Processing method and laser processing device

Abstract

To provide a processing method capable of precisely processing a hole with a minute step.SOLUTION: A method of processing a hole with a step in a workpiece is for forming a hole H with a step in a workpiece having a predetermined thickness from a first surface to a second surface, and includes: a first step of irradiating a first surface of the workpiece with laser light L to form a through hole penetrating from the first surface to the second surface of the workpiece with a first diameter; and a second step of inserting a distal end of a drill D into the through hole having the first diameter and forming a hole having a second diameter larger than the first diameter in the workpiece in a thickness direction of the workpiece.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a processing method and a laser processing apparatus. [Background technology]

[0002] Patent Document 1 discloses a machining method that can machine a through-hole with a small inner diameter without generating burrs. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-203332 [Patent Document 2] Patent No. 6910086 specification Summary of the Invention [Problem to be solved by the invention]

[0004] Probe cards and other devices used in testing electronic components often require highly accurate, fine stepped holes. Generally, stepped holes are formed by drilling multiple times using drills of different diameters. However, drill diameters that meet the required hole dimensions are very thin and prone to bending. This can lead to problems such as drill bending during the drilling process, reducing the drilling accuracy and the concentricity of the large-diameter and small-diameter holes.

[0005] Therefore, an object of the present disclosure is to provide a processing method and a laser processing apparatus that can accurately process minute stepped holes. [Means for solving the problem]

[0006] A processing method according to one aspect of the present invention includes: A processing method for forming a stepped hole in a workpiece having a predetermined thickness from a first surface to a second surface, a first step of irradiating the first surface of the workpiece with laser light to form a through hole having a first diameter that penetrates from the first surface to the second surface of the workpiece; a second step of inserting a tip of a drill into the through hole of the first diameter to form a hole of a second diameter in the thickness direction of the workpiece, the second diameter being larger than the first diameter; Equipped with.

[0007] Furthermore, a laser processing apparatus according to one aspect of the present invention includes: A laser processing device for forming a stepped hole in a workpiece having a predetermined thickness from a first surface to a second surface, a first step of irradiating the first surface of the workpiece with laser light to form a through hole having a first diameter that penetrates from the first surface to the second surface of the workpiece; a second step of inserting a tip of a drill into the through hole of the first diameter to form a hole of a second diameter in the thickness direction of the workpiece, the second diameter being larger than the first diameter; It is used in a processing method having the following. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a processing method and a laser processing device that can accurately process a minute stepped hole. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram of a processing device according to this embodiment. [Figure 2] FIG. 2 is a schematic diagram of the laser processing unit according to this embodiment. [Figure 3] FIG. 3 is a schematic view of the drilling section according to this embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing an example of inspecting an electronic component using a probe card. [Figure 5] FIG. 5 is a cross-sectional view showing a method for forming a stepped hole according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Fig. 1 is a block diagram of a processing device 1 according to this embodiment. As shown in Fig. 1, the processing device 1 includes a laser processing unit 2, a drill processing unit 3, a workpiece support unit 4, and a control unit 5. The control unit 5 controls the laser processing unit 2, the drill processing unit 3, and the workpiece support unit 4.

[0011] FIG. 2 is a schematic diagram of the laser processing unit 2 and workpiece support unit 4 according to this embodiment. As shown in FIG. 2, the laser processing unit 2 is used in a manner that irradiates laser light L onto a workpiece W fixed to the workpiece support unit 4. As shown in FIG. 2, the workpiece support unit 4 has a fixed stage 101 and a movable stage 102. The movable stage 102 can move the workpiece W to be processed on the fixed stage 101 in the left-right, depth, and up-down directions of the plane of FIG. 2. The laser processing unit 2 in this embodiment can irradiate laser light L onto the workpiece W to drill a hole in the workpiece W.

[0012] The illustrated laser processing unit 2 emits laser light L downward. The laser processing unit 2 has an oscillator 10 and a processing head 20. The oscillator 10 oscillates the laser light L to be irradiated onto the workpiece W. The processing head 20 has a focusing lens and a holder. The processing head 20 adjusts the focusing range of the laser light L oscillated by the oscillator 10 and can guide the laser light L to the workpiece W. In the following description, the emission direction of the laser light L may be referred to as the optical axis L1. The laser processing unit 2 in this embodiment has a scanning unit 30 between the oscillator 10 and the processing head 20. The scanning unit 30 is composed of a galvano optical system or the like and adjusts the irradiation direction of the laser light L. The control unit 5 controls the operation of the oscillator 10 and the scanning unit 30.

[0013] 3 is a schematic diagram of the drilling unit 3. The drilling unit 3 has a main body 50 and a drill D. In this embodiment, the drill D is made of metal. The main body 50 holds the drill D and has a motor for rotating the drill D. The control unit 5 can adjust the rotation speed of the drill D and the vertical movement speed of the drill D via the main body 50.

[0014] As shown in Fig. 3, the drilling unit 3 is used in such a manner that a drill D is pressed vertically against a workpiece W fixed to a workpiece support unit 4 while rotating, thereby drilling a hole in the workpiece W. The workpiece support unit 4 and workpiece W shown in Fig. 3 are the same as the workpiece support unit 4 and workpiece W shown in Fig. 2.

[0015] In the processing method according to this embodiment, the laser processing unit 2 and the drill processing unit 3 process a stepped hole in the same workpiece W fixed to the workpiece support unit 4 using two processing methods, a laser beam L and a drill D. In this disclosure, a "stepped hole" refers to a through hole drilled in the workpiece, which has at least two or more portions with different diameters at different positions in the depth direction of the hole.

[0016] Fig. 4 is a cross-sectional view showing an example of inspecting an electronic component T using a probe card. As shown in Fig. 4, in the probe card used to inspect the electronic component T, pin-shaped probes P provided on the probe card are inserted into stepped holes H provided in a wiring board inspection jig WA to inspect the electrical state of the electronic component. Fig. 4 is a cross-sectional view showing an example of inspecting an electronic component using a probe card. As shown in Fig. 4, when the probe P of the probe card is inserted into the stepped holes H, a tip P1 thereof slightly protrudes from the wiring board inspection jig WA so as to be able to abut against the electronic component T.

[0017] High precision is required for the stepped holes H formed in the wiring board inspection jig WA used to inspect electronic components T. "High precision" here refers to the high degree of coincidence of the centers of the holes of multiple diameters formed in the stepped holes H (high concentricity) and the fact that each of the holes of multiple diameters is close to a cylindrical shape (high cylindricity). In other words, this refers to the accuracy of the positions of the holes of multiple diameters (high hole position precision) and the accuracy of the hole diameters of the holes of multiple diameters (high hole diameter precision). If the concentricity of the stepped hole H is low, when the probe P is inserted into the stepped hole, the tip P1 of the probe P may get caught halfway inside the stepped hole H. Also, if the cylindricity of the stepped hole H is low, the probe P may not be able to be inserted perpendicularly into the wiring board inspection jig WA, which may cause problems such as the tip P1 of the probe P not being able to protrude from the wiring board inspection jig WA.

[0018] Generally, a stepped hole H can be machined using multiple drills D of different diameters. However, when the diameter of the stepped hole is small, it is necessary to use a drill D with a small drill diameter. Because such a thin drill D has low strength, there is a problem in that the drill D is prone to bending during machining, making it difficult to perform high-precision machining.

[0019] A processing method according to the present disclosure that solves the above problems will be described with reference to Fig. 5. Fig. 5 is a cross-sectional view showing a method for processing a stepped hole according to this embodiment, with (A) showing during laser processing, (B) showing after laser processing, (C) showing during drilling, and (D) showing after drilling. In this embodiment, a stepped hole H is created in a workpiece W, which is composed of a first hole H1 with a diameter R1 and a second hole H2 with a diameter R2 larger than that of the first hole H1.

[0020] 5A and 5B, a laser beam L is irradiated onto one surface of the workpiece W to form a first hole H1 having a diameter R1 that penetrates the workpiece W. At this time, the laser beam L is irradiated so that the first hole H1 is formed perpendicular to the surface of the workpiece W.

[0021] Next, as shown in Figures 5C and 5D, a second hole H2 having a diameter R2 and a predetermined length is formed in the workpiece W by the drilling unit 3. At this time, processing is started with the tip of the drill D inserted into the already drilled first hole H1, and processing is performed so that the center line of the second hole H2 formed by the drill D and the center line of the first hole H1 formed by the laser light L are the same center line (center line C in Figure 5D). The drilling unit 3 drills the first hole H1, which has already been drilled with the laser beam L, for a predetermined length so that the hole diameter is expanded to R2, and then the drilling is terminated. This allows a stepped hole H to be formed in the workpiece W.

[0022] According to the processing method of the present disclosure, a small diameter hole (first hole H1) is first drilled with laser light L, and the through hole is used as a pilot hole, and then a large diameter hole (second hole H2) is drilled with a drill D. As a result, when drilling the second hole H2, the drilling progresses along the laser-machined pilot hole, improving the concentricity of the small diameter hole and the large diameter hole. This makes it possible to provide a processing method that can accurately drill a fine stepped hole.

[0023] Furthermore, if a small-diameter drill D is used, the strength of the drill may be insufficient, and the machining accuracy of the hole to be created, such as cylindricity, may decrease. According to the machining method of the present disclosure, small-diameter holes are machined using laser light L, so there is no need to use a drill D suitable for small-diameter holes. In other words, because the small-diameter hole (first hole H1) is machined by irradiating it with laser light L, the cylindricity and straightness of the machined hole can be improved compared to when a drill D suitable for small-diameter holes is used, and it is possible to provide a machining method capable of machining a fine stepped hole with high accuracy.

[0024] Furthermore, according to the processing method of the present disclosure, the small diameter hole (first hole H1) is first processed by the laser beam L. As a result, when the large diameter hole (second hole H2) is processed, the peripheral speed of the drill D is slow and the central portion, which is inefficient in processing, has already been removed, improving processing efficiency and reducing the amount of wear on the drill D that accompanies processing. As a result, the life of the drill D can be extended.

[0025] Furthermore, according to the present disclosure, the second hole H2 is drilled with the drill D inserted into the first hole H1, which has a smaller diameter than the second hole already drilled in the workpiece. This makes it possible to improve the concentricity of the first hole H1 and the second hole H2.

[0026] Furthermore, according to the present disclosure, the thickness of the workpiece (workpiece W) may be 0.5 mm or less, and the ratio of the diameter of the first hole H1 to the thickness may be 1 / 3. The processing method according to the present disclosure is particularly effective when the ratio of the small diameter of the through hole to the thickness is 1 / 3.

[0027] Furthermore, according to the present disclosure, it is preferable that the inner peripheral wall of the through hole of the first diameter (first hole H1) and the inner peripheral wall of the hole of the second diameter (second hole H2) extend substantially parallel to each other.

[0028] The processing method according to the present disclosure is particularly effective when applied to insulating materials such as insulating resins and ceramics.

[0029] In wiring board inspection jigs such as probe cards used to inspect electronic components that are expected to be processed by the processing method according to the present disclosure, high concentricity and high cylindricity are required for the stepped holes H. However, holes that are typically formed by simply irradiating a workpiece W with laser light L often have a tapered shape.

[0030] Therefore, in the processing method according to the present disclosure, it is desirable to irradiate the laser beam L onto the workpiece W while rotating it. This makes it possible to form a through-hole with higher cylindricity than when the laser beam L is simply irradiated perpendicularly onto the workpiece W.

[0031] As a processing method for irradiating laser light L while rotating it, for example, the laser irradiation method disclosed in Patent Document 2 can be adopted. In the laser irradiation method disclosed in Patent Document 2, the laser light can be rotated and emitted by a beam rotator. The scanning unit 30 mounted on the laser processing unit 2 according to the present disclosure may be equipped with the beam rotator disclosed in Patent Document 2.

[0032] Although the embodiments of the present disclosure have been described above, it goes without saying that the technical scope of the present disclosure should not be interpreted as being limited by the description of the present embodiments. The present embodiments are merely examples, and it will be understood by those skilled in the art that various modifications of the embodiments are possible within the scope of the invention described in the claims. The technical scope of the present disclosure should be determined based on the scope of the invention described in the claims and its equivalents.

[0033] In the above-described embodiment, an example has been described in which the processing device 1 is provided with a common control unit 5 that controls both the laser processing unit 2 and the drill processing unit 3, but the present invention is not limited to this. The processing device may be configured to include a laser processing unit that includes a control unit that controls the oscillation and irradiation direction of the laser light, and a drill processing unit that includes a control unit that controls the rotation speed and feed motion of the drill.

[0034] In the above-described embodiment, an example has been described in which the machining device 1 has a workpiece support section 4 that is common to the laser machining section 2 and the drill machining section 3, but the present invention is not limited to this. The section that supports the workpiece W in the laser machining section 2 and the section that supports the workpiece W in the drill machining section 3 may be configured separately.

[0035] Alternatively, the laser processing unit 2 may be configured as a single laser processing machine that performs only the laser processing of the processing method of the present disclosure, and a drill processing machine configured separately from the laser processing machine may be used to perform drilling on the workpiece W that has been laser processed by this laser processing machine. In this case, the processing device 1 may also be expressed as a processing system including the laser processing machine and the drill processing machine. [Explanation of symbols]

[0036] 1 Processing equipment 2 Laser processing section 3 Drilling section 4 Work support part 5. Control section 10 Oscillators 20 Processing head 30 Scanning unit 40 Galvano Optical System 50 Main body 101 Fixed Stage 102 Moving Stage H1 first hole H2 second hole P1 tip R1,R2 diameter

Claims

1. A processing method for forming a stepped hole in a workpiece having a predetermined thickness from a first surface to a second surface, a first step of irradiating the first surface of the workpiece with laser light to form a through hole having a first diameter that penetrates from the first surface to the second surface of the workpiece; a second step of inserting a tip of a drill into the through hole of the first diameter to form a hole of a second diameter in the thickness direction of the workpiece, the second diameter being larger than the first diameter; A method for machining a stepped hole in a workpiece, comprising:

2. The thickness of the workpiece is 0.5 mm or less, The processing method according to claim 1 , wherein a ratio of the first diameter of the through hole to the thickness is 1 / 3 or less.

3. The processing method according to claim 1 or 2, wherein an inner peripheral wall of the through hole of the first diameter and an inner peripheral wall of the hole of the second diameter extend substantially parallel to each other.

4. In the first step, the first surface is irradiated with laser light; The processing method according to claim 1 or 2, wherein in the second step, a tip of the drill is inserted into the through hole opened in the second surface.

5. A wiring board inspection jig comprising the workpiece processed by the processing method according to claim 1 or 2.

6. A laser processing device for forming a stepped hole in a workpiece having a predetermined thickness from a first surface to a second surface, a first step of irradiating the first surface of the workpiece with laser light to form a through hole having a first diameter that penetrates from the first surface to the second surface of the workpiece; a second step of inserting a tip of a drill into the through hole of the first diameter to form a hole of a second diameter in the thickness direction of the workpiece, the second diameter being larger than the first diameter; A laser processing device used in a processing method having the above-mentioned steps.

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