Through increasing screen electrode, the small chip dimension that is as high as 1000V encloses MLCC of large electric capacity to be able to resist electric arc discharges, rise greatly thereby electric car and but second birth the sources of energy generates electricity the dependability of circuit of the high pressure in waiting for application. Base the ArcShield watch of beautiful electron sticks MLCC to have screen electrode patent to design, can overcome measure of prevention and cure of discharge of traditional electric arc (for example cascade electrode or protect form coating) defect, need not protect coating to be able to obtain permanent protection thereby. Relative to the traditional MLCC at larger size or via pottery and porcelain and film capacitor, they still offerred the replacement scheme that can save a space to design an engineer.

 

The preventive of electric arc discharge of innovation can realize small size tall volmeter to stick MLCC, it is electric car thereby may second birth the sources of energy generates electricity medium burgeoning application offers tall sex price to compare and the solution of economic space.

 

High-pressured application tries to save a space

In wind-force / solar energy inverter or electric car (EV) in the very tall to energy-saving requirement application such as dynamical system, conduce to with high-pressured means distribution reduce I2R loss. For example, in EV application, the dc link that is inverter power supply may be 3-400V, and adjust to wind-force or solar energy and character criterion may be taller. However, voltage of this kind of expensive work brought additional safe challenge to final user not only, and be opposite —— of yuan of parts of an apparatus even if those imprint on crust having —— of yuan of parts of an apparatus of appropriate and rated voltage also is such. Let us look multilayer capacitor of pottery and porcelain (MLCC) —— common use includes filter wave, go Ou or amortize —— is how to suffer place of hundreds bend over to add bias voltage to affect.

Accepted physical law tells us, tall MLCC rated voltage and small enclosing dimension cannot coexist at the same time: Increase rated voltage to need to add layer of thick interpose report between plate, this can increase the size of parts of an apparatus again conversely. Even if is such, industry is right small-sized the demand with equipment of light-duty power source, the requirement realizes high electric capacity and tall rated voltage inside less and less chip dimension rough sketch. EV inverter or wind-force / the design personnel of dynamo of solar energy miniature, connect regular meeting to try to use the 0603 X7R with 0805 crust dimension MLCC to wait for capacitor, its are rated voltage is 500V, 630V or 1000VDC.

 

Prevent to electric arc discharge damages and be destroyed

Yuan manufacturer of parts of an apparatus can pass the capacitor stuff with be used better and tectonic technology to satisfy these requirement. However, if the graph is shown 1 times, in practice, climb report (electric field diffuses apparently naturally in dielectric) and strong electric field may be caused all round the element such as air happening ionization, meeting menace works to high pressure the security of yuan of parts of an apparatus. When producing ionization, if what add bias voltage to exceed ionization airy initiative voltage, the parts of an apparatus of different potential can form electric access between terminal or electrode, bring about corona discharge or electric arc discharge thereby.

 

Graph 1. Ionization is terminal and terminal or arc discharge is pulled to create a condition between terminal and electrode.
 

The initiative tension that electric arc discharge produces suffers the effect of a variety of elements, for example air temperature and pressure, humidity and terminal climb electric distance to wait. Conversely, distance climbing report suffers surface of parts of an apparatus to whether have contaminant effect again, for example electric dirt grain or accumulative moisture. The stuff of pottery and porcelain that has tall dielectric constant (for example X7R material) , its hole is led (namely the space that material surface exists) can compare other dielectric (for example C0G) taller. These space often contain moisture and dirt, make yuan of parts of an apparatus more incidental thereby electric arc discharge.

 

Electric arc discharge happens to be able to last between terminal, but if produce corona repeatedly in surface of parts of an apparatus,discharge, criterion the elapse as time, can produce carbonization course, build electric gateway thereby. Continue to happen as discharge, this can cause short circuit trouble finally.

More immediate problem is, if the graph is shown 2 times, discharge to happening likely between electrode in the exterior component of parts of an apparatus and the first interior that are located in contrary potential. This can cause breakdown of quick mind report normally, cause short circuit trouble thereby, often accompany quick capacitor is destroyed.

 

Graph 2. Terminal discharges to electric arc arising between electrode with the first, can cause capacitor normally fast invalidation.
 

Look from the history, capacitor manufacturer and material experts had developed all sorts of technologies, with will reduce the cause that causes ionization and corona discharge. Among them one of it is to use tall insulation polymer or MLCC of Fu of besmear of vitreous shape coating, form smooth imperforate surface, make contaminant or the possibility that water divides accumulation happening the least thereby. Although the fact proves this kind of technology is effective, but also put in a certain number of defect, include the cost of material and the additional craft expense that apply it. In addition, if main body of parts of an apparatus was not enclosed completely, perhaps have coating damage, criterion the effectiveness of coating can be affected.

 

In addition, if use, is to besmear beforehand parts of an apparatus, criterion personnel of circuit board design must ensure the place in coating material and PCB component uses other data compatible. On the other hand, if be coating of Fu of the besmear after be being assembled, must notice to ensure without space or clearance, be in for example the area below parts of an apparatus. These circumstances can damage the integrality of coating and possible generation and did not besmear the electric arc with Fu identical parts of an apparatus discharges.

 

Float electrode

Or, can pass adjust internal composition, make capacitor bears tall bring to bear on the ability of electric field increases.

An example is design of cascade interior electrode. This kind of method calls float electrode or skill of series connection capacitor again, it is OK with joining with series connection the way with many same capacitor heightens rated tension, add space climbing report effectively, reduce thereby in bring to bear on the possibility that electric arc produces when intensity of tall electric field. If plan institute is shown, float electrode design still can be passed prevent there is break to cross between a pair of any opposite electrode, short-circuit, will be reduced effectively flinch crack. The open circuit trouble that can cause capacitance loss or safety only with the interstitial likelihood related bending. A defect is, join like series connection schism capacitor is same, method of series connection capacitor can reduce effective electric capacity.

 

In-house screen

A the closest development is in parts of an apparatus interior adds electrode of a screen, it and the closest terminal are in same potential, and to opposite terminal outspread, if pursue,3 are shown. Can imagine it into like Faraday basket same, and it and photograph of structure of series connection capacitor are compared, can realize more traditional electrode position. Accordingly, to given rated voltage and dimension of parts of an apparatus, capacitance is OK taller. In addition, screen electrode and flexible terminal is compatible, can produce stress craze in order to prevent.

 

Graph 3. Screen electrode can reduce capacitor surface and the first field to electrode area strong.
 

When terminal two end are added have high-pressured bias and more than ionization airy is initiative all round capacitor when voltage, use this screen electrode to be able to prevent corona discharge to cause terminal is opposite with the first dielectric puncture happens between electrode, prevent to appear thereby in front graph 2 in mode of narrates breakdown of fast short circuit.

 

Because screen electrode and the closest potential with located terminal are same, so electric field centers confine in screen electrode is not terminal surface is opposite with the first corresponding electrode position. This is OK the voltage that utmost ground reduces edge chip surface, increase capacity of distance climbing report. Accordingly, even if small size parts of an apparatus or the parts of an apparatus that use tall hole to lead dielectric to make (be like X7R) , also can fight faze from buildup electric arc discharge be benefited in the gender, and make the possibility of relevant attaint or breakdown of parts of an apparatus is reduced.

 

Base beautiful electron is right already this technology patent application, so that found ArcShield™ series to fight electric arc MLCC, and provide tall voltage and large electric capacity with dimension of crust of small-sized EIA standard. Dimension from 0603 be used to the business of 1812 or capacitor of ArcShield of AEC-Q200 car class already offerred money now, capacitance value is as high as 0.33μF when 500VDC rating, 0.15μF is when 630VDC, 0.10μF is when 1000VDC.

 

Summary

Through increasing screen electrode, the small chip dimension that is as high as 1000V encloses MLCC of large electric capacity to be able to resist electric arc discharges, rise greatly thereby electric car and but second birth the sources of energy generates electricity the dependability of circuit of the high pressure in waiting for application. Base the ArcShield watch of beautiful electron sticks MLCC to have screen electrode patent to design, can overcome measure of prevention and cure of discharge of traditional electric arc (for example cascade electrode or protect form coating) defect, need not protect coating to be able to obtain permanent protection thereby. Relative to the traditional MLCC at larger size or via pottery and porcelain and film capacitor, they still offerred the replacement scheme that can save a space to design an engineer.