An Analysis of the Core Differences in Dielectric Properties Between Hydrocarbon Resins and Epoxy Resins

As the global electronic information industry advances into the 5G, 6G, and AI computing era, printed circuit boards (PCBs)—as the carriers of signal transmission—are facing unprecedented frequency challenges. In high-frequency, high-speed circuit design, the selection of substrate materials directly determines the quality and efficiency of signal transmission. For a long time, epoxy resin has dominated half of the PCB market; however, under GHz-level frequency conditions, Hydrocarbon resin Leveraging its unparalleled dielectric advantages, it has become the inevitable choice for high-performance substrates. 
I. Molecular Structure Determines the Dielectric Nature 
The fundamental difference in performance between epoxy resins and hydrocarbon resins stems from their distinct microscopic chemical structures. Traditional epoxy resins feature polymer chains rich in highly polar functional groups such as hydroxyl and ether linkages. Under the influence of a high-frequency electric field, these polar groups undergo vigorous dipole reorientation polarization as the field direction alternates, resulting in substantial dielectric loss. 
In comparison, Hydrocarbon resin It is primarily composed of nonpolar carbon–hydrogen and carbon–carbon bonds. Its molecular structure is highly symmetrical and exhibits extremely low polarity, resulting in virtually no orientational polarization at high frequencies. This intrinsic physical property confers inherent advantages to hydrocarbon resins in terms of dielectric constant and dielectric loss tangent. Typically, the Df of epoxy resins ranges from 0.015 to 0.020, whereas high-performance hydrocarbon resins can maintain a Df below 0.002—a critical performance metric in applications with stringent signal-integrity requirements, such as radar systems, antennas, and data centers.

II. Signal Loss and the Leap in Transmission Rate 
In PCB design, signal transmission loss is directly proportional to the Df value. Using Hydrocarbon resin The substrate material can significantly reduce signal energy absorption within the dielectric layer. For high-frequency signals, low loss translates into longer transmission distances and higher fidelity. Moreover, hydrocarbon resins’ lower dielectric constant (typically between 3.0 and 3.5, compared with FR-4’s typical value of 4.2 or higher) effectively shortens signal propagation delay and enhances system response speed. In millimeter-wave radar sensing for autonomous driving, this nanosecond-level speed advantage is directly linked to system safety. 
III. Comparison of Environmental Stability and Reliability 
In addition to its superior electrical performance, hydrocarbon resin also outperforms epoxy resin in terms of environmental reliability. Epoxy resins exhibit a certain degree of water absorption; as highly polar molecules, water molecules can significantly increase the dielectric constant (Dk) and dissipation factor (Df) when they penetrate the substrate, leading to impedance mismatch in the circuit. In contrast, hydrocarbon resins boast excellent hydrophobicity, with a typical water absorption rate of less than 0.05%, which ensures that printed circuit boards maintain stable electrical performance even under extreme high-temperature and high-humidity conditions. 
Meanwhile, in conjunction with advanced crosslinking agents and coupling agents, Hydrocarbon resin Copper-clad laminates (CCL) exhibit excellent thermal and dimensional stability, enabling them to withstand multiple thermal shocks during lead-free soldering without delamination or via cracking. 
Although epoxy resins offer advantages in terms of cost and processing maturity, carbon-hydrogen resins have become the irreplaceable core substrate in high-frequency, high-speed applications. Desytek has devoted itself to the modification and R&D of high-performance carbon-hydrogen resin systems; through systematic formulation optimization, it has not only overcome the challenge of poor adhesion in carbon-hydrogen materials but also translated their exceptional dielectric performance into a key competitive advantage for end products. In the selection of substrates for high-frequency PCBs, choosing carbon-hydrogen resins means choosing the path to future communication efficiency.

Desytek New Materials It is a pioneering innovator in advanced optoelectronic materials. Its main products include: Hydrocarbon resin, high-frequency and high-speed hydrocarbon resin, crosslinking agent, coupling agent, reactive flame retardant Please feel free to call our consultation hotline: 027-81801908 or 13971395740 (same number on WeChat). We will provide you with tailored, professional services!