An electrophysiological catheter comprising: an elongated body; a distal electrode assembly (15, 115) comprising: a plurality of spines (42, 142), each spine having a free distal end and a proximal end extending from a distal end of the elongated body; and a flexible panel (80, 180) wrapped around and affixed to an outer surface of at least one spine, the flexible panel having a substrate (81, 181) conforming to the outer surface of the at least one spine, at least one pair of microelectrodes (85, 185), a trace for each microelectrode (87, 187), and a soldering pad (88,188) for each microelectrode, wherein each trace electrically couples a respective microelectrode and a respective soldering pad, wherein said substrate comprises a first layer (81a, 181a), a second layer (81b, 181b) and a third layer (81c, 181c), and wherein said at least one pair of microelectrodes is disposed on the first layer, and wherein electrical traces are disposed on the second layer and the third layer, and wherein through holes (86, 186) are formed in the first layer and second layer to provide connection access between the microelectrodes and the electrical traces. an elongated body; a distal electrode assembly (15, 115) comprising: a plurality of spines (42, 142), each spine having a free distal end and a proximal end extending from a distal end of the elongated body; and a flexible panel (80, 180) wrapped around and affixed to an outer surface of at least one spine, the flexible panel having a substrate (81, 181) conforming to the outer surface of the at least one spine, at least one pair of microelectrodes (85, 185), a trace for each microelectrode (87, 187), and a soldering pad (88,188) for each microelectrode, wherein each trace electrically couples a respective microelectrode and a respective soldering pad, wherein said substrate comprises a first layer (81a, 181a), a second layer (81b, 181b) and a third layer (81c, 181c), and wherein said at least one pair of microelectrodes is disposed on the first layer, and wherein electrical traces are disposed on the second layer and the third layer, and wherein through holes (86, 186) are formed in the first layer and second layer to provide connection access between the microelectrodes and the electrical traces. a plurality of spines (42, 142), each spine having a free distal end and a proximal end extending from a distal end of the elongated body; and a flexible panel (80, 180) wrapped around and affixed to an outer surface of at least one spine, the flexible panel having a substrate (81, 181) conforming to the outer surface of the at least one spine, at least one pair of microelectrodes (85, 185), a trace for each microelectrode (87, 187), and a soldering pad (88,188) for each microelectrode, wherein each trace electrically couples a respective microelectrode and a respective soldering pad, wherein said substrate comprises a first layer (81a, 181a), a second layer (81b, 181b) and a third layer (81c, 181c), and wherein said at least one pair of microelectrodes is disposed on the first layer, and wherein electrical traces are disposed on the second layer and the third layer, and wherein through holes (86, 186) are formed in the first layer and second layer to provide connection access between the microelectrodes and the electrical traces.