Laser drilling system and method for selective removal of insulating layer

Abstract

This invention relates to a laser drilling system and a method for selectively removing an insulating layer. [Solution] The process includes a workpiece containing a metal layer and an insulating layer placed thereon, a stage on which the workpiece is placed, a laser beam generator that outputs laser light, an optical transmission system through which the laser light passes through a mask and is selectively transmitted to the insulating layer, a blowing-suction device placed 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 by the laser beam generator and / or the optical transmission system in accordance with the surface shape information. The mask is configured to remove the insulating layer in multiple stages or selectively to match the target depth and shape by including a projection region and a phase conversion region A (multiple phase conversion regions as needed) that transmit laser light and project depth etching lasers of different intensities toward the insulating layer when viewed from above, and a light-shielding region that blocks the laser light.

Description

Technical Field

[0001] Embodiments are related to a laser drilling system and a method for selectively removing an insulating layer, etc., which can simplify the process and proceed efficiently, and can also form a hole shape intended by general lithography techniques such as small holes and high aspect ratios even when it is difficult to form.

Background Art

[0002] In the manufacturing process for electronic components, the front-end (FE) process can implement a circuit on a semiconductor wafer, and the back-end (BE) process can assemble the wafer into a state where it can be used for an actual product. The packaging process may be included in the back-end process.

[0003] In recent years, the four core technologies of the semiconductor industry that have enabled the leap-forward development of electronic products include semiconductors, semiconductor packaging, semiconductor manufacturing, and software technology.

[0004] Semiconductor technology has developed in various fields such as sub-micron nanoscale line widths, over 10 million cells, high-speed operation, and heat dissipation. However, the complete packaging technology may not be supported. Therefore, the electrical performance of a semiconductor is determined more by the packaging technology and the electrical connection thereby than by the performance of the semiconductor technology itself.

[0005] One of the methods introduced for improving electrical performance is vertical connection. A via is an example of this vertical connection structure, and laser drilling can be applied to form it. When using lithography methods such as exposure and development to form a small via, technical difficulties may occur as the depth of the via hole increases. For example, it is difficult to ensure the reliability of the outer shape of the hole such as the size of the hole opening and the aspect ratio, so additional processes such as plasma etching must be added, resulting in difficulties such as complex steps and equipment and a decrease in yield.

[0006] On the other hand, the aforementioned background technology is technical information that the inventor possessed in order to derive the present invention, or acquired during the process of deriving the present invention, and is not necessarily publicly known technology that was disclosed to the general public before the filing of the present invention.

[0007] 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. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The examples aim to provide a laser drilling system that simplifies the process and enables efficient operation, as well as a method for selectively removing insulating layers. Furthermore, the examples aim to provide a laser drilling system capable of creating patterns with varying shapes, sizes, and depths, such as lines, holes, and pads, in essentially a single laser drilling pass. The examples also aim to provide a laser drilling system capable of creating holes even in cases where it is difficult to form the desired hole shape using conventional exposure techniques, such as small holes or holes with high aspect ratios. [Means for solving the problem]

[0009] This summary is provided to illustrate some of the simplified forms of the concept, which are further explained in the detailed description below. This summary is not intended to distinguish the main or core features claimed as a right, nor is it intended to be used to help determine the scope of the claimed right.

[0010] A laser drilling system according to one embodiment includes a workpiece including a metal layer and an insulating layer disposed on the metal layer; a stage on which the workpiece is placed; a laser beam generator that outputs laser light; an optical transmission system disposed between the workpiece and the laser beam generator to selectively transmit the laser light through a mask to the insulating layer; a monitoring-inspection device for inspecting the surface shape of the workpiece; and a control device that controls the laser light generated by the laser beam generator, the optical transmission system, or all of these in accordance with the surface shape information.

[0011] The mask may include, when viewed from above, a projection region that transmits the laser light and projects a first depth etching laser of a first intensity toward the insulating layer; a phase conversion region A that transmits the laser light and projects a second depth etching laser of a second intensity toward the insulating layer; and a light-shielding region that blocks the laser light.

[0012] Via holes may be formed in the insulating layer corresponding to the light-emitting region.

[0013] The mask may further include a phase conversion region B, when viewed from above, which transmits the laser light and projects a third depth etching laser with a third intensity in the direction of the insulating layer.

[0014] The mask may include: a light-transmitting layer which, when viewed in cross-section, transmits the laser light; a first phase-converting layer disposed on the light-transmitting layer and capable of projecting a second depth-etching laser having a second intensity toward the insulating layer by controlling the phase and intensity of the laser light; and a light-shielding layer disposed on the first phase-converting layer that blocks the laser light.

[0015] The first phase conversion layer and the light-shielding layer may be selectively etched to embody the pattern formed on the insulating layer.

[0016] The mask may include: a light-transmitting layer which, when viewed in cross-section, transmits the laser light; a first phase-converting layer disposed on the light-transmitting layer and capable of projecting a second depth-etching laser having a second intensity toward the insulating layer by controlling the phase and intensity of the laser light; a second phase-converting layer disposed on the first phase-converting layer for controlling the phase and intensity of the laser light; and a light-shielding layer disposed on the second phase-converting layer for blocking the laser light.

[0017] The laser light that has passed through the second phase conversion layer and the first phase conversion layer is projected toward the insulating layer as a third depth etching laser having a third intensity, with the phase and intensity controlled, and the first phase conversion layer, the second phase conversion layer, and the light shielding layer may be selectively etched to embody a pattern formed on the insulating layer.

[0018] The blowing-suction device may be further provided, positioned between the workpiece and the optical transmission system.

[0019] In the insulating layer, the region etched by irradiation with the first intensity laser is called the first depth etched region, the region etched by irradiation with the second intensity laser is called the second depth etched region, the region corresponding to the light-shielding region is called the unetched region, the height of the unetched region is called the reference height, the distance from the reference height to the first depth etched region is called the first etched depth, the distance from the reference height to the second depth etched region is called the second etched depth, and the first etched depth may be greater than the second etched depth.

[0020] The bottom surface of the first depth etching region may expose the metal layer.

[0021] Via electrodes may be placed in the first depth etching region.

[0022] Conductive lines may be placed in the second depth etched region.

[0023] The laser drilling system can simultaneously form via holes with controlled depth and diameter, pads with controlled depth and diameter, lines with controlled depth and width, or patterns including all of these in the insulating layer.

[0024] The laser drilling system according to an embodiment includes a processing target including a metal layer and an insulating layer disposed on the metal layer; a stage on which the processing target 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 processing target and the optical transmission system; a monitoring-inspection device inspecting the surface shape of the processing target; and a control device controlling the laser light generated by the laser beam generator and / or the optical transmission system in reflection of the surface shape information.

[0025] The laser light output by the laser beam generator is primary laser light, and the light emitted to the insulating layer by the optical transmission system is secondary laser light.

[0026] The primary laser light can be converted into secondary laser light by passing through a mask in the optical transmission system.

[0027] The laser light can form via holes with controlled depth and diameter, pads with controlled depth and diameter, lines with controlled depth and width, or patterns including all of these in the insulating layer through the optical transmission system.

[0028] The mask and the processing target can each have alignment marks.

[0029] The control device can control the positions of the mask and the processing target through the alignment marks.

[0030] The mask and the processing target can each have alignment marks.

[0031] The control device can control the processing height using the laser light.

[0032] The blowing-suction device can remove particulate impurities or smear generated when the insulating layer is removed by the laser light from the insulating layer using air pressure.

[0033] The control device is capable of controlling the temperature and humidity within the laser drilling system.

[0034] A selective removal method for an insulating layer according to an embodiment includes a positioning step of placing the workpiece on a stage while controlling its position relative to the mask of the optical transmission system; and an etching step of in which primary laser light output from a laser beam generator is incident on the mask, and the laser light, which has been converted into secondary laser light by passing through the mask, is irradiated onto the workpiece.

[0035] The object to be processed may include a metal layer and an insulating layer disposed on the metal layer.

[0036] The secondary laser beam can form via holes, pads, lines, or patterns including all of these in the insulating layer.

[0037] The insulating layer removal method may further include a particle removal step simultaneously with or after the chipping step.

[0038] The particle removal step can be performed by blowing, suctioning, or all of the above on the surface of the workpiece to remove or collect particulate impurities or smears.

[0039] The aforementioned placement step allows the stage to secure the workpiece with clamps or vacuum and to position it while easing warpage.

[0040] The aforementioned control step is the step of checking and controlling the machining parameters.

[0041] The processing parameters may include the position alignment of the workpiece, key confirmation of the alignment mark, the height of the workpiece to be cut, and processing drawing data having processing purpose data.

[0042] The control step can be controlled so that the cutting step proceeds in units of holes, pads, and lines. [Effects of the Invention]

[0043] The laser drilling system in this example simplifies the process and allows for efficient execution, enabling the creation of patterns with varying shapes, sizes, and depths, such as lines, holes, and pads, in virtually a single laser drilling pass. Furthermore, it can create small holes or holes with high aspect ratios, even when conventional exposure techniques struggle to achieve the desired hole shape.

[0044] The laser drilling system and selective removal method for the insulating layer, as demonstrated in the examples, simplify the process and allow for efficient execution. They also enable the formation of desired hole shapes, such as small holes or those with high aspect ratios, which are difficult to achieve with conventional exposure techniques. [Brief explanation of the drawing]

[0045] [Figure 1] This is a conceptual diagram illustrating the progression of the etching stage in an optical transmission system related to a concrete example, using a cross-sectional view (top: conceptual diagram illustrating the mask and laser light, middle: graph showing the intensity of the secondary laser light, bottom: object to be processed before etching). [Figure 2a] The diagram (top) conceptually illustrates the cross-section of the mask in the concrete example, and the graph (bottom) shows the intensity of the secondary laser light. [Figure 2b] The image shows a graph (top) illustrating the intensity of the secondary laser light in a concrete example, and a conceptual diagram (bottom) illustrating the etched workpiece in cross-section. [Figure 3]This is a conceptual diagram illustrating the process of etching the workpiece using a concrete example (top: graph showing the intensity of the secondary laser light, middle: optical transmission system and blowing-suction device, bottom: workpiece and particulate impurities). [Figure 4a] This is a conceptual diagram illustrating the processed object after mincing, as shown in cross-section, in a concrete example. [Figure 4b] This is a conceptual diagram illustrating, in cross-section, the appearance of a processed object after an additional metal layer has been formed on it following the etching process, as shown in the concrete example. [Figure 5] This is a conceptual diagram illustrating a laser drilling system as an example of its implementation. [Figure 6] This is a conceptual diagram illustrating the progression of the carving stage in an optical transmission system related to a concrete example, using a cross-sectional view. [Modes for carrying out the invention]

[0046] The following detailed descriptions are provided to help you understand the methods, apparatus and / or systems described herein comprehensively. However, after understanding the disclosures of this application, it will become clear that there are various changes, modifications and equivalents to the methods, apparatus and / or systems described herein. For example, the work sequences described herein are merely illustrative and are not limited to the work explicitly stated herein, with the exception of work that may be obviously changed after understanding the disclosures of this application and must always be performed in a specific order. Also, descriptions of features known after understanding the disclosures of this application may be omitted for clarity and conciseness, and this omission of features does not imply that the descriptions are common knowledge.

[0047] The features described herein may be embodied in other forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many possible ways of embodiing the methods, apparatus and / or systems described herein, which will become apparent after understanding the disclosure of this application.

[0048] Terms such as “first,” “second,” and “third” may be used herein to describe various components, components, regions, layers, or sections, but such components, components, regions, layers, or sections are not limited by such terms. Rather, these terms are used to distinguish one member, part, region, layer, or section from other members, parts, regions, layers, or sections. Accordingly, a first member, part, region, layer, or section referred to in the examples described herein may be referred to as a second member, part, region, layer, or section without departing from the teachings of the examples.

[0049] Throughout the specification, any technique in which an element such as a layer, region, or substrate is “on,” “connected,” or “joined” to another element means that it is directly “on,” “connected,” or “joined” to the other element, or that one or more other elements may be intervening between them. Conversely, if an element is described as being “directly on,” “directly connected,” or “directly joined,” then no other elements may be intervening between them. Similarly, expressions such as “between” and “directly between” and “indirectly introduced” and “directly introduced” may be interpreted as described above.

[0050] The terms used herein are for illustrative purposes only and are not intended to limit this disclosure. The singular forms “a,” “an,” and “the” as used herein may include plural forms unless the context clearly indicates otherwise. The terms “and / or” as used herein include one or more combinations of the listed items. The terms “include,” “comprise,” and “have” as used herein indicate the presence of an expressed feature, number, operation, element, component, and / or combination thereof, but do not exclude the presence or addition of one or more other features, numbers, operations, elements, components, and / or combinations thereof. Where the term “may” is used herein in relation to an example (for example, in relation to what an example or example includes or can embody), it means that where such a feature is included or embodied, there is at least one example or example, but not all examples are limited thereto.

[0051] Throughout this specification, “B being positioned on A” means that B is positioned in direct contact with A or on A separated by another layer or structure, and is not construed as being limited to B being positioned in direct contact with A. Unless otherwise defined, all terms used in this document have the same meaning as that generally understood by an ordinary technician in the art to which this document relates, given the understanding of this document, and this is consistent with the understanding of this document hereafter.

[0052] 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 this disclosure, and not as an ideal or overly formal meaning unless expressly defined herein.

[0053] Figure 1 is a conceptual diagram illustrating the progression of the etching stage in the optical transmission system of the embodiment (top: conceptual diagram illustrating the mask and laser light, middle: graph showing the intensity of the secondary laser light, bottom: workpiece before etching), and Figure 5 is a conceptual diagram illustrating the laser drilling system of the embodiment. Figure 2a is a diagram conceptually illustrating the cross-section of the mask of the embodiment (top) and a graph showing the intensity of the secondary laser light (bottom), and Figure 2a is a graph showing the intensity of the secondary laser light of the embodiment (top) and a conceptual diagram illustrating the etched workpiece in cross-section (bottom). Also, Figure 3 is a conceptual diagram illustrating the process of etching the workpiece in cross-section using the embodiment (top: graph showing the intensity of the secondary laser light, middle: optical transmission system and blowing-suction device, bottom: workpiece and particulate impurities). Figure 4a is a conceptual diagram illustrating the workpiece after etching in cross-section according to the embodiment, and Figure 4b is a conceptual diagram illustrating the appearance of the workpiece after an additional metal layer has been formed on it after etching according to the embodiment. A more detailed explanation of the actual implementation will be given with reference to the aforementioned drawings.

[0054] To achieve the above objective, a laser drilling system according to one embodiment of the embodiment processes the workpiece 10, comprising a stage 100; an optical transmission system 400; a laser beam generator 300; a monitoring-inspection device 600; and a control device 200 (see Figure 5). Specifically, these components are interconnected to carry out selective etching of the workpiece 10 within the laser drilling system.

[0055] The laser drilling system may further include a blowing-suction device 500;

[0056] The object to be processed 10 includes a metal layer 13 and an insulating layer 15 placed on the metal layer 13 (see the lower part of Figure 1).

[0057] Exemplary, the object to be processed 10 may be a packaging substrate applied to the packaging of a semiconductor device. When the object to be processed 10 is applied to the packaging substrate, a glass core 11 may be applied. Specifically, the object to be processed 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.

[0058] The workpiece 10 has an insulating layer, and the metal layer is formed above and / or below the insulating layer. Selective removal of the insulating layer will result in the formation of a metal layer (electrically conductive layer) on the workpiece 10 in a subsequent step, which can become a wire pattern on the packaging substrate.

[0059] In existing processes, forming a metal layer (electrically conductive layer) required a very complex multi-step process.

[0060] In existing processes, such a process is carried out to form a pattern on the workpiece that includes holes, pads, and lines. 1) The substrate to be processed is cleaned, 2) a metal layer is formed by a method such as sputtering, 3) pretreatment is carried out, 4) lithography is carried out, 5) plating is carried out, 6) annealing and etching are carried out, 7) another cleaning process is carried out, 8) pretreatment is carried out again, 9) insulating material is placed, 10) cured to produce an insulating layer, 11) via holes are formed, 12) desmear is carried out, 13) cleaning is carried out, 14) thereafter a metal layer is formed, 15) pretreatment is carried out, 16) lithography is carried out, 17) plating is carried out, and 18) annealing and etching are carried out. This process is repeated to form a single layer of pattern.

[0061] In this concrete example, the portion where the pattern is formed with an insulating layer is removed. However, instead of separately forming lines and holes as described above, holes, pads, and lines can be created through the laser drilling process, thus simplifying and improving the efficiency of the process. Once the portion where the pattern is formed with an insulating layer is removed, a process such as plating can be carried out to efficiently form a metal layer in the shape of a pattern.

[0062] Stage 100 is the apparatus on which the workpiece 10 is placed.

[0063] The workpiece 10 is positioned on the stage 100 by an automated device (e.g., a robotic arm), and its position after positioning can be checked and corrected by a monitoring-inspection device 600 and a control device 200. At this time, alignment marks (not shown) are placed on the workpiece 10, and the monitoring-inspection device 600 detects its relative position to the stage 100, etc. This information is transmitted to the control device 200, which can then check whether the position is appropriate and adjust the position of the workpiece 10, etc.

[0064] The laser beam generator 300 is connected to the optical transmission system 400 and outputs laser light L.

[0065] The laser light L may be one that has an absorption rate suitable for processing metal materials such as copper and titanium. Furthermore, the laser light L may be one that has an absorption rate suitable for 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.

[0066] Specifically, the laser light L may be one having a UV wavelength. For example, the laser light L may have wavelengths 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 also have wavelengths of 100 nm or more.

[0067] 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 energies are applied, insulating layers and the like can be removed more efficiently.

[0068] The laser light L may have a pulse repetition rate of 10 Hz or higher, 50 Hz or higher, 100 Hz or higher, 300 Hz or higher, 600 Hz or higher, 900 Hz or higher, 1,000 Hz or higher, 2,000 Hz or higher, 3,000 Hz or higher, 4,000 Hz or higher, or 5,000 Hz or higher. The pulse repetition rate may be 10 kHz or lower.

[0069] The aforementioned laser beam L can process shapes with high resolution while simultaneously applying a relatively high repetition rate and relatively high energy.

[0070] The aforementioned laser beam L can realize reliable vias having a diameter of 20 μm or less, especially when the depth is 20 μm or less.

[0071] The optical transmission system 400 is positioned on the stage 100 and transmits the laser light L to the insulating layer 15.

[0072] The laser light L is not immediately transmitted to the workpiece 10, but rather the laser light is transmitted after passing through the optical transmission system 400 and being converted.

[0073] The laser light L output by the laser beam generator 300 is called the primary laser light, and the light emitted from the optical transmission system 400 to the insulating layer 15 is called the secondary laser light.

[0074] In the optical transmission system 400, the primary laser light passes through the mask 450 and is converted into secondary laser light.

[0075] The optical transmission system 400 is positioned between the workpiece 10 and the laser beam generator 300, and can transmit the laser light L, which has been selectively converted, through the mask 450 to the insulating layer 15.

[0076] Detailed information about the mask and the laser light it converts will be provided later.

[0077] The laser light L can, through the optical transmission system 400, form patterns on the insulating layer 15 including via holes with controlled depth and diameter, pads with controlled depth and diameter, lines with controlled depth and width, or all of these.

[0078] The pattern is formed by etching with the aforementioned laser light. This pattern is formed by selectively removing a portion of the insulating layer. If such particulate byproducts remain within the etching pattern in the insulating layer, cleaning may become difficult in subsequent processes, potentially leading to disconnections or other problems in those processes.

[0079] During the engraving process using the aforementioned laser light L, particulate impurities or smears P, which are processing by-products, may be formed. These must be removed before proceeding with subsequent processes.

[0080] The system may further include a blowing-suction device 500 positioned between the workpiece 10 and the optical transmission system 400.

[0081] 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.

[0082] The blowing-suction device 500 is positioned between the workpiece 10 and the optical transmission system 400. This arrangement makes it easier to remove particulate impurities or smears.

[0083] Blowing can, for example, involve the application of gases such as CDA (Clean Dry Air) and N2, but it is not limited to these.

[0084] These particulate by-products or smears are present in part of the etched pattern and may fall onto the insulating layer. A processing protection layer (not shown) can be selectively placed on the insulating layer, thereby making the particulate by-products or smears easier to remove. Specifically, the particulate by-products or smears can be guided to fall onto the processing protection layer rather than directly onto the surface of the insulating layer. This allows for easier removal of the particulate by-products or smears during subsequent processes, such as removing the processing protection layer, and then easily removing the processing protection layer during subsequent cleaning processes.

[0085] The monitoring and inspection device 600 is a device for inspecting the surface shape information of the workpiece 10.

[0086] The control device 200 controls the laser light L generated by the laser beam generator 300 and / or the optical transmission system 400 in accordance with the surface shape information.

[0087] The monitoring and inspection device 600 and the control device 200 acquire information from the workpiece and use this information to perform calculations that help ensure appropriate laser irradiation and selective removal of the insulating layer.

[0088] For example, the mask 450 and the workpiece 10 each have alignment marks, and the control device 200 can control the positions of the mask 450 and the workpiece 10 through the alignment marks.

[0089] For example, the mask 450 and the workpiece 10 each have alignment marks, and the control device 200 can control the processing height by the laser beam L.

[0090] For example, the mask 450 and the workpiece 10 each have alignment marks, and the control device 200 can control the size of the focal point of the laser beam L.

[0091] The control device 200 can control the temperature and humidity within the laser drilling system.

[0092] The laser drilling system allows for the sequential formation of etched patterns in the insulating layer by dividing it into regions. The shape, width, and depth of the patterns can be controlled through the control of the radar beam, enabling high-precision laser drilling in a relatively fast process time.

[0093] The control device 200 checks and controls the machining parameters.

[0094] The processing parameters may include the positional alignment of the workpiece 10, key confirmation of the alignment marks, the height of the food to be cut on the workpiece 10, and processing drawing data having processing purpose data.

[0095] The control device 200 can control the holes, pads, and lines to proceed with the engraving in unit units.

[0096] We will now provide a detailed explanation of Mask 450, which is an example of this implementation.

[0097] The mask 450, when viewed in cross-section, includes a light-transmitting layer 452; a first phase-conversion layer 454; and a light-shielding layer 458. The mask 450 may further include a second phase-conversion layer 456 when viewed in cross-section. The second phase-conversion layer 456 may be positioned between the first phase-conversion layer 454 and the light-shielding layer 458. These are selectively etched and applied to correspond to the pattern to be formed.

[0098] The light-transmitting layer 452 is a layer that transmits the laser light L. The light-transmitting layer transmits the laser light in such a way that the changes in the phase and intensity of the laser light are minimal.

[0099] The first phase conversion layer 454 is arranged on the light transmission layer 452 and controls the phase and intensity of the laser light L so that a second depth etching laser L53 having a second intensity F53 can be projected in the direction of the insulating layer 15.

[0100] The second phase conversion layer 456 is arranged on the first phase conversion layer 454 and can control the phase and intensity of the laser light L.

[0101] 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 so that it can project a third depth etching laser L55 having a third intensity F55 in the direction of the insulating layer 15.

[0102] The light-shielding layer 458 is disposed on the first phase conversion layer 454 or the second phase conversion layer 456. The light-shielding layer substantially suppresses the transmission of the laser light through the mask and substantially prevents etching of the insulating layer.

[0103] The mask may be selectively etched so as to embody the pattern formed on the insulating layer 15, with the first phase conversion layer 454 and the light-shielding layer 458 being the same.

[0104] The mask may be selectively etched so as to embody the pattern formed on the insulating layer 15, with respect to the first phase conversion layer 454, the second phase conversion layer 456, and the light-shielding layer 458.

[0105] The mask 450, when viewed from above, includes a light-emitting region 21; a phase-conversion region A(23); and a light-shielding region 29. The mask 450 may further include a phase-conversion region B(25) when viewed from above.

[0106] The light projection area 21 transmits the laser light L and projects a first depth etching laser L51 with a 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.

[0107] The phase conversion region A(23) transmits the laser light L and projects a second depth etching laser L53 with a second intensity F53 in the direction of the insulating layer 15. The second depth etching laser L53 can etch the insulating layer 15 with a second etching depth H53.

[0108] The phase conversion region B(25) transmits the laser light L and projects a third depth etching laser L55 with a third intensity F55 in the direction of the insulating layer 15. The third depth etching laser L55 can etch the insulating layer 15 with a third etching depth H55.

[0109] A first depth etching region 51 can be formed in the insulating layer 15 by irradiating it with the first intensity laser F51 and etching the region.

[0110] A second depth etching region 53 can be formed in the insulating layer 15 by irradiating it with the second intensity laser F53 and etching the region.

[0111] The region of the insulating layer 15 corresponding to the light-shielding region 29 may be an unetched region 59.

[0112] The height of the unetched region 59 in the insulating layer 15 is referred to as the reference height HB.

[0113] The distance between the reference height HB and the first depth of the carving region 51 is the first carving depth H51.

[0114] The distance between the reference height HB and the second depth of the erosion region 53 is the second erosion depth H53.

[0115] The first graft depth H51 may be greater than the second graft depth H53.

[0116] The distance between the reference height HB and the third depth of the erosion region 55 is the third erosion depth H55.

[0117] The third graft depth H55 may be greater than the second graft depth H53.

[0118] Via holes may be formed in the first depth etching region 51 of the insulating layer 15 corresponding to the light projection region 21.

[0119] The metal layer 13 can be exposed at the bottom surface of the first depth etching region 51.

[0120] Via electrodes can be placed in the first depth etching region 51.

[0121] Conductive lines may be placed in the second depth etching region 53.

[0122] Via electrodes, conductive lines, and the like can be implemented by forming a copper layer using methods such as electroplating.

[0123] The laser drilling system is capable of simultaneously forming via holes with controlled depth and diameter; pads with controlled depth and diameter; lines with controlled depth and width; or patterns including all of these in the insulating layer 15.

[0124] Examples of this technology include providing a simplified and efficient laser drilling system. Furthermore, it enables the creation of patterns with varying shapes, sizes, and depths—such as lines, holes, and pads—in virtually a single laser drilling pass.

[0125] Figure 5 is a conceptual diagram illustrating a laser drilling system in a real-world example, and Figure 6 is a conceptual diagram illustrating the progression of the etching stage in the optical transmission system in a real-world example using a cross-sectional view. The real-world example will be described in more detail below with reference to Figures 5 and 6.

[0126] To achieve the above objective, a laser drilling system according to one embodiment of the embodiment includes 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 Figure 5).

[0127] The aforementioned components are connected to each other to carry out selective cutting of the workpiece 10 within the laser drilling system.

[0128] The object to be processed 10 includes a metal layer 13 and an insulating layer 15 placed on the metal layer 13 (see Figure 6).

[0129] Exemplary, the object to be processed 10 may be a packaging substrate applied to the packaging of a semiconductor device. When the object to be processed 10 is applied to the packaging substrate, a glass core 11 may be applied. Specifically, the object to be processed 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.

[0130] The workpiece 10 has an insulating layer, and the metal layer is formed above and / or below the insulating layer. Selective removal of the insulating layer will result in the formation of a metal layer (electrically conductive layer) on the workpiece 10 in a subsequent step, which can become a wire pattern on the packaging substrate.

[0131] In existing processes, forming a metal layer (electrically conductive layer) required a very complex multi-step process.

[0132] In existing processes, such a process is carried out to form a pattern on the workpiece that includes holes, pads, and lines. 1) The substrate to be processed is cleaned, 2) a metal layer is formed by a method such as sputtering, 3) pretreatment is carried out, 4) lithography is carried out, 5) plating is carried out, 6) annealing and etching are carried out, 7) another cleaning process is carried out, 8) pretreatment is carried out again, 9) insulating material is placed, 10) cured to produce an insulating layer, 11) via holes are formed, 12) desmear is carried out, 13) cleaning is carried out, 14) thereafter a metal layer is formed, 15) pretreatment is carried out, 16) lithography is carried out, 17) plating is carried out, and 18) annealing and etching are carried out. This process is repeated to form a single layer of pattern.

[0133] In this concrete example, the portion where the pattern is formed with an insulating layer is removed. However, instead of separately forming lines and holes as described above, holes, pads, and lines can be created through the laser drilling process, thus simplifying and improving the efficiency of the process. Once the portion where the pattern is formed with an insulating layer is removed, a process such as plating can be carried out to efficiently form a metal layer in the shape of a pattern.

[0134] Stage 100 is the apparatus on which the workpiece 10 is placed.

[0135] The workpiece 10 is positioned on the stage 100 by an automated device (e.g., a robotic arm), and its position after positioning can be checked and corrected by a monitoring-inspection device 600 and a control device 200. At this time, alignment marks (not shown) are placed on the workpiece 10, and the monitoring-inspection device 600 detects its relative position to the stage 100, etc. This information is transmitted to the control device 200, which can then check whether the position is appropriate and adjust the position of the workpiece 10, etc.

[0136] The laser beam generator 300 is connected to the optical transmission system 400 and outputs laser light L.

[0137] The laser light L may be one that has an absorption rate suitable for processing metal materials such as copper and titanium. Furthermore, the laser light L may be one that has an absorption rate suitable for 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.

[0138] Specifically, the laser light L may be one having a UV wavelength. For example, the laser light L may have wavelengths 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 also have wavelengths of 100 nm or more.

[0139] 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 energies are applied, insulating layers and the like can be removed more efficiently.

[0140] The laser light L may have a pulse repetition rate of 10 Hz or higher, 50 Hz or higher, 100 Hz or higher, 300 Hz or higher, 600 Hz or higher, 900 Hz or higher, 1,000 Hz or higher, 2,000 Hz or higher, 3,000 Hz or higher, 4,000 Hz or higher, or 5,000 Hz or higher. The pulse repetition rate may be 10 kHz or lower.

[0141] The aforementioned laser beam L can process shapes with high resolution while simultaneously applying a relatively high repetition rate and relatively high energy.

[0142] The aforementioned laser beam L can realize reliable vias having a diameter of 20 μm or less, especially when the depth is 20 μm or less.

[0143] The optical transmission system 400 is positioned on the stage 100 and transmits the laser light L to the insulating layer 15.

[0144] The laser light L is not immediately transmitted to the workpiece 10, but rather the laser light is transmitted after passing through the optical transmission system 400 and being converted.

[0145] The laser light L output by the laser beam generator 300 is called the primary laser light L1, and the light emitted from the optical transmission system 400 to the insulating layer 15 is called the secondary laser light L2.

[0146] In the optical transmission system 400, the primary laser light L1 passes through the mask 450 and is converted into secondary laser light L2.

[0147] The mask 450 is a blank mask that has been engraved with an intended pattern, and is sometimes called a photomask. The mask 450 is controlled so that the primary laser beam L1 passes through it and the laser beam is emitted in an intended shape and intensity, and this emitted secondary laser beam L2 is transmitted to the workpiece 10.

[0148] The laser light L can, through the optical transmission system 400, form patterns on the insulating layer 15 including via holes with controlled depth and diameter, pads with controlled depth and diameter, lines with controlled depth and width, or all of these.

[0149] The pattern is formed by etching with the aforementioned laser light. This pattern is formed by selectively removing a portion of the insulating layer. If such particulate byproducts remain within the etching pattern in the insulating layer, cleaning may become difficult in subsequent processes, potentially leading to disconnections or other problems in those processes.

[0150] During the engraving process using the laser light L, particulate impurities or smears P, which are processing by-products, are formed. These must be removed before proceeding to subsequent processes.

[0151] 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.

[0152] The blowing-suction device 500 is positioned between the workpiece 10 and the optical transmission system 400. This arrangement makes it easier to remove particulate impurities or smears.

[0153] Blowing can, for example, involve the application of gases such as CDA (Clean Dry Air) and N2, but it is not limited to these.

[0154] These particulate by-products or smears are present in part of the etched pattern and may fall onto the insulating layer. A processing protection layer (not shown) can be selectively placed on the insulating layer, thereby making the particulate by-products or smears easier to remove. Specifically, the particulate by-products or smears can be guided to fall onto the processing protection layer rather than directly onto the surface of the insulating layer. This allows for easier removal of the particulate by-products or smears during subsequent processes, such as removing the processing protection layer, and then easily removing the processing protection layer during subsequent cleaning processes.

[0155] The monitoring and inspection device 600 is a device for inspecting the surface shape information of the workpiece 10.

[0156] The control device 200 controls the laser light L generated by the laser beam generator 300 and / or the optical transmission system 400 in accordance with the surface shape information.

[0157] The monitoring and inspection device 600 and the control device 200 acquire information from the workpiece and use this information to perform calculations that help ensure appropriate laser irradiation and selective removal of the insulating layer.

[0158] For example, the mask 450 and the workpiece 10 each have alignment marks, and the control device 200 can control the positions of the mask 450 and the workpiece 10 through the alignment marks.

[0159] For example, the mask 450 and the workpiece 10 each have alignment marks, and the control device 200 can control the processing height by the laser beam L.

[0160] For example, the mask 450 and the workpiece 10 each have alignment marks, and the control device 200 can control the size of the focal point of the laser beam L.

[0161] The control device 200 can control the temperature and humidity within the laser drilling system.

[0162] The laser drilling system allows for the sequential formation of etched patterns in the insulating layer by dividing it into regions. The shape, width, and depth of the patterns can be controlled through the control of the radar beam, enabling high-precision laser drilling in a relatively fast process time.

[0163] Another embodiment of the method for removing an insulating layer includes a placement step and an etching step, wherein the insulating layer to be processed is etched to form an incised pattern.

[0164] In the placement stage, the workpiece 10 is positioned on the stage 100 while controlling its position relative to the mask 450 of the optical transmission system 400.

[0165] The arrangement step may include a process in which the stage 100 secures the workpiece 10 with clamps or vacuum and relieves warpage.

[0166] The object to be processed 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 beneath the insulating layer in the packaging substrate. Alternatively, the metal layer 13 may be a seed layer disposed beneath the insulating layer in the packaging substrate.

[0167] The insulating layer 15 may be an organic layer or an organic-inorganic composite layer. For example, the insulating layer may be formed by placing a sheet-like insulating material on the metal layer 13 together with a release film such as a PET film, and then curing or partially curing it after vacuum lamination or the like.

[0168] The aforementioned release film, such as the PET film, may be used as the processing protection layer as described above, if necessary.

[0169] In the etching stage, the primary laser light L1 output from the laser beam generator 300 is incident on the mask 450, and the laser light L, which has been converted into secondary laser light L2 after passing through the mask 450, is irradiated onto the workpiece 10.

[0170] The secondary laser beam L2 forms via holes, pads, lines, or patterns including all of these on the insulating layer 15.

[0171] The insulating layer removal method may further include a particle removal step simultaneously with or after the etching step.

[0172] The particle removal step can remove or collect particulate impurities or smear P on the surface of the workpiece 10 by blowing, suction, or all of the above.

[0173] The aforementioned control step is the step of checking and controlling the machining parameters.

[0174] The processing parameters may include the positional alignment of the workpiece 10, key confirmation of the alignment marks, the height of the food to be cut on the workpiece 10, and processing drawing data having processing purpose data.

[0175] The control step can control the holes, pads, and lines so that the carving step proceeds in unit units.

[0176] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. Various modifications and improvements by those skilled in the art, utilizing the basic concepts of the present invention as defined in the following claims, also fall within the scope of the present invention. [Explanation of symbols]

[0177] 10: Target for processing 11: Glass core 13: Metal layer 15: Insulating layer 21: Lighting area 23: Phase conversion layer A 25: Phase conversion layer B 29: Shading area 51: First depth erosion region 53: Second depth erosion region 55: Third depth etch region 59: Unetched area 100: Stage 200: Control device 300: Laser beam generator 400: Optical transmission system 450: Mask 452: Light transmission layer 454: First Phase Transformation Layer 456: Second Phase Conversion Layer 458: Light blocking layer 500: Blowing-Suction Device 600: Monitoring - Inspection Equipment F51: 1st strength F53: Second Intensity F55: 3rd strength H51: Depth of first incision H53: Depth of second meal H55: Depth of third meal HB: Reference height L: Laser light L1: Primary laser light L2: Secondary laser light L51: First depth etching laser L53: Second depth etching laser L55: Third depth etching laser P: Particulate impurities (particles), smear

Claims

1. A workpiece including a metal layer and an insulating layer disposed on the metal layer, A stage on which the workpiece is placed, A laser beam generator that emits laser light, An optical transmission system is placed between the workpiece and the laser beam generator to selectively transmit laser light through the mask to the insulating layer. A monitoring and inspection device for inspecting the surface shape of the workpiece, A laser beam generated by the laser beam generator in accordance with the surface shape information, the optical transmission system, or a control device that controls all of these, Includes, When viewed from above, the aforementioned mask A projection region that transmits the aforementioned laser light and projects a first depth etching laser having a first intensity in the direction of the insulating layer, A phase conversion region A transmits the aforementioned laser light and projects a second depth etching laser with a second intensity in the direction of the insulating layer, A light-shielding region that blocks the laser light, A laser drilling system, including...

2. When viewed in cross-section, the aforementioned mask The aforementioned light-transmitting layer is a layer that transmits laser light, A first phase conversion layer is disposed on the light-transmitting layer and capable of projecting 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 light-shielding layer is placed on the first phase conversion layer and blocks the laser light, Includes, The laser drilling system according to claim 1, wherein the first phase conversion layer and the light shielding layer are selectively etched to embody a pattern formed on the insulating layer.

3. When viewed in cross-section, the aforementioned mask The aforementioned light-transmitting layer is a layer that transmits laser light, A first phase conversion layer is disposed on the light-transmitting layer and capable of projecting 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 is disposed on the first phase conversion layer and controls the phase and intensity of the laser light, A light-shielding layer is placed on the second phase conversion layer and blocks the laser light, Includes, The laser light that has passed 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. The laser drilling system according to claim 2, wherein the first phase conversion layer, the second phase conversion layer, and the light shielding layer are selectively etched to embody a pattern formed on the insulating layer.

4. In the aforementioned insulating layer The region etched by the first intensity laser is the first depth etched region. The region etched by the second intensity laser is the second depth etched region. The region corresponding to the light-shielding region is the unetched region. The height of the un-etched region is called the reference height. The distance between the reference height and the first depth carving region is the first carving depth. The distance between the reference height and the second depth carving region is the second carving depth. The laser drilling system according to claim 1, wherein the first cutting depth is greater than the second cutting depth.

5. The laser drilling system according to claim 1, further comprising a blowing-suction device disposed between the workpiece and the optical transmission system.

6. The laser drilling system according to claim 1, wherein via holes are formed in the insulating layer corresponding to the light projection area.

7. A via electrode is placed in the first depth etching region. The laser drilling system according to claim 4, wherein conductive lines are arranged in the second depth etching region.

8. The setup stage involves positioning the object to be processed on the stage while controlling its position relative to the mask of the optical transmission system, The process includes an engraving step in which a primary laser beam output from a laser beam generator is incident on the mask, and the laser beam, converted into a secondary laser beam after passing through the mask, is irradiated onto the workpiece, The aforementioned workpiece is It includes a metal layer and an insulating layer disposed on the metal layer, A method for selectively removing an insulating layer, wherein the secondary laser light forms via holes, pads, lines, or a pattern including all of these in the insulating layer.

9. The insulating layer removal method further includes a particle removal step simultaneously with or after the chipping step, The method for removing an insulating layer according to claim 8, wherein the particle removal step involves removing or collecting particulate impurities or smear by blowing, suction, or all of the above on the surface of the workpiece.

10. The aforementioned control step is a step in which the machining parameters are checked and controlled. The processing parameters include the position alignment of the workpiece, key confirmation of the alignment mark, the height of the workpiece to be cut, and processing drawing data having processing purpose data. The method for removing an insulating layer according to claim 8, wherein the control step is controlled so that the etching step proceeds in units of holes, pads, and lines.

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