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Frequency High-speed PCB Board Material Requirements are Introduced

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The rapid progress of the communications industry, the original civilian communications frequency band congestion, high frequency communications part of the frequency band (military) gradually let the civilian. Civilian high frequency communications to obtain extraordinary speed development. Satellite reception, base station, navigation, medical, transportation and other fields to show their hands.

High confidentiality and high transmission quality require cell phones, automobile power stations, and wireless communications to develop in the direction of high frequency. High picture quality requires high frequency broadcasting of programs for radio and television transmission. High information transmission requires satellite communications, microwave communications, and fiber optic communications to be high frequency.

Computer technology to increase the processing capacity, information storage capacity increases, the urgent need for high-speed information transmission. Therefore,electronic information products, high frequency, high-speed PCB board put forward the requirements of high frequency characteristics.

A, High Frequency and High-speed PCB Board Material Requirements

  1. a, Low dielectric constant (Low Dk): low dielectric constant can enhance the signal transmission speed.
  2. b, Low fugitive (dissipation) factor (Low Df): with the increase in frequency, the loss of strength will also increase, so high frequency high-speed communication more low fugitive factor materials to design and production.
  3. c, Conductor surface roughness.

The higher the signal frequency, the more pronounced skin effect (Skin effect), so the signal transmission conductor surface the flatter the better.

εeff: dielectric constant (Effective dielectric constant).

tanδ: Dissipation factor (Dissipation factor).

f: Frequency.

c: Speed of light (Light speed).

B, The Dielectric Constant: Dk or Er(ε)

Each "unit volume" of insulating material, in each unit of the "potential gradient" can save "electrostatic energy" of the amount. How much electrostatic energy can be stored per unit of potential gradient." The "dielectric constant" (or transmittance) of the insulating material should be as small as possible. Currently the board to Teflon (PTFE), in the 1MHZ frequency dielectric constant of 2.5 is the best, FR-4 about 4.7. circuit board can be regarded as a capacitive device, the wire signal transmission, there will be part of the energy is accumulated by the circuit board, resulting in transmission delays, the higher the delay is more pronounced frequency.

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C, Fugitive Factor: Df

A measure of the loss of AC power in function. A characteristic of insulating materials (resins). Proportional to the loss of electrical work seen, and the cycle frequency (f), the square of the potential gradient (E2), and the unit volume is inversely proportional.

D, The Conductor Surface Roughness

Conductor surface roughness morphology of the resistance to heat, resulting in the loss of signal energy, both for the conductor loss. The higher the frequency, the shorter the wavelength, the signal traveling between the conductor, will only be concentrated on the surface of the conductor, that is, the "skin effect". The flatter the surface roughness is, the more favorable the signal transmission, the PCB layer followed by the strength of the conductor surface roughness. The higher the surface roughness of the conductor, the larger the adhesion area between the resin and the conductor, and the higher the adhesion strength.

E, Copper Foil

  1. a, According to the production process can be divided into:
    ① Electrodeposited copper foil (Electrodeposited copper foil)
    Advantages: cheap; can have a variety of sizes and thickness;
    Disadvantages: poor ductility; very high stress can not be bent and easily broken.
    ② Rolling copper foil (Rolled-wrought copper foil)
    Advantages: high ductility, excellent reliability for FPC use in dynamic environments; low surface prisms, very favorable for Microwave electronic applications;
    Disadvantages: poor adhesion to the substrate; high cost; limited width due to technical problems.
  2. b, According to the performance of copper foil can be divided into:
    ① High-temperature extensibility copper foil with reverse side treatment;
    ② Double-sided treatment of copper foil ultra-low diamond wire copper foil;
    ③ Ultra-thin copper foil standard electrolytic copper foil.

We are a professional 2-36 layers of high frequency PCB circuit board manufacturers, can be expedited production of PCB boards, high frequency boards, special circuit boards, microwave RF boards, antenna boards and other products, standing Rogers, Taconic, F4B, TP-2, FR-4 and other boards, dielectric constant 2.2 -The dielectric constant varies from 2.2 to 10.6. You can contact us if you have any demand.

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