Signal Integrity Analysis Of High Speed Flip Chip Package Interconnection

With the decreasing of the volume of the integrated circuit and continuous improving of the frequency,the requirements of the integrated circuit package are becoming more and more stringent,and the improvement of the integrated circuit packaging technology is very urgent.As the packaging technology is improving,the need for different packaging methods to ensure the signal integrity is also highlighted,and the resulting impact may even bring failure of the integrated circuit production.To solve the electromagnetic compatibility problems caused by packaging technology,we need to start with its structure and explore the design rules to find the source of problems.Flip-chip as a kind of advanced packaging technology has wide application.Traditional methods focus mostly on the material properties of solder joints,which is limited to the reliability of encapsulation,consuming many resources and losing efficiency.This paper combined with the actual application scenario by full wave analysis and lumped parameter parsing analysis its magnetic properties,and the reliability of analysis is verified by experiment,which provides certain guidance function for the design.The main content of this paper are as follows:(1)This paper introduces the multi-port network matrix that can be represented by impedance,admittance and scattering matrix,the corresponding physical meaning and the transformation between them.Secondly,this paper introduces the analysis of the time domain,frequency domain and boundary conditions of transmission line.Moreover,it also analyzes the various discontinuity problems of signal integrity in transmission by combining the lumped parameter model.In order to study the coupling mechanism of crosstalk,capacitive and inductive crosstalk are carried out by analytical analysis.(2)This paper uses 3D full-wave electromagnetic simulation software CST Microwave Studio to study flip-chip packaging in time domain.The signal integrity performance is illustrated by simulating the related structural parameters.Then it gives the simulation of high-speed pulse signal propagation and field distribution.The occurrence of resonance phenomena and crosstalk are analyzed.The differential signal are used to improve the transmission performance.In turn,with reference to the simulation results,the method of experimental test and model parameters are determined.Using the proposed experiment method,on the premise of guarantee required feature model,effectively reduces the cost of the experiment.At the same time,the simulation results are verified.(3)Combining with full wave simulation model,this paper establishes the corresponding analytical structure.Circuit simulation software is used to extract the equivalent circuit parameters.The physical meaning of each part can be specific by establishing the equivalent circuit.In addition,the circuit helps to understand the impact of parasitic parameters on the device.After that,the simulation and test for common discontinuity in the high-speed interconnection structure,such as: signal properties of solder joints,interconnection of a transmission line can be continued.This method can be used to improve the model parameters and make the structure optimization more effective.