TWI830560B - Transparent copper foil substrate and manufacturing method thereof - Google Patents

Abstract

The invention provides a transparent copper foil substrate, which includes: a transparent substrate including a first surface and a second surface; a blackened layer formed on the first surface of the transparent substrate by electroless plating, and the blackened layer includes Nickel and zinc, with a zinc/nickel weight ratio of 0.1 to 0.21; and a copper layer, which is formed on the side of the blackened layer away from the transparent substrate, and is combined with the blackened layer to form a metal conductive layer. In addition, the present invention also provides a method for manufacturing a transparent copper foil substrate, which includes: step (A), providing a transparent substrate; step (B), forming a blackened layer on one side of the transparent substrate by electroless plating, and the blackened layer The system includes nickel and zinc, and the weight ratio of zinc/nickel is 0.1~0.21; and step (C), forming a copper layer on the side of the blackened layer away from the transparent substrate by electroplating, and compounding it with the blackened layer to form a metal conductive layer. Among them, the sheet resistance of the blackened layer is less than 30Ω/m ² , the reflectivity of the incident light measured from the second surface of the transparent substrate to the first surface of the transparent copper foil substrate is less than 25%, and the transparent substrate The peeling strength from the metal conductive layer is greater than 0.5kgf/cm. Through the aforementioned transparent copper foil substrate and its manufacturing method, it is possible to reduce the reflectivity while solving the problem of excessive pinholes in the blackened layer and the undercutting problem when forming wiring, and to obtain a substrate with low reflectivity and sufficient peel strength. Transparent copper foil substrate.

Description

Transparent copper foil substrate and manufacturing method thereof

The present invention relates to a transparent copper foil substrate and a manufacturing method thereof, in particular to a transparent copper foil substrate with low reflectivity and sufficient peel strength and a manufacturing method thereof.

In the field of display manufacturing, copper metal wiring is generally formed on a transparent substrate to be used as a transparent copper foil substrate. However, since copper has metallic luster, there is a problem that the visibility of the display is reduced due to light reflection.

In response to the above problems, it has been proposed to form a blackened layer between the copper metal wiring and the transparent substrate by vacuum sputtering to reduce the reflectivity of the transparent conductive substrate.

However, the conventional technology uses vacuum sputtering to form a blackened layer on a transparent substrate, which easily results in a large number of pinholes in the formed blackened layer, which in turn causes the transparent substrate and the transparent copper foil substrate to be subsequently formed. The problem of poor peel strength of the metal conductive layer. In addition, the composition of the blackened layer in the conventional technology is metal oxide, which leads to the problem of undercutting when forming circuit patterns of metal (for example, copper) wiring.

Therefore, there is room for further improvement for a transparent copper foil substrate with a blackened layer with few pinholes, sufficient peel strength, and low reflectivity.

The inventors of the present invention have discovered that by utilizing an electroless plating method and a specific composition of the blackened layer, the reflectivity of the transparent copper foil substrate can be reduced while simultaneously solving the problem of excessive pinholes in the blackened layer and the The problem of undercutting when forming wiring is eliminated, and a transparent copper foil substrate with low reflectivity and sufficient peel strength can be obtained.

In order to solve the above problems, a transparent copper foil substrate according to one aspect of the present invention includes: a transparent base material including a first surface and a second surface; and a blackened layer formed on the transparent base by electroless plating. The first surface of the material, the blackened layer includes nickel and zinc, and the weight ratio of zinc/nickel is 0.1~0.21, and the sheet resistance of the blackened layer is less than 30Ω/ ^m2 ; the copper layer is formed on the blackened layer The side of the layer away from the transparent substrate is composited with the blackened layer to form a metal conductive layer; wherein, the incident angle of the transparent copper foil substrate measured from the direction of the second surface of the transparent substrate penetrating into the first surface The light reflectance is less than 25%, and the peeling strength between the transparent substrate and the metal conductive layer is greater than 0.5kgf/cm.

In order to solve the above problems, a method for manufacturing a transparent copper foil substrate according to one aspect of the present invention includes: step (A), providing a transparent substrate including a first surface and a second surface; step (B), by Electroless plating forms a blackened layer on the first surface of the transparent substrate, and the blackened layer includes nickel and zinc, and the weight ratio of zinc/nickel is 0.1~0.21, and the sheet resistance of the blackened layer is less than 30Ω. /m ² ; and step (C), forming a copper layer on the side of the blackened layer away from the transparent substrate by electroplating, and the copper layer and the blackened layer are combined into a metal conductive layer; wherein, the transparent copper The reflectivity of the incident light measured from the second surface of the transparent substrate to the first surface of the foil substrate is less than 25%, and the peeling strength of the transparent substrate and the metal conductive layer is greater than 0.5kgf/cm .

In an embodiment, the transmittance of the transparent substrate is greater than 87%, and is selected from the group consisting of: polyimide (PI), polyethylene terephthalate (PET), cyclic olefin polymerization material (COP) and polycarbonate (PC).

In embodiments, the thickness of the copper layer is 0.2~20 μm.

In embodiments, the blackened layer further contains phosphorus.

In an embodiment, a polymer coating exists between the transparent substrate and the blackened layer, and the transmittance of the polymer coating is greater than 85%.

In the embodiment, after step (A) and before step (B), the polymer coating is attached to one side of the transparent substrate, and the polymer coating is located on the transparent substrate and the blackened layer between, and the light transmittance of the polymer coating is greater than 85%.

In embodiments, the material of the polymer coating is selected from the group consisting of polyimide (PI), polyurethane (PU), acrylic resin and epoxy resin.

One aspect of the present invention has been accomplished in view of the above-mentioned conventional problems, and an object thereof is to provide a transparent copper foil substrate. The aforementioned transparent copper foil substrate can reduce the reflectivity while solving the problem of excessive pinholes in the blackened layer and the problem of undercutting when forming wiring.

Furthermore, one aspect of the present invention was completed in view of the above-mentioned conventional problems, and its purpose is to provide a method for manufacturing a transparent copper foil substrate. Through the aforementioned manufacturing method, a transparent copper foil substrate with low reflectivity and sufficient peel strength can be obtained.

1:Transparent substrate

11: First surface

12: Second surface

2: Blackened layer

3: Copper layer

100:Transparent copper foil substrate

L: incident light

Figure 1 is a schematic cross-sectional view of a transparent copper foil substrate according to an embodiment of the present invention.

Figure 2 is a manufacturing flow chart of a transparent copper foil substrate according to an embodiment of the present invention.

Figure 3 is a schematic diagram of the reflectivity measurement of the transparent copper foil substrate of the present invention.

Figure 4 is a bottom appearance photo of the etched circuit in Example 3 of the present invention and Comparative Examples 1 and 8.

Figure 5 is a comparative chart of reflectance in the visible light region between Example 3 of the present invention and Comparative Examples 1 and 8.

The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can understand other advantages and effects of the present invention from the content disclosed in this specification. invention It can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

Unless the context indicates otherwise, the term "or" used in the specification and the appended claims includes the meaning of "and/or".

Unless otherwise stated in the text, the terms "A~B" used in the specification and the appended patent application scope include the meaning of "above A and below B". For example, the term "10 to 40% by weight" includes the meaning of "more than 10% by weight and less than 40% by weight".

<Transparent copper foil substrate>

First, please refer to FIG. 1 , which is a schematic cross-sectional view of a transparent copper foil substrate according to an embodiment of the present invention. As shown in FIG. 1 , a transparent copper foil substrate 100 according to an embodiment of the present invention includes: a transparent base material 1 ; a blackened layer 2 ; and a copper layer 3 . The transparent substrate 1 includes a first surface 11 and a second surface 12, and the blackened layer 2 and the copper layer 3 can be combined into a metal conductive layer. In addition, the reflectivity of the incident light measured in the direction of the second surface 12 of the transparent substrate 1 penetrating into the first surface 11 of the transparent copper foil substrate 100 is less than 25% (see Figure 3), and the transparent substrate 1 The peeling strength from the metal conductive layer is greater than 0.5kgf/cm, preferably greater than 0.55kgf/cm.

Next, as shown in Figure 1, the blackened layer 2 is formed on the first surface 11 of the transparent substrate 1, and the copper layer 3 is formed on the side of the blackened layer 2 away from the transparent substrate 1, that is, the transparent copper foil substrate The structure of 100 is a transparent substrate 1, a blackened layer 2 and a copper layer 3 in order. Next, the transparent copper foil substrate 100 of the present invention will be described in detail.

<<Transparent substrate>>

As long as the material has a transmittance greater than 87%, it is not particularly limited and can be used as the transparent base material of the present invention. In addition, in consideration of lightweight, etc., the transparent base material is preferably made of plastic material. Specifically, the material of the transparent substrate can be selected from the group consisting of: polyimide (PI), polyterephthalene Ethylene formate (PET), cycloolefin polymer (COP) and polycarbonate (PC). In a specific example, the transparent substrate is polyimide (PI). The material source of the above-mentioned transparent substrate can be commercially available products. For example, the transparent substrate can be a transparent polyimide film made by Damai Technology, model number OT2-025.

<<Blackened layer>>

The blackened layer includes nickel and zinc, and the weight ratio of zinc/nickel is 0.1~0.21, and the sheet resistance of the blackened layer is less than 30Ω/m ² . In addition, since phosphorus is a strong reducing agent, adding phosphorus facilitates electroless plating. Specifically, by including sodium hypophosphite as a reducing agent in the electroless plating solution, phosphorus will also co-precipitate as one of the alloy components during the reduction deposition process of nickel ions; among them, the content of phosphorus is relatively high. It is best to precipitate 1~14% by weight of the alloy, and can be controlled by the composition and operating conditions of the electroless plating solution. In one embodiment, the blackened layer includes a ternary alloy of nickel, zinc and phosphorus. In addition, the thickness of the blackened layer is preferably 50~250nm. If the thickness of the blackened layer is less than 50nm, the resistance of the blackened layer will be too high (greater than 30Ω/m ² ), which is not conducive to subsequent electroplating of the copper layer; if the blackened layer If the thickness of the blackened layer is greater than 250nm, the stress in the blackened layer will be large and there will be micro cracks inside, which will be detrimental to the flow of current.

In the present invention, the blackened layer is formed on one side of the transparent substrate by electroless plating. As for electroless plating, it can be the commonly known electroless plating method (based on the principle of redox reaction, using a strong reducing agent in a solution containing metal ions to reduce metal ions into metal and deposit them on the surface of various materials to form a dense coating. method) and is not particularly limited. In addition, as a specific example of electroless plating, the transparent substrate is first subjected to corona modification treatment, and the operating conditions are power 3kw, speed 3m/minute, and then immersed in a 2% potassium hydroxide (KOH) solution at 40°C. It takes 150 seconds to complete the hydrophilization treatment of the transparent substrate film surface. Then refer to the SLP metallization process (SLP process) of Japan Okuno Pharmaceutical Co., Ltd., use the SLP system A series of electroless nickel plating reagents (including SLP-200, SLP-300, SLP-400, SLP-500, SLP-660) are used to sequentially perform charge adjustment, pre-soaking, catalysis, acceleration, reduction nickel plating and other steps. Operating conditions Instructions are as follows.

1. Soak the transparent substrate in the SLP-200 solution at 65°C for 75 seconds to adjust the charge, take it out and wash it with water. 2. Continuously soak in SLP-300 solution at 25°C for 25 seconds and SLP-400 solution for 75 seconds to make the catalyst adhere to the surface of the transparent substrate, take it out and wash it with water. 3. Then soak it in SLP-500 solution at 35°C for 75 seconds to activate the catalyst, take it out and wash it with water. 4. Finally, soak in the SLP-660 solution with 0~0.014 mole/L zinc sulfate added, and control the pH value to 8.5~9.0, the temperature to 40~75°C, and react for 3~25 minutes. Take it out and wash it with water to complete the plating. Transparent substrate + blackened layer with different thicknesses of blackened layer.

<<Copper Layer>>

The copper layer of the present invention is not particularly limited as long as it is a copper layer that can form subsequent etching circuits. Furthermore, in one embodiment of the present invention, it is preferable to use electroplating to plate the copper layer on the blackened layer. As for the electroplating solution used for the copper layer, it can be a commercial product, for example, copper sulfate electroplating can be used. Liquid (purchased from Jiwei Industrial Co., Ltd.), etc. In addition, the thickness of the copper layer is preferably 0.2~20 μm.

Next, in one embodiment, in order to increase the bonding force between the transparent substrate and the blackened layer, a polymer coating (not shown) can be present between the transparent substrate and the blackened layer. In order to ensure the overall light transmittance of the transparent copper foil substrate, the light transmittance of the polymer coating needs to be greater than 85%. Specifically, the material of the polymer coating can be selected from the group consisting of: polyimide (PI), polyurethane (PU), acrylic resin and epoxy resin. Likewise, the material source of the above-mentioned polymer coating can be commercially available products.

<Manufacturing method of transparent copper foil substrate>

First, please refer to FIG. 2 , which is a manufacturing flow chart of a transparent copper foil substrate according to an embodiment of the present invention. As shown in Figure 2, a method for manufacturing a transparent copper foil substrate according to an embodiment of the present invention includes: providing a transparent substrate 1, which includes a first surface 11 and a second surface 12 (step A); Chemical layer 2 is formed in the transparent The first surface 11 of the base material 1 is exposed (step B); the copper layer 3 is formed on the side of the blackened layer 2 away from the transparent base material 1 by electroplating (step C).

Furthermore, in order to increase the bonding force between the transparent substrate and the blackened layer, in one embodiment, after step A and before step B, a polymer coating (not shown) is coated on the first surface of the transparent substrate. , and the polymer coating is located between the transparent substrate and the blackened layer.

Next, as for electroplating, a conventional electroplating method can be used, such as roll-to-roll (RTR, Roll to Roll) electroplating in an electroplating tank added with a plating solution. The energization conditions can be current 2.7A/voltage 3V, and the average plating speed is 0.5μm/min. By controlling the plating time, copper layers of different thicknesses can be plated. Moreover, the plating solution may be one containing 150 g/L H ₂ SO ₄ , 120 g/L CuSO ₄ and a chloride ion concentration of 50 ppm, and is not particularly limited.

Here, the details about electroless plating, transparent substrate, blackened layer, copper layer and polymer coating are as mentioned above and will not be repeated here.

[Example]

Hereinafter, although each Example and a comparative example are used to demonstrate this invention concretely, this invention is not limited to these Examples and Comparative examples.

[Measurement of reflectivity]

The reflectance of the transparent copper foil substrate was measured using the Spectrophotometer (Model: X-Rite/Ci60) of Zhongcan Technology Co., Ltd. First, calibrate the spectrophotometer and adjust the analysis mode to reflectance measurement, and then place the sample to be measured on a 10cm*10cm transparent copper foil substrate on a white bottom plate.

Next, refer to FIG. 3 , which is a schematic diagram of measuring the reflectivity of the transparent copper foil substrate of the present invention. As shown in Figure 3, make the transparent substrate 1 face up, press down the spectrophotometer, and let the incident light pass through the second surface 12. In the direction of the first surface 11, the reflectance of the incident light L with an incident angle of 10° and a wavelength range of 400nm~700nm can be measured.

[Measurement of Peel Strength]

Use Guanglian Instrument's universal tensile machine (model: ΩC-538M1) to measure the peel strength of the transparent substrate and the metal conductive layer in the transparent copper foil substrate. First, adjust the thickness of the copper layer of the transparent copper foil substrate to 18 μm. According to the specifications of IPC-TM-650 2.4.9, the circuit is produced and the peel strength test is performed at a 90° angle on a universal tensile machine.

[Measurement of sheet resistance]

The sheet resistance of the transparent substrate with a blackened layer was measured using the low impedance analyzer of North and South Trading Co., Ltd. (Model: LORESTA/MCP-T370) to evaluate whether a copper layer can be further electroplated on the blackened layer. First, place a 10cm*10cm sample of a transparent substrate with a blackened layer on the measuring table, and measure the sheet resistance by evenly contacting the four-point probe probe with the nickel surface of the blackened layer. In addition, the measurement results of reflectance, peel strength, and sheet resistance of each of the following Examples and Comparative Examples are summarized in Tables 1 to 2.

<Example 1>

(Transparent substrate pre-treatment)

Use the transparent polyimide film (model OT2-025) produced by Damai Technology as the transparent substrate, and perform continuous hydrophilic modification on a corona treatment machine (manufactured by Japan WEDGE Co., Ltd.). The operating conditions are: Power 3kw, speed 3m/min. Then cut the transparent substrate into a size of 15cm*15cm and soak it in a 2% potassium hydroxide (KOH) solution at 40°C for 150 seconds.

(Electroless plating black layer)

The SLP metallization process (SLP process) of Japan Okuno Pharmaceutical Co., Ltd. is used to successively carry out steps such as charge adjustment, pre-impregnation, catalysis, acceleration, reduction and blackening layer plating. The operating conditions are described below. 1. Soak the pre-treated transparent substrate in the SLP-200 solution at 65°C for 75 seconds for charge adjustment, take it out and wash it; 2. Continuously soak it in the SLP-300 solution at 25°C for 25 seconds and SLP-400 Soak in the solution for 75 seconds to make the catalyst adhere to the surface of the substrate, take it out and wash it with water; 3. Then soak it in the SLP-500 solution at 35°C for 75 seconds to activate the catalyst, take it out and wash it with water; 4. Finally soak it in the solution with zinc sulfate added of SLP-660 solution to form a transparent substrate coated with a blackened layer on both sides. Among them, the plating solution for the blackened layer contains about 17~20g/L sodium hypophosphite, about 4.6~5.0g/L nickel, and 0.006 mole/L zinc sulfate, and is soaked at pH=9.0 and a temperature of 45°C. In 10 minutes, the electroless black plating layer can be completed. Then, one side of the blackened layer is etched with a CuCl ₂ solution to obtain a transparent substrate plated with a blackened layer containing a nickel/zinc/phosphorus ternary alloy on one side (the first surface). In addition, the electroless plating conditions, the composition of the blackened layer, and the characteristics of the blackened layer coating of Example 1 are summarized in Table 1.

(Electroplated copper layer)

The aforementioned transparent substrate plated with a blackened layer containing nickel/zinc/phosphorus ternary alloy on one side is fixed on a stainless steel frame, first soaked in 3% H ₂ SO ₄ solution for 1 minute to clean the surface, and then placed in the electroplating tank Perform RTR plating. The electroplating solution contains 150g/L H ₂ SO ₄ , 120g/L CuSO ₄ and chloride ions with a concentration of 50ppm. The energization conditions are current 2.7A/voltage 3V, and the average plating speed is 0.5μm/min. By controlling the time, a 0.2~20μm thick copper layer can be deposited as required.

<Comparative Examples 1 to 6 and Examples 2 to 7>

Next, in the same manner as in Example 1, the same blackened layer plating solution was used, and the electroless plating conditions and the composition of the blackened layer were changed based on Table 1 below to form Comparative Examples 1 to 6 and Examples 2 to 7 transparent copper foil substrate.

First, it can be seen from Table 1 that because Examples 1 to 7 all use electroless plating to form the blackened layer, and the weight ratio of zinc/nickel in the blackened layer is between 0.1 and 0.21, the sheet resistance of the blackened layer is less than 30Ω/m ² , so it is possible to obtain a transparent copper foil substrate with a reflectivity of less than 25% of the incident light measured in the direction of the second surface of the transparent substrate penetrating into the first surface, and at the same time having sufficient peel strength (> 0.5kgf/cm).

Next, because the weight ratio of zinc/nickel in the blackened layer of Comparative Examples 1 to 3 is less than 0.1, the reflectivity of the transparent copper foil substrates produced in these comparative examples is greater than 25%, which does not meet the requirements. In addition, because the weight ratio of zinc/nickel in the blackened layer of Comparative Example 6 is greater than 0.21, the plating rate is too low and the sheet resistance is too high (more than 30Ω/m ² ), which is not conducive to subsequent electroplating of the copper layer.

Furthermore, because the thickness of the blackened layer in Comparative Examples 4 to 5 is less than 50 nm and greater than 250 nm respectively, the sheet resistance is too high (more than 30Ω/m ² ), which is not conducive to subsequent electroplating of the copper layer.

<Comparative Example 7>

The main difference between Comparative Example 7 and the above-mentioned Examples 1 to 7 and Comparative Examples 1 to 6 is that Comparative Example 7 uses vacuum sputtering to produce the blackened layer, and the blackened layer is metal oxide (copper oxide).

First, a 10cm*10cm transparent polyimide film is used as a transparent substrate and adhered to the glass substrate, and then placed into the chamber of a sputtering machine (vacuum magnetron plasma sputtering system, manufactured by Goldon Technology Co., Ltd.) body, close the hatch and start vacuuming.

Next, the first layer of metal oxide is plated, and copper oxide is selected as the target material to form the sputtering layer 1 (blackened layer). Coating conditions: Working pressure 4.8*10 ^-3 torr, argon flow 30sccm, power 150w, time 14min, a copper oxide layer (blackened layer) with a thickness of 622Å can be obtained, with a black appearance.

Then, without taking out the glass substrate and in a vacuum atmosphere, a copper target is used to sputter a second layer of metal on the sputtering layer 1 to form a sputtering layer 2 (copper layer). Coating conditions: power 75w, time 5min, a copper layer with a thickness of 911Å can be obtained.

<Comparative Example 8>

Comparative Example 8 is similar to Comparative Example 7 in that the blackened layer is produced by sputtering, but the sputtering conditions and the composition of the blackened layer are different from Comparative Example 7.

First, the first layer of metal oxide is sputtered, using a copper-nickel alloy target (the Cu/Ni ratio of the target is 85/15), and passing in oxygen for reactive coating to form sputtering layer 1 (blackened layer) ). Coating conditions: Working pressure 6.0*10 ^-3 torr, argon flow 21sccm, oxygen flow 9sccm, power 300w, time 7min, a copper-nickel oxide alloy layer (blackened layer) with a thickness of 564Å can be obtained, with a black appearance.

Then, without taking out the glass substrate and stopping the supply of oxygen, a copper target is used to sputter a second layer of metal on the sputtering layer 1 to form the sputtering layer 2 (copper layer). Coating conditions: power 150w, time 3min, a copper layer with a thickness of 989Å can be obtained. Next, the coating characteristics of Comparative Examples 7 to 8 are shown in Table 2.

As shown in Table 2, although the sheet resistance and reflectivity of Comparative Examples 7 to 8 meet the requirements, because Comparative Examples 7 to 8 use sputtering to form the blackened layer, there are a large number of pinholes and poor quality. Therefore, the peel strength of the subsequently formed transparent copper foil substrate is only about 0.3kgf/cm, which does not meet the requirements.

[Test example]

Next, circuits were implemented using the transparent copper foil substrates obtained in Example 3, Comparative Example 1, and Comparative Example 8, and the etched circuits were tested.

(line production)

The transparent copper foil substrates obtained in Example 3, Comparative Example 1 and Comparative Example 8 were successively subjected to semi-additive circuit processes such as pre-treatment, lamination, exposure, development, copper plating, film removal, and rapid etching. process), correspondingly prepare transparent flexible circuit boards 1~3 with line width/line spacing of 45/45μm.

(Etched line test)

Place the aforementioned transparent flexible circuit boards 1 to 3 on the observation table of a metallographic microscope (Nikon LV100 metallographic microscope, purchased from Guoxiang Trading), with the transparent PI side facing up, and inspect the bottom of the line of sight with a 20x objective lens to confirm the wiring. The degree of under-cut of the blackened layer. The results are shown in Figure 4.

Figure 4 is a photo of the bottom appearance of etched circuits in Example 3, Comparative Example 1 and Comparative Example 8 of the present invention. (A), (B) and (C) in Figure 4 correspond to Example 3 (electroless plating, nickel/zinc/phosphorus alloy), Comparative Example 1 (electroless plating, nickel/phosphorus alloy) and Comparative Example 8 (vacuum) respectively. sputtering, oxidized copper alloy).

As shown in Figure 4 (A), because the reflectivity of the transparent copper foil substrate of Example 3 is low and the blackened layer is formed using electroless plating, the bottom appearance photo of the etched circuit appears non-reflective and has no side etching. state; on the other hand, as shown in Figure 4(B), since the blackened layer of Comparative Example 1 does not contain zinc and the reflectivity of the transparent copper foil substrate is high, the appearance photo shows a reflective state although there is no undercutting. ; Also, as shown in Figure 4 (C), because the blackened layer of Comparative Example 8 is formed by vacuum sputtering, there are pinholes in the blackened layer, so it is Although the exterior photos are non-reflective, they show severe side erosion. In addition, although Comparative Example 8 uses a copper-nickel alloy target, the nickel component can reduce the etching rate of the plating layer and reduce the degree of undercutting of the metal oxide in the fabricated circuits. However, severe undercutting was still found at the bottom of the circuit in Comparative Example 8.

Next, please refer to FIG. 5 , which is a comparison chart of reflectance in the visible light region of Example 3 of the present invention and Comparative Examples 1 and 8. As shown in Figure 5, as the wavelength of the incident light increases from 400nm to 700nm, the reflectance of Comparative Example 1 tends to increase, while the reflectance of Comparative Example 8 first decreases and then increases. It can be seen that the reflection of the two comparative examples The reflectivity of Example 3 exhibits a generally stable trend, making the quality of subsequent electronic products (such as displays) unstable.

The present invention is not limited to the above-described embodiments, and various changes can be made within the scope indicated in the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the present invention. within the technical scope.

1:Transparent substrate

11: First surface

12: Second surface

2: Blackened layer

3: Copper layer

Claims (11)

A transparent copper foil substrate, which includes: a transparent base material, which includes a first surface and a second surface; a blackened layer, which is formed on the first surface of the transparent base material by electroless plating, and the blackened layer Including nickel and zinc, the weight ratio of zinc/nickel is 0.1~0.21, and the sheet resistance of the blackened layer is less than 30Ω/ ^m2 ; and a copper layer is formed on the blackened layer away from the transparent substrate One side is combined with the blackened layer to form a metal conductive layer; wherein the reflectivity of the incident light measured from the second surface of the transparent substrate to the first surface of the transparent copper foil substrate is less than 25%. , and the peeling strength between the transparent substrate and the metal conductive layer is greater than 0.5kgf/cm. The transparent copper foil substrate according to claim 1, wherein the transmittance of the transparent substrate is greater than 87%, and is selected from the group consisting of: polyimide (PI), polyethylene terephthalate Diester (PET), cycloolefin polymer (COP) and polycarbonate (PC). The transparent copper foil substrate as claimed in claim 1, wherein a polymer coating exists between the transparent substrate and the blackened layer, and the transmittance of the polymer coating is greater than 85%. The transparent copper foil substrate according to claim 3, wherein the material of the polymer coating is selected from the group consisting of: polyimide (PI), polyurethane (PU), acrylic resin and epoxy resin. The transparent copper foil substrate according to any one of claims 1 to 4, wherein the blackened layer further includes phosphorus. A method for manufacturing a transparent copper foil substrate, which includes: Step (A), providing a transparent substrate including a first surface and a second surface; Step (B), forming a blackened layer on the transparent substrate through electroless plating The first surface of the substrate, and the blackened layer includes nickel and zinc, and the weight ratio of zinc/nickel is 0.1~0.21, and the sheet resistance of the blackened layer is less than 30Ω/ ^m2 ; and step (C), A copper layer is formed on the side of the blackened layer away from the transparent substrate by electroplating, and the copper layer and the blackened layer are combined into a metal conductive layer; wherein, the transparent copper foil substrate is composed of The reflectivity of the incident light measured in the direction of the second surface penetrating into the first surface is less than 25%, and the peeling strength of the transparent substrate and the metal conductive layer is greater than 0.5kgf/cm. The manufacturing method of a transparent copper foil substrate as described in claim 6, wherein the transmittance of the transparent substrate is greater than 87%, and is selected from the group consisting of: polyimide (PI), polyparaphenylene Ethylene dicarboxylate (PET), cycloolefin polymer (COP) and polycarbonate (PC). The manufacturing method of a transparent copper foil substrate as claimed in claim 6, wherein the thickness of the copper layer is 0.2~20 μm. The manufacturing method of a transparent copper foil substrate as claimed in claim 6, wherein after step (A) and before step (B), a polymer coating is coated on the first surface of the transparent substrate, and The polymer coating is located between the transparent substrate and the blackened layer. The manufacturing method of a transparent copper foil substrate as claimed in claim 9, wherein the transmittance of the polymer coating is greater than 85%, and the material of the polymer coating is selected from the group consisting of: polyamide Amine (PI), polyurethane (PU), acrylic resin and epoxy resin. The method for manufacturing a transparent copper foil substrate according to any one of claims 6 to 10, wherein the blackened layer further includes phosphorus.