JP2023516457A - Composite wire for anode lead wire of tantalum capacitor and manufacturing method - Google Patents

Abstract

Kind Code: A1 The present invention discloses a composite wire for an anode lead wire of a tantalum capacitor and a manufacturing method thereof.
SOLUTION: However, the composite wire material for the anode lead wire of the tantalum capacitor includes a core made of a metal other than pure tantalum, a tantalum alloy or another metal alloy, and a tantalum metal layer covering the outer surface of the core. including. According to the technical solution of the present invention, the composite wire for the anode lead of a tantalum capacitor has a core made of a metal or alloy other than pure tantalum, and a tantalum metal layer covering the outer surface of the core, such Secondly, by making full use of the characteristic that the tantalum metal on the surface layer can form an oxide film with a high dielectric constant and high reliability on the surface by anodization, and by filling the core with an inexpensive metal or alloy, The high dielectric constant of the anode lead required for tantalum capacitors is satisfied, and the cost is greatly reduced.
[Selection drawing] Fig. 1

Description

TECHNICAL FIELD The present invention relates to the technical field of capacitors, and more particularly to a composite wire for anode lead wires of tantalum capacitors and a manufacturing method thereof.

Currently, tantalum capacitors are widely used in the fields of communications, computers, automobiles, home appliances, and aerospace. A tantalum capacitor manufactured with tantalum powder as the anode and tantalum wire as the anode lead has advantages such as small volume, large capacitance, easy surface mounting, high reliability, and long service life. Therefore, it can operate stably in harsh conditions where many other capacitors (eg, ceramic, aluminum thin film capacitors, etc.) are not suitable.

However, tantalum, as a rare metal, is scarce in resources, difficult to extract and smelt, and has a high cost. Although it guarantees a high dielectric constant and highly reliable oxide film, its high cost also greatly limits its application and scope, since tantalum metal is expensive.

Therefore, there is an urgent need to develop anode leads that are relatively low in cost but whose dielectric constant can meet the requirements of tantalum capacitors.

SUMMARY OF THE INVENTION The object of the present invention is to provide a composite wire for the anode lead wire of a tantalum capacitor and a manufacturing method, so as to provide an anode lead wire that is relatively low in cost but whose dielectric constant can meet the requirements of the tantalum capacitor. and

In order to achieve the above object, according to one aspect of the present invention, a composite wire for an anode lead wire of a tantalum capacitor is provided. The composite wire for the anode lead wire of the tantalum capacitor includes a core made of a metal other than pure tantalum, a tantalum alloy, or another metal alloy, and a tantalum metal layer covering the outer surface of the core.

Furthermore, when the material of the tantalum metal layer is a tantalum-niobium alloy, the content of tantalum is greater than 50% and the sum of the contents of tantalum and niobium is greater than 95%, and the material of the tantalum metal layer is other than a tantalum-niobium alloy. other alloys, the tantalum content is greater than 95%.

Furthermore, the cross-section of the composite wire for the anode lead of the tantalum capacitor is circular, elliptical, or polygonal.

Furthermore, the ratio of the cross-sectional area of the tantalum metal layer to the cross-sectional area of the composite wire for the anode lead wire of the tantalum capacitor is 1% to 80%, preferably 1% to 50%.

Furthermore, the cross section of the composite wire is axially symmetrical, with the longest axis≦3.0 mm and the shortest axis≧0.1 mm.

Furthermore, the core material is one or more selected from the group consisting of niobium, zirconium, tungsten, molybdenum, titanium, nickel, iron, copper, aluminum, magnesium, cobalt and alloys thereof.

SUMMARY OF THE INVENTION According to one aspect of the present invention, a method for manufacturing a composite wire for an anode lead of a tantalum capacitor is provided. The manufacturing method includes a step S1 of providing a core and a step S2 of coating the outer surface of the core with a tantalum metal layer to obtain a composite wire for the anode lead of a tantalum capacitor.

Further, after S2, the step of processing the composite wire for the anode lead wire of the tantalum capacitor into a required size using one or more processing methods of extrusion, rolling, rotary swaging and drawing is further included.

In addition, coating the outer surface of the core with a tantalum metal layer in S2 is achieved by methods of powder metallurgy, build-up welding, explosive crimping (explosion clad), tube sheath clad or cast clad, and vapor deposition.

According to the technical solution of the present invention, the composite wire for the anode lead of a tantalum capacitor comprises a core made of a metal other than pure tantalum, a tantalum alloy or other alloys, and a tantalum metal layer covering the outer surface of the core. In this way, the tantalum metal of the surface layer can form an oxide film with a high dielectric constant and high reliability on the surface by anodization, and the core part is made of an inexpensive metal or alloy. By filling with , the high dielectric constant of the anode lead required for tantalum capacitors is satisfied, and the cost is greatly reduced.

The drawings of the specification, which forms part of the present application, are used to provide a further understanding of the invention, and the illustrative embodiments of the invention and their descriptions are used to interpret the invention, and the description thereof. The invention is not to be unduly limited.

1 is a schematic view showing a cross-sectional structure of a composite wire for anode lead of a tantalum capacitor manufactured according to one embodiment of the present invention; FIG.

It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other when not inconsistent. The present invention will now be described in detail with reference to the drawings and together with examples.

The tantalum wire or alloy wire with high tantalum content is used as the wire material for the anode lead wire of the tantalum capacitor, mainly because tantalum is very thin on the surface due to anodization, has a high dielectric constant, and has high reliability. This is because an oxide film can be formed. However, the tantalum wire or high tantalum content alloy wire produced by the prior art is expensive, cannot be widely used, or the performance cannot meet all the quality requirements of tantalum capacitors. The present invention proposes the following technical solutions to these technical problems.

According to an exemplary embodiment of the present invention, a composite wire for a tantalum capacitor anode lead is provided. The composite wire material for the anode lead wire of the tantalum capacitor includes, as shown in FIG. , or a tantalum alloy or other metal alloy.

According to the technical solution of the present invention, the composite wire for the anode lead of a tantalum capacitor comprises a core made of a metal other than pure tantalum, or a tantalum alloy or other metal alloy, and a tantalum metal layer covering the outer surface of the core. In this way, the tantalum metal of the surface layer can form an oxide film with a high dielectric constant and high reliability on the surface by anodization, and the core is made of an inexpensive metal or alloy. By filling the part, the high dielectric constant of the anode lead required for the tantalum capacitor is satisfied and the cost is greatly reduced.

When the material of the tantalum metal layer is a tantalum-niobium alloy, the tantalum content is greater than 50% and the sum of the tantalum and niobium contents is greater than 95%, and the material of the tantalum metal layer is other than the tantalum-niobium alloy. , the tantalum content is greater than 95%. Typically, the tantalum content in the tantalum metal layer is 95% so as to ensure that the surface layer of the composite wire for the anode lead of a tantalum capacitor can form a high dielectric constant oxide film on its surface by anodization. That's it. The core is sufficient for cost reduction if the tantalum content in the tantalum alloy used is less than 90%, of course the tantalum content in the tantalum alloy is less than 80%, 70%, 60%. and more preferably less than 50%, 40%, 30%, 20%, 10%, etc. In an exemplary embodiment of the invention, the core material is one or more selected from the group consisting of niobium, zirconium, tungsten, molybdenum, titanium, nickel, iron, copper, aluminum, magnesium, cobalt and alloys thereof. be. The cross section of the composite wire for the anode lead wire of the tantalum capacitor can be set to any shape, such as circular, oval or polygonal, according to the actual demand, provided that the polygon can be square, rectangular, Rhombus, pentagon, hexagon, etc.

A coverage ratio of 1% to 80% of the tantalum metal layer is preferred to allow the full performance of tantalum and not be too costly to ensure its excellent performance indicators. , more preferably 1% to 50%, that is, the ratio range of the cross-sectional area of the surface tantalum metal layer to the cross-sectional area of the composite wire for the anode lead wire of the tantalum capacitor is 1% to 80%, more preferably. is between 1% and 50%.

According to a typical embodiment of the present invention, the cross-section of said composite wire is axially symmetrical, with the longest axis≦3.0 mm and the shortest axis≧0.1 mm.

SUMMARY OF THE INVENTION Under the inventive object of the present invention, a tantalum capacitor is provided according to an exemplary embodiment of the present invention. The tantalum capacitor includes an anode lead wire, and the anode lead wire is produced using the composite wire material for the anode lead wire of the tantalum capacitor. Since the composite wire material for the anode lead wire of the tantalum capacitor of the present invention is used, the tantalum capacitor is excellent in performance and significantly reduced in cost.

According to a typical embodiment of the present invention, there is provided a method of manufacturing a composite wire for the anode lead of the tantalum capacitor. The manufacturing method includes a step S1 of providing a core and a step S2 of coating the outer surface of the core with a tantalum metal layer to obtain a composite wire for the anode lead of a tantalum capacitor.

In a typical embodiment of the present invention, after S2, the composite wire for the anode lead wire of the tantalum capacitor is processed according to the actual demand, using methods that are not limited to extrusion, rolling, rotary swaging, and drawing. further comprising machining to suitable dimensions. However, coating the outer surface of the core with a tantalum metal layer in S2 can be accomplished using methods such as, but not limited to, powder metallurgy, overlay welding, explosive crimping, tube sheathing cladding, or cast cladding.

The beneficial effects of the present invention will be further described below in conjunction with examples.
(Example 1)
A Ta-40%Nb alloy rod with a diameter of 30 mm and a length of 600 mm was put into a thin-walled plastic pipe with an inner diameter of 50 mm and a length of 700 mm, one end was first sealed with a bakelite cap, and 3 kg of tantalum powder was put into the pipe. , to distribute it uniformly around the Ta-40%Nb alloy rod. The other end is then sealed with a bakelite cap. It is isostatically pressed under a pressure of 200 MPa, sintered at 2000° C. for 180 minutes under a vacuum of 5×10 −2 Pa or more, and isostatically pressed at 250 MPa and 180° C. under vacuum at 2200° C. After sintering for a minute, a composite bar with an outer diameter of 35 mm is obtained.

This composite rod was subjected to rotary swaging so as to have a diameter of 13 mm, pickled, annealed at 1250° C. for 60 minutes under vacuum, and further subjected to rotary swaging so as to have a diameter of 3 mm, After pickling, annealed at 1250°C for 60 minutes under vacuum, multi-die drawing (2 or more dies continuously twice or twice) to form a composite wire with a diameter of 1.2 mm. It is pickled, annealed at 1250° C. for 60 minutes under vacuum, and multi-die drawing is performed to obtain a composite wire with a diameter of 0.25 mm.

(Example 2)
A Nb-1%Zr alloy rod with a diameter of 30 mm and a length of 600 mm is placed in a thin-walled plastic pipe with an inner diameter of 50 mm and a length of 700 mm. Niobium powder 5%) is put into the pipe and it is evenly distributed around the Nb-1%Zr alloy rod. The other end is then sealed with a bakelite cap. It is isostatically pressed under a pressure of 200 MPa, sintered at 2000° C. for 180 minutes under a vacuum of 5×10 −2 Pa or more, and isostatically pressed at 250 MPa and 180° C. under vacuum at 2200° C. After sintering for a minute, a composite bar with an outer diameter of 35 mm is obtained.

This composite rod was subjected to rotary swaging so as to have a diameter of 13 mm, pickled, annealed at 1250° C. for 60 minutes under vacuum, and further subjected to rotary swaging so as to have a diameter of 3 mm, After pickling, the wire is annealed at 1,250°C for 60 minutes under vacuum, drawn with a multi-die to form a composite wire with a diameter of 1.2 mm, pickled, and vacuumed at 1,250°C for 60 minutes. It is heat-retained and annealed, and multi-die drawing is performed so as to obtain a composite wire having a diameter of 0.25 mm.

(Example 3)
As shown in FIG. 1, a tantalum tape having a length of 1000 mm, a width of 39 mm, and a thickness of 0.5 mm is applied to an SS304 stainless steel bar having a diameter of 12 mm and a length of 1000 mm. The tape is seam-welded by argon arc welding to form a composite bar with an outer diameter of 13 mm, which is annealed under vacuum at 1250° C. for 180 minutes.

The subsequent working process of the 13 mm diameter composite bar is the same as in Example 1, finally obtaining a 0.25 mm diameter composite wire.

(Example 4)
For a Ta-50%Nb alloy rod with a diameter of 24 mm and a length of 500 mm, a tantalum tape having a length of 500 mm, a width of 78 mm and a thickness of 0.5 mm was applied to the surface of the alloy rod as shown in FIG. The tantalum tape is seam-welded by argon arc welding to form a composite bar with an outer diameter of 25 mm, which is annealed under vacuum at 1250° C. for 180 minutes.

The subsequent working process of the 25 mm diameter composite bar is the same as in Example 1, finally obtaining a 0.80 mm diameter composite wire.

(Example 5)
A nickel rod with a diameter of 12 mm and a length of 1000 mm is penetrated into a tantalum pipe with an outer diameter of 17 mm, an inner diameter of 12.5 mm and a length of 1000 mm, and is annealed under vacuum at 1250° C. for 180 minutes to obtain an outer diameter of A 17 mm composite bar is obtained.

The subsequent processing process of the 17 mm diameter composite bar is the same as in Example 1 to finally obtain a 0.15 mm diameter composite wire.

(Example 6)
A nickel rod with a diameter of 10.5 mm and a length of 1000 mm is penetrated into a tantalum pipe with an outer diameter of 12 mm, an inner diameter of 11 mm and a length of 1000 mm, and is annealed under vacuum at 1250° C. for 180 minutes to obtain an outer diameter of A 12 mm composite bar is obtained.

This composite rod is rotary swaged to a diameter of 3 mm, pickled, annealed at 1250° C. for 60 minutes under vacuum, and multi-die drawn to a composite wire with a diameter of 1.2 mm. and pickled, annealed at 1250° C. for 60 minutes under vacuum, and rolled with a small multi-roller rolling mill to form a composite flat wire of 1.5 mm×0.5 mm.

(Example 7)
A 12 mm diameter, 1000 mm long 65 brass rod was penetrated into a 14 mm outer diameter, 12.5 mm inner diameter, and 1000 mm long micrograin-doped tantalum pipe (containing 500 PPM silicon and 200 PPM lanthanum). and annealed at 1250° C. for 180 minutes under vacuum to obtain a composite bar with an outer diameter of 14 mm.

This composite rod is rotary swaged to a diameter of 3 mm, pickled, annealed at 1250° C. for 60 minutes under vacuum, and multi-die drawn to a composite wire with a diameter of 1.2 mm. and pickled, annealed at 1250° C. for 60 minutes under vacuum, and rolled with a small multi-roller rolling mill to form a composite flat wire of 1.5 mm×0.5 mm.

Table 1-4 below shows the detection results for the composite anode lead wire and the pure metal tantalum wire of the tantalum capacitor produced in Example 1-7.

From the above results, it can be seen that each detection result of the composite wire meets or exceeds the requirements of the Chinese national standard for pure metal tantalum wire (GB/T 26012-2010). Equivalent to level.

The composite wire and the pure metal tantalum wire produced according to Examples 1, 2, and 3 above are respectively pressed with tantalum powder and sintered to manufacture the anode block of the tantalum capacitor. The detection results are compared below. Shown in Tables 5, 6 and 7.

In this experiment, the composite wire and pure metal tantalum wire were pressed with tantalum powder and sintered to produce the anode block of the tantalum capacitor. The test values of the tantalum wire are basically equivalent, and they all exceed or meet the requirements of the Chinese national standard (GB/T 2612-2010).

As can be seen from the above description, the above embodiments of the present invention achieve the following technical effects.
1) The surface of the composite wire produced in the above embodiment of the present invention has a high dielectric constant of tantalum, which can meet the application requirements of tantalum capacitors and has excellent electrical performance.
2) Inexpensive metals or alloys are used for the core portion, the amount of rare resource tantalum used is greatly reduced, and the cost is greatly reduced.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention, and various modifications and changes are possible for those skilled in the art. All modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall all fall within the protection scope of the present invention.

Claims (10)

a core made of metal other than pure tantalum, or a tantalum alloy or other metal alloy;
a tantalum metal layer covering the outer surface of the core;
A composite wire for an anode lead wire of a tantalum capacitor, characterized by: When the material of the tantalum metal layer is a tantalum-niobium alloy, the tantalum content is greater than 50% and the sum of the tantalum and niobium contents is greater than 95%, and the material of the tantalum metal layer is other than the tantalum-niobium alloy. the tantalum content is greater than 95%, if other alloys of
The composite wire for anode lead wire of a tantalum capacitor according to claim 1, characterized in that: The cross section of the composite wire for the anode lead wire of the tantalum capacitor is circular, elliptical, or polygonal.
The composite wire for anode lead wire of a tantalum capacitor according to claim 1, characterized in that: The ratio of the cross-sectional area of the tantalum metal layer to the cross-sectional area of the composite wire for the anode lead of the tantalum capacitor is 1% to 80%, preferably 1 to 50%.
The composite wire for anode lead wire of a tantalum capacitor according to claim 1, characterized in that: The cross section of the composite wire is axially symmetrical, with the longest axis ≤ 3.0 mm and the shortest axis ≥ 0.1 mm.
The composite wire for anode lead wire of a tantalum capacitor according to claim 4, characterized in that: The material of the core is one or more selected from the group consisting of niobium, zirconium, tungsten, molybdenum, titanium, nickel, iron, copper, aluminum, magnesium, cobalt and alloys thereof.
The composite wire for anode lead wire of a tantalum capacitor according to claim 1, characterized in that: A tantalum capacitor comprising an anode lead wire, wherein the anode lead wire is manufactured using the composite wire for the anode lead wire of a tantalum capacitor according to any one of claims 1 to 6,
A tantalum capacitor characterized by: A method for manufacturing a composite wire for an anode lead wire of a tantalum capacitor according to any one of claims 1 to 6,
a step S1 of providing a core;
and a step S2 of coating the outer surface of the core with a tantalum metal layer to obtain a composite wire for the anode lead of the tantalum capacitor.
A method for producing a composite wire for an anode lead wire of a tantalum capacitor, characterized by: After S2, the step of processing the composite wire for the anode lead wire of the tantalum capacitor to a required size using one or more processing methods of extrusion, rolling, rotary swaging, and drawing,
The manufacturing method according to claim 8, characterized in that: Coating the outer surface of the core with a tantalum metal layer in S2 is achieved by a method of powder metallurgy, overlay welding, explosive crimping, tube sheathing clad, cast clad or vapor phase epitaxy.
The manufacturing method according to claim 8, characterized in that:

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