Sandwich-Layered Dielectric Film with Intrinsically Excellent Adhesion, Low Dielectric Constant, and Ultralow Dielectric Loss for a High-Frequency Flexible Printed Circuit

Abstract

With the high-frequency development of highspeed communication electronic devices, excellently adhesive materials with low dielectric constant and ultralow dielectric loss have been highlighted. However, intrinsically strong adhesive materials (e.g., epoxy) with numerous polar functional groups disappointingly deteriorate their high-frequency dielectric properties. Herein, a double cross-linked network of maleic-anhydride polybutadiene−amino-terminated polyimide oligomers (MAPB-PIO) is synthesized, and then a novel sandwich-layered dielectric film (MAPB-PIO/polytetrafluoroethylene (PTFE)/MAPB-PIO) is prepared through double-sided coating. The MAPB-PIO/PTFE/ MAPB-PIO film exhibits low dielectric constant (D k = 1.9929) and ultralow dielectric loss (D f = 0.0012) at 10 GHz. Meanwhile, the interface peel strength reaches 0.912 N/mm. Additionally, the MAPB-PIO/PTFE/MAPB-PIO film is successfully applied to manufacture a flexible printed circuit board (PCB) and shows an outstanding high-frequency signal transmission capability; i.e., signal loss is 26.45 dB at 18 GHz, which is only 43% of the commercially available epoxy resin PCB. All results indicate that the flexible MAPB-PIO/PTFE/MAPB-PIO film is highly promising for applications in next-generation flexible electronics and radiofrequency devices, especially in the millimeter wave field.

Perfluorocyclobutyl-containing transparent polyimides with low dielectric constant and low dielectric loss

“…Polymers with excellent dielectric properties have drawn great attention in the field of integrated circuits (ICs), especially for ultra-large-scale integration (ULSI) circuits and high-speed IC packing, as well as for flexible printed circuit boards (FPCBs) at high frequency. [1][2][3][4][5] With the rapid development of ULSI circuits, advanced chips generally integrate billions of transistors. The average size of metal interconnects has shrunk to the order of 10 nm; however, this is accompanied with increased wire resistance and RC signal delay.…”

Hydrocarbon Resin-Based Composites with Low Thermal Expansion Coefficient and Dielectric Loss for High-Frequency Copper Clad Laminates

“…Based on ternary composite materials (PB/styrene/butadiene/styrene triblock copolymer (SBS)/ethylene/propylene/dicyclopentadiene (EPDM)), Bo and Wu et al found that appropriate crosslinking agents can more effectively enhance the degree of the crosslinking reaction in the material, and the modification of SiO 2 microspheres can improve the interfacial compatibility of different phases [ 15 , 16 , 17 , 18 ]. Xuan and Zhang et al designed a sandwich-structure composite material [ 19 , 20 ], with an intermediate layer of polytetrafluoroethylene (PTFE) and outer layers consisting of PB films or malefic–anhydride polybutadiene–amino-terminated polyamide oligomers films, achieving an ultra-low D f (0.0012). All these developed copper-clad laminate materials with excellent performance have made important contributions to the field of high-frequency substrates.…”

Structure, Properties, and Modification of Polytrifluorochloroethylene: A Review

“…Ultra-large-scale integrated circuits (ICs) with ultrahigh integration, lower power consumption, and higher performance raise more stringent requirements for high-frequency dielectric polymeric materials. Nevertheless, along with the high integration and miniaturization of ICs, mutual interference easily occurs between nearby interconnects, resulting in resistance-capacitance delay and an increase in crosstalk (Zhao and Liu, 2010;Zhang et al, 2021). Therefore, novel polymer materials with controlled dielectric constant and low loss have attracted more and more attention all over the world.…”