Multilayer substrate and manufacturing method of multilayer substrate

Abstract

This invention provides a laminated substrate that ensures long-term reliability by preventing stress on the conductive paste used to electrically connect multiple multilayer substrates during the manufacturing process. [Solution] A laminated substrate 100 is formed by stacking multiple multilayer substrates 10, and each multilayer substrate 10 has a through-hole 30 that penetrates the multilayer substrate 10, has its inner wall surface plated and is filled with resin 32, and bonding lands 34 that are electrically connected to the through-hole 30 are formed on the upper and lower surfaces of the through-hole 30, and between each multilayer substrate 10 there is an insulating adhesive layer 40 and conductive paste vias 50 that electrically connect the bonding lands 34 of opposing multilayer substrates by conductive paste filled in through-holes 46 formed in the insulating adhesive layer 40, and the conductive paste vias 50 are at positions different from the through-holes 30. It is provided at three locations around the through-hole 30.

Description

Technical Field

[0001] The present invention relates to a multilayer substrate and a method for manufacturing the same.

Background Art

[0002] Conventionally, circuit boards such as printed wiring boards have been widely used in general in order to incorporate electronic components compactly into electronic devices. On the other hand, with the demands for miniaturization, high performance, and low cost of electronic devices, the miniaturization, multilayerization of electronic circuits on circuit boards, and high-density mounting of electronic components have advanced rapidly, and the study of multilayer substrates with a multilayer structure of printed wiring boards has become active.

[0003] When forming through-holes in a multilayer substrate, the drill diameter for drilling the through-holes must be increased as the number of layers increases and the board thickness increases. Then, since it is impossible to cope with fine pitch, it has been studied to prepare a multilayer substrate in which through-holes are formed with a drill having as thin a diameter as possible in a state where the number of layers is not too large, and to stack a plurality of these multilayer substrates to finally obtain a multilayer laminated substrate.

[0004] For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2011-258779) discloses a laminated substrate in which an adhesive layer is laminated on the upper surface of one multilayer substrate, through-holes are formed in this adhesive layer, a conductive paste is filled in these through-holes, and the other multilayer substrate is laminated on the adhesive layer and the conductive paste. In addition, each multilayer substrate is interlayer-connected by through-holes whose inner walls are plated, and bonding lands formed of metal layers are formed on the upper and lower surfaces of these through-holes. The above-described conductive paste electrically connects these bonding lands.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] In the aforementioned Patent Document 1, a configuration is disclosed in which bonding lands of through-holes that penetrate each multilayer substrate and connect the layers are electrically connected by conductive paste.

[0007] However, the through-holes formed in each multilayer substrate are filled with resin to bond the layers that make up the multilayer substrate. Therefore, if conductive paste is placed directly above the through-holes, when the multilayer substrates are joined together by thermocompression bonding, the thermal expansion of the resin will put stress on the conductive paste, which may impair the long-term reliability of the conductive paste.

[0008] Therefore, the present invention has been made to solve the above problems, and its objective is to provide a laminated substrate and a method for manufacturing a laminated substrate that can ensure long-term reliability by preventing stress on the conductive paste used to electrically connect multiple multilayer substrates when manufacturing a laminated substrate by stacking multiple multilayer substrates. [Means for solving the problem]

[0009] The laminated substrate according to the present invention is a laminated substrate formed by stacking a plurality of multilayer substrates, each multilayer substrate having a through-hole that penetrates the multilayer substrate, has a plated inner wall surface and is filled with resin, and has bonding lands formed on the upper and lower surfaces of the through-hole that are electrically connected to the through-hole, and an insulating adhesive layer and conductive paste vias that electrically connect each bonding land of opposing multilayer substrates are provided between each multilayer substrate, the conductive paste vias being provided at positions different from the positions where the through-holes are formed, the bonding lands being formed to a size that can accommodate the through-holes and the plurality of conductive paste vias, and the bonding lands being characterized in that they have a shape in which a first circular portion centered on the through-hole and three second circular portions arranged around the first circular portion and centered on the conductive paste are connected, such that the conductive paste vias are provided at three locations around the through-hole. By adopting this configuration, even if the resin inside the through-hole undergoes thermal expansion, the conductive paste vias are provided at three locations around the through-hole, ensuring long-term reliability without being subjected to stress due to thermal expansion. Furthermore, by providing three conductive paste vias for each through-hole, even in cases where relatively large currents flow, such as in power supply through-holes, the resistance value is reduced, preventing an increase in heat generation. By preventing an increase in heat generation, the risk of melting is eliminated.

[0010] Furthermore, the second circular portion is characterized in that it is arranged around the first circular portion at intervals of 120° from each other.

[0011] The laminated substrate according to the present invention is a laminated substrate formed by stacking a plurality of multilayer substrates, wherein each multilayer substrate has a through-hole that penetrates the multilayer substrate, has a plated inner wall surface and is filled with resin, and has bonding lands on the upper and lower surfaces of the through-hole that are electrically connected to the through-hole, and between each multilayer substrate there is an insulating adhesive layer and conductive paste vias which electrically connect each bonding land of the opposing multilayer substrates by conductive paste filled in through holes formed in the insulating adhesive layer, the conductive paste vias are provided at positions different from the positions where the through-holes are formed, the bonding lands are formed to a size that allows for the arrangement of the through-holes and the plurality of conductive paste vias, and the bonding lands are characterized by being oval in shape such that the conductive paste vias are provided at two locations that are point-symmetric with respect to the through-holes. By adopting this configuration, even if the resin inside the through-hole undergoes thermal expansion, the conductive paste vias are provided at two locations around the through-hole, ensuring long-term reliability without being subjected to stress due to thermal expansion. Furthermore, by providing two conductive paste vias for each through-hole, even in cases where relatively large currents flow, such as in power supply through-holes, the resistance value is reduced, preventing an increase in heat generation. Additionally, the oval-shaped bonding land reduces the area of ​​the bonding land, thus reducing noise even in through-holes where noise countermeasures are necessary, such as signal lines.

[0012] The present invention relates to a method for manufacturing a laminated substrate, which involves stacking multiple multilayer substrates, each having through-holes with plated inner walls and resin-filled interiors, and bonding lands on the upper and lower surfaces of the through-holes that are electrically connected to the through-holes. The method comprises the steps of: stacking an insulating adhesive layer on the upper surface of one multilayer substrate; and creating through-holes through the insulating adhesive layer at a position different from the position of the through-holes and around the through-holes, so as to electrically connect the bonding lands of one multilayer substrate and another multilayer substrate facing the first multilayer substrate. The process includes the steps of forming multiple locations, filling the through holes with conductive paste to form conductive paste vias, and thermally bonding multiple multilayer substrates to cure the insulating adhesive layer and the conductive paste and integrate the multiple multilayer substrates, and is characterized in that, before the step of laminating the insulating adhesive layer on the upper surface of one multilayer substrate, the process includes filling the recesses between the bonding lands and other metal layers or other bonding lands on the upper surface of one multilayer substrate and the lower surface of the other multilayer substrates with insulating resin and polishing the surface to flatten it so that there are no irregularities on the surface facing the other multilayer substrates. According to this method, even if the resin inside the through-hole expands due to thermal expansion, the conductive paste vias are provided at multiple locations around the through-hole. Therefore, a laminated substrate can be obtained that maintains long-term reliability without being subjected to stress due to the thermal expansion of the through-hole, and the flatness of the laminated substrate can be maintained, and the electrical connection layer by conductive paste vias can be made uniform throughout the substrate, preventing the occurrence of abnormal resistance values. [Effects of the Invention]

[0013] According to the present invention, when manufacturing a laminated substrate by stacking multiple multilayer substrates, long-term reliability can be ensured by preventing stress on the conductive paste used to electrically connect them. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic cross-sectional view showing an example of a multilayer substrate. [Figure 2]It is a schematic plan view of a bonding land showing an example when three conductive paste vias are arranged in one through hole. [Figure 3] It is a schematic plan view showing an example when a plurality of the bonding lands shown in FIG. 2 are arranged. [Figure 4] It is a schematic plan view of a bonding land showing an example when two conductive paste vias are arranged in one through hole. [Figure 5] It is a schematic plan view showing an example when a plurality of the bonding lands shown in FIG. 4 are arranged. [Figure 6] It is a schematic cross-sectional view (part 1) showing an example of a method for manufacturing a multilayer substrate in the present embodiment. [Figure 7] It is a schematic cross-sectional view (part 2) showing an example of a method for manufacturing a multilayer substrate in the present embodiment. [Figure 8] It is a schematic cross-sectional view (part 3) showing an example of a method for manufacturing a multilayer substrate in the present embodiment. [Figure 9] It is a schematic cross-sectional view (part 4) showing an example of a method for manufacturing a multilayer substrate in the present embodiment. [Figure 10] It is a schematic cross-sectional view (part 5) showing an example of a method for manufacturing a multilayer substrate in the present embodiment.

Mode for Carrying Out the Invention

[0015] (Laminated Substrate) Hereinafter, embodiments of the present invention will be described based on the drawings. FIG. 1 shows a schematic cross-sectional view of a laminated substrate. In the present embodiment, for the sake of convenience, there may be cases where "upper surface" or "lower surface" is described based on the vertical direction in the drawings. However, the upper surface and the lower surface of the laminated substrate 100 or the multilayer substrate 10 include cases where they do not coincide with the actual vertical directions. Further, in the laminated substrate 100 or the multilayer substrate 10, there may be cases where "side surface" is described, and the side surface means the side surface with respect to the above-described upper surface and lower surface.

[0016] The stacked substrate 100 shown in FIG. 1 is, as an example, configured by stacking two multilayer substrates 10 in the vertical direction and electrically connecting them to each other. However, it is not limited to the stacking of two multilayer substrates 10 and can be applied to the stacking of two or more multilayer substrates 10. In addition, the stacked substrate 100 shown in FIG. 1 is described by taking as an example the case where both are MLB (multilayer printed wiring boards).

[0017] Each multilayer substrate 10 has an insulating layer 20 made of a plurality of insulating substrates and a metal layer (not shown) formed on the upper or lower surface of each insulating layer 20, and through holes 30 penetrating in the vertical direction are formed.

[0018] The insulating layer 20 is not particularly limited as long as it is an insulating layer used in a multilayer substrate and can be appropriately selected according to the purpose. As an example, an inorganic base material such as an inorganic woven fabric or non-woven fabric using glass cloth, or a base material hardened by an organic base material such as an organic woven fabric or non-woven fabric can be adopted.

[0019] More specifically, as an example, the insulating layer 20 can adopt a glass epoxy base material (a glass woven fabric base material impregnated with an epoxy resin, a glass non-woven fabric base material impregnated with an epoxy resin), a glass woven fabric base material impregnated with a bismaleimide triazine resin, an aramid non-woven fabric base material impregnated with an epoxy resin, a glass woven fabric base material impregnated with a modified polyphenylene ether resin, etc.

[0020] The through hole 30 has a plating layer 35 formed by plating the inner wall with a metal such as copper, and a resin 32 is filled in the hollow portion further inside the plating layer 35. The resin 32 is filled to bond the layers constituting each multilayer substrate so that they do not separate.

[0021] On the upper and lower surfaces of each multilayer substrate 10, bonding lands 34 are formed for electrically connecting to through-holes 30 of other multilayer substrates 10 and semiconductor elements (not shown). The bonding lands 34 are electrically connected to the plating layer 35 of the through-holes 30 and can be formed from a metal such as copper.

[0022] An insulating adhesive layer 40 is interposed between the multilayer substrates 10. A thermosetting resin can be used as the insulating adhesive layer 40, and one example is a glass epoxy prepreg.

[0023] In Figure 1, the bonding land 34 on the upper surface of the lower multilayer substrate 10 and the bonding land 34 on the lower surface of the upper multilayer substrate 10 are electrically connected by vias. These vias are conductive paste vias 50 made of conductive paste. The conductive paste can contain a conductive filler and a binder resin.

[0024] The conductive paste vias 50 are located at positions different from the through-holes 30, that is, at positions away from directly above and below the through-holes 30. In other words, although the through-holes 30 of the two multilayer substrates 10 are arranged in a straight line in the vertical direction, the conductive paste vias 50 are located at positions away from this straight line.

[0025] In other words, if conductive paste vias 50 are provided directly above and below through-holes 30, the resin 32 inside the through-holes 30 may expand due to thermal compression during the bonding of multilayer substrates 10, which can cause stress on the conductive paste vias 50 and potentially impair the long-term reliability of the conductive paste vias 50. Therefore, by positioning the conductive paste vias 50 away from directly above and below the through-hole 30, the conductive paste vias 50 are not subjected to stress due to the thermal expansion of the resin 32 inside the through-hole 30, thereby ensuring long-term reliability.

[0026] Furthermore, the placement of the conductive paste via 50 must be at a distance from the resin 32 such that it is not affected by the thermal expansion of the resin 32 within the through-hole 30, and this distance is set appropriately based on the type of resin 32 and the diameter of the through-hole 30.

[0027] Furthermore, insulating resin 42 is placed between the bonding land 34 on the upper surface of the lower multilayer substrate 10 and the adjacent metal layer 38 (or a bonding land 34 in an adjacent position), and between the bonding land 34 on the lower surface of the upper multilayer substrate 10 and the adjacent metal layer 38 (or a bonding land 34 in an adjacent position), in order to flatten the surface of the multilayer substrate 10.

[0028] In other words, since the metal layer 38 containing bonding lands 34 protrudes from the surface of the insulating layer 20 on the upper and lower surfaces of the multilayer substrate 10, insulating resin 42 is placed to fill the step, and the upper surface of the multilayer substrate 10 placed on the lower side and the lower surface of the multilayer substrate 10 placed on the upper side can be flattened. Furthermore, if the step caused by the metal layer 38, including the bonding land 34, protruding from the surface of the insulating layer 20 is less than or equal to a predetermined thickness (for example, 18 μm or less), it is not necessary to fill the step with the insulating resin 42. In this case, the step can be filled by the insulating adhesive layer 40 when forming the insulating adhesive layer 40 on the multilayer substrate 10 placed below.

[0029] Figures 2 and 3 show schematic plan views of the joint land area. In the example shown in Figure 2, a bonding land 34 is used that is large enough to accommodate three conductive paste vias 50 for a single through-hole 30. The conductive paste vias 50 are provided in three locations around the through-hole 30.

[0030] The specific planar shape of the bonding land 34 is a shape in which a first circular portion 52 centered on the through-hole 30 and three second circular portions 54 arranged around the first circular portion 52, each centered on a conductive paste via 50, are connected. In Figure 2, the through-hole 30 is shown with a dashed line. Furthermore, the three conductive paste vias 50 are arranged at 120° intervals from each other with respect to the through-hole 30, and are equally spaced with respect to the through-hole 30. In other words, the second circular portion 54 is also formed around the first circular portion 52 at 120° intervals from each other.

[0031] As an example, in the bonding land 34 shown in Figure 2, when the diameter of the through-hole 30 is 150 μm and the diameter of the conductive paste via 50 is 180 μm, the diameter of the first circular section can be 400 μm and the diameter of the second circular section can be 300 μm. In this case, the distance between the conductive paste vias 50 is 389.7 μm.

[0032] Furthermore, Figure 3 shows a plan view of an example of the arrangement when multiple joining lands 34 are formed as shown in Figure 2. Figure 3 shows an example of the arrangement when four bonding lands 34, as shown in Figure 2, are formed, with the through-holes 30 spaced 900 μm apart. In this case, each bonding land 34 is arranged so that the orientation of one conductive paste via 50 faces toward the center relative to the others.

[0033] As shown in Figures 2 and 3, one example of a case where multiple conductive paste vias 50 are placed on a single through-hole 30 bonding land 34 is when a relatively large current flows, such as in the case of a power supply through-hole 30. By providing multiple conductive paste vias 50 on a through-hole 30 through which a large current flows, the resistance value is reduced, and the amount of heat generated can be kept from increasing. In this way, by keeping the amount of heat generated from increasing, the risk of melting at the stacking points between multilayer substrates 10 can be eliminated.

[0034] In the example shown in Figure 4, a bonding land 34 is used that is large enough to accommodate two conductive paste vias 50 on a single through-hole 30 bonding land 34. The conductive paste vias 50 are provided at two points symmetrical with respect to the through-hole 30. That is, in the example in Figure 4, the through-hole 30 and the two conductive paste vias 50 are arranged in a straight line.

[0035] The joint land 34 shown in Figure 4 is oval-shaped. Here, oval shape refers to a shape in which both ends of the longitudinal direction of a rectangle are formed into semicircles.

[0036] As an example, the bonding land 34 shown in Figure 4 can have an oval shape with a longitudinal length of 740 μm and an oval shape with a width of 300 μm, when the diameter of the through-hole 30 is 150 μm and the diameter of the conductive paste via 50 is 180 μm. In this case, the distance between the conductive paste vias 50 is 440 μm.

[0037] Furthermore, Figure 5 shows a plan view of an example of the arrangement when multiple joining lands 34 are formed as shown in Figure 4. Figure 5 shows an example of the arrangement when four bonding lands 34, as shown in Figure 4, are formed, with the spacing between the through-holes 30 being 800 μm. In this case, the longitudinal directions of each bonding land 34 are parallel to each other, and the bonding lands 34 are arranged in a grid pattern.

[0038] As shown in Figures 4 and 5, when two conductive paste vias 50 are placed on a bonding land 34 of a single through-hole 30, the resistance value is reduced by providing two conductive paste vias 50 to the through-hole 30 through which a large current flows, thus preventing an increase in heat generation. In this way, by preventing an increase in heat generation, the risk of melting at the stacking points of the multilayer substrates 10 can be eliminated. Furthermore, by using an oval-shaped bonding land 34, the area of ​​the bonding land can be reduced even when multiple conductive paste vias 50 are provided, thus reducing the impact of noise even in through-holes where noise countermeasures such as signal lines are necessary.

[0039] (Method of manufacturing a laminated substrate) Next, the manufacturing method of the multilayer substrate will be explained with reference to Figure 6. Note that the multilayer substrate 10 in Figure 6 is the same as that shown in Figure 1, and its structure is denoted by the same reference numerals as in Figure 1, so its explanation is omitted. First, when stacking the multilayer substrates 10, insulating resin 42 is filled into the recesses between the bonding lands 34 and the metal layer 38 (or other adjacent bonding lands 34) in order to make the surface facing the other multilayer substrate 10 flat. Then, the insulating resin 42 is polished to flatten the surface facing the other multilayer substrate 10 so that there are no irregularities. This maintains the flatness of the stacked substrate 100 and makes the electrical connection layer by conductive paste vias 50 uniform throughout the substrate, preventing the occurrence of abnormal resistance values.

[0040] Next, as shown in Figure 7, an insulating adhesive layer 40 is laminated on the surface facing the other multilayer substrate 10 to be laminated. As mentioned above, a thermosetting resin can be used as the insulating adhesive layer 40, and as an example, a glass epoxy prepreg can be used. Note that if the step caused by the metal layer 38 including the bonding land 34 protruding from the surface of the insulating layer 20 is less than or equal to a predetermined thickness (for example, 18 μm or less), it is not necessary to fill the step with the insulating resin 42. In this case, the step can be filled by the insulating adhesive layer 40 when forming the insulating adhesive layer 40 on the multilayer substrate 10 placed below. Furthermore, a resin film 44 that protects the surface of the insulating adhesive layer 40 is laminated on the upper surface of the insulating adhesive layer 40. The insulating adhesive layer 40 and the resin film 44 may be in the form of a pre-integrated sheet.

[0041] Next, as shown in Figure 8, through holes 46 are formed in the insulating adhesive layer 40 and the resin film 44. The through-hole 46 is a closed-bottomed through-hole 46 that penetrates the insulating adhesive layer 40 and the resin film 44, with the bonding land 34 at its bottom. The through-hole 46 can be made, for example, by laser processing. Examples of laser processing methods include CO2 lasers and YAG lasers, but are not limited to these, and can be appropriately selected depending on the purpose.

[0042] In this case, as shown in Figure 1, multiple conductive paste vias 50 are placed on the bonding land 34 of a single through-hole 30. Therefore, multiple through-holes 46 are drilled at positions different from where the through-hole 30 is formed, and at positions away from directly above the through-hole 30. In the examples shown in Figures 2 and 3, through-holes 46 are formed at three locations around the through-hole 30, while in the examples shown in Figures 4 and 5, through-holes 46 are formed at two locations that are point-symmetrical with respect to the through-hole 30.

[0043] Next, as shown in Figure 9, conductive paste is filled into the through hole 46, and then the resin film 44 is peeled off. As a result, conductive paste vias 50 are formed, and by peeling off the resin film 44, the conductive paste protrudes above the insulating adhesive layer 40 by the thickness of the resin film 44. Because the conductive paste protrudes from the insulating adhesive layer 40, the conductive paste can be reliably bonded to the bonding lands 34 of other multilayer substrates 10.

[0044] Next, as shown in Figure 10, another multilayer substrate 10 is laminated onto the multilayer substrate 10 on which the insulating adhesive layer 40 and conductive paste vias 50 are formed. Here, the lower surface of the other multilayer substrate 10 is flattened so that there are no irregularities, by filling the recesses between the bonding lands 34 and the metal layer 38 (or other adjacent bonding lands 34) with insulating resin 42. Then, the multilayer substrates 10 are heat-pressed together. By heat-pressing, the insulating adhesive layer 40 and the conductive paste vias 50 harden, and a laminated substrate 100 is formed by stacking multiple multilayer substrates 10.

[0045] (Other embodiments of multilayer substrates) The specific types of the multilayer substrates 10 and the substrates of the multilayer substrates 10 that make up the laminated substrate 100 are as shown in Figure 1. Both may be MLBs (multilayer printed circuit boards), or the lower multilayer substrate 10 may be an MLB (multilayer printed circuit board) and the upper multilayer substrate 10 may be a PKG (semiconductor package substrate). Alternatively, the lower multilayer substrate 10 may be an MLB (multilayer printed circuit board) and the upper multilayer substrate 10 may be a CL (coreless semiconductor package substrate). Furthermore, a configuration in which a multilayer substrate 10 that is a CL (coreless semiconductor package substrate) is laminated on both the upper and lower surfaces of the lower multilayer substrate 10 that is an MLB (multilayer printed circuit board) is also possible.

[0046] The laminated substrate 100 in this embodiment can be used as a motherboard (support substrate) and also as an interposer (relay substrate). In particular, it can be used as a motherboard or interposer for server systems and high-speed communication systems, and can also be used as a circuit board that constitutes semiconductor elements. Furthermore, it can be applied to inspection equipment and probe cards used for determining the quality of semiconductors. [Explanation of symbols]

[0047] 10 Multilayer board 20 Insulating layer 30 through-holes 32 resin 34 Joining Land 35 Plating layer 38 Metal layer 40 Insulating adhesive layer 42 Insulating resin 44 Resin film 46 Through hole 50 conductive paste vias 52 First circular section 54 Second circular section 100 Multilayer Substrates

Claims

1. A laminated substrate formed by stacking multiple multilayer substrates, Each multilayer substrate has a through-hole that penetrates the substrate, has a plated inner wall surface, and is filled with resin, and bonding lands are formed on the upper and lower surfaces of the through-hole that are electrically connected to the through-hole. Between each multilayer substrate, Insulating adhesive layer, Conductive paste vias are provided, which electrically connect each of the bonding lands of opposing multilayer substrates by filling through holes formed in the insulating adhesive layer with conductive paste. The conductive paste via is provided at a position different from the position where the through-hole is formed. The bonding land is formed to a size that allows for the arrangement of the through-hole and the plurality of conductive paste vias. The bond land is characterized by having a shape in which a first circular portion centered on the through-hole and three second circular portions arranged around the first circular portion and centered on the conductive paste are connected, such that the conductive paste vias are provided at three locations around the through-hole.

2. The laminated substrate according to claim 1, characterized in that the second circular portion is arranged around the first circular portion at intervals of 120° from each other.

3. A laminated substrate formed by stacking multiple multilayer substrates, Each multilayer substrate has a through-hole that penetrates the substrate, has a plated inner wall surface, and is filled with resin, and bonding lands are formed on the upper and lower surfaces of the through-hole that are electrically connected to the through-hole. Between each multilayer substrate, Insulating adhesive layer, Conductive paste vias are provided, which electrically connect each of the bonding lands of opposing multilayer substrates by filling through holes formed in the insulating adhesive layer with conductive paste. The conductive paste via is provided at a position different from the position where the through-hole is formed. The bonding land is formed to a size that allows for the arrangement of the through-hole and the plurality of conductive paste vias. The laminated substrate is characterized in that the bonding land is oval-shaped such that the conductive paste vias are provided at two locations that are point-symmetrical with respect to the through-hole.

4. A method for manufacturing a laminated substrate by stacking multiple multilayer substrates, each having a through-hole with a plated inner wall surface and filled with resin inside, and bonding lands on the upper and lower surfaces of the through-holes that are electrically connected to the through-holes, A step of laminating an insulating adhesive layer onto the upper surface of a multilayer substrate, A step of forming through-holes that penetrate the insulating adhesive layer at multiple locations around the through-holes, at positions different from the through-holes, so that the bonding lands of one multilayer substrate and another multilayer substrate facing the first multilayer substrate can be electrically connected to each other, The steps include filling the through-hole with conductive paste to form a conductive paste via, The process includes a step of thermally pressing multiple multilayer substrates together to cure the insulating adhesive layer and the conductive paste, thereby integrating the multiple multilayer substrates, Before the step of laminating an insulating adhesive layer onto the upper surface of the first multilayer substrate, A method for manufacturing a laminated substrate, comprising the steps of filling the recesses between the bonding lands and other metal layers or other bonding lands on the upper surface of one multilayer substrate and the lower surface of the other multilayer substrate with insulating resin, and polishing the surface to flatten it so that there are no irregularities on the surface facing the other multilayer substrate.

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