In Pcb assembly, patch inductance is mainly responsible for choke, decoupling, filtering and tuning.There are two types of patch inductance: winding type and laminated type.So in PCB assembly, how to choose the appropriate patch inductance?Next, the technician of FASTPCBA introduces the selection principle of patch inductance.
1. The width of the patch inductor should be less than the width of the inductor to prevent excessive solder from causing excessive tensile stress during cooling and changing the inductance value.
2. Most of the chip inductance accuracy available on the market is plus or minus 10%. If the required accuracy is higher than plus or minus 5%, an order shall be placed in advance.
3. Some patch inductors can be soldered by reflow welding and wave soldering, but some patch inductors cannot be soldered by wave soldering.
4. During maintenance, the patch inductance cannot be replaced only by the amount of inductance.Know the working frequency band of patch inductance even, ability assures working performance.
5. The shape and size of the patch inductance are basically similar, and there is no obvious mark on the shape.Do not misposition or take the wrong part during manual welding or manual patch.
6. Currently, there are three kinds of common patch inductors: the first type is high-frequency inductance for microwave.Suitable for use in 1GHz and above frequency band.Second, high frequency patch inductance.Suitable for resonant circuit and frequency selection circuit.Third, universal inductance.Generally applicable to dozens of megahertz circuit.
7. Different products have different coil diameters, same inductance and different dc resistance.In high frequency loop, dc resistance has a great influence on Q value, so attention should be paid to the design.
8. The maximum allowable current is also an indicator of the patch inductance.Capacitance must be taken into account when a circuit is required to carry a large current through it.
9. When power induction is used in DC/DC converter, its inductance directly affects the working state of the circuit. In practice, the inductance can often be changed by adding or subtracting coils to obtain the best effect.
10. Coil inductors are commonly used in communication equipment working in the frequency range of 150~900MHz.Microwave high frequency inductor must be used in frequency circuit above 1GHz.
The above is the PCB assembly, the choice of patch inductance when the ten points of attention.Better selection of patch inductance, in order to better ensure PCB assembly quality.FASTPCBA (www.cnpcba.cn) will also continuously improve the quality to provide customers with better service.