Manufacturing method of high-temperature-resistant and high-humidity-resistant long-service-life solid-liquid mixed type aluminum electrolytic capacitor

Abstract

The invention discloses a manufacturing method of a high-temperature-resistant and high-humidity-resistant long-service-life solid-liquid mixed type aluminum electrolytic capacitor, which comprises the following steps of: nailing a guide pin on an anode aluminum foil and a cathode aluminum foil, separating the guide pin by using an isolating layer, winding the guide pin into a capacitor core, performing formation repair and drying on the core, then impregnating PEDOT / PSS dispersion liquid, and impregnating functional liquid after drying, thereby obtaining the high-temperature-resistant and high-humidity-resistant long-service-life solid-liquid mixed type aluminum electrolytic capacitor. And finally, aging and sorting are carried out, so that the high-temperature-resistant and high-humidity-resistant long-service-life solid-liquid mixed type aluminum electrolytic capacitor can be obtained. The phosphate ester compound in the functional liquid not only can reduce the influence of moisture on the product, but also can play a role in preventing the conductive polymer from being degraded, so that the stability of the conductive polymer of the product in a high-temperature and high-humidity environment is improved; according to the technical scheme, the temperature resistance and the moisture resistance of the product can be effectively improved, so that the solid-liquid mixed type aluminum electrolytic capacitor with high temperature resistance, high humidity resistance and long service life is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of solid aluminum electrolytic capacitors, and in particular relates to a method for manufacturing a high-temperature, high-humidity, long-life solid-liquid hybrid electrolytic capacitor. Background Art

[0002] As one of the important components of modern electronic devices, capacitors are playing an increasingly important role in the development of the electronics industry, where demand is growing rapidly. Aluminum electrolytic capacitors are favored worldwide due to their excellent performance, low price and wide range of uses, especially in growth areas such as automobiles, information and telecommunications, industrial equipment and energy-saving home appliances.

[0003] Automobiles are undergoing an electrification transformation, which is progressing more rapidly. Due to electrification, the number of electronic control units (ECUs) is increasing, and the number of capacitors used in a single car is also rising: capacitors used in ECUs are in great need of capacitors with higher ambient temperature and humidity and longer life than before.

[0004] At present, one of the key factors affecting the life of capacitors is that the rubber plug is prone to deterioration in a long-term high temperature and high humidity environment. Moisture can easily penetrate the rubber plug into the product, causing the product to fail in a short period of time. Therefore, it is of great application significance to develop a manufacturing method to reduce the impact of moisture on capacitor products after rubber plug aging. Summary of the invention

[0005] (1) Technical issues to be resolved

[0006] The object of the present invention is to provide a method for manufacturing a high temperature, high humidity, long life solid-liquid hybrid electrolytic capacitor, which can effectively improve the temperature resistance of the product, thereby obtaining a high temperature, high humidity, long life solid-liquid hybrid capacitor.

[0007] (2) Technical solution

[0008] In order to solve the above technical problems, the present invention provides a method for preparing a high temperature, high humidity and long life solid-liquid hybrid aluminum electrolytic capacitor, which is characterized by comprising the following steps:

[0009] Step 1: After cutting the aluminum foil and electrolytic paper, they are rolled, welded and chemically formed to obtain a core;

[0010] Step 2: Immerse the core in the PEDOT / PSS dispersion and dry it after immersion;

[0011] Step 3: Immersing the dried core into the functional liquid, and obtaining a core containing the conductive polymer and the functional liquid after the impregnation is completed;

[0012] Step 4: Seal and assemble the core impregnated with the functional liquid and the aluminum shell;

[0013] Step 5: Aging the sealed product to obtain a high temperature, high humidity, long life solid-liquid hybrid aluminum electrolytic capacitor.

[0014] Furthermore, the functional liquid in step (3) is a phosphate compound.

[0015] Furthermore, the phosphate compound in the functional liquid in step (3) has a benzene ring structure.

[0016] Furthermore, when the phosphate compound with a benzene ring structure in the functional liquid in step (3) is hydrolyzed, the products are phenol and a compound with phosphorus element.

[0017] Furthermore, the mass fraction of the phosphate compound in the functional liquid in step (3) is in the range of 5% to 20%.

[0018] (3) Beneficial effects

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The invention discloses a method for manufacturing a high-temperature, high-humidity, long-life solid-liquid hybrid aluminum electrolytic capacitor. The method adopts the method of adding a phosphate compound with a benzene ring structure into a functional liquid. When moisture enters the interior of the capacitor, the substance undergoes a hydrolysis reaction to generate phenol and a compound with a phosphorus element. On the one hand, the substance can consume moisture, thereby inhibiting the influence of moisture on the dedoping of a conductive polymer and improving the stability of the conductive polymer under a high-temperature and high-humidity environment. On the other hand, the generated phenol substance can also replace the oxidation of the conductive polymer, greatly reducing the possibility of oxidation of the conductive polymer, improving the stability of the conductive polymer under a high-temperature environment, and effectively inhibiting the degradation of the conductive polymer, thereby improving the temperature resistance of the product. In addition, the generated compound with a phosphorus element can also passivate an aluminum foil oxide film, inhibit the hydration reaction of the aluminum foil caused by moisture, thereby improving the stability of the oxide film and achieving the purpose of improving the temperature resistance of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for describing the specific implementation methods or the prior art are briefly introduced below. Obviously, the drawings described below are only the manufacturing process flow charts of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1The present invention is a flow chart of a method for manufacturing a high-temperature, high-humidity, long-life solid-liquid hybrid aluminum electrolytic capacitor. DETAILED DESCRIPTION

[0023] The above contents of the present invention are further described in detail below through specific implementation modes in the form of examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples.

[0024] For ease of understanding, the present application embodiment and comparative example are described by taking the preparation process of a 35V270, 10*10.2 model high temperature, high humidity, long life solid-liquid hybrid aluminum electrolytic capacitor as an example.

[0025] Example 1

[0026] (1) Cut the positive electrode foil and the negative electrode foil to a width of 5 mm, and the electrolytic paper to a width of 5.6 mm, and roll them into a core. The core is welded to a stainless steel bar, and then powered on to form a core in sections. Finally, a formed core is obtained.

[0027] (2) placing the formed core into a sealed container to vacuum impregnate the dispersion, and then drying at 120°C;

[0028] (3) impregnating the dried core with a functional liquid at a vacuum degree of -80 kPa for 5 min. The functional liquid is a mixed solution, which contains triphenyl phosphate (7% by mass) in addition to ethylene glycol, γ-butyrolactone, cyclopentane sulfone, terephthalic acid and other substances, to obtain a core impregnated with the functional liquid;

[0029] (4) Sealing and assembling the core impregnated with the functional liquid;

[0030] (5) The sealed assembled capacitor is aged to obtain a high temperature, high humidity, long life solid-liquid hybrid aluminum electrolytic capacitor.

[0031] Example 2

[0032] The difference from Example 1 is that triphenyl phosphate in the functional liquid is replaced by diphenyl phosphate.

[0033] Example 3

[0034] The difference from Example 1 is that triphenyl phosphate in the functional liquid is replaced by diphenyl phosphite.

[0035] Example 4

[0036] The difference from Example 1 is that the mass fraction of hydroquinone is 5%.

[0037] Example 5

[0038] The difference from Example 1 is that the mass fraction of hydroquinone is 20%.

[0039] Comparative Example 1

[0040] The difference from Example 1 is that triphenyl phosphate is not contained.

[0041] Comparative Example 2

[0042] The difference from Example 1 is that the mass fraction of triphenyl phosphate is 2%.

[0043] Comparative Example 3

[0044] The difference from Example 1 is that tributyl phosphate is contained.

[0045] In order to reduce the experimental error, the number of tests for each embodiment is 100, and the test results are averaged. The performance of the obtained high temperature, high humidity and long life solid-liquid hybrid aluminum electrolytic capacitor was tested. The initial characteristic test was to test the capacitance and loss at 120Hz and the ESR at 100kHz. The capacitor with a leakage current value of 94.5μA or more after applying the rated voltage for 1 minute was regarded as a defective product. In order to evaluate the long-term reliability, the increase in capacity and ESR (ΔC and ΔESR) was confirmed after maintaining the humidity at 85℃ / 85% for 2000 hours while applying the rated voltage. The capacity change rate and ESR change rate are expressed as the ratio (ΔC / C0 and ΔESR / ESR0) of the increase (ΔC and ΔESR) to the initial value (C0 and ESR0). Capacity change rates exceeding ±20% and ESR change rates exceeding 200% are collectively referred to as defective products. The test results are detailed in the following table data:

[0046] Table 1 High temperature and high humidity test results of various embodiments and comparative examples

[0047]

[0048] As can be seen from Table 1, compared with the capacitors prepared in Comparative Example 1, the addition of phosphate compounds with a benzene ring structure into the functional liquid in the embodiments of the manufacturing method of the present invention can effectively improve the ESR change rate and product failure rate of the capacitor in a long-term high temperature and high humidity environment.

[0049] Compared with the capacitors prepared in the embodiments of the manufacturing method of the present invention and the comparative example 2, adding a phosphate compound with a mass fraction of 2% (outside the range of 5% to 10%) to the functional liquid cannot fully inhibit the degradation of the conductive polymer, resulting in an increase in the ESR change rate and the capacitor failure rate.

[0050] Compared with the capacitors prepared in the embodiments of the manufacturing method of the present invention and the comparative example 3, the added functional liquid does not contain a phosphate compound with a benzene ring structure. Although it can inhibit the influence of some moisture, no phenol substances are generated and the effect of replacing the oxidized conductive polymer cannot be played, thereby failing to fully improve the ESR change rate and product failure rate of the capacitor in a long-term high-temperature environment.

[0051] In summary, the method for manufacturing a high-temperature, high-humidity, long-life solid-liquid hybrid aluminum electrolytic capacitor of the present invention can effectively improve the temperature resistance and moisture resistance of the product, and can obtain a high-temperature, long-life solid-liquid hybrid aluminum electrolytic capacitor.

[0052] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for manufacturing a high temperature, high humidity, long life solid-liquid hybrid aluminum electrolytic capacitor, characterized in that: It includes the following steps: Step 1: After cutting the aluminum foil and electrolytic paper, they are rolled, welded and chemically formed to obtain a core; Step 2: Immerse the core in the PEDOT / PSS dispersion and dry it after immersion; Step 3: Immersing the dried core into the functional liquid, and obtaining a core containing the conductive polymer and the functional liquid after the impregnation is completed; Step 4: Seal and assemble the core impregnated with the functional liquid and the aluminum shell; Step 5: Aging the sealed product to obtain a high temperature, high humidity, long life solid-liquid hybrid aluminum electrolytic capacitor.

2. The method for manufacturing a high temperature, high humidity and long life solid-liquid hybrid aluminum electrolytic capacitor according to claim 1, characterized in that: The functional liquid in step (3) is a phosphate compound.

3. The method for manufacturing a high temperature, high humidity and long life solid-liquid hybrid aluminum electrolytic capacitor according to claim 2, characterized in that: The phosphate compound in step (3) has a benzene ring structure.

4. The method for manufacturing a high temperature, high humidity and long life solid-liquid hybrid aluminum electrolytic capacitor according to claim 3, characterized in that: When the phosphate compound with a benzene ring structure in step (3) is hydrolyzed, the products are phenol and a compound with phosphorus.

5. The method for manufacturing a high temperature, high humidity and long life solid-liquid hybrid aluminum electrolytic capacitor according to claim 1, characterized in that: The mass fraction of the phosphate compound in the functional liquid in the step (3) is in the range of 5% to 20%.

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