TGV Substrate Metal Pillar Defect Inspection System Using Multiple Inspection Modules and Control Method Thereof

Abstract

The present invention relates to a system for inspecting defects in metal pillars within a TGV substrate using multiple inspection modules and a control method thereof. The control method of the system for inspecting defects in metal pillars within a TGV substrate using multiple inspection modules comprises the steps of: preparing a substrate having a plurality of via holes formed therein (S1); forming pillars by filling material into the via holes of the substrate (S2); placing the substrate on a stage containing a signal generator that operates by an electrical signal, at a predetermined distance from the signal generator (S3); moving an inspection module that detects a change in an electrical signal by the electrical signal in a vertical and horizontal direction on the upper side of the substrate (S4); positioning the inspection module at least one of the pillars at a predetermined distance (S5); and detecting a change in capacitance passing through the pillar by applying an electrical signal from the signal generator when the inspection module is positioned on the pillar (S6). In this method, an electrical signal is applied from the lower surface of the substrate through a signal generator embedded in the stage, and the substrate By applying a through-type measurement structure that measures using a capacitance sensor on the top surface, defects such as internal bubbles, electrical discontinuities, and density non-uniformity, which were impossible to detect with conventional optical inspection, can be precisely detected in a non-contact and non-destructive manner, thereby reducing costs and time. Furthermore, since external and internal defects of the pillars can be detected through a single module using a capacitance sensor, a visible light optical system, or an X-ray method, the risk of contamination or damage to the substrate is eliminated, and the Turnaround Time (TAT) can be significantly shortened.

Description

Technology Field

[0001] The following embodiments relate to a metal pillar defect inspection system within a TGV substrate using multiple inspection modules and a control method thereof. Background Technology

[0003] In accordance with the recent trend of miniaturization in semiconductor packaging technology, via holes formed on a substrate are filled with a material having high thermal conductivity (hereinafter referred to as "pillars") to serve as electrical connection paths. The shape precision of these pillars is directly related to the electrical reliability, thermal characteristics, and mechanical bonding strength of the package.

[0004] For example, the TGV manufacturing process is largely composed of a via processing step for forming through holes in a glass substrate, a seed layer formation step for coating the inner walls of the through holes with a conductive metal, a plating step for forming pillars by filling the inside of the through holes with a metal such as copper, and an inspection step for checking the quality of the filled pillars.

[0005] In the via processing step, through holes having an hourglass-shaped cross-section are formed through laser drilling and wet etching, with larger diameters on the upper and lower surfaces of the glass substrate and a narrower diameter in the middle. Subsequently, in the plating step, metal material is filled into these through holes to form metal pillars, which serve as electrical connection paths between the upper chip and the lower substrate.

[0006] According to this, there is an advantage in that the hourglass-shaped cross-sectional dimensions inside the through hole can be rapidly measured using a non-contact optical method by utilizing the transparency of the glass substrate, but there was also a problem in that it was difficult to inspect defects in the metal material filled inside the pillar, that is, the via hole. In other words, when metal material is filled into the through hole of the glass substrate, the transparency of the glass is blocked, so there was a problem in that the transmitted light-based optical inspection method itself was fundamentally impossible to apply.

[0007] In addition, conventional methods had a fundamental limitation in that they could not detect defects such as voids, underfills, or seed layer defects occurring inside the column by observing only the external shape of the column as a two-dimensional image.

[0008] In addition, since the number of through holes formed on a single TGV glass substrate ranges from hundreds of thousands to up to 2 million, separate 3D measuring equipment (white light interferometer, confocal microscope, etc.) is required to individually and precisely measure the height of the pillars, which leads to excessive inspection time and increased costs. Prior art literature

[0010] 1. Republic of Korea Patent Application No. 10-2025-0026852 (March 5, 2025) 2. Republic of Korea Patent Application No. 10-2025-0083994 (June 25, 2025) The problem to be solved

[0011] The present invention provides a metal pillar defect inspection system for a multi-inspection module TGV substrate and a control method thereof, which can detect defects such as height defects, surface shape distortions, and internal bubbles of fine metal pillars formed on a substrate in a non-contact and non-destructive manner within a single integrated system.

[0012] However, the technical problems that the embodiments aim to solve are not limited to the technical problems described above, and other technical problems may exist. means of solving the problem

[0014] The present invention relates to a metal pillar defect inspection system within a TGV substrate using multiple inspection modules and a control method thereof. The control method of the metal pillar defect inspection system within a TGV substrate using multiple inspection modules comprises: a step of preparing a substrate having a plurality of via holes formed therein (S1); a step of forming pillars by filling material into the via holes of the substrate (S2); a step of placing the substrate on a stage containing a signal generator that operates by an electrical signal, at a predetermined distance from the signal generator (S3); a step of moving an inspection module that detects a change in an electrical signal by the electrical signal in a vertical and horizontal direction on the upper side of the substrate (S4); a step of positioning the inspection module at least one of the pillars at a predetermined distance (S5); and a step of detecting a change in capacitance passing through the pillar by applying an electrical signal from the signal generator when the inspection module is positioned on the pillar (S6).

[0015] Additionally, the inspection module may include a control unit that includes a fixed part comprising a sensor provided on the leading end facing the substrate, and applies either a direct current or alternating current signal through the signal generator to energize the pillar of the substrate, receives the energization value measured by the sensor, and compares it with a preset value to determine whether the pillar is defective.

[0016] Additionally, the stage comprises a main body, a substrate mounting portion formed facing each other on the main body, and an optical system for capturing images of the mark portion and the substrate on the main body; and the control unit may include an alignment mode that receives an image from the optical system and determines whether the substrate is located within a preset threshold value in the mark portion, and a notification mode that provides a notification to an external user device if the substrate falls outside the threshold value according to the alignment mode.

[0017] Additionally, the device includes a gantry unit that slides in the longitudinal direction on the main body, and the inspection module includes a body part that slides in the width direction on the main body from the gantry unit, and a lifting part connected to the fixed part to raise and lower on the body part, and the sensor includes at least one of a capacitance sensor, a visible light optical system sensor, and a CT X-ray module, and the control unit can slide the gantry unit and the lifting part to correspond to a column within the substrate to receive data from at least one of a visible light optical system or a CT X-ray and extract the shape of the column.

[0018] In addition, the stage may include a stage driving unit comprising a tilting part that adjusts the inclination angle of the substrate mounting part by adjusting a plurality of cylinders, each operating in a vertical direction at each corner of the substrate mounting part, to different heights, and a moving part that moves the substrate mounting part in a lateral direction. Effects of the invention

[0020] According to the metal pillar defect inspection system within a TGV substrate using a multi-inspection module of the present invention and the control method thereof, the following effects are achieved.

[0021] First, according to the TGV substrate defect inspection system and control method using a multi-inspection module according to the present invention, by applying a through-type measurement structure in which an electrical signal is applied from the lower surface of the substrate through a signal generator embedded in the stage and measured by a capacitance sensor on the upper surface of the substrate, defects such as internal bubbles, electrical discontinuities, and density non-uniformity, which were impossible to detect with conventional optical inspection, can be precisely detected in a non-contact and non-destructive manner, thereby having the effect of reducing costs and shortening time.

[0022] Secondly, according to the metal pillar defect inspection system and control method within a TGV substrate using a multi-inspection module according to the present invention, external defects and internal defects of the pillars can be detected through a single module using a capacitance sensor, a visible light optical system, or an X-ray method, thereby eliminating the risk of contamination, damage, etc. occurring on the substrate and significantly shortening the inspection processing time (TAT).

[0023] Secondly, according to the metal pillar defect inspection system and control method in a TGV substrate using a multi-inspection module according to the present invention, since the inspection is performed by precisely adjusting the horizontality of the substrate, high-reliability inspection based on the positional precision of the micro-pillars is possible, and the effect of preventing false detection due to misalignment is achieved.

[0024] Thirdly, according to the metal pillar defect inspection system and control method in a TGV substrate using a multi-inspection module according to the present invention, the transmission efficiency of electrical signals and measurement sensitivity are improved by maintaining a constant distance between the capacitance sensor and the substrate, thereby lowering the detection limit of micro-defects and having the effect of lowering the defect rate.

[0025] Fourth, according to the metal pillar defect inspection system and control method in a TGV substrate using a multi-inspection module according to the present invention, the visible light optical system can detect the shape of the pillar in three dimensions in the vertical direction, the inclined direction, or both directions, thereby enabling the detection of surface shape distortion defects and improving accuracy. Brief explanation of the drawing

[0027] FIG. 1 is a flowchart illustrating a metal pillar defect inspection system within a TGV substrate using a multi-inspection module according to one embodiment and a control method thereof. Figure 2 is a block diagram of the system of Figure 1. Figure 3 is a drawing showing a metal column defect inspection system. Figure 4 is a drawing showing a vertical cross-section of the substrate and part of the stage of Figure 3. Figure 5 is a drawing showing the stage drive unit of Figure 3 from the front of the stage. Figure 6 is a drawing shown on the right side of Figure 5. Figures 7 and 8 are drawings showing the vertical drive of the stage in Figure 5. Figures 9 and 10 are drawings illustrating the tilting drive of a stage. Figures 11 and 12 are drawings showing the horizontal movement of the stage. Specific details for implementing the invention

[0028] 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.

[0029] Specific structural or functional descriptions of the embodiments are disclosed for illustrative purposes only and may be modified and implemented in various forms. Accordingly, the embodiments are not limited to the specific disclosed forms, and the scope of this specification includes modifications, equivalents, or substitutions that fall within the technical concept.

[0030] Terms such as "first" or "second" may be used to describe various components, but these terms should be interpreted solely for the purpose of distinguishing one component from another. For example, the first component may be named the second component, and similarly, the second component may be named the first component.

[0031] When it is stated that a component is "connected" to another component, it should be understood that it may be directly connected to or coupled with that other component, or that there may be other components in between.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0036] In the embodiments of the present invention, 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 present invention pertains. 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 the embodiments of the present invention.

[0037] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are exemplary, and therefore the present invention is not limited to the depicted details. Furthermore, in describing the present invention, if it is determined that a detailed description of related known technology may unnecessarily obscure the essence of the present invention, such detailed description is omitted. Where terms such as "includes," "has," or "is made up" are used in this specification, other parts may be added unless "only" is used. Where a component is expressed in the singular, it includes cases where it includes the plural unless specifically stated otherwise.

[0038] In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit statement.

[0039] In the case of describing a positional relationship, for example, when the positional relationship between two parts is described using expressions such as 'on,' 'upper,' 'lower,' or 'next to,' one or more other parts may be located between the two parts unless 'immediately' or 'directly' is used.

[0040] When elements or layers are referred to as "on" another element or layer, this includes cases where another layer or element is placed directly on top of or in between. Throughout the specification, the same reference numerals refer to the same components.

[0041] The size and thickness of each component shown in the drawings are illustrated for convenience of explanation, and the present invention is not necessarily limited to the size and thickness of the illustrated components.

[0042] The features of each of the various embodiments of the present invention may be combined or combined with one another, either partially or wholly, and as will be fully understood by those skilled in the art, various technical interlocking and operation are possible, and each embodiment may be implemented independently of one another or together in an interlocking relationship.

[0043] Hereinafter, a metal pillar defect inspection system within a TGV substrate using a multi-inspection module according to an embodiment of the present invention and a control method thereof will be described with reference to the attached drawings.

[0044] FIG. 1 is a flowchart for explaining a metal pillar defect inspection system within a TGV substrate using a multi-inspection module according to an embodiment and a control method thereof; FIG. 2 is a block diagram of the system of FIG. 1; FIG. 3 is a drawing showing a metal pillar defect inspection system; FIG. 4 is a drawing showing a vertical cross-section of a part of the substrate and stage of FIG. 3; FIG. 5 is a drawing showing the stage driving unit of FIG. 3 from the front of the stage; FIG. 6 is a drawing showing the right side of FIG. 5; FIG. 7 and FIG. 8 are drawings showing the vertical driving of the stage in FIG. 5; FIG. 9 and FIG. 10 are drawings showing the tilting driving of the stage; and FIG. 11 and FIG. 12 are drawings showing the horizontal movement of the stage.

[0045] Referring to FIGS. 1 to 12, an embodiment of a control method for a metal pillar defect inspection system within a TGV substrate using a multi-inspection module according to the present invention is described. The metal pillar defect inspection system within a TGV substrate using a multi-inspection module (hereinafter referred to as the 'inspection system') comprises a substrate (10), a stage (20), a signal generator (30), an inspection module (40), a gantry unit (50), an optical system (60), a stage driving unit (70, 80), and a control unit (C).

[0046] A substrate (10) is a substrate having a plurality of via holes formed therein, and a metal material (e.g., copper (Cu), tin (Sn), nickel (Ni), etc.) may be filled into each via hole to form a metal pillar (11, hereinafter referred to as 'pillar').

[0047] The stage (20) can place a substrate (10) to be inspected. The stage (20) can move the position and horizontally align the substrate (10). The stage (20) includes a main body (21) and a substrate mounting portion (22) on which the substrate (10) is placed.

[0048] The main body (21) includes guide grooves (211) on both sides of one side that guide the gantry unit (50) in the longitudinal direction from both sides, and may include a transfer unit (not shown) inside that moves the gantry unit (50). The transfer unit is driven by a conveyor, and since the driving relationship is similar to that of a conveyor, a detailed description thereof is omitted as it is a known technology.

[0049] The main body (21) may be provided with a groove (201) formed between guide grooves (211) and a substrate mounting portion (22) in the groove (201).

[0050] The substrate mounting portion (22) may include a receiving groove (G1) in which the substrate (10) is mounted and supported, with both sides protruding in the longitudinal direction, and a predetermined distance from the substrate (10) is formed between the two sides.

[0051] The substrate mounting portion (22) may include a signal generator (30) embedded in the receiving groove (G1).

[0052] The signal generator (30) generates a direct current (DC) or alternating current (AC) electric signal, and the generated electric signal is applied to the lower surface of the substrate (10) through the upper surface of the substrate mounting portion (22). The applied electric signal is transmitted along the pillar (m) within the substrate (10) toward the upper surface of the substrate (10).

[0053] Meanwhile, the signal generator (30) may include a common electrode that efficiently transmits an electric signal through a pillar (m) on the lower surface of the substrate (10). The common electrode distributes the electric signal from the signal generator (30) evenly across the entire lower surface of the substrate (10), thereby ensuring uniformity in the application of the electric signal to individual pillars (m).

[0054] Additionally, the substrate mounting portion (22) provides a flat mounting surface for mounting the substrate (10), and a plurality of mark portions (a) formed facing each other are arranged on the mounting surface. The mark portions (a) function as alignment reference points for the substrate (10), and the control unit (C) can determine whether the substrate (10) is aligned through the optical system (60) described later.

[0055] For example, at least two mark portions (a) are arranged near the diagonal corners of the upper surface of the substrate mounting portion (22) to simultaneously detect positional deviation and rotational deviation of the substrate (10).

[0056] The inspection module (40) can be moved on the upper side of the substrate (10) by the gantry unit (50) so as to determine whether there is a defect in the pillar (m) within the substrate (10).

[0057] The inspection module (40) includes a body part (41), a lifting part (42), a fixed part (43), and a sensor (45). The body part (41) can slide in the width direction of the main body (21) in the gantry unit (50).

[0058] The lifting unit (42) can be raised from the body unit (41) by being connected to the fixed unit (43). The lifting unit (42) is equipped with a motor so that the fixed unit (43) can be raised by the motor.

[0059] The fixed part (43) may include a linear or area-type sensor (45) positioned at the lower part of the inspection module (40), that is, on the leading side facing the substrate (10).

[0060] The sensor (45) may be at least one of a capacitance sensor, a visible light optical system sensor, and a CT X-ray module, and two or more may be mounted and operated simultaneously or sequentially to improve precision.

[0061] For example, the capacitance sensor is composed of an array of field sensor pixels, and each pixel individually measures the capacitance formed between the upper end of the pillar (m) on the upper surface of the substrate (10). Accordingly, when the signal generator (30) applies a direct current or alternating current electric signal to the lower surface of the substrate (10) through the upper surface of the stage (20), the applied electric signal is conducted upward along the pillar (m) inside the substrate (10). The capacitance sensor detects the electric field emitted from the top of the column (m) to measure the capacitance value. Normal columns (m1, m2, m4) have a uniform cross-sectional area and height, so they exhibit a constant capacitance value (normal signal level). In contrast, a column (m3) with a height defect has a different distance from the sensor (45), causing the capacitance value to deviate from the normal range. A column (m5) with a surface shape distortion has a fluctuating capacitance value due to asymmetry in the electric field distribution, and a column (m5) with internal bubbles has incomplete electrical signal conduction, causing the capacitance value to decrease compared to normal. The control unit (C) compares the measured capacitance value with a preset value (normal signal level) to determine whether the column (m) is defective and the type of defect.

[0062] In addition, the visible light optical system includes a light source in the visible light band and an image sensor (camera) to optically observe the external shape of the pillar (m). In one embodiment, the visible light optical system module may include a vertical optical system that observes the pillar (m) in a vertical direction (vertically above the substrate) and an inclined optical system that observes it in an inclined direction. The vertical optical system observes the top surface shape and diameter of the pillar (m), and the inclined optical system observes the side shape and verticality of the pillar (m). By observing simultaneously in the vertical and inclined directions, the shape of the pillar (m) can be determined in three dimensions. Furthermore, by operating multiple visible light optical system modules simultaneously to inspect multiple pillars (m) in parallel, the inspection speed can be improved.

[0063] In addition, CT X-ray includes an X-ray source and an X-ray detector, allowing for non-destructive observation of the internal structure of the column (m). In X-ray mode, a transmission image of the column (m) is acquired to determine the presence of internal voids, and in CT mode, the transmission images taken from multiple angles are reconstructed to visualize the three-dimensional internal structure of the column (m).

[0064] Meanwhile, by applying multiple sensors (45) used in the inspection module (40), a multi-stage inspection sequence can be executed in which the external shape of a column (m) is screened first using a visible light optical system sensor in the first inspection stage, electrical characteristics are checked using a capacitance sensor in the second inspection stage for columns suspected of having external defects, and if necessary, the internal structure is precisely analyzed using a CT X-ray in the third inspection stage.

[0065] Meanwhile, the accuracy and sensitivity of the measurement by the capacitance sensor can be improved by a predetermined gap (due to the receiving groove) spaced apart between the substrate (10) and the signal generator (30) and a predetermined gap (G2) between the substrate (10) and the inspection module (40).

[0066] Additionally, a flexible dielectric with a high dielectric constant may be included between the capacitance sensor and the substrate (10). The dielectric enhances the electric field focusing between the sensor (45) and the top of the pillar (m), thereby improving the transmission efficiency of the electric signal and enhancing measurement sensitivity. The dielectric may be formed from a material that combines flexibility and high dielectric constant, such as polyimide (PI), PVDF, or a high dielectric constant ceramic composite film. Due to the flexible nature of the dielectric, even if there are fine curvatures on the upper surface of the substrate (10) or height variations in the pillar (m), it can adhere closely to form a uniform electric field distribution.

[0067] The gantry unit (50) may be provided on the main body (21) so that the inspection module (40) can slide along the longitudinal direction of the main body (21) from the upper side of the substrate (10). The gantry unit (50) may slide along the longitudinal direction by connecting both sides to the guide groove (211) in the width direction of the main body (21).

[0068] The gantry unit (50) may be equipped with a conveyor that transports the inspection module (40) inside so that the inspection module (40) can move between both sides. Since this conveyor is driven by a known technology as described above, a detailed description is omitted.

[0069] The gantry unit (50), in accordance with the command of the control unit (C), sequentially moves along the scan path to the area where pillars (m) are formed on the substrate (10), and places the inspection module (40) on the top of each pillar (m). At this time, the alignment correction value of the substrate (10) calculated by the optical system (60) is reflected in the scan path so that the actual position of the pillar (m) and the center of the sensor (45) of the inspection module (40) can be aligned.

[0070] The optical system (60) can simultaneously recognize the mark portion (a) formed on the substrate mounting portion (22) and the mark portion (a) on the substrate (10) to detect the alignment state of the substrate (10).

[0071] The optical system (60) may include a camera module. The camera module captures images of the substrate (10), the pillar (m), and the mark portion (a) and transmits them to the control unit (C). The control unit (C) performs image processing on the image data received from the optical system (60) to calculate the current position and rotation state of the substrate (10) and executes an alignment mode that compares this with a preset threshold value. In the alignment mode, if the position deviation of the substrate (10) is within the threshold value, the process proceeds to an inspection process; if it deviates from the threshold value, a correction command is transmitted to the stage drive unit (70, 80), or an alert mode is executed to provide a notification to an external user device (e.g., monitor, alarm device, network-connected management system, etc.).

[0072] The stage drive unit (70, 80) can precisely adjust the position and orientation of the substrate mounting portion (22). The stage drive unit (70, 80) includes a tilting portion (70) that tilts in the longitudinal and transverse directions and adjusts the angle of inclination, and a moving portion (80) that moves the substrate mounting portion (22) in the transverse direction, that is, in the width direction of the main body (21).

[0073] The tilting unit (70) can be controlled by a control unit (C) to correct the inclination so that the substrate (10) is precisely level with respect to the inspection module (40) and to maintain a predetermined gap (G2) between the inspection module (40) and the substrate (10).

[0074] For example, the tilting part (70) may include a cover (222) that supports the substrate mounting part (22) by being seated in the groove (201) and has a receiving hole (2221) formed inside between it and the substrate mounting part (22), and a plurality of cylinders that are positioned at each corner of the substrate mounting part (22) and support it inside the receiving hole (2221).

[0075] These cylinders include a first cylinder (71), a second cylinder (72), a third cylinder (73), and a fourth cylinder, but the first cylinder (71) to the third cylinder (73) shown in the drawing are described as examples. The first cylinder (71) and the second cylinder (72) are arranged parallel to each other on the front side, and the third cylinder (73) and the fourth cylinder are arranged parallel to each other on the rear side corresponding to the first cylinder (71) and the second cylinder (72). The third cylinder (73) and the fourth cylinder are raised to be inclined toward the front side, or the first cylinder (71) and the second cylinder (72) are raised while the third cylinder (73) and the fourth cylinder are kept in a state without being lowered or raised to be inclined toward the rear side, or all of the first cylinder (71) to the fourth cylinder are raised. The distance from the inspection module (40) can be adjusted.

[0076] In addition, since the first cylinder (71), the fourth cylinder, the second cylinder (72), and the third cylinder (73) are operated as described above to raise and lower both sides of the front and rear, thereby adjusting the angle of inclination, each cylinder can be raised and lowered independently to form various angles of inclination. By doing so, the inclination caused by warpage or seating error of the substrate (10) is corrected in real time, so that the upper surface of the column (m) remains parallel to the sensor surface of the inspection module (40), thereby reducing errors or errors and lowering the defect rate.

[0077] The moving part (80) may be provided in a receiving part (202) formed inside the main body (21) to move the substrate mounting part (22) in the width direction, which is the lateral direction. The moving part (80) includes a driving motor (81) provided in the receiving part (202), a rod (82) that slides in the width direction of the main body (21) by the driving motor (81), and a plurality of rollers (82) that support the rod (82) in the main body (21).

[0078] The rod (82) includes a first engagement hole (821) formed in an uneven shape toward the cover (222). At this time, the cover (222) may have a second engagement hole (223) formed in an uneven shape similar to the first engagement hole (821) on its outer surface, and may include an opening hole (203) so that the first engagement hole (821) is exposed to the outside.

[0079] According to this, as the first engaging hole (821) engages with the second engaging hole (223) through the opening hole (203), the rod (82) slides slightly horizontally by the operation of the drive motor (81), and the substrate mounting portion (22) can be finely adjusted in the width direction of the main body (21) by the second engaging hole (223) engaged with the first engaging hole (821).

[0080] The control unit (C) can comprehensively control the entire operation of the inspection system. The control unit (C) may be a computing device including a processor, memory, a communication interface, etc., and may be used in conjunction with an external server or a user terminal.

[0081] The control unit (C) includes an alignment mode that calculates the positional deviation and rotational deviation of the substrate (10) by image processing image data received from the optical system (60) and determines whether the calculated deviation is within a preset threshold value. If it is within the threshold value, it proceeds to an inspection process, and if it is outside the threshold value, it transmits a correction command to the stage driving unit (70, 80) or executes a notification mode.

[0082] The notification mode sends a warning notification to an external user device (monitor, alarm device, MES / EES system, etc.) when the alignment state of the substrate (10) deviates from a threshold value and automatic correction is impossible.

[0083] In the inspection mode, the inspection module (40) mounted on the inspection module (40) can determine whether the column (m) is normal or defective by comparing the defect status with a pre-stored threshold value. When measured by a capacitance sensor, the signal generator (30) is commanded to apply a DC or AC signal, and the measurement value received from the capacitance sensor is compared with a pre-set value (normal signal level) to determine normal / defective. The control unit (C) can classify the defect type of the column (m) into height defect, surface shape distortion, or internal bubble based on the direction and magnitude of deviation of the measured capacitance value.

[0084] For example, if the capacitance value is higher than the normal range, it is determined that the height is higher than normal and classified as defective; if the capacitance value is lower than the normal range and the decrease is large, it is determined that there are internal bubbles; and if there is a large local variation in the capacitance value, it is determined that there is surface shape distortion and classified as defective.

[0085] In addition, the control unit (C) can match the coordinate information of each column (m), the measured capacitance value, and the defect determination result to generate a defect distribution map (Defect Map) for the entire substrate (10) and store it as a map.

[0086] Meanwhile, the sensor (45) includes an eddy current induction coil that applies a pulse current to an eddy current induction coil, and the optical system (60) may be equipped with an infrared thermal imaging camera.

[0087] According to this, the control unit (C) may include an eddy current mode that induces eddy current in a column (m) by applying a pulse current to an eddy current induction coil mounted on an inspection module (40), and analyzes the temperature distribution data of the column (m) by receiving a captured image, and determines the metal column as defective if an abnormal temperature region exceeding a preset temperature deviation threshold is detected.

[0088] For example, the eddy current mode induces eddy currents in a column (m) by applying a predetermined pulse current to an eddy current induction coil. The induced eddy currents generate Joule heating proportional to the electrical conductivity of the column (m). A normal column (m) has uniform electrical conductivity and exhibits a uniform temperature distribution; however, if voids or underfill areas exist within it, the electrical conductivity in those areas changes discontinuously, distorting the flow of eddy currents and resulting in localized temperature anomalies (hot spots or cold spots). That is, the eddy current mode analyzes thermal image data received from an infrared thermal imaging camera, and if an abnormal temperature area exceeding a preset temperature deviation threshold is detected within the column (m) area, the metal column is determined to be defective. Furthermore, based on the shape and distribution pattern of the abnormal temperature area, the type of defect (internal voids, sidewall incomplete plating, seed layer discontinuity, etc.) can be classified.

[0089] According to this, by visualizing the two-dimensional spatial distribution of defects as a thermal image, the location and shape of bubbles and unfilled areas can be intuitively identified, there is no problem of substrate patterns overlapping compared to X-rays, and the inspection speed is completed within seconds, which has the effect of shortening the 100% inspection speed.

[0090] Additionally, the sensor (45) includes an excitation coil of a pulse eddy current probe, and the control unit (C) may include an eddy current profiling mode that applies a pulse signal containing multiple frequency components to the excitation coil, analyzes an impedance transient response signal received from the detection coil in the time domain to reconstruct an electrical conductivity profile for each depth of the column, and compares the reconstructed profile with a reference profile to determine that a defect exists at a specific depth if a decrease in electrical conductivity is detected at that depth.

[0091] The eddy current profiling mode according to this applies a predetermined pulse signal to the excitation coil of the pulse eddy current probe, and the applied pulse signal includes multiple frequency components, whereby the high-frequency component penetrates only near the surface of the column (m), and the low-frequency component can penetrate deep inside the column (m). The detection coil detects the temporal change of the secondary magnetic field generated by the eddy current within the column (m) and receives an impedance transient response signal.

[0092] The eddy current profiling mode analyzes the received transient response signal in the time domain to reconstruct the depth-dependent electrical conductivity profile of the pillar (m). For example, the initial time interval of the response signal reflects electrical conductivity information near the upper surface of the pillar (m), and the later time interval reflects electrical conductivity information at the lower part of the pillar (m) (deep region inside the substrate). The eddy current profiling mode compares the reconstructed depth-dependent electrical conductivity profile with a reference profile of a normal metal pillar that is stored in advance, and if an area where electrical conductivity drops sharply in a specific depth interval is detected, it classifies that a defect (bubble, incomplete filling, seed layer discontinuity, etc.) exists at that depth.

[0093] As a result, it is possible to non-destructively identify the location of defects in the depth direction of the pillars, precisely detect the incomplete filling of the middle section (minimum diameter section) of the hourglass-shaped vias unique to TGV substrates along with depth information, and simultaneously analyze all depths with a single pulse, thereby enabling non-destructive detection of whether defects exist depending on the depth of the pillars (m).

[0094] To explain the control method of a metal pillar defect inspection system within a TGV substrate using a multi-inspection module according to one embodiment, step S1 involves preparing a substrate (10) having a plurality of via holes formed therein. A metal material is filled into the via holes of the substrate (10) through a plating process or the like to form pillars (m).

[0095] Step S2 involves placing the substrate (10) onto the stage (20). A signal generator (30) can be electrically connected to the stage (20).

[0096] In step S3, the optical system (60) photographs the mark portion (a) on the substrate mounting portion (22), and the alignment mode of the control unit (C) calculates the positional deviation and rotational deviation of the substrate (10). If the deviation exceeds a threshold value, the stage driving unit (70, 80) performs a correction operation or executes a notification mode.

[0097] In step S4, the inspection module (40) slides on the upper side of the substrate (10) by the gantry unit (50) to sequentially search the area where a pillar (m) is formed along the scan path.

[0098] Step S5 corresponds the inspection module (40) to be positioned on the upper part of the individual column (m). At this time, the alignment correction value is applied so that the center of the sensor and the center of the column (m) are accurately aligned.

[0099] Step S6 detects a change in capacitance passing through the pillar by applying an electrical signal from the signal generator (30). The signal generator (30) applies an electrical signal through the stage (20), and the electrical signal transmitted through the pillar (m) is measured by the capacitance sensor, and the defect is determined by comparing the measured capacitance value with a set value. Alternatively, if a visible light optical system sensor or CT X-ray is used, an external inspection or an internal inspection is performed according to the detection principle of each module.

[0100] Step S7 generates a defect map by recording the inspection results (normal / defective judgment, defect type, measured value) for each column (m) along with coordinate information.

[0101] According to the metal pillar defect inspection system and control method within a TGV substrate using the multi-inspection module of the present invention, by applying a through-type measurement structure in which an electrical signal is applied from the lower surface of the substrate through a signal generator embedded in the stage and measured by a capacitance sensor on the upper surface of the substrate, defects such as internal bubbles, electrical discontinuities, and density non-uniformity, which were impossible to detect with conventional optical inspection, can be precisely detected in a non-contact and non-destructive manner, thereby reducing costs and shortening time. Additionally, since defects regarding the external shape and internal defects of the pillars can be detected through a single module using a capacitance sensor, a visible light optical system, or an X-ray method, the risk of contamination and damage occurring on the substrate can be eliminated, and the inspection processing time (TAT) can be significantly shortened.

[0102] In addition, according to the metal pillar defect inspection system and control method within a TGV substrate using a multi-inspection module of the present invention, since the inspection is performed by precisely adjusting the horizontality of the substrate, high-reliability inspection based on the positional precision of micro-pillars is possible, and false detection due to misalignment can be prevented. Furthermore, by maintaining a constant distance between the capacitance sensor and the substrate, the transmission efficiency of electrical signals and measurement sensitivity are improved, thereby lowering the detection limit of micro-defects and reducing the defect rate. Additionally, the visible light optical system identifies the shape of the pillars in three dimensions in the vertical direction, the inclined direction, or both directions, enabling the detection of surface shape distortion defects and thus improving accuracy.

[0103] Although embodiments of the present invention have been described in more detail with reference to the attached drawings, the present invention is not necessarily limited to these embodiments and may be modified in various ways within the scope of the technical spirit of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of protection of the present invention shall be interpreted by the claims below, and all technical spirits within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

[0104] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below. Explanation of the symbols

[0106] 10: Substrate 20: Stage 30: Signal generator 40: Inspection Module 50: Gantry unit

Claims

Claim 1 The method comprises the steps of: preparing a substrate having a plurality of via holes formed therein (S1); filling the via holes of the substrate with material to form pillars (S2); mounting the substrate on a stage containing a signal generator that operates by an electrical signal, at a predetermined distance from the signal generator (S3); moving an inspection module that detects a change in an electrical signal by the electrical signal in the vertical and horizontal directions on the upper side of the substrate (S4); positioning the inspection module at least one of the pillars at a predetermined distance (S5); and detecting a change in capacitance passing through the pillar by applying an electrical signal from the signal generator when the inspection module is positioned on the pillar (S6); wherein the inspection module includes a fixed part including a sensor provided on the leading end facing the substrate, and applying either a direct current or alternating current signal through the signal generator to energize the pillar of the substrate, receiving an energization value measured by the sensor, and comparing it with a preset value to determine whether the pillar is defective. A control method for a metal pillar defect inspection system within a TGV substrate using multiple inspection modules, characterized by including a control unit. Claim 2 delete Claim 3 A control method for a metal pillar defect inspection system within a TGV substrate using a multi-inspection module, wherein, in claim 1, the stage comprises a main body, a substrate mounting portion formed facing each other on the main body, and an optical system for capturing images of the mark portion and the substrate on the main body; and the control unit comprises an alignment mode for receiving an image from the optical system and determining whether the substrate is located within a preset threshold value in the mark portion, and a notification mode for providing a notification to an external user device if the substrate falls outside the threshold value according to the alignment mode.

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