Through-electrode substrate and method for manufacturing through-electrode substrate

Abstract

This through electrode substrate includes: a substrate including a first surface, a second surface located on the opposite side of the first surface, and a plurality of through holes penetrating from the first surface to the second surface; and a plurality of through electrodes reaching the second surface from the first surface through the through holes. Each of the plurality of through electrodes includes a plurality of internal portions positioned inside the plurality of through holes, a first portion positioned on the first surface and connected to the plurality of internal portions, and a second portion positioned on the second surface and connected to the plurality of internal portions. The first portions of the plurality of through electrodes each have a contour surrounding the plurality of through holes in the plan view.

Description

Through-electrode substrate and method for manufacturing the same

[0001] FIELD Embodiments of the present disclosure relate to a through hole electrode substrate and a method for manufacturing a through hole electrode substrate.

[0002] Through-hole electrode substrates are used in a variety of applications. A through-hole electrode substrate is a component including a substrate having a first surface and a second surface, through holes formed in the substrate, and through electrodes located in the through holes. A through-hole electrode substrate is used, for example, as an interposer. An interposer is a component interposed between two electrical components. For example, a through-hole electrode substrate is interposed between two LSI chips in the thickness direction. A through-hole electrode substrate may also be interposed between an element such as an LSI chip and a mounting substrate such as a motherboard. A through-hole electrode substrate is also used as a component constituting passive components such as an inductor or a capacitor.

[0003] For example, as disclosed in Patent Document 1, the through electrodes of the through electrode substrate have various structures. A first example of the through electrode is an example in which the entire through hole is filled with a conductive material such as copper. A second example is an example in which a layer of a conductive material such as copper is formed on the wall surface of the through hole. A third example is an example in which a layer of a conductive material such as copper is formed on the wall surface of the through hole, and a layer of a conductive material that closes the through hole is formed along the first surface or the second surface of the substrate. In the second and third examples, a resin material is filled in the space of the through hole where no conductive material is present.

[0004] International Publication No. 2022 / 173057

[0005] There is a demand for increasing the maximum value of current that can be passed through the through electrode (hereinafter also referred to as allowable current). In the through electrode of the first example, the larger the dimension of the through hole in the surface direction, the higher the allowable current of the through electrode. However, the larger the dimension of the through hole, the more likely defects such as voids will occur in the conductive material filled in the through hole. In the through electrodes of the second and third examples as well, the larger the dimension of the through hole in the surface direction, the higher the allowable current of the through electrode. The larger the dimension of the through hole, the more likely defects such as voids will occur in the resin material filled in the through hole.

[0006] An object of the embodiments of the present disclosure is to provide a through hole electrode substrate and a method for manufacturing a through hole electrode substrate that can effectively solve such problems.

[0007] Embodiments of the present disclosure relate to the following [1] to

[23] .

[0008] [1] A through electrode substrate comprising: a substrate including a first surface, a second surface located opposite the first surface, and a plurality of through holes penetrating from the first surface to the second surface; and a plurality of through electrodes extending from the first surface through the through holes to the second surface, wherein each of the plurality of through electrodes includes a plurality of internal portions located inside the plurality of through holes, a first portion located on the first surface and connected to the plurality of internal portions, and a second portion located on the second surface and connected to the plurality of internal portions, and wherein each of the first portions of the plurality of through electrodes has an outline that surrounds the plurality of through holes in a planar view.

[0009] [2] In the through electrode substrate described in [1], each of the plurality of through holes may have a wall surface including a first end connected to the first surface, a second end connected to the second surface, and a smallest portion located between the first end and the second end, and the through hole may have a minimum dimension at the smallest portion that is the smallest value of the dimension of the through hole in the surface direction of the first surface, and each of the plurality of internal portions may include a closing portion that closes the through hole at least at the smallest portion, a third portion located on the wall surface between the first portion and the closing portion, and a fourth portion located on the wall surface between the second portion and the closing portion.

[0010] [3] In the through electrode substrate described in [2], the closed portion may include a first closed surface and a second closed surface, the first closed surface may be a surface of the closed portion facing the first surface, and the second closed surface may be a surface of the closed portion facing the second surface, the through electrode may have a first distance that is the maximum value of the distance from the first surface to the first closed surface in the thickness direction of the substrate, and a second distance that is the maximum value of the distance from the second surface to the second closed surface in the thickness direction of the substrate, the ratio of the first distance to the thickness of the substrate may be 0.10 or more, and the ratio of the second distance to the thickness of the substrate may be 0.10 or more.

[0011] [4] The through electrode substrate according to [2] or [3] may comprise a plurality of internal resins located inside each of the plurality of through holes, and each of the plurality of internal resins may include a first internal resin located inside the third portion and a second internal resin located inside the fourth portion.

[0012] [5] In the through electrode substrate described in [1], each of the plurality of through holes may have a wall surface including a first end connected to the first surface and a second end connected to the second surface, and each of the plurality of internal portions may be located on the wall surface so as to reach from the first end to the second end, and the through electrode substrate may have a plurality of internal resins located inside the internal portions of the through electrodes in each of the plurality of through holes.

[0013] [6] In the through electrode substrate described in [5], each of the plurality of through holes may include a minimum portion located between the first end and the second end, and the through holes may have a minimum dimension at the minimum portion that is the minimum value of the dimensions of the through holes in the surface direction of the first surface.

[0014] [7] In the through electrode substrate according to any one of [4] to [6], the first portions of the plurality of through electrodes may each include a plurality of openings in which the internal resin is located.

[0015] [8] In the through hole electrode substrate according to [1], a ratio of a thickness of the internal portion to a thickness of the substrate may be 0.80 or more and 1.20 or less.

[0016] [9] The through electrode substrate described in any one of [1] to [8] may include a plurality of first conductive layers connected to the first portions of the plurality of through electrodes, respectively, and a first resin layer located between the first portions of the plurality of through electrodes and the plurality of first conductive layers in the thickness direction of the substrate.

[0017]

[10] In the through hole electrode substrate according to [9], the plurality of first conductive layers may each have an outline surrounding the plurality of through holes in a plan view.

[0018]

[11] The through electrode substrate described in

[10] may include a plurality of third conductive layers connected to one of the first conductive layers, and a third resin layer located between the one of the first conductive layers and the plurality of third conductive layers in the thickness direction of the substrate.

[0019]

[12] In the through electrode substrate according to

[10] or

[11] , the plurality of through electrodes may include a first through electrode and a second through electrode adjacent to the first through electrode in a planar view, the first conductive layer connected to the first through electrode may extend outward beyond the contour of the first portion of the first through electrode, the first portion of the second through electrode may extend outward beyond the contour of the first conductive layer connected to the second through electrode, and a portion of the first conductive layer connected to the first through electrode and a portion of the first portion of the second through electrode may face each other in the thickness direction of the substrate.

[0020]

[13] In the through electrode substrate according to any one of [9] to

[12] , the first resin layer may include an opening in which a part of the first conductive layer is located and which has a fourth dimension in a plan view, and the through hole may have a first dimension on the first surface, and the fourth dimension may be larger than the first dimension.

[0021]

[14] A through electrode substrate, comprising: a substrate including a first surface, a second surface located opposite the first surface, and a plurality of through holes penetrating from the first surface to the second surface; a plurality of through electrodes extending from the first surface through the through holes to the second surface; and a first wiring layer located on the first surface and including at least one insulating layer and at least one conductive layer, wherein the plurality of through electrodes each include a plurality of internal portions located inside the plurality of through holes, and a ratio of a thickness of the internal portions to a thickness of the substrate is 0.80 or more and 1.20 or less, the at least one insulating layer includes a first resin layer located on the first surface, the first resin layer includes a plurality of openings, each of the plurality of openings overlapping the internal portions in a planar view, the first resin layer overlapping a boundary between a wall surface of the through hole and the internal portions in a planar view, and the at least one conductive layer includes a conductive layer electrically connected to a plurality of the internal portions.

[0022]

[15] In the through electrode substrate described in

[14] , the at least one conductive layer may include a first conductive layer connected to a plurality of the internal portions in a plurality of the openings of the first resin layer, and the first conductive layer may be the conductive layer electrically connected to a plurality of the internal portions.

[0023]

[16] In the through electrode substrate described in

[14] , the at least one conductive layer may include a plurality of first conductive layers each connected to the internal portion in a plurality of the openings of the first resin layer, and the conductive layer electrically connected to a plurality of the first conductive layers.

[0024]

[17] In the through electrode substrate according to any one of [1] to

[16] , the through electrodes may be arranged at a first pitch in the planar direction of the first surface, and the through holes in which the internal portions included in one through electrode are located may be arranged at a second pitch in the planar direction of the first surface, and the ratio of the first pitch to the second pitch may be 2.0 or more.

[0025]

[18] In the through hole electrode substrate according to

[17] , a ratio of the first pitch to the second pitch may be 5.0 or less.

[0026]

[19] In the through electrode substrate according to

[17] or

[18] , the through holes may have a first dimension on the first surface, and a ratio of the second pitch to the first dimension may be 1.5 or greater.

[0027]

[20] In the through hole electrode substrate according to

[19] , the first dimension may be 50 μm or more and 100 μm or less.

[0028]

[21] A mounting board comprising: the through electrode substrate according to any one of [1] to

[20] ; and an element electrically connected to the plurality of through electrodes of the through electrode substrate.

[0029]

[22] A method for manufacturing a through electrode substrate, comprising: a step of preparing a substrate including a first surface, a second surface located opposite the first surface, and through holes penetrating from the first surface to the second surface; and a through electrode forming step of forming a plurality of through electrodes that extend from the first surface through the through holes to the second surface, wherein each of the plurality of through electrodes includes a plurality of internal portions located inside the plurality of through holes, a first portion located on the first surface and connected to the plurality of internal portions, and a second portion located on the second surface and connected to the plurality of internal portions, and wherein each of the first portions of the plurality of through electrodes has an outline that surrounds the plurality of through holes in a planar view.

[0030]

[23] A method for manufacturing a through electrode substrate, comprising: a step of preparing a substrate including a first surface, a second surface located opposite the first surface, and through holes penetrating from the first surface to the second surface; a through electrode forming step of forming a plurality of through electrodes that pass from the first surface through the through holes to the second surface; and a step of forming a first wiring layer located on the first surface and including at least one insulating layer and at least one conductive layer, wherein each of the plurality of through electrodes includes a plurality of internal portions located inside the plurality of through holes, and each of the plurality of internal portions is a filled via, the at least one insulating layer includes a first resin layer located on the first surface, the first resin layer includes a plurality of openings, and each of the plurality of openings overlaps with the internal portion in a planar view, the first resin layer overlaps with a boundary between a wall surface of the through hole and the internal portion in a planar view, and the at least one conductive layer includes a conductive layer electrically connected to a plurality of the internal portions.

[0031] According to the embodiments of the present disclosure, it is possible to increase the allowable current of the through electrode while suppressing defects such as voids.

[0032] 19 is a plan view showing a through electrode substrate according to an embodiment; FIG. 19 is a plan view showing a portion of the through electrode substrate of FIG. 1; FIG. 2 is a cross-sectional view taken along line III-III of the through electrode substrate of FIG. 2; FIG. 29 is a cross-sectional view showing an example of a through electrode of a through electrode substrate; FIG. 30 is a cross-sectional view showing an example of a through hole in a substrate; FIG. 31 is a cross-sectional view showing an example of a through electrode; FIG. 32 is a cross-sectional view showing an example of a dimension of a through electrode; FIG. 33 is a cross-sectional view showing an example of a step of preparing a substrate; FIG. 34 is a cross-sectional view showing an example of a seed layer forming step; FIG. 35 is a cross-sectional view showing an example of a plating layer forming step; FIG. 36 is a cross-sectional view showing an example of a plating layer forming step; FIG. 37 is a cross-sectional view showing an example of a step of removing a portion of a seed layer; FIG. 38 is a cross-sectional view showing an example of a resin layer forming step; FIG. 39 is a cross-sectional view showing a modified example of a through electrode of a through electrode substrate; FIG. 39 is a cross-sectional view showing a modified example of a through electrode of a through electrode substrate; FIG. 39 is a cross-sectional view showing a modified example of a through electrode of a through electrode substrate; FIG. 39 is a plan view showing a modified example of a through electrode substrate; FIG. 39 is a cross-sectional view taken along line XX-XX of the through electrode substrate of FIG. 19; FIG. 39 is a cross-sectional view taken along line XXI-XXI of the through electrode substrate of FIG. 19; FIG. 39 is a cross-sectional view showing a modified example of a through electrode substrate; 32. A cross-sectional view showing a modified example of a through electrode substrate. A cross-sectional view showing a modified example of a through electrode substrate. A cross-sectional view showing a modified example of a through electrode substrate. A plan view showing a modified example of a through electrode substrate. A diagram showing an example of a product on which a through electrode substrate is mounted. A table showing evaluation results of Examples 1 to 5. A cross-sectional view showing a modified example of a through electrode substrate. A plan view showing a modified example of a through electrode substrate. A cross-sectional view taken along line XXXII-XXXII of the through electrode substrate of FIG. 31. A plan view showing a modified example of a through electrode substrate. A cross-sectional view taken along line XXXIV-XXXIV of the through electrode substrate of FIG. 33. A cross-sectional view showing a modified example of a through electrode substrate. A cross-sectional view showing a modified example of a through electrode substrate. A cross-sectional view showing a modified example of a through electrode substrate.

[0033] The configuration of a through-hole electrode substrate and a manufacturing method thereof will be described in detail with reference to the drawings. The embodiments described below are examples of embodiments of the present disclosure, and the present disclosure is not limited to these embodiments, but will be interpreted without omission. In this specification, terms such as "substrate," "base material," "sheet," and "film" are not distinguished from one another solely based on differences in name. For example, the concept of "substrate" includes components that may be called sheets or films. "Surface" refers to a surface that coincides with the planar direction of the target plate-like component when viewed holistically and comprehensively. The normal direction used with respect to a plate-like component refers to the normal direction to the component's surface. As used in this specification, terms such as "parallel" and "orthogonal," as well as length and angle values, that specify shape, geometric conditions, and their degrees, are interpreted without strict meaning, but include a range within which similar functions can be expected.

[0034] In this specification, when multiple upper limit value candidates and multiple lower limit value candidates are listed for a certain parameter, the numerical range of the parameter may be constructed by combining any one upper limit value candidate with any one lower limit value candidate. For example, consider a description that reads, "Parameter B is, for example, A1 or more, or may be A2 or more, or may be A3 or more. Parameter B is, for example, A4 or less, or may be A5 or less, or may be A6 or less." In this case, the numerical range of parameter B may be A1 or more and A4 or less, A1 or more and A5 or less, A1 or more and A6 or less, A2 or more and A4 or less, A2 or more and A5 or less, A2 or more and A6 or less, A3 or more and A4 or less, A3 or more and A5 or less, or A3 or more and A6 or less.

[0035] In the drawings referred to in this embodiment, the same or similar reference numerals are used to designate the same parts or parts having similar functions, and repeated explanations thereof may be omitted. Furthermore, the dimensional ratios of the drawings may differ from the actual ratios for the sake of explanation, and some components may be omitted from the drawings.

[0036] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present disclosure will be described. Fig. 1 is a plan view showing an example of a through hole electrode substrate 10. Fig. 2 is a plan view showing a portion of the through hole electrode substrate 10 of Fig. 1. Fig. 3 is a cross-sectional view of the through hole electrode substrate 10 of Fig. 2 taken along line III-III.

[0037] The through electrode substrate 10 includes a substrate 12 and a plurality of through electrodes 20. The substrate 12 includes a first surface 13 and a second surface 14 located on the opposite side of the first surface 13 in the thickness direction of the substrate 12. The thickness direction is also referred to as a third direction D3. The substrate 12 further includes a plurality of through holes 15 that penetrate from the first surface 13 to the second surface 14. Each of the plurality of through electrodes 20 extends from the first surface 13 through the through hole 15 to the second surface 14.

[0038] 1 , the plurality of through electrodes 20 may be arranged in a plane direction of the first surface 13. For example, the plurality of through electrodes 20 may be arranged in a first direction D1. The first direction D1 is one of the plane directions of the first surface 13. For example, the plurality of through electrodes 20 may also be arranged in a second direction D2 different from the first direction D1. The second direction D2 is also one of the plane directions of the first surface 13. The second direction D2 may be perpendicular to the first direction D1.

[0039] The plurality of through electrodes 20 may be arranged at a first pitch P1 in the surface direction of the first surface 13. For example, the plurality of through electrodes 20 may be arranged at the first pitch P1 in the first direction D1 and the second direction D2. The first pitch P1 is the distance between the center points C1 of two adjacent through electrodes 20 in a planar view. "Planar view" means that the object is viewed along the normal direction of the first surface 13.

[0040] The first pitch P1 is, for example, 200 μm or more, may be 400 μm or more, or may be 600 μm or more. The first pitch P1 is, for example, 3000 μm or less, may be 2000 μm or less, or may be 1000 μm or less.

[0041] The first pitch P1 may vary depending on the position in the first direction D1 or the position in the second direction D2. When multiple values ​​of the first pitch P1 are measured, it is determined whether the first pitch P1 satisfies the numerical range described in this specification based on the smallest value among the multiple first pitches P1.

[0042] The substrate 12 and the through electrodes 20 will now be described in detail.

[0043] (Substrate) The substrate 12 includes an insulating inorganic material. For example, the substrate 12 is a glass substrate, a quartz substrate, a sapphire substrate, a resin substrate, a silicon substrate, a silicon carbide substrate, an alumina (Al2O3) substrate, an aluminum nitride (AlN) substrate, a zirconia oxide (ZrO2) substrate, or a laminate of these substrates. The substrate 12 may partially include a substrate made of a conductive material, such as an aluminum substrate or a stainless steel substrate.

[0044] An example of the glass used for the substrate 12 is alkali-free glass. The alkali-free glass is glass that does not contain alkali components such as sodium or potassium. The alkali-free glass contains, for example, boric acid instead of an alkali component. The alkali-free glass also contains, for example, an alkaline earth metal oxide such as calcium oxide or barium oxide.

[0045] The thickness T0 of the substrate 12 is, for example, 100 μm or more, or may be 200 μm or more, or 300 μm or more. The thickness T0 of the substrate 12 is, for example, 800 μm or less, or may be 600 μm or less, or may be 400 μm or less.

[0046] 2 and 3 , the through hole 15 includes a wall surface 16 extending from the first surface 13 to the second surface 14. The wall surface 16 includes a first end 161 and a second end 162. The first end 161 is a portion of the wall surface 16 that is connected to the first surface 13. The second end 162 is a portion of the wall surface 16 that is connected to the second surface 14. The first end 161 and the second end 162 may have a circular outline in a plan view.

[0047] (Through Electrode) FIG. 4 is a cross-sectional view showing an example of a through electrode 20. As shown in FIGS. 2 to 4 , each of the plurality of through electrodes 20 includes one first portion 21, one second portion 22, and multiple internal portions 26. The internal portions 26 are conductive materials that are part of the conductive material constituting the through electrode 20 and are located inside the through holes 15. Each of the multiple internal portions 26 is located inside the corresponding through hole 15. In other words, each internal portion 26 is located inside a corresponding one of the through holes 15. Therefore, each of the plurality of through electrodes 20 includes one first portion 21, one second portion 22, and multiple internal portions 26 located inside the multiple through holes 15. In this embodiment, each of the plurality of through electrodes 20 includes one first portion 21, one second portion 22, and four internal portions 26 located inside the four through holes 15.

[0048] A structure in which one through electrode 20 includes a plurality of internal portions 26 located inside a plurality of through holes 15 is also called a multi-via structure.

[0049] The number of through holes 15 overlapping one first portion 21 in plan view is, for example, 2 or more, and may be 4 or more. The number of through holes 15 overlapping one first portion 21 in plan view is, for example, 16 or less, may be 12 or less, 9 or less, 8 or less, or may be 6 or less.

[0050] The multiple internal portions 26 of each through electrode 20 are connected to one first portion 21 on the first surface 13 and to one second portion 22 on the second surface 14. The first portion 21 is located on the first surface 13. The second portion 22 is located on the second surface 14.

[0051] The first portion 21 has a contour 211. The contour 211 is an outer edge of the first portion 21 in a plan view. As shown in FIG. 2 , the contours 211 of the first portions 21 of the plurality of through electrodes 20 may each surround a first end 161 of the wall surface 16 of the plurality of through holes 15 in a plan view. Over the entire area of ​​the contour 211, the distance from a center point C1 in a plan view to the contour 211 may be greater than the distance from the center point C1 in a plan view to the first end 161.

[0052] The plurality of through holes 15 in which the plurality of internal portions 26 included in one through electrode 20 are located may be arranged at a second pitch P2 in the planar direction of the first surface 13. For example, the plurality of through holes 15 may be arranged at the second pitch P2 in the first direction D1 and the second direction D2. The second pitch P2 is the distance between the center points C2 of two adjacent through holes 15 in a planar view. In the present embodiment, the plurality of through holes 15 in which the plurality of internal portions 26 included in one through electrode 20 are located are surrounded by the outline of one first portion 21 in a planar view.

[0053] The second pitch P2 is, for example, 80 μm or more, and may be 100 μm or more, 125 μm or more, 150 μm or more, 175 μm or more, 200 μm or more, 300 μm or more, or 350 μm or more. The second pitch P2 is, for example, 1000 μm or less, 700 μm or less, or 500 μm or less. The smaller the second pitch P2, the higher the distribution density of the through holes 15, and therefore the higher the allowable current of the through electrodes 20. The larger the second pitch P2, the more easily the stress generated in the internal portion 26 is alleviated, and therefore the higher the reliability of the through electrode substrate 10.

[0054] The second pitch P2 is smaller than the first pitch P1. The ratio P1 / P2 of the first pitch P1 to the second pitch P2 is, for example, 2.0 or more, or may be 2.5 or more, or may be 3.0 or more. P1 / P2 is, for example, 5.0 or less, or may be 4.5 or less, or may be 4.0 or less.

[0055] 2, the symbol P3 represents the shortest distance between the through holes 15 of two adjacent through electrodes 20. The two adjacent through electrodes 20 are also referred to as a first through electrode 20A and a second through electrode 20B. The shortest distance P3 is measured between the center point C2 of the through hole 15 of the first through electrode 20A and the center point C2 of the through hole 15 of the second through electrode 20B.

[0056] The smaller the difference between the second pitch P2 and the shortest distance P3, the more uniform the distribution density of the through holes 15 in the substrate 12. The more uniform the distribution density of the through holes 15, the more the positional variation in stress generated in the substrate 12 is suppressed. P3 / P2, which is the ratio of the shortest distance P3 to the second pitch P2, is, for example, 0.90 or more, or may be 0.95 or more, or may be 1.00 or more. P3 / P2 is, for example, 2.00 or less, or may be 1.50 or less, or may be 1.20 or less.

[0057] The second portion 22 has a contour 221. The contour 221 is the outer edge of the second portion 22 in a plan view. Although not shown, the contours 221 of the second portions 22 of the plurality of through electrodes 20 may each surround the second ends 162 of the wall surfaces 16 of the plurality of through holes 15 in a plan view. Over the entire area of ​​the contour 221, the distance from the center point C1 in a plan view to the contour 221 may be greater than the distance from the center point C1 in a plan view to the second ends 162.

[0058] The through electrode substrate 10 may include a plurality of internal resins 30. The internal resins 30 are resin materials located inside the through holes 15. As shown in FIG. 3 , the internal resins 30 may be located in a portion of the internal space of the through holes 15 where the internal portions 26 are not located.

[0059] 2 to 4 , the first portions 21 of the plurality of through electrodes 20 may each include a plurality of openings 212 that overlap the through holes 15 in a plan view. One opening 212 may overlap one through hole 15. The internal resin 30 may be located in each of the plurality of openings 212. By forming the plurality of openings 212 in the first portions 21, stress generated in the through electrodes 20 is easily alleviated.

[0060] The second portions 22 of the plurality of through electrodes 20 may also each include a plurality of openings 222 that overlap the through holes 15 in a plan view. One opening 222 may overlap one through hole 15. The internal resin 30 may be located in each of the plurality of openings 222.

[0061] The configuration of the through hole 15 and the through electrode 20 will be described in detail below. FIG. 5 is a cross-sectional view showing an example of the through hole 15 in the substrate 12.

[0062] The through hole 15 has a first dimension R1 at a first end 161 in the plane direction of the first surface 13. The through hole 15 has a second dimension R2 at a second end 162 in the plane direction of the first surface 13. The through hole 15 may include a minimum portion 163 located between the first end 161 and the second end 162. The through hole 15 has a minimum dimension R3 at the minimum portion 163 in the plane direction of the first surface 13. The minimum portion 163 is defined as the portion of the wall surface 16 where the dimension of the through hole 15 in the plane direction of the first surface 13 is minimum.

[0063] The first end 161, the second end 162, and the smallest portion 163 may have a circular outline in a plan view. In this case, the first dimension R1, the second dimension R2, and the smallest dimension R3 refer to the diameters of the first end 161, the second end 162, and the smallest portion 163.

[0064] The first end 161, the second end 162, and the minimum portion 163 may have an outline other than a circle in a plan view. When an outline other than a circle is adopted, the first dimension R1, the second dimension R2, and the minimum dimension R3 may be equivalent circle diameters. For example, the first dimension R1 may be the diameter of a circle having an area equal to the area enclosed by the outline of the first end 161. For example, the second dimension R2 may be the diameter of a circle having an area equal to the area enclosed by the outline of the second end 162. For example, the minimum dimension R3 may be the diameter of a circle having an area equal to the cross-sectional area of ​​the through hole 15 at the minimum portion 163.

[0065] The minimum dimension R3 is smaller than the first dimension R1. The dimension of the through hole 15 may decrease monotonically from the first end 161 to the minimum portion 163. The minimum dimension R3 is smaller than the second dimension R2. The dimension of the through hole 15 may decrease monotonically from the second end 162 to the minimum portion 163.

[0066] The minimum dimension R3 is, for example, 40 μm or more, and may be 50 μm or more, or 60 μm or more. The larger the minimum dimension R3, the higher the allowable current of the internal portion 26 of the through electrode 20. The minimum dimension R3 is, for example, 90 μm or less, and may be 80 μm or less, or 70 μm or less. The smaller the minimum dimension R3, the easier it is to form a closed portion 25, which will be described later, in the minimum portion 163.

[0067] The first dimension R1 is, for example, 50 μm or more, or may be 60 μm or more, or 70 μm or more. The first dimension R1 is, for example, 100 μm or less, or may be 90 μm or less, or may be 80 μm or less.

[0068] The ratio R1 / R3 of the first dimension R1 to the minimum dimension R3 is, for example, 2.0 or more, or may be 2.2 or more, or may be 2.5 or more. Since the ratio R1 / R3 is 2.0 or more, the allowable current of the internal portion 26 of the through electrode 20 is sufficiently increased. The ratio R1 / R3 is, for example, 3.0 or less, or may be 2.8 or less.

[0069] The ratio R2 / R3 of the second dimension R2 to the minimum dimension R3 is, for example, 2.0 or more, and may be 2.2 or more, or 2.5 or more. Since the ratio R2 / R3 is 2.0 or more, the allowable current of the internal portion 26 of the through electrode 20 is sufficiently increased. The ratio R2 / R3 is, for example, 3.0 or less, and may be 2.8 or less. The ratio R2 / R3 may be the same as or different from the ratio R1 / R3.

[0070] It is preferable that the difference between the first dimension R1 and the second dimension R2 is small. The ratio R2 / R1 of the second dimension R2 to the first dimension R1 is, for example, 0.8 or more, and may be 0.9 or more. The ratio R2 / R1 is, for example, 1.2 or less, and may be 1.1 or less. By reducing the difference between the first dimension R1 and the second dimension R2, it is possible to efficiently increase the allowable current of the through electrode 20 while suppressing defects such as voids.

[0071] It is preferable that the first dimension R1 is sufficiently small with respect to the second pitch P2 of the through holes 15. The ratio P2 / R1 of the second pitch P2 to the first dimension R1 is, for example, 1.5 or more, or may be 1.6 or more, or 1.8 or more, or may be 2.0 or more. P2 / R1 is, for example, 3.0 or less, or may be 2.5 or less, or may be 2.3 or less.

[0072] As will be described in the examples, the dimensions of the through hole 15 may be determined to satisfy the condition that "when a direct current of 1 A flows through the through electrode 20, the temperature rise occurring in the through electrode 20 is 10°C or less." A test in which a current is passed through the through electrode 20 and the temperature is measured is carried out based on JIS C 5012:1993. A current is passed through the through electrode 20 until the temperature stabilizes. In the following description, the above condition is also referred to as a current-withstand condition. A through electrode 20 that satisfies the current-withstand condition is also referred to as a "through electrode 20 having current-withstand capability."

[0073] A through electrode 20 that satisfies the conditions for current resistance preferably includes four or more internal portions 26, has a first dimension R1 and a second dimension R2 of 70 μm or more, and has a minimum dimension R3 of 35 μm or more.

[0074] 5, the minimum portion 163 may be located midway between the first surface 13 and the second surface 14 in the thickness direction of the substrate 12. In Fig. 5, the symbol K3 represents the distance from the first surface 13 to the minimum portion 163 in the thickness direction of the substrate 12. When the minimum portion 163 is located midway between the first surface 13 and the second surface 14, the ratio K3 / T0 of the distance K3 to the thickness T0 of the substrate is 0.50.

[0075] Although not shown, the position of the minimum portion 163 in the thickness direction of the substrate 12 may be shifted from the midpoint between the first surface 13 and the second surface 14. That is, the ratio K3 / T0 may be shifted from 0.50. The ratio K3 / T0 may be, for example, 0.40 or more, or 0.45 or more. The ratio K3 / T0 may be, for example, 0.60 or less, or 0.55 or less.

[0076] 6 is a cross-sectional view showing an example of the through electrode 20. The internal portion 26 of the through electrode 20 is partially located in the through hole 15. "Partially" means that the entire space of the through hole 15 is not occupied by the internal portion 26. The internal portion 26 extends along the wall surface 16 of the through hole 15 from the first surface 13 to the second surface 14.

[0077] The through electrode 20 includes a conductive material. The through electrode 20 includes at least a plating layer 201. The plating layer 201 is a conductive layer formed by a plating method such as electrolytic plating. The through electrode 20 may include a seed layer 202. The seed layer 202 is located between the plating layer 201 and a surface of the substrate 12, such as the first surface 13, the second surface 14, or the wall surface 16. The seed layer 202 is a conductive layer formed by physical film formation such as sputtering.

[0078] Most of the through electrode 20 is formed by the plating layer 201. The ratio of the thickness of the plating layer 201 to the thickness of the through electrode 20 located on the wall surface 16 is, for example, 0.80 or more, and may be 0.90 or more.

[0079] The plating layer 201 may contain a metal such as copper, gold, silver, platinum, rhodium, tin, aluminum, nickel, titanium, chromium, or zinc, or an alloy using any of these metals. The seed layer 202 may contain a metal material such as copper, nickel, titanium, chromium, or zinc. The seed layer 202 may also contain a compound of these metal materials.

[0080] The internal portion 26 of the through electrode 20 may include a third portion 23, a fourth portion 24, and a closed portion 25. The closed portion 25 is located on the smallest portion 163 of the wall surface 16 of the through hole 15. The closed portion 25 closes the through hole 15 at the smallest portion 163. The third portion 23 is located on the wall surface 16 between the first portion 21 and the closed portion 25. The third portion 23 is connected to the first portion 21 and the closed portion 25. The fourth portion 24 is located on the wall surface 16 between the second portion 22 and the closed portion 25. The fourth portion 24 is connected to the second portion 22 and the closed portion 25.

[0081] The closed portion 25 includes a first closed surface 251 and a second closed surface 252. The first closed surface 251 is the surface of the closed portion 25 facing the first surface 13. The second closed surface 252 is the surface of the closed portion 25 facing the second surface 14.

[0082] The third portion 23 and the fourth portion 24 extend along the wall surface 16 of the through hole 15 so as to surround the center of the through hole 15 in a plan view.

[0083] The first portion 21, the second portion 22, the third portion 23, the fourth portion 24 and the closed portion 25 of the through electrode 20 may all include the plating layer 201 and the seed layer 202 described above.

[0084] (Internal Resin) The internal resin 30 is partially located in the through hole 15. The internal resin 30 is made of a resin material filled in the space of the through hole 15 where no through electrode 20 is present. The internal resin 30 includes a first internal resin 31 located inside the third portion 23 of the through electrode 20 and a second internal resin 32 located inside the fourth portion 24 of the through electrode 20. The "inside" refers to the direction approaching the center point C2 of the through hole 15 in a planar view. The "outside" described below refers to the direction moving away from the center point C2 of the through hole 15 in a planar view.

[0085] The internal resin 30 includes an insulating resin material, such as an organic material such as polyimide, epoxy, acrylic, or polyphenyl ether.

[0086] The dimensions of the components of the through electrode 20 will be described with reference to Fig. 7. Fig. 7 is a cross-sectional view showing an example of the dimensions of the through electrode 20. In Fig. 7, the internal resin 30 is omitted.

[0087] 7, symbol K1 represents the maximum distance from the first surface 13 to the first closed surface 251 of the closed portion 25 in the thickness direction of the substrate 12. Distance K1 is also referred to as the first distance. Symbol K2 represents the maximum distance from the second surface 14 to the second closed surface 252 of the closed portion 25 in the thickness direction of the substrate 12. Distance K2 is also referred to as the second distance. Symbol T5 represents the thickness of the closed portion 25. The thickness T5 is calculated by subtracting the first distance K1 and the second distance K2 from the thickness T0 of the substrate 12. That is, T5 = T0 - (K1 + K2).

[0088] The greater the thickness T5 of the closed portion 25, the higher the allowable current of the through electrode 20. However, the greater the thickness T5 of the closed portion 25, the more likely defects such as voids are to occur in the plating layer 201. In consideration of these points, it is preferable that the first distance K1 and the second distance K2 are relatively large.

[0089] The ratio K1 / T0 of the first distance K1 to the thickness T0 of the substrate 12 is, for example, 0.10 or more, or may be 0.15 or more, or may be 0.20 or more. The ratio K1 / T0 is, for example, 0.40 or less, or may be 0.35 or less, or may be 0.30 or less.

[0090] The ratio K2 / T0 of the second distance K2 to the thickness T0 of the substrate 12 is, for example, 0.10 or more, or may be 0.15 or more, or may be 0.20 or more. The ratio K2 / T0 is, for example, 0.40 or less, or may be 0.35 or less, or may be 0.30 or less. The ratio K2 / T0 may be the same as or different from the ratio K1 / T0.

[0091] The ratio T5 / T0 of the thickness T5 of the closing portion 25 to the thickness T0 of the substrate 12 is, for example, 0.20 or more, and may be 0.25 or more. The ratio T5 / T0 is, for example, 0.40 or less, and may be 0.35 or less.

[0092] In FIG. 7 , the symbol θ1 represents the angle between the first surface 13 and the wall surface 16 at the first end 161. The angle θ1 may be greater than 90°. Because the through-hole 15 includes the minimum portion 163, the angle θ1 can be greater than 90°. The angle θ1 is, for example, 95° or greater, 100° or greater, or 105° or greater. The angle θ1 is, for example, 150° or less, 135° or less, or 120° or less.

[0093] 7, the symbol θ2 represents the angle between the second surface 14 and the wall surface 16 at the second end 162. Similar to the angle θ1, the angle θ2 may be greater than 90°. The numerical range for the angle θ2 may be the same as the numerical range for the angle θ1 described above.

[0094] If the thermal expansion coefficient of the through electrode 20 differs from the thermal expansion coefficient of the substrate 12, a change in the temperature of the through electrode 20 causes expansion or contraction of the through electrode 20 relative to the substrate 12. The expansion or contraction generates stress between the substrate 12 and the through electrode 20. Stress caused by temperature changes is also called thermal stress. It is believed that expansion or contraction of the internal portion 26 of the through electrode 20 generates large thermal stress at the first end 161 and the second end 162 of the through hole 15.

[0095] In the present embodiment, since the through hole 15 includes the narrowest portion 163, the angle θ1 and the angle θ2 can be greater than 90°. The angle θ1 and the angle θ2 being greater than 90° can reduce thermal stress at the first end 161 and the second end 162.

[0096] 7 , the symbol T3 represents the thickness of the third portion 23 of the through electrode 20. The thickness T3 of the third portion 23 is determined at a position that is a distance S3 away from the first surface 13 in the thickness direction of the substrate 12. The distance S3 is 50 μm. The symbol T4 represents the thickness of the fourth portion 24 of the through electrode 20. The thickness T4 of the fourth portion 24 is determined at a position that is a distance S4 away from the second surface 14 in the thickness direction of the substrate 12. The distance S4 is 50 μm. Both the thickness T3 and the thickness T4 are dimensions of the through electrode 20 in the planar direction of the first surface 13.

[0097] The larger the thickness T3 and the thickness T4, the higher the allowable current of the through electrode 20. However, the larger the thickness T3 and the thickness T4, the lower the uniformity of the thickness of the third portion 23 and the thickness of the fourth portion 24.

[0098] The thicknesses T3 and T4 are, for example, 20 μm or more, or may be 25 μm or more, or 30 μm or more. The thicknesses T3 and T4 are, for example, 50 μm or less, or may be 40 μm or less, or may be 35 μm or less.

[0099] By appropriately determining the upper limits of the thickness T3 and the thickness T4, uniformity in the thickness of the third portion 23 and the thickness of the fourth portion 24 can be ensured.

[0100] The thickness uniformity of the third portion 23 is evaluated by measuring the thickness of the third portion 23 at multiple positions in the thickness direction of the substrate 12. For example, if the difference between the maximum and minimum values ​​of the thicknesses T3, T31, and T32 of the third portion 23 is 0.10 μm or less, the thickness variation of the third portion 23 is determined to be 0.10 μm or less. The thickness T3 is the thickness of the third portion 23 measured at a position that is a distance S3 away from the first surface 13 in the thickness direction of the substrate 12. The thickness T31 is the thickness of the third portion 23 measured at a position that is (S3 + 20 μm) away from the first surface 13 in the thickness direction of the substrate 12. The thickness T32 is the thickness of the third portion 23 measured at a position that is (S3 - 20 μm) away from the first surface 13 in the thickness direction of the substrate 12.

[0101] As with the third portion 23, the thickness uniformity of the fourth portion 24 is evaluated by measuring the thickness of the fourth portion 24 at multiple positions in the thickness direction of the substrate 12. For example, if the difference between the maximum and minimum values ​​of the thicknesses T4, T41, and T42 of the fourth portion 24 is 0.10 μm or less, the thickness variation of the fourth portion 24 is determined to be 0.10 μm or less. The thickness T4 is the thickness of the fourth portion 24 measured at a position that is a distance S4 away from the second surface 14 in the thickness direction of the substrate 12. The thickness T41 is the thickness of the fourth portion 24 measured at a position that is (S4 + 20 μm) away from the second surface 14 in the thickness direction of the substrate 12. The thickness T42 is the thickness of the fourth portion 24 measured at a position that is (S4 - 20 μm) away from the second surface 14 in the thickness direction of the substrate 12.

[0102] The ratio R3 / T3 of the minimum dimension R3 to the thickness T3 of the third portion 23 is, for example, 1.2 or more, or may be 1.5 or more, or 1.8 or more. Because the ratio R3 / T3 is 1.2 or more, the reliability of the through electrode 20 can be improved. The ratio R3 / T3 is, for example, 3.0 or less, or may be 2.4 or less, or may be 2.2 or less. Because the ratio R3 / T3 is 3.0 or less, the allowable current of the through electrode 20 is sufficiently increased.

[0103] The ratio R3 / T4 of the minimum dimension R3 to the thickness T4 of the fourth portion 24 is, similar to the ratio R3 / T3, for example, 1.2 or more, or may be 1.5 or more, or 1.8 or more. Similarly to the ratio R3 / T3, the ratio R3 / T4 is, for example, 3.0 or less, or may be 2.4 or less, or may be 2.2 or less.

[0104] The first portion 21 located on the first surface 13 has a thickness T1. The thickness T1 of the first portion 21 may be the same as the thickness T3 of the third portion 23. The thickness T1 of the first portion 21 may be greater or smaller than the thickness T3 of the third portion 23.

[0105] The second portion 22 located on the second surface 14 has a thickness T2. The thickness T2 of the second portion 22 may be the same as the thickness T4 of the fourth portion 24. The thickness T2 of the second portion 22 may be greater or less than the thickness T4 of the fourth portion 24.

[0106] The above-mentioned distances and dimensions of the substrate 12 and the through electrodes 20 are calculated based on a planar or cross-sectional image of the through electrode substrate 10 obtained by an electron microscope.

[0107] (Method for Manufacturing the Through Electrode Substrate) An example of a method for manufacturing the through electrode substrate 10 will be described.

[0108] (Through hole forming process) The substrate 12 is prepared. Next, a resist layer is provided on at least one of the first surface 13 or the second surface 14. After that, an opening is provided in the resist layer at a position corresponding to the through hole 15. Next, the substrate 12 is processed through the opening in the resist layer. As a result, as shown in FIG. 8 , the through hole 15 is formed in the substrate 12. The through hole 15 includes a wall surface 16 extending from the first surface 13 to the second surface 14. Methods that can be used to process the substrate 12 include dry etching, wet etching, and the like. Dry etching methods include reactive ion etching, deep reactive ion etching, and the like.

[0109] The through holes 15 may be formed in the substrate 12 by irradiating the substrate 12 with a laser. In this case, a resist layer does not need to be provided. The laser may be an excimer laser, an Nd:YAG laser, a femtosecond laser, or the like. When an Nd:YAG laser is used, a fundamental wave with a wavelength of 1064 nm, a second harmonic with a wavelength of 532 nm, or a third harmonic with a wavelength of 355 nm may be used.

[0110] The process of forming the through hole 15 in the substrate 12 may include a process of irradiating the first surface 13 and the second surface 14 of the substrate 12 with a laser and a wet etching process. In this case, the laser is used not to process the substrate 12, but to partially form modified layers on the first surface 13 and the second surface 14 of the substrate 12. In the wet etching process, the modified layer is preferentially etched compared to other portions. By wet etching, a recess is formed in the modified layer on the first surface 13, and a recess is formed in the modified layer on the second surface 14. The recess on the first surface 13 and the recess on the second surface 14 are connected to form the through hole 15 having a wall surface extending from the first surface 13 to the second surface 14.

[0111] (Through Electrode Forming Step) Subsequently, a through electrode forming step is performed to form the through electrode 20 in the through hole 15. The through electrode forming step includes a seed layer forming step and a plating layer forming step.

[0112] 9, in the seed layer formation step, a seed layer 202 is formed on the first surface 13, the second surface 14, and the wall surface 16 of the substrate 12. For example, the seed layer 202 is formed by sputtering.

[0113] The plating layer forming process includes a resist layer forming process, a plating process, and a resist layer removing process. Fig. 10 is a cross-sectional view showing an example of the resist layer forming process. In the resist layer forming process, a first resist layer 81 is formed partially on the seed layer 202 located on the first surface 13, and a second resist layer 82 is formed partially on the seed layer 202 located on the second surface 14. The first resist layer 81 and the second resist layer 82 are provided so as to cover areas of the seed layer 202 where the plating layer 201 is not formed.

[0114] 11 is a cross-sectional view showing an example of a plating process. In the plating process, a plating layer 201 is formed on a seed layer 202 by electrolytic plating. For example, the substrate 12 on which the seed layer 202 and the resist layers 81 and 82 are formed may be immersed in an electrolytic plating solution. By passing a current through the seed layer 202, the plating layer 201 is deposited on the seed layer 202.

[0115] The through hole 15 of the substrate 12 includes a thinnest portion 163. As the growth of the plating layer 201 progresses, the plating layers 201 formed along the circumferential direction of the through hole 15 in the thinnest portion 163 are connected to each other. That is, as shown in FIG. 11 , the through hole 15 is closed by the plating layer 201 in the thinnest portion 163. That is, a closed portion 25 is formed. In the subsequent plating process, the electrolytic plating solution circulates in the first space SP1 and the second space SP2. The first space SP1 is a space located between the thinnest portion 163 and the first surface 13 in the thickness direction of the substrate 12. The second space SP2 is a space located between the thinnest portion 163 and the second surface 14 in the thickness direction of the substrate 12.

[0116] The plating process before the through hole 15 in the thinnest portion 163 is closed by the plating layer 201 is also referred to as a first plating process. The plating process after the through hole 15 in the thinnest portion 163 is closed by the plating layer 201 is also referred to as a second plating process.

[0117] In the second plating step, the plating layer 201 grows in the first space SP1 and the second space SP2. For example, as shown in FIG. 12 , the closed portion 25 grows in the thickness direction of the substrate 12. The time of the second plating step is adjusted so that the above-mentioned numerical ranges for the first distance K1, the second distance K2, the thickness T5 of the closed portion 25, etc. are achieved. For example, the second plating step is performed so that the ratio of the thickness T5 of the closed portion 25 to the thickness T0 of the substrate 12 is 0.20 or more and 0.40 or less.

[0118] 13, a resist layer removal step is performed to remove the first resist layer 81 and the second resist layer 82. Then, a seed layer removal step is performed to remove a portion of the seed layer 202. In the seed layer removal step, as shown in FIG. 13, the seed layer 202 that overlaps the first resist layer 81 and the second resist layer 82 in plan view is removed. In this manner, the through electrode 20 is obtained.

[0119] (Resin Layer Forming Process) Next, a resin layer forming process is performed to form the internal resin 30. For example, a layer containing a resin material is formed on the first surface 13 and the second surface 14. For example, a resin film including a layer containing a resin material is attached to the first surface 13 and the second surface 14. Next, the layer containing the resin material located on the first surface 13 is pressed into the space inside the third portion 23. Furthermore, the layer containing the resin material located on the second surface 14 is pressed into the space inside the fourth portion 24. Next, the resin material is hardened. For example, the layer containing the resin material is irradiated with ultraviolet light. As a result, a first internal resin 31 and a second internal resin 32 are formed, as shown in FIG. 14 . In this manner, a through electrode substrate 10 including a substrate 12, through electrodes 20, and internal resin 30 is obtained.

[0120] Each of the plurality of through electrodes 20 of the through electrode substrate 10 of this embodiment includes a plurality of internal portions 26 located inside the plurality of through holes 15. That is, in this embodiment, a multi-via structure is adopted. Compared to conventional through electrodes, the through electrodes 20 of this embodiment can increase the allowable current of the through electrodes 20 while suppressing defects such as voids.

[0121] A conventional through electrode includes only one internal portion 26 located inside one through hole 15. A structure in which one through electrode 20 includes only one internal portion 26 located inside one through hole 15 is also called a single via structure. Two means can be considered to increase the allowable current of the through electrode 20 of the single via structure. The first means is to increase the first dimension R1 and second dimension R2 of the through hole 15. The second means is to increase the thickness of the plating layer 201.

[0122] In the first method, to satisfy the above-mentioned current resistance condition, it is preferable that the first dimension R1 and the second dimension R2 are 180 μm or more, and the minimum dimension R3 is 60 μm or more. If the first dimension R1 and the second dimension R2 are large, the space of the through hole 15 where no plating layer is present becomes large. As a result, there is a concern that defects such as voids may occur in the resin material. In the second method, if the thickness of the plating layer is large, defects such as voids may easily occur in the plating layer. Furthermore, the thickness of the plating layer may easily vary depending on the position.

[0123] In this embodiment, a multi-via structure is employed. In this multi-via structure, the allowable current of the through electrode 20 can be increased by increasing the number of through holes 15 that overlap one first portion 21 in a plan view. Therefore, according to this embodiment, even when the dimensions of the through holes 15 are small and the thickness of the plating layer 201 is thin, a sufficient allowable current of the through electrode 20 can be achieved. For example, even when the first dimension R1 and the second dimension R2 are less than 180 μm and the minimum dimension R3 is less than 60 μm, the above-mentioned current resistance condition can be satisfied. Therefore, compared to conventional through electrodes, the through electrode 20 of this embodiment can increase the allowable current of the through electrode 20 while suppressing defects such as voids.

[0124] Preferably, the through electrode 20 includes a first portion 21, a second portion 22, a third portion 23, a fourth portion 24, and a closed portion 25, and the internal resin 30 includes a first internal resin 31 and a second internal resin 32. In other words, the internal resin 30 is divided into the first internal resin 31 and the second internal resin 32 in the third direction D3 by the closed portion 25. With this configuration, the volumes of the first internal resin 31 and the second internal resin 32 are limited, thereby making it possible to suppress the occurrence of defects such as voids in the resin material.

[0125] The above-described embodiment can be modified in various ways. Modified examples will be described with reference to the drawings as necessary. In the following description and the drawings used in the following description, parts that can be configured similarly to the above-described embodiment will be designated by the same reference numerals as those used for corresponding parts in the above-described embodiment. Duplicate descriptions will be omitted. Furthermore, if it is clear that the effects obtained in the above-described embodiment can also be obtained in the modified examples, the description of those effects may be omitted.

[0126] 15 is a cross-sectional view showing a through electrode substrate 10 in a first modified example. The internal portion 26 of the through electrode 20 of the through electrode substrate 10 may not include the closed portion 25. For example, the internal portion 26 may be located on the wall surface 16 so as to reach from the first end 161 to the second end 162. A through electrode 20 including such an internal portion 26 is also referred to as a conformal via. The numerical ranges for the thicknesses T3 and T4 described above may be adopted as the numerical ranges for the thicknesses of the internal portion 26.

[0127] 15 , the through electrode substrate 10 may include a plurality of internal resins 30 located inside the internal portion 26 in each of the plurality of through holes 15. Each of the plurality of internal resins 30 may extend continuously inside the through hole 15 from the first surface 13 to the second surface 14.

[0128] 15 , the through hole 15 of the through electrode substrate 10 may include a minimum portion 163 located between a first end 161 and a second end 162. By including the minimum portion 163 in the through hole 15, the volume of the internal resin 30 can be reduced. By reducing the volume of the internal resin 30, it is possible to prevent defects such as voids from occurring in the resin material. The numerical ranges for the first dimension R1, the second dimension R2, and the minimum dimension R3 described above may be adopted as the numerical ranges for the dimensions of the through hole 15.

[0129] In the first modified example as well, each of the plurality of through electrodes 20 includes a plurality of internal portions 26 located inside the plurality of through holes 15. That is, the multi-via structure is also adopted in the first modified example. The first modified example also makes it possible to increase the allowable current of the through electrodes 20 while suppressing defects such as voids.

[0130] (Second Modification) Fig. 16 is a cross-sectional view showing a through hole electrode substrate 10 in a second modification. The through hole 15 of the through hole electrode substrate 10 in Fig. 16 differs from the through hole 15 of the through hole electrode substrate 10 in Fig. 15 in that it does not include the narrowest portion 163. For example, the through hole 15 of the through hole electrode substrate 10 in Fig. 16 may have a constant dimension regardless of the position in the third direction D3.

[0131] In order for a conformal via with a single via structure formed by a through hole 15 that does not include the smallest portion 163 to satisfy the above-mentioned current resistance conditions, it is preferable that, for example, the first dimension R1 and the second dimension R2 are 104 μm or more, and the thickness of the internal portion 26 is 30 μm or more.

[0132] In the second modification, each of the plurality of through electrodes 20 also includes a plurality of internal portions 26 located inside the plurality of through holes 15. That is, the multi-via structure is also adopted in the second modification. According to the second modification, even if the dimensions of the through holes 15 are small, it is possible to increase the allowable current of the through electrodes 20 while suppressing defects such as voids. For example, even if the first dimension R1 and the second dimension R2 are less than 104 μm, the above-mentioned condition for current resistance can be satisfied.

[0133] 17 is a cross-sectional view showing a through electrode substrate 10 in a third modified example. As shown in Fig. 17, the entire space of the through hole 15 may be occupied by an internal portion 26. A through electrode 20 including such an internal portion 26 is also called a filled via.

[0134] 17, when the entire space of the through-hole 15 is occupied by the internal portion 26, the thickness T6 of the internal portion 26 is equal to the thickness T0 of the substrate 12.

[0135] 17 , the through hole 15 of the through electrode substrate 10 may include a minimum portion 163 located between a first end 161 and a second end 162. By including the minimum portion 163 in the through hole 15, the volume of the internal portion 26 can be reduced. By reducing the volume of the internal portion 26, it is possible to prevent defects such as voids from occurring in the conductive material. The numerical ranges for the dimensions of the through hole 15 may be the numerical ranges for the first dimension R1, the second dimension R2, and the minimum dimension R3 described above.

[0136] In the third modification, each of the plurality of through electrodes 20 includes a plurality of internal portions 26 located inside the plurality of through holes 15. That is, the multi-via structure is also adopted in the first modification. The third modification can also increase the allowable current of the through electrodes 20 while suppressing defects such as voids.

[0137] (Fourth Modification) Fig. 18 is a cross-sectional view showing a through hole electrode substrate 10 in a fourth modification. The through hole 15 of the through hole electrode substrate 10 in Fig. 18 differs from the through hole 15 of the through hole electrode substrate 10 in Fig. 17 in that it does not include the thinnest portion 163. For example, the through hole 15 of the through hole electrode substrate 10 in Fig. 18 may have a constant dimension regardless of the position in the third direction D3.

[0138] In order for a filled via of a single via structure formed by a through hole 15 not including the minimum portion 163 to satisfy the above-mentioned condition for current resistance, it is preferable that the first dimension R1 and the second dimension R2 are 94 μm or more, for example.

[0139] In the fourth modification, each of the plurality of through electrodes 20 also includes a plurality of internal portions 26 located inside the plurality of through holes 15. That is, the multi-via structure is also adopted in the fourth modification. According to the fourth modification, even if the dimensions of the through holes 15 are small, it is possible to increase the allowable current of the through electrodes 20 while suppressing defects such as voids. For example, even if the first dimension R1 and the second dimension R2 are less than 94 μm, the above-mentioned condition for current resistance can be satisfied.

[0140] (Fifth Modification) Fig. 19 is a plan view showing a through hole electrode substrate 10 in a fifth modification. Fig. 20 is a cross-sectional view of the through hole electrode substrate 10 of Fig. 19 taken along line XX-XX. Fig. 21 is a cross-sectional view of the through hole electrode substrate 10 of Fig. 19 taken along line XXI-XXI.

[0141] The through-hole electrode substrate 10 may include a first wiring layer 50A and a second wiring layer 50B. The first wiring layer 50A is located on the first surface 13 of the substrate 12. The second wiring layer 50B is located on the second surface 14 of the substrate 12. The first wiring layer 50A includes at least one insulating layer and at least one conductive layer. The second wiring layer 50B includes at least one insulating layer and at least one conductive layer.

[0142] The first wiring layer 50A of the through electrode substrate 10 may include a plurality of first conductive layers 35 and a first resin layer 33. The plurality of first conductive layers 35 are each connected to the first portions 21 of the corresponding through electrodes 20. In other words, the corresponding first conductive layer 35 is connected to each of the first portions 21 of the plurality of through electrodes 20. The first resin layer 33 is located between the plurality of first portions 21 and the plurality of first conductive layers 35 in the third direction D3.

[0143] The first conductive layer 35 includes a conductive material, which may include a metal such as copper, gold, silver, platinum, rhodium, tin, aluminum, nickel, titanium, chromium, or zinc, or an alloy using any of these metals.

[0144] 19 , the plurality of first conductive layers 35 may each have an outline 351 that surrounds the plurality of through holes 15 in a plan view. The outline 351 of the first conductive layer 35 may extend along the outline 211 of the first portion 21 in a plan view.

[0145] The first resin layer 33 contains an insulating resin material, such as an organic material such as polyimide, epoxy, acrylic, or polyphenyl ether.

[0146] 19 and 21 , the first resin layer 33 may include a plurality of openings 331. Each of the plurality of openings 331 in the first resin layer 33 overlaps a first portion 21 in a plan view. One opening 331 may be formed in a portion of the first resin layer 33 that overlaps one first portion 21 in a plan view. A part of the first conductive layer 35 may be located in the opening 331. For example, the first conductive layer 35 may be connected to the first portion 21 of the through electrode 20 in the opening 331 in the first resin layer 33.

[0147] The opening 331 in the first resin layer 33 has a fourth dimension R4 in a plan view. The opening 331 may have a circular outline in a plan view. In this case, the fourth dimension R4 refers to the diameter of the opening 331. The opening 331 may have an outline other than a circle in a plan view. If an outline other than a circle is adopted, the fourth dimension R4 may be a circle-equivalent diameter. For example, the fourth dimension R4 may be the diameter of a circle having an area equal to the area of ​​the opening 331 in a plan view.

[0148] The fourth dimension R4 of the opening 331 may be larger than the first dimension R1 of the through hole 15. R4 / R1, which is the ratio of the fourth dimension R4 to the first dimension R1, is, for example, 1.2 or more, or may be 1.5 or more, or may be 2.0 or more. The larger R4 / R1 is, the more the contact resistance between the first portion 21 of the through electrode 20 and the first conductive layer 35 can be reduced. R4 / R1 is, for example, 5.0 or less, or may be 4.0 or less, or may be 3.0 or less.

[0149] 19 , symbol P4 represents the shortest distance between the center point C4 of the opening 331 and the center point C2 of the through hole 15 in a plan view. The shortest distance P4 may be smaller than the second pitch P2. P4 / P2, which is the ratio of the shortest distance P4 to the second pitch P2, is, for example, 0.9 or less, or may be 0.8 or less, or may be 0.7 or less.

[0150] 20 and 21 , the first resin layer 33 may include a portion in contact with the first surface 13. The first resin layer 33 may include a portion in contact with the first portion 21.

[0151] 21 , the first resin layer 33 may be integral with the first internal resin 31 of the internal resin 30. For example, the first resin layer 33 and the first internal resin 31 may be formed from the same resin film in the resin layer formation step.

[0152] 19 to 21 , the second wiring layer 50B of the through electrode substrate 10 may include a plurality of second conductive layers 36 and a second resin layer 34. The plurality of second conductive layers 36 are each connected to the second portions 22 of the corresponding through electrodes 20. In other words, the corresponding second conductive layer 36 is connected to each of the second portions 22 of the plurality of through electrodes 20. The second resin layer 34 is located between the plurality of second portions 22 and the plurality of second conductive layers 36 in the third direction D3.

[0153] The second conductive layer 36 includes a conductive material, which may include a metal such as copper, gold, silver, platinum, rhodium, tin, aluminum, nickel, titanium, chromium, or zinc, or an alloy using any of these metals.

[0154] Each of the plurality of second conductive layers 36 may have an outline 361 that includes the plurality of through holes 15 in a plan view. The outline 361 of the second conductive layer 36 may extend along the outline 221 of the second portion 22 in a plan view.

[0155] The second resin layer 34 includes an insulating resin material, such as an organic material such as polyimide, epoxy, acrylic, or polyphenyl ether.

[0156] The second resin layer 34 may include a plurality of openings 341. Each of the plurality of openings 341 in the second resin layer 34 overlaps the second portion 22 in a plan view. A part of the second conductive layer 36 may be located in the opening 341. For example, the second conductive layer 36 may be connected to the second portion 22 of the through electrode 20 in the opening 341 in the second resin layer 34.

[0157] 20 and 21 , the second resin layer 34 may include a portion in contact with the second surface 14. The second resin layer 34 may include a portion in contact with the second portion 22.

[0158] 21 , the second resin layer 34 may be integral with the second internal resin 32 of the internal resin 30. For example, the second resin layer 34 and the second internal resin 32 may be formed from the same resin film in the resin layer formation step.

[0159] (Sixth Modification) Fig. 22 is a cross-sectional view showing a through hole electrode substrate 10 in a sixth modification. The through hole electrode substrate 10 in Fig. 22 differs from the through hole electrode substrate 10 in Fig. 21 in that it includes a plurality of first bumps 51. The through hole electrode substrate 10 may also include a plurality of second bumps 52.

[0160] Each of the plurality of first bumps 51 may be located on a conductive layer of the first wiring layer 50A. For example, each of the plurality of first bumps 51 may be located on a first conductive layer 35 connected to the first portion 21 of the through electrode 20. The first bumps 51 may include solder.

[0161] Each of the second bumps 52 may be located on a conductive layer of the second wiring layer 50B. For example, each of the second bumps 52 may be located on the second conductive layer 36 connected to the second portion 22 of the through electrode 20. The second bumps 52 may include solder.

[0162] (Seventh Modification) Fig. 23 is a cross-sectional view showing a through hole electrode substrate 10 in a seventh modification. The through hole electrode substrate 10 in Fig. 23 differs from the through hole electrode substrate 10 in Fig. 22 in that it includes an element 60. The through hole electrode substrate 10 on which the element 60 is mounted is also called a mounting substrate.

[0163] The element 60 may be a semiconductor element. The semiconductor element includes a transistor formed of a semiconductor such as silicon. The semiconductor element is, for example, a CPU, a GPU, an FPGA, a sensor, a memory, etc. The semiconductor element may be a chiplet in which semiconductor elements such as a CPU, a GPU, an FPGA, a sensor, a memory, etc. are divided by function.

[0164] The element 60 may include a plurality of terminals 61. Each of the plurality of terminals 61 may be connected to a corresponding first bump 51.

[0165] Although not shown, the through hole electrode substrate 10 on which the element 60 is mounted may be mounted on a wiring substrate such as a motherboard. For example, each of the second bumps 52 may be connected to a corresponding pad on the wiring substrate.

[0166] 24 is a cross-sectional view showing a through hole electrode substrate 10 in an eighth modification. The first wiring layer 50A of the through hole electrode substrate 10 in Fig. 24 differs from the through hole electrode substrate 10 in Fig. 21 in that it includes a plurality of third conductive layers 39 and a third resin layer 37.

[0167] 24 , a plurality of third conductive layers 39 may be connected to each of a plurality of first conductive layers 35. In other words, a plurality of third conductive layers 39 may be connected to one first conductive layer 35. The third resin layer 37 is located between the first conductive layer 35 and the plurality of third conductive layers 39 in the third direction D3.

[0168] The third conductive layer 39 includes a conductive material, which may include a metal such as copper, gold, silver, platinum, rhodium, tin, aluminum, nickel, titanium, chromium, or zinc, or an alloy using any of these metals.

[0169] The third resin layer 37 contains an insulating resin material, such as an organic material such as polyimide, epoxy, acrylic, or polyphenyl ether.

[0170] As shown in FIG. 24 , the through hole electrode substrate 10 may include a plurality of first bumps 51 located on a plurality of third conductive layers 39 .

[0171] 25 , the through hole electrode substrate 10 may include an element 60. The element 60 may include a plurality of terminals 61. The plurality of terminals 61 may be connected to corresponding first bumps 51, respectively.

[0172] The number and arrangement of the third conductive layers 39 connected to one first conductive layer 35 are determined according to the number and arrangement of the terminals 61 of the element 60. According to the eighth modification, by connecting multiple third conductive layers 39 to one first conductive layer 35, the through electrode substrate 10 can accommodate various arrangements of multiple terminals 61.

[0173] 26 is a cross-sectional view showing a through electrode substrate 10 in a ninth modification. Two adjacent through electrodes 20 are also referred to as a first through electrode 20A and a second through electrode 20B. The first through electrode 20A may be connected to a power supply potential, and the second through electrode 20B may be connected to a ground potential.

[0174] The first conductive layer 35 connected to the first through electrode 20A may extend outward beyond an outline 211 of the first portion 21 of the first through electrode 20A. The first portion 21 of the second through electrode 20B may extend outward beyond an outline 351 of the first conductive layer 35 connected to the first portion 21 of the second through electrode 20B. In the third direction D3, a portion of the first conductive layer 35 connected to the first through electrode 20A and a portion of the first portion 21 of the second through electrode 20B may face each other. A portion of the first resin layer 33 is located between the portion of the first conductive layer 35 and the portion of the first portion 21 that face each other. A capacitor 70 is formed by the portion of the first conductive layer 35, the portion of the first portion 21, and the portion of the first resin layer 33.

[0175] The capacitance of the capacitor 70 is, for example, 1 pF or more, and may be 10 pF or more. The capacitance of the capacitor 70 is, for example, 1 nF or less, and may be 100 pF or less. The capacitor 70 can improve the stability of the power supply voltage of the element 60.

[0176] 27 is a cross-sectional view showing a through electrode substrate 10 in a tenth modification. The through electrode substrate 10 may include a plurality of through electrodes 80 having a single via structure in addition to a plurality of through electrodes 20 having a multi-via structure. The plurality of through electrodes 20 may be electrically connected to a power supply potential or a ground potential. The plurality of through electrodes 80 may be electrically connected to wiring or terminals through which data is transmitted.

[0177] 28 is a diagram showing an example of a product in which the through electrode substrate 10 is mounted. The through electrode substrate 10 can be used in a variety of products. For example, the through electrode substrate 10 is mounted in a notebook personal computer 110, a tablet terminal 120, a mobile phone 130, a smartphone 140, a digital video camera 150, a digital camera 160, a digital clock 170, a server 180, and the like.

[0178] 30 is a cross-sectional view showing a through hole electrode substrate 10 in a tenth modification. The example shown in Fig. 30 differs from the example shown in Fig. 23 in that a plurality of terminals 61 of an element 60 are connected to second bumps 52.

[0179] Although not shown, the through hole electrode substrate 10 on which the element 60 is mounted may be mounted on a wiring substrate such as a motherboard. For example, the plurality of first bumps 51 may be connected to corresponding pads on the wiring substrate.

[0180] (Twelfth Modification) Fig. 31 is a plan view showing a part of the through hole electrode substrate 10 in a twelfth modification. Fig. 32 is a cross-sectional view of the through hole electrode substrate 10 of Fig. 31 taken along the line XXXII-XXXII.

[0181] The first wiring layer 50A may include a plurality of first conductive layers 35 connected to the plurality of first portions 21, respectively. That is, a plurality of first conductive layers 35 may be connected to one first portion 21. The plurality of first conductive layers 35 connected to one first portion 21 may be spaced apart from each other in the in-plane direction of the first surface 13.

[0182] The first resin layer 33 of the first wiring layer 50A may include a plurality of openings 331. The plurality of openings 331 of the first resin layer 33 overlap the first portion 21 in a plan view. The plurality of openings 331 of the first resin layer 33 may overlap the through hole 15 and the internal portion 26 in a plan view. The plurality of first conductive layers 35 connected to one first portion 21 may each be connected to the first portion 21 at the opening 331.

[0183] The second wiring layer 50B may include a plurality of second conductive layers 36 connected to the plurality of second portions 22, respectively. That is, a plurality of second conductive layers 36 may be connected to one second portion 22. The plurality of second conductive layers 36 connected to one second portion 22 may be spaced apart from each other in the in-plane direction of the second surface 14.

[0184] The second resin layer 34 of the second wiring layer 50B may include a plurality of openings 341. The plurality of openings 341 of the second resin layer 34 overlap the second portions 22 in a plan view. The plurality of openings 341 of the second resin layer 34 may overlap the through holes 15 and the internal portions 26 in a plan view. The plurality of second conductive layers 36 connected to one second portion 22 may each be connected to the second portion 22 at the openings 341.

[0185] Each of the multiple internal portions 26 connected to one first portion 21 may be a filled via.

[0186] Although not shown, each of the multiple internal portions 26 may be a type of via other than a filled via. When each of the multiple internal portions 26 is a type of via other than a filled via, each of the multiple openings 331 of the first resin layer 33 does not have to overlap with the through hole 15 and the internal portion 26 in a plan view.

[0187] (Thirteenth Modification) Fig. 33 is a plan view showing a portion of a through hole electrode substrate 10 in a thirteenth modification. Fig. 34 is a cross-sectional view of the through hole electrode substrate 10 of Fig. 33 taken along line XXXIV-XXXIV. The through hole electrode substrate 10 includes a substrate 12, a plurality of through holes 20, a first wiring layer 50A, and a second wiring layer 50B.

[0188] The through electrode substrate 10 in the thirteenth modification example differs from the above-described embodiment and modifications in that the through electrode 20 does not include the first portion 21 and the second portion 22 .

[0189] In the through electrode substrate 10 of the thirteenth modification, the internal portions 26 located in the plurality of through holes 15 are each filled vias. Each of the plurality of internal portions 26 includes a first end face 261 and a second end face 262. The first end face 261 and the second end face 262 are end faces of the internal portion 26 in the thickness direction of the substrate 12. The first end face 261 is adjacent to the first surface 13. The second end face 262 is adjacent to the second surface 14.

[0190] The internal portion 26 has a thickness T6 in the thickness direction of the substrate 12. The thickness T6 of the internal portion 26 may be approximately equal to the thickness T0 of the substrate 12. The ratio T6 / T0 of the thickness T6 of the internal portion 26 to the thickness T0 of the substrate 12 is, for example, 0.80 or more, 0.85 or more, or 0.90 or more. The ratio T6 / T0 is, for example, 1.20 or less, 1.15 or less, or 1.10 or less. The thickness T6 is measured along an imaginary straight line that passes through the center point of the through hole 15 in a plan view and extends in the thickness direction. An internal portion 26 that satisfies the above numerical range for T6 / T0 is called a filled via.

[0191] In this modification, as in the above-described embodiment and modification, a single through electrode 20 is configured by electrically connecting multiple internal portions 26 to each other. That is, a multi-via structure is also adopted in this modification. Therefore, even if the dimensions of the through hole 15 are small, a sufficient allowable current of the through electrode 20 can be realized. Because the dimensions of the through hole 15 are small, the occurrence of defects such as voids in the internal portion 26 is suppressed.

[0192] In this modification, the multiple internal portions 26 are electrically connected to one another by at least one conductive layer included in the first wiring layer 50 A. The first wiring layer 50 A will be described.

[0193] 33 , the first wiring layer 50A may include a first resin layer 33 and a plurality of first conductive layers 35. As shown in FIG. 34 , the first resin layer 33 is located on the first surface 13. The first resin layer 33 may be in contact with the first surface 13.

[0194] The first resin layer 33 includes a plurality of openings 331 penetrating the first resin layer 33. As shown in Figures 33 and 34 , each of the plurality of openings 331 of the first resin layer 33 may overlap one through hole 15 and one internal portion 26 in plan view. In the example shown in Figures 33 and 34 , each of the four openings 331 overlaps a corresponding one of the four internal portions 26.

[0195] In a plan view, the first resin layer 33 may overlap the boundary between the wall surface 16 of the through hole 15 and the internal portion 26. For example, the first resin layer 33 may overlap a first end 161 of the wall surface 16 in a plan view. The first end 161 defines the boundary between the wall surface 16 and the internal portion 26 on the first surface 13.

[0196] Gas may be generated during the manufacturing process of the through hole electrode substrate 10. For example, gas may be generated from the internal portion 26. The gas may be, for example, water vapor. The gas may be generated during the process of heating the components of the through hole electrode substrate 10, for example.

[0197] The gas accumulates in gaps inside the through-hole electrode substrate 10. For example, the gas accumulates in gaps between the wall surface 16 and the internal portion 26. If the gas continues to accumulate in gaps inside the through-hole electrode substrate 10, there is a concern that deformation, damage, etc. may occur inside the through-hole electrode substrate 10 due to the pressure of the gas.

[0198] In this modification, the first resin layer 33 overlaps the boundary between the wall surface 16 and the internal portion 26 of the through hole 15 in a plan view. The molecular structure of the resin material constituting the first resin layer 33 is larger than the molecular structure of gases such as water vapor. Gas in the gap between the wall surface 16 and the internal portion 26 passes through the first resin layer 33 and is released to the outside of the through electrode substrate 10. Therefore, deformation, damage, and the like are prevented from occurring inside the through electrode substrate 10.

[0199] Each of the multiple first conductive layers 35 is located on the first resin layer 33. Each of the multiple first conductive layers 35 has a contour 351. The contour 351 is the outer edge of the first conductive layer 35 in a plan view. As shown in FIG. 33 , the contours 351 of the multiple first conductive layers 35 may each surround the first ends 161 of the wall surfaces 16 of the multiple through holes 15 in a plan view. In other words, the first ends 161 of the wall surfaces 16 of the multiple through holes 15 may be located inside the contour 351 of one first conductive layer 35.

[0200] Each first conductive layer 35 may be connected to a plurality of internal portions 26 at a plurality of openings 331. As a result, the plurality of internal portions 26 are electrically connected to one another by one first conductive layer 35. The plurality of internal portions 26 electrically connected by one first conductive layer 35 constitute one through electrode 20.

[0201] The multiple internal portions 26 may also be electrically connected to one another by at least one conductive layer included in the second wiring layer 50 B. The second wiring layer 50 B will now be described.

[0202] The second wiring layer 50B may include a second resin layer 34 and a plurality of second conductive layers 36. The second resin layer 34 is located on the second surface 14. The second resin layer 34 may be in contact with the second surface 14.

[0203] The second resin layer 34 includes a plurality of openings 341 that penetrate the second resin layer 34. The plurality of openings 341 of the second resin layer 34 may overlap the through-holes 15 and the internal portions 26, respectively, in a plan view.

[0204] The second resin layer 34 may overlap the boundary between the wall surface 16 of the through hole 15 and the internal portion 26 in a plan view. For example, the second resin layer 34 may overlap the second end 162 of the wall surface 16 in a plan view. The second end 162 defines the boundary between the wall surface 16 and the internal portion 26 on the second surface 14.

[0205] As with the first resin layer 33, the molecular structure of the resin material constituting the second resin layer 34 is larger than the molecular structure of gases such as water vapor. Gas in the gap between the wall surface 16 and the internal portion 26 passes through the second resin layer 34 and is released to the outside of the through-hole electrode substrate 10. Therefore, deformation, breakage, and the like inside the through-hole electrode substrate 10 are suppressed.

[0206] Each of the multiple second conductive layers 36 is located on the second resin layer 34. The outlines 361 of the multiple second conductive layers 36 may surround the second ends 162 of the wall surfaces 16 of the multiple through holes 15 in a plan view. That is, the second ends 162 of the wall surfaces 16 of the multiple through holes 15 may be located inside the outline 361 of one second conductive layer 36.

[0207] Each second conductive layer 36 may be connected to a plurality of internal portions 26 at a plurality of openings 341. As a result, the plurality of internal portions 26 are electrically connected to one another by one second conductive layer 36.

[0208] There are no particular limitations on the specific configuration of the internal portion 26 made of filled vias and the specific configuration of the through hole 15. For example, as shown in Fig. 34, the internal portion 26 and the through hole 15 may have constant dimensions regardless of their positions in the third direction D3.

[0209] 35 is a cross-sectional view showing an example of a through hole electrode substrate 10. The through hole 15 may include a minimum portion 163. In this case, the dimension of the internal portion 26 in the surface direction of the substrate 12 is minimum at the minimum portion 163.

[0210] 36 is a cross-sectional view showing an example of a through hole electrode substrate 10. An internal portion 26 consisting of a filled via may include a plating layer 201 and a seed layer 202. The plating layer 201 is located so as to overlap the center point of the through hole 15 in a plan view. The seed layer 202 is located between the plating layer 201 and the wall surface 16.

[0211] 37 is a cross-sectional view showing a through hole electrode substrate 10 in a fourteenth modification example. The through hole electrode substrate 10 includes a substrate 12, a plurality of through holes 20, a first wiring layer 50A, and a second wiring layer 50B.

[0212] The through electrode substrate 10 in the 14th modified example differs from the through electrode substrate 10 in the 13th modified example in that the first wiring layer 50A includes multiple insulating layers and multiple conductive layers stacked in the thickness direction of the substrate 12.

[0213] As shown in FIG. 37, the first wiring layer 50A may include a first resin layer 33, a third resin layer 37, a fifth resin layer 41, a first conductive layer 35, and a third conductive layer 39.

[0214] As in the thirteenth modification, a plurality of internal portions 26 may be electrically connected to one another by a single first conductive layer 35 .

[0215] The third resin layer 37 is located on the first resin layer 33 and the first conductive layer 35. The third resin layer 37 includes a plurality of openings 371. The third conductive layer 39 is located on the third resin layer 37. The third conductive layer 39 may be connected to the first conductive layer 35 at the plurality of openings 371 in the third resin layer 37.

[0216] The fifth resin layer 41 is located on the third resin layer 37 and the third conductive layer 39. The fifth resin layer 41 includes at least one opening 411. The opening 411 in the fifth resin layer 41 may overlap the third conductive layer 39 in a plan view. In other words, a portion of the third conductive layer 39 may be exposed in the opening 411 in the fifth resin layer 41.

[0217] The through-hole electrode substrate 10 may include a first bump 51 located on the conductive layer of the first wiring layer 50A. For example, as shown in FIG. 37 , the first bump 51 may be located on the third conductive layer 39 in an opening 411 of the fifth resin layer 41.

[0218] One first bump 51 may be electrically connected to a plurality of internal portions 26. In the example shown in Fig. 37 , one first bump 51 is electrically connected to a plurality of internal portions 26 via the third conductive layer 39 and the first conductive layer 35. The through-hole electrode substrate 10 may include a plurality of first bumps 51, each electrically connected to a plurality of internal portions 26.

[0219] Although not shown, the through hole electrode substrate 10 including the plurality of first bumps 51 may be mounted on a wiring substrate such as a motherboard. For example, the plurality of first bumps 51 may be connected to corresponding pads on the wiring substrate.

[0220] The opening in the resin layer of the first wiring layer 50A, which is related to the electrical path between the internal portion 26 and the first bump 51, preferably has a dimension of 50 μm or more in the in-plane direction of the first surface 13. For example, the dimension of the opening 331 in the first resin layer 33 and the dimension of the opening 371 in the third resin layer 37 are preferably each 50 μm or more. As a result, the electrical resistance in the path between the internal portion 26 and the first bump 51 is reduced. Therefore, a sufficient allowable current of the first bump 51 can be realized.

[0221] As shown in FIG. 37, the second wiring layer 50B may include a second resin layer 34, a fourth resin layer 38, a second conductive layer 36, and a plurality of fourth conductive layers 40.

[0222] As in the thirteenth modification, a plurality of internal portions 26 may be electrically connected to one another by a single second conductive layer 36 .

[0223] The fourth resin layer 38 is located on the second resin layer 34 and the second conductive layer 36. The fourth resin layer 38 includes a plurality of openings 381. The plurality of fourth conductive layers 40 are located on the fourth resin layer 38. The plurality of fourth conductive layers 40 may be connected to one second conductive layer 36 at the plurality of openings 381 in the fourth resin layer 38. The plurality of fourth conductive layers 40 connected to one second conductive layer 36 may be spaced apart from each other in the in-plane direction of the second surface 14.

[0224] Although not shown, the through electrode substrate 10 may include a plurality of second bumps respectively located on the plurality of fourth conductive layers 40. Although not shown, a plurality of terminals of the element may be connected to the corresponding second bumps.

[0225] 38 is a cross-sectional view showing a through hole electrode substrate 10 in a fifteenth modification example. The through hole electrode substrate 10 includes a substrate 12, a plurality of through holes 20, a first wiring layer 50A, and a second wiring layer 50B.

[0226] As shown in FIG. 38, the first wiring layer 50A may include a first resin layer 33, a third resin layer 37, a fifth resin layer 41, a plurality of first conductive layers 35 and a third conductive layer 39.

[0227] The through electrode substrate 10 in the fifteenth modified example differs from the through electrode substrate 10 in the fourteenth modified example in that the multiple internal portions 26 are electrically connected to each other by the third conductive layer 39 rather than the first conductive layer 35.

[0228] In this modification, each of the multiple first conductive layers 35 is connected to one internal portion 26 at one opening 331 in the first resin layer 33. For example, four first conductive layers 35 are each connected to one internal portion 26 at a corresponding one of the four openings 331. The multiple first conductive layers 35 are spaced apart from one another in the in-plane direction of the first surface 13. Therefore, the multiple internal portions 26 are not electrically connected by the first conductive layers 35.

[0229] The third resin layer 37 is located on the first resin layer 33 and the plurality of first conductive layers 35. The third resin layer 37 includes a plurality of openings 371. Each of the plurality of openings 371 overlaps a first conductive layer 35. One third conductive layer 39 is connected to the plurality of first conductive layers 35 at the plurality of openings 371. As a result, the plurality of internal portions 26 are electrically connected to one another by the third conductive layer 39. In this modification as well, the plurality of internal portions 26 that are electrically connected to one another constitute one through electrode 20. That is, in this modification as well, a multi-via structure is adopted.

[0230] Similar to the above-described embodiment and modified examples, the through electrode substrate 10 may include a plurality of through electrodes 20. Each of the plurality of through electrodes 20 may include a plurality of internal portions 26 electrically connected to each other by a third conductive layer 39.

[0231] The conductive layer of the first wiring layer 50A that electrically connects the multiple internal portions 26 may be a conductive layer other than the third conductive layer 39. For example, although not shown, a fifth conductive layer located on the fifth resin layer 41 may electrically connect the multiple internal portions 26.

[0232] The opening in the resin layer of the first wiring layer 50A, which is related to the electrical path between the internal portion 26 and the first bump 51, preferably has a dimension of 50 μm or more in the in-plane direction of the first surface 13. For example, the dimension of the opening 331 in the first resin layer 33 and the dimension of the opening 371 in the third resin layer 37 are preferably each 50 μm or more. As a result, the electrical resistance in the path between the internal portion 26 and the first bump 51 is reduced. Therefore, a sufficient allowable current of the first bump 51 can be realized.

[0233] As shown in FIG. 38, the second wiring layer 50B may include a second resin layer 34, a fourth resin layer 38, a plurality of second conductive layers 36, and a plurality of fourth conductive layers 40.

[0234] The multiple second conductive layers 36 may each be connected to the internal portion 26 at the opening 341 of the second resin layer 34. The multiple second conductive layers 36 may be spaced apart from one another in the in-plane direction of the second surface 14. In this case, the multiple internal portions 26 are not electrically connected by the second conductive layers 36.

[0235] The plurality of fourth conductive layers 40 may each be connected to the second conductive layer 36 at the openings 381 in the fourth resin layer 38. The plurality of fourth conductive layers 40 may be spaced apart from one another in the in-plane direction of the second surface 14. In this case, the plurality of internal portions 26 are not electrically connected by the fourth conductive layers 40.

[0236] Although several modifications to the above-described embodiment have been described, it is of course possible to combine a plurality of modifications as appropriate and apply them to the above-described embodiment.

[0237] Next, the embodiments of the present disclosure will be described more specifically with reference to examples. However, the embodiments of the present disclosure are not limited to the description of the following examples as long as they do not depart from the gist of the present disclosure.

[0238] (Example 1-1) A glass substrate having a thickness T0 of 800 μm was prepared as the substrate 12. Next, a plurality of through holes 15 shown in FIG. 4 were formed in the substrate 12. Each through hole 15 included a first end 161 having a first dimension R1, a second end 162 having a second dimension R2, and a minimum portion 163 having a minimum dimension R3. The first end 161, the second end 162, and the minimum portion 163 had a circular outline in a plan view. The first dimension R1, the second dimension R2, and the minimum dimension R3 were 85 μm, 85 μm, and 50 μm, respectively.

[0239] Next, a plurality of through electrodes 20 and a plurality of internal resins 30 shown in FIG. 4 were formed on the substrate 12. Each of the plurality of through electrodes 20 included a copper plating layer 201 and a seed layer 202. Each of the plurality of through electrodes 20 included one first portion 21, one second portion 22, and four internal portions 26. Each internal portion 26 included a third portion 23, a fourth portion 24, and a closed portion 25. The thickness T3 of the third portion 23 and the thickness T4 of the fourth portion 24 were both 20 μm. The distance from the first surface 13 to the first closed surface 251 of the closed portion 25 in the thickness direction of the substrate 12, i.e., the first distance K1, was 150 μm. The distance from the second surface 14 to the second closed surface 252 of the closed portion 25 in the thickness direction of the substrate 12, i.e., the second distance K2, was 150 μm. The thickness T5 of the closed portion 25 in the thickness direction of the substrate 12 was 500 μm. The second pitch P2 of the plurality of through holes 15 overlapping the first portion 21 of one through electrode 20 was 100 μm.

[0240] The reliability of the through hole electrode substrate 10 of Example 1-1 was evaluated.

[0241] In the reliability evaluation, the through hole electrode substrate 10 is subjected to 1000 thermal cycles, and then the appearance of the through hole electrode substrate 10 is observed. Specifically, the appearance of the through holes 20 of the through hole electrode substrate 10 is checked to see if there are any defects such as cracks. If there are any defects such as cracks, the through hole electrode substrate 10 being evaluated is judged as "NG." If there are no defects such as cracks, the through hole electrode substrate 10 is subjected to another 1000 thermal cycles, and then the appearance of the through hole electrode substrate 10 is observed. If there are any defects such as cracks after a total of 2000 thermal cycles, the through hole electrode substrate 10 being evaluated is judged as "Good." If there are no defects such as cracks after a total of 2000 thermal cycles, the through hole electrode substrate 10 being evaluated is judged as "Excellent."

[0242] One thermal cycle includes a temperature increase step, a high-temperature holding step, a temperature decrease step, and a low-temperature holding step. The temperature increase step is a step of changing the ambient environment of the through-hole electrode substrate 10 from -55°C to +125°C over 30 minutes. The high-temperature holding step is a step of holding the ambient environment of the through-hole electrode substrate 10 at +125°C for 30 minutes. The temperature increase step is a step of changing the ambient environment of the through-hole electrode substrate 10 from +125°C to -55°C over 30 minutes. The low-temperature holding step is a step of holding the ambient environment of the through-hole electrode substrate 10 at -55°C for 30 minutes.

[0243] In the through hole electrode substrate 10 of Example 1-1, defects such as cracks were generated after 1000 heat cycles, and the through hole electrode substrate 10 of Example 1-1 was judged as "NG".

[0244] Examples 1-2 to 1-9 The second pitch P2 of the plurality of through holes 15 was changed from the value in Example 1-1 to fabricate a through hole electrode substrate 10. Subsequently, the reliability of the through hole electrode substrate 10 was evaluated in the same manner as in Example 1-1. The results are shown in FIG.

[0245] (Example 2-1) A glass substrate having a thickness T0 of 400 μm was prepared as the substrate 12. Next, a plurality of through holes 15 shown in FIG. 15 were formed in the substrate 12. Each through hole 15 included a first end 161 having a first dimension R1, a second end 162 having a second dimension R2, and a minimum portion 163 having a minimum dimension R3. The first end 161, the second end 162, and the minimum portion 163 had a circular outline in a plan view. The first dimension R1, the second dimension R2, and the minimum dimension R3 were 85 μm, 85 μm, and 70 μm, respectively.

[0246] Next, a plurality of through electrodes 20 and a plurality of internal resins 30 shown in FIG. 15 were formed on the substrate 12. Each of the plurality of through electrodes 20 included a plating layer 201 and a seed layer 202 made of copper. Each of the plurality of through electrodes 20 included one first portion 21, one second portion 22, and four internal portions 26. Each internal portion 26 was located on the wall surface 16 so as to extend from the first end 161 to the second end 162. The thickness of the internal portion 26 was 20 μm. The second pitch P2 of the plurality of through holes 15 overlapping the first portion 21 of one through electrode 20 was 100 μm.

[0247] As in Example 1-1, the reliability of the through hole electrode substrate 10 was evaluated. The results are shown in FIG.

[0248] (Examples 2-2 to 2-9) The second pitch P2 of the plurality of through holes 15 was changed from the value in Example 2-1 to fabricate a through hole electrode substrate 10. Subsequently, similar to the case of Example 1-1, the reliability of the through hole electrode substrate 10 was evaluated. The results are shown in FIG.

[0249] (Example 3-1) A glass substrate having a thickness T0 of 400 μm was prepared as the substrate 12. Next, a plurality of through holes 15 shown in FIG. 16 were formed in the substrate 12. Each through hole 15 included a first end 161 having a first dimension R1 and a second end 162 having a second dimension R2. The first end 161 and the second end 162 had a circular outline in a plan view. The first dimension R1 and the second dimension R2 were 85 μm and 85 μm, respectively.

[0250] Next, a plurality of through electrodes 20 and a plurality of internal resins 30 shown in FIG. 16 were formed on the substrate 12. Each of the plurality of through electrodes 20 included a plating layer 201 and a seed layer 202 made of copper. Each of the plurality of through electrodes 20 included one first portion 21, one second portion 22, and four internal portions 26. Each internal portion 26 was located on the wall surface 16 so as to extend from the first end 161 to the second end 162. The thickness of the internal portion 26 was 20 μm. The second pitch P2 of the plurality of through holes 15 overlapping the first portion 21 of one through electrode 20 was 100 μm.

[0251] As in Example 1-1, the reliability of the through hole electrode substrate 10 was evaluated. The results are shown in FIG.

[0252] (Examples 3-2 to 3-9) The second pitch P2 of the plurality of through holes 15 was changed from the value in Example 3-1 to fabricate a through hole electrode substrate 10. Subsequently, similar to the case of Example 1-1, the reliability of the through hole electrode substrate 10 was evaluated. The results are shown in FIG.

[0253] (Example 4-1) A glass substrate having a thickness T0 of 500 μm was prepared as the substrate 12. Next, a plurality of through holes 15 shown in FIG. 17 were formed in the substrate 12. Each through hole 15 included a first end 161 having a first dimension R1, a second end 162 having a second dimension R2, and a minimum portion 163 having a minimum dimension R3. The first end 161, the second end 162, and the minimum portion 163 had a circular outline in a plan view. The first dimension R1, the second dimension R2, and the minimum dimension R3 were 85 μm, 85 μm, and 50 μm, respectively.

[0254] Next, a plurality of through electrodes 20 shown in FIG. 17 were formed on the substrate 12. Each of the plurality of through electrodes 20 included a plating layer 201 and a seed layer 202 made of copper. Each of the plurality of through electrodes 20 included one first portion 21, one second portion 22, and four internal portions 26. Each internal portion 26 occupied the entire space of the through hole 15. The second pitch P2 of the plurality of through holes 15 overlapping the first portion 21 of one through electrode 20 was 100 μm.

[0255] As in Example 1-1, the reliability of the through hole electrode substrate 10 was evaluated. The results are shown in FIG.

[0256] (Examples 4-2 to 4-9) The second pitch P2 of the plurality of through holes 15 was changed from the value in Example 4-1 to fabricate a through hole electrode substrate 10. Subsequently, similar to the case of Example 1-1, the reliability of the through hole electrode substrate 10 was evaluated. The results are shown in FIG.

[0257] (Example 5-1) A glass substrate having a thickness T0 of 600 μm was prepared as the substrate 12. Next, a plurality of through holes 15 shown in FIG. 18 were formed in the substrate 12. The through holes 15 included a first end 161 having a first dimension R1 and a second end 162 having a second dimension R2. The first end 161 and the second end 162 had a circular outline in a plan view. The first dimension R1 and the second dimension R2 were 50 μm and 50 μm, respectively.

[0258] Next, a plurality of through electrodes 20 shown in FIG. 18 were formed on the substrate 12. Each of the plurality of through electrodes 20 included a plating layer 201 and a seed layer 202 made of copper. Each of the plurality of through electrodes 20 included one first portion 21, one second portion 22, and four internal portions 26. Each internal portion 26 occupied the entire space of the through hole 15. The second pitch P2 of the plurality of through holes 15 overlapping the first portion 21 of one through electrode 20 was 100 μm.

[0259] As in Example 1-1, the reliability of the through hole electrode substrate 10 was evaluated. The results are shown in FIG.

[0260] (Examples 5-2 to 5-9) The second pitch P2 of the plurality of through holes 15 was changed from the value in Example 5-1 to fabricate a through hole electrode substrate 10. Subsequently, similar to the case of Example 1-1, the reliability of the through hole electrode substrate 10 was evaluated. The results are shown in FIG.

[0261] In the through electrodes 20 shown in Figure 4 or 15, the second pitch P2 is preferably 125 µm or more, and more preferably 300 µm or more. In the through electrodes 20 shown in Figure 16, the second pitch P2 is preferably 150 µm or more, and more preferably 350 µm or more. In the through electrodes 20 shown in Figure 17, the second pitch P2 is preferably 175 µm or more, and more preferably 350 µm or more. In the through electrodes 20 shown in Figure 18, the second pitch P2 is preferably 200 µm or more.

[0262] (Example 6) A through hole electrode substrate 10 was designed, which includes a filled via with a single via structure formed by a through hole 15 that does not include a minimum portion 163, and a copper plate located on the surface of the substrate 12. The substrate 12 is made of FR4 and has a thickness T0 of 400 μm. The copper plate has a width of 0.5 mm and a thickness of 18 μm. Next, a simulation was carried out to simulate the heat dissipation of the through hole electrode substrate 10. The finite element method was used in the simulation. It was assumed that heat is dissipated by convection on the surface of the copper plate. The heat flux formula is as follows: q = h (T Cu -T air ) q is the heat flux. The unit of heat flux q is W / m ２ h is the thermal conductivity in convection. The unit of thermal conductivity h is W / m ２ ・It is K. T Cu is the temperature of the copper plate. air is the temperature of the air. The thermal conductivity h is 373 [W / m ２ This value was calculated based on the heat dissipation characteristics of wiring boards described in JIS C 5012:1993. Specifically, in the test described in JIS C 5012:1993, a copper plate having a width of 0.6 mm and a thickness of 18 μm was placed on the board, and when a direct current of 1 A was passed through the copper plate, a temperature rise of 10°C occurred. Applying this test result to the above heat flux formula, the result was 373 [W / m ２The thermal conductivity h of copper is calculated as follows: Thermal conductivity of copper: 400 [W / m·K] Resistivity of copper: 1.68×10 －８ [Ω·m] Thermal conductivity of FR4: 0.3 [W / m·K]

[0263] Based on the simulation, the first dimension R1 and the second dimension R2 were calculated when the through hole electrode substrate 10 of Example 6 satisfied the above-mentioned current resistance condition. When the first dimension R1 and the second dimension R2 were 94 μm, the temperature rise was 10° C., and the value of the current flowing through the copper plate and the filled via was 0.96 A. Therefore, it is presumed that the above-mentioned current resistance condition is satisfied when the first dimension R1 and the second dimension R2 are 94 μm or more.

[0264] When a multi-via structure is employed, it is estimated that the above-mentioned condition for current resistance is met even if the first dimension R1 and the second dimension R2 are less than 94 μm.

[0265] The thermal stress generated between the substrate 12 and the filled via was calculated based on a simulation when the first dimension R1 and the second dimension R2 were 94 μm, the value of the current flowing through the copper plate and the filled via was 0.96 A, and the temperature of the through hole substrate 10 was 260° C. The thermal stress at the first end 161 of the through hole 15 showed a maximum value of 187 MPa.

[0266] Example 7 A through electrode substrate 10 was designed, which included a conformal via with a single via structure formed by a through hole 15 that did not include a minimum portion 163, and a copper plate located on the surface of the substrate 12.

[0267] As in Example 6, the first dimension R1, the second dimension R2, and the thickness of the internal portion 26 were calculated based on a simulation when the through hole electrode substrate 10 of Example 7 satisfied the above-mentioned current resistance condition. When the first dimension R1 and the second dimension R2 were 104 μm and the thickness of the internal portion 26 was 30 μm, the temperature rise was 10° C. and the value of the current flowing through the copper plate and the conformal via was 0.97 A. Therefore, it is presumed that the above-mentioned current resistance condition is satisfied when the first dimension R1 and the second dimension R2 are 104 μm or more and the thickness of the internal portion 26 is 30 μm or more.

[0268] When a multi-via structure is employed, it is estimated that the above-mentioned conditions for current resistance are met even if the first dimension R1 and the second dimension R2 are less than 104 μm and the thickness of the internal portion 26 is less than 30 μm.

[0269] The thermal stress generated between the substrate 12 and the conformal via was calculated based on a simulation when the first dimension R1 and the second dimension R2 were 104 μm, the thickness of the internal portion 26 was 30 μm, the value of the current flowing through the copper plate and the filled via was 0.97 A, and the temperature of the through hole electrode substrate 10 was 260° C. The thermal stress at the first end 161 of the through hole 15 showed a maximum value of 171 MPa.

[0270] Example 8 A through electrode substrate 10 was designed, which includes a through electrode with a single via structure formed by a through hole 15 including a minimum portion 163, and a copper plate located on the surface of the substrate 12. The through electrode includes an internal portion 26 shown in FIG.

[0271] As in Example 6, the first dimension R1, second dimension R2, minimum dimension R3, and thickness of the internal portion 26 were calculated based on simulations when the through hole electrode substrate 10 of Example 8 satisfied the above-mentioned current resistance conditions. When the first dimension R1 and second dimension R2 were 180 μm, the minimum dimension R3 was 60 μm, and the thicknesses T3 and T4 of the internal portion 26 were 30 μm, the temperature rise was 10°C, and the value of the current flowing through the copper plate and conformal via was 0.96 A. Therefore, it is presumed that the above-mentioned current resistance conditions are satisfied when the first dimension R1 and second dimension R2 are 180 μm or more, the minimum dimension R3 is 60 μm or more, and the thicknesses T3 and T4 of the internal portion 26 are 30 μm or more.

[0272] When a multi-via structure is adopted, it is estimated that the above-mentioned current resistance conditions are met even if the first dimension R1 and the second dimension R2 are less than 180 μm, the minimum dimension R3 is less than 60 μm, and the thickness T3 and the thickness T4 are less than 30 μm.

[0273] The thermal stress generated between the substrate 12 and the through electrode was calculated based on a simulation when the first dimension R1 and the second dimension R2 were 180 μm or more, the minimum dimension R3 was 60 μm or more, the thicknesses T3 and T4 of the internal portion 26 were 30 μm or more, the value of the current flowing through the copper plate and the filled via was 0.96 A, and the temperature of the through electrode substrate 10 was 260° C. The thermal stress at the first end 161 of the through hole 15 exhibited a maximum value of 93 MPa.

[0274] The maximum value of the thermal stress in Example 8 was approximately half of the maximum value of the thermal stress in Examples 6 and 7. In Example 8, since the through hole 15 includes the minimum portion 163, the angle θ1 and the angle θ2 are greater than 90°, which is thought to have reduced the thermal stress.

[0275] (Example 9) A through electrode substrate 10 was designed, which included through electrodes with a multi-via structure constituted by through holes 15 including a minimum portion 163, and a copper plate located on the surface of the substrate 12. One through electrode 20 included four internal portions 26 shown in Figure 4. The second pitch P2 of the four through holes 15 was 250 µm.

[0276] As in Example 6, the first dimension R1, second dimension R2, minimum dimension R3, and thickness of the internal portion 26 were calculated based on simulations when the through electrode substrate 10 of Example 9 satisfied the above-mentioned current resistance condition. The above-mentioned current resistance condition was satisfied when the first dimension R1 and second dimension R2 were 70 μm, the minimum dimension R3 was 35 μm, and the thicknesses T3 and T4 of the internal portion 26 were 30 μm. Therefore, it is presumed that the above-mentioned current resistance condition is satisfied when the through electrode 20 includes four or more internal portions 26, the first dimension R1 and second dimension R2 are 70 μm or more, the minimum dimension R3 is 35 μm or more, and the thicknesses T3 and T4 of the internal portion 26 are 30 μm or more.

[0277] 10 Through electrode substrate 12 Substrate 13 First surface 14 Second surface 15 Through hole 16 Wall surface 161 First end 162 Second end 163 Thinnest part 20 Through electrode 201 Plating layer 202 Seed layer 21 First part 211 Outline 212 Opening 22 Second part 23 Third part 24 Fourth part 25 Closed part 26 Internal part 30 Internal resin 31 First internal resin 32 Second internal resin 33 First resin layer 331 Opening 34 Second resin layer 35 First conductive layer 351 Outline 36 Second conductive layer 37 Third resin layer 38 Fourth resin layer 39 Third conductive layer 40 Fourth conductive layer 41 Fifth resin layer 50A First wiring layer 50B Second wiring layer 51 First bump 52 Second bump 60 Element 61 Terminal 70 Capacitor 81 First resist layer 82 Second resist layer

Claims

1. A through electrode substrate comprising: a substrate including a first surface, a second surface located opposite the first surface, and a plurality of through holes penetrating from the first surface to the second surface; and a plurality of through electrodes extending from the first surface through the through holes to the second surface, each of the plurality of through electrodes including a plurality of internal portions located inside the plurality of through holes, a first portion located on the first surface and connected to the plurality of internal portions, and a second portion located on the second surface and connected to the plurality of internal portions, each of the first portions of the plurality of through electrodes having an outline that surrounds a plurality of the through holes in a planar view.

2. The through electrode substrate according to claim 1, wherein each of the plurality of through holes has a wall surface including a first end connected to the first surface, a second end connected to the second surface, and a minimum portion located between the first end and the second end, and the through hole has a minimum dimension at the minimum portion that is the minimum value of the dimensions of the through hole in the planar direction of the first surface, and each of the plurality of internal portions includes a closing portion that closes the through hole at least at the minimum portion, a third portion located on the wall surface between the first portion and the closing portion, and a fourth portion located on the wall surface between the second portion and the closing portion.

3. The through electrode substrate according to claim 2, wherein the closed portion includes a first closed surface and a second closed surface, the first closed surface being a surface of the closed portion facing the first surface, the second closed surface being a surface of the closed portion facing the second surface, the through electrode having a first distance which is a maximum distance from the first surface to the first closed surface in the thickness direction of the substrate, and a second distance which is a maximum distance from the second surface to the second closed surface in the thickness direction of the substrate, a ratio of the first distance to a thickness of the substrate is 0.10 or more, and a ratio of the second distance to a thickness of the substrate is 0.10 or more.

4. The through electrode substrate according to claim 2, comprising a plurality of internal resins located inside each of the plurality of through holes, each of the plurality of internal resins including a first internal resin located inside the third portion and a second internal resin located inside the fourth portion.

5. The through electrode substrate according to claim 1, wherein each of the plurality of through holes has a wall surface including a first end connected to the first surface and a second end connected to the second surface, each of the plurality of internal portions is located on the wall surface so as to reach from the first end to the second end, and the through electrode substrate comprises a plurality of internal resins located inside the internal portions of the through electrodes within each of the plurality of through holes.

6. The through electrode substrate according to claim 5, wherein each of the plurality of through holes includes a minimum portion located between the first end and the second end, and the through holes have a minimum dimension at the minimum portion that is the minimum value of the dimensions of the through holes in the planar direction of the first surface.

7. The through electrode substrate according to any one of claims 4 to 6, wherein the first portions of the plurality of through electrodes each include a plurality of openings in which the internal resin is located.

8. The through hole electrode substrate according to claim 1, wherein the ratio of the thickness of the inner portion to the thickness of the substrate is 0.80 or more and 1.20 or less.

9. A through electrode substrate as described in any one of claims 1 to 6 and 8, comprising: a plurality of first conductive layers connected to the first portions of the plurality of through electrodes, respectively; and a first resin layer located between the first portions of the plurality of through electrodes and the plurality of first conductive layers in the thickness direction of the substrate.

10. The through electrode substrate according to claim 9, wherein each of the plurality of first conductive layers has an outline surrounding the plurality of through holes in a plan view.

11. The through electrode substrate as described in claim 10, comprising: a plurality of third conductive layers connected to one of the first conductive layers; and a third resin layer located between the one of the first conductive layers and the plurality of third conductive layers in the thickness direction of the substrate.

12. A through electrode substrate as described in claim 10, wherein the plurality of through electrodes include a first through electrode and a second through electrode adjacent to the first through electrode in a planar view, the first conductive layer connected to the first through electrode extends outwardly beyond the contour of the first portion of the first through electrode, the first portion of the second through electrode extends outwardly beyond the contour of the first conductive layer connected to the second through electrode, and a portion of the first conductive layer connected to the first through electrode faces a portion of the first portion of the second through electrode in the thickness direction of the substrate.

13. The through electrode substrate described in claim 9, wherein the first resin layer includes an opening in which a portion of the first conductive layer is located and which has a fourth dimension in a planar view, the through hole has a first dimension on the first surface, and the fourth dimension is greater than the first dimension.

14. A through electrode substrate comprising: a substrate including a first surface, a second surface located opposite the first surface, and a plurality of through holes penetrating from the first surface to the second surface; a plurality of through electrodes extending from the first surface through the through holes to the second surface; and a first wiring layer located on the first surface and including at least one insulating layer and at least one conductive layer, wherein each of the plurality of through electrodes includes a plurality of internal portions located inside the plurality of through holes, and a ratio of a thickness of the internal portions to a thickness of the substrate is 0.80 or more and 1.20 or less, the at least one insulating layer includes a first resin layer located on the first surface, the first resin layer includes a plurality of openings, each of the plurality of openings overlapping the internal portions in a planar view, the first resin layer overlaps a boundary between a wall surface of the through hole and the internal portions in a planar view, and the at least one conductive layer includes a conductive layer electrically connected to a plurality of the internal portions.

15. The through electrode substrate according to claim 14, wherein the at least one conductive layer includes a first conductive layer connected to a plurality of the internal portions in a plurality of the openings in the first resin layer, and the first conductive layer is the conductive layer that is electrically connected to a plurality of the internal portions.

16. The through electrode substrate according to claim 14, wherein the at least one conductive layer includes a plurality of first conductive layers each connected to the internal portion in a plurality of the openings of the first resin layer, and the conductive layer electrically connected to a plurality of the first conductive layers.

17. A through electrode substrate according to any one of claims 1 to 6, 8 and 14 to 16, wherein the through electrodes are arranged at a first pitch in the planar direction of the first surface, the through holes in which the internal portions included in one through electrode are located are arranged at a second pitch in the planar direction of the first surface, and the ratio of the first pitch to the second pitch is 2.0 or more.

18. The through hole electrode substrate according to claim 17, wherein a ratio of the first pitch to the second pitch is 5.0 or less.

19. The through hole electrode substrate of claim 17, wherein the through holes have a first dimension at the first surface, and a ratio of the second pitch to the first dimension is 1.5 or greater.

20. The through hole electrode substrate according to claim 19, wherein the first dimension is not less than 50 μm and not more than 100 μm.

21. A mounting board comprising: a through electrode substrate according to any one of claims 1 to 6, 8, and 14 to 16; and an element electrically connected to a plurality of the through electrodes of the through electrode substrate.

22. A method for manufacturing a through electrode substrate, comprising: a step of preparing a substrate including a first surface, a second surface located opposite the first surface, and a through hole penetrating from the first surface to the second surface; and a through electrode forming step of forming a plurality of through electrodes extending from the first surface through the through hole to the second surface, wherein each of the plurality of through electrodes includes a plurality of internal portions located inside the plurality of through holes, a first portion located on the first surface and connected to the plurality of internal portions, and a second portion located on the second surface and connected to the plurality of internal portions, and each of the first portions of the plurality of through electrodes has an outline that surrounds a plurality of the through holes in a planar view.

23. A method for manufacturing a through electrode substrate, comprising: a step of preparing a substrate including a first surface, a second surface located opposite to the first surface, and a through hole penetrating from the first surface to the second surface; a step of forming a through electrode forming a plurality of through electrodes that reach the second surface from the first surface through the through hole; and a step of forming a first wiring layer located on the first surface and including at least one insulating layer and at least one conductive layer, wherein each of the plurality of through electrodes includes a plurality of internal portions located inside the plurality of through holes, each of the plurality of internal portions being filled vias, the at least one insulating layer includes a first resin layer located on the first surface, the first resin layer includes a plurality of openings, each of the plurality of openings overlapping the internal portion in a planar view, the first resin layer overlaps a boundary between a wall surface of the through hole and the internal portion in a planar view, and the at least one conductive layer includes a conductive layer electrically connected to the plurality of internal portions.

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