A manufacturing method of an oleophobic and hydrophobic film on a 5000 series aluminum alloy, comprising:
- a step of performing primary anodic oxidation on a 5000 series aluminum alloy for 1 to 10 minutes at 35 to 45 V (step 1);
- a step of performing pore widening by immersing the alloy in 0.05 to 1.0 M phosphoric acid (H3PO4) solution for 10 to 60 minutes (step 2);
- a step of performing secondary anodic oxidation for 1 to 10 minutes at 35 to 45 V (step 3);
- and
- a step of coating with a coating composition including a cross-linked polydimethylsiloxane (PDMS) derivative represented by Chemical Formula 1 and an organic solvent (step 4),
- wherein prior to step 1, a pre-patterning process is omitted,
- wherein in Chemical Formula 1, x and y are each an integer of 1 to 30.