JP2016111221A - Method of manufacturing wiring board and wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that when a through hole is formed by forming a resin layer on the opposite sides of a glass substrate and then irradiating with laser light, stress is generated in the glass substrate by deformation of the resin layer during laser irradiation, to cause cracking of the glass substrate, and since the opening size in the resin layer becomes larger than that in the glass substrate, it may be difficult to make the pitch of through holes narrower.SOLUTION: In a method of manufacturing a wiring board, a core substrate having a resin layer formed on the first surface of a glass substrate is prepared, a plurality of through holes are formed in the core substrate by laser irradiation from the second surface where the resin layer is not formed, a connection conductor layer is formed continuously from the surface of the resin layer on the core substrate, and a first conductor layer is formed, as a conductor layer connected with the connection conductor layer, on the first surface of the core substrate, and a second conductor layer is formed on the second surface.SELECTED DRAWING: Figure 1

Description

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

  Conventionally, as a wiring board on which a semiconductor chip can be mounted, a wiring board using a glass core layer (also referred to as “glass substrate”) is known (for example, Patent Documents 1 and 2). A wiring board using a glass substrate is less likely to warp and swell compared to a wiring board having a resin core layer, and has excellent handling properties, and also improves wiring density and thickness of the wiring board. This is also advantageous. Particularly in recent years, in order to increase the wiring density, it is desired to reduce the pitch of through holes formed in the core layer (narrow pitch). Note that in a wiring board using a glass substrate, a through hole penetrating the glass substrate is generally formed by laser light irradiation.

JP 2014-127701 A JP 2014-093406 A

  By the way, in the wiring board using a glass substrate, there exists a subject that a possibility that a crack and a crack will generate | occur | produce in a glass substrate in the manufacturing process of a wiring board is high, and a yield is low. In order to improve the yield, a resin layer is generally formed on both surfaces of the glass substrate. However, when the inventors of the present application form a through hole by irradiating a laser beam after forming a resin layer on both surfaces of the glass substrate, stress is generated in the glass substrate due to the deformation of the resin layer at the time of laser irradiation. It has been found that there is a problem that cracks often occur. In addition, since the laser processability of the resin layer is higher than that of the glass substrate, the opening diameter in the resin layer becomes larger than the opening diameter in the glass substrate, which makes it difficult to narrow the pitch of the through holes. I also found out.

  The present invention has been made to solve the above-described problems, and can be realized as the following forms.

(1) According to one form of this invention, the manufacturing method of a wiring board is provided. The manufacturing method includes a step of preparing a core substrate having a glass substrate having a first surface and a second surface facing each other and a resin layer formed on the first surface of the glass substrate, and forming the resin layer Forming a plurality of through-holes in the core substrate having an inner diameter that increases from the first surface toward the second surface by laser irradiation from the second surface side that has not been formed; As a conductor layer connected to the connection conductor layer, a step of forming a connection conductor layer that continues from the surface of the resin layer formed on the first surface to the second surface via the inner surface of the through hole, Forming a first conductor layer on the first surface side of the core substrate and forming a second conductor layer on the second surface side.
According to this manufacturing method, since laser irradiation is performed from the second surface side where the resin layer is not formed, stress due to deformation of the resin layer during laser irradiation hardly occurs in the glass substrate, and the glass substrate resulting from this stress The occurrence of cracks can be suppressed. Furthermore, since the opening diameter in the first surface with the resin layer is smaller than the opening diameter in the second surface without the resin layer, the opening diameter of the resin layer is reduced by the heat of laser irradiation. Even when the opening diameter is larger than the opening diameter on one surface, the opening diameter on the second surface can be suppressed to the same size. Therefore, the pitch of the through holes can be reduced.

(2) In the manufacturing method, the opening diameter of the through hole on the first surface of the glass substrate is t1, the opening diameter of the through hole on the second surface of the glass substrate is t2, and the resin The opening diameter of the through hole on the surface of the layer may be 1.2 × t2 ≧ t3> t1, where t3 is an opening diameter.
According to this manufacturing method, among the opening diameters of the through holes, the opening diameter t3 on the surface of the resin layer is approximately the same as the opening diameter t2 on the second surface of the glass substrate, so that it is possible to reduce the pitch of the through holes. It is.

(3) The wiring board may be t2 ≧ t3> t1.
According to this manufacturing method, since the pitch of the through holes is determined not by the opening diameter t3 in the resin layer but by the opening diameter t2 in the second surface of the glass substrate, the through holes can be further narrowed.

(4) In the manufacturing method, the resin layer may be made of a thermosetting resin, and the thickness of the resin layer may be 1/10 or less of the thickness of the glass substrate.
If the thickness of the resin layer is 1/10 or less of the thickness of the glass substrate, the stress caused by the shrinkage of the resin layer and the stress caused by the difference in thermal expansion between the resin layer and the glass substrate are reduced. Warpage can be suppressed sufficiently small.

(5) In the above manufacturing method, the glass substrate may have a thickness of 500 μm or less.
According to this manufacturing method, the thickness of the entire wiring board can be reduced and the weight can be reduced. In addition, when the thickness of the glass substrate is 500 μm or less, it may be slightly warped and may be slightly inferior in handling properties. However, since the resin layer is formed on the first surface of the glass substrate, sufficient handling properties are obtained. can get.

(6) According to another aspect of the present invention, a wiring board is provided. The wiring board includes a glass substrate having a first surface and a second surface facing each other, a core substrate including a resin layer formed on the first surface, and the first surface toward the second surface. A plurality of through holes penetrating the core substrate and a surface of the resin layer formed on the first surface of the glass substrate through an inner surface of the through hole. A connection conductor layer formed to continue to two surfaces, and a conductor layer connected to the connection conductor layer, the first conductor layer and the second surface formed on the first surface side of the core substrate And a second conductor layer formed on the side.
According to this wiring board, the through hole is formed so that the opening diameter on the first surface with the resin layer is smaller than the opening diameter on the second surface without the resin layer. Pitching is possible.

  The present invention can be realized in various forms such as a wiring board and a manufacturing method of the wiring board.

Explanatory drawing of the manufacturing process of the wiring board in embodiment. Explanatory drawing which shows the preferable relationship of opening diameter t1, t2, t3 of a through-hole. Explanatory drawing which shows the measuring method of opening diameter t3 in the surface of a resin layer. Explanatory drawing which shows the structure and evaluation result of an Example and a comparative example.

  FIG. 1 is an explanatory view showing a manufacturing process of a wiring board in one embodiment of the present invention. In the step of FIG. 1A, a glass substrate 10 having a first surface 11 and a second surface 12 facing each other is prepared. The first surface 11 and the second surface 12 are preferably parallel. The thickness of the glass substrate 10 is preferably 100 μm or more and 500 μm or less, and more preferably 100 μm or more and 300 μm or less. If the thickness of the glass substrate 10 is 500 μm or less, the thickness of the entire wiring substrate can be reduced and the weight can be reduced. From this viewpoint, the thickness of the glass substrate 10 is more preferably 300 μm or less. However, when the thickness of the glass substrate 10 is 500 μm or less, the glass substrate 10 is slightly warped, which may be slightly inferior in terms of handling properties. However, in the present embodiment, as will be described later, since a resin layer as a protective layer (or a reinforcing layer) is formed on the first surface 11 of the glass substrate 10, sufficient handling properties can be obtained. On the other hand, if the thickness of the glass substrate 10 is excessively reduced, the handling property is lowered. Therefore, the thickness of the glass substrate 10 is preferably 100 μm or more. In Examples described later, non-alkali glass (thickness: 200 μm) was used as the glass substrate 10.

  In the step of FIG. 1B, the core substrate 60 in which the resin layer 20 is formed on the first surface 11 is prepared by forming the resin layer 20 on the first surface 11 of the glass substrate 10. Since the resin layer 20 reinforces the glass substrate 10 and makes it difficult to warp, the handling property of the glass substrate 10 is improved. The resin layer 20 is preferably formed on the entire first surface 11 of the glass substrate 10. Further, it is preferable that no resin layer is formed on the second surface 12 of the glass substrate 10. As a material of the resin layer 20, various insulating resin materials such as a thermosetting resin, a thermoplastic resin, and a photocurable resin can be used. The resin material of the resin layer 20 may contain a filler such as a silica filler. As will be described later, by adjusting the material of the resin material of the resin layer 20 and the content of the filler, the size of the opening diameter of the resin layer 20 at the time of laser irradiation can be adjusted. The thickness of the resin layer 20 can be 10-50 micrometers, for example. In the examples described later, an epoxy resin containing 40 to 50% by weight of silica filler was used, and the thickness of the resin layer 20 was set to 15 μm. Instead of forming the resin layer 20, the core substrate 60 having the resin layer 20 formed on the first surface 11 may be prepared by purchasing the glass substrate 10 on which the resin layer 20 is formed. .

  In the process of FIG. 1C, the laser beam LB is irradiated to the glass substrate 10 from the second surface 12 side where the resin layer 20 is not formed using the laser emission unit 200, whereby a plurality of through holes 13 are formed. Is formed on the core substrate 60 (the glass substrate 10 with the resin layer 20). As the opening diameter of the through-hole 13, the opening diameter t1 on the first surface 11 of the glass substrate 10, the opening diameter t2 on the second surface 12 of the glass substrate 10, and the opening diameter t3 on the surface of the resin layer 20 The three types of opening diameters can be defined. Of the two opening diameters t 1 and t 2 in the glass substrate 10, the opening diameter t 2 in the second surface 12 on which the laser beam LB enters is usually larger than the opening diameter t 1 in the first surface 11. This is because the second surface 12 on which the laser beam LB is incident receives more heat. Accordingly, the through hole 13 has a shape in which the inner diameter gradually increases from the first surface 11 to the second surface 12 of the glass substrate 10. The shape of such a through hole 13 is usually a tapered shape. Further, the opening diameter t3 on the surface of the resin layer 20 is larger than the opening diameter t1 on the first surface 11 of the glass substrate 10. This is because the resin has a larger thermal shrinkage than the glass.

FIG. 2 is an explanatory diagram illustrating an example of a preferable relationship between the three opening diameters t1, t2, and t3 of the through hole 13. In Example 1 shown in FIG. 2A, the opening diameter t3 in the resin layer 20 is not more than the opening diameter t2 in the second surface 12 of the glass substrate 10, and the relationship of the following expression (1) is established. .
t2 ≧ t3> t1 (1)

  By the way, generally, the minimum value (minimum possible pitch) that can be set as the pitch p13 of the through holes 13 is often limited to about twice or more the largest value among the three opening diameters t1, t2, and t3. . For example, when the relationship of the above expression (1) is established, the minimum value of the through-hole pitch p13 is not the opening diameter t3 in the resin layer 20, but the opening diameter in the second surface 12 of the glass substrate 10. It is determined by t2 and is limited to a value equal to or greater than twice the value (2 × t2). Therefore, in this case, it is advantageous in reducing the pitch of the through holes 13 as compared with the case where the opening diameter t3 in the resin layer 20 is larger than the opening diameter t2 in the second surface 12.

In Example 2 shown in FIG. 2B, the opening diameter t3 in the resin layer 20 is larger than that in Example 1, and is not more than 1.2 times the opening diameter t2 in the second surface 12 of the glass substrate 10. The relationship of equation (2) is established.
1.2 × t2 ≧ t3> t1 (2)
When the relationship of the expression (2) is established, the opening diameter t3 on the surface of the resin layer 20 among the opening diameters t1, t2, and t3 of the through hole 13 is the second surface of the glass substrate 10. 12, the pitch of the through holes 13 can be narrowed. From the viewpoint of narrowing the pitch of the through holes 13, Example 1 in FIG. 2A is more preferable than Example 2 in FIG. 2B. However, the relationship between the three opening diameters t1, t2, and t3 of the through-hole 13 may be a relationship other than that shown in FIG. For example, the opening diameter t3 in the resin layer 20 may be set to a value exceeding 1.2 times the opening diameter t2 in the second surface 12 of the glass substrate 10. However, if the through holes 13 are formed so as to satisfy the above formula (1) or (2), it is advantageous from the viewpoint of narrowing the pitch.

In one example, the through hole 13 was formed using a CO ₂ laser (wavelength: 10.6 μm). As the opening diameters t1, t2, and t3 of the through holes 13, t1 = 40 μm, t2 = 70 μm, and t3 = 60 μm were obtained. These satisfy both the above-mentioned formulas (1) and (2).

  The relationship between the three opening diameters t1, t2, and t3 of the through-hole 13 is that the laser processing conditions (focal position, energy, number of shots, etc. of the laser beam LB), the resin material that forms the resin layer 20, and the resin layer 20 It can be changed by adjusting one or more of the thicknesses. For example, the opening diameter t1 on the first surface 11 and the opening diameter t2 on the second surface 12 of the glass substrate 10 increase as the energy of the laser beam LB and the number of shots increase. Moreover, the opening diameter t3 on the surface of the resin layer 20 becomes smaller as the thermal contraction rate when the resin material is heated is smaller. For example, the opening diameter t3 on the surface of the resin layer 20 can be reduced by increasing the content of the filler contained in the resin material. Moreover, the opening diameter t3 can be made small by making the thickness of the resin layer 20 small. The opening diameter t3 on the surface of the resin layer 20 is measured by the method described below.

  FIG. 3 is an explanatory diagram showing a method for measuring the opening diameter t3 on the surface of the resin layer 20. As shown in FIG. As shown in this example, when the through-hole 13 is formed by irradiation with the laser beam LB, the opening end of the resin layer 20 serving as the bottom of the through-hole 13 often becomes a gentle curved surface due to heat. At this time, the opening diameter t3 on the surface 20s of the resin layer 20 has a tangent line TG drawn on the surface 20s of the resin layer 20 in the longitudinal section (FIG. 3) passing through the center of the through hole 13, and the length of the tangent line TG ( Defined as being equal to the distance between two intersections where the tangent TG and the surface 20s intersect. Actually, since many through holes 13 having the same specification are formed in the glass substrate 10, the opening diameter t <b> 3 is calculated as an average value of values in the plurality of through holes 13. In addition, the opening diameter t1 in the 1st surface 11 of the glass substrate 10 and the opening diameter t2 in the 2nd surface 12 are measured by the same method.

  By the way, when the resin layer 20 is formed on the first surface 11 of the glass substrate 10 in the step of FIG. 1B, the resin material may shrink and cause stress on the glass substrate 10. In addition, when the laser beam LB is irradiated in the process of FIG. 1C described above, the resin layer 20 is thermally contracted, so that stress is generated in the glass substrate 10. In particular, when the resin layer 20 is formed of a thermosetting resin, the stress tends to increase because the degree of thermal contraction is large. Furthermore, stress may be generated in the glass substrate 10 due to a difference in thermal expansion coefficient between the resin layer 20 and the glass substrate 10. These stresses are not preferable because they cause warping of the glass substrate 10 or cause damage such as cracking of the glass substrate 10. Moreover, these stresses tend to increase as the thickness of the resin layer 20 increases. Therefore, in order not to increase the stress excessively, it is preferable that the thickness of the resin layer 20 is 1/10 or less of the thickness of the glass substrate 10. By doing so, the stress caused by the shrinkage of the resin layer 20 and the stress caused by the difference in thermal expansion between the resin layer 20 and the glass substrate 10 are reduced, so that the warpage of the glass substrate 10 can be suppressed sufficiently small. Further, the possibility of causing damage such as cracks in the glass substrate 10 can be reduced.

  In the step of FIG. 1C, it is preferable that the resin layer is not formed in the region irradiated with the laser beam LB among the entire region of the second surface 12 of the glass substrate 10, but the laser beam LB A resin layer may be formed in a region not irradiated with. For example, when the second surface 12 is viewed in plan, the resin layer may be formed in a frame shape in the outermost region of the entire region. By doing so, the glass substrate 10 is reinforced by the resin layer, so that the handling property is further improved.

  In the step of FIG. 1D, the connection conductor layer 30 is formed across the first surface 11 and the second surface 12 of the glass substrate 10 on which the plurality of through holes 13 are formed, and the inner surface of the through hole 13. The connection conductor layer 30 is made of, for example, Cu (copper). The connection conductor layer 30 can be formed, for example, by forming a Cu thin film by electroless Cu plating and then increasing the thickness of the connection conductor layer 30 by electrolytic Cu plating.

  In the step of FIG. 1E, unnecessary portions of the connection conductor layer 30 are removed by etching the connection conductor layer 30. That is, the connecting conductor layer 30 is continuous over the inner surface (inner wall) of the through hole 13 and the surface on the first surface 11 side and the surface on the second surface 12 side of the core substrate 60 (the glass substrate 10 with the resin layer 20). The part of is left. As a result, a connection conductor layer 30 is formed that extends from the surface of the resin layer 20 formed on the first surface 11 of the glass substrate 10 to the second surface 12 of the glass substrate 10 through the inner surface of the through hole 13. The connection conductor layer 30 is formed on the surface of the resin layer 20 on the first surface 11 side of the glass substrate 10, and is directly formed on the second surface 12 on the second surface 12 side. Note that, after the etching, some surface treatment may be performed on the connection conductor layer 30 and the surface of the core substrate 60 (the glass substrate 10 with the resin layer 20).

  In the step of FIG. 1 (F), the resin layer 40 that covers both surfaces of the glass substrate 10 with the resin layer 20 is filled. As a material of the resin layer 40, various insulating resin materials such as a thermosetting resin, a thermoplastic resin, and a photocurable resin can be used.

  In the step of FIG. 1G, a plurality of via holes are formed in the resin layer 40 on the connecting conductor layer 30 on the first surface 11 side of the glass substrate 10, and a conductor is filled in each via hole. One conductor layer 51 is formed. Similarly, a plurality of via holes are formed in the resin layer 40 on the connection conductor layer 30 on the second surface 12 side of the glass substrate 10, and a conductor is filled in each via hole to form the second conductor layer 52. . The formation of the via hole that exposes the connection conductor layer 30 can be performed by, for example, irradiating a laser beam. The first conductor layer 51 and the second conductor layer 52 can be formed by, for example, forming a conductor pattern using electroless Cu plating and electrolytic Cu plating and patterning using etching. The first conductor layer 51 and the second conductor layer 52 are electrically connected via the connection conductor layer 30. Thereafter, a plurality of layers (insulating layer and conductor layer) may be further formed as necessary. The wiring board 100 manufactured in this way is completed by cutting into pieces as necessary. The completed wiring board 100 is used as an interposer, for example.

FIG. 4 is an explanatory diagram showing configurations and evaluation results of examples and comparative examples of the present invention. The sample described as “Example” in FIG. 4 is a sample prepared according to the process of FIG. 1 described above. The manufacturing conditions of this example are as follows.
<Conditions for creating examples>
(1) Glass substrate 10: non-alkali glass (thickness 200 μm)
(2) Resin layer 20: An epoxy resin containing 40 to 50% by weight of silica filler was formed to a thickness of 15 μm.
(3) The through-hole 13 was formed using a laser: CO ₂ laser (wavelength: 10.6 μm). (4) Opening diameters of the through-holes 13 were obtained: t1 = 40 μm, t2 = 70 μm, t3 = 60 μm. These satisfy both the above-mentioned formulas (1) and (2).

Comparative Examples 1 to 3 were prepared in the same manner as in the above example except for the resin layer 20. The differences between the comparative examples are as follows.
<Comparative Example 1> After the resin layer 20 is formed not only on the first surface 11 (lower surface) but also on the second surface 12 (upper surface) of the glass substrate 10, the through-hole 13 is irradiated by laser irradiation from the second surface 12 side. Formed.
Comparative Example 2 Laser irradiation from the second surface 12 side after forming the resin layer 20 on the second surface 12 (upper surface) without forming the resin layer on the first surface 11 (lower surface) of the glass substrate 10. Through hole 13 was formed.
<Comparative example 3> Without forming the resin layer on either the first surface 11 (lower surface) or the second surface 12 (upper surface) of the glass substrate 10, the through hole 13 is formed by laser irradiation from the second surface 12 side. Formed.

  As evaluation items of Examples and Comparative Examples 1 to 3, four items of (a) panel yield, (b) laser workability, (c) through-hole pitch, and (d) comprehensive evaluation were used. Hereinafter, these four evaluation items will be sequentially described.

(A) Panel yield:
In the “Panel Yield” column, 100 samples are prepared according to the manufacturing process of the wiring substrate 100 (FIG. 1), and the percentage of non-defective products is calculated with the samples that have been visually observed as cracks or chips as defective. Shows the value. The panel yield of the example was 96%, and the panel yields of Comparative Examples 1 to 3 were 98%, 96%, and 70%, respectively. The panel yield is sufficiently good if it is 96% or more, and sufficiently high yields are obtained in the examples and comparative examples 1 and 2. On the other hand, Comparative Example 3 is not preferable because the panel yield is as low as 70%. This is because, in Comparative Example 3, since the resin layer 20 that functions as the protective layer of the glass substrate 10 is not formed, deflection and warpage are likely to occur, and the strength is also inferior, so at any point in the manufacturing process. This is presumably because cracks and chips are likely to occur. Therefore, from the viewpoint of panel yield, it is preferable to form the resin layer 20 on at least one of the first surface 11 and the second surface 12 of the glass substrate 10.

(B) Laser processability:
The column of “laser processability” indicates whether or not there is a sample in which cracks are generated around the through hole 13 in the step of forming the through hole 13 by laser irradiation (FIG. 1C). Here, when even one sample with cracks around the through-hole 13 is present, it is described as “× (crack)”, and there is also one sample with cracks around the through-hole 13. When there was not, it described as "(circle)". In Example and Comparative Example 3, cracks did not occur around the through hole 13, and in Comparative Examples 1 and 2, cracks sometimes occurred around the through hole 13. It is estimated that the reason why the crack occurred in Comparative Examples 1 and 2 was that the resin layer 20 was thermally contracted by the heat of the laser beam, and a relatively large stress was generated at the boundary between the resin layer 20 and the glass substrate 10. The That is, in Comparative Examples 1 and 2, since the resin layer 20 is formed on the second surface 12 on which the laser light is incident, it is presumed that the influence of heat by the laser light is large and a relatively large stress is generated. . On the other hand, in Example and Comparative Example 3, since the resin layer 20 is not formed on the second surface 12 on which the laser light is incident, it is presumed that no great stress was generated. Therefore, from the viewpoint of laser processability, it is preferable not to form the resin layer 20 on the second surface 12 on which the laser light is incident.

(C) Through-hole pitch:
The column of “through-hole pitch” indicates dimensions that can be adopted as the through-hole pitch (p13 in FIG. 2). As described above, the through hole pitch is usually limited to at least twice the opening diameter of the through hole 13. For example, in the configuration of the embodiment, as shown in FIG. 2 described above, since one through hole 13 has three opening diameters t1, t2, and t3, the through hole pitch is 2 of the largest opening diameters. Limited to more than double value. As described above, among the three opening diameters t1, t2, and t3 of the embodiment, the opening diameter t2 on the second surface 12 of the glass substrate 10 is the largest at 70 μm, so the through hole pitch is 140 μm, which is twice that of the opening diameter t2. Limited to the above. On the other hand, in Comparative Examples 1 and 2, the opening diameter t4 on the surface of the resin layer 20 formed on the second surface 12 of the glass substrate 10 was maximum at 85 μm. Therefore, in Comparative Examples 1 and 2, the through-hole pitch is limited to 170 μm or more. In Comparative Example 3, as in the example, the opening diameter t2 on the second surface 12 of the glass substrate 10 is the largest at 70 μm, so the pitch of the through holes 13 is limited to 140 μm or more, which is twice that. Thus, from the viewpoint of the through hole pitch, it is preferable not to form the resin layer on the surface irradiated with the laser beam.

(D) Overall evaluation:
Summarizing the three evaluation items described above, in the example, the panel yield is sufficiently high, the laser workability is good, and the through-hole pitch is also sufficiently small, so that it is the best overall. In Comparative Examples 1 and 2, although the panel yield is good, there is a problem that the laser workability is slightly inferior and the through-hole pitch (via pitch) is large. Although Comparative Example 3 has good laser processability and through-hole pitch, it is not preferable in that the panel yield is lower than that of Examples and Comparative Examples 1 and 2.

  As described above, in the above-described embodiments and examples, the resin layer 20 is formed on the first surface 11 of the glass substrate 10, and laser irradiation from the second surface 12 side where the resin layer is not formed is performed. Since the plurality of through-holes 13 whose inner diameter increases from the first surface 11 toward the second surface 12 are formed in the core substrate 60 (the glass substrate 10 with the resin layer 20), the resin at the time of laser irradiation The stress due to the deformation of the layer is hardly generated in the glass substrate 10, and the occurrence of cracks in the glass substrate 10 due to this stress can be suppressed. Moreover, since the opening diameter t1 in the 1st surface 11 in which the resin layer 20 is formed becomes smaller than the opening diameter t2 in the 2nd surface 12 without a resin layer, the through-hole 13 is resin by the heat | fever of laser irradiation. Even when the opening diameter t3 on the surface of the layer 20 is larger than the opening diameter t1 on the first surface 11 of the glass substrate 10, the opening diameter t3 is comparable to the opening diameter t2 on the second surface 12. It can be suppressed. Therefore, it is possible to reduce the pitch of the through holes 13.

Modification Examples The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the scope of the invention.

・ Modification 1:
In the above embodiment, the resin layer 20 is formed on the first surface 11 of the glass substrate 10 and the resin layer is not formed on the second surface 12 of all the through holes 13 formed in the wiring substrate 100. However, a resin layer may be formed on the second surface 12 for some of the through holes. Specifically, for example, it is assumed that a plurality of first-type through holes having a small through-hole pitch and a second plurality of through-holes having a larger through-hole pitch are formed in the glass substrate 10. To do. In this case, a resin layer may be formed on both the first surface 11 and the second surface 12 of the glass substrate 10 for the plurality of second-type through holes having a large through-hole pitch. Also in this case, it is possible to realize a narrow pitch for the plurality of first type through holes having a smaller through hole pitch.

DESCRIPTION OF SYMBOLS 10 ... Glass substrate 11 ... 1st surface 12 ... 2nd surface 13 ... Through-hole 20 ... Resin layer 20s ... Surface of resin layer 30 ... Connection conductor layer 40 ... Resin layer 51 ... 1st conductor layer 52 ... 2nd conductor layer 60 ... Core substrate 100 ... Wiring substrate 200 ... Laser emission unit

Claims (10)

A method for manufacturing a wiring board, comprising:
Preparing a core substrate having a glass substrate having a first surface and a second surface facing each other and a resin layer formed on the first surface of the glass substrate;
Forming a plurality of through-holes in the core substrate having an inner diameter increasing from the first surface toward the second surface by laser irradiation from the second surface side where the resin layer is not formed;
Forming a connection conductor layer that continues from the surface of the resin layer formed on the first surface of the glass substrate to the second surface through the inner surface of the through hole;
Forming a first conductor layer on the first surface side of the core substrate as a conductor layer connected to the connection conductor layer and forming a second conductor layer on the second surface side;
A method for manufacturing a wiring board, comprising: It is a manufacturing method of the wiring board according to claim 1,
An opening diameter of the through hole on the first surface of the glass substrate is t1,
The opening diameter of the through hole on the second surface of the glass substrate is t2,
When the opening diameter of the through hole on the surface of the resin layer is t3,
A method of manufacturing a wiring board, wherein 1.2 × t2 ≧ t3> t1. It is a manufacturing method of the wiring board according to claim 2,
A method of manufacturing a wiring board, wherein t2 ≧ t3> t1. It is a manufacturing method of the wiring board according to any one of claims 1 to 3,
The resin layer is made of a thermosetting resin,
The thickness of the resin layer is 1/10 or less of the thickness of the glass substrate. It is a manufacturing method of the wiring board according to any one of claims 1 to 4,
The method of manufacturing a wiring board, wherein the glass substrate has a thickness of 500 μm or less. A wiring board,
A core substrate including a glass substrate having a first surface and a second surface facing each other; and a resin layer formed on the first surface;
A shape in which an inner diameter increases from the first surface toward the second surface, and a plurality of through holes penetrating the core substrate;
A connection conductor layer formed so as to continue from the surface of the resin layer formed on the first surface of the glass substrate to the second surface via the inner surface of the through hole;
A conductor layer connected to the connection conductor layer, the first conductor layer formed on the first surface side of the core substrate and the second conductor layer formed on the second surface side;
A wiring board comprising: The wiring board according to claim 6,
An opening diameter of the through hole on the first surface of the glass substrate is t1,
The opening diameter of the through hole on the second surface of the glass substrate is t2,
When the opening diameter of the through hole on the surface of the resin layer is t3,
A wiring board characterized by 1.2 × t2 ≧ t3> t1. The wiring board according to claim 7,
A wiring board, wherein t2 ≧ t3> t1. A wiring board according to any one of claims 6 to 8,
The thickness of the said resin layer is 1/10 or less of the thickness of the said glass substrate, The wiring board characterized by the above-mentioned. The wiring board according to any one of claims 6 to 9,
The thickness of the said glass substrate is 500 micrometers or less, The wiring board characterized by the above-mentioned.

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