Method for manufacturing printed circuit board

Abstract

To provide a simple method for manufacturing a printed circuit board in which a high-accuracy circuit is formed, and surface-treated copper foil copper foil.SOLUTION: A method for manufacturing a printed circuit board equipped with a resin substrate and a wiring pattern formed on the surface of the resin substrate includes the steps of: forming a masking layer in a part of the surface of copper foil 21; forming protrusions 22 containing copper and / or copper oxide on the surface of the copper foil on which the masking layer is not formed; treating the surface of the copper foil by releasability improver; laminating the resin substrate and the copper foil such that the resin substrate and the protrusions formed on the surface of the copper foil come in contact to form a laminate; separating the resin substrate from the copper foil and transferring the protrusions formed on the surface of the copper foil onto the resin substrate to form a seed layer containing copper and / or copper oxide on the surface of the resin substrate; and performing a plating treatment to the surface of the resin substrate by using plating liquid.SELECTED DRAWING: Figure 15

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a printed circuit board. [Background technology]

[0002] In recent years, there has been an increasing demand for finer wiring in printed circuit boards such as printed wiring boards and semiconductor package substrates. Known methods for forming circuits on these substrates include the subtractive method, semi-additive methods such as the SAP method (Semi-Additive Process) and the M-SAP method (Modified Semi-Additive Process) (Patent Document 1), and the full-additive method.

[0003] The subtractive method involves preparing a laminate of a resin base material and copper foil, covering the necessary areas of the copper foil (areas where wiring is to be formed) with resist, and then etching the copper foil. After etching, the resist on the copper foil is removed, and the copper foil in the areas covered with resist remains, and this becomes the copper wiring.

[0004] In the semi-additive method, a resin substrate with a metal seed layer on its surface is coated with a resist on the areas where wiring is not to be made, and then plated. After removing the resist, the remaining seed layer is etched to form fine circuits. Among these methods, the SAP method forms a seed layer by performing electroless plating on the surface of the resin substrate. Meanwhile, the MSAP method uses a resin substrate with copper foil attached as the seed layer.

[0005] The full additive method is a method that allows selective formation of circuits by electrolessly plating only the wiring parts directly on the substrate. Unlike the subtractive method and the semi-additive method, the full additive method does not require etching of the copper foil, and is therefore useful in terms of shortening the process and reducing the environmental load, but has problems such as the time required for electroless plating deposition and the difficulty of maintaining and managing the electroless plating solution. As a method for selectively forming circuits other than the full additive method, there is a method of applying metal nanoparticles in the wiring shape by inkjet (Patent Document 2). There is also a method of directly drawing a metal wiring pattern by laser irradiation. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-034216 A [Patent Document 2] JP 2018-074055 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, the method of applying metal nanoparticles in a wiring shape by inkjet has problems such as the difficulty of application due to the use of silver nanoparticles, the low precision of the resulting wiring pattern, and the high cost. Also, the method using laser irradiation has problems such as the long takt time (i.e., the time required for manufacturing) for forming a circuit.

[0008] As described above, the conventional methods require a metal (e.g., copper foil) etching process and have long tact times, which are troublesome. Furthermore, the precision of the resulting circuits is not high. Therefore, a method capable of forming a highly precise circuit in a simple manner is required.

[0009] Therefore, an object of the present invention is to provide a method for manufacturing a printed circuit board that is capable of forming a highly accurate circuit in a simple manner, a method for manufacturing a resin base material for forming such a printed circuit board, and a surface-treated copper foil used in manufacturing such a printed circuit board and a method for manufacturing the same. [Means for solving the problem]

[0010] As a result of intensive research into achieving the above object, the present inventors have found that the above problems can be solved by a specific manufacturing method. The present invention has been completed based on these findings.

[0011] That is, in the present invention, A method for manufacturing a printed circuit board comprising a resin base material and a wiring pattern formed on a surface of the resin base material, comprising: forming a masking layer on a portion of a surface of the copper foil; forming protrusions containing copper and / or copper oxide on the surface of the copper foil on which the masking layer is not formed; A step of treating the surface of the copper foil with a release agent; laminating a resin base material and the copper foil such that the resin base material and the protrusions formed on the surface of the copper foil are in contact with each other to form a laminate; a step of separating the resin substrate from the copper foil and transferring protrusions formed on the surface of the copper foil to the resin substrate, thereby forming a seed layer containing copper and / or copper oxide on the surface of the resin substrate; A step of plating a surface of the resin substrate using a plating solution; The present invention provides a method for manufacturing a printed circuit board, comprising:

[0012] The step of forming the protrusions includes: It is preferable that the step is a step of forming protrusions containing copper oxide by oxidation treatment.

[0013] The oxidation treatment is preferably carried out using an oxidizing agent.

[0014] After the step of treating the surface of the copper foil with a release agent, The method preferably includes a step of plating the surface of the copper foil using a plating solution.

[0015] After the step of treating the surface of the copper foil with a release agent, It is preferred that the method includes removing the masking layer from the surface of the copper foil.

[0016] The resin substrate preferably contains at least one insulating resin selected from the group consisting of polyphenylene ether (PPE), epoxy, polyphenylene oxide (PPO), polybenzoxazole (PBO), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP), thermoplastic polyimide (TPI), fluororesin, polyetherimide, polyetheretherketone, polycycloolefin, bismaleimide resin, low dielectric constant polyimide, and cyanate resin.

[0017] In the step of plating the surface of the resin substrate with a plating solution, the plating is preferably an electroless plating.

[0018] In the step of plating the surface of the resin substrate with a plating solution, the plating is preferably an electroless plating process using Cu.

[0019] In addition, in the present invention, A method for producing a resin substrate comprising: a resin substrate; and a seed layer containing copper and / or copper oxide formed on a surface of the resin substrate, forming a masking layer on a portion of a surface of the copper foil; forming protrusions containing copper and / or copper oxide on the surface of the copper foil on which the masking layer is not formed; A step of treating the surface of the copper foil with a release agent; laminating a resin base material and the copper foil such that the resin base material and the protrusions formed on the surface of the copper foil are in contact with each other to form a laminate; a step of separating the resin substrate from the copper foil and transferring protrusions formed on the surface of the copper foil to the resin substrate, thereby forming a seed layer containing copper and / or copper oxide on the surface of the resin substrate; The present invention provides a method for producing a resin substrate, comprising the steps of:

[0020] In addition, in the present invention, A method for producing a surface-treated copper foil, comprising the steps of: forming a masking layer on a portion of a surface of the copper foil; forming protrusions containing copper and / or copper oxide on the surface of the copper foil on which the masking layer is not formed; The present invention provides a method for treating the surface of a copper foil, comprising the steps of:

[0021] After the step of forming the protrusions, It is preferable to include a step of treating the surface of the copper foil with a release improver.

[0022] In addition, in the present invention, Copper foil and A masking layer formed on a portion of the surface of the copper foil; protrusions containing copper and / or copper oxide formed on a surface of the copper foil on which the masking layer is not formed; The present invention provides a surface-treated copper foil comprising: Effect of the Invention

[0023] Since the method for manufacturing a printed circuit board of the present invention includes specific steps, the desired wiring pattern can be formed on a resin substrate with high precision, and therefore the method is simple in that steps such as copper etching are not required, and useful in that highly precise circuits can be obtained. [Brief description of the drawings]

[0024] [Figure 1] 1 shows photographs of the copper foil surface after masking in Examples 1 to 3. (A) is Example 1, (B) is Example 2, and (C) is Example 3. [Diagram 2]1 shows photographs of the copper foil surfaces after oxidation treatment in Examples 1 to 3. (A) is Example 1, (B) is Example 2, and (C) is Example 3. [Diagram 3] 1 shows photographs of the copper foil surfaces after electrolytic plating treatment in Examples 1 to 3. (A) is Example 1, (B) is Example 2, and (C) is Example 3. [Figure 4] 1 shows photographs of the copper foil surfaces after removing the masking in Examples 1 to 3. (A) is Example 1, (B) is Example 2, and (C) is Example 3. [Diagram 5] Photographs of the copper foil surface after the transfer of protrusions in Examples 1 to 3. (A) is Example 1, (B) is Example 2, and (C) is Example 3. In each case, the left side is the copper foil side, and the right side is the resin substrate side. [Figure 6] 1 is a photograph of the copper foil surface after masking in Example 4. [Figure 7] 1 is a photograph of the copper foil surface after the oxidation treatment in Example 4. [Figure 8] 1 is a photograph of the copper foil surface after electrolytic plating treatment in Example 4. [Figure 9] 1 is a photograph of the copper foil surface after removing the masking in Example 4. [Figure 10] 1 is a photograph of the copper foil surface after the transfer of protrusions in Example 4. The left side is the copper foil side, and the right side is the resin substrate side. [Figure 11] This is the surface of the copper foil on which no masking layer is formed. [Figure 12] This is the surface of the copper foil on which the masking layer was formed. [Figure 13] FIG. 2 is a schematic diagram of a seed layer in one embodiment of the present invention. [Figure 14] FIG. 1 is a diagram illustrating an example of a printed circuit board on which electronic components are mounted. [Figure 15] 1A to 1C are diagrams illustrating a method for measuring / calculating the height of a protrusion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] One embodiment of the present invention (hereinafter referred to as embodiment 1) is a method for producing a printed circuit board. The printed circuit board includes a resin base material and a wiring pattern formed on a surface of the resin base material. The above method includes at least one of the following steps: a masking step, a protrusion forming step, a peelability improving step, a laminate forming step, a laminate separating step, and a resin substrate plating step, and may further include at least one step selected from the group consisting of a copper foil plating step, and a masking removal step. A process of forming a masking layer on part of the copper foil surface (masking process) A step of forming protrusions containing copper and / or copper oxide on the surface of the copper foil on which the masking layer is not formed (protrusion forming step). A process of treating the surface of the copper foil with a peelability improving agent (peeling improvement process) A step of plating the surface of the copper foil using a plating solution (copper foil plating step). A process of removing the masking layer from the surface of the copper foil (masking removal process). A process of laminating a resin base material and the copper foil so that the resin base material and the protrusions formed on the surface of the copper foil are in contact with each other to form a laminate (laminate formation process). A process of separating the resin substrate from the copper foil and transferring protrusions formed on the surface of the copper foil to the resin substrate, thereby forming a seed layer containing copper and / or copper oxide on the surface of the resin substrate (laminate separation process). A step of plating the surface of the resin substrate using a plating solution (resin substrate plating step).

[0026] Another embodiment of the present invention (hereinafter referred to as embodiment 2) is a method for producing a resin substrate comprising a resin substrate and a seed layer containing copper and / or copper oxide formed on the surface of the resin substrate. The present invention may be referred to as a "method for producing a resin substrate". The above method includes at least a masking step, a protrusion forming step, a peelability improving step, a laminate forming step, and a laminate separating step, and may further include at least one step selected from the group consisting of a copper foil plating step, and a masking removal step.

[0027] Yet another embodiment of the present invention (hereinafter referred to as embodiment 3) is a method for producing a surface-treated copper foil. The present invention may be referred to as a "method for producing a surface-treated copper foil". The above method includes at least a masking step, a protrusion forming step, and a peelability improving step, and may further include at least one step selected from the group consisting of a copper foil plating step, a masking removal step, a laminate formation step, and a laminate separation step.

[0028] Yet another embodiment of the present invention (hereinafter referred to as embodiment 4) is a surface-treated copper foil comprising a copper foil, a masking layer formed on a portion of the surface of the copper foil, and protrusions containing copper and / or copper oxide formed on the surface of the copper foil on which the masking layer is not formed.

[0029] Hereinafter, the present invention will be described in accordance with a method for producing a printed circuit board according to a first embodiment.

[0030] [Masking process] The masking step is a step of forming a masking layer on a part of the surface of the copper foil. By forming a masking layer on a part of the surface of the copper foil, in the protrusion forming step, protrusions containing copper and / or copper oxide are formed on the surface of the copper foil on which the masking layer is not formed. On the other hand, the formation of the protrusions is inhibited on the surface of the copper foil on which the masking layer is formed.

[0031] (copper foil) The copper foil used in the masking step is not particularly limited, but is preferably made of pure copper having a purity of 95% by mass or more, 99% by mass or more, or 99.9% by mass or more. Examples of such pure copper include tough pitch copper, deoxidized copper, and oxygen-free copper. Among them, oxygen-free copper having an oxygen content of 0.001 to 0.0005% by mass is preferable. The thickness of the copper foil is not particularly limited, but is preferably 0.1 to 100 μm, more preferably 0.5 to 50 μm, and even more preferably 1 to 30 μm.

[0032] (Masking layer) The masking layer is a layer formed from a masking material. The masking material is not particularly limited as long as it has the property of inhibiting the formation of protrusions containing copper and / or copper oxide in the protrusion forming step described below, and examples thereof include organic solvents, resins, curable compounds, metal plates, masking tapes, masking films, masking sheets, etc.

[0033] Examples of the organic solvent include water; alcohols (particularly monoalcohols having 4 to 10 carbon atoms) such as methanol, ethanol, isopropanol, isobutyl alcohol, benzyl alcohol, ethylene glycol, propylene glycol, and glycerin; ketones such as methyl ethyl ketone (MEK), acetone, cyclohexanone, and methyl isobutyl ketone; aliphatic hydrocarbons such as hexane, heptane, octane, decane, and isododecane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; dimethylformamide (DMF), dimethylacetamide, N-methylpyrrolidone, dimethylsulfate, and the like. Examples of suitable organic solvents include aprotic polar solvents such as sulfoxide; halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane, and chlorobenzene; linear or cyclic ethers such as diethyl ether, diisopropyl ether, dimethoxyethane, tetrahydrofuran, dioxane, and propylene glycol monomethyl ether; esters such as ethyl acetate, butyl acetate, and ethyl propionate; nitriles such as acetonitrile; petroleum components such as kerosene, gasoline, light oil, and heavy oil; animal and vegetable oils such as sunflower oil, olive oil, soybean oil, corn oil, castor oil, beef tallow, jojoba oil, and squalane; and silicone oils such as dimethylpolysiloxane and methylphenylpolysiloxane. Among these, monoalcohols, ketones, esters, linear or cyclic ethers having 4 to 10 carbon atoms are preferred. The organic solvents may be used alone or in combination.

[0034] Among the above organic solvents, those with high hydrophobicity tend to be preferred. The reason for this is unclear, but it is thought that organic solvents with high hydrophilicity have a high affinity with the plating solution and oxidizing agent that can be used in the protrusion formation process, and therefore the formation of protrusions progresses even on the surface of the copper foil on which the masking layer is formed, resulting in a decrease in the accuracy of the final circuit. On the other hand, organic solvents with high hydrophobicity tend to exhibit an appropriate masking effect, perhaps because they are less likely to mix with the plating solution and oxidizing agent.

[0035] Examples of the resin include thermoplastic resins such as polyolefin resins, polyamide resins, styrene resins, polycarbonate resins, polyvinyl chloride, polyvinylidene chloride, polycarbonate resins, acrylic resins, methacrylic resins, polyester resins, polyacetal resins, and polyphenylene sulfide resins, and thermosetting resins such as curable acrylic resins, unsaturated polyester resins, epoxy resins, melamine resins, silicone resins, and urethane resins. Only one type of the resins may be used, or two or more types may be used.

[0036] Examples of the curable compound include compounds having an ethylenically unsaturated group such as a vinyl group, an allyl group, a butenyl group, an ethynyl group, and a (meth)acryloyl group. Among them, compounds having a (meth)acryloyl group are preferred from the viewpoint of reactivity, and examples thereof include (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate, hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate, and cyano (meth)acrylates such as 2-cyanoethyl (meth)acrylate. The curable compounds may be used alone or in combination of two or more.

[0037] The resin or the curable compound may be mixed with the organic solvent and used in the form of a composition. The composition may further contain additives such as inorganic fillers, coupling agents, ion trapping agents, leveling agents, pigments, and antioxidants. In addition, when the composition contains the thermosetting resin or the curable compound, it may contain a curing agent, a photopolymerization initiator, a thermal polymerization initiator, a curing agent, and the like.

[0038] Other examples of the masking material include mercapto group-containing silane coupling agents such as 3-mercaptopropyltrimethoxysilane; silane coupling agents (particularly silane coupling agents having an amino group) such as N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane; and organic rust inhibitors such as benzotriazole derivatives such as 1,2,3-benzotriazole and benzothiazole derivatives such as 2-mercaptobenzothiazole.

[0039] After being applied to the copper foil, the composition may be dried as necessary and cured by heating or exposure to ultraviolet light to form a masking layer.

[0040] When the masking material is the resin, the organic solvent, or the composition, it is preferable in that it can be applied by an inkjet method or flexographic printing, and therefore the masking layer can be easily formed.

[0041] Examples of the metal plate include metal plates made of metals such as stainless steel (SUS), chromium, tungsten, molybdenum, and titanium.

[0042] The masking layer may be one layer or two or more layers. The thickness of the masking layer is not particularly limited, but is preferably, for example, 0.1 to 1000 μm. When the masking layer is two or more layers, the above thickness is the total value of all layers.

[0043] [Protrusion formation process] The protrusion forming step is a step of forming protrusions containing copper and / or copper oxide on the surface of the copper foil on which the masking layer is not formed after the masking step. The method of forming the protrusions is not particularly limited. For example, the protrusions containing copper can be formed by forming particles of copper or a copper alloy by plating. In addition, for example, the protrusions containing copper oxide can be formed by oxidizing the surface of the copper foil. In this way, the adhesion to the resin substrate is further improved by forming protrusions on the surface of the copper foil by copper plating or oxidation.

[0044] In this step, before the copper plating treatment or oxidation treatment, a surface roughening treatment such as soft etching or etching, a degreasing treatment, an acid cleaning treatment for removing a natural oxide film on the copper foil, an alkali treatment after the acid cleaning treatment, etc. may be performed. The alkali treatment is not particularly limited, but examples thereof include a method of treating with an alkaline aqueous solution (e.g., an aqueous sodium hydroxide solution) of 0.1 to 10 g / L or 1 to 2 g / L at 30 to 50° C. for about 0.5 to 2 minutes.

[0045] The method of the oxidation treatment is not particularly limited, and examples thereof include a method using an oxidizing agent, a method using thermal oxidation, a method using electrolytic oxidation, and the like. Among these, the method using an oxidizing agent is preferred from the viewpoint of improving adhesion to a resin substrate.

[0046] The oxidizing agent is not particularly limited, and for example, an aqueous solution of a chlorate such as sodium chlorite, sodium hypochlorite, potassium chlorate, or potassium perchlorate is preferably used. The oxidizing agent may contain additives such as a phosphate such as trisodium phosphate dodecahydrate, or a surface active molecule. The surface active molecule is used to adjust the size of the protrusions to be formed, and examples of the surface active molecule include porphyrin, porphyrin macrocycle, expanded porphyrin, ring-contracted porphyrin, linear porphyrin polymer, porphyrin sandwich coordination complex, porphyrin array, silane, tetraorgano-silane, aminoethyl-aminopropyltrimethoxysilane, (3-aminopropyl)trimethoxysilane, (1-[3-(trimethoxysilyl)propyl]urea), (3-aminopropyl)triethoxysilane, ((3-glycidyloxypropyl)trimethoxysilane, Examples of the oxidizing agent include silane, (3-chloropropyl)trimethoxysilane, (3-glycidyloxypropyl)trimethoxysilane, dimethyldichlorosilane, 3-(trimethoxysilyl)propyl methacrylate, ethyltriacetoxysilane, triethoxy(isobutyl)silane, triethoxy(octyl)silane, tris(2-methoxyethoxy)(vinyl)silane, chlorotrimethylsilane, methyltrichlorosilane, silicon tetrachloride, tetraethoxysilane, phenyltrimethoxysilane, chlorotriethoxysilane, ethylene-trimethoxysilane, amines, and sugars. Only one type of the oxidizing agent may be used, or two or more types may be used.

[0047] When the oxidation treatment is carried out using an oxidizing agent, the reaction temperature is not particularly limited, but is preferably, for example, 30 to 95° C., and more preferably, 40 to 80° C. The reaction time is not particularly limited, but is preferably, for example, 0.2 to 30 minutes, and more preferably, 0.4 to 10 minutes. The concentration of the oxidizing agent (e.g., the concentration of the chlorate) is not particularly limited, but is preferably, for example, 5 to 400 g / L, and more preferably, 10 to 300 g / L.

[0048] After the protrusion forming step, the surface of the copper foil may be reduced with a reducing agent. The reduction may form cuprous oxide (copper (I) oxide) on the surface of the copper foil. The reducing agent is not particularly limited, but examples thereof include aqueous solutions of boron compounds such as dimethylamine borane (DMAB), diborane, sodium borohydride, and hydrazine.

[0049] The size, thickness, height, length, etc. of the protrusions containing copper oxide may be adjusted by a chelating treatment using a chelating agent (particularly a biodegradable chelating agent) on the surface of the copper foil. The chelating agent is not particularly limited, but examples thereof include solutions of ethylenediaminetetraacetic acid, diethanolglycine, tetrasodium L-glutamic acid diacetate, ethylenediamine-N,N'-disuccinic acid, sodium 3-hydroxy-2,2'-iminodisuccinate, trisodium methylglycine diacetate, tetrasodium aspartic acid diacetate, disodium N-(2-hydroxyethyl)iminodiacetate, sodium gluconate, etc. The pH of the chelating agent is not particularly limited, but is preferably alkaline, more preferably pH 8 to 10.5, even more preferably pH 9.0 to 10.5, and even more preferably pH 9.8 to 10.2. The chelating agents may be used alone or in combination of two or more.

[0050] In the protrusion forming step, the height of the protrusions containing copper and / or copper oxide formed on the surface of the copper foil on which the masking layer is not formed is not particularly limited, but is preferably 20 nm or more, more preferably 30 nm or more, even more preferably 45 nm or more, and particularly preferably 60 nm or more. Also, it is preferably 1000 nm or less, more preferably 800 nm or less, even more preferably 500 nm or less, particularly preferably 300 nm or less, and most preferably 250 nm or less. The height of the protrusions can be measured, for example, by measuring the length of the protrusions as the distance between the midpoint of the line segment connecting the minimum points of adjacent recesses across the protrusions and the maximum point of the protrusion between the recesses in a cross-sectional image of the copper foil obtained using a scanning electron microscope (SEM), and calculating the average value. More specifically, it can be measured, for example, by the method used in the examples described later.

[0051] In the protrusion forming step, the formation of protrusions containing copper and / or copper oxide is inhibited on the surface of the copper foil on which the masking layer is formed, so the height of the protrusions containing copper and / or copper oxide on the surface is, for example, preferably 5 nm or less, more preferably 1 nm or less, even more preferably 0.1 nm or less, and most preferably 0.01 nm or less. Note that, in the masking removal step described below, the height can be measured in the same manner as described above from a cross-sectional image of the copper foil after removing the masking layer.

[0052] In the protrusion forming process, the value obtained by subtracting the height [2] of the protrusions containing copper and / or copper oxide on the surface of the copper foil on which a masking layer is formed from the height [1] of the protrusions containing copper and / or copper oxide on the surface of the copper foil on which a masking layer is formed (=[1]-[2]) is not particularly limited, but is, for example, preferably 10 nm or more, more preferably 20 nm or more, even more preferably 30 nm or more, particularly preferably 45 nm or more, and most preferably 60 nm or more.

[0053] [Removability improvement process] The peelability improving step is a step of treating the surface of the copper foil with a peelability improving agent after the protrusion forming step. This treatment is for facilitating peeling of the surface layer portion of the copper foil including the protrusions from the copper foil. In other words, the peelability improving agent is an agent having properties for facilitating peeling of the surface layer portion of the copper foil including the protrusions from the copper foil. This step may be carried out simultaneously with the copper foil plating step described below. In this case, the surface of the copper foil is treated with a mixture of the peelability improving agent and the plating solution in the copper foil plating step.

[0054] The peelability improver is not particularly limited, but examples thereof include aqueous solutions of chlorides (nickel chloride, potassium chloride, zinc chloride, iron chloride, chromium chloride, tin(II) chloride, etc.), ammonium salts (ammonium citrate, ammonium chloride, ammonium sulfate, ammonium nickel sulfate, etc.), chelating agents (ethylenediaminetetraacetic acid, diethanolglycine, tetrasodium L-glutamic acid diacetate, ethylenediamine-N,N'-disuccinic acid, sodium 3-hydroxy-2,2'-iminodisuccinate, trisodium methylglycine diacetate, tetrasodium aspartic acid diacetate, disodium N-(2-hydroxyethyl)iminodiacetate, sodium gluconate, etc.), and citric acid.

[0055] The concentration of the peelability improver is not particularly limited, but for example, when treating with nickel chloride, it is preferable to immerse the copper foil on which the protrusions are formed in a nickel chloride solution (concentration 45 g / L or more) at room temperature or a temperature higher than room temperature for 5 seconds or more, 10 seconds or more, or 15 seconds or more. When performing the treatment simultaneously with the plating treatment, it is preferable to, for example, include nickel chloride in the plating solution, immerse the copper foil in the plating solution for 5 seconds or more, 10 seconds or more, or 15 seconds or more, and then perform the plating treatment.

[0056] [Copper foil plating process] The plating process is a process of plating the surface of the copper foil using a plating solution. The plating method is not particularly limited, and examples thereof include electrolytic plating, electroless plating, vacuum deposition, and chemical conversion treatment. However, electrolytic plating is preferred from the viewpoint of forming a uniform plating layer. By going through this process, the heat resistance and chemical resistance of the resin base material and the printed circuit board obtained through the laminate separation process described below tend to be improved. This process may be performed after the peelability improvement process, or may be performed simultaneously with the peelability improvement process as described above.

[0057] As electrolytic plating, nickel plating and nickel alloy plating are preferred. Examples of metals contained in the plating layer formed by nickel plating and nickel alloy plating include pure nickel, Ni-Cu alloy, Ni-Cr alloy, Ni-Co alloy, Ni-Zn alloy, Ni-Mn alloy, Ni-Pb alloy, Ni-P alloy, etc. The above electrolytic plating may be used alone or in combination of two or more.

[0058] Examples of metal salts used for plating include nickel sulfate, nickel sulfamate, nickel chloride, nickel bromide, zinc oxide, zinc chloride, diamminedichloropalladium, iron sulfate, iron chloride, chromic anhydride, chromium chloride, sodium chromium sulfate, copper sulfate, copper pyrophosphate, cobalt sulfate, and manganese sulfate.

[0059] In nickel plating, the composition of the plating solution is not particularly limited, and preferably contains, for example, nickel sulfate (concentration, for example, 100 to 350 g / L), nickel sulfamate (concentration, for example, 100 to 600 g / L), nickel chloride (concentration, for example, more than 0 g / L and not more than 300 g / L), and mixtures thereof. In addition, the plating solution may further contain, as an additive, sodium citrate (concentration, for example, more than 0 g / L and not more than 100 g / L) or boric acid (concentration, for example, more than 0 g / L and not more than 60 g / L).

[0060] When electrolytic plating is applied to the surface of copper foil that has been oxidized, an electric charge is used to reduce the copper oxide on the surface to cuprous oxide or pure copper. Then, the metal corresponding to the electrolytic plating used starts to precipitate, forming a metal layer. The amount of electric charge required varies depending on the type of plating solution and the amount of copper oxide. For example, when Ni plating is applied to copper foil, the area of ​​the copper foil to be electrolytically plated is dm 2 It is preferable to apply a charge of 5 C or more and 90 C or less, and more preferable to apply a charge of 10 C or more and 65 C or less, per unit time.

[0061] The current density in electrolytic plating is not particularly limited, but is preferably 0.2 A / dm 2 ~10A / dm 2 It is preferable to use a current having a different current density for the time required for partially reducing the oxide contained in the protrusions on the surface of the copper foil and for the time required for plating to cover the copper foil.

[0062] The amount of metal formed on the surface of the copper foil by plating is not particularly limited, but is preferably 0.8 to 6.0 mg / dm 2 The amount of metal attached can be calculated, for example, by dissolving the copper foil surface in an acidic solution, measuring the amount of metal by ICP analysis, and dividing the amount by the planar field area of ​​the structure.

[0063] [Masking removal process] The masking removal step is a step of removing a masking layer from the surface of the copper foil. The method of removing the masking layer is not particularly limited, and can be carried out by a general means as a method of removing the corresponding masking material. This step may be performed after the peelability improvement step or after the copper foil plating treatment step. By including this step, it is preferable in that the disadvantages caused by the presence of the masking layer in the laminate formation step described later can be avoided. The above disadvantages include, for example, in the laminate formation step and laminate separation step described later, the masking material has reactivity with the resin substrate to form a chemical bond, making it difficult to separate the resin substrate and the copper foil, and the surface of the resin substrate is roughened.

[0064] As a method for removing the masking material, for example, when an organic solvent, resin, or composition is used as the masking material, a method of washing off with a highly compatible solvent can be mentioned. When the resin is a thermoplastic resin, it may be washed off with an appropriate solvent after heating. In addition, the resin may be decomposed by a chemical method such as hydrolysis by contacting an acid or alkali solution with the resin, and washed off with an appropriate solvent. When a metal plate, masking tape, masking film, or masking sheet is used as the masking material, a method of peeling it off from the copper foil by hand or machine can be mentioned. When the masking layer is a cured composition containing a thermosetting resin or a curable compound, it may be washed off with a solvent that can dissolve the cured product, or it may be peeled off from the copper foil by hand or machine.

[0065] [Laminate formation process] The laminate formation step is a step of laminating a resin substrate and a copper foil so that the resin substrate and the protrusions formed on the surface of the copper foil are in contact with each other to form a laminate. In this step, the laminate may be formed by applying pressure while heating the laminate as necessary. That is, this step may be a step of laminating a resin substrate and a copper foil so that the resin substrate and the protrusions formed on the surface of the copper foil are in contact with each other, and forming a laminate by applying pressure while heating as necessary. This step is a step performed after the dissolution treatment step. When the present invention includes a copper foil plating step and a masking removal step, this step may be performed thereafter.

[0066] The resin substrate is not particularly limited, but preferably contains at least one insulating resin selected from the group consisting of polyphenylene ether (PPE), epoxy, polyphenylene oxide (PPO), polybenzoxazole (PBO), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP), thermoplastic polyimide (TPI), fluororesin, polyetherimide, polyetheretherketone, polycycloolefin, bismaleimide resin, low dielectric constant polyimide, and cyanate resin.

[0067] The thickness of the resin substrate is not particularly limited, but is preferably 0.1 to 100 μm, more preferably 0.5 to 50 μm, and even more preferably 1 to 30 μm. The resin substrate may further contain an inorganic filler or glass fiber. The relative dielectric constant of the resin substrate is preferably 5.0 or less, more preferably 4.0 or less, and even more preferably 3.8 or less.

[0068] When the resin substrate and the copper foil are laminated, the surface profile of the copper foil including the protrusions is transferred to the resin substrate. As a method for laminating the resin substrate and the copper foil, for example, a method is mentioned in which the surface of the copper foil is laminated to the resin substrate while heating a part or all of the copper foil as necessary, and pressure is applied from the copper foil side or the resin substrate side, or both, under predetermined conditions. The above-mentioned predetermined conditions (for example, temperature, pressure, time, etc.) can be appropriately set, and conditions recommended by each substrate manufacturer may be used. The above-mentioned predetermined conditions are explained below.

[0069] (A) When the resin substrate contains or is made of an epoxy resin, it is preferable to thermocompression bond the copper foil to the resin substrate by applying a pressure of 0 to 20 MPa at a temperature of 50°C to 300°C for 1 minute to 5 hours.

[0070] When the (A-1) resin substrate is R-1551 (manufactured by Panasonic Corporation), it is heated under a pressure of 1 MPa, and after the temperature reaches 100°C, it is held at that temperature for 5 to 10 minutes. Thereafter, it is further heated under a pressure of 3.3 MPa, and after the temperature reaches 170 to 180°C, it is held at that temperature for 50 minutes, thereby completing thermocompression bonding. (A-2) When the resin substrate is R-1410A (manufactured by Panasonic Corporation), it is heated under a pressure of 1 MPa, and after the temperature reaches 130°C, it is held at that temperature for 10 minutes. It is then further heated under a pressure of 2.9 MPa, and after the temperature reaches 200°C, it is held at that temperature for 70 minutes to achieve thermocompression bonding. (A-3) If the resin substrate is EM-285 (manufactured by Elite Materials Co., Ltd.), it can be thermocompression bonded by heating under a pressure of 0.4 MPa, and after the temperature reaches 100°C, increasing the pressure to 2.4 to 2.9 MPa and heating further, and after the temperature reaches 195°C, maintaining the temperature for 50 minutes. (A-4) When the resin substrate is GX13 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), it can be thermocompression bonded by heating while applying a pressure of 1.0 MPa and holding at 180°C for 60 minutes.

[0071] (B) When the resin substrate contains or consists of a PPE resin, it is preferable to thermocompression bond the copper foil to the resin substrate by applying a pressure of 0 to 20 MPa at a temperature of 50°C to 350°C for 1 minute to 5 hours.

[0072] (B-1) When the resin substrate is R5620 (manufactured by Panasonic Corporation), the substrate is thermocompression-bonded while being heated to 100°C under a pressure of 0.5 MPa, and then the temperature and pressure are increased to 2.0 to 3.0 MPa and 200 to 210°C, and the substrate is held for 120 minutes, thereby enabling further thermocompression bonding. (B-2) When the resin substrate is R5670 (manufactured by Panasonic Corporation), it can be thermocompression bonded by heating to 110°C under a pressure of 0.49 MPa, and then increasing the temperature and pressure to 2.94 MPa and 210°C for 120 minutes. (B-3) When the resin substrate is R5680 (manufactured by Panasonic Corporation), thermocompression bonding is performed while heating to 110°C under a pressure of 0.5 MPa, and then the temperature and pressure are increased to 3.0 to 4.0 MPa and 195°C, and the substrate is maintained for 75 minutes, thereby completing thermocompression bonding. (B-4) When the resin substrate is N-22 (manufactured by Nelco Corporation), it can be thermocompression bonded by heating under pressure of 1.6 to 2.3 MPa, holding at 177°C for 30 minutes, and then further heating and holding at 216°C for 60 minutes.

[0073] When the (C) resin substrate contains or is made of a PTFE resin, it is preferable to thermocompress the copper foil to the resin substrate by applying a pressure of 0 to 20 MPa at a temperature of 50°C to 400°C for 1 minute to 5 hours.

[0074] (C-1) When the resin substrate is NX9255 (manufactured by Park Electrochemical Co., Ltd.), it can be thermocompression bonded by heating it to 260°C while applying a pressure of 0.69 MPa, increasing the pressure to 1.03 to 1.72 MPa and heating it to 385°C, and holding it at 385°C for 10 minutes. (C-2) If the resin substrate is RO3003 (manufactured by Rogers Co., Ltd.), it can be thermocompression bonded by applying a pressure of 2.4 MPa 50 minutes after the start of pressing (approximately 220°C) and holding at 371°C for 30 to 60 minutes.

[0075] (D) When the resin substrate contains or is made of a liquid crystal polymer (LCP), it is preferable to thermocompression bond the copper foil to the resin substrate by applying a pressure of 0 to 20 MPa for 1 minute to 5 hours at a temperature of 50 to 400° C. For example, when the resin substrate is CT-Z (manufactured by Kuraray Co., Ltd.), it can be thermocompression bonded by heating under a pressure of 0 MPa, holding at 260° C. for 15 minutes, further heating while applying a pressure of 4 MPa, and holding at 300° C. for 10 minutes.

[0076] [Laminate separation process] The laminate separation step is a step of separating the resin substrate from the copper foil after the laminate formation step, and transferring the protrusions formed on the surface of the copper foil to the resin substrate, thereby forming a seed layer containing copper and / or copper oxide on the surface of the resin substrate. The term "transfer" as used herein means that the protrusions move to the resin substrate side, and as a result, the surface profile of the copper foil containing the protrusions is imparted to the resin substrate. Methods for confirming that the transfer has been completed include a change in color of the resin substrate surface, observation of the cross section of the resin substrate, and component analysis of the resin substrate surface (for example, detection of copper foil components by EDS analysis or XPS analysis), etc.

[0077] The method for separating the resin substrate from the copper foil is not particularly limited, but may be, for example, a method of peeling the copper foil from the resin substrate. In this step, if necessary, the copper oxide derived from the copper foil transferred to a portion other than the desired portion on the surface of the resin substrate may be removed by etching. The desired portion may be, for example, a portion that represents the shape of the electronic circuit on the printed circuit board.

[0078] The seed layer will be explained using Figure 13. 1 is the resin substrate, and 2 is the protrusion. The black parts represent the protrusions transferred to the resin substrate. When the copper foil and the resin substrate are separated, the protrusions formed on the surface of the copper foil are transferred to the resin substrate by piercing the surface. The lower part of Figure 13, that is, from the base of the protrusion to its tip, is the seed layer, and D is the thickness of the seed layer.

[0079] The method for peeling the copper foil from the resin substrate is not particularly limited, but may be performed based on a 90° peel test (Japanese Industrial Standards (JIS) C5016 "Test Method for Flexible Printed Wiring Boards"; corresponding international standards IEC249-1:1982, IEC326-2:1990). In this case, the angle of the direction in which the copper foil is peeled is kept at 90±5° with respect to the surface on which pressure was applied for adhesion. The copper foil may also be peeled manually, in which case it is peeled at an angle of 80 to 180° with respect to the surface on which pressure was applied.

[0080] [Resin substrate plating process] The resin substrate plating process is a process of plating the surface of the resin substrate using a plating solution after the laminate separation process. More specifically, it is a process of plating the surface of the resin substrate on which the seed layer is formed, thereby plating copper or copper oxide on the surface of the resin substrate. In this process, the copper or copper oxide on the surface of the resin substrate is plated, while the resin substrate is not plated, so that the metal layer formed by plating can be used as wiring for a printed circuit board (particularly a printed wiring board, a semiconductor package board, etc.).

[0081] The plating method is not particularly limited, and may be electrolytic plating or electroless plating. The metal contained in the plating is also not particularly limited, and at least one metal selected from the group consisting of Ni, Sn, Al, Cr, Co, and Cu may be used, and electroless plating using copper is preferable from the viewpoint of obtaining a highly accurate wiring pattern. Furthermore, it is particularly preferable to carry out electroless plating using copper in the absence of a catalyst. By not using a catalyst, there is a tendency that electroless plating can be selectively carried out on the transferred pattern. The thickness of the plating is not particularly limited, and may be about 0.02 to 2 μm.

[0082] By manufacturing printed circuit boards (particularly printed wiring boards and semiconductor package substrates, etc.) in this manner, the etching step using a resist, which is required in the conventional subtractive method, SAP method, MSAP method, etc., is not necessary.

[0083] The printed wiring board and the semiconductor package substrate as the printed circuit board will be described with reference to Fig. 14. In Fig. 14, 11 is an example of a printed circuit board on which electronic components are mounted. 12 is a sealing body, 13 is a semiconductor chip, 14 is solder bumps, 15 is a semiconductor package substrate, 16 is a ball grid array (BGA), and 17 is a printed wiring board. The semiconductor package substrate 15 is a substrate used to transmit electrical signals between the semiconductor chip 13 and the printed wiring board 17.

[0084] [Method of manufacturing resin substrate] The method for producing a resin substrate having a seed layer containing copper and / or copper oxide formed on the surface of the resin substrate, which is a second embodiment of the present invention, comprises the steps of: The above method includes the above-mentioned masking step, protrusion forming step, peelability improving step, laminate forming step, and laminate separating step, and may further include at least one step selected from the group consisting of a copper foil plating step, and a masking removal step.

[0085] That is, forming a masking layer on a portion of a surface of the copper foil; forming protrusions containing copper and / or copper oxide on the surface of the copper foil on which the masking layer is not formed; A step of treating the surface of the copper foil with a release agent; If necessary, plating the surface of the copper foil with a plating solution; Optionally, removing the masking layer from the surface of the copper foil; laminating a resin base material and the copper foil such that the resin base material and the protrusions formed on the surface of the copper foil are in contact with each other to form a laminate; a step of separating the resin substrate from the copper foil and transferring protrusions formed on the surface of the copper foil to the resin substrate, thereby forming a seed layer containing copper and / or copper oxide on the surface of the resin substrate; The manufacturing method includes:

[0086] [Surface-treated copper foil and manufacturing method of surface-treated copper foil] The method for producing a surface-treated copper foil according to the third embodiment of the present invention includes the above-mentioned masking step, protrusion forming step, and peelability improving step, and may further include at least one step selected from the group consisting of a copper foil plating step, a masking removing step, a laminate forming step, and a laminate separating step. The surface-treated copper foil according to the fourth embodiment of the present invention is obtained by the method according to the third embodiment of the present invention.

[0087] That is, forming a masking layer on a portion of a surface of the copper foil; forming protrusions containing copper and / or copper oxide on the surface of the copper foil on which the masking layer is not formed; A step of treating the surface of the copper foil with a release agent; If necessary, plating the surface of the copper foil with a plating solution; Optionally, removing the masking layer from the surface of the copper foil; If necessary, laminating a resin base material and the copper foil such that the resin base material and the protrusions formed on the surface of the copper foil are in contact with each other to form a laminate; If necessary, a step of separating the resin substrate from the copper foil and transferring protrusions formed on the surface of the copper foil to the resin substrate to form a seed layer containing copper and / or copper oxide on the surface of the resin substrate; The manufacturing method includes:

[0088] In the method for producing a surface-treated copper foil, the laminate separation step can be rephrased as a step of separating the resin substrate and the copper foil, and transferring the protrusions formed on the surface of the copper foil to the resin substrate, thereby forming a copper foil from which the protrusions on the surface have been peeled off.

[0089] The surface-treated copper foil of the present invention includes a copper foil, a masking layer formed on a part of the surface of the copper foil, and protrusions containing copper and / or copper oxide formed on the surface of the copper foil on which the masking layer is not formed. The surface-treated copper foil may be treated with a peelability improving agent. EXAMPLES

[0090] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0091] [Examples 1 to 3] (1) Copper foil treatment The following treatment was carried out using the shiny side of a copper foil (product name: DR-WS, thickness: 18 μm, manufactured by Furukawa Electric Co., Ltd.). The shiny side is also called the glossy side, and refers to the side that is flat compared to the other side. The other side is called the matte side (non-glossy side).

[0092] (1-1) Acid treatment The copper foil was immersed in 8% by volume sulfuric acid at a liquid temperature of 25° C. for 2 minutes to remove dirt from the copper surface, and then the copper foil was washed with water.

[0093] (1-2) Masking The shiny side of the copper foil after the treatment according to (1-1) was masked by drawing the following patterns A to C. The treatments of the copper foil masked with the above three patterns are referred to as Examples 1 to 3, respectively. Pattern A: The pattern shown in Figure 1(A), drawn with an oil-based marker (product name: Peace Marker, manufactured by Mitsubishi Pencil Co., Ltd.). Pattern B: The pattern shown in Figure 1(B). Drawn with a marker using alcohol-based oil-based ink (product name: Tough Name, manufactured by Pentel Co., Ltd.). Pattern C: The pattern shown in Figure 1(C), drawn with an oil-based marker (product name: Peace Marker, manufactured by Mitsubishi Pencil Co., Ltd.).

[0094] (1-3) Acid treatment The copper foil on which the above pattern was drawn was immersed in 8% by volume sulfuric acid at a liquid temperature of 25°C for 2 minutes to remove dirt from the copper surface. This was done to remove any copper oxide that may have formed, as oxidation of the copper foil surface may progress during drawing. The copper foil was then washed with water.

[0095] (1-4) Pretreatment The copper foil after the treatment according to (1-3) was degreased by immersing it in a 5 g / L aqueous potassium hydroxide solution at a liquid temperature of 25° C. for 1 minute to remove dirt from the copper surface. The copper foil was then washed with water.

[0096] (1-5) Oxidation treatment The shiny side of the copper foil after the treatment according to (1-4) was immersed in an oxidizing agent (sodium chlorite 227.5 g / L, potassium hydroxide 18 g / L, 3-glycidoxypropyltrimethoxysilane 0.5 g / L) at a liquid temperature of 50°C for 1 minute to perform an oxidation treatment, thereby forming fine protrusions on the surface of the copper foil. The copper foil thus obtained was then washed with water and dried. The thickness of the formed copper oxide layer was 56 nm. The thickness of the copper oxide layer refers to the thickness when converted into a uniform state by SERA measurement. The same applies to the thickness of the copper oxide layer described below. Figures 2 (A) to (C) show photographs of the copper foil surfaces.

[0097] (1-6) Pre-plating treatment The copper foil after the treatment in (1-5) was immersed in a 45 g / L aqueous solution of nickel chloride hexahydrate at a liquid temperature of 45°C for 2 minutes as a pre-plating treatment. The copper foil was then washed with water.

[0098] (1-7) Electrolytic plating The copper foil after the treatment according to (1-6) was immersed in a Ni electroplating solution (nickel sulfate hexahydrate 240 g / L, trisodium citrate 20 g / L) at a liquid temperature of 45°C, and then subjected to a current density of 0.5 A / dm 2 Electrolytic plating was performed under the conditions of 1000 s, 41 s, and 100 s. The obtained copper foil was then washed with water and dried. The obtained Ni thickness was 28 nm. The amount of Ni attached was calculated by dissolving the copper foil surface in an acidic solution, measuring the amount of Ni by ICP analysis, and dividing the amount by the planar field area of ​​the structure. The same applies to the Ni thickness described below. Figure 3 (A) to (C) show photographs of each copper foil surface.

[0099] (1-8) Masking removal After the treatment in (1-7), the shiny side of the copper foil was washed off with thinner (product name: NTX-820 thinner, manufactured by Sankyo Chemical Co., Ltd.) applied with a dropper. Photographs of the copper foil surface are shown in (A) to (C) of FIG. 4.

[0100] (2) Formation and separation of laminate (2-1) Method A prepreg made by Panasonic Corporation, R-5680NK (t=0.06 mm, R / C=77%), was laminated onto the shiny side of the copper foil after the above treatment. The prepreg was heated to 110°C under a pressure of 0.5 MPa in a vacuum using a vacuum high-pressure press, and then the pressure was increased to 3.5 MPa and the temperature was held at 195°C for 75 minutes to thermocompress the copper foil to the resin substrate.

[0101] The copper foil that had been thermocompression-bonded to the resin substrate was manually peeled off, and the bonded surfaces of the copper foil and the resin substrate were observed. Figure 5 is a photograph of the copper foil surface after the transfer of the protrusions.

[0102] (2-2) Results As shown in FIG. 5, no chipping or other defects were observed in any of the copper foil surface patterns, and it was found that the copper foil surface profile was imparted to the resin substrate exactly in accordance with the drawn pattern.

[0103] [Example 4] (3) Copper foil treatment (1) In the same manner as in the treatment of copper foil, the following treatment was carried out using the shiny side of copper foil (product name: DR-WS, thickness: 18 μm, manufactured by Furukawa Electric Co., Ltd.).

[0104] (3-1) Acid treatment The copper foil was immersed in 8% by volume sulfuric acid at a liquid temperature of 25° C. for 2 minutes to remove dirt from the copper surface, and then the copper foil was washed with water.

[0105] (3-2) Masking Four strips of masking tape for plating (manufactured by TRUSCO NAKAYAMA CORPORATION) were attached to the shiny surface of the copper foil after the treatment in (3-1) to form a masking layer. Figure 6 shows a photograph of the copper foil surface after masking.

[0106] (3-3) Acid treatment The copper foil on which the above pattern was drawn was immersed in 8% by volume sulfuric acid at a liquid temperature of 25°C for 2 minutes to remove dirt from the copper surface. This was done to remove any copper oxide that may have formed, as oxidation of the copper foil surface may progress during drawing. The copper foil was then washed with water.

[0107] (3-4) Pretreatment The copper foil after the treatment according to (3-3) was degreased by immersing it in a 5 g / L aqueous potassium hydroxide solution at a liquid temperature of 25° C. for 1 minute to remove dirt from the copper surface. The copper foil was then washed with water.

[0108] (3-5) Oxidation treatment The shiny side of the copper foil after the treatment according to (3-4) was immersed in an oxidizing agent (sodium chlorite 227.5 g / L, potassium hydroxide 18 g / L, 3-glycidoxypropyltrimethoxysilane 0.5 g / L) at a liquid temperature of 50°C for 1 minute to perform an oxidation treatment, thereby forming fine protrusions on the surface of the copper foil. The copper foil thus obtained was then washed with water and dried. The thickness of the copper oxide layer thus obtained was 56 nm. Figure 7 shows a photograph of the copper foil surface after the oxidation treatment.

[0109] (3-6) Pre-plating treatment The copper foil after the treatment in (3-5) was immersed in a 45 g / L aqueous solution of nickel chloride hexahydrate at 45°C for 2 minutes as a pre-plating treatment. The copper foil was then washed with water.

[0110] (3-7) Electrolytic plating The copper foil after the treatment in (3-6) was immersed in a Ni electroplating solution (nickel sulfate hexahydrate 240 g / L, trisodium citrate 20 g / L) at a liquid temperature of 45°C, and then subjected to a current density of 0.5 A / dm 2 Electrolytic plating was performed under the conditions of 1000 s, 41 s, and 100 s. The obtained copper foil was then washed with water and dried. The thickness of the obtained Ni was 28 nm. Figure 8 shows a photograph of the copper foil surface after electrolytic plating.

[0111] (3-8) Masking Removal The tape was peeled off from the shiny side of the copper foil after the treatment according to (3-7). Figure 9 shows a photograph of the copper foil surface after removing the masking.

[0112] (4) Formation and separation of laminate (4-1) Method A prepreg made by Panasonic Corporation, R-5680NK (t=0.06 mm, R / C=77%), was laminated onto the shiny side of the copper foil after the above treatment. The prepreg was heated to 110°C under a pressure of 0.5 MPa in a vacuum using a vacuum high-pressure press, and then the pressure was increased to 3.5 MPa and the temperature was held at 195°C for 75 minutes to thermocompress the copper foil to the resin substrate.

[0113] The copper foil that had been thermocompression-bonded to the resin substrate was manually peeled off, and the bonding surfaces of the copper foil and the resin substrate were observed. Figure 10 shows a photograph of the copper foil surface after the transfer of the protrusions.

[0114] (4-2) Results As shown in FIG. 10, no chips or other defects were observed on the copper foil surface, and it was found that the copper foil surface profile was imparted to the resin substrate exactly in accordance with the drawn pattern.

[0115] (5) Evaluation / protrusion height How to measure / calculate the height of a protrusion Using a FIB-SEM (AURIGA, manufactured by Carl Zeiss Co., Ltd.), a cross section perpendicular to the copper foil is exposed, and a cross-sectional image is taken at an acceleration voltage of 2 kV and a magnification of 30,000 times. In the cross-sectional image obtained, the distance between the midpoint of the line segment connecting the minimum points of adjacent concave portions across the convex portion and the maximum point of the convex portion between the concave portions is taken as the height of the protrusion and its length is measured. In the same manner, the height of five protrusions is measured and the average value is calculated. The method of measuring / calculating the height of the protrusion will be explained using Figure 15. 21 is the copper foil, 22 is the protrusion, and 23 (white line) is the protrusion height.

[0116] In Example 1, the height (average value) of the protrusions on the copper foil surface without the masking layer (FIG. 11) and on the copper foil surface with the masking layer (FIG. 12) obtained through the masking removal process was calculated for the copper foil. As a result, the former was 226 nm and the latter was 0 nm. [Explanation of symbols]

[0117] 1 Resin substrate 2 protrusions D seed layer (thickness) 11 Printed circuit board with electronic components mounted 12 Sealing body 13. Semiconductor Chips 14 Solder Bumps 15 Semiconductor package substrate 16 Ball Grid Array (BGA) 17 Printed Wiring Boards 21 Copper foil 22 protrusions 23 Protrusion height

Claims

1. A method for manufacturing a printed circuit board comprising a resin base material and a wiring pattern formed on a surface of the resin base material, comprising: forming a masking layer on a portion of a surface of the copper foil; forming protrusions containing copper and / or copper oxide on the surface of the copper foil on which the masking layer is not formed; treating the surface of the copper foil with a release agent; laminating a resin base material and the copper foil such that the resin base material and the protrusions formed on the surface of the copper foil are in contact with each other to form a laminate; a step of separating the resin substrate from the copper foil and transferring protrusions formed on the surface of the copper foil to the resin substrate, thereby forming a seed layer containing copper and / or copper oxide on the surface of the resin substrate; A step of plating a surface of the resin substrate using a plating solution; A method for manufacturing a printed circuit board, comprising:

2. The step of forming the protrusions includes: The method for producing a printed circuit board according to claim 1 , further comprising the step of forming protrusions containing copper oxide by oxidation treatment.

3. The method for producing a printed circuit board according to claim 1 or 2, wherein the oxidation treatment is carried out using an oxidizing agent.

4. After the step of treating the surface of the copper foil with a release agent, 3. The method for producing a printed circuit board according to claim 1, further comprising the step of plating a surface of the copper foil with a plating solution.

5. After the step of treating the surface of the copper foil with a release agent, The method for producing a printed circuit board according to claim 1 or 2, further comprising the step of removing the masking layer from the surface of the copper foil.

6. 3. The method for producing a printed circuit board according to claim 1, wherein in the step of forming the protrusions, the height of the protrusions containing copper and / or copper oxide formed on the surface of the copper foil on which the masking layer is not formed is 20 nm or more.

7. 3. The method for producing a printed circuit board according to claim 1, wherein in the step of forming the protrusions, the height of the protrusions containing copper and / or copper oxide formed on the surface of the copper foil on which the masking layer is formed is 5 nm or less.

8. 3. The method for manufacturing a printed circuit board according to claim 1 or 2, wherein in the step of forming the protrusions, a value obtained by subtracting the height of the protrusions containing copper and / or copper oxide formed on a surface of the copper foil on which a masking layer is formed from the height of the protrusions containing copper and / or copper oxide formed on a surface of the copper foil on which a masking layer is formed is 10 nm or more.

9. 3. The method for producing a printed circuit board according to claim 1 or 2, wherein the resin substrate comprises at least one insulating resin selected from the group consisting of polyphenylene ether (PPE), epoxy, polyphenylene oxide (PPO), polybenzoxazole (PBO), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP), thermoplastic polyimide (TPI), fluororesin, polyetherimide, polyetheretherketone, polycycloolefin, bismaleimide resin, low dielectric constant polyimide, and cyanate resin.

10. 3. The method for producing a printed circuit board according to claim 1, wherein in the step of plating the surface of the resin base material with a plating solution, the plating is an electroless plating treatment.

11. 3. The method for producing a printed circuit board according to claim 1, wherein in the step of plating the surface of the resin base material with a plating solution, the plating is an electroless plating process using Cu.

12. A method for producing a resin substrate comprising: a resin substrate; and a seed layer containing copper and / or copper oxide formed on a surface of the resin substrate, forming a masking layer on a portion of a surface of the copper foil; forming protrusions containing copper and / or copper oxide on the surface of the copper foil on which the masking layer is not formed; treating the surface of the copper foil with a release agent; laminating a resin base material and the copper foil such that the resin base material and the protrusions formed on the surface of the copper foil are in contact with each other to form a laminate; a step of separating the resin substrate from the copper foil and transferring protrusions formed on the surface of the copper foil to the resin substrate, thereby forming a seed layer containing copper and / or copper oxide on the surface of the resin substrate; A method for producing a resin substrate comprising the steps of:

13. A method for producing a surface-treated copper foil, comprising the steps of: forming a masking layer on a portion of a surface of the copper foil; forming protrusions containing copper and / or copper oxide on the surface of the copper foil on which the masking layer is not formed; A surface treatment method for copper foil comprising the steps of:

14. After the step of forming the protrusions, The method for treating a surface of a copper foil according to claim 13, further comprising the step of treating the surface of the copper foil with a release property improver.

15. Copper foil and A masking layer formed on a portion of the surface of the copper foil; protrusions containing copper and / or copper oxide formed on a surface of the copper foil on which the masking layer is not formed; A surface-treated copper foil comprising:

Images