Electrolytic copper foil

Abstract

Provided is an electrolytic copper foil. The electrolytic copper foil has a drum side and a deposited side, wherein Rz is less than 0.8 m; the electrolytic copper foil has a transverse direction, wherein the electrolytic copper foil is divided into 10 test pieces with the same width and the same length, and each two adjacent ones of the 10 test pieces have a weight deviation therebetween, and a count of the weight deviation(s) greater than or equal to 1.5% is smaller than a count of the weight deviations smaller than 1.5%; wherein n represents any one of the test piece numbers from 1 to 9, and the $\mathrm{weight}\mathrm{deviation}\mathrm{between}\mathrm{each}\mathrm{two}\mathrm{adjacent}\mathrm{ones}\mathrm{of}\mathrm{the}10\mathrm{test}\mathrm{pieces}\left(\%\right)=\frac{\begin{array}{c}.Math.\mathrm{the}\mathrm{weight}\mathrm{of}\mathrm{test}\mathrm{piece}\left(n\right)-\\ \mathrm{the}\mathrm{weight}\mathrm{of}\mathrm{test}\mathrm{piece}\left(n+1\right).Math.\end{array}}{\begin{array}{c}\mathrm{the}\mathrm{smaller}\mathrm{weight}\mathrm{in}\mathrm{test}\\ \mathrm{piece}\left(n\right)\mathrm{and}\mathrm{test}\mathrm{piece}\left(n+1\right)\end{array}}100\%.$

Claims

1. An electrolytic copper foil comprising: a drum side and a deposited side opposite the drum side; an absolute value of a difference in surface roughness between the deposited side and the drum side being less than 0.8 m; and wherein the electrolytic copper foil having a transverse direction and a machine direction, wherein when the electrolytic copper foil is divided into 10 test pieces with the same width and the same length along the transverse direction, and when a weight deviation between each two adjacent ones of the 10 test pieces is obtained, there are a total of 9 sets of weight deviations among the 10 test pieces, and then the following conditions are satisfied: (1) a total count of the weight deviation(s) greater than or equal to 1.5% is smaller than a total count of the weight deviations smaller than 1.5%; and (2) at least one of the 9 sets of the weight deviations is greater than 0.00% and equal to or smaller than 2.20%, with the other(s) of the 9 sets of the weight deviation(s) being equal to or greater than 0.00% and equal to or smaller than 2.20%, wherein the weight deviation between each two adjacent ones of the 10 test pieces is calculated by the following formula, wherein n represents any one of the test piece numbers from 1 to 9: $\mathrm{the}\mathrm{weight}\mathrm{deviation}\mathrm{between}\mathrm{each}\mathrm{two}\mathrm{adjacent}\mathrm{ones}\mathrm{of}\mathrm{the}10\mathrm{test}\mathrm{pieces}\left(\%\right)=\frac{\begin{array}{c}.Math.\mathrm{the}\mathrm{weight}\mathrm{of}\mathrm{test}\mathrm{piece}\left(n\right)-\\ \mathrm{the}\mathrm{weight}\mathrm{of}\mathrm{test}\mathrm{piece}\left(n+1\right).Math.\end{array}}{\begin{array}{c}\mathrm{the}\mathrm{smaller}\mathrm{weight}\mathrm{in}\mathrm{test}\\ \mathrm{piece}\left(n\right)\mathrm{and}\mathrm{test}\mathrm{piece}\left(n+1\right)\end{array}}100\%.$

2. The electrolytic copper foil as claimed in claim 1, wherein the absolute value of the difference in surface roughness between the deposited side and the drum side is equal to or larger than 0.1 m and equal to or smaller than 0.75 m.

3. The electrolytic copper foil as claimed in claim 1, wherein the absolute value of the difference in surface roughness between the deposited side and the drum side is equal to zero.

4. The electrolytic copper foil as claimed in claim 1, wherein each of the 9 sets of the weight deviations between each two adjacent ones of the 10 test pieces is greater than 0.00% and equal to or smaller than 2.20%.

5. The electrolytic copper foil as claimed in claim 2, wherein each of the 9 sets of the weight deviations between the each two adjacent ones of the 10 test pieces is greater than 0.00% and equal to or smaller than 2.20%.

6. The electrolytic copper foil as claimed in claim 3, wherein each of the 9 sets of the weight deviations between each two adjacent ones of the 10 test pieces is greater than 0.00% and equal to or smaller than 2.20%.

7. The electrolytic copper foil as claimed in claim 1, wherein a quotient of the count of the weight deviation(s) greater than or equal to 1.5% divided by 9 is smaller than or equal to 0.45.

8. The electrolytic copper foil as claimed in claim 2, wherein a quotient of the count of the weight deviation(s) greater than or equal to 1.5% divided by 9 is smaller than or equal to 0.45.

9. The electrolytic copper foil as claimed in claim 3, wherein a quotient of the count of the weight deviation(s) greater than or equal to 1.5% divided by 9 is smaller than or equal to 0.45.

10. The electrolytic copper foil as claimed in claim 4, wherein a quotient of the count of the weight deviation(s) greater than or equal to 1.5% divided by 9 is smaller than or equal to 0.45.

11. The electrolytic copper foil as claimed in claim 1, wherein the transverse direction of the electrolytic copper foil is perpendicular to the machine direction of the electrolytic copper foil.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) FIG. 1A is a schematic perspective view of making an electrolytic copper foil of the instant disclosure.

(2) FIG. 1B is a schematic side view of making the electrolytic copper foil of the instant disclosure.

(3) FIG. 2A is a schematic view showing that the electrolytic copper foil of Examples is wound on the take-up roll at the terminal state.

(4) FIG. 2B is a sectional view of FIG. 2A.

(5) FIG. 3A is a schematic view showing that the electrolytic copper foil of Comparative Examples is wound on the take-up roll at the terminal state.

(6) FIG. 3B is a sectional view of FIG. 3A.

DETAILED DESCRIPTION OF THE DISCLOSURE

(7) Hereinafter, one skilled in the art can easily realize the advantages and effects of the instant disclosure from the following examples. Therefore, it should be understood that the descriptions proposed herein are just preferable examples for the purpose of illustrations only, not intended to limit the scope of the disclosure. Various modifications and variations could be made in order to practice or apply the instant disclosure without departing from the spirit and scope of the disclosure.

(8) The Instrument Model Used in the Following Examples:

(9) 1. -type surface roughness measuring instrument: SE 1700 manufactured by Kosaka Laboratory; and

(10) 2. microbalance: AG-204 manufactured by Mettler Toledo International Inc.

(11) Electrolytic Copper Foil of Example 1

(12) Preparation of a Copper Sulfate Electrolyte Solution for an Electrolytic Bath:

(13) A copper wire was dissolved in a 50 wt % of sulfuric acid aqueous solution to prepare an essential solution including copper sulfate (CuSO.sub.4.5H.sub.2O) and sulfuric acid. In the essential solution, a concentration of copper sulfate was 320 g/liter (g/L) and a concentration of sulfuric acid was 100 g/L. Then, 5 mg of PVA (i.e. 5 ppm of PVA), 5 mg of hydroxyethyl cellulose (HEC, purchased from DAICEL Corporation) and 3 mg of sodium 3-mercapto-1-propanesulphonate (MPS, purchased from HOPAX Fine Chemicals) were added in each liter of the essential solution to form the copper sulfate electrolyte solution for the electrolytic bath.

(14) With reference to FIGS. 1A and 1B, a T-shaped feed pipe 10 had a diameter D1 of 3 inches. In the electrolytic bath set at 50 C., the aforesaid copper sulfate electrolyte solution 20 was continuously supplied via the feed pipe 10. A horizontal tube of the feed pipe 10 which was parallel to the transverse direction of the electrolytic copper foil 50 had one hundred pores 101 on its surface. The length of the horizontal tube of the feed pipe 10 was 1390 mm, and a pore size D2 of each pore 101 was 7 mm. Each two adjacent pores 101 had a same distance therebetween. Overall, the ratio of pore distribution of the feed pipe 10 was 84.39%. A current with a current density of 40 A/dm.sup.2 flowed between the cathode drum 30 and the anode plate 40 which was disposed along the curved surface of the cathode drum 30. Therefore, copper ions included in the copper sulfate electrolyte solution 20 were electrodeposited on the curved surface of the cathode drum 30 to form the electrolytic copper foil 50. Subsequently, the electrolytic copper foil 50 was peeled off from the cathode drum 30 and continuously rolled by a series of guiding rolls 60 and finally rolled up on a take-up roll 61. The electrolytic copper foil 50 had a transverse width of 1380 mm and a thickness of 8 m. The electrolytic copper foil 50 had a drum side 501 and a deposited side 502 opposite the drum side 501.

(15) In some cases, the electrolytic copper foil 50 might be subsequently treated by a surface treatment, such as a roughening treatment, a passivation treatment, an anti-corrosion treatment, and a silane coupling treatment, or a combination thereof. The anti-corrosion treatment might be performed by an electric plating with a chromate solution at a temperature of 31.5 C. The chromate solution comprised chromic acid with a concentration of 1.5 g/L. A current used in the electric plating had a current density of 0.5 A/dm.sup.2. After completion of the treatment, the drum side 501 and the deposited side 502 each respectively had an inorganic anti-corrosion layer comprising chromates.

(16) Electrolytic Copper Foil of Example 2

(17) The process used to manufacture the electrolytic copper foil of Example 2 was similar to the process used to manufacture the electrolytic copper foil of Example 1. The differences between the processes were that the feed pipe with 100 pores whose size was 7 mm used in Example 1 was replaced with the feed pipe with 80 pores whose size was 6.7 mm, and the ratio of pore distribution of the feed pipe used in Example 2 was 61.85%.

(18) Electrolytic Copper Foil of Example 3

(19) The process used to manufacture the electrolytic copper foil of Example 3 was similar to the process used to manufacture the electrolytic copper foil of Example 1. The differences between the processes were that the feed pipe with 100 pores whose size was 7 mm used in Example 1 was replaced with the feed pipe with 115 pores whose size was 6.7 mm, and the ratio of pore distribution of the feed pipe used in Example 3 was 88.91%.

(20) Electrolytic Copper Foil of Example 4

(21) The process used to manufacture the electrolytic copper foil of Example 4 was similar to the process used to manufacture the electrolytic copper foil of Example 3. The differences between the processes were that the copper sulfate electrolyte solution containing 5 ppm of PVA used in Example 3 was replaced with the copper sulfate electrolyte solution containing 2.5 ppm of PVA.

(22) Electrolytic Copper Foil of Example 5

(23) The process used to manufacture the electrolytic copper foil of Example 5 was similar to the process used to manufacture the electrolytic copper foil of Example 3. The differences between the processes were that the copper sulfate electrolyte solution containing 5 ppm of PVA used in Example 3 was replaced with the copper sulfate electrolyte solution containing 7.5 ppm of PVA.

(24) Electrolytic Copper Foil of Example 6

(25) The process used to manufacture the electrolytic copper foil of Example 6 was similar to the process used to manufacture the electrolytic copper foil of Example 1. The differences between the processes were that the copper sulfate electrolyte solution containing 5 ppm of PVA used in Example 1 was replaced with the copper sulfate electrolyte solution containing 2.5 ppm of PVA. In addition, the cathode drum used in Example 1 was changed to another cathode drum with a different width so that the obtained electrolytic copper foil of Example 6 had a transverse width of 400 mm and a thickness of 8 m.

(26) Electrolytic Copper Foil of Example 7

(27) The process used to manufacture the electrolytic copper foil of Example 7 was similar to the process used to manufacture the electrolytic copper foil of Example 1. The differences between the processes were that the copper sulfate electrolyte solution containing 5 ppm of PVA used in Example 1 was replaced with the copper sulfate electrolyte solution containing 5.5 ppm of PVA.

(28) Electrolytic Copper Foil of Comparative Example 1

(29) The process used to manufacture the electrolytic copper foil of Comparative Example 1 was similar to the process used to manufacture the electrolytic copper foil of Example 1. The differences between the processes were that the feed pipe with 100 pores whose size was 7 mm used in Example 1 was replaced with the feed pipe with 100 pores whose size was 5.0 mm, and the ratio of pore distribution of the feed pipe used in Comparative Example 1 was 43.06%.

(30) Electrolytic Copper Foil of Comparative Example 2

(31) The process used to manufacture the electrolytic copper foil of Comparative Example 2 was similar to the process used to manufacture the electrolytic copper foil of Example 1. The differences between the processes were that the feed pipe with 100 pores whose size was 7 mm used in Example 1 was replaced with the feed pipe with 100 pores whose size was 10 mm, and the ratio of pore distribution of the feed pipe used in Comparative Example 2 was 172.22%.

(32) Electrolytic Copper Foil of Comparative Example 3

(33) The process used to manufacture the electrolytic copper foil of Comparative Example 3 was similar to the process used to manufacture the electrolytic copper foil of Example 1. The differences between the processes were that the copper sulfate electrolyte solution containing 5 ppm of PVA used in Example 1 was replaced with the copper sulfate electrolyte solution free of PVA.

(34) Electrolytic Copper Foil of Comparative Example 4

(35) The process used to manufacture the electrolytic copper foil of Comparative Example 4 was similar to the process used to manufacture the electrolytic copper foil of Example 1. The differences between the processes were that the copper sulfate electrolyte solution containing 5 ppm of PVA used in Example 1 was replaced with the copper sulfate electrolyte solution containing 10 ppm of PVA.

(36) Electrolytic Copper Foil of Comparative Example 5

(37) The process used to manufacture the electrolytic copper foil of Comparative Example 5 was similar to the process used to manufacture the electrolytic copper foil of Example 1. The differences between the processes were that the feed pipe with 100 pores whose size was 7 mm used in Example 1 was replaced with the feed pipe with 150 pores whose size was 6.7 mm, and the ratio of pore distribution of the feed pipe used in Comparative Example 5 was 115.97%.

(38) Electrolytic Copper Foil of Comparative Example 6

(39) The process used to manufacture the electrolytic copper foil of Comparative Example 6 was similar to the process used to manufacture the electrolytic copper foil of Comparative Example 3. The differences between the processes were that the feed pipe with 100 pores whose size was 7 mm used in Comparative Example 3 was replaced with the feed pipe with 115 pores whose size was 6.7 mm, and the ratio of pore distribution of the feed pipe used in Comparative Example 6 was 88.91%.

(40) Electrolytic Copper Foil of Comparative Example 7

(41) The process used to manufacture the electrolytic copper foil of Comparative Example 7 was similar to the process used to manufacture the electrolytic copper foil of Comparative Example 2. The differences between the processes were that the copper sulfate electrolyte solution containing 5 ppm of PVA used in Comparative Example 2 was replaced with the copper sulfate electrolyte solution containing 10 ppm of PVA.

(42) Electrolytic Copper Foil of Comparative Example 8

(43) The process used to manufacture the electrolytic copper foil of Comparative Example 8 was similar to the process used to manufacture the electrolytic copper foil of Comparative Example 7. The differences between the processes were that the copper sulfate electrolyte solution containing 10 ppm of PVA used in Comparative Example 7 was replaced with the copper sulfate electrolyte solution containing 7.5 ppm of PVA. In addition, the cathode drum used in Comparative Example 8 was changed to another cathode drum with a different width so that the obtained electrolytic copper foil of Comparative Example 8 had a transverse width of 400 mm and a thickness of 8 m.

(44) Analysis 1: Analyzing the Statistical Standard Deviation of the Weight of the Electrolytic Copper Foils

(45) Each of the electrolytic copper foils of Examples 1 to 7 (expressed as E1 to E7) and Comparative Examples 1 to 8 (expressed as C1 to C8) was cut into a sample of 10 cm in length along the machine direction, and each sample of Examples 1 to 7 and Comparative Examples 1 to 8 was divided into 10 test pieces with the same width along the transverse direction. Therefore, each test piece had the same width and the same length (10 cm). Each test piece was weighed by the microbalance, and then a standard deviation in statistics represented by a three sigma (3) between the weight values of the 10 test pieces was calculated in each of Examples 1 to 7 and Comparative Examples 1 to 8. The 3 values of Examples 1 to 7 and Comparative Examples 1 to 8 were shown in Table 1-1.

(46) TABLE-US-00001 TABLE 1-1 3 values of Examples 1 to 7 and Comparative Examples 1 to 8 Example No. E1 E2 E3 E4 E5 E6 E7 3 (%) 1.5 2.78 1.24 2.64 2.25 2.14 2.47 Example No. C1 C2 C3 C4 C5 C6 C7 C8 3 (%) 2.46 2.43 2.24 1.97 2.69 2.49 2.44 2.78

(47) Analysis 2: Analyzing the Statistical Relative Range of the Weight of the Electrolytic Copper Foils

(48) Each of the electrolytic copper foils of Examples 1 to 7 and Comparative Examples 1 to 8 was cut into a sample of 10 cm in length along the machine direction, and each sample of Examples 1 to 7 and Comparative Examples 1 to 8 was divided into 10 test pieces with the same width along the transverse direction. Therefore, each test piece had the same width and the same length (10 cm). Each test piece was weighed by the microbalance, and then a relative range for the weight values of the 10 test pieces was calculated in each of Examples 1 to 7 and Comparative Examples 1 to 8. The relative range was calculated by the following formula. The relative ranges of Examples 1 to 7 and Comparative Examples 1 to 8 were shown in Table 1-2.

(49) $\mathrm{The}\mathrm{relative}\mathrm{range}\mathrm{for}\mathrm{the}\mathrm{weight}\mathrm{values}\mathrm{of}10\mathrm{test}\mathrm{pieces}\left(\%\right)=\frac{.Math.\mathrm{the}\mathrm{maximum}\mathrm{weight}-\mathrm{the}\mathrm{minimum}\mathrm{weight}.Math.}{\mathrm{the}\mathrm{average}\mathrm{weight}\mathrm{of}10\mathrm{test}\mathrm{pieces}}100\%.$

(50) TABLE-US-00002 TABLE 1-2 Relative range of Examples 1 to 7 and Comparative Examples 1 to 8 Example No. E1 E2 E3 E4 E5 E6 E7 Relative 1.56 2.30 1.37 2.06 2.07 1.82 2.58 range (%) Example No. C1 C2 C3 C4 C5 C6 C7 C8 Relative 2.10 1.91 2.11 1.80 2.33 2.32 2.40 2.86 range (%)

(51) Analysis 3: Analyzing the Weight Deviation Between Each Two Adjacent Ones of the 10 Test Pieces of the Electrolytic Copper Foils

(52) Each of the electrolytic copper foils of Examples 1 to 7 and Comparative Examples 1 to 8 was cut into a sample of 10 cm in length along the machine direction, and each sample of Examples 1 to 7 and Comparative Examples 1 to 8 was divided into 10 test pieces with the same width along the transverse direction. Therefore, each test piece had the same width and the same length (10 cm). Each test piece was weighed by the microbalance, and then a weight deviation between each two adjacent ones of the 10 test pieces was calculated by the following formula.

(53) $\mathrm{The}\mathrm{weight}\mathrm{deviation}\mathrm{between}\mathrm{each}\mathrm{two}\mathrm{adjacent}\mathrm{ones}\mathrm{of}\mathrm{the}10\mathrm{test}\mathrm{pieces}\left(\%\right)=\frac{\begin{array}{c}.Math.\mathrm{the}\mathrm{weight}\mathrm{of}\mathrm{test}\mathrm{piece}\left(n\right)-\\ \mathrm{the}\mathrm{weight}\mathrm{of}\mathrm{test}\mathrm{piece}\left(n+1\right).Math.\end{array}}{\begin{array}{c}\mathrm{the}\mathrm{smaller}\mathrm{weight}\mathrm{in}\mathrm{test}\\ \mathrm{piece}\left(n\right)\mathrm{and}\mathrm{test}\mathrm{piece}\left(n+1\right)\end{array}}100\%;$

(54) wherein n represents any one of the test piece numbers from 1 to 9.

(55) When calculating the weight deviation between each two adjacent ones of the 10 test pieces, it obtained 9 sets of data in each of Examples 1 to 7 and Comparative Examples 1 to 8. The obtained data were shown in Table 2. In addition, a counting was performed to figure out how many sets of the weight deviations were greater than or equal to 1.5% among the 9 sets of data. The counts of each of Examples 1 to 7 and Comparative Examples 1 to 8 were shown in Table 2. Moreover, a quotient of the count of the weight deviation(s) greater than or equal to 1.5% divided by 9 was calculated and listed in Table 3.

(56) As listed in Table 2, the count of the weight deviation(s) greater than or equal to 1.5% was abbreviated to count of 1.5%.

(57) TABLE-US-00003 TABLE 2 analytical results of the weight deviations between each set of test pieces (n) and (n + 1) of Examples 1 to 7 and Comparative Examples 1 to 8 Weight deviation between test pieces (n) and (n + 1) (%) Count that n 1 2 3 4 5 6 7 8 9 weight deviation n + 1 2 3 4 5 6 7 8 9 10 1.5% E1 1.03 0.51 0.13 0.36 0.45 0.31 0.92 1.57 0.51 1 E2 1.59 0.34 0.27 1.62 1.67 0.44 2.14 0.18 0.12 4 E3 0.27 0.41 0.45 0.84 0.75 0.32 0.29 0.09 0.08 0 E4 0.18 0.02 2.05 0.27 0.09 1.31 0.86 0.79 1.84 2 E5 0.53 0.51 0.82 2.09 1.01 0.35 0.41 0.06 1.73 2 E6 1.02 0.91 0.07 0.82 0.48 1.36 0.22 1.83 0.07 1 E7 0.54 0.51 0.04 0.94 0.55 0.07 0.38 0.78 1.74 1 C1 0.03 1.60 0.46 1.66 0.38 0.03 1.59 1.81 1.59 5 C2 1.58 1.05 0.51 1.53 1.71 1.64 1.82 1.54 1.53 7 C3 2.10 0.19 0.68 0.02 0.05 0.01 0.95 1.29 1.55 2 C4 0.97 1.62 1.13 0.43 0.89 0.05 0.32 1.09 0.00 1 C5 1.65 0.09 0.20 1.02 1.86 0.25 1.67 2.08 2.20 5 C6 1.19 0.21 1.08 0.74 0.71 0.59 1.56 1.90 2.16 3 C7 1.58 2.00 0.86 1.55 1.64 1.53 1.52 0.23 0.29 6 C8 0.41 1.93 1.62 0.46 1.64 0.95 0.20 2.14 1.68 5

(58) Analysis 4: Analyzing the Surface Roughness of the Electrolytic Copper Foils

(59) According to the standard JIS B 0601-1994, the electrolytic copper foils of Examples 1 to 7 and Comparative Examples 1 to 8 were analyzed for the surface roughness of the drum sides and the deposited sides of the electrolytic copper foils by using the -type surface roughness measuring instrument. The surface roughness of the instant disclosure was represented by ten-point mean roughness. Rz of the drum sides and the deposited sides of the electrolytic copper foils of Examples 1 to 7 and Comparative Examples 1 to 8 was shown in Table 3.

(60) Moreover, an absolute value of a difference in surface roughness between the deposited side and the drum side of the electrolytic copper foils of Examples 1 to 7 and Comparative Examples 1 was respectively calculated by the following formula and listed in Table 3.
Rz=|Rz(the drum side)Rz(the deposited side)|.

(61) Analysis 5: Analyzing the Misalignment Degree of the Electrolytic Copper Foils During the Winding Process of the Electrolytic Copper Foils

(62) In the roll-to-roll process set with a tension of 55 kg, each of the electrolytic copper foils of Examples 1 to 7 and Comparative Examples 1 to 8 was wound by a take-up roll of a diameter of 220 mm at a rolling speed of 8 meters/min.

(63) With reference to FIGS. 2A, 2B, 3A and 3B, the innermost layer of the electrolytic copper foil 50 on the take-up roll 61 had two endpoints A and B, and a distance between endpoints A and B was a transverse width W of the electrolytic copper foil 50. The rolling process was stopped when the length of the electrolytic copper foil 50 wound up on the take-up roll 61 reached 1000 meters. Then, the outermost layer of the electrolytic copper foil 50 on the take-up roll 61 had two endpoints A and B, and a distance between endpoints A and B was also the transverse width W of the electrolytic copper foil 50.

(64) A distance between endpoints A and A was measured and defined as a misaligned length L of the electrolytic copper foil of Examples 1 to 7 and Comparative Examples 1 to 8.

(65) A misalignment ratio was defined as a ratio of the misaligned length L divided by the transverse width W of the electrolytic copper foil 50.

(66) The misaligned lengths and the misalignment ratios of the electrolytic copper foil of Examples 1 to 7 and Comparative Examples 1 to 8 were shown in Table 3.

(67) As listed in Table 3, the quotient of the count of the weight deviation(s) greater than or equal to 1.5% divided by 9 was abbreviated to ratio of the weight deviation(s).

(68) TABLE-US-00004 TABLE 3 ratio of the weight deviation, Rz of the drum side and deposited side, Rz, L, and misalignment ratios of the electrolytic copper foil of Examples 1 to 7 and Comparative Examples 1 to 8 Ratio of the Rz of the Rz of the weight drum side deposited Rz Misalignment deviation(s) (m) side (m) (m) L (mm) ratio (%) E1 0.11 1.02 1.29 0.27 0 0 E2 0.44 1.09 1.39 0.30 0 0 E3 0 1.01 1.27 0.26 0 0 E4 0.22 1.07 1.81 0.74 0 0 E5 0.22 1.09 1.70 0.61 0 0 E6 0.11 1.05 1.55 0.50 0 0 E7 0.11 1.08 1.08 0.00 0 0 C1 0.56 1.09 1.53 0.44 87 6.3 C2 0.78 1.06 1.57 0.51 205 14.9 C3 0.22 1.07 2.02 0.95 26 1.9 C4 0.11 1.04 2.13 1.09 46 3.3 C5 0.56 1.08 1.45 0.37 102 7.4 C6 0.33 1.02 1.89 0.87 37 2.7 C7 0.67 1.06 1.97 0.91 185 13.4 C8 0.56 1.08 1.75 0.67 30 7.5

(69) Discussion of the Results

(70) As shown in Table 1-1, from the analytical results of the statistical standard deviation of the weight of the electrolytic copper foils of Examples 1 to 7 and Comparative Examples 1 to 8, it is not distinguishable whether the electrolytic copper foils of Examples 1 to 7 and Comparative Examples 1 to 8 are prone to misalignment. For example, as shown in Table 1-1, the 3 value of Comparative Example 4 is smaller than the 3 values of Examples 2, 4, and 5 to 7. However, from the results of the misalignment ratio in winding tests in Table 3, it is found that the electrolytic copper foil of Comparative Example 4 still incurs a misalignment during the winding process of the electrolytic copper foil. In addition, as shown in Table 1-2, from the analytical results of the statistical relative range of the weight of the electrolytic copper foils of Examples 1 to 7 and Comparative Examples 1 to 8, it is also not distinguishable whether the electrolytic copper foils of Examples 1 to 7 and Comparative Examples 1 to 8 are prone to misalignment. For example, as shown in Table 1-2, the relative ranges of Comparative Examples 2 and 4 are smaller than the relative ranges of Examples 2, 4, 5 and 7. However, from the results of the misalignment ratio in winding tests in Table 3, it is found that both the electrolytic copper foils of Comparative Examples 2 and 4 still respectively have a misalignment during the winding process. It can be seen that even if the weight of the electrolytic copper foil is controlled within an appropriate range of the standard deviation or within a relatively small range of the relative range, the poor production efficiency of manufacturing the electrolytic copper foil cannot be solved.

(71) As shown in Table 2, from the comparison results of Examples 1 to 7 and Comparative Examples 1 to 8, the counts of the weight deviation(s) greater than or equal to 1.5% of each electrolytic copper foil of Examples 1 to 7 are smaller than or equal to 4. That is, the count of the weight deviation(s) greater than or equal to 1.5% is smaller than the count of the weight deviations smaller than 1.5%. In contrast, the counts of the weight deviations greater than or equal to 1.5% of each electrolytic copper foil of Comparative Examples 1, 2, 5, 7 and 8 are larger than or equal to 5. That is, the count of the weight deviation(s) greater than or equal to 1.5% is larger than a count of the weight deviations smaller than 1.5% in Comparative Examples 1, 2, 5, 7 and 8.

(72) Since each of the electrolytic copper foils of Examples 1 to 7 has the absolute difference in surface roughness between the drum side and deposited side within an appropriate range and each of the electrolytic copper foils is divided into 10 test pieces with the same area along the transverse direction and the counts of the weight deviation(s) between each two adjacent ones of the 10 test pieces are controlled at greater than or equal to 1.5% within an appropriate range, the both sides of the electrolytic copper foils of Examples 1 to 7 can respectively apply similar contact forces to a series of guiding rolls during the winding process. Therefore, it demonstrates that the electrolytic copper foil of the instant disclosure can reduce, even avoid misalignment during the transportation in the roll-to-roll process. Even for the electrolytic copper foil having a wider transverse width such as Examples 1 to 5 and 7 or the electrolytic copper foil having a narrower transverse width such as Example 6, all of them can avoid incurring a misalignment as shown in FIGS. 2A and 2B, in which the endpoints of the outermost layer A and B respectively overlap the endpoints of the innermost layer A and B. As a result, the yield of manufacturing the electrolytic copper foil can be increased, and then the production cost will be reduced.

(73) Moreover, as the Rz of the electrolytic copper foils of Examples 1 to 7 shown in Table 3, even if there is no difference in surface roughness between the deposited side and the drum side of the electrolytic copper foil such as Example 7, as long as the relative weight deviation of the electrolytic copper foil along the transverse direction is controlled in the range defined by the present disclosure, the electrolytic copper foil can avoid incurring the misalignment during the winding process.

(74) Furthermore, from the comparison results of Comparative Examples 1 to 8, the misaligned degrees in Comparative Examples 1, 2, 5, 7 and 8 are higher than the misaligned degrees in Comparative Examples 3 and 6. It demonstrates that the more uniform the thickness of each sub-region of the electrolytic copper foil along the transverse direction is and the more similar the weight of each sub-region of the electrolytic copper foil along the transverse direction is, the misalignment during the winding process is less prone to occur. However, because the electrolytic copper foils of Comparative Examples 3 and 6 do not control the difference in surface roughness between the deposited side and the drum side in the appropriate range, the misalignment still occur (as shown in FIGS. 3A and 3B).

(75) Based on the above experimental results, the instant disclosure can effectively reduce or even avoid incurring the misalignment during the winding process of the electrolytic copper foils by controlling the range of the absolute difference in surface roughness between the opposite sides of the electrolytic copper foils and the range of the relative weight deviation along the width direction of the electrolytic copper foil. Therefore, the instant disclosure can obtain the non-misaligned electrolytic copper foil without cutting off the misaligned part of the electrolytic copper foil in the manufacturing process or improving the manufacturing equipment. Consequently, the aim of increasing the yield of making the electrolytic copper foil and avoiding the increase in production cost can be achieved.

(76) Even though numerous characteristics and advantages of the instant disclosure have been set forth in the foregoing description, together with details of the structure and features of the disclosure, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.