wherein the anode is composed of an inorganic substrate. When the coefficient of linear expansion of the insulating substrate is set to CTE1, the coefficient of linear expansion of the inorganic substrate of the capacitor portion is set to CTE2, the coefficient of linear expansion of the cavity core is set to CTE3, and the coefficient of linear expansion of the filling resin is set to CTE4, |CTE3-CTE1|<|CTE4-CTE1| and |CTE3-CTE1|<|CTE2-CTE1|.

[0013] The effects of the invention

[0014] According to the present invention, it is possible to provide a capacitor-embedded substrate that is less prone to delamination and has high reliability. Attached Figure Description

[0015] Figure 1 This is a cross-sectional view schematically illustrating an example of a capacitor-embedded substrate according to the first embodiment of the present invention.

[0016] Figure 2 This is a cross-sectional view schematically showing an example of the capacitor-embedded substrate of the first embodiment of the present invention together with the flow of current.

[0017] Figure 3 It is magnified Figure 1 The cross-sectional view obtained from the portion shown in III of the capacitor's built-in substrate.

[0018] Figure 4 A, B, and C are schematic cross-sectional views illustrating an example of the process of preparing a cored capacitor element.

[0019] Figure 5 This is a cross-sectional view schematically illustrating an example of the process of preparing an insulating substrate.

[0020] Figure 6 This is a cross-sectional view schematically illustrating an example of a process of mounting a cored capacitor element in a cavity of an insulating substrate.

[0021] Figure 7 This is a cross-sectional view schematically illustrating an example of a process of filling a cavity in an insulating substrate with filling resin.

[0022] Figure 8 This is a cross-sectional view schematically illustrating an example of the process of forming a circuit insulating layer on a main surface of an insulating substrate.

[0023] Figure 9 This is a cross-sectional view schematically illustrating an example of the process of forming a circuit insulation layer on another main surface of an insulating substrate.

[0024] Figure 10 This is a cross-sectional view schematically illustrating an example of the process of forming the circuit section.

[0025] Figure 11 This is a cross-sectional view schematically showing an example of the capacitor-embedded substrate of the second embodiment of the present invention together with the flow of current.

[0026] Figure 12 This is a cross-sectional view schematically showing an example of the capacitor-embedded substrate of the third embodiment of the present invention together with the flow of current.

[0027] Figure 13 It is a schematic representation of the composition. Figure 12 A partial perspective view of the core capacitor element of the capacitor-embedded substrate shown.

[0028] Figure 14 This is a cross-sectional view schematically showing a first modified example of the capacitor-embedded substrate according to the first embodiment of the present invention, together with the flow of current.

[0029] Figure 15 This is a cross-sectional view schematically showing a second variation of the capacitor-embedded substrate of the first embodiment of the present invention, together with the flow of current. Detailed Implementation

[0030] The capacitor-embedded substrate of the present invention will now be described. Furthermore, the present invention is not limited to the embodiments described below, and appropriate modifications may be made without changing the spirit of the invention. Additionally, embodiments combining multiple structures from the preferred structures described in the following embodiments are also part of the present invention.

[0031] The embodiments shown below are illustrative, and it is self-evident that parts of the structure shown in different embodiments can be replaced or combined. From the second embodiment onwards, descriptions of matters common to the first embodiment are omitted, and the differences are mainly explained. In particular, the same effects achieved by the same structure are not mentioned repeatedly in each embodiment.

[0032] In the following description, without specifically distinguishing between different embodiments, it is simply referred to as "the capacitor-embedded substrate of the present invention".

[0033] In this specification, terms indicating the relationship between elements (such as "perpendicular", "parallel", "orthogonal") and terms indicating the shape of elements are not merely expressions with strict meanings, but rather expressions indicating substantially equal ranges, including, for example, differences of several percentage points.

[0034] The accompanying drawings are schematic diagrams, and their dimensions, aspect ratios, and scales may differ from the actual product. Identical or equivalent parts in the drawings use the same reference numerals. Furthermore, identical reference numerals are used for the same elements across different drawings, and redundant descriptions are omitted.

[0035] [First Implementation]

[0036] In the capacitor-embedded substrate of the first embodiment of the present invention, capacitor portions are disposed on both sides of the cavity core.

[0037] Figure 1 This is a cross-sectional view schematically illustrating an example of a capacitor-embedded substrate according to the first embodiment of the present invention. Figure 2 This is a cross-sectional view schematically showing an example of the capacitor-embedded substrate of the first embodiment of the present invention together with the flow of current. Figure 3 It is magnified Figure 1 The cross-sectional view obtained from the portion shown in III of the capacitor's built-in substrate.

[0038] Figure 1 The capacitor-embedded substrate 1 shown includes an insulating substrate 10, a core capacitor element 20, and a filling resin 30.

[0039] The insulating substrate 10 has a thickness direction (in Figure 1 The first main surface 11 and the second main surface 12 are opposite each other in the vertical direction. The insulating substrate 10 can be an organic insulating substrate such as a resin substrate, or an inorganic insulating substrate such as a glass substrate.

[0040] A cavity 15 is provided in the insulating substrate 10 (see below). Figure 5 ).

[0041] The core capacitor element 20 is embedded in the cavity 15 of the insulating substrate 10.

[0042] The filling resin 30 fills the cavity 15 between the insulating substrate 10 and the core capacitor element 20. The filling resin 30 may also contain fillers such as inorganic fillers.

[0043] The cored capacitor element 20 includes a cavity core 40 and a capacitor section 50.

[0044] The cavity core 40 has a thickness direction (in Figure 1The first surface 41 and the second surface 42 are opposite each other in the vertical direction. The cavity core 40 can be made of organic materials such as resin or inorganic materials such as glass.

[0045] exist Figure 1 In the example shown, the capacitor section 50 is disposed on the first surface 41 and the second surface 42 of the cavity core section 40. Specifically, the capacitor section 50 includes: a first capacitor section 51 disposed on the first surface 41 of the cavity core section 40; and a second capacitor section 52 disposed on the second surface 42 of the cavity core section 40.

[0046] The capacitor section 50 is composed of an anode, a dielectric, and a cathode, and the anode is composed of an inorganic substrate.

[0047] The type of capacitor constituting the capacitor section 50 is not particularly limited. Figure 1 In the example shown, the capacitor section 50 includes an anode plate 110 and a dielectric layer 130 (see reference). Figure 3 ), cathode layer 120.

[0048] Anode plate 110 includes: a core 111 having a thickness direction (in the thickness direction) Figure 1 A pair of opposing main surfaces (in the vertical direction); and a porous portion 112, which is located on at least the main surface of the core 111 opposite to the cavity core 40. Dielectric layer 130 (see reference) Figure 3 The cathode layer 120 is disposed on the surface of the porous portion 112. The cathode layer 120 is disposed on the surface of the dielectric layer 130. Thus, the capacitor portion 50 constitutes an electrolytic capacitor.

[0049] exist Figure 1 In the example shown, in the capacitor section 50, the core 111 of the anode plate 110 constitutes an inorganic substrate, the dielectric layer 130 constitutes a dielectric, and the cathode layer 120 constitutes a cathode.

[0050] The cathode layer 120 may include, for example, a solid electrolyte layer 121 disposed on the surface of the dielectric layer 130. When the cathode layer 120 includes a solid electrolyte layer 121, the capacitor section 50 constitutes a solid electrolytic capacitor.

[0051] exist Figure 1 In this context, the solid electrolyte layer 121 is shown to be completely separated from the porous portion 112 of the anode plate 110, but preferably, as shown in the image. Figure 3 As shown, the solid electrolyte layer 121 is partially disposed inside the pores (recesses) of the dielectric layer 130. The same applies in the subsequent cross-sectional views.

[0052] Preferably, the cathode layer 120 further includes a conductive layer 122 disposed on the surface of the solid electrolyte layer 121.

[0053] The conductive layer 122 may include, for example, a first conductive layer 122A disposed on the surface of the solid electrolyte layer 121; and a second conductive layer 122B disposed on the surface of the first conductive layer 122A. Thus, it is preferable that the conductive layer 122 comprises multiple conductive layers.

[0054] As an example, the conductor layer 122 includes a carbon layer as a first conductor layer 122A and a copper layer as a second conductor layer 122B.

[0055] It could also be, such as Figure 1 As shown, the capacitor section 50 further includes an insulating shielding layer 140 on the surface of the porous section 112 on the side opposite to the cavity core section 40. In this case, it is preferable that the insulating shielding layer 140 is provided on the surface of the porous section 112 on the side opposite to the cavity core section 40 in the region where the cathode layer 120 is not formed.

[0056] Alternatively, the insulating shielding layer 140 may be disposed on the surface of the dielectric layer 130 on the porous portion 112. Furthermore, it is preferable that... Figure 3 As shown, the insulating shielding layer 140 is provided in such a way that it fills the pores (recesses) of the porous portion 112 or the dielectric layer 130.

[0057] Preferably, the capacitor element 20 further includes a sealing layer 55 disposed in a manner that covers the capacitor portion 50. The capacitor portion 50 is protected by the sealing layer 55.

[0058] Preferably, such as Figure 1 As shown, when the capacitor section 50 includes a first capacitor section 51 and a second capacitor section 52, the sealing layer 55 is provided such that it covers the first capacitor section 51 on the first surface 41 side of the cavity core section 40 and covers the second capacitor section 52 on the second surface 42 side of the cavity core section 40.

[0059] The sealing layer 55 may consist of a single layer or two or more layers. When the sealing layer 55 consists of two or more layers, the materials constituting each layer may be the same or different.

[0060] The sealing layer 55 is formed, for example, by hot-pressing an insulating resin sheet or by heat-curing an insulating resin slurry after application, in order to seal the capacitor portion 50.

[0061] Alternatively, the core capacitor element 20 may also include a wiring layer 60 disposed on at least one main surface of the sealing layer 55. The wiring layer 60 may include an anode wiring layer 61 electrically connected to the anode of the capacitor section 50 (e.g., the core 111 of the anode plate 110), or a cathode wiring layer 62 electrically connected to the cathode of the capacitor section 50 (e.g., the cathode layer 120).

[0062] In the capacitor-embedded substrate 1, when the coefficient of linear expansion of the insulating substrate 10 is set to CTE1, the coefficient of linear expansion of the inorganic substrate of the capacitor section 50 (e.g., the core 111 of the anode plate 110) is set to CTE2, the coefficient of linear expansion of the cavity core 40 is set to CTE3, and the coefficient of linear expansion of the filling resin 30 is set to CTE4, |CTE3-CTE1|<|CTE4-CTE1| and |CTE3-CTE1|<|CTE2-CTE1|.

[0063] Here, |CTE3-CTE1| refers to the absolute value of the difference between CTE3 and CTE1. Similarly, |CTE4-CTE1| refers to the absolute value of the difference between CTE4 and CTE1, and |CTE2-CTE1| refers to the absolute value of the difference between CTE2 and CTE1.

[0064] Furthermore, the "coefficient of linear expansion" refers to the coefficient of linear expansion relative to the thickness direction (…). Figure 1 The linear expansion coefficient (in the vertical direction) refers to the value measured by TMA (thermomechanical analysis) between 0℃ and 100℃.

[0065] When functional components such as capacitors are embedded inside an insulating substrate, a delamination-like peeling may occur due to the mismatch between the linear expansion coefficients of the functional components and the insulating substrate, thereby compromising the overall reliability of the embedded substrate.

[0066] Therefore, in the capacitor-in-place substrate 1, instead of simply placing the capacitor portion 50 inside the cavity 15 of the insulating substrate 10, a cored capacitor element 20 with a cavity core 40 for matching the coefficient of linear expansion of the capacitor portion 50 is placed inside the cavity 15 of the insulating substrate 10. As a result, the difference in the overall thermal properties of the capacitor-in-place substrate 1 is reduced, thereby improving the reliability of the capacitor-in-place substrate 1.

[0067] Among them, such as Figure 1 As shown, when capacitor sections 50 are arranged on both sides of the cavity core 40, the balance of the back of the watch becomes good, thus further improving reliability.

[0068] Furthermore, when capacitor sections 50 are arranged on both sides of the cavity core 40, the impedance characteristics are also optimized.

[0069] When capacitor sections 50 are arranged on both sides of the cavity core 40, and each capacitor section 50 includes a first capacitor section 51 and a second capacitor section 52, the first capacitor section 51 and the second capacitor section 52 may have different capacitances. In this case, the impedance characteristics can be maintained at a lower level over a wider frequency band. Alternatively, the first capacitor section 51 and the second capacitor section 52 may have the same capacitance.

[0070] It could also be, such as Figure 1 As shown, the porous portion 112 of the anode plate 110 is also provided on the main surface of the core 111 on the side of the cavity core 40. In this case, it is preferable that a portion of the material constituting the cavity core 40 enters the porous portion 112. This improves the adhesion between the cavity core 40 and the capacitor portion 50. When the capacitor portion 50 is arranged on both sides of the cavity core 40, it is also possible to provide the porous portion 112 on the main surface of the core 111 on the side of the cavity core 40 only at one capacitor portion 50.

[0071] Alternatively, a portion of the material constituting the cavity core 40 may enter the entire porous portion 112 on the main surface of the cavity core 40 side of the core 111, but only a portion of the porous portion 112 on the main surface of the cavity core 40 side of the core 111 is required.

[0072] The materials constituting the insulating substrate 10 and the cavity core 40 are not particularly limited, but preferably, the insulating substrate 10 and the cavity core 40 comprise glass, silicon dioxide, or silicon. The material constituting the insulating substrate 10 may be the same as or different from the material constituting the cavity core 40.

[0073] For example, when the insulating substrate 10 and the cavity core 40 contain glass, they may contain either glass cloth or glass filler. The glass cloth is made of glass yarn, for example, woven in a lattice pattern. Alternatively, the insulating substrate 10 and the cavity core 40 may be made of glass.

[0074] Alternatively, the capacitor-embedded substrate 1 may also include a through conductor 70 disposed in such a way that it passes through the core capacitor element 20 in the thickness direction. The through conductor 70 is disposed in such a way that it passes through the capacitor portion 50 and the cavity core portion 40 of the core capacitor element 20 in the thickness direction. By providing the through conductor 70, the circuit connection distance on the back of the device can be shortened as a whole as the capacitor-embedded substrate 1.

[0075] Furthermore, by providing a through conductor 70 through the cavity core 40, warping of the capacitor's built-in substrate 1 can be suppressed.

[0076] Furthermore, by supporting the circuit section 80 (described later) with the through conductor 70, delamination can be suppressed, further improving reliability.

[0077] The through conductor 70 only needs to be provided on at least the inner wall surface of the through hole that penetrates the core capacitor element 20 in the thickness direction. That is, the through conductor 70 can be provided only on the inner wall surface of the through hole, or it can be provided entirely inside the through hole.

[0078] exist Figure 1Although not shown, when a through conductor 70 is provided on the inner wall surface of a through hole through which the core capacitor element 20 extends in the thickness direction, a resin-filled portion made of resin material can be provided inside the through conductor 70. In this case, the resin-filled portion is provided in the space surrounded by the through conductor 70 within the through hole through which the core capacitor element 20 extends in the thickness direction. If the space within the through hole is eliminated by providing the resin-filled portion, the delamination of the through conductor 70 is suppressed. Furthermore, the resin-filled portion can be either a conductor or an insulator.

[0079] like Figure 1 As shown, the through conductor 70 may include, for example, an anode through conductor 71 electrically connected to the anode of the capacitor section 50 (e.g., the core 111 of the anode plate 110), or a cathode through conductor 72 electrically connected to the cathode of the capacitor section 50 (e.g., the cathode layer 120).

[0080] For example, the anode through conductor 71 is electrically connected to the anode wiring layer 61. The anode wiring layer 61 is electrically connected to the core 111 of the anode plate 110, for example, via the through conductor (not shown) of the through capacitor section 50.

[0081] Preferably, except for the portion connected to the anode wiring layer 61, an insulating material is filled between the anode through conductor 71 and the capacitor portion 50.

[0082] There is no particular limitation on the number of anode through conductors 71; they can be one or more.

[0083] The cross-sectional shape of the anode through conductor 71 perpendicular to the thickness direction is not particularly limited, for example, it is a circular shape.

[0084] The diameter of the anode through conductor 71 can be constant or different in the thickness direction. Furthermore, the diameter of the through conductor refers to the diameter when the planar shape is circular, and to the equivalent circular diameter when the shape is not circular.

[0085] For example, the cathode through conductor 72 is electrically connected to the cathode wiring layer 62. The cathode wiring layer 62 is electrically connected to the cathode layer 120, for example, via the through conductor 63 of the through sealing layer 55.

[0086] Preferably, except for the portion connected to the cathode wiring layer 62, an insulating material is filled between the cathode through conductor 72 and the capacitor portion 50.

[0087] There is no particular limitation on the number of cathode conductors 72; it can be one or more. The number of cathode conductors 72 can be the same as, more than, or less than the number of anode conductors 71.

[0088] The cross-sectional shape of the cathode through conductor 72 perpendicular to the thickness direction is not particularly limited; for example, it can be circular. The cross-sectional shape of the cathode through conductor 72 can be the same as or different from that of the anode through conductor 71.

[0089] The diameter of the cathode through conductor 72 can be constant or different in the thickness direction. The diameter of the cathode through conductor 72 can be the same as or different from the diameter of the anode through conductor 71.

[0090] Alternatively, the capacitor-embedded substrate 1 may also include a through conductor 75 disposed in such a way that it penetrates the insulating substrate 10 in the thickness direction.

[0091] The through conductor 75 only needs to be provided on at least the inner wall surface of the through hole that penetrates the insulating substrate 10 in the thickness direction. That is, the through conductor 75 can be provided only on the inner wall surface of the through hole, or it can be provided throughout the entire interior of the through hole.

[0092] exist Figure 1 Although not shown, when the through conductor 75 is provided on the inner wall surface of the through hole penetrating the insulating substrate 10 in the thickness direction, a resin-filled portion made of resin material can be provided inside the through conductor 75. In this case, the resin-filled portion is provided in the space surrounded by the through conductor 75 within the through hole penetrating the insulating substrate 10 in the thickness direction. If the space within the through hole is eliminated by providing the resin-filled portion, the occurrence of delamination of the through conductor 75 is suppressed. Furthermore, the resin-filled portion can be either a conductor or an insulator.

[0093] There is no particular limitation on the number of conductors 75; it can be one or more. The number of conductors 75 can be the same as, more than, or less than the number of conductors 70.

[0094] The cross-sectional shape of the through conductor 75 perpendicular to the thickness direction is not particularly limited; for example, it can be circular. The cross-sectional shape of the through conductor 75 can be the same as or different from that of the through conductor 70.

[0095] The diameter of the through conductor 75 can be constant or different in the thickness direction. The diameter of the through conductor 75 can be the same as or different from the diameter of the through conductor 70.

[0096] Alternatively, the capacitor-embedded substrate 1 may also include a circuit section 80 disposed on at least one of the first main surface 11 and the second main surface 12 of the insulating substrate 10. The circuit section 80 is disposed such that it covers not only the insulating substrate 10, but also the core capacitor element 20 and the filling resin 30.

[0097] The circuit section 80 includes one or more circuit insulating layers 81 and one or more circuit conductor layers 82. When the circuit section 80 includes two or more circuit conductor layers 82, adjacent circuit conductor layers 82 in the stacking direction are electrically connected to each other via a through conductor 83.

[0098] The material of the circuit insulating layer 81 constituting the circuit section 80 can be the same as or different from the material constituting the insulating substrate 10.

[0099] The material of the circuit conductor layer 82 constituting the circuit section 80 can be the same as or different from the material constituting the wiring layer 60.

[0100] Figure 1 The capacitor-embedded substrate 1 shown is manufactured, for example, by the following method.

[0101] Figure 4 A, B, and C are schematic cross-sectional views illustrating an example of the process of preparing a cored capacitor element.

[0102] exist Figure 4 In A, an anode plate 110, a prepreg 200, a hollow core 40, a prepreg 200, and an anode plate 110 are prepared.

[0103] exist Figure 4 In the example shown in A, the anode plate 110 includes a core 111 and porous portions 112 disposed on two main surfaces of the core 111. Figure 4 Although not shown in A, a dielectric layer 130 is provided on the surface of the porous portion 112 (see reference). Figure 3 ).

[0104] For example, by performing anodizing on an anode plate 110 which has porous portions 112 on two main surfaces of the core 111, a dielectric layer 130 can be formed on the surface of the porous portions 112.

[0105] Alternatively, an anode plate 110 with a dielectric layer 130 on the surface of the porous portion 112 can be prepared as a foil.

[0106] exist Figure 4 In section B, the anode plate 110 and the cavity core 40 are bonded together using methods such as hot pressing and with the help of prepreg 200 to form an integrated structure. Furthermore, in... Figure 4 In B, the prepreg 200 is omitted.

[0107] exist Figure 4 In step C, a cathode layer 120 is formed on the anode plate 110, thereby forming a capacitor section 50. Furthermore, a sealing layer 55, a wiring layer 60, and a through conductor 70 are formed. Through these processes, a cored capacitor element 20 is manufactured.

[0108] Figure 5 This is a cross-sectional view schematically illustrating an example of the process of preparing an insulating substrate.

[0109] exist Figure 5 In the middle, an insulating substrate 10 with a cavity 15 is prepared.

[0110] Figure 6 This is a cross-sectional view schematically illustrating an example of a process of mounting a cored capacitor element in a cavity of an insulating substrate.

[0111] exist Figure 6 In this process, a core capacitor element 20 is mounted on a support substrate 210 such as a fixing strip and in a cavity 15 of an insulating substrate 10.

[0112] Figure 7 This is a cross-sectional view schematically illustrating an example of a process of filling a cavity in an insulating substrate with filling resin.

[0113] exist Figure 7 In this process, the filling resin 30 is filled into the cavity 15 between the insulating substrate 10 and the core capacitor element 20.

[0114] Figure 8 This is a cross-sectional view schematically illustrating an example of the process of forming a circuit insulating layer on a main surface of an insulating substrate.

[0115] exist Figure 8 In, for example, by moving from the side opposite to the support substrate 210 to one main surface of the insulating substrate 10 (in Figure 8 The prepreg is pasted onto the upper surface to form a circuit insulation layer 81.

[0116] Figure 9 This is a cross-sectional view schematically illustrating an example of the process of forming a circuit insulation layer on another main surface of an insulating substrate.

[0117] exist Figure 9 For example, after removing the support substrate 210, by means of another main surface of the insulating substrate 10 (on Figure 9 The prepreg is pasted onto the lower surface to form a circuit insulation layer 81.

[0118] Furthermore, when the core capacitor element 20 is fixed to the insulating substrate 10 by filling with resin 30, a circuit insulation layer 81 may also be formed on one main surface and the other main surface of the insulating substrate 10.

[0119] Figure 10 This is a cross-sectional view schematically illustrating an example of the process of forming the circuit section.

[0120] exist Figure 10In this process, a circuit conductor layer 82 and a conductive conductor 83 are formed on the circuit insulating layer 81. The process of forming the circuit insulating layer 81, the circuit conductor layer 82, and the conductive conductor 83 is repeated as needed. Through these processes, the circuit section 80 is formed.

[0121] After the above steps, the product is made Figure 1 The capacitor's built-in substrate 1 is shown.

[0122] [Second Implementation]

[0123] In the capacitor-embedded substrate of the second embodiment of the present invention, at least a portion of the anode through conductor connecting the anode of the first capacitor section and the anode of the second capacitor section is present around the anode.

[0124] Figure 11 This is a cross-sectional view schematically showing an example of the capacitor-embedded substrate of the second embodiment of the present invention together with the flow of current.

[0125] exist Figure 11 In the capacitor-embedded substrate 2 shown, at least partially, a magnetic material 90 is present around the anode through conductor 71 that connects the anode of the first capacitor section 51 (e.g., the core 111 of the anode plate 110) and the anode of the second capacitor section 52 (e.g., the core 111 of the anode plate 110). Other structures are similar. Figure 1 The capacitor's built-in substrate 1 shown is common.

[0126] In the capacitor-embedded substrate 2, the inductive component can be efficiently imparted by at least a portion of the cavity core 40 using a magnetic material 90. As a result, the cored capacitor element 20 can be configured as a π-type filter.

[0127] The magnetic body 90 can be disposed either locally around the anode through conductor 71 or as a whole around the anode through conductor 71.

[0128] The thickness direction of the insulating substrate 10 (in) Figure 11 The size of the magnetic body 90 in the vertical direction can be equal to, smaller than or larger than the size of the cavity core 40 in the thickness direction of the insulating substrate 10.

[0129] [Third Implementation]

[0130] In the capacitor-embedded substrate of the third embodiment of the present invention, the inorganic substrate of the capacitor portion is divided into two or more parts.

[0131] Figure 12This is a cross-sectional view schematically showing an example of the capacitor-embedded substrate of the third embodiment of the present invention together with the flow of current. Figure 13 It is a schematic representation of the composition. Figure 12 A partial perspective view of the core capacitor element of the capacitor-embedded substrate shown.

[0132] exist Figure 12 In the capacitor built-in substrate 3 shown, as Figure 13 As shown, the capacitor section 50 is divided into two or more parts. Other structures are similar to... Figure 1 The capacitor's built-in substrate 1 shown is common.

[0133] Specifically, at least the inorganic substrate of the capacitor portion 50 (e.g., the core portion 111 of the anode plate 110) is divided into two or more parts. Preferably, in addition to the core portion 111 of the anode plate 110, the porous portion 112 is also divided into two or more parts. That is, preferably, the anode plate 110 as a whole is divided into two or more parts.

[0134] If the inorganic substrate of the capacitor section 50 is divided into two or more parts, the continuity of the capacitor section 50 is interrupted, thereby suppressing movement. Therefore, the thermal properties of the core capacitor element 20 are easily comparable to the thermal properties of the insulating substrate 10.

[0135] Preferably, a material homogeneous with the insulating substrate 10 is incorporated between adjacent inorganic substrates. If the inorganic substrate is divided into three or more parts, it is sufficient that the material homogeneous with the insulating substrate 10 is incorporated between at least one set of inorganic substrates. Furthermore, the material homogeneous with the insulating substrate 10 may be incorporated entirely between adjacent inorganic substrates, but it is sufficient that it is incorporated at least partially between adjacent inorganic substrates.

[0136] In this specification, "homogeneous material" includes not only materials with exactly the same composition, i.e., "completely identical materials," but also materials that are "substantially identical." "Substantially identical materials" include materials that, even if not completely identical in composition, have substantially the same function; for example, materials with slightly different filler content.

[0137] Furthermore, adjacent capacitor sections 50 can be physically disconnected from each other. Therefore, adjacent capacitor sections 50 can be electrically disconnected or electrically connected to each other.

[0138] Preferably, such as Figure 13 As shown, the cavity core 40 is not segmented.

[0139] [Other Implementation Methods]

[0140] The capacitor-embedded substrate of the present invention is not limited to the above-described embodiments. Various applications and modifications can be applied within the scope of the present invention regarding the structure of the insulating substrate, the core capacitor element (cavity core, capacitor part), the filling resin, etc., and the manufacturing conditions of the capacitor-embedded substrate.

[0141] In the capacitor-embedded substrate of the present invention, the capacitor portion may be disposed only on one side of the cavity core.

[0142] Figure 14 This is a cross-sectional view schematically showing a first modified example of the capacitor-embedded substrate according to the first embodiment of the present invention, together with the flow of current.

[0143] exist Figure 14 In the capacitor-embedded substrate 1A shown, the capacitor section 50 includes only the first capacitor section 51 disposed on the first surface 41 of the cavity core section 40. Other structures are similar to... Figure 1 The capacitor's built-in substrate 1 shown is common.

[0144] In the capacitor built-in substrate of the present invention, the porous part may not be provided on the main surface of the cavity core side of the core.

[0145] Figure 15 This is a cross-sectional view schematically showing a second variation of the capacitor-embedded substrate of the first embodiment of the present invention, together with the flow of current.

[0146] exist Figure 15 In the capacitor-embedded substrate 1B shown, the porous portion 112 is not provided on the main surface of the cavity core 40 side of the core portion 111. Other structures are similar to... Figure 1 The capacitor's built-in substrate 1 shown is common.

[0147] Furthermore, when capacitor portions 50 are arranged on both sides of the cavity core portion 40, and the capacitor portions 50 include a first capacitor portion 51 and a second capacitor portion 52, it is also possible that, in either case, a porous portion 112 is provided on the main surface of the core portion 111 on the side of the cavity core portion 40, and in the other case, a porous portion 112 is not provided on the main surface of the core portion 111 on the side of the cavity core portion 40.

[0148] In the capacitor-embedded substrate of the present invention, as long as |CTE3-CTE1|<|CTE4-CTE1| and |CTE3-CTE1|<|CTE2-CTE1| are satisfied, for example, the linear expansion coefficient CTE1 of the insulating substrate can be the same as, smaller than, or larger than the linear expansion coefficient CTE3 of the cavity core. That is, the value of CTE3-CTE1 can be 0, positive, or negative. In addition, the linear expansion coefficient CTE1 of the insulating substrate can be smaller or larger than the linear expansion coefficient CTE2 of the inorganic matrix of the capacitor section. Moreover, the linear expansion coefficient CTE1 of the insulating substrate can be smaller or larger than the linear expansion coefficient CTE4 of the filling resin.

[0149] In the capacitor-embedded substrate of the present invention, the capacitor section is not limited to electrolytic capacitors such as solid electrolytic capacitors. In the capacitor-embedded substrate of the present invention, the capacitor section may also be configured as a ceramic capacitor using barium titanate, a thin film capacitor using silicon nitride (SiN), silicon dioxide (SiO2), hydrogen fluoride (HF), etc., or a trench capacitor having a MIM (Metal Insulator Metal) structure, etc.

[0150] In the capacitor-embedded substrate of the present invention, multiple cored capacitor elements may be embedded in a cavity.

[0151] The detailed structure of the core capacitor element 20 is described below.

[0152] The planar shape of the cavity core 40 when viewed from the thickness direction can be, for example, a rectangle (square or rectangular), a quadrilateral other than a rectangle, a polygon such as a triangle, a pentagon, or a hexagon, a circle, an ellipse, or a combination of these shapes. In addition, the planar shape of the cavity core 40 can also be L-shaped, C-shaped (Japanese "コ" shape), stepped, etc.

[0153] The planar shape of the cavity core 40 when viewed in the thickness direction can be the same as or different from the planar shape of the capacitor section 50. Furthermore, the area of ​​the cavity core 40 when viewed in the thickness direction can be the same as, larger than, or smaller than the area of ​​the capacitor section 50.

[0154] The planar shape of the capacitor section 50 when viewed from the thickness direction can be, for example, a rectangle (square or rectangular), a quadrilateral other than a rectangle, a triangle, a pentagon, a hexagon or other polygon, a circle, an ellipse, or a combination of these shapes. In addition, the planar shape of the capacitor section 50 can also be L-shaped, C-shaped (Japanese "コ" shape), stepped, etc.

[0155] Preferably, the anode plate 11 is made of a valve-acting metal that performs the valve function. Examples of valve-acting metals include individual metals such as aluminum, tantalum, niobium, titanium, and zirconium, or alloys containing at least one of these metals. Among these, aluminum or an aluminum alloy is preferred.

[0156] The anode plate 110 is preferably flat, and more preferably foil-shaped. Thus, in this specification, "plate-shaped" also includes "foil-shaped".

[0157] The anode plate 110 may have a porous portion 112 on only one main surface of the core 111, or it may have a porous portion 112 on both main surfaces of the core 111. The porous portion 112 is preferably a porous layer formed on the surface of the core 111, and more preferably an etched layer.

[0158] The thickness of the anode plate 110 before etching is preferably 60 μm or more and 200 μm or less. The thickness of the unetched core 111 after etching is preferably 15 μm or more and 70 μm or less. The thickness of the porous portion 112 is designed according to the required voltage withstand and electrostatic capacitance, but preferably, the total thickness of the porous portions 112 on both sides of the core 111 is 10 μm or more and 180 μm or less.

[0159] The pore size of the porous portion 112 is preferably 10 nm or more and 600 nm or less. Furthermore, the pore size of the porous portion 112 refers to the median pore size D50 measured by a mercury porosimeter. The pore size of the porous portion 112 can be controlled, for example, by adjusting various etching conditions.

[0160] The dielectric layer 130 disposed on the surface of the porous portion 112 reflects the surface state of the porous portion 112 and becomes porous, having a finely textured surface shape. Preferably, the dielectric layer 130 is composed of an oxide film of the valve-acting metal described above. For example, when using aluminum foil as the anode plate 110, the dielectric layer 130 composed of an oxide film can be formed by anodizing the surface of the aluminum foil in an aqueous solution containing ammonium adipate or the like (also known as a chemical formation process).

[0161] The thickness of the dielectric layer 130 is designed according to the required voltage withstand and electrostatic capacitance, but preferably is above 10nm and below 100nm.

[0162] When the cathode layer 120 includes a solid electrolyte layer 121, conductive polymers such as polypyrrole, polythiophene, and polyaniline can be used as materials constituting the solid electrolyte layer 121. Among these, polythiophene is preferred, and poly(3,4-ethylenedioxythiophene) known as PEDOT is particularly preferred. Furthermore, the aforementioned conductive polymers may also contain dopants such as polystyrene sulfonic acid (PSS). Moreover, it is preferable that the solid electrolyte layer 121 includes an inner layer filling the pores (recesses) of the dielectric layer 130 and an outer layer covering the dielectric layer 130.

[0163] The thickness of the solid electrolyte layer 121 from the surface of the porous portion 112 is preferably 2 μm or more and 20 μm or less.

[0164] The solid electrolyte layer 121 is formed, for example, by forming a polymer film of poly(3,4-ethylenedioxythiophene) on the surface of the dielectric layer 130 using a treatment solution containing monomers such as 3,4-ethylenedioxythiophene, or by coating a dispersion of polymers such as poly(3,4-ethylenedioxythiophene) onto the surface of the dielectric layer 130 and drying it.

[0165] The solid electrolyte layer 121 can be formed in a predetermined area by applying the above-mentioned processing liquid or dispersion to the surface of the dielectric layer 130 using methods such as sponge transfer, screen printing, dispenser coating, inkjet printing, etc.

[0166] When the cathode layer 120 includes a conductive layer 122, the conductive layer 122 comprises at least one of a conductive resin layer and a metal layer. The conductive layer 122 may also be only a conductive resin layer or only a metal layer. Preferably, the conductive layer 122 covers the entire surface of the solid electrolyte layer 121.

[0167] Examples of conductive resin layers include conductive adhesive layers comprising at least one conductive filler selected from the group consisting of silver filler, copper filler, nickel filler, and carbon filler.

[0168] Examples of metal layers include metal coatings and metal foils. Preferably, the metal layer is composed of at least one metal selected from the group consisting of nickel, copper, silver, and alloys thereof. Furthermore, "main component" refers to the element with the largest weight percentage.

[0169] The conductive layer 122 may include, for example, a carbon layer disposed on the surface of the solid electrolyte layer 121 and a copper layer disposed on the surface of the carbon layer.

[0170] The carbon layer is provided to electrically and mechanically connect the solid electrolyte layer 121 and the copper layer. The carbon layer can be formed in a predetermined area by applying carbon paste to the surface of the solid electrolyte layer 121 using methods such as sponge transfer, screen printing, dispenser coating, or inkjet printing. The thickness of the carbon layer is preferably 2 μm or more and 20 μm or less.

[0171] The copper layer can be formed in a predetermined area by applying copper paste to the surface of the carbon layer using methods such as sponge transfer, screen printing, spray coating, dispenser coating, and inkjet printing. The thickness of the copper layer is preferably 2 μm or more and 20 μm or less.

[0172] The insulating shielding layer 140 is made of an insulating material. In this case, it is preferable that the insulating shielding layer 140 contains an insulating resin.

[0173] Insulating resins contained in the insulating shielding layer 140 include, for example, polyphenylene sulfone resin, polyether sulfone resin, cyanate ester resin, fluoropolymer (tetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, etc.), polyimide resin, polyamide-imide resin, epoxy resin, and their derivatives or precursors.

[0174] Alternatively, the insulating shielding layer 140 may be made of the same resin as the sealing layer 55. If the insulating shielding layer 140 contains inorganic fillers, unlike the sealing layer 55, it may adversely affect the effective capacitance of the capacitor section 50. Therefore, it is preferable that the insulating shielding layer 140 is made of a single type of resin.

[0175] The insulating shielding layer 140 can be formed in a predetermined area by applying a shielding material, such as a composition containing an insulating resin, to the surface of the porous portion 112 using methods such as sponge transfer, screen printing, dispenser coating, or inkjet printing.

[0176] The insulating shielding layer 140 can be formed in the porous portion 112 either before or after the dielectric layer 130.

[0177] The sealing layer 55 is made of an insulating material. In this case, it is preferable that the sealing layer 55 contains an insulating resin.

[0178] The insulating resin contained in the sealing layer 55 can be, for example, epoxy resin, phenolic resin, etc.

[0179] Preferably, the sealing layer 55 also contains fillers such as inorganic fillers.

[0180] Inorganic fillers contained in the sealing layer 55 include, for example, silica particles and alumina particles.

[0181] Alternatively, a stress-relieving layer, a moisture-proof film, or other layer may be provided between the capacitor section 50 and the sealing layer 55.

[0182] The following information is disclosed in this specification.

[0183] <1>

[0184] A capacitor-embedded substrate includes: an insulating substrate having a first main surface and a second main surface opposite to each other in the thickness direction, and a cavity therein; a core capacitor element embedded in the cavity of the insulating substrate; and a filling resin filling the cavity between the insulating substrate and the core capacitor element, wherein the core capacitor element includes: a cavity core having a first surface and a second main surface opposite to each other in the thickness direction; and a capacitor portion disposed on the first surface and the second main surface of the cavity core. In at least one of the second surfaces, the capacitor portion is composed of an anode, a dielectric, and a cathode. The anode is composed of an inorganic substrate. When the coefficient of linear expansion of the insulating substrate is set to CTE1, the coefficient of linear expansion of the inorganic substrate of the capacitor portion is set to CTE2, the coefficient of linear expansion of the cavity core portion is set to CTE3, and the coefficient of linear expansion of the filling resin is set to CTE4, |CTE3-CTE1|<|CTE4-CTE1| and |CTE3-CTE1|<|CTE2-CTE1|.

[0185] <2>

[0186] According to <1>, the capacitor embedded substrate includes an anode plate, a dielectric layer, and a cathode layer. The anode plate includes a core having a pair of main surfaces opposite each other in the thickness direction, and a porous portion having at least one main surface of the core opposite to the cavity core. The dielectric layer is disposed on the surface of the porous portion, and the cathode layer is disposed on the surface of the dielectric layer. The core constitutes the inorganic substrate, the dielectric layer constitutes the dielectric, and the cathode layer constitutes the cathode.

[0187] <3>

[0188] According to <2>, the capacitor-embedded substrate further includes a through conductor disposed in such a way that it penetrates the core capacitor element in the aforementioned thickness direction.

[0189] <4>

[0190] According to the capacitor-embedded substrate described in <3>, the capacitor portion includes: a first capacitor portion disposed on the first surface of the cavity core; and a second capacitor portion disposed on the second surface of the cavity core.

[0191] <5>

[0192] According to the capacitor-embedded substrate described in <4>, the first capacitor section and the second capacitor section have different capacitances.

[0193] <6>

[0194] According to the capacitor embedded substrate of <5>, the through conductor includes an anode through conductor that connects the anode of the first capacitor portion and the anode of the second capacitor portion, and at least partially a magnetic body is present around the anode through conductor.

[0195] <7>

[0196] The capacitor built-in substrate according to any one of <2> to <6>, wherein the porous portion is further provided on the main surface of the cavity core side of the core portion.

[0197] <8>

[0198] According to the capacitor built-in substrate described in <7>, a portion of the material constituting the cavity core enters the porous portion.

[0199] <9>

[0200] The capacitor embedded substrate according to any one of <1> to <8>, wherein the insulating substrate and the cavity core comprise glass, silicon dioxide or silicon.

[0201] <10>

[0202] According to any one of <1> to <9>, the capacitor embedded substrate is wherein the inorganic substrate of the capacitor portion is divided into two or more parts.

[0203] <11>

[0204] According to <10>, the capacitor embedded substrate contains a material of the same composition as the insulating substrate, which is inserted between adjacent inorganic substrates.

[0205] <12>

[0206] The capacitor-embedded substrate according to any one of <1> to <11> further includes a circuit portion disposed on at least one of the first main surface and the second main surface of the insulating substrate, wherein the circuit portion includes one or more circuit insulating layers and one or more circuit conductor layers.

[0207] Explanation of reference numerals in the attached figures

[0208] 1, 1A, 1B, 2, 3, Capacitor-embedded substrate; 10, Insulating substrate; 11, First main surface; 12, Second main surface; 15, Cavity; 20, Core capacitor element; 30, Filling resin; 40, Cavity core; 41, First surface; 42, Second surface; 50, Capacitor section; 51, First capacitor section; 52, Second capacitor section; 55, Sealing layer; 60, Wiring layer; 61, Anode wiring layer; 62, Cathode wiring layer; 63, Through conductor; 70, 75, Through conductor; 7 1. Anode through conductor; 72. Cathode through conductor; 80. Circuit section; 81. Circuit insulation layer; 82. Circuit conductor layer; 83. Conductor; 90. Magnetic material; 110. Anode plate; 111. Core; 112. Porous material section; 120. Cathode layer; 121. Solid electrolyte layer; 122. Conductor layer; 122A. First conductor layer; 122B. Second conductor layer; 130. Dielectric layer; 140. Insulating shielding layer; 200. Prepreg; 210. Support substrate.

Claims

1. A capacitor-embedded substrate, wherein, The capacitor's built-in substrate includes: An insulating substrate having a first main surface and a second main surface opposite each other in the thickness direction, and having a cavity thereon; A capacitor element with a core, which is embedded in the cavity of the insulating substrate; and A filling resin is used to fill the cavity between the insulating substrate and the capacitor element with a core. The cored capacitor element comprises: a hollow core having a first surface and a second surface opposite each other in the thickness direction; and a capacitor portion disposed on at least one of the first surface and the second surface of the hollow core. The capacitor section consists of an anode, a dielectric, and a cathode, with the anode being made of an inorganic substrate. When the coefficient of linear expansion of the insulating substrate is set to CTE1, the coefficient of linear expansion of the inorganic matrix of the capacitor portion is set to CTE2, the coefficient of linear expansion of the cavity core portion is set to CTE3, and the coefficient of linear expansion of the filling resin is set to CTE4, |CTE3-CTE1|<|CTE4-CTE1| and |CTE3-CTE1|<|CTE2-CTE1|.

2. The capacitor-embedded substrate according to claim 1, wherein, The capacitor section includes an anode plate, a dielectric layer, and a cathode layer. The anode plate comprises: a core having a pair of main surfaces opposite each other in the thickness direction; and a porous portion disposed on at least one of the main surfaces of the core opposite to the hollow core. The dielectric layer is disposed on the surface of the porous portion. The cathode layer is disposed on the surface of the dielectric layer. The core constitutes the inorganic substrate, the dielectric layer constitutes the dielectric, and the cathode layer constitutes the cathode.

3. The capacitor-embedded substrate according to claim 2, wherein, The capacitor's built-in substrate also includes a through conductor disposed in such a way that it passes through the core capacitor element in the thickness direction.

4. The capacitor-embedded substrate according to claim 3, wherein, The capacitor section includes: a first capacitor section disposed on the first surface of the cavity core; and a second capacitor section disposed on the second surface of the cavity core.

5. The capacitor-embedded substrate according to claim 4, wherein, The first capacitor section and the second capacitor section have different capacitances.

6. The capacitor-embedded substrate according to claim 5, wherein, The through conductor includes an anode through conductor that connects the anode of the first capacitor section and the anode of the second capacitor section. A magnetic body is present at least locally around the anode through conductor.

7. The capacitor-embedded substrate according to any one of claims 2 to 6, wherein, The porous material is also provided on the main surface of the cavity core side of the core.

8. The capacitor-embedded substrate according to claim 7, wherein, A portion of the material constituting the hollow core enters the porous part.

9. The capacitor-embedded substrate according to any one of claims 1 to 8, wherein, The insulating substrate and the cavity core comprise glass, silicon dioxide, or silicon.

10. The capacitor-embedded substrate according to any one of claims 1 to 9, wherein, The inorganic substrate of the capacitor section is divided into two or more parts.

11. The capacitor-embedded substrate according to claim 10, wherein, A material of the same composition as the insulating substrate is introduced between adjacent inorganic substrates.

12. The capacitor-embedded substrate according to any one of claims 1 to 11, wherein, The capacitor's built-in substrate also includes a circuit portion disposed on at least one of the first main surface and the second main surface of the insulating substrate. The circuit section includes one or more circuit insulation layers and one or more circuit conductor layers.

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