TWI809441B - Surface-treated copper foil and copper clad laminate - Google Patents

Abstract

A surface-treated copper foil includes a treated surface, where the peak extreme height (Sxp) of the treated surface is 0.4 to 3.0μm. When the surface-treated copper foil is heated at a temperature of 200℃ for 1 hour, the ratio of the integrated intensity of (111) peak to the sum of the integrated intensities of (111) peak, (200) peak, and (220) peak of the treated surface is at least 60%.

Description

Surface treatment of copper foil and copper foil substrate

The disclosure relates to the technical field of copper foil, in particular to a surface-treated copper foil and its copper foil substrate.

With the gradual development of electronic products towards thinner and lighter and the transmission of high-frequency signals, the demand for copper foil and copper foil substrates is also increasing. Generally speaking, the copper conductive circuit of the copper foil substrate is carried by an insulating carrier, and through the layout design of the conductive circuit, it can transmit electrical signals to a predetermined area along a predetermined path. In addition, for copper foil substrates used to transmit high-frequency electrical signals (such as higher than 10GHz), the conductive lines of the copper foil substrates must be further optimized to reduce signal transmission due to skin effect. Loss (signal transmission loss). The so-called skin effect means that as the frequency of the electrical signal increases, the current transmission path will be more concentrated on the surface of the wire, such as the surface of the wire next to the carrier. In order to reduce the signal transmission loss caused by the skin effect, the current practice is to planarize the surface of the wire in the copper foil substrate that is adjacent to the carrier as much as possible. In addition, in order to maintain the adhesion between the surface of the wire and the carrier, reverse treated copper foil (RTF) can also be used to make the wire. Wherein, the reversed copper foil refers to a copper foil whose drum side is roughened.

Even if the above method can reduce the signal transmission loss caused by the copper foil substrate, when the surface of the wire is too flat, it will still cause the adhesion between the wire and the carrier to decrease, making the wire in the copper foil substrate It is easy to peel off from the surface of the carrier board, so that the electrical signal cannot be transmitted to the predetermined area along the predetermined path.

Therefore, it is still necessary to provide a surface-treated copper foil and copper foil substrate to solve the deficiencies and deficiencies in the prior art.

In view of this, the present disclosure provides an improved surface-treated copper foil and copper foil substrate, which solves the deficiencies in the prior art.

According to an embodiment of the present disclosure, a surface-treated copper foil is provided. The surface-treated copper foil includes a treated surface, wherein the pole height (Sxp) of the treated surface is 0.4 to 3.0 μm. When the surface-treated copper foil is heated at 200 ° C for 1 hour, the integrated intensity of the diffraction peak of the (111) crystal plane on the treated surface and the winding of the (111) crystal plane, (200) crystal plane and (220) crystal plane The ratio of the sum of the peak integrated intensities is at least 60%.

According to another embodiment of the present disclosure, a copper foil substrate is provided. The copper foil substrate includes a carrier and a surface-treated copper foil disposed on at least one surface of the carrier. Wherein, the surface-treated copper foil includes a main body copper foil and a surface treatment layer, and the surface treatment layer is arranged between the main body copper foil and the carrier, wherein the surface treatment layer includes a treatment surface facing the carrier, and the pole height (Sxp) of the treatment surface is 0.4 to 3.0 μm, and the ratio of the integrated diffraction peak intensity of the (111) crystal plane of the treated surface to the sum of the integrated diffraction peak intensity of the (111) crystal plane, (200) crystal plane and (220) crystal plane is at least 60 %.

According to the above-mentioned embodiment, when the pole height (Sxp) of the treated surface of the surface-treated copper foil is 0.4 to 3.0 μm, and when the surface-treated copper foil is heated in an environment of 200° C. for 1 hour, the (111) crystal plane of the treated surface When the ratio of the integrated intensity of the diffraction peak of the (111) crystal plane, (200) crystal plane, and (220) crystal plane is at least 60%, the surface-treated copper foil is subsequently laminated to After the substrate is loaded, in addition to maintaining the adhesion and reliability between the treated surface and the substrate, it can also maintain a low degree of signal transmission loss. At the same time, the surface-treated copper foil also has sufficient peel strength after tinning, which can be used in downstream processes. When performing tin floating, the circuit formed by the surface-treated copper foil can be maintained on the carrier without peeling off, so it can meet the industry's requirements for surface-treated copper foil. Foil and copper foil substrate needs.

100: surface treatment copper foil

100A: Treatment surface

110: main body copper foil

110A: first side

110B: the second side

112a: first surface treatment layer

112b: second surface treatment layer

114:Coarsening layer

116a: first passivation layer

116b: second passivation layer

118a: the first anti-rust layer

118b: Second anti-rust layer

120:Coupling layer

300: Stripline

302: wire

304: Dielectric body

306-1: Ground electrode

306-2: Ground electrode

t: thickness

w: width

In order to make the following easier to understand, you can refer to the drawings and their detailed descriptions at the same time when reading this disclosure. Through the specific embodiments herein and referring to the corresponding drawings, the specific embodiments of the present disclosure are explained in detail, and the working principle of the specific embodiments of the present disclosure is explained. In addition, for the sake of clarity, the various features in the drawings may not be drawn according to the actual scale, so the size of some features in some drawings may be intentionally enlarged or reduced.

FIG. 1 is a schematic cross-sectional view of a surface-treated copper foil according to some embodiments of the present disclosure.

FIG. 2 is a schematic diagram of the relationship between the pole height (Sxp) and the loading ratio (mr) of the surface-treated copper foil according to some embodiments of the present disclosure.

FIG. 3 is a schematic diagram of a stripline of some embodiments of the present disclosure.

Hereinafter, specific implementations of the surface-treated copper foil and the copper-clad substrate are described, so that those skilled in the art can realize the present invention. For these detailed descriptions, reference may be made to the corresponding drawings, so that these drawings constitute a part of the embodiments. Although the embodiments of the present disclosure are disclosed as follows, they are not intended to limit the present disclosure, and those skilled in the art may make some modifications and modifications without departing from the spirit and scope of the present disclosure. Wherein, the methods used in each embodiment and experimental examples are conventional methods unless otherwise specified.

With regard to the space-related descriptive vocabulary mentioned in this disclosure, the terms "on" and "above" in this disclosure should be interpreted in the broadest way such that "on" and "on Terms such as "over" not only refer to being directly on something, but can also include being on something with intermediate features or intervening layers in between, and "on" or "above" not only refers to On or above something, and can also include the aspect of being on or over something (ie, directly on something) without an intermediate feature or layer in between.

In addition, unless otherwise indicated below, the numerical parameters described in this disclosure and the scope of claims are approximate numbers, which can be changed as needed, or at least should be based on the disclosed meaningful digits and use the usual rounding method, to interpret each numeric parameter. In this disclosure, ranges may be expressed as being from one endpoint to another, or between two endpoints. All ranges in this disclosure are inclusive of endpoints unless otherwise stated.

It should be noted that without departing from the spirit of the present disclosure, technical features in different implementations described below may be replaced, reorganized, and mixed with each other to form other embodiments.

The surface-treated copper foil described herein includes a treated surface, which can face and be attached to the carrier when the surface-treated copper foil is subsequently laminated to the carrier.

The surface-treated copper foil may include a main body copper foil and an optional surface treatment layer. The main body copper foil can be formed through an electrolytic deposition (or called electrolysis, electrodeposition, electroplating) process, which can have two opposite drum sides and a deposited side. Optionally, the surface treatment layer may be disposed on at least one of the roller surface and the deposition surface of the main copper foil. The surface treatment layer can be a single-layer structure or a multi-layer stack structure. For example, the surface treatment layer may be a multi-layer stack structure including multiple sub-layers, and each surface treatment layer may be respectively disposed on the roller surface and the deposition surface of the main copper foil, but is not limited thereto. The sub-layers in each surface treatment layer can be selected from the group consisting of roughening layer, passivation layer, anti-rust layer and coupling layer, but not limited thereto.

FIG. 1 is a schematic cross-sectional view of a surface-treated copper foil according to some embodiments of the present disclosure. As shown in FIG. 1 , the surface-treated copper foil 100 includes at least a treated surface 100A, and the surface-treated copper foil 100 includes at least a main body copper foil 110 .

According to some embodiments of the present disclosure, the main copper foil 110 may be an electrolytic copper foil or a rolled copper foil, and its thickness is generally greater than or equal to 6 μm, for example, between 7 and 250 μm, or between 9 and 210 μm. time, but not limited to this. Among them, the electrolytic copper foil can be formed through an electrodeposition (or called electrolysis, electrolytic deposition, electroplating) process. The main body copper foil 110 has two oppositely disposed first surfaces 110A and second surfaces 110B. According to some embodiments of the present disclosure, when the main body copper foil 110 is an electrolytic copper foil, the drum side of the electrolytic copper foil may correspond to the first side 110A of the main body copper foil 110 , and the deposition side of the electrolytic copper foil The (deposited side) may correspond to the second surface 110B of the main body copper foil 110 , but is not limited thereto. When the main body copper foil 110 is an electrolytic copper foil, and the first surface 110A of the main body copper foil 110 is the roller surface of the electrolytic copper foil, in the process of forming the electrolytic copper foil by performing electrodeposition (electrodeposition), the electrolytic copper The roll side of the foil can be affected by the grain number or grain size number of the cathode roll of the foil machine, so that the roll side of the electrolytic copper foil can exhibit a specific surface topography, such as grinding marks , and the spatial distribution of the grinding marks can be isotropic or anisotropic, preferably anisotropic.

According to an embodiment of the present disclosure, the first surface 110A and the second surface 110B of the main body copper foil 110 may be respectively provided with surface treatment layers, for example, the first surface treatment layer 112a may be provided on the first surface 110A, and/or The second surface 110B is provided with a second surface treatment layer 112b. The outer surface of the first surface-treated layer 112a can be regarded as the treated surface 100A of the surface-treated copper foil 100 , and the treated surface 100A will contact the carrier through the subsequent process of bonding the surface-treated copper foil 100 to the carrier. According to other embodiments of the present disclosure, the first surface 110A and the second surface 110B of the main body copper foil 110 may be further provided with other single-layer or multi-layer structures, or the surface treatment layers of the first surface 110A and the second surface 110B may be Replaced by other single-layer or multi-layer structures, or the first surface 110A and the second surface 110B are not provided with any layer, but not limited thereto. Therefore, in these embodiments, the treated surface 100A of the surface-treated copper foil 100 will not correspond to the outer surface of the first surface treatment layer 112a, but may correspond to the outer surface of other single-layer or multi-layer structures, or may be Corresponding to the first surface 110A or the second surface 110B of the main body copper foil 110 , but not limited thereto.

Each of the aforementioned first surface treatment layer 112a and second surface treatment layer 112b may be a single layer, or a stacked layer including a plurality of sub-layers. For the case where the first surface treatment layer 112a is a stacked layer, each sub-layer can be selected from the roughening layer 114, the first passivation layer 116a, the first anti-rust layer 118a and the coupling layer 120. Group; and for the case where the second surface treatment layer 112b is a stacked layer including a plurality of sub-layers, each sub-layer may be selected from a group formed by the second passivation layer 116b and the second anti-rust layer 118b. Compositions of the first passivation layer 116a and the second passivation layer 116b may be the same or different from each other, and compositions of the first anti-rust layer 118a and the second anti-rust layer 118b may be the same or different.

The aforementioned rough layer 114 includes rough particles (nodules). The roughening particles can be used to improve the surface roughness of the main copper foil 110 , which can be copper roughening particles or copper alloy roughening particles. Wherein, in order to prevent the roughened particles from peeling off from the main copper foil 110 , the roughened layer 114 may further include a covering layer disposed on the roughened particles to cover the roughened particles. According to an embodiment of the present disclosure, in the case where the roughened particles in the roughened layer 114 are formed on the first surface 110A of the main body copper foil 110 through electrolytic deposition, the distribution of the roughened particles can be influenced by the main body copper foil below it. The influence of the surface topography of 110 makes the arrangement of the coarsened particles appear isotropic or anisotropic. For example, when the surface topography of the first surface 110A of the main body copper foil 110 exhibits anisotropic arrangement, the corresponding roughening particles disposed on the first surface 110A may also present anisotropic arrangement. According to some embodiments of the present disclosure, since the total thickness of the first passivation layer 116a, the first antirust layer 118a, and the coupling layer 120 in the first surface treatment layer 112a is much smaller than the thickness of the roughened layer 114, the surface treatment copper foil The surface topography of the treated surface 100A of 100 , such as peak extreme height (Sxp) and texture aspect ratio (Str), is mainly affected by the roughening layer 114 . In addition, the surface roughness of the treated surface 100A of the surface-treated copper foil 100 can be adjusted by adjusting the quantity and size of the roughened particles in the roughened layer 114 . For example, for the roughened particles and covering layer formed by electrolytic deposition, the type and arrangement of the roughened particles can be adjusted by adjusting the additive type, additive concentration and/or current density in the electrolyte, but not limited here.

Since the treated surface of the surface-treated copper foil will be bonded to the carrier in the subsequent process, the pole height (Sxp) of the treated surface will affect the adhesion between the surface-treated copper foil and the carrier (such as peel strength after tin bleaching) and reliability. In addition, the pole height (Sxp) of the treated surface will also affect the signal transmission loss of the wire formed by the surface treated copper foil. According to some embodiments of the present disclosure, the pole height (Sxp) of the processing surface may be 0.4 μm to 3.0 μm, such as 0.25 μm, 0.75 μm, 1.50 μm, 1.75 μm, 2.25 μm, 2.75 μm, 3.0 μm or any value therein. Preferably it is 0.5 μm to 2.5 μm, more preferably 1.5 μm to 2.5 μm. The measurement method of the above-mentioned pole height (Sxp) is based on the definition of ISO 25178-2:2012, and its calculation method can refer to Figure 2.

FIG. 2 is a schematic diagram of the relationship between the pole height (Sxp) and the material ratio (mr) of the surface-treated copper foil according to an embodiment of the present disclosure. Wherein, the pole height (Sxp) is the absolute difference between the corresponding height H1 of the first data point P1 and the corresponding height H2 of the second data point P2. According to the definition of ISO 25178-2:2012, the load rate M1 corresponding to the first data point P1 is 2.5%, and the load rate M2 corresponding to the second data point P1 is 50%. Since the pole height (Sxp) excludes the high peaks with a load rate lower than 2.5%, the effect of a small number of high peaks on the roughness can be excluded. The pole height (Sxp) refers to the height difference between the surface average surface (loading rate M2 is 50%) and the surface peak (loading rate M1 is 2.5%). When the value of the pole height (Sxp) is high, it means that the surface treated copper After the foil is bonded to the carrier, its depth into the carrier is higher, so it is beneficial to increase the adhesion between the surface-treated copper foil and the carrier (such as peel strength after tin bleaching), so when the value of the pole height (Sxp) is higher The higher the value, the better the peel strength and reliability of the surface-treated copper foil, but when the value of the pole height (Sxp) is too high, the degree of signal loss may be aggravated, so the pole height of the surface-treated copper foil (Sxp) control can meet the needs of all aspects within a certain range.

The aspect ratio of the above-mentioned surface properties (Str) refers to an index to measure the consistency of the surface texture of a certain surface in all directions, that is, to measure the isotropy and anisotropy of the surface. Degree. The value of the surface texture aspect ratio (Str) falls between 0 and 1. When the surface texture aspect ratio (Str) is 0 or close to 0, it means that the surface texture of the surface is significantly anisotropic, and presents Highly regular surface topography. For example, when the aspect ratio (Str) of the surface texture is 0, the adjacent peaks and troughs may all present stripes and be arranged parallel to each other. In contrast, when the surface texture aspect ratio (Str) is 1 or close to 1, it means that the surface texture of the surface is strongly isotropic and presents a highly random surface topography. For example, when the aspect ratio (Str) of the surface texture is 1, the peaks and troughs are randomly arranged. according to this According to some embodiments, the surface texture aspect ratio (Str) of the treated surface of the surface-treated copper foil is less than 0.68, such as 0.05, 0.15, 0.25, 0.35, 0.45, 0.55, 0.65, 0.68 or any value therein. It is preferably less than 0.68, more preferably 0.10 to 0.65, and even more preferably less than 0.60.

For the surface-treated copper foil of the disclosed embodiment, the pole height (Sxp) of the treated surface is 0.4 to 3.0 μm, and the aspect ratio (Str) of the surface texture is less than 0.68. In addition, when the surface-treated copper foil is heated at 200 ° C for 1 hour, the integrated intensity of the diffraction peak of the (111) crystal plane on the treated surface and the (111) crystal plane, (200) crystal plane and (220) crystal plane The ratio of the sum of the integrated intensities of the diffraction peaks may be at least 60%. Since the treated surface of the surface-treated copper foil will be bonded to the carrier in the subsequent process, by controlling the pole height (Sxp) and surface aspect ratio (Str) of the treated surface of the surface-treated copper foil within the above numerical range, Compared with the existing surface-treated copper foil, the peel strength and reliability between the surface-treated copper foil and the carrier of the disclosed embodiment can be further improved. In addition to the normal peel strength, it can also be bleached in the downstream process. Tin can increase the peel strength after tin bleaching, and can pass the reliability test of solder bath. In addition, when the ratio of the integrated intensity of the diffraction peaks of each crystal plane is further controlled within the above-mentioned range, a lower high-frequency signal transmission loss can be further achieved.

The diffraction peak integral intensity of the (111) crystal plane, (200) crystal plane and (220) crystal plane of the above-mentioned treatment surface refers to the copper (111) crystal plane, copper (200) crystal plane and copper (220) crystal plane Diffraction peak integrated intensity, which is measured by low grazing angle X-ray diffraction (grazing angle can be 0.5° to 1.0°) on the treated surface of surface-treated copper foil to characterize the surface area of surface-treated copper foil ( For example, it is the proportion of each crystal plane in a region whose depth from the processing surface is 0 μm to 1 μm). Therefore, by low-grazing angle X-ray diffraction, the crystal plane characteristics of the surface region of the copper foil can be revealed instead of the crystal plane characteristics of the inner region of the copper foil. In addition, since the copper (111) crystal plane is less likely to damage the electrical signal when transmitting high-frequency electrical signals, increasing the proportion of the copper (111) crystal plane can reduce the loss of high-frequency electrical signals. On the other hand, since the proportion of each crystal plane of the main copper foil of the surface-treated copper foil may change due to the temperature and duration of the subsequent heat treatment process (for example: thermocompression process), this disclosure is based on The surface-treated copper foil was heated for 1 hour in an environment of 200° C. to simulate the crystal plane characteristics of the surface-treated copper foil after a thermal compression bonding process. According to an embodiment of the present disclosure, when the surface is treated in an environment of 200°C After heating the treated copper foil for 1 hour, the ratio of the integrated intensity of the diffraction peak of the (111) crystal plane on the treated surface to the sum of the integrated intensity of the diffraction peaks of the (111) crystal plane, (200) crystal plane and (220) crystal plane At least 60%, preferably 60% to 90%, or the integrated intensity of the diffraction peak of the (220) crystal plane of the treatment surface and the winding of the (111) crystal plane, (200) crystal plane and (220) crystal plane The ratio of the sum of the peak integrated intensities may be further less than 16.50%.

Referring again to the surface-treated copper foil 100 in FIG. 1, the aforementioned passivation layers, such as the first passivation layer 116a and the second passivation layer 116b, may be of the same or different compositions, such as metal layers or metal alloy layers. Wherein, the metal layer can be selected from but not limited to nickel, zinc, chromium, cobalt, molybdenum, iron, tin, and vanadium, such as: nickel layer, nickel-zinc alloy layer, zinc layer, zinc-tin alloy layer or chromium layer. In addition, the metal layer and the metal alloy layer may be a single layer or a multilayer structure, such as zinc-containing layers and nickel-containing layers stacked on top of each other. When it is a multi-layer structure, the stacking order of the layers can be adjusted according to needs, without certain limitation, for example, the zinc-containing layer is stacked on the nickel-containing layer, or the nickel-containing layer is stacked on the zinc-containing layer. According to an embodiment of the present disclosure, the first passivation layer 116 a is a double-layer structure of a zinc-containing layer and a nickel-containing layer stacked on each other, and the second passivation layer 116 b is a single-layer structure of a zinc-containing layer.

三硫醇及其組合，該卟啉基係由卟啉、卟啉大環、擴大卟啉、收縮卟啉、線性卟啉聚合物、卟啉夾層配位複合物、卟啉陣列、5,10,15,20-四(4-胺基苯基)-卟啉-鋅(II)及其組合所組成。根據本揭露一實施例，第一防鏽層118a及第二防鏽層118b皆採用鉻。 The aforementioned anti-rust layer, such as the first anti-rust layer 118a and the second anti-rust layer 118b, is applied to the coating layer of the metal, which can be used to prevent the metal from being corroded or oxidized and deteriorated. The antirust layer contains metal or an organic compound, but is not limited thereto. When the antirust layer includes metal, the metal may be chromium or a chromium alloy, and the chromium alloy may further include one selected from the group consisting of nickel, zinc, cobalt, molybdenum, vanadium, and combinations thereof. When the antirust layer comprises organic compounds, non-limiting examples of organic molecules that can be used to form the organic antirust layer include porphyrinyl, benzotriazole, tri

Trithiols and combinations thereof, the porphyrin-based system consisting of porphyrin, porphyrin macrocycle, expanded porphyrin, contracted porphyrin, linear porphyrin polymer, porphyrin sandwich coordination complex, porphyrin array, 5,10 ,15,20-Tetrakis(4-aminophenyl)-porphyrin-zinc(II) and its combination. According to an embodiment of the present disclosure, both the first anti-rust layer 118 a and the second anti-rust layer 118 b are made of chromium.

The coupling layer 120 can be made of silane, which can be used to improve the adhesion between the surface-treated copper foil 100 and other materials (such as carrier film). The coupling layer 120 can be selected from but not limited to 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxy base silane, shrinkage Hydroglyceryloxypropyltrimethoxysilane, Glycidoxypropyltriethoxysilane, 8-Glycidoxyoctyltrimethoxysilane, 3-Methacryloxypropyltriethoxysilane Silane, 8-methacryloxyoctyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidylpropyltrimethoxysilane , 1-[3-(trimethoxysilyl)propyl]urea, (3-chloropropyl)trimethoxysilane, dimethyldichlorosilane, 3-(trimethoxymethylsilyl)methacrylic acid Propyl ester, ethyltriacetoxysilane, isobutyltriethoxysilane, n-octyltriethoxysilane, tris(2-methoxyethoxy)vinylsilane), trimethyl chloride Silane, methyltrichlorosilane, silicon tetrachloride, tetraethoxysilane, phenyltrimethoxysilane, chlorotriethoxysilane, ethylene-trimethoxysilane, alkoxide having 1 to 20 carbon atoms silanes, vinylalkoxysilanes having 1 to 20 carbon atoms, (meth)acylsilanes and combinations thereof, but not limited thereto.

The aforementioned surface-treated copper foil 100 can be further processed to make a copper clad laminate (CCL). The copper foil substrate includes at least a carrier plate and a surface-treated copper foil. The surface-treated copper foil is disposed on at least one surface of the carrier, and the surface-treated copper foil includes a treated surface. Wherein, the treated surface of the surface-treated copper foil may face and directly contact the carrier.

The above-mentioned carrier board can be a bakelite board, a polymer board, or a glass fiber board, but is not limited thereto. The macromolecule composition of described macromolecular plate can for example be like: epoxy resin, phenolic resin, polyester resin, polyimide resin, acrylic, formaldehyde resin, bismaleimide triazine resin, cyanic acid Ester resin (cyanate ester resin), fluoropolymer, polyether resin, cellulose thermoplastic, polycarbonate, polyolefin, polypropylene, polysulfide, polyurethane, polyimide resin, liquid crystal polymer (LCP) , Polyoxyxylene (PPO). The above-mentioned glass fiber board may be a prepreg formed by soaking the glass fiber non-woven material in the aforementioned polymer (such as epoxy resin).

The aforementioned copper foil substrate can be further processed into a printed circuit board, and the steps include patterning the electrolytic copper foil to make wires, and blackening the wires. Wherein, the blackening process is a chemical bath treatment process and may include at least one pretreatment (such as applying microetching or cleaning to the surface of the wire, etc.). this In addition, electronic components can be further soldered on the printed circuit board, for example, surface mount technology (SMT) reflow soldering, or wave soldering (wave soldering) and other processes. For the wave soldering process, a tin furnace will be used during the soldering process, and the tin furnace will be heated to a temperature sufficient to melt the tin bar and form a molten tin liquid. When the tin liquid in the tin furnace is calm and waveless, it is called "advection". When the tin liquid is stirred, it is called a "turbulent wave". Before wave soldering, electronic components (such as passive components or active components) may be disposed on the printed circuit board, and pins of the electronic components may protrude or be exposed from one side of the printed circuit board. During wave soldering, the printed circuit board can slide over the surface of the calm or slightly wavy tin liquid, allowing the tin liquid to adhere to the pins of the electronic parts, the wires of the printed circuit board, and/or the pins and between the wires. After passing through the tin liquid, the printed circuit board can be cooled rapidly, so that the solder on the printed circuit board is solidified and the electronic parts are soldered to the printed circuit board. Although most electronic parts can meet the requirements of surface mount soldering reflow soldering (such as small size parts and reflow high temperature resistance), there are still a few electronic parts that cannot meet the requirements of the surface mount soldering process, so in some cases it is still A wave soldering process must be used.

In order to verify whether the wires on the printed circuit board can withstand the wave soldering process, a tin float test is usually performed on the copper foil substrate to simulate the conditions of the wave soldering. Among them, in the tin-floating test, the copper foil substrate will slide over the surface of the tin liquid under the set tin-floating conditions, and then measure the peel strength of the surface-treated copper foil in the copper foil substrate after tin-flooding. The strength needs to be higher than a certain value, such as 4 pounds per inch (lb/in), to ensure that the wires of the printed circuit board remain on the carrier without peeling off. According to the embodiment of the present disclosure, the pole height (Sxp) of the treated surface of the surface-treated copper foil is 0.4 to 3.0 μm , which can meet the requirement of a peel strength higher than 4ib/in after tin bleaching.

In the following, the surface-treated copper foil and the manufacturing method of the copper foil substrate are further exemplarily described. Each step in the preparation method is described as follows:

(1) Step A

Step A is performed to provide a main body copper foil, such as electrolytic copper foil. A foil machine can be used, The electrolytic copper foil is formed by means of electrodeposition (electrodeposition), or is called a raw foil (bare copper foil). Specifically, the foil making machine may at least include a roller as a cathode, a pair of insoluble metal anode plates, and an electrolyte inlet manifold. Wherein, the roller is a rotatable metal roller, and its surface is a mirror-polished surface. The metal anode plate can be separated and fixed on the lower half of the roller to surround the lower half of the roller. The feed pipe can be fixed directly under the roller and between two metal anode plates.

During the electrowinning process, the electrolyte feed pipe will continuously supply the electrolyte between the roller and the metal anode plate. By applying a current or voltage between the roller and the metal anode plate, copper can be electrolytically deposited on the roller to form the main copper foil. In addition, continuous main copper foil can be produced by continuously rotating the roller and peeling the electrolytic copper foil from one side of the roller. Wherein, the surface of the main copper foil facing the roller can be called the roller surface, and the surface of the main copper foil away from the roller can be called the deposition surface. In addition, during the electrolytic deposition process, the surface of the cathode roller will be slightly oxidized, resulting in an uneven surface, thereby reducing the flatness of the roller surface of the main copper foil. Therefore, a polishing roller (polish buff) may be further provided adjacent to the cathode roller, so that there is a contact surface between the cathode roller and the polishing roller. By rotating the cathode roller and the polishing roller in opposite directions, the oxide layer on the surface of the cathode roller can be removed by the polishing roller, thereby maintaining the surface flatness of the cathode roller.

Examples of manufacturing parameter ranges for main body copper foil are as follows:

<1.1 Electrolyte composition and electrolysis conditions of raw foil>

Copper sulfate (CuSO ₄ ‧5H ₂ O): 320g/L

Sulfuric acid: 95g/L

Chloride ion (from hydrochloric acid, RCI Labscan Ltd.): 30mg/L (ppm)

Liquid temperature: 50°C

Current density: 70A/ ^dm2

Raw foil thickness: 35 μ m

<1.2 Cathode roller>

Material: Titanium

Surface grain size number (grain size number): 6, 7, 7.5, 9

<1.3 Polishing roller>

Model (Nippon Tokushu Kento Co.,Ltd): #500, #1000, #1500, #2000

(2) Step B

In this step B, the surface cleaning process is performed on the above-mentioned main copper foil to ensure that the surface of the copper foil is free from pollutants (such as oil stains and oxides). The range of manufacturing parameters is as follows:

<2.1 Composition and cleaning conditions of cleaning solution>

Copper sulfate: 200g/L

Sulfuric acid: 100g/L

Liquid temperature: 25°C

Dipping time: 5 seconds

(3) Step C

This step C is to form a roughened layer on the roller surface of the above-mentioned main body copper foil. For example, the roughening particles can be formed on the roller surface of the main copper foil through electrolytic deposition. In addition, in order to prevent the roughened particles from falling, a covering layer may be further formed on the roughened particles. Examples of manufacturing parameter ranges for roughened layers (including roughened particles and covering layers) are as follows:

<3.1 Parameters for making coarse particles>

Copper sulfate (CuSO ₄ ‧5H ₂ O): 150g/L

Sulfuric acid: 100g/L

Titanium sulfate (Ti(SO ₄ ) ₂ ): 150~750mg/L(ppm), for example 450ppm

Sodium tungstate (Na ₂ WO ₄ ): 50~450mg/L(ppm), for example 250ppm

Liquid temperature: 25°C

Current density: 40A/ ^dm2

Time: 10 seconds

<3.2 Parameters for making the covering layer>

Copper sulfate (CuSO ₄ ‧5H ₂ O): 220g/L

Sulfuric acid: 100g/L

Liquid temperature: 40°C

Current density: 15A/ ^dm2

Time: 10 seconds

(4) Step D

This step D is to form a passivation layer on each side of the above-mentioned main body copper foil, for example, through an electrolytic deposition process, so as to form a passivation layer with a double-layer stacked structure (for example: a nickel-containing layer) on the side where the main body copper foil is provided with a roughened layer /Zinc-containing layer, but not limited thereto), and a passivation layer with a single-layer structure (for example: zinc-containing layer, but not limited thereto) is formed on the side of the main copper foil that is not provided with a roughening layer. Examples of manufacturing parameter ranges are as follows:

<4.1 Electrolyte composition and electrolysis conditions of nickel-containing layer>

Nickel sulfate (NiSO ₄ ‧7H ₂ O): 180g/L

Boric acid (H ₃ BO ₃ ): 30g/L

Sodium hypophosphite (NaH ₂ PO ₂ ): 3.6g/L

Liquid temperature: 20°C

Current density: 0.2A/ ^dm2

Time: 10 seconds

<4.2 Electrolyte composition and electrolysis conditions of the zinc-containing layer>

Zinc sulfate (ZnSO ₄ ‧7H ₂ O): 9g/L

Ammonium vanadate ((NH ₄ ) ₃ VO ₄ ): 0.3g/L

Liquid temperature: 20°C

Current density: 0.2A/ ^dm2

Time: 10 seconds

(5) Step E

In this step E, an anti-rust layer, such as a chromium-containing layer, is formed on the passivation layer on each side of the above-mentioned main body copper foil, and its manufacturing parameter range is exemplified as follows:

<5.1 Electrolyte composition and electrolysis conditions of chromium-containing layer>

Chromium trioxide (CrO ₃ ): 5g/L

Liquid temperature: 30°C

Current density: 5A/ ^dm2

Time: 10 seconds

(6) Step F

In this step F, a coupling layer is formed on the side of the above-mentioned main body copper foil with a roughening layer, a passivation layer, and an antirust layer. For example, after the above electrolytic deposition process is completed, the copper foil is washed with water, but the surface of the copper foil is not dried. Afterwards, the aqueous solution containing the silane coupling agent is sprayed onto the antirust layer on the side of the copper foil with the roughened layer, so that the silane coupling agent is adsorbed on the surface of the antirust layer. Afterwards, the copper foil can be placed in an oven to dry. Examples of manufacturing parameter ranges are as follows:

<6.1 Parameters of silane coupling agent>

Silane coupling agent: 3-glycidoxypropyl trimethoxysilane (3-glycidoxypropyl trimethoxysilane, KBM-403)

Concentration of silane coupling agent in aqueous solution: 0.25wt.%

Spraying time: 10 seconds

(7) Step G

In this step G, the surface-treated copper foil formed through the above steps (including the main copper foil and the surface treatment layers disposed on each side of the main copper foil) is pressed onto the carrier to form a copper foil substrate. According to an embodiment of the present disclosure, a copper foil substrate can be formed by hot-pressing the surface-treated copper foil 100 shown in FIG. 1 onto a carrier.

In order to enable those skilled in the art to realize the present disclosure, the specific embodiments of the present disclosure will be further described in detail below, so as to specifically illustrate the surface-treated copper foil and the copper foil substrate of the present disclosure. It should be noted that the following examples are only illustrative, and the present disclosure should not be construed as a limitation. That is, without going beyond the scope of the present disclosure, the materials used in each embodiment, the amount and ratio of materials used, and the processing flow can be appropriately changed.

Example 1~15

Examples 1-15 are surface-treated copper foils, and their manufacturing procedures include step A to step F in the above-mentioned manufacturing method. The different manufacturing parameters between Examples 1-15 and the above-mentioned manufacturing method are recorded in Table 1. Among them, for the surface-treated copper foils of Examples 1 to 15, the structure as shown in Figure 1 is adopted, and a nickel-containing layer, a zinc-containing layer, a chromium-containing layer, and a coupling layer are sequentially formed on the roughened layer. A zinc-containing layer and a chromium-containing layer are sequentially formed on the side of the main copper foil that is not provided with a roughened layer. The thickness of the surface-treated copper foil was 35 μm.

The test results of the surface-treated copper foils and corresponding copper foil substrates of the above-mentioned embodiments 1 to 15 are further described below, such as: <pole height (Sxp)>, <surface texture aspect ratio (Str)>, <crystal plane Ratio>, <Peel strength after tin bleaching>, <Reliability>, and <Signal transmission loss>. Each detection method is described as follows, and each detection result is recorded in Table 2.

<Pole height (Sxp)> and <Surface texture aspect ratio (Str)>

According to the standard ISO 25178-2:2012, the surface texture analysis of the laser microscope (LEXT OLS5000-SAF, Olympus Co.) is used to measure the pole height (Sxp) and the surface texture aspect ratio (Str ). The specific measurement conditions are as follows: light source wavelength: 405nm

Objective lens magnification: 100x objective lens (MPLAPON-100x LEXT, Olympus Co.)

Optical zoom: 1.0 times

Observation area: 129 μ m×129 μ m

Resolution: 1024 pixels × 1024 pixels

Condition: Enable the automatic tilt removal function of the laser microscope (Auto tilt removal)

Filter: no filter (unfiltered)

Air temperature: 24±3℃

Relative humidity: 63±3%

<Crystal surface ratio>

The oven temperature was set to 200°C. When the temperature of the oven reaches 200° C., put the surface-treated copper foil of any embodiment above into the oven to heat-treat the surface-treated copper foil. After heat treatment for 1 hour, the surface-treated copper foil was taken out from the oven and placed at room temperature. Followed by low-grazing incidence X-ray diffraction analysis (grazing incidence X-ray diffraction, GIXRD) on the treated surface of the surface-treated copper foil (that is, the side provided with the roughened layer, passivation layer, anti-rust layer, and coupling layer). ), to judge the integrated intensity of the crystal plane diffraction peak of the surface-treated copper foil adjacent to the treatment surface, such as the roller surface of the main copper foil and the copper (111) crystal plane, copper (200 ) crystal plane and copper (220) crystal plane integrated intensity of the diffraction peak. The specific measurement conditions are as follows: Measuring instrument: X-ray diffraction analyzer (D8 ADVANCE Eco, Bruker Co.)

Grazing Angle: 0.8°

<Peel strength after tin bleaching>

6 commercially available resin sheets (S7439G, Shengyi Technology Co.) each with a thickness of 0.09mm were stacked together to form a stacked layer of resin sheets, and the surface-treated copper foil (size: 125mm × 25mm ) is disposed facing the stacked layer of the resin sheet, and then the two are pressed together to form a copper foil substrate. The pressing conditions are as follows: a temperature of 200° C., a pressure of 400 psi, and a pressing time of 120 minutes.

After that, carry out the tin-floating test on the copper foil substrate, the tin-floating conditions are as follows: Temperature: 288°C

Time: 10 seconds

Times: 10 times

After tin bleaching, according to the standard JIS C 6471, use a universal testing machine to peel the surface-treated copper foil from the copper foil substrate at an angle of 90°. The stripping conditions are as follows: stripping instrument: Shimadzu AG-I universal tensile machine

Peeling angle: 90°

Evaluation standard: the peel strength after tin bleaching should be higher than 4 lb/in

〈Reliability〉

Stack 6 commercially available resin sheets (S7439G, Shengyi Technology Corp.) each with a thickness of 0.076mm to form a stack of resin sheets, and place the surface-treated copper foil of any of the above-mentioned embodiments on the treated side facing the resin sheet The stacked layers are arranged, and then the two are pressed together to form a copper foil substrate. The pressing conditions are as follows: a temperature of 200° C., a pressure of 400 psi, and a pressing time of 120 minutes.

Afterwards, the pressure cooker test (pressure cooker test, PCT) was carried out, and the conditions in the oven were Set the temperature at 121° C., pressure at 2 atm, and humidity at 100% RH, and place the copper foil substrate in the oven for 30 minutes, then take it out and cool it to room temperature. Then, a solder bath test was performed, and the copper foil substrate processed by the pressure cooker test was immersed in a molten solder bath at a temperature of 288° C. for 10 seconds.

The solder bath test can be performed repeatedly on the same sample, and after each solder bath test is completed, observe whether there are abnormal phenomena such as blisters, cracks, or delamination on the copper foil substrate. Any of the above abnormal phenomena means that the copper foil substrate is judged to have failed the solder bath test. The test results are recorded in Table 2. The evaluation criteria are as follows:

A: After more than 50 solder bath tests, the copper foil substrate still has no abnormal phenomenon

B: After 10~50 solder bath tests, the copper foil substrate will produce abnormal phenomena

C: After less than 10 solder bath tests, the copper foil substrate has abnormal phenomena

<Signal transmission loss>

Fabricate the surface-treated copper foil of any of the above embodiments into a stripline as shown in FIG. 3 , and measure its corresponding signal transmission loss. Among them, regarding the preparation method of the strip line 300, the surface-treated copper foil of any of the above-mentioned embodiments is first pasted on a commercially available resin sheet (S7439G, Shengyi Technology Co.) with a thickness of 152.4 μm, and then the surface-treated copper foil Foil is made into wire 302, and then use two other commercially available resin sheets (S7439G, Shengyi Technology Co.) with a thickness of 152.4 μm to cover the surfaces on both sides respectively, so that wire 302 is arranged on dielectric body 304 (commercially available resin sheet S7439G, Shengyi Technology Co. Shengyi Technology Co.). The stripline 300 may further include two ground electrodes 306 - 1 and 306 - 2 respectively disposed on opposite sides of the dielectric body 304 . The ground electrode 306-1 and the ground electrode 306-2 can be electrically connected to each other through the conductive via, so that the ground electrode 306-1 and the ground electrode 306-2 have the same potential. The specifications of each component in the stripline 300 are as follows: the length of the wire 302: 100mm

Width w of wire 302: 120 μm

Thickness t of wire 302: 35 μm

The dielectric properties of the dielectric body 304: Dk=3.74, Df=0.006 (according to IPC-TM 650 No.2.5.5.5, measured with 10GHz signal)

Characteristic impedance: 50Ω

Status: without cover film

When measuring the signal transmission loss, according to the standard Cisco S3 method, the signal analyzer is used to input the electrical signal from one end of the wire 302 under the condition that the ground electrodes 306-1 and 306-2 are both at ground potential, and measure The output value at the other end of the wire 302 is measured to determine the signal transmission loss generated by the stripline 300 . The specific measurement conditions are as follows: Signal analyzer: PNA N5227B (Keysight Technologies Co.)

Electrical signal frequency: 10MHz to 20GHz

Scan points: 2000 points

Calibration method: E-Cal (cal kit: N4692D)

With the electrical signal frequency being 10 GHz, the degree of signal transmission loss of the stripline of each embodiment was evaluated. Among them, when the absolute value of the signal transmission loss is smaller, it means that the loss degree of the signal is less during transmission. The evaluation criteria are as follows:

A (represents the best performance in signal transmission): the absolute value of signal transmission loss is less than 0.80dB/in

B (represents good signal transmission performance): the absolute value of signal transmission loss is between 0.80dB/in and 0.85dB/in

C (represents the worst signal transmission performance): the absolute value of signal transmission loss is greater than 0.85dB/in

According to Table 2, for Examples 1-9, when the pole height (Sxp) of the treated surface of the surface-treated copper foil is 0.4 to 3.0 μm, and the surface-treated copper foil is heat-treated, the copper (111) crystal plane of the treated surface When the ratio of the integrated intensity of the diffraction peak of the copper (111) crystal plane, the copper (200) crystal plane and the copper (220) crystal plane is at least 60% (for example, 60% to 90%) , and the corresponding peel strengths after tin bleaching are all higher than 4.0 lb/in, reliability are A grade or B grade, and signal transmission loss is A grade or B grade.

In addition, for Examples 1 to 9, 13, and 15, when the surface texture aspect ratio (Str) of the treated surface is 0.68 or less (for example, 0.10 to 0.65), the pole height (Sxp) is 3.0 μm or less, and the surface treated copper After the heat treatment of the foil, the sum of the integrated intensity of the diffraction peak of the copper (111) crystal plane on the treated surface and the integrated intensity of the diffraction peaks of the copper (111) crystal plane, copper (200) crystal plane and copper (220) crystal plane When the ratio is at least 60%, the corresponding signal transmission loss is A grade or B grade.

In addition, for Examples 1 to 12 and 14, when the pole height (Sxp) of the treated surface is above 0.4 μm, the corresponding peel strength after tin bleaching is higher than 4.0 lb/in.

For Examples 1-10, 12, and 14, when the pole height (Sxp) of the treated surface is more than 0.4 μm, and the aspect ratio (Str) of the surface texture is less than 0.68, the corresponding reliability is A grade or B grade.

For Examples 1-9, 13, and 15, when the pole height (Sxp) of the treated surface is 3.0 μm or less, and when the surface-treated copper foil is heat-treated, the diffraction peak integral of the copper (111) crystal plane on the treated surface When the ratio of the intensity to the sum of the integrated intensity of the diffraction peaks of the copper (111) crystal plane, copper (200) crystal plane and copper (220) crystal plane is at least 60%, and the diffraction peak of the (220) crystal plane of the treatment surface When the ratio of the integrated intensity to the sum of the integrated intensity of the diffraction peaks of the (111) crystal plane, (200) crystal plane, and (220) crystal plane is less than 16.50%, the corresponding signal transmission loss is grade A or grade B.

According to various embodiments of the present disclosure, by controlling the surface topography of the treated surface of the surface-treated copper foil, for example, controlling the pole height (Sxp) and/or surface texture aspect ratio (Str) of the treated surface within a certain range, and To control the proportion of each crystal plane of the main copper foil adjacent to the roller surface, for example, to control the proportion of (111) crystal plane and/or (220) crystal plane of the treatment surface, for the corresponding copper foil substrate and printed circuit board, except It can improve the adhesion between the surface-treated copper foil and the carrier (such as improving the peel strength after tin bleaching) and reliability, and can also reduce the signal transmission loss when high-frequency electrical signals are transmitted in the printed circuit board.

The above description is only a preferred embodiment of the present invention, and all equivalents done according to the patent scope of the present invention Changes and modifications should fall within the scope of the present invention.

100: surface treatment copper foil

100A: Treatment surface

110: main body copper foil

110A: first side

110B: the second side

112a: first surface treatment layer

112b: second surface treatment layer

114:Coarsening layer

116a: first passivation layer

116b: second passivation layer

118a: the first anti-rust layer

118b: Second anti-rust layer

120:Coupling layer

Claims (11)

A surface-treated copper foil, comprising: a main body copper foil; and a surface treatment layer disposed on at least one surface of the main body copper foil, wherein the surface treatment layer includes a sub-layer, the sub-layer is a roughened layer, and the The outermost side of the surface treatment layer is a treatment surface, wherein the pole height (Sxp) of the treatment surface is 0.4 to 3.0 μm, and when the surface treatment copper foil is heated in an environment of 200 ° C for 1 hour, the surface of the treatment surface The ratio of the integrated diffraction peak intensity of the (111) crystal plane to the sum of the integrated diffraction peak intensities of the (111) crystal plane, (200) crystal plane and (220) crystal plane is at least 60%. The surface-treated copper foil according to claim 1, wherein the surface texture aspect ratio (Str) of the treated surface is 0.68 or less. The surface-treated copper foil according to claim 1, wherein the surface texture aspect ratio (Str) of the treated surface is 0.10 to 0.65. The surface-treated copper foil as claimed in claim 1, wherein the integrated intensity of the diffraction peak of the (111) crystal plane and the diffraction peaks of the (111) crystal plane, (200) crystal plane and (220) crystal plane of the treated surface The ratio of the sum of integral intensities is 60% to 90%. The surface-treated copper foil as claimed in claim 1, wherein the integrated intensity of the diffraction peaks of the (111) crystal plane, (200) crystal plane and (220) crystal plane of the treated surface is obtained by low-grazing angle X-ray diffraction Obtained by the method, and the grazing angle of the low grazing angle X-ray diffraction method is 0.5° to 1.0°. The surface-treated copper foil as claimed in item 1, wherein when the surface-treated copper foil is at 200°C After heating in the environment for 1 hour, the integrated intensity of the diffraction peak of the (220) crystal plane and the sum of the integrated intensity of the diffraction peaks of the (111) crystal plane, (200) crystal plane and (220) crystal plane of the treated surface The ratio is less than 16.50%, and the absolute value of the signal transmission loss of the surface-treated copper foil is less than or equal to 0.85dB/in. The surface-treated copper foil as described in Claim 1, wherein when the surface-treated copper foil is subjected to tin-flooding conditions of 288°C and 10 seconds for 10 times, the peel strength of the surface-treated copper foil after tin-flooding is higher than 4.0lb/ in. The surface-treated copper foil as claimed in claim 1, wherein the main copper foil is electrolytic copper foil. The surface-treated copper foil according to claim 1, wherein the surface treatment layer further includes at least one other sublayer, and the at least one other sublayer is selected from the group consisting of a passivation layer, an antirust layer, and a coupling layer Group. A copper foil substrate, comprising: a carrier; and a surface-treated copper foil disposed on at least one surface of the carrier, wherein the surface-treated copper foil includes: a main body copper foil; and a surface-treated layer disposed on the Between the main body copper foil and the carrier, wherein the surface treatment layer includes a sub-layer, the sub-layer is a roughened layer, and the surface treatment layer includes a treatment surface facing the carrier, and the pole height of the treatment surface ( Sxp) is 0.4 to 3.0 μm, and the sum of the integrated intensity of the diffraction peak of the (111) crystal plane of the treatment surface and the integrated intensity of the diffraction peak of the (111) crystal plane, (200) crystal plane and (220) crystal plane ratio of at least 60%. The copper foil substrate as claimed in claim 10, wherein the treated surface of the surface treated layer is straight Contact the carrier board.

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