JP2017005205A - Wiring board and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively suppress generation of cracks or the like on a glass substrate caused by heat stress.SOLUTION: A wiring board (1) comprises: a glass substrate (2); a through-hole (5) whose inner diameter gradually reduces from a front surface (21) of the glass substrate (2) toward a back surface (22) thereof; and a through electrode (6) provided at the through-hole (5). The through electrode (6) includes a recess (61) having an opening on the side of the front surface (21) of the glass substrate (2).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wiring board and a manufacturing method of the wiring board.

  In recent years, with the increase in the density of electronic components, etc., it has been demanded that the wiring board be compatible with higher density and higher current. In a wiring substrate using glass as a base material, the thermal expansion coefficient of wiring metal (for example, 17 ppm / ° C. in the case of copper) is significantly larger than the thermal expansion coefficient of glass (for example, 3 ppm / ° C.). For this reason, when a through electrode made of a metal such as copper is provided on a glass substrate, a thermal stress is generated in the through hole of the glass substrate due to a temperature change, which causes a gap or a crack. For this reason, a technique for reducing the influence of thermal stress on a wiring board based on glass has been proposed.

  FIG. 6 is a cross-sectional view showing a conventional example of a wiring board using glass as a base material. As shown in FIG. 6, in Patent Document 1, the shape of the through hole 102 formed in the glass substrate 101 is made to be a drum shape, thereby relieving thermal stress and removing the via electrode 103 provided in the through hole 102. Techniques to prevent it have been proposed.

  FIG. 7 is a cross-sectional view showing another conventional example of a wiring board based on glass. As shown in FIG. 7, in Patent Document 2, glass material is filled by filling a brazing material 205 having a low thermal expansion coefficient between an anchor metal film 203 and a metal core material 204 provided in a via 202 of a glass substrate 201. Techniques have been proposed for preventing damage to the substrate 201 and the occurrence of a gap in the via 202.

JP 2003-218525 A (released July 31, 2003) JP 2006-60119 A (published March 2, 2006)

  However, in the conventional wiring board as described above, when the through electrode capable of flowing a larger current is provided on the glass substrate, the influence of the thermal stress due to the difference in the thermal expansion coefficient between the glass substrate and the through electrode is reduced. It cannot be suppressed sufficiently. For this reason, the subject that a crack etc. generate | occur | produce in a through hole by the influence of a thermal stress still exists.

  The present invention has been made in view of the above-described conventional problems, and its purpose is to alleviate the influence of thermal stress caused by the difference in thermal expansion coefficient between the glass substrate and the through electrode, and to prevent through-holes in the glass substrate. An object of the present invention is to provide a wiring board capable of effectively suppressing the occurrence of cracks and the like and a manufacturing method thereof.

  In order to solve the above-described problem, a wiring board according to one embodiment of the present invention is formed on each of a glass substrate, a first surface of the glass substrate, and a second surface of the glass substrate facing the first surface. A wiring pattern, a through hole that penetrates the glass substrate and has an inner diameter that gradually decreases from the first surface toward the second surface, and is formed in the first surface. A through-electrode that electrically connects the wiring pattern and the wiring pattern formed on the second surface, wherein the through-electrode has a concave shape opened on the first surface side. Yes.

  In order to solve the above problems, a method for manufacturing a wiring board according to one aspect of the present invention includes a step of forming a wiring pattern on a second surface of a glass substrate, and a first step of the glass substrate facing the second surface. By forming a through hole with a gradually decreasing inner diameter in the glass substrate from one surface until reaching the wiring pattern, and plating the inside of the through hole from the first surface side, the first And a step of forming a recessed through electrode opened on the surface side in the through hole.

  According to one aspect of the present invention, the influence of thermal stress due to the difference in thermal expansion coefficient between the glass substrate and the through electrode can be alleviated, and cracks and the like can be effectively suppressed from occurring in the through hole of the glass substrate. An effect is provided that a simple wiring board and a method for manufacturing the same can be provided.

It is sectional drawing which shows the wiring board which concerns on Embodiment 1 of this invention. (A)-(m) is sectional drawing which shows each process of the manufacturing method of the wiring board shown by FIG. It is sectional drawing which shows the wiring board which concerns on Embodiment 2 of this invention. (A)-(m) is sectional drawing which shows each process of the manufacturing method of the wiring board shown by FIG. It is sectional drawing which shows the wiring board which concerns on Embodiment 3 of this invention. It is sectional drawing which shows the prior art example of the wiring board which used glass as the base material. It is sectional drawing which shows the other conventional example of the wiring board which used glass as the base material.

Embodiment 1
Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2 as follows.

<Configuration of wiring board 1>
FIG. 1 is a cross-sectional view showing a configuration of a wiring board 1 according to the present embodiment. As shown in FIG. 1, the wiring substrate 1 includes a glass substrate 2, a first wiring pattern (wiring pattern) 3, a second wiring pattern (wiring pattern) 4, a through hole (through hole) 5, a through electrode 6, and a filling A material 7 is provided.

(Glass substrate 2)
The glass substrate 2 is a plate-like member that becomes a base material of the wiring substrate 1. The glass substrate 2 has a front surface (first surface) 21 and a back surface (second surface) 22 that is a surface facing the front surface 21. A first wiring pattern 3 is formed on the surface 21 of the glass substrate 2. A second wiring pattern 4 is formed on the back surface 22 of the glass substrate 2.

  The shape and dimensions of the glass substrate 2 serving as the base material of the wiring board 1 can be appropriately changed according to the use of the wiring board 1 and the like. As an example, the thickness of the glass substrate 2 is 0.1 mm or more and 1 mm or less, for example, Preferably it is 0.3 mm or more and 0.6 mm or less.

(First wiring pattern 3)
The first wiring pattern 3 is a conductive pattern formed on the surface 21 of the glass substrate 2. The first wiring pattern 3 includes a first seed metal layer 31 and a first plating layer 32 formed on the surface 21 of the glass substrate 2.

  The first seed metal layer 31 is a thin film for forming the first plating layer 32 on the surface 21 of the glass substrate 2 by electrolytic (electric) plating. The first seed metal layer 31 is formed on the surface 21 of the glass substrate 2 by sputtering, CVD or the like of a noble metal or a refractory metal, for example.

  The first seed metal layer 31 is preferably a laminated film having a two-layer structure. For example, when a copper plating layer is formed as the first plating layer 32, the first thin film (thickness: about 0.2 μm) and the copper thin film (thickness: about 0.3 μm) stacked in this order from the surface 21 of the glass substrate 2. It is preferable to form one seed metal layer 31.

  Thereby, the first seed metal layer 31 can be brought into close contact with the surface 21 of the glass substrate 2, and the first seed metal layer 31 formed on the surface 21 of the glass substrate 2 is made of copper by electrolytic plating. The first plating layer 32 can be formed.

  The first plating layer 32 is a conductive layer formed on the first seed metal layer 31. As the metal constituting the first plating layer 32, copper can be suitably used. When the 1st plating layer 32 is comprised with copper, it is preferable that the thickness of the 1st plating layer 32 is 30 micrometers or more and 100 micrometers or less.

  However, a metal other than copper (for example, chromium, lead, nickel, gold, silver, tin, zinc, etc.) may be used or used in combination as the first plating layer 32 as necessary.

(Second wiring pattern 4)
The second wiring pattern 4 is a conductive pattern formed on the back surface 22 of the glass substrate 2. The second wiring pattern 4 includes a second seed metal layer 41 and a second plating layer 42 formed on the back surface 22 of the glass substrate 2.

  The second seed metal layer 41 is a thin film for forming the second plating layer 42 on the back surface 22 of the glass substrate 2 by an electrolytic (electric) plating method. The second seed metal layer 41 is formed on the back surface 22 of the glass substrate 2 by sputtering, CVD, or the like using a noble metal or a refractory metal, for example.

  The second seed metal layer 41 is preferably a laminated film having a two-layer structure, like the first seed metal layer 31 described above. That is, when a copper plating layer is formed as the second plating layer 42, the second layer is laminated in the order of a titanium thin film (thickness of about 0.2 μm) and a copper thin film (thickness of about 0.3 μm) from the back surface 22 of the glass substrate 2. It is preferable to form the seed metal layer 41.

  Thus, the second seed metal layer 41 can be brought into close contact with the back surface 22 of the glass substrate 2, and the second seed metal layer 41 formed on the back surface 22 of the glass substrate 2 is made of copper by electrolytic plating. Two plating layers 42 can be formed.

  The second plating layer 42 is a conductive layer formed on the second seed metal layer 41. Copper can be suitably used as the metal constituting the second plating layer 42. When the 2nd plating layer 42 is comprised with copper, it is preferable that the thickness of the 2nd plating layer 32 is 30 micrometers or more and 100 micrometers or less.

  However, a metal other than copper (for example, chromium, lead, nickel, gold, silver, tin, zinc, etc.) may be used or used together as the second plating layer 42 as necessary.

  In the second wiring pattern 4, a part (end portion) of the second wiring pattern 4 covers (closes) the second opening (opening) 52 of the through hole 5 opened on the back surface 22 side of the glass substrate 2. It is provided as follows.

(Through hole 5)
The through hole 5 is a through hole formed in the out-of-plane direction of the glass substrate 2. The through hole 5 extends from the front surface 21 to the rear surface 22 of the glass substrate 2, has a first opening 51 on the front surface 21 side of the glass substrate 2, and a second opening on the rear surface 22 side of the glass substrate 2. 52.

  The through hole 5 has a tapered shape in which the inner diameter (diameter) gradually decreases from the front surface 21 to the rear surface 22 of the glass substrate 2. For this reason, the through hole 5 has the maximum inner diameter of the first opening 51 and the minimum inner diameter of the second opening 52.

  By making the through-hole 5 have a tapered shape as described above, the thermal stress generated in the through-hole 5 due to the difference in thermal expansion coefficient between the glass substrate 2 and the through electrode 6 is caused in the plane of the glass substrate 2. It is possible to suppress concentration in the direction.

  The dimension of the through hole 5 can be appropriately changed according to the magnitude of the current flowing through the through electrode 6. However, in order to cope with an increase in current of the wiring board 1, it is preferable that at least the diameter of the second opening 52 is 300 μm or more.

(Penetration electrode 6)
The through electrode 6 is an electrode that electrically connects the first wiring pattern 3 provided on the front surface 21 of the glass substrate 2 and the second wiring pattern 4 provided on the back surface 22 of the glass substrate 2. The through electrode 6 is provided in a tapered through hole 5 formed in the glass substrate 2.

  The through electrode 6 includes a first seed metal layer 31 and a first plating layer 32, and is configured integrally with the first wiring pattern 3. That is, in the wiring substrate 1, the portion located on the surface 21 of the glass substrate 2 of the first seed metal layer 31 and the first plating layer 32 functions as the first wiring pattern 3, and the portion located in the through hole 5. It functions as the through electrode 6.

  In the present embodiment, the through electrode 6 has the inner surface of the second wiring pattern 4 that covers the inner peripheral surface of the through hole 5 and the second opening 52 of the through hole 5 (that is, the through hole 5 side of the second seed metal layer 41). The first seed metal layer 31 and the first plating layer 32 are laminated in this order, and have a concave shape opened on the surface 21 side of the glass substrate 2.

  By making the through electrode 6 into the shape having the recess 61 as described above, it is possible to suitably reduce the influence of the thermal stress caused by the difference in thermal expansion coefficient between the glass substrate 2 and the through electrode 6. It becomes.

(Filler 7)
The filler 7 is a substance that fills the recess 61 of the through electrode 6. The filler 7 is preferably made of a material having a lower elastic modulus than the glass substrate 2 and the through electrode 6. Thereby, distortion of the penetration electrode 6 accompanying a temperature change, etc. can be suppressed, and the high reliability of the penetration electrode 6 can be ensured.

  The material of the filler 7 is not particularly limited as long as it has an elastic modulus lower than that of the glass substrate 2 and the through electrode 6. For example, an epoxy resin can be suitably used.

  Note that the filler 7 is not an essential component, and the filler 7 may be omitted as appropriate.

<Method for Manufacturing Wiring Board 1>
Next, a method for manufacturing the wiring board 1 will be described. 2A to 2M are cross-sectional views showing the respective steps of the method for manufacturing the wiring board 1.

  First, as shown to (a) of FIG. 2, the glass substrate 2 of arbitrary shapes and dimensions is shape | molded. The shape and dimensions of the glass substrate 2 serving as the base material of the wiring board 1 can be appropriately changed according to the use of the wiring board 1 and the like.

  Next, as shown in FIG. 2B, a second seed metal layer 41 is formed on the entire back surface 22 of the glass substrate 2. Specifically, the second seed metal layer 41 is formed by depositing a noble metal or a refractory metal on the back surface 22 of the glass substrate 2 by sputtering, CVD, or the like.

  Next, as shown in FIG. 2C, a pattern of the photoresist 18 is formed on the second seed metal layer 41. Specifically, a photoresist 18 is applied to the second seed metal layer 41 formed on the back surface 22 of the glass substrate 2, and a pattern of the photoresist 18 having a thickness of about 150 μm is formed by ordinary photolithography such as exposure and development. Form. The pattern of the photoresist 18 serves as a mask when forming the second plating layer 42 in the next step.

  Next, as shown in FIG. 2D, a second plating layer 42 is formed on the second seed metal layer 41. Specifically, the second plating layer 42 is formed on the second seed metal layer 41 located in the opening portion of the photoresist 18 by an electrolytic plating method.

  Next, as shown in FIG. 2E, the photoresist 18 is removed. Thereby, the second seed metal layer 41 covered with the photoresist 18 is exposed.

  Next, as shown in FIG. 2F, the exposed second seed metal layer 41 is etched. Thereby, the unnecessary second seed metal layer 41 is removed from the back surface 22 of the glass substrate 2, and the second wiring pattern 4 is formed on the back surface 22 of the glass substrate 2.

  Next, as shown in FIG. 2G, tapered through holes 5 are formed in the glass substrate 2. Specifically, the tapered through hole 5 whose inner diameter gradually decreases from the front surface 21 of the glass substrate 2 toward the second wiring pattern 4 is formed on the inner surface of the second wiring pattern 4 (that is, the back surface of the glass substrate 2). It is formed until it reaches the surface of the second seed metal layer 41 on the 22 side. Thereby, the through hole 5 in which the second opening 52 is covered with the second wiring pattern 4 is formed.

  As a method for forming the tapered through hole 5 on the glass substrate 2, a sand blasting method using a sand blasting apparatus for cutting the glass substrate 2 by spraying an abrasive (metal powder or the like) is suitable. When using the sandblasting method, the cutting speed for cutting the second seed metal layer 41 is lower than the cutting speed for cutting the glass substrate 2. For this reason, after the through-hole 5 reaches the second seed metal layer 41, the second seed metal layer 41 is adjusted by adjusting the processing time of the sand blasting device so that the sand blasting device stops at the timing when the cutting speed decreases. It is possible to form the through hole 5 in the glass substrate 2 in a state where the is left. Thereby, the glass substrate 2 can be selectively cut, and the through hole 5 reaching the second seed metal layer 41 can be easily and efficiently formed.

  However, the method of forming the tapered through hole 5 in the glass substrate 2 is not limited to the sandblast method. As another method for forming the through hole 5 in the glass substrate 2, for example, only the glass substrate 2 can be selectively etched without etching the second seed metal layer 41, and the tapered through hole 5 can be formed. A wet etching method or a plasma etching method may be used. In this case, only the glass substrate 2 can be selectively etched by forming the second seed metal layer 41 with a metal that is not etched when the through hole 5 is formed (that is, when the glass substrate 2 is etched). Thereby, the through hole 5 reaching the second seed metal layer 41 can be easily and efficiently formed.

  Next, as shown in FIG. 2H, a first seed metal layer 31 is formed on the entire surface 21 of the glass substrate 2. Specifically, the first seed metal layer 31 is formed by depositing a noble metal or a refractory metal on the surface 21 of the glass substrate 2 by sputtering, CVD, or the like. At this time, the first seed metal layer 31 is formed on the entire surface 21 of the glass substrate 2, and at the same time, the first seed metal layer 41 covering the inner wall of the through hole 5 and the second opening 52 of the through hole 5 is covered with the first seed metal layer 41. A seed metal layer 31 is formed.

  Next, as shown in FIG. 2I, a pattern of the photoresist 18 is formed on the first seed metal layer 31. Specifically, the photoresist 18 is applied to the first seed metal layer 31 formed on the surface 21 of the glass substrate 2, and the pattern of the photoresist 18 is formed by photolithography such as exposure and development. The pattern of the photoresist 18 serves as a mask when the first plating layer 32 is formed in the next step.

  Next, as shown in (j) of FIG. 2, a first plating layer 32 is formed on the first seed metal layer 31. Specifically, the first seed metal layer 31 formed on the surface 21 of the glass substrate 2 located in the opening portion of the photoresist 18 and the first seed metal layer 31 in the through hole 5 are electroplated. A first plating layer 32 is formed. Thereby, the through electrode 6 having a shape having the recess 61 opened on the surface 21 side of the glass substrate 2 is formed in the through hole 5.

  Note that the thickness of the through electrode 6 (the sum of the thickness of the first seed metal layer 31 and the thickness of the first plating layer 32) is less than ½ of the diameter of the second opening 52 of the through hole 5. Is preferred. Thereby, the penetration electrode 6 having the shape having the recess 61 can be suitably formed.

  Next, as shown in FIG. 2K, the photoresist 18 is removed. As a result, the first seed metal layer 31 covered with the photoresist 18 is exposed.

  Next, as shown in FIG. 2L, the exposed first seed metal layer 31 is etched. Thereby, the unnecessary first seed metal layer 31 is removed from the surface 21 of the glass substrate 2, and the first wiring pattern 3 is formed on the surface 21 of the glass substrate 2.

  Finally, as shown in (m) of FIG. 2, the wiring substrate 1 can be manufactured by filling the filling material 7 in the concave portion 61 of the through electrode 6. However, when the filler 7 is not filled in the recess 61 of the through electrode 6, the step shown in FIG.

  The above description is an example in which the first wiring pattern 3, the second wiring pattern 4, and the through electrode 6 are formed by an electrolytic plating method. Therefore, even if the 1st wiring pattern 3, the 2nd wiring pattern 4, and the penetration electrode 6 form the 1st wiring pattern 3, the 2nd wiring pattern 4, and the penetration electrode 6 by well-known methods other than the electroplating method, it is. Good.

<Effect of wiring board 1>
As described above, the wiring substrate 1 includes the glass substrate 2, the first wiring pattern 3 provided on the front surface 21 of the glass substrate 2, the second wiring pattern 4 provided on the back surface 22 of the glass substrate 2, and the glass substrate. 2, the through hole 5 having an inner diameter that gradually decreases from the front surface 21 toward the back surface 22, and the first wiring pattern 3 and the second wiring pattern 4 are electrically connected to each other. The through electrode 6 has a shape having a recess 61 that is open on the surface 21 side.

  In the wiring substrate 1, the through hole 5 has a tapered shape with an inner diameter gradually decreasing from the front surface 21 to the back surface 22 of the glass substrate 2, so that the difference in thermal expansion coefficient between the glass substrate 2 and the through electrode 6 is caused. This makes it possible to suppress the thermal stress generated in the through hole 5 from being concentrated in the in-plane direction of the glass substrate 2. Further, in the wiring board 1, the through electrode 6 has a shape having the concave portion 61 opened on the surface 21 side of the glass substrate 2, so that the influence of the thermal stress generated in the through hole 5 can be suitably reduced. Become.

  Therefore, according to the present embodiment, it is possible to realize the wiring substrate 1 that can effectively suppress the occurrence of cracks or the like in the through holes 5 of the glass substrate 2.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIGS. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

  The wiring board 10 according to the present embodiment is mainly different from the wiring board 1 according to the first embodiment described above in that it further includes a through hole in which no through electrode is provided.

<Configuration of Wiring Board 10>
FIG. 3 is a cross-sectional view showing the wiring board 10 according to the present embodiment. As shown in FIG. 3, the wiring substrate 10 includes a glass substrate 2, a first wiring pattern 3, a second wiring pattern 4, a through hole 5, a through electrode 6, a filler 7, and a second through hole (through hole) 8. Is provided.

(Second through hole 8)
The second through hole 8 is a through hole formed in the glass substrate 2. The second through hole 8 extends from the front surface 21 to the back surface 22 of the glass substrate 2, has a first opening 81 on the front surface 21 side of the glass substrate 2, and a second on the back surface 22 side of the glass substrate 2. An opening 82 is provided.

  The second through hole 8 has a tapered shape in which the inner diameter (diameter) gradually decreases from the front surface 21 to the rear surface 22 of the glass substrate 2. That is, in the second through hole 8, the inner diameter of the first opening 81 is the maximum, and the inner diameter of the second opening 82 is the minimum.

  As described above, the wiring substrate 10 further includes the second through hole 8 in which the through electrode 6 is not provided, so that the second through hole 8 is used for interlayer connection between multilayer substrates or mounting of a through hole of an electronic component. be able to.

<Method for Manufacturing Wiring Board 10>
Next, a method for manufacturing the wiring board 10 will be described. The wiring board 10 can be manufactured by adding the second through hole 8 to the glass substrate 2 of the wiring board 1 according to the first embodiment.

  4A to 4M are cross-sectional views showing respective steps of the method for manufacturing the wiring substrate 10. In addition, each process shown to (a)-(f) of FIG. 4 is the same as each process shown to (a)-(f) of FIG.

  As a method for manufacturing the wiring substrate 10, for example, as shown in FIG. 4G, in the step of forming a through hole in the glass substrate 2, a second through hole 8 is further formed together with the through hole 5. As shown in (i) of FIG. 4, in the step of forming the photoresist 18, the photoresist 18 may be formed so as to fill the second through hole 8. As a result, as shown in FIG. 4J, in the step of forming the first plating layer 32 on the first seed metal layer 31, the photoresist 18 serves as a mask, and the first into the second through hole 8 is formed. Formation of the plating layer 32 is suppressed.

  Thereafter, the photoresist 18 formed in the second through hole 8 is removed in the step shown in FIG. 4K, and further formed in the second through hole 8 in the step shown in FIG. By removing the first seed metal layer 31 formed, the second through hole 8 in which the through electrode 6 is not provided can be formed in the glass substrate 2.

<Effect of the wiring board 10>
As described above, since the wiring board 10 further includes the second through hole 8 in which the through electrode 6 is not provided, the second through hole 8 is connected to the interlayer connection between the multilayer boards or the through hole mounting of the electronic component. For example, the second through hole 8 can be used.

  Therefore, according to the present embodiment, it is possible to realize the wiring substrate 10 corresponding to high-density mounting of electronic components while effectively suppressing the occurrence of cracks or the like in the through holes 5 of the glass substrate 2.

[Embodiment 3]
The following will describe another embodiment of the present invention with reference to FIG. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

  The wiring board 11 according to the present embodiment is described above in that a glass substrate having a partially different thickness is provided in the same substrate and that a through electrode is provided in each of the regions having different thicknesses of the glass substrate. It is mainly different from the wiring board 1 according to the first embodiment.

<Configuration of wiring board 11>
FIG. 5 is a cross-sectional view showing the wiring board 11 according to the present embodiment. As shown in FIG. 5, the wiring substrate 11 includes a glass substrate 20, a first wiring pattern 3, a second wiring pattern 4, a through hole 5, a through electrode 6, a filler 7, a second through hole 8, and a second through hole. An electrode (through electrode) 9 is provided.

(Glass substrate 20)
The glass substrate 20 is a plate-like member serving as a base material for the wiring substrate 11 and includes two regions having partially different thicknesses. Specifically, the glass substrate 20 includes a first region 20a having a predetermined thickness and a second region 20b having a smaller thickness than the first region 20a.

  A through hole 5 is formed in the first region 20 a of the glass substrate 20. A through electrode 6 is provided in the through hole 5. On the other hand, the second through hole 8 is formed in the second region 20 b of the glass substrate 20. A second through electrode 9 is provided in the second through hole 8.

(Second through electrode 9)
The second through electrode 9 includes a first wiring pattern 3 provided on the front surface 21 of the second region 20b of the glass substrate 20, and a second wiring pattern 4 provided on the back surface 22 of the second region 20b of the glass substrate 20. Is an electrode for electrically connecting the two. The second through electrode 9 is provided in the tapered second through hole 8 formed in the second region 20 b of the glass substrate 20.

  The second through electrode 9 includes the first seed metal layer 31 and the first plating over the inner peripheral surface of the second through hole 8 and the inner surface of the second wiring pattern 4 covering the second opening 82 of the second through hole 8. The layer 32 is a coating film laminated in this order, and has a concave shape opened on the surface 21 side of the second region 20 b of the glass substrate 20.

  By making the 2nd penetration electrode 9 into the shape which has the above recessed parts 91, the influence of the thermal stress which arose due to the difference in the thermal expansion coefficient of the glass substrate 2 and the 2nd penetration electrode 9 is reduced suitably. It becomes possible to do.

<Method for Manufacturing Wiring Board 11>
Next, a method for manufacturing the wiring board 11 will be described. The method of forming the second through hole 8 and the second through electrode 9 in the second region 20b of the glass substrate 20 included in the wiring substrate 11 is the same as that of the first embodiment described in the first embodiment. The method of forming can be used.

  However, in the wiring substrate 11, the film of the first plating layer 32 formed in the second region 20 b of the glass substrate 20 is larger than the film thickness of the first plating layer 32 formed in the first region 20 a of the glass substrate 20. The thickness may be increased. For example, the film thickness of the first plating layer 32 formed in the second region 20b of the glass substrate 20 is set to a difference between the thickness of the first region 20a of the glass substrate 20 and the thickness of the second region 20b of the glass substrate 20. It may be a corresponding thickness.

  The first plating layer 32 having such a thickness is formed of the photoresist 18 having a sufficient thickness corresponding to the difference between the thickness of the first region 20a of the glass substrate 20 and the thickness of the second region 20b of the glass substrate 20. It can obtain easily by forming the 1st plating layer 32 using it.

<Effect of the wiring board 11>
As described above, in the wiring substrate 11, the glass substrate 20 includes the first region 20 a having a predetermined thickness and the second region 20 b having a smaller thickness than the first region 20 a, and the first region of the glass substrate 20. A through electrode 6 having a shape having a tapered through hole 5 and a recessed portion 61 is provided in 20a, and a second shape having a tapered second through hole 8 and a recessed portion 91 in the second region 20b of the glass substrate 20 is provided. A through electrode 9 is provided.

  Therefore, according to the present embodiment, the first wiring pattern 3 and the second wiring pattern 4 are formed in the regions (first region 20a and second region 20b) having different thicknesses of the glass substrate 20, respectively. It is possible to realize the wiring board 11 including wiring patterns having different inter-wiring capacitances across the board 20.

[Summary]
The wiring board according to the first aspect of the present invention is formed on each of the glass substrate, the first surface (front surface 21) of the glass substrate, and the second surface (back surface 22) of the glass substrate facing the first surface. Through-holes (through-holes 5) that penetrate the wiring substrate (first wiring pattern 3, second wiring pattern 4) and the glass substrate and gradually decrease in inner diameter from the first surface toward the second surface. ) And a through electrode that is provided in the through hole and electrically connects the wiring pattern formed on the first surface and the wiring pattern formed on the second surface, The concave shape is open on the first surface side.

  In the above configuration, the through hole has a tapered shape in which the inner diameter is gradually reduced from the first surface of the glass substrate toward the second surface, and thus is caused by a difference in thermal expansion coefficient between the glass substrate and the through electrode. Thus, it is possible to suppress the thermal stress generated in the through hole from being concentrated in the in-plane direction of the glass substrate. Further, in the above configuration, since the through electrode has a recess (hollow / hollow) shape opened on the first surface side of the glass substrate, the influence of the thermal stress generated in the through hole can be suitably mitigated. It becomes.

  Therefore, according to said structure, the influence of the thermal stress resulting from the difference in the thermal expansion coefficient of a glass substrate and a penetration electrode can be relieve | moderated, and it can suppress effectively that a crack etc. generate | occur | produce in the through-hole of a glass substrate. A simple wiring board can be realized.

  In the wiring board according to the second aspect of the present invention, in the first aspect, a part of the wiring pattern formed on the second surface covers an opening on the second surface side of the through hole, The through electrode may be a coating film provided over an inner peripheral surface of the through hole and a surface on the through hole side of the wiring pattern that covers the opening.

  According to said structure, the opening part of the through-hole in the 2nd surface side of a glass substrate is covered with the wiring pattern. For this reason, by providing a coating film over the inner peripheral surface of the through-hole and the surface on the through-hole side of the wiring pattern covering the opening, it is possible to easily form the concave-shaped through-electrode opened on the first surface side of the glass substrate. Can be formed.

  In the wiring board according to aspect 3 of the present invention, in the above aspect 2, the coating film may include a plating layer.

  According to said structure, a penetration electrode can be formed suitably by the electrolytic (electro) plating method etc., for example.

  In the wiring board which concerns on aspect 4 of this invention, in the said aspects 1-3, it further comprises the filler with which it fills in the recessed part of the said through-electrode, The said filler has an elastic modulus rather than the said glass substrate and the said through-electrode. Is preferably made of a low material.

  According to said structure, the distortion of the penetration electrode accompanying a temperature change, etc. can be suppressed and the high reliability of a penetration electrode can be ensured.

  In the wiring board which concerns on aspect 5 of this invention, in the said aspects 1-4, it has several said through-holes, The said through-electrode is provided in the said some through-holes among several said through-holes. Also good.

  According to the above configuration, since the wiring board is provided with a through hole in which no through electrode is provided, a through hole in which no through electrode is provided is connected to an interlayer connection between multilayer boards or through hole mounting of an electronic component. It can be used for

  In the method for manufacturing a wiring board according to aspect 6 of the present invention, the wiring pattern is formed on the second surface of the glass substrate, and the wiring pattern is reached from the first surface of the glass substrate facing the second surface. And forming a through hole having a gradually reduced inner diameter in the glass substrate, and forming a concave shape through the first surface side by plating the inside of the through hole from the first surface side. And a step of forming an electrode in the through hole.

  According to the above method, the wiring that can reduce the influence of thermal stress caused by the difference in thermal expansion coefficient between the glass substrate and the through electrode and effectively suppress the occurrence of cracks in the through hole of the glass substrate. A substrate manufacturing method can be realized.

  In the method for manufacturing a wiring board according to aspect 7 of the present invention, in the above aspect 6, the through hole is formed by selectively cutting or etching the glass substrate in the step of forming the through hole. Also good.

  According to said method, the through-hole which reaches | attains the wiring pattern formed in the 2nd surface of the glass substrate from the 1st surface of a glass substrate can be formed easily and efficiently.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

[Supplement]
It can also be expressed as follows. That is, the wiring board according to the present invention includes a substrate (glass substrate 2) having a glass plate as a base material, a through hole formed in the substrate, a through electrode formed in the through hole by electrolytic copper plating, and the substrate. The through-hole is small on the second copper plating wiring (second plating layer 42) side and large on the first copper plating wiring (first plating layer 32) side. The through hole is hollow, or the hollow is filled with a low elastic modulus substance (filler 7).

  In the method for manufacturing a wiring board according to the present invention, a second copper plating wiring is formed on one surface (back surface 22) of the glass plate, and the second seed metal layer becomes smaller as it becomes deeper than the opposite surface (front surface 21). A tapered through-hole reaching up to 1 mm is formed, and then the first seed metal layer formed is used to simultaneously form the first copper-plated wiring in the through-hole, and the through electrode in the through-hole becomes hollow It is characterized by.

  The wiring board manufacturing method according to the present invention is characterized in that the processing of the through hole is automatically stopped at the second seed metal layer.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used for a wiring substrate having a through electrode provided with glass as a base material, and can improve the reliability of the through electrode.

1, 10, 11: Wiring substrate 2, 20: Glass substrate 3: First wiring pattern (wiring pattern)
4: Second wiring pattern (wiring pattern)
5: Through hole (through hole)
6: Through electrode 7: Filler 8: Second through hole (through hole)
9: Second through electrode (through electrode)
21: Surface (first surface)
22: Back side (second side)
52, 82: second opening (opening)
61, 91: recess

Claims (5)

A glass substrate;
A wiring pattern formed on each of the first surface of the glass substrate and the second surface of the glass substrate facing the first surface;
A through-hole penetrating the glass substrate and having an inner diameter gradually decreasing from the first surface toward the second surface;
A through electrode provided in the through hole and electrically connecting the wiring pattern formed on the first surface and the wiring pattern formed on the second surface;
The wiring substrate according to claim 1, wherein the through electrode has a concave shape opened on the first surface side. A part of the wiring pattern formed on the second surface covers the opening on the second surface side of the through hole,
2. The wiring according to claim 1, wherein the through electrode is a coating film provided over an inner peripheral surface of the through hole and a surface on the through hole side of the wiring pattern that covers the opening. substrate. Further comprising a filler filled in the recess of the through electrode,
The wiring board according to claim 1, wherein the filler is made of a material having a lower elastic modulus than the glass substrate and the through electrode. Forming a wiring pattern on the second surface of the glass substrate;
Forming a through hole with a gradually decreasing inner diameter in the glass substrate from the first surface of the glass substrate facing the second surface until reaching the wiring pattern;
Forming a recess-shaped through electrode that opens on the first surface side by plating the inside of the through hole from the first surface side. Production method.   The method for manufacturing a wiring board according to claim 4, wherein in the step of forming the through hole, the through hole is formed by selectively cutting or etching the glass substrate.

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