Glass substrate, multilayer wiring board, and glass substrate manufacturing method

Abstract

To provide a technique for obtaining a highly reliable through electrode in which a side surface of an open hole is smooth.SOLUTION: A glass substrate includes a first surface, a second surface, at least one open hole penetrating from the first surface to the second surface. An angle of a side surface of the open hole is 4°- 7°when a distance from the first surface is between 0% and 10%. In a cross-sectional view, when the side surfaces of the open hole are the left side surface and the right side surface, a difference between an inclination angle of the left side surface and that of the right side surface is 1.0°or less. At a distance between 10% and 100% from the first surface, the angle of the side surface is between -7° and -15°, and the difference between the inclination angle of the left side surface and the inclination angle of the right side surface is 1.0°or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a glass substrate, a multilayer wiring substrate, and a method for manufacturing a glass substrate. [Background technology]

[0002] In recent years, three-dimensional packaging technology in which circuit boards are stacked has been used. In such packaging technology, through electrodes are formed in the circuit board. The through electrodes are formed by forming through holes in a substrate made of an insulator and placing a conductor in the through holes. As the integration of circuit boards increases, the through holes also need to be made finer.

[0003] For example, Patent Document 1 discloses a technique for providing a glass substrate having a plurality of through holes by irradiating a plate-shaped glass with an excimer laser beam. Patent Document 2 discloses a method for producing a high-density array of holes in glass, including a step of irradiating a front surface of a glass product with a UV laser beam. Patent Document 3 discloses a shape of a through hole that includes a substrate including a through hole and a conductor arranged along the inner side surface of the through hole, and satisfies the condition that the total value of the inclination angle of the inner side surface with respect to the central axis of the through hole (the angle at which the first surface side expands is defined as a positive inclination angle) at positions at distances of 6.25%, 18.75%, 31.25%, 43.75%, 56.25%, 68.75%, 81.25%, and 93.75% from the first surface in the section from the first surface to the second surface is 8.0° or more. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2010 / 087483 [Patent Document 2] Special Publication No. 2014-501686 [Patent Document 3] Patent No. 6809511 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the contents of Patent Documents 1 to 3 do not consider the effect of the side roughness of the through hole on the transmission characteristics of the through electrode. Therefore, the side of the through hole described in Patent Documents 1 to 3 has a distributed roughness of 1,000 nm or more and a PV (Peak to Valley) of 1,500 nm or more. Therefore, it is difficult to maintain the transmission characteristics of the through electrode sufficiently good due to the roughness of the side of the through hole, especially in high frequency bands such as the sub-6 GHz band among the frequency bands used for 5G.

[0006] In addition, when a wiring layer is formed on a glass substrate and a through electrode is formed to connect them, the influence of thermal stress is a concern because the CTE (COEFFICIENT OF THERMAL EXPANSION) of glass differs from the CTE of Cu, which is the material of the wiring and through electrode. For this reason, an accelerated test called TCT (Thermal Cycle Test) is performed as one of the reliability tests to evaluate the reliability of the device. However, in the conventional technology, sufficient consideration has not been given to the shape of the through hole to improve the reliability of the through electrode against thermal stress, and it has been confirmed that the wiring layer breaks at the interface between the through electrode and the wiring layer.

[0007] Therefore, an object of the present invention is to provide a glass substrate capable of forming a through electrode having good transmission characteristics and high reliability, and a multilayer wiring board including such a glass substrate. [Means for solving the problem]

[0008] In order to solve the above problems, one representative glass substrate of the present invention is a glass substrate having a first surface and a second surface, and comprising at least one through hole penetrating from the first surface to the second surface, wherein the side of the through hole has an angle of 4° or more and 7° or less within a distance range of 0% or more and less than 10% from the first surface, and when the side of the through hole is defined as the left side and the right side in a cross-sectional view, the difference in the inclination angle of the left side and the inclination angle of the right side is 1.0° or less, and within a distance range of 10% or more and 100% or less from the first surface, the side angle is -7° or more and -15° or less, and the difference in the inclination angle of the left side and the right side is 1.0° or less. Effect of the Invention

[0009] According to the present invention, it is possible to provide a glass substrate capable of forming a through electrode having good transmission characteristics and high reliability, and a multilayer wiring board including such a glass substrate. Problems, configurations and effects other than those described above will become apparent from the following description of the preferred embodiment of the invention. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing a method for measuring the cross section and inclination angle of a truncated cone-shaped through hole. [Diagram 2] FIG. 2 is a diagram showing a method for measuring the side surface roughness of a through hole. [Diagram 3] FIG. 3 is a diagram for explaining shape characteristics of a through hole according to Example 2 of the embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing the measurement results of the inclination angle of the through hole in Example 2 in the first embodiment. [Diagram 5] FIG. 5 is a diagram showing the measurement results of the inclination angle of the through hole in Example 3 in the first embodiment. [Figure 6] FIG. 6 is a diagram showing a cross-sectional shape of a through hole of Comparative Example 1 in the first embodiment. [Figure 7]FIG. 7 is a diagram showing the measurement results of the inclination angle of the through hole of Comparative Example 1 in the first embodiment. [Figure 8] FIG. 8 is a diagram showing a cross-sectional shape of a through hole of Comparative Example 2 in the first embodiment. [Figure 9] FIG. 9 is a diagram showing the measurement results of the inclination angle of the through hole in Comparative Example 2 in the first embodiment. [Figure 10] FIG. 10 is a diagram showing a cross-sectional shape of a through hole of Comparative Example 3 in the first embodiment. [Figure 11] FIG. 11 is a diagram showing the measurement results of the inclination angle of the through hole in Comparative Example 3 in the first embodiment. [Figure 12] FIG. 12 is a diagram showing the measurement results of the inclination angle of the through-hole in Application Example 1. In FIG. [Figure 13] FIG. 13 is a diagram showing the measurement results of the inclination angle of the through-hole in Application Example 2. In FIG. [Figure 14] FIG. 14 is a diagram showing the measurement results of the inclination angle of the through-hole in Application Example 3. In FIG. [Figure 15A] FIG. 15A is a graph showing Table 5. [Figure 15B] FIG. 15B is a diagram showing a schematic diagram in which a through electrode is formed. [Figure 15C] FIG. 15C is a diagram illustrating the characteristics of the through-holes and through-electrodes formed in the present disclosure. [Figure 16A] FIG. 16A is a diagram showing an SEM image of a typical cross-sectional shape of a through hole in each of the examples and comparative examples according to the first embodiment. [Figure 16B] FIG. 16B is a diagram showing SEM images of cross sections of through holes in each of the examples and comparative examples according to the first embodiment. [Figure 16C] FIG. 16C is a diagram illustrating ridgelines of through holes in each example of the first embodiment. [Figure 16D] FIG. 16D is a diagram showing a case where a through electrode is formed in the through hole in the first embodiment. [Figure 17] FIG. 17 is a diagram showing the transmission characteristics of the through electrode of Example 1 and the transmission characteristics of the through electrode of Comparative Example 1 in the first embodiment. [Figure 18] FIG. 18 is a diagram illustrating an example of the configuration of the multilayer wiring board according to the first embodiment. [Figure 19] FIG. 19 is a diagram showing another example of the configuration of the multilayer wiring board in the first embodiment. [Figure 20] FIG. 20 is a diagram showing a step of laminating a glass substrate to a first support. [Figure 21] FIG. 21 is a diagram showing a process for forming a laser modified portion. [Figure 22] FIG. 22 is a diagram showing a process of forming a first wiring layer. [Figure 23] FIG. 23 is a diagram showing a step of adhering a second support. [Figure 24] FIG. 24 is a diagram showing a step of peeling off the first support. [Diagram 25] FIG. 25 is a diagram showing a process of forming a through hole. [Figure 26] FIG. 26 is a diagram showing a process of forming a through electrode. [Figure 27] FIG. 27 is a diagram showing a process of forming an insulating resin layer. [Figure 28] FIG. 28 is a diagram showing a step of peeling off the second support and the second adhesive layer. [Figure 29] FIG. 29 is a diagram showing a process of forming a first wiring layer and a second wiring layer. [Diagram 30] FIG. 30 is a diagram showing a case where a multilayer wiring board is used as an interposer board for a semiconductor element and a BGA board. [Diagram 31] FIG. 31 is a diagram showing a cross section of the case of FIG. [Diagram 32] FIG. 32 is a diagram showing a case where a multilayer wiring board and a semiconductor element are used in an electronic device for communication. [Diagram 33] FIG. 33 is a diagram showing a cross section in the case of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The scope of the present invention is not limited to the illustrated and described exemplary embodiments and examples, but includes various modifications. For example, the embodiments and examples in this disclosure have been described in detail to clearly explain the present invention, and are not necessarily limited to those having all the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment and example with the configuration of another embodiment and example, and it is also possible to add the configuration of another embodiment and example to the configuration of one embodiment and example. In addition, it is possible to add, delete, or replace a part of the configuration of each embodiment and example with another configuration. Furthermore, the present invention also includes all embodiments that provide effects equivalent to those intended by the present invention.

[0012] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0013] In this disclosure, "surface" may refer not only to the surface of a plate-like member, but also to the interface of a layer contained in the plate-like member that is approximately parallel to the surface of the plate-like member. Furthermore, "upper surface" and "lower surface" refer to the surface shown at the top or bottom of the drawing when the plate-like member or the layer contained in the plate-like member is illustrated. Furthermore, the "upper surface" and "lower surface" may also be referred to as the "first surface" and the "second surface".

[0014] The term "side surface" refers to a surface of a plate-like member or a layer included in a plate-like member, or a portion of the thickness of a layer. Furthermore, a part of a surface and a side surface may be collectively referred to as an "end portion." Furthermore, the "side surface of a through hole" refers to the interface on the object that forms the through hole when the through hole is provided in the object. In addition, "upward" refers to the vertically upward direction when a plate-like member or layer is placed horizontally. Furthermore, "upward" and its opposite, "downward," are sometimes referred to as the "Z-axis positive direction" and the "Z-axis negative direction," and the horizontal direction is sometimes referred to as the "X-axis direction" and the "Y-axis direction."

[0015] Furthermore, the distance in the Z-axis direction is called the "height," and the distance on the XY plane defined by the X-axis and Y-axis directions is called the "width." When referring to the height of a layered object, it is also called the "thickness." Furthermore, the term "through electrode provided in a glass substrate" refers to a conductive path provided to electrically connect the first and second surfaces of a glass substrate when the glass substrate is used as part of a multilayer wiring substrate, and does not necessarily have to completely penetrate the glass substrate with a single conductive material. If the conductive path from the first surface and the conductive path from the second surface are connected, they are included in the through electrode. Furthermore, the form of the through electrode may be a filled type in which a through hole (including both bottomed and completely through holes) is filled with a conductive material, or a conformal type in which only the sidewall portion of the through hole is covered with a conductive material.

[0016] Additionally, the terms "planar shape" and "plan view" refer to the shape of a surface or layer when viewed from above. Furthermore, the terms "cross-sectional shape" and "cross-sectional view" refer to the shape of a plate-like member or layer when cut in a specific direction and viewed from the horizontal direction. Furthermore, the term "central portion" refers to the central portion other than the peripheral portion of the surface or layer, and the term "toward the center" refers to the direction from the peripheral portion of the surface or layer toward the center of the planar shape of the surface or layer.

[0017] <Measurement method> In order to explain the shape of the through hole provided in the glass substrate according to the first embodiment of the present invention, first, a method for measuring the inclination angle of the through hole 12 and a method for measuring the side surface roughness will be described below.

[0018] Here, points to note when measuring the inclination angle depending on the position of the side wall of the glass substrate through hole and recording the value will be described. When a particular position in a through hole is specified as a depth position from one side of a glass substrate, the angle of the side surface at that position depends greatly on the scale at which the shape of the side surface at that position is observed. In other words, the results can be significantly different when observing the inclination angle of the sidewall at a certain position on the sidewall using a scale that overlooks the entire through hole in the glass substrate, compared to when the sidewall near the measurement point is enlarged to clearly show the minute irregularities on the sidewall at that position, and a precise determination is made as to where on that irregularity the point at which the angle is specified corresponds, and the inclination angle of the tangent at that position is used to determine the desired angle. The inclination angle of the glass substrate through hole in the present disclosure corresponds to the former, and means an inclination angle that reflects the tendency when the entire through hole is viewed from above, without being overly influenced by the unevenness of the side surface. One example of a measurement method is to set a tangent at a measurement point in a cross-sectional photograph taken at a scale and resolution that allows a bird's-eye view of the entire through hole and where minute irregularities on the side surface cannot be seen with the naked eye, so as to reflect as closely as possible the tendency of inclination at the measurement point and its vicinity.

[0019] (Method of measuring the inclination angle of a through hole) First, FIG. 1 illustrates the shape of the through hole 12 obtained in the first embodiment of the present invention. FIG. 1 is a diagram showing a method for measuring the cross section and inclination angle of the truncated cone-shaped through hole 12. The cross section of the through hole 12 shown in FIG. 1 is obtained by fracturing (cutting) the through hole 12 from the first surface 101 side in the thickness direction of the glass substrate with a scriber to obtain a cross section (cut surface), and analyzing the SEM image observed by a SEM (Scanning Electron Microscope) using image analysis software. In FIG. 1, the portion shown by the pattern design indicates the glass substrate 10. The through hole 12 shown in FIG. 1 has a minimum value where the diameter of the through hole is minimal between the first surface 101 and the second surface 102. A truncated cone shape is formed on the first surface 101 side, and a truncated cone shape is also formed on the second surface 102 side, sandwiching the point having the minimum value. It should be noted that the scales of 5%, 10%, . . . 95% shown in FIG. 1 indicate the percentage of the length from the first surface 101 to the second surface 102 of the glass substrate 10. A center line TC is drawn perpendicular to the first surface 101 at the center of the through hole 12 on the first surface 101 side of the glass substrate 10. Next, the center line TC is translated toward either one of the two sides of the through hole 12 as shown by the arrow, and the translated center line TC is brought into contact with a point where the diameter of the through hole 12 is at a minimum value, and the point of contact is defined as a reference point RP. Then, a tangent line ss is drawn at the cross-sectional position at each of the heights of the scale positions from 5% to 100% from the reference point RP, and the inclination angle of the tangent line ss is measured, and the inclination angle is defined as the inclination angle at each of the cross-sectional positions from 5% to 95%. The inclination angle is defined as positive in the direction in which the diameter of the through hole 12 expands upward.

[0020] As described above, in the first embodiment, the method for measuring the inclination angle includes the steps (1) to (3) of (1) creating a center line of the through hole 12, (2) moving the center line horizontally to a position where the opening has a minimum value to create a reference point, and (3) drawing a tangent line from the reference point to a specific position of the through hole to measure the angle. In particular, by using the step (2) of creating the reference point, it is possible to perform a highly reliable measurement on a scale that overlooks the entire through hole and that is not affected by minute irregularities on the side wall.

[0021] In a specific measurement of the inclination angle, the through hole 12 is cut (cut) at the center from the first surface 101 side using a scribe and a precision breaker to expose the cross section of the through hole 12. As a method of cutting, for example, three-point bending can be applied. Thereafter, the exposed cross section is observed with an SEM, and the angle of the through hole 12 is measured by image analysis of the SEM image of the cross section.

[0022] (Method of measuring side surface roughness) Next, a method for measuring the side roughness of the through hole 12 will be described. To measure the side roughness of the through hole 12, the cross section of the through hole 12 is observed by SEM in the same manner as in the measurement of the side angle, and the observed SEM image is analyzed using image analysis software. To measure the side roughness of the through hole, the measurement range is usually the range from the first surface 101 to the second surface 102 of the through hole. However, if the through hole has irregularities, two or more measurement ranges excluding the irregularities are set, and the results of the measurement ranges are averaged to determine the side roughness. In addition, when calculating the side roughness, the same measurement is performed on five through holes (sample number n=5) created under the same conditions, and the average value is defined as the side roughness of the through hole created under those conditions. FIG. 2 is a diagram showing a method for measuring the side roughness of a through hole. For the purpose of explanation, the through hole 12 shown in FIG. 2 has a general shape. FIG. 2(a) shows an SEM image of the cross section of the through hole 12. FIG. 2(b) shows a diagram in which the contour of the side of the through hole 12 is extracted from an SEM image of the cross section of the through hole 12. Measurements of the average distributed roughness and the unevenness width are carried out from the extracted contour data. FIG. 2(c) is a diagram showing a formula for calculating the average distributed roughness and the unevenness width. With respect to the contour data extracted in FIG. 2(b), a roughness curve f(x) showing the roughness of the contour is measured in a set region L set based on the first surface 101. The average distributed roughness (hereinafter also simply referred to as "dispersed roughness") Ra is obtained by integrating the absolute value of the roughness curve f(x) squared over the set region L and then dividing it by the length of the set region L, as shown in formula (1). The roughness width (hereinafter also referred to as "unevenness width") a is the difference between the peak portion showing the maximum roughness value and the bottom portion showing the minimum roughness value in the roughness curve f(x). In addition, when multiple roughness curves f(x) are set for one through hole, the average roughness of the through hole is calculated from the average value of the roughness values ​​calculated from those curves.

[0023] (Method of measuring transmission characteristics) The transmission characteristics are measured using the S parameter (S21), which indicates the frequency dependency of the degree of the propagating wave relative to the input wave. S21 is expressed as the logarithm of the power ratio (transmitted wave power / input wave power), and the smaller the absolute value, the smaller the transmission loss. A network analyzer was used to measure the S parameter (S21). A measurement sample was prepared by surrounding the periphery of the through electrode 11 formed on the glass substrate with a conductor and grounding the conductor, and S21 between the first surface 101 side and the second surface 102 side of the through electrode 11 was measured.

[0024] <Examples and Comparative Examples According to the First Embodiment> The shape of the through hole 12 in the first embodiment will be described. In the embodiment, as shown in Fig. 25 described later, etching is performed on the glass substrate 10 on which the laser modified portion 65 is formed from the second surface 102 side of the glass substrate 10. Therefore, the formed through hole 12 has a truncated cone shape whose diameter narrows from the second surface 102 toward the first surface 101. The inclination angle of the side surface of the through hole 12 changes depending on the laser processing conditions and etching conditions for the glass substrate 10. In each example of the present invention, laser processing is performed on a glass substrate under irradiation conditions of the pulse width and number of shots shown in Table 1, and through-hole 12 is formed by subsequent etching. In example 1 of the first embodiment, the pulse width is 5 ps and the number of shots is 1, in example 2, the pulse width is 15 ps and the number of shots is 1, and in example 3, the pulse width is 25 ps and the number of shots is 1. The comparative examples are through holes created by modifying the manufacturing method and laser processing method shown in the first embodiment. That is, in comparative example 1, the pulse width is 30 ps and the number of shots is 1, in comparative example 2, the pulse width is 30 ns and the number of shots is 50, and in comparative example 3, the pulse width is 50 μs and the number of shots is 5. In each of the examples and comparative examples, the opening diameter on the second surface 102 side of the glass substrate 10 was 80 μm on average, and in this case, 3σ, which is the average value of the measured values ​​plus three times the standard deviation, was 4.5 μm or less. Max and the minimum value φ Min The difference was less than 10 μm.

[0025] [Table 1]

[0026] (Through hole inclination angle) Hereinafter, the shapes and characteristic shapes of the through holes of each of the examples and comparative examples of the first embodiment will be described with reference to FIG. 3 to FIG. FIG. 3 is a diagram showing the measurement results of the inclination angle of the through hole in Example 1 in the first embodiment. FIG. 4 is a diagram showing the measurement results of the inclination angle of the through hole in Example 2 in the first embodiment. FIG. 5 is a diagram showing the measurement results of the inclination angle of the through hole in Example 3 in the first embodiment. FIG. 6 is a diagram showing a cross-sectional shape of a through hole of Comparative Example 1 in the first embodiment. FIG. 7 is a diagram showing the measurement results of the inclination angle of the through hole of Comparative Example 1 in the first embodiment. FIG. 8 is a diagram showing a cross-sectional shape of a through hole of Comparative Example 2 in the first embodiment. FIG. 9 is a diagram showing the measurement results of the inclination angle of the through hole in Comparative Example 2 in the first embodiment. FIG. 10 is a diagram showing a cross-sectional shape of a through hole of Comparative Example 3 in the first embodiment. FIG. 11 is a diagram showing the measurement results of the inclination angle of the through hole in Comparative Example 3 in the first embodiment.

[0027] (Tilt angle) Table 2 is a table showing the results of measuring the inclination angle of the side of the through hole 12 in each example of the embodiment and each comparative example. In each example of the embodiment, it is confirmed that there is a difference between the value of the side angle of the through hole 12 in the range of 0% to less than 10% of the distance from the first surface and the value in the range of 10% to 95% of the distance from the first surface. In other words, it is confirmed that the side angle of the through hole 12 is almost constant in the range of 0% to less than 10% of the distance from the first surface (the side angle is in the range of 4° to 7°), and the side angle that is almost constant in the range of 10% to 95% of the distance from the first surface is in the range of -7° to -15°). In addition, the inclination angle of the side of the through hole 12 in the range of 95% to 100% of the distance from the first surface is the same as the inclination angle of the side of the through hole 12 in the range of 10% to 95% of the distance from the first surface, and the difference in the inclination angle between the two ranges is 1.0° or less. It can be seen that in each comparative example, the inclination angle of the side surface of through hole 12 varies at each position between 5% and 95% of the distance. It can be seen that the shapes of the inclination angle of the side surface of the through hole are significantly different between each embodiment of the present invention and the comparative example.

[0028] [Table 2]

[0029] (Average dispersion roughness and unevenness width) Next, the average dispersion roughness and unevenness width of the side surface of through hole 12 will be described for each example and each comparative example in the first embodiment with reference to Table 3. As shown in Table 3, in each of the first examples, the dispersion roughness of the side surface shape at the cut surface of through hole 12 in the thickness direction of the glass substrate is 1,000 nm or less and the unevenness width is 1,500 nm or less. In each comparative example, the dispersion roughness is 1,500 nm or more and the unevenness width is 1,500 nm or more, confirming that there is a difference in the roughness of the side surface of the through hole.

[0030] [Table 3]

[0031] (Inclination angle of application examples) Next, Figs. 12 to 14 show the results of forming the inflection point of the side inclination angle of the through hole 12 in the range of 1% to 5% of the distance from the first surface as application examples of the first embodiment of the present invention. Fig. 12 is a diagram showing the measurement result of the inclination angle of the through hole in application example 1. Fig. 13 is a diagram showing the measurement result of the inclination angle of the through hole in application example 2. Fig. 14 is a diagram showing the measurement result of the inclination angle of the through hole in application example 3. Table 4 shows the measurement result of the inclination angle of the side of the through hole 12 in each application example. As described later, the etching process is performed by immersion treatment using a jet, but each application example is formed by switching the direction of the jet more slowly than each comparative example. The conditions of the pulse number and the shot number of each application example are the same as those of each example. In each application example, it was confirmed that the side angle of the through hole 12 was almost constant in the range of 0% to 5% of the distance from the first surface, and was almost constant in the range of 5% to 95% of the distance from the first surface. In addition, the inclination angle of the side of the through hole 12 in the range of 95% to 100% of the distance from the first surface is the same as the inclination angle of the side of the through hole 12 in the range of 10% to 95% of the distance from the first surface, and the difference in the inclination angle in the two ranges is 1.0° or less. Regarding the roughness of the side of the through hole, since the same laser processing conditions and the composition of the etching solution as those in Examples 1 to 3 are used, the values ​​are the same as those in Table 3, that is, the dispersion roughness is 1000 nm or less and the unevenness width is 1500 nm or less.

[0032] [Table 4]

[0033] (Opening diameter) Table 5 and FIG. 15A are used to explain the relationship between the opening diameters of the first surface and the second surface of the through hole according to the embodiment of the present invention. Table 5 shows the diameters of the openings of the through hole 12 on the first surface 101 and the second surface 102 when the thickness of the glass substrate 10 is changed from 100 μm to 200 μm under the conditions of Example 1. FIG. 15A is a graph showing Table 5. According to the first embodiment, regardless of the opening diameter of the second surface 102, the relationship between the opening diameter of the second surface 102 and the opening diameter of the first surface 101 is first surface side opening diameter Φ1 / second surface side opening diameter Φ2≧0.4 or more.

[0034] [Table 5]

[0035] Next, the first surface opening diameter and the second surface opening diameter of each example and each comparative example in the first embodiment are shown in Table 6. Table 6 shows typical values ​​of the opening diameter Φ1 on the first surface 101 side of through hole 12 and the opening diameter Φ2 on the second surface 102 side measured in each example and each comparative example in the first embodiment.

[0036] [Table 6]

[0037] Here, the relationship between the aperture diameter and the transmission characteristics will be described with reference to FIG. 15B. FIG. 15B is a diagram showing a typical case where the through electrode 11 is formed. The aperture diameter of the through hole 12 can be made smaller than Φ2, as shown by the relationship Φ1 / Φ2≧0.4. For example, when used as a communication device described later, the through electrode 11 is used to form a coil, and the relationship between Φ1 and Φ2 makes it possible to ensure the design freedom of the coil. In addition, since the distance Dp between the pads can be ensured, the Q value can be reduced when a circuit including a coil is formed, and transmission loss can be suppressed. From the above, it is possible to stabilize the signal of the through electrode (reduce signal loss).

[0038] (Features of the Through Hole and Through Electrode of the Present Disclosure) 15C is a diagram for explaining the characteristics of the through hole and through electrode formed in the present disclosure. FIG. 15C is a diagram showing, for example, an enlarged view of region Ra in FIG. 29. As shown in FIG. 15C, a conductive electrode 31 can be formed directly on the through hole 12 (or the through electrode 11). This is because the through hole 12 has a so-called bottomed shape. By making the through hole 12 have a bottomed shape, it becomes possible to form the conductive electrode 31 directly on the through hole 12. This shortens the transmission distance of the electrode as a whole, improving the transmission characteristics and enabling the through hole 12 to be miniaturized. As described in the embodiment, the side surface of the through hole 12 in the present disclosure does not have an inflection point at which the side shape changes, and the surface is smooth. Therefore, when plating is performed on the through hole 12, a uniform metal film or the like can be formed, so that the generation of parasitic capacitance can be suppressed on the side surface of the through hole 12. The shape of the through hole 12 can be a shape having an inflection point or a so-called straight shape in which the diameter hardly changes from the first surface to the second surface of the glass substrate, but from the viewpoint of transmission characteristics, the shape shown in the present disclosure that can suppress the generation of parasitic capacitance is desirable.

[0039] (Cross-sectional shape) Next, the side shape of the through hole 12 will be described. Figures 16A to 16D are diagrams for explaining the side surface of the through hole in each example and comparative example. Figure 16A is a diagram showing an SEM image of a typical cross-sectional shape of the through hole in each example and comparative example in the first embodiment.

[0040] The SEM images were taken of the cut surface of the through hole in the thickness direction of the glass substrate. The SEM images shown in Figures 16A to 16D are at a magnification of 1000 times (one division of the scale is 5 μm). 16A, in order to facilitate observation of the cross-sectional shape of the glass substrate according to the first embodiment, the through-hole 12 is filled with a resin material. It can be seen that the inclination angle of the side surface changes from the first surface 101 toward the second surface 102.

[0041] Fig. 16B is a diagram showing SEM images of the cross-sectional shapes of the through-holes of each example and each comparative example in the first embodiment. In Fig. 16B, the inclination angle and cross-sectional shapes are different from those described above, but the pulse width and shot number conditions are as described in each example and each comparative example. The appearance of the SEM image and the smoothness of the cross section of the through-hole have common properties. In the SEM image, the areas that have high contrast and appear white are the areas where the angle of the inclined plane of the sample surface changes and becomes the ridge of the inclined plane. Therefore, the areas that appear as white lines indicate the peak or bottom of the roughness of the sample surface, and the presence and degree of the ridges formed on the side of these through holes make it possible to grasp the roughness of the side of the through holes, which affects the transmission characteristics of the through electrodes.

[0042] In each example of the first embodiment shown in Figure 16B, multiple white ridge lines extending in a direction parallel or approximately parallel to the first surface 101 of the glass substrate 10 appear and can be seen, forming a band-like striped pattern. Here, the ridge lines of the cross section of the through hole will be described with reference to Fig. 16C. Fig. 16C is a diagram for explaining the ridge lines of the through hole in each example in the first embodiment. Fig. 16C(a) is an enlarged view of Example 3 in Fig. 16B. Fig. 16C(b) is a diagram showing the ridge lines of the side and cross section of the through hole observed in the SEM image by solid lines. In the example shown in Fig. 16C(b), the widest interval between the substantially parallel ridgelines is between ridgelines Rl1 and Rl2. In the example shown in Fig. 16C(b), the interval between the ridgelines on the side surface in the direction perpendicular to the first surface 101 is equal to or less than Rs. As shown in Fig. 16C(a), in Example 3, the interval between the ridgelines is equal to or less than 15.5 μm. When the state of the ridgelines was checked by a similar method, the distance between the ridgelines in the direction perpendicular to the first surface 101 was in the range of 2 μm to 3 μm in Example 1. In addition, in Example 2, the distance between the ridgelines in the direction perpendicular to the first surface 101 of the glass substrate 10 was in the range of 5 μm to 6 μm.

[0043] Moreover, as is clear from Figure 16B, as the first embodiment changes from Example 3 to Example 1, that is, as the dispersion roughness, which is the smoothness of the side surface of the through hole, decreases, the white lines that can be recognized as ridge lines extending in a direction parallel to the first surface 101 of the glass substrate 10 on the side surface of the through hole 12 become denser and the distance between the ridge lines becomes narrower. Conversely, as the dispersion roughness increases (i.e., when changing from Example 1 to Example 3, and further from Comparative Example 1 to Comparative Example 3), the spacing between the ridgelines increases and the number of ridgelines extending in a direction not parallel to the first surface 101 also increases. Furthermore, it can be seen that the frequency of occurrence of ridgelines extending in a direction perpendicular to the first surface 101 and white lines extending in a direction between the direction parallel to the first surface 101 and the direction perpendicular to the first surface 101 (hereinafter also referred to as "diagonal directions") increases. This indicates that the proportion of ridgelines extending in a vertical direction and ridgelines extending in diagonal directions decreases as the dispersion roughness decreases. For example, in Example 2, when the average dispersion roughness is 500 nm and the unevenness width is 980 nm, white lines extending in a direction between the direction parallel to the first surface 101 and the direction perpendicular to the first surface 101 (i.e., diagonal directions) become visible.

[0044] On the other hand, when the side surface of the through hole becomes rough (dispersion average roughness is greater than 1,000 nm and unevenness width is greater than 1,500 nm) as in Comparative Examples 1 to 3 in the embodiment, the proportion of white lines extending in a direction perpendicular to the first surface 101 of the glass substrate 10 or in a diagonal direction between a direction perpendicular to the first surface 101 and a direction parallel to the first surface 101 increases. That is, multiple ridge lines become visible in the diagonal direction. It can be seen that such smoothness (roughness) of the side surface of the through hole 12 appears in the SEM image and also affects the transmission characteristics of the through electrode.

[0045] Fig. 16D is a diagram showing an SEM image of a cross section when a through electrode is formed in the through hole in the first embodiment. In Fig. 16D, the inclination angle and cross section shape are different from those described above, but the pulse width and the number of shots are as described in each example and each comparative example. The appearance of the SEM image and the smoothness of the cross section of the through hole have common properties. As shown here, the area indicated by the arrow and surrounded by the dashed line has a shape with a raised end. In other words, there is no gradual change between the side surface of the through hole 12 and the second surface 102 of the glass substrate 10, and the angle changes completely in cross-sectional view. In other words, the side surface of the through hole 12 and the second surface 102 of the glass substrate 10 have a shape with a raised end, and the side surface and the second surface region can be clearly distinguished in a 1000x SEM image.

[0046] (Transmission characteristics) Next, the transmission characteristics of the through electrodes of each example and each comparative example in the first embodiment of the present invention will be described with reference to FIG. 17. FIG. 17 is a diagram showing the transmission characteristics of the through electrodes of Example 1 in the first embodiment and the transmission characteristics of the through electrodes of Comparative Example 1. FIG. 17 shows the results of measuring the transmission loss S21 as the transmission characteristics in the through electrodes. Since Examples 1 to 3 showed the same tendency in the transmission characteristics, Example 1 is shown as a representative. Furthermore, since Comparative Examples 1 to 3 showed almost the same tendency in the transmission characteristics, Comparative Example 1 is shown as a representative. The formation conditions of the seed layer for forming the electrode and the plating process were the same for both the examples and the comparative examples. As shown in FIG. 17, it is shown that the transmission loss of the examples is smaller than the transmission loss of the comparative examples in any frequency range. Therefore, it can be seen that the smaller the values ​​of the dispersion roughness and the unevenness width are for the side surface of the through hole, the smaller the loss in the through electrode formed in the through hole, and the better the transmission characteristics are.

[0047] (Transmission characteristics when glass substrate thickness is changed) In addition, the transmission characteristic S21 was also measured for each example and each comparative example when the thickness of the glass substrate 10 was changed. The results are shown in Table 6. As shown in Table 7, the thickness of the glass substrate 10 was set to 100 μm, 150 μm, and 200 μm, and through holes and through electrodes were created under conditions based on each example and each comparative example, and the transmission characteristics were measured. As shown in Table 7, it is confirmed that the examples in the first embodiment show better transmission characteristic S21 values ​​than the comparative examples.

[0048] The transmission characteristics shown in Table 7 are those of a single through electrode, and in a multilayer wiring board that requires multiple through electrodes, improving the transmission characteristics of a single through electrode leads to a significant performance improvement. By using each example of the first embodiment, it is possible to obtain a multilayer wiring board that realizes good transmission characteristics of the through electrode in the high frequency band compared to existing technologies. From the viewpoint of transmission characteristics, the through electrodes shown in Examples 1 to 3 have achieved better results than the through electrodes shown in Comparative Examples 1 to 3. Comparing the Examples, it can be said that Example 1 is the most preferable, followed by Example 2 and Example 3.

[0049] [Table 7]

[0050] The reliability evaluation results of the TCT test (Temperature Cycling Test) are shown in Tables 8 and 9. The reliability test conditions are as follows: -Setting conditions: Lower limit temperature -40℃ / 30 minutes, upper limit temperature 150℃ / 30 minutes. Test equipment TSA-43EL (manufactured by Espec) Measure the increase in resistance of the wiring path including the through electrode at each cycle number. NG criteria: If the resistance value after cycling is more than 10 times the initial resistance value, it is judged as NG.

[0051] As shown in Tables 8 and 9, each of the examples according to the embodiment of the present invention shows higher reliability than each of the comparative examples.

[0052] [Table 8]

[0053] [Table 9]

[0054] <Configuration of Multilayer Wiring Board in First Embodiment> FIG. 18 is a diagram showing an example of the configuration of the multilayer wiring board 1 in the first embodiment. FIG. 19 is a diagram showing another example of the configuration of the multilayer wiring board 1 in the first embodiment. The multilayer wiring board 1 includes a glass substrate 10, a first wiring layer 21, and a second wiring layer 22. The first wiring layer 21 is disposed on the first surface 101 side of the glass substrate 10, and the second wiring layer 22 is disposed on the second surface 102 side of the glass substrate 10. The glass substrate 10 includes a through hole 12 penetrating from the first surface 101 side to the second surface 102 side. The through electrode 11 is formed of a conductor formed along the side surface of the through hole 12. The through electrode 11 electrically connects a part of the first wiring layer 21 and a part of the second wiring layer 22. The first wiring layer 21 and the second wiring layer 22 include an insulating resin layer 25. The first wiring layer 21 and the second wiring layer 22 may be configured by stacking a plurality of layers, and the number of layers may be set as necessary. The through electrode 11 is an electrode for establishing an electrical connection between the first wiring layer 21 and the second wiring layer 22. The conductive electrode 31 is an electrode for ensuring electrical continuity in the thickness direction of the multilayer wiring board 1. The semiconductor element bonding pad 50 is a member for connecting a semiconductor circuit mounted on the multilayer wiring board 1. The board bonding pad 54 is a member for bonding the multilayer wiring board 1 to another board. In addition, as long as the through electrode can electrically connect from the first surface 101 side to the second surface 102 side of the glass substrate 10, a conductor may be placed only on the side of the through hole 12 as shown in Figure 18, or a conductor may be embedded in the through hole 12 as shown in Figure 19. In the first embodiment, it is possible to arrange the conduction electrodes 31 above the through electrodes 11 of the first wiring layer 21 in the Z-axis direction.

[0055] 18 and 19, the shape of the through-hole 12 is not shown in detail. The same is also omitted in Figures 20 to 29.

[0056] The thickness of the multilayer wiring board 1 is, for example, in the range of 100 μm to 400 μm.

[0057] <Method of Manufacturing the Multilayer Wiring Board in the First Embodiment> A method for manufacturing the multilayer wiring board 1 will be described with reference to Figures 3 to 12. First, the process of forming the through holes 12 in the glass substrate 10 will be described.

[0058] [First support bonding process] FIG. 20 is a diagram showing a process of bonding the glass substrate 10 to the first support 62. As shown in FIG. The thickness of the glass substrate 10 can be appropriately set depending on the application, taking into consideration the thickness after etching.

[0059] As shown in FIG. 20, a first support 62 is attached to the glass substrate 10 via a first adhesive layer 61, and a laminated structure 63 including the glass substrate 10, the first adhesive layer 61, and the first support 62 is formed.

[0060] The glass substrate 10 and the first support 62 are temporarily fixed by a first adhesive layer 61 . In order to bond the first support to the glass substrate 10, for example, a laminator, a vacuum pressure press, a reduced pressure bonding machine, or the like can be used.

[0061] The first support 62 is desirably made of the same material as the glass substrate 10, for example. When the glass substrate 10 is made of alkali-free glass with an SiO2 ratio in the range of 55 mass % to 81 mass %, the first support 62 is desirably made of alkali-free glass. The thickness of the first support 62 can be appropriately set according to the thickness of the glass substrate 10. However, it is desirably a thickness that allows transport during the manufacturing process, and the thickness of the support is, for example, in the range of 300 μm to 1,500 μm.

[0062] For the glass substrate 10, for example, alkali-free glass with an SiO2 ratio in the range of 55% by mass to 81% by mass can be used. If the SiO2 ratio of the glass substrate 10 is greater than 81% by mass, the etching speed decreases, the side angle of the through hole 12 decreases, and poor adhesion occurs when forming the through electrode 11 described below. If the SiO2 ratio is less than 55% by mass, there is a high possibility that alkali metals will be contained in the glass, which will affect the reliability of the multilayer wiring board after the electronic device is mounted. If the SiO2 ratio of the alkali-free glass is greater than 55% by mass to 81% by mass, the ratio may be set appropriately.

[0063] [Laser modification process] Next, FIG. 21 is a diagram showing a process of forming a laser modified portion. A laser modified portion 65 is formed on the glass substrate 10 by performing laser processing on the glass substrate 10. The laser modified portion 65 is processed into a shape of Φ3 μm or less on the glass substrate 10, and is continuously formed in the thickness direction of the glass substrate 10. At this time, it is desirable that minute cracks (hereinafter also referred to as "microcracks") of 5 μm or more do not occur around the laser modified portion 65. If microcracks of 5 μm or more occur around the laser modified portion 65, the dispersion roughness on the side of the through hole 12 after etching will be 1000 nm or more and the unevenness width will be 1500 nm or more, making it difficult to obtain a through hole 12 with a smooth side. In addition, if microcracks of 5 μm or more occur, as described later, roughness that changes at intervals will occur on the side of the through hole 12 after etching in a direction perpendicular to the first surface 101 of the glass substrate 10.

[0064] For processing the laser modified portion 65, it is preferable to use, for example, a femtosecond laser or a picosecond laser, and to use any one of the laser oscillation wavelengths of 1064 nm, 532 nm, or 355 nm. If the laser pulse width is 25 picoseconds or more, microcracks of 5 μm or more tend to occur around the laser modified portion 65, so the laser pulse width is desirably 25 picoseconds or less. In addition, since microcracks tend to occur when processing is performed by multiple pulse irradiation, it is desirable to form the laser modified portion 65 with one pulse. As long as microcracks of 5 μm or more do not occur around the laser modified portion 65, the laser oscillation wavelength and the laser output may be appropriately set according to the thickness of the glass substrate 10. That is, in the laser modification step (first step), a laser is irradiated to the portion to be formed with a through hole on the glass substrate, and the maximum length of the microcracks occurring around the laser irradiation is 5 μm.

[0065] [Formation of the first wiring layer] 22 is a diagram showing a process of forming the first wiring layer 21. As shown in FIG. 22, the first wiring layer 21 made of a conductive layer and an insulating resin layer is formed on the first surface 101 on the glass substrate 10 of the laminated structure 63. Here, after a seed layer including a hydrofluoric acid resistant metal layer is formed on the glass substrate 10, the through electrode connection portion 41 (or wiring between the through electrodes) is formed on the first surface 101 by a semi-additive (SAP) process. After removing the seed layer that is no longer necessary, the insulating resin layer 25 is formed.

[0066] Regarding the formation of the seed layer, the hydrofluoric acid resistant metal layer on the glass substrate 10 is an alloy layer containing chromium, nickel, or both, and can be formed in the range of 10 nm to 1,000 nm by sputtering. Then, a conductive metal film is formed on the hydrofluoric acid resistant metal with a desired thickness. The conductive metal film can be appropriately selected from, for example, Cu, Ni, Al, Ti, Cr, Mo, W, Ta, Au, Ir, Ru, Pd, Pt, AlSi, AlSiCu, AlCu, NiFe, ITO, IZO, AZO, ZnO, PZT, TiN, and Cu3N4.

[0067] In the semi-additive process, a desired pattern is formed using a photoresist in order to form a wiring pattern by plating. Generally, a dry film resist is used, but a liquid resist may also be used. After the desired pattern is formed by exposure and development, a plating film is formed by electrolytic plating, the unnecessary resist is peeled off, and the seed layer is etched to form wiring.

[0068] [Insulating resin layer] Next, regarding the formation of the insulating resin layer 25, the insulating resin layer 25 is a thermosetting resin, and the material thereof is a material that contains at least one of an epoxy resin, a polyimide resin, and a polyamide resin, and also contains a silica SiO2 filler. The material of the insulating resin layer 25 can be appropriately selected according to need. However, when a photosensitive insulating resin material is used, it becomes difficult to fill the silica SiO2 filler in order to ensure photolithography properties, so although a photosensitive insulating resin material can also be used, it is more preferable to use a thermosetting resin.

[0069] [Second support adhesion process] 23 is a diagram showing a step of adhering a second support body. As shown in FIG. 23, a second adhesive layer 71 is formed on the first wiring layer 21 of the laminated structure 63, and a second support body 70 is disposed on the second adhesive layer 71 and adhered thereto. The second support 70 may be made of, for example, glass, and is preferably made of the same material as the glass substrate 10. When the glass substrate 10 is made of alkali-free glass, the second support 70 is preferably made of alkali-free glass. The thickness of the second support 70 can be appropriately set according to the thickness of the glass substrate 10. However, it is preferable that the thickness be such that the second support 70 can be transported, and the range of this thickness is from 300 μm to 1,500 μm.

[0070] [Peeling process] 24 is a diagram showing a step of peeling off the first support 62. As shown in FIG.

[0071] [Formation of through holes] Next, FIG. 25 is a diagram showing a process of forming the through holes 12. As shown in FIG.

[0072] [Etching process] The glass substrate 10 on which the laser modified portion 65 has been formed is subjected to an etching process using a predetermined etching solution to form the through-hole 12. At the same time, the second surface of the glass substrate 10 is also etched, and the thickness of the glass substrate 10 is reduced. The etching is performed from the second surface 102 side of the glass substrate 10.

[0073] [Etching solution] The etching solution contains hydrofluoric acid in a range of 0.2 mass% to 20.0 mass%, nitric acid in a range of 4.0 mass% to 25.0 mass%, and inorganic acid other than hydrofluoric acid and nitric acid in a range of 0.5 mass% to 11.0 mass%. Examples of inorganic acids other than hydrofluoric acid and nitric acid include hydrochloric acid, sulfuric acid, phosphoric acid, and sulfamic acid, and at least one inorganic acid is contained depending on the type of components other than silicon contained in the glass substrate 10. The etching solution preferably contains hydrochloric acid and sulfuric acid, and the etching rate for the glass substrate 10 is appropriately adjusted to be in the range of 0.1 μm / min to 10 μm / min. The etching rate for the glass substrate 10 is preferably in the range of 0.25 μm / min to 4 μm / min, and more preferably in the range of 0.25 μm / min to 0.5 μm / min. The etching temperature is not particularly limited and can be appropriately adjusted, but is, for example, in the range of 10° C. or more and 30° C. or less.

[0074] Regarding the etching process, etching is performed by immersion processing using a jet or spray processing to form the through hole 12. In the case of immersion processing using a jet, for example, in order to efficiently etch the bottom of the through hole 12, the direction of the jet is switched in the etching solution. By setting the timing of switching the direction of the jet early, it is possible to apply pressure to the bottom of the through hole 12, thereby changing the inclination angle of the TGV side at a position 1 to 10% away from the first surface. Similarly, in the etching process by spray processing, it is possible to change the inclination angle of the TGV side at a position 1% to 10% away from the first surface by applying pressure to the bottom of the through hole 12 by setting the oscillation speed of the spray having an injection port for injecting the etching solution or the oscillation speed of the substrate fast. In the immersion treatment using a jet flow and the etching process by spray treatment, the processing conditions differ depending on the size of the device used, so it is desirable to set the processing conditions after confirming the shape of the through hole 12. In the immersion treatment using a jet flow, ultrasonic waves or the like may be used in combination as another mechanism.

[0075] [Formation of through electrodes] Next, a process for forming the through electrodes 11 will be described with reference to Fig. 26. Fig. 26 is a diagram showing a process for forming the through electrodes 11.

[0076] A metal layer for electrolytic plating is formed on the second surface 102 of the glass substrate 10 in which the through-hole 12 is formed. The metal layer may be any metal that functions as a seed layer for electrolytic plating, such as metals including Cu, Ti, Cr, W, Ni, etc. At least one of the above metals is used for the metal layer, and it is preferable that a Cu layer is formed on the outermost surface of the metal layer. It is preferable that Ti, Cr, W, and Ni are used as an adhesive layer with the glass substrate 10 below the Cu layer. The thickness of the metal layer is appropriately set to a range that can cover the side surface of the through-hole 12. As a forming method, for example, a forming method by deposition using sputtering can be adopted.

[0077] Next, the through electrode 11 is formed by electrolytic plating using the metal layer as a seed layer. In order to selectively grow the inside of the through hole 12, a mask is formed on the second surface 102 of the glass substrate 10 in the through hole 12 and a predetermined area around the through hole 12 using an insulator such as a resist, and then electrolytic plating is performed. As a material used for electrolytic plating, for example, Cu can be used, and as other metals, metals including Au, Ag, Pt, Ni, Sn, etc. can also be used. Depending on the application of the multilayer wiring board, electrolytic plating may be performed so that the inside of the through hole 12 is filled with a conductor such as the above metal.

[0078] Further, the process of forming the insulating resin layer 25 will be described with reference to Fig. 27. Fig. 27 is a diagram showing the process of forming the insulating resin layer. After performing the electrolytic plating process for forming the through electrodes, the insulator such as resist is removed, and the metal film serving as the seed layer formed on the second surface 102 of the glass substrate 10 is removed. After each of the multiple through electrodes 11 formed on the glass substrate 10 is electrically isolated, the insulating resin layer 25 is formed on the second surface side as shown in Fig. 27.

[0079] [Removal of the second support] Next, the step of peeling off the second support 70 and the second adhesive layer 71 will be described with reference to Fig. 28. Fig. 28 is a diagram showing the step of peeling off the second support 70 and the second adhesive layer 71. As shown in Fig. 28, the second adhesive layer 71 and the second support 70 formed above the first wiring layer 21 are peeled off from the interface between the first wiring layer 21 and the second adhesive layer 71 on the first surface 101 side. Thereby, as shown in Fig. 28, a glass substrate 10 is obtained in a state in which the first wiring layer 21 is formed on the first surface 101 side and the second wiring layer 22 is formed on the second surface 102 side. When peeling the second support 70 from the second wiring layer 22, a peeling method according to the material used can be appropriately selected from UV light irradiation, heat treatment, physical peeling, etc., depending on the material used in the second adhesive layer 71. Furthermore, if a residue of the second adhesive layer 71 remains on the bonding surface between the first wiring layer 21 and the second adhesive layer 71, plasma cleaning, ultrasonic cleaning, water washing, solvent cleaning using alcohol, etc. may be performed.

[0080] [Formation of the first and second wiring layers] Next, with reference to FIG. 29, the formation of the first wiring layer 21 and the second wiring layer 22 formed on the glass substrate 10 will be described. FIG. 29 is a diagram showing a process of forming the first wiring layer 21 and the second wiring layer 22. For the glass substrate 10 on which the through electrodes 11 are formed, the first wiring layer 21 is formed on the first surface 101, and the second wiring layer 22 is formed on the second surface 102. In the process of forming the first wiring layer 21 and the second wiring layer 22, first, a mask having a pattern is formed by a photosensitive resist or a dry film resist, and then wiring is formed by electrolytic plating. Then, after performing a physical adhesion treatment or a chemical adhesion treatment, the insulating resin layer 25 is laminated. For the conductive electrode 31, a hole is formed in the insulating resin layer 25 by laser processing or the like, and then a metal film is formed by electroless plating or deposition treatment by sputtering. A mask having a pattern is formed on the above-mentioned metal film using a resist, and a conductor is filled in the hole formed by electrolytic plating. Then, the mask and the excess metal film are removed. The above process is repeated multiple times according to the required number of layers to form the first wiring layer 21 and the second wiring layer 22. It is preferable that the first wiring layer 21 and the second wiring layer 22 have the same number of layers in order to suppress warping of the multilayer wiring board 1. When the first wiring layer 21 and the second wiring layer 22 have different layer thicknesses, the number of layers of the first wiring layer 21 and the second wiring layer 22 may be different. The number of layers of the first wiring layer 21 and the number of layers of the second wiring layer 22 may be set appropriately depending on the application of the multilayer wiring board.

[0081] Second Embodiment Fig. 30 is a diagram showing a case where a multilayer wiring board 1 is used as an interposer board for a semiconductor element 100 and a BGA (Ball Grid Array) board 90. Fig. 31 is a diagram showing a cross section of the case of Fig. 30. Fig. 32 is a diagram showing a case where the multilayer wiring board 1 and the semiconductor element 100 are used in an electronic device for communication. Fig. 33 is a diagram showing a cross section of the case of Fig. 32. The electronic device used has a layer thickness of 800 μm or less. The applications of the above electronic devices are limited due to the influence of the transmission characteristics of the through electrodes, but the use of a multilayer wiring board using the glass substrate of the present invention makes it possible to apply electronic devices to high frequency band regions.

[0082] <Actions and Effects> As described above, according to the present invention, it is possible to obtain a glass substrate in which a through electrode having good transmission characteristics and high reliability can be formed, and a multilayer wiring substrate including such a glass substrate.

[0083] (Other embodiments) The present disclosure also includes the following aspects. (Aspect 1) A glass substrate having a first surface and a second surface, and at least one through hole extending from the first surface to the second surface, The side surface of the through hole is Within a range of a distance of 0% or more and less than 10% from the first surface, the angle of the side surface is in a range of 4° or more and 7° or less, and when the side surfaces of the through hole are the left side surface and the right side surface in a cross-sectional view, the difference between the inclination angle of the left side surface and the inclination angle of the right side surface is 1.0° or less, Within a distance range of 10% to 100% from the first surface, the angle of the side surface is in a range of -7° to -15°, and the difference between the inclination angle of the left side surface and the inclination angle of the right side surface is 1.0° or less. Glass substrate. (Aspect 2) The glass substrate according to embodiment 1, The glass substrate, wherein the side surface of the through hole has an inflection point at which the inclination angle changes within a range of 1% to 5% from the first surface. (Aspect 3) 3. The glass substrate according to claim 1 or 2, The through hole has an opening diameter Φ2 on the second surface side and an opening diameter Φ1 on the first surface side such that Φ1 / Φ2≧0.4 or more. (Aspect 4) 4. The glass substrate according to claim 1, The shape of the side surface of the through hole in the thickness direction of the glass substrate A glass substrate having a dispersion roughness of 1,000 nm or less and a width of irregularities of 1,500 nm or less. (Aspect 5) A glass substrate according to any one of aspects 1 to 4, The distributed roughness is an arithmetic average roughness calculated by extracting a roughness curve based on the profile data of the side surface, setting a set interval on the roughness curve, and calculating the arithmetic average roughness in the set interval using Equation 1, A glass substrate, wherein the unevenness width is the difference between the highest part and the lowest part in the set section.

number

[0084] 1: Glass multilayer wiring board with through electrodes 10: Glass substrate 11:Through electrode 12:Through hole 21: First wiring layer 22:Second wiring layer 25: Insulating resin layer 31: Conduction electrode 50: Bonding pad for semiconductor elements 54:Board bonding pad 61:First adhesive layer 62:First support 63:Laminated structure 65: Laser modification section 70:Second support 71:Second adhesive layer 90:BGA board 100: Semiconductor element 101: First surface of glass substrate 10 102: second surface of glass substrate 10 TC: Center line of through hole SS: Tangent to the side of the through hole

Claims

1. A glass substrate having a first surface and a second surface, and at least one through hole extending from the first surface to the second surface, A glass substrate, wherein the dispersion roughness of the side shape of the cut surface of the through hole in the thickness direction of the glass substrate is 1,500 nm or more and the unevenness width is 1,500 nm or more.

2. 2. The glass substrate according to claim 1, A glass substrate, wherein a shape of a cut section of the through hole in a thickness direction of the glass substrate includes a portion having a truncated cone shape.

3. 3. The glass substrate according to claim 1, The distributed roughness is an arithmetic average roughness calculated by extracting a roughness curve based on the profile data of the side surface, setting a set interval on the roughness curve, and calculating the arithmetic average roughness in the set interval using Equation 1, A glass substrate, wherein the unevenness width is a difference between the highest part and the lowest part in the set section.

4. A glass substrate having a first surface and a second surface, and at least one through hole extending from the first surface to the second surface, In a SEM image of a cut surface of the through hole in the thickness direction of the glass substrate at a magnification of 1000 times, a plurality of ridge lines extending in a direction substantially parallel to the first surface can be visually recognized within a side wall surface of the through hole, A glass substrate, wherein the distance between ridgelines in a direction perpendicular to the first surface is 15.5 μm or less.

5. The glass substrate according to claim 3, The glass substrate has a SiO 2 ratio in the range of 55% by mass to 81% by mass.

6. 5. The glass substrate according to claim 4, The SiO of the glass substrate ２ A glass substrate having a ratio of 55% by mass or more and 81% by mass or less.

7. A multilayer wiring board including the glass substrate according to claim 3, The thickness of the electronic device mounted on the multilayer wiring board is 800 μm or less; The thickness of the multilayer wiring board is in the range of 100 μm or more and 400 μm or less.

8. A multilayer wiring substrate including the glass substrate according to claim 4, The thickness of the electronic device mounted on the multilayer wiring board is 800 μm or less; The thickness of the multilayer wiring board is in the range of 100 μm or more and 400 μm or less.

9. A method for producing a glass substrate according to claim 1 or 2, comprising the steps of: A first step of irradiating a laser onto a portion of a glass substrate where a through hole is to be formed; A second step of etching the glass substrate irradiated with a laser to form a through hole. A method for manufacturing a glass substrate having the above structure.

10. A method for producing a glass substrate according to claim 9, A method for manufacturing a glass substrate, wherein in the first step, the laser irradiated has a laser oscillation wavelength of any one of 1064 nm, 532 nm, and 355 nm and a pulse width of 25 picoseconds or less.

11. A method for producing a glass substrate according to claim 9, The method for manufacturing a glass substrate, wherein in the first step, the maximum length of microcracks generated in the peripheral portion of the laser irradiation is 5 μm.

12. A method for producing a glass substrate according to claim 9, In the second step, an etching solution containing hydrofluoric acid in a range of 0.2 mass% or more and 20.0 mass% or less, nitric acid in a range of 4.0 mass% or more and 25.0 mass% or less, and an inorganic acid other than hydrofluoric acid and nitric acid in a range of 0.5 mass% or more and 11.0 mass% or less is used.

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