CN118471694B - Thin film capacitor for electric automobile controller with low thermal resistance and high power density - Google Patents

Abstract

The invention discloses a thin film capacitor for an electric vehicle controller with low thermal resistance and high power density, and belongs to the technical field of capacitors. A thin film capacitor for an electric automobile controller with low thermal resistance and high power density comprises a shell and a capacitor core, and further comprises: a metallized security film comprising the capacitor core; the capacitor cores are provided with a plurality of groups; the metallized safety film comprises a base film and a plating layer, wherein the plating layer is arranged above the base film; the invention can realize larger capacitance, higher voltage resistance and stronger ripple current resistance in a limited space, and meanwhile, the capacitor has lower thermal resistance and stronger heat dissipation capability, thereby reducing the loss caused by reactive power in the working process of the capacitor, reducing the temperature rise and prolonging the service life.

Description

Thin film capacitor for electric automobile controller with low thermal resistance and high power density

Technical Field

The invention relates to the technical field of capacitors, in particular to a thin film capacitor for an electric automobile controller with low thermal resistance and high power density.

Background

In an electric automobile three-electric system (a battery, a motor and a motor controller), the motor controller is used as an inversion unit, energy is required to be provided for 2 motors at the same time, a film capacitor is used as a key part of a direct-current support loop, ripple current of 2 switching devices (IGBT 1 and IGBT 2) is required to be provided and high ripple voltage is required to be resisted, and under some working modes, such as range extension, the 2 motors are mutually driven, namely the IBGT1 current passes through the capacitor and then drives the IGBT2, the capacitor is required to bear larger direct-current, and the power requirement on the film capacitor is higher.

In the dual-motor controller system, because a high-power controller is needed for simultaneously providing power for 2 motors, but the relation between the whole vehicle space and the quality, especially the HEV space is very small, the film capacitor needs to achieve high power density in a limited space, namely higher bus voltage and larger phase current, the voltage resistance of the capacitor in the unit space is higher, the capacitance is larger, the equivalent series resistance is lower, the thermal resistance is lower and the like corresponding to specific requirements of the capacitor. The voltage withstand capability of the thin film capacitor is proportional to the thickness of the adopted thin film, the thicker the film is, the higher the voltage is, but the smaller the capacitance in unit space is, the larger the equivalent series resistance is, which is a contradiction, therefore, a special thin film needs to be designed, namely, the thin film with the thinner thickness is adopted, and the higher voltage withstand capability and the smaller equivalent series resistance are ensured while the capacitance requirement can be met.

The polypropylene film (OPP) has the advantages of low loss tangent value, good frequency temperature characteristic, high cost performance and the like, is applied in the field of automobile capacitors in a large batch, adopts the polypropylene film as a dielectric material, the problems of ensuring higher voltage resistance and smaller equivalent series resistance while meeting the capacitance requirement in unit space are effectively solved by changing the plating layer pattern and adjusting the square resistance value. Through the calculation formula of the capacitance, when the thickness of the film is reduced after the dielectric material is determined, the capacitance is increased.

However, the voltage-withstanding capability of the polypropylene film is generally 250+20vdc/um, and how to improve the voltage-withstanding value is what is that the patent adopts a half-width small-grid-shaped safety film pattern, designs a narrower fuse width, and improves the fuse sensitivity.

Disclosure of Invention

The invention aims to solve the problems in the prior art, and provides a thin film capacitor for an electric automobile controller with low thermal resistance and high power density.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

Including shell and capacitor core, still include: a metallized security film comprising the capacitor core; the capacitor core is provided with a plurality of groups which are all positioned in the shell, the capacitor core is provided with a negative copper bar and a positive copper bar which are used for current conduction, and a grounding copper bar is arranged between the negative copper bar and the positive copper bar; an EMC filter is arranged on one side surface inside the shell; the metallized safety film comprises a base film and a plating layer, wherein the plating layer is arranged above the base film; the plating layer and the base film form a metallized film with the width W, the plating layer is divided into a thickening area, a transition area, an active area and a margin area when viewed from the cross section, the thickness of the plating layer is represented by square resistance, wherein the plating layer comprises square resistance I positioned in the thickening area, square resistance II positioned in the transition area and square resistance III positioned in the active area; the active area part is provided with a plurality of grids with E.times.F size, and a fuse with the width of G is arranged between two adjacent grids of each row; through the size of the fuse width G on the regulation net, the safety factor is improved, and the voltage interval of safe operation of the capacitor is reached: Wherein, the value range: e is more than or equal to 3mm 6mm,2mm less than or equal to F less than or equal to 5mm, G is more than or equal to 0.1mm and less than or equal to 0.15mm, Representing the amount of charge stored on the capacitor,Representing the capacitance of the capacitor,Representing the voltage across the capacitor,Representing the distance between the two plates of the capacitor,Represents the dielectric constant and k represents the electrostatic force constant.

Preferably, the metallized safety film is wound by a large-diameter a reel, and flattened to be in a flattened capacitor core design with a smaller dimension t, so that the metallized safety film has lower thermal resistance.

Preferably, the two metallized safety films are stacked upside down and then wound, wherein the distance between the edge of the thickened area of one metallized safety film and the edge of the margin area of the other metallized safety film is e.

Further, the coating and the margin area are coated with antioxidant oil to form an antioxidant oil coating.

Preferably, an epoxy cover plate is arranged above the shell, a mounting plate is arranged on the shell, and the negative electrode copper bar and the positive electrode copper bar are fixedly mounted through the mounting plate.

Further, the shell is provided with a connecting copper bar.

Preferably, an NTC temperature sensor is provided on the housing, and a detection end of the NTC temperature sensor is disposed between the plurality of capacitor cores.

Preferably, the outside of a plurality of the condenser cores is wrapped with an insulating film, a heat dissipation aluminum plate is arranged below the insulating film, and the heat dissipation aluminum plate is fixedly connected with the shell.

Preferably, the grounding copper bar is formed by splicing a plurality of groups of first trapezoid plates and second trapezoid plates in sequence, and triangular grooves are formed in the second trapezoid plates of the first trapezoid plates.

Preferably, the shell is made of high-heat-conductivity polyphenylene sulfide material, the built-in radiating aluminum plate is U-shaped, a water cooling system can be assembled, and the large-area radiating function of the shell is realized.

Compared with the prior art, the invention provides the thin film capacitor for the electric automobile controller with low thermal resistance and high power density, which has the following beneficial effects:

1. The thin film capacitor for the low thermal resistance high power density electric automobile controller can increase the effective electrode area of the capacitor under the condition of not increasing the whole film thickness by increasing the grid number of the E-F size of the active area part, and is beneficial to reducing the voltage drop of unit area because the voltage is distributed on a larger area, thereby enhancing the voltage resistance of the active area.

2. This film capacitor for electric automobile controller of high power density of low thermal resistance, the triangular groove of seting up on the trapezoidal board of trapezoidal board one can be better let the heat conduction silica gel be full of the connection gap of ground connection copper bar and negative pole copper bar or anodal copper bar, and the heat conduction is effectual, lets the hot air can flow out through trapezoidal hole that forms between trapezoidal board one and trapezoidal board two and negative pole copper bar or the anodal copper bar, and the radiating effect is good.

The invention provides a thin film capacitor design method for a direct current support loop of an electric automobile double-motor controller, which has the advantages of realizing larger capacitance, higher voltage resistance and stronger ripple current resistance in a limited space, simultaneously having lower thermal resistance and stronger heat dissipation capability, reducing the loss generated by reactive power in the working process of the capacitor, reducing temperature rise and prolonging the service life by special thin film, copper bar and heat dissipation structure designs and optimizing the process condition designs of a capacitor core, a potting material and the like.

Drawings

FIG. 1 is a schematic diagram of the whole structure of a thin film capacitor for an electric vehicle controller with low thermal resistance and high power density;

FIG. 2 is an exploded view of the whole thin film capacitor for the electric vehicle controller with low thermal resistance and high power density;

FIG. 3 is a cross-sectional view of a film capacitor grounding copper bar for an electric vehicle controller with low thermal resistance and high power density;

FIG. 4 is a schematic diagram of the structure of the thin film capacitor for the controller of the electric vehicle, which is provided by the invention and has low thermal resistance and high power density, in which the portion A in FIG. 3 is enlarged;

FIG. 5 is a cross-sectional view of a metallized film of a film capacitor for an electric vehicle controller with low thermal resistance and high power density according to the present invention;

FIG. 6 is a plan view of a metallized film of a film capacitor for an electric vehicle controller with low thermal resistance and high power density according to the present invention;

FIG. 7 is a schematic diagram of the enlarged structure of the portion B in FIG. 6 of a film capacitor stop lever for an electric vehicle controller with low thermal resistance and high power density according to the present invention;

FIG. 8 is a schematic diagram of a thin film capacitor core for an electric vehicle controller with low thermal resistance and high power density;

fig. 9 is a circuit diagram of a thin film capacitor EMC filter for an electric vehicle controller with low thermal resistance and high power density according to the present invention.

In the figure: 1. a base film; 2. plating; 3. an oxidation-resistant oil coating; 4. a thickened region; 5. a transition zone; 6. an active area; 7. a margin area; 8. a housing; 9. a capacitor core; 10. a mounting plate; 11. a negative copper bar; 12. a positive copper bar; 13. connecting copper bars; 14. a grounding copper bar; 1401. a trapezoid board I; 1402. a trapezoid plate II; 15. a heat-dissipating aluminum plate; 16. an NTC temperature sensor; 17. EMC filter; 18. an insulating film; 19. triangular grooves; 20. an epoxy cover plate.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments.

In the description of the present invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present invention and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

Referring to fig. 1 to 9, comprising a case 8 and a capacitor core 9, further comprising: a metallized security film constituting the capacitor core 9; the capacitor core 9 is provided with a plurality of groups which are all positioned in the shell 8, the capacitor core 9 is provided with a negative copper bar 11 and a positive copper bar 12 for current conduction, and a grounding copper bar 14 is arranged between the negative copper bar 11 and the positive copper bar 12; an EMC filter 17 is arranged on one side surface inside the shell 8; the metallized safety film comprises a base film 1 and a plating layer 2, wherein the plating layer 2 is arranged above the base film 1; the plating layer 2 and the base film 1 form a metallized film with the width W, the plating layer 2 is divided into a thickening area 4, a transition area 5, an active area 6 and a margin area 7 when viewed from the cross section, the thickness of the plating layer 2 is represented by square resistance, wherein the plating layer comprises square resistance I positioned in the thickening area 4, square resistance II positioned in the transition area 5 and square resistance III positioned in the active area 6; the active area 6 is provided with a plurality of grids with E.times.F size, and a fuse with the width G is arranged between two adjacent grids in each row; through the size of the fuse width G on the regulation net, the safety factor is improved, and the voltage interval of safe operation of the capacitor is reached: Wherein, the value range: e is more than or equal to 3mm 6mm,2mm less than or equal to F less than or equal to 5mm, G is more than or equal to 0.1mm and less than or equal to 0.15mm, Representing the amount of charge stored on the capacitor,Representing the capacitance of the capacitor,Representing the voltage across the capacitor,Representing the distance between the two plates of the capacitor,Represents the dielectric constant and k represents the electrostatic force constant.

In the invention, the thickness of a metallized film of a capacitor used in a new energy automobile is required to be thinned, because the thinner the film is, more metallized film layers can be contained in the same volume, so that the effective electrode area of the capacitor is increased, the capacitance of the capacitor is increased due to the increase of the effective electrode area, and the energy density of the capacitor is further improved, but the electric field distribution in a material is more concentrated due to the reduction of the thickness of the film, electrons are more easily accelerated by the electric field, and thus breakdown phenomenon occurs under lower voltage, and the voltage resistance is low;

Based on the problems, the invention designs the thickened area 4 to occupy 40% of the whole width W, reduces the square resistance I, ensures that the equivalent series resistance of the capacitor is small, the heat is low, and the thickened area 4 occupying 40% can bear more current, thereby reducing the burden of the active area 6 and prolonging the service life of the capacitor; by increasing the number of grids of the size E x F of the active area 6, the effective electrode area of the capacitor can be increased without increasing the overall film thickness, which helps to reduce the voltage drop per unit area, since the voltage is distributed over a larger area, thereby reducing the risk of breakdown, and by adjusting the size of the fuse width G on the grid, the safety factor is increased, achieving a voltage interval for safe operation of the capacitor: Wherein, the value range: e is more than or equal to 3mm 6mm,2mm less than or equal to F less than or equal to 5mm, G is more than or equal to 0.1mm and less than or equal to 0.15mm, Representing the amount of charge stored on the capacitor,Representing the capacitance of the capacitor,Representing the voltage across the capacitor,Representing the distance between the two plates of the capacitor,Represents the dielectric constant, k represents the electrostatic force constant, and the value thereof is about。

The method is characterized in that a film with smaller width W is adopted, a metal aluminum coating is evaporated on the film, a plurality of grids with E.times.F size are designed in a region with the width of about 1/2W, the calculation of the electric energy of a single grid shows that when failure occurs, the smaller the grid area E.times.F is, the smaller the electric energy is, the lighter the failure degree is, and meanwhile, the safety coefficient is improved by adjusting the size of the fuse width G on the grid, so that the voltage interval for safe operation of the capacitor is achieved;

On the other hand, through lengthening the size of the fuse A, zinc is secondarily evaporated on the pure aluminum plating layer 2 in the thickened area 4 and the transition area 5, the thickness of the plating layer 2 is increased, the values of the sheet resistance I and the sheet resistance II are reduced, the purposes of reducing the plating resistance and the contact resistance of the subsequent core metal spraying process are achieved, and the value range is: w is more than or equal to 35 percent and less than or equal to 45 percent;

The design of the isolated half-width small-grid-shaped metallized film with the size A, the longitudinal size W and the low square resistance (square resistance I and square resistance II) of the thickened area 4 ensures that the metallized film has higher voltage withstand capability and lower equivalent series resistance under the thinner thickness;

The EMC filter 17 is built in, the EMC filter 17 is an X capacitor in the middle, four Y capacitors on two sides are ground-crossing capacitors, the Y capacitors are usually connected between a high-voltage positive electrode and a high-voltage negative electrode and a vehicle body ground respectively, namely C2 and C3, the X capacitors are overline capacitors and are capacitors used on a high-voltage direct-current bus, the Y capacitors mainly serve to reduce common-mode electromagnetic interference, reduce electromagnetic noise and electromagnetic pollution, protect personal safety, and provide a certain degree of protection particularly when electric equipment leaks electricity, the X capacitors mainly serve to reduce electromagnetic interference and protect electronic elements from voltage peaks, are used for filtering on the high-voltage direct-current bus and are beneficial to stabilizing voltage and current; the grounding copper bar 14 is thermally pressed between the anode copper bar 12 and the cathode copper bar 11 of the capacitor by adopting heat conduction silica gel, and is used for EMC shielding and also used as a local hot spot heat dissipation device;

The EMC filter 17 is used to suppress the common mode and differential mode interference of the motor controller, and the present invention provides an example of a filter circuit composed of an X2 capacitor and a Y2 capacitor, as shown in fig. 9, whose value ranges are as follows:

0.056μF ≤C1=C2≤0.15μF ， Y2

0.022μF ≤C3=C4≤0.1μF ， Y2

0.47μF ≤C5≤1μF ， X2

Referring to fig. 1-9, the metallized safety film is wound by a large-diameter a reel, and flattened capacitor core 9 with smaller thickness t is designed to have lower thermal resistance; the two metallized safety films are stacked upside down and then wound, wherein the distance e between the edge of the thickened region 4 of one metallized safety film and the edge of the margin 7 of the other metallized safety film is shown at the lower right side of fig. 8.

In the invention, the flattened capacitor core 9 with smaller size t is designed, and because the height of the capacitor core 9 is small, the space is saved, the heat dissipation is convenient, the closer the capacitor core 9 is to the center, the higher the temperature is, the thermal resistance can be reduced by reducing the height of the capacitor core 9, and the heat dissipation is facilitated.

In one embodiment, the two metallized safety films on the capacitor core 9 are stacked upside down, when the two metallized safety films are stacked oppositely, the small grids on the two metallized safety films can repeatedly cross, and the structure can more effectively disperse and bear voltage, so that the voltage endurance capacity of the capacitor is remarkably improved, the cross stacked metallized safety film structure is beneficial to uniform distribution of current, local concentration of current is reduced, and the stability of current is improved.

Referring to fig. 1 to 9, the plating layer 2 and the margin area 7 are coated with an anti-oxidation oil to form an anti-oxidation oil coating 3; an epoxy resin cover plate 20 is arranged above the shell 8, a mounting plate 10 is arranged on the shell 8, and a negative electrode copper bar 11 and a positive electrode copper bar 12 are fixedly mounted through the mounting plate 10; the housing 8 is provided with connecting copper bars 13.

In the invention, the cathode copper bar 11 and the anode copper bar 12 adopt oxygen-free copper with the thickness of 0.8-1 mm, the copper bar design for reducing the internal resistance is realized by the shortest current path from the first alternating current side to the second alternating current side, and the copper bar is externally provided with a large-area heat dissipation area which can contact a water cooling system to reduce the temperature of the copper bar;

The connecting copper bar 13 is used as a conductor of current and is responsible for efficiently and safely transmitting electric energy from the battery pack to the film capacitor and further transmitting the electric energy to various components such as an electric driving system, an inverter, a charging system and the like, the connecting copper bar 13 also has the function of connecting firmly, the connecting copper bar 13 ensures stable connection between positive and negative copper bars, connection looseness caused by vibration or temperature change is avoided, continuity and stability of current transmission are ensured, the connecting copper bar 13 can also improve heat dissipation performance, the connecting copper bar 13 has good heat conduction performance, heat generated by the film capacitor is helped to be quickly transmitted, and proper working temperature of the film capacitor is kept.

Referring to fig. 1 to 9, an NTC temperature sensor 16 is provided on the housing 8, and a detection end of the NTC temperature sensor 16 is disposed between the plurality of capacitor cores 9; the outside of the plurality of capacitor cores 9 is wrapped with an insulating film 18, a heat dissipation aluminum plate 15 is arranged below the insulating film 18, and the heat dissipation aluminum plate 15 is fixedly connected with the shell 8.

In the invention, the NTC temperature sensor 16 is used for detecting the temperature of the capacitor cores 9, if the over-temperature occurs, the use limit is reduced, the safety of capacitor products is protected, and the detection end of the NTC temperature sensor 16 is arranged among a plurality of capacitor cores 9, so that the temperature change of the capacitor cores 9 can be detected more accurately and more rapidly; the heat dissipation aluminum plate 15 is fixedly connected with the shell 8, and the heat dissipation aluminum plate and the shell 8 are integrally formed, so that the structural strength of the shell 8 is higher; the insulating film 18 electrically isolates the capacitor core 9, thereby avoiding occurrence of a short circuit.

Referring to fig. 1-9, the grounding copper bar 14 is formed by sequentially splicing a plurality of groups of first trapezoid plates 1401 and second trapezoid plates 1402, and triangular grooves 19 are formed in the second trapezoid plates 1402 of the first trapezoid plates 1401; the shell 8 is made of high-heat-conductivity polyphenylene sulfide, the built-in heat-dissipation aluminum plate 15 is U-shaped, a water cooling system can be assembled, and the large-area heat dissipation function of the shell is realized.

In the invention, the triangle has high stability and high strength, and the triangular groove 19 formed on the second trapezoid plate 1402 of the first trapezoid plate 1401 can effectively improve the strength of the second trapezoid plate 1402 of the first trapezoid plate 1401, so that the compressive capacity of the second trapezoid plate 1402 is stronger;

Further, the first trapezoid plate 1401 is in a mountain shape (positive trapezoid), the second trapezoid plate 1402 is in a valley shape (inverted trapezoid), the highest position of the first trapezoid plate 1401 is opposite to the negative electrode copper bar 11, the lowest position of the second trapezoid plate 1402 is opposite to the positive electrode copper bar 12, the grounding copper bar 14 is formed by hot-pressing heat conducting silica gel between the negative electrode copper bar 11 and the positive electrode copper bar 12 of the capacitor, the triangular groove 19 formed in the second trapezoid plate 1402 of the first trapezoid plate 1401 can be better filled with the heat conducting silica gel to fill the connecting gap between the grounding copper bar 14 and the negative electrode copper bar 11 or the positive electrode copper bar 12, the heat conducting effect is good, hot air can flow out through trapezoid holes formed between the first trapezoid plate 1401 and the second trapezoid plate 1402 and the negative electrode copper bar 11 or the positive electrode copper bar 12, and meanwhile the strength of the first trapezoid plate 1401 and the second trapezoid plate 1402 formed by the first trapezoid plate 1401 and the second trapezoid plate 1402 is high.

The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art, who is within the scope of the present invention, should make equivalent substitutions or modifications according to the technical scheme of the present invention and the inventive concept thereof, and should be covered by the scope of the present invention.

Claims (7)

1. A film capacitor for a low thermal resistance high power density electric vehicle controller, comprising a housing (8) and a capacitor core (9), characterized by further comprising:

A metallized security film constituting the capacitor core (9);

The capacitor core (9) is provided with a plurality of groups which are all positioned in the shell (8), the capacitor core (9) is provided with a negative copper bar (11) and a positive copper bar (12) which are used for current conduction, and a grounding copper bar (14) is arranged between the negative copper bar (11) and the positive copper bar (12);

an EMC filter (17) is arranged on one side surface inside the shell (8);

the metallized safety film comprises a base film (1) and a plating layer (2), wherein the plating layer (2) is arranged above the base film (1);

the plating layer (2) and the base film (1) form a metallized film with a width W, the plating layer (2) is divided into a thickening area (4), a transition area (5), an active area (6) and a margin area (7) when viewed from the cross section, the thickness of the plating layer (2) is represented by a square resistor, wherein the plating layer comprises a square resistor I positioned in the thickening area (4), a square resistor II positioned in the transition area (5) and a square resistor III positioned in the active area (6);

The movable area (6) is provided with a plurality of grids with E-F size, and a fuse with the width of G is arranged between two adjacent grids of each row;

Through the size of the fuse width G on the regulation net, the safety factor is improved, and the voltage interval of safe operation of the capacitor is reached: Wherein, the value range: e is more than or equal to 3mm 6mm,2mm less than or equal to F less than or equal to 5mm, G is more than or equal to 0.1mm and less than or equal to 0.15mm, Representing the amount of charge stored on the capacitor,Representing the capacitance of the capacitor,Representing the voltage across the capacitor,Representing the distance between the two plates of the capacitor,Represents a dielectric constant, k represents an electrostatic force constant;

An insulating film (18) is wrapped outside the plurality of capacitor cores (9), a heat dissipation aluminum plate (15) is arranged below the insulating film (18), and the heat dissipation aluminum plate (15) is fixedly connected with the shell (8);

The grounding copper bar (14) is formed by sequentially splicing a plurality of groups of first trapezoid plates (1401) and second trapezoid plates (1402), and triangular grooves (19) are formed in the second trapezoid plates (1402) of the first trapezoid plates (1401);

The first trapezoid plate (1401) is in a mountain shape, the second trapezoid plate (1402) is in a valley shape, the highest position of the first trapezoid plate (1401) is opposite to the negative electrode copper bar (11), the lowest position of the second trapezoid plate (1402) is opposite to the positive electrode copper bar (12), and the grounding copper bar (14) is hot-pressed between the negative electrode copper bar (11) and the positive electrode copper bar (12) of the capacitor by adopting heat-conducting silica gel;

the shell (8) is made of high-heat-conductivity polyphenylene sulfide material, the built-in radiating aluminum plate (15) is U-shaped, a water cooling system can be assembled, and the large-area radiating function of the shell is achieved.

2. The thin film capacitor for the electric automobile controller with low thermal resistance and high power density according to claim 1, wherein the metallized safety film is wound by a large-diameter a reel, and the flattened thickness is designed as a flattened capacitor core (9) with a smaller size t, so that the flattened capacitor core has lower thermal resistance.

3. A film capacitor for a low thermal resistance high power density electric vehicle controller according to claim 1, characterized in that two of said metallized safety films are stacked upside down on each other and then wound up, wherein the distance between the edge of the thickened region (4) of one of said metallized safety films and the edge of the margin region (7) of the other of said metallized safety films is e.

4. A thin film capacitor for a low thermal resistance high power density electric vehicle controller according to claim 3, wherein the plating layer (2) and the margin (7) are coated with an anti-oxidation oil to form an anti-oxidation oil coating (3).

5. The thin film capacitor for the electric automobile controller with low thermal resistance and high power density according to claim 1, wherein an epoxy cover plate (20) is arranged above the shell (8), a mounting plate (10) is arranged on the shell (8), and the negative electrode copper bar (11) and the positive electrode copper bar (12) are fixedly mounted through the mounting plate (10).

6. The thin film capacitor for a low thermal resistance high power density electric vehicle controller according to claim 5, wherein the case (8) is provided with a connection copper bar (13).

7. The thin film capacitor for the low thermal resistance high power density electric automobile controller according to claim 1, characterized in that the shell (8) is provided with an NTC temperature sensor (16), and the detection end of the NTC temperature sensor (16) is arranged among a plurality of capacitor cores (9).