Method of repairing glass substrate

Abstract

The present invention relates to a method for repairing a glass substrate, comprising a first calculation step, a second calculation step, and a repair step. The first calculation step calculates a first volume of a normal hole formed through the glass substrate. The second calculation step calculates the dimensions of a repair hole such that the first volume of the normal hole matches the second volume of the repair hole to be formed by irradiation with a laser beam. The repair step irradiates a laser beam into the defective hole to form a repair hole corresponding to the dimensions of the repair hole.

Description

Technology Field

[0001] The present invention relates to a method for repairing a glass substrate, and more specifically, to a method for repairing a defective hole that occurs during the process of forming a via hole in a glass substrate. Background Technology

[0002] As the structure of semiconductors and displays changes from a planar type to a three-dimensional stacked type, the demand for interposers to block unnecessary electrical flow between layers is increasing.

[0003] An interposer is a microcircuit board additionally inserted between an Integrated Circuit (IC) and a Printed Circuit Board (PCB) when the size of the I / O pads of an Integrated Circuit (IC) manufactured using a microprocess does not match the size of the I / O connection pads manufactured on the PCB.

[0004] Silicon interposers made of silicon form via holes for electrical signal communication between layers, which are called TSVs (Through Silicon Via holes). Pulsed lasers are used to form TSVs in silicon interposers, and techniques such as applying a Bessel beam to form TSVs with a single laser pulse have been developed.

[0005] However, in 5G communication, it has become difficult to completely block unnecessary electrical flow using silicon interposers, so glass interposers are being developed. The via holes formed in the glass interposer are called TGVs (Thorough Glass Via holes). To form via holes in the glass interposer, an ultrashort pulse laser beam is converted into a Bessel beam to form local modification lines inside the glass interposer. Then, the local modification lines are etched using an etching solution such as KOH or HF to complete the via holes.

[0006] There is a problem where economic losses increase if the entire glass substrate is discarded due to defects in a few of the via holes, even though millions of via holes are formed on average in glass substrates used for interposers. Prior art literature

[0007] Korean Patent Publication No. 10-2423292 (Registered July 15, 2022) The problem to be solved

[0008] Therefore, the objective of the present invention is to solve the aforementioned conventional problems by providing a glass substrate repair method that can reduce the production cost of an interposer glass substrate by irradiating a laser beam onto a defective hole in the interposer glass substrate to form a repair hole similar to a normal hole. means of solving the problem

[0009] To achieve the above objective, the glass substrate repair method of the present invention comprises: a first calculation step for calculating a first volume of a normal hole formed through the glass substrate; a second calculation step for calculating the dimensions of the repair hole such that the first volume of the normal hole matches the second volume of the repair hole to be formed by irradiation of a laser beam; and a repair step for irradiating a laser beam into a defective hole to form a repair hole corresponding to the dimensions of the repair hole.

[0010] The glass substrate repair method of the present invention may further include an inspection step performed prior to the first calculation step, for inspecting defective holes present in the glass substrate.

[0011] In the glass substrate repair method of the present invention, the inspection step can determine whether the upper diameter of a via hole formed in the glass substrate is a normal hole or a defective hole by inspecting the diameter of the via hole formed in the glass substrate.

[0012] In the glass substrate repair method of the present invention, the first calculation step can calculate the first volume of the normal hole by measuring the upper diameter, lower diameter, and waist diameter of the normal hole formed in the glass substrate.

[0013] In the glass substrate repair method of the present invention, the first volume of the normal hole can be the sum of the volume of a first truncated cone composed of a bottom surface having the upper diameter and a top surface having the waist diameter, and the volume of a second truncated cone composed of a bottom surface having the lower diameter and a top surface having the waist diameter.

[0014] In the glass substrate repair method of the present invention, the laser beam for repairing the defective hole may be emitted from an excimer laser.

[0015] In the glass substrate repair method of the present invention, the second calculation step can calculate the diameter of the repair hole from the first volume of the normal hole and the second volume of the repair hole.

[0016] In the glass substrate repair method of the present invention, the second calculation step can calculate the upper diameter and lower diameter of the repair hole from the first volume of the normal hole and the second volume of the repair hole.

[0017] The glass substrate repair method of the present invention may further include a masking step performed prior to the repair step, wherein a mask having a mask hole corresponding to the dimensions of the repair hole is placed on the upper side of the glass substrate. Effects of the invention

[0018] According to the glass substrate repair method of the present invention, the production cost of a glass substrate for an interposer can be reduced.

[0019] In addition, according to the glass substrate repair method of the present invention, the electrical characteristics of the glass substrate for the interposer can be maintained uniformly, and the production process of the interposer can be maintained smoothly. Brief explanation of the drawing

[0020] FIG. 1 is a drawing sequentially illustrating a glass substrate repair method according to one embodiment of the present invention, and FIG. 2 is a drawing for explaining normal holes and defective holes formed in a glass substrate, and FIG. 3 is a diagram for explaining the first calculation step of the glass substrate repair method of FIG. 1, and FIG. 4 is a diagram for explaining the second calculation step of the glass substrate repair method of FIG. 1, and Figure 5 is a diagram illustrating the masking step and the repair step of the glass substrate repair method of Figure 1. Specific details for implementing the invention

[0021] Hereinafter, embodiments of the glass substrate repair method according to the present invention will be described in detail with reference to the attached drawings.

[0022] FIG. 1 is a drawing sequentially illustrating a glass substrate repair method according to an embodiment of the present invention, FIG. 2 is a drawing for explaining normal holes and defective holes formed in a glass substrate, FIG. 3 is a drawing for explaining the first calculation step of the glass substrate repair method of FIG. 1, FIG. 4 is a drawing for explaining the second calculation step of the glass substrate repair method of FIG. 1, and FIG. 5 is a drawing for explaining the masking step and the repair step of the glass substrate repair method of FIG. 1.

[0023] Referring to FIGS. 1 to 5, the glass substrate repair method according to the present embodiment is for repairing defective holes that occur during the process of forming via holes in a glass substrate, and includes an inspection step (S110), a first calculation step (S120), a second calculation step (S130), a masking step (S140), and a repair step (S150).

[0024] The above inspection step (S110) inspects for defective holes (20) present in the glass substrate (1).

[0025] Referring to FIG. 2, a normal hole (10) and a defective hole (20, 20') can be formed by a via hole formation method.

[0026] As mentioned above, a method for forming via holes in a glass substrate (1) for an interposer involves forming a deformation line inside the glass substrate (1) by making an ultrashort pulse laser beam into a Bessel beam, and then etching the deformation line using an etching solution such as KOH or HF to form via holes. Since this method is already widely known in the relevant technical field, further detailed explanation is omitted.

[0027] The normal hole (10) formed through this via hole formation method can be formed such that, as shown in FIG. 2, the upper diameter (11) and the lower diameter (12) have substantially the same length, and the waist diameter (13) is smaller than the upper diameter (11) (or lower diameter (12)).

[0028] The normal hole (10) of the present embodiment is shown as having a shape in which a pair of truncated cones are attached so that their upper surfaces are in contact, but is not limited thereto and may be formed in a cylindrical shape in which the upper diameter, lower diameter, and waist diameter are the same.

[0029] The defective hole (20, 20') may be formed in a shape (20) that does not penetrate the glass substrate (1) or in a shape (20') that is formed to penetrate the glass substrate (1) but does not have a normal diameter.

[0030] Accordingly, in the inspection step (S110) of the present embodiment, the upper diameter of the via hole formed in the glass substrate (1) is inspected, and via holes that fall within the range of the reference diameter are determined to be normal holes (10), and via holes that fall outside the range of the reference diameter are determined to be defective holes (20).

[0031] When the inspection is completed, coordinates of the location where the defective hole (20) exists on the glass substrate (1) are generated, and repairs to the defective hole (20) can be performed based on these coordinate information.

[0032] The first calculation step (S120) above calculates the first volume (V1) of a normal hole (10) formed through the glass substrate (1).

[0033] First, the upper diameter (11), lower diameter (12), and waist diameter (13) of the normal hole (10) formed in the glass substrate (1) are measured. The diameters of the normal hole (10) can be measured using a vision inspection device or the like.

[0034] Referring to FIG. 3, since the normal hole (10) is formed in the shape of a pair of truncated cones, the first volume (V1) of the normal hole (10) can be obtained by adding the volumes of the two truncated cones.

[0035] That is, the volume (V11) of the first truncated cone (10a) composed of a bottom surface having an upper diameter (11) and a top surface having a waist diameter (13), and the volume (V12) of the second truncated cone (10b) composed of a bottom surface having a lower diameter (12) and a top surface having a waist diameter (13), can be calculated by adding them up, thereby the first volume (V1) of the normal hole (10).

[0036] If, as a result of measurement, the upper diameter (11), lower diameter (12), and waist diameter (13) of the normal hole (10) are formed to be substantially the same, the shape of the normal hole (10) can be set to a cylindrical shape and its volume can be calculated.

[0037] The above second calculation step (S130) calculates the dimensions of the repair hole (30) such that the first volume (V1) of the normal hole (10) and the second volume (V2) of the repair hole (30) to be formed by irradiation of the laser beam (L) match.

[0038] After forming via holes in the glass substrate (1) for the interposer, a plating process for injecting metal into the via holes and a polishing process for polishing the surface of the glass substrate (1) are performed.

[0039] If the volume (V2) of the repair hole (30) is larger than the volume (V1) of the normal hole (10), the amount of plating accommodated in the repair hole (30) is insufficient, and thus the electrical characteristics of the part connected by the repair hole (30) may differ from other parts.

[0040] On the other hand, if the volume (V2) of the repair hole (30) is smaller than the volume (V1) of the normal hole (10), some of the plating injected into the repair hole (30) may overflow onto the surface of the glass substrate (1), making the subsequent polishing process difficult.

[0041] Accordingly, by matching the volume (V1) of the normal hole (10) and the volume (V2) of the repair hole (30), the amount of plating applied to the normal hole (10) and the amount of plating applied to the repair hole (30) are substantially the same, thereby maintaining the electrical characteristics of the glass substrate (1) for the interposer uniformly and maintaining the production process of the interposer smoothly.

[0042] Referring to FIG. 4, the repair hole (30) to be formed by the laser beam (L) can be formed in the shape of a truncated cone, where the upper diameter (31) is somewhat larger than the lower diameter (32).

[0043] Through the first volume (V1) of the normal hole (10), the second volume of the repair hole (30) to be formed later can be known, the thickness of the glass substrate (1) is known, and the usual angle of inclination (θ) of the repair hole (30) to be formed by the laser beam (L) is also known, so the lower diameter (32) can be expressed as "coefficient x upper diameter (31)". Through the calculation process of these values, the upper diameter (31) and lower diameter (32) of the repair hole (30) can be calculated.

[0044] If the repair hole (30) to be formed by the laser beam (L) has a cylindrical shape, the diameter (31 or 32) of the repair hole (30) can be calculated based on the fact that the first volume (V1) of the normal hole (10) and the second volume (V2) of the repair hole (30) match.

[0045] The above masking step (S140) places a mask (5) having a mask hole (50) corresponding to the dimensions of the repair hole (30) on the upper side of the glass substrate (1).

[0046] Referring to FIG. 5, the diameter of the repair hole (30) to be formed in the glass substrate (1) can be controlled by placing a mask (5) having a mask hole (50) with dimensions substantially the same as the upper diameter (31) of the previously calculated repair hole (30) between the laser source and the glass substrate (1).

[0047] The repair step (S150) involves irradiating a laser beam (L) onto a defective hole (20) to form a repair hole (30) corresponding to the dimensions of the repair hole (30).

[0048] At this time, the defective hole (20) can be repaired by forming a repair hole (30) using an excimer laser.

[0049] The glass substrate repair method of the present invention configured as described above can achieve the effect of reducing the production cost of the interposer glass substrate by irradiating a laser beam onto a defective hole in the interposer glass substrate to form a repair hole similar to a normal hole.

[0050] In addition, the glass substrate repair method of the present invention configured as described above can achieve the effect of maintaining uniform electrical characteristics of the glass substrate for the interposer and maintaining a smooth production process of the interposer by forming a repair hole such that the volume of the normal hole matches the volume of the repair hole.

[0051] The scope of the present invention is not limited to the embodiments and variations described above, but may be implemented in various forms of embodiments within the scope of the appended claims. It is deemed that the scope of the claims of the present invention includes various ranges in which modifications are possible by anyone with ordinary knowledge in the technical field to which the invention belongs, without departing from the essence of the invention claimed in the claims. Explanation of the symbols

[0052] 1 : Glass substrate 10: Normal Hall 11: Upper diameter 12: Lower diameter 13: Waist diameter 20: Defective hole 30: Repair hole

Claims

Claim 1 An inspection step for inspecting defective holes present in a glass substrate; a first calculation step for calculating a first volume of a normal hole formed through the glass substrate; and a second calculation step for calculating the dimensions of the repair hole such that the first volume of the normal hole matches the second volume of the repair hole to be formed by irradiation of a laser beam. A repair step comprising irradiating a laser beam onto a defective hole to form a repair hole corresponding to the dimensions of the repair hole; wherein the first calculation step calculates a first volume of the normal hole by measuring the upper diameter, lower diameter, and waist diameter of the normal hole formed in the glass substrate, and the first volume of the normal hole is calculated by summing the volume of a first truncated cone composed of a bottom surface having the upper diameter and a top surface having the waist diameter, and the volume of a second truncated cone composed of a bottom surface having the lower diameter and a top surface having the waist diameter; wherein the second calculation step calculates the upper diameter and lower diameter of the repair hole from the first volume of the normal hole and the second volume of the repair hole, and the lower diameter of the repair hole is calculated from the upper diameter of the repair hole, the thickness of the glass substrate, and the angle of inclination of the repair hole to be formed by the laser beam. Claim 2 delete Claim 3 A glass substrate repair method according to claim 1, wherein the inspection step is characterized by inspecting the upper diameter of a via hole formed in a glass substrate to determine whether it is a normal hole or a defective hole. Claim 4 delete Claim 5 delete Claim 6 A glass substrate repair method according to claim 1, characterized in that the laser beam for repairing the defective hole is emitted from an excimer laser. Claim 7 delete Claim 8 delete Claim 9 A glass substrate repair method according to claim 1, further comprising a masking step performed prior to the repair step, wherein a mask having a mask hole corresponding to the dimensions of the repair hole is placed on the upper side of the glass substrate.

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