The SMT chip mounter equipment must be inspected regularly to improve production efficiency; in addition, the total width of the SMT chip inductor is lower than the total width of the inductor.
SMT chip processing should pay attention to the placement process, and the placement machine equipment must be checked regularly to improve production efficiency; in addition, the total width of the chip inductor should be lower than the total width of the inductor to avoid excessive welding materials When the water is cooled, excessive tensile stress changes the inductor value. Next, I will introduce you to the detailed content.
1. Precautions for SMT chip processing
1. When performing smt patch processing, everyone knows that solder paste is basically applied. For the newly purchased solder paste, if it is not applied immediately, the SMT factory needs to store it in an environment of 5-10 degrees, so as not to affect the application of the solder paste. In a zero degree environment, it will not work if it is higher than 10 degrees.
2. In the placement process, the placement machine equipment must be checked regularly. If the SMT factory equipment is aging or some components are damaged, in order to ensure that the placement will not be crooked, In the event of high dumping, the equipment needs to be repaired or replaced with new equipment in time. Only in this way can production costs be reduced and production efficiency improved.
3. When performing smt processing, if you want to ensure the quality of PCBA processing and soldering, you need to pay attention to whether the setting of reflow soldering process technical parameters is more reasonable. If there is a problem with the parameter setting, SMT patch soldering The quality cannot be guaranteed. Therefore, under normal circumstances, the furnace temperature needs to be tested twice a day, at least once. Only by continuously improving the temperature curve and setting the temperature curve of the welding product can the quality of the processed product be guaranteed.
Second, SMT chip processing selects the way of chip inductors
1. The total width of the chip inductor should be lower than the total width of the inductor to avoid excessive soldering materials from causing excessive tensile stress to change the inductor value during water cooling.
2. The precision of chip inductors available on the sales market is mostly ±10%. If the specified precision is higher than ±5%, you must order in advance.
3. Some chip inductors can be welded by reflow oven and wave soldering, but there are also some chip inductors that cannot be welded by wave soldering.
4. When overhauling, it is not possible to replace the inductor with a chip inductor only by the amount of inductor. In order to ensure the operating characteristics, it is also necessary to understand the operating frequency range of the chip inductors.
5. The appearance design and specification basis of the chip inductors are similar, and the appearance design does not have a significant mark. When hand-soldering or hand-made patches, you must be very careful and don’t make mistakes or pick up the wrong parts.
6. At this stage, there are three common chip inductors: the first one is high-frequency inductors for microwave heating. Applicable to frequency range applications around 1GHz. The second type is high-frequency chip inductors. It is suitable for series resonance control circuit and frequency selective power supply circuit. The third type is practical inductors. Generally applicable to power circuits of tens of megahertz.
7. Different products use different diameters of magnetic coils. Even if the same amount of inductor is used, the resistance measurement displayed is not the same. In the high-frequency control loop, resistance measurement is very harmful to the Q value, so pay attention to the PCBA design.
8. Allowable is an index value of chip inductance according to the larger amount of current. When the power supply circuit must be responsible for the large amount of current, this index value of the capacitor must be taken into consideration.
9. When power inductors are used in DC/DC converters, the size of their inductors immediately endangers the working attitude of the power supply circuit. According to the actual situation, the method of adjusting the magnetic coil can usually be used to change the inductors to achieve the best practical effect.
10. PCBA communication equipment working in the frequency range of 150~900MHz, usually wire-wound inductors. In the PCB frequency power circuit around 1GHz, microwave heating high-frequency inductors must be used.