Substrates and Modules

Abstract

A substrate 100 comprises: a core substrate 10 which has a first surface 11 and a second surface 12 on an opposite side from the first surface 11 and is internally provided with an opening portion 13; an electronic component 20 and a metal post 90 provided in the same opening portion 13; and a sealant 30 which is filled in the opening portion 13 and has a third surface 31 on the first surface 11 side and a fourth surface 32 on the second surface 12 side. The metal post 90 is exposed from the third surface 31 of the sealant 30 and is exposed from the fourth surface 32 of the sealant 30.

Description

[Technical field]

[0001] The present invention relates to a substrate and a module. [Background technology]

[0002] Patent Document 1 describes a printed wiring board that includes a core substrate having an opening penetrating a core material, multiple types of electronic components housed in the opening, and resin formed in the opening for fixing the multiple types of electronic components to the core substrate (see, for example, FIG. 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-207978 A Summary of the Invention [Problem to be solved by the invention]

[0004] It is assumed that electronic components such as a CPU will be mounted on the printed wiring board described in Patent Document 1. The printed wiring board may also be connected to a motherboard, etc. In such cases, it is necessary to ensure electrical continuity between the top and bottom surfaces of the printed wiring board.

[0005] The core substrate of the printed wiring board described in Patent Document 1 is provided with a through-hole conductor for electrical continuity between the upper surface and the lower surface. However, a through-hole conductor cannot be provided in the opening. Therefore, in order to obtain electrical continuity from an electronic component mounted at a position directly above the opening to directly below the opening on the opposite side of the opening, it is necessary to route wiring from the opening to connect to the through-hole conductor, and route the wiring to directly below the opening on the opposite side. In other words, it is necessary to provide wiring that bypasses the opening on the upper and lower surfaces of the printed wiring board. If such a bypass wiring is formed, there is a problem that the wiring length becomes long.

[0006] The present invention has been made to solve the above problems, and aims to provide a substrate having a structure that allows easy connection from directly above to directly below an opening without increasing the wiring length. [Means for solving the problem]

[0007] The substrate of the present invention comprises a core substrate having a first surface and a second surface opposite the first surface and having an opening therein, an electronic component and a metal post provided in the same opening, and a sealing material filled in the opening and having a third surface on the first surface side and a fourth surface on the second surface side, wherein the metal post is exposed from the third surface of the sealing material and also from the fourth surface of the sealing material.

[0008] The module of the present invention is a module in which a heating element is mounted on the first surface side of the core substrate of the substrate of the present invention, and when viewed from above in a plane parallel to the first surface, the heating element and the metal post are positioned to overlap, and the heating element and the metal post are directly connected, or the heating element and the metal post are connected via a first material having a higher thermal conductivity than the sealing material. Effect of the Invention

[0009] According to the present invention, it is possible to provide a substrate having a structure that allows easy connection from directly above to directly below an opening without increasing the wiring length. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view that illustrates an example of a substrate according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the core substrate, electronic components, and metal posts included in the board shown in FIG. [Diagram 3] FIG. 3 is a plan view that illustrates an example of a substrate according to an embodiment of the present invention, in which the metal posts have different shapes as viewed from above. [Figure 4A] FIG. 4A is a perspective view that illustrates an example of a process for producing a coaxial cable. [Figure 4B] FIG. 4B is a perspective view that illustrates an example of a process for producing a coaxial cable. [Figure 4C] FIG. 4C is a perspective view that illustrates an example of a process for producing a coaxial cable. [Figure 4D] FIG. 4D is a perspective view that illustrates an example of a process for producing a coaxial cable. [Diagram 5] FIG. 5 is a plan view that illustrates an example of a substrate according to an embodiment of the present invention, in which a part of a metal post is a coaxial cable. [Figure 6] FIG. 6 is a cross-sectional view illustrating a schematic example of a module according to an embodiment of the present invention. [Figure 7] FIG. 7 is a plan view of the module shown in FIG. 6, showing the positional relationship between the heating element and each component of the board. [Figure 8] FIG. 8 is a diagram that illustrates an example of a process for attaching an adhesive film for fixing electronic components to a core substrate. [Figure 9] FIG. 9 is a cross-sectional view that illustrates an example of a process for arranging electronic components and metal posts on an adhesive film. [Figure 10] FIG. 10 is a cross-sectional view that illustrates an example of a step of filling the openings in the core substrate with a sealing material. [Figure 11] FIG. 11 is a cross-sectional view that illustrates an example of a step of grinding or polishing the sealing material and the metal posts. [Figure 12] FIG. 12 is a cross-sectional view illustrating an example of a process for forming a via. [Figure 13] FIG. 13 is a cross-sectional view illustrating an example of a process for forming a wiring layer. [Figure 14] FIG. 14 is a cross-sectional view that illustrates an example of a step of forming a build-up layer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The substrate and module of the present invention will be described below. However, the present invention is not limited to the following configurations, and can be modified as appropriate within the scope of the present invention. Note that the present invention also includes a combination of two or more of the individual desirable configurations described below.

[0012] [substrate] Fig. 1 is a cross-sectional view showing a schematic example of a substrate according to an embodiment of the present invention. Fig. 2 is a plan view of a core substrate, an electronic component, and a metal post included in the substrate shown in Fig. 1. Fig. 1 is a cross-sectional view taken along line XX shown in Fig. 2.

[0013] The substrate 100 shown in Figures 1 and 2 comprises a core substrate 10 having a first surface 11 and a second surface 12 opposite the first surface 11 and having an opening 13 therein, an electronic component 20 and a metal post 90 provided in the same opening 13, and a sealing material 30 filled in the opening 13 and having a third surface 31 on the first surface 11 side and a fourth surface 32 on the second surface 12 side.

[0014] Furthermore, the electronic component 20 further includes a first via conductor 40 connected to the first electrode 21 of the electronic component 20 or the fifth surface 91 of the metal post 90, a second via conductor 50 connected to the second electrode 22 of the electronic component 20 or the sixth surface 92 of the metal post 90, a first buildup layer (rewiring layer) 60 provided in contact with the first surface 11 of the core substrate 10 and the third surface 31 of the sealing material 30, and a second buildup layer (rewiring layer) 70 provided in contact with the second surface 12 of the core substrate 10 and the fourth surface 32 of the sealing material 30.

[0015] The core substrate 10 may be a resin substrate, a glass substrate, a ceramic substrate, or the like. The core substrate 10 may be a printed wiring board having conductor wiring on its surface or inside. The core substrate 10 may preferably be an insulating support substrate (core material) made of a resin such as an epoxy resin and a reinforcing material such as a glass cloth. The support substrate may contain inorganic particles such as silica particles and alumina particles.

[0016] The first surface 11 and the second surface 12 of the core substrate 10 are parallel to each other and constitute a pair of opposing main surfaces of the core substrate 10.

[0017] Opening 13 of core substrate 10 penetrates core substrate 10. The shape of opening 13 when core substrate 10 is viewed in plan is not particularly limited, and may be a rectangle as shown in Fig. 2, a circle, an ellipse, an oval, an n-sided shape (n is an integer of 5 or more), or the like.

[0018] The substrate 100 is a component-embedded substrate in which an electronic component 20 is embedded, and the electronic component 20 is accommodated not on the first surface 11 and the second surface 12 of the core substrate 10 but in an opening 13 of the core substrate 10. A metal post 90 is accommodated in the same opening 13 in which the electronic component 20 is accommodated.

[0019] The electronic components 20 and the metal posts 90 may be arranged two-dimensionally within the opening 13 as shown in Fig. 2, or may be arranged one-dimensionally within the opening 13. In the former case, the electronic components 20 and the metal posts 90 may be arranged, for example, in a matrix (Fig. 2) or in a staggered pattern.

[0020] The electronic component 20 is not particularly limited, and examples thereof include passive components such as a capacitor (for example, a multilayer ceramic capacitor (MLCC)) and an inductor. The electronic component 20 is a chip component having an elongated shape such as a rectangular parallelepiped or cylindrical shape.

[0021] In addition, only one type of electronic component 20 may be arranged in one opening 13, or two or more types of electronic components 20 may be arranged (mixed). In the latter case, the same type of electronic components 20 are components of the same size standardized by the size notation of chip components. The size notation is a notation defined by JIS (Japanese Industrial Standards) and EIA (Electronic Industries Alliance), and in the case of JIS, for example, notation such as 0603 can be mentioned. The same type of electronic components 20 may be components of the same type among basic components of an electric circuit, such as capacitors or inductors. The same type of electronic components 20 may be components of the same type among capacitors or inductors, for example, having the same model.

[0022] In the vertical cross section, it is preferable that the dimension of each electronic component 20 in the height direction (direction along a first direction D1 or a second direction D2 described later), which is a direction along the thickness direction of the core substrate 10, is larger than the dimension in other directions perpendicular to the height direction. This allows the electronic components 20 to be arranged with higher density.

[0023] Moreover, electronic component 20 has first electrode 21 in first direction D1 that is perpendicular to second surface 12 of core substrate 10 and faces first surface 11, and has second electrode 22 in second direction D2 opposite to first direction D1. By mounting electronic components 20 vertically in this manner, elongated electronic components 20 can be arranged at a higher density.

[0024] In each electronic component 20, the first electrode 21 and the second electrode 22 are located at one end and the other end in the longitudinal direction of the elongated electronic component 20, respectively.

[0025] The sealing material 30 is a member for sealing the electronic component 20 and the metal post 90 in the opening 13, and is filled around the electronic component 20 and the metal post 90 in the opening 13. The sealing material 30 contains a resin such as an epoxy resin, and a filler composed of inorganic particles such as silica particles and alumina particles.

[0026] There is a concern that a short circuit may occur if the electronic component 20 and the metal post 90 come into contact within the opening 13. Therefore, in order to prevent a short circuit when the electronic component 20 and the side of the metal post 90 come into contact with each other, the side of the metal post 90 may be coated with an insulating resin, or an oxide film may be formed on the side of the metal post 90 to provide insulation. The side surfaces of the metal post 90 are surfaces other than the fifth surface 91 and the sixth surface 92 of the metal post 90, and are surfaces that are not used for connection to other conductors.

[0027] In the substrate 100 shown in FIG. 1, at least one first via conductor 40 is provided for each of the electronic component 20 and the metal post 90, and the electronic component 20 and the metal post 90 are electrically connected to the first buildup layer 60 via the first via conductor 40. The first via conductor 40 connected to the electronic component 20 penetrates at least the insulating layer 61 of the first buildup layer 60 that is closest to the core substrate 10 and the third surface 31 of the encapsulant 30, and reaches the first electrode 21 of the corresponding electronic component 20. The first via conductor 40 connected to the metal post 90 penetrates at least the insulating layer 61 of the first buildup layer 60 that is closest to the core substrate 10, and reaches the fifth surface 91, which is the surface of the corresponding metal post 90 exposed from the third surface 31 of the encapsulant 30.

[0028] 1, at least one second via conductor 50 is provided for each of the electronic component 20 and the metal post 90, and the electronic component 20 and the metal post 90 are electrically connected to the second buildup layer 70 via the second via conductor 50. The second via conductor 50 connected to the electronic component 20 penetrates at least the insulating layer 71 of the second buildup layer 70 that is closest to the core substrate 10, and reaches the second electrode 22 of the corresponding electronic component 20. The second via conductor 50 connected to the metal post 90 penetrates at least the insulating layer 71 of the second buildup layer 70 that is closest to the core substrate 10, and reaches the sixth surface 92, which is the surface of the corresponding metal post 90 exposed from the fourth surface 32 of the sealing material 30.

[0029] The first build-up layer 60 electrically connects the electronic components 20 to each other, the metal posts 90 to each other, and the electronic components 20 and the metal posts 90 to other components, through holes, terminals, etc., and is formed by alternately stacking at least one insulating layer 61 and at least one wiring layer 62.

[0030] The second build-up layer 70 similarly electrically connects the electronic components 20 to each other, the metal posts 90 to each other, and the electronic components 20 and the metal posts 90 to other components, through holes, terminals, etc., and is formed by alternately stacking at least one insulating layer 71 and at least one wiring layer 72.

[0031] The metal post 90 is exposed from the third surface 31 of the sealing material 30 and is also exposed from the fourth surface 32 of the sealing material 30. In the board 100 shown in Fig. 1, the first via conductor 40 on the first surface 11 side of the core board 10 is connected to the fifth surface 91 of the metal post 90, and the second via conductor 50 on the second surface 12 side of the core board 10 is connected to the sixth surface 92 of the metal post 90, so that the first via conductor 40 and the second via conductor 50 are electrically connected via the metal post 90. In other words, the metal post 90 enables electrical conduction between the first surface 11 side and the second surface 12 side of the core board 10.

[0032] Since the metal post 90 is a columnar conductor provided within the opening 13, providing the metal post 90 within the opening 13 allows for a simple connection from directly above to directly below the opening 13 in a straight line without increasing the wiring length. In other words, there is no need to form wiring that detours around the opening 13.

[0033] In the substrate 100 shown in FIG. 1, the fifth surface 91 of the metal post 90 is located on the same surface as the first surface 11 of the core substrate and the third surface 31 of the sealing material 30, and the fifth surface 91 of the metal post 90 is exposed from the third surface 31 of the sealing material 30. In a substrate manufactured by a manufacturing process described below, the positional relationship between these surfaces is as described above. However, the position of the fifth surface 91 of the metal post 90 is not limited to this position, and it may protrude from or be recessed into the third surface 31 of the sealing material 30. In other words, the fifth surface 91 of the metal post 90 may be located above or below the third surface 31 of the sealing material 30 in FIG. 1. The fifth surface 91 of the metal post 90 being exposed from the third surface 31 of the sealing material 30 means that the fifth surface 91 of the metal post 90 is not covered by the sealing material 30 which is an insulating layer. Moreover, it is preferable that the fifth surface 91 of the metal post 90 is directly connected to a conductor (first via conductor 40 in FIG. 1) located on the first surface 11 side of the core substrate 10. Furthermore, a relatively thin insulator or a highly thermally conductive resin may be present between the fifth surface 91 of the metal post 90 and the conductor located on the first surface 11 side of the core substrate 10.

[0034] Similarly, in the substrate 100 shown in FIG. 1, the sixth surface 92 of the metal post 90 is located on the same surface as the second surface 12 of the core substrate and the fourth surface 32 of the encapsulant, and the sixth surface 92 of the metal post 90 is exposed from the fourth surface 32 of the encapsulant 30. In a substrate manufactured by a manufacturing process described below, the positional relationship between these surfaces is as described above. However, the position of the sixth surface 92 of the metal post 90 is not limited to this position, and it may protrude from or be recessed into the fourth surface 32 of the encapsulant 30. In other words, the sixth surface 92 of the metal post 90 may be located below or above the fourth surface 32 of the encapsulant 30 in FIG. 1. The sixth surface 92 of the metal post 90 being exposed from the fourth surface 32 of the sealing material 30 means that the sixth surface 92 of the metal post 90 is not covered with the sealing material 30 which is an insulating layer. Moreover, it is preferable that the sixth surface 92 of the metal post 90 is directly connected to a conductor located on the second surface 12 side of the core substrate 10 (the second via conductor 50 in FIG. 1). Furthermore, a relatively thin insulator or a highly thermally conductive resin may be present between the sixth surface 92 of the metal post 90 and the conductor located on the second surface 12 side of the core substrate 10 .

[0035] Metal post 90 preferably has a shape in which the dimension in the height direction, which is the direction along the thickness direction of core substrate 10, is larger than the dimensions in other directions perpendicular to the height direction. This shape can also be called a columnar shape, and the longitudinal direction of columnar metal post 90 is the direction along the thickness direction of core substrate 10.

[0036] The metal post 90 is made of a metal material, and is preferably made of copper or a copper alloy. Because the metal post 90 is made of a metal material, it has high electrical conductivity and can electrically connect linearly from directly above to directly below the opening 13 with low electrical resistance. Copper and copper alloys have a low volume resistivity as a material, so electrical resistance can be further reduced. In addition, a heat dissipation effect can be achieved from directly above to directly below the opening 13.

[0037] The relationship between the electronic component and the metal post in the same opening will now be described. 2 shows electronic components 20 and metal posts 90 provided in opening 13. Electronic components 20 and metal posts 90 are arranged in a lattice pattern, but may also be arranged in a staggered pattern or in other arrangements, and the arrangement pattern is not particularly limited.

[0038] 2, the distance between the metal post 90 and the wall surface 13a of the opening 13 is indicated by a double-headed arrow S1, and the distance between the metal post 90 and the electronic component 20 closest to the metal post 90 is indicated by a double-headed arrow S2. It is preferable that the distance S2 between the metal post 90 and the electronic component 20 closest to the metal post 90 is smaller than the distance S1 between the metal post 90 and the wall surface 13a of the opening 13. In this case, when the electronic component 20 is a component that generates heat during operation, the heat generated from the electronic component 20 can be dissipated to the outside via the metal post 90. In other words, if the metal post and the electronic component are positioned apart in the same opening, the heat dissipation effect of the metal post is less likely to be exhibited, so it can be said that it is preferable to dispose the metal post near the electronic component.

[0039] Distance S1 is obtained by image analysis of a photograph of substrate 100. More specifically, an enlarged photograph of a cross section parallel to second surface 12 of core substrate 10 is obtained by a scanning electron microscope (SEM) or a transmission electron microscope (TEM), and line segments are drawn on the opposing contour lines of metal posts 90 and wall surfaces 13a of openings 13 using image analysis software to obtain an average distance between the line segments. Then, the distances between all metal posts 90 and wall surfaces 13a of openings 13 are obtained, and the average value is set as distance S1. X-ray photographs may be used instead of photographs taken by a scanning electron microscope (SEM) or a transmission electron microscope (TEM).

[0040] Distance S2 is obtained by image analysis of a photograph of the substrate 100. More specifically, an enlarged photograph of a cross section parallel to the second surface 12 of the core substrate 10 is obtained using a scanning electron microscope (SEM) or a transmission electron microscope (TEM), and for each of the metal posts 90 and the nearest electronic component 20, line segments are drawn on the opposing contour lines using image analysis software to obtain the average distance between the line segments. Then, the distances between all metal posts 90 and the nearest electronic component are obtained, and the average value is set as distance S2. X-ray photographs may be used instead of photographs taken with a scanning electron microscope (SEM) or a transmission electron microscope (TEM).

[0041] In addition, when an electronic component is a component that generates heat during operation, it means that the temperature of the electronic component becomes higher during operation than when the electronic component is not in operation. An example of the temperature of an electronic component during operation is a component whose temperature rises to about 100°C.

[0042] The metal post 90 is made of a metal material and has high thermal conductivity, resulting in excellent heat dissipation. The material of the metal post 90 preferably has a thermal conductivity of 100 W / mK or more, and more preferably has a thermal conductivity of 300 W / mK or more.

[0043] In the substrate 100 shown in FIG. 2, a plurality of electronic components 20 are provided in the opening 13. The distance between the central axis of the metal post 90 and the central axis of the electronic component 20 closest to the metal post 90 is indicated by a double-headed arrow C1, and the distance between the central axes of the plurality of electronic components 20 is indicated by a double-headed arrow C2. It is preferable that the distance C1 between the central axis of the metal post 90 and the central axis of the electronic component 20 closest to the metal post 90 is approximately equal to the distance C2 between the central axes of the plurality of electronic components 20. Note that approximately equal distance does not mean that the distances C1 and C2 are completely equal, but means that the lower limit of the distance C2 is within a range of 95% and the upper limit of the distance C2 is within a range of 105% as a relative value when the distance C1 is 100%. In addition, the values ​​of the distances C1 and C2 can be measured at multiple points in one opening, so the average value is used. If the electronic components 20 and the metal posts 90 are closely packed in the same opening 13, the relationship between the distances C1 and C2 will be as described above. From the viewpoint of effectively using the space within the opening 13, it is preferable that there is as little empty space within the opening 13 as possible and that the electronic components 20 and the metal posts 90 are arranged as closely as possible.

[0044] In FIG. 1, the height dimension of the metal post 90 is indicated by a double-headed arrow H90, and the height dimension of the electronic component 20 is indicated by a double-headed arrow H20. In the substrate 100 shown in FIG. 1, the height dimension H90 of the metal post 90, which is the direction along the thickness direction of the core substrate 10, is larger than the height dimension H20 of the electronic component 20. This is because, when the metal post 90 is provided in the opening 13 in the manufacturing process of the substrate 100 described later, the upper end of the metal post 90 is ground or polished to align the positions of the first surface 11 of the core substrate 10 and the third surface 31 of the sealing material 30 with the fifth surface 91 of the metal post 90. Since the first electrode 21 of the electronic component 20 is not ground or polished, the height dimension H20 of the electronic component 20 is smaller. The difference between the dimension H90 of the metal post 90 in the height direction and the dimension H20 of the electronic component in the height direction is preferably, for example, 20 μm or more and 600 μm or less.

[0045] 1, the fifth surface 91 of the metal post 90 and the first surface 21 of the electronic component 20 vary in height, whereas the sixth surface 92 of the metal post 90 and the second surface 22 of the electronic component 20 are uniform in height. As a result, the fourth surface 32 of the encapsulant 30 is flatter than the third surface 31 of the encapsulant 30. Fine wiring can be formed on the fourth surface 32 of the encapsulant 30, which is a flatter surface. Therefore, it is preferable that the smallest value of the wiring width (line) of the wiring layer 72 provided on the fourth surface 32 of the encapsulant 30 is thinner than the smallest value of the wiring width (line) of the wiring layer 62 provided on the third surface 31 of the encapsulant 30. This allows more precise vias and wiring to be formed on the fourth surface 32 side of the encapsulant 30, which is flatter than the third surface 31 of the encapsulant 30. Furthermore, when multiple wires are arranged at equal intervals, the distance between the wires is called a space, and it is preferable that the minimum space between the wires in the wiring layer 72 is narrower than the minimum space between the wires in the wiring layer 62. The lines and spaces are collectively called lines and spaces, and the thinner the lines and spaces, the finer the wiring. Since the wiring in the wiring layer 72 can form finer wiring, it is preferable that the minimum line and space of the wiring in the wiring layer 72 is thinner than the minimum line and space of the wiring in the wiring layer 62.

[0046] In addition, when manufacturing the board using a different method, such as cutting the metal post 90 to a predetermined length approximately the same as the longitudinal length of the electronic component 20 and then arranging it, the height dimension H90 of the metal post 90 and the height dimension H20 of the electronic component 20 may be the same or the height dimension H90 of the metal post 90 may be smaller than the height dimension H20 of the electronic component 20, but such cases are not excluded from the scope of the present invention.

[0047] The cross section of the substrate 100 shown in FIG. 1 is a cross section perpendicular to the second surface 12 of the core substrate 10. In this cross section, the metal post 90 is disposed between the wall surface 13a of the opening 13 and the electronic component 20, and it is preferable that the linear expansion coefficient of the metal post 90 is between the linear expansion coefficient of the core substrate 10 and the linear expansion coefficient of the electronic component 20. The linear expansion coefficient of the resin material used as the core substrate is about 40 ppm / K, and the linear expansion coefficient of the multilayer ceramic capacitor assumed as the electronic component is about 10 ppm / K, and thermal stress is applied when the temperature changes due to the difference in the linear expansion coefficient. The linear expansion coefficient of copper assumed as the metal post 90 is about 16, which is between the linear expansion coefficient of the core substrate 10 and the linear expansion coefficient of the electronic component 20. Therefore, by placing metal post 90 between wall surface 13a of opening 13 and electronic component 20, i.e., between core substrate 10 and electronic component 20, the effect of the difference between the linear expansion coefficient of core substrate 10 and the linear expansion coefficient of electronic component 20 can be mitigated, and the thermal stress applied between core substrate 10 and electronic component 20 can be mitigated, thereby preventing defects such as the occurrence of cracks due to thermal stress.

[0048] 2, the electronic component 20 and the metal post 90 are drawn to have approximately the same shape and size, but they may be the same or different. By making the metal post 90 relatively large, the heat dissipation effect can be improved.

[0049] In the substrate of the present invention, in a cross section parallel to the second surface, the top view shape of the electronic component is rectangular, and the top view shape of the metal post may be a quadrangle or higher polygon with rounded vertices, a pentagon or higher polygon, a circle, an ellipse, an oval, or a racetrack shape. Furthermore, the area of ​​the metal post in a top view may be equal to or larger than the area of ​​the electronic component in a top view.

[0050] Fig. 3 is a plan view showing an example of a substrate according to an embodiment of the present invention, in which the shape of the metal post is different when viewed from above. Fig. 3 shows a substrate 101 including a metal post 93 having a circular shape when viewed from above. Furthermore, in the substrate 101, the shape of the electronic component 20 when viewed from above is rectangular, and the four corners are angular (not chamfered).

[0051] In a method for manufacturing a substrate (described in detail later), when the electronic component 20 is sealed with the sealing material 30, an uncured film containing a thermosetting resin and a filler is laminated on the first surface 11 of the core substrate 10 under vacuum. The film is then softened by hot pressing, and the thermosetting resin and the filler are filled into the opening 13. In this case, compared to the case where the electronic component 20 and the metal post 90 are all rectangular in top view as shown in FIG. 2, if the metal post 93 is circular in top view as shown in FIG. 3, the fluidity of the softened resin in the vicinity of the metal post 93 is increased, and as a result, air bubbles and clogging of the filler are suppressed, improving the filling property. The improved filling property prevents stress concentration, and peeling, breakage, and damage to the resin can be prevented. This effect is exerted so long as the shape of the metal post when viewed from above is less angular than a rectangle, and is similarly exerted even when the shape of the metal post when viewed from above is a polygon with R-chamfered vertices of four or more sides, a polygon with five or more sides, an ellipse, an oval, or a racetrack shape.

[0052] The metal post may be in the form of a coaxial cable in which the outer periphery of a metal wire is covered with a resin coating layer, and the outer periphery of the resin coating layer is covered with a metal coating layer. Figures 4A, 4B, 4C, and 4D are perspective views that typically show an example of a process for producing a coaxial cable. Also, Figure 5 is a plan view that typically shows an example of a substrate according to an embodiment of the present invention in which a part of the metal post is a coaxial cable.

[0053] Coaxial cable 97 (see FIG. 4C) is obtained by coating the outer periphery of metal wire 94 shown in FIG. 4A with resin coating layer 95 shown in FIG. 4B, and coating the outer periphery of resin coating layer 95 with metal coating layer 96 shown in FIG. 4C. When using a coaxial cable as the metal post, coaxial cable 97 is cut so that its length is the same as or slightly longer than the thickness of opening 13 (see FIG. 4D).

[0054] Copper or a copper alloy is preferably used for the metal wire 94 and the metal coating layer 96. For the resin coating layer 95, polyethylene, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkylvinylether copolymer resin (PFA), or the like is preferably used.

[0055] The substrate 102 shown in Fig. 5 includes a metal post 90 made of metal and a metal post made of a coaxial cable 97. The coaxial cable 97 also enables electrical conduction between the first surface 11 side and the second surface 12 side of the core substrate 10. In addition, since the coaxial cable 97 has excellent high-frequency characteristics, it can be used as wiring for transmitting high-frequency signals. In addition, since it is difficult in the manufacturing process to give a through-hole as a conductor penetrating the core substrate 10 a structure like that of a coaxial cable, by arranging the coaxial cable 97 in the opening 13, it is possible to easily provide wiring for vertical conduction with excellent high-frequency characteristics.

[0056] 5 includes both metal posts 90 made of metal and metal posts made of coaxial cables 97, but may include only coaxial cables 97 as metal posts. Furthermore, the positional relationship and the ratio of the numbers of metal posts 90 made of metal and metal posts made of coaxial cables 97 are not particularly limited.

[0057] [Module] Next, a module of the present invention in which a heating element is mounted on a substrate of the present invention will be described. The module of the present invention is a module in which a heating element is mounted on the first surface side of a core substrate of the substrate of the present invention, and when viewed from above in a plane parallel to the first surface, the heating element and metal post are positioned to overlap, and the heating element and metal post are directly connected, or the heating element and metal post are connected via a first material having a higher thermal conductivity than the sealing material. In addition, when viewed from above in a plane parallel to the first surface, it is preferable that the area of ​​the portion where the metal posts overlap with the area of ​​the heating element is 10% or more and 100% or less.

[0058] Fig. 6 is a cross-sectional view showing a schematic example of a module according to an embodiment of the present invention. Fig. 7 is a plan view of the module showing the positional relationship between the heating element and each component of the board in the module shown in Fig. 6. Note that Fig. 6 is a cross-sectional view taken along line YY of the board (shown in Fig. 7), and the position of the heating element is added to Fig. 7 by a two-dot chain line.

[0059] The module 200 shown in FIGS. 6 and 7 is a module in which a heating element 110 is mounted on the first surface 11 side (more precisely, on top of the first buildup layer 60) of the core substrate 10 of the substrate 100 shown in FIGS.

[0060] Examples of the heating element 110 include electronic components such as semiconductor components such as a CPU, a memory, a light emitting element such as an LED, and passive components such as an inductor, a capacitor, etc. The heating element 110 is not particularly limited as long as it is a component that generates heat during use.

[0061] The position where the heating element 110 is mounted is such that the heating element 110 and the metal post 90 overlap in top view in a plane parallel to the first surface 11, as shown in Fig. 7. In other words, it can be said that the metal post 90 is located directly below the heating element 110. With this positional relationship, the heat generated by the heating element 110 can be transferred (dissipated) to the second surface 12 side of the core substrate 10 via the metal post 90. The path of heat dissipation from the heating element 110 is shown by arrows in Fig. 6. The heating element 110 may also be electrically connected to the metal post 90 located directly below it.

[0062] When the heating element and the metal post are electrically connected, the heating element and the metal post may be directly connected to each other, or may be connected to each other via a first material having a higher thermal conductivity than the sealing material. The embodiment shown in FIG. 6 is the latter embodiment, in which the first material is the first via conductor 40 and the wiring layer 62 of the first build-up layer 60. The first via conductor 40 and the wiring layer 62 are conductive materials having a higher thermal conductivity than the sealing material 30. The first material is preferably a metal material, and more preferably copper or a copper alloy. Since the thermal conductivity of the first material is higher than that of the sealing material 30, heat from the heating element 110 is efficiently transferred to the metal post 90 via the first material.

[0063] Furthermore, when the heating element and the metal post are not electrically connected, it is preferable that thermal conductivity be maintained between the heating element and the metal post by having a relatively thin insulator or a highly thermally conductive resin between the heating element and the metal post. It is also preferable that the thermal resistance in the path from the heating element to the fourth surface of the sealing material via the third surface and the metal post is smaller than the thermal resistance of the path from the heating element to the fourth surface of the sealing material via the third surface of the sealing material without passing through the metal post.

[0064] In addition, it is preferable that a second material having a higher thermal conductivity than the sealing material is provided on the second surface side of the core substrate, and the metal post and the second material are connected. In Fig. 6, the second material corresponds to the second via conductor 50 and the wiring layer 72 of the second build-up layer 70. In Fig. 6, the metal post 90 and the second via conductor 50 are connected on the second surface 12 side of the core substrate 10, and the wiring layer 72 is further connected to the second via conductor 50. Since the second via conductor 50 and the wiring layer 72 are conductive, they can play a role in transmitting signals to the second surface 12 side of the core substrate when transmission of an electric signal from the heating element 110 is required.

[0065] Furthermore, if the second via conductor 50 and the wiring layer 72 are made of a material having a higher thermal conductivity than the sealing material 30, the heat from the heating element 110 can be transferred via the second material to the surface opposite to the surface on which the heating element 110 is mounted. The second material is preferably a metal material, and more preferably copper or a copper alloy.

[0066] In addition, in the module of the present invention, in addition to the heating element mounted on the first surface side of the core substrate, another heating element mounted on the second surface side may be provided. The heating element mounted on the core substrate may be one or more. When a plurality of heating elements are mounted, it is preferable that the heating element and the metal post overlap in a top view parallel to the first surface for each heating element, but the heating element and the metal post do not have to overlap for all heating elements. If there is even one heating element in which the heating element and the metal post overlap in a top view, it is included in the module of the present invention. In addition, since there is no distinction between the first surface and the second surface of the core substrate in the substrate of the present invention, if a heating element is mounted on either surface of the substrate, the surface on which the heating element is mounted is regarded as the surface on the first surface side of the core substrate.

[0067] [Substrate manufacturing method] The substrate 100 can be manufactured by the following method: Figure 8 is a schematic diagram showing an example of a process for attaching an adhesive film for fixing electronic components to a core substrate.

[0068] First, as shown in FIG. 8, openings 13 are formed in core substrate 10, and adhesive film 80 for fixing electronic components and metal posts is attached to second surface 12 of core substrate 10.

[0069] FIG. 9 is a cross-sectional view that illustrates an example of a process for arranging electronic components and metal posts on an adhesive film.

[0070] 9, the electronic component 20 is placed on the adhesive film 80. For example, the electronic component 20 is placed on the adhesive film 80 so that the first electrode 21 faces upward and the second electrode 22 faces downward. This causes the second electrode 22 to be attached to the adhesive film 80. In addition, a metal post 90 is also placed on the adhesive film 80. The height of the metal post 90 is set to be higher than the first electrode 21 of the electronic component 20 and the first surface 11 of the core substrate 10.

[0071] FIG. 10 is a cross-sectional view that illustrates an example of a step of filling the openings in the core substrate with a sealing material.

[0072] 10, the electronic component 20 and the metal post 90 are sealed with a sealant 30. Specifically, an uncured film containing a thermosetting resin and a filler is laminated on the first surface 11 of the core substrate 10 under vacuum. Then, the film is softened by hot pressing, so that the thermosetting resin and the filler are filled around the electronic component 20 and the metal post 90 in the opening 13.

[0073] FIG. 11 is a cross-sectional view that illustrates an example of a step of grinding or polishing the sealing material and the metal posts.

[0074] 11, the sealing material 30 and the metal post 90 are ground or polished on the first surface 11 side of the core substrate 10. The first surface 11 of the core substrate 10, the third surface 31 of the sealing material 30, and the fifth surface 91 of the metal post 90 are aligned. After grinding or polishing, the fifth surface 91 of the metal post 90 is exposed from the third surface 31 of the sealing material 30. Meanwhile, the first electrode 21 of the electronic component 20 is covered by the sealing material 30 and is not exposed. In this process, the electronic component 20 is not ground or polished.

[0075] FIG. 12 is a cross-sectional view illustrating an example of a process for forming a via.

[0076] Next, as shown in FIG. 12, after peeling off the adhesive film 80, an insulating layer 61 is formed on the first surface 11 of the core substrate 10 and the third surface 31 of the sealing material 30, and an insulating layer 71 is formed on the second surface 12 of the core substrate 10 and the fourth surface 32 of the sealing material 30 (lower in FIG. 12). The adhesive film 80 can be used as it is without being peeled off. Then, a via 82 is formed in the insulating layer 61 by using a CO2 laser or the like to expose the first electrode 21 of the electronic component 20 and the fifth surface 91 of the metal post 90, and a via 83 is formed in the insulating layer 71 to expose the second electrode 22 of the electronic component 20 and the sixth surface 92 of the metal post 90. When forming the via 82, the sealing material 30 covering the first electrode 21 of the electronic component 20 is also removed to form the via 82.

[0077] FIG. 13 is a cross-sectional view illustrating an example of a process for forming a wiring layer.

[0078] Next, as shown in FIG. 13, plating (for example, a semi-additive process) is used to fill the vias 82 and 83 to form the first via conductors 40 and the second via conductors 50, and also to form the wiring layers 62 and 72.

[0079] FIG. 14 is a cross-sectional view that illustrates an example of a step of forming a build-up layer.

[0080] Thereafter, as shown in FIG. 14, layers are added as necessary to form a first buildup layer 60 and a second buildup layer 70.

[0081] In this manner, the substrate 100 can be manufactured. In the substrate 100 manufactured by this process, the fifth surface 91 of the metal post 90 is located at the same height as the third surface 31 of the sealing material 30, is exposed from the third surface 31 of the sealing material 30, and is connected to the first via conductor 40. In addition, the sixth surface 92 of the metal post 90 is located at the same height as the fourth surface 32 of the sealing material 30, is exposed from the fourth surface 32 of the sealing material 30, and is connected to the second via conductor 50. In addition, the height dimension of the metal post 90 is greater than the height dimension of the electronic component 20.

[0082] The present specification discloses the following:

[0083] <1> a core substrate having a first surface and a second surface opposite to the first surface, the core substrate having an opening therein; an electronic component and a metal post provided in the same opening; a sealant filled in the opening and having a third surface on the first surface side and a fourth surface on the second surface side, the metal post is exposed from the third surface of the encapsulant and is also exposed from a fourth surface of the encapsulant.

[0084] <2> The metal post has a shape in which a dimension in a height direction, which is a direction along the thickness direction of the core substrate, is larger than dimensions in other directions perpendicular to the height direction. <1> The substrate according to claim 1.

[0085] <3> the electronic component generates heat during operation, and the distance between the metal post and the nearest electronic component is smaller than the distance between the metal post and a wall surface of the opening; <1> or <2> The substrate according to claim 1.

[0086] <4> A plurality of the electronic components are provided in the opening, In a cross section parallel to the second surface, a distance between a central axis of the metal post and a central axis of the electronic component closest to the metal post is approximately equal to a distance between the central axes of the plurality of electronic components. <1> from <3> 2. A substrate according to any one of claims 1 to 11.

[0087] <5> the metal post has a height dimension along the thickness direction of the core substrate that is greater than a height dimension of the electronic component; <1> from <4> 2. A substrate according to any one of claims 1 to 11.

[0088] <6> a linear expansion coefficient of the metal post is between a linear expansion coefficient of the core substrate and a linear expansion coefficient of the electronic component; In a cross section perpendicular to the second surface, the metal post is disposed between a wall surface of the opening and the electronic component. <1> from <5> 2. A substrate according to any one of claims 1 to 11.

[0089] <7> In a cross section parallel to the second surface, The electronic component has a rectangular shape when viewed from above, The top view shape of the metal post is a quadrilateral or higher polygon with R-chamfered vertices, a pentagon or higher polygon, a circle, an ellipse, an oval, or a racetrack shape. <1> from <6> 2. A substrate according to any one of claims 1 to 11.

[0090] <8> The metal post is made of copper or a copper alloy. <1> from <7> 2. A substrate according to any one of claims 1 to 11.

[0091] <9> The metal post is in the form of a coaxial cable in which an outer periphery of a metal wire is covered with a resin coating layer, and an outer periphery of the resin coating layer is covered with a metal coating layer. <1> from <8> 2. A substrate according to any one of claims 1 to 11.

[0092] <10> <1> from <9> 2. A module in which a heating element is mounted on the first surface side of the core substrate of the substrate according to any one of claims 1 to 11, When viewed from above in a plane parallel to the first surface, the heating element and the metal post are positioned to overlap each other, A module, wherein the heating element and the metal post are directly connected to each other, or the heating element and the metal post are connected to each other via a first material having a higher thermal conductivity than the sealing material.

[0093] <11> The first material is a metallic material. <10> The module described in.

[0094] <12> A second material having a higher thermal conductivity than the sealing material is provided on a second surface side of the core substrate, and the metal post and the second material are connected to each other. <10> or <11> The module described in.

[0095] <13> The second material is a metallic material. <12> The module described in. [Explanation of symbols]

[0096] 10 Core Board 11 Page 1 12 Side 2 13 Opening 13a Opening wall 20 Electronic Components 21 1st electrode 22 2nd electrode 30 Encapsulating material 31 Page 3 32 Page 4 40 First via conductor 50 Second via conductor 60 First build-up layer 61 Insulating layer 62 wiring layer 70 Second build-up layer 71 Insulating layer 72 wiring layer 80 Adhesive Film 82, 83 Via 90, 93 Metal Post 91 Page 5 92 Page 6 94 Metal Wire 95 Resin coating layer 96 Metal coating layer 97 Coaxial Cable 100, 101, 102 Boards 110 Heating element 200 Module C1 Distance between the central axis of the metal post and the central axis of the electronic component C2 Distance between the central axes of multiple electronic components D1 1st direction D2 2nd direction H20 Height of electronic components H90 Metal post height S1 Distance between metal post and wall of opening S2 Distance between metal post and electronic components

Claims

1. a core substrate having a first surface and a second surface opposite to the first surface, the core substrate having an opening therein; an electronic component and a metal post provided in the same opening; a sealant filled in the opening and having a third surface on the first surface side and a fourth surface on the second surface side, A substrate, wherein one of the metal posts penetrates the sealing material in a thickness direction and is exposed from both the third surface of the sealing material and the fourth surface of the sealing material.

2. a core substrate having a first surface and a second surface opposite to the first surface, the core substrate having an opening therein; an electronic component and a metal post provided in the same opening; a sealant filled in the opening and having a third surface on the first surface side and a fourth surface on the second surface side, The metal post is exposed from the third surface of the sealing material and is also exposed from the fourth surface of the sealing material, and the metal post is in the shape of a coaxial cable, with the outer periphery of a metal wire coated with a resin coating layer and the outer periphery of the resin coating layer coated with a metal coating layer.

3. a core substrate having a first surface and a second surface opposite to the first surface, the core substrate having an opening therein; an electronic component and a metal post provided in the same opening; a sealant filled in the opening and having a third surface on the first surface side and a fourth surface on the second surface side, one of the metal posts penetrates the sealing material in a thickness direction and is exposed from both the third surface of the sealing material and the fourth surface of the sealing material, and a linear expansion coefficient of the metal post is between a linear expansion coefficient of the core substrate and a linear expansion coefficient of the electronic component; In a cross section perpendicular to the second surface, the metal post is disposed between a wall surface of the opening and the electronic component.

4. a core substrate having a first surface and a second surface opposite to the first surface, the core substrate having an opening therein; an electronic component and a metal post provided in the same opening; a sealant filled in the opening and having a third surface on the first surface side and a fourth surface on the second surface side, the metal post is exposed from the third surface of the sealing material, and a heating element is mounted on a substrate exposed from a fourth surface of the sealing material on the first surface side of the core substrate, When viewed from above in a plane parallel to the first surface, the heating element and the metal post are positioned to overlap each other, A module, wherein the heating element and the metal post are directly connected to each other, or the heating element and the metal post are connected to each other via a first material having a higher thermal conductivity than the sealing material.

5. A substrate as described in any one of claims 1 to 3, or a module as described in claim 4, wherein the metal post has a shape in which the height dimension, which is the direction along the thickness direction of the core substrate, is greater than the dimension in another direction perpendicular to the height direction.

6. The substrate according to any one of claims 1 to 3, or the module according to claim 4, wherein the electronic component is a component that generates heat during operation, and the distance between the metal post and the closest electronic component is smaller than the distance between the metal post and the wall surface of the opening.

7. A plurality of the electronic components are provided in the opening, The substrate according to any one of claims 1 to 3, or the module according to claim 4, wherein, in a cross section parallel to the second surface, the distance between the central axis of the metal post and the central axis of the electronic component closest to the metal post is approximately equal to the distance between the central axes of multiple of the electronic components.

8. A substrate as described in any one of claims 1 to 3, or a module as described in claim 4, wherein the metal post has a height dimension, which is a direction along the thickness direction of the core substrate, that is greater than the height dimension of the electronic component.

9. a linear expansion coefficient of the metal post is between a linear expansion coefficient of the core substrate and a linear expansion coefficient of the electronic component; The substrate according to claim 2 or the module according to claim 4, wherein in a cross section perpendicular to the second surface, the metal post is disposed between a wall surface of the opening and the electronic component.

10. In a cross section parallel to the second surface, The electronic component has a rectangular shape when viewed from above, The substrate according to any one of claims 1 to 3, or the module according to claim 4, wherein the top view shape of the metal post is a quadrilateral or higher polygon with rounded vertices, a pentagon or higher polygon, a circle, an ellipse, an oval, or a racetrack shape.

11. The substrate according to any one of claims 1 to 3 or the module according to claim 4, wherein the metal posts are made of copper or a copper alloy.

12. The module of claim 4 , wherein the first material is a metallic material.

13. The module according to claim 4 , wherein a second material having a higher thermal conductivity than the sealing material is provided on a second surface side of the core substrate, and the metal post and the second material are connected to each other.

14. The module of claim 13 , wherein the second material is a metallic material.

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