Her 36-hole total is a record 14-under 130.
The Frenchwoman holds a two-shot lead over Korea's Hee-Won Han (67).
The former 36-hole scoring record of 131 was set by Michelle Estill in 2004 and matched by Beth Bader in 2007.
"My driving was not so good as yesterday, so I missed some of the fairways," Icher said on the LPGA's Web site. "(But) it's nice to get the record for two low rounds."
Mikaela Parmlid (67), Seon Hwa Lee (67), Na Yeon Choi (68), Sarah Kemp (68), Soo-Yun Kang (69) and Sandra Gal (69) share third place at 10-under 134.
Among those who missed the 3-under 141 cut were Brandie Burton (142), Angela Park (142) and Laura Davies (143).