Novel high-safety metallized film resonant capacitor
By using two metallized polypropylene aluminum films with a gap and a non-inductive winding method, the problem of rapid heat increase in metallized thin-film resonant capacitors under high frequency and high current is solved, thereby improving safety and reducing losses.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-25
- Publication Date
- 2026-03-20
AI Technical Summary
Existing metallized thin-film resonant capacitors, under high-frequency and high-current conditions, suffer from heat generation due to misalignment errors in the gap between the upper and lower metal layers of the double-sided metallized polyester aluminum film. This leads to a rapid increase in internal heat, temperature rise, and safety issues such as breakdown or fire.
The structure uses two metallized polypropylene aluminum films with a gap in the middle to form an equivalent capacitor. It is manufactured using a non-inductive winding method to ensure that the dielectric of the small capacitor is a low-loss polypropylene film, thereby reducing heat generation.
Under high-frequency and high-current operating conditions, it avoids a rapid increase in internal heat of the capacitor, improves product safety and overcurrent capacity, and reduces losses.
Smart Images
Figure CN224020617U_ABST
Abstract
Description
Technical Field
[0001] This utility model patent relates to the field of thin-film resonant capacitor technology, and in particular to a novel high-safety metallized thin-film resonant capacitor. Background Technology
[0002] Metallized film capacitors are essential electronic components in electronic devices. They employ a non-inductive wound structure with metallized film, exhibiting excellent self-healing properties, high insulation resistance, and stable capacitance. Suitable for DC and pulsating circuits, they are widely used in various electronic appliances, electrical equipment, and new energy fields for filtering, resonance, DC blocking, bypassing, coupling, and noise reduction.
[0003] Metallized thin-film resonant capacitors are mainly used in resonant circuits, which are characterized by high frequency and large current. Due to their stable frequency characteristics, high voltage withstand and safety performance, metallized thin-film resonant capacitors are widely used in this field.
[0004] like Figure 6 As shown, existing metallized thin-film resonant capacitor structures mainly employ a double-sided metallized film structure, comprising, from top to bottom, a double-sided metallized polyester aluminum film, a polypropylene film, and a metallized polypropylene aluminum film. Gaps are left between the upper and lower metallized aluminum layers of the double-sided metallized polyester aluminum film, and gaps are left at both ends of the metallized aluminum layers of the metallized polypropylene aluminum film. From the structure, it can be seen that this type of metallized thin-film resonant capacitor can theoretically be equivalent to two capacitors C1 and C2 with polypropylene films as the dielectric (e.g., ...). Figure 6 (As shown) in series. However, in actual production, there will be errors in the correspondence between the gap shielding areas between the upper and lower metal layers of the double-sided metallized polyester aluminum film, resulting in phenomena such as... Figure 7 There is a misalignment error between gaps S7 and S8. Figure 7 The structure shows that this metallized thin-film resonant capacitor can theoretically be equivalent to two capacitors C1 and C2 with polypropylene film dielectrics connected in series. However, this error will cause small capacitors C3 and C4 (such as...) with a polyester and polypropylene film dielectric mixture to be connected in parallel in the actual equivalent circuit. Figure 7 As shown in the figure.
[0005] Because the dielectric loss of polyester film is generally 0.005, while that of polypropylene film is generally 0.0002, this data comparison shows that when polyester film is used as the dielectric, the capacitance loss will increase significantly. Under high-frequency and high-current conditions, the small capacitors C3 and C4 will generate heat, causing the internal heat of the metallized film capacitor to increase sharply, the temperature to rise, and eventually the product will break down. In severe cases, it may cause safety problems such as fire. Utility Model Content
[0006] To solve the above existing metalized film resonant capacitor because of the double-sided metalized polyester aluminum film, the upper and lower metal aluminum layer gap exists misregistration error, in the high frequency large current working condition, small capacitance C3 and C4 will produce heat, resulting in the internal heat of the metalized film capacitor increases sharply, temperature rises, the product finally appears breakdown, serious time to appear fire safety problems, the utility model discloses a kind of new high safety metalized film resonant capacitor, double-sided metalized polyester aluminum film is changed into two middle gap metalized polypropylene aluminum film, even if the metal aluminum layer gap of two metalized polypropylene aluminum films exists misregistration error, form Figure 3 And Figure 5 Equivalent capacitance as shown, but because the small capacitance C3 and C4 medium in parallel in the capacitor are all very small loss polypropylene film, in the high frequency large current working condition, small capacitance C3 and C4 produce heat limited, thereby avoid the internal heat of the capacitor because of sharp increase, temperature rises, the product finally appears breakdown, serious time to appear fire and other safety problems.
[0007] To achieve the above object, the utility model discloses a kind of new high safety metalized film resonant capacitor, including first electrode layer, polypropylene light film and second electrode layer from top to bottom sequentially laminated, the first electrode layer includes first metalized polypropylene aluminum film and second metalized polypropylene aluminum film, first metalized polypropylene aluminum film and second metalized polypropylene aluminum film are all by single-sided evaporation aluminum-containing metal aluminum layer on polypropylene film, and the metal aluminum layer middle is left gap, the metal aluminum layer of first metalized polypropylene aluminum film and the metal aluminum layer of second metalized polypropylene aluminum film are oppositely arranged, the second electrode layer is set as third metalized polypropylene aluminum film, third metalized polypropylene aluminum film is by single-sided evaporation aluminum-containing metal aluminum layer on polypropylene film, the metal aluminum layer both sides are left gap, and the metal aluminum layer is towards polypropylene light film setting.
[0008] As further improvement of the present technology, a kind of new high safety metalized film resonant capacitor includes first electrode layer and second electrode layer from top to bottom sequentially laminated, the first electrode layer includes first metalized polypropylene aluminum film and second metalized polypropylene aluminum film, first metalized polypropylene aluminum film and second metalized polypropylene aluminum film are all by single-sided evaporation aluminum-containing metal aluminum layer on polypropylene film, the metal aluminum layer middle is left gap, and the metal aluminum layer of first metalized polypropylene aluminum film and the metal aluminum layer of second metalized polypropylene aluminum film are oppositely arranged, the second electrode layer includes third metalized polypropylene aluminum film and fourth metalized polypropylene aluminum film, third metalized polypropylene aluminum film and fourth metalized polypropylene aluminum film are all by single-sided evaporation aluminum-containing metal aluminum layer on polypropylene film, the metal aluminum layer both sides are left gap, and the metal aluminum layer of third metalized polypropylene aluminum film and the metal aluminum layer of fourth metalized polypropylene aluminum film are oppositely arranged.
[0009] As a further improvement of the present technology, the left and right edges of the first and second metalized polypropylene aluminum films are all cut into wavy edges.
[0010] The wavy edges can increase the contact with the lead electrodes.
[0011] As a further improvement of the present technology, a first gap is provided in the middle of the metal aluminum layer of the first metalized polypropylene aluminum film, and the width of the first gap is S1; a second gap is provided in the middle of the metal aluminum layer of the second metalized polypropylene aluminum film, and the width of the second gap is S2; S1=S2; the range of S1 and S2 is 2-3 mm; the first gap and the second gap are arranged in an up-down corresponding manner, and the misalignment error is 0-0.5 mm.
[0012] As a further improvement of the present technology, a third gap and a fourth gap are respectively provided at the two sides of the metal aluminum layer of the third metalized polypropylene aluminum film, the width of the third gap is S3, and the width of the fourth gap is S4; S3=S4; the range of S3 and S4 is 1-2 mm.
[0013] As a further improvement of the present technology, a third gap and a fourth gap are respectively provided at the two sides of the metal aluminum layer of the third metalized polypropylene aluminum film, the width of the third gap is S3, and the width of the fourth gap is S4; S3=S4; the range of S3 and S4 is 1-2 mm; a fifth gap and a sixth gap are respectively provided at the two sides of the metal aluminum layer of the fourth metalized polypropylene aluminum film, the width of the fifth gap is S5, and the width of the sixth gap is S6; S5=S6; the range of S5 and S6 is 1-2 mm.
[0014] As a further improvement of the present technology, the metalized film resonant capacitor is made by using the non-inductive winding method, and the capacitor wound by the non-inductive winding method has better performance in a high-frequency circuit, and can reduce signal distortion and energy loss caused by distributed inductance.
[0015] Compared with the prior art, the utility model patent has the beneficial effects that: the utility model patent changes the double-sided metalized polyester aluminum film into two metalized polypropylene aluminum films with a gap in the middle of the metal aluminum layer, even if there is a misalignment error in the middle gap of the metal aluminum layer of the two metalized polypropylene aluminum films, the equivalent capacitance shown in the formula Figure 3 and Figure 5 is formed, but because the dielectrics of the small capacitors C3 and C4 in parallel in the capacitor are both polypropylene films with very small loss, the heat generated by the small capacitors C3 and C4 is limited under the working condition of high frequency and large current, so that the safety problems such as breakdown and fire of the product caused by the sharp increase of heat and temperature in the capacitor are avoided, the product loss is greatly reduced by using the non-inductive winding method, the internal heat of the product is reduced, and the overcurrent capacity and safety of the product are finally improved. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the theoretical structure and its equivalent circuit diagram of Embodiment 1 of this utility model patent;
[0017] Figure 2 for Figure 1 Enlarged view of point A in the middle;
[0018] Figure 3 This is a schematic diagram of the actual structure of Embodiment 1 of the present utility model patent and its equivalent circuit diagram;
[0019] Figure 4 This is a schematic diagram of the theoretical structure and its equivalent circuit diagram of Embodiment 2 of this utility model patent;
[0020] Figure 5 This is a schematic diagram of the actual structure and its equivalent circuit diagram of Embodiment 2 of this utility model patent.
[0021] Figure 6 A schematic diagram of the theoretical structure of an existing metallized thin-film resonant capacitor and its equivalent circuit diagram;
[0022] Figure 7 This is a schematic diagram of the actual structure of an existing metallized thin-film resonant capacitor and its equivalent circuit diagram.
[0023] In the figure: 1. First metallized polypropylene aluminum film, 101. First polypropylene film, 102. First metallized aluminum layer, 2. Second metallized polypropylene aluminum film, 201. Second polypropylene film, 202. Second metallized aluminum layer, 3. Polypropylene light film, 4. Third metallized polypropylene aluminum film, 401. Third polypropylene film, 402. Third metallized aluminum layer, 5. Fourth metallized polypropylene aluminum film, 501. Fourth polypropylene film, 502. Fourth metallized aluminum layer, 6. Double-sided metallized polyester aluminum film, 601. Polyester film, 602. Fifth metallized aluminum layer, 603. Sixth metallized aluminum layer. Detailed Implementation
[0024] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0025] like Figure 1 As shown, Embodiment 1 of this utility model patent:
[0026] The first electrode layer, the polypropylene light film 3 and the second electrode layer are stacked from top to bottom, the first electrode layer includes the first metalized polypropylene film 1 and the second metalized polypropylene film 2, the first metalized polypropylene film 1 is formed by evaporating the first metal aluminum layer 102 containing aluminum on one side of the first polypropylene film 101, and the first metal aluminum layer 102 has a first gap in the middle, the width of the first gap is S1, S1 = 2 mm, the second metalized polypropylene film 2 is formed by evaporating the second metal aluminum layer 202 containing aluminum on one side of the second polypropylene film 201, and the second metal aluminum layer 202 has a second gap in the middle, the width of the second gap is S2, S2 = 2 mm, the first metal aluminum layer 102 of the first metalized polypropylene film 1 and the second metal aluminum layer 202 of the second metalized polypropylene film 2 are oppositely arranged; the second electrode layer is the third metalized polypropylene film 4, the third metalized polypropylene film 4 is formed by evaporating the third metal aluminum layer 402 containing aluminum on one side of the third polypropylene film 401, the third metal aluminum layer 402 has a third gap and a fourth gap on the two sides, the width of the third gap is S3, the width of the fourth gap is S4, S3 = S4 = 1 mm.
[0027] As shown in Figure 2 , the left and right ends of the first metalized polypropylene film 1 and the second metalized polypropylene film 2 are all cut into wavy edges. The wavy edges can increase the contact with the lead electrodes.
[0028] The metalized film resonant capacitor of the present embodiment 1 is made by using the non-inductive winding method. The capacitor wound by the non-inductive winding method has better performance in high-frequency circuits, and can reduce signal distortion and energy loss caused by distributed inductance.
[0029] In theory, the width of the first gap and the second gap in the present embodiment 1 is equal, and the upper and lower positions correspond completely, which is equivalent to two metalized film capacitors C1 and C2 with polypropylene film as the medium connected in series.
[0030] As shown in Figure 3 , in the actual production process of the present embodiment 1, the width of the first gap and the second gap is equal, but the upper and lower positions will have a misalignment error, which is set to 0-0.5 mm, which is equivalent to two metalized film capacitors C1 and C2 with polypropylene film as the medium connected in series, and the capacitor C1 is connected in parallel with a small capacitor C3, and the capacitor C2 is connected in parallel with a small capacitor C4, and C3 and C4 are both metalized film capacitors with polypropylene film as the medium, and the dielectric loss of polypropylene film is generally 0.0002. Under the working condition of high frequency and large current, although the small capacitors C3 and C4 will generate heat, they will not cause the heat in the metalized film capacitor to increase sharply, the temperature to rise, and the product to have safety problems such as breakdown or fire.
[0031] As shown in Figure 4The utility model patent embodiment 2 is shown:
[0032] Including first electrode layer and second electrode layer that from top to bottom are stacked in proper order, first electrode layer includes first metalized polypropylene aluminum film 1 and second metalized polypropylene aluminum film 2, first metalized polypropylene aluminum film 1 is evaporated with first metal aluminum layer 102 containing aluminum on the single side of first polypropylene film 101, and first metal aluminum layer 102 is evenly left with first gap in the middle, and first gap width is S1, S1=3mm, second metalized polypropylene aluminum film 2 is evaporated with second metal aluminum layer 202 containing aluminum on the single side of second polypropylene film 201, and second metal aluminum layer 202 is evenly left with second gap in the middle, and second gap width is S2, S2=3mm, and first metal aluminum layer 102 of first metalized polypropylene aluminum film 1 and second metal aluminum layer 202 of second metalized polypropylene aluminum film 2 are oppositely arranged;Second electrode layer includes third metalized polypropylene aluminum film 4 and fourth metalized polypropylene aluminum film 5, third metalized polypropylene aluminum film 1 is evaporated with third metal aluminum layer 402 containing aluminum on the single side of third polypropylene film 401, and third metal aluminum layer 402 is left with third gap and fourth gap on both sides respectively, and third gap and fourth gap width are S3 and S4 respectively, S3=S4=2mm, fourth metalized polypropylene aluminum film 5 is evaporated with fourth metal aluminum layer 502 containing aluminum on the single side of fourth polypropylene film 501, and fourth metal aluminum layer 502 is left with fifth gap and sixth gap on both sides respectively, and fifth gap and sixth gap width are S5 and S6 respectively, S5=S6=2mm, and third metal aluminum layer 402 of third metalized polypropylene aluminum film 4 and fourth metal aluminum layer 502 of fourth metalized polypropylene aluminum film 5 are oppositely arranged.
[0033] In embodiment 2, the left and right ends of first metalized polypropylene aluminum film 1 and second metalized polypropylene aluminum film 2 are all cut into wave-shaped edges.
[0034] The metalized film resonant capacitor of the embodiment 2 is made by non-inductive winding method, and the capacitor wound by the non-inductive winding method shows better performance in high-frequency circuit, which can reduce signal distortion and energy loss caused by distributed inductance.
[0035] In theory, the first gap and the second gap in embodiment 2 are equal in width, and the upper and lower positions correspond completely, which is equivalent to two metalized film capacitors C1 and C2 with polypropylene film as dielectric in series connection.
[0036] As Figure 5As shown, in actual production process, the first gap and the second gap of the embodiment 2 have equal width, but the upper and lower positions will have misalignment error, and the misalignment error is set to 0-0.5mm, which is equivalent to that two metallized film capacitors C1 and C2 with polypropylene film as medium are connected in series, and the capacitor C1 is connected in parallel with a small capacitor C3, the capacitor C2 is connected in parallel with a small capacitor C4, and C3 and C4 are both metallized film capacitors with polypropylene film as medium, and the dielectric loss of the polypropylene film is generally 0.0002. Under the working condition of high frequency and large current, although the small capacitors C3 and C4 will generate heat, they will not cause the internal heat of the metallized film capacitors to increase sharply, and the temperature to rise, and the product will not have safety problems such as breakdown or fire.
[0037] As shown in the Figure 6 comparative example,
[0038] comprises a first electrode layer, a polypropylene light film 3 and a second electrode layer stacked in order from top to bottom, the first electrode layer is a double-sided metallized polyester aluminum film, the double-sided metallized polyester aluminum film is formed by evaporating a fifth metal aluminum layer 602 and a sixth metal aluminum layer 603 containing aluminum on the upper and lower surfaces of a polyester film 601 respectively, the fifth metal aluminum layer 602 and the sixth metal aluminum layer 603 have a seventh gap and an eighth gap in the middle respectively, the widths of the seventh gap and the eighth gap are set as S7 and S8 respectively, S7=S8=2mm; the second electrode layer is set as a third metallized polypropylene aluminum film 4, the third metallized polypropylene aluminum film 4 is formed by evaporating a third metal aluminum layer 402 containing aluminum on one surface of a third polypropylene film 401, the third metal aluminum layer 402 has a third gap and a fourth gap on both sides respectively, the width of the third gap is set as S3, and the width of the fourth gap is set as S4, S3=S4=1mm.
[0039] In theory, the seventh gap and the eighth gap in the comparative example have equal width, and the upper and lower positions completely correspond, which is equivalent to that two metallized film capacitors C1 and C2 with polypropylene film as medium are connected in series.
[0040] As shown in the Figure 7 comparative example, in actual production process, the seventh gap and the eighth gap have equal width, but the upper and lower positions will have misalignment error, and the misalignment error is 0-0.5mm, which is equivalent to that two metallized film capacitors C1 and C2 with polypropylene film as medium are connected in series, and the capacitor C1 is connected in parallel with a small capacitor C3, the capacitor C2 is connected in parallel with a small capacitor C4, and the medium of the small capacitors C3 and C4 is a mixture of polyester and polypropylene film.
[0041] The dielectric loss of polyester film is generally 0.005, while the dielectric loss of polypropylene film is generally 0.0002. From the data comparison, it can be seen that the loss of the capacitor using polyester film as the dielectric will be greatly increased. In the working condition of high frequency and large current, the small capacitors C3 and C4 will generate heat, which will cause the heat in the metallized film capacitor to increase sharply, the temperature to rise, and the product to finally break down. In severe cases, fire and other safety problems will occur.
[0042] Performance detection: make the metallized film resonant capacitor products with a capacity of 12nF by using the examples 1, 2 and the comparative example, respectively, and conduct high-frequency current temperature rise test on 3 pieces of products of the examples 1, 2 and the comparative example, respectively. The test conditions are: ambient temperature 125℃, current effective value 3.75A, frequency 100Khz. The experimental results are shown in Table 1.
[0043] Table 1
[0044]
[0045] From the data in Table 1, it can be seen that even if the misalignment error of the upper and lower gaps in the first electric level layer of the examples 1 and 2 reaches 0.5mm, the metallized film resonant capacitor products will not be broken down or burned out under the working condition of high frequency and large current (3.75A, 100Khz). However, in the comparative example, the misalignment error reaches 0.2mm, and the metallized film resonant capacitor product will be broken down under the working condition of high frequency and large current (3.75A, 100Khz). When the misalignment error reaches 0.3mm, the metallized film resonant capacitor product will be burned out under the working condition of high frequency and large current (3.75A, 100Khz).
[0046] The above is only the preferred embodiment of the present utility model patent. It should be pointed out that for ordinary skilled persons in the technical field, some improvements and substitutions can be made without departing from the technical principles of the present utility model patent. These improvements and substitutions should also be considered as the protection scope of the present utility model patent.
Claims
1. A novel high-safety metallized thin-film resonant capacitor, characterized in that: The device comprises a first electrode layer, a polypropylene optical film, and a second electrode layer, which are stacked sequentially from top to bottom. The first electrode layer includes a first metallized polypropylene aluminum film and a second metallized polypropylene aluminum film. Both the first metallized polypropylene aluminum film and the second metallized polypropylene aluminum film are formed by evaporating an aluminum-containing metal layer on one side of a polypropylene film, and there is a gap in the middle of the metal layer. The metal layers of the first metallized polypropylene aluminum film and the second metallized polypropylene aluminum film are stacked opposite each other. The second electrode layer is a third metallized polypropylene aluminum film, which is formed by evaporating an aluminum-containing metal layer on one side of a polypropylene film, and there are gaps on both sides of the metal layer. The metal layer faces the polypropylene optical film.
2. The novel high-safety metallized thin-film resonant capacitor according to claim 1, characterized in that: The device includes a first electrode layer and a second electrode layer stacked sequentially from top to bottom. The second electrode layer includes a third metallized polypropylene aluminum film and a fourth metallized polypropylene aluminum film. Both the third metallized polypropylene aluminum film and the fourth metallized polypropylene aluminum film are made by vapor-depositing an aluminum-containing metal layer on one side of a polypropylene film. There are gaps on both sides of the metal aluminum layer, and the metal aluminum layers of the third metallized polypropylene aluminum film and the fourth metallized polypropylene aluminum film are stacked opposite each other.
3. The novel high-safety metallized thin-film resonant capacitor according to claim 1, characterized in that: The left and right edges of both the first and second metallized polypropylene aluminum films are cut into wavy edges.
4. A novel high-safety metallized thin-film resonant capacitor according to claim 1, characterized in that: The first metallized polypropylene aluminum film has a first gap in the middle of the aluminum layer, and the width of the first gap is set as S1. The second metallized polypropylene aluminum film has a second gap in the middle of the aluminum layer, and the width of the second gap is set as S2. S1=S2, and the range of S1 and S2 is set to 2~3mm. The positions of the first gap and the second gap are corresponding vertically, and the allowable misalignment error is 0~0.5mm.
5. A novel high-safety metallized thin-film resonant capacitor according to claim 1, characterized in that: The third metallized polypropylene aluminum film has a third gap and a fourth gap on both sides of the aluminum layer. The width of the third gap is set as S3, and the width of the fourth gap is set as S4. S3=S4, and the range of S3 and S4 is 1~2mm.
6. A novel high-safety metallized thin-film resonant capacitor according to claim 2, characterized in that: The third metallized polypropylene aluminum film has a third gap and a fourth gap on both sides of the aluminum layer. The width of the third gap is set to S3, and the width of the fourth gap is set to S4. S3 = S4, and the range of S3 and S4 is 1 to 2 mm. The fourth metallized polypropylene aluminum film has a fifth gap and a sixth gap on both sides of the aluminum layer. The width of the fifth gap is set to S5, and the width of the sixth gap is set to S6. S5 = S6, and the range of S5 and S6 is 1 to 2 mm.
7. A novel high-safety metallized thin-film resonant capacitor according to any one of claims 1 to 6, characterized in that: The metallized thin-film resonant capacitor is manufactured using a non-inductive winding method. Capacitors wound using this method exhibit better performance in high-frequency circuits and can reduce signal distortion and energy loss caused by distributed inductance.