為了滿足電子產(chǎn)品向高速化、小型化和低成本方向發(fā)展的需要，貼片式電容器也在迅速的發(fā)展，其中貼片電容是SMT貼片加工中使用最多的一種元器件，在線路板中發(fā)揮自己的作用，保證使用安全。那么貼片電容的技術(shù)指標(biāo)又有哪些呢？
In order to meet the needs of high-speed, miniaturization and low-cost development of electronic products, SMT capacitor is also developing rapidly. SMT capacitor is one of the most used components in SMT chip processing, which plays its own role in the circuit board to ensure the safety of use. What are the technical specifications of SMC?
1、溫度系數(shù)Temperature coefficient
電容值隨溫度的變化情況。一定溫度范圍內(nèi)，溫度每上升一攝氏度，電容值的相對變化值。對于貼片電容來說，溫度系數(shù)越小越好。
The change of capacitance value with temperature. Within a certain temperature range, the relative change value of capacitance value for each degree of temperature rise. For chip capacitors, the smaller the temperature coefficient, the better.
2、容量與誤差Capacity and error
標(biāo)稱電容和實(shí)際電容之間的最大偏差范圍。和電阻器的標(biāo)識方法相似，常用貼片電容的精度等級一般用英文字母表示。D級，±0.5%；F級，±1%；G級，±2%；J級，±5%；K級，±10%；M級，±20%。
The maximum deviation range between the nominal capacitance and the actual capacitance. Similar to the identification method of resistors, the accuracy level of common chip capacitors is generally expressed in English letters. Grade D, ± 0.5%; F, ± 1%; G, ± 2%; J, ± 5%; K, ± 10%; m, ± 20%.
3、絕緣電阻Insulation resistance
表明漏電大小的指標(biāo)。容量越小的貼片電容，絕緣電阻越大，漏電量越小。一般在幾百兆歐到幾千兆歐。一般電解電容的絕緣電阻較小。漏電越小也代表貼片電容的性能越好。
An indicator indicating the magnitude of leakage. The smaller the capacitance, the greater the insulation resistance and the smaller the leakage. It's usually in the range of hundreds to thousands. Generally, the insulation resistance of electrolytic capacitor is small. The smaller the leakage, the better the performance of SMC.
4、額定工作電壓Rated operating voltage
在電路中，電容器能長期穩(wěn)定工作所能承受的最大直流電壓。對于其他條件都相同的貼片電容，額定工作電壓越高，體積也越大。
In the circuit, the maximum DC voltage that the capacitor can withstand when it can work stably for a long time. The higher the rated working voltage, the larger the volume of SMC.
5、損耗Loss
在電路中，每個(gè)貼片電容因?yàn)榘l(fā)熱而消耗的能量。一般來自于介質(zhì)損耗和金屬損耗。
In a circuit, the energy consumed by each chip capacitor due to heating. It usually comes from dielectric loss and metal loss.
6、頻率特性Frequency characteristics
在不同電場頻率下貼片電容數(shù)值隨之變化的特性。在高頻電路工作的電容器，因?yàn)榻殡姵?shù)的改變，電容值會相應(yīng)減小，損耗隨頻率增加而增加。在高頻電路中工作時(shí)，貼片電容自身的基片電阻、電感等因素都會影響其性能。這也使得在選用貼片電容的時(shí)候需要考慮電路板的頻率特性。
The characteristic of chip capacitance changing with the change of electric field frequency. Because of the change of dielectric constant, the capacitance value of the capacitor in high frequency circuit will decrease correspondingly, and the loss will increase with the increase of frequency. When working in high frequency circuit, the substrate resistance and inductance of SMC will affect its performance. This also makes it necessary to consider the frequency characteristics of the circuit board when selecting chip capacitors.
7、存儲時(shí)間Storage time
對于很穩(wěn)定的電容器來說，電容值隨儲存時(shí)間的變化不大。但是對于一些不穩(wěn)定的電容器來說，每存放1000小時(shí)電容值的變化量可以高達(dá)5%~10%。但這類變化是可逆的，在使用前將電容器在150℃的環(huán)境中預(yù)熱1小時(shí)，電容值就會恢復(fù)正常。
For a very stable capacitor, the capacitance value changes little with the storage time. However, for some unstable capacitors, the variation of capacitance value can be as high as 5% ~ 10% every 1000 hours. However, this kind of change is reversible. If the capacitor is preheated at 150 ℃ for 1 hour before use, the capacitance value will return to normal.
熟悉了電容器的各種特性以及選用貼片電容的技術(shù)指標(biāo)，在選用貼片電容是就不會只考慮價(jià)格和體積，而導(dǎo)致電容器選用錯(cuò)誤，進(jìn)而影響整個(gè)電路的的性能。
Familiar with the various characteristics of capacitors and the technical indicators of selecting chip capacitors, when selecting chip capacitors, we will not only consider the price and volume, which will lead to the wrong selection of capacitors, and then affect the performance of the whole circuit。