Metal-resin composite, surface treatment method, and substrate of circuit board for high-frequency and high-speed signal transmission

A manufacturing method of a surface-treated metal for metal-resin bonding, wherein the metal is aluminum or an aluminum alloy, wherein a nano-scale pore array for filling of a resin is provided to extend from a surface to an interior of a metal, and nano-scale pillars are provided to extend from bottoms to openings of at least one of nano-scale pores of the nano-scale pore array;

• the nano-scale pores each have a depth of 20 nm to 10 μm and a pore size of 20 nm to 1 μm;
• the nano-scale pillars each have a length of 10 nm to 9.9 um and a diameter of 20 nm to 950nm;
• the surface of the metal has a porosity of 0.1 to 0.9;
• the nano-scale pillars have a same chemical composition as walls of the nano-scale pores;
• a material for the walls of the nano-scale pores is a metal oxide;
• an included angle between a central axis of each of the nano-scale pores and the surface of the metal is 60° to 90°;
• an included angle between each of the nano-scale pillars and a central axis of a corresponding nano-scale pore is 0° to 30°;
• the nano-scale pores provided with the nano-scale pillars account for 10% to 100% of all the nano-scale pores on the surface of the metal;
• and
• the metal is selected from a group consisting of aluminum, magnesium, copper, titanium, iron, zinc, and an alloy thereof;
• and the resin is selected from a group consisting of a thermoplastic resin and a thermosetting resin, wherein the manufacturing method comprises the following steps:
• S1:
• cleaning a surface of an original metal to obtain a first metal intermediate, and placing the first metal intermediate as a first anode in an electrolytic cell for polishing to obtain a second metal intermediate;
• S2:
• placing the second metal intermediate as a second anode in a first acidic solution, and conducting anodic oxidation at a voltage of 10 V to 100 V and a temperature of −10° C. to 30° C. for 3 min to 300 min to obtain a third metal intermediate, wherein the first acidic solution comprises 0.1 wt % to 25 wt % of one or more acids selected from a group consisting of sulfuric acid, phosphoric acid, oxalic acid, chromic acid, boric acid, benzoic acid, citric acid, and tartaric acid, and a solvent of the first acidic solution is pure water or a water-ethylene glycol mixed solvent comprising 0.1 wt % to 80 wt % of ethylene glycol;
• and a current density for the anodic oxidation is less than 1.5 mA/cm2;
• S3:
• soaking the third metal intermediate in a second acidic solution I time to 20 times for 1 min to 90 min each time to allow pore expansion to obtain a fourth metal intermediate, wherein the second acidic solution comprises 0.1 wt % to 25 wt % of one or more acids selected from the group consisting of sulfuric acid, phosphoric acid, oxalic acid, chromic acid, boric acid, benzoic acid, citric acid, and tartaric acid, and has a strong acidity, but exhibits a weak dissolution-oxidation ability for a metal oxide;
• a temperature of the second acidic solution is maintained at 0° C. to 100° C.;
• and a metal product obtained after the soaking each time is washed with water and then blow-dried with cold air;
• and
• S4:
• rinsing and oven-drying the fourth metal intermediate.