Component-embedded substrate and method of manufacturing component-embedded substrate

Abstract

To improve quality of a component-embedded substrate.SOLUTION: A component-embedded substrate 100 of the embodiment includes: a first insulating layer 21 having a first surface 210; a second insulating layer 23 stacked on the first surface 210 side of the first insulating layer 21; a recess 8 penetrating the second insulating layer 23; a component 5 accommodated in the recess 8; and a third insulating layer 24 stacked on the second insulating layer 23. The recess 8 is filled with constituent material of the third insulation layer 24. An upper surface 5a of the component 5 on a side opposite to the first insulating layer 21 side is located on the side opposite to the first insulating layer 21 side with respect to an upper surface 23a of the second insulating layer 23 on a side opposite to the first insulating layer 21 side.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a component-embedded substrate and a method for manufacturing a component-embedded substrate. [Background technology]

[0002] Patent Document 1 discloses a component-embedded wiring board that has an electronic component built in. The electronic component is accommodated in a recess that penetrates a first resin insulating layer. The recess that accommodates the electronic component is filled with the material of a third resin insulating layer that is laminated above the first resin insulating layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-131743 Summary of the Invention [Problem to be solved by the invention]

[0004] In the component-embedded wiring board disclosed in Patent Document 1, the amount of resin supplied may be limited so that the resin insulating layer on the electronic component fits within the required dimensions. As a result, the recesses may not be filled sufficiently, resulting in, for example, voids. If voids exist in the recesses, migration may occur in the voids, which may cause problems such as short circuits between electrodes or connection pads of the electronic component. [Means for solving the problem]

[0005] The component-embedded substrate of the present invention includes a first insulating layer having a first surface, a second insulating layer laminated on the first surface side of the first insulating layer, a recess penetrating the second insulating layer, and a component accommodated in the recess. and a third insulating layer laminated on the second insulating layer, the recess is filled with a constituent material of the third insulating layer, and the surface of the component opposite to the first insulating layer is located on the opposite side to the first insulating layer with respect to the surface of the second insulating layer opposite to the first insulating layer.

[0006] A method for manufacturing a component-embedded substrate of the present invention includes: preparing a first insulating layer having a conductor pad on its surface; forming a second insulating layer on the surface side of the first insulating layer; removing a portion of the second insulating layer to form a recess exposing the conductor pad on its bottom surface; placing a component on the conductor pad exposed in the recess; and forming a third insulating layer on the second insulating layer to fill the recess with a constituent material of the third insulating layer. The second insulating layer is formed so that the surface of the second insulating layer opposite to the first insulating layer is located closer to the first insulating layer than the surface of the component mounted on the conductor pad opposite to the conductor pad.

[0007] According to an embodiment of the present invention, in a component-embedded substrate, it is possible to prevent insufficient filling of the recesses in which the components are housed while limiting an increase in the thickness of the insulating layer that covers the embedded components, and it may be possible to prevent defects such as short circuits. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing an example of a component-embedded substrate according to a first embodiment of the present invention. [Figure 2] Enlarged view of part II in Figure 1. [Figure 3A] 2 is a cross-sectional view showing a part corresponding to part II in FIG. 1 in a first modified example of the component-embedded substrate in FIG. 1; [Figure 3B] 1. FIG. 4 is a cross-sectional view showing a part corresponding to part II in FIG. 1 in a second modified example of the component-embedded substrate in FIG. [Figure 4A] 5A to 5C are cross-sectional views showing an example of a method for manufacturing a component-embedded substrate according to an embodiment of the present invention. [Figure 4B]5A to 5C are cross-sectional views showing an example of a method for manufacturing a component-embedded substrate according to an embodiment of the present invention. [Figure 4C] 5A to 5C are cross-sectional views showing an example of a method for manufacturing a component-embedded substrate according to an embodiment of the present invention. [Figure 4D] 5A to 5C are cross-sectional views showing an example of a method for manufacturing a component-embedded substrate according to an embodiment of the present invention. [Figure 4E] 5A to 5C are cross-sectional views showing an example of a method for manufacturing a component-embedded substrate according to an embodiment of the present invention. [Figure 4F] 5A to 5C are cross-sectional views showing an example of a method for manufacturing a component-embedded substrate according to an embodiment of the present invention. [Figure 5A] FIG. 6 is a cross-sectional view showing an example of a component-embedded substrate according to a second embodiment of the present invention. [Figure 5B] FIG. 10 is a cross-sectional view showing an example of a component-embedded substrate according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Component-embedded substrate according to one embodiment> A component-embedded substrate according to one embodiment (first embodiment) of the present invention will be described with reference to the drawings. FIG. 1 shows a cross-sectional view of a component-embedded substrate 100, which is an example of the component-embedded substrate of this embodiment, and FIG. 2 shows an enlarged view of part II in FIG. 1 . Note that the component-embedded substrate 100 shown in FIGS. 1 and 2 is merely an example of the component-embedded substrate of the embodiment. The layered structure of the component-embedded substrate of the embodiment is not limited to the layered structure of the component-embedded substrate 100, and the number of conductor layers and insulating layers of the component-embedded substrate of the embodiment is not limited to the number of conductor layers and insulating layers included in the component-embedded substrate 100. That is, the component-embedded substrate of the embodiment may include any number of insulating layers and conductor layers in addition to the insulating layers and conductor layers included in the component-embedded substrate 100, and may not include all of the insulating layers and conductor layers included in the component-embedded substrate 100. Note that in the drawings referred to in the following description, certain portions may be drawn enlarged to facilitate understanding of the disclosed embodiments. Therefore, the components may not be drawn to exact proportions relative to one another in terms of size or length.

[0010] 1, the component-embedded substrate 100 includes a core substrate 3 and insulating layers and conductor layers alternately stacked on each of two main surfaces (surfaces 3a and 3b) of the core substrate 3 that face each other in the thickness direction. The core substrate 3 includes an insulating layer 32 and conductor layers 31 formed on each of the two surfaces of the insulating layer 32. The core substrate 3 further includes a cylindrical through-hole conductor 33 that penetrates the insulating layer 32 and connects the conductor layers 31 on both surfaces of the insulating layer 32. The hollow portion of the cylindrical through-hole conductor 33 is filled with a filler 33a made of, for example, epoxy resin.

[0011] In the description of the embodiments, the side of the component-embedded substrate 100 farther from the insulating layer 32 in the thickness direction is also referred to as the "upper side" or "outside," "upper," or simply "upper," and the side closer to the insulating layer 32 is also referred to as the "lower side" or "inside," "lower," or simply "lower." Furthermore, in each conductor layer and each insulating layer, the surface facing away from the insulating layer 32 is also referred to as the "upper surface," and the surface facing the insulating layer 32 is also referred to as the "lower surface."

[0012] Two insulating layers 20 and two conductor layers 10 are laminated on the surface 3a of the core substrate 3. Specifically, two pairs of insulating layers 20 and conductor layers 10 are alternately laminated in this order from the surface 3a side. Then, on these two pairs of insulating layers 20 and conductor layers 10, insulating layer 21, conductor layer 11, insulating layer 22, conductor layer 12, insulating layer 23, and insulating layer 24 are laminated in this order. That is, the component-embedded substrate 100 includes insulating layer 21 (first insulating layer), conductor layer 11 (first conductor layer), insulating layer 22 (fourth insulating layer), conductor layer 12, insulating layer 23 (second insulating layer), and insulating layer 24 (third insulating layer). The component-embedded substrate 100 of FIG. 1 further includes a conductor layer 13 formed on the insulating layer 24.

[0013] The insulating layer 21 has a first surface 210, which is the surface opposite to the core substrate 3. The conductor layer 11 is formed on the first surface 210 of the insulating layer 21. The insulating layer 22 is stacked on the first surface 210 of the insulating layer 21 and the conductor layer 11. The insulating layer 23 is stacked on the first surface 210 side of the insulating layer 21. Specifically, the insulating layer 23 is stacked on the insulating layer 22 and the conductor layer 12, and is interposed between the insulating layer 22 and the conductor layer 12 and the insulating layer 24. The conductor layer 12 and the insulating layer 22 are covered by the insulating layer 23. The conductor layer 12 is a lower conductor layer relative to the conductor layer 13, and the conductor layer 13 is an upper conductor layer relative to the conductor layer 12. The conductor layer 12 is protected by the insulating layer 23 from various external stresses during the manufacture of the component-embedded substrate 100. The insulating layer 23 also serves as a protective layer for the conductor layer 12.

[0014] On the other hand, four insulating layers 20 and four conductor layers 10 are laminated on the surface 3b side of the core substrate 3. The insulating layers 20 and the conductor layers 10 are laminated alternately from the top of the surface 3b. On these four sets of insulating layers 20 and conductor layers 10, insulating layers 25 and 26 are further laminated, and conductor layers 14 are formed on the insulating layers 26.

[0015] The component-embedded substrate 100 further includes a recess 8 penetrating the insulating layer 22 and the insulating layer 23, a component 5 accommodated in the recess 8, and a component mounting pad 111. The recess 8 is formed by a through-hole penetrating the insulating layer 22 and the insulating layer 23. The component mounting pad 111 is formed on the first surface 210 of the insulating layer 21. The component mounting pad 111 is a conductive pad included in the conductive layer 11. The component mounting pad 111 may be a solid conductive pattern that fills a predetermined area defined for the component mounting pad 111. The recess 8 exposes most of the central area of ​​the component mounting pad 111 from the insulating layer 22 and the insulating layer 23. Meanwhile, the peripheral edge of the component mounting pad 111 is covered with the insulating layer 22.

[0016] The component 5 is placed on a component mounting pad 111 exposed inside the recess 8. The recess 8 and the conductor pad constituting the component mounting pad 111 form a component accommodating portion (cavity) for accommodating the component, and the component 5 is accommodated therein. In the example of the component-embedded substrate 100 shown in FIG. 1, the recess 8 penetrates the insulating layer 22 and the insulating layer 23 all at once. Therefore, the component 5 is covered by the insulating layer 24, not by the insulating layer 23. The recess 8 accommodating the component 5 is filled with the constituent material of the insulating layer 24. The component 5 is sealed in the recess 8 by the insulating layer 24. Therefore, the insulating layer 24 also functions as a sealing layer. The insulating layer 24 is stacked directly on the insulating layer 23 without a conductor layer therebetween. The insulating layer 24 directly covers the entire surface 23a of the insulating layer 23 opposite the insulating layer 21 side. Therefore, it is considered that the insulating layer 24 and the insulating layer 23 are firmly adhered to each other.

[0017] Examples of the component 5 include electronic components such as active components such as semiconductor integrated circuit devices and transistors, and passive components such as electrical resistors. The component 5 may also be a wiring material (e.g., an interposer) including fine wiring formed on a semiconductor substrate. When the component 5 is a semiconductor component, the component 5 may be sealed (packaged) with resin or metal, or may be in the form of an unsealed bare chip. The component 5 mounted in the form of a bare chip may be mounted face-up or face-down.

[0018] The component-embedded substrate 100 of FIG. 1 further includes a via conductor 41 (first via conductor) and a via conductor 42 (second via conductor). The via conductor 41 penetrates the insulating layer 24 and connects to an electrode 51 (see FIG. 2) of the component 5. The via conductor 41 connects the electrode 51 of the component 5 to the conductor layer 13. Meanwhile, the via conductor 42 penetrates the insulating layer 23 and the insulating layer 24 continuously and connects the conductor layer 12 and the conductor layer 13. The via conductor 41, the via conductor 42, and the conductor layer 13 are integrally formed. In each of the insulating layers 20 to 22, a via conductor 40 is formed, which penetrates the insulating layer and connects adjacent conductor layers via the insulating layer. In the insulating layer 25 and the insulating layer 26, a via conductor 43 is formed, which penetrates the insulating layer 25 and the insulating layer 26 continuously and connects the conductor layer 10 and the conductor layer 14.

[0019] 1 further includes a solder resist 7. The solder resist 7 is formed on the surface of the component-embedded substrate 100 on both the surface 3a side and the surface 3b side of the core substrate 3. The solder resist 7 includes openings that expose a portion of the conductor layer 13 or the conductor layer 14. The solder resist 7 is formed using any insulating material, such as an epoxy resin or a polyimide resin.

[0020] Each of the insulating layers 20, 21 to 26, and 32 is mainly formed of an arbitrary insulating resin. Examples of insulating resins used to form each insulating layer include thermosetting resins such as epoxy resin, bismaleimide triazine resin (BT resin), and phenolic resin, as well as thermoplastic resins such as fluororesin, liquid crystal polymer (LCP), fluoroethylene (PTFE) resin, polyester (PE) resin, and modified polyimide (MPI) resin. Note that the resins listed as materials for each insulating layer are merely examples of materials that can form each insulating layer. Each insulating layer can be formed of any material that can provide insulation between conductor layers in the component-embedded substrate 100.

[0021] 1, insulating layer 32 includes a core material (reinforcing material) 32a made of, for example, glass fiber or aramid fiber. Although not shown in FIG. 1, each insulating layer other than insulating layer 32 may include a core material made of, for example, glass fiber. Insulating layers 20 to 26 and insulating layer 32 may further include a filler made of, for example, silicon oxide, alumina, or mullite.

[0022] Each of the conductor layers 10, 11-14, and 31, as well as the through-hole conductor 33 and via conductors 40-43, is formed using any metal such as copper or nickel. While each conductor layer is depicted in FIG. 1 as being composed of a single layer, each conductor layer may have a multi-layer structure. For example, the conductor layer 31 may have a three-layer or five-layer structure including a metal foil, an electroless plated film or a sputtered film, and an electrolytic plated film. Meanwhile, the conductor layers 10-14 and the via conductors 40-43 may each have a two-layer structure including an electroless plated film or a sputtered film, and an electrolytic plated film.

[0023] The conductor layers 10 to 14 and the conductor layer 31 each include an arbitrary conductor pattern. As described above, the conductor layer 11 includes the component mounting pad 111. In the component-embedded substrate 100 of FIG. 1, the conductor layer 13 includes connection pads 131 and 132 used for connection to an external circuit. The connection pads 131 and 132 are partially exposed from openings in the solder resist 7.

[0024] 2, in the component-embedded substrate 100, the component 5 is disposed on the component mounting surface 111a of the component mounting pad 111 via a bonding material 6. The bonding material 6 is made of any material, such as a metal such as solder or gold, a conductive adhesive, or an insulating adhesive made of epoxy resin or the like. In other words, the component 5 is bonded to the component mounting pad 111 using the bonding material 6.

[0025] As shown in FIG. 2 , in the component-embedded substrate 100 of the embodiment, the surface 5a of the component 5 opposite the insulating layer 21 side is located on the opposite side (upper side) of the insulating layer 23 opposite the insulating layer 21 side. That is, the height from the first surface 210 of the insulating layer 21 to the surface (upper surface) 5a of the component 5 is greater than the height from the first surface 210 of the insulating layer 21 to the surface (upper surface) 23a of the insulating layer 23. The distance from the first surface 210 of the insulating layer 21 to the surface 5a of the component 5 is greater than the distance from the first surface 210 of the insulating layer 21 to the surface 23a of the insulating layer 23. The surface 5a of the component 5 is farther from the first surface 210 of the insulating layer 21 than the surface 23a of the insulating layer 23. In other words, the depth of the recess 8 is smaller than the height (thickness T5) of the component 5. Therefore, the surface 5a of the component 5 protrudes toward the opposite side of the insulating layer 21 than the surface 23a of the insulating layer 23. As a result, the thickness T24 of the insulating layer 24 on the insulating layer 23 is greater than the thickness T24a of the insulating layer 24 on the component 5.

[0026] In this way, in the component-embedded substrate of the embodiment in which the upper surface of the built-in component protrudes above the upper surface of the insulating layer surrounding the component accommodating portion, it is presumed that the component accommodating portion is easily filled sufficiently, and therefore voids are less likely to occur within the component accommodating portion. In addition, it is presumed that, when a sufficiently large amount of filler material (e.g., resin) is supplied to provide such desirable filling of the component accommodating portion, an insulating layer of an appropriate thickness, not an excessively thick one, can be provided on the built-in component and on the insulating layer surrounding the component accommodating portion.

[0027] That is, in a component-embedded substrate in which an internal component is housed in a component housing portion formed by a recess, if the top surface of the internal component and the top surface of the insulating layer surrounding the opening of the recess are substantially flush with each other, a sufficient gap may not be secured between the outer edge of the top surface of the internal component and the inner edge of the opening of the recess, which may make it difficult for the resin or the like filling the component housing portion to penetrate into the recess.

[0028] In contrast, in the component-embedded substrate 100 of the embodiment, as shown in FIG. 2 , a step D is formed between the surface 5 a of the component 5 and the surface 23 a of the insulating layer 23 in the depth direction of the recess 8 because the surface 5 a of the component 5 protrudes higher than the surface 23 a of the insulating layer 23. The gap between the outer edge of the surface 5 a of the component 5 and the inner edge of the opening of the recess 8 widens by a length corresponding to this step D. This allows the material of the insulating layer 24 to easily penetrate into the recess 8, making it easy to sufficiently fill the interior of the recess 8. Therefore, it is believed that voids and other cavities are unlikely to occur within the recess 8. Furthermore, because the depth of the recess 8 is small relative to the thickness T5 of the component 5, the material of the insulating layer 24 easily reaches the bottom of the recess 8 (the component mounting pad 111). This also contributes to the low occurrence of voids and other cavities within the recess 8.

[0029] In the component-embedded substrate 100, the gap G between the inner wall of the recess 8, i.e., the inner wall of the insulating layer 22 and the insulating layer 23 exposed in the recess 8, and the side surface of the component 5 is, for example, 50 μm or more and 90 μm or less. A gap G of this size in the recess 8 is considered preferable for preventing voids and other cavities because the interior of the recess 8 is easily filled. Furthermore, because the recess 8 is not excessively large relative to the component 5, it is considered unlikely to hinder miniaturization of the component-embedded substrate 100. Note that, if the recess 8 has a tapered shape in which the width decreases toward the insulating layer 21 side, as shown in FIG. 2, the gap G varies in the depth direction of the recess 8. In this case, it is preferable that the gap G is 50 μm or more and 90 μm or less throughout the entire depth direction of the recess 8. However, the gap G may be 50 μm or more and 90 μm or less in a portion of the depth direction of the recess 8 (e.g., at the surface 23a of the insulating layer 23).

[0030] From the viewpoint of efficiency in manufacturing a component-embedded substrate, it is considered preferable to fill recesses 8 with the constituent material of insulating layer 24 that covers components 5, as in component-embedded substrate 100 of FIG. 1. An insulating layer such as insulating layer 24 can be easily and efficiently formed by laminating a film- or sheet-shaped resin (hereinafter also collectively referred to as a "resin film") on components 5 and insulating layer 23 and thermocompressing it. On the other hand, in order to sufficiently fill recesses 8, it is preferable to supply a sufficient amount of filler material such as resin, as described above, and in order to supply a large amount of filler material to recesses 8, it is preferable to use a thick resin film.

[0031] If the surface 5a of the component 5 is flush with the surface 23 of the insulating layer 23 or is located closer to the insulating layer 21 than the surface 23a, a thick insulating layer 24 based on a resin film thickness that is suitable for sufficiently filling the recesses 8 may be formed on the insulating layer 23. This may prevent the desired thickness of the component-embedded substrate from being achieved. In addition, a thick insulating layer 24 that is disadvantageous for forming small-diameter via conductors 41 may also be formed on the component 5.

[0032] However, in the component-embedded substrate 100 of the embodiment, the surface 5 a of the component 5 protrudes above the surface 23 a of the insulating layer 23, which may facilitate the provision of an insulating layer 24 of a desired thickness on the component 5 and the insulating layer 23. That is, among the constituent materials of the resin film laminated on the component 5 and the insulating layer 23, the constituent material on the component 5 presumably flows down not only into the recess 8 but also onto the surface 23 a of the insulating layer 23 located below the surface 5 a of the component 5 (closer to the insulating layer 21) when softened during thermocompression bonding. Therefore, an insulating layer 24 having an appropriate thickness that is clearly thinner than the thickness of the resin film laminated before thermocompression bonding is readily formed on the component 5. Providing an insulating layer 24 of an appropriate thickness on the surface 5 a of the component 5 may facilitate the formation of small-diameter via conductors 41 with a relatively small aspect ratio on the component 5. Furthermore, a component-embedded substrate 100 may be obtained in which the thickness falls within a predetermined range and the insulating layer 24 protects the component 5 from external stress.

[0033] Furthermore, surface 23a of insulating layer 23, into which the constituent material of the softened resin film flows from surface 5a of component 5, is located below surface 5a of component 5. Therefore, even if insulating layer 24 is formed thicker on surface 23a of insulating layer 23 than on surface 5a, it is unlikely to increase the thickness of component-embedded substrate 100, and it is unlikely to hinder the thinning of component-embedded substrate 100.

[0034] As described above, with the component-embedded substrate of the embodiment, it is presumed that not only is the component accommodating portion sufficiently filled, but also an insulating layer of an appropriate thickness can be provided on the built-in components and on the insulating layer surrounding the component accommodating portion. Therefore, with the component-embedded substrate of the embodiment, it is possible to prevent insufficient filling of the recess in which the component is accommodated while limiting an increase in the thickness of the insulating layer that covers the built-in components, and it is thought that this can prevent defects such as short circuits.

[0035] 2, in the component-embedded substrate 100, the height H from the component mounting surface 111a of the component mounting pad 111 to the surface 23a of the insulating layer 23 is smaller than the total thickness H5 of the thickness T5 of the component 5 and the thickness of the bonding material 6. In other words, the depth of the recess 8 is smaller than the total thickness H5 of the thickness T5 of the component 5 and the thickness of the bonding material 6. An example of the total thickness H5 of the thickness of the component 5 and the thickness of the bonding material 6 (the height H5 from the component mounting surface 111a to the surface 5a of the component 5) is approximately 60 μm. Meanwhile, an example of the height H from the component mounting surface 111a to the surface 23a of the insulating layer 23 is approximately 57.5 μm.

[0036] The step D in the depth direction of the recess 8 between the surface 5a of the component 5 and the surface 23a of the insulating layer 23 is, for example, about 1 μm or more and 4 μm or less. If a step of this magnitude is provided, it is possible to provide a sufficient amount of filling material to fill the recess 8, without significantly increasing the thickness of the component-embedded substrate 100 on each of the component 5 and the insulating layer 23, and to obtain an insulating layer 24 thick enough to adequately protect the component 5.

[0037] In the component-embedded substrate 100 of the embodiment, the insulating layers 22 to 24 may each have any thickness. An example of the thickness T22 of the insulating layer 22 is approximately 47.5 μm. An example of the thickness T23 of the insulating layer 23 is approximately 10 μm. An example of the thickness T24 of the insulating layer 24 on the insulating layer 23 is approximately 15 μm. The thickness T23 of the insulating layer 23 is the distance between the interface between the insulating layer 23 and the insulating layer 24 and the upper surface of the conductor layer 12. The thickness T22 of the insulating layer 22 is the distance between the interface between the insulating layer 22 and the insulating layer 23 and the upper surface of the conductor layer 11.

[0038] Furthermore, the ratio of the thickness T23 of the insulating layer 23 to the total thickness T234 of the thickness T23 of the insulating layer 23 and the thickness T24 of the insulating layer 24 on the insulating layer 23 may be, for example, 0.35 or more and 0.5 or less. When the ratio of the thickness T23 to the thickness T234 is within this range, an appropriate amount of the constituent material of the insulating layer 24 that flows down from the surface 5a of the component 5 during the formation of the insulating layer 24 can be received on the insulating layer 23, which may prevent a significant increase in the thickness of the entire component-embedded substrate 100 and the thickness of the insulating layer 24 on the component 5. It is also believed that the conductor layer 12 is appropriately protected by the insulating layer 23.

[0039] 1 and 2, in the example of the component-embedded substrate 100 shown in FIG. 2, the thickness T23 of the insulating layer 23 is smaller than the thickness T22 of the insulating layer 22 and is also smaller than the thickness T24 of the insulating layer 24 on the insulating layer 23. As described above, it is believed that an increase in the thickness of the insulating layer 24 on the component 5 and in the overall thickness of the component-embedded substrate 100 is suppressed, and the conductor layer 12 is appropriately protected. Furthermore, because the thickness T23 of the insulating layer 23 is smaller than the thickness T22 of the insulating layer 22, it may be possible to easily position the surface 23a of the insulating layer 23 closer to the insulating layer 21 than the surface 5a of the component 5 while ensuring a sufficient withstand voltage between the conductor layers 11 and 12.

[0040] Meanwhile, the thickness T24a of the insulating layer 24 on the surface 5a of the component 5 may be, for example, 6.5 μm or more and 18.5 μm or less. As mentioned above, the insulating layer 24 protects the component 5 from external stress and may easily form small-diameter via conductors 41. For example, the width of the via conductor 41 at the interface with the electrode 51 may be 10 μm or more and 25 μm or less. A component 5 having electrodes 51 arranged at a fine pitch can be embedded in the component-embedded substrate 100. The "width" of the via conductor 41 is the maximum distance between any two points on the periphery of the via conductor 41 in a cross section perpendicular to the axial direction.

[0041] <Modification of component-embedded substrate> Fig. 3A shows a cross-sectional view of a component-embedded substrate 100a1, which is a first modified example of the component-embedded substrate 100 of Fig. 1, and Fig. 3B shows a cross-sectional view of a component-embedded substrate 100a2, which is a second modified example. Figs. 3A and 3B show enlarged views of regions of the component-embedded substrates 100a1 and 100a2, respectively, which correspond to part II in Fig. 1. In both the component-embedded substrate 100a1 and the component-embedded substrate 100a2, the surface 5a of the component 5 is located on the opposite side to the insulating layer 21 with respect to the surface 23a of the insulating layer 23.

[0042] In the component-embedded substrate 100a1 of FIG. 3A, the thickness T23 of the insulating layer 23 is greater than the thickness T22 of the insulating layer 22 and greater than the thickness T24 of the insulating layer 24 on the insulating layer 23. Compared to the component-embedded substrate 100 of FIG. 1, the magnitude relationship between the thicknesses T22 and T23 is reversed, which may make it easier to position the surface 23a of the insulating layer 23 closer to the insulating layer 21 than the surface 5a of the component 5 while ensuring a higher withstand voltage between the conductor layer 12 and the conductor layer 13. Also, compared to the component-embedded substrate 100 of FIG. 1, the magnitude relationship between the thicknesses T23 and T24 is reversed, which may make it possible to obtain a component-embedded substrate having a desired thickness while reliably protecting the conductor layer 12 with the thick insulating layer 23. In the component-embedded substrate of the embodiment, as in the component-embedded substrate 100a1, the insulating layer 23 that surrounds the recess 8 together with the insulating layer 22 may be thicker than the insulating layer 22. Furthermore, the insulating layer 23 whose surface 23a is entirely covered with the insulating layer 24 filling the recess 8 may be thicker than the insulating layer 24 on the insulating layer 23.

[0043] 3B differs from the component-embedded substrate 100 of FIG. 1 in that the only insulating layer interposed between the insulating layer 21 and the insulating layer 24 is the insulating layer 23 (second insulating layer). That is, in the component-embedded substrate 100a2, only one insulating layer (insulating layer 23) is stacked between the insulating layer 21 and the insulating layer 24. That is, the recess 8 penetrates only the insulating layer 23. Therefore, the inner wall exposed to the recess 8 is composed only of the insulating layer 23. Meanwhile, the conductor layer 12 is formed on the surface 23a of the insulating layer 23 opposite to the insulating layer 21 side. Therefore, the insulating layer 24 covers not only the insulating layer 23 but also the conductor layer 12. Furthermore, the via conductor 42 penetrates only the insulating layer 24 to connect the conductor layer 12 and the conductor layer 13. The component-embedded substrate of the embodiment may include a recess surrounded by the wall surface of a single insulating layer as a component accommodating portion, as in the component-embedded substrate 100a2 of FIG. 3B. Since the number of laminated insulating layers is small, the wiring board of the embodiment may be easily manufactured.

[0044] <Manufacturing method for component-embedded substrates> Next, a method for manufacturing a component-embedded substrate according to an embodiment will be described with reference to FIGS. 4A to 4F, using the component-embedded substrate 100 of FIG. 1 as an example.

[0045] As shown in FIG. 4A, the manufacturing method of the component-embedded substrate of the embodiment includes preparing an insulating layer 21 (first insulating layer) having conductor pads 11a on its surface (first surface 210). The conductor pads 11a form component-mounting pads 111 (see FIG. 1) in the completed component-embedded substrate 100. When manufacturing the component-embedded substrate 100 of FIG. 1, a core substrate 3 is first formed. For example, a starting substrate (e.g., a double-sided copper-clad laminate) is prepared, which includes an insulating layer that will become the insulating layer 32 of the core substrate 3 and metal foils laminated on both surfaces of the insulating layer. Through-hole conductors 33 are formed by forming through-holes and panel plating. The hollow portions of the cylindrical through-hole conductors 33 are filled with a filler 33a containing, for example, epoxy resin. Furthermore, panel plating is performed using, for example, electroless plating and electrolytic plating. Then, a conductor layer 31 having a desired conductor pattern is formed by patterning using a subtractive method. A core substrate 3 is obtained, which includes the insulating layer 32 and the conductor layers 31 on both surfaces of the insulating layer 32.

[0046] Insulating layers 20 and conductor layers 10 are alternately formed on surfaces 3a and 3b of the core substrate 3. After two pairs of insulating layers 20 and conductor layers 10 are formed on surfaces 3a and 3b, respectively, an insulating layer 21 is formed on the surface 3a side. Another insulating layer 20 is also formed on the surface 3b side. To form each insulating layer 20 and insulating layer 21, for example, a film-like or sheet-like epoxy resin is laminated on the core substrate 3 or on the previously formed insulating layer 20 and conductor layer 10 and thermocompression bonded. As a result, the insulating layer 21 or each insulating layer 20 is formed.

[0047] Through holes for forming via conductors 40 are formed in each of insulating layers 20 and 21 by, for example, irradiation with carbon dioxide laser light. After the through holes are formed, a desmearing process is performed as necessary to remove resin residue (smear) generated by the formation of the through holes. For example, the smear inside the through holes is removed by exposing the inner walls of the through holes to a treatment liquid such as an alkaline permanganate solution.

[0048] Each conductor layer 10 is formed by, for example, a semi-additive method. That is, a metal film is formed by electroless plating or sputtering on the entire surface of the insulating layer 20 that serves as the base for each conductor layer 10, and in through holes formed in the insulating layer 20. A plating film is formed by pattern plating, including electrolytic plating, using the metal film as a power supply layer. Via conductors 40 are formed in the through holes formed in each insulating layer 20. Thereafter, unnecessary portions of the metal film are removed by, for example, etching. As a result, each conductor layer 10 including a predetermined conductor pattern is formed. Each conductor layer 10 and via conductors 40 are formed using any metal, such as copper or nickel.

[0049] A conductor layer 11 including conductor pads 11a is formed on the first surface 210 of the insulating layer 21. Via conductors 40 are formed integrally with the conductor layer 11 in the through holes of the insulating layer 21. The conductor pads 11a are formed so as to encompass, in plan view, the opening regions of recesses 8 (see FIG. 4C ) formed in a later process on the first surface 210 of the insulating layer 21. The conductor layer 11 is formed using, for example, a semi-additive method in the same manner as the method for forming the conductor layer 10 described above. A further conductor layer 10 is formed on the outermost insulating layer 20 on the surface 3b side of the core substrate 3 using the same method as the method for forming the conductor layer 11.

[0050] 4B, when the component-embedded substrate 100 of FIG. 1 is manufactured, an insulating layer 22 (fourth insulating layer) is formed. The manufacturing method of the component-embedded substrate of the embodiment may include forming an insulating layer 22 that covers the insulating layer 21 and the conductor pad 11a in this manner. The first surface 210 of the insulating layer 21 is covered with the insulating layer 22. An insulating layer 20 is further formed on the front surface 3b side of the core substrate 3. The insulating layer 22 and the insulating layer 20 further formed on the front surface 3b side are formed, for example, in the same manner as the method for forming the insulating layer 21 described above, by stacking a sheet-like or film-like resin having appropriate insulating properties, such as an epoxy resin, on the insulating layer 21 or the already formed insulating layer 20, and applying heat and pressure.

[0051] 1 is manufactured, the conductor layer 12 is formed on the insulating layer 22, for example, by a method similar to that used to form the conductor layer 11. In the insulating layer 22, the via conductors 40 are formed integrally with the conductor layer 12. Furthermore, on the front surface 3b side of the core substrate 3, the conductor layer 10 is further formed by a method similar to that used to form the conductor layer 11.

[0052] The method for manufacturing a component-embedded substrate according to the embodiment further includes forming an insulating layer 23 (second insulating layer) on the surface 210 side of the insulating layer 21. When the component-embedded substrate 100 of FIG. 1 is manufactured, the insulating layer 23 is formed to cover the insulating layer 22. An insulating layer 25 is formed on the outermost insulating layer 20 and the conductor layer 10 on the surface 3b side of the core substrate 3. When the component-embedded substrate 100a2 of the example of FIG. 3B is manufactured, the insulating layer 23 is formed directly on the surface 210 of the insulating layer 21, rather than on both the insulating layer 22 and the insulating layer 23, and the conductor layer 12 is formed on the surface 23a of the insulating layer 23. The insulating layer 23 and the insulating layer 25 are formed, for example, in the same manner as in the method for forming the insulating layer 21 described above, by laminating a sheet- or film-shaped resin having appropriate insulating properties, such as an epoxy resin, on the insulating layer 22 or the already formed insulating layer 20, and applying heat and pressure.

[0053] In the method for manufacturing a component-embedded substrate according to the embodiment, insulating layer 23 is formed to have a thickness selected so that surface 23a of insulating layer 23 is located closer to insulating layer 21 than surface 5a of component 5 (see FIG. 4C) that will be mounted on conductor pad 11a in a subsequent process. When component-embedded substrate 100 of FIG. 1 is manufactured as in the example of FIG. 4B, insulating layer 22 may be formed to have a thickness selected so that surface 23a of insulating layer 23 is located in this manner. Note that surface 23a of insulating layer 23 is the surface of insulating layer 23 opposite to the insulating layer 21 side. Furthermore, surface 5a of component 5 is the surface of component 5 opposite to the conductor pad 11a side.

[0054] By forming insulating layer 23 or both insulating layers 22 and 23 in this manner, as described above for component-embedded substrate 100 of the embodiment, it is possible to sufficiently fill the recesses in which the components are housed without significantly increasing the thickness of the insulating layer covering the embedded components. It is believed that this makes it possible to manufacture a component-embedded substrate in which defects such as short circuits are suppressed. Note that surface 23a of insulating layer 23 can be positioned closer to insulating layer 21 than surface 5a of component 5 by appropriately selecting the thickness of insulating layer 23 or the thickness of at least one of insulating layers 22 and 23. The thicknesses of insulating layers 22 and 23 can be adjusted, for example, by appropriately selecting the thickness of the sheet-like or film-like resin used to form insulating layers 22 and 23, respectively.

[0055] As shown in Fig. 4C, the manufacturing method of the component-embedded substrate of the embodiment includes forming a recess 8 that exposes the conductor pad 11a at the bottom surface by removing a portion of the insulating layer 23. In the example of Fig. 4C, the recess 8 is also formed by removing a portion of the insulating layer 22. The recess 8 is formed in a predetermined region that includes an area where the component 5 is to be mounted. The recess 8 exposes the center of the conductor pad 11a. By forming the recess 8, a component accommodating portion 80 is provided that penetrates the insulating layer 23 and the insulating layer 22 and whose bottom surface is formed by the conductor pad 11a.

[0056] The recesses 8 are formed by any processing means. For example, the recesses 8 may be formed by laser processing, drilling, or the like. The conductor pad 11a may be used as a stopper for the laser light or drill bit used to form the recesses 8. The conductor pad 11a protects the insulating layer 21 from stress caused by processing the recesses 8. Examples of laser light used to form the recesses 8 include carbon dioxide laser light and YAG laser light, but the laser light used to form the recesses 8 is not limited to these.

[0057] After the recesses 8 are formed, a desmear treatment is performed as needed by exposing the inner walls of the recesses 8 to a treatment liquid such as an alkaline permanganate solution. Furthermore, preferably, the component mounting surfaces 111a of the conductor pads 11a exposed at the bottoms of the recesses 8 are roughened. The component mounting surfaces 111a can be roughened by any method. For example, the exposed surfaces of the conductor layer 11, such as the component mounting surfaces 111a, can be roughened by a surface oxidation treatment known as a blackening treatment or a browning treatment, or a microetching treatment using an acidic solvent. The roughening treatment of the component mounting surface 111a improves the adhesive strength between the bonding material 6 used in a subsequent process and the component mounting surface 111a.

[0058] The method for manufacturing a component-embedded substrate of the embodiment further includes placing a component 5 on the conductor pad 11a exposed in the recess 8. The component 5 is placed in the component accommodating portion 80. The conductor pad 11a functions as the component mounting pad 111 in FIG. 1. According to the method for manufacturing a component-embedded substrate of the embodiment, the surface 23a of the insulating layer 23 is located closer to the insulating layer 21 than the surface 5a of the component 5. In other words, the surface 5a of the component 5 protrudes further than the surface 23a of the insulating layer 23 to the side opposite the insulating layer 21. A step D is generated between the surface 5a of the component 5 and the surface 23a of the insulating layer 23 in the depth direction of the recess 8.

[0059] As described above, the component 5 may be an active component such as a semiconductor integrated circuit device or a transistor, a passive component such as an electrical resistor, or a wiring material including fine wiring formed on a semiconductor substrate. The component 5 may be packaged or in the form of a bare chip. The component 5 mounted in the form of a bare chip may be mounted face-up or face-down.

[0060] In the example of FIG. 4C , the component 5 is bonded to the conductor pad 11a using a bonding material 6. For example, a metal pellet such as solder or copper, or a conductive or insulating paste, is supplied onto the conductor pad 11a as the bonding material 6. Then, the component 5 is placed on the conductor pad 11a via the bonding material 6. Preferably, the component 5 is pressed against the conductor pad 11a under a vacuum to remove any voids that may have been trapped under the component 5 during placement. If necessary, the component 5 is bonded to the conductor pad 11a by a curing process such as heating the bonding material 6. Note that stress or damage that may be incurred by the conductor layer 12 during the period from the formation of the recess 8 to the placement of the component 5 is reduced by the insulating layer 23 covering the conductor layer 12.

[0061] After the component 5 is placed on the conductor pad 11a, the upper surface 5a of the component 5 is preferably roughened by, for example, a surface oxidation treatment such as blackening or browning, or a microetching treatment using an acidic solvent. The roughening treatment of the upper surface 5a of the component 5 improves the adhesive strength between the insulating layer 24 (see FIG. 4E) formed in a later process and the upper surface 5a of the component 5.

[0062] As shown in Figures 4D and 4E, the method for manufacturing a component-embedded substrate according to the embodiment includes forming an insulating layer 24 (third insulating layer) on an insulating layer 23, thereby filling the interior of the recess 8 with the constituent material of the insulating layer 24. An insulating layer 26 is formed on the insulating layer 25 on the front surface 3b side of the core substrate 3. The insulating layers 24 and 26 are formed, for example, by a method similar to the method for forming the insulating layer 21 described above. For example, as shown in Figure 4D, an insulating material 2a formed in a film or sheet shape is laminated on the insulating layer 23 and the component 5. An insulating material 2a is also laminated on the insulating layer 25.

[0063] Then, insulating material 2a is heated and pressurized, and thermocompression-bonded to insulating layer 23 and component 5, or insulating layer 25. As a result, insulating layer 24 and insulating layer 26 are formed. When insulating layer 24 is formed by thermocompression, the constituent material of insulating layer 24, such as epoxy resin, softens due to the heat and pressure and flows into recess 8. Recess 8 is then filled with the constituent material of insulating layer 24. As a result, component 5 is sealed in recess 8 with the constituent material of insulating layer 24, such as epoxy resin. Thus, in the manufacturing method of a component-embedded substrate according to the embodiment, forming insulating layer 24 may include layering insulating material 2a having a predetermined thickness T2a on component 5 and softening it. Because surface 23a of insulating layer 23 is located closer to insulating layer 21 than surface 5a of component 5, creating step D, it is believed that recess 8 is easily filled sufficiently, and insulating layer 24 of a desired thickness is easily formed on component 5 and insulating layer 23.

[0064] The constituent material of the insulating material 2a is selected from resins having appropriate insulating properties, such as thermosetting resins such as epoxy resin or BT resin, and thermoplastic resins such as fluororesin or LCP, which were previously exemplified as materials for the insulating layers 20 to 26 of the component-embedded substrate 100. Furthermore, from the viewpoint of sufficiently filling the recesses 8 and realizing the desired thickness of the insulating layer 24 on the components 5 and the insulating layer 23, the insulating material 2a has a predetermined thickness T2a.

[0065] The predetermined thickness T2a of the insulating material 2a may be, for example, 10% to 25% thicker than the thickness T24a of the insulating layer 24 on the component 5 after the formation of the insulating layer 24. In other words, by using an insulating material 2a having a thickness T2a that is 1.1 to 1.25 times the thickness T24a, it is believed that the recesses 8 are sufficiently filled and the insulating layer 24 of the desired thickness is easily formed on the component 5 and the insulating layer 23.

[0066] Thus, according to the manufacturing method of the component-embedded substrate of the embodiment, it is possible to prevent insufficient filling of the recesses that house the components while limiting an increase in the thickness of the insulating layer that covers the embedded components in the component-embedded substrate, and it may be possible to prevent defects such as short circuits.

[0067] As shown in Fig. 4F, conductor layers 13 and 14 and via conductors 41 to 43 are formed. Connection pads 131 and 132 used for connection to an external circuit are provided on conductor layer 13. In the example of Fig. 4F, conductor layer 13 is connected to conductor layer 12 by via conductor 42 that penetrates insulating layer 24 and insulating layer 23. Conductor layer 14 is connected to conductor layer 10 by via conductor 43 that penetrates insulating layer 26 and insulating layer 25. Then, connection pad 132 is connected to electrode 51 of component 5 (see Fig. 2) by via conductor 41 that penetrates insulating layer 24 on component 5.

[0068] The conductor layers 13 and 14 and the via conductors 42 and 43 can be formed by the same method and using the same materials as the conductor layer 11 and the via conductor 40. In forming the via conductor 41, for example, ultraviolet (UV) laser light is irradiated from the surface of the insulating layer 24 toward the component 5 to form a through hole that exposes an electrode (not shown) of the component 5. The via conductor 41 is formed by filling the through hole with a plating film while forming the conductor layer 13. It is believed that the manufacturing method of the component-embedded substrate according to the embodiment, which can prevent a significant increase in the thickness of the insulating layer 24, makes it easy to form the via conductors 41 arranged at a fine pitch.

[0069] Thereafter, solder resist 7 is formed on conductor layer 13 and insulating layer 24, and solder resist 7 is also formed on conductor layer 14 and insulating layer 26. Openings that expose connection pads 131, 132 are provided in solder resist 7 on conductor layer 13, and appropriate openings are also provided in solder resist 7 on conductor layer 14. Solder resist 7 and its openings are formed by forming a resin layer containing photosensitive epoxy resin or polyimide resin, and then exposing and developing it using a mask with an appropriate opening pattern. By going through the above steps, the component-embedded substrate 100 of the example in FIG. 1 is completed.

[0070] <Other embodiments> 5A and 5B each show a component-embedded substrate of an embodiment different from the first embodiment shown in Fig. 1. Fig. 5A shows a cross-sectional view of a component-embedded substrate 100b of a second embodiment, and Fig. 5B shows a cross-sectional view of a component-embedded substrate 100c of a third embodiment. In both component-embedded substrate 100b and component-embedded substrate 100c, surface 5a of component 5 is located on the opposite side from insulating layer 21 with respect to surface 23a of insulating layer 23.

[0071] The component-embedded substrate 100b shown in FIG. 5A generally differs from the component-embedded substrate 100 of the first embodiment in that it does not include the core substrate 3 of FIG. 1. That is, the component-embedded substrate 100b includes a so-called coreless substrate that does not have a core substrate. Specifically, the component-embedded substrate 100b does not include the insulating layer 32 and the components (conductor layers 31, 10, 14, insulating layers 20, 25, 26, and solder resist 7) ​​formed on the surface 3b of the core substrate 3 that are included in the component-embedded substrate 100 of FIG. 1. The component-embedded substrate 100b is manufactured by forming the conductor layers 10-13, the insulating layers 20-24, the recess 8, the via conductors 40, 41, 42, and the solder resist 7 on a support plate (not shown) generally by the method described with reference to FIGS. 4A to 4F. Like the component-embedded substrate 100b, the component-embedded substrate of the embodiment may be composed of a so-called coreless substrate and an embedded component such as a component 5.

[0072] The component-embedded substrate 100c shown in FIG. 5B differs from the component-embedded substrate 100 of FIG. 1 in that the conductor layer 11 including the component mounting pad 111, together with the insulating layer 21, constitutes the core substrate 3. That is, the component mounting pad 111 is formed on the first surface 210 of the insulating layer 21, which, together with the upper surface 110 of the conductor layer 11, constitutes the front surface 3a of the core substrate 3. The recess 8 penetrates the insulating layer 23 and the insulating layer 22 covering the front surface 3a of the core substrate 3, exposing the component mounting pad 111. The component mounting pad 111 exposed in the recess 8 is included in the conductor layer 11 that constitutes the core substrate 3. The component 5 is disposed on the component mounting pad 111 that constitutes the core substrate 3 as part of the conductor layer 11. The core substrate 3, insulating layers 20, 22-26, and conductor layers 10 and 12-14 that constitute the component-embedded substrate 100c can be generally formed by the methods described with reference to FIGS. 4A-4F. In the component-embedded substrate of the embodiment, such as component-embedded substrate 100c, an embedded component may be mounted on a component mounting pad included in a conductive layer that constitutes a core substrate.

[0073] The component-embedded substrate of the embodiment is not limited to those having the structures illustrated in the drawings and the structures, shapes, and materials illustrated in this specification. As described above, the component-embedded substrate of the embodiment may have any laminated structure. The component-embedded substrate of the embodiment may have any number of conductor layers and insulating layers. A conductor layer such as the conductor layer 11 including the component mounting pad 111 may be a conductor layer of any hierarchical level with three or more insulating layers stacked on the outer layer side. The recess 8 does not need to have a tapered shape as in the example shown in FIG. 1 . Furthermore, the peripheral edge of a conductor pad that forms the bottom surface of the component accommodating portion, such as the component mounting pad 111, does not need to be covered with an insulating layer.

[0074] The manufacturing method of the component-embedded substrate of the embodiment is not limited to the method described with reference to the drawings. For example, the conductor layers 10 to 14 may be formed by a full additive method. The insulating layers 20 to 26 are not limited to film-like resins and may be formed using any type of resin. The manufacturing method of the component-embedded substrate of the embodiment may include any additional steps in addition to the steps described above, or some of the steps described above may be omitted. [Explanation of symbols]

[0075] 100, 100a1, 100a2, 100b, 100c component embedded board 10~14 Conductor layers 111 Component mounting pad 111a Component mounting surface 11a Contact pad 2a insulation material 21 Insulating layer (first insulating layer) 210 Page 1 22 Insulating layer (fourth insulating layer) 23 Insulation layer (second insulation layer) 23a Surface of insulating layer 23 24 Insulation layer (third insulation layer) 3 Core board 41 via conductor (first via conductor) 42 Via conductor (second via conductor) 5 parts 5a Surface of the part 6 Bonding material 8 recess G Gap between the inner wall of the recess and the side of the part H: Height from the component mounting surface to the surface of the insulating layer 23 H5 Total thickness of part and joining material T2a: Predetermined thickness of insulation T5 Part Thickness T22, T23: Thickness of insulating layers 22 and 23 T24: Thickness of insulating layer 24 above insulating layer 23 T24a: Thickness of insulating layer 24 on the component

Claims

1. a first insulating layer having a first surface; a second insulating layer laminated on the first surface side of the first insulating layer; a recess penetrating the second insulating layer; a component housed within the recess; and a third insulating layer laminated on the second insulating layer; A component-embedded substrate comprising: the recess is filled with a constituent material of the third insulating layer, The surface of the component opposite to the first insulating layer side is located on the opposite side to the first insulating layer side with respect to the surface of the second insulating layer opposite to the first insulating layer side.

2. 2. The component-embedded substrate according to claim 1, further comprising a component mounting pad formed on the first surface of the first insulating layer, the component is placed on the component mounting surface of the component mounting pad via a bonding material, The height from the component mounting surface of the component mounting pad to the surface of the second insulating layer is smaller than the total thickness of the component and the bonding material.

3. 2. A component-embedded substrate according to claim 1, wherein the ratio of the thickness of the second insulating layer to the total thickness of the second insulating layer and the thickness of the third insulating layer on the second insulating layer is 0.35 or more and 0.5 or less.

4. 2. The component-embedded substrate according to claim 1, further comprising a fourth insulating layer laminated on the first surface and covered by the second insulating layer, The recess penetrates the second insulating layer and the fourth insulating layer.

5. 5. The component-embedded substrate according to claim 4, The thickness of the second insulating layer is less than the thickness of the fourth insulating layer and less than the thickness of the third insulating layer on the second insulating layer.

6. 2. The component-embedded substrate according to claim 1, further comprising a via conductor that penetrates the third insulating layer and connects to an electrode of the component, The via conductor has a width of 10 μm or more and 25 μm or less at the interface with the electrode.

7. 2. The component-embedded substrate according to claim 1, wherein the third insulating layer directly covers the entire surface of the second insulating layer.

8. 8. The component-embedded substrate according to claim 7, further comprising: a lower conductor layer covered by the second insulating layer; an upper conductor layer formed on the third insulating layer; a via conductor that continuously passes through the second insulating layer and the third insulating layer and connects the lower conductor layer and the upper conductor layer; It is equipped with:

9. 2. The component-embedded substrate according to claim 1, wherein a gap between an inner wall of the recess and a side surface of the component is 50 μm or more and 90 μm or less.

10. providing a first insulating layer having a contact pad thereon; forming a second insulating layer on the surface side of the first insulating layer; removing a portion of the second insulating layer to form a recess exposing the conductive pad at a bottom surface; placing a component on the contact pad exposed in the recess; forming a third insulating layer on the second insulating layer to fill the recess with a constituent material of the third insulating layer; A method for manufacturing a component-embedded substrate, comprising: The second insulating layer is formed so that the surface of the second insulating layer opposite the first insulating layer is positioned closer to the first insulating layer than the surface of the component mounted on the conductor pad opposite the conductor pad.

11. The method for manufacturing a component-embedded substrate according to claim 10, forming the third insulating layer includes laminating an insulating material having a predetermined thickness on the component and softening the insulating material; The predetermined thickness is greater than or equal to 10% and less than or equal to 25% of the thickness of the third insulating layer on the component after the third insulating layer is formed.

Images