JP6885161B2 - A method for manufacturing a glass substrate having a through hole and a method for forming a through hole in the glass substrate. - Google Patents

Description

The present invention relates to a method for manufacturing a glass substrate having through holes and a method for forming through holes in the glass substrate.

Conventionally, there has been known a technique for forming one or more through holes in a glass substrate by irradiating the glass substrate with a laser beam generated from a laser light source (for example, Patent Document 1).

A glass substrate having such through holes is used, for example, in a glass interposer in which the through holes are filled with a conductive filler.

Japanese Unexamined Patent Publication No. 2003-226551

Usually, a glass substrate having a through hole as described above is used.
(1) A step of preparing a glass substrate having the first and second surfaces, and
(2) By irradiating the laser beam from the side of the first surface of the glass substrate, it penetrates from the first opening of the first surface of the glass substrate to the second opening of the second surface of the glass substrate. The process of forming a through hole and
(3) A step of expanding the through hole to a desired size by wet-etching the glass substrate, and
Manufactured through.

Here, when the step (3) is carried out, there may often be a problem that a narrowed portion is formed at a substantially central portion of the through hole along the overall length direction of the through hole.

This is because the through hole formed in the step (2) usually has a diameter relatively small compared to the thickness of the glass substrate. That is, when a wet etching process is performed on such a "fine" through hole in the step (3), the concentration diffusion of the etching solution does not proceed sufficiently inside the through hole, and the etching reaction occurs. The product of is stagnant in the through hole. As a result, it becomes difficult for the etching reaction to proceed sufficiently inside the through hole, and a narrowed portion is formed.

In particular, in the field of glass interposers, extremely fine through holes are formed in the step (2). Therefore, in the manufacturing process of the glass interposer, there is a problem that such a narrowed portion is more likely to occur in the through hole.

An object of the present invention is to provide a method for manufacturing a glass substrate having through holes having a relatively well-shaped shape. Another object of the present invention is to provide a method for forming through holes having a relatively well-shaped shape in a glass substrate. Another object of the present invention is to provide a glass substrate manufacturing system for forming through holes having a relatively well-shaped shape in the glass substrate.

The present invention is a method for manufacturing a glass substrate having through holes.
(1) A step of forming initial holes in the glass substrate by irradiating a laser beam from the side of the first surface of the glass substrate having first and second surfaces facing each other.
(2) Using the first etching solution, the glass substrate is subjected to the first etching process, and the second hole is formed through the initial hole and the first opening formed on the first surface. When a first through hole extending to the second opening formed on the surface is formed, the thickness of the glass substrate is d _1, and the diameter of the first opening is R _t 1, the ratio is d _1. The process of making / R _t1 in the range of 10 to 20 and
(3) After the step (2), the glass substrate is second-etched with a second etching solution having an etching rate higher than that of the first etching solution. A step of performing a process to expand the first through hole and
Manufacturing method having.
Is provided.

Further, in the present invention, it is a method of forming a through hole in a glass substrate.
(1) A step of forming initial holes in the glass substrate by irradiating a laser beam from the side of the first surface of the glass substrate having first and second surfaces facing each other.
(2) Using the first etching solution, the glass substrate is subjected to the first etching process, and the second hole is formed through the initial hole and the first opening formed on the first surface. When a first through hole extending to the second opening formed on the surface is formed, the thickness of the glass substrate is d _1, and the diameter of the first opening is R _t 1, the ratio is d _1. The process of making / R _t1 in the range of 10 to 20 and
(3) After the step (2), the glass substrate is second-etched with a second etching solution having an etching rate higher than that of the first etching solution. A step of performing a process to expand the first through hole and
The method of having is provided.

The present invention can provide a method for manufacturing a glass substrate having through holes having a relatively well-shaped shape. Further, the present invention can provide a method for forming a through hole having a relatively well-shaped shape in a glass substrate. Further, the present invention can provide a glass substrate manufacturing system for forming through holes having a relatively well-shaped shape in the glass substrate.

It is a flow chart which roughly showed the manufacturing method of the glass substrate which has the conventional through hole. It is a figure which showed typically one step in the manufacturing method of the glass substrate which has the conventional through hole shown in FIG. 1. It is a figure which showed typically an example of the flow of the manufacturing method of the glass substrate which has a through hole by one Embodiment of this invention. It is a figure which showed typically one step in the manufacturing method of the glass substrate which has a through hole by one Embodiment of this invention shown in FIG. It is a figure which showed typically one step in the manufacturing method of the glass substrate which has a through hole by one Embodiment of this invention shown in FIG. It is a figure which showed typically one step in the manufacturing method of the glass substrate which has a through hole by one Embodiment of this invention shown in FIG. It is a figure which showed typically one step in the manufacturing method of the glass substrate which has a through hole by one Embodiment of this invention shown in FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(Conventional method for manufacturing a glass substrate having through holes)
First, in order to better understand the features of the present invention, a conventional method for manufacturing a glass substrate having through holes will be briefly described with reference to FIGS. 1 and 2.

FIG. 1 schematically shows a flow of a conventional method for manufacturing a glass substrate having through holes (hereinafter, simply referred to as “conventional manufacturing method”). Further, FIG. 2 schematically shows one step in the conventional manufacturing method shown in FIG.

As shown in FIG. 1, the conventional manufacturing method is
The process of preparing the glass substrate (process S10) and
A step of irradiating a glass substrate with a laser beam to form a through hole (step S20).
A step of wet-etching a glass substrate having a through hole to widen the through hole to a desired size (step S30).
Have.

Of these, in step S10, as shown in FIG. 2A, a glass substrate 10 having a first surface 12 and a second surface 14 is prepared.

Next, in step S20, as shown in FIG. 2B, a through hole 20 is formed in the glass substrate 10. The through hole 20 is formed by irradiating a laser beam (not shown) from the side of the first surface 12 of the glass substrate 10.

The through hole 20 has a first opening 22 on the first surface 12 of the glass substrate 10 and a second opening 24 on the second surface 14. The diameter of the first opening 22 is φ _t0 , and the diameter of the second opening 24 is φ _{b 0} .

Next, in step S30, the glass substrate 10 is wet-etched in order to expand the diameter of the through hole 20 to a desired dimension.

_{Here, when the diameter φ t0} (or the diameter φ _b0 of the second opening 24) of the first opening 22 of the through hole 20 formed in step S20 is sufficiently large, the etching solution is applied during the wet etching process. , It can be uniformly and sufficiently supplied along the entire length of the through hole 20. Therefore, the through hole 20 is etched relatively uniformly.

However, when the diameter φ _{t0 of the first opening 22 and the diameter φ b 0} of the second opening 24 become smaller, the etching reaction proceeds sufficiently inside such a fine through hole 20 during the wet etching process. It becomes difficult to make it. This is because the concentration diffusion of the etching solution does not proceed sufficiently inside the through hole 20, and the product of the etching reaction tends to stay in the through hole 20. Further, in such a fine through hole 20, it may be difficult to sufficiently supply the etching solution to the inside of the through hole 20.

Therefore, in the through hole 20, the first and second openings 22, 24 and their vicinity are selectively etched. In other words, it becomes difficult to sufficiently etch the through hole 20 inside the through hole 20.

As a result, after the step S30, as shown in FIG. 2C, an expansion through hole 30 having a so-called “hourglass-shaped” cross section is formed. That is, the expanded through hole 30 to be formed has a predetermined size on the side of the first opening 32 and the second opening 34, but inside the through hole 30, a narrowed portion 36 having a size less than the predetermined size is formed. To have.

As described above, in the conventional manufacturing method, especially when the diameter of the through hole 20 (φ _t0 , φ _b0 ) is relatively small with respect to the thickness of the glass substrate 10, the expansion through hole 30 has a conspicuous narrowed portion 36. There is a problem that it becomes.

(Method for manufacturing a glass substrate having a through hole according to an embodiment of the present invention)
Next, an example of a method for manufacturing a glass substrate having a through hole according to an embodiment of the present invention will be described with reference to FIGS. 3 to 7.

FIG. 3 schematically shows an example of a flow of a method for manufacturing a glass substrate having a through hole according to an embodiment of the present invention. Further, FIGS. 4 to 7 schematically show aspects of each step in the method for manufacturing a glass substrate having through holes according to an embodiment of the present invention.

As shown in FIG. 3, a method for manufacturing a glass substrate having a through hole according to an embodiment of the present invention (hereinafter, referred to as “first manufacturing method”) is described.
(0) A step of preparing glass substrates having first and second surfaces facing each other (step S110).
(1) A step of forming an initial hole in the glass substrate by irradiating a laser beam from the side of the first surface of the glass substrate (step S120).
(2) A step of performing a first etching process on the initial holes using the first etching solution.
As a result, a first through hole extending from the first opening to the second opening is formed in the glass substrate.
When the thickness of the glass substrate after the step (2) is d ₁ and the diameter of the first opening of the first through hole is R _{t 1} , the ratio d 1 / R _t 1 is 10 to 20. The process (process S130), which is in the range of
(3) A step of performing a second etching process on the first through hole using the second etching solution (step S140).
Have.

Hereinafter, each step will be described in detail with reference to FIGS. 4 to 7.

(Step S110)
First, a glass substrate 110 having a cross-sectional shape as shown in FIG. 4 is prepared. The glass substrate 110 has a first surface 112 and a second surface 114 that face each other. Further, the glass substrate 110 has an initial thickness d ₀ .

The initial thickness d ₀ is, for example, preferably 0.1 mm to 0.7 mm, more preferably 0.2 mm to 0.5 mm, and particularly preferably 0.3 mm to 0.5 mm. If the initial thickness d ₀ is less than 0.3 mm, it may be difficult to form the hourglass-shaped expansion through hole as described above even in the conventional manufacturing method.

The composition of the glass substrate 110 is not particularly limited. The glass substrate 110 may be, for example, soda lime glass, non-alkali glass, or the like.

(Step S120)
Next, by irradiating the glass substrate 110 with a laser beam from the side of the first surface 112, one or more initial holes are formed in the glass substrate 110.

The type and irradiation conditions of the laser beam are not limited as long as the initial holes can be formed in the glass substrate 110. The laser beam may be, for example, a CO ₂ laser, a UV laser, or the like. Further, the laser beam may be a laser beam oscillated from a short pulse laser (for example, a picosecond laser or a femtosecond laser).

The form of the initial hole is not particularly limited, and the initial hole may be a through hole or a non-through hole. Further, the initial holes may be a void array composed of a plurality of voids arranged along the thickness direction of the glass substrate 110. When a short pulse laser is used, a void array is likely to be formed as an initial hole.

FIG. 5 shows a state in which the initial holes 120 are formed in the glass substrate 110. In the example shown in FIG. 5, the initial hole 120 is a through hole, and is referred to as an “initial through hole” 120 here.

As shown in FIG. 5, the initial through hole 120 is a second formed on the second surface 114 of the glass substrate 110 from the first initial opening 122 formed on the first surface 112 of the glass substrate 110. It extends to the initial opening 124. In the initial through hole 120, the diameter of the first initial opening 122 _{is referred to as R t0,} and the diameter of the second initial opening 124 is referred _{to as R b0.}

_{Here, the ratio of the thickness d 0} of the glass substrate 110 to _{the diameter R t} 0 of the first initial opening 122 at this stage, that is, d ₀ / R _t 0 is, for example, 25 or more. The ratio d ₀ / R _t 0 is preferably 30 or more. When the ratio d ₀ / R _t 0 is 25 or more, a large effect can be obtained by changing the conventional manufacturing method to the first manufacturing method. That is, when the ratio d ₀ / R _t 0 is 25 or more, in the conventional manufacturing method, a large constricted portion is generated in the through hole by the etching step. However, in the first production method, this narrowed portion can be significantly suppressed.

_{The diameter R t0} of the first initial opening 122 is, for example, 15 μm or less, and may be 13 μm or less.

In the example shown in FIG. 5, for simplification, the diameter R _{t0 of the first initial opening 122 of the initial through hole 120 and the diameter R b0} of the second initial opening 124 are substantially equal to each other. It is shown. However, the initial through hole 120 formed by laser light irradiation may actually have a tapered shape in which the diameter gradually decreases from the first initial opening 122 to the second initial opening 124. It should be noted that there are many. Therefore, usually, R _t0 > R _b0 .

Although only a single initial through hole 120 is shown in FIG. 5, a plurality of initial through holes 120 may be formed in the glass substrate 110.

(Step S130)
Next, in order to increase the diameter of the initial through hole 120, the initial through hole 120 is etched using the first etching solution (hereinafter, referred to as "first etching process" or "first etching step"). ).

The type of the first etching solution is not particularly limited as long as the initial through hole 120 can be properly etched. For example, the first etching solution may be an acid solution containing hydrofluoric acid. Further, the first etching solution may be a mixed acid solution containing at least one other acid in addition to hydrofluoric acid. For example, the first etching solution may be a mixed acid solution of hydrofluoric acid and hydrochloric acid or a mixed acid solution of hydrofluoric acid and nitric acid.

The etching rate _{V 1} to the glass substrate 110 of the first etching solution in the first etching process is, for example, 0.5 [mu] m / min or less, preferably 0.2 [mu] m / min or less, 0.02 [mu] m / min It is more preferable that it is as follows.

The first etching step may be carried out at any suitable temperature, and the treatment temperature may be, for example, room temperature.

The first etching step may be carried out, for example, by selectively supplying the first etching solution into the initial through hole 120 (hereinafter, such a method is referred to as "local etching treatment (method)". ). In the local etching treatment method, the diameter of the initial through hole 120 can be expanded without changing the thickness of the glass substrate 110. For example, an etching protective film may be attached so as not to block the initial through hole 120, and etching may be performed.

Alternatively, the first etching step may be carried out by exposing the entire glass substrate 110 to the first etching solution (hereinafter, such a method is referred to as "overall etching process (method)"). For example, the first etching step may be carried out by immersing the glass substrate 110 having the initial through hole 120 in a bathtub containing the first etching solution (dip method). Alternatively, the first etching step may be a method (shower type) in which the first etching solution is directly poured onto the glass substrate. In the case of the whole etching treatment method, the thickness of the glass substrate 110 itself also changes (decreases) from d _{0 to d 1.}

Further, in the first etching step, ultrasonic waves may be applied to the glass substrate 110, the glass substrate 110 may be vibrated, or the etching solution may be bubbled. This allows for more uniform etching.

Hereinafter, as an example, a case where the first etching step is carried out by the whole etching processing method will be described.

FIG. 6 schematically shows a cross section of the glass substrate 110 after the first etching step by the whole etching treatment method.

As shown in FIG. 6, the glass substrate 110 changes to _{a thickness d 1 by the first etching step.} That is, the glass substrate 110 comes to have a first new surface 113 and a second new surface 115.

Further, the initial through hole 120 changes to the first through hole 130. The first through hole 130 extends from the first opening 132 formed in the first new surface 113 to the second opening 134 formed in the second new surface 115.

Here, the first manufacturing method is characterized in that the ratio d ₁ / R _t1 is in the range of 10 to 20 when the diameter of the first opening 132 is R _t1. The ratio d ₁ / R _t1 is more preferably in the range of 10 to 15.

By setting the ratio d ₁ / R _t 1 to such a range, it is possible to significantly suppress the narrowed portion that may be formed in the through hole in the subsequent step S140.

That is, by expanding the initial through hole 120 so that the ratio d ₁ / R _t1 is 20 or less in the first etching step, the inside of the expanded first through hole 130 is formed in the second etching step. , It is possible to suppress the occurrence of a remarkable stenosis.

_{The reason why the} ratio d ₁ / R t1 is set to 10 or more is _{that even if the first etching step is performed until the ratio d 1} / R _t1 becomes less than 10, there is almost no change in the second etching step. This is because it does not occur. That is, by _{setting the ratio d 1} / R _t 1 to 10 or more, the processing time of the first etching step can be shortened.

The first new surface 113 of the glass substrate obtained by the whole etching treatment method as described above may be particularly referred to as "a surface corresponding to the first surface of the glass substrate". Similarly, the second new surface 115 may be referred to, in particular, as "the surface corresponding to the second surface of the glass substrate".

(Step S140)
Next, in order to further increase the diameter of the first through hole 130, that is, to expand the through hole to a desired diameter, the first through hole 130 is etched using the second etching solution (the first through hole 130 is etched (). Hereinafter, it is referred to as "second etching process" or "second etching step").

The second etching step may be carried out by a local etching treatment method or a total etching treatment method as in the case of the first etching step described above. Further, the second etching step may be the same processing method (method) as the first etching step, or may be a different processing method (method). For example, the first etching step may be a dip method, and the second etching step may be a shower method. In the first etching step, the processing time tends to be long, so the dip method is preferable from the viewpoint of productivity (cost). In the second etching step, a shower method is preferable because it is easy to adjust the hole diameter while suppressing a decrease in the thickness of the glass substrate.

Here, a case where the second etching step is carried out by the whole etching processing method will be described as an example.

In the whole etching treatment method, the second etching step may be carried out, for example, by immersing the glass substrate 110 having the first through hole 130 in a bathtub containing the second etching solution. As a result, the thickness of the glass substrate 110 changes (decreases) from d _{1 to d 2.}

The second etching solution may be, for example, an acid solution containing hydrofluoric acid. Further, the second etching solution may be a mixed acid solution containing at least one other acid in addition to hydrofluoric acid. The mixed acid solution may be the same as the first etching solution. The second etching step may be carried out at any suitable temperature, and the processing temperature may be, for example, room temperature.

Here, the second etching solution is selected from those capable of increasing the etching rate with respect to the glass substrate 110 as compared with the above-mentioned first etching solution.

_{For example, the etching rate V 2} of the second etching solution with respect to the glass substrate 110 in the second etching process may be three times or more the _{etching rate V 1} of the first etching solution with respect to the glass substrate 110. 10 times or more is preferable, and 100 times or more is more preferable. For example, the etching rate V2 of the _second etching solution with respect to the glass substrate 110 is 5.0 μm / min or less, preferably 2.0 μm / min or less, and more preferably 1.5 μm / min or less. preferable. The etching rate V ₂ may be, for example, in the range of 1.0 μm / min to 1.5 μm / min.

FIG. 7 schematically shows a cross section of the glass substrate 110 after the second etching step.

As shown in FIG. 7, the glass substrate 110 changes to _{a thickness d 2 by the second etching step.} That is, the glass substrate 110 will have a third new surface 117 and a fourth new surface 119.

Further, the first through hole 130 changes to the second through hole 140. The second through hole 140 extends from the third opening 142 formed in the third new surface 117 to the fourth opening 144 formed in the fourth new surface 119.

Through the above steps, the glass substrate 110 in which the second through hole 140 having a desired size is formed can be manufactured.

Here, in the first manufacturing method, a through hole (second through hole 140) is formed through at least two etching steps of a first etching step and a second etching step.

Among them, in the first etching step, using the etching rate V ₁ is a relatively small first etching solution, the initial holes 120 are etched.

Since the etching rate V1 of the _first etching solution is relatively small, a considerable amount of time is required for the etching process. Therefore, the concentration diffusion of the first etching solution in the initial through hole 120 becomes relatively rapid. That is, since the etching rate V1 of the _first etching solution with respect to the glass substrate 110 is relatively small, the glass substrate 110 near the first initial opening 122 of the initial through hole 120 and the second initial opening 124 is etched. In comparison with the above, the first etching solution diffuses into the initial through hole 120 relatively quickly. Therefore, the difference between the degree to which the glass substrate 110 near the first initial opening 122 and the second initial opening 124 is etched and the degree to which the glass substrate 110 is etched at the center of the initial through hole 120 becomes small. As a result, the product of the etching reaction is likely to diffuse from the inside of the initial through hole 120 to the outside, and the stagnation inside the initial through hole 120 is significantly suppressed.

Therefore, by the first etching step, the initial through hole can be expanded to a sufficient diameter while suppressing the remarkable occurrence of the narrowed portion in the initial through hole.

Next, in the second etching step, a second etching solution having _{a relatively large etching rate V 2 is used.}

However, the initial through hole 120 has already been sufficiently expanded by the first etching step. Therefore, in the second etching step, the second etching solution can be distributed relatively quickly and uniformly with respect to the first through hole 130. In addition, the product of the etching reaction rapidly moves from the inside of the first through hole 130, and the stagnation inside the first through hole 130 is significantly suppressed.

Therefore, the first through hole 130 is etched relatively uniformly, and a remarkable constricted portion is less likely to occur in the first through hole 130 even in the second etching step.

As a result of the above, in the first manufacturing method, the formation of the narrowed portion can be significantly suppressed as compared with the case where the initial through hole is expanded only by a single etching step as in the conventional case, and the shape is relatively large. It is possible to form a well-organized through hole.

The method according to one embodiment of the present invention is effective especially when an initial hole (void row) having a relatively high aspect ratio is formed, such as when a UV laser or a short pulse laser is used. This is because when the aspect ratio of the initial pores is high, it becomes more difficult for the concentration diffusion of the etching solution to proceed, and it becomes more difficult to supply the etching solution to the inside of the initial pores.

As described above, with reference to FIGS. 3 to 7, an example of a method for manufacturing a glass substrate having a through hole according to an embodiment of the present invention has been described. However, it is clear to those skilled in the art that the above description is merely an example and that the present invention may be implemented in other embodiments.

For example, in the above description, the initial hole formed in step S120 is the initial through hole 120. However, the initial holes may be non-through holes and a row of voids composed of a plurality of voids arranged along the thickness direction of the glass substrate. In this case, through holes are formed after the first etching step, and such through holes are expanded by the second etching step.

In addition, the first manufacturing method has a two-step etching step. However, in the method for manufacturing a glass substrate having through holes according to one embodiment of the present invention, the etching step may be carried out in three or more steps. In this case, in the first etching step, a first etching solution having a relatively small etching rate is used, and in the second etching step, a second etching solution having a medium etching rate is used, and a third etching solution is used. In the etching step of the above, a third etching solution having a relatively large etching rate may be used.

Further, the method for manufacturing a glass substrate having a through hole can also be applied to a method for forming a through hole in the glass substrate.
(Method for manufacturing a glass substrate having through holes according to another embodiment of the present invention)
The method for manufacturing a glass substrate having a through hole according to another embodiment of the present invention is a method for manufacturing a glass substrate having a through hole.
(1) A step of forming initial holes in a glass substrate by having first and second surfaces facing each other and irradiating a laser beam from the side of the first surface.
(2) A step of performing a first wet etching treatment on the initial pores using the first etching solution.
As a result, a first through hole extending from the first surface of the glass substrate or the surface corresponding to the first surface to the second surface of the glass substrate or the surface corresponding to the second surface is formed. Process and
(3) A step of performing a second wet etching process on the first through hole using the second etching solution.
As a result, a second through hole is formed in which the first through hole is etched.
The second etching solution has a higher etching rate than the first etching solution with respect to the glass substrate.
It is a manufacturing method having.

As described above, by allowing the second etching solution to have a higher etching rate with respect to the glass substrate than that of the first etching solution, it is possible to form through holes having a relatively well-shaped shape. .. In particular, when a UV laser or a short pulse laser is used, an initial hole having a relatively high aspect ratio is formed, so that it is effective to apply the manufacturing method of the present embodiment.

The method for manufacturing a glass substrate having a through hole can also be applied to a method for forming a through hole in the glass substrate.

In this embodiment, the configurations of one embodiment with reference to FIGS. 3 to 7 described above can be appropriately combined. The description of the specific configuration will be omitted because the description of the above-described embodiment can be applied mutatis mutandis.
(A system for producing a glass substrate having through holes according to another embodiment of the present invention)
A system for producing a glass substrate having through holes according to another embodiment of the present invention
A system for manufacturing glass substrates with through holes.
A laser processing system that forms initial holes in the glass substrate by irradiating the glass substrate with laser light.
An etching system for forming through holes by etching initial holes with respect to the glass substrate is provided.
The etching system
It has a first etching system and a second etching system.
The first etching system is a system in which a first etching process using a first etching solution is performed.
The second etching system is a system in which a second etching process is performed on the glass substrate using a second etching solution having an etching rate higher than that of the first etching solution.
The etching system is a system configured to process the glass substrate in the first etching system and then process the glass substrate in the second etching system.

The laser processing system preferably includes a UV laser. Further, the laser processing system may include a short pulse laser such as a picosecond laser or a femtosecond laser.

As described above, by using an etching solution having an etching rate higher than that of the first etching solution with respect to the glass substrate as the second etching solution, it is possible to form through holes having a relatively well-shaped shape. it can. In particular, when a UV laser or a short pulse laser is used, initial holes having a relatively high aspect ratio are formed. Therefore, it is effective to form a glass substrate having through holes using the system of the present embodiment.

The etching system preferably further has a cleaning system. It is preferable to perform the cleaning treatment by the cleaning system between the first etching treatment by the first etching system and the second etching treatment by the second etching system. Since the concentrations of the etching solutions used in the first etching treatment and the second etching treatment are different, it is preferable to wash between the two treatments. For the cleaning treatment, for example, pure water is used.

The system can also be applied to a method of forming through holes in a glass substrate.

In this embodiment, the configurations of the above-described embodiments can be appropriately combined. The description of the specific configuration will be omitted because the description of the above-described embodiment can be applied mutatis mutandis.

Hereinafter, examples of the present invention will be described. In the following description, Examples 1 to 4 are Examples, and Example 5 is a Comparative Example.

(Example 1)
A glass substrate having through holes having predetermined dimensions was produced by the following method.

(Laser light irradiation)
First, a glass substrate (non-alkali glass substrate) having a length of 50 mm, a width of 50 mm, and a thickness (d _{0) of 400 μm was prepared.}

Next, UV laser light was irradiated from the side of the first surface (one surface of 50 mm in length × 50 mm in width) of the glass substrate to form an initial through hole. _{The diameter R t0} of the first initial opening (opening on the first surface side) of the initial through hole _{is about 13 μm, and the diameter R b0} of the second initial opening on the second surface on the opposite side is about 3 μm. Met. Therefore, in this glass substrate, the ratio d ₀ / R _t 0 is about 30.8.

(First etching process)
Next, the obtained glass substrate was subjected to the first etching treatment.

The first etching solution was a 0.4 wt% hydrofluoric acid solution. The first etching treatment was carried out by immersing the glass substrate in this hydrofluoric acid solution for 80 minutes. The processing temperature is room temperature. The glass substrate was etched in a stationary state (that is, in a state where no vibration was applied).

As a result, the initial through hole was etched to obtain the first through hole. The glass substrate itself was also etched so that the thickness d ₁ = 390 μm.

_{The diameter R t1} of the first opening of the first through hole on the first surface side of the glass substrate _{is 25.1 μm, and the diameter R b1} of the second opening on the second surface side is 10.4 μm. Met. Therefore, the ratio d ₁ / R _t 1 is about 15.6.

(Second etching process)
Next, the glass substrate was subjected to a second etching process.

The second etching solution was a 2 wt% hydrofluoric acid solution. The second etching treatment was carried out by immersing the glass substrate in this hydrofluoric acid solution for 25 minutes. The processing temperature is room temperature. The glass substrate was etched in a stationary state (that is, in a state where no vibration was applied). The etching rate V ₂ of the second etching solution is about 10 times _{the etching rate V 1 of the first etching solution.}

As a result, the first through hole was etched to obtain a second through hole. The glass substrate itself was also etched so that the thickness d ₂ = 360 μm.

_{The diameter R t2} of the third opening of the second through hole on the first surface side of the glass substrate _{is 46.3 μm, and the diameter R b2} of the fourth opening on the second surface side is 33.8 μm. Met. Therefore, the ratio d ₂ / R _t 2 is about 7.8.

(Example 2)
A glass substrate having through holes of predetermined dimensions was produced by the same method as in Example 1.

However, in this Example 2, in the first etching step, the etching time with the first etching solution was set to 120 minutes. Further, in the second etching step, the etching time with the second etching solution was set to 21 minutes.

The thickness of the glass substrate after the first etching step _{was d 1} = 385 μm. _{Further, the diameter R t1} of the first opening of the first through hole on the first surface side of the glass substrate is 28.7 μm, and the diameter R _b1 of the second opening on the second surface is 15. It was 6 μm. Therefore, the ratio d ₁ / R _t 1 is about 13.4.

On the other hand, the thickness of the glass substrate after the second etching step _{was d 2} = 360 μm. _{The diameter R t2} of the third opening of the second through hole on the first surface side of the glass substrate _{is 46.0 μm, and the diameter R b2} of the fourth opening on the second surface side is 34.3 μm. Met. Therefore, the ratio d ₂ / R _t 2 is about 7.8.

(Example 3)
A glass substrate having through holes of predetermined dimensions was produced by the same method as in Example 1.

However, in this Example 3, in the first etching step, the etching time with the first etching solution was set to 210 minutes. Further, in the second etching step, the etching time with the second etching solution was set to 8 minutes.

The thickness of the glass substrate after the first etching step _{was d 1} = 370 μm. _{Further, the diameter R t1} of the first opening of the first through hole on the first surface side of the glass substrate _{is 36.8 μm, and the diameter R b1} of the second opening on the second surface side is 23. It was .1 μm. Therefore, the ratio d ₁ / R _t 1 is about 10.

On the other hand, the thickness of the glass substrate after the second etching step _{was d 2} = 360 μm. _{The diameter R t2} of the third opening of the second through hole on the first surface side of the glass substrate _{is 46.4 μm, and the diameter R b2} of the fourth opening on the second surface side is 33.3 μm. Met. Therefore, the ratio d ₂ / R _t 2 is about 7.8.

(Example 4)
A glass substrate having through holes of predetermined dimensions was produced by the same method as in Example 1.

However, in this Example 4, in the first etching step, the etching time with the first etching solution was set to 40 minutes. Further, in the second etching step, the etching time with the second etching solution was set to 30 minutes.

_{The thickness d 1} of the glass substrate after the first etching step was about 395 μm. _{Further, the diameter R t1} of the first opening of the first through hole on the first surface side of the glass substrate _{is 18.9 μm, and the diameter R b1} of the second opening on the second surface side is 7. It was 0.6 μm. Therefore, the ratio d ₁ / R _t 1 is about 20.9.

On the other hand, the thickness of the glass substrate after the second etching step _{was d 2} = 360 μm. _{Further, the diameter R t2} of the third opening of the second through hole on the first surface side of the glass substrate _{is 45.6 μm, and the diameter R b2} of the fourth opening on the second surface side is 34. It was 0.0 μm. Therefore, the ratio d ₂ / R _t 2 is about 7.9.

(Example 5)
A glass substrate having through holes of predetermined dimensions was produced by the same method as in Example 1.

However, in this example 5, the first etching step was not carried out. That is, after irradiating the glass substrate with UV laser light to form an initial through hole in the glass substrate, only the second etching step was performed on the glass substrate. In the second etching step, the etching time with the second etching solution was set to 33 minutes.

The thickness of the glass substrate after the second etching step _{was d 2} = 360 μm. _{Further, the diameter R t2} of the third opening of the second through hole on the first surface side of the glass substrate _{is 45.6 μm, and the diameter R b2} of the fourth opening on the second surface side is 32. It was 0.7 μm. Therefore, the ratio d ₂ / R _t 2 is about 7.9.

Table 1 below summarizes the thickness of the glass substrate in each step, the diameter of the opening of the through hole, and the like when the glass substrates of Examples 1 to 5 are manufactured.

（評価）
前述のようにして製造された各ガラス基板において、第２の貫通孔の形態を観察した。より具体的には、第２の貫通孔において、延伸方向に垂直な断面が最も小さい狭窄部の直径Ｒ_ｃを測定した。

(Evaluation)
The morphology of the second through hole was observed in each glass substrate manufactured as described above. _{More specifically, in the second through hole, the diameter R c of the} constricted portion having the smallest cross section perpendicular to the stretching direction was measured.

The results are summarized in Table 2. In any of the glass substrates of Examples 1 to 5, the narrowed portion of the second through hole was present at substantially the center of the entire length of the through hole.

この結果から、例５では、第２の貫通孔の狭窄部の直径Ｒ_ｃは、極めて小さく、比Ｒ_ｃ／Ｒ_ｔ２は、０．４を下回ることがわかった。例４では、第２の貫通孔の狭窄部の直径Ｒ_ｃは、例５と比較して拡張されることがわかった。さらに、例１乃至例３では、第２の貫通孔の狭窄部の直径Ｒ_ｃは、有意に拡張されており、比Ｒ_ｃ／Ｒ_ｔ２は、少なくとも０．５を超えることがわかった。

From this result, it was found that _{in Example 5, the diameter R c} of the narrowed portion of the second through hole was extremely small, and the ratio R _c / R _{t 2 was less than 0.4. In Example 4, it was found that the diameter R c} of the narrowed portion of the second through hole was expanded as compared with Example 5. _{Furthermore, in Examples 1 to 3, it was found that the diameter R c} of the narrowed portion of the second through hole was significantly expanded, and the ratio R _c / R _{t 2} exceeded at least 0.5.

By carrying out the two-step etching process in this way, it is possible to suppress the remarkable occurrence of narrowed portions of the through holes. Further, a two-step etching step is carried out, and the ratio d ₁ / R _t1 of _{the thickness d 1 of the glass substrate after the first etching step and the diameter R t} 1 of the first opening of the first through hole is determined. , It was confirmed that a through hole having a relatively well-shaped shape can be formed by setting the range to 10 to 20.

10 Glass substrate 12 First surface 14 Second surface 20 Through hole 22 First opening 24 Second opening 30 Expansion through hole 32 First opening 34 Second opening 36 Constriction 110 Glass substrate 112 First Surface 113 First new surface 114 Second surface 115 Second new surface 117 Third new surface 119 Fourth new surface 120 Initial through hole 122 First initial opening 124 Second initial opening 130 First Through hole 132 First opening 134 Second opening 140 Second through hole 142 Third opening 144 Fourth opening

Claims (15)

A method for manufacturing a glass substrate having through holes.
(1) A step of forming initial holes in the glass substrate by irradiating a laser beam from the side of the first surface of the glass substrate having first and second surfaces facing each other.
(2) Using the first etching solution, the glass substrate is subjected to the first etching process, and the second hole is formed through the initial hole and the first opening formed on the first surface. When a first through hole extending to the second opening formed on the surface is formed, the thickness of the glass substrate is d _1, and the diameter of the first opening is R _t 1, the ratio is d _1. The process of making / R _t1 in the range of 10 to 20 and
(3) After the step (2), the glass substrate is second-etched with a second etching solution having an etching rate higher than that of the first etching solution. A step of performing a process to expand the first through hole and
Manufacturing method having. The production method according to claim ₁ , wherein the ratio V ₂ / V _{1 of the etching rate V 2} of the second etching solution to the etching rate V 1 of the first etching solution is 3 or more. The production method according to claim 1 or 2, wherein the etching rate V _{1 of the first etching solution is 0.5 μm / min or less.} The production method according to any one of claims 1 to 3, wherein the etching rate V ₂ of the second etching solution is in the range of 1 μm / min to 5 μm / min. The manufacturing method according to any one of claims 1 to 4, wherein the thickness d ₁ is smaller than the thickness d _0. The manufacturing method according to any one of claims 1 to 5, wherein the thickness d _{0 is 0.3 mm or more.} The production method according to any one of claims 1 to 6, wherein the thickness d _{0 is 0.5 mm or less.} When the said first diameter of the opening in the surface of the initial hole formed in the step (1) was R _t0, the ratio d _{0 /} R _t0 is 25 or more, one of the claims 1 to 7 The manufacturing method described in one. The manufacturing method according to any one of claims 1 to 7, wherein the initial hole formed in the step (1) is a through hole or a void row. It is a method of forming through holes in a glass substrate.
(1) A step of forming initial holes in the glass substrate by irradiating a laser beam from the side of the first surface of the glass substrate having first and second surfaces facing each other.
(2) Using the first etching solution, the glass substrate is subjected to the first etching process, and the second hole is formed through the initial hole and the first opening formed on the first surface. When a first through hole extending to the second opening formed on the surface is formed, the thickness of the glass substrate is d _1, and the diameter of the first opening is R _t 1, the ratio is d _1. The process of making / R _t1 in the range of 10 to 20 and
(3) After the step (2), the glass substrate is second-etched with a second etching solution having an etching rate higher than that of the first etching solution. A step of performing a process to expand the first through hole and
Method to have. The method according to claim 10, wherein the etching rate V ₂ of the second etching solution is in the range of 1 μm / min to 5 μm / min. A system for manufacturing glass substrates with through holes.
A laser processing system that forms initial holes in the glass substrate by irradiating the glass substrate with laser light.
The glass substrate is provided with an etching system for forming through holes having a first opening on the surface of the glass substrate by etching the initial holes.
The etching system
It has a first etching system and a second etching system.
The first etching system is a system in which a first etching process using a first etching solution is performed.
The second etching system is a system in which a second etching process is performed on the glass substrate using a second etching solution having an etching rate higher than that of the first etching solution.
The etching system has a ratio of d _{1 when the thickness of the glass substrate is d 1} and the diameter of the first opening is R _t 1 after the glass substrate is processed by the first etching system. A system in which / R _t1 is configured to be in the range of 10 to 20, and then the glass substrate is processed by the second etching system. The etching system also has a cleaning system
The system according to claim 12, wherein a cleaning process is performed by the cleaning system between the first etching process and the second etching process. The system according to claim 12 or 13, wherein the laser processing system includes one short pulse laser selected from a picosecond laser or a femtosecond laser. The system according to claim 12 or 13, wherein the laser processing system includes a UV laser.

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