#58pcba

[grandepcba]

What is the function of capacitors in circuits?

You know, the basic function of the capacitor that is “blocking DC current but passing AC current”, which is why the capacitor is usually used in the circuit to separate DC current and let the AC current signal pass. Thus, capacitors, in the filter circuit, tuned circuit, coupling circuit, bypass circuit, time-delay circuit, shaping circuit and other circuits play an important role.

Meanwhile, the capacitor is able to form an LC resonant circuit with the inductor; And with the resistor, it can constitute an RC phase-shifting circuit. While it can be combined with an amplifier to form an LC oscillator or an RC oscillator.

BTW, there are many types of capacitors whose materials are also various. So the point is choosing different capacitors’ specifications based on different circuit requirements.

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[grandepcba]

What is a PCB prototype?

PCB prototyping is to manufacture a real circuit board from a designed PCB. And the main intention of prototyping is to not only test the concept and functionality of the design, but also perfect and grow it stage by stage, limiting final fabrication failure as much as possible.

When it comes to

the benefits of PCB prototyping, here are a couple of aspects for your reference:

        1. Testing PCB design in small quantities before mass production;

2. Ensuring manufacturability, quality and functionality; 3. Reducing costly reworks, especially for multi-layer or high-density boards; 4. Be fine-tuned and validated PCB design;5. Eliminating possible failures early, etc.

[grandepcba]

What is a PCB green mask?

PCB green mask, a kind of solder ink that is called as solder mask in PCB. Solder mask is applied to circuits and substrates where PCBs do not need to be soldered, or just be used as a solder resist.

When it comes to the roles of solder mask, here are a couple of points for your reference:

1. Preventing short circuits caused by bridging in the welding technology;

2. Welding only in the positions where they must be welded;

3. Preventing insulation deterioration and corrosion caused by external environmental factors such as dust and moisture in order to protect the circuit for a long term;

4. With high insulativity, making the high density of the circuit possible.

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[grandepcba]

What are the different types of solder?

According to the melting point, which can be divided into hard solder and soft solder;

Based on the composition, which can be divided into tin-lead solder, silver solder, copper solder and so on;

BTW, during the process of soldering, tin-lead alloy solder is generally used, which is mainly composed of tin, lead and trace metals such as bismuth.

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[grandepcba]

What is the main circuit board of a computer? What are its functions?

In fact, the main components on the mainboard are the chipset, bus, input and output interfaces and power connectors.

Mainboard Functions:

1. Connecting those core components such as CPU and memory through the bus and chipset and forming the core of the computer;

2. Receiving and distributing the power provided by the computer power supply and supplying power to the above core components;

3. Receiving the power-on switch and the operating system to start, shut down, restart, standby and hibernate operations;

4. Connecting the hard disk, optical drive, keyboard, mouse, display and other devices to the bus.

In a nutshell, the mainboard provides a convenient installation platform for CPU, memory, hard disk, optical drive, keyboard, mouse, display and other components, because the above components are directly or indirectly connected to it.

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[grandepcba]

How do I design a rigid-flex PCB?

Frankly speaking, the design of rigid-flex board is much more complicated than other traditional PCB design so that there are plenty of aspects that we should pay attention to, such as rigid-flex transitional areas, related routing, vias design, etc.

In other words, the rigid-flex PCB design has to follow the requirements of corresponding design rules like:

1. The location of vias

2. The design of pads and vias

3. Routing design

4. Copper laying design

PS: Rigid-flex PCB tends to be used in certain products with special requirements, which is of great help to save product internal space, reduce finished product volume and improve product performance.

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[grandepcba]

If you are soldering something, how long does it take for the solder to cool?

Well, it actually depends upon the components that we are soldering; In general, it usually takes 10 seconds for those SMD resistors and capacitors to cool. However, for ICs, which mainly replies on the its volume. For example, it takes about 20 seconds for a small IC, but about 40 seconds for a big one.

In short, the longer soldering time, the longer solder cooling time is. In other words, unless you can't feel the obvious temperature by hand before you power on and do the test.

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[grandepcba]

How can cold solder joints be prevented?

As we all know, cold solder joint is one of the common line faults of PCBA, so why does it happen?

One is improper production process: Due to improper production process so that it leads to an unstable state; (The component only looks like be soldered, but it's not actually.)

The other is burn-in phenomenon: The electrical appliances, after long-term using, whose components with more serious heating, its soldering spot is pretty easy to appear aging peeling phenomenon.

Thus, it’s much vital for us to pay more attention to the production process and board washing(cold solder joints can be founded), especially for those manual welding.

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