Through-electrode substrate

Abstract

To provide a through-hole electrode substrate that can suppress the occurrence of cracks in a filling material filled in a through-hole, and the occurrence of gaps between the filling material and the through-hole electrode formed along the side of the through-hole, due to thermal stress.SOLUTION: A through-hole electrode substrate according to the present disclosure includes a substrate having a through hole, a through electrode located on a side surface of the through hole, and a filling material located on the through electrode and filling the through hole, wherein the filling material includes a resin and a filler dispersed within the resin, the product of the elastic modulus and thermal expansion coefficient of the filling material is 20 Pa / K or more and 50 Pa / K or less, and the filler has a thermal expansion coefficient of -3×10-6 / K or more and 9×10-6 / K or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a through-electrode substrate provided with through electrodes.

Background Art

[0002] As disclosed in, for example, Patent Document 1, a through-electrode substrate includes a substrate including a first surface and a second surface, a plurality of through-holes provided in the substrate, and through electrodes provided inside the through-holes so as to extend from the side of the first surface of the substrate to the side of the second surface. Such through-electrode substrates have been conventionally used in various applications, and are, for example, mounted on electronic devices such as mobile phones. The through electrodes of such through-electrode substrates are generally classified into a filling type (also called a field via) that fills the entire through-hole and a non-filling type (also called a conformal via) that is provided on the side surface of the through-hole and has a hollow shape. As a method of forming through electrodes, for example, a method of forming a seed layer on the side surface of a through-hole and forming a plating layer on the seed layer by an electrolytic plating method is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A through-electrode substrate is subjected to a heat cycle test as a reliability test related to bonding with an element. This heat cycle test is, for example, a test in which the through-electrode substrate is heated from -55°C to 125°C over 1 hour, held at 125°C for 1 hour, and then cooled from 125°C to -55°C over 1 hour. There is also a test in which this heat cycle is applied to the through-electrode substrate 1000 times. The thermal stress from this heat cycle test can cause problems such as cracks forming in the conductive material, such as copper (Cu), filling the through-hole if the through-electrode is a filled via, or gaps forming between the through-electrode and the side of the through-hole. Furthermore, if the through-electrode is a conformal via as described above, there are problems such as cracks forming in the filler material (e.g., resin) that fills the through-hole, and gaps forming between the filler material and the through-electrode formed along the side of the through-hole.

[0005] This disclosure aims to provide a through-electrode substrate that can effectively solve the above-mentioned problems. [Means for solving the problem]

[0006] One embodiment of the present disclosure comprises a substrate having a first surface and a second surface located opposite the first surface, and having through holes; a through electrode located on the side surface of the through hole; and a filler located on the through electrode and filling the through hole, wherein the filler comprises a resin and a filler dispersed within the resin, the product of the elastic modulus and thermal expansion coefficient of the filler is 20 Pa / K or more and 50 Pa / K or less, and the thermal expansion coefficient of the filler is -3 × 10 -6 / K or more 9×10 -6 This is a through-electrode substrate with a temperature of / K or less.

[0007] In a through-electrode substrate according to one embodiment of the present disclosure, the resin may include a block polyimide copolymer having fluorine groups and silicone groups.

[0008] Furthermore, in a through-electrode substrate according to one embodiment of the present disclosure, the resin includes polymer A represented by the following general formula (1), polymer B represented by the following general formula (2), and polymer C represented by the following general formula (3), and the total content of polymer A, polymer B, and polymer C combined may be in the range of 100% by mass or less, with the content of polymer A being greater than 15% by mass and 40% by mass or less, the content of polymer B being between 15% by mass and 30% by mass or less, and the content of polymer C being between 30% by mass and 70% by mass or less.

[0009] [ka]

[0010] [ka]

[0011] [ka]

[0012] Furthermore, in a through-electrode substrate according to one embodiment of the present disclosure, the filler has a first connection portion on the side of the first surface of the substrate and a second connection portion on the side of the second surface of the substrate, the first connection portion and the second connection portion are electrically connected to the through-electrode, and an opening is formed in both the first connection portion and the second connection portion, or in either the first connection portion or the second connection portion, in which the filler is partially exposed.

[0013] Furthermore, in a through-electrode substrate according to one embodiment of the present disclosure, the through-hole may have a constricted portion inside which the hole diameter is smaller than the hole diameter of the opening on the first surface side of the substrate and the hole diameter of the opening on the second surface side of the substrate.

Advantages of the Invention

[0014] According to the embodiments of the present disclosure, it is possible to suppress the occurrence of cracks in the filler filled in the through-holes and the occurrence of gaps between the filler and the through electrodes formed along the side surfaces of the through-holes due to thermal stress.

Brief Description of the Drawings

[0015] [Figure 1] Cross-sectional view showing the main part of a through electrode substrate according to an embodiment [Figure 2] Diagram showing the manufacturing process of a through electrode substrate [Figure 3] Diagram showing the manufacturing process of a through electrode substrate following FIG. 2 [Figure 4] Diagram showing the manufacturing process of a through electrode substrate following FIG. 3 [Figure 5] Diagram showing the manufacturing process of a through electrode substrate following FIG. 4 [Figure 6] Diagram showing the manufacturing process of a through electrode substrate following FIG. 5 [Figure 7] Diagram showing the manufacturing process of a through electrode substrate following FIG. 6 [Figure 8] Diagram showing the manufacturing process of a through electrode substrate following FIG. 7 [Figure 9] Cross-sectional view showing a through electrode substrate according to another embodiment ' [Figure 10] Cross-sectional view showing a through electrode substrate according to another embodiment

Modes for Carrying Out the Invention

[0016] Hereinafter, a through-electrode substrate and a method for manufacturing the same according to the embodiments of this disclosure will be described in detail with reference to the drawings. The embodiments shown below are examples of embodiments of this disclosure, and this disclosure is not to be construed as being limited to these embodiments. Furthermore, in this specification, terms such as "substrate," "base material," "sheet," and "film" are not distinguished from each other solely on the basis of differences in designation. For example, "substrate" and "base material" are concepts that also include components that may be called sheets or films. Furthermore, terms such as "parallel" and "orthogonal," as well as values ​​of length and angle, used in this specification to specify shape, geometric conditions, and their degree, are to be interpreted not in strict terms, but to include a range that can be expected to have similar functions. In addition, in the drawings referenced in this embodiment, the same or similar reference numerals are used for identical parts or parts having similar functions, and repeated explanations may be omitted. Furthermore, the dimensional ratios in the drawings may differ from the actual ratios for the sake of explanation, and some components may be omitted from the drawings.

[0017] <Through-hole electrode substrate> Embodiments of this disclosure will be described below. First, the configuration of the through-electrode substrate 1 according to one embodiment of this disclosure will be described with reference to Figure 1. Here, Figure 1 is a cross-sectional view showing the main part of the through-electrode substrate 1.

[0018] As shown in Figure 1, the through-electrode substrate 1 includes a substrate 10 that includes a first surface 11 and a second surface 12 located opposite the first surface 11 and has a through-hole (a through-hole 13 in Figure 2, which will be described later), a through-electrode 20 located on the side surface of the through-hole of the substrate 10, and a filler 30 located on the through-electrode 20 and filling the through-hole. In other words, the through-electrode 20 of the through-electrode substrate 1 corresponds to one form of conformal via described above.

[0019] In the through-electrode substrate 1, the through-holes provided in the substrate 10 are filled with through-electrodes 20 and filler material 30. Therefore, Figure 1 does not show the through-holes provided in the substrate 10 (through-holes 13 in Figure 2). The shape of the through-holes 13 is shown in Figure 2, which will be described later. Furthermore, while Figure 1 shows an enlarged cross-sectional view of one through electrode (through electrode 20) on the through electrode substrate 1 as an example, typically the through electrode substrate 1 is provided with multiple through electrodes. The following describes each component of the through-electrode substrate 1.

[0020] (substrate) As shown in Figure 1, the substrate 10 includes a first surface 11 and a second surface 12 located on the opposite side of the first surface 11. The substrate 10 is also provided with a through hole 13 (see Figure 2) extending from the first surface 11 to the second surface 12.

[0021] The substrate 10 contains an inorganic material having a certain degree of insulating properties. In embodiments of this disclosure, the substrate 10 can be any material that can be used as a substrate for a through-electrode substrate. For example, the substrate 10 is a glass substrate or a quartz substrate. Examples of glass used in the substrate 10 include alkali-free glass.

[0022] Alkali-free glass is glass that does not contain alkaline components such as sodium or potassium. Alkali-free glass may contain, for example, boric acid instead of alkaline components. Alternatively, it may contain alkaline earth metal oxides such as calcium oxide or barium oxide. Examples of alkali-free glass include EN-A1 from Asahi Glass and Eagle XG from Corning.

[0023] The thickness (G) of the substrate 10 is not particularly limited, as long as it is suitable for use as a substrate for a through-electrode substrate. However, for example, the manufacturing process of a through-electrode substrate may include a polishing process, typically a CMP (Chemical Mechanical Polishing) process. If the substrate 10 is too thin, it may lack sufficient strength and break during this polishing process.

[0024] Furthermore, the manufacturing process for through-electrode substrates includes a step of forming a seed layer in order to form through-electrodes with sufficient thickness by electroplating. However, if the thickness of the substrate 10 is too large, the depth of the through-holes becomes larger than the opening, and if the seed layer is formed by sputtering, it may not be possible to form a seed layer of the required thickness deep inside the through-holes. Consequently, the through-electrodes formed by subsequent electroplating may not be of the desired quality.

[0025] Taking the above into consideration, the thickness (G) of the substrate 10 can be, for example, 300 μm or more and 500 μm or less.

[0026] (Through hole) The substrate 10 is provided with through holes 13 (see Figure 2) extending from the first surface 11 to the second surface 12. In the through-electrode substrate 1 shown in Figure 1, the diameter of the opening on the first surface 11 side of the through-hole 13 (HF) is larger than the diameter of the opening on the second surface 12 side (HB). In other words, in a cross-sectional view, the side surface of the through-hole 13 formed in the substrate 10 has a tapered shape that narrows from the first surface 11 side to the second surface 12 side of the substrate 10. The reason the through-hole 13 has a tapered shape is that machining with a vertical side surface is difficult, and if the side surface is vertical, it becomes difficult to form a seed layer for forming the through-electrode 20 inside the through-hole 13.

[0027] Here, the term "tapered" as described above means that the shape is tapered when viewed in a broad sense. In a cross-sectional view of the through-hole 13, the sides of each part are not limited to extending in a straight line. Even if they extend in a curved shape, include a curved section, or have both straight and curved sections, as long as they are tapered when viewed in a broad sense, these shapes are included in the concept of a tapered shape.

[0028] If the diameter of the through-hole 13 is too large, it becomes unsuitable for high-density mounting. On the other hand, if it is too small, it becomes difficult to form the desired through-electrode. Taking these factors into consideration, the diameter of the through-hole 13 can be set to, for example, 30 μm or more and 150 μm or less.

[0029] In the embodiments of this disclosure, the cross-sectional shape of the through-hole is not particularly limited and can be any shape that can be used as a through-hole for a through-electrode substrate. For example, the through-hole may have a constricted portion inside that has a smaller diameter than the hole diameter of the opening on the first surface 11 side or the hole diameter of the opening on the second surface 12 side (see Figure 10, described later).

[0030] (Through electrode) The through electrode 20 is a conductive material and, as shown in Figure 1, is located on the side surface of the through hole 13 (see Figure 2) in the through electrode substrate 1. As described above, the through electrode 20 of the through electrode substrate 1 corresponds to a form of conformal via.

[0031] Here, the through electrode 20 is usually composed of multiple layers. For example, in the example shown in Figure 1, the through electrode 20 has a seed layer 21 on the side of the through hole 13, and a plating layer 22 on top of the seed layer 21.

[0032] The seed layer 21 is a conductive layer that serves as a base for depositing metal ions in the plating solution and growing the plating layer 22 during the electroplating process in which the plating layer 22 is formed by electroplating. The material of the seed layer 21 can be a conductive material such as copper (Cu), titanium (Ti), or a combination thereof. The material of the seed layer 21 may be the same as or different from the material of the plating layer 22. The thickness of the seed layer 21 is, for example, 50 nm to 1000 nm. To form this seed layer 21, methods such as sputtering, vapor deposition, or a combination of sputtering and vapor deposition can be used.

[0033] The plating layer 22 is a conductive layer formed on the seed layer 21 by electroplating. The materials that make up the plating layer 22 can be metals such as copper (Cu), gold (Au), silver (Ag), platinum (Pt), rhodium (Rh), tin (Sn), aluminum (Al), nickel (Ni), and chromium (Cr), or alloys using these, or laminates of these materials.

[0034] The thickness (T) of the through-electrode 20 depends on the thickness (G) of the substrate 10 and the diameter of the through-hole opening (HF, HB), but any thickness within the range suitable for use as a through-electrode for conformal vias can be used. Here, the through electrode 20 is electrically connected to the terminal of the element, but if the thickness (T) is too small, there is a problem that the electrical resistance will become large. On the other hand, if the thickness (T) is too large, there is a problem that thermal stress will easily cause cracks in the filler or a gap will easily form between the filler and the through electrode.

[0035] Taking these factors into consideration, the thickness (T) of the through electrode 20 can be, for example, 5 μm or more and 15 μm or less.

[0036] (filling) In the through-electrode substrate 1 shown in Figure 1, the filler 30 is located above the through-electrode 20 (i.e., closer to the center of the through-hole 13 than the through-electrode 20 which is located above the side surface of the through-hole 13) and is formed to fill the through-hole 13. The through-electrode substrate according to the embodiment of this disclosure is characterized by the filler 30, and because it has the filler 30, it is possible to suppress crack formation in the filler 30 due to thermal stress and the formation of gaps between the filler 30 and the through-electrode 20.

[0037] The filler 30 has a resin composed of a specific composition described later, and a specific filler dispersed within this resin, and the product of its elastic modulus and thermal expansion coefficient is 20 Pa / K or more and 50 Pa / K or less. The above values, which represent the product of the elastic modulus and the coefficient of thermal expansion, are based on measurements of the elastic modulus and coefficient of thermal expansion of the filler material while it is filling the through-electrode substrate. The filler and resin that make up the packing material 30 will be described below.

[0038] (Filler) The filler in the packing material 30 has a thermal expansion coefficient of -3 × 10 -6 / K or more 9×10 -6 It has a thermal expansion coefficient of 0.5 or less and is dispersed in the resin described later. Fused silica can be preferably given as a filler having the above-mentioned coefficient of thermal expansion. For example, Denka's fused silica has a thermal expansion coefficient of 0.5 × 10⁻⁶ from 0°C to 1000°C. -6 There is something called / K. Furthermore, it is preferable that the content of the filler in the filler 30 be 70% by volume or more and 80% by volume or less of the filler 30. If the content of the filler is within this range, as in the examples described later, it is possible to suppress the occurrence of cracks in the filler filled in the through-hole of the through-electrode substrate due to thermal stress, and the occurrence of gaps between the filler and the through-electrode formed along the side surface of the through-hole.

[0039] (resin) The resin constituting the filler 30 includes a block polyimide copolymer having fluorine groups and silicone groups. Preferably, the resin constituting the filler 30 includes polymer A represented by the following general formula (1), polymer B represented by the following general formula (2), and polymer C represented by the following general formula (3), wherein the combined content of polymer A, polymer B, and polymer C is within the range of 100% by mass or less, the content of polymer A is greater than 15% by mass and 40% by mass or less, the content of polymer B is between 15% by mass and 30% by mass or less, and the content of polymer C is between 30% by mass and 70% by mass or less.

[0040] [ka]

[0041] [ka]

[0042] [ka]

[0043] The resin constituting the filler 30 may contain a photosensitive material. It may also contain various other additives. For example, if the resin contains a photosensitive material, a film of the resin containing the photosensitive material can be attached to the first surface 11 and the second surface 12 of the substrate 10 by a method such as vacuum lamination, and then exposed and developed to form a filler 30 in the through-hole 13.

[0044] <Manufacturing method for through-electrode substrates> Next, an example of a manufacturing method for the through-electrode substrate 1 shown in Figure 1 will be explained with reference to Figures 2 to 8.

[0045] (Manufacturing of substrates with through holes) First, a substrate is prepared that includes a first surface 11 and a second surface 12 located on the opposite side of the first surface 11. By irradiating a laser from the side where the opening of the through-hole has a larger hole diameter (in the case of the through-electrode substrate 1 shown in Figure 1, the side of the first surface 11), a substrate 10 is manufactured with through-holes 13 of the desired shape, as shown in Figure 2.

[0046] For laser processing, excimer lasers, Nd:YAG lasers, femtosecond lasers, etc., can be used. When using an Nd:YAG laser, the fundamental wave with a wavelength of 1064 nm, the second harmonic with a wavelength of 532 nm, the third harmonic with a wavelength of 355 nm, etc., can be used.

[0047] Alternatively, as a different manufacturing method, a resist layer having an opening at a position corresponding to the through-hole 13 may be provided, and the through-hole 13 may be formed by etching from the opening in the resist layer. Etching methods include dry etching methods such as reactive ion etching and deep reactive ion etching, as well as wet etching methods.

[0048] Furthermore, the above-mentioned laser irradiation and wet etching can be combined as appropriate. For example, first, a modified layer can be formed in the region of the substrate where the through-holes 13 are to be formed by laser irradiation, and then the substrate can be immersed in hydrogen fluoride or the like to etch the modified layer. The through-holes 13 may be formed by this method.

[0049] Alternatively, the through-holes 13 may be formed by a blasting process in which an abrasive material is sprayed onto the substrate.

[0050] (Formation of through-electrodes) Next, a through electrode 20 is formed. First, a seed layer 21A is formed on the first surface 11, the second surface 12, and the side surface of the through-hole 13 of the substrate by sputtering, vapor deposition, or a combination thereof, as shown in Figure 3. Next, as shown in Figure 4, a resist layer 41 is partially formed on the seed layer 21A formed on the first surface 11, and a resist layer 42 is partially formed on the seed layer 21A formed on the second surface 12. Next, as shown in Figure 5, a plating layer 22 is formed on the seed layer 21A, which is not covered by the resist layers 41 and 42, by electroplating. Next, as shown in Figure 6, the resist layers 41 and 42 are removed, and then, as shown in Figure 7, the portion of the seed layer 21A that was covered by the resist layers 41 and 42 is removed, for example, by wet etching. In this manner, the through electrode 20 can be formed.

[0051] (Formation of the filling) Subsequently, as shown in Figure 8, a filler 30 is formed on the through electrode 20 (towards the center of the through hole 13) of the through electrode substrate 1 manufactured as described above.

[0052] To form the filler 30, for example, first, a film made of the resin containing the filler is attached to both the first surface 11 and the second surface 12 of the substrate 10 by a method such as vacuum lamination, filling the openings 13 of the through holes 13 on the first surface 11 and the second surface 12 of the substrate 10. The excess film on the first surface 11 and the second surface 12 of the substrate can be removed, for example, by scraping it off with a squeegee. Alternatively, it can be removed by a discam treatment using oxygen gas. In this way, the through-electrode substrate 1 shown in Figure 1 can be obtained.

[0053] (Other Embodiment 1) Next, other embodiments will be described. First, the through-electrode substrate 2 will be described using Figure 9. Here, Figure 9 is a cross-sectional view showing the main part of the through-electrode substrate 2. Note that components similar to those of the through-electrode substrate 1 described above will be denoted by the same reference numerals and described below.

[0054] As shown in Figure 9, in the through-electrode substrate 2, similar to the through-electrode substrate 1 shown in Figure 1, the substrate 10 is provided with through-holes extending from the first surface 11 to the second surface 12, a through-electrode 20 is provided on the side surface of the through-hole, and a filler 30 is formed on top of the through-electrode 20 (towards the center of the through-hole) to fill the through-hole. Although not shown in the diagram, the through-electrode substrate 2 may also have a configuration in which the through-electrode 20 has a seed layer on the side of the through-hole and a plating layer on top of the seed layer.

[0055] Here, the through-electrode 20 of the through-electrode substrate 1 shown in Figure 1 had a portion that extended outward from the center of the through-hole 13 on the first surface 11 and the second surface 12 of the substrate 10. In the through-electrode substrate 1, the through-electrode 20 and the terminals of the element, etc., are connected at this extended portion.

[0056] On the other hand, in the through-electrode substrate 2 shown in Figure 9, a first connection portion 51 is formed on the first surface 11 side of the filler 30 formed in the through-hole, and a second connection portion 52 is formed on the second surface 12 side. The first connection portion 51 and the second connection portion 52 are electrically connected to the through-electrode 20. In the through-electrode substrate 2, the through-electrode 20 is connected to the terminals of an element or the like at the first connection portion 51 and the second connection portion 52. In other words, the form of the through-electrode substrate 2 shown in Figure 9 corresponds to a so-called metal cap structure. An advantage of this configuration is that connections to terminals of components can be made at the opening of the through-hole (or within the opening) in a plan view, allowing for higher density mounting, similar to the case of filled vias.

[0057] Furthermore, in this embodiment, it is preferable that openings are formed in both the first connection portion 51 and the second connection portion 52, or in either the first connection portion 51 or the second connection portion 52, so that the filler 30 is partially exposed. This is because having such openings allows gas generated from the filler 30 to be released. For example, in the through-electrode substrate 2 shown in Figure 9, an opening 60 is provided in the first connection portion 51.

[0058] (Another Embodiment 2) Next, the through-electrode substrate 3 will be described using Figure 10. Here, Figure 10 is a cross-sectional view showing the main part of the through-electrode substrate 3. Components similar to those of the through-electrode substrate 1 described above will be denoted by the same reference numerals and described below.

[0059] As shown in Figure 10, in the through-electrode substrate 3, similar to the through-electrode substrate 1 shown in Figure 1, the substrate 10 is provided with through-holes extending from the first surface 11 to the second surface 12, and through-electrodes 20 are provided on the side surface of the through-holes, and a filler 30 is formed on top of the through-electrodes 20 (towards the center of the through-holes) to fill the through-holes. Although not shown in the diagram, the through-electrode substrate 3 may also have a configuration in which the through-electrode 20 has a seed layer on the side of the through-hole and a plating layer on top of the seed layer.

[0060] In this case, the through-hole 13 of the through-electrode substrate 1 shown in Figure 1 has a hole diameter (HF) on the side of the opening on the first surface 11 that is larger than the hole diameter (HB) on the side of the opening on the second surface 12. In cross-sectional view, the side surface of the through-hole 13 formed in the substrate 10 has a tapered shape that narrows from the first surface 11 side to the second surface 12 side of the substrate 10.

[0061] On the other hand, the through-holes of the through-electrode substrate 3 shown in Figure 10 have a constricted portion 70 inside which the diameter of the opening on the first surface 11 side and the opening on the second surface 12 side are smaller. More specifically, in the through-holes of the through-electrode substrate 3 shown in Figure 10, the diameter of the opening on the first surface 11 side and the diameter of the opening on the second surface 12 side are the same size (HF3), and the diameter of the hole in the constricted portion 70 (P) is smaller than the diameter of each of the above-mentioned openings (HF3). One advantage of this configuration is that it prevents the opening of the through-holes in the through-electrode substrate from becoming larger in proportion to the substrate thickness, thus enabling higher density mounting.

[0062] For example, in the through-electrode substrate 1 shown in Figure 1, the hole diameter (HB) of the opening on the second surface 12 side is the smallest hole diameter of the through-hole 13, and considering the connection to elements, this smallest hole diameter cannot be made smaller. Therefore, as long as the side surface of the through-hole is not vertical but inclined, as the thickness (G) of the substrate 10 increases, the hole diameter (HF) of the opening on the first surface 11 side will become larger than the hole diameter (HB) of the opening on the second surface 12 side.

[0063] On the other hand, in the through-electrode substrate 3 shown in Figure 10, the minimum hole diameter of the through-hole in the through-electrode substrate 3 is the hole diameter (P) of the constricted portion 70. Even if this hole diameter (P) is the same size as the hole diameter (HB) of the opening on the second surface 12 side of the through-hole 13 in the through-electrode substrate 1 shown in Figure 1, for example, if the angle of inclination of the side surface of the through-hole is the same angle as the angle of inclination of the side surface of the through-hole 13 in the through-electrode substrate 1 shown in Figure 1, the hole diameter (HF3) of the opening on the first surface 11 side and the hole diameter (HF3) of the opening on the second surface 12 side can be made smaller than or equal to the hole diameter (HF) of the opening on the first surface 11 side of the through-electrode substrate 1 shown in Figure 1, until the thickness of the substrate 10 becomes twice that of the through-electrode substrate 1 shown in Figure 1.

[0064] The through-electrode 20 of the through-electrode substrate 3 shown in Figure 10 has a portion that extends outward from the center of the through-hole on the first surface 11 and the second surface 12 of the substrate 10, similar to the through-electrode substrate 1 shown in Figure 1. However, this embodiment is not limited to this, and may have a so-called metal cap structure, such as the through-electrode substrate 2 shown in Figure 9. In other words, the through-electrode substrate 3 shown in Figure 10 may have a first connection portion on the first surface 11 side of the filler 30 formed in the through-hole, and a second connection portion on the second surface 12 side, and the first connection portion and the second connection portion may be electrically connected to the through-electrode 20. In this case as well, since connections to the terminals of elements can be made at the opening position (or within the opening) of the through-hole in a plan view, higher density mounting becomes possible, similar to the case of filled vias. [Examples]

[0065] The embodiments of this disclosure will be described in detail below with reference to examples and comparative examples. However, the embodiments of this disclosure are not limited to the examples.

[0066] (Examples 1-7) For Examples 1 to 7, through-electrode substrates having through-electrodes with the structure shown in Figure 1 were manufactured.

[0067] First, through-holes were formed on an alkali-free glass substrate (EN-Al, manufactured by Asahi Glass Co., Ltd.) with a diameter of 200 mm and a thickness of 400 μm by laser processing and wet etching using hydrogen fluoride. Here, the hole diameter (HF) of the opening on the first side (front side) of the through-hole was set to 85 μm, and the hole diameter (HB) of the opening on the second side (back side) was set to 50 μm.

[0068] Next, a seed layer consisting of 1 μm thick copper (Cu) on top of 50 nm thick titanium (Ti) was formed by sputtering, and then a 6 μm thick plating layer made of copper (Cu) was formed on top of that by electroplating to create a through electrode.

[0069] Next, films having the filler content and resin composition shown in Table 1 were attached to both the first and second surfaces of the substrate by vacuum lamination to form fillers that would fill the through-holes. The excess film on the first and second surfaces of the substrate was first scraped off with a squeegee, and then removed by a discam treatment using oxygen gas. The filler has a thermal expansion coefficient of 0.5 × 10 -6 Using fused silica of / K, the resin used consisted of polymer A represented by the above general formula (1), polymer B represented by general formula (2), and polymer C represented by general formula (3), in the respective contents shown in Table 1.

[0070] (Measurement of filler content) Cross-sections of the through-holes in each through-electrode substrate were obtained using FIB (Focused Ion Beam). These cross-sections were further etched with oxygen plasma to a depth of 50 nm. The obtained samples were observed using SEM to acquire images, the filler portion was identified from the images, and the area ratio of the filler was obtained and defined as the filler content.

[0071] (Measurement of resin composition content) An IRT-1000 micro-measurement unit was attached to the sample chamber of a JASCO FTIR4600, and IR (infrared spectroscopy) measurements were performed through an ATR (Attenuated Total Reflection) measurement prism. The mass percentages of polymers A, B, and C were calculated from the peak intensities derived from the functional groups of polymers A, B, and C.

[0072] (Measurement of elastic modulus) An ion milling system (Hitachi High-Tech Corporation, IM-4000) was used to obtain cross-sections of the through-holes in each through-electrode substrate. For this cross-section, the modulus of elasticity (E) was measured using a KLA Corporation iNanoInForce50 instrument in accordance with ISO 14577, with a Berkovich indenter, an approach speed of 100 nm / s, and an approach speed of 50 mN / s.

[0073] (Measurement of thermal expansion coefficient) After polishing the first (front) and second (back) surfaces of each through-electrode substrate until the filler formed in the through-hole was exposed, the substrate was etched with hydrofluoric acid to a thickness of 5 μm to create a sample in which the filler protruded 5 μm convexly from the substrate surface. For this sample, the temperature was varied from 0°C to 300°C, and measurements were taken using a laser thermal expansion meter (LIX-2) manufactured by Advance Riko Co., Ltd. in accordance with JIS R3251-1995, employing a dual-path Michelson laser interferometry method. The coefficient of thermal expansion (α) was calculated from the amount of deformation.

[0074] (Comparative Examples 1-6) Through-electrode substrates for Comparative Examples 1 to 6, having the filler content and resin composition shown in Table 2, were manufactured in the same manner as in Examples 1 to 7. In this comparison, Comparative Example 1 has a lower filler content than the values ​​in Examples 1-7, while Comparative Example 2 has a higher filler content than the values ​​in Examples 1-7. Furthermore, Comparative Examples 3-6 have different resin compositions from Examples 1-7.

[0075] (Rating 1) To evaluate the filling performance of the filler material, the cross-sections of the through-holes in each of the through-electrode substrates in Examples 1-7 and Comparative Examples 1-6 were observed using SEM to evaluate whether the filler material was properly filling the through-holes. Substrates showing voids or other defects were deemed unacceptable. (Rating 2) As a heat cycle test to evaluate reliability, each through-electrode substrate was subjected to 1000 cycles of heating from -55°C to 125°C and cooling from 125°C to -55°C. Subsequently, the first and second surfaces of each through-electrode substrate were observed with an optical microscope to evaluate whether or not cracks had occurred in the filler material of the through-holes. Furthermore, the cross-section of the through-holes was observed with a scanning electron microscope to evaluate whether or not cracks had occurred in the filler material of the through-holes, and whether or not a gap had formed between the filler material and the through-electrode. Items with cracks or gaps were deemed unacceptable. (judgement) A "pass" rating was given to those who passed both Evaluation 1 and Evaluation 2 above. Conversely, a "fail" rating was given to those who failed either Evaluation 1 or Evaluation 2 above. The results are shown in Tables 1 and 2.

[0076] [Table 1]

[0077] [Table 2]

[0078] As shown in Table 1, in all of Examples 1 to 7, the product of the elastic modulus (E) and the coefficient of thermal expansion (α) of the filler (E × α) was between 20 Pa / K and 50 Pa / K, and all of the above evaluations were judged as passing.

[0079] On the other hand, as shown in Table 2, Comparative Examples 1 to 6 all received a failing grade. Comparative Examples 2, 5, and 6 had already received a failing grade of 1. [Explanation of Symbols]

[0080] 1, 2, 3 Through-electrode substrate 10 circuit boards 11 Page 1 12 Side 2 13 Through hole 20 Through electrode Seed layer 21, 21A 22 Plating layer 30 fillings 41, 42 Resistance Layers 51 First connection section 52 Second connection section 60 opening 70 Stenosis

Claims

1. A substrate having a first surface and a second surface located opposite the first surface, and having through holes, A through electrode located on the side surface of the through hole, A filler located on the through electrode and filling the through hole, The filler comprises a resin and a filler dispersed within the resin. The aforementioned filler has a product of its elastic modulus and thermal expansion coefficient of 20 Pa / K or more and 50 Pa / K or less. The aforementioned filler has a thermal expansion coefficient of -3 × 10 －６ / K or more 9×10 －６ / K or less, The filler is contained in the filling in an amount of 70% or more and 80% or less by volume. The through-hole is a through-electrode substrate in which the diameter of the opening on the first surface side of the substrate is larger than the diameter of the opening on the second surface side of the substrate.

2. The through-electrode substrate according to claim 1, wherein the resin comprises a block polyimide copolymer having fluorine groups and silicone groups.

3. The aforementioned resin is It comprises polymer A represented by the following general formula (1), polymer B represented by the following general formula (2), and polymer C represented by the following general formula (3), The combined content of polymer A, polymer B, and polymer C is within the range of 100% by mass or less. The content of polymer A is greater than 15% by mass and 40% by mass or less. The content of polymer B is 15% by mass or more and 30% by mass or less. The through-electrode substrate according to claim 2, wherein the content of the polymer C is 30% by mass or more and 70% by mass or less. 【Chemistry 1】 【Chemistry 2】 【Transformation 3】

4. The filling material has a first connecting portion on the side of the first surface of the substrate, The filling material has a second connecting portion on the side of the second surface of the substrate, The first connection portion and the second connection portion are electrically connected to the through electrode. The through-electrode substrate according to any one of claims 1 to 3, wherein an opening is formed in both the first connection portion and the second connection portion, or in either the first connection portion or the second connection portion, in which the filler is partially exposed.

5. The aforementioned through hole is The through-electrode substrate according to any one of claims 1 to 4, having a constricted portion inside which the hole diameter is smaller than the hole diameter of the opening on the first surface side of the substrate and the hole diameter of the opening on the second surface side of the substrate.

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