ICC中用route_flip_chip对RDL层进行route，为什么不成功啊？求帮助

我用ICC的route_flip_chip命令对RDL层自动route，但每次都不成功，请问是什么原因?有什么解决方法呢?

icc的命令提示如下：

tr: traversing final connectivity.....
[attempts# = 6, 0 has global point(s)]
[push along links # = 0]
total of 1 nets in the target
total of 0 completed nets
total of 0 nets with violations
total of 1 incomplete nets
total of 2 remaining opens
total of 0 remaining violations

tr: Time Usage Information:
-----------------------------------------------------------------
Stages Elapse CPU Elapse CPU
Pass 1:
.... pushing 0:00:00 0:00:00
.... rip-up 0:00:00 0:00:00
.... normal routing 0:00:00 0:00:00
.... force routing 0:00:00 0:00:00
.... total in pass 0:00:00 0:00:00
Last Push: 0:00:00 0:00:00
TOTAL: 0:00:46 0:00:45
------------------------------------------------------------------

tr: Violation/Open Information:
-----------------------------------------------------------------
Pass violation# net# w/vio open# net# w/open
1 0 0 <-- at starting
0 0 <-- after pushing
0 0 2 1 <-- after routing
Last-P 0 0 <-- after last pushing
-------------------------------------------
FINAL 0 0 1 1 (0 portInsts w/ violations)
-----------------------------------------------------------------
tr: (tuning): maximum failing heapTop before success route after swap = 0
tr: recovery temporarily ignored var rule for 1 nets
tr: flip chip routing target ended.
tr: A net group of 1 nets is created for target
tr: 1 open in net bPci_ad[23]
tr: total of 1 nets in file .trUnrouted

木有人知道吗?