Since the width of flip-flop standard cells is relatively much longer than that of the cells of primitive gates, the impact of flipping flip-flop cells horizontally in the placement on routing complexity and timing is significant. However, as yet, no work has addressed the issue of how we can effectively exploit the well-known cell flipping technique to multi-bit flip-flop cells in placement. To this end, in this work, we introduce a concept of D-to-Q signal flipping for cell instances of multi-bit flip-flop where the directions of D-t-Q signal flow of the individual flip-flop instances can be controlled separately and independently. Then, we propose an effective multi-bit cell flipping methodology based on the D-to-Q signal flipping concept with the objective of enhancing routing complexity as well as timing slack in the placement optimization stage. In summary, by using the concept of D-to-Q signal flipping in our cell flipping, we are able to save the total wire length by 0.54% and TNS by 35.60% and WNS by 14.03% on average over the conventional flipping.