Circuit board and manufacturing method thereof

[0065] Example 1

[0066] (1) Pre-treatment

[0067] After the aluminum substrate is cleaned, it is immersed in a degreasing solution at a temperature of 50-60° C. for 10 minutes, and then the degreasing aluminum substrate is placed in a polishing solution for 15 minutes of polishing. Among them, the composition of the solution used in degreasing is: NaOH 10g / L, Na 3 PO 4 30g / L, Na 2 CO 3 15g / L, sodium dodecyl sulfonate 6g / L, with water as solvent. The composition of the polishing liquid used for polishing is: H 2 SO 4 20% by weight, HNO 3 10% by weight, H 3 PO 4 70% by weight, with water as solvent.

[0068] (2) Anodizing

[0069] The aluminum substrate obtained in step (1) is used as the anode and immersed in the electrolyte at a temperature of 40°C, while the stainless steel is used as the cathode, the cathode and the anode are electrically connected to the positive and negative electrodes of the power supply, and then a voltage of 18V is applied for electrolysis , An a

[0090] Example 2

[0091] The circuit board was prepared by the same method as in Example 1, except that step (3) was performed by the following method:

[0092] The aluminum substrate obtained in step (2) is immersed in a lanthanum chloride aqueous solution at 96° C. for 30 minutes. Wherein, the concentration of lanthanum chloride in the solution is 0.05 mol / L, and the pH value of the solution is in the range of 5-5.5.

[0093] After testing, the content of lanthanum in the alumina layer was 0.11% by weight.

[0094] After calculation, the plating speed is 2.0μm / h. After testing, the adhesion of the coating formed by electroless plating is ISO grade 0, the thermal conductivity of the obtained circuit board is 17W / (m·K), and the breakdown voltage is 2.3kV.

[0095] Example 3

[0096] The circuit board was prepared by the same method as in Example 1, except that step (4) was performed by the following method:

[0097] At least part of the surface of the aluminum oxide layer on the surface of the aluminum substrate obtained in step (3) is irradiated with a laser to form a circuit pattern. Among them, the conditions of laser irradiation include: using a fiber laser, a laser wavelength of 1064nm, a power of 25W, a frequency of 50kHz, a line speed of 100mm / s, and a filling interval of 0.05mm.

[0098] After calculation, the plating speed is 2.5μm / h. After testing, the adhesion of the plating layer formed by electroless plating is ISO grade 0, the thermal conductivity of the obtained circuit board is 16W / (m·K), and the breakdown voltage is 2.3kV.