Signal Integrity Analysis Of The Die-PCB Interconnect Structure

The ever-increasing demands of digital computing and wireless communication have been driving the semiconductor technology to change with each passing day.BGA package can meet the intensive design requirements and package thickness of Integrated circuit(IC),but produce complex electromagnetic environment,which made signal integrity(SI)become one of the main issues in IC design.With the increase of frequency,the parasitic between the interconnect unit composed of the via,the solder ball and the printed wire,can affect SI seriously.The past research methods which was suitable for low frequency is no longer applicable,so it is necessary to use accurate method to represent SI in circuit design.The main work of this paper includes:1.Based on the analysis of the basic theory of signal integrity,this paper focuses on the analysis of the electromagnetic effect and the commonly modeling methods of electronic packaging.2.Taking the BGA-PCB interconnection structure as the research object,the equivalent circuit model is established.Using CST to simulate the interconnect structure,and the vector network analyzer(VNA)is used to test the real circuit board.A comparison will be made,and the experimental results are basically consistent,and verify the validity of the experiment.3.The experimental study on the SI of interconnection structure.Firstly,a single interconnect structure model was introduce,then analyze the transmission characteristics of variable factors,like ball shape,solder ball diameter,substrate material,and the number of grounded holes.Then a series of experiments are carried out to establish the adjacent and differential BGA-PCB interconnect structure.Due to the electromagnetic coupling effect by high frequency,the near and far end crosstalk is studied based on key parameters are analyzed,and discuss how to achieve better differential mode transmission characteristics and reduce the effect of common mode interference.According to the research results,suggestions are made to apply to modeling and signal integrity research of high speed circuit and packaging,and provided theoretical basis for the design,manufacture and test of high speed circuit.