Manufacturing method for packaging substrates

Abstract

A method for manufacturing a packaging substrate that can realize an electrically conductive layer with excellent electrical reliability and stable bonding force to the insulating layer within the contact holes. [Solution] A method for manufacturing a packaging substrate includes a preparation step of providing a base substrate 100 including a core layer 10, a first electrical conductive layer 20 disposed on the core layer, and an insulating layer 30 disposed on the first electrical conductive layer, and a desmear step of desmearing the base substrate. The insulating layer includes contact holes 31 that penetrate in the thickness direction. The upper surface of the first electrical conductive layer includes an exposed region exposed by the contact holes. In the desmear step, the base substrate is plasma desmeared with a reaction gas containing oxygen gas and a fluorine-based gas. In the desmear step, the ratio of the flow rate of the fluorine-based gas to the flow rate of the oxygen gas introduced into the atmosphere on which the base substrate is placed is 4.5 or more.

Description

Technical Field

[0001] The embodiment relates to a method for manufacturing a packaging substrate.

Background Art

[0002] In fabricating electronic components, the process of implementing circuits on a semiconductor wafer is called the front-end process (FE), and the process of assembling the wafer into a state where it can be used as an actual product is called the back-end process (BE). The back-end process includes a packaging process.

[0003] The four core technologies of the semiconductor industry that have enabled the rapid development of recent electronic products are semiconductor technology, semiconductor packaging technology, manufacturing process technology, and software technology. Semiconductor technology has evolved into various forms such as line widths in nano units below micro, over ten million cells, high-speed operation, and a large amount of heat dissipation. However, there is no technology that can perfectly package this relatively. Therefore, the electrical performance of a semiconductor may sometimes be determined by the packaging technology and the electrical connections it provides rather than the performance of the semiconductor technology itself.

[0004] As materials for packaging substrates, ceramics or resins are applied. In the case of ceramic substrates, it is not easy to mount high-performance high-frequency semiconductor elements because of their high resistance or high dielectric constant. In the case of resin substrates, relatively high-performance high-frequency semiconductor elements can be mounted, but there is a limit to reducing the wiring pitch.

[0005] Recently, research has been underway to apply silicon or glass to high-end packaging substrates. By forming through-holes in silicon or glass substrates and applying conductive substances to these through-holes, the wiring length between elements and the motherboard can be shortened, and excellent electrical characteristics can be achieved.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Korean Published Patent No. 10-2021-0127188 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The objective of this embodiment is to provide a method for manufacturing a packaging substrate that can realize an electrically conductive layer that has excellent electrical reliability within the contact hole and stable bonding force to the insulating layer. [Means for solving the problem]

[0008] A method for manufacturing a packaging substrate according to one embodiment of this specification comprises: a preparation step of providing a base substrate including a core layer, a first electrical conductive layer disposed on the core layer, and an insulating layer disposed on the first electrical conductive layer; and a desmear step of desmearing the base substrate.

[0009] The insulating layer includes contact holes that penetrate the insulating layer in the thickness direction.

[0010] The upper surface of the first conductive layer includes an exposed region exposed by the contact hole.

[0011] In the desmear step, the base substrate is plasma desmeared with a reaction gas containing oxygen gas and a fluorine-based gas.

[0012] In the desmear step, the ratio of the flow rate of the fluorine-based gas to the flow rate of the oxygen gas introduced into the atmosphere in which the base substrate is placed is 4.5 or more.

[0013] The difference between the thickness of the insulating layer before the desmear step and the thickness of the insulating layer after the desmear step may be 0.7 μm or less.

[0014] The arithmetic mean roughness Ra of the upper surface of the insulating layer in the base substrate after the desmear step may be 125 nm or less.

[0015] The maximum height roughness Rz value of the upper surface of the insulating layer in the base substrate after the desmear step may be 4.5 μm or less.

[0016] The insulating layer may contain a filler.

[0017] The average particle size (D50) of the filler may be 1 μm or less.

[0018] The maximum particle size of the filler may be 10 μm or less.

[0019] The contact hole may include a first opening located on the upper side of the insulating layer, a second opening located on the lower side of the insulating layer, and an inner surface of the insulating layer formed in the thickness direction of the insulating layer, connecting the first opening and the second opening.

[0020] The diameter of the first opening may be larger than the diameter of the second opening.

[0021] The ratio of the diameter of the first opening to the diameter of the second opening may be 1.1 or greater.

[0022] The method for manufacturing the packaging substrate may further include a step of forming an electrical conductive layer on the insulating layer in the base substrate after the desmear step has been completed.

[0023] The electrical conductive layer formation step may include a seed layer formation process in which a seed layer is formed on the inner surface of the insulating layer, and a conductive layer formation process in which a conductive layer is formed on the seed layer to provide a second electrical conductive layer.

[0024] The seed layer may include any one selected from the group consisting of titanium, tungsten, tantalum, molybdenum, nickel, chromium, and combinations thereof.

[0025] The peel strength of the second electrically conductive layer with respect to the upper surface of the insulating layer may be 400 gf / cm or more.

Advantages of the Invention

[0026] The method for manufacturing the packaging substrate of the embodiment can realize an electrically conductive layer having excellent electrical reliability in the contact hole and a stable bonding force with respect to the insulating layer.

Brief Description of the Drawings

[0027] [Figure 1] It is a cross-sectional view of the base substrate provided by the preparation step of the embodiment. [Figure 2A] It is a conceptual diagram for explaining the seed layer provided by the seed layer formation process of the embodiment. [Figure 2B] It is a conceptual diagram for explaining the packaging substrate of the embodiment.

Best Mode for Carrying Out the Invention

[0028] Hereinafter, for the convenience of those with ordinary knowledge in the technical field to which the present invention pertains to easily implement, the embodiments will be described in detail with reference to the accompanying drawings. However, the present invention can be realized in various different forms and is not limited to the embodiments described herein. The same reference numerals are given to similar parts throughout the specification.

[0029] Throughout this specification, the term "combinations thereof" included in the Markush-type expressions means one or more mixtures or combinations selected from the group consisting of the components described in the Markush-type expressions, and means including one or more selected from the group consisting of the components.

[0030] Throughout this specification, terms such as “First,” “Second,” or “A,” “B” are used to distinguish identical terms from one another. Furthermore, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0031] In this specification, "~system" may mean that the compound contains a compound corresponding to "~" or a derivative of "~".

[0032] In this specification, the meaning of B being located on A means either B being in direct contact with A, or B being located on A with other layers located between them, and is not limited to B being in contact with the surface of A.

[0033] In this specification, the meaning of B being connected to A means either that A and B are directly connected, or that A and B are connected through other components between them, and is not limited to the direct connection of A and B unless otherwise specified.

[0034] In this specification, unless otherwise specified, singular expressions are interpreted to include singular or plural, as interpreted in the context.

[0035] In this specification, the form, relative size, angles, etc., of each component in the drawings are illustrative and may be exaggerated for illustrative purposes, and the rights shall not be construed as being limited to the drawings.

[0036] In this specification, "adjacent to A and B" means that A and B are located touching each other, or that A and B are not touching but are located close to each other. In this specification, the expression "adjacent to A and B" is not construed to mean that A and B are located touching each other unless otherwise specified.

[0037] In this specification, unless otherwise specified, the physical properties of each component within the packaging substrate are assumed to have been measured at room temperature. Room temperature is defined as 20°C to 25°C.

[0038] After forming contact holes within the insulating layer, plasma desmearing can be performed to remove residual particles and other materials within the contact holes. However, when forming an electrical conductive layer on the upper surface of the insulating layer after desmearing, a stable bonding force may not be formed between the insulating layer and the electrical conductive layer. This is thought to be because the upper surface of the insulating layer is excessively roughened during the desmearing process.

[0039] The inventors of the embodiment applied technical features such as adjusting the flow rate ratio of different reaction gases during the desmear process. Through this, the inventors experimentally confirmed that they could effectively remove residue from the contact holes and form a stable bonding force between the desmeared insulating layer and the electrically conductive layer placed on the insulating layer, thus completing the embodiment.

[0040] The following provides a detailed explanation of specific examples.

[0041] Figure 1 is a cross-sectional view of the base substrate provided by the preparation step. A concrete example will be described below with reference to Figure 1.

[0042] The manufacturing method for a packaging substrate in the embodiment includes a preparation step of providing a base substrate 100 including a core layer, a first electrical conductive layer disposed on the core layer, and an insulating layer disposed on the first electrical conductive layer, and a desmear step of desmearing the base substrate 100.

[0043] Preparation Steps The base substrate 100 can be provided in the preparation step.

[0044] The base substrate 100 may include a core layer 10. The core layer 10 has a substrate shape and can function as a support layer in a packaging substrate. The core layer 10 is not limited as long as it is applicable in the field of packaging substrates. For example, the core layer 10 may be an organic substrate, a glass fiber impregnated substrate, a ceramic substrate, a glass substrate, etc.

[0045] 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 such cases, the core layer 10 can have mechanical properties suitable for application to a packaging substrate.

[0046] The base substrate 100 may include a first electrical conductive layer 20 disposed on the core layer 10, and an insulating layer 30 disposed on the first electrical conductive layer 20.

[0047] In the preparation step, a base substrate 100 on which a first electrical conductive layer 20 and an insulating layer 30 are already formed on the core layer 10 can be introduced. The base substrate 100 can be provided by forming the insulating layer 30 on a substrate on which the core layer 10 and the first electrical conductive layer 20 are already formed. The base substrate 100 can be provided by forming the first electrical conductive layer 20 and the insulating layer 30 on the core layer 10.

[0048] The first conductive layer 20 may be formed in contact with the upper surface of the core layer 10, or other components such as an insulating layer 30 may be placed between the first conductive layer 20 and the core layer 10, so that the first conductive layer 20 is separated from the upper surface of the core layer 10.

[0049] When forming a first electrical conductive layer 20 on the core layer 10, the first electrical conductive layer 20 may be formed using a dry method or a wet method.

[0050] The dry method is a method in which a seed layer is formed by sputtering in the region on the core layer 10 where the first electrical conductive layer 20 is placed, and then the electrical conductive layer is formed by plating in the region where the seed layer is formed. When forming the seed layer, a metal containing any one selected from the group consisting of titanium, tungsten, tantalum, molybdenum, nickel, chromium, and combinations thereof may be sputtered, or the aforementioned metal and copper may be applied together for sputtering. Through sputtering, an anchoring effect appears in which the surface on which the first electrical conductive layer 20 is placed and the deposited metal particles interact, which can improve the adhesion force of the first electrical conductive layer 20.

[0051] The wet method is a method in which a primer is applied to the area where the first electrical conductive layer 20 needs to be formed, and then metal plating is performed. The primer may include a compound having a functional group such as an amine. Depending on the desired degree of adhesion, the primer may contain both a compound having a functional group such as an amine and a silane coupling agent. When using a silane coupling agent, the surface to be primed can be pretreated with the silane coupling agent, and then a compound having an amine group can be applied to the pretreated area to form the primer layer.

[0052] After forming a seed layer or primer layer, a metal can be plated to form the first electrical conductive layer 20. Copper plating may be applied during the formation of the first electrical conductive layer 20, but is not limited to this. Before metal plating, portions of the seed layer or primer layer where the formation of the first electrical conductive layer 20 is unnecessary can be deactivated, or portions where the formation of the first electrical conductive layer 20 is necessary can be activated before plating. The activation or deactivation treatment method may include light irradiation treatment using a laser of a specific wavelength, chemical treatment, etc. However, after metal plating without applying activation or deactivation treatment, the first electrical conductive layer 20 can be etched and patterned according to a pre-designed shape.

[0053] The insulating layer 30 may be placed on the first conductive layer 20. The insulating layer 30 may be formed to surround at least a portion of the first conductive layer 20. The insulating layer 30 may be formed to surround at least a portion of the upper surface of the first conductive layer 20. The insulating layer 30 may be formed to surround at least a portion of the upper and side surfaces of the first conductive layer 20.

[0054] The insulating layer 30 and the first conductive layer 20 may be arranged together on the core layer 10. The first conductive layer 20, which has a patterned shape, may be formed in a form embedded within the insulating layer 30.

[0055] The insulating layer 30 can be any material that can be used as an insulating layer in the field of packaging substrates. For example, the insulating layer 30 may be an epoxy resin containing a filler. The insulating layer 30 may, but is not limited to, a build-up layer material such as Ajinomoto's ABF (Ajinomoto Build-up Film) or an undercoat material.

[0056] The insulating layer 30 may contain a filler. The filler is not limited as long as it is one that is commonly applicable in the field of insulating layers. For example, the filler may be silica, alumina, titania, etc.

[0057] In practice, the average particle size of the filler can be controlled within a preset range. In such a case, even if the resin is etched more than the filler during the desmear step due to the difference in etching characteristics between the filler and the resin contained in the insulating layer 30, it is possible to prevent the upper surface of the insulating layer 30 from becoming excessively rough.

[0058] The average particle size (D50) of the filler may be 1 μm or less. The average particle size may be 0.9 μm or less. The average particle size may be 0.8 μm or less. The average particle size may be 0.7 μm or less. The average particle size may be 0.1 μm or more.

[0059] The maximum particle size of the filler may be 10 μm or less. The maximum particle size may be 9 μm or less. The maximum particle size may be 8 μm or less. The maximum particle size may be 7 μm or less. The maximum particle size may be 0.1 μm or more.

[0060] In such cases, it may be helpful to form a stable bonding force between the insulating layer 30 and the electrically conductive layer formed on the insulating layer 30.

[0061] When forming an insulating layer 30 on the first electrical conductive layer 20, the insulating layer 30 can be formed by laminating an uncured or semi-cured insulating film and then curing it.

[0062] The insulating layer 30 may include contact holes 31 that penetrate the insulating layer 30 in the thickness direction. The contact holes 31 can provide a space in which an electrical conductive layer can be formed in the thickness direction of the packaging substrate. The electrical conductive layer formed in the contact holes 31 can electrically connect the first electrical conductive layer 20 and the electrical conductive layer formed on the first electrical conductive layer 20.

[0063] The contact hole 31 can expose a portion of the upper surface of the first conductive layer 20. The upper surface of the first conductive layer 20 may include an exposed region 21 exposed by the contact hole 31.

[0064] The contact hole 31 may include a first opening 311 located on the upper side of the insulating layer 30, a second opening 312 located on the lower side of the insulating layer 30, and an inner surface 313 of the insulating layer that connects the first opening 311 and the second opening 312 and is formed in the thickness direction of the insulating layer 30.

[0065] The inner surface 313 of the insulating layer can form an inclined surface. When the base substrate 100 is observed in cross-section, the profile of the inner surface 313 of the insulating layer may be straight, curved, or may include both straight and curved surfaces.

[0066] In this embodiment, the diameter of the first opening 311 can be adjusted to be larger than the diameter of the second opening 312. This allows the plasma gas to smoothly reach the contact hole 31 during the desmear step and effectively remove any residue within the contact hole 31. Furthermore, a seed layer can be easily formed on the inner surface 313 of the insulating layer with a relatively uniform thickness by sputtering or the like.

[0067] The ratio of the diameter of the first opening 311 to the diameter of the second opening 312 may be 1.1 or greater. The ratio may be 1.15 or greater. The ratio may be 1.2 or greater. The ratio may be 1.3 or greater. The ratio may be 3 or less. In such cases, it may be helpful to form an electrically conductive layer with excellent electrical reliability and durability within the contact hole 31.

[0068] When the base substrate 100 is observed in cross-section in the thickness direction, the angle between the profile of the inner surface 313 of the insulating layer and the profile of the exposed area 21 may be 92° or more. The angle may be 95° or more. The angle may be 120° or less. The angle may be 115° or less. In such cases, it is possible to facilitate a smooth desmear process and suppress the formation of voids during the process of forming the electrical conductive layer in the contact hole 31.

[0069] If the profile of the inner surface 313 of the insulating layer includes a curved surface, the method for measuring the angle between the profile of the inner surface 313 of the insulating layer and the profile of the exposed area 21 is as follows: Identify a first point where the profile of the inner surface 313 of the insulating layer and the profile of the upper surface of the insulating layer 30 are in contact, and a second point where the profile of the inner surface 313 of the insulating layer and the profile of the lower surface of the insulating layer 30 are in contact. Measure the angle between the straight line connecting the first and second points and the profile of the exposed area 21, and define this angle as the angle between the profile of the inner surface 313 of the insulating layer and the profile of the exposed area 21.

[0070] The contact holes 31 can be formed by etching the region in the insulating layer 30 where the contact holes 31 are located. The contact holes 31 may be formed by laser etching, dry etching, wet etching, etc. Laser etching may be applied for precise control of the shape of the contact holes 31.

[0071] Desmia Steppe Process conditions The manufacturing method for the packaging substrate in the embodiment includes a desmear step in which the base substrate 100 is desmeared. In the desmear step, the base substrate 100 is plasma desmeared with a reaction gas containing oxygen gas and a fluorine-based gas. Specifically, in the desmear step, the reaction gas is introduced into the atmosphere in which the base substrate 100 is placed, and the base substrate 100 is plasma-etched with the reaction gas to remove residue in the contact holes 31.

[0072] Oxygen gas can exhibit relatively high etching properties with respect to the resin contained in the insulating layer 30. Fluorine-based gas can exhibit relatively high etching properties with respect to the filler contained in the insulating layer 30.

[0073] Fluorine-containing gases can be fluorinated carbon compounds. Fluorine-containing gases include CF4, C2F2, C2F4, C2F6, C3F6, C3F8, C4F8, and C4F 10 And any one selected from the group consisting of these combinations. The fluorine-based gas may be CF4.

[0074] In one concrete example, the ratio of the flow rate of fluorine-based gas to the flow rate of oxygen gas introduced into the atmosphere on which the base substrate 100 is placed can be controlled within a preset range. In such a case, it is possible to suppress the roughening of the upper surface of the insulating layer 30 due to an excessive difference in etching rates between the resin and filler contained in the insulating layer 30 during the desmear step.

[0075] In the desmear step, the ratio of the flow rate of the fluorine-based gas to the flow rate of the oxygen gas introduced into the atmosphere on which the base substrate 100 is placed may be 4.5 or more. The ratio may be 4.7 or more. The ratio may be 5 or more. The ratio may be 8 or more. The ratio may be 10 or more. The ratio may be 12 or more. The ratio may be 15 or more. The ratio may be 17 or more. The ratio may be 20 or more. The ratio may be 25 or more. The ratio may be 30 or more. The ratio may be 35 or more. The ratio may be 80 or less. In such a case, it is possible to suppress excessive etching of the resin in the insulating layer 30 compared to the filler during the desmear step.

[0076] In the desmear step, the flow rate of oxygen gas introduced into the atmosphere in which the base substrate 100 is placed may be 400 sccm or less. The flow rate may be 350 sccm or less. The flow rate may be 300 sccm or less. The flow rate may be 250 sccm or less. The flow rate may be 10 sccm or more.

[0077] In the desmear step, the flow rate of the fluorine-based gas introduced into the atmosphere on which the base substrate 100 is placed may be 45 sccm or more. The flow rate may be 100 sccm or more. The flow rate may be 200 sccm or more. The flow rate may be 300 sccm or more. The flow rate may be 400 sccm or more. The flow rate may be 500 sccm or more. The flow rate may be 600 sccm or more. The flow rate may be 700 sccm or more. The flow rate may be 800 sccm or more. The flow rate may be 2,000 sccm or less.

[0078] In such cases, it can contribute to providing a reaction gas in which the difference in etching characteristics between the resin and filler within the insulating layer 30 is reduced.

[0079] The reaction gas may further contain other gases besides oxygen gas and fluorine-based gases, if necessary.

[0080] In the desmear step, a plasma gas can be formed by irradiating the reaction gas with a plasma beam. The discharge power applied to the plasma beam may be 3,000 W or more. The discharge power may be 4,000 W or more. The discharge power may be 5,000 W or more. The discharge power may be 6,000 W or more. The discharge power may be 10,000 W or less.

[0081] The frequency applied to the plasma beam may be 10 kHz or higher. The frequency may be 20 kHz or higher. The frequency may be 30 kHz or higher. The frequency may be 200 kHz or lower. The frequency may be 150 kHz or lower. The frequency may be 100 kHz or lower.

[0082] In such cases, it may be helpful to ensure that a sufficient amount of reaction gas is formed in the atmosphere in which the base substrate 100 is placed.

[0083] The aforementioned discharge power is the discharge power per nozzle from which the plasma beam is emitted.

[0084] In the desmear step, controlling the distance between the base substrate and the electrode that generates the plasma allows for sufficient removal of residue within the contact hole and suppression of excessive damage to the upper surface of the insulating layer.

[0085] In the desmear step, the distance between the base substrate and the electrode may be 150 mm or less. The distance may be 120 mm or less. The distance may be 100 mm or less. The distance may be 80 mm or less. The distance may be 60 mm or less. The distance may be 10 mm or more. The distance may be 20 mm or more. In such cases, it is possible to form a redistribution layer with excellent electrical reliability within the base substrate.

[0086] Characteristics of the insulating layer after the desmear step In practice, the difference in thickness of the insulating layer 30 before and after the desmear step can be adjusted. Specifically, the difference in thickness can control the thickness to which the insulating layer 30 is etched by the plasma gas during the desmear step, keeping it within a preset range. In such a case, excessive damage to the upper surface of the insulating layer 30 by the plasma gas can be suppressed. In particular, it is possible to suppress the upper surface of the insulating layer 30 from becoming rougher than a certain level due to the plasma gas, and to prevent the insulating layer 30 from having a thickness thinner than intended.

[0087] The thickness of the insulating layer 30 before the desmear step and the thickness of the insulating layer 30 after the desmear step are measured at the same location within the insulating layer 30. The measurement location for the thickness of the insulating layer 30 is specified to be a location within the insulating layer 30 where no contact holes 31 or the like are formed.

[0088] The difference between the thickness of the insulating layer 30 before the desmear step and the thickness of the insulating layer 30 after the desmear step may be 0.7 μm or less. The value may be 0.5 μm or less. The value may be 0.4 μm or less. The value may be 0.3 μm or less. The value may be 0.2 μm or less. The value may be 0 μm or more. In such cases, excessive damage to the upper surface of the insulating layer 30 by the plasma gas can be suppressed.

[0089] One concrete example is that by controlling the roughness characteristics of the upper surface of the insulating layer 30, the influence of irregularities on the upper surface of the insulating layer 30 on the bonding force between the upper surface of the insulating layer 30 and the electrical conductive layer can be reduced.

[0090] The arithmetic mean roughness Ra value of the upper surface of the insulating layer 30 in the base substrate 100 after the desmear step may be 125 nm or less. The Ra value may be 115 nm or less. The Ra value may be 100 nm or less. The Ra value may be 80 nm or less. The Ra value may be 60 nm or less. The Ra value may be 50 nm or less. The Ra value may be 40 nm or less. The Ra value may be 30 nm or less. The Ra value may be 10 nm or more.

[0091] The maximum height roughness Rz value of the upper surface of the insulating layer 30 in the base substrate 100 after the desmear step may be 4.5 μm or less. The Rz value may be 4.3 μm or less. The Rz value may be 4.0 μm or less. The Rz value may be 3.5 μm or less. The Rz value may be 3.0 μm or less. The Rz value may be 2.5 μm or less. The Rz value may be 2.0 μm or less. The Rz value may be 1.5 μm or less. The Rz value may be 1.0 μm or less. The Rz value may be 0.05 μm or more.

[0092] In such cases, an environment suitable for forming a stable bonding force between the upper surface of the insulating layer 30 and the electrically conductive layer can be provided.

[0093] Ra and Rz values ​​are measured in accordance with the provisions of the standard ISO 4287:1997.

[0094] Electrical conductive layer formation step Figure 2A is a conceptual diagram illustrating the seed layer formed by the seed layer formation process in the embodiment. Figure 2B is a conceptual diagram illustrating the packaging substrate in the embodiment. The embodiment will be described below with reference to Figures 2A and 2B.

[0095] The base substrate 100, core layer 10, first electrical conductive layer 20, insulating layer 30, and contact holes 31 are the same as those described in Figure 1 above. The differences will be explained below.

[0096] The manufacturing method of the packaging substrate in the embodiment may further include a conductive layer formation step in which a second conductive layer 45 is formed on the insulating layer 30 in the base substrate 100 after the desmear step has been completed.

[0097] The second electrical conductive layer 45 is distinguished from the first electrical conductive layer 20 formed beneath the insulating layer 30 by being formed on the insulating layer 30 and within the contact holes 31.

[0098] The second electrical 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.

[0099] The seed layer 40 may include any one selected from the group consisting of titanium, tungsten, tantalum, molybdenum, nickel, chromium, and combinations thereof. The seed layer 40 may include a first seed layer 40 and a second seed layer placed on the first seed layer. The first seed layer may include any one selected from the group consisting of titanium, tungsten, tantalum, molybdenum, nickel, chromium, and combinations thereof. The second seed layer may include the same metallic element as the metallic element applied to the conductive layer 41. The second seed layer may include copper. A seed layer 40 having such a structure and composition may help the second electrically conductive layer 45 to have excellent bonding strength to the insulating layer 30.

[0100] The conductive layer 41 may contain copper.

[0101] The electrical conductive layer formation step in the embodiment may include a seed layer formation process in which a seed layer 40 is formed on the inner surface 313 of the insulating layer, and a conductive layer formation process in which a conductive layer 41 is formed on the seed layer 40 to provide a second electrical conductive layer 45. Specifically, in the embodiment, during the seed layer formation process, a seed layer 40 having a uniform thickness distribution can be formed on the inner surface 313 of the insulating layer, whose inclination angle has been adjusted. This suppresses the occurrence of bonding defects between the inner surface 313 of the insulating layer and the seed layer 40, and allows the second electrical conductive layer 45 to be stably fixed within the contact hole 31 of the insulating layer 30.

[0102] Except for forming a seed layer 40 on the inner surface 313 of the insulating layer and the thickness of the layer, the second electrical conductive layer 45 can be formed in the same manner as the first electrical conductive layer 20. A detailed explanation of the method for forming the second electrical conductive layer 45 will be omitted as it will overlap with the content described above.

[0103] The peel strength of the second electrical conductive layer 45 to the upper surface of the insulating layer 30 may be 400 gf / cm or more. The peel strength may be 500 gf / cm or more. The peel strength may be 600 gf / cm or more. The peel strength may be 650 gf / cm or more. The peel strength may be 700 gf / cm or more. The peel strength may be 1,000 gf / cm or less. In such cases, the second electrical conductive layer 45 can be stably fixed on the insulating layer 30.

[0104] The peel strength is measured by the following method: After cutting the second electrical conductive layer 45 to a width of 10 mm and a length of 100 mm on the insulating layer 30, the peel strength is measured by pulling one end of the cut second electrical conductive layer 45 in the longitudinal direction at a 90° angle with respect to the upper surface of the insulating layer 30.

[0105] In practice, a packaging substrate can be manufactured by forming a second electrical conductive layer 45 on an insulating layer 30.

[0106] If necessary, the electrical conductive layer formation step of the embodiment may further include the process of forming an insulating layer 30 disposed on the second electrical conductive layer 45, and other electrical conductive layers disposed on the insulating layer 30. If necessary, the electrical conductive layer formation step of the embodiment may further include the process of forming an insulating layer 30 disposed beneath the core layer 10, and other electrical conductive layers disposed beneath the insulating layer 30. The insulating layer 30 and the electrical conductive layers may be provided in the same manner as described above.

[0107] Other steps If necessary, upper terminals and the like can be additionally formed on the upper and / or lower sides of the packaging substrate, and bumps can be additionally formed on the lower side of the packaging substrate. The bumps can be positioned in a predetermined manner below the redistribution layer, which is a layer containing an insulating layer 30 and an electrically conductive layer, located below the core layer 10. Exemplariously, the bumps may be positioned on a portion of the lower surface of the packaging substrate so as to be in contact with the main board or the like.

[0108] The following examples will provide a more detailed explanation of the implementation through specific embodiments. These embodiments are merely illustrative to aid in understanding the implementation, and the scope of implementation is not limited to them.

[0109] Manufacturing example: Formation of packaging substrates Example 1: A Copper Clad Laminate (CCL) with a thickness of 0.5 mm was provided. An insulating layer was formed on both sides of the CCL by laminating and curing a 20 μm thick build-up film, ABF GL103 (average particle size of fillers in the film: 0.5 μm, maximum particle size: 5 μm). Multiple contact holes were formed in the insulating layer formed on both sides of the CCL using a UV laser, and a base substrate was provided. The diameter of the first opening of the contact holes was set to 40 μm. It was confirmed that the contact holes were formed in a tapered shape, with the first opening being larger than the second opening.

[0110] After placing the base substrate into the chamber, plasma desmearing was performed for 60 seconds. During desmearing, the discharge power of the nozzle emitting the plasma beam was set to 7000W, the frequency to 50kHz, the flow rate of oxygen gas introduced into the chamber to 20sccm, the flow rate of fluorine-based gas CF4 to 1000sccm, and the distance between the base substrate and the electrode to 40mm.

[0111] A first seed layer, a titanium layer with a thickness of 150 nm, was 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 of the base substrate after desmearing. A second seed layer, a copper layer with a thickness of 300 nm, was formed on the first seed layer by sputtering. An electroless plating process was performed on the second seed layer to fill the contact holes with a copper layer, and a copper layer with a thickness of 20 μm was formed on the upper surface of the insulating layer to provide a conductive layer, thus completing the second electrical conductive layer.

[0112] Example 2: The packaging substrate was prepared under the same conditions as in Example 1, except that the oxygen gas flow rate was set to 50 sccm when performing plasma desmearing.

[0113] Example 3: The packaging substrate was prepared under the same conditions as in Example 1, except that the oxygen gas flow rate was set to 200 sccm when performing plasma desmearing.

[0114] Example 4: The packaging substrate was prepared under the same conditions as in Example 1, except that the plasma desmear was performed for 90 seconds and the oxygen gas flow rate was set to 50 sccm.

[0115] Example 5: The packaging substrate was prepared under the same conditions as in Example 4, except that the oxygen gas flow rate was set to 100 sccm when performing plasma desmearing.

[0116] Example 6: The packaging substrate was prepared under the same conditions as in Example 4, except that the oxygen gas flow rate was set to 200 sccm when performing plasma desmearing.

[0117] Example 7: The packaging substrate was prepared under the same conditions as in Example 1, except that the plasma desmear was performed for 120 seconds and the oxygen gas flow rate was set to 50 sccm.

[0118] Example 8: The packaging substrate was prepared under the same conditions as in Example 7, except that the oxygen gas flow rate was set to 100 sccm when performing plasma desmearing.

[0119] Example 9: The packaging substrate was prepared under the same conditions as in Example 7, except that the oxygen gas flow rate was set to 200 sccm when performing plasma desmearing.

[0120] Example 10: The packaging substrate was prepared under the same conditions as in Example 1, except that the plasma desmear was performed for 180 seconds and the oxygen gas flow rate was set to 50 sccm.

[0121] Comparative Example 1: The packaging substrate was prepared under the same conditions as in Example 1, except that the oxygen gas flow rate was set to 1,000 sccm and the CF4 flow rate to 100 sccm when performing plasma desmearing.

[0122] The process conditions for each example and comparative example are shown in Table 1 below.

[0123] Evaluation example: Evaluation of the extent of damage to the upper part of the insulating layer. In the manufacturing process of the packaging substrates for each example and comparative example, the thickness of the insulating layer was measured before plasma desmearing. Subsequently, the thickness of the insulating layer was measured again after the plasma desmearing was completed. After the measurements were completed, the difference between the two thicknesses was calculated.

[0124] The measured values ​​for each example and comparative example are shown in Table 2 below.

[0125] Evaluation example: Evaluation of the roughness characteristics of the upper surface of the insulating layer In the manufacturing process of the packaging substrates for each example and comparative example, after plasma desmearing and before forming the first seed layer, the arithmetic mean roughness (Ra value) and the maximum height roughness (Rz value) of the upper surface of the insulating layer were measured in accordance with ISO 4287:1997.

[0126] The measured values ​​for each example and comparative example are shown in Table 2 below.

[0127] Evaluation Example: Evaluation of the peel strength of the second electrical conductive layer against the insulating layer. After cutting the second conductive layer to a size of 10 mm in width and 100 mm in length on the insulating layer of the packaging substrate for each example and comparative example, one end of the second conductive layer in the longitudinal direction was pulled at a 90° angle with respect to the upper surface of the packaging substrate, and the peel strength of the second conductive layer relative to the insulating layer was measured.

[0128] The evaluation results for each example and comparative example are shown in Table 2 below.

[0129] Evaluation example: QVP (Quick Via Pull) evaluation After peeling off the second electrical conductive layer from the packaging substrates for each example and comparative example, the inside of the contact holes was observed using a Scanning Electron Microscope (SEM). A "Fail" rating was given if the copper layer of CCL was observed at the bottom of the contact hole, and a "Pass" rating was given if a portion of the second electrical conductive layer was observed at the bottom of the contact hole, or if an organic layer located beneath the copper layer of CCL was observed.

[0130] The evaluation results for each example and comparative example are shown in Table 2 below.

[0131] [Table 1]

[0132] [Table 2]

[0133] In Table 2, Examples 1 to 10 showed a peel strength of 600 gf / cm or more, while Comparative Example 1 showed a peel strength of 100 gf / cm or less. This result indicates that when the roughness characteristics of the upper surface of the insulating layer are controlled within a range predetermined in the examples, the bonding force of the second electrical conductive layer to the upper surface of the insulating layer can be significantly improved.

[0134] In the QVP test, Examples 1-10 were all evaluated as Pass, while Comparative Example 2 was evaluated as Fail. This is thought to be because, in Examples 1-10, the residue in the contact holes was substantially removed by desmearing, resulting in a stable connection between the second electrical conductive layer and the copper layer of the CCL, whereas in Comparative Example 1, the residue in the contact holes was not sufficiently removed, resulting in a poor electrical connection between the second electrical conductive layer and the copper layer of the CCL.

[0135] 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 appended claims, also fall within the scope of the present invention. [Explanation of symbols]

[0136] 100 base board 10-core layer 20 First electrical conduction layer 21 Exposure area 30 Insulating layer 31 Contact Holes 311 First opening 312 Second opening 313 Inner surface of the insulating layer 40 Seed Layer 41 Conductive layer 45 Second electrical conduction layer

Claims

1. A method for manufacturing a packaging substrate, comprising: a preparation step of providing a base substrate including a core layer, a first electrical conductive layer disposed on the core layer, and an insulating layer disposed on the first electrical conductive layer; and a desmear step of desmearing the base substrate, The insulating layer includes contact holes penetrating the insulating layer in the thickness direction, and the upper surface of the first conductive layer includes an exposed region exposed by the contact holes. In the desmear step, the base substrate is plasma desmeared with a reaction gas containing oxygen gas and a fluorine-based gas. A method for manufacturing a packaging substrate, wherein in the desmear step, the ratio of the flow rate of the fluorine-based gas to the flow rate of the oxygen gas introduced into the atmosphere on which the base substrate is placed is 4.5 or more.

2. The method for manufacturing a packaging substrate according to claim 1, wherein the difference between the thickness of the insulating layer before the desmear step and the thickness of the insulating layer after the desmear step is 0.7 μm or less.

3. The method for manufacturing a packaging substrate according to claim 1, wherein the arithmetic mean roughness Ra of the upper surface of the insulating layer in the base substrate after the desmear step is 125 nm or less.

4. The method for manufacturing a packaging substrate according to claim 1, wherein the maximum height roughness Rz of the upper surface of the insulating layer in the base substrate after the desmear step is 4.5 μm or less.

5. The insulating layer includes a filler, The method for manufacturing a packaging substrate according to claim 1, wherein the average particle size of the filler is 1 μm or less.

6. The method for manufacturing a packaging substrate according to claim 5, wherein the maximum particle size of the filler is 10 μm or less.

7. The contact hole includes a first opening located on the upper side of the insulating layer, a second opening located on the lower side of the insulating layer, and an inner surface of the insulating layer formed in the thickness direction of the insulating layer, connecting the first opening and the second opening. The method for manufacturing a packaging substrate according to claim 1, wherein the diameter of the first opening is larger than the diameter of the second opening.

8. The method for manufacturing a packaging substrate according to claim 7, wherein the ratio of the diameter of the first opening to the diameter of the second opening is 1.1 or more.

9. The process further includes a conductive layer formation step in which a second conductive layer is formed on the insulating layer in the base substrate after the desmear step has been completed, The method for manufacturing a packaging substrate according to claim 7, wherein the step of forming an electrical conductive layer includes a seed layer formation step of forming a seed layer on the inner surface of the insulating layer and a conductive layer formation step of forming a conductive layer on the seed layer to provide a second electrical conductive layer.

10. The method for manufacturing a packaging substrate according to claim 9, 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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