Substrate having built-in electronic components

Abstract

A substrate 100 having built-in electronic components is provided with a core substrate 10 having a through hole 20 and electronic components 40 provided in the through hole 20, the core substrate 10 being provided with a first main surface 11 and a second main surface 12 opposite the first main surface 11. In a planar view taken from the first main surface 11 toward the second main surface 12, the through hole 20 is shaped so as to accommodate the shapes that are given to each of the electronic components 40. The through hole 20 has first through hole sections 21 filled with resin 30 and a second through hole section 22 connecting a part of the interval between the first through hole sections 21 of adjacently-positioned electronic components 40.

Description

Electronic component embedded board

[0001] The present invention relates to a substrate with built-in electronic components.

[0002] Patent document 1 describes a wiring board characterized by comprising an electronic component embedded in a through hole provided in a core substrate, and a through-hole conductor located around the through hole and penetrating between the front and back surfaces of the core substrate, wherein the electrodes of the electronic component and the through-hole conductor are connected via wiring formed on the core substrate.

[0003] Japanese Patent Application Laid-Open No. 2002-134919

[0004] The wiring board of Patent Document 1 has a large through hole that can accommodate a plurality of electronic components, and the plurality of electronic components are accommodated in the through hole, which is then filled with resin.

[0005] Generally, the linear expansion coefficient of a core substrate such as a glass cloth resin substrate is smaller than the linear expansion coefficient of electronic components or metal materials built into the through holes of the core substrate, or the linear expansion coefficient of the resin used for filling.

[0006] In the wiring board of Patent Document 1, electronic components, metal materials, and resins with large linear expansion coefficients are present within the large through holes, and since the area with a large linear expansion coefficient occupies a large proportion of the wiring board, there is a problem that the wiring board warps.

[0007] In contrast, if one electronic component is embedded in each through hole and resin is filled in each through hole, the proportion of the area with a high linear expansion coefficient in the wiring board is reduced. However, the thermal expansion of the material with a high linear expansion coefficient present in the through hole applies stress to the core board, which can cause warping of the wiring board. As a result, the mechanical stress on the electronic components embedded in the core board can cause fluctuations in the characteristics of the electronic components or reduce the reliability of the electronic components.

[0008] The present invention has been made to solve the above problems, and has an object to provide a substrate with built-in electronic components that prevents the occurrence of warpage of the substrate.

[0009] The electronic component-embedded substrate of the present invention is an electronic component-embedded substrate comprising a core substrate having a first main surface and a second main surface opposite the first main surface, and having a through hole, and an electronic component provided in the through hole, wherein the electronic component-embedded substrate has a plurality of the electronic components provided therein, and in a planar view looking from the first main surface toward the second main surface, the through hole has a shape that is set for each of the electronic components and can accommodate the shape of each of the electronic components, and has a first through hole portion filled with resin and a second through hole portion that connects a portion between the first through hole portions of adjacent electronic components.

[0010] According to the present invention, it is possible to provide a substrate with built-in electronic components in which the occurrence of warping of the substrate is prevented.

[0011] FIG. 1 is a cross-sectional view schematically showing an example of an electronic component built-in substrate. FIG. 2 is a plan view schematically showing an example of an electronic component built-in substrate. FIG. 3A is a plan view schematically showing a through hole that houses four electronic components. FIG. 3B is a plan view schematically showing a through hole that houses four electronic components. FIG. 3C is a plan view schematically showing a through hole that houses four electronic components. FIG. 3D is a plan view schematically showing a through hole that houses four electronic components. FIG. 4A is a plan view schematically showing an area in which electronic components are arranged on a core substrate. FIG. 4B is a plan view schematically showing the total area of ​​the through holes. FIG. 4C is a plan view schematically showing the total area of ​​first through hole portions. FIG. 5 is a plan view schematically showing an example of a configuration using electronic components that are circular in plan view. 6 is a plan view schematically illustrating an example of a configuration in which the second through hole portion connects corners of the first through hole portions of adjacent electronic components, and FIG. 7 is a plan view schematically illustrating another example of a configuration in which the second through hole portion connects corners of the first through hole portions of adjacent electronic components.

[0012] The electronic component-embedded substrate of the present invention will be described below. However, the present invention is not limited to the following configuration, and can be appropriately modified and applied within the scope of the present invention. Note that a combination of two or more of the individual desirable configurations described below also constitutes the present invention.

[0013] 1 is a cross-sectional view showing an example of an electronic component built-in substrate. The electronic component built-in substrate 100 includes a core substrate 10 having a first main surface 11 and a second main surface 12 opposite to the first main surface 11, the core substrate 10 having a through hole 20, and an electronic component 40 disposed in the through hole 20.

[0014] The first main surface 11 and the second main 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. The through holes 20 of the core substrate 10 penetrate the core substrate 10.

[0015] 1 also illustrates a sealing material 30 that is filled in the through hole 20 and provided across the first main surface 11 and the second main surface 12 of the core substrate 10. A part of the sealing material 30 is also a resin that fills the first through hole portion, which will be described later.

[0016] The electronic component-embedded substrate also includes a first via conductor 51 connected to a first electrode 41 of the electronic component 40, a second via conductor 52 connected to a second electrode 42 of the electronic component 40, a first buildup layer (rewiring layer) 61 provided in contact with the sealing material 30 on the first main surface 11 side of the core substrate 10, and a second buildup layer (rewiring layer) 62 provided in contact with the sealing material 30 on the second main surface 12 side of the core substrate 10. The first via conductor 51, the second via conductor 52, the first buildup layer 61, and the second buildup layer 62 are not essential components of the electronic component-embedded substrate of the present invention.

[0017] The core substrate may be a glass substrate, a semiconductor substrate, a glass-containing resin substrate (glass cloth resin substrate, glass filler-containing resin substrate), a ceramic substrate, or the like. The core substrate may be a printed wiring board having conductor wiring on its surface or inside. A glass epoxy substrate containing epoxy resin and glass cloth is preferably used as the core substrate. The core substrate may also contain inorganic particles such as silica particles and alumina particles.

[0018] The linear expansion coefficient of the core substrate is lower than the linear expansion coefficient of the resin filled in the through holes (first through hole portions) of the core substrate. The value of the linear expansion coefficient of the core substrate is, for example, 3 ppm / °C or more and 10 ppm / °C or less. When the core substrate is a glass-containing resin substrate, it is preferably 4 ppm / °C or more and 10 ppm / °C or less, when the core substrate is a glass substrate, it is preferably 3 ppm / °C or more and 8 ppm / °C or less, and when the core substrate is a semiconductor substrate, it is preferably 3 ppm / °C or more and 4 ppm / °C or less.

[0019] The electronic component 40 is disposed within the through-hole 20. The electronic component 40 is not particularly limited, and examples thereof include passive components such as capacitors (e.g., multilayer ceramic capacitors (MLCCs)) and inductors, or metal pillars. The electronic component 40 may be a chip component having a longitudinal shape such as a rectangular parallelepiped or cylindrical shape, or a metal pillar having a prismatic or cylindrical shape, and its shape in plan view is preferably quadrangular (square or rectangular) or circular. If the shape of the electronic component in plan view is quadrangular, it is preferably a quadrangle with one side measuring 0.2 mm or more and 3.0 mm or less. Furthermore, if the shape of the electronic component in plan view is circular, it is preferably a circle with a diameter of 0.2 mm or more and 3.0 mm or less.

[0020] In this specification, the term "plan view" refers to a view from the first main surface of the core substrate toward the second main surface (viewpoint shown in FIG. 2).

[0021] The linear expansion coefficient of the electronic component is preferably larger than that of the core substrate, and is preferably 1.2 times or more the linear expansion coefficient of the core substrate. The linear expansion coefficient of the electronic component may be 5 times or less the linear expansion coefficient of the core substrate. When the electronic component is an MLCC, the linear expansion coefficient of the electronic component is preferably, for example, 12 ppm / °C or more and 15 ppm / °C or less. When the linear expansion coefficient of the electronic component varies depending on the measurement direction, the value measured in the planar view direction (vertical or horizontal direction in FIG. 2 ) is used.

[0022] In the vertical cross section, it is preferable that the dimension of each electronic component 40 in the height direction (direction along the first direction D1 or second direction D2 described later), which is the 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 40 to be arranged with higher density.

[0023] Furthermore, electronic component 40 has first electrodes 41 in a first direction D1 that is perpendicular to second main surface 12 of core substrate 10 and extends toward first main surface 11, and has second electrodes 42 in a second direction D2 that is opposite to first direction D1. By mounting electronic components 40 in the vertical direction in this manner, it is possible to arrange elongated electronic components 40 at a higher density.

[0024] In each electronic component 40, the first electrode 41 and the second electrode 42 are located at one end and the other end of the longitudinal direction of the elongated electronic component 40, respectively.

[0025] Fig. 2 is a plan view schematically illustrating an example of an electronic component-embedded substrate, showing the configuration of the electronic component-embedded substrate 100 shown in Fig. 1 as viewed from the first main surface 11 of the core substrate 10, with the first via conductors 51 and the first buildup layer 61 omitted to show the first electrodes 41 of the electronic components 40.

[0026] 2 , four electronic components 40 are embedded in one continuous through hole 20. The through hole 20 has a shape that is set for each electronic component 40 to be embedded in the through hole 20 and can accommodate the shape of the electronic component 40, and has a first through hole portion 21 filled with resin 30 and a second through hole portion 22 that connects portions of the first through hole portions 21 of adjacent electronic components 40.

[0027] One first through-hole portion 21 is provided for each electronic component.

[0028] In plan view, the first through-hole portion has a shape that can accommodate the shape of an electronic component, and is preferably an approximately square, an approximately rectangular, or an approximately circular shape. The term "approximately square or approximately rectangular" not only includes a square or a rectangle, but also includes a shape that remains when a corner of a square or a rectangle overlaps with a second through-hole portion and the overlapping portion is cut out from the square or rectangle (the shapes in Figures 6 and 7 described below). Hereinafter, in this specification, when the terms "square," "rectangle," and "circle" are used, they include not only a perfect square, rectangle, or circle, but also an approximately square, an approximately rectangular, or an approximately circular shape.

[0029] When the shape of the through hole of the electronic component-embedded substrate is viewed in plan, a shape that can accommodate the shape of the electronic component and has the largest area is drawn and defined as the first through hole portion (square, rectangle, or circle). For example, if the shape of the electronic component is circular and a square that can accommodate the circle of the electronic component can be drawn as the first through hole portion (as in the case of Figure 5 described below), a circle that can accommodate the circle of the electronic component can also be drawn as the first through hole portion, but the square shape that has the larger area is defined as the shape of the first through hole portion.

[0030] 3A, 3B, 3C, and 3D are plan views schematically illustrating through-holes containing four electronic components. In each of these figures, the elements and hatching are shown differently depending on the matters described in this specification, but the same elements are illustrated.

[0031] Fig. 3A shows a state in which an electronic component 40 is built into the through hole 20 and the through hole 20 is filled with resin 30 as a sealing material. Fig. 3B shows the shape of the through hole 20 without showing the electronic component 40 and resin 30. Fig. 3C shows the through hole 20 as being divided into four first through hole portions 21a, 21b, 21c, and 21d and three second through hole portions 22a, 22b, and 22c. The three second through hole portions 22a, 22b, and 22c are hatched. In Figs. 3A and 3B, the through hole 20 is shown without distinguishing between the first through hole portion and the second through hole portion.

[0032] As shown in Fig. 3B, through holes 20 are provided in the core substrate 10. As shown in Fig. 3C, the through holes 20 are divided into four first through hole portions 21 and three second through hole portions 22 connecting adjacent first through hole portions 21.

[0033] In a plan view looking from the first main surface 11 toward the second main surface 12 of the core substrate 10, the shape of the first through-hole portion 21 is square. The area of ​​this square is larger than the area of ​​the planar shape of each electronic component 40 provided in the through-hole 20 (the planar shape of the electronic component 40 shown in FIG. 3A is square).

[0034] The shape of the first through-hole portion can be similar to the shape of the electronic component in a planar view, and when the shape of the electronic component in a planar view is square, it is preferable that the shape of the first through-hole portion be square. For example, there is an example of a combination in which the shape of the electronic component in a planar view is a square with one side of 0.2 mm to 2.0 mm, and the shape of the first through-hole portion is a square with one side of 0.3 mm to 2.1 mm. Furthermore, when the shape of the electronic component in a planar view is rectangular, it is preferable that the shape of the first through-hole portion be rectangular.

[0035] The shape of the first through-hole portion may be a shape that is not similar to the shape of the electronic component in a plan view, and when the shape of the electronic component in a plan view is circular, the shape of the first through-hole portion may be square. For example, there is an example of a combination in which the shape of the electronic component in a plan view is circular with a diameter of 0.2 mm to 3.0 mm, and the shape of the first through-hole portion is square with one side measuring 0.3 mm to 3.1 mm.

[0036] An electronic component is provided in the first through-hole, and a resin is filled around the electronic component. The linear expansion coefficient of the resin is preferably larger than that of the core substrate, and is preferably 1.2 times or more the linear expansion coefficient of the core substrate. The linear expansion coefficient of the resin may be 20 times or less, or may be 14 times or less the linear expansion coefficient of the core substrate. The linear expansion coefficient of the resin is preferably, for example, 15 ppm / °C or more and 40 ppm / °C or less.

[0037] The resin is preferably a resin used as a sealing material, and is preferably a resin composition containing a resin such as an epoxy resin and a filler composed of inorganic particles such as silica particles, alumina particles, etc. As the sealing material, for example, ABF (registered trademark: manufactured by Ajinomoto Fine-Techno Co., Inc.) can be used.

[0038] The second through-hole portion connects a portion between the first through-hole portions of adjacent electronic components in a plan view from the first main surface toward the second main surface. The shape of the second through-hole portion is not particularly limited, and may be rectangular, square, circular, or the like.

[0039] 3C shows three second through hole portions. The second through hole portion 22a connects a portion between the first through hole portion 21a and the first through hole portion 21b. The second through hole portion 22b connects a portion between the first through hole portion 21a and the first through hole portion 21c. The second through hole portion 22c connects a portion between the first through hole portion 21c and the first through hole portion 21d. The first through hole portion 21b and the first through hole portion 21d are not connected by a second through hole portion. The second through hole portions 22a, 22b, and 22c are all rectangular in shape.

[0040] The second through-holes 22a, 22b, and 22c are each filled with resin 30. The resin is preferably the same as the resin filled in the first through-holes, but may be a different resin. The second through-holes may also be filled with a conductor (conductive paste). The second through-holes may also be left unfilled.

[0041] Although warping of the core substrate occurs due to thermal stress applied to the resin filled in the first through-hole portion and the electronic components inside the first through-hole portion, when the second through-hole portion connecting the first through-hole portions is provided, the force that tends to warp the core substrate at the portion where the core substrate is continuous is blocked by the second through-hole portion, thereby preventing warping of the substrate due to stress on the core substrate. Furthermore, fluctuations in the characteristics of the electronic components built into the core substrate due to mechanical stress on the electronic components are prevented, improving the reliability of the electronic components.

[0042] The second through-hole portion connects a portion of the space between adjacent first through-hole portions, but does not connect the entire space between them. If the second through-hole portion connects the entire space between adjacent first through-hole portions, the configuration will be similar to that of a substrate with built-in electronic components, such as the wiring board described in Patent Document 1, in which a large proportion of the electronic components and resin occupy a large portion of the through-hole. This means that the proportion of the area with a large linear expansion coefficient will be high, which can cause the problem of the substrate warping.

[0043] The second through-hole portion may be located anywhere between the first through-hole portions of adjacent electronic components, as determined for the numerous electronic components and the first through-hole portions, in a plan view of the entire electronic component-embedded substrate. There may be a first through-hole portion that is not connected to the first through-hole portions of any adjacent electronic components. Furthermore, the position at which the second through-hole portion connects the first through-hole portions of adjacent electronic components is not particularly limited. In Figure 3C, the second through-hole portion 22 connects the first through-hole portions 21 at a position along the outer periphery of the first through-hole portion 21, but the second through-hole portion 22 may also connect adjacent first through-hole portions near the center of the opposing sides.

[0044] In a plan view, the area of ​​one of the second through-hole portions is preferably smaller than the area of ​​one of the first through-hole portions. The area of ​​the first through-hole portions in which electronic components are arranged is larger than the area of ​​the second through-hole portions connecting the first through-hole portions, which means that the electronic components are arranged at a high density. As a specific example of the area of ​​the second through-hole portions, in a plan view, the area of ​​one of the second through-hole portions is preferably 2% or more and 40% or less of the area of ​​one of the first through-hole portions.

[0045] Furthermore, it is preferable that the width W2 of the second through hole portion (the dimension indicated by the double-headed arrow W2 in FIG. 3C ) be 0.1 mm or more and 0.5 mm or less. It is also preferable that the ratio (W2 / W1) of the width W2 of the second through hole portion to the width of the first through hole portion (the dimension indicated by the double-headed arrow W1 in FIG. 3C ) at the portion where the second through hole portion is connected be 0.13 or more and 0.67 or less. In order to prevent thermal stress applied to the resin filled in the first through hole portion and the electronic component in the first through hole portion from being transmitted to the core substrate, it is preferable that the width W2 of the second through hole portion be somewhat large. However, if the width W2 of the second through hole portion is too large, the through hole becomes too large and the substrate becomes more likely to warp.

[0046] Furthermore, in a plan view, there may be a portion between the first through holes of adjacent electronic components where there is no second through hole portion and only the core substrate is present. Even if there are no second through holes between all of the first through holes of adjacent electronic components, the effect of the electronic component-embedded substrate of the present invention can be achieved as long as there are portions between the first through holes of adjacent electronic components where there are second through holes. In Figure 3D, the portion between the first through holes of adjacent electronic components where there are no second through holes and only the core substrate is shown by a region P surrounded by a dotted line. Region P is the region between first through hole portion 21b and first through hole portion 21d, which are adjacent first through hole portions, where there are no second through holes and only the core substrate is present.

[0047] The number of electronic components housed in one continuous through hole is not particularly limited, and two or more first through hole portions are connected by one or more second through hole portions. Figures 3A, 3B, and 3C show a configuration in which four first through hole portions are connected by three second through hole portions.

[0048] Furthermore, in a plan view, it is preferable that the total area of ​​the through holes is 90% or less of the area of ​​the core substrate in the region where the electronic components are arranged on the core substrate. Furthermore, in a plan view, it is preferable that the total area of ​​the first through hole portions is 50% or more of the area of ​​the core substrate in the region where the electronic components are arranged on the core substrate. When determining these regulations, the region where the electronic components are concentrated on the core substrate is defined as the "region where the electronic components are arranged on the core substrate," and the total area of ​​the through holes and the total area of ​​the first through hole portions are considered relative to the area of ​​the region.

[0049] Figure 4A is a plan view schematically showing the area in which electronic components are arranged on the core substrate, Figure 4B is a plan view schematically showing the total area of ​​the through holes, and Figure 4C is a plan view schematically showing the total area of ​​the first through hole portion.

[0050] Figure 4A schematically shows region A surrounded by a dotted line, which is a region in which electronic components are arranged on a core substrate. The core substrate shown in Figure 4A has electronic components concentrated near its center. A region is defined along the periphery of the region in which the electronic components are arranged, and this region is referred to as the "region in which electronic components are arranged on the core substrate." The area of ​​region A surrounded by the dotted line is referred to as the "area of ​​the core substrate in the region in which electronic components are arranged on the core substrate."

[0051] Figure 4B schematically shows region B surrounded by a dotted line as the area of ​​the through holes in the "region where electronic components are arranged on the core substrate" shown in Figure 4A. Figure 4B shows four regions B, and the total area of ​​the through holes is the sum of the areas of the four regions B. The total area of ​​the through holes is the sum of the areas of the first through hole portions and second through hole portions present in region A.

[0052] Fig. 4C schematically shows an area C surrounded by a dotted line as the area of ​​the first through-hole portion in the "area where electronic components are arranged on the core substrate" shown in Fig. 4A. Fig. 4C shows 16 areas C, and the total area of ​​the first through-hole portion is the sum of the areas of the 16 areas C.

[0053] In a plan view, the total area of ​​the through holes (total area of ​​region B) is preferably 90% or less of the area of ​​the core substrate in the region where the electronic components are arranged on the core substrate (area of ​​region A). If this area ratio is too high, the configuration will be similar to that of an electronic component-embedded substrate, such as the wiring board of Patent Document 1, in which a large proportion of the electronic components and resin occupy large through holes, resulting in a high proportion of areas with a high linear expansion coefficient, which can cause problems such as warping of the substrate. Furthermore, the total area of ​​the through holes (total area of ​​region B) is preferably 50% or more of the area of ​​the core substrate in the region where the electronic components are arranged on the core substrate (area of ​​region A).

[0054] In a plan view, the total area of ​​the first through-hole portions (total area of ​​region C) is preferably 50% or more of the area of ​​the core substrate in the region where the electronic components are arranged on the core substrate (area of ​​region A). The problem of the present invention is likely to occur when the ratio of the total area of ​​the first through-hole portions is relatively large, so the effects of the present invention are more effectively achieved in an electronic component-embedded substrate that satisfies the above-mentioned specifications. Furthermore, the total area of ​​the first through-hole portions (total area of ​​region C) is preferably 90% or less of the area of ​​the core substrate in the region where the electronic components are arranged on the core substrate (area of ​​region A).

[0055] Fig. 5 is a plan view schematically illustrating an example of a configuration using an electronic component that is circular in plan view. Fig. 5 shows the same positional relationship as Fig. 3A , except that the shape of electronic component 45 is circular. Although electronic component 45 is circular, a square can be drawn as the first through-hole portion to accommodate the circular electronic component, so the shape of first through-hole portion 21 is square. The shape and position of second through-hole portion 22 are the same as those of the configuration shown in Fig. 3A .

[0056] The second through-hole portion may connect corners of the first through-hole portions of adjacent electronic components. This embodiment will be described. Fig. 6 is a plan view schematically showing an example of an embodiment in which the second through-hole portion connects corners of the first through-hole portions of adjacent electronic components. Fig. 6 shows the same positional relationship as Fig. 3A except for the shape and position of the second through-hole portion.

[0057] 6 , the second through hole portion 25 connects the corners of the first through hole portions 21 of adjacent electronic components. The second through hole portion 25 is a conductor portion extending from the first main surface toward the second main surface and can function as a through-hole conductor penetrating from the first main surface to the second main surface. By providing the second through hole portion 25, which is a through-hole conductor, at a position connecting the corners of the first through hole portions 21 of adjacent electronic components, a large number of through-hole conductors can be installed.

[0058] When the second through-hole portion is a through-hole conductor, it is preferable that the second through-hole portion does not come into contact with the electrode of the electronic component. When the second through-hole portion is a through-hole conductor, the second through-hole portion may be filled with a conductive paste, may be a metal post, or may be through-hole plated on the wall surface of the through-hole and filled with a resin. When the second through-hole portion is made of metal, its linear expansion coefficient is preferably 14 ppm / °C or more and 30 ppm / °C or less. Since the linear expansion coefficient of the metal is higher than that of the core substrate, it can function as the second through-hole portion. Furthermore, when the second through-hole portion is filled with resin, it can also function as the second through-hole portion because the linear expansion coefficient of the resin is higher than that of the core substrate.

[0059] In the embodiment shown in Fig. 6, the square corners of the first through hole portion are connected by the circular second through hole portion. The square corners of the first through hole portion overlap with the circular second through hole portion, and this overlapping portion is defined as the second through hole portion. Therefore, the first through hole portion has a substantially square shape that is left after the corners of the square have been cut off. When determining the area of ​​the first through hole portion, it is defined as the area of ​​the substantially square shape after the corners of the square have been cut off.

[0060] 6, the electronic component 40 has a square shape, the first through-hole portion 21 has a square shape, and the second through-hole portion 25 has a circular shape, but these shapes are not particularly limited. The second through-hole portion 25 connecting the corners of the first through-hole portion 21 may also have a square or rectangular shape.

[0061] In a plan view, the electronic component preferably has a circular shape, the area of ​​the circle of the electronic component is 50% or more of the area of ​​the first through hole portion, and the second through hole portion connects the corners of the first through hole portions of adjacent electronic components. Figure 7 is a plan view schematically showing another example of a configuration in which the second through hole portion connects the corners of the first through hole portions of adjacent electronic components. Figure 7 shows the same positional relationship as Figure 6 except that the shape of the electronic component 45 is circular. Although the shape of the electronic component 45 is circular, the shape of the first through hole portion 21 is square because a square can be drawn to fit the circle of the electronic component as the first through hole portion. The shape and position of the second through hole portion 25 are the same as those of the configuration shown in Figure 6. In the configuration shown in Figure 7, the area of ​​the circle of the electronic component is preferably 50% or more of the area of ​​the first through hole portion. With this configuration, even without using a chip mounter, contact between the electronic component provided in the first through-hole portion and the second through-hole portion is prevented, and if the second through-hole portion is a through-hole conductor, electrical conduction between the second through-hole portion and the electrode of the electronic component is prevented.

[0062] A specific example of a process for manufacturing an electronic component-embedded substrate of the present invention will be described below. A through hole is formed in a core substrate (e.g., 1 mm thick) such as a glass epoxy substrate using a laser. The shape of the through hole can be, for example, the shape shown in FIG. 4B. As an example of dimensions for the shape shown in FIG. 4B, the shape of the first through hole portion is a square of 0.75 mm x 0.75 mm, and the width of the second through hole portion is 0.10 mm. A large number of through holes shaped as shown in FIG. 4B are formed repeatedly in a matrix.

[0063] A temporary fixing material is attached to one side of the core substrate, and electronic components (e.g., 1005-size MLCCs or copper pillars with a diameter of 0.65 mm and thickness of 1 mm) are mounted vertically in the through holes using a chip mounter or similar tool. Adjacent electronic components are arranged at 1 mm intervals, and the total area of ​​the through holes is 50% to 90% of the area of ​​the core substrate in the region where the electronic components are arranged. The total area of ​​the first through-holes is also 50% to 90%. Next, the through-holes are filled with a sealant such as ABF (registered trademark: manufactured by Ajinomoto Fine-Techno Co., Inc.), and the temporary fixing material is peeled off. This process results in an electronic component-embedded substrate having a first through-hole filled with resin and a second through-hole connecting a portion of the first through-holes of adjacent electronic components.

[0064] Below, as a specific example of a process for manufacturing an electronic component-embedded substrate of the present invention, a process for manufacturing an electronic component-embedded substrate in which second through hole portions connect the corners of the first through hole portions of multiple adjacent electronic components will be described.

[0065] Through holes are formed in a core substrate (e.g., 1 mm thick) such as a glass epoxy substrate using a laser. The shape of the through holes can be a square, which is the shape assumed when the second through hole portion 25 in FIG. 6 is not present. The shape of the through holes that will become the first through hole portions is a square of 0.75 mm x 0.75 mm. A large number of through holes are formed in a matrix pattern with the spacing between adjacent squares being 0.1 mm.

[0066] A temporary fixing material is attached to one side of the core substrate, and an electronic component (e.g., a 1005-size MLCC or a copper pillar with a diameter of 0.65 mm and thickness of 1 mm) is mounted vertically in the through hole using a chip mounter or the like. When the electronic component is a 1005-size MLCC, the total area of ​​the through holes is set to 50% or more and 90% or less of the area of ​​the core substrate in the region where the electronic component is arranged. Furthermore, the total area of ​​the first through hole portions is set to 50% or more and 90% or less. When the electronic component is a copper pillar with a diameter of 0.65 mm and thickness of 1 mm, the total area of ​​the through holes is set to 50% or more and 90% or less of the area of ​​the core substrate in the region where the electronic component is arranged. Furthermore, the total area of ​​the first through hole portions is set to 50% or more and 90% or less. Next, the through hole is filled with a sealing material such as ABF (registered trademark: manufactured by Ajinomoto Fine-Techno Co., Inc.), and the temporary fixing material is peeled off.

[0067] At positions where the corners of the first through-hole portions of adjacent electronic components are to be connected, through-holes (0.2 mm in diameter) that will become second through-hole portions are formed using a drill or a laser. The size and dimensions of the through-holes that will become second through-hole portions are designed so that the electronic components do not come into contact with the second through-hole portions.

[0068] The through-hole conductors are formed by forming metal posts or applying metal plating to the through-holes that become the second through-hole portions, and this process results in an electronic component-embedded substrate in which the second through-hole portions connect the corners of the first through-hole portions of adjacent electronic components.

[0069] The present specification discloses the following:

[0070] <1> An electronic component-embedded substrate comprising: a core substrate including a first main surface and a second main surface opposite the first main surface, the core substrate having a through hole; and an electronic component provided in the through hole, wherein a plurality of the electronic components are provided in the electronic component-embedded substrate, and in a plan view looking from the first main surface toward the second main surface, the through hole has a shape that is set for each of the electronic components and can accommodate a shape of the electronic component, and has a first through hole portion filled with resin, and a second through hole portion that connects a portion between the first through hole portions of adjacent electronic components.

[0071] <2> The electronic component built-in substrate according to <1>, wherein, in the plan view, an area of ​​one of the second through-hole portions is smaller than an area of ​​one of the first through-hole portions.

[0072] <3> The electronic component-embedded substrate according to <2>, wherein, in the plan view, the area of ​​one of the second through-hole portions is 2% to 40% of the area of ​​one of the first through-hole portions.

[0073] <4> The electronic component-embedded substrate according to any one of <1> to <3>, wherein a conductor portion extending from the first main surface toward the second main surface is provided in the second through-hole portion.

[0074] <5> The electronic component-embedded substrate according to any one of <1> to <4>, wherein, in the plan view, the electronic component has a circular shape, an area of ​​the circle of the electronic component is 50% or more of an area of ​​the first through hole portion, and the second through hole portion connects corners of the first through hole portions of adjacent electronic components.

[0075] <6> The electronic component-embedded substrate according to any one of <1> to <5>, wherein, in the plan view, there is a location between the first through hole portions of adjacent electronic components where the second through hole portion is not present and only the core substrate is present.

[0076] <7> The electronic component-embedded substrate according to any one of <1> to <6>, wherein, in the plan view, a total area of ​​the through holes is 90% or less of an area of ​​the core substrate in a region where the electronic components are arranged on the core substrate.

[0077] <8> The electronic component-embedded substrate according to any one of <1> to <7>, wherein, in the plan view, a total area of ​​the first through hole portions is 50% or more of an area of ​​the core substrate in a region where the electronic components are arranged on the core substrate.

[0078] <9> The electronic component-embedded substrate according to any one of <1> to <8>, wherein the coefficient of linear expansion of the electronic component and the coefficient of linear expansion of the resin are both greater than the coefficient of linear expansion of the core substrate.

[0079] <10> The electronic component-embedded substrate according to <9>, wherein the linear expansion coefficient of the electronic component and the linear expansion coefficient of the resin are both 1.2 times or more the linear expansion coefficient of the core substrate.

[0080] <11> The electronic component-embedded substrate according to any one of <1> to <10>, wherein the electronic component includes a metal post.

[0081] <12> The electronic component-embedded substrate according to any one of <1> to <11>, wherein the electronic component includes a passive component.

[0082] <13> The electronic component-embedded substrate according to any one of <1> to <12>, wherein the electronic component has a rectangular prism shape or a cylindrical shape.

[0083] REFERENCE SIGNS LIST 10 Core substrate 11 First main surface 12 Second main surface 20 Through hole 21, 21a, 21b, 21c, 21d First through hole portion 22, 22a, 22b, 22c, 25 Second through hole portion 30 Sealant (resin) 40, 45 Electronic component 41 First electrode 42 Second electrode 51 First via conductor 52 Second via conductor 61 First buildup layer (rewiring layer) 62 First buildup layer (rewiring layer) 100 Electronic component embedded substrate

Claims

1. An electronic component-embedded substrate comprising: a core substrate having a first main surface and a second main surface opposite the first main surface, the core substrate having a through hole; and an electronic component disposed in the through hole, wherein a plurality of electronic components are disposed in the electronic component-embedded substrate, and in a plan view looking from the first main surface toward the second main surface, the through hole has a shape set for each of the electronic components that can accommodate the shape of each electronic component, and has a first through hole portion filled with resin, and a second through hole portion connecting a portion between the first through hole portions of adjacent electronic components.

2. The electronic component built-in substrate according to claim 1, wherein, in the plan view, the area of ​​one of the second through-hole portions is smaller than the area of ​​one of the first through-hole portions.

3. The electronic component-embedded substrate according to claim 2, wherein, in the plan view, the area of ​​one of the second through-hole portions is 2% or more and 40% or less of the area of ​​one of the first through-hole portions.

4. An electronic component-embedded substrate according to any one of claims 1 to 3, wherein a conductor portion extending from the first main surface toward the second main surface is provided in the second through-hole portion.

5. The electronic component built-in substrate according to any one of claims 1 to 4, wherein, in the plan view, the electronic component has a circular shape, the circular area of ​​the electronic component is 50% or more of the area of ​​the first through-hole portion, and the second through-hole portion connects corners of the first through-hole portions of adjacent electronic components.

6. An electronic component-embedded substrate according to any one of claims 1 to 5, wherein, in the plan view, there is a location between the first through hole portions of adjacent electronic components where the second through hole portion is not present and only the core substrate is present.

7. An electronic component-embedded substrate according to any one of claims 1 to 6, wherein, in the plan view, the total area of ​​the through holes is 90% or less of the area of ​​the core substrate in the region where the electronic components are arranged on the core substrate.

8. An electronic component-embedded substrate according to any one of claims 1 to 7, wherein, in the plan view, the total area of ​​the first through hole portions is 50% or more of the area of ​​the core substrate in the region where the electronic components are arranged on the core substrate.

9. The electronic component-embedded substrate according to any one of claims 1 to 8, wherein the linear expansion coefficient of the electronic component and the linear expansion coefficient of the resin are both greater than the linear expansion coefficient of the core substrate.

10. The electronic component built-in substrate according to claim 9, wherein the linear expansion coefficient of the electronic component and the linear expansion coefficient of the resin are both 1.2 times or more the linear expansion coefficient of the core substrate.

11. The substrate with built-in electronic components according to any one of claims 1 to 10, wherein the electronic components include metal posts.

12. The substrate with built-in electronic components according to any one of claims 1 to 11, wherein the electronic components include passive components.

13. The electronic component-embedded substrate according to any one of claims 1 to 12, wherein the electronic component has a square pillar or cylindrical shape.

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