JP4870424B2 - Drilling method - Google Patents

Description

  The present invention relates to a drilling method for providing holes in a wafer.

In general, for example, when a hole is provided in glass, a sandblasting device (perforating means) is used (for example, see Patent Document 1). The perforation by the sand blasting apparatus is performed by spraying the granular material toward the wafer fixed to the table provided therein. Here, a mask is applied to the fixed wafer, and only the part to be perforated is opened and the surface of the wafer is exposed by photolithography. In this state, the table is reciprocated, and the sandblast spray nozzle is also reciprocated to scrape off the uncured mask, and the wafer is shaved when the mask is finished. That is, the part to be cut becomes a part to be perforated. The diameter of the hole cut in this way becomes gradually smaller in the wafer thickness direction. In other words, the diameter of the through hole provided in the wafer is reduced as it goes from the surface on which the granular material is sprayed to the opposite surface.
Therefore, for example, when a through hole drilled by this sandblasting device is provided in a package of an electronic component composed of a substrate and a lid, the smaller diameter of the through hole is positioned on the joint surface between the substrate and the lid.

JP 2000-302488 A (paragraphs 0002 to 0007)

  However, in the drilling by such a sandblasting device or the like, chipping occurred when the hole penetrated, and the periphery of the hole on the surface where the chipping occurred was in a depressed state. As a result, when the substrate and the lid are bonded, the concave state is caused, so that an effective bonding area between the lid and the substrate cannot be secured, and further, there is a risk of causing an airtight leak from the portion. .

  Therefore, an object of the present invention is to provide a drilling method that solves the above-described problems and prevents chipping.

  In order to solve the above-mentioned problems, the present invention provides a pressurizing process in which two wafers having a flat surface are stacked and a predetermined pressure is applied, and when the two wafers are brought into close contact with each other by the pressurizing process, the pressure is applied. A pressurizing end step for ending this, a mask step for applying a mask to the exposed surfaces of the two wafers, and making a through hole in the wafer on which the mask is provided from one side of the mask by a punching means, A first punching step that communicates with the through-hole and provides a hole that does not pass through the wafer farthest from the mask that has started drilling; a second punching step that allows the non-penetrating hole to pass through by the punching means; and the mask After the peeling, or before the peeling, a contact release process for releasing the contact state between the two wafers is provided.

  In the present invention, the mask process may be performed before the pressurizing process.

  In this way, the perforation can prevent chipping on the through side of the hole provided in the wafer.

  Next, the best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described in detail with reference to the drawings as appropriate. In each embodiment, the same constituent elements are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
FIG. 1A is a conceptual diagram illustrating an example of a state where two stacked wafers are being pressed, and FIG. 1B is a diagram illustrating a state where two wafers are in close contact with each other. (C) is a fragmentary sectional view which shows the state which two wafers contact | adhered, (d) is a fragmentary sectional view which shows the process following (c), (e) follows (d). It is a fragmentary sectional view showing a process, and (f) is a fragmentary sectional view showing a process following (e). 2A is a partial cross-sectional view showing a state where two wafers are in close contact with each other, FIG. 2B is a partial cross-sectional view showing a state in which two wafers are in close contact, and FIG. It is the fragmentary sectional view which shows the process following b), (d) is the fragmentary sectional view which shows the process following (c), (e) is the fragmentary sectional view which shows the process following (d). . FIG. 3 is a partial cross-sectional view showing a step following the step shown in FIG.

As shown in FIGS. 1A to 1F, in the punching method according to the first embodiment of the present invention, both the wafers 11 and 12 are placed in a state in which the two wafers 11 and 12 are brought into close contact with each other. A mask 13 is applied to the second wafer 12 by punching means K from one wafer 11 side, and then the punching means K is changed from the wafer side provided with holes that do not pass through by changing the punching direction. The hole 15 which does not penetrate is penetrated by this, and the contact | adherence state of the two wafers 11 and 12 is cancelled | released after that.
Here, the components used in the drilling method of the present invention will be described.

First, each of the wafers 11 and 12 is formed in a plate shape having a flat surface.
Here, the wafers may be made of different materials for the wafer 11 on which punching is started and the wafer 12 on which punching is finished, or may be made of the same material.
For example, the wafer 11 on the side where the perforation is started may be made of crystal or ceramic, and the wafer 12 on the side where the perforation is finished may be made of glass.
Further, for example, the wafer 11 on the side where the perforation is started and the wafer 12 on the side where the perforation is finished may be made of crystal or glass.

  As shown in FIG. 2B, the mask 13 is provided on the exposed surfaces of the wafers 11 and 12 by a well-known photolithographic technique. The portion 13A where the perforation is performed is opened, and the portion 13B where the perforation is not performed is cured. Provided in a state.

The punching means K is, for example, a sandblasting device or a laser processing device, and plays a role of punching from the mask 13 side toward the two wafers 11 and 12.
Here, in this embodiment, a case where a sandblasting device is used as the punching means K will be described. In this case, the punching means K can form holes or the like in the wafer by injecting the granular material (not shown) onto the wafer, and the injection for injecting the granular material onto the wafer. A nozzle (not shown) is provided.
When a laser processing apparatus is used, the wafers 11 and 12 on which the mask 13 is provided are made of a non-transparent material such as ceramic.

  Next, the drilling method of the present invention will be described.

(1)
As shown in FIGS. 1A and 1B, the pressurizing step is performed by applying a predetermined pressure by overlapping two wafers 11 and 12 having a flat surface between the overlapping wafers 11 and 12. In this step, the intervening air is removed to create a vacuum between the two wafers 11 and 12.

  Specifically, as shown in FIG. 1A, wafers 11 and 12 having flat surfaces are overlapped with each other, and a predetermined pressure is applied to a predetermined portion (in the present embodiment, a central portion) S of wafers 11 and 12. , The minute space formed between the two wafers 11 and 12 at the portion S is blocked, in other words, air is excluded, and the surfaces of the wafers 11 and 12 are mutually connected. Is in close contact. This phenomenon spreads to the outer peripheral edge G of the wafer, and the air is removed from between the two wafers 11 and 12, that is, the two wafers are in close contact (vacuum state) (FIG. 1B). reference).

For example, when the central portion S of the wafers 11 and 12 is pressed in a state where the two wafers 11 and 12 are overlapped, the surfaces of the wafers 11 and 12 in the central portion S are in close contact with each other. Air is excluded. Then, the closely contacted state spreads to the outer peripheral edge G of the wafers 11 and 12, and the entire wafers 11 and 12 are in close contact.
In addition, the pressurization in this process is performed in a normal temperature atmosphere.

(2)
As shown in FIG. 2 (a), the pressurization end step ends the application of the pressure when the two wafers 11 and 12 are brought into close contact with each other in the pressurization step, that is, the step of ending unnecessary pressurization. It is.
When the two wafers 11 and 12 are in close contact with each other, the close contact state is maintained even if no pressure is applied. Therefore, when this state is confirmed, the application of pressure is terminated.

(3)
As shown in FIG. 2B, the mask process is divided into a portion where the masks 13 are applied to the surfaces of the two wafers 11 and 12 and a portion where the wafers 11 and 12 are not perforated. Is a process of protecting The mask 13 is applied to the exposed surfaces of the wafers 11 and 12.

(4)
In the first drilling step, as shown in FIG. 2 (c), a through-hole 14 is formed in the wafer 11 on which the mask 13 is provided from the mask 13 by the punching means K, and communicated with the through-hole 14. This is a step of providing a hole 15 that does not penetrate the wafer 12 farthest from the mask 13.
Specifically, the granular material (not shown) ejected from the punching means K passes through the opening 13A of the mask 13 and reaches the wafer 11 on which the mask 13 is applied. Then, the wafer 11 is shaved to form a through hole 14 penetrating the wafer 11, and the wafer 12 farthest from the mask 13 in close contact with the wafer 11 is also shaved to form a hole 15 that does not penetrate the wafer 12. .

(5)
In the second punching step, as shown in FIG. 2 (d), the wafer 12 provided with the holes 15 not penetrating is directed toward the punching means K side, and as shown in FIG. This is a step of providing a through hole 15 ′ that penetrates through the wafer 12 so as to be connected to the hole 15 that does not penetrate.
Specifically, the granular material (not shown) ejected from the punching means K passes through the opening 13A of the mask 13 and reaches the wafer 12 on which the mask 13 is applied. Then, the wafer 12 on which the mask 13 is applied is shaved and communicated with a non-penetrating hole 15 provided in the wafer 12 to form a through hole 15 ′.

(5)
As shown in FIG. 3, in the adhesion release step, after the mask 13 is peeled off or before the mask 13 is peeled off, the two wafers 11 and 12 are released from the contact state, and the through-holes 14 and 15 ′ without chipping are formed. This is a process of obtaining wafers 11 and 12.
Here, the two wafers 11 and 12 that are brought into close contact with each other by pressurization are released from each other by providing a space between the two wafers 11 and 12 in the outer peripheral edge G so that a space is provided therebetween. be able to.

  Therefore, since the wafer 11 provided with the mask 13 to be first drilled is pressed by the wafer 12 to which the penetrating side of the through-hole 14 is in close contact, there is no action by pulling as in the conventional case, so that the chipping is not performed. The through-hole 14 can be formed without raising. Similarly, since the wafer 12 provided with the mask 13 to be drilled next is pressed by the wafer 11 to which the penetrating side of the through-hole 15 ′ is in close contact, there is no effect of pulling as in the conventional case when penetrating. The through hole 15 ′ can be formed without causing chipping.

According to the punching method in the first embodiment of the present invention, since the two wafers 11 and 12 are brought into close contact with each other only by pressurization, for example, the two wafers are brought into close contact using an adhesive. Compared to the case, it is possible to reduce the time used for the step for adhesion, and it is not necessary to use an extra material (adhesive), so that the manufacturing cost can be reduced.
In addition, when the two wafers 11 and 12 are peeled off, the time required for the peeling process can be shortened as compared with the case where the two wafers are brought into close contact with an adhesive, and unnecessary materials ( Since the solution for removing the adhesive is not necessary, the manufacturing cost can be reduced.

In addition, since an adhesive or a solution for removing the adhesive is not used, the environmental load can be reduced.
Further, since the two wafers 11 and 12 which are brought into close contact with each other can be perforated, productivity can be improved.

(Second embodiment)
FIG. 4 is a view showing a perforation method according to the second embodiment of the present invention, in which (a) shows a state in which a mask is applied to the exposed surfaces of both wafers and then overlapped with the other mask. It is a fragmentary sectional view, (b) is a fragmentary sectional view showing the process following (a), (c) is the fragmentary sectional view showing the process following (b), (d) is ( It is a fragmentary sectional view showing the process following c).

As shown in FIGS. 4A to 4E, the drilling method according to the second embodiment of the present invention is different from the first embodiment in that the mask process is performed before the pressurizing process.
Thus, even if the masking process is performed before the pressurizing process, the through holes 14 and 15 'can be provided without causing chipping, and the two wafers 11 and 12 are brought into close contact as in the first embodiment. If the state is solved (see FIG. 3), wafers 11 and 12 provided with through holes 14 and 15 'without chipping can be obtained.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, if the wafer surface is in a mirror state, the material used for the wafer is not limited.
The punching means is not limited as long as it can cut the wafer.

(A) is a conceptual diagram which shows an example of the state which has pressurized the two laminated wafers, (b) is a figure which shows the state which two wafers contact | adhered. (C) is a fragmentary sectional view which shows the state which two wafers contact | adhered, (d) is a fragmentary sectional view which shows the process following (c), (e) follows (d). It is a fragmentary sectional view showing a process, and (f) is a fragmentary sectional view showing a process following (e). (A) is a partial cross-sectional view showing a state where two wafers are in close contact, (b) is a partial cross-sectional view showing a state where two wafers are in close contact, and (c) is (b) FIG. 4D is a partial cross-sectional view illustrating a process following (d), (d) is a partial cross-sectional view illustrating the process following (c), and (e) is a partial cross-sectional view illustrating the process following (d). FIG. 3 is a partial cross-sectional view showing a step that follows FIG. It is a figure which shows the punching method which concerns on 2nd embodiment of this invention, Comprising: (a) is a fragmentary sectional view which shows the state which gave the mask to the exposed surface of both wafers, and then overlapped with the other mask. (B) is a partial cross-sectional view showing the process following (a), (c) is a partial cross-sectional view showing the process following (b), and (d) follows (c). It is a fragmentary sectional view showing a process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Wafer 12 Wafer 13 Mask 14 Through-hole 15 Hole which does not penetrate 15 'Through-hole G Outer peripheral edge K Perforation means

Claims (2)

A pressurizing step in which two wafers having a flat surface are stacked and a predetermined pressure is applied;
A pressurization end process for terminating the application of the pressure when the two wafers are in close contact with each other by the pressurization process;
A mask process for applying a mask to the exposed surfaces of the two wafers;
A through hole is formed in the wafer on which the mask is provided from one surface of the mask by a punching means, and a hole that does not pass through the wafer that is in communication with the through hole and is farthest from the mask that has started drilling is provided. Drilling process;
A second drilling step of passing the non-penetrating hole by the punching means;
After releasing the mask or before removing, the contact release process for releasing the contact state of the two wafers;
A perforation method comprising:   The perforation method according to claim 1, wherein the mask process is performed before the pressurizing process.

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