Phosphinated polyimide hybrid films with reduced melt-flow and enhanced adhesion for flexible copper clad laminates

Wang

et al. 2022

Ind. Eng. Chem. Res.

In the manufacturing field of high-frequency print circuit boards (HFPCBs), traditional adhesive films (such as epoxy resin and polyimide adhesive films) have attracted enormous attention because of their superior adhesive property. However, their molecular chains intrinsically contained numerous polar groups (carboxyl, carbonyl, and amino), which markedly increased the dielectric constant (D k ) and dielectric loss (D f ) of the adhesive film, causing miserable deterioration of the fidelity and transmission rate of signals. In this work, a novel sandwich-like adhesive film was felicitously designed and fabricated by double-sided coating. The core layer as a supporting structure was a polytetrafluoroethylene film with a low dielectric constant and low dielectric loss, and the surface layer as a principal part of the adhesive function was polybutadiene with high vinyl content. Moreover, to further improve the interfacial adhesive strength between the adhesive film and copper foil, the fluorine-containing groups were controllably introduced onto the surface of the sandwich-like adhesive film via environment-friendly plasma treatment. Based on low polarizability and only superficial distribution of the fluorine-containing groups, the interfacial adhesive strength of the film greatly improved from 0.41 to 1.09 N/mm. Unexpectedly, the high-frequency dielectric properties slightly changed (without treatment D k = 2.42 and D f = 0.0036 at 10 GHz, treatment D k = 2.46 and D f = 0.0039 at 10 GHz). This work provided the key adhesive materials for the next generation of high-throughput data transmission equipment, remote sensing controllers, and unmanned aerial vehicles in high-frequency ranges.

Section: Resultsmentioning

confidence: 99%

Section: Atomic Force Microscopymentioning

confidence: 99%

Ingenious Sandwich-like Adhesive Films and Controllable Introduction of Fluorine-Containing Groups toward Strong Adhesive Strength and Low Dielectric Characteristics

Wang

et al. 2022

Ind. Eng. Chem. Res.

ACS Appl. Polym. Mater.

“…Among the plenty of organic polymer-based materials, polytetrafluoroethylene (PTFE), polystyrene (PS), fluorinated polymers, and polyimide (PI) have drawn considerable attention. Among them, PI and composite PI materials has been widely used as CCLs due to their great thermal stability and electrical insulation. − Regardless, the CTE of commercial PI films such as Kapton is still relatively high, which may lead to poor compatibility with common conductive materials. Besides, the high dielectric constant at high frequencies cannot meet the demand for high-speed transmission of fifth-generation (5G) signals .…”

Section: Introductionmentioning

confidence: 99%

Flexible, Strong, and Easy-Manufacturable PPTA Film and Its Potential Application for High-Frequency Flexible Copper Clad Laminates

Li,

Jiang,

Zhang

et al. 2024

As an irreplaceable basic material of fifth-generation mobile communication, stringent requirements have been proposed for the polymer-based copper clad laminates (CCLs). Thus, state-of-the-art mechanically and thermally robust CCLs with desirable dielectric properties are very sparse. Herein, the flexible poly(p-phenylene terephthalamide) (PPTA) film, for CCLs, based on PPTA fibrids and spontaneous-gelling low-molecular-weight PPTA solution was obtained by gelation, washing, and pressing. The fabricated composite PPTA film was proved to combine desirable mechanical properties, minimal coefficient of thermal expansion, outstanding dielectric properties, and superior thermal stability. Significantly, this study provides a facile and low-cost strategy for the fabrication of extraordinary CCLs to satisfy the demand of industrialization for the rapid development of electronic information.

Int J RF Mic Comp-Aid Eng

“…Besides Dk and Df, the electrical performances of designed circuits are related to some other parameters of CCL, such as the moisture absorption, thermal coefficient, copper peel, and so on, and even the CCL manufacturing process, especially for the frequency of millimeter‐wave or terahertz bands. In recent years, the researchers mainly focus on some areas for circuit performance improvements, such as the performance investigation for accurate design of various circuits, 1,2 flexion modification for flexible or conformal applications, 3–5 improvement of manufacturing process, 6,7 usage of advanced material, 8 and gap waveguide technique 9,10 . It is known that the adhesive layer is normally necessary in traditional lamination process, which is composed of epoxy and acrylic resin.…”

Section: Introductionmentioning

confidence: 99%

Cyclic olefin copolymer‐based copper clad laminate and the application for low loss broadband baluns

Zheng

Chen

et al. 2021

In this article, a novel copper clad laminate based on cyclic olefin copolymer (COC) is proposed and manufactured by using lamination process. The loss characteristic of manufactured laminate is investigated by comparing the measured results of two microstrips on proposed COC‐based laminate and traditional Rogers RT/duroid 5880, respectively. Moreover, the SIW/HMSIW baluns operated at X‐band are designed on the proposed laminate, and the measured results verify the inherent out‐of‐phase performance and good amplitude characteristics in broadband frequency range. This work shows a novel type of high‐frequency circuit boards on COC material, which is significantly to be one of the advanced candidates for microwave/millimeter wave circuit applications.