Method for manufacturing substrate with roughened surface and method for manufacturing substrate with plating layer

Abstract

To provide a method for manufacturing a substrate with a roughened surface and a method for manufacturing a substrate with a plated layer, which enables easy production of the substrate with the plated layer.SOLUTION: One of the embodiments is a method for manufacturing a substrate with a roughened surface for forming wiring, comprising the step of performing laser ablation on a substrate containing at least resin on the surface, and the laser light irradiated in the laser ablation is a laser light with a pulse width of 1 ps or less, a wavelength of 320 nm or more and an output of 1 w or less.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing a substrate having a roughened surface and a method for manufacturing a substrate having a plating layer. [Background technology]

[0002] Mobile communication systems require large capacity and simultaneous connections, and to meet these requirements, high-density fine wiring boards are required.

[0003] For example, Patent Document 1 discloses a method for surface modification and metal film formation of a resin molded body, which comprises a first step of irradiating a surface layer of the resin molded body with a low-power laser beam having a wavelength of 194 nm to 1064 nm, and vaporizing the fragile layer on the surface of the molded body and the moisture contained in the fragile layer, which inhibits adhesive bonding between the resin molded body and the electroless plating film, with light energy, a second step of applying a molecular bonding agent that adhesively bonds a plating film formed in a later step to the laser-irradiated resin molded body, and then exposing the molded body to UV light having a wavelength of 185 nm to 365 nm to fix the molecular bonding agent to the surface layer of the molded body, a third step of supporting a metal catalyst that serves as an electroless plating catalyst on the molecular bonding agent fixed to the surface layer of the molded body, and a fourth step of forming an electroless plating layer on the resin molded body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-55174 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, the invention disclosed in Patent Document 1 prescribes vaporizing low molecular weight substances and moisture remaining on the surface layer of a resin molded body, applying a molecular bonding agent to the surface layer of the resin molded body, and then providing an electroless plating layer after the application and adhesion of the molecular bonding agent. If a substrate having a plating layer were to be manufactured using the invention described in Patent Document 1, a very complicated process would be required.

[0006] Therefore, an object of the present disclosure is to provide a method for manufacturing a substrate having a roughened surface, which enables easy production of a substrate having a plating layer, and a method for manufacturing a substrate having a plating layer. [Means for solving the problem]

[0007] The present inventors conducted intensive research to solve the above problems and discovered that a substrate obtained by performing laser ablation under specific conditions can be easily manufactured into a substrate having a plating layer, which led to the present disclosure.

[0008] An example aspect of this embodiment is described as follows.

[0009] (1) A method for manufacturing a substrate having a roughened surface for forming wiring, comprising the steps of: A step of performing laser ablation on a substrate containing a resin at least on a surface thereof, A method for manufacturing a substrate, wherein the laser light irradiated in the laser ablation has a pulse width of 1 ps or less, a wavelength of 320 nm or more, and an output of 1 W or less. (2) The method for manufacturing a substrate according to (1), wherein the laser light has a pulse width of 0.1 ps or more. (3) The method for producing a substrate according to (1) or (2), wherein the laser light has a wavelength of 1064 nm or less. (4) The method for producing a substrate according to any one of (1) to (3), wherein the laser light has an output of 0.05 W or more. (5) A substrate containing a resin at least on its surface, A substrate having a roughened surface, the arithmetic mean height Sa being 50 to 200 nm, and the amount (area ratio) of functional groups in the C1s spectrum determined from the XPS spectrum being 10% or more. (6) performing electroless plating on a surface of the substrate obtained by the method for producing a substrate according to any one of (1) to (4) or the substrate according to (5) to form an electroless plating layer; performing electrolytic plating on the electroless plating layer to form an electrolytic plating layer; and A method for manufacturing a substrate having a plating layer, comprising a step of performing an annealing treatment on a substrate having an electrolytic plating layer formed thereon. (7) performing dry plating on a surface of the substrate obtained by the method for producing a substrate according to any one of (1) to (4) or the substrate according to (5) to form a dry plating layer; performing electrolytic plating on the dry plating layer to form an electrolytic plating layer; and A method for manufacturing a substrate having a plating layer, comprising a step of performing an annealing treatment on a substrate having an electrolytic plating layer formed thereon. (8) before the step of forming a dry plating layer, A method for producing a substrate having a plating layer according to (7), comprising a step of performing plasma treatment on a surface of a substrate obtained by the method for producing a substrate according to any one of (1) to (4), or the substrate according to (5). (9) The method for producing a substrate having a plating layer according to (8), wherein the plasma treatment is at least one type of plasma treatment selected from H2 / Ar plasma treatment and O2 / Ar plasma treatment. (10) A step of plating a surface of the substrate obtained by the method for producing a substrate according to any one of (1) to (4) or the substrate according to (5) to form a plating layer; and A method for manufacturing a substrate having a plating layer, comprising a step of performing laser annealing treatment on the formed plating layer. (11) The step of forming the plating layer comprises: A step of performing electroless plating on the surface of the substrate obtained by the method for producing a substrate according to any one of (1) to (4) or the substrate according to (5) to form an electroless plating layer, and a step of performing electrolytic plating on the electroless plating layer to form an electrolytic plating layer, or The method includes the steps of: performing dry plating on a surface of the substrate obtained by the method for producing a substrate according to any one of (1) to (4) or the substrate according to (5) to form a dry plating layer; and performing electrolytic plating on the dry plating layer to form an electrolytic plating layer. A method for producing a substrate having a plating layer according to (10). (12) The method for producing a substrate having a plating layer according to (10) or (11), wherein the wavelength of the laser light irradiated onto the plating layer during the laser annealing treatment is 600 nm or less. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide a method for manufacturing a substrate having a roughened surface, which allows easy production of a substrate having a plating layer, and a method for manufacturing a substrate having a plating layer. Also, according to the present disclosure, it is possible to provide a substrate having a roughened surface. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 shows SEM images of the laser ablated ABF film obtained in Example 1 and the wet roughened ABF film obtained in Comparative Example 1. [Diagram 2] FIG. 2 shows the amount of functional groups (area ratio) determined by performing XPS observation on the surfaces of the ABF film, the ABF film that was subjected to laser ablation obtained in Example 1, and the ABF film that was subjected to wet roughening obtained in Comparative Example 1 to obtain C1s (carbon atom 1s orbital) spectra and performing peak division. [Diagram 3] FIG. 3 shows the peel strength of the substrates having the copper plating layers obtained in Example 2 and Comparative Example 2. [Figure 4]FIG. 4 shows the amount of functional groups (area ratio) determined by performing XPS observation of the surface of the ABF film that was subjected to the H2 / Ar plasma treatment and the O2 / Ar plasma treatment in Example 3, obtaining a C1s (carbon atom 1s orbital) spectrum, and performing peak division. [Diagram 5] FIG. 5 shows the peel strength of the substrate having the copper plating layer obtained in Example 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the method for producing a substrate having a roughened surface, the method for producing a substrate having a roughened surface, and the method for producing a substrate having a plating layer according to this embodiment will be described in detail.

[0013] (Method for manufacturing a substrate with a roughened surface) The method for manufacturing a substrate having a roughened surface of this embodiment is a method for manufacturing a substrate having a roughened surface for forming wiring, and includes a step of performing laser ablation on a substrate containing at least a resin on its surface, in which the laser light irradiated in the laser ablation has a pulse width of 1 ps or less, a wavelength of 320 nm or more, and an output of 1 W or less.

[0014] In the method for producing a substrate having a roughened surface according to the present embodiment, a large number of fine irregularities can be formed on the surface of the substrate obtained by performing laser ablation under specific conditions. The substrate obtained also has an improved amount of functional groups (amount of COO groups and C=O groups) on the surface. The substrate obtained in the present embodiment (substrate having a roughened surface) has a large number of fine irregularities and a large amount of functional groups, and therefore is preferable because when a plating layer is formed, the adhesion strength between the plating layer and the substrate is excellent.

[0015] The substrate containing a resin at least on the surface on which the laser ablation is performed is not particularly limited, including a substrate for forming a conventional wiring. Examples of the resin include polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP), polyphenylene ether (PPE), modified polyphenylene ether (m-PPE), polyimide (PI), modified polyimide (MPI), bismaleimide triazine resin (BT), epoxy resin, low-k epoxy resin (low-Dk (low dielectric constant)-low-Df (low dielectric loss tangent) epoxy resin), and the like. The resin is preferably a high-frequency compatible low-dielectric substrate that can be used in high-speed communication (e.g., 5th generation mobile communication system, 6th generation mobile communication system) and millimeter wave compatible communication (e.g., automotive use). In this embodiment, the laser ablation is performed on the substrate, and the laser ablation is performed by irradiating a specific laser light onto the surface of the substrate, more specifically, by irradiating the laser light onto the surface of the substrate on which the resin is present.

[0016] The surface of the substrate may contain a resin, but may also contain components other than resin, such as glass fiber, silica-based filler, ceramic-based filler, Al2O3, AlN, BN, etc.

[0017] The substrate may be a substrate having a single layer structure formed only from a layer formed from the resin, or a substrate having a structure of two or more layers (multi-layer structure) including a layer formed from the resin and another layer. There is no particular limitation on the other layer.

[0018] In this embodiment, the laser light irradiated in the laser ablation has a pulse width of 1 ps or less, a wavelength of 320 nm or more, and an output of 1 W or less. By using the laser light, it is possible to form fine irregularities on the substrate surface, and also to increase the amount of functional groups (the amount of COO groups and C=O groups) on the substrate surface.

[0019] In one preferred embodiment, the laser light has a pulse width of 0.1 ps or more. The pulse width is preferably 0.9 ps or less, and more preferably 0.85 ps or less. The pulse width is preferably 0.2 ps or more, and more preferably 0.3 ps or more.

[0020] In one preferred embodiment, the laser light has a wavelength of 1064 nm or less. The wavelength of the laser light varies depending on the light source (laser medium). For example, by using Yb:YAG, it is possible to irradiate a laser light having a wavelength of 1030 nm or a laser light having a wavelength of 515 nm (double wave), and by using YAG, it is possible to irradiate a laser light having a wavelength of 1064 nm, a laser light having a wavelength of 532 nm (double wave), or a laser light having a wavelength of 355 nm (triple wave). For example, Yb:YAG, YAG, etc. can be used as the light source.

[0021] In one preferred embodiment, the laser light has an output of 0.05 W or more. The output is preferably 0.8 W or less, and more preferably 0.6 W or less. The output is preferably 0.07 W or more, and more preferably 0.1 W or more.

[0022] The energy fluence during laser ablation is preferably 15 μJ / cm 2 More preferably, it is 13 μJ / cm or less. 2 or less, and particularly preferably 10 μJ / cm 2 The energy fluence is preferably 1 μJ / cm 2 More preferably, it is 5 μJ / cm 2 That's all.

[0023] The device used for laser ablation is not particularly limited as long as it can irradiate the laser light, and examples thereof include LodeStone (manufactured by Esi) and Monaco series (manufactured by COHERENT).

[0024] (Substrate with roughened surface) The surface-roughened substrate of this embodiment is a substrate containing at least a resin on the surface, having an arithmetic mean height Sa of 50 to 200 nm, and a functional group amount (area ratio) of 10% or more in a C1s spectrum obtained from an XPS (X-ray photoelectron spectroscopy) spectrum. This substrate is generally used as a substrate for forming wiring.

[0025] The substrate having a roughened surface of this embodiment can be manufactured by the above-mentioned method for manufacturing a substrate having a roughened surface.

[0026] When the arithmetic mean height Sa is within the above range, it is suggested that the substrate has fine irregularities, i.e., the surface is roughened. Also, when the amount of functional groups (area ratio) in the C1s spectrum obtained from the XPS spectrum is 10% or more, it is suggested that the amount of functional groups (amount of COO groups and C=O groups) on the substrate surface is sufficiently high.

[0027] In the case where a plating layer is formed on the substrate having a roughened surface according to this embodiment, the adhesion strength between the plating layer and the substrate is excellent, which is preferable.

[0028] The arithmetic mean height Sa of the substrate having a roughened surface can be measured using a laser roughness meter.

[0029] The amount (area ratio) of functional groups in the C1s spectrum obtained from the XPS spectrum can be calculated by dividing the C1s (carbon atom 1s orbital) peak in the XPS spectrum, calculating the peak area derived from the COO group and the peak area derived from the C═O group as shown in the following formula, and dividing the sum by the total C1s peak area. Amount of functional group (area ratio) = [(peak area derived from COO group + peak area derived from C=O group) / total C1s peak area] x 100

[0030] The amount (area ratio) of the functional group is 10% or more, preferably 11% or more, and more preferably 12% or more. The amount (area ratio) of the functional group is usually 20% or less, preferably 17% or less, and more preferably 15% or less.

[0031] (Method of manufacturing a substrate having a plating layer) There are three main embodiments of the present invention as a method for producing a substrate having a plating layer. The substrate having a plating layer obtained by the method for producing a substrate having a plating layer has excellent peel strength of the plating layer, and can be used for various applications such as high-density fine wiring boards required for high-speed communication (e.g., 5th generation mobile communication system, 6th generation mobile communication system) and millimeter wave compatible communication (e.g., automotive applications). Examples of metals constituting the plating layer include copper, gold, silver, nickel, chromium, aluminum, etc., with copper and gold being preferred, and copper being more preferred.

[0032] The method for manufacturing a substrate having a plating layer of this embodiment-A includes the steps of performing electroless plating on the surface of a substrate obtained by the method for manufacturing a substrate of this embodiment, or the surface of the substrate of this embodiment, to form an electroless plating layer, performing electrolytic plating on the electroless plating layer to form an electrolytic plating layer, and performing an annealing treatment on the substrate on which the electrolytic plating layer has been formed.

[0033] The method for manufacturing a substrate having a plating layer of this embodiment B is a method for manufacturing a substrate having a plating layer, comprising the steps of performing dry plating on a substrate obtained by the method for manufacturing a substrate of this embodiment or on the surface of the substrate of this embodiment to form a dry plating layer, performing electrolytic plating on the dry plating layer to form an electrolytic plating layer, and performing an annealing treatment on the substrate on which the electrolytic plating layer has been formed.

[0034] The method for manufacturing a substrate having a plating layer of this embodiment-C is a method for manufacturing a substrate having a plating layer, which includes a step of plating a surface of a substrate obtained by the method for manufacturing a substrate of this embodiment or the substrate of this embodiment to form a plating layer, and a step of performing a laser annealing treatment on the formed plating layer.

[0035] The method for manufacturing a substrate having a plating layer of this embodiment-A includes a step of performing electroless plating on the substrate obtained by the method for manufacturing a substrate of this embodiment or the surface of the substrate of this embodiment to form an electroless plating layer. The electroless plating solution can be selected according to the metal species constituting the plating layer, and can be used without particular limitation, including known autocatalytic electroless plating solutions. As the electroless plating solution, electroless copper plating solution, electroless gold plating solution, electroless silver plating solution, electroless nickel plating solution, electroless chromium plating solution, etc. can be used, and electroless copper plating solution is usually used for wiring substrate applications. In addition, known conditions can be appropriately applied as plating conditions for electroless plating. The electroless plating layer preferably has an average thickness of 600 nm or less, more preferably 240 to 160 nm, and particularly preferably 220 to 180 nm. One of the preferred aspects is that the electroless plating layer is an electroless copper plating layer. The substrate having a plating layer obtained by the method for manufacturing a substrate having a plating layer of this embodiment-A is preferable because the plating layer and the substrate are firmly bonded to each other and have high peel strength. The substrates having a plating layer obtained by the manufacturing methods of the substrate having a plating layer of the present embodiment-A, the present embodiment-B, and the present embodiment-C are preferable because they have excellent adhesion strength between the plating layer and the substrate without the need for an adhesion layer formed of Cr or Ti, which is conventionally provided when performing dry plating.

[0036] The method for manufacturing a substrate having a plating layer according to the present embodiment-B includes a step of performing dry plating on the substrate obtained by the method for manufacturing a substrate according to the present embodiment or on the surface of the substrate according to the present embodiment to form a dry plating layer. Examples of dry plating include sputtering, ion plating, and vacuum deposition. As dry plating, sputtering is preferred from the viewpoint of adhesion to the substrate. That is, one of the preferred aspects is that the dry plating layer is a sputtered layer. When performing dry plating, copper, gold, silver, nickel, chromium, aluminum, and the like can be used as a target, and copper is usually used for wiring substrates.

[0037] Dry plating can be carried out by appropriately applying known conditions. That is, it can be carried out by known sputtering, ion plating, vacuum deposition, etc. The dry plating layer preferably has an average thickness of 600 nm or less, more preferably 250 to 150 nm, and particularly preferably 240 to 160 nm. One of the preferred embodiments is that the dry plating layer is a dry copper plating layer. The substrate having a plating layer obtained by the method for producing a substrate having a plating layer of this embodiment B has sufficient peel strength, even though the plating layer adjacent to the substrate is a dry plating layer formed by dry plating, which is generally difficult to bond to the substrate. Dry plating tends to be less environmentally hazardous than electroless plating, which is a type of wet plating, and is therefore preferred from the viewpoint of reducing the environmental load.

[0038] In the method for producing a substrate having a plating layer according to the present embodiment-B, a step of performing a plasma treatment on the substrate obtained by the method for producing a substrate according to the present embodiment or on the surface of the substrate according to the present embodiment before the step of forming a dry plating layer is preferably included. The step of performing a plasma treatment is preferable because it can further improve the amount of functional groups (area ratio) in the C1s spectrum obtained from the XPS spectrum of the substrate. Note that, although the step of performing a plasma treatment is most effective when performed in the method for producing a substrate having a plating layer according to the present embodiment-B, it may be performed in other methods, for example, before the step of forming an electroless plating layer in the method for producing a substrate having a plating layer according to the present embodiment-A.

[0039] The plasma treatment is preferably at least one type of plasma treatment selected from H2 / Ar plasma treatment and O2 / Ar plasma treatment. H2 / Ar plasma treatment is a method of plasma treating a substrate using hydrogen and argon, and O2 / Ar plasma treatment is a method of plasma treating a substrate using oxygen and argon, and each can be performed by appropriately applying known conditions. As the plasma treatment, H2 / Ar plasma treatment and O2 / Ar plasma treatment are preferably performed, and O2 / Ar plasma treatment is particularly preferably performed after H2 / Ar plasma treatment. By performing H2 / Ar plasma treatment, the surface can be cleaned, and then by performing O2 / Ar plasma treatment, functional groups can be introduced.

[0040] The method for manufacturing a substrate having a plating layer of this embodiment A includes a step of performing electrolytic plating on an electroless plating layer to form an electrolytic plating layer. Also, the method for manufacturing a substrate having a plating layer of this embodiment B includes a step of performing electrolytic plating on a dry plating layer to form an electrolytic plating layer. These steps can be performed in the same way, except that the target for electrolytic plating is an electroless plating layer or a dry plating layer.

[0041] As the electrolytic plating solution, an electrolytic copper plating solution, an electrolytic gold plating solution, an electrolytic silver plating solution, an electrolytic nickel plating solution, an electrolytic chromium plating solution, an electrolytic tin plating solution, etc. can be used, and in the application of a wiring board, an electroless copper plating solution is usually used. In addition, as the plating conditions of the electrolytic plating, known conditions can be appropriately applied. In an embodiment, the electrolytic plating may be a solid-phase electrodeposition method (SED), which is a plating method using a solid electrolyte film. In the application of the electrolytic plating layer to a wiring board, the average line width (also simply referred to as width) of the wiring is preferably 30 μm or less, more preferably 10 μm or less, and further preferably 5 μm or less. In addition, the average line width is preferably 1 μm or more. From the viewpoint of fine wiring, the aspect ratio of the thickness to the width of the wiring (thickness / width) is preferably 0.85 to 1.15, and more preferably 0.9 to 1.1. In one preferred embodiment, the electrolytic plating layer is an electrolytic copper plating layer. Furthermore, it is preferable that the electroless plated layer and the electrolytic plated layer, or the dry plated layer and the electrolytic plated layer, are layers formed from the same type of metal, and it is more preferable that they are layers formed from copper.

[0042] The method for manufacturing a substrate having a plating layer according to the present embodiment A includes a step of performing an annealing treatment on the substrate having an electrolytic plating layer formed thereon. Also, the method for manufacturing a substrate having a plating layer according to the present embodiment B includes a step of performing an annealing treatment on the substrate having an electrolytic plating layer formed thereon.

[0043] The annealing treatment is generally performed by heating the substrate on which the electrolytic plating layer is formed. The heating temperature varies depending on the type of resin constituting the substrate and the type of metal constituting the plating layer, but is, for example, 100 to 210°C, preferably 110 to 200°C. The annealing treatment is usually performed by heating the substrate at a temperature and time that is equal to or higher than the glass transition point (Tg) of the resin constituting the substrate and ensures shape retention. In addition, one of the preferred embodiments of the annealing treatment is to gradually increase the temperature from a low temperature. For example, when the Tg of the resin constituting the substrate is 150°C, a low-temperature annealing treatment can be performed at 100 to 140°C, preferably 110 to 140°C, and then a high-temperature annealing treatment can be performed at 150 to 210°C, preferably 150 to 200°C. When the annealing treatment is performed at a constant temperature, the annealing treatment is performed at, for example, 150 to 210°C, preferably 160 to 200°C. In the annealing treatment, heating at a temperature equal to or higher than the Tg of the resin is performed for usually 10 to 90 minutes, preferably 30 to 60 minutes. When the annealing treatment is performed by increasing the temperature stepwise from a low temperature, each step is performed for usually 10 to 90 minutes, preferably 30 to 60 minutes.

[0044] The annealing treatment may be carried out in air or in an inert gas such as nitrogen or a rare gas. From the viewpoint of cost, it is preferable to carry out the annealing treatment in air, and from the viewpoint of suppressing side reactions, it is preferable to carry out the annealing treatment in an inert gas.

[0045] The annealing treatment may be carried out under normal pressure, reduced pressure, or pressurized pressure, but is usually carried out under normal pressure.

[0046] The annealing treatment is generally performed by heating the substrate on which the electrolytic plating layer is formed, but may also be performed by performing a laser annealing treatment on the electrolytic plating layer of the substrate on which the electrolytic plating layer is formed. The laser annealing treatment is synonymous with the laser annealing treatment in the method for producing a substrate having a plating layer of this embodiment-C.

[0047] The method for manufacturing a substrate having a plating layer according to the present embodiment-C includes a step of plating the substrate obtained by the method for manufacturing a substrate according to the present embodiment or the surface of the substrate according to the present embodiment to form a plating layer. The plating in this step is not particularly limited, and includes electroless plating, dry plating, electrolytic plating, and any combination thereof. The step of forming the plating layer preferably includes a step of performing electroless plating on the substrate obtained by the method for manufacturing a substrate according to the present embodiment or the surface of the substrate according to the present embodiment to form an electroless plating layer, and a step of performing electrolytic plating on the electroless plating layer to form an electrolytic plating layer, or a step of performing dry plating on the substrate obtained by the method for manufacturing a substrate according to the present embodiment or the surface of the substrate according to the present embodiment to form a dry plating layer, and a step of performing electrolytic plating on the dry plating layer to form an electrolytic plating layer. That is, it is preferable to form an electroless plating layer and an electrolytic plating layer, or to form a dry plating layer and an electrolytic plating layer, by the methods described in the above-mentioned present embodiments-A and B.

[0048] The method for manufacturing a substrate having a plating layer of this embodiment C includes a step of performing a laser annealing treatment on the formed plating layer. The laser annealing treatment is a method of irradiating a laser beam onto the formed plating layer to perform an annealing treatment on the portion irradiated with the laser beam. The wavelength of the laser beam irradiated onto the plating layer is preferably a wavelength that can be absorbed by the plating layer, and although it varies depending on the metal type of the plating layer, it is usually 600 nm or less, and more preferably 550 nm or less. There is no particular limit to the lower limit of the wavelength, but it is preferably, for example, 200 nm or more.

[0049] The conditions for irradiating the laser light are not particularly limited as long as the interface temperature between the plating layer and the substrate is equal to or higher than the glass transition point of the resin constituting that portion of the substrate, and can be appropriately set depending on the apparatus, type of resin, metal type and thickness of the plating layer, etc.

[0050] Laser annealing treatment differs depending on the area of ​​the portion to be annealed, but generally, it is desirable to show sufficient peel strength in a short time, for example, within 10 minutes, preferably within 3 minutes, compared to annealing treatment by heating. In laser annealing treatment, local heating of the interface between the substrate and the plating layer is possible by laser light, so heating can be performed without concern about the shape retention of the substrate. For this reason, heating by laser light may be performed to a temperature exceeding the temperature at which shape retention can be guaranteed when general heating, i.e., when the entire substrate is heated (for example, 200°C, although this varies depending on the type of resin). EXAMPLES

[0051] The present embodiment will be described below with reference to examples, but the present disclosure is not limited to these examples.

[0052] In the examples, an ABF film (ABF GX92, manufactured by Ajinomoto Fine-Techno Co., Ltd.) was used. ABF GX92 is distributed in a state in which a layer formed of an insulating material (epoxy resin containing silica-based filler) is formed on a PET film, but in the examples, the PET film was peeled off, and the layer formed of an insulating material (epoxy resin containing silica-based filler) was attached to a support (epoxy resin containing glass fiber) to be used as an ABF film (substrate). In the examples, the surface on the side of the layer formed of the insulating material (hereinafter also simply referred to as the surface) was used as the target for laser ablation or wet roughening, not the surface on the support side.

[0053] [Example 1] The surface of the ABF film was irradiated with laser light under the following conditions to perform laser ablation (target roughness Sa 200 nm). (Laser irradiation conditions) Equipment: LodeStone (manufactured by Esi) Wavelength: 515nm Pulse width: 0.8ps Beam diameter: φ10μm Output power: 0.15W Repetition frequency: 100KHz Scanning speed: 500mm / s Overlap: 5μm

[0054] [Comparative Example 1] The surface of the ABF film was wet-roughened (target roughness Sa 200 nm) by desmearing with permanganic acid.

[0055] [SEM observation] The surfaces of the laser-ablated ABF film obtained in Example 1 and the wet-roughened ABF film obtained in Comparative Example 1 were observed under the following conditions, and SEM images were obtained. The surface roughness Sa (arithmetic mean height) was measured using a confocal laser roughness meter, and the surface roughness Sa of the laser-ablated ABF film obtained in Example 1 was 170 nm, and the surface roughness Sa of the wet-roughened ABF film obtained in Comparative Example 1 was 220 nm. Note that Sa is the arithmetic mean height of the contour curved surface, and means the absolute average of the ordinate value z(x, y) in the reference region A. The SEM images are shown in FIG. 1.

[0056] 1, three-dimensional holes (deep holes) were formed in the ABF film subjected to wet roughening obtained in Comparative Example 1, whereas many relatively small irregularities were formed on the surface of the ABF film subjected to laser ablation obtained in Example 1. The specific surface area of ​​the ABF film subjected to laser ablation obtained in Example 1 was larger.

[0057] [XPS observation] The surfaces of the ABF film, the laser ablated ABF film obtained in Example 1, and the wet-roughened ABF film obtained in Comparative Example 1 were subjected to XPS observation under the following conditions, and C1s (carbon atom 1s orbital) spectra were obtained, peak division was performed, and the amount (area ratio) of functional groups was calculated. As functional groups, COO groups and C=O groups were analyzed by peak division. The amount of functional groups is shown in FIG. 2.

[0058] 2, it can be seen that the amount of functional groups in the ABF film increases by carrying out the treatments of Example 1 and Comparative Example 1. In particular, it was confirmed that the amount of functional groups increased significantly in Example 1 compared to the ABF film before treatment and the ABF film that had been subjected to wet roughening obtained in Comparative Example 1. The increase in the amount of functional groups is considered to be a favorable change that can be expected to improve the adhesive strength with the plating layer.

[0059] [Example 2] An electroless copper plating layer was formed by electroless copper plating under the following conditions on the surface of the ABF film that had been subjected to laser ablation obtained in Example 1. Next, electrolytic copper plating was performed on the electroless copper plating layer under the following conditions to form an electrolytic copper plating layer. (Electroless copper plating) Electroless copper plating solution: PEA ver.3 (Uemura Kogyo Co., Ltd.) Processing temperature: 33℃ Soaking time: 30 minutes Electroless copper plating layer average thickness: 0.5μm (Electrolytic copper plating) Electrolytic copper plating solution: Formulated based on Cover Cream 125A / 125B (manufactured by Rohm & Haas) Current density: 2A / dm 2 Plating time: 60 minutes, room temperature Average thickness of electrolytic copper plating layer: 20μm

[0060] The substrate on which the electrolytic copper plating layer was formed was subjected to a heat treatment (annealing treatment) at 180° C. for 30 minutes in an air atmosphere to obtain a substrate having a copper plating layer.

[0061] [Comparative Example 2] An electroless copper plating layer was formed by electroless copper plating under the following conditions on the surface of the ABF film that had been subjected to the wet roughening treatment obtained in Comparative Example 1. Next, electrolytic copper plating was performed on the electroless copper plating layer under the following conditions to form an electrolytic copper plating layer. (Electroless copper plating) Electroless copper plating solution: PEA ver.3 (Uemura Kogyo Co., Ltd.) Processing temperature: 33℃ Soaking time: 30 minutes Electroless copper plating layer average thickness: 0.5μm (Electrolytic copper plating) Electrolytic copper plating solution: Formulated based on Cover Cream 125A / 125B (manufactured by Rohm & Haas) Current density: 2A / dm 2 Plating time: 30 minutes Average thickness of electrolytic copper plating layer: 20μm

[0062] The substrate on which the electrolytic copper plating layer was formed was subjected to a heat treatment (annealing treatment) at 180° C. for 30 minutes in an air atmosphere to obtain a substrate having a copper plating layer.

[0063] [Peel strength measurement] The peel strength of the substrates having the copper plating layers obtained in Example 2 and Comparative Example 2 was measured. A 10 mm wide cut was made in the electrolytic copper plating layer using a cutter knife, and the peel strength (kN / m) was measured using a peel strength tester (digital force gauge ZTA-DPU, manufactured by IMADA Co., Ltd.) The peel strength measurement results are shown in Figure 3.

[0064] 3 suggests that the peel strength is significantly improved in Example 2 compared to Comparative Example 2. Although it was possible to achieve a general target peel strength (0.6 kN / m) in Comparative Example 2 as well, the substrate having the copper plating layer obtained in Example 2 has a further improved peel strength, suggesting that the substrate having the copper plating layer obtained in Example 2 is useful for high-density fine wiring substrates.

[0065] [Example 3] The ABF film that had been subjected to laser ablation obtained in Example 1 was subjected to H2 / Ar plasma treatment under the following conditions, and then to O2 / Ar plasma treatment. (H2 / Ar plasma treatment conditions) Hydrogen 3% / Argon 97% (volume fraction) Equipment: High-speed sputtering equipment (Shimadzu Corporation) Pressure: 30Pa Output: 1750W Processing time: 60s TS (distance between anode plasma source and substrate sample (stage)): 180 mm BGP (background pressure): 0.5 Pa (O2 / Ar plasma treatment conditions) Oxygen 95% / Argon 5% (volume fraction) Equipment: High-speed sputtering equipment (Shimadzu Corporation) Pressure: 30Pa Output: 2100W Processing time: 180s TS: 180mm BGP: 0.5Pa

[0066] Next, the surface of the obtained H2 / Ar plasma-treated and O2 / Ar plasma-treated ABF film was subjected to copper sputtering under the following conditions to form a sputtered copper layer (dry copper plating layer). Next, electrolytic copper plating was performed on the sputtered copper layer under the following conditions to form an electrolytic copper plating layer. (Copper sputtering) Sputter source: Copper Power: 35KW Argon flow rate: 270sccm Gas pressure: 1.6Pa Sputtering time: 10s TS: 180mm BGP: 0.5Pa Average thickness of sputtered copper layer: 0.5μm (Electrolytic copper plating) Electrolytic copper plating solution: Formulated based on Cover Cream 125A / 125B (manufactured by Rohm & Haas) Current density: 2A / dm 2 Plating time: 30 minutes Average thickness of electrolytic copper plating layer: 20μm

[0067] The substrate on which the electrolytic copper plating layer was formed was heat-treated in an air atmosphere at 120° C. for 30 minutes (low-temperature annealing treatment), and then heat-treated at 200° C. for 1 hour (high-temperature annealing treatment) to obtain a substrate having a copper plating layer.

[0068] [XPS observation] The surface of the ABF film obtained in Example 3 and subjected to the H2 / Ar plasma treatment and O2 / Ar plasma treatment was observed by XPS under the following conditions, and a C1s (carbon atom 1s orbital) spectrum was obtained, and peak division was performed to calculate the amount (area ratio) of functional groups. As functional groups, COO groups and C=O groups were analyzed by peak division. The amount of functional groups is shown in FIG. 4.

[0069] It was confirmed from Figures 4 and 2 that the amount of functional groups was further increased by performing H2 / Ar plasma treatment and O2 / Ar plasma treatment. The increase in the amount of functional groups is considered to be a favorable change that is expected to improve the adhesive strength with the plating layer.

[0070] [Peel strength measurement] The peel strength of the substrate having the copper plating layer obtained in Example 3 was measured. A 10 mm wide cut was made in the electrolytic copper plating layer using a cutter knife, and the peel strength (kN / m) was measured using a peel strength tester (digital force gauge ZTA-DPU, manufactured by IMADA Co., Ltd.) The peel strength measurement results are shown in Figure 5.

[0071] Generally, it is known that even if a copper layer is formed on a resin by sputtering, the adhesion is low, and an adhesion layer (e.g., a sputtered Ti layer or a sputtered Cr layer) has been provided between the resin and the copper layer in the past. However, from FIG. 5, it was found that in Example 3, it is possible to achieve a general target peel strength (0.6 kN / m).

[0072] [Example 4] On the surface of the ABF film obtained in Example 1 that had been subjected to laser ablation, an electroless copper plating layer and an electrolytic copper plating layer were formed by the method described in Example 2.

[0073] The substrate on which the electrolytic copper plating layer was formed was subjected to laser annealing treatment under the following conditions to obtain a substrate having a copper plating layer. (Laser annealing) The electrolytic copper plating layer was irradiated with laser light under the following conditions to perform a laser annealing treatment. Equipment: LDH-G0610 (Spectronics) Wavelength: 532nm Pulse frequency: 200kHz (step 0.25μm) Speed: 50mm / sec Beam diameter after focusing: approx. φ19μm Beam diameter after defocus: φ approx. 5 mm Output: 20w Laser irradiation time: 1 minute, 2 minutes, 3 minutes, 5 minutes, 10 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes, or 120 minutes

[0074] [Comparative Example 3] A substrate having a copper plating layer was obtained in the same manner as in Example 4, except that the laser annealing treatment was not performed.

[0075] [Peel strength measurement] The peel strength of the substrates having the copper plating layers obtained in Example 4 and Comparative Example 3 was measured. A cutter knife was used to make a 10 mm wide cut in the electrolytic copper plating layer, and the peel strength (kN / m) was measured using a peel strength tester (digital force gauge ZTA-DPU, manufactured by IMADA Co., Ltd.). The laser irradiation time and the measurement results of the peel strength are shown in Table 1. Note that the laser irradiation time of 0 minutes in Table 1 corresponds to Comparative Example 3.

[0076] [Table 1]

[0077] From Table 1, it was found that by performing laser annealing treatment, the peel strength is improved compared to when laser annealing treatment is not performed, and a substrate having a copper plating layer exceeding a general target peel strength (0.6 kN / m) can be obtained. It was suggested that laser annealing treatment can obtain a substrate having a copper plating layer with excellent peel strength in a shorter time than general heat treatment.

[0078] The upper limit and / or lower limit of the numerical ranges described in this specification can be arbitrarily combined to define a preferred range. For example, the upper limit and lower limit of the numerical range can be arbitrarily combined to define a preferred range, the upper limit of the numerical range can be arbitrarily combined to define a preferred range, and the lower limit of the numerical range can be arbitrarily combined to define a preferred range.

[0079] Although the present embodiment has been described in detail above, the specific configuration is not limited to this embodiment, and even if there are design changes within the scope that does not deviate from the gist of this disclosure, they are included in this disclosure.

Claims

1. A method for manufacturing a substrate having a roughened surface for forming wiring, comprising the steps of: The method includes a step of performing laser ablation on a substrate containing at least a resin on a surface thereof so that the arithmetic mean height Sa is 50 to 200 nm and the amount (area ratio) of functional groups in a C1s spectrum obtained from an XPS spectrum is 10% or more; A method for manufacturing a substrate, wherein the laser light irradiated in the laser ablation has a pulse width of 1 ps or less, a wavelength of 320 nm or more, and an output of 1 W or less.

2. The method for manufacturing a substrate according to claim 1 , wherein the laser light has a pulse width of 0.1 ps or more.

3. The method for manufacturing a substrate according to claim 1 or 2, wherein the laser light has a wavelength of 1064 nm or less.

4. The method for manufacturing a substrate according to any one of claims 1 to 3, wherein the laser light has an output of 0.05 W or more.

5. The substrate includes a resin at least on a surface thereof, A substrate having a roughened surface, the substrate having an arithmetic mean height Sa of 50 to 200 nm and a functional group amount (area ratio) of 10% or more in a C1s spectrum determined from an XPS spectrum.

6. A step of performing electroless plating on a surface of the substrate obtained by the method for producing a substrate according to any one of claims 1 to 4 or the substrate according to claim 5 to form an electroless plating layer; performing electrolytic plating on the electroless plating layer to form an electrolytic plating layer; and A method for manufacturing a substrate having a plating layer, comprising a step of performing an annealing treatment on a substrate having an electrolytic plating layer formed thereon.

7. A step of performing dry plating on a surface of the substrate obtained by the method for producing a substrate according to any one of claims 1 to 4 or the substrate according to claim 5 to form a dry plating layer; performing electrolytic plating on the dry plating layer to form an electrolytic plating layer; and A method for manufacturing a substrate having a plating layer, comprising a step of performing an annealing treatment on a substrate having an electrolytic plating layer formed thereon.

8. Before the step of forming a dry plating layer, A method for producing a substrate having a plating layer according to claim 7, comprising a step of performing a plasma treatment on a surface of a substrate obtained by the method for producing a substrate according to any one of claims 1 to 4, or the substrate according to claim 5.

9. The plasma treatment is ２ / Ar plasma treatment and O ２ The method for producing a substrate having a plating layer according to claim 8 , wherein the plasma treatment is at least one type of plasma treatment selected from a Ar plasma treatment and a H plasma treatment.

10. A step of plating a surface of the substrate obtained by the method for producing a substrate according to any one of claims 1 to 4 or the substrate according to claim 5 to form a plating layer; and A method for manufacturing a substrate having a plating layer, comprising a step of performing laser annealing treatment on the formed plating layer.

11. The step of forming the plating layer includes: A method for producing a substrate according to any one of claims 1 to 4, or a method for producing a substrate according to claim 5, comprising the steps of: performing electroless plating on a surface of the substrate obtained by the method for producing a substrate according to any one of claims 1 to 4, to form an electroless plating layer; and performing electrolytic plating on the electroless plating layer to form an electrolytic plating layer. The method includes a step of performing dry plating on a surface of the substrate obtained by the method for producing a substrate according to any one of claims 1 to 4 or the substrate according to claim 5 to form a dry plating layer, and a step of performing electrolytic plating on the dry plating layer to form an electrolytic plating layer. A method for producing a substrate having the plating layer according to claim 10.

12. 12. The method for producing a substrate having a plating layer according to claim 10, wherein the wavelength of the laser light irradiated onto the plating layer during the laser annealing treatment is 600 nm or less.

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