The role of motherboard capacitors and signing

The importance of capacitors:

Capacitors are mainly used in the motherboard to ensure voltage and current stability (filtering). Today's personal computers are getting faster and faster. As the CPU frequency and system bus operating frequency increase, the requirements for power supply to the motherboard are becoming more and more strict. Therefore, the prerequisite for stable operation of the motherboard is that there must be a pure current supply. The current from the chassis power supply will be found by the oscilloscope. There are many spikes and clutter. These spikes and clutter are the enemy of the stable operation of the motherboard. Therefore, the motherboard must filter and purify the power supply to use it. The clutter is filtered and purified with different components. The main components are choke coils and capacitors. The original current first flows through the choke coil (commonly known as the coil). Because the coil has an energy storage characteristic, it can filter out some high frequency clutter and then enter the capacitor group to further filter, purify and level (pulse the peak shape into Square wave).

The appearance of tantalum and aluminum capacitors:

Common capacitors on the motherboard are tantalum capacitors and aluminum capacitors (electrolytic capacitors). Aluminum capacitors have large capacity and low price, but are susceptible to temperature and accuracy, and will gradually fail over time. Tantalum capacitors have long life, high temperature resistance, and high accuracy, but they are small in capacity and high in price. Unless it is where large-capacity filtering is required (such as near a CPU socket), it is best to use tantalum capacitors in principle because it is less prone to waveform distortion.

Identification of capacitance:

So, how to judge the quality of the motherboard capacitor from the appearance? You can start from the following aspects:

According to the color to distinguish: the black capacitor is the worst, the green capacitor is better, the blue capacitor is stronger than the green capacitor. Therefore, the filter capacitors around the CPU that we generally see on the motherboard are all green, while others are black.

The difference from the indicator: the range of the capacitor voltage is very important, you can see the word "+, -" on the capacitor, this is the tolerance range of the capacitor voltage, the smaller the value, the better the capacitor.

Look at the capacity of the capacitor: According to the Intel motherboard technology white paper, the filter capacitor near the CPU socket of the motherboard has a single capacity of 1000μF at the minimum. Generally, the motherboard uses 1000μF electrolytic capacitor (it will be carefully calculated), but on Intel's original motherboard. This kind of capacitor has a single capacity of up to 3300μF, which is one of the reasons why everyone respects the stability of Intel motherboards.

At present, some motherboards like to replace a small number of small capacitors with a small number of large capacitors, so the cost is increased from the material, but it is reduced in terms of production cost, because these capacitors are manually installed. The fewer parts, the fewer steps to install, the lower the labor costs, the easier maintenance, and the lower production costs. This is a digression, no more to say. In short, a high-performance motherboard must have high-quality capacitors.