A high heat-resistant electrolytic copper foil and its preparation method

Abstract

This invention belongs to the field of copper foil technology and discloses a high-heat-resistant electrolytic copper foil and its preparation method. The invention first electrolyzes the copper foil in an electrolyte containing additives to obtain electrolytic copper foil; then, the electrolytic copper foil is sequentially acid-washed and roughened to obtain roughened electrolytic copper foil; next, the surface of the roughened electrolytic copper foil is sequentially subjected to blackening treatment, heat-resistant treatment, passivation treatment, and coupling agent treatment to obtain a high-heat-resistant electrolytic copper foil. By optimizing the additives and electrolysis conditions in the electrolytic process, this invention produces electrolytic copper foil with good heat resistance and elongation, exhibiting good stability during processing. Furthermore, this invention combines blackening treatment, heat-resistant treatment, and passivation treatment to significantly improve the heat resistance and oxidation resistance of the electrolytic copper foil, meeting the requirements for the preparation of high-performance printed circuit boards. The silane coupling agent treatment on the surface also increases the adhesion between the electrolytic copper foil and the substrate.

Description

Technical Field

[0001] This invention relates to the field of copper foil technology, and in particular to a high heat-resistant electrolytic copper foil and its preparation method. Background Technology

[0002] With the development of electronic information technology, the application fields of electronic components are becoming increasingly widespread, and the performance requirements for electronic components are also becoming increasingly stringent. Printed circuit boards (PCBs), as providers of electrical connections for electronic components, occupy an important position in the electronics industry. Copper, due to its excellent conductivity, can carry electrical charge without losing signals; therefore, the metal foil made from copper, as a crucial component of printed circuit boards, determines the performance of signal transmission.

[0003] Currently, printed circuit boards (PCBs) require higher dimensional stability, lower dielectric loss, and higher dielectric constant, which necessitates electrolytic copper foil with superior performance, particularly in terms of heat resistance and oxidation resistance. However, current electrolytic copper foil production methods do not meet the heat resistance requirements, typically relying on imported copper foil. Therefore, developing an electrolytic copper foil with high heat resistance is of great significance to the rapid development of the electronics industry. Summary of the Invention

[0004] The purpose of this invention is to provide a high heat-resistant electrolytic copper foil and its preparation method, thereby solving the problem of poor heat resistance and oxidation resistance of existing electrolytic copper foils.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for preparing high heat-resistant electrolytic copper foil, comprising the following steps:

[0007] (1) Electrolysis is carried out in an electrolyte containing additives to obtain electrolytic copper foil;

[0008] (2) The electrolytic copper foil is subjected to pickling and roughening treatment in sequence to obtain roughened electrolytic copper foil;

[0009] (3) The surface of the roughened electrolytic copper foil is subjected to blackening treatment, heat resistance treatment, passivation treatment and coupling agent treatment in sequence to obtain high heat resistance electrolytic copper foil.

[0010] Preferably, in the above-mentioned method for preparing a high heat-resistant electrolytic copper foil, the electrolyte containing additives in step (1) contains 80-100 g / L of copper ions, 100-200 g / L of sulfuric acid, 10-15 mg / L of chloride ions, 10-30 mg / L of sodium dodecylbenzene sulfonate, 10-40 mg / L of polyacrylamide, 50-100 mg / L of gelatin, 1-8 mg / L of thiourea, and 1-20 mg / L of sodium polydisulfide dipropane sulfonate.

[0011] Preferably, in the above-mentioned method for preparing a high heat-resistant electrolytic copper foil, the electrolysis conditions in step (1) are: a temperature of 40–70°C and a current density of 60–80 A / dm³. 2 The flow rate is 40-50 m³ / h 3 / h.

[0012] Preferably, in the above-mentioned method for preparing a high heat-resistant electrolytic copper foil, the roughening treatment conditions in step (2) are as follows: the electrolyte is copper sulfate 10-30 g / L, sulfuric acid 100-200 g / L; and the current density is 10-25 A / dm³. 2 The time is 10-20 seconds.

[0013] Preferably, in the above-mentioned method for preparing a high heat-resistant electrolytic copper foil, the conditions for the blackening treatment in step (3) are as follows: the electrolyte consists of 1-10 g / L copper sulfate, 1-5 g / L cobalt acetate, 40-100 g / L sodium citrate, and 30-50 g / L ethylenediamine, with a pH value of 5-6; the current density is 3-10 A / dm³. 2 The time is 1 to 15 seconds.

[0014] Preferably, in the above-mentioned method for preparing a high heat-resistant electrolytic copper foil, the heat-resistant treatment conditions in step (3) are as follows: the electrolyte consists of 10-20 g / L nickel sulfate, 5-20 g / L zinc chloride, 40-70 g / L ammonium chloride, and 20-50 g / L boric acid, with a pH value of 4-5.5; the current density is 1-7 A / dm³. 2 The time is 1 to 20 seconds.

[0015] Preferably, in the above-mentioned method for preparing a high heat-resistant electrolytic copper foil, the passivation treatment conditions in step (3) are as follows: the electrolyte is 1-5 g / L chromium phosphate, 2-5 g / L sodium phosphate, 20-50 g / L potassium pyrophosphate, and the pH value is 9-11; the current density is 1-5 A / dm³. 2 The time is 1 to 10 seconds.

[0016] Preferably, in the above-mentioned method for preparing a high heat-resistant electrolytic copper foil, the conditions for the coupling agent treatment in step (3) are as follows: the coupling agent is KH-560; the concentration of the coupling agent is 0.4-0.5%.

[0017] The present invention also provides a method for preparing a high heat-resistant electrolytic copper foil.

[0018] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention optimizes the additives and electrolysis conditions during the electrolysis process of electrolytic copper foil, resulting in electrolytic copper foil with excellent heat resistance and elongation, exhibiting good stability during processing. Furthermore, this invention combines blackening treatment, heat-resistant treatment, and passivation treatment, significantly improving the heat resistance and oxidation resistance of the electrolytic copper foil, meeting the requirements for the fabrication of high-performance printed circuit boards. The surface treatment with a silane coupling agent also increases the adhesion between the electrolytic copper foil and the substrate. Detailed Implementation

[0020] A method for preparing high heat-resistant electrolytic copper foil includes the following steps:

[0021] (1) Electrolysis is carried out in an electrolyte containing additives to obtain electrolytic copper foil;

[0022] (2) The electrolytic copper foil is subjected to pickling and roughening treatment in sequence to obtain roughened electrolytic copper foil;

[0023] (3) The surface of the roughened electrolytic copper foil is subjected to blackening treatment, heat resistance treatment, passivation treatment and coupling agent treatment in sequence to obtain high heat resistance electrolytic copper foil.

[0024] In this invention, the electrolyte containing additives in step (1) preferably contains 80-100 g / L of copper ions, 100-200 g / L of sulfuric acid, 10-15 mg / L of chloride ions, 10-30 mg / L of sodium dodecylbenzene sulfonate, 10-40 mg / L of polyacrylamide, 50-100 mg / L of gelatin, 1-8 mg / L of thiourea, and 1-20 mg / L of sodium polydisulfide dipropane sulfonate.

[0025] In this invention, the electrolyte containing additives in step (1) preferably contains 87-96 g / L of copper ions, 110-180 g / L of sulfuric acid, 11-14 mg / L of chloride ions, 12-27 mg / L of sodium dodecylbenzenesulfonate, 16-35 mg / L of polyacrylamide, 53-91 mg / L of gelatin, 2-7 mg / L of thiourea, and 4-16 mg / L of sodium polydisulfide dipropane sulfonate.

[0026] In this invention, the electrolyte containing additives in step (1) is preferably 89 g / L for copper ions, 140 g / L for sulfuric acid, 12 mg / L for chloride ions, 18 mg / L for sodium dodecylbenzenesulfonate, 22 mg / L for polyacrylamide, 65 mg / L for gelatin, 4 mg / L for thiourea, and 11 mg / L for sodium polydisulfide dipropanesulfonate.

[0027] In this invention, the electrolysis conditions in step (1) are: the preferred temperature is 40–70°C, and the preferred current density is 60–80 A / dm³. 2 The preferred flow rate is 40-50 m³ / h. 3 / h.

[0028] In this invention, the electrolysis conditions in step (1) are: the temperature is preferably 45-65°C, and the current density is preferably 62-76 A / dm³. 2 The flow rate is further optimized to be 42–49 m³ / s. 3 / h.

[0029] In this invention, the electrolysis conditions in step (1) are: a temperature more preferably 52°C, and a current density more preferably 72 A / dm³. 2 The preferred flow rate is 46m³ / h. 3 / h.

[0030] In this invention, the acid washing in step (2) is preferably carried out using sulfuric acid.

[0031] In this invention, the conditions for the roughening treatment in step (2) are as follows: the electrolyte is preferably copper sulfate at 10-30 g / L and sulfuric acid at 100-200 g / L; the current density is preferably 10-25 A / dm³. 2 The optimal time is 10–20 seconds.

[0032] In this invention, the conditions for the roughening treatment in step (2) are as follows: the electrolyte is preferably copper sulfate at 12-26 g / L and sulfuric acid at 120-160 g / L; the current density is preferably 13-22 A / dm³. 2 The optimal time is further selected to be 13–18 seconds.

[0033] In this invention, the conditions for the roughening treatment in step (2) are as follows: the electrolyte is preferably copper sulfate at 21 g / L and sulfuric acid at 150 g / L; the current density is preferably 18 A / dm³. 2 The preferred time is 14 seconds.

[0034] In this invention, the conditions for the blackening treatment in step (3) are as follows: the electrolyte is preferably 1-10 g / L copper sulfate, preferably 1-5 g / L cobalt acetate, preferably 40-100 g / L sodium citrate, preferably 30-50 g / L ethylenediamine, and preferably 5-6 pH value; the current density is preferably 3-10 A / dm³. 2 The optimal time is 1 to 15 seconds.

[0035] In this invention, the conditions for the blackening treatment in step (3) are as follows: the electrolyte is preferably 3-8 g / L copper sulfate, preferably 2-4 g / L cobalt acetate, preferably 47-85 g / L sodium citrate, preferably 32-48 g / L ethylenediamine, and preferably 5.2-5.9 pH; the current density is preferably 4-8 A / dm³. 2 The optimal time is further selected as 3–14 seconds.

[0036] In this invention, the conditions for the blackening treatment in step (3) are as follows: the electrolyte is preferably 6 g / L copper sulfate, preferably 3 g / L cobalt acetate, preferably 70 g / L sodium citrate, preferably 38 g / L ethylenediamine, and preferably pH 5.4; the current density is preferably 7 A / dm³. 2 The preferred time is 7 seconds.

[0037] In this invention, the conditions for heat resistance treatment in step (3) are as follows: the electrolyte is preferably 10-20 g / L for nickel sulfate, 5-20 g / L for zinc chloride, 40-70 g / L for ammonium chloride, 20-50 g / L for boric acid, and pH is preferably 4-5.5; the current density is preferably 1-7 A / dm³. 2 The optimal time is 1–20 seconds.

[0038] In this invention, the conditions for heat resistance treatment in step (3) are as follows: the electrolyte is preferably nickel sulfate at 13-19 g / L, zinc chloride at 7-17 g / L, ammonium chloride at 47-65 g / L, boric acid at 25-43 g / L, and pH at 4.3-5.3; the current density is preferably 2-6 A / dm³. 2 The optimal time is further selected to be 4–16 seconds.

[0039] In this invention, the conditions for heat resistance treatment in step (3) are as follows: the electrolyte is preferably 16 g / L nickel sulfate, preferably 11 g / L zinc chloride, preferably 58 g / L ammonium chloride, preferably 36 g / L boric acid, and preferably 4.8; the current density is preferably 5 A / dm³. 2 The preferred time is 13 seconds.

[0040] In this invention, the passivation treatment conditions in step (3) are as follows: the electrolyte is preferably 1-5 g / L for chromium phosphate, 2-5 g / L for sodium phosphate, 20-50 g / L for potassium pyrophosphate, and the pH value is preferably 9-11; the current density is preferably 1-5 A / dm³. 2 The optimal time is 1 to 10 seconds.

[0041] In this invention, the passivation treatment conditions in step (3) are as follows: the electrolyte is preferably 2-4 g / L for chromium phosphate, 2-4 g / L for sodium phosphate, 29-43 g / L for potassium pyrophosphate, and 9.7-10.8 for pH; the current density is preferably 2-4 A / dm³. 2 The optimal time is further selected as 3–9 seconds.

[0042] In this invention, the passivation treatment conditions in step (3) are as follows: the electrolyte is preferably 3 g / L for chromium phosphate, 3 g / L for sodium phosphate, 34 g / L for potassium pyrophosphate, and a pH value preferably 10.1; the current density is preferably 3 A / dm³. 2 The preferred time is 7 seconds.

[0043] In this invention, the conditions for the coupling agent treatment in step (3) are as follows: the coupling agent is preferably KH-560; the concentration of the coupling agent is preferably 0.4-0.5%, more preferably 0.42-0.47%, and even more preferably 0.45%.

[0044] The present invention also provides a method for preparing a high heat-resistant electrolytic copper foil.

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Example 1

[0047] This embodiment provides a method for preparing high heat-resistant electrolytic copper foil, including the following steps:

[0048] (1) Electrolysis was carried out in an electrolyte containing additives to obtain electrolytic copper foil; the electrolyte consisted of: copper ions 92 g / L, sulfuric acid 130 g / L, chloride ions 12 mg / L, sodium dodecylbenzene sulfonate 21 mg / L, polyacrylamide 10 mg / L, gelatin 60 mg / L, thiourea 3 mg / L, and sodium polydithiopropane sulfonate 8 mg / L; the electrolysis conditions were: temperature 45℃, current density 65 A / dm³. 2 The flow rate is 40m³. 3 / h;

[0049] (2) The electrolytic copper foil was acid-washed with sulfuric acid and then roughened to obtain roughened electrolytic copper foil; the electrolyte for the roughening treatment was 14 g / L copper sulfate, 150 g / L sulfuric acid, and the current density was 17 A / dm³. 2The time is 16 seconds;

[0050] (3) Blackening treatment, heat resistance treatment, passivation treatment and coupling agent treatment are performed sequentially on the roughened electrolytic copper foil to obtain a high heat resistance electrolytic copper foil;

[0051] The conditions for the blackening treatment were as follows: the electrolyte consisted of 3 g / L copper sulfate, 4 g / L cobalt acetate, 50 g / L sodium citrate, and 34 g / L ethylenediamine; the pH value was 5.2; and the current density was 6 A / dm³. 2 The time is 7 seconds.

[0052] The conditions for heat resistance treatment were as follows: the electrolyte consisted of 16 g / L nickel sulfate, 9 g / L zinc chloride, 54 g / L ammonium chloride, and 30 g / L boric acid, with a pH of 4.5; the current density was 3 A / dm³. 2 The time is 12 seconds.

[0053] The passivation treatment conditions were as follows: the electrolyte consisted of 3 g / L chromium phosphate, 5 g / L sodium phosphate, and 40 g / L potassium pyrophosphate, with a pH of 9; the current density was 2 A / dm³. 2 The time is 3 seconds.

[0054] The conditions for coupling agent treatment are: spraying with a 0.4% KH-560 aqueous solution.

[0055] The high heat-resistant electrolytic copper foil prepared above has a thickness of 22 μm and a surface roughness of 2.4 μm. When pressed onto the FR-4 substrate, it has a peel strength of 1.9 kg / cm at room temperature. After being immersed in a 50% hydrochloric acid solution at 200°C for 3 hours, it did not oxidize or change color, and no expansion occurred between the electrolytic copper foil and the FR-4 substrate, demonstrating good heat resistance.

[0056] Example 2

[0057] This embodiment provides a method for preparing high heat-resistant electrolytic copper foil, including the following steps:

[0058] (1) Electrolysis was carried out in an electrolyte containing additives to obtain electrolytic copper foil; the electrolyte consisted of: 90 g / L copper ions, 170 g / L sulfuric acid, 10 mg / L chloride ions, 30 mg / L sodium dodecylbenzene sulfonate, 30 mg / L polyacrylamide, 65 mg / L gelatin, 4 mg / L thiourea, and 16 mg / L sodium polydithiopropane sulfonate; the electrolysis conditions were: temperature 50℃, current density 60 A / dm³. 2 The flow rate is 50m³. 3 / h;

[0059] (2) The electrolytic copper foil was acid-washed with sulfuric acid and then roughened to obtain roughened electrolytic copper foil; the electrolyte for the roughening treatment was 25 g / L copper sulfate, 130 g / L sulfuric acid, and the current density was 18 A / dm³. 2 The time is 10 seconds;

[0060] (3) Blackening treatment, heat resistance treatment, passivation treatment and coupling agent treatment are performed sequentially on the roughened electrolytic copper foil to obtain a high heat resistance electrolytic copper foil;

[0061] The conditions for the blackening treatment were as follows: the electrolyte consisted of 5 g / L copper sulfate, 4 g / L cobalt acetate, 70 g / L sodium citrate, and 38 g / L ethylenediamine, with a pH of 5.7; the current density was 7 A / dm³. 2 The time is 4 seconds.

[0062] The conditions for heat resistance treatment were as follows: the electrolyte consisted of 14 g / L nickel sulfate, 15 g / L zinc chloride, 60 g / L ammonium chloride, and 40 g / L boric acid, with a pH of 4.9; the current density was 4 A / dm³. 2 The time is 13 seconds.

[0063] The passivation treatment conditions were as follows: the electrolyte consisted of 2 g / L chromium phosphate, 4 g / L sodium phosphate, and 28 g / L potassium pyrophosphate, with a pH of 10.5; the current density was 2 A / dm³. 2 The time is 6 seconds.

[0064] The conditions for coupling agent treatment are: spraying with a 0.4% KH-560 aqueous solution.

[0065] The high heat-resistant electrolytic copper foil prepared above has a thickness of 27 μm and a surface roughness of 2.1 μm. When pressed onto the FR-4 substrate, its peel strength at room temperature is 2.5 kg / cm. After being immersed in a 50% hydrochloric acid solution at 200°C for 3 hours, it did not oxidize or change color, and no expansion occurred between the electrolytic copper foil and the FR-4 substrate, demonstrating good heat resistance.

[0066] Example 3

[0067] This embodiment provides a method for preparing high heat-resistant electrolytic copper foil, including the following steps:

[0068] (1) Electrolysis was carried out in an electrolyte containing additives to obtain electrolytic copper foil; the electrolyte consisted of: 82 g / L copper ions, 110 g / L sulfuric acid, 15 mg / L chloride ions, 20 mg / L sodium dodecylbenzene sulfonate, 31 mg / L polyacrylamide, 70 mg / L gelatin, 7 mg / L thiourea, and 6 mg / L sodium polydithiopropane sulfonate; the electrolysis conditions were: temperature 60℃, current density 75 A / dm³. 2 The flow rate is 45m³. 3 / h;

[0069] (2) The electrolytic copper foil was acid-washed with sulfuric acid and then roughened to obtain roughened electrolytic copper foil; the electrolyte for the roughening treatment was 22 g / L copper sulfate, 180 g / L sulfuric acid, and the current density was 21 A / dm³. 2 The time is 14 seconds;

[0070] (3) Blackening treatment, heat resistance treatment, passivation treatment and coupling agent treatment are performed sequentially on the roughened electrolytic copper foil to obtain a high heat resistance electrolytic copper foil;

[0071] The conditions for the blackening treatment were as follows: the electrolyte consisted of 5 g / L copper sulfate, 1 g / L cobalt acetate, 60 g / L sodium citrate, and 45 g / L ethylenediamine, with a pH of 5.5; the current density was 5 A / dm³. 2 The time is 12 seconds.

[0072] The conditions for heat resistance treatment were as follows: the electrolyte consisted of 16 g / L nickel sulfate, 18 g / L zinc chloride, 60 g / L ammonium chloride, and 37 g / L boric acid, with a pH of 5.1; the current density was 5 A / dm³. 2 The time is 15 seconds.

[0073] The passivation conditions were as follows: the electrolyte consisted of 4 g / L chromium phosphate, 2 g / L sodium phosphate, and 30 g / L potassium pyrophosphate, with a pH of 11; the current density was 4 A / dm³. 2 The time is 3 seconds.

[0074] The conditions for coupling agent treatment are: spraying with a 0.4% KH-560 aqueous solution.

[0075] The high heat-resistant electrolytic copper foil prepared above has a thickness of 25 μm and a surface roughness of 2.3 μm. When pressed onto the FR-4 substrate, it has a peel strength of 2.4 kg / cm at room temperature. After being immersed in a 50% hydrochloric acid solution at 200°C for 3 hours, it did not oxidize or change color, and no expansion occurred between the electrolytic copper foil and the FR-4 substrate, demonstrating good heat resistance.

[0076] Example 4

[0077] This embodiment provides a method for preparing high heat-resistant electrolytic copper foil, including the following steps:

[0078] (1) Electrolysis was carried out in an electrolyte containing additives to obtain electrolytic copper foil; the electrolyte consisted of: 100 g / L copper ions, 200 g / L sulfuric acid, 14 mg / L chloride ions, 10 mg / L sodium dodecylbenzene sulfonate, 40 mg / L polyacrylamide, 50 mg / L gelatin, 8 mg / L thiourea, and 20 mg / L sodium polydithiopropane sulfonate; the electrolysis conditions were: temperature 70℃, current density 80 A / dm³. 2The flow rate is 45m³. 3 / h;

[0079] (2) The electrolytic copper foil was acid-washed with sulfuric acid and then roughened to obtain roughened electrolytic copper foil; the electrolyte for the roughening treatment was 30 g / L copper sulfate, 200 g / L sulfuric acid, and the current density was 20 A / dm³. 2 The duration is 18 seconds;

[0080] (3) Blackening treatment, heat resistance treatment, passivation treatment and coupling agent treatment are performed sequentially on the roughened electrolytic copper foil to obtain a high heat resistance electrolytic copper foil;

[0081] The conditions for blackening treatment were as follows: the electrolyte consisted of 9 g / L copper sulfate, 5 g / L cobalt acetate, 100 g / L sodium citrate, and 40 g / L ethylenediamine, with a pH of 6; the current density was 8 A / dm³. 2 The time is 15 seconds.

[0082] The conditions for heat resistance treatment were as follows: the electrolyte consisted of 10 g / L nickel sulfate, 20 g / L zinc chloride, 70 g / L ammonium chloride, and 40 g / L boric acid, with a pH of 4.7; the current density was 5 A / dm³. 2 The time is 17 seconds.

[0083] The passivation conditions were as follows: the electrolyte consisted of 3 g / L chromium phosphate, 3 g / L sodium phosphate, and 40 g / L potassium pyrophosphate, with a pH of 11; the current density was 4 A / dm³. 2 The time is 7 seconds.

[0084] The conditions for coupling agent treatment are: spraying with a 0.5% KH-560 aqueous solution.

[0085] The high heat-resistant electrolytic copper foil prepared above has a thickness of 28 μm and a surface roughness of 2.5 μm. When pressed onto the FR-4 substrate, it has a peel strength of 2.7 kg / cm at room temperature. After being immersed in a 50% hydrochloric acid solution at 200°C for 3 hours, it did not oxidize or change color, and no expansion occurred between the electrolytic copper foil and the FR-4 substrate, demonstrating good heat resistance.

[0086] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for producing a highly heat-resistant electrolytic copper foil, characterized by, It comprises the following steps: (1) electrolyzing in an electrolyte containing additives to obtain an electrolytic copper foil; (2) sequentially subjecting the electrolytic copper foil to pickling and roughening treatment to obtain a roughened electrolytic copper foil; (3) sequentially subjecting the surface of the roughened electrolytic copper foil to blackening treatment, heat-resistant treatment, passivation treatment and coupling agent treatment to obtain a high-heat-resistant electrolytic copper foil. The conditions of the blackening treatment in step (3) are as follows: electrolyte is copper sulfate 1-10 g / L, cobalt acetate 1-5 g / L, sodium citrate 40-100 g / L, ethylenediamine 30-50 g / L, pH value is 5-6; current density is 3-10 A / dm 2 ; time is 1-15 s; The conditions of the heat treatment in the step (3) are as follows: the electrolyte is nickel sulfate 10-20 g / L, zinc chloride 5-20 g / L, ammonium chloride 40-70 g / L, boric acid 20-50 g / L, pH value is 4-5.5; the current density is 1-7 A / dm 2 ; the time is 1-20 s.

2. The method for preparing a high heat-resistant electrolytic copper foil according to claim 1, characterized in that, In the electrolyte containing additives in step (1), the copper ion is 80-100 g / L, the sulfuric acid is 100-200 g / L, the chloride ion is 10-15 mg / L, the sodium dodecyl benzene sulfonate is 10-30 mg / L, the polyacrylamide is 10-40 mg / L, the gelatin is 50-100 mg / L, the thiourea is 1-8 mg / L and the sodium polydithiopropane sulfonate is 1-20 mg / L.

3. The method of claim 2, wherein the electrolytic copper foil has a thickness of 5 to 100 μm. The conditions of the electrolysis in step (1) are: temperature 40-70°C, current density 60-80 A / dm 2 , flow rate 40-50 m 3 / h.

4. A method for preparing a high heat-resistant electrolytic copper foil according to claim 1 or 3, characterized in that, The conditions of the roughening treatment in step (2) are as follows: electrolyte is copper sulfate 10-30 g / L, sulfuric acid 100-200 g / L; current density is 10-25 A / dm 2 ; time is 10-20 s.

5. The method for preparing a high heat-resistant electrolytic copper foil according to claim 1, characterized in that, The conditions of the passivation treatment in step (3) are: electrolyte is chromium phosphate 1-5 g / L, sodium phosphate 2-5 g / L, potassium pyrophosphate 20-50 g / L, pH value is 9-11; current density is 1-5 A / dm 2 ; time is 1-10 s.

6. The method for preparing a high heat-resistant electrolytic copper foil according to claim 5, characterized in that, In step (3), the coupling agent is KH-560 and the concentration of the coupling agent is 0.4-0.5%.

7. A high-heat-resistant electrolytic copper foil prepared by the method of any one of claims 1-6.