Manufacture method for a packaging substrate

Abstract

The method for fabricating the package substrate of the example includes the following steps to prepare the package substrate: a preparation step, preparing a substrate substrate including a core layer, a first conductive layer disposed on the core layer, and an insulating layer disposed on the first conductive layer; and a desmearing step, desmearing the substrate substrate. The insulating layer includes contact holes for penetrating the insulating layer in the thickness direction. The upper surface of the first conductive layer includes an exposed area exposed by the contact holes. In the desmearing step, a reactive gas containing oxygen and a fluorine gas is used to perform plasma desmearing on the substrate substrate. In the desmearing step, the ratio of the flow rate of the fluorine gas to the flow rate of the oxygen introduced into the atmosphere in which the substrate substrate is disposed is 4.5 or more.

Description

[Technical Field]

[0001] The example relates to a method for manufacturing a packaging substrate. [Previous Technology]

[0002] In the process of manufacturing electronic components, the process of incorporating circuits into semiconductor wafers is called the front-end process (FE), and the process of assembling wafers into a state that can be used in actual products is called the back-end process (BE). Furthermore, the subsequent process includes the packaging process.

[0003] Recently, the four core technologies driving the rapid development of electronic products in the semiconductor industry include semiconductor technology, semiconductor packaging technology, manufacturing process technology, and software technology. Although semiconductor technology is developing in various forms, such as linewidths below the micrometer level, tens of millions of individual cells, high-speed operation, and extensive heat dissipation, it lacks the support of complete packaging technology. Therefore, compared to the performance of the semiconductor technology itself, the electrical performance of the semiconductor is determined by packaging technology and corresponding electrical connections.

[0004] Ceramic or resin is suitable as the material for the packaging substrate. In the case of ceramic substrates, high-performance, high-frequency semiconductor devices cannot be easily mounted due to their high resistance or high dielectric constant. In the case of resin substrates, although high-performance, high-frequency semiconductor devices can be mounted relatively easily, there are limitations in reducing the spacing of wiring.

[0005] Recently, research has been conducted on using silicon or glass as high-end packaging substrates. By forming through-holes in the silicon or glass substrate and applying a conductive material to these through-holes, the wiring length between the component and the motherboard is shortened, and excellent electrical characteristics can be achieved. Prior art literature: Korean Patent Publication No. 10-2021-0127188 [Summary of the Invention]

[0006] The problem that the invention is intended to solve

[0007] The purpose of this example is to provide a method for manufacturing a package substrate that can exhibit a conductive layer with excellent electrical reliability and stable bonding force to the insulating layer within the contact hole.

[0008] Technical means to solve the problem

[0009] A method for manufacturing a packaging substrate according to an embodiment of this specification includes the following steps to prepare the packaging substrate: a preparation step, which prepares a substrate including a core layer, a first conductive layer disposed on the core layer and an insulating layer disposed on the first conductive layer; and a desmearing step, which desmears the substrate.

[0010] The insulating layer includes a contact hole for allowing the insulating layer to pass through in the thickness direction.

[0011] The upper surface of the first conductive layer includes an exposed area exposed by the contact hole.

[0012] In the descaling step, a reactive gas containing oxygen and fluorine is used to perform plasma descaling on the substrate.

[0013] In the descaling step, the ratio of the flow rate of the fluorine gas introduced into the atmosphere in which the substrate is disposed to the flow rate of the oxygen is 4.5 or more.

[0014] The difference between the thickness of the insulating layer before the desmearing step and the thickness of the insulating layer after the desmearing step can be less than 0.7 μm.

[0015] The arithmetic mean illuminance Ra value of the upper surface of the insulating layer in the substrate after the descaling step is completed can be below 125 nm.

[0016] The maximum height illuminance Rz value of the upper surface of the insulating layer in the substrate after the descaling step is completed can be less than 4.5 μm.

[0017] The insulating layer may contain fillers.

[0018] The average particle size (D50) of the filler can be less than 1 μm.

[0019] The maximum particle size of the filler can be less than 10 μm.

[0020] The contact hole may include: a first opening disposed on the upper surface of the insulating layer; a second opening disposed on the lower surface of the insulating layer; and an inner surface of the insulating layer, connecting the first opening and the second opening, and formed in the thickness direction of the insulating layer.

[0021] The diameter of the first opening may be larger than the diameter of the second opening.

[0022] The ratio of the diameter of the first opening to the diameter of the second opening can be 1.1 or higher.

[0023] The method for manufacturing the packaging substrate may further include a conductive layer forming step in which a second conductive layer is formed in the insulating layer within the substrate after the desmearing step.

[0024] The conductive layer forming step may include: a seed layer forming process, forming a seed layer on the inner side of the insulating layer; and a conductive layer forming process, forming a conductive layer on the seed layer to prepare a second conductive layer.

[0025] The seed layer may contain one of the following: titanium, tungsten, tantalum, molybdenum, nickel, chromium, and combinations thereof.

[0026] The peel strength of the second conductive layer relative to the upper surface of the insulating layer can be 400 gf / cm or more.

[0027] Compared with the effectiveness of previous technologies

[0028] The method of fabricating the packaging substrate of the example can incorporate an electrically conductive layer with excellent electrical reliability and stable bonding force to the insulating layer within the contact hole.

Implementation Method

[0030] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, enabling those skilled in the art to easily implement the invention. However, the invention can be embodied in many different forms and is not limited to the embodiments described herein. Throughout the specification, similar parts are given the same reference numerals.

[0031] Throughout this specification, the term “combinations thereof” included in the Markush form of expression means a mixture or combination of one or more of the groups of structural elements described in the Markush form of expression, and means including one or more of the groups of said structural elements.

[0032] Throughout this specification, terms such as “first,” “second,” or “A,” “B” are used to distinguish between identical terms. Furthermore, singular expressions include plural expressions unless there is a clear difference in meaning within the context.

[0033] In this specification, “~” can mean that the compound contains a compound corresponding to “~” or a derivative of “~”.

[0034] In this specification, B being located at A means that B is located at A in direct contact with A or that B is located at A with other layers between them, and should not be construed as B being positioned in contact with the surface of A.

[0035] In this specification, the connection between A and B means that A and B are directly connected or connected between A and B through other structural elements. Unless otherwise specified, it should not be interpreted restrictively as A and B being directly connected.

[0036] In this specification, unless otherwise specified, the expression of singular shall be interpreted as including the meaning of singular or plural as interpreted in the context.

[0037] In this specification, the shape, relative size, angle, etc. of each structure in the drawings are illustrative and may be expressed in an exaggerated manner for the purpose of explanation. The scope of protection should not be limited to the drawings for interpretation.

[0038] In this specification, "A and B are adjacent" means that A and B are placed in contact, or that although A and B are not in contact, they are placed close to each other. In this specification, unless otherwise specified, the expression "A and B are adjacent" should not be interpreted restrictively as "A and B are placed in contact".

[0039] Unless otherwise specified in this specification, the physical properties of the structural elements within the package substrate shall be interpreted as having been measured indoors. The room temperature is 20°C to 25°C.

[0040] After forming a contact hole within the insulating layer, plasma descaling can be performed to remove particles and other residues from the contact hole. However, if a conductive layer is formed on the upper surface of the insulating layer after descaling, a stable bond may not form between the insulating layer and the conductive layer. This may be because the upper surface of the insulating layer becomes too rough during the descaling process.

[0041] The inventors of the example applied technical features such as adjusting the flow rate ratio of different reactive gases during the descaling process. Thus, the inventors experimentally confirmed that residues in the contact hole could be effectively removed, and a stable bonding force was formed between the insulating layer at the end of the descaling process and the conductive layer disposed on the insulating layer, thereby completing the example.

[0042] The following is a detailed explanation of the examples.

[0043] Figure 1 is a cross-sectional view of the substrate prepared by the preparation steps. Hereinafter, an example will be described with reference to Figure 1.

[0044] The method for manufacturing the packaging substrate of the example includes the following steps to prepare the packaging substrate: a preparation step, which prepares a substrate 100 including a core layer, a first conductive layer disposed on the core layer and an insulating layer disposed on the first conductive layer; and a desmearing step, which desmears the substrate 100.

[0045] Preparation Steps

[0046] The substrate 100 can be prepared in the preparation step.

[0047] The substrate 100 may include a core layer 10. The core layer 10 has a substrate shape and can function as a support layer in the packaging substrate. The core layer 10 is not limited as long as it is applicable in the field of packaging substrates. For example, glass substrates, glass fiber impregnated substrates, ceramic substrates, and glass substrates can be used as the core layer 10.

[0048] The thickness of the core layer 10 may be 100 μm or more. The thickness may be 200 μm or more. The thickness may be 300 μm or more. The thickness may be 3000 μm or less. The thickness may be 2000 μm or less. The thickness may be 1000 μm or less. In this case, the core layer 10 may have mechanical properties suitable for use with a packaging substrate.

[0049] The substrate 100 may include a first conductive layer 20 disposed on the core layer 10 and an insulating layer 30 disposed on the first conductive layer 20.

[0050] In the preparation step, a substrate 100 with a first conductive layer 20 and an insulating layer 30 already formed can be introduced into the core layer 10. An insulating layer 30 can be formed on the substrate with the core layer 10 and the first conductive layer 20 to prepare the substrate 100. The first conductive layer 20 and the insulating layer 30 can be formed on the core layer 10 to prepare the substrate 100.

[0051] The first conductive layer 20 may be formed in contact with the upper surface of the core layer 10. Other structural elements such as an insulating layer 30 may be disposed between the first conductive layer 20 and the core layer 10, such that the first conductive layer 20 is disposed separately from the upper surface of the core layer 10.

[0052] When the first conductive layer 20 is formed in the core layer 10, the first conductive layer 20 can be formed by dry method or wet method.

[0053] The dry method involves sputtering the area in the core layer 10 where the first conductive layer 20 needs to be disposed to form a seed layer, and then depositing the area where the seed layer is formed to form the conductive layer. When forming the seed layer, a metal selected from the group consisting of titanium, tungsten, tantalum, molybdenum, nickel, chromium, and combinations thereof can be sputtered, and said metal and copper can be used together for sputtering. Through sputtering, an anchoring effect is achieved between the surface where the first conductive layer 20 is disposed and the deposited metal particles, thereby improving the adhesion of the first conductive layer 20.

[0054] The wet process is a method of applying a metal plating after treating the portion where a primer is applied to form the first conductive layer 20. The primer may contain compounds having functional groups such as amines. Depending on the desired degree of adhesion, the primer may contain a compound having functional groups such as amines and a silane coupling agent. When a silane coupling agent is used, the surface of the object to be treated with the primer can be pretreated with the silane coupling agent, and then a compound having amine groups can be applied to the pretreated area to form a primer layer.

[0055] After forming the seed layer or primer layer, metal can be plated to form the first conductive layer 20. Copper plating can be used when forming the first conductive layer 20, but it is not limited to this. Before metal plating, the portions of the seed layer or primer layer where the first conductive layer 20 is not to be formed can be deactivated, or the portions where the first conductive layer 20 is to be formed can be activated before plating. Activation or deactivation methods can include light irradiation treatment such as irradiation with a laser of a specific wavelength, chemical treatment, etc. However, after metal plating is performed without applying activation or deactivation treatment, the first conductive layer 20 can be etched according to a pre-designed shape to achieve patterning.

[0056] The insulating layer 30 may be disposed on the first conductive layer 20. The insulating layer 30 may be formed in a manner that surrounds at least a portion of the first conductive layer 20. The insulating layer 30 may be formed in a manner that surrounds at least a portion of the upper surface of the first conductive layer 20. The insulating layer 30 may be formed in a manner that surrounds at least a portion of the upper surface and the side surface of the first conductive layer 20.

[0057] The insulating layer 30 and the first conductive layer 20 may be mixed in the core layer 10 for configuration. The first conductive layer 20 having a patterned shape may be formed in a form embedded in the insulating layer 30.

[0058] Any material suitable for use as an insulating layer 30 in the field of packaging substrates can be used as an insulating layer 30. For example, the insulating layer 30 can be made of epoxy resin containing fillers. For example, the insulating layer 30 can be formed by build-up materials such as Ajinomoto Build-up Film (ABF), base coating materials, etc., but is not limited to these.

[0059] The insulating layer 30 may contain a filler. The filler is not limited as long as it is generally applicable to the field of the insulating layer 30. For example, silicon dioxide, aluminum oxide, titanium, etc., may be used as fillers.

[0060] The average particle size of the filler can be controlled within a preset range. In this case, during the desmearing step, due to the difference in etching characteristics between the filler and the resin contained in the insulating layer 30, even if the insulating layer 30 is etched more than the filler, the upper surface of the insulating layer 30 can be prevented from becoming excessively rough.

[0061] The average particle size (D50) of the filler can be 1 μm or less. The average particle size can be 0.9 μm or less. The average particle size can be 0.8 μm or less. The average particle size can be 0.7 μm or less. The average particle size can be 0.1 μm or more.

[0062] The maximum particle size of the filler can be less than 10 μm. The maximum particle size can be less than 9 μm. The maximum particle size can be less than 8 μm. The maximum particle size can be less than 7 μm. The maximum particle size can be greater than 0.1 μm.

[0063] In this case, it can help to form a stable bonding force between the insulating layer 30 and the conductive layer formed on the insulating layer 30.

[0064] When the first conductive layer 20 forms an insulating layer 30, the insulating layer 30 can be formed by curing after the uncured or semi-cured insulating film is laminated.

[0065] The insulating layer 30 may include a contact hole 31 extending through the insulating layer 30 in the thickness direction. The contact hole 31 may provide space for forming a conductive layer in the thickness direction of the package substrate. The conductive layer formed in the contact hole 31 may electrically connect the first conductive layer 20 and the conductive layer formed in the first conductive layer 20.

[0066] The contact hole 31 may expose a portion of the upper surface of the first conductive layer 20. The upper surface of the first conductive layer 20 may include the exposed area 21 exposed by the contact hole 31.

[0067] The contact hole 31 may include: a first opening 311 disposed on the upper surface of the insulating layer 30; a second opening 312 disposed on the lower surface of the insulating layer 30; and an inner surface 313 of the insulating layer, connecting the first opening 311 and the second opening 312, and formed in the thickness direction of the insulating layer 30.

[0068] The inner surface 313 of the insulating layer may be formed as an inclined surface. When the substrate 100 is viewed in cross section, the outline of the inner surface 313 of the insulating layer may be a straight line or a curve, and may include both straight lines and curves.

[0069] In this example, the diameter of the first opening 311 can be adjusted to be larger than the diameter of the second opening 312. Therefore, during the descaling step, plasma gas can smoothly reach the contact hole 31, thereby effectively removing residue from the contact hole 31. Furthermore, by sputtering or the like, a seed layer can be easily formed on the inner surface 313 of the insulating layer with a relatively uniform thickness.

[0070] The ratio of the diameter of the first opening 311 to the diameter of the second opening 312 can be 1.1 or more. The ratio can be 1.15 or more. The ratio can be 1.2 or more. The ratio can be 1.3 or more. The ratio can be 3 or less. In this case, it can help to form an electrically conductive layer with excellent electrical reliability and durability within the contact hole 31.

[0071] When the substrate 100 is viewed in cross-section along the thickness direction, the angle formed by the outline of the inner side surface 313 of the insulating layer and the outline of the exposed area 21 can be 92 degrees or more. The angle can be 95 degrees or more. The angle can be 120 degrees or less. The angle can be 115 degrees or less. In this case, it can help to achieve a smooth desmearing process and prevent the formation of gaps during the formation of a conductive layer within the contact hole 31.

[0072] When the contour of the inner surface 313 of the insulating layer includes a curved surface, the method for measuring the angle formed by the contour of the inner surface 313 of the insulating layer and the contour of the exposed area 21 is as follows. A first point is identified as the point where the contour of the inner surface 313 of the insulating layer contacts the contour of the upper surface of the insulating layer 30, and a second point is identified as the point where the contour of the inner surface 313 of the insulating layer contacts the contour of the lower surface of the insulating layer 30. The angle formed by the straight line connecting the first point and the second point and the contour of the exposed area 21 is measured, and the angle is made to be the angle formed by the contour of the inner surface 313 of the insulating layer and the contour of the exposed area 21.

[0073] The area within the insulating layer 30 used for configuring the contact hole 31 can be etched to form the contact hole 31. The contact hole 31 can be formed by laser etching, dry etching, wet etching, etc. Laser etching can be used to precisely control the shape of the contact hole 31.

[0074] Drill Stain Removal Steps

[0075] Process Conditions

[0076] The method for fabricating the packaging substrate of the example includes a desmearing step of removing desmearing from the substrate 100. In the desmearing step, a reactive gas containing oxygen and fluorine gas is used to plasma desmear the substrate 100. Specifically, in the desmearing step, the reactive gas may be introduced into an atmosphere in which the substrate 100 is disposed, and the reactive gas may be used to plasma etch the substrate 100 to remove residue in the contact holes 31.

[0077] Oxygen can exhibit relatively high etching characteristics to the resin contained in the insulating layer 30. Fluorine gases can exhibit relatively high etching characteristics to the fillers contained in the insulating layer 30.

[0078] Fluorine gases can be fluorocarbon compounds. Fluorine gases can be one of the groups selected from CF4, C2F2, C2F4, C2F6, C3F6, C3F8, C4F8, C4F10, and combinations thereof. Fluorine gases can be CF4.

[0079] In this example, the ratio of the flow rate of fluorine gas to the flow rate of oxygen introduced into the atmosphere in which the substrate 100 is disposed can be controlled within a preset range. In this case, during the descaling step, the upper surface of the insulating layer 30 can be prevented from becoming rough due to excessive difference in etching rates between the resin and filler contained in the insulating layer 30.

[0080] In the desmearing step, the ratio of the flow rate of the fluorine gas to the flow rate of the oxygen gas introduced into the atmosphere in which the substrate 100 is disposed can be 4.5 or more. The ratio can be 4.7 or more. The ratio can be 5 or more. The ratio can be 8 or more. The ratio can be 10 or more. The ratio can be 12 or more. The ratio can be 15 or more. The ratio can be 17 or more. The ratio can be 20 or more. The ratio can be 25 or more. The ratio can be 30 or more. The ratio can be 35 or more. The ratio can be 80 or less. In this case, in the desmearing step, excessive etching of the resin in the insulating layer 30 compared to the filler can be suppressed.

[0081] In the descaling step, the oxygen flow rate introduced into the atmosphere in which the substrate 100 is disposed can be 400 sccm or less. The flow rate can be 350 sccm or less. The flow rate can be 300 sccm or less. The flow rate can be 250 sccm or less. The flow rate can be 10 sccm or more.

[0082] In the descaling step, the flow rate of the fluorine gas introduced into the atmosphere in which the substrate 100 is disposed can be 45 sccm or more. The flow rate can be 100 sccm or more. The flow rate can be 200 sccm or more. The flow rate can be 300 sccm or more. The flow rate can be 400 sccm or more. The flow rate can be 500 sccm or more. The flow rate can be 600 sccm or more. The flow rate can be 700 sccm or more. The flow rate can be 800 sccm or more. The flow rate can be 2000 sccm or less.

[0083] In this case, it may help to reduce the difference in etching characteristics between the resin and filler within the insulating layer 30.

[0084] Depending on the needs, the reaction gas may also include other gases besides oxygen and fluorine gases.

[0085] In the descaling step, a plasma beam can be irradiated onto the reactive gas to form plasma gas. The discharge power suitable for the plasma beam can be 3000W or higher. The discharge power can be 4000W or higher. The discharge power can be 5000W or higher. The discharge power can be 6000W or higher. The discharge power can be 10000W or lower.

[0086] The frequency applicable to the plasma beam can be 10 kHz or higher. The frequency can be 20 kHz or higher. The frequency can be 30 kHz or higher. The frequency can be 200 kHz or lower. The frequency can be 150 kHz or lower. The frequency can be 100 kHz or lower.

[0087] In this case, it can help to form a sufficient amount of reactive gas in the atmosphere in which the substrate 100 is disposed.

[0088] The discharge power is the discharge power of each nozzle that does not release the plasma beam.

[0089] In the descaling step, the distance between the electrodes that generate the substrate and the plasma can be controlled, thereby not only fully removing the residue in the contact hole, but also suppressing excessive damage to the upper surface of the insulating layer.

[0090] In the descaling step, the distance between the substrate and the electrode can be 150 mm or less. The distance can be 120 mm or less. The distance can be 100 mm or less. The distance can be 80 mm or less. The distance can be 60 mm or less. The distance can be 10 mm or more. The distance can be 20 mm or more. In this case, it can help to form a redistribution layer with excellent electrical reliability within the substrate.

[0091] Characteristics of the insulation layer after the descaling process is completed

[0092] The example allows for adjustment of the thickness difference of the insulating layer 30 before and after the desmearing step. Specifically, the thickness difference can be controlled within a predetermined range during the desmearing step by controlling the thickness of the insulating layer 30 etched by plasma gas. In this case, excessive damage to the upper surface of the insulating layer 30 due to plasma gas can be suppressed. In particular, the roughness of the upper surface of the insulating layer 30 due to plasma gas can be suppressed to a specified level, and the thickness of the insulating layer 30 can be prevented from being thinner than expected.

[0093] The thickness of the insulation layer 30 before and after the desmearing step is measured at the same location within the insulation layer 30. Specifically, the location for measuring the thickness of the insulation layer 30 is a position within the insulation layer 30 where no contact holes 31, etc., are formed.

[0094] The difference between the thickness of the insulating layer 30 before the desmearing step and the thickness of the insulating layer 30 after the desmearing step can be 0.7 μm or less. The value can be 0.5 μm or less. The value can be 0.4 μm or less. The value can be 0.3 μm or less. The value can be 0.2 μm or less. The value can be 0 μm or more. In this case, excessive damage to the upper surface of the insulating layer 30 due to plasma gas can be suppressed.

[0095] The example can control the illuminance characteristics of the upper surface of the insulating layer 30 to reduce the influence of the unevenness of the upper surface of the insulating layer 30 on the bonding force between the upper surface of the insulating layer 30 and the conductive layer.

[0096] The arithmetic mean illuminance Ra value of the upper surface of the insulating layer 30 within the substrate 100 after the descaling step is completed can be 125 nm or less. The Ra value can be 115 nm or less. The Ra value can be 100 nm or less. The Ra value can be 80 nm or less. The Ra value can be 60 nm or less. The Ra value can be 50 nm or less. The Ra value can be 40 nm or less. The Ra value can be 30 nm or less. The Ra value can be 10 nm or more.

[0097] The maximum height illuminance Rz value of the upper surface of the insulating layer 30 within the substrate 100 after the descaling step is completed can be 4.5 μm or less. The Rz value can be 4.3 μm or less. The Rz value can be 4.0 μm or less. The Rz value can be 3.5 μm or less. The Rz value can be 3.0 μm or less. The Rz value can be 2.5 μm or less. The Rz value can be 2.0 μm or less. The Rz value can be 1.5 μm or less. The Rz value can be 1.0 μm or less. The Rz value can be 0.05 μm or more.

[0098] In this case, an environment suitable for forming a stable bonding force between the upper surface of the insulating layer 30 and the conductive layer can be provided.

[0099] The Ra and Rz values ​​are determined in accordance with the provisions of standard ISO 4287:1997.

[0100] Steps for forming the conductive layer

[0101] Figure 2A is a conceptual diagram illustrating the seed layer prepared through the seed layer formation process of the example. Figure 2B is a conceptual diagram illustrating the packaging substrate of the example. Hereinafter, the example will be described with reference to Figures 2A and 2B.

[0102] The contents described in FIG1 above will be directly applied to the substrate 100, core layer 10, first conductive layer 20, insulating layer 30 and contact hole 31. Hereinafter, the description will focus on the parts that have differences.

[0103] The method for manufacturing the packaging substrate of the example may further include a conductive layer forming step in which a second conductive layer 45 is formed in the insulating layer 30 within the substrate 100 after the desmearing step.

[0104] The second conductive layer 45 is formed within the insulating layer 30 and the contact hole 31, which distinguishes it from the first conductive layer 20 formed below the insulating layer 30.

[0105] The second conductive layer 45 may include a seed layer 40 and a conductive layer 41 disposed on the seed layer 40. The conductive layer 41 may be disposed in contact with the seed layer 40.

[0106] Seed layer 40 may contain one selected from the group consisting of titanium, tungsten, tantalum, molybdenum, nickel, chromium, and combinations thereof. Seed layer 40 may include a first seed layer 40 and a second seed layer disposed on the first seed layer. The first seed layer may contain one selected from the group consisting of titanium, tungsten, tantalum, molybdenum, nickel, chromium, and combinations thereof. The second seed layer may contain the same metal element as suitable for conductive layer 41. The second seed layer may contain copper. Seed layer 40 having this structure and composition can help to achieve excellent adhesion between the second conductive layer 45 and the insulating layer 30.

[0107] The conductive layer 41 may contain copper.

[0108] The conductive layer formation step of the example may include: a seed layer formation process, forming a seed layer 40 on the inner surface 313 of the insulating layer; and a conductive layer formation process, forming a conductive layer 41 on the seed layer 40 to prepare a second conductive layer 45. Specifically, in the example, during the seed layer formation process, a seed layer 40 with a uniform thickness distribution may be formed on the inner surface 313 of the insulating layer where the tilt angle is adjusted. This can suppress poor bonding between the inner surface 313 of the insulating layer and the seed layer 40, and allow the second conductive layer 45 to be stably fixed within the contact hole 31 of the insulating layer 30.

[0109] Except for forming a seed layer 40 on the inner surface 313 of the insulating layer and the thickness of the layer, the second conductive layer 45 can be prepared in the same manner as the formation method of the first conductive layer 20. The specific description of the formation method of the second conductive layer 45 is repeated above, so it is omitted.

[0110] The peel strength of the second conductive layer 45 relative to the upper surface of the insulating layer 30 can be 400 gf / cm or more. The peel strength can be 500 gf / cm or more. The peel strength can be 600 gf / cm or more. The peel strength can be 650 gf / cm or more. The peel strength can be 700 gf / cm or more. The peel strength can be 1000 gf / cm or less. In this case, the second conductive layer 45 can be stably fixed within the insulating layer 30.

[0111] The peel strength is determined by the following method. After cutting the second conductive layer 45 in the insulating layer 30 with a width of 10 mm and a length of 100 mm, the peel strength is measured by pulling one end of the cut second conductive layer 45 in the length direction in a 90-degree direction with the upper surface of the insulating layer 30 as a reference.

[0112] In this example, a second conductive layer 45 can be formed in the insulating layer 30 to fabricate a packaging substrate.

[0113] As needed, the conductive layer forming step of the example may further include the process of forming an insulating layer 30 disposed on the second conductive layer 45 and another conductive layer disposed on the insulating layer 30. As needed, the conductive layer forming step of the example may further include the process of forming an insulating layer 30 disposed below the core layer 10 and another conductive layer disposed below the insulating layer 30. The insulating layer 30 and the conductive layer can be prepared in the same manner as described above.

[0114] Other steps

[0115] As needed, upper terminals, etc., may be further formed on the upper part and / or sides of the packaging substrate, and bumps may be further formed on the lower part of the packaging substrate. The bumps can be configured in a predetermined shape below a redistribution layer, which includes an insulating layer 30 and a conductive layer disposed below the core layer 10. Examplely, the bumps may be disposed on a portion of the lower surface of the packaging substrate to contact the motherboard, etc.

[0116] Hereinafter, specific embodiments will be used to further illustrate the examples. The following embodiments are merely illustrative to help understand the examples, and the scope of the examples is not limited thereto.

[0117] Manufacturing Example: Formation of Packaging Substrate

[0118] Example 1: A copper clad laminate (CCL) with a thickness of 0.5 mm was prepared. An insulating layer was prepared by laminating and curing a 20 μm thick build-up film ABF GL103 (average particle size of the filler in the film: 0.5 μm, maximum particle size: 5 μm) on both sides of the CCL. Multiple contact holes were formed on the insulating layer formed on both sides of the CCL using a UV laser, thereby preparing a substrate. The diameter of the first opening of the contact hole was 40 μm. It was confirmed that the contact hole was formed in a tapered shape with the first opening larger than the second opening.

[0119] After the substrate was inserted into the chamber, plasma desmearing was performed for 60 seconds. During desmearing, the discharge power of the nozzle releasing the plasma beam was 7000W, the frequency was 50kHz, the flow rate of oxygen introduced into the chamber was 20sccm, the flow rate of CF4 as a fluorine gas was 1000sccm, and the distance between the substrate and the electrode was 40mm.

[0120] A first seed layer with a thickness of 150 nm, serving as a titanium layer, is formed by sputtering on the upper surface of the insulating layer, the inner surface of the insulating layer, and the surface of the CCL exposed by the contact holes on the substrate after drilling and descaling. A second seed layer with a thickness of 300 nm, serving as a copper layer, is formed on the first seed layer by sputtering. An electroless plating process is performed on the second seed layer to fill the contact holes with the copper layer, and a copper layer with a thickness of 20 μm is formed on the upper surface of the insulating layer, thereby preparing a conductive layer and completing the second conductive layer.

[0121] Example 2: Except that an oxygen flow rate of 50 sccm was used during plasma descaling, the packaging substrate was prepared under the same conditions as in Example 1.

[0122] Example 3: Except that an oxygen flow rate of 200 sccm was used during plasma descaling, the packaging substrate was prepared under the same conditions as in Example 1.

[0123] Example 4: The packaging substrate was prepared under the same conditions as in Example 1, except that a 90-second desmearing was performed during plasma desmearing and an oxygen flow rate of 50 sccm was applied.

[0124] Example 5: The packaging substrate was prepared under the same conditions as in Example 4, except that an oxygen flow rate of 100 sccm was used when performing plasma descaling.

[0125] Example 6: The packaging substrate was prepared under the same conditions as in Example 4, except that an oxygen flow rate of 200 sccm was used when performing plasma descaling.

[0126] Example 7: Except for performing a 120-second desmearing process during plasma desmearing and applying an oxygen flow rate of 50 sccm, the packaging substrate was prepared under the same conditions as in Example 1.

[0127] Example 8: The packaging substrate was prepared under the same conditions as in Example 7, except that an oxygen flow rate of 100 sccm was used when performing plasma descaling.

[0128] Example 9: The packaging substrate was prepared under the same conditions as in Example 7, except that an oxygen flow rate of 200 sccm was used when performing plasma descaling.

[0129] Example 10: The packaging substrate was prepared under the same conditions as in Example 1, except that a 180-second desmearing was performed during plasma desmearing and an oxygen flow rate of 50 sccm was applied.

[0130] Comparative Example 1: The packaging substrate was prepared under the same conditions as in Example 1, except that an oxygen flow rate of 1000 sccm and a CF4 flow rate of 100 sccm were used during plasma descaling.

[0131] The process conditions for each embodiment and comparative example are described in Table 1 below.

[0132] Evaluation Example: Evaluate the degree of damage on the upper side of the insulation layer.

[0133] During the fabrication of the packaging substrate in different embodiments and comparative examples, the thickness of the insulating layer was measured before plasma desmearing was performed. Then, the thickness of the insulating layer was measured after the plasma desmearing was completed. The difference between the two thicknesses was calculated after the measurement was completed.

[0134] The measured values ​​of different embodiments and comparative examples are recorded in Table 2 below.

[0135] Evaluation Example: Evaluation of Illuminance Characteristics of the Upper Surface of the Insulation Layer

[0136] During the fabrication of the packaging substrate in different embodiments and comparative examples, after the plasma descaling was completed and before the first seed layer was formed, the Ra value, which is the arithmetic mean illuminance of the upper surface of the insulating layer, and the Rz value, which is the maximum height illuminance, were measured according to ISO 4287:1997.

[0137] The measured values ​​of different embodiments and comparative examples are recorded in Table 2 below.

[0138] Evaluation Example: Evaluation of the peel strength of the second conductive layer relative to the insulating layer

[0139] The second conductive layer was cut into the insulating layer of the packaging substrate in each embodiment and comparative example with a width of 10 mm and a length of 100 mm. Then, taking the upper surface of the packaging substrate as a reference, one end of the second conductive layer in the length direction was pulled at an angle of 90 degrees to measure the peel strength of the second conductive layer relative to the insulating layer.

[0140] The evaluation results of different embodiments and comparative examples are recorded in Table 2 below.

[0141] Evaluation Example: Quick Via Pull (QVP) Evaluation

[0142] After stripping the second conductive layer of the packaging substrate of different embodiments and comparative examples, the interior of the contact hole was observed by scanning electron microscopy (SEM). If a copper layer of CCL was observed on the bottom surface of the contact hole, it was evaluated as Fail; if a portion of the second conductive layer was observed on the bottom surface of the contact hole or an organic layer disposed below the copper layer of CCL was observed, it was evaluated as Pass.

[0143] The evaluation results of different embodiments and comparative examples are recorded in Table 2 below.

[0144] Table 1 Time to remove drilling contaminants (seconds) O2 flow (sccm) CF4 flow rate (sccm) Example 1 60 20 1000 Example 2 60 50 1000 Example 3 60 200 1000 Example 4 90 50 1000 Example 5 90 100 1000 Example 6 90 200 1000 Example 7 120 50 1000 Example 8 120 100 1000 Example 9 120 200 1000 Example 10 180 50 1000 Comparative Example 1 60 1000 100

[0145] Table 2 Difference in insulation layer thickness (μm) Ra (nm) Rz (μm) Peel strength (gf / cm) QVP test Example 1 0 20.6 0.33 600.2 Pass Example 2 0.19 38.4 0.52 662.45 Pass Example 3 0.216 38.4 0.52 625.92 Pass Example 4 0.10 95.2 2.27 603.67 Pass Example 5 0.35 112.5 1.97 720.61 Pass Example 6 0.33 121.3 3.49 637.65 Pass Example 7 0.23 105.8 2.91 656.96 Pass Example 8 0.24 105.5 2.93 683.41 Pass Example 9 0.26 67.9 2.63 685.84 Pass Example 10 0.13 68.5 2.38 716.85 Pass Comparative Example 1 1 140.4 5.1 60.4 Fail

[0146] In Table 2, Examples 1 to 10 exhibited peel strengths of 600 gf / cm or higher, while Comparative Example 1 exhibited peel strengths of 100 gf / cm or lower. This result indicates that when the illuminance characteristics of the upper surface of the insulating layer are controlled within a predetermined range in the examples, the bonding force of the second conductive layer relative to the upper surface of the insulating layer can be significantly improved.

[0147] In the QVP test, Examples 1 to 10 were all evaluated as Pass, while Comparative Example 2 was evaluated as Fail. This may be because in Examples 1 to 10, the residue in the contact holes was substantially removed by desmearing, thereby stably connecting the second conductive layer and the copper layer of the CCL. In contrast, in Comparative Example 1, the residue in the contact holes was not sufficiently removed, resulting in poor electrical connection between the second conductive layer and the copper layer of the CCL.

[0148] Although the preferred embodiments of the present invention have been described in detail above, the scope of protection of the present invention is not limited thereto. Various modifications and improvements made by those skilled in the art using the basic concepts of the present invention as defined in the claims are also within the scope of protection of the present invention. [Simplified Explanation of the Diagram]

[0029] Figure 1 is a cross-sectional view of the substrate prepared according to the preparation steps of the example. Figure 2A is a conceptual diagram illustrating the seed layer prepared according to the seed layer formation process of the example. Figure 2B is a conceptual diagram illustrating the packaging substrate of the example.

Claims

1. A method for manufacturing a packaging substrate, used to prepare a packaging substrate, wherein, include: Preparation steps include preparing a substrate comprising a core layer, a first conductive layer disposed on the core layer, and an insulating layer disposed on the first conductive layer; The process includes a desmearing step, in which the substrate is desmeared. The insulating layer includes contact holes for penetrating the insulating layer in the thickness direction. The upper surface of the first conductive layer includes an exposed area exposed by the contact holes. In the desmearing step, a reactive gas containing oxygen and fluorine gas is used to perform plasma desmearing on the substrate. In the desmearing step, the ratio of the flow rate of the fluorine gas to the flow rate of the oxygen introduced into the atmosphere in which the substrate is disposed is 4.5 or more. The insulating layer includes a filler, and the average particle size of the filler is 1 μm or less.

2. The method for manufacturing the packaging substrate as described in claim 1, wherein, The difference between the thickness of the insulating layer before the desmearing step and the thickness of the insulating layer after the desmearing step is less than 0.7 μm.

3. The method for manufacturing the packaging substrate as described in claim 1, wherein, The arithmetic mean illuminance Ra value of the upper surface of the insulating layer in the substrate after the descaling step is 125 nm or less.

4. The method for manufacturing the packaging substrate as described in claim 1, wherein, The maximum height illuminance Rz value of the upper surface of the insulating layer in the substrate after the descaling step is 4.5 μm or less.

5. A method for manufacturing the packaging substrate as described in claim 1, wherein, The maximum particle size of the filler is less than 10 μm.

6. A method for manufacturing the packaging substrate as described in claim 1, wherein, The contact hole includes: a first opening disposed on the upper surface of the insulating layer; a second opening disposed on the lower surface of the insulating layer; and an inner surface of the insulating layer connecting the first opening and the second opening and forming in the thickness direction of the insulating layer, wherein the diameter of the first opening is larger than the diameter of the second opening.

7. The method for manufacturing the packaging substrate as described in claim 6, wherein, The ratio of the diameter of the first opening to the diameter of the second opening is 1.1 or more.

8. The method for manufacturing the packaging substrate as described in claim 6, wherein, It also includes a conductive layer forming step in which a second conductive layer is formed in the insulating layer within the substrate after the desmearing step, the conductive layer forming step comprising: a seed layer forming process, forming a seed layer on the inner side of the insulating layer; and a conductive layer forming process, forming a conductive layer on the seed layer to prepare the second conductive layer.

9. A method for manufacturing a packaging substrate as described in claim 8, wherein, The seed layer comprises one selected from the group consisting of titanium, tungsten, tantalum, molybdenum, nickel, chromium, and combinations thereof.

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