Copper wire embeding antenna inlay

The traditional prewinding copper wire embeding antenna processing to manufacture a contactless card since last century, the only way for producing low frequency card inlay, low and High frequency, card ,tag in any shape
WAFER + COB (chip on PCB borad) + Copper Coil Antenna
Advantage:
1, Manual producing, no special machine need,
2, Flexibility of Quantity, antenna customize , low cost,
3, Only Choice for Low frequency card
Weakness:
1, Un-flatness in card surface, position of COB visible
2, Tolerance of antenna frequency
3, Thickness of card