Production process of strippable copper foil

Abstract

The invention relates to the technical field of copper foil production, in particular to a production process of strippable copper foil. The preparation method comprises the following steps: by taking an HTE copper foil as a base material, completing pretreatment of the copper foil by adopting a vapor deposition process; after the pretreated copper foil is washed, high voltage is applied to the cathode and the anode in an inert gas environment, so that a metal isolation layer is formed on the surface of the pretreated copper foil, and a carrier copper foil is obtained; the obtained carrier copper foil is put into an electrolyte containing cerous nitrate, gluconic acid and tetradecanoic acid, a compact organic cerium protective film layer is generated on the surface of the carrier copper foil after electro-deposition, and the organic cerium protective film layer and the metal isolation layer are mutually cooperated and matched, so that the corrosion resistance and the oxidation resistance of the strippable copper foil are further improved; the strippable copper foil produced by the invention not only has excellent corrosion resistance, oxidation resistance and mechanical properties, but also has excellent stripping performance, so that the service life of the strippable copper foil is prolonged, and the quality of the strippable copper foil is effectively ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of copper foil production, and in particular to a production process of peelable copper foil. Background Art

[0002] Copper foil has the characteristics of low surface oxygen, can adhere to various different substrates, such as metals, insulating materials, etc., and has a wide temperature range of use. It is mainly used for electromagnetic shielding and antistatic. Placing the conductive copper foil on the substrate surface and combining with the metal substrate has excellent electrical conductivity and provides the effect of electromagnetic shielding. With the continuous development of electronic devices, the demand for copper foil is increasing day by day, especially in the fields of lithium-ion batteries, printed circuit boards, etc.

[0003] In the patent document with the application number "CN202310141540.0", a high-performance ultra-thin electronic copper foil and its preparation method and application are disclosed. Although the technical solution recorded in this patent document has the technical advantages of simple preparation method, continuous and stable production, easy adjustment of the system, and high yield of copper foil production. However, the electronic copper foil product prepared by it has the technical problem of difficult peeling between the copper foil and the substrate during the subsequent processing, which is likely to cause damage to the copper foil or affect the product quality. Moreover, its antioxidant and corrosion resistance properties are also relatively poor, which to a certain extent affects its service life. Therefore, the present invention provides a production process of peelable copper foil to solve the above-mentioned technical problems! Summary of the Invention

[0004] The purpose of the present invention is to provide a production process of peelable copper foil. The peelable copper foil produced not only has excellent anti-corrosion performance, antioxidant performance and mechanical properties, but also has excellent peeling performance, which not only prolongs its service life, but also effectively guarantees its quality and quality.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A production process of peelable copper foil includes the following steps:

[0007] Step 1: Charge an inert gas into the ion-type chemical vapor deposition coating machine after vacuum treatment, and keep the vacuum degree of the ion-type chemical vapor deposition coating machine at 10 -2 ~10 -3 torr; then use HTE copper foil as the substrate, and use 99.99% copper sheet and 99.99% molybdenum sheet as the composite alloy cathode target, and form a pretreated copper foil through chemical vapor deposition; wherein, the mass ratio of the copper sheet to the molybdenum sheet is 8-9:1;

[0008] Step 2: After the deposition is completed, the pretreated copper foil is washed with water and pickled, and then used as a carrier. Then, nickel sheets with a purity of 99.99% and molybdenum sheets with a purity of 99.99% are used as cathode targets. Under an inert gas environment with a vacuum degree of 10 -2 ~10 -3 torr, a high voltage is applied to the cathode and anode, so as to form a metal isolation layer on the surface of the pretreated copper foil, and the carrier copper foil is obtained;

[0009] Step 3: The electrolyte is put into a passivation tank. A metal titanium plate is used as the anode, and the carrier copper foil is used as the cathode. Electroplating treatment is carried out for 25 - 35 s under the conditions of a current density of 30 - 50 A / m 2 ², a temperature of 40 - 60 °C; after the electroplating is completed, the carrier copper foil is taken out, and after being washed with water and dried in sequence, a modified copper foil is obtained;

[0010] Step 4: An ultrathin copper foil layer with a thickness of 2 - 4 μm is deposited on the surface of the modified copper foil by an electroplating process. Then, an adhesive is evenly sprayed on the surface of the ultrathin copper foil layer, and heat preservation treatment is carried out at a temperature of 35 - 50 °C for 40 - 70 min; then, a peelable adhesive is evenly coated on the surface of the adhesive layer, and after curing treatment, heat treatment is carried out;

[0011] Step 5: After the heat treatment is completed, the obtained copper foil is cut into specific sizes as required, and the cutting size accuracy is controlled within ±1 mm. After cutting, packaging treatment is carried out, and the finished peelable copper foil is obtained.

[0012] Furthermore, the inert gas in the step 1 is selected from any one of argon, neon, and xenon.

[0013] Furthermore, the preparation method of the electrolyte in the step 3 is: mixing an aqueous solution of cerium nitrate and gluconic acid with an ethanol solution of tetradecanoic acid and stirring evenly to obtain the electrolyte; wherein, the concentration of cerium nitrate in the electrolyte is 0.005 - 0.02 mol / L, the concentration of tetradecanoic acid is 0.1 - 0.4 mol / L, the concentration of gluconic acid is 0.05 - 0.2 mol / L, and the volume ratio of ethanol to water is 5 - 15:100.

[0014] Furthermore, the specific steps of the drying treatment in the step 3 are: placing the carrier copper foil in a vacuum drying oven, and then drying it at a temperature of 70 - 100 °C for 8 - 12 h.

[0015] Furthermore, the adhesive in the step 4 is selected from any one of silica gel adhesives, polyurethane adhesives, and phenolic resins.

[0016] Furthermore, the dosage of the adhesive in the step 4 is 45 - 55% of the mass of the HTE copper foil.

[0017] Further, the peelable adhesive in step 4 is selected from any one of pressure-sensitive adhesives, modified polyimides, and thermoreversible adhesives.

[0018] Further, the dosage of the peelable adhesive is 20-35% of the mass of the HTE copper foil, and the coating rate is 2-4 m / min.

[0019] Further, the curing treatment process in step 4 is as follows: Place the modified copper foil coated with the peelable adhesive under an ultraviolet lamp and cure it for 20-25 s under a light intensity of 90-100 mW / cm 2 of the light intensity.

[0020] Further, in the heat treatment process of step 4, the heat treatment temperature is set to 160-200 °C, and the heat treatment time is set to 1-3 h.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] In the present invention, the HTE copper foil is used as the substrate, and the pretreatment of the copper foil is completed by the chemical vapor deposition process. After washing the pretreated copper foil, a high voltage is applied to the cathode and anode in an inert gas environment, so as to form a metal isolation layer on the surface of the pretreated copper foil, and the carrier copper foil is obtained. The obtained carrier copper foil is put into an electrolyte containing cerium nitrate, gluconic acid, and tetradecanoic acid. After electrodeposition, a dense organic cerium protective film layer is formed on the surface of the carrier copper foil. The organic cerium protective film layer and the metal isolation layer cooperate with each other and further improve the anti-corrosion performance and anti-oxidation performance of the peelable copper foil. Moreover, the electrodeposition process is very fast, and the deposition effect is relatively uniform and dense. Furthermore, in the present invention, an adhesive is first sprayed on the surface of the modified copper foil, and then a peelable adhesive is coated, which greatly reduces the peeling force between the copper foil and the substrate, facilitates the peeling operation in the subsequent processing, and reduces the risk of damage to the peelable copper foil.

[0023] In summary, the peelable copper foil produced by the present invention not only has excellent anti-corrosion performance, anti-oxidation performance, and mechanical properties, but also has excellent peeling performance, which not only extends its service life, but also effectively guarantees its quality and quality. Specific Embodiments

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] Example 1

[0026] A production process of a peelable copper foil, comprising the following steps:

[0027] Step 1: Argon is filled into the ion-type chemical vapor deposition coating machine after vacuum treatment, and the vacuum degree of the ion-type chemical vapor deposition coating machine is maintained at 0.01 torr; then, using the HTE copper foil as the substrate and 99.99% copper sheet and 99.99% molybdenum sheet as the composite alloy cathode target, a pretreated copper foil is formed by chemical vapor deposition; wherein, the mass ratio of the copper sheet to the molybdenum sheet is 8:1;

[0028] Step 2: After the deposition is completed, the pretreated copper foil is washed with water and pickled and then used as a carrier. Then, using 99.99% nickel sheet and 99.99% molybdenum sheet as the cathode target, in an inert gas environment with a vacuum degree of 0.01 torr, a high voltage is applied to the cathode and the anode, so as to form a metal isolation layer on the surface of the pretreated copper foil to obtain a carrier copper foil;

[0029] Step 3: The electrolyte is put into the passivation tank, using a titanium metal plate as the anode and the carrier copper foil as the cathode, and electro-deposition treatment is carried out for 25 s under the conditions of a current density of 30 A / m 2 ² and a temperature of 40 °C; after the electro-deposition is completed, the carrier copper foil is taken out and sequentially washed with water and dried to obtain a modified copper foil;

[0030] The preparation method of the electrolyte is: mixing an aqueous solution of cerium nitrate and gluconic acid with an ethanol solution of tetradecanoic acid and stirring evenly to obtain the electrolyte; wherein, the concentration of cerium nitrate in the electrolyte is 0.005 mol / L, the concentration of tetradecanoic acid is 0.1 mol / L, the concentration of gluconic acid is 0.05 mol / L, and the volume ratio of ethanol to water is 1:20;

[0031] The specific steps of the drying treatment are: placing the carrier copper foil in a vacuum drying oven and then drying it at a temperature of 70 °C for 12 h;

[0032] Step 4: A 3-μm-thick ultra-thin copper foil layer is deposited on the surface of the modified copper foil by an electro-deposition process, and then an adhesive is evenly sprayed on the surface of the ultra-thin copper foil layer and kept warm at a temperature of 35 °C for 70 min; then, a peelable adhesive is evenly coated on the surface of the adhesive layer, and after curing treatment, heat treatment is carried out;

[0033] The adhesive is selected as a silica gel adhesive, and the dosage of the adhesive is 45% of the mass of the HTE copper foil;

[0034] The peelable adhesive is selected as a pressure-sensitive adhesive, and the dosage of the peelable adhesive is 20% of the mass of the HTE copper foil and the coating rate is 2 m / min;

[0035] The curing treatment process is: placing the modified copper foil with the peelable adhesive coated on the surface under an ultraviolet lamp and at 90 mW / cm2 Curing treatment is carried out for 25 s under the light intensity of

[0036] The heat treatment temperature is set at 160 °C, and the heat treatment time is set at 3 h.

[0037] Step Five: After the heat treatment is completed, the obtained copper foil is cut into specific sizes as required, and the cutting size accuracy is controlled within ±1 mm. After cutting, packaging treatment is carried out to obtain the finished product of the peelable copper foil.

[0038] Example 2

[0039] A production process of a peelable copper foil includes the following steps:

[0040] Step One: Neon gas is filled into the ionized physical vapor deposition coating machine after vacuum treatment, and the vacuum degree of the ionized physical vapor deposition coating machine is maintained at 0.01 torr. Then, using the HTE copper foil as the substrate and 99.99% copper sheet and 99.99% molybdenum sheet as the composite alloy cathode targets, a pretreated copper foil is formed by physical vapor deposition. Among them, the mass ratio of the copper sheet to the molybdenum sheet is 9:1.

[0041] Step Two: After the deposition is completed, the pretreated copper foil is washed with water and pickled, and then used as a carrier. Then, using 99.99% nickel sheet and 99.99% molybdenum sheet as the cathode targets, a high voltage is applied to the cathode and anode in an inert gas environment with a vacuum degree of 0.01 torr, so as to form a metal isolation layer on the surface of the pretreated copper foil to obtain a carrier copper foil.

[0042] Step Three: The electrolyte is put into the passivation tank, using a metal titanium plate as the anode and the carrier copper foil as the cathode, and electro-deposition treatment is carried out for 30 s under the conditions of a current density of 40 A / m 2 and a temperature of 50 °C. After the electro-deposition is completed, the carrier copper foil is taken out and sequentially washed with water and dried to obtain a modified copper foil.

[0043] The preparation method of the electrolyte is: mixing an aqueous solution of cerium nitrate and gluconic acid with an ethanol solution of tetradecanoic acid and stirring evenly to obtain the electrolyte. Among them, the concentration of cerium nitrate in the electrolyte is 0.01 mol / L, the concentration of tetradecanoic acid is 0.2 mol / L, the concentration of gluconic acid is 0.1 mol / L, and the volume ratio of ethanol to water is 1:10.

[0044] The specific steps of the drying treatment are: placing the carrier copper foil in a vacuum drying oven, and then drying it at a temperature of 80 °C for 10 h.

[0045] Step 4: Deposit a 3-μm-thick ultra-thin copper foil layer on the surface of the modified copper foil by electroplating process. Then, evenly spray the adhesive on the surface of the ultra-thin copper foil layer and keep it at 45°C for heat preservation treatment for 60 min. Then, evenly coat the peelable adhesive on the surface of the adhesive layer, and after curing treatment, perform heat treatment;

[0046] The adhesive is selected as silicone adhesive, and the dosage of the adhesive is 50% of the mass of the HTE copper foil;

[0047] The peelable adhesive is selected as pressure-sensitive adhesive, the dosage of the peelable adhesive is 30% of the mass of the HTE copper foil, and the coating rate is 3 m / min;

[0048] The curing treatment process is as follows: Place the modified copper foil with the peelable adhesive coated on its surface under an ultraviolet lamp and cure it for 20 s under the light intensity of 100 mW / cm 2 ;

[0049] The heat treatment temperature is set at 180°C and the heat treatment time is set at 2 h;

[0050] Step 5: After the heat treatment is completed, cut the obtained copper foil into specific sizes as required, control the cutting size accuracy within ±1 mm, and perform packaging treatment after cutting to obtain the finished peelable copper foil.

[0051] Example 3

[0052] A production process of peelable copper foil, including the following steps:

[0053] Step 1: Fill argon into the ion-type physical vapor deposition coating machine after evacuation, and keep the vacuum degree of the ion-type physical vapor deposition coating machine at 0.001 torr. Then, use the HTE copper foil as the substrate and the 99.99% copper sheet and 99.99% molybdenum sheet as the composite alloy cathode target, and form a pre-treated copper foil by physical vapor deposition. Among them, the mass ratio of the copper sheet to the molybdenum sheet is 9:1;

[0054] After the deposition is completed, wash and pickle the pre-treated copper foil and use it as a carrier. Then, use the 99.99% nickel sheet and 99.99% molybdenum sheet as the cathode target, and apply a high voltage to the cathode and anode in an inert gas environment with a vacuum degree of 0.001 torr, so as to form a metal isolation layer on the surface of the pre-treated copper foil to obtain a carrier copper foil;

[0055] Step 3: Put the electrolyte into the passivation tank, use the metal titanium plate as the anode and the carrier copper foil as the cathode, and perform electroplating treatment for 35 s under the conditions of a current density of 50 A / m 2 and a temperature of 60°C. After the electroplating is completed, take out the carrier copper foil, and obtain the modified copper foil after washing and drying in sequence;

[0056] The preparation method of the electrolyte is as follows: Mix an aqueous solution of cerium nitrate and gluconic acid with an ethanol solution of tetradecanoic acid and stir evenly to obtain the electrolyte; wherein, the concentration of cerium nitrate in the electrolyte is 0.02 mol / L, the concentration of tetradecanoic acid is 0.4 mol / L, the concentration of gluconic acid is 0.2 mol / L, and the volume ratio of ethanol to water is 15:100;

[0057] The specific steps of the drying treatment are as follows: Place the carrier copper foil in a vacuum drying oven and then dry it at a temperature of 100 °C for 8 h;

[0058] Step Four: Deposit a 3-μm-thick ultra-thin copper foil layer on the surface of the modified copper foil by electroplating, then evenly spray the adhesive on the surface of the ultra-thin copper foil layer, and keep it warm at a temperature of 50 °C for 40 min; then evenly coat the peelable adhesive on the surface of the adhesive layer, and after curing treatment, perform heat treatment;

[0059] The adhesive selected is a silica gel adhesive, and the dosage of the adhesive is 55% of the mass of the HTE copper foil.

[0060] The peelable adhesive selected is a pressure-sensitive adhesive, the dosage of the peelable adhesive is 35% of the mass of the HTE copper foil, and the coating rate is 4 m / min.

[0061] The curing treatment process is as follows: Place the modified copper foil with the peelable adhesive coated on its surface under an ultraviolet lamp and cure it for 20 s under a light intensity of 100 mW / cm 2 2.

[0062] The heat treatment temperature is set at 200 °C, and the heat treatment time is set at 1 h.

[0063] Step Five: After the heat treatment is completed, cut the obtained copper foil into specific sizes as required, control the cutting size accuracy within ±1 mm, and perform packaging treatment after cutting to obtain the finished product of the peelable copper foil.

[0064] Comparative Example: The main difference between this comparative example and Example 1 is that this comparative example does not include Step Three, that is, in this comparative example, the carrier copper foil is directly used instead of the modified copper foil for subsequent operations.

[0065] Performance Test: Test the relevant performances of the peelable copper foil samples produced in Examples 1 to 3 and the comparative example respectively, and record the obtained test data in the following table:

[0066]

[0067] Note: 1. Test method for high-temperature oxidation resistance performance in the table: Place the peelable copper foil samples provided in Examples 1-3 and the comparative example in a high-temperature oven respectively, and bake continuously at a temperature of 270°C for 60 minutes, and then observe the oxidation and discoloration of each group of peelable copper foil samples.

[0068] 2. Test method for high-humidity oxidation resistance performance: Place the peelable copper foil samples provided in Examples 1-3 and the comparative example at a temperature of 85°C and a humidity of 90% for 24 hours respectively, and then observe the oxidation of each group of peelable copper foil samples.

[0069] 3. Test method for hydrochloric acid deterioration rate resistance: Place the peelable copper foil samples provided in Examples 1-3 and the comparative example in an 18 wt% hydrochloric acid solution respectively, and soak at room temperature for 30 minutes, and then take out each group of peelable copper foil samples and test their anti-peeling strength values. The percentage of attenuation of the anti-peeling strength after soaking in the hydrochloric acid solution is the hydrochloric acid deterioration rate resistance.

[0070] By comparing and analyzing the relevant data in the table, it can be seen that the peelable copper foil produced by the present invention not only has excellent anti-corrosion performance, oxidation resistance performance and mechanical properties, but also has excellent peeling performance, which not only extends its service life, but also effectively guarantees its quality and quality. This shows that the production process of a peelable copper foil provided by the present invention has a broader market prospect and is more suitable for popularization.

[0071] In the description of this specification, the description of reference terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0072] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A production process for a peelable copper foil, characterized in that: The following steps are involved: Step 1: Fill the vacuum-treated ion vapor deposition coating machine with inert gas to maintain the vacuum degree of the ion vapor deposition coating machine at 10 -2 ~10 -3 torr; then, HTE copper foil is used as a substrate, 99.99% copper sheet and 99.99% molybdenum sheet are used as composite alloy cathode targets, and pre-treated copper foil is formed by vapor deposition; wherein the mass ratio of the copper sheet to the molybdenum sheet is 8 to 9:1; Step 2: After the deposition is completed, the pre-treated copper foil is washed with water and pickled and used as a carrier. Then, 99.99% nickel sheet and 99.99% molybdenum sheet are used as cathode targets. -2 ~10 -3 In an inert gas environment of 0.1 torr, a high voltage is applied to the cathode and the anode, thereby forming a metal isolation layer on the surface of the pretreated copper foil to obtain a carrier copper foil; Step 3: Pour the electrolyte into the passivation tank, use the titanium plate as the anode and the copper foil as the cathode, and place the electrolyte in the passivation tank at a current density of 30-50A / m 2 , electroplating for 25 to 35 seconds at a temperature of 40 to 60° C.; after the electroplating is completed, taking out the carrier copper foil, and washing and drying the carrier copper foil in sequence to obtain a modified copper foil; Step 4: depositing an ultra-thin copper foil layer with a thickness of 2 to 4 μm on the surface of the modified copper foil by an electrodeposition process, and then spraying an adhesive evenly on the surface of the ultra-thin copper foil layer, and heat-treating it at a temperature of 35 to 50° C. for 40 to 70 minutes; then evenly coating the surface of the adhesive layer with a peelable adhesive, and then heat-treating it after curing; Step 5: After the heat treatment is completed, the obtained copper foil is cut into specific sizes as required, and the cutting size accuracy is controlled within ±1mm. After cutting, it is packaged to obtain a peelable copper foil finished product.

2. The production process of a peelable copper foil according to claim 1, characterized in that: The inert gas in step one is selected from any one of argon, neon and xenon.

3. The production process of a peelable copper foil according to claim 1, characterized in that: The preparation method of the electrolyte in step three is: mixing and stirring the aqueous solution of cerium nitrate and gluconic acid with the ethanol solution of tetradecanoic acid to obtain the electrolyte; wherein the concentration of cerium nitrate in the electrolyte is 0.005-0.02 mol / L, the concentration of tetradecanoic acid is 0.1-0.4 mol / L, the concentration of gluconic acid is 0.05-0.2 mol / L, and the volume ratio of ethanol to water is 5-15:

100.

4. The production process of a peelable copper foil according to claim 1, characterized in that: The specific steps of the drying treatment in step three are: placing the carrier copper foil in a vacuum drying oven, and then drying it at a temperature of 70 to 100° C. for 8 to 12 hours.

5. The production process of a peelable copper foil according to claim 1, characterized in that: The adhesive in step 4 is selected from any one of silicone adhesive, polyurethane adhesive or phenolic resin.

6. The production process of a peelable copper foil according to claim 1, characterized in that: The amount of adhesive used in step 4 is 45-55% of the mass of the HTE copper foil.

7. The production process of a peelable copper foil according to claim 1, characterized in that: The removable adhesive in step 4 is selected from any one of pressure-sensitive adhesive, modified polyimide and thermoreversible adhesive.

8. The production process of a peelable copper foil according to claim 1, characterized in that: The amount of the strippable adhesive is 20-35% of the mass of the HTE copper foil, and the coating rate is 2-4 m / min.

9. The production process of a peelable copper foil according to claim 1, characterized in that: The curing process in step 4 is as follows: placing the modified copper foil coated with the peelable adhesive under a UV lamp at 90-100 mW / cm 2 Curing treatment is carried out under light intensity of 20 to 25 seconds.

10. The production process of a peelable copper foil according to claim 1, characterized in that: In the heat treatment process in step 4, the heat treatment temperature is set to 160-200° C., and the heat treatment time is set to 1-3 hours.

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