Composite copper part with voids

Abstract

The present application provides a composite copper member in which a layer containing copper oxide is formed on at least a part of the surface of a copper member, and a void is present in the layer containing copper oxide.

Description

TECHNICAL FIELD

[0001] The present application relates to a composite copper member having a void. BACKGROUND

[0002] Copper foils used for printed wiring boards are required to have adhesion to an insulating resin base material. In order to improve the adhesion, a method of roughening the surface of the copper foil by etching or the like is employed to improve the mechanical bonding force by so-called anchoring effect. However, from the viewpoint of high density of printed wiring boards and transmission loss in a high frequency band, planarization of the surface of the copper foil is required. In order to satisfy these opposing requirements, a copper surface treatment method of performing an oxidation step and a reduction step or the like has been developed (International Publication No. 2014 / 126193). In this method, the copper foil is pretreated, the surface of the copper foil is oxidized and formed with unevenness of copper oxide by immersion in a liquid containing an oxidizing agent, and then the copper oxide is reduced by immersion in a liquid containing a reducing agent, whereby the unevenness of the surface is adjusted and the roughness of the surface is finished. Further, as a method of improving adhesion by treating the copper foil using oxidation and reduction, a method of adding a surface active molecule in the oxidation step (Japanese Laid-Open Patent Publication No. 2013-534054) or a method of forming a protective film on the surface of the copper foil using an amino-thiazole compound or the like after the reduction step (Japanese Laid-Open Patent Publication No. 8-97559) has been developed.

[0003] For the bonding between a resin base material and a metal, in addition to the mechanical bonding force, 1) a physical bonding force caused by intermolecular forces between the resin and the metal, and 2) a chemical bonding force caused by covalent bonds or the like of functional groups of the resin and the metal also contribute. Since the insulating resin for high frequency circuits has a low dielectric constant and a low dielectric loss tangent, the proportion of OH groups (hydroxyl groups) is reduced, but since the OH groups of the resin participate in bonding with the metal, the chemical bonding force with the copper foil is weakened (International Publication No. 2017 / 150043). Therefore, a stronger mechanical bonding force is required for the bonding of the insulating resin for high frequency circuits and the copper foil.

[0004] The inventors of the present application have also developed a composite copper foil having excellent adhesion obtained by plating Ni on a roughened copper foil by electrolytic plating (International Publication No. 2019 / 093494). SUMMARY

[0005] Technical problem to be solved by the invention

[0006] The present application provides a novel composite copper member and a printed wiring board using the same, and a plated metal copper member that functions as a carrier.

[0007] Technical solution for solving the technical problem

[0008] The inventors of the present application have conducted intensive studies, and as a result, have newly found that, by generating voids in a layer containing copper oxide generated by coarsening treatment, rather than increasing the strength of the layer containing copper oxide that forms unevenness, the strength of the layer is decreased, whereby a composite copper member suitable for forming a circuit of a printed wiring board and a semiconductor package substrate, particularly, a semi-additive process (SAP method) or a M-SAP (Modified Semi-Additive Process) (MSAP method) can be produced.

[0009] The present application has the following embodiments: [1]

[0011] A composite copper member in which a layer containing copper oxide is formed on at least a part of a surface of a copper member,

[0012] The layer containing copper oxide has a plurality of voids. [2]

[0014] The composite copper member according to [1], in which at least a part of the plurality of voids is present at an interface between the layer containing copper oxide and the surface of the copper member. [3]

[0016] The composite copper member according to [1] or [2], in which a peeling strength between the layer containing copper oxide and the surface of the copper member is 0.001 kgf / cm or more and 0.30 kgf / cm or less. [4]

[0018] The composite copper member according to any one of [1] to [3], in which, when a photograph image of a cross section is obtained using a scanning electron microscope, and the photograph image is binarized, the number of the voids detected is 30 or more per 3.8 μm in any of 3.8 μm in a direction parallel to the layer containing copper oxide when measured. [5]

[0020] The composite copper member according to any one of [1] to [4], in which a surface of the layer containing copper oxide of the composite copper member is thermocompression-bonded to a resin base material under prescribed conditions to form a laminate, and a photograph image of a cross section of the laminate is obtained using a scanning electron microscope, and the photograph image is binarized, the number of the voids detected is 30 or more per 3.8 μm in any of 3.8 μm in a direction parallel to the laminated surface when measured. [6]

[0022] The composite copper member according to [4] or [5], in which, in the photograph image of the binarized cross section, an average distance between the voids is 100 nm or less. [7]

[0024] The composite copper member as claimed in [4] or [5], wherein, in the captured image of the above-mentioned binary cross section, the proportion of the distance between the voids being 50 nm or less is 40% or more of the entire void distance. [8]

[0026] The composite copper member as claimed in any one of [5] to [7], wherein the resin base material contains at least one insulating resin selected from the group consisting of polyphenylene ether (PPE), epoxy resin, polyphenylene oxide (PPO), polybenzoxazole (PBO), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP), or triphenylphosphite (TPPI), fluororesin, polyetherimide, polyether ether ketone, polynorbornene, bismaleimide resin, low dielectric constant polyimide, and cyanate ester resin. [9]

[0028] The composite copper member as claimed in any one of [5] to [8], wherein the prescribed conditions of the hot-pressing are in the range of a temperature of 50°C to 400°C, a pressure of 0 to 20 MPa, and a time of 1 minute to 5 hours.

[10]

[0030] The composite copper member as claimed in any one of [5] to [9], wherein the Ra of the surface on which the layer containing copper oxide is formed is 0.04 μm or more, and when the copper member is peeled from the resin base material after the hot-pressing under prescribed conditions, the proportion of the Ra of the surface of the copper member peeled from the resin base material with respect to the Ra of the surface on which the layer containing copper oxide is formed is less than 100%.

[11]

[0032] The composite copper member as claimed in any one of [5] to

[10] , wherein the proportion of the surface area of the copper member peeled from the resin base material after the hot-pressing with respect to the surface area of the surface on which the layer containing copper oxide is formed is less than 100%.

[12]

[0034] The composite copper member as claimed in any one of [1] to

[11] , wherein the layer containing copper oxide contains a metal other than copper.

[13]

[0036] The composite copper member as claimed in

[12] , wherein the metal other than copper is Ni.

[14]

[0038] The composite copper member as claimed in any one of [1] to

[11] , wherein the layer containing copper oxide contains a copper plating layer.

[15]

[0040] A metal foil with a carrier comprising the composite copper member described in any one of

[12] to

[14] ,

[0041] The layer containing copper oxide described above is used as a metal foil, and the copper member described above is used as a carrier for the metal foil.

[16]

[0043] A laminate in which at least a part of the surface of the layer containing copper oxide of the composite copper member described in any one of [1] to

[14] is laminated with a resin base material.

[17]

[0045] The laminate described in

[16] , wherein the resin base material contains at least one insulating resin selected from the group consisting of polyphenylene ether (PPE), epoxy resin, polyphenylene oxide (PPO), polybenzoxazole (PBO), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP), or triphenylphosphite (TPPI), fluororesin, polyetherimide, polyether ether ketone, polynorbornene, bismaleimide resin, low dielectric constant polyimide, and cyanate ester resin.

[18]

[0047] The composite copper member described in any one of [1] to

[14] for use in the production of a printed wiring board.

[19]

[0049] The composite copper member described in

[18] for use in the production of a printed wiring board using a Semi-Additive Process (SAP method) or a Modified Semi-Additive Process (MSAP) method.

[20]

[0051] A production method of a printed wiring board for producing a printed wiring board using the composite copper member described in any one of [1] to

[14] , the production method comprising:

[0052] 1) a step of thermocompression bonding a resin base material on the layer containing copper oxide of the composite copper member under prescribed conditions;

[0053] 2) a step of peeling the copper member from the resin base material under prescribed conditions to obtain a resin base material having a part or all of the metal forming the layer containing copper oxide; and

[0054] 3) a step of performing copper plating treatment on the surface of the resin base material having a part or all of the metal forming the layer containing copper oxide.

[21]

[0056] A method for manufacturing a resin substrate having a metal, comprising:

[0057] 1) a step of thermally pressure bonding a resin substrate to the layer containing copper oxide of the composite copper member described in any one of [1] to

[14] under prescribed conditions; and

[0058] 2) a step of peeling the composite copper member from the resin substrate under prescribed conditions to obtain a resin substrate having a part or all of the metal forming the layer containing copper oxide.

[22]

[0060] A method for manufacturing a composite copper member described in any one of [1] to

[11] , the method comprising:

[0061] 1) a step of locally applying a silane coupling agent to the surface of the composite copper member; and

[0062] 2) a step of oxidizing the surface after the local application.

[23]

[0064] A method for manufacturing a composite copper member described in any one of [1] to

[11] , the method comprising:

[0065] 1) a step of locally applying a silane coupling agent to the surface of the composite copper member;

[0066] 2) a step of oxidizing the surface after the local application; and

[0067] 3) a step of treating the surface of the layer containing the formed copper oxide with a modifier,

[0068] wherein the modifier contains a compound selected from the group consisting of nickel chloride, zinc chloride, iron chloride, chromium chloride, ammonium citrate, ammonium chloride, potassium chloride, ammonium sulfate, nickel ammonium sulfate, ethylenediaminetetraacetic acid, diethanolglycine, L-glutamic acid diacetic acid tetrasodium, ethylenediamine-N,N'-disuccinic acid, 3-hydroxy-2,2'-iminodiacetic acid sodium, methylglycine diacetic acid trisodium, aspartic acid diacetic acid tetrasodium, N-(2-hydroxyethyl)iminodiacetic acid disodium, and sodium gluconate.

[24]

[0070] A method for manufacturing a composite copper member described in

[12] , the method comprising:

[0071] 1) a step of locally applying a silane coupling agent to the surface of the composite copper member;

[0072] 2) a step of subjecting the surface after the above partial coating to oxidation treatment; and

[0073] 3) a step of forming a layer containing a metal other than copper on the surface after the oxidation treatment.

[25]

[0075] A method for manufacturing the composite copper member according to

[12] , the method comprising:

[0076] 1) a step of subjecting the surface of the copper member to oxidation treatment;

[0077] 2) a step of subjecting the surface after the oxidation treatment to treatment with a modifier; and

[0078] 3) a step of forming a layer containing a metal other than copper on the surface after the treatment with the modifier,

[0079] wherein the modifier contains a compound selected from the group consisting of nickel chloride, zinc chloride, iron chloride, chromium chloride, ammonium citrate, ammonium chloride, potassium chloride, ammonium sulfate, nickel ammonium sulfate, ethylenediaminetetraacetic acid, diethanolglycine, tetrasodium L-glutamic acid diacetate, ethylenediamine-N,N'-disuccinic acid, 3-hydroxy-2,2'-iminodisuccinic acid sodium, trisodium methylglycine diacetate, tetrasodium aspartic acid diacetate, disodium N-(2-hydroxyethyl)iminodiacetic acid, and sodium gluconate.

[26]

[0081] A method for manufacturing the composite copper member according to

[12] , the method comprising:

[0082] 1) a step of subjecting the surface of the copper member to partial coating with a silane coupling agent;

[0083] 2) a step of subjecting the surface after the above partial coating to oxidation treatment;

[0084] 3) a step of subjecting the surface after the oxidation treatment to treatment with a modifier; and

[0085] 4) a step of forming a layer containing a metal other than copper on the surface after the treatment with the modifier,

[0086] wherein the modifier contains a compound selected from the group consisting of nickel chloride, zinc chloride, iron chloride, chromium chloride, ammonium citrate, ammonium chloride, potassium chloride, ammonium sulfate, nickel ammonium sulfate, ethylenediaminetetraacetic acid, diethanolglycine, tetrasodium L-glutamic acid diacetate, ethylenediamine-N,N'-disuccinic acid, 3-hydroxy-2,2'-iminodisuccinic acid sodium, trisodium methylglycine diacetate, tetrasodium aspartic acid diacetate, disodium N-(2-hydroxyethyl)iminodiacetic acid, and sodium gluconate.

[0087] Cross Reference to Related Applications

[0088] This application is based on Japanese Patent Application No. 2020-033411 filed on February 28, 2020, the contents of which are incorporated herein by reference in its entirety. BRIEF DESCRIPTION OF DRAWINGS

[0089] Figure 1 is a schematic view of a cross section of the composite copper member of the present application before thermal compression bonding and after peeling.

[0090] Figure 2 is an image showing the peeling surface after peeling of the composite copper foil of Examples and Comparative Examples after thermal compression bonding to a resin substrate. The numerical value indicates the peeling strength at the time of peeling.

[0091] Figure 3 is a cross-sectional image (magnification 30000 times) obtained by observation with a scanning electron microscope (SEM) after thermal compression bonding of the composite copper foils of Examples 1 to 3 and Comparative Examples 2 and 3 to a resin substrate. The interface between the layer containing copper oxide and the copper member is indicated by a dotted line.

[0092] Figure 4 is a cross-sectional image of Figure 3 after inversion and binarization. The blanked portion is a void. Only the image of Example 1 is annotated with a straight line indicating the distance between the voids.

[0093] Figure 5 is a graph showing the number and size of voids (A), the average distance between voids (B), and the distribution of the distance between voids (C) obtained by image analysis of Figure 4

[0094] Figure 6 is a SEM image obtained by observing the cross section of the composite copper foil of Example 3 and Comparative Example 3 after thermal compression bonding to a resin substrate.

[0095] Figure 7 is a schematic view of the cross section in each processing step when the composite copper foil of one embodiment of the present application ("transfer + transfer") and the existing copper foil for transfer ("transfer only") are applied to the SAP method. DETAILED DESCRIPTION

[0096] ​The following describes the preferred embodiments of the present application with reference to the drawings, but is not necessarily limited thereto. The object, features, advantages and concept of the present application are apparent from the description of the present specification, and the present application can be easily reproduced by those skilled in the art based on the description of the present specification. The embodiments and specific examples of the application described below represent the preferred embodiments of the present application, and are intended to illustrate or explain, and do not limit the present application thereto. Those skilled in the art can clearly understand that various changes and modifications can be made based on the description of the present specification within the intended scope and range of the present application disclosed in the present specification.

[0097] == Composite Copper Member ==

[0098] One embodiment of the present application is a composite copper member in which a layer containing copper oxide is formed on at least a part of the surface of a copper member. The copper member contains Cu as a main component and constitutes a part of a structure. Specifically, the copper member is a copper foil such as electrolytic copper foil or rolled copper foil, copper wire, copper plate, copper lead frame, copper powder, or the like, but is not limited thereto. The copper member is preferably capable of electrolytic plating. The copper member is preferably formed of a material composed of pure copper having a Cu purity of 99.9 mass% or more, more preferably of tough-pitch copper, deoxidized copper, oxygen-free copper, and further preferably of oxygen-free copper having an oxygen content of 0.001 mass% to 0.0005 mass%.

[0099] In the case where the copper member is a copper foil, the thickness thereof is not particularly limited, and is preferably 0.1 μm or more and 100 μm or less, and more preferably 0.5 μm or more and 50 μm or less.

[0100] In the case where the copper member is a copper plate, the thickness thereof is preferably more than 100 μm. Although not particularly limited, it is more preferably 1 mm or more, 2 mm or more, or 10 mm or more, and further preferably 10 cm or less, 5 cm or less, or 2.5 cm or less.

[0101] The layer containing copper oxide is formed on the surface of the copper member, and contains cupric oxide (CuO) and / or cuprous oxide (Cu2O). The layer containing copper oxide can be formed by subjecting the surface of the copper member to oxidation treatment. By the oxidation treatment, the surface of the copper member is roughened. The shape of the convex portion of the surface of the copper member after oxidation can be adjusted by using a dissolving agent on the layer containing copper oxide. In addition, the surface of the layer containing copper oxide can be subjected to reduction treatment using a reducing agent. The specific resistance of pure copper is 1.7 x 10 －8 (Ωm), whereas that of cupric oxide is 1 to 10 (Ωm), and that of cuprous oxide is 1 x 10 6 ~ 1 x 10 7(Ωm), and thus the layer containing copper oxide has low electrical conductivity, and for example, even if the amount of the layer containing copper oxide transferred to the resin substrate is large, when a circuit is formed using the composite copper member to form a printed wiring board or a semiconductor package substrate, transmission loss is not easily caused due to skin effect.

[0102] The layer containing copper oxide has a plurality of voids. The voids can be connected to the outside or can be closed. It is preferable that even if a resin substrate is thermocompression bonded to the layer containing copper oxide, the resin substrate does not enter the voids, and the voids are maintained. The voids can be detected in a SEM cross-sectional image of the composite copper member. The voids exist in the layer containing copper oxide, and preferably include the case where they exist at an interface between the layer containing copper oxide and the surface of the copper member. For example, the interface can be distinguished by a difference in depth caused by the composition in the SEM cross-sectional image, or a difference in depth caused by the presence or absence of a copper crystal structure constituting the copper member, and the like. Figure 3 There is no particular limitation, and more preferably, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, 95% or more, or 100% of the voids exist at the interface between the layer containing copper oxide and the surface of the copper member.

[0103] Specifically, the voids can be determined from the SEM image of the cross section of the composite copper member, for example, by the following steps.

[0104] 1) The SEM cross-sectional image is obtained on the image with the layer of copper oxide on top and the copper member on the bottom.

[0105] 2) The region surrounded by a straight line parallel to the layer containing copper oxide through the apex of the region surrounded by copper and copper oxide existing on the copper member side or the region surrounded by copper oxide, and a straight line parallel to the layer containing copper oxide through the apex of the highest convex portion of the layer containing copper oxide is set as the measurement range.

[0106] 3) After adjusting the contrast of the image of the measurement range, inversion processing is performed to invert the bright and dark portions of the image.

[0107] 4) Automatic 2-value processing is performed, and the region surrounded by copper and copper oxide or the region surrounded by copper oxide is selected.

[0108] 5) A region of 1 pixel square is deleted as noise.

[0109] 6) The upper left of the image is taken as the origin, and the image is taken as the X axis downward and the Y axis to the right. The region (1) selected by the automatic binarization existing at X = maximum, Y = minimum is taken as the starting point, and the region at the nearest distance in the Y axis direction is taken as the region (2). The region at the nearest distance from the region (2) in the Y axis direction is taken as the region (3), and then in the measurement range, until Y = maximum is reached, the regions (4) to (N) are determined in the same procedure. The regions (1) to (N) determined here are voids.

[0110] Alternatively, the voids can also be determined from the SEM image of the cross section of the composite copper part after the lamination of the resin base material using the same procedure.

[0111] The image is processed by taking the depth of the image with a prescribed threshold value cut-off, taking the threshold value or more as 1 and taking less than the threshold value as 0, thereby performing binarization. The binarization can be performed by Otsu's method (discriminant analysis method), Sauvola's method, Goto's method, and the like.

[0112] The maximum horizontal chord length of the voids is preferably a size that can be detected when the SEM cross-sectional image with a magnification of 30000 times and a resolution of 1024 x 768 pixels is binarized. There is no particular limitation, and it is preferably 500 nm or less on each side, 400 nm or less on each side, 300 nm or less on each side, 200 nm or less on each side, 100 nm or less on each side, or 50 nm or less on each side, and it is preferably 4 nm or more on each side, 5 nm or more on each side, 10 nm or more on each side, 15 nm or more on each side, 20 nm or more on each side, 25 nm or more on each side, 50 nm or more on each side, 100 nm or more on each side, or 200 nm or more on each side. In the binarized SEM cross-sectional image, the number of voids is preferably 25 or more, 30 or more, 40 or more, or 50 or more per 3.8 μm in any direction parallel to the face on which the layer containing copper oxide is formed, and is preferably 500 or less, 400 or less, 300 or less, 200 or less, 100 or less, 90 or less, 80 or less, 70 or less, or 60 or less.

[0113] Further, the distance between the voids can also be calculated on the image to calculate the average distance between the voids.

[0114] The average distance between the voids is preferably 200 nm or less, 150 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, or 50 nm or less, and is preferably 40 nm or more, 30 nm or more, 20 nm or more, or 10 nm or more.

[0115] In addition, the distribution of the distance between the gaps is preferably such that the proportion of the gaps with a distance of less than 50 nm is 35%, 40%, 45% or more of the total distance between the gaps.

[0116] Due to the presence of this gap, the copper oxide layer is more prone to cracking than the copper component. Without particular limitation, the peel strength between the copper oxide layer and the surface of the copper component is preferably 0.30 kgf / cm or less, 0.20 kgf / cm or less, 0.15 kgf / cm or less, or 0.15 kgf / cm or less, and preferably 0.001 kgf / cm or more, 0.002 kgf / cm or more, 0.003 kgf / cm or more, or 0.004 kgf / cm or more.

[0117] Regarding peel strength, after hot-pressing a resin substrate onto a layer containing copper oxide, the peel strength is measured according to the 90° peel test (Japanese Industrial Standard (JIS) C5016 "Test Method for Flexible Printed Wiring Boards"; corresponding to international standards IEC249-1:1982, IEC326-2:1990).

[0118] The layer containing copper oxide may also contain metals other than copper. The metals contained are not particularly limited and may include at least one metal selected from Sn, Ag, Zn, Al, Ti, Bi, Cr, Fe, Co, Ni, Pd, Au, and Pt. In particular, to impart acid and heat resistance, it is preferable to include metals with higher acid and heat resistance than copper, such as Ni, Pd, Au, and Pt.

[0119] Metals other than copper can be plated onto the surface of copper components. The plating method is not particularly limited, and examples include electroplating, electroless plating, vacuum evaporation, and chemical surface treatment. A uniform and thin plating layer is preferred, therefore electroplating is preferred. When electroplating is performed on an oxidized copper foil surface, the surface copper oxide is first reduced, and the charge is used to form cuprous oxide or pure copper. Therefore, a time delay occurs before plating, and then the metal to form the metal layer begins to precipitate. The amount of charge varies depending on the type of plating solution and the amount of copper oxide. For example, when plating Ni onto a copper component, to ensure the thickness is within a preferred range, the area of ​​the electroplated copper component per dm² is... 2 Preferably, a charge of 15C or more but less than 75C is imparted, and more preferably a charge of 25C or more but less than 65C is imparted.

[0120] The average thickness of the metal other than copper formed on the outermost surface of the copper component by plating in the vertical direction is not particularly limited, but is preferably 6 nm or more, more preferably 10 nm or more, 14 nm or more, 18 nm or more, or 20 nm or more. Preferably 80 nm or less, more preferably 70 nm or less or 60 nm or less.

[0121] Further, the average thickness of the metal other than copper contained in the layer containing copper oxide in the vertical direction can be measured by dissolving the layer containing copper oxide with an acid solution, measuring the amount of metal by ICP analysis, and dividing by the area of the composite copper member to calculate. Alternatively, the amount of metal contained in the layer containing copper oxide can be calculated by dissolving the composite copper member itself and measuring only the amount of metal contained in the layer containing copper oxide.

[0122] If the surface of the composite copper member on which the layer containing copper oxide is formed is thermally press-fitted to a resin substrate, the surface profile of the composite copper member is transferred to the resin substrate. Further, when the composite copper member is peeled from the resin substrate after thermal press-fitting, the metal contained in the layer containing copper oxide is transferred from the composite copper member to the resin substrate. An embodiment of the composite copper member is illustrated in FIG. 1. Figure 1 .

[0123] The resin substrate is a material containing resin as a main component, and can be used for circuit formation of printed wiring boards and semiconductor package substrates, etc. The resin is not particularly limited, and can be a thermoplastic resin or a thermosetting resin, and is preferably polyphenylene ether (PPE), epoxy resin, polyphenylene oxide (PPO), polybenzoxazole (PBO), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP), triphenylphosphite (TPPI), fluororesin, polyetherimide, polyether ether ketone, polycycloolefin, bismaleimide resin, low dielectric constant polyimide, cyanate ester resin, or a mixed resin thereof. The resin substrate can also contain inorganic fillers, glass fibers.

[0124] In order to thermally press-fit the resin substrate to the surface of the composite copper member, for example, by making the resin substrate and the composite copper member adhere to each other and stacking them, the resin substrate and the composite copper member can be joined by processing under prescribed conditions. As the prescribed conditions (e.g., temperature, pressure, time), the recommended conditions of the manufacturer of each substrate can be used. As the prescribed conditions, for example, the following conditions can be considered.

[0125] 1) In the case where the resin substrate contains or consists of epoxy resin, it is preferable to thermally press-fit the composite copper member 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.

[0126] For example,

[0127] 1-1) In the case where the resin substrate is R-1551 (manufactured by Panasonic),

[0128] heating under a pressure of 1 MPa, reaching 100°C, and maintaining at this temperature for 5 to 10 minutes;

[0129] Then, further heating under a pressure of 3.3 MPa was performed, and after reaching 170 to 180°C, the temperature was maintained for 50 minutes, whereby thermal compression bonding was performed.

[0130] 1-2) In the case where the resin base material is R-1410A (manufactured by Panasonic),

[0131] Heating under a pressure of 1 MPa was performed, and after reaching 130°C, the temperature was maintained for 10 minutes; then, further heating under a pressure of 2.9 MPa was performed, and after reaching 200°C, the temperature was maintained for 70 minutes, whereby thermal compression bonding was performed.

[0132] 1-3) In the case where the resin base material is EM-285 (manufactured by EMC),

[0133] Heating under a pressure of 0.4 MPa was performed, and after reaching 100°C, the pressure was increased to 2.4 to 2.9 MPa, and further heating was performed, and after reaching 195°C, the temperature was maintained for 50 minutes, whereby thermal compression bonding was performed.

[0134] 1-4) In the case where the resin base material is GX13 (manufactured by Ajinomoto), heating was performed while applying a pressure of 1.0 MPa, and the temperature was maintained at 180°C for 60 minutes, whereby thermal compression bonding was performed.

[0135] 2) In the case where the resin base material contains or consists of a PPE resin, it is preferable to apply a pressure of 0 to 20 MPa at a temperature of 50°C to 350°C for 1 minute to 5 hours, whereby the composite copper member is thermally compression-bonded to the resin base material.

[0136] For example,

[0137] 2-1) In the case where the resin base material is R5620 (manufactured by Panasonic),

[0138] Thermal compression bonding was performed while heating to 100°C under a pressure of 0.5 MPa, and then the temperature and the pressure were increased, and maintained at 2.0 to 3.0 MPa and 200 to 210°C for 120 minutes, whereby further thermal compression bonding was performed.

[0139] 2-2) In the case where the resin base material is R5670 (manufactured by Panasonic),

[0140] Thermal compression bonding was performed while heating to 110°C under a pressure of 0.49 MPa, and then the temperature and the pressure were increased, and maintained at 2.94 MPa and 210°C for 120 minutes, whereby thermal compression bonding was performed.

[0141] 2-3) In the case where the resin base material is R5680 (manufactured by Panasonic), heat press bonding was performed by heating to 110°C under a pressure of 0.5 MPa, and then increasing the temperature and the pressure, and maintaining at 3.0 to 4.0 MPa and 195°C for 75 minutes.

[0142] 2-4) In the case where the resin base material is N-22 (manufactured by Nelco), heat press bonding was performed by heating under pressurization of 1.6 to 2.3 MPa, and maintaining at 177°C for 30 minutes, and then further heating, and maintaining at 216°C for 60 minutes.

[0143] 3) In the case where the resin base material contains or consists of a PTFE resin, it is preferable to apply a pressure of 0 to 20 MPa at a temperature of 50°C to 400°C for 1 minute to 5 hours to heat press bond the composite copper member to the resin base material.

[0144] For example,

[0145] 3-1) In the case where the resin base material is NX9255 (manufactured by Park Electrochemical), heat press bonding was performed by heating to 260°C under pressurization of 0.69 MPa, increasing the pressure to 1.03 to 1.72 MPa, and heating to 385°C, and maintaining at 385°C for 10 minutes.

[0146] 3-2) In the case where the resin base material is RO3003 (manufactured by Rogers), heat press bonding was performed by pressurizing to 2.4 MPa after 50 minutes from the start of pressurization (about 220°C), and maintaining at 371°C for 30 to 60 minutes.

[0147] The conditions for peeling the copper member from the resin base material are not particularly limited, and can be performed according to the 90° peel test (Japanese Industrial Standard (JIS) C5016 "Test methods for flexible printed wiring boards", corresponding to International Standard IEC 249-1:1982, IEC 326-2:1990).

[0148] The metal contained in the layer containing copper oxide is transferred to the resin base material after peeling the copper member. The metal transferred to the surface of the resin base material after peeling the copper member can be detected by various methods (for example, X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), ICP emission spectroscopy (high-frequency inductively coupled plasma emission spectroscopy, ICP-OES / ICP-AES)).

[0149] XPS is a method in which X-rays are irradiated to an object, and photoelectrons e –The method for performing energy analysis is described. By XPS, the kind of element present on the surface of the sample, or up to a prescribed depth from the surface (for example, up to a depth of 6 nm), the amount present, the chemical bonding state, and the like can be investigated. As the analysis spot diameter (i.e., the diameter of the section when the cylindrical portion that can be analyzed is truncated in a manner that the section becomes a circle), 1 μm or more to 1 mm or less is suitable.

[0150] The arithmetic average roughness (Ra) of the surface of the composite copper member on which the layer containing copper oxide is formed is preferably 0.04 μm or more, more preferably 0.1 μm or more, and further preferably 0.3 μm or less, and more preferably 0.2 μm or less.

[0151] The maximum height roughness (Rz) of the surface of the composite copper member on which the layer containing copper oxide is formed is preferably 0.2 μm or more, more preferably 1.0 μm or more, and further preferably 2.0 μm or less, and more preferably 1.7 μm or less.

[0152] If the Ra and Rz are too small, the adhesion to the resin base material is insufficient, and if they are too large, the fine wiring formability and the high frequency characteristics are deteriorated.

[0153] wherein the arithmetic average roughness (Ra) represents the average of the absolute values of Z(x) (i.e., the height of the mountain and the depth of the valley) in the profile curve (y = Z(x)) represented by the following equation in a reference length 1.

[0154]

[0155] The maximum height roughness (Rz) represents the sum of the maximum value of the mountain height Zp and the maximum value of the valley depth Zv of the profile curve (y = Z(x)) in a reference length 1.

[0156] The Ra and Rz can be calculated by the method prescribed in JIS B 0601:2001 (according to the international reference ISO 4287-1997).

[0157] The ratio of the Ra after peeling of the surface of the composite copper member on which the layer containing copper oxide is formed to the Ra before heat pressure bonding is preferably lower than 100%, lower than 96%, lower than 95%, lower than 94%, lower than 93%, lower than 92%, lower than 91%, lower than 90%, lower than 80%, lower than 70%, lower than 65%, or lower than 60%. The smaller the ratio, the more the metal forming the layer containing copper oxide is transferred to the resin base material.

[0158] The proportion of the surface area of the composite copper member after peeling to the surface area before heat pressing is preferably less than 100%, less than 98%, less than 97%, less than 96%, less than 95%, less than 94%, less than 93%, less than 92%, less than 91%, less than 90%, less than 80%, or less than 75%. The smaller the proportion, the more the metal forming the layer containing copper oxide is transferred to the resin base material.

[0159] The surface area can be measured using a confocal microscope or an atomic force microscope.

[0160] In the composite copper member of one embodiment of the present application, the average length (RSm) of the roughness curve elements of the surface of the composite copper member in which the layer containing copper oxide is formed is not particularly limited and is preferably 1500 nm or less, 1400 nm or less, 1300 nm or less, 1200 nm or less, 1100 nm or less, 1000 nm or less, 900 nm or less, 800 nm or less, 750 nm or less, 700 nm or less, 650 nm or less, 600 nm or less, 550 nm or less, 450 nm or less, or 350 nm or less, and is preferably 100 nm or more, 200 nm or more, or 300 nm or more. Here, RSm represents the average of the lengths (i.e., lengths of the profile curve elements: Xs1 to Xsm) of the concave-convexes included in the roughness curve in a certain reference length (lr) and is calculated by the following formula.

[0161]

[0162] Here, the concave-convexes of one period are defined by taking 10 % of the arithmetic average roughness (Ra) as the minimum height in the concave-convexes and taking 1 % of the reference length (lr) as the minimum length. As an example, Rsm can be measured and calculated in accordance with "Method for Measuring Surface Roughness of Fine Ceramic Films by Atomic Force Microscope (JIS R 1683: 2007)".

[0163] ΔE of the surface of the composite copper member before heat pressing and the surface of the copper member after peeling ＊ ab is preferably 13 or more, 15 or more, 20 or more, 25 or more, 30 or more, or 35 or more. The larger the difference, the more the metal forming the layer containing copper oxide (i.e., the metal forming the concave-convexes) is transferred to the resin base material.

[0164] == Method for manufacturing composite copper member ==

[0165] One embodiment of the present application is a method for manufacturing a composite copper member, which includes a step of providing a void in a layer containing copper oxide so that the layer is easily broken (fractured) from the copper member.

[0166] In this process, the method of providing a void in the layer containing copper oxide to make it easy to break from the copper member is not particularly limited, and is performed by 1) partial coating of the surface of the copper member with a coating agent such as a silane coupling agent before the oxidation treatment; 2) treatment of the layer containing copper oxide with a modifier such as nickel chloride after the oxidation treatment; or a combination of these methods.

[0167] The layer containing copper oxide is preferably formed by treating the surface of the copper member with an oxidizing agent. The oxidizing agent is not particularly limited, and for example, an aqueous solution of sodium chlorite, sodium hypochlorite, potassium chlorate, potassium perchlorate, potassium persulfate, or the like can be used. Various additives (for example, a phosphate such as trisodium phosphate dodecahydrate) can be added to the oxidizing agent.

[0168] The oxidation reaction conditions are not particularly limited, and the reaction temperature is preferably 40 to 95°C, and more preferably 45 to 80°C. The reaction time is preferably 0.5 to 30 minutes, and more preferably 1 to 10 minutes.

[0169] Before the oxidation treatment, acid cleaning for degreasing treatment, natural oxidation film removal, and uniform treatment, or alkaline treatment for preventing the introduction of acid into the oxidation process after acid cleaning can be performed. Acid cleaning can be performed, for example, by immersing the copper surface in 5 to 20% by weight sulfuric acid at a liquid temperature of 20 to 50°C for 1 to 5 minutes, and then washing with water. After acid treatment, in order to reduce treatment unevenness and prevent the mixing of the acid used for cleaning treatment into the oxidizing agent, alkaline treatment can be further performed. The method of alkaline treatment is not particularly limited, and an aqueous alkali solution, for example, an aqueous sodium hydroxide solution, is used at a concentration of preferably 0.1 to 10 g / L, and more preferably 1 to 2 g / L, and treatment is performed at 30 to 50°C for about 0.5 to 2 minutes.

[0170] In addition, the layer containing copper oxide can be dissolved with a dissolving solution containing a dissolving agent, and the protrusions on the surface of the copper member can be adjusted, or the copper oxide in the layer containing copper oxide can be reduced with a reducing solution containing a reducing agent.

[0171] The dissolving agent is not particularly limited, and is preferably a chelating agent, and particularly a biodegradable chelating agent, and examples include L-glutamic acid diacetic acid tetrasodium (CMG-40), ethylenediaminetetraacetic acid (sodium salt), diethanolglycine, L-glutamic acid diacetic acid tetrasodium, ethylenediamine-N,N'-disuccinic acid, 3-hydroxy-2,2'-iminodisuccinic acid sodium, methylglycinediacetic acid trisodium, aspartic acid diacetic acid tetrasodium, N-(2-hydroxyethyl)iminodiacetic acid disodium, sodium gluconate, and the like.

[0172] As the reducing agent, DMAB (dimethylamine borane), diborane, sodium borohydride, hydrazine, or the like can be used. In addition, the reducing solution is a liquid containing a reducing agent, an alkaline compound (for example, sodium hydroxide, potassium hydroxide, or the like), and a solvent (for example, pure water, or the like).

[0173] The layer containing copper oxide can contain a metal other than copper. The metal other than copper can be contained, for example, by performing plating treatment on the layer containing copper oxide with a metal other than copper. The plating treatment method can use a known technique, and as the metal other than copper, Sn, Ag, Zn, Al, Ti, Bi, Cr, Fe, Co, Ni, Pd, Au, Pt, or various alloys can be used. The plating process is not particularly limited, and plating can be performed by electrolytic plating, electroless plating, vacuum evaporation, chemical surface treatment, or the like, and electrolytic plating is preferred because a uniform and thin plated layer is formed.

[0174] In the case of electrolytic plating, plating of nickel and plating of a nickel alloy are preferred. The metal formed by plating of nickel and plating of a nickel alloy can be exemplified by pure nickel, a Ni-Cu alloy, a Ni-Cr alloy, a Ni-Co alloy, a Ni-Zn alloy, a Ni-Mn alloy, a Ni-Pb alloy, a Ni-P alloy, and the like.

[0175] As the metal salt used in plating, nickel sulfate, nickel sulfamate, nickel chloride, nickel bromide, zinc oxide, zinc chloride, palladium dichlorodiammine, iron sulfate, iron chloride, anhydrous chromic acid, chromium chloride, sodium chromic sulfate, copper sulfate, copper pyrophosphate, cobalt sulfate, manganese sulfate, and the like can be exemplified.

[0176] In plating of nickel, the plating bath composition is preferably, for example, nickel sulfate (100 g / L or more and 350 g / L or less), nickel sulfamate (100 g / L or more and 600 g / L or less), nickel chloride (0 g / L or more and 300 g / L or less), and a mixture containing these, and as an additive, sodium citrate (0 g / L or more and 100 g / L or less), boric acid (0 g / L or more and 60 g / L or less) can also be contained.

[0177] In the case of electroless plating of nickel, electroless plating using a catalyst is preferred. As the catalyst, iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, or a salt thereof is preferably used. By performing electroless plating using a catalyst, the heat resistance of the composite copper foil is improved.

[0178] One embodiment of the method for manufacturing a composite copper member of the present application is a method for manufacturing a composite copper member, which includes: 1) a step of locally applying a silane coupling agent to the surface of a copper member; and 2) a step of performing oxidation treatment on the surface of the copper member to which the silane coupling agent has been locally applied, or which includes: 1) a step of locally applying a silane coupling agent to the surface of a copper member; 2) a step of performing oxidation treatment on the surface of the copper member to which the silane coupling agent has been locally applied; and 3) a step of forming a layer containing a metal other than copper on the surface of the copper member after the oxidation treatment.

[0179] By partially coating the surface of the copper member with a coating agent such as a silane coupling agent, the portion is exempted from the oxidation treatment, and a void is created in the layer containing copper oxide, particularly in the vicinity of the interface portion with the copper member, and the layer containing copper oxide is easily broken from the copper member.

[0180] Therefore, the treatment with the silane coupling agent is preferably performed to partially coat (e.g., 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% or more and less than 100%) the surface of the copper member, and for this purpose, the silane coupling agent is preferably reacted at a concentration of 0.1%, 0.5%, 1%, or 2% or more at room temperature for 30 seconds, 1 minute, or 2 minutes or more.

[0181] The silane coupling agent is not particularly limited, and examples thereof include silane, tetraorgano-silane, aminoethyl-aminopropyl-trimethoxysilane, (3-aminopropyl)trimethoxysilane, (1-[3-(trimethoxysilyl)propyl]urea), (3-aminopropyl)triethoxysilane, ((3-glycidyloxypropyl)trimethoxysilane), (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, and the like.

[0182] The treatment with the silane coupling agent can be performed at any time as long as it is performed before the oxidation treatment, and can be performed simultaneously with acid cleaning for degreasing treatment, natural oxide film removal, and uniform treatment, or with alkali treatment after the acid cleaning for preventing the introduction of acid into the oxidation step.

[0183] One embodiment of the method for manufacturing a composite copper member of the present application is a method for manufacturing a composite copper member including: 1) a step of performing an oxidation treatment on the surface of a copper member; and 2) a step of performing a treatment on the surface of the copper member after the oxidation treatment with a finishing agent, or a method for manufacturing a composite copper member including: 1) a step of performing an oxidation treatment on the surface of a copper member; 2) a step of performing a treatment on the surface of the copper member after the oxidation treatment with a finishing agent; and 3) a step of forming a layer containing a metal other than copper on the surface of the composite copper member after the treatment with the finishing agent.

[0184] It can be considered that by the treatment with the modification agent, the copper oxide near the interface of the copper member and the layer containing copper oxide is partially dissolved to generate voids, and thus the layer containing copper oxide becomes easy to be broken from the copper member.

[0185] The modification agent for breaking the layer containing copper oxide from the copper member is not limited to nickel chloride, and can be a chloride (zinc chloride, iron chloride, chromium chloride, etc.), an ammonium salt (ammonium citrate, ammonium chloride, ammonium sulfate, nickel ammonium sulfate, etc.), a chelating agent (ethylenediaminetetraacetic acid, diethanolglycine, L-glutamic acid diacetic acid tetrasodium, ethylenediamine-N,N'-disuccinic acid, 3-hydroxy-2,2'-iminodisuccinic acid sodium, methylglycine diacetic acid trisodium, aspartic acid diacetic acid tetrasodium, N-(2-hydroxyethyl)iminodiacetic acid disodium, sodium gluconate, etc.), or the like.

[0186] In the case of treatment with nickel chloride, there is no particular limitation, and it is preferable to immerse the copper member 5 seconds or more on which the layer containing copper oxide is formed in a nickel chloride solution (concentration of 45 g / L or more) at room temperature or at a temperature higher than room temperature. In addition, the treatment can be performed with nickel chloride alone, simultaneously with the oxidation treatment, or after the oxidation treatment and simultaneously with the plating treatment. For example, the nickel chloride can be contained in the plating solution, and the copper member on which the layer containing copper oxide is formed can be immersed in the plating solution for 5 seconds, 10 seconds, 15 seconds, 20 seconds, 30 seconds, 1 minute, or 2 minutes before plating. The immersion time can be appropriately changed depending on the oxidation film thickness.

[0187] One embodiment of the manufacturing method of the composite copper member of the present application is a manufacturing method of a composite copper member including: 1) a step of locally applying a silane coupling agent to the surface of a copper member; 2) a step of performing oxidation treatment on the surface of the copper member to which the silane coupling agent is locally applied; and 3) a step of performing treatment with a modification agent on the surface of the copper member after the oxidation treatment, or a manufacturing method of a composite copper member including: 1) a step of locally applying a silane coupling agent to the surface of a copper member; 2) a step of performing oxidation treatment on the surface of the copper member to which the silane coupling agent is locally applied; 3) a step of performing treatment with a modification agent on the surface of the copper member after the oxidation treatment; and 4) a step of forming a layer containing a metal other than copper on the surface of the copper member after the treatment with the modification agent.

[0188] == Method for using the composite copper member ==

[0189] The composite copper member according to the present application can be used for:

[0190] (1) heat-pressing to a resin base material to manufacture a laminate;

[0191] (2) heat-pressing to a resin base material, peeling, and obtaining a resin base material having a part or all of the metal on which the layer containing copper oxide is formed;

[0192] (3) In the SAP method or the MSAP method, the thermocompression bonding to the resin substrate, the peeling, the resin substrate having a part or all of the metal forming the layer containing copper oxide, the copper plating treatment on the surface of the resin substrate after the peeling, and thus the printed wiring board is manufactured.

[0193] (4) The plating of copper or a metal other than copper is performed on the layer containing copper oxide to form a metal foil, and thus a carrier-attached metal foil using the layer containing copper oxide and the plating of copper or a metal other than copper as the metal foil, or the like, is manufactured.

[0194] In (1) to (3), the resin substrate and the conditions of the thermocompression bonding to the resin substrate can be the same as or different from those at the time of obtaining the SEM cross-sectional image.

[0195] In (2) to (3), the conditions of the peeling can be the same as or different from those at the time of obtaining the SEM cross-sectional image.

[0196] In (3), the method of the copper plating can be electrolytic plating or non-electrolytic plating.

[0197] In (4), the method of the plating of the metal to the outermost surface of the layer containing copper oxide can be electrolytic plating or non-electrolytic plating, and the metal can be an alloy.

[0198] Examples

[0199] <1. Manufacture of composite copper foil>

[0200] Examples 1 to 3, Comparative Examples 2 and 3 use the matte surface (glossy surface. The surface that is more flat when compared with the opposite surface) of the copper foil (DR-WS, thickness: 18 μm) manufactured by Furukawa Electric Co., Ltd. Comparative Example 1 uses the rough surface of the copper foil (FV-WS, thickness: 18 μm) manufactured by Furukawa Electric Co., Ltd. in an untreated state as a test piece.

[0201] (1) Pretreatment

[0202] Examples 1 and 2 are immersed in a solution of potassium carbonate 5 g / L; KBE-903 (3-aminopropyltriethoxysilane; manufactured by Shin-Etsu Silicone Co., Ltd.) 1 vol% at 25°C for 1 minute.

[0203] Comparative Examples 2 and 3 and Example 3 are immersed in a solution of potassium carbonate 5 g / L at 25°C for 1 minute.

[0204] (2) Oxidation treatment

[0205] The copper foil subjected to the pretreatment is immersed in an oxidizing agent to perform the oxidation treatment.

[0206] In Examples 1 and 2, a solution of sodium chlorite 52.5 g / L, potassium hydroxide 18 g / L, potassium carbonate 35 g / L was used as the oxidizing agent.

[0207] In Example 3, a solution of sodium chlorite 37.5 g / L, potassium hydroxide 10 g / L, KBM-403 (3-glycidylpropyltrimethoxysilane; manufactured by Shin-Etsu Silicone Co., Ltd.) 1.5 g / L was used as the oxidizing agent.

[0208] In Comparative Example 2, a solution of sodium chlorite 53.5 g / L, potassium hydroxide 8 g / L, potassium carbonate 2 g / L, KBM-403 (3-glycidylpropyltrimethoxysilane; manufactured by Shin-Etsu Silicone Co., Ltd.) 1.5 g / L was used as the oxidizing agent.

[0209] In Comparative Example 3, a solution of sodium chlorite 195 g / L, potassium hydroxide 18 g / L, KBM-403 (3-glycidylpropyltrimethoxysilane; manufactured by Shin-Etsu Silicone Co., Ltd.) 0.5 g / L was used as the oxidizing agent.

[0210] In Examples 1 and 2, immersion in the oxidizing agent was carried out at 73°C for 6 minutes, in Example 3 and Comparative Example 2, immersion in the oxidizing agent was carried out at 73°C for 2 minutes, and in Comparative Example 3, immersion in the oxidizing agent was carried out at 50°C for 1 minute.

[0211] (3) Electrolytic plating treatment

[0212] After the oxidation treatment, in Examples 2, 3 and Comparative Example 2, electrolytic plating was carried out using a Ni electrolytic plating solution (nickel sulfate 250 g / L; nickel chloride 50 g / L; sodium citrate 25 g / L). In Comparative Example 3, electrolytic plating was carried out using a Ni electrolytic plating solution (nickel sulfate 250 g / L; boric acid 35 g / L). In Example 3, immersion in the Ni electrolytic plating solution was carried out for 1 minute before the electrolytic plating. In Comparative Examples 2, 3 and Examples 2, 3, electrolytic plating was carried out at 50°C at a current density of 0.5 A / dm 2 x 45 seconds (= 22.5 C / dm 2 of copper foil area).

[0213] With respect to the examples and comparative examples, a plurality of test pieces were produced under the same conditions, respectively (Table 1).

[0214] [Table 1]

[0215]

[0216] <2. Crimping and peeling of resin base material>

[0217] The test pieces of Examples 1 to 3 and Comparative Examples 1 to 3 were removed of the solution used for the treatment just before the lamination of the prepreg, and were sufficiently dried. To these test pieces, the prepreg (R5670KJ, manufactured by Panasonic) was laminated, and hot-pressing was performed in a vacuum using a vacuum autoclave at a press pressure of 2.9 MPa, a temperature of 210°C, and a press time of 120 minutes, thereby obtaining a laminate test piece. The cross section of the obtained laminate test piece was obtained by FIB (Focused Ion Beam) processing under the conditions of an acceleration voltage of 30 kV and a probe current of 4 nA. Using a focused ion beam scanning electron microscope (Auriga, manufactured by Carl Zeiss), the obtained cross section was observed under the conditions of a magnification of 30,000 times and a resolution of 1024 x 768, and a SEM cross-sectional image was obtained. Figure 3

[0218] To these laminate test pieces, the copper member was peeled from the resin base material according to a 90° peeling test (Japanese Industrial Standard (JIS) C5016). The image and the peeling strength (kgf / cm) of the test piece after peeling are shown in Figure 2 , and the SEM cross-sectional images of the laminate test pieces before and after peeling are shown in Figure 6 . In Figure 6 , regarding Comparative Example 3, after the Pt deposition layer was laminated to the resin base material side in order to protect the processed surface, the image was obtained. As shown in Figure 2 and Figure 6 , only in the examples, the needle-shaped (nodular) copper oxide or the needle-shaped protrusions of substantially the same thickness as the needle-shaped (nodular) copper oxide, on which nickel plating was performed, were substantially transferred from the copper foil to the resin base material side. In addition, the peeling strength of the examples was also extremely small compared to the comparative examples.

[0219] <3. Binarization of SEM Cross-Sectional Image after Hot-Pressing>

[0220] The SEM cross-sectional image of the obtained laminate test piece (arranged so that the needle-shaped protrusions face the upper side of the image; width of the image = 3.78 pm x 2.61 pm; resolution = 1024 x 768) was binarized using image analysis software WinROOF2018 (Mitsuyoshi Corporation, Ver 4.5.5) according to the following procedure.

[0221] <Operation>

[0222] 1) Range Selection (Rectangular ROI)

[0223] The area surrounded by a straight line parallel to the laminated surface passing through the vertex of the gap present on the copper side, and a straight line parallel to the laminated surface passing through the vertex of the highest protrusion formed on the surface of the copper was used as the measurement range.

[0224] ​2) Image processing → emphasis (brightness ± 0, contrast + 20)

[0225] In order to easily perform image processing, adjustment of contrast is performed.

[0226] 3) Image processing → emphasis → inversion

[0227] In order to select voids in the binarization process, inversion processing is performed to invert the bright and dark portions of the image.

[0228] 4) Automatic binarization (discriminant analysis method)

[0229] Automatic binarization is performed to select regions surrounded by copper and copper oxide and regions surrounded by copper oxide. Determination of the threshold is performed by the discriminant analysis method.

[0230] 5) Noise removal

[0231] 1-pixel square cases are treated as noise, and regions having an area of 15 nm 2 The following section is removed.

[0232] 6) Void distance calculation

[0233] When the image is arranged with the direction of the convex portion oriented toward the upper side of the image, the upper left of the image is taken as the origin, and the image downward is taken as the X axis and the rightward as the Y axis. The region selected by the automatic 2-valueization existing at X = maximum, Y = minimum is taken as the starting point, and the distance to the region in the Y axis direction with the closest distance is calculated as the distance between two points. Each region selected is defined as a void when the distance between two points is calculated.

[0234] 7) Void size measurement

[0235] The maximum horizontal chord length of the void is calculated and taken as the size of each void.

[0236] SEM cross-sectional images of each of the laminated sample after inversion binarization are shown in Figure 4 .

[0237] The results of the calculation of the average distance between the voids and the voids are shown in Figure 5 .

[0238] In Comparative Examples 2 and 3, only the regions surrounded by copper oxide (i.e., the gaps of the concavities and convexities of the copper oxide layer) are counted as voids, and in the Examples, the regions surrounded by copper oxide and the regions surrounded by copper and copper oxide (i.e., the regions existing at the interface between the layer containing copper oxide and the copper foil) are counted as voids, so the number of voids counted in the Examples is greater, and the distance between the voids is also short. In addition, the proportion of cases in which the distance between the voids is 50 nm or less is 40% or more of the total in the Examples.

[0239] <4. Measurement of Ra and surface area of the composite copper foil before thermal compression bonding and after peeling>

[0240] (1) Method

[0241] For the composite copper foil test pieces of Examples 1 to 3 and Comparative Examples 1 and 2, the surface area before thermal compression bonding and after peeling was calculated using a confocal scanning electron microscope OPTELICS H1200 (manufactured by Lasertec Corporation). As the measurement conditions, the mode was set to the confocal mode, the scanning area was set to 100 pm x 100 pm, the light source was set to blue, and the threshold was set to 1 / 5. The objective lens was set to x 100, the eyepiece was set to x 14, the digital zoom was set to x 1, and the Z interval was set to 10 nm, and data at three points were obtained, and the surface area was taken as the average of the three points.

[0242] (2) Results

[0243] As described in Table 2, in the Examples, the Ra and the surface area decreased before thermal compression bonding and after peeling, and in the Comparative Examples, on the contrary, they increased. This indicates that in the Examples, the protrusions of the composite copper member were all or partially transferred to the resin side, and in the Comparative Examples, on the contrary, a part of the resin was transferred to the composite copper member.

[0244] [Table 2]

[0245]

[0246] Industrial applicability

[0247] According to the present application, a novel composite copper member can be provided. The composite copper member is suitable for the SAP method or the MSAP method Figure 7 In order to make the plating solution penetrate to the deepest part of the end of the recess, the shape of the recess needs to be large to a certain extent, and is not suitable for the formation of fine wiring (Japanese Patent Application Publication No. 2017-034216). However, in the case of using the composite copper foil of the present application, the layer containing copper oxide forming the protrusion and the recess is itself transferred, and therefore it is not necessary to make the plating solution penetrate to the deepest part of the recess, and it is sufficient to perform (pattern) copper plating on the layer containing the transferred copper oxide, which does not have the protrusion and the recess, even if the shape of the recess on the surface of the original composite copper member is long and fine, the possibility of generating a gap between the resin base material and the (pattern) copper plated layer is small, and it is suitable for the formation of fine wiring.

[0248] Furthermore, since the copper plating is performed on the layer containing copper oxide, the binding affinity of the copper plating to the layer containing copper oxide is high, and the peeling strength between the resin base material and the (pattern) copper plated layer is ensured by the binding of the layer containing copper oxide to the copper plated layer.

[0249] Even if a metal to be oxidized is made as a release layer for a carrier foil, the peel strength is not stable (International Publication No. 2010 / 027052). However, by forming a void in the layer containing copper oxide, the composite copper member according to the present application can be directly used for a copper member that functions as a (extremely thin) metal foil with a carrier, or the production thereof. Even if it is a carrier foil, an excessively thin metal foil cannot withstand the heat pressure bonding process to a resin base material from the strength aspect. The composite copper foil of, for example, Examples 2 and 3, since the copper foil portion functions as a carrier, can cause the layer containing copper oxide and the nickel plating layer to be transferred, so that the electrically conductive Ni of only several tens of nm in thickness can be heat pressure bonded to a resin base material. Since the layer containing copper oxide is also transferred together, the physical strength of the Ni layer is enhanced by the presence of the transferred layer containing copper oxide, while on the other hand, since the layer containing copper oxide has extremely low electrical conductivity, current does not flow, and transmission loss due to the presence of the layer containing copper oxide does not substantially occur.

Claims

1. A composite copper member characterized by: a layer containing copper oxide is formed on at least a part of a surface of a copper member, a plurality of voids are present in the layer containing copper oxide, at least a part of the voids is present at an interface between the layer containing copper oxide and the surface of the copper member, a surface of the layer containing copper oxide of the composite copper member is heat-pressed on a resin base material under prescribed conditions to form a laminate, a photograph of a cross section of the laminate is obtained using a scanning electron microscope, and when the photograph is binarized, the number of the voids is detected to be 30 or more per 3.8 μm in any measurement in a direction parallel to a surface of the laminate, Ra of the surface on which the layer containing copper oxide is formed is 0.03 μm or more, and when the copper member is peeled from the resin base material after heat-pressing under prescribed conditions, the proportion of Ra of the surface of the copper member peeled from the resin base material with respect to the Ra is less than 65%.

2. A composite copper member characterized by: a layer containing copper oxide is formed on at least a part of a surface of a copper member, a plurality of voids are present in the layer containing copper oxide, at least a part of the voids is present at an interface between the layer containing copper oxide and the surface of the copper member, a surface of the layer containing copper oxide of the composite copper member is heat-pressed on a resin base material under prescribed conditions to form a laminate, a photograph of a cross section of the laminate is obtained using a scanning electron microscope, and when the photograph is binarized, the number of the voids is detected to be 30 or more per 3.8 μm in any measurement in a direction parallel to a surface of the laminate, Ra of the surface on which the layer containing copper oxide is formed is 0.03 μm or more, and a peeling strength between the layer containing copper oxide and the surface of the copper member is 0.001 kgf / cm or more and 0.30 kgf / cm or less.

3. The composite copper member according to claim 1, wherein: the peeling strength between the layer containing copper oxide and the surface of the copper member is 0.001 kgf / cm or more and 0.30 kgf / cm or less.

4. The composite copper member according to claim 1 or 2, wherein: the number of the voids is detected to be 30 or more per 3.8 μm in any measurement in a direction parallel to the layer containing copper oxide when a photograph of a cross section is obtained using a scanning electron microscope and the photograph is binarized.

5. The composite copper member according to claim 1 or 2, wherein: an average distance between the voids in the photograph of the cross section after the binarization is 100 nm or less.

6. The composite copper member according to claim 1 or 2, wherein: the proportion of a distance between the voids being 50 nm or less in the photograph of the cross section after the binarization is 40% or more of the entire distance between the voids.

7. The composite copper member according to claim 1 or 2, wherein: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The resin base material contains at least one insulating resin selected from the group consisting of polyphenylene ether (PPE), epoxy resin, polyphenylene oxide (PPO), polybenzoxazole (PBO), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP), triphenylphosphite (TPPI), fluororesin, polyetherimide, polyether ether ketone, polynorbornene, bismaleimide resin, low dielectric constant polyimide, and cyanate ester resin.

8. The composite copper member according to claim 1 or 2, wherein: The prescribed condition of the thermal compression bonding is in the range of a temperature of 50°C to 400°C, a pressure of 0 to 20 MPa, and a time of 1 minute to 5 hours.

9. The composite copper member according to claim 1 or 2, wherein: The proportion of the surface area of the copper member peeled from the resin base material after the thermal compression bonding to the surface area of the surface on which the layer containing copper oxide is formed is less than 75%.

10. The composite copper member according to claim 1 or 2, wherein: The layer containing copper oxide contains a metal other than copper.

11. The composite copper member according to claim 10, wherein: The metal other than copper is nickel.

12. The composite copper member according to claim 1 or 2, wherein: The layer containing copper oxide contains a copper plating layer.

13. A metal foil with a carrier, comprising: the composite copper member according to claim 10, the layer containing copper oxide is used as a metal foil, and the copper member is used as a carrier for the metal foil.

14. A laminate, comprising: a resin base material laminated on at least a part of the surface of the layer containing copper oxide of the composite copper member according to claim 1 or 2.

15. The laminate according to claim 14, wherein: The resin base material contains at least one insulating resin selected from the group consisting of polyphenylene ether (PPE), epoxy resin, polyphenylene oxide (PPO), polybenzoxazole (PBO), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP), triphenylphosphite (TPPI), fluororesin, polyetherimide, polyether ether ketone, polynorbornene, bismaleimide resin, low dielectric constant polyimide, and cyanate ester resin.

16. The composite copper member according to claim 1 or 2, wherein: it is used for manufacturing a printed wiring board.

17. The composite copper member according to claim 16, wherein: it is used for manufacturing a printed wiring board using a Semi-Additive Process (SAP method) or a Modified Semi-Additive Process (MSAP) method.

18. A manufacturing method of a printed wiring board for manufacturing a printed wiring board using the composite copper member according to claim 1 or 2, the manufacturing method comprising: 1) a step of thermally compressing a resin base material on the layer containing copper oxide of the composite copper member under a prescribed condition; 2) a step of peeling the copper member from the resin base under prescribed conditions to obtain a resin base having a part or all of the metal forming the layer containing copper oxides; and 3) a step of performing copper plating treatment on the surface of the resin base having a part or all of the metal forming the layer containing copper oxides.

19. A method for producing a resin substrate having a metal, characterized by, comprising: 1) a step of thermocompression bonding a resin base to the layer containing copper oxides of the composite copper member described in claim 1 or 2 under prescribed conditions; and 2) a step of peeling the copper member from the resin base under prescribed conditions to obtain a resin base having a part or all of the metal forming the layer containing copper oxides.

20. A manufacturing method of a composite copper member for manufacturing the composite copper member described in claim 1 or 2, the manufacturing method characterized by comprising: 1) a step of locally applying a silane coupling agent to the surface of the copper member; and 2) a step of forming the layer containing copper oxides by oxidizing the locally applied surface.

21. A manufacturing method of a composite copper member for manufacturing the composite copper member described in claim 1 or 2, the manufacturing method characterized by comprising: 1) a step of locally applying a silane coupling agent to the surface of the copper member; 2) a step of oxidizing the locally applied surface; and 3) a step of forming a layer containing a metal other than copper on the surface of the layer containing the formed copper oxides, wherein the modifying agent contains a compound selected from the group consisting of nickel chloride, zinc chloride, iron chloride, chromium chloride, ammonium citrate, ammonium chloride, potassium chloride, ammonium sulfate, and nickel ammonium sulfate.

22. A manufacturing method of a composite copper member for manufacturing the composite copper member described in claim 10, the manufacturing method characterized by comprising: 1) a step of locally applying a silane coupling agent to the surface of the copper member; 2) a step of oxidizing the locally applied surface; and 3) a step of forming a layer containing a metal other than copper on the oxidized surface.

23. A manufacturing method of a composite copper member for manufacturing the composite copper member described in claim 10, the manufacturing method characterized by comprising: 1) a step of oxidizing the surface of the copper member; 2) a step of treating the oxidized surface with a modifying agent; and 3) a step of forming a layer containing a metal other than copper on the surface treated with the modifying agent, wherein the modifying agent contains a compound selected from the group consisting of nickel chloride, zinc chloride, iron chloride, chromium chloride, ammonium citrate, ammonium chloride, potassium chloride, ammonium sulfate, and nickel ammonium sulfate.

24. A manufacturing method of a composite copper member for manufacturing the composite copper member described in claim 10, the manufacturing method characterized by comprising: 1) a step of locally applying a silane coupling agent to the surface of the copper member; 2) a step of oxidizing the locally applied surface; 3) a step of treating the oxidized surface with a modifying agent; and 4) a step of forming a layer containing a metal other than copper on the surface after the treatment with the modification agent, wherein the modification agent contains a compound selected from the group consisting of nickel chloride, zinc chloride, iron chloride, chromium chloride, ammonium citrate, ammonium chloride, potassium chloride, ammonium sulfate, and nickel ammonium sulfate.

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