patterned first metal layer 223 323 a patterned first insulating layer 225 u2032 325 u2032 a patterned semiconductor layer 227 327 a patterned metal multilayer 229 329 a patterned second insulating layer 235 335 and a patterned conducting layer 237 337 from bottom to top the materials of each layer the devices included in each layer the corresponding positions between each layer and each device and the equal alterations are substantially as aforesaid and are not described herein as shown in fig8 a and 14a the characteristics of the active device array substrate according to the present invention is that the second metal layer 229 a 329 a of the patterned metal multilayer 229 329 among the active device array substrate is provided with under cut structures at the openings 239 a 239 b 339 a 339 b i e the inward apertures between the patterned second insulating layer 235 335 and the third metal layer 229 b 329 b besides as shown in fig8 b and fig1 b the second metal layer 229 a 329 a is also provided with under cut structures and still as shown in fig8 c and fig1 c the upper metal layer 223 a 323 a also has under cut structures because.