Research On Auto-routing Algorithm In FPC Channel

Routing is a very important and time-consuming stage in EDA,and its degree of automation is very high in integrated circuit design.However,the automation efficiency in printed circuit board(PCB)layout design,especially flexible printed circuit(FPC),is not high,and can not meet the requirements of FPC non right angle routing.According to the actual requirements of Huawei Terminal Co.,Ltd.for mobile phone design,according to the characteristics of FPC cabling,this thesis proposes a FPC top-level planning algorithm based on simulated annealing and a fast channel detailed routing algorithm.The channel in FPC routing area is divided,and the global routing planning is realized by simulated annealing.Finally,the detailed routing of FPC channel is realized based on computational geometry.The main work of this thesis is as follows:The main work of the thesis is as follows:(1)Through the analysis and induction of many FPC cases,this thesis summarizes the characteristics of FPC routing problems,such as fewer routable areas,available route direction references and fewer obstacles in routing area,and their similarities and differences with other PCB routing problems,which lays a foundation for the modeling of FPC routing problem.(2)According to the characteristics of FPC,a top-level planning algorithm of FPC based on simulated annealing is proposed.Firstly,the FPC routing area is divided into fan-out area and channel area.The fan-out area routing problem is similar to the PCB,while the channel routing problem is very different from the PCB scene.The FPC channel routing resources are limited and cannot meet the signal integrity.The algorithm proposed in this thesis considers both the signal integrity of each network and the hierarchical planning of the network that meets the electrical constraints.Taking the minimum number of through holes and the minimum fan out cross-section resource occupancy as the optimization objectives,the simulated annealing algorithm is used to optimize,and the hierarchical sequencing and ranking of each network are obtained to realize the global routing planning.(3)A fast detailed routing algorithm in channel area is proposed.Firstly,the algorithm builds a pin-line-channel(PLC)model to extract the hidden routing direction information in the channel area,which can automatically identify the routing channels and routing objects;Then,the detailed routing of FPC channel area is realized based on computational geometry,which makes the routing result have high space resource utilization and routing efficiency under the condition of meeting the layout design rules;Finally,the thesis optimizes the linetype of some networks that violate the design rule check(DRC).