Laser Drilling System and Method for Selective Removal of Insulating Layers

Abstract

An embodiment relates to a laser drilling system and a method for selectively removing an insulating layer, comprising a workpiece including a metal layer and an insulating layer disposed thereon, a stage on which the workpiece is disposed, a laser beam generator that outputs laser light, an optical transmission system disposed between the workpiece and the laser beam generator so that the laser light passes through a mask and is selectively transmitted to the insulating layer, a blowing-suction device disposed between the workpiece and the optical transmission system, a monitoring-inspection device for inspecting the surface shape of the workpiece, and a control device that controls the laser light generated from the laser beam generator and / or the optical transmission system by reflecting the surface shape information. In addition, the mask is configured to remove the insulating layer in multiple stages or selectively according to the target depth and shape by including a light-transmitting area and a phase-conversion area A (multiple phase-conversion areas as needed) that transmit laser light when viewed from the top surface and project depth-etching lasers of different intensities toward the insulating layer, and a light-blocking area that blocks the laser light.

Description

Technology Field

[0001] The embodiment relates to a laser drilling system and a method for selectively removing an insulating layer, which can simplify the process to enable efficient execution and can form holes even when it is difficult to form the intended hole shape using conventional exposure techniques, such as small holes or high aspect ratios. Background Technology

[0003] In a manufacturing process for electronic components, front-end (FE) processes can implement circuits on semiconductor wafers, and back-end (BE) processes can assemble the wafers into a state usable as actual products. A packaging process may be included in the back-end processes.

[0004] The four core technologies of the semiconductor industry that have enabled the rapid development of electronic products in recent years are semiconductors, semiconductor packaging, semiconductor manufacturing, and software technology.

[0005] Semiconductor technology has advanced in various areas, including sub-micro and nano-scale linewidths, over 10 million cells, high-speed operation, and heat dissipation. However, complete packaging technology may not be able to support this. Therefore, the electrical performance of a semiconductor is sometimes determined by packaging technology and the resulting electrical connections, rather than by the performance of the semiconductor technology itself.

[0006] One method introduced to improve electrical performance is vertical connection. Via are an example of this vertical connection structure, and laser drilling can be applied to form them. When using lithography methods such as photolithography and formation to form small vias, technical difficulties may arise as the depth of the via hole increases. For example, because it is difficult to reliably secure hole shapes such as hole opening size and aspect ratio, additional processes such as plasma etching must be added, leading to difficulties such as increased complexity of steps and equipment and reduced yield.

[0007] Meanwhile, the aforementioned background technology is technical information that the inventor possessed for the derivation of the present invention or acquired during the process of deriving the present invention, and it cannot be considered as prior art disclosed to the general public prior to the filing of the present invention.

[0008] Related prior art includes Korean registered patent 10-1496843, Korean published patent 10-2022-0041219, Korean registered patent 10-1690874, and Korean published patent 10-2018-0010242. The problem to be solved

[0010] The embodiment aims to provide a laser drilling system that can be efficiently carried out by simplifying the process, a method for selectively removing an insulating layer, etc. In addition, it aims to provide a laser drilling system that can effectively create patterns with different shapes, sizes, and depths, such as lines, holes, and pads, in a single laser drilling operation. The embodiment also provides a laser drilling system that can form holes even when it is difficult to form the intended hole shape using conventional exposure techniques, such as small holes or high aspect ratios. means of solving the problem

[0012] This summary is provided to explain some of the concepts in a simplified form, which are explained in more detail in the detailed description below. This summary is not intended to distinguish the principal or core features claimed as a right, nor is it intended to be used to assist in determining the scope of the claimed right.

[0013] A laser drilling system according to one embodiment comprises: a workpiece comprising a metal layer and an insulating layer disposed on the metal layer; a stage on which the workpiece is disposed; a laser beam generator that outputs laser light; an optical transmission system disposed between the workpiece and the laser beam generator and which selectively transmits the laser light to the insulating layer by passing the laser light through a mask; a monitoring-inspection device for inspecting the surface shape of the workpiece; and a control device that controls the laser light generated from the laser beam generator, the optical transmission system, or both, by reflecting the surface shape information.

[0014] The above mask may include, when viewed from above, a light-transmitting region that transmits the laser light and projects a first depth etching laser of first intensity in the direction of the insulating layer; a phase-conversion region A that transmits the laser light and projects a second depth etching laser of second intensity in the direction of the insulating layer; and a light-blocking region that blocks the laser light.

[0015] The insulating layer corresponding to the light-transmitting area may have via holes formed therein.

[0016] The above mask may further include a phase conversion region B that transmits the laser light when viewed from above and projects a third depth etching laser of third intensity in the direction of the insulating layer.

[0017] The above mask may include: a light-transmitting layer which transmits the laser light when viewed in cross-section; a first phase-conversion layer disposed on the light-transmitting layer and capable of transmitting a second depth-etching laser having a second intensity in the direction of the insulating layer by controlling the phase and intensity of the laser light; and a light-blocking layer disposed on the first phase-conversion layer and blocking the laser light.

[0018] The first phase conversion layer and the light-blocking layer may be optionally etched to implement a pattern to be formed on the insulating layer.

[0019] The above mask may include: a light-transmitting layer which transmits the laser light when viewed in cross-section; a first phase-conversion layer disposed on the light-transmitting layer and capable of transmitting a second depth-etching laser having a second intensity in the direction of the insulating layer by controlling the phase and intensity of the laser light; a second phase-conversion layer disposed on the first phase-conversion layer and controlling the phase and intensity of the laser light; and a light-blocking layer disposed on the second phase-conversion layer and blocking the laser light.

[0020] The laser light passing through the second phase conversion layer and the first phase conversion layer has its phase and intensity controlled to project a third depth etching laser having a third intensity in the direction of the insulating layer, and the first phase conversion layer, the second phase conversion layer, and the light-blocking layer may be selectively etched to implement a pattern to be formed on the insulating layer.

[0021] It may further include a blowing-suction device disposed between the processing target and the optical transmission system.

[0022] In the insulating layer, the area etched by irradiating a laser of the first intensity is the first depth etching area, the area etched by irradiating a laser of the second intensity is the second depth etching area, the area corresponding to the light-blocking area is the unetched area, the height of the unetched area is the reference height, the distance between the reference height and the first depth etching area is the first etching depth, the distance between the reference height and the second depth etching area is the second etching depth, and the first etching depth may be greater than the second etching depth.

[0023] The bottom surface of the first depth etching region may expose the metal layer.

[0024] A via electrode may be disposed in the first depth etching region.

[0025] A conductive line may be placed in the above second depth etching region.

[0026] The laser drilling system can simultaneously form via holes with controlled depth and diameter in the insulating layer; pads with controlled depth and diameter; lines with controlled depth and width; or a pattern including all of these.

[0027] A laser drilling system according to an embodiment comprises: a workpiece comprising a metal layer and an insulating layer disposed on the metal layer; a stage on which the workpiece is disposed; an optical transmission system disposed on the stage and transmitting laser light to the insulating layer; a laser beam generator connected to the optical transmission system and outputting laser light; a blowing-suction device disposed between the workpiece and the optical transmission system; a monitoring-inspection device for inspecting the surface shape of the workpiece; and a control device for controlling the laser light generated from the laser beam generator and / or the optical transmission system by reflecting the surface shape information.

[0028] The laser light output from the above laser beam generator is primary laser light, and the light emitted from the above optical transport system to the insulating layer is secondary laser light.

[0029] In the above optical transport system, the primary laser light can pass through a mask and be converted into secondary laser light.

[0030] The laser light can form a pattern in the insulating layer through the optical transmission system, comprising via holes with controlled depth and diameter; pads with controlled depth and diameter; lines with controlled depth and width; or all of these.

[0031] The above mask and the above processing target may each have alignment marks.

[0032] The above control device can control the position of the mask and the processing target through the alignment mark.

[0033] The above mask and the above processing target may each have alignment marks.

[0034] The above control device can control the processing height by the laser light.

[0035] The blowing-suction device above can remove particulate impurities or smear generated when the insulating layer is removed by the laser light from the insulating layer using air pressure.

[0036] The above control device can control the temperature and humidity within the laser drilling system.

[0037] A method for selectively removing an insulating layer according to an embodiment comprises: a placement step of placing a processing target on a stage while controlling its position relative to a mask of an optical transmission system; and an etching step of irradiating a processing target with a primary laser beam output from a laser beam generator onto the mask and irradiating the laser beam, which has passed through the mask and been converted into a secondary laser beam, onto the processing target.

[0038] The above processing target may include a metal layer and an insulating layer disposed on the metal layer.

[0039] The above secondary laser light can form a pattern including via holes, pads, lines, or all of these in the insulating layer.

[0040] The above method for removing the insulating layer may further include a particle removal step simultaneously with or after the etching step.

[0041] The particle removal step described above can remove or collect particulate impurities or smears by performing blowing, suction, or both on the surface of the workpiece.

[0042] The above placement step allows the stage to place the workpiece while relieving warping by fixing it with a clamp or vacuum.

[0043] The above control step is a step of verifying and controlling processing parameters.

[0044] The above processing parameters may include position alignment of the processing target, key verification of the alignment mark, height of the etching target from the processing target, and processing drawing data having processing purpose data.

[0045] The above control step can be controlled so that the etching step proceeds in units of holes, pads, and lines. Effects of the invention

[0047] The laser drilling system of the embodiment simplifies the process and allows for efficient execution, and can effectively create patterns with different shapes, sizes, and depths, such as lines, holes, and pads, in a single laser drilling step. In addition, it can also create holes in cases where it is difficult to form the intended hole shape using conventional exposure techniques, such as small holes or holes with high aspect ratios.

[0048] The laser drilling system and the method for selectively removing an insulating layer of the embodiment can simplify the process and proceed efficiently, and can even form holes in cases where it is difficult to form the intended hole shape using conventional exposure techniques, such as small holes or holes with high aspect ratios. Brief explanation of the drawing

[0050] FIG. 1 is a conceptual diagram illustrating the etching step in an optical transport system according to an embodiment (top: conceptual diagram illustrating the mask and laser light, middle: graph showing the intensity of the secondary laser light, bottom: workpiece before etching). FIG. 2a is a diagram conceptually illustrating a cross-section of a mask according to an embodiment (top) and a graph showing the intensity of a secondary laser light (bottom). FIG. 2a is a graph showing the intensity of secondary laser light according to an embodiment (top) and a conceptual diagram explaining a visualized processing target in cross-section (bottom). FIG. 3 is a conceptual diagram illustrating, in cross-section, the process of etching a workpiece according to an embodiment (Top: graph showing the intensity of the secondary laser light, Middle: optical transport system and blowing-suction device, Bottom: workpiece and particulate impurities). FIG. 4a is a conceptual diagram illustrating a cross-sectional view of a processing target after etching according to an embodiment. FIG. 4b is a conceptual diagram illustrating, in cross-section, the appearance of a processing target after etching and additionally forming a metal layer according to an embodiment. FIG. 5 is a conceptual diagram illustrating a laser drilling system according to an embodiment. FIG. 6 is a conceptual diagram illustrating the etching step in an optical transport system according to an embodiment. Specific details for implementing the invention

[0051] The following detailed description is provided to aid in a comprehensive understanding of the methods, apparatuses, and / or systems described herein. However, various changes, modifications, and equivalents to the methods, apparatuses, and / or systems described herein will become apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the operations specified herein, but may be clearly changed after understanding the disclosure of this application, with the exception of operations that must be performed in a specific order. Furthermore, descriptions of features known after understanding the disclosure of this application may be omitted to enhance clarity and conciseness, and the omission and description of features are not an acknowledgment that such descriptions are of general knowledge.

[0052] The features described herein may be implemented in other forms and are not to be interpreted as being limited to the examples described herein. Rather, the examples described herein are provided merely to illustrate some of the many possible ways to implement the methods, apparatuses, and / or systems described herein that will become apparent after understanding the disclosure of this application.

[0053] Terms such as “first,” “second,” and “third” may be used in this specification to describe various components, components, regions, layers, or sections, but such components, components, regions, layers, or sections are not limited by these terms. Rather, these terms are used to distinguish one component, part, region, layer, or section from another component, part, region, layer, or section. Accordingly, a first component, part, region, layer, or section mentioned in the embodiments described herein may also be referred to as a second component, part, region, layer, or section without departing from the teachings of the embodiments.

[0054] Throughout the specification, descriptions in which an element, such as a layer, region, or substrate, is "on top of," "connected to," or "joined" to another element may be directly "on top of," "connected to," or "joined" to the other element, or one or more other elements may intervene between them. Conversely, if an element is described as being "directly on top of," "directly connected to," or "directly joined," no other elements may intervene between them. Likewise, expressions such as, for example, "between" and "directly between," and "indirectly introduced" and "directly introduced," may be interpreted as described above.

[0055] The terms used herein are for the purpose of describing specific examples only and are not intended to limit the disclosure. The singular forms “a,” “an,” and “the” used herein may include plural forms unless the context clearly indicates otherwise. The term “and / or” used herein includes one or more combinations of the listed items. The terms “include,” “comprise,” and “have” used herein specify the presence of the specified features, numbers, operations, elements, components, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, numbers, operations, elements, components, and / or combinations thereof. The use of the term “may” in this specification in relation to embodiments (e.g., in relation to what the examples or embodiments may include or implement) means that while at least one example or embodiment exists where such features are included or implemented, all examples are not limited thereto.

[0056] Throughout this specification, "B being placed on A" means that B is placed in direct contact with A or placed on A with another layer or structure in between, and is not to be interpreted as being limited to B being placed in direct contact with A. Unless otherwise defined, all terms used in this document have the same meaning as generally understood by a person skilled in the art to which this document relates, provided that this document is understood, and this will be consistent after understanding this document.

[0057] Terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology and the present disclosure, and should not be interpreted in an ideal or overly formal sense unless explicitly defined herein.

[0059] FIG. 1 is a conceptual diagram illustrating the etching step in an optical transport system according to an embodiment (top: conceptual diagram illustrating the mask and laser light, middle: graph showing the intensity of the secondary laser light, bottom: processing target before etching), and FIG. 5 is a conceptual diagram illustrating a laser drilling system according to an embodiment. FIG. 2a is a diagram conceptually illustrating a cross-section of a mask according to an embodiment (top) and a graph showing the intensity of the secondary laser light (bottom), FIG. 2a is a conceptual diagram illustrating a cross-section of a visualized processing target and a graph showing the intensity of the secondary laser light according to an embodiment (top) and a cross-section of the processing target according to an embodiment (bottom). Also, FIG. 3 is a conceptual diagram illustrating a cross-section of the process of etching a processing target according to an embodiment (top: graph showing the intensity of the secondary laser light, middle: optical transport system and blowing-suction device, bottom: processing target and particulate impurities). FIG. 4a is a conceptual diagram illustrating a cross-sectional view of a processing target after etching according to an embodiment, and FIG. 4b is a conceptual diagram illustrating a cross-sectional view of a processing target after etching with an additional metal layer formed thereon according to an embodiment. With reference to the drawings, an embodiment will be described in more detail.

[0061] To achieve the above objective, a laser drilling system according to one embodiment of the embodiment processes a workpiece (10) by including a stage (100); an optical transport system (400); a laser beam generator (300); a monitoring-inspection device (600); and a control device (200) (see FIG. 5). Specifically, the components are connected to each other to perform selective etching of the workpiece (10) within the laser drilling system.

[0062] The laser drilling system may further include a blowing-suction device (500).

[0063] The workpiece (10) includes a metal layer (13) and an insulating layer (15) disposed on the metal layer (13) (see bottom of FIG. 1).

[0064] For example, the processing target (10) may be a packaging substrate applied to the packaging of semiconductor devices. When the processing target (10) is applied as the packaging substrate, a glass core (11) may be applied. Specifically, the processing target (10) may include a glass core (11) having through-vias, a metal layer (13) disposed on both surfaces of the glass core (11) and on the through-vias, and an insulating layer (15) disposed on the metal layer (13).

[0065] The above processing target (10) has an insulating layer disposed thereon, and a metal layer may be placed on the upper and / or lower part of the insulating layer. The selective removal of the insulating layer allows a metal layer (electrically conductive layer) to be formed on the processing target (10) in a subsequent process, which may become a wire pattern on the packaging substrate.

[0066] In the existing process, the formation of the metal layer (electrically conductive layer) required a considerably complex multi-stage process.

[0067] Conventionally, a process like this is carried out to form a pattern having holes, pads, and lines on a workpiece. A pattern of one layer is formed by repeating the following steps: 1) cleaning the workpiece substrate, 2) forming a metal layer by means such as sputtering, 3) performing pretreatment, 4) performing a lithography process, 5) performing plating, 6) performing annealing and etching, 7) performing a cleaning process again, 8) performing pretreatment again, 9) placing an insulating material, 10) curing to produce an insulating layer, 11) forming via holes, 12) performing desmearing, 13) performing cleaning, 14) subsequently forming a metal layer, 15) performing pretreatment, 16) performing a lithography process, 17) performing plating, and 18) performing annealing and etching.

[0068] In the embodiment, when removing the portion to be patterned from the insulating layer, instead of forming lines and holes separately as described above, holes, pads, and lines can be formed through a laser drilling process, thereby simplifying and improving process efficiency. Once the portion to be patterned is removed from the insulating layer in this way, the formation of a patterned metal layer can be efficiently achieved by proceeding with processes such as plating.

[0069] The stage (100) is a device on which the processing target (10) is placed.

[0070] A workpiece (10) is placed on a stage (100) by an automated device (e.g., a robot arm, etc.), and its position after placement can be checked and corrected by a monitoring-inspection device (600) and a control device (200). At this time, an alignment mark (not shown) is placed on the workpiece (10), and the relative position to the stage (100) is detected by the monitoring-inspection device (600). When the information is transmitted to the control device (200), the control device (200) can check whether the position is appropriate and adjust the position of the workpiece (10).

[0071] The laser beam generator (300) is connected to the optical transport system (400) and outputs laser light (L).

[0072] The laser light (L) may be applied having an absorption rate capable of processing metal materials such as copper and titanium. Additionally, the laser light (L) may be applied having an absorption rate capable of processing organic layers or organic-inorganic composite layers, such as insulating layers (e.g., the cured layer of Ajinomoto build-up film), polyimide layers, and photoresist layers.

[0073] Specifically, the laser light (L) may have a UV wavelength. For example, the laser light (L) may have a wavelength of 400 nm or less, 350 nm or less, 340 nm or less, 330 nm or less, 320 nm or less, 310 nm or less, 300 nm or less, 290 nm or less, 280 nm or less, 270 nm or less, 260 nm or less, or 250 nm or less. The laser light (L) may have a wavelength of 100 nm or more.

[0074] The laser light (L) may have a pulse energy of 10 mJ or more, 15 mJ or more, 20 mJ or more, 25 mJ or more, 30 mJ or more, 35 mJ or more, 40 mJ or more, 45 mJ or more, 50 mJ or more, 55 mJ or more, 60 mJ or more, 65 mJ or more, 70 mJ or more, or 75 mJ or more. The pulse energy may be 200 mJ or less, 150 mJ or less, or 1 J or less. When such pulse energy is applied, the insulating layer, etc. can be removed more efficiently.

[0075] The laser light (L) may have a pulse repetition rate of 10 Hz or more, 50 Hz or more, 100 Hz or more, 300 Hz or more, 600 Hz or more, 900 Hz or more, 1,000 Hz or more, 2,000 Hz or more, 3,000 Hz or more, 4,000 Hz or more, or 5,000 Hz or more. The pulse repetition rate may be 10 kHz or less.

[0076] The above laser light (L) can be processed into a high-resolution phone shape by simultaneously applying a relatively high repetition rate and relatively high energy.

[0077] The above laser light (L) enables the implementation of a reliable via having a diameter of 20 µm or less, especially when the depth is 20 µm or less.

[0078] An optical transmission system (400) is placed on the stage (100) and transmits laser light (L) to the insulating layer (15).

[0079] The above laser light (L) is not transmitted directly to the processing target (10), but rather the converted laser light is transmitted by passing through the optical transmission system (400).

[0080] The laser light (L) output from the laser beam generator (300) is called the primary laser light, and the light emitted from the optical transport system (400) to the insulating layer (15) is called the secondary laser light.

[0081] In the above optical transmission system (400), the primary laser light passes through the mask (450) and is converted into secondary laser light.

[0082] The optical transmission system (400) is positioned between the processing target (10) and the laser beam generator (300) and allows laser light (L) to pass through the mask (450) and selectively transmit converted laser light to the insulating layer (15).

[0083] Detailed information regarding the mask and the laser light converted by it will be described later.

[0084] The laser light (L) can form a pattern in the insulating layer (15) through the optical transmission system (400) that includes via holes with controlled depth and diameter; pads with controlled depth and diameter; lines with controlled depth and width; or all of these.

[0085] The formation of the pattern is carried out by etching with the laser light. This pattern is formed by selectively removing a portion of the insulating layer. If such particulate by-products continue to exist within the etched pattern in the insulating layer, cleaning may become difficult in subsequent processes, and disconnection may occur in subsequent processes.

[0086] During the etching process using the laser light (L) described above, particulate impurities or smears (P), which are processing byproducts, may be formed. These need to be removed before proceeding with subsequent processes.

[0087] It may further include a blowing-suction device (500) disposed between the processing target (10) and the optical transmission system (400).

[0088] The blowing-suction device (500) removes particulate impurities or smear (P) generated when the insulating layer (15) is removed by the laser light (L) from the insulating layer (15) using air pressure.

[0089] The blowing-suction device (500) is positioned between the processing target (10) and the optical transmission system (400). This arrangement can make it easier to remove the particulate impurities or smear.

[0090] For blowing, gases such as CDA (Clean Dry Air) and N2 may be used as examples, but are not limited thereto.

[0091] This particulate byproduct or smear may exist on a portion of the etched pattern and may fall onto the insulating layer. Optionally, a processing protection layer (not shown) may be placed on the insulating layer, thereby allowing the particulate byproduct or smear to be removed more easily. Specifically, the particulate byproduct or smear may be induced to fall onto the processing protection layer rather than directly onto the surface of the insulating layer. This allows the particulate byproduct or smear to be removed more easily by removing the processing protection layer during a subsequent process, and then easily removed by removing the processing protection layer during a subsequent cleaning process.

[0092] The monitoring-inspection device (600) is a device that inspects the surface shape information of the processing target (10).

[0093] The control device (200) controls the laser light (L) generated from the laser beam generator (300) and / or the optical transmission system (400) by reflecting the surface shape information.

[0094] The monitoring-inspection device (600) and the control device (200) obtain information from the processing target and perform calculations therefrom to help enable appropriate laser irradiation and selective removal of the insulating layer.

[0095] For example, the mask (450) and the processing target (10) each have an alignment mark, and the control device (200) can control the position of the mask (450) and the processing target (10) through the alignment mark.

[0096] For example, the mask (450) and the processing target (10) each have alignment marks, and the control device (200) can control the processing height by the laser light (L).

[0097] For example, the mask (450) and the processing target (10) each have an alignment mark, and the control device (200) can control the focal size of the laser light (L).

[0098] The above control device (200) can control the temperature and humidity within the laser drilling system.

[0099] By the above laser drilling system, a pattern etched into the insulating layer can be formed sequentially by dividing the insulating layer into regions, and the shape, width, depth, etc. of the pattern can be controlled through the control of radar light, and laser drilling can be performed with high accuracy in a relatively fast process time.

[0100] The above control device (200) checks and controls processing parameters.

[0101] The above processing parameters may include position alignment of the processing target (10), key verification of the alignment mark, height of the etching target in the processing target (10), and processing drawing data having processing purpose data.

[0102] The above control device (200) can control the etching to proceed in units of holes, pads, and lines.

[0104] The mask (450) according to the embodiment is described in detail.

[0105] The above mask (450) includes, when viewed in cross-section, a light-transmitting layer (452); a first phase-conversion layer (454); and a light-blocking layer (458). The above mask (450) may further include a second phase-conversion layer (456) when viewed in cross-section. The second phase-conversion layer (456) may be disposed between the first phase-conversion layer (454) and the light-blocking layer (458). These are selectively etched and applied to correspond to a pattern to be formed.

[0106] The light-transmitting layer (452) is a layer that transmits the laser light (L). The light-transmitting layer transmits the laser light with minimal changes in phase or intensity.

[0107] The first phase conversion layer (454) is disposed on the light transmission layer (452) and controls the phase and intensity of the laser light (L) to enable the second depth etching laser (L53) having a second intensity (F53) to be projected toward the insulating layer (15).

[0108] The second phase conversion layer (456) is disposed on the first phase conversion layer (454) and can control the phase and intensity of the laser light (L).

[0109] The laser light (L) that has passed through the second phase conversion layer (456) and the first phase conversion layer (454) has its phase and intensity controlled to enable the third depth etching laser (L55) having a third intensity (F55) to be projected toward the insulating layer (15).

[0110] The light-blocking layer (458) is disposed on the first phase conversion layer (454) or on the second phase conversion layer (456). The light-blocking layer substantially suppresses the mask transmission of the laser light, thereby not substantially inducing etching in the insulating layer.

[0111] The above mask may be optionally etched so that the first phase conversion layer (454) and the light-blocking layer (458) implement a pattern to be formed on the insulating layer (15).

[0112] The above mask may have the first phase conversion layer (454), the second phase conversion layer (456), and the light-blocking layer (458) optionally etched to implement a pattern to be formed on the insulating layer (15).

[0113] The above mask (450) includes, when viewed from above, a light-transmitting area (21); a phase-shifting area A (23); and a light-blocking area (29). The above mask (450) may further include a phase-shifting area B (25) when viewed from above.

[0114] The light-transmitting area (21) transmits the laser light (L) and projects a first depth etching laser (L51) of first intensity (F51) in the direction of the insulating layer (15). The first depth etching laser (L51) can etch the insulating layer (15) to a first etching depth (H51).

[0115] The phase conversion region A (23) transmits the laser light (L) and projects a second depth etching laser (L53) of second intensity (F53) in the direction of the insulating layer (15). The second depth etching laser (L53) can etch the insulating layer (15) to a second etching depth (H53).

[0116] The phase conversion region B (25) transmits the laser light (L) and projects a third depth etching laser (L55) of third intensity (F55) in the direction of the insulating layer (15). The third depth etching laser (L55) can etch the insulating layer (15) to a third etching depth (H55).

[0117] In the above insulating layer (15), a laser of the first intensity (F51) is irradiated to form a first depth etching region (51) in which an etched region is formed.

[0118] In the above insulating layer (15), a laser of the second intensity (F53) is irradiated to form a second depth etching region (53) in which the etched region can be formed.

[0119] The area corresponding to the light-blocking area (29) in the insulating layer (15) above may be an unetched area (59).

[0120] In the above insulating layer (15), the height of the above unetched area (59) is called the reference height (HB).

[0121] The distance between the reference height (HB) and the first depth etching region (51) is the first etching depth (H51).

[0122] The distance between the reference height (HB) and the second depth etching region (53) is the second etching depth (H53).

[0123] The first etching depth (H51) may be greater than the second etching depth (H53).

[0124] The distance between the reference height (HB) and the third depth etching region (55) is the third etching depth (H55).

[0125] The third etching depth (H55) may be greater than the second etching depth (H53).

[0126] A via hole may be formed in the first depth etching region (51), which is the insulating layer (15) corresponding to the light-transmitting region (21).

[0127] The metal layer (13) may be exposed on the bottom surface of the first depth etching area (51).

[0128] A via electrode may be placed in the first depth etching region (51).

[0129] A conductive line may be placed in the second depth etching area (53) above.

[0130] via electrodes, conductive lines, etc., can be implemented by forming a copper layer through methods such as electroplating.

[0131] The laser drilling system can simultaneously form via holes with controlled depth and diameter in the insulating layer (15); pads with controlled depth and diameter; lines with controlled depth and width; or a pattern including all of these.

[0132] An exemplary embodiment can provide a laser drilling system that can be simplified and carried out efficiently. In addition, patterns with different shapes, sizes, and depths, such as lines, holes, and pads, can be realized in a single laser drilling operation.

[0134] FIG. 5 is a conceptual diagram illustrating a laser drilling system according to an embodiment, and FIG. 6 is a conceptual diagram illustrating a cross-sectional view illustrating the etching step in an optical transport system according to an embodiment. With reference to FIG. 5 and FIG. 6, an embodiment will be described in more detail below.

[0135] To achieve the above objective, a laser drilling system according to one embodiment of the embodiment comprises: a stage (100); an optical transmission system (400); a laser beam generator (300); a blowing-suction device (500); a monitoring-inspection device (600); and a control device (200) (see FIG. 5).

[0136] The above components are connected to each other to perform selective etching of the workpiece (10) within the laser drilling system.

[0137] The workpiece (10) includes a metal layer (13) and an insulating layer (15) disposed on the metal layer (13) (see FIG. 6).

[0138] For example, the processing target (10) may be a packaging substrate applied to the packaging of semiconductor devices. When the processing target (10) is applied as the packaging substrate, a glass core (11) may be applied. Specifically, the processing target (10) may include a glass core (11) having through-vias, a metal layer (13) disposed on both surfaces of the glass core (11) and on the through-vias, and an insulating layer (15) disposed on the metal layer (13).

[0139] The above processing target (10) has an insulating layer disposed thereon, and a metal layer may be placed on the upper and / or lower part of the insulating layer. The selective removal of the insulating layer allows a metal layer (electrically conductive layer) to be formed on the processing target (10) in a subsequent process, which may become a wire pattern on the packaging substrate.

[0140] In the existing process, the formation of the metal layer (electrically conductive layer) required a considerably complex multi-stage process.

[0141] Conventionally, a process like this is carried out to form a pattern having holes, pads, and lines on a workpiece. A pattern of one layer is formed by repeating the following steps: 1) cleaning the workpiece substrate, 2) forming a metal layer by means such as sputtering, 3) performing pretreatment, 4) performing a lithography process, 5) performing plating, 6) performing annealing and etching, 7) performing a cleaning process again, 8) performing pretreatment again, 9) placing an insulating material, 10) curing to produce an insulating layer, 11) forming via holes, 12) performing desmearing, 13) performing cleaning, 14) subsequently forming a metal layer, 15) performing pretreatment, 16) performing a lithography process, 17) performing plating, and 18) performing annealing and etching.

[0142] In the embodiment, when removing the portion to be patterned from the insulating layer, instead of forming lines and holes separately as described above, holes, pads, and lines can be formed through a laser drilling process, thereby simplifying and improving process efficiency. Once the portion to be patterned is removed from the insulating layer in this way, the formation of a patterned metal layer can be efficiently achieved by proceeding with processes such as plating.

[0143] The stage (100) is a device on which the processing target (10) is placed.

[0144] A workpiece (10) is placed on a stage (100) by an automated device (e.g., a robot arm, etc.), and its position after placement can be checked and corrected by a monitoring-inspection device (600) and a control device (200). At this time, an alignment mark (not shown) is placed on the workpiece (10), and the relative position to the stage (100) is detected by the monitoring-inspection device (600). When the information is transmitted to the control device (200), the control device (200) can check whether the position is appropriate and adjust the position of the workpiece (10).

[0145] The laser beam generator (300) is connected to the optical transport system (400) and outputs laser light (L).

[0146] The laser light (L) may be applied having an absorption rate capable of processing metal materials such as copper and titanium. Additionally, the laser light (L) may be applied having an absorption rate capable of processing organic layers or organic-inorganic composite layers, such as insulating layers (e.g., the cured layer of Ajinomoto build-up film), polyimide layers, and photoresist layers.

[0147] Specifically, the laser light (L) may have a UV wavelength. For example, the laser light (L) may have a wavelength of 400 nm or less, 350 nm or less, 340 nm or less, 330 nm or less, 320 nm or less, 310 nm or less, 300 nm or less, 290 nm or less, 280 nm or less, 270 nm or less, 260 nm or less, or 250 nm or less. The laser light (L) may have a wavelength of 100 nm or more.

[0148] The laser light (L) may have a pulse energy of 10 mJ or more, 15 mJ or more, 20 mJ or more, 25 mJ or more, 30 mJ or more, 35 mJ or more, 40 mJ or more, 45 mJ or more, 50 mJ or more, 55 mJ or more, 60 mJ or more, 65 mJ or more, 70 mJ or more, or 75 mJ or more. The pulse energy may be 200 mJ or less, 150 mJ or less, or 1 J or less. When such pulse energy is applied, the insulating layer, etc. can be removed more efficiently.

[0149] The laser light (L) may have a pulse repetition rate of 10 Hz or more, 50 Hz or more, 100 Hz or more, 300 Hz or more, 600 Hz or more, 900 Hz or more, 1,000 Hz or more, 2,000 Hz or more, 3,000 Hz or more, 4,000 Hz or more, or 5,000 Hz or more. The pulse repetition rate may be 10 kHz or less.

[0150] The above laser light (L) can be processed into a high-resolution phone shape by simultaneously applying a relatively high repetition rate and relatively high energy.

[0151] The above laser light (L) enables the implementation of a reliable via having a diameter of 20 µm or less, especially when the depth is 20 µm or less.

[0152] An optical transmission system (400) is placed on the stage (100) and transmits laser light (L) to the insulating layer (15).

[0153] The above laser light (L) is not transmitted directly to the processing target (10), but rather the converted laser light is transmitted by passing through the optical transmission system (400).

[0154] The laser light (L) output from the laser beam generator (300) is called the primary laser light (L1), and the light emitted from the optical transport system (400) to the insulating layer (15) is called the secondary laser light (L2).

[0155] In the optical transmission system (400), the primary laser light (L1) passes through the mask (450) and is converted into secondary laser light (L2).

[0156] The above mask (450) is etched to have an intended pattern on a blank mask and is also called a photomask. The mask (450) is controlled so that a laser beam is emitted with an intended shape and intensity as a primary laser beam (L1) passes through it, and the emitted secondary laser beam (L2) is delivered to the processing target (10).

[0157] The laser light (L) can form a pattern in the insulating layer (15) through the optical transmission system (400) that includes via holes with controlled depth and diameter; pads with controlled depth and diameter; lines with controlled depth and width; or all of these.

[0158] The formation of the pattern is carried out by etching with the laser light. This pattern is formed by selectively removing a portion of the insulating layer. If such particulate by-products continue to exist within the etched pattern in the insulating layer, cleaning may become difficult in subsequent processes, and disconnection may occur in subsequent processes.

[0159] During the etching process using the laser light (L) mentioned above, particulate impurities or smear (P), which are processing byproducts, are formed. These need to be removed before proceeding with subsequent processes.

[0160] The blowing-suction device (500) removes particulate impurities or smear (P) generated when the insulating layer (15) is removed by the laser light (L) from the insulating layer (15) using air pressure.

[0161] The blowing-suction device (500) is positioned between the processing target (10) and the optical transmission system (400). This arrangement can make it easier to remove the particulate impurities or smear.

[0162] For blowing, gases such as CDA (Clean Dry Air) and N2 may be used as examples, but are not limited thereto.

[0163] This particulate byproduct or smear may exist on a portion of the etched pattern and may fall onto the insulating layer. Optionally, a processing protection layer (not shown) may be placed on the insulating layer, thereby allowing the particulate byproduct or smear to be removed more easily. Specifically, the particulate byproduct or smear may be induced to fall onto the processing protection layer rather than directly onto the surface of the insulating layer. This allows the particulate byproduct or smear to be removed more easily by removing the processing protection layer during a subsequent process, and then easily removed by removing the processing protection layer during a subsequent cleaning process.

[0164] The monitoring-inspection device (600) is a device that inspects the surface shape information of the processing target (10).

[0165] The control device (200) controls the laser light (L) generated from the laser beam generator (300) and / or the optical transmission system (400) by reflecting the surface shape information.

[0166] The monitoring-inspection device (600) and the control device (200) obtain information from the processing target and perform calculations therefrom to help enable appropriate laser irradiation and selective removal of the insulating layer.

[0167] For example, the mask (450) and the processing target (10) each have an alignment mark, and the control device (200) can control the position of the mask (450) and the processing target (10) through the alignment mark.

[0168] For example, the mask (450) and the processing target (10) each have alignment marks, and the control device (200) can control the processing height by the laser light (L).

[0169] For example, the mask (450) and the processing target (10) each have an alignment mark, and the control device (200) can control the focal size of the laser light (L).

[0170] The above control device (200) can control the temperature and humidity within the laser drilling system.

[0171] By the above laser drilling system, a pattern etched into the insulating layer can be formed sequentially by dividing the insulating layer into regions, and the shape, width, depth, etc. of the pattern can be controlled through the control of radar light, and laser drilling can be performed with high accuracy in a relatively fast process time.

[0173] A method for removing an insulating layer according to another embodiment includes a placement step; and an etching step; and etches the insulating layer of a workpiece to form an intaglio pattern.

[0174] The placement step places the processing target (10) on the stage (100) while controlling its position relative to the mask (450) of the optical transmission system (400).

[0175] The above placement step may include a process in which the stage (100) fixes the processing target (10) with a clamp or vacuum and relieves warping.

[0176] The above processing target (10) includes a metal layer (13) and an insulating layer (15) disposed on the metal layer (13). The metal layer (13) may be an electrically conductive layer (i.e., a patterned metal layer) disposed below the insulating layer in a packaging substrate. Alternatively, the metal layer (13) may be a seed layer disposed below the insulating layer in a packaging substrate.

[0177] The insulating layer (15) may be an organic layer or an organic-inorganic composite layer, etc. For example, the insulating layer may be formed by placing a sheet-shaped insulating material together with a release film such as a PET film on the metal layer (13), and then performing pressure lamination and then curing or semi-curing.

[0178] The release film, such as the above PET film, may also be utilized as the processing protection layer described above as needed.

[0179] The etching step involves irradiating the primary laser light (L1) output from the laser beam generator (300) onto the mask (450), and irradiating the laser light (L) that passes through the mask (450) and is converted into secondary laser light (L2) onto the processing target (10).

[0180] The above secondary laser light (L2) forms a pattern including via holes, pads, lines, or all of these in the insulating layer (15).

[0181] The above method for removing the insulating layer may further include a particle removal step simultaneously with or after the etching step.

[0182] The above particle removal step can remove or collect particulate impurities or smear (P) by performing blowing, suction, or both on the surface of the processing target (10).

[0184] The above control step is a step of verifying and controlling processing parameters.

[0185] The above processing parameters may include position alignment of the processing target (10), key verification of the alignment mark, height of the etching target in the processing target (10), and processing drawing data having processing purpose data.

[0186] The above control step can control the etching step to proceed in units of holes, pads, and lines.

[0188] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention. Explanation of the symbols

[0190] 10: Target for processing 11: Glass core 13: Metal layer 15: Insulating layer 21: Light-transmitting area 23: Phase conversion layer A 25: Phase conversion layer B 29: Light-blocking area 51: 1st depth etching region 53: 2nd depth etching region 55: Third depth etching region 59: Unetched region 100: Stage 200: Control device 300: Laser beam generator 400: Optical transport system 450: Mask 452: Light-transmitting layer 454: First phase conversion layer 456: Second phase conversion layer 458: Shading layer 500: Blowing-Suction Device 600: Monitoring-Inspection Device F51: 1st strength F53: 2nd strength F55: Third strength H51: 1st etch depth H53: 2nd etch depth H55: Third etch depth HB: Standard height L: Laser light L1: Primary laser beam L2: Secondary laser beam L51: 1st depth etching laser L53: 2nd depth etching laser L55: Third depth etching laser P: Particulate impurities (particles), smear

Claims

Claim 1 A processing target comprising a metal layer and an insulating layer disposed on the metal layer; a stage on which the processing target is disposed; a laser beam generator that outputs laser light; an optical transmission system disposed between the processing target and the laser beam generator and configured to selectively transmit laser light through a mask to the insulating layer; a monitoring-inspection device for inspecting the surface shape of the processing target; and a control device that controls the laser light generated from the laser beam generator, the optical transmission system, or both, by reflecting the surface shape information; wherein the mask comprises, when viewed from above, a projection area that transmits the laser light to project a first depth etching laser of a first intensity toward the insulating layer; and a phase conversion area A that transmits the laser light to project a second depth etching laser of a second intensity toward the insulating layer. A laser drilling system comprising: a light-transmitting layer which transmits the laser light, wherein the light-transmitting layer which transmits the laser light; a first phase-conversion layer disposed on the light-transmitting layer which controls the phase and intensity of the laser light to project a second depth-etching laser having a second intensity toward the insulating layer; a second phase-conversion layer disposed on the first phase-conversion layer which controls the phase and intensity of the laser light; and a light-blocking layer disposed on the second phase-conversion layer which blocks the laser light; wherein the laser light passing through the second phase-conversion layer and the first phase-conversion layer has its phase and intensity controlled to project a third depth-etching laser having a third intensity toward the insulating layer, and wherein the first phase-conversion layer, the second phase-conversion layer, and the light-blocking layer are selectively etched to implement a pattern to be formed on the insulating layer. Claim 2 delete Claim 3 delete Claim 4 A laser drilling system according to claim 1, wherein the area etched by irradiating a laser of the first intensity in the insulating layer is a first depth etching area, the area etched by irradiating a laser of the second intensity is a second depth etching area, the area corresponding to the light-blocking area is an unetched area, the height of the unetched area is a reference height, the distance between the reference height and the first depth etching area is a first etching depth, the distance between the reference height and the second depth etching area is a second etching depth, and the first etching depth is greater than the second etching depth. Claim 5 A laser drilling system according to claim 1, further comprising a blowing-suction device disposed between the processing target and the optical transmission system. Claim 6 A laser drilling system according to claim 1, wherein the insulating layer corresponding to the light-transmitting area has via holes formed therein. Claim 7 A laser drilling system according to claim 1, wherein a via electrode is disposed in the first depth etching region and a conductive line is disposed in the second depth etching region. Claim 8 A method for selectively removing an insulating layer by applying a laser drilling system according to claim 1, comprising: a placement step of placing a processing target on a stage while controlling its position relative to a mask of an optical transmission system; and an etching step of irradiating a processing target with a primary laser beam output from a laser beam generator onto the mask and irradiating the processing target with a laser beam converted into a secondary laser beam that passes through the mask; wherein the processing target comprises a metal layer and an insulating layer placed on the metal layer, and the secondary laser beam forms a pattern including via holes, pads, lines, or all of these on the insulating layer. Claim 9 In claim 8, the method for removing the insulating layer further comprises a particle removal step simultaneously with or after the etching step, wherein the particle removal step removes or collects particulate impurities or smears by performing blowing, suction, or both on the surface of the workpiece. Claim 10 In claim 8, the control step is a step of verifying and controlling processing parameters, wherein the processing parameters include position alignment of the processing target, key verification of alignment marks, height of the etching target from the processing target, and processing drawing data having processing purpose data, and the control step is a method for selectively removing an insulating layer, wherein the etching step is controlled to proceed in units of holes, pads, and lines.

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