What are the parameters of एपॉक्सी राल बोर्ड

In order to achieve the best use effect of epoxy resin board, some parameters are required. In the following, professional manufacturers will give us a detailed introduction. Come and learn more about it.

Parameter classification of epoxy resin sheet: dielectric constant parameter, dielectric loss parameter, TG value parameter

Epoxy resin sheet is a double-sided copper-clad PCB sheet made of epoxy resin + glass cloth. The commonly used FR4 copper-clad sheet has a relative dielectric constant of 4.2-4.7. This dielectric constant will change with temperature. In the temperature range of 0-70 degrees, the maximum change range can reach 20%. A change in the dielectric constant will cause a 10% change in the line delay, and the higher the temperature, the greater the delay. The dielectric constant will also change with the signal frequency. The higher the frequency, the smaller the dielectric constant. In general, the classic value of the dielectric constant is 4.4. The dielectric constant changes with frequency as shown in Fig.

The dielectric constant (Dk, ε, Er) determines the speed at which electrical signals travel in the medium. The speed at which electrical signals travel is inversely proportional to the square root of the dielectric constant. The lower the dielectric constant, the faster the signal transmission. Let’s make a visual analogy. It’s like you are running on the beach, and the depth of water submerges your ankles. The viscosity of water is the dielectric constant. The more viscous the water, the higher the dielectric constant, and the slower you run.

The dielectric constant is not very simple to measure or define. It is not only related to the characteristics of the medium itself, but also to the test method, test frequency, and the state of the material before and during the test. The dielectric constant will also change with the change of temperature. Some special materials take into account the temperature factor in the development. Humidity is also an important factor affecting the dielectric constant, because the dielectric constant of water is 70, and there is very little moisture. , will cause significant changes.

Dielectric loss of epoxy resin sheet: the energy loss inside the insulating material due to the hysteresis effect of dielectric conductance and dielectric polarization under the effect of electric field. Also called dielectric loss, referred to as dielectric loss. Under the effect of the alternating electric field, the complementary angle δ of the included angle (power factor angle Φ) between the current phasor and the voltage phasor flowing in the dielectric is called the dielectric loss angle. The dielectric loss of epoxy resin sheet is generally 0.02, and the dielectric loss will increase with the increase of frequency.

TG value of epoxy resin sheet: also known as glass transition temperature, generally 130 ℃, 140 ℃, 150 ℃, 170 ℃.