Новости PCB - анализ линейных импедансов при проектировании панелей PCB

At present, in the PCB manufacturing of printed circuit boards, the wires are mostly copper wires. физические свойства самого медного металла определяют определённое сопротивление в процессе проводимости. The inductance components in the wires will affect the transmission of voltage signals and resistance. Этот элемент будет влиять на передачу токовых сигналов, and the influence of the inductance in the high-frequency line is particularly prominent.

провод на печатной плате можно рассматривать как прямоугольную медную ленту с необычными правилами. Let’s take a piece of wire 10cm long, 1.5mm wide, в качестве примера можно привести 50 тысяч штук толщиной. The impedance can be seen by calculation. .
The wire resistance can be calculated by the formula:
R=ρL/s (Ω)
where L is the length of the wire (meters), s is the cross-sectional area of the wire (square millimeters), and ρ is the resistivity ρ=0. 02. The resistance value of the wire is calculated to be about 0.026 ©.
When a piece of wire far away from other conductors is much longer than its width, коэффициент самоиндукции проводов составляет 0.8: 00/m, затем индуктивность 10 - сантиметрового провода длиной в 0.08μH. Then we can use the following formula to find the inductive reactance presented by the copy board wire:
XL=2πfL
where π is a constant, f is the frequency of the signal passing through the wire (Hz), and L is the self-inductance per unit length of the wire (H). In this way, we can calculate the inductance of the wire at low frequency and high frequency respectively:
When f=10KHz, XL = 6.28*10*103*0. 08*10-6≈0. 005Ω;
When f=30MHz, XL = 6.28*30*106*0.08*10-6≈16Ω
Through the above formula calculation, мы видим, что при передаче сигналов низкой частоты сопротивление проводов превышает индуктивность проводов, while the wire inductance is much greater than the wire resistance in high-frequency signals.

The above is the introduction of wire impedance interference analysis of PCB copy board design. Ipcb is also provided to Производители PCB технология производства PCB