Jotrin Electronics
Cart
Description Quantity Total (USD) Operation
loading

Shopping cart products : 0
  • All CategoriesALL CATEGORIES

More Product Categories

Home > Technology List > The function of ceramic capacitor and the precautions for use

The function of ceramic capacitor and the precautions for use

Published time: 2018-11-02

Guide Read:

Ceramic capacitors are currently the most widely used type of capacitors in electronic devices, accounting for about 50% of the total number of capacitors used. However,due to insufficient understanding of their characteristics, many people lack the attention they deserve.In this article you will learn about the function of ceramic capacitors, and what should we pay attention to when using ceramic capacitors.

Ceramic Capacitor

The function of Ceramic Capacitor

Ceramic capacitors have the advantages of good heat resistance, excellent insulation performance, simple structure and low price.

Different ceramic materials lead to very different characteristics.Ceramic capacitors are classified into high frequency ceramic capacitors and low frequency ceramic capacitors according to frequency characteristics.According to the pressure resistance, there are high voltage ceramic capacitors (above 1KVDC) and low voltage ceramic capacitors (500VDC or less).

High-frequency ceramic capacitors can be used up to 1000MHz.This type of ceramic capacitor has excellent temperature characteristics and is suitable for circuits with high requirements on capacity and stability such as high frequency resonance, filtering and temperature compensation.

Ceramic capacitors have many advantages, but they also have defects. Due to the low mechanical strength and fragility of ceramic materials, the geometry of the wafers is limited, which is the main reason for the different capacity ranges of different temperature characteristics.


Generally, the allowable diameter of the low-voltage wafer capacitor is D ≤ 12 mm, and the disk of the high-voltage capacitor allows the diameter D ≤ 16 mm. If it exceeds this size, the production process difficulty and the scrap rate will increase greatly, and the micro cracks generated on the ceramic body will have a negative impact on the reliability of the capacitor.

Different manufacturers have different manufacturing levels in material development and process manufacturing, which leads to differences in their dimensional dimensions. Therefore, there are some differences in the nominal capacity range. Therefore, the above capacity allocation table is only the result of a summary of the industry average. In the future, as the material process is further improved, the size of the ceramic capacitor will be further reduced, and the capacity range will be further expanded.


How to distinguish the encapsulation form of wafer ceramic capacitor

The encapsulation form of wafer ceramic capacitors is usually divided by voltage. The CC1 and CT1 series of low voltage products below 500VDC are encapsulated by phenolic resin.

The resin has poor insulation strength and moisture resistance, but the cost is low. To improve moisture resistance, such encapsulated outer layers are impregnated with a thin layer of wax.

In addition to wafer-type ceramic capacitors, the widely used capacitors are axial-lead color-ring ceramic capacitors and chip-type ceramic capacitors. Their internal structure is laminated, even if the volume is small, the capacity can reach more than 1μF. It is very conducive to assembly, but due to its structural limitations, insulation resistance and withstand voltage can not be made very high, so the current low voltage (within 50V) products are more abundant, the loss and temperature characteristics are the same as the wafer capacitance.

Ceramic capacitors have many advantages, but they also have defects. Due to the low mechanical strength and fragility of ceramic materials, the geometry of the wafers is limited, which is the main reason for the different capacity ranges of different temperature characteristics.



ceramic capacitors

Precautions for use when using ceramic capacitors

Jotrin Electronics Engineer King, a veteran in the electronics industry, said the following:

1)Ensure the versatility and standardization of material selection.Because different temperature characteristics correspond to different capacity ranges and accuracy standards, it must meet the series standards when selecting, and the value should be selected in accordance with the E24 (or E96) series.

2)According to the working conditions and environmental conditions of the line, select the appropriate model, the main parameters should meet the line. According to the working conditions and environmental conditions of the line, select the appropriate model and use requirements.

3) For high-frequency resonant circuits, we need to require small capacitor losses, and also require good temperature stability. Under normal circumstances, we should use Class 1 ceramic capacitors, where CH characteristics are also called zero. The temperature coefficient product, its capacity does not change with temperature, but its capacity is only between a few PF ~ several hundred PF.

4) For low-frequency coupling, bypass, and filter capacitors, we need to miniaturize and low-cost. This is the main consideration, but the temperature stability of loss and capacity is not high. Generally, 2 types of ceramic capacitors can be selected. , its capacity selection range is wide.

5) Although the ceramic capacitor has a larger voltage margin than the film capacitor and the electrolytic capacitor, it is not allowed to be used under the condition that its rated voltage is exceeded. Otherwise, the metal ions in the electrode migrate in the ceramic medium under the action of a strong electric field. The speed is increased and the insulation resistance of the capacitor is lowered, which affects the reliability of the long-term operation of the whole machine.

6) For capacitors operating under high temperature and high voltage conditions, attention should be paid to the selection of products with high insulation resistance to prevent the capacitor from failing due to the increase of leakage. 

In summary, the difference between ceramic capacitors and other capacitors is that ceramic capacitors have many different temperature groups depending on the material, and their characteristics and capacity ranges are quite different.


Famous Ceramic capacitors manufacturers:Murata, ATC, AVX, KEMET, TDK, Vishay.

Buy brand Ceramic capacitors by electroncis parts distributor

 

Account Center

Email:

sales@jotrin.com

Skype:

jotrin03

Phone:

86-755-83666342