Hole inspection device

Abstract

The present invention relates to a hole inspection device. According to one embodiment of the present invention, the hole inspection device comprises: a lighting unit for emitting light to a to-be-inspected object including a hole; an optical unit including a dark field optical system for detecting the light emitted from the lighting unit and scattered and reflected from the hole of the to-be-inspected object; and a detection unit for detecting the scattered and reflected light. The light is a line beam.

Description

Hall inspection device

[0001] The present invention relates to a hole inspection device.

[0002] Through glass vias (TGVs) are fine conductive holes (vias) ranging in size from tens to hundreds of micrometers (μm) formed in a glass substrate, and are utilized in various industries such as semiconductor packaging, optical modules, MEMS, and RF modules. The TGV process requires highly precise manufacturing technology, and it is essential to inspect the diameter, depth, positional accuracy, shape, and presence of defects of the holes.

[0003] In fact, defective TGVs cause electrical short circuits or open circuits, which increase the failure rate. In parts requiring electrical connections, the uniformity inside the hole and the quality of the insulation layer directly affect the signal transmission quality. Since uneven hole diameter and depth can lead to increased signal loss and failures, inspection technology for hole size imbalance, wall defects, contamination, cracks, etc., that may occur during processing is a very important technology.

[0004] In particular, since TGV manufacturing is a high-throughput process, it must be inspected at a high speed.

[0005] Traditional microscopic inspection methods are too slow to perform high-speed inspections, while general machine vision systems capable of high-speed inspection struggle to detect hole boundaries due to the transparency of glass substrates. Confocal laser microscopy allows for high-resolution measurement of hole depth, wall quality, and shape, but it suffers from the disadvantage of very slow inspection speeds, whereas White Light Interferometry (WLI) has difficulty detecting defects on the sides of holes.

[0006] Although much research is being conducted on TGV inspection methods, effective inspection methods have not yet been developed.

[0007] The aforementioned background technology is one that the inventor possessed or acquired in the process of deriving the disclosure of the present invention, and it cannot be considered as prior art disclosed to the general public prior to the filing of this application.

[0008] The present invention is intended to solve the aforementioned problems, and the objective of the present invention is to provide a hole inspection device that can measure the shape and size of a hole in an object to be inspected in a simple way and quickly detect defects (breakage, crack, foreign matter, etc.) that occur in the hole.

[0009] However, the problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below.

[0010] A hole inspection device according to one embodiment of the present invention comprises: an illumination unit that irradiates light onto an object to be inspected that includes a hole; an optical unit that includes a dark field optical system that detects light irradiated from the illumination unit and scattered and reflected from the hole of the object to be inspected; and a detection unit that detects the scattered and reflected light, wherein the light is a line beam.

[0011] In one embodiment, the object to be inspected may include a glass substrate, a plastic substrate, or both.

[0012] In one embodiment, the line beam may be irradiated in a direction inclined at an angle of 45° or less with respect to the object to be inspected.

[0013] In one embodiment, the line beams are a plurality of lines, and the plurality of line beams may be irradiated to intersect each other on the object to be inspected.

[0014] In one embodiment, the line beam is two, and on the object to be inspected It is irradiated in a U-shape, or the line beam is three, and on the object to be inspected It may be investigated in the shape of a letter.

[0015] In one embodiment, the center where the line beams overlap may be such that the remaining line beams are blocked, excluding one line beam.

[0016] In one embodiment, the illumination unit and the dark field optical system may be arranged so that zero-order light, which is irradiated from the illumination unit and specularly reflected from the object to be inspected, is not incident.

[0017] In one embodiment, the dark field optical system may be a Scheimpflug configuration.

[0018] In one embodiment, the dark field optical system may be telecentric in the thickness direction (y-axis direction) of the object to be inspected.

[0019] In one embodiment, the dark field optical system may be telecentric in a direction perpendicular to the thickness of the object to be inspected (x-axis direction).

[0020] In one embodiment, it may further include a bright field optical system that detects a portion of zero-order light that is irradiated from the lighting unit and specularly reflected from the object to be inspected.

[0021] In one embodiment, the optical part may include at least one selected from a laser, a laser diode (LD), a light-emitting diode (LED), or a lamp.

[0022] In one embodiment, the detection unit may include a Charge Coupled Device (CCD) image sensor.

[0023] A hole inspection device according to one embodiment of the present invention can rapidly inspect the diameter, depth, shape, circularity, taper angle, etc. of a hole in an object. In addition, it is possible to inspect manufacturing precision, contamination and foreign substances, internal residue, metal contamination, cracks and fissures inside the glass and on the hole wall, and alignment precision.

[0024] FIG. 1 is a schematic diagram showing a hole inspection device according to one embodiment of the present invention.

[0025] FIGS. 2 to 5 are drawings showing a lighting unit configured in various ways for a hole inspection device according to an embodiment of the present invention. The arrow indicates the direction of the object to be inspected (200).

[0026] FIGS. 6 and 7 are schematic diagrams illustrating the configuration of a dark field optical system according to one embodiment of the present invention.

[0027] Hereinafter, embodiments are described in detail with reference to the attached drawings. However, various modifications may be made to the embodiments, and thus the scope of the patent application is not limited or restricted by these embodiments. It should be understood that all modifications, equivalents, and substitutions to the embodiments are included within the scope of the rights.

[0028] The terms used in the embodiments are for illustrative purposes only and should not be interpreted as intended to be limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0029] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the embodiments pertain. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0030]

[0031] In addition, when describing with reference to the attached drawings, identical components are assigned the same reference numeral regardless of drawing symbols, and redundant descriptions thereof are omitted. In describing the embodiments, if it is determined that a detailed description of related prior art could unnecessarily obscure the essence of the embodiments, such detailed description is omitted.

[0032] In addition, terms such as first, second, A, B, (a), (b), etc. may be used when describing the components of the embodiments. These terms are used merely to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by the terms.

[0033] Components included in any one embodiment and components having common functions shall be described using the same names in other embodiments. Unless otherwise stated, the description in any one embodiment may also apply to other embodiments, and specific descriptions shall be omitted to the extent of overlap.

[0034]

[0035] Hereinafter, the hole inspection device of the present invention will be described in detail with reference to the embodiments and drawings. However, the present invention is not limited to these embodiments and drawings.

[0036]

[0037] A hole inspection device according to one embodiment of the present invention comprises: an illumination unit that irradiates light onto an object to be inspected that includes a hole; an optical unit that includes a dark field optical system that detects light irradiated from the illumination unit and scattered and reflected from the hole of the object to be inspected; and a detection unit that detects the scattered and reflected light.

[0038] A hole inspection device according to one embodiment of the present invention detects defects (breakage, foreign matter, etc.) in a hole, and since the surface of the hole is not polished like a glass substrate but has a rough surface, information about the shape of the hole can be obtained from scattered light generated from such a rough surface.

[0039] A hole inspection device according to one embodiment of the present invention may measure the shape and size of a hole and detect defects (breakage, cracks, foreign matter, etc.) occurring in the hole. Additionally, since the scattering intensity changes when plating is partially applied to the hole, it is possible to measure plating defects as well.

[0040] FIG. 1 is a schematic diagram showing a hole inspection device according to one embodiment of the present invention.

[0041] Referring to FIG. 1, a hole inspection device (100) according to one embodiment of the present invention includes a lighting unit (110), an optical unit (120), and a detection unit (130).

[0042] The above lighting unit (110) irradiates light onto an inspection target (200) that includes a hole.

[0043] The above inspection target (200) may include a glass substrate, a plastic substrate, or both.

[0044] The hole in the above-mentioned object (200) may be a through glass via (TGV).

[0045] The light may be a line beam. Since the line beam obtains an image through scanning of the optical unit (120) or the object to be inspected (200), measurement can be performed at a high speed.

[0046] The above line beam is basically a line beam perpendicular to the scanning direction, and if necessary, the lime beam can be tilted or multiple multi-lime beams can be used. In this case, the tilted angle is not very significant.

[0047] FIGS. 2 to 5 are drawings showing a lighting unit configured in various ways for a hole inspection device according to an embodiment of the present invention. The arrow indicates the direction of the object to be inspected (200).

[0048] As shown in FIG. 2, the line beam irradiating the lighting unit (110) may be perpendicular to the object to be inspected (200).

[0049] As shown in FIG. 3, the line beam may be irradiated at a predetermined angle with respect to the object to be inspected (200).

[0050] Specifically, the line beam may be irradiated in a direction inclined at an angle of 45° or less with respect to the object to be inspected (200). It is a zero-order beam, that is, light irradiated at an angle in which specularly reflected light is not incident on the Hall detection optical system.

[0051] As shown in FIGS. 4 and 5, the line beam may be multiple. Multiple line beams can inspect defects in the object to be inspected more clearly, thereby increasing the reliability of image detection.

[0052] The plurality of line beams may be irradiated to intersect each other on the object to be inspected (200).

[0053] As shown in FIG. 4, the line beam is two, and on the inspection target (200) It may be investigated in the shape of a letter.

[0054] As shown in FIG. 5, the line beams are three in number and on the inspection target (200). It may be investigated in the shape of a letter.

[0055] If necessary, four or more line beams can be irradiated to intersect each other at regular angle intervals.

[0056] The center where the above line beams overlap may be a place where the remaining line beams are blocked, except for one line beam. This is because the center where the line beams overlap becomes relatively brighter.

[0057] The configuration of the above lighting unit (110) can be configured in various ways depending on the arrangement of holes in the object to be inspected (200), in addition to the configuration shown in FIGS. 2 to 5.

[0058] The optical unit (120) includes a dark field optical system that detects light scattered and reflected from the hole of the object to be inspected, which is irradiated from the lighting unit (110).

[0059] There are two main methods for optically inspecting for defects within an object. These are classified into the Bright Field method, which illuminates the area to be inspected and uses the reflected light to check for defects, and the Dark Field method, which uses diffusely reflected light. The Dark Field method receives the reflected and scattered light at the inspection unit and identifies points exceeding a certain intensity as defects.

[0060] The scattered light mentioned above may be light that is not specular reflection of the zeroth order.

[0061] The above dark field optical system can be used primarily to inspect an object to be inspected (200) when a defect occurs due to foreign substances being mixed in. Additionally, if there is no defect on the wall surface of the hole, most of the light irradiated onto the object to be inspected by the dark field optical system is reflected and does not enter the detection unit (130). On the other hand, if there is a defect, the light irradiated onto the object to be inspected by the dark field optical system is diffusely reflected at the defect area and enters the detection unit (130).

[0062] Accordingly, the detection unit (130) can analyze whether a defect exists in the object to be inspected and, if so, the location of the defect based on the amount of light received and the intensity of light received.

[0063] The above lighting unit (110) and the dark field optical system may be positioned so that zero-order light, which is irradiated from the lighting unit (110) and specularly reflected from the object to be inspected, is not incident. By installing the optical system at an angle rather than perpendicular to the substrate to obtain an image of the hole, and illuminating in a direction such that zero-order light is not incident on the optical system to form a dark field, only the light scattered at the boundary of the hole can be collected to secure the boundary of the hole and the defect.

[0064] When the diameter of the hole of the above-mentioned object (200) is 10 μm or more, scattering is expected to be mainly Mie scattering, so it is advantageous to configure the angle of incidence to be as small as possible so that zero-order light does not enter the optical system.

[0065] The above dark field optical system may be a Scheimpflug configuration. Since the dark field optical system is positioned at an angle relative to the substrate, it must be configured as a Scheimpflug.

[0066] FIGS. 6 and 7 are schematic diagrams illustrating the configuration of a dark field optical system according to one embodiment of the present invention.

[0067] As shown in FIG. 6, the dark field optical system may be telecentric in the thickness direction (y-axis direction) of the object to be inspected (200).

[0068] As shown in FIG. 7, the dark field optical system may be telecentric in a direction perpendicular to the thickness of the object to be inspected (x-axis direction). In the case of a telecentric configuration, it has the advantage that there is no change in magnification with respect to changes in the position of the hole of the object to be inspected (200) that may change during the measurement process.

[0069] In one embodiment, it may further include a bright field optical system that detects a portion of zero-order light that is irradiated from the lighting unit (110) and specularly reflected from the object to be inspected (200).

[0070] Bright field optical systems can be primarily used to inspect inherent defects of the object being inspected (e.g., pattern anomalies).

[0071] In one embodiment, the optical part (120) may include at least one selected from a laser, a laser diode (LD), a light-emitting diode (LED), or a lamp.

[0072] The above detection unit (130) detects scattered and reflected light.

[0073] The detection unit (130) can obtain a light signal by detecting light scattered by foreign matter present in the hole of the object to be inspected (200) or by the rough surface of the hole. When foreign matter in the hole of the object to be inspected (200) is exposed to laser light, light scattering occurs and the scattered light reaches the detection unit (130). Unlike when there is no foreign matter, strong scattered light reaches the unit, and through this, the presence of foreign matter can be detected.

[0074] The above detection unit (130) may include a Charge Coupled Device (CCD) image sensor that images the interference pattern of light.

[0075] The above CCD image sensor includes a plurality of photodiodes and can generate an image (captured image) based on the amount of electrons generated according to the amount of light (light intensity) incident on the photodiodes.

[0076] A hole inspection device according to one embodiment of the present invention can rapidly inspect the diameter, depth, shape, circularity, taper angle, etc. of a hole in an object. In addition, it is possible to inspect manufacturing precision, contamination and foreign substances, internal residue, metal contamination, cracks and fissures inside the glass and on the hole wall, and alignment precision.

[0077]

[0078] Although the embodiments have been described above with reference to the limited drawings, those skilled in the art can apply various technical modifications and variations based on the above. For example, suitable results may be achieved even if the described techniques are performed in a different order than described, and / or if the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents.

[0079] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below.

Claims

1. A lighting unit that irradiates light onto an object to be inspected, including a hole; An optical unit comprising a dark field optical system that detects light irradiated from the illumination unit and scattered and reflected from the hole of the inspection target; and A detection unit for detecting the scattered and reflected light mentioned above; Includes, The above light is a line beam, Hole inspection device.

2. In Paragraph 1, The above inspection subject is, A glass substrate, a plastic substrate, or a combination of both. Hole inspection device.

3. In Paragraph 1, The above line beam is, The above-mentioned inspection target being irradiated in a direction tilted at an angle of 45° or less, Hole inspection device.

4. In Paragraph 1, The above line beam is multiple, and The above plurality of line beams, That which is investigated to intersect with one another on the above-mentioned inspection target, Hole inspection device.

5. In Paragraph 1, The above line beams are two in number, and on the object to be inspected Investigated in the shape of a letter, The above line beams are three in number, and on the object to be inspected That which is investigated in the shape of a letter, Hole inspection device.

6. In Paragraph 4 or 5, The center where the above line beams overlap is, Blocking of the remaining line beams except for one line beam, Hole inspection device.

7. In Paragraph 1, The above lighting unit and the above dark field optical system are arranged so that zero-order light, which is irradiated from the lighting unit and specularly reflected from the object to be inspected, is not incident. Hole inspection device.

8. In Paragraph 1, The above dark field optical system is a Scheimpflug configuration, Hole inspection device.

9. In Paragraph 1, The above dark field optical system is configured to be telecentric in the thickness direction (y-axis direction) of the object to be inspected. Hole inspection device.

10. In Paragraph 1, The above dark field optical system is configured to be telecentric in a direction perpendicular to the thickness of the object to be inspected (x-axis direction). Hole inspection device.

11. In Paragraph 1, The bright field optical system further includes a portion of zero-order light that is irradiated from the lighting unit and specularly reflected from the object to be inspected. Hole inspection device.

12. In Paragraph 1, The above optical unit is, A comprising at least one selected from a laser, a laser diode (LD), a light-emitting diode (LED), or a lamp, Hole inspection device.

13. In Paragraph 1, The above detection unit includes a Charge Coupled Device (CCD) image sensor. Hole inspection device.

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