Through electrode substrate and method for manufacturing the same

Abstract

To provide a through electrode substrate ensuring high airtightness at a low cost and a method for manufacturing the same.SOLUTION: A through electrode substrate includes: a substrate 12 including a first surface 13 and a second surface 14 located on an opposite side of the first surface, and provided with a through hole 20; and a through electrode 22 located in the through hole. A sidewall 21 of the through hole includes: a tapered first sidewall part 21A tapering from the first surface to an inner side of the substrate; a tapered second sidewall part 21B tapering from the second surface to the inner side of the substrate; and a boundary part 21C in which a tip of the first sidewall part and a tip of the second sidewall part are coupled together. The through electrode fills at least the boundary part of the sidewall.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Embodiments of the present disclosure relate to a through electrode substrate and a method for manufacturing the same. [Background technology]

[0002] As disclosed in Patent Document 1, for example, a through electrode substrate includes a substrate including a first surface and a second surface, a plurality of holes provided in the substrate, and an electrode portion provided inside the hole so as to extend from the first surface side to the second surface side of the substrate. Such through electrode substrates have been used for various purposes and are mounted in electronic devices such as mobile phones. In the following description, the electrode portion is referred to as a through electrode.

[0003] The through electrodes of such through electrode substrates are generally classified into a filled type in which the entire hole is filled, and a so-called conformal type in which the hole is provided on the inner peripheral surface of the hole and is hollow. The above-mentioned Patent Document 1 discloses a filled type through electrode. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-3925 A Summary of the Invention [Problem to be solved by the invention]

[0005] When the filled-type through electrode is entirely made of a conductive material, a through electrode substrate with excellent airtightness can be provided, but this requires a large amount of material and takes a long time to manufacture.

[0006] The embodiments of the present disclosure have been made in consideration of the above-mentioned circumstances, and an object of the present disclosure is to provide a through electrode substrate that can ensure high airtightness at low cost, and a manufacturing method thereof. [Means for solving the problem]

[0007] One embodiment of the present disclosure is a through electrode substrate comprising: a substrate including a first surface and a second surface opposite to the first surface, the substrate having a through hole; and a through electrode located in the through hole, wherein a sidewall of the through hole has a tapered first sidewall portion tapering from the first surface toward an inner side of the substrate, a tapered second sidewall portion tapering from the second surface toward an inner side of the substrate, and a boundary portion where an end portion of the first sidewall portion and an end portion of the second sidewall portion are joined to each other, and the through electrode fills at least the boundary portion of the sidewall.

[0008] In a through electrode substrate according to one embodiment of the present disclosure, at least one of an end face on the first surface side of the through electrode and an end face on the second surface side of the through electrode may have a recess that recesses toward the boundary portion.

[0009] Furthermore, the through electrode substrate according to an embodiment of the present disclosure may further include an organic material layer provided in the recess and including an organic material.

[0010] In the through hole electrode substrate according to the embodiment of the present disclosure, the maximum dimension of the boundary portion in an in-plane direction of the substrate may be 30 μm or more and 50 μm or less.

[0011] In the through electrode substrate according to the embodiment of the present disclosure, the substrate may be made of a glass substrate.

[0012] One embodiment of the present disclosure is a method for manufacturing a through electrode substrate, the method including: preparing a substrate including a first surface and a second surface opposite to the first surface, the substrate having a through hole, the sidewall of the through hole having a tapered first sidewall portion tapering from the first surface toward an inner side of the substrate, a tapered second sidewall portion tapering from the second surface toward an inner side of the substrate, and a boundary portion where an end portion of the first sidewall portion and an end portion of the second sidewall portion are joined to each other; growing a plating layer from the boundary side of the through hole and growing the plating layer until the plating layer fills at least the boundary portion; and forming a through electrode in the through hole using the plating layer.

[0013] A manufacturing method for a through electrode substrate according to one embodiment of the present disclosure may include growing the plating layer so that a recess is provided on at least one of an end face of the plating layer on the first surface side and an end face of the plating layer on the second surface side, the recess being recessed toward the boundary side.

[0014] Furthermore, the method for manufacturing a through hole electrode substrate according to an embodiment of the present disclosure may further include a step of providing an organic material layer containing an organic material in the recess.

[0015] In the method for manufacturing a through hole electrode substrate according to an embodiment of the present disclosure, the maximum dimension of the boundary portion in an in-plane direction of the substrate may be 30 μm or more and 50 μm or less.

[0016] In the method for manufacturing a through hole electrode substrate according to an embodiment of the present disclosure, the substrate may be a glass substrate. Effect of the Invention

[0017] According to the embodiments of the present disclosure, it is possible to provide a through electrode substrate that can ensure high airtightness at low cost. [Brief description of the drawings]

[0018] [Figure 1]1 is a cross-sectional view showing a through electrode substrate according to an embodiment. [Diagram 2] 2 is an enlarged cross-sectional view of a through hole and a through electrode of the through electrode substrate shown in FIG. [Diagram 3] 2A to 2C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 4] 2A to 2C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Diagram 5] 2A to 2C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 6] 2A to 2C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 7] 2A to 2C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 8] 2A to 2C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 9] FIG. 11 is a cross-sectional view showing a through electrode substrate according to another embodiment. [Figure 10] 10A to 10C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 11] 10A to 10C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 12] 10A to 10C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 13] 10A to 10C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 14] 10A to 10C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 15] FIG. 11 is a cross-sectional view showing a through electrode substrate according to yet another embodiment. [Figure 16] 16A to 16C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 17] 16A to 16C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 18] 16A to 16C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 19] 16A to 16C are diagrams illustrating a manufacturing process of the through hole electrode substrate shown in FIG. [Figure 20] FIG. 11 is a cross-sectional view showing a through electrode substrate according to yet another embodiment. [Figure 21] 1A to 1C are diagrams showing examples of products on which a through electrode substrate is mounted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, the through-hole electrode substrate and the manufacturing method thereof according to the embodiment of the present disclosure will be described in detail with reference to the drawings. Note that the embodiment shown below is an example of the embodiment of the present disclosure, and the present disclosure is not limited to these embodiments. In addition, in this specification, terms such as "substrate", "substrate", "sheet" and "film" are not distinguished from each other based only on the difference in name. For example, "substrate" and "substrate" are concepts that include members that can be called sheets and films. Furthermore, terms such as "parallel" and "orthogonal" and values ​​of length and angle, which specify the shape and geometric conditions and their degree, used in this specification, are interpreted to include the range in which similar functions can be expected without being bound by strict meaning. In addition, in the drawings referred to in this embodiment, the same parts or parts having similar functions are given the same or similar symbols, and repeated explanations thereof may be omitted. In addition, the dimensional ratios of the drawings may differ from the actual ratios for convenience of explanation, and some of the configurations may be omitted from the drawings.

[0020] Through-hole electrode substrate Hereinafter, an embodiment of the present disclosure will be described. First, the configuration of a through electrode substrate 10 according to this embodiment will be described. Fig. 1 is a cross-sectional view showing the through electrode substrate 10, and Fig. 2 is an enlarged view of a main part of Fig. 1.

[0021] The through electrode substrate 10 includes a substrate 12, a through electrode 22, a first wiring layer 30, a second wiring layer 40, a first organic material layer 50, and a second organic material layer 60. Each of the components of the through electrode substrate 10 will be described below.

[0022] (substrate) The substrate 12 includes a first surface 13 and a second surface 14 located on the opposite side to the first surface 13. The substrate 12 also has a plurality of through holes 20 extending from the first surface 13 to the second surface 14.

[0023] The substrate 12 includes an inorganic material having a certain insulating property. For example, the substrate 12 may be a glass substrate, a quartz substrate, a sapphire substrate, a resin substrate, a silicon substrate, a silicon carbide substrate, an alumina (Al 2 O 3 ) substrate, aluminum nitride (AlN) substrate, zirconia oxide (ZrO 2 ) substrate, or a laminate of such substrates. The substrate 12 may partially include a substrate made of a conductive material, such as an aluminum substrate or a stainless steel substrate.

[0024] An example of the glass used for the substrate 12 is non-alkali glass. The alkali-free glass is glass that does not contain an alkali component 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 an alkaline earth metal oxide such as calcium oxide or barium oxide. Examples of the alkali-free glass include EN-A1 manufactured by Asahi Glass Co., Ltd. and Eagle XG manufactured by Corning Co., Ltd. By including glass in the substrate 12, the insulating properties of the substrate 12 can be improved.

[0025] When the substrate 12 includes glass, the thickness of the substrate 12 is, for example, not less than 250 μm and not more than 450 μm.

[0026] As shown enlarged in Figure 2, side wall 21 of through hole 20 formed in substrate 12 has a tapered first side wall portion 21A that tapers from first surface 13 toward the inside of substrate 12, a tapered second side wall portion 21B that tapers from second surface 14 toward the inside of substrate 12, and a boundary portion 21C where the tip of first side wall portion 21A and the tip of second side wall portion 21B are joined to each other.

[0027] In this example, the first side wall portion 21A is circular in a plan view and tapers from the first surface 13 to the second surface 14. The second side wall portion 21B is circular in a plan view and tapers from the second surface 14 to the first surface 13. The first side wall portion 21A and the second side wall portion 21B are joined to each other at a boundary portion 21C located in the center of the substrate 12 in the thickness direction.

[0028] The tapered shape mentioned above means that the shape is "tapered" from a broad perspective, and is not limited to a shape in which the first side wall portion 21A and the second side wall portion 21B extend linearly in a cross-sectional view on a plane extending along the axial direction of the through hole 20 as shown in Figures 1 and 2. Even if the first side wall portion 21A and the second side wall portion 21B each extend in a curved shape overall in this cross-sectional view, include a curved portion in part, or have a straight portion and a curved portion, as long as the shape is "tapered" from a broad perspective, these shapes are included in the concept of a tapered shape.

[0029] 2, the angle α between each of the first side wall portion 21A and the second side wall portion 21B of the through hole 20 and the normal direction nd of the substrate 12 is 1.0 degree or more. This angle α is preferably set in the range of 1.0 degree or more and 3.0 degrees or less.

[0030] The length of through hole 20, i.e., the dimension of through hole 20 in the normal direction to first surface 13, is equal to the thickness of substrate 12. A dimension S1 (see FIG. 3) of an end of through hole 20 on the first surface 13 side in the in-plane direction of first surface 13 is, for example, 40 μm or more and 150 μm or less, and a dimension S2 (see FIG. 3) of an end of through hole 20 on the second surface 14 side in the in-plane direction of second surface 14 is, for example, 40 μm or more and 150 μm or less. A dimension S3, which is the maximum dimension of boundary portion 21C in the in-plane direction of first surface 13 to second surface 14, is 30 μm or more and 50 μm or less, and preferably 35 μm or more and 45 μm or less.

[0031] In this example, since boundary portion 21C has a circular cross section, dimension S3, which is the maximum dimension of boundary portion 21C in the in-plane direction, is the diameter of boundary portion 21C. In addition, the ratio of the length to the width of through hole 20, i.e., the aspect ratio of through hole 20, may be, for example, 4 or more and 10 or less.

[0032] (Through electrode) The through electrode 22 is a conductive member located inside the through hole 20. The through electrode 22 is electrically connected to each of the first wiring layer 30 and the second wiring layer 40, but in Fig. 2, for convenience of explanation, the boundary between the through electrode 22 and the first wiring layer 30 and the boundary between the through electrode 22 and the second wiring layer 40 are indicated by two-dot chain lines.

[0033] As shown in FIG. 2, the through electrode 22 includes a seed layer 221 and a plating layer 222 arranged in this order from the sidewall 21 side of the through hole 20 toward the center side of the through hole 20 .

[0034] The seed layer 221 is a conductive layer that serves as a base for growing the plating layer 222 by precipitating metal ions in a plating solution during an electrolytic plating process in which the plating layer 222 is formed by electrolytic plating. The seed layer 221 may be made of a conductive material such as copper, titanium, or a combination of these. The material of the seed layer 221 may be the same as or different from the material of the plating layer 222. The seed layer 221 has a thickness of 50 nm or more. The seed layer 221 is formed by a sputtering method, a vapor deposition method, or a combination of a sputtering method and a vapor deposition method.

[0035] The plating layer 222 is a conductive layer formed by a plating process. The material constituting the plating layer 222 may be metals such as copper, gold, silver, platinum, rhodium, tin, aluminum, nickel, chromium, or alloys using these metals, or layers of these metals.

[0036] As is clear from FIG. 1 and FIG. 2, the through electrode 22 in this embodiment fills at least the boundary portion 21C of the side wall 21. More specifically, the through electrode 22 in this embodiment fills the range from the midpoint of the first side wall portion 21A between the first surface 13 and the boundary portion 21C to the midpoint of the second side wall portion 21B between the second surface 14 and the boundary portion 21C. On the other hand, the through electrode 22 covers the portion from the midpoint of the first side wall portion 21A to the first surface 13 and the portion from the midpoint of the second side wall portion 21B to the second surface 14 in a state in which a space is formed on the center side of the through hole 20. That is, the through electrode 22 is formed in a conformal via state in the portion close to the first surface 13 and the portion close to the second surface 14. As a result, in this embodiment, the end face of the through electrode 22 on the first surface 13 side and the end face on the second surface 14 side are provided with recesses 22A and 22B recessed toward the boundary portion 21C side.

[0037] (1st wiring layer) The first wiring layer 30 is a layer having conductivity located on the first surface 13, and in the illustrated example, the first wiring layer 30 and the through electrode 22 are electrically connected. The first wiring layer 30 includes a seed layer 221 and a plating layer 222 stacked in order on the first surface 13 of the substrate 12, similar to the through electrode 22. The material constituting the first wiring layer 30 is the same as the material constituting the through electrode 22. The seed layer 221 of the first wiring layer 30 is formed simultaneously with the seed layer 221 of the through electrode 22, and is formed by a sputtering method, a vapor deposition method, or a combination of a sputtering method and a vapor deposition method. The plating layer 222 of the first wiring layer 30 is formed simultaneously with the plating layer 222 of the through electrode 22. The thickness of the first wiring layer 30 is, for example, 1 μm or more and 20 μm or less.

[0038] (2nd wiring layer) The second wiring layer 40 is a layer having conductivity located on the second surface 14, and in the illustrated example, the second wiring layer 40 and the through electrode 22 are electrically connected. The second wiring layer 40 includes a seed layer 221 and a plating layer 222 stacked in order on the second surface 14 of the substrate 12, similar to the through electrode 22 and the first wiring layer 30. The material constituting the second wiring layer 40 is the same as the material constituting the through electrode 22. The seed layer 221 of the second wiring layer 40 is formed simultaneously with the seed layer 221 of the through electrode 22, and is formed by a sputtering method, a vapor deposition method, or a combination of a sputtering method and a vapor deposition method. The plating layer 222 of the second wiring layer 40 is formed simultaneously with the plating layer 222 of the through electrode 22. The thickness of the second wiring layer 40 is, for example, 1 μm or more and 20 μm or less.

[0039] (1st organic material layer) The first organic material layer 50 is a layer including an organic material provided in the recess 22A on the first surface 13 side of the through electrode 22, and has insulating properties. In this example, the recess 22A is filled with the first organic material layer 50. The organic material of the first organic material layer 50 can be polyimide, epoxy, or the like. In the illustrated example, the position of the end face of the first organic material layer 50 on the first surface 13 side and the position of the first surface 13 are equivalent in the position in the normal direction of the first surface 13. The term "equivalent" here means that the difference in the position of the faces is 10 μm or less. Note that the position of the end face of the first organic material layer 50 on the first surface 13 side and the position of the surface of the first wiring layer 30 may be equivalent in the position in the normal direction of the first surface 13. The end face of the first organic material layer 50 on the first surface 13 side may be located closer to the boundary portion 21C than the first surface 13, or may be located between the first surface 13 and the surface of the first wiring layer 30.

[0040] (Second organic material layer) The second organic material layer 60 is a layer containing an organic material provided in the recess 22B on the second surface 14 side of the through electrode 22, and has insulating properties similar to the first organic material layer 50. The second organic material layer 60 is also filled in the recess 22A. The organic material of the second organic material layer 60 may be polyimide, epoxy, or the like. In the illustrated example, the position of the end face of the second organic material layer 60 on the second surface 14 side and the position of the second surface 14 are equivalent in the position in the normal direction of the second surface 14. The term "equivalent" here means that the difference in the position of the surface is 10 μm or less, as described above. Note that the position of the end face of the second organic material layer 60 on the second surface 14 side and the position of the surface of the second wiring layer 40 may be equivalent in the position in the normal direction of the second surface 14. In addition, the end face of the second organic material layer 60 on the second surface 14 side may be located closer to the boundary portion 21C than the second surface 14, or may be located between the second surface 14 and the surface of the second wiring layer 40.

[0041] Manufacturing method of through-hole electrode substrate Hereinafter, an example of a method for manufacturing the above-mentioned through electrode substrate 10 will be described with reference to FIGS.

[0042] (Through hole formation process) First, the substrate 12 is prepared. Next, a resist layer is provided on at least one of the first surface 13 and the second surface 14. After that, an opening is provided in the resist layer at a position corresponding to the through hole 20. Next, the substrate 12 is processed at the opening in the resist layer, thereby forming the through hole 20 in the substrate 12 as shown in FIG. 3. Methods for processing the substrate 12 include dry etching methods such as reactive ion etching and deep reactive ion etching, and wet etching.

[0043] The through holes 20 may be formed in the substrate 12 by irradiating the substrate 12 with a laser. In this case, the resist layer does not need to be provided. As a laser for the laser processing, an excimer laser, a Nd:YAG laser, a femtosecond laser, or the like can be used. 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, a third harmonic with a wavelength of 355 nm, or the like can be used.

[0044] Laser irradiation and wet etching can also be appropriately combined. Specifically, first, an altered layer is formed in the region of the substrate 12 where the through hole 20 is to be formed by laser irradiation. Then, the substrate 12 is immersed in hydrogen fluoride or the like to etch the altered layer. In this way, the through hole 20 can be formed in the substrate 12. Alternatively, the through hole 20 can be formed in the substrate 12 by a blasting process in which an abrasive is sprayed on the substrate 12.

[0045] For example, by processing the substrate 12 from both the first surface 13 and the second surface 14, an hourglass-shaped through hole 20 having tapered first side wall portion 21A and second side wall portion 21B as shown in Fig. 2 can be formed. This results in the preparation of the substrate 12 provided with the through hole 20 having the tapered first side wall portion 21A, the tapered second side wall portion 21B, and a boundary portion 21C therebetween. Here, the maximum dimension of the boundary portion 21C in the in-plane direction of the substrate 12 is determined in the range of 30 µm to 50 µm, preferably 35 µm to 45 µm, as described above. (Through electrode formation process) Next, a through electrode 22 is formed on a side wall 21 of the through hole 20. In this embodiment, simultaneously with the through electrode 22, a first wiring layer 30 is formed on a portion of the first surface 13, and a second wiring layer 40 is formed on a portion of the second surface 14.

[0046] As shown in FIG. 4, a seed layer 221 is formed on the first surface 13, the second surface 14, and the sidewall 21 of the through-hole 20 by sputtering, vapor deposition, or a combination of these. Next, as shown in Fig. 5, a resist layer 37 is formed partially on the seed layer 221. Next, as shown in Fig. 6, a plating layer 222 is formed by electrolytic plating on the seed layer 221 that is not covered by the resist layer 37. Thereafter, as shown in Fig. 7, the resist layer 37 is removed. Furthermore, the portion of the seed layer 221 that was covered by the resist layer 37 is removed by, for example, wet etching. In this manner, the through electrode 22, the first wiring layer 30, and the second wiring layer 40 can be formed.

[0047] The step of forming the plating layer 222 will be described in detail. In this embodiment, the plating layer 222 is grown from the boundary 21C side of the through hole 20 until the plating layer 222 fills at least the boundary 21C. More specifically, after the plating layer 222 fills the boundary 21C, the growth of the plating layer 222 is stopped before the plating layer 222 fills the entire through hole 20. More specifically, before the plating layer 222 fills the entire through hole 20, when the plating layer 222 on the first surface 13 and the second surface 14 has a sufficient thickness for forming the wiring layers 30 and 40, the growth of the plating layer 222 is stopped. This allows the plating layer 222 to be grown so that the recesses 22A and 22B recessed toward the boundary 21C are provided on both the end surface on the first surface 13 side of the plating layer 222 constituting the through electrode 22 and the end surface on the second surface 14 side of the plating layer 222.

[0048] The present inventors have found that when a plating layer 222 is formed after a seed layer 221 is formed on the sidewall 21 of a through-hole 20 formed in an hourglass shape in a substrate 12, the plating layer 222 grows from the boundary portion 21C side and can fill or plug the boundary portion 21C quickly, and material costs and manufacturing time can be significantly reduced compared to when the through-hole is cylindrical. Based on this knowledge, the present inventors have devised the above-mentioned manufacturing procedure.

[0049] Furthermore, when the plating layer 222 is grown as described above, recesses 22A, 22B tend to be formed on the end face of the plating layer 222 on the first surface 13 side and the end face of the plating layer 222 on the second surface 14 side, and such recesses 22A, 22B tend to gradually disappear by ensuring a long growth time for the plating layer 222. Here, the present inventor intentionally leaves the recesses 22A, 22B formed on the through electrode 22 in this embodiment in order to reduce material costs by growing the plating layer 222 so as to leave such recesses 22A, 22B.

[0050] (Organic material layer formation process) Next, as shown in FIG. 8, a first organic material layer 50 is formed in the recess 22A of the through electrode 22 on the first surface 13 side. For example, first, a film having a photosensitive layer containing an organic material and a base material is attached to the first surface 13 side of the substrate 12. Then, the film is subjected to an exposure process and a development process. This allows the first organic material layer 50, which is made of the photosensitive layer of the film and fills only the recess 22A, to be formed. Similarly, a second organic material layer 60 is also formed in the recess 22B of the through electrode 22 on the second surface 14 side. In this case, for example, first, a film having a photosensitive layer containing an organic material and a base material is attached to the second surface 14 side of the substrate 12. Then, the film is subjected to an exposure process and a development process. This allows the second organic material layer 60, which is made of the photosensitive layer of the film and fills only the recess 22B, to be formed.

[0051] The first organic material layer 50 and the second organic material layer 60 may be formed by providing a photosensitive layer containing an organic material on the first surface 13 and the second surface 14 by coating, and then developing unnecessary portions.

[0052] In the through electrode substrate 10 according to the present embodiment described above, the material of the through electrode 22 provided to fill at least a part of the through hole 20 can be reduced compared to the case where the material is filled into a cylindrical through hole having the same maximum width dimension. Also, the through electrode 22 can be manufactured with a significantly reduced manufacturing time compared to the case where the through hole is filled into a cylindrical through hole. Therefore, it becomes possible to ensure high airtightness at low cost. In addition, when high airtightness is ensured in the through hole 20 by the through electrode 22 as in the present embodiment, for example, under the use condition where the first surface 13 side or the second surface 14 side is in a vacuum environment, it is possible to prevent air or moisture from entering the vacuum environment side through the through hole 20. Therefore, the through electrode substrate 10 can specifically improve the reliability of the device into which it is incorporated at low cost.

[0053] In this embodiment, recesses 22A, 22B recessed toward the boundary portion 21C are provided on the end face of the through electrode 22 on the first surface 13 side and the end face on the second surface 14 side, thereby making it possible to reduce material costs.

[0054] The recess 22A is filled with the first organic material layer 50, and the recess 22B is filled with the second organic material layer 60. As a result, the organic material layers 50 and 60 can alleviate the stress generated in the substrate 12, and the durability of the through-hole electrode substrate 10 can be improved. In detail, for example, when an element is connected to the first wiring layer 30 via a bump, pressure is applied to the first wiring layer 30, which can cause stress, but the first organic material layer 50 absorbs the pressure applied to the first wiring layer 30. In addition, the first wiring layer 30 and the second wiring layer 40 can be deformed by heat, but such deformation of the first wiring layer 30 and the second wiring layer 40 can be absorbed by the organic material layers 50 and 60. As a result, the organic material layers 50 and 60 can alleviate the stress generated in the substrate 12.

[0055] (Another embodiment 1) Next, a through hole electrode substrate 10' according to another embodiment will be described with reference to Figures 9 to 14. Components similar to those in the above embodiment will be denoted by the same reference numerals and will be described below.

[0056] 9 shows a through electrode substrate 10' according to this embodiment. This embodiment differs from the embodiment shown in FIG. 1 etc. in that the first side wall 21A and the second side wall 21B are joined to each other at a boundary 21C located closer to the second surface 14 than the center in the thickness direction of the substrate 12. This embodiment also differs from the embodiment shown in FIG. 1 etc. in that a recess 22A recessed toward the boundary 21C is provided only on the end face of the through electrode 22 on the first surface 13 side.

[0057] 10, when manufacturing the through electrode substrate 10′, first, the substrate 12 is prepared, and then the through electrode 22 is formed on the side wall 21 of the through hole 20. In this embodiment, simultaneously with the through electrode 22, the first wiring layer 30 is formed on a part of the first surface 13, and the second wiring layer 40 is formed on a part of the second surface 14.

[0058] As shown in FIG. 11, a seed layer 221 is formed on the first surface 13, the second surface 14, and the sidewall 21 of the through hole 20 by sputtering, vapor deposition, or a combination of these. Next, as shown in FIG. 12, a resist layer 37 is partially formed on the seed layer 221, and then, by electrolytic plating, a plating layer 222 is formed on the seed layer 221 that is not covered by the resist layer 37. Then, as shown in FIG. 13, the resist layer 37 is removed. In addition, the portion of the seed layer 221 that was covered by the resist layer 37 is removed by, for example, wet etching. In this manner, the through electrode 22, the first wiring layer 30, and the second wiring layer 40 can be formed.

[0059] In the present embodiment, when the plating layer 222 is formed as described above, the plating layer 222 is grown from the boundary 21C side of the through hole 20 until the plating layer 222 fills at least the boundary 21C. More specifically, as shown in FIG. 12, after the plating layer 222 fills the boundary 21C and the portion from the boundary 21C to the second surface 14 of the through hole 20, the growth of the plating layer 222 is stopped before the plating layer 222 fills the portion from the boundary 21C to the first surface 13 of the through hole 20. More specifically, before the plating layer 222 fills the portion from the boundary 21C to the first surface 13, the growth of the plating layer 222 is stopped when the plating layer 222 on the first surface 13 and the second surface 14 has a thickness sufficient for forming the wiring layers 30 and 40. This allows the plating layer 222 constituting the through electrode 22 to grow so that the end face on the first surface 13 side of the plating layer 222 is provided with a recess 22A recessed toward the boundary portion 21C.

[0060] The present inventors have found that when the boundary 21C where the first side wall 21A and the second side wall 21B are joined to each other is located closer to the second surface 14 than the center in the thickness direction of the substrate 12, the plating layer 222 grows earlier on the second side wall 21B side than the first side wall 21A, and when the plating layer 222 fills the entire second side wall 21B, a recess 22A tends to be formed on the end face of the plating layer 222 on the first side wall 21A side. Based on this finding, the present inventors have devised the above-mentioned manufacturing procedure. In addition, the above-mentioned recess 22A tends to gradually disappear by ensuring a long growth time for the plating layer 222, but here, the present inventors intentionally leave the recess 22A formed on the through electrode 22 in this embodiment in order to suppress material costs by growing the plating layer 222 so as to leave such a recess 22A.

[0061] 14, a first organic material layer 50 is formed in the recess 22A of the through electrode 22 on the first surface 13 side. The first organic material layer 50 is formed by the same method as in the embodiment shown in FIG.

[0062] The through hole electrode substrate 10' according to this embodiment described above also provides the same effects as those provided by the embodiment shown in FIG. 1 and the like.

[0063] (Another embodiment 2) Next, a through hole electrode substrate 10'' according to another embodiment will be described with reference to FIGS. 15 to 19. Components similar to those in the above-described embodiment will be denoted by the same reference numerals and will be described below.

[0064] FIG. 15 shows a through electrode substrate 10'' according to this embodiment. In this embodiment, the first side wall portion 21A and the second side wall portion 21B are joined to each other at a boundary portion 21C located at the center in the thickness direction of the substrate 12, but differs from the embodiment shown in FIG. 1 etc. in that a recess 22A recessed toward the boundary portion 21C is provided only on the end face on the first surface 13 side of the through electrode 22.

[0065] 1 and the like in that a portion of the side wall 21 of the through electrode 22 from the boundary portion 21C to a midpoint of the first side wall portion 21A between the boundary portion 21C and the first surface 13 is filled with a part of the through electrode 22 made only of the plating layer 222. In detail, the portion of the through electrode 22 provided within the first side wall portion 21A is composed of a first portion 22X made of the plating layer 222 filling from the boundary portion 21C to a midpoint of the first side wall portion 21A, and a second portion 22Y made of the seed layer 221 and the plating layer 222 covering from the midpoint of the first side wall portion 21A to the first surface 13.

[0066] When manufacturing the through electrode substrate 10'' in this embodiment, first, as shown in FIG. 16, a substrate 12 is prepared, and then a through electrode 22 is formed on a side wall 21 of a through hole 20. In this embodiment, simultaneously with the through electrode 22, a first wiring layer 30 is formed on a portion of the first surface 13, and a second wiring layer 40 is formed on a portion of the second surface 14.

[0067] In this embodiment, as shown in FIG. 16, a seed layer 221 is formed only on the second surface 14 and on the second side wall portion 21B of the through hole 20 by a sputtering method, a vapor deposition method, or a combination of these. Then, as shown in FIG. 17, a plating layer 222 is formed on the seed layer 221 by electrolytic plating. Here, when forming the plating layer 222, the plating layer 222 is grown from the boundary portion 21C side of the through hole 20 until the plating layer 222 fills at least the boundary portion 21C. More specifically, after the plating layer 222 fills the boundary portion 21C and the portion from the boundary portion 21C of the through hole 20 to the second surface 14, the growth of the plating layer 222 is stopped. More specifically, when the plating layer 222 fills the portion from the boundary portion 21C to the second surface 14 and the plating layer 222 on the second surface 14 has a thickness sufficient for forming the wiring layer 40, the growth of the plating layer 222 is stopped. At this time, in this embodiment, since the seed layer 221 is not formed on the first sidewall 21A of the through hole 20, the growth of the plating layer 222 on the first sidewall 21A side does not proceed early, and when the plating layer 222 fills the portion from the boundary 21C to the second surface 14, the plating layer 222 on the first sidewall 21A side grows only to fill up to the midpoint of the first sidewall 21A between the boundary 21C and the first surface 13. As a result, the first portion 22X made of the plating layer 222 filling up the portion from the boundary 21C to the midpoint of the first sidewall 21A is formed to constitute a part of the through electrode 22.

[0068] Next, as shown in FIG. 18, in this embodiment, a seed layer 221 is formed on the portion of the first sidewall 21A that is not covered by the first portion 22X and on the first surface 13. The seed layer 221 is formed by a sputtering method, a vapor deposition method, or a combination of these. Next, as shown in FIG. 19, a plating layer 222 is formed on the seed layer 221 on the first sidewall 21A and the first surface 13 by electrolytic plating. The formation of the plating layer 222 is stopped before the plating layer 222 fills the first sidewall 21A. As a result, the through electrode 22, the first wiring layer 30, and the second wiring layer 40 are formed. Then, the recess 22A is formed by the first portion 22X and the second portion 22Y.

[0069] Thereafter, a first organic material layer 50 is formed in the recess 22A of the through electrode 22 on the first surface 13 side. The first organic material layer 50 is formed by the same method as in the embodiment shown in FIG. 1 etc. In this manner, the through electrode substrate 10'' according to this embodiment is manufactured.

[0070] The through hole electrode substrate 10'' according to this embodiment described above also provides the same effects as those provided by the embodiment shown in FIG. 1 and the like.

[0071] (Other embodiment 3) Next, a through hole electrode substrate 10''' according to another embodiment will be described with reference to Fig. 20. Components similar to those in the above embodiment will be denoted by the same reference numerals and will be described below.

[0072] The through electrode substrate 10''' according to the embodiment shown in FIG. 20 differs from the embodiment shown in FIG. 1 etc. in that the end face of the through electrode 22 on the first surface 13 side and the end face on the second surface 14 side do not have recesses 22A, 22B recessed toward the boundary portion 21C side. The through electrode substrate 10''' can be manufactured by ensuring a long time for forming the plating layer 222 in the manufacturing method of the through electrode substrate 10 according to the embodiment shown in FIG. 1 etc. This through electrode substrate 10''' also provides the same effects as those obtained in the embodiment of FIG. 1 etc.

[0073] Examples of products equipped with through-hole electrode substrates 21 is a diagram showing an example of a product in which the through electrode substrate 10 according to the embodiment of the present disclosure and the like can be mounted. The through electrode substrate 10 according to the embodiment of the present disclosure and the like can be used in various products. For example, the through electrode substrate 10 and the like can be 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. [Explanation of symbols]

[0074] 10,10',10'',10''...Through-hole electrode substrate 12...Substrate 13...Side 1 14…Second side 20...Through hole 21...Side wall 21A...First side wall part 21B...Second side wall part 21C…Boundary part 22...Through electrode 22A, 22B...Concave 22X…1st part 22Y…Second part 221…Seed layer 222…Plating layer 30…1st wiring layer 37...Resist layer 40…Second wiring layer 50...first organic material layer 60…Second organic material layer nd...normal direction

Claims

[Claim 1] a substrate including a first surface and a second surface located opposite to the first surface and having a through hole; a through electrode located in the through hole, a side wall of the through hole has a first tapered side wall portion tapered from the first surface toward an inner side of the substrate, a second tapered side wall portion tapered from the second surface toward the inner side of the substrate, and a boundary portion at which a tip end of the first side wall portion and a tip end of the second side wall portion are joined to each other, The through electrode fills at least the boundary portion of the side wall, The portion of the through electrode provided within the first side wall portion 21 is composed of a first portion consisting of only a plating layer filling from the boundary portion to a midpoint of the first side wall portion A, and a second portion 22 consisting of a seed layer and a plating layer covering from the midpoint of the first side wall portion to the first surface, a recessed portion recessed toward the boundary portion is provided on an end surface of the through electrode on the first surface side, The through electrode substrate has an organic material layer including an organic material provided in the recess.

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