CN115846901A - Large-size multi-interface silver-copper composite belt and preparation method thereof - Google Patents
Large-size multi-interface silver-copper composite belt and preparation method thereof Download PDFInfo
- Publication number
- CN115846901A CN115846901A CN202211558973.8A CN202211558973A CN115846901A CN 115846901 A CN115846901 A CN 115846901A CN 202211558973 A CN202211558973 A CN 202211558973A CN 115846901 A CN115846901 A CN 115846901A
- Authority
- CN
- China
- Prior art keywords
- silver
- copper
- copper composite
- strips
- interface
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Abstract
The invention belongs to the technical field of fuse melt materials, and particularly relates to a large-size multi-interface silver-copper composite belt and a preparation method thereof. The preparation method of the large-size multi-interface silver-copper composite belt comprises the steps of processing a plurality of blind hole grooves on an oxygen-free copper plate, impregnating a layer of carbon nanotube-containing brazing filler metal liquid into silver strips, embedding the silver strips into the high-temperature brazing filler metal-coated blind hole grooves, thus realizing the impregnation brazing connection of the silver strips and the oxygen-free copper, and then cutting the silver-copper composite belt to obtain the silver-copper composite belt. The preparation method of the invention really realizes the integrated preparation of the large-size and multi-interface silver-copper composite belt, the number and the bandwidth of silver strips in the composite belt are not limited by pressure any more, and multiple rolling is not needed, the method is simple and has high efficiency, the prepared composite belt has high interface bonding strength, moderate resistivity and excellent comprehensive quality, and has wide application prospect in the field of melt materials for large-voltage direct current circuits.
Description
Technical Field
The invention belongs to the technical field of fuse melt materials, and particularly relates to a large-size multi-interface silver-copper composite belt and a preparation method thereof.
Background
The silver-copper composite belt is a composite metal material formed by firmly combining silver and copper materials along a contact surface. At present, as a substitute material of a pure silver tape, the silver-copper composite tape not only keeps the rapid fusing characteristic of the original pure silver tape, but also saves the material cost of noble metal silver, is an ideal substitute material for fusing pure silver, and is widely applied to low-voltage appliances and fuses. For example, chinese patents with publication numbers CN109585235B, CN216928470U, CN209454299U and CN207602503U all use silver-copper composite belts to replace pure silver belts, thereby obtaining good application effect.
In recent years, with the continuous and rapid development of high-end equipment manufacturing industries such as high-speed trains, new energy automobiles, photovoltaic inverters and the like in China, higher requirements are put forward on fuse materials. Taking a new energy automobile as an example, along with the increase of the endurance mileage of a battery pack and the popularization of a quick charging technology, the safety problem of a high-voltage direct-current circuit is increasingly highlighted, so that a higher requirement is put on the fusing sensitivity of the silver-copper composite belt, and the silver-copper composite belt with large size (the total width is more than or equal to 120 mm) and multiple interfaces (the number of silver strips is more than or equal to 6) is technically necessary to meet the application requirement of a fusing material of the high-voltage direct-current circuit.
However, in the prior art, the integrated precise forming technology of the large-size and multi-interface silver-copper composite belt has great implementation difficulty. This is because, when the traditional hot-pressing diffusion lamination is adopted, because there are many silver-copper interfaces and diffusion pressure is transmitted layer by layer, the phenomenon of inconsistent load transmission caused by the change of the contact area of silver and copper is easy to occur, thereby causing the situation of too large deformation and even silver material 'crushing' between silver and copper, or the problem that the accurate diffusion lamination of silver and copper cannot be effectively realized when under-pressure exists. When the traditional mechanical inlaying method is adopted for compounding, due to the fact that the number of silver-copper compounding interfaces of the large-size multi-interface silver-copper compounding belt is too large, dislocation of a plurality of interfaces is prone to occurring in the compounding process, and the contact area changes, so that accurate compounding is difficult. However, if the existing lap joint method is adopted for forming, for example, two silver-copper composite belts with the width of 72mm are overlapped through resistance welding to form a composite belt melt with the width of 140mm, and the problem that the integrated forming cannot be realized still exists.
Therefore, it is an urgent technical problem to develop a silver-copper composite tape and a method for preparing the same to realize the integrated molding of the large-size, multi-interface and high-quality silver-copper composite tape.
Disclosure of Invention
The invention aims to provide a preparation method of a large-size multi-interface silver-copper composite belt, which can realize the integrated molding of the large-size multi-interface silver-copper composite belt, is not limited by pressure in the molding process, does not need multi-pass rolling, and is high in composite strength of the silver-copper interface of the prepared composite belt, moderate in resistivity and suitable for industrial application.
The second purpose of the invention is to provide a large-size multi-interface silver-copper composite belt, which has high composite strength of a silver-copper interface and moderate resistivity, and is suitable for a large-voltage direct-current circuit fusing material.
In order to realize the purpose, the preparation method of the large-size multi-interface silver-copper composite belt adopts the technical scheme that:
a preparation method of a large-size multi-interface silver-copper composite belt comprises the following steps:
(1) Uniformly cutting a preset number of blind hole grooves along the length direction of the oxygen-free copper plate, and brushing brazing flux on the inner walls of the blind hole grooves;
taking pure silver strips with the same quantity and size as the blind hole grooves, and heating the pure silver strips and the oxygen-free copper plate coated with the soldering flux;
melting the BAg72Cu alloy block into metal liquid, adding the carbon nano tube into the metal liquid, and uniformly mixing to obtain mixed liquid;
(2) Immersing the heated pure silver strips obtained in the step (1) into the mixed solution, then sequentially embedding the pure silver strips into blind hole grooves of the oxygen-free copper plate obtained after heating, and cooling to obtain a silver-copper composite belt preform;
(3) And cutting the silver-copper composite belt preform to obtain a large-size multi-interface silver-copper composite belt finished product.
The invention provides a preparation method of a large-size multi-interface silver-copper composite belt, which comprises the steps of cutting a plurality of uniformly distributed blind hole grooves along the length direction of an oxygen-free copper plate in a linear mode, impregnating a layer of BAg72Cu brazing filler metal liquid containing carbon nano tubes on the surface of a pure silver strip, sequentially embedding the silver strip into a high-temperature blind hole groove coated with silver brazing flux, enabling the pure silver strip and the blind hole grooves to realize impregnation brazing connection, and finally continuously cutting the composite belt with a certain thickness through cutting, thereby obtaining the large-size multi-interface silver-copper composite belt with excellent combination quality.
The preset number of the blind hole grooves is not limited, and can be selected according to the use requirement. For preparing the large-sized composite tape, it is preferable that the predetermined number is not less than 6 in the step (1).
In the step (1), the thickness of the selected oxygen-free copper plate determines the number of the finally obtained large-size and multi-interface silver-copper composite belt finished products, the size of the blind hole groove determines the size of the silver strips in the composite belt, and the size can be selected according to the preparation requirement and the use requirement, and the invention is not specially limited.
In the step (1), the blind hole groove is wetted by the brazing flux to realize the tight combination of the pure silver strip and the oxygen-free copper plate. Preferably, the type of the soldering flux is any one of FB102, FB103, FB104 and FB 302.
The size fit clearance of the pure silver strips and the blind hole grooves is equivalent to a brazing clearance, and the brazing clearance has certain influence on the bonding strength of a silver-copper interface. Preferably, in the step (1), the size fit clearance between the pure silver strips and the blind hole grooves is 0.05-0.2 mm.
Further, in the step (1), the temperature of the heating treatment is 780-850 ℃, and the time of the heating treatment is 25-40 min.
The choice of materials for the molten metal needs to be made with the cost, conductivity, melting point, and dip brazing properties of the composite strip in mind. The BAg72Cu alloy block is used as an interface material, belongs to eutectic alloy, is moderate in price, low in melting point, good in dip soldering operability and good in conductivity, and becomes the optimal brazing filler metal choice. More preferably, in the step (1), the temperature at which the BAg72Cu alloy ingot is melted into the molten metal is 780 to 800 ℃.
The resistivity of the BAg72Cu material is relatively large compared to pure silver, and the conductivity is somewhat deficient. The invention adds the carbon nano tube to ensure that the carbon nano tube has the same conductive capability with silver, and further increases the bonding strength of the brazing seam. In the step (1), the addition amount of the carbon nanotubes is preferably 0.03 to 0.06%, more preferably 0.05%, by mass of the molten metal.
Preferably, in the step (2), the immersion is to completely immerse the pure silver strip into the molten metal, and the immersion time is 8 to 10 seconds.
Further, in the step (2), after the cooling, a step of mechanically removing the excess soldering flux and the excess oxygen-free copper is further included.
In the step (3), the cutting is the thickness cutting of the silver-copper composite tape preform. After the silver-copper composite belt preform is prepared, the silver-copper composite belt with the required thickness can be obtained only by cutting without rolling. Preferably, in the step (3), the cutting is cutting by a picosecond laser; the output power of the picosecond laser is 3-5W, the focusing light plate is 4-6 mu m, and the moving speed is 400-600 mm/s.
The invention provides a large-size multi-interface silver-copper composite belt, which adopts the technical scheme that:
the large-size multi-interface silver-copper composite belt is prepared by the preparation method, and is mainly formed by sequentially arranging pure silver strips and oxygen-free copper strips along the width direction; forming a BAg72Cu material layer at the interface of the pure silver strip and the oxygen-free copper strip; the number of the oxygen-free copper strips is 1 greater than that of the pure silver strips, and the outermost side of the silver-copper composite belt is the oxygen-free copper strips.
In the large-size multi-interface silver-copper composite strip, the width of the silver strip and the width of the oxygen-free copper strip are not particularly limited. Because different circuits need to carry different currents, the requirements on the width of the silver strips and the copper strips are different. Therefore, the widths of the silver strips and the oxygen-free copper strips are limited by the requirements of various use manufacturers and can be customized according to the requirements of the manufacturers.
As a further preferable scheme, the width of the silver-copper composite belt is more than or equal to 120mm, and the number of pure silver strips in the silver-copper composite belt is more than or equal to 6; the lengths and the thicknesses of the oxygen-free copper strip and the pure silver strip in the silver-copper composite strip are equal; the thickness of the silver-copper composite belt is 0.1-0.3 mm.
More preferably, the width of the silver-copper composite belt is more than or equal to 200mm, and the number of pure silver strips in the silver-copper composite belt is more than or equal to 10.
Compared with the prior art, the invention has the following beneficial effects:
(1) At present, the traditional methods for preparing the large-size multi-interface silver-copper composite belt, such as a hot-pressing diffusion composite method, a mechanical embedding method and a lapping method, cannot realize the integrated precise composite of the large-size multi-interface silver-copper composite belt.
The composite strip preparation method comprises the steps of processing a plurality of blind hole grooves on an oxygen-free copper plate, immersing a layer of carbon nanotube-containing brazing filler metal liquid in silver bars, and then embedding the silver bars into the high-temperature brazing filler metal-coated blind hole grooves, so that immersion brazing connection of the silver bars and the oxygen-free copper is realized, and finally, successful preparation of the composite strip is realized through a simple cutting process. By adopting the preparation process, the number of silver strips in the composite tape and the bandwidth are not limited by pressure, the number of the composite silver strips can exceed 6, and the width can be more than or equal to 120mm, so that the large-size multi-interface silver-copper composite tape is integrally prepared, the complexity of process operation is reduced, and the composite quality is ensured.
(2) The carbon nano tube in the brazing filler metal adopted by the invention can make up the loss of the decreased brazing filler metal seam conductive capability caused by the loss of silver content in the brazing filler metal on one hand, and enhance the conductive performance of silver-copper impregnated brazing filler metal seams, and on the other hand, the carbon nano tube can play an effective role in supporting a framework by being embedded into the brazing filler metal seams, thereby enhancing the bonding strength of silver-copper interfaces.
(3) The preparation method of the silver-copper composite belt provides a brand new preparation idea and preparation approach for integrally preparing the large-size multi-interface silver-copper composite belt. The method does not need multiple rolling, is simple and high in efficiency, the interface bonding strength of the prepared composite belt is up to 166-170 MPa, and the resistivity is only (1.85-1.88) multiplied by 10 -8 Omega.m, excellent comprehensive quality, and wide application prospect in the field of melt material preparation for large-voltage direct current circuits.
Drawings
FIG. 1 is a schematic view of a sectional structure of a blind hole groove cut on an oxygen-free copper plate in step (1) in the preparation of the silver-copper composite strip of the present invention;
fig. 2 is a schematic structural diagram of a silver-copper composite tape preform obtained in step (2) (left drawing) and a silver-copper composite tape finished product obtained in step (3) (right drawing) when the silver-copper composite tape is prepared according to the present invention;
FIG. 3 is an external view of a silver-copper composite tape obtained by conventional hot-pressing diffusion lamination;
FIG. 4 is an external view of a silver-copper composite tape obtained by conventional mechanical damascene process;
FIG. 5 is an external view of a silver-copper composite tape obtained by compounding the silver-copper composite tape according to the production method of example 1 of the present invention;
wherein, in fig. 1-2: 1-blind hole groove, 2-oxygen-free copper plate, 3-pure silver strip and 4-oxygen-free copper strip.
Detailed Description
The technical solution of the present invention will be further described with reference to the following embodiments. It will be understood by those skilled in the art that the following examples are illustrative of the present invention only and are not to be construed as limiting the invention. The specific conditions not specified in the examples were carried out according to the conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used, unless otherwise specified, are conventional products available from commercial sources.
In the following examples, the oxygen content of oxygen-free copper is not more than 0.003%, the total impurity content is not more than 0.05%, and the purity of copper is more than 99.95%; the pure silver contains 99.99 percent of Ag, not more than 0.01 percent of Pb, not more than 0.01 percent of Pd and not more than 0.1 percent of impurity. The BAg72Cu alloy block is a silver-copper binary eutectic material and comprises the following main chemical components in percentage by mass: ag72 +/-1%, and the balance of copper; the carbon nanotube has a diameter of 10-20 nm and a length of 6-10 μm.
In the following examples, when the large-sized, multi-interface silver-copper composite tape is prepared, the schematic cross-sectional view of the blind via groove cut in the oxygen-free copper plate in step (1) is shown in fig. 1. In fig. 1, the blind via grooves 1 are uniformly cut along the length of the oxygen-free copper plate 2, thereby obtaining a plurality of uniformly distributed blind via grooves.
In the following examples, when the silver-copper composite tape is manufactured, the structure of the silver-copper composite tape preform obtained in the step (2) and the structure of the silver-copper composite tape product obtained in the step (3) are schematically illustrated in fig. 2. Wherein, the left figure of fig. 2 is a silver-copper composite belt preform, and the right figure of fig. 2 is a silver-copper composite belt finished product. The silver-copper composite belt preform obtained in the step (2) is formed by uniformly and alternately sequentially arranging the pure silver strips 3 and the oxygen-free copper strips 4 after cutting off redundant brazing filler metal and redundant oxygen-free copper layers, and the silver-copper composite belt finished product formed by sequentially arranging the pure silver strips 3 and the oxygen-free copper strips 4 can be obtained after the step (3) is subjected to thickness cutting.
Example 1
The large-size multi-interface silver-copper composite belt is formed by sequentially arranging pure silver strips and oxygen-free copper strips along the width direction; the number of the pure silver strips in the silver-copper composite strip is 10, the number of the oxygen-free copper strips is 11, the oxygen-free copper strips are arranged on the outermost side of the composite strip, and a BAg72Cu material layer is formed at the interface of the pure silver strips and the oxygen-free copper strips. The width of the silver-copper composite belt is 200mm, and the thickness of the silver-copper composite belt is 0.1mm; the oxygen-free copper strip and the pure silver strip in the silver-copper composite strip have equal length and thickness, the width of the pure silver strip is 4.6mm, and the width of the oxygen-free copper strip is 14mm.
The preparation method of the large-size multi-interface silver-copper composite belt comprises the following steps:
(1) Cutting 10 uniformly distributed blind hole grooves along the length direction of the oxygen-free copper plate, wherein the length of each blind hole groove almost penetrates through the length direction, a small machining allowance is left at two ends, and then brushing a layer of silver brazing agent QJ102 on the inner wall of each blind hole groove;
taking 10 pure silver strips with the size fit clearance of 0.05-0.2 mm with the blind hole groove, and putting the pure silver strips and the oxygen-free copper plate coated with the soldering flux into a box type resistance furnace together for heating treatment; the temperature of the heating treatment is 780-850 ℃, and the time is 25min;
putting the BAg72Cu eutectic alloy block into a graphite crucible, performing induction heating to 780-800 ℃, melting into molten metal, stirring in the molten metal, adding 0.05% of carbon nano tubes, and mixing uniformly to obtain a mixed solution for later use;
(2) Completely immersing the heated pure silver strip obtained in the step (1) into the mixed solution obtained in the step (1) for 8s, taking out the pure silver strip, embedding the pure silver strip into a blind hole groove of the oxygen-free copper plate obtained after heating, cooling, and mechanically removing redundant brazing filler metal and redundant oxygen-free copper layer to obtain a silver-copper composite belt preform;
(3) And (3) continuously cutting the silver-copper composite tape preform into a composite tape with the thickness of 0.1mm by a second laser cutting machine, wherein the laser is a 355nm picosecond laser, the output power is 4W, the focusing light spot is 5 mu m, and the moving speed is 500 mm/s.
Example 2
The large-size multi-interface silver-copper composite belt is formed by sequentially arranging pure silver strips and oxygen-free copper strips along the width direction; the number of the pure silver strips in the silver-copper composite strip is 11, the number of the oxygen-free copper strips is 12, the oxygen-free copper strips are arranged on the outermost side of the composite strip, and a BAg72Cu material layer is formed at the interface of the pure silver strips and the oxygen-free copper strips. The width of the silver-copper composite belt is 220mm, and the thickness of the silver-copper composite belt is 0.2mm; the length and thickness of the oxygen-free copper strip and the pure silver strip in the silver-copper composite belt are equal, the width of the silver strip is 5mm, and the width of the oxygen-free copper strip is 13.75mm.
The preparation method of the large-size multi-interface silver-copper composite tape of the present embodiment is basically the same as the preparation method of embodiment 1, and the difference between the two methods is as follows: the size and quantity parameters of the raw materials for preparing the silver-copper composite belt are set according to the embodiment 2; meanwhile, in the step (1), the temperature of the heating treatment is 800-820 ℃ and the time is 30min.
Example 3
The large-size multi-interface silver-copper composite belt is formed by sequentially arranging pure silver strips and oxygen-free copper strips along the width direction; the number of the pure silver strips in the silver-copper composite strip is 12, the number of the oxygen-free copper strips is 13, the oxygen-free copper strips are arranged on the outermost side of the composite strip, and a BAg72Cu material layer is formed at the interface of the pure silver strips and the oxygen-free copper strips. The width of the silver-copper composite belt is 240mm, and the thickness of the silver-copper composite belt is 0.3mm; the length and thickness of the oxygen-free copper strip and the pure silver strip in the silver-copper composite strip are equal, and the width of the silver strip is 7mm. The width of the oxygen-free copper strip is 12mm.
The preparation method of the large-size multi-interface silver-copper composite tape of the present embodiment is basically the same as the preparation method of embodiment 1, and the difference between the two methods is as follows: the size and quantity parameters of the raw materials for preparing the silver-copper composite belt are set according to the embodiment 3; in the step (1), the temperature of the heating treatment is 820-850 ℃ and the time is 35min.
Example 4
The large-size multi-interface silver-copper composite belt is formed by sequentially arranging pure silver strips and oxygen-free copper strips in the width direction; the number of the pure silver strips in the silver-copper composite strip is 13, the number of the oxygen-free copper strips is 14, the oxygen-free copper strips are arranged on the outermost side of the composite strip, and a BAg72Cu material layer is formed at the interface of the pure silver strips and the oxygen-free copper strips. The width of the silver-copper composite belt is 250mm, and the thickness of the silver-copper composite belt is 0.1mm; the lengths and the thicknesses of the oxygen-free copper strip and the pure silver strip in the silver-copper composite strip are equal, the width of the silver strip is 5.3mm, and the width of the oxygen-free copper strip is 13mm.
The preparation method of the large-size multi-interface silver-copper composite tape of the present embodiment is basically the same as the preparation method of embodiment 1, and the difference between the two methods is as follows: the size and quantity parameters of the raw materials for preparing the silver-copper composite belt are carried out according to the setting of the example 4; in the step (1), the temperature of the heating treatment is 800-820 ℃ and the time is 40min.
Example 5
The large-size multi-interface silver-copper composite belt is formed by sequentially arranging pure silver strips and oxygen-free copper strips along the width direction; the number of the pure silver strips in the silver-copper composite strip is 15, the number of the oxygen-free copper strips is 16, the oxygen-free copper strips are arranged on the outermost side of the composite strip, and a BAg72Cu material layer is formed at the interface of the pure silver strips and the oxygen-free copper strips. The width of the silver-copper composite belt is 280mm, and the thickness of the silver-copper composite belt is 0.2mm; the length and thickness of the oxygen-free copper strip and the pure silver strip in the silver-copper composite strip are equal, the width of the silver strip is 4mm, and the width of the oxygen-free copper strip is 13.75mm.
The preparation method of the large-size multi-interface silver-copper composite tape of the present embodiment is basically the same as the preparation method of embodiment 1, and the difference between the two methods is as follows: the size and quantity parameters of the raw materials for preparing the silver-copper composite belt are carried out according to the setting of the example 5; in the step (1), the temperature of the heating treatment is 820-850 ℃ and the time is 40min.
Comparative example 1
The silver-copper composite strip provided in comparative example 1 is the same as that of example 1 in material composition and size, namely, the silver-copper composite strip is formed by arranging pure silver strips and oxygen-free copper strips in sequence along the width direction; the number of the pure silver strips in the silver-copper composite strip is 10, the number of the oxygen-free copper strips is 11, the oxygen-free copper strips are arranged on the outermost side of the composite strip, and a BAg72Cu material layer is formed at the interface of the pure silver strips and the oxygen-free copper strips. The width of the silver-copper composite belt is 200mm, and the thickness of the silver-copper composite belt is 0.1mm; the length and thickness of the oxygen-free copper strip and the pure silver strip in the silver-copper composite belt are equal, the width of the pure silver strip is 4.6mm, and the width of the oxygen-free copper strip is 14mm.
The silver-copper composite tape of comparative example 1 was prepared in substantially the same manner as in example 1, except that: in the step (1), when the mixed solution is prepared, the carbon nano tube is not added, and the other steps and parameters are the same.
Comparative example 2
The silver-copper composite strip provided in comparative example 2 is the same as that in example 1 in material composition and size, that is, is composed of pure silver strips and oxygen-free copper strips arranged in sequence in the width direction; the number of the pure silver strips in the silver-copper composite strip is 10, the number of the oxygen-free copper strips is 11, the oxygen-free copper strips are arranged on the outermost side of the composite strip, and a BAg72Cu material layer is formed at the interface of the pure silver strips and the oxygen-free copper strips. The width of the silver-copper composite belt is 200mm, and the thickness of the silver-copper composite belt is 0.1mm; the length and thickness of the oxygen-free copper strip and the pure silver strip in the silver-copper composite belt are equal, the width of the pure silver strip is 4.6mm, and the width of the oxygen-free copper strip is 14mm.
The silver-copper composite tape of comparative example 2 was prepared in substantially the same manner as in example 1, except that: in the step (1), when the mixed solution is prepared, the carbon nano tube is replaced by 0.05 percent of nano graphite powder, and the rest steps and parameters are the same.
Comparative example 3
The silver-copper composite strip provided in comparative example 3 is the same as that in example 1 in material composition and size, that is, is composed of pure silver strips and oxygen-free copper strips arranged in sequence in the width direction; the number of the pure silver strips in the silver-copper composite strip is 10, the number of the oxygen-free copper strips is 11, the oxygen-free copper strips are arranged on the outermost side of the composite strip, and a BAg72Cu material layer is formed at the interface of the pure silver strips and the oxygen-free copper strips. The width of the silver-copper composite belt is 200mm, and the thickness of the silver-copper composite belt is 0.1mm; the length and thickness of the oxygen-free copper strip and the pure silver strip in the silver-copper composite belt are equal, the width of the pure silver strip is 4.6mm, and the width of the oxygen-free copper strip is 14mm.
The silver-copper composite tape of comparative example 3 was prepared in substantially the same manner as in example 1, except that: in the step (1), when the mixed solution is prepared, the carbon nano tube is replaced by 0.05 percent of nano cubic boron nitride, and the rest steps and parameters are the same.
Comparative example 4
The silver-copper composite strip provided in comparative example 4 is the same as that in example 1 in material composition and size, that is, is composed of pure silver strips and oxygen-free copper strips which are sequentially arranged in the width direction; the number of the pure silver strips in the silver-copper composite strip is 10, the number of the oxygen-free copper strips is 11, the oxygen-free copper strips are arranged on the outermost side of the composite strip, and a BAg72Cu material layer is formed at the interface of the pure silver strips and the oxygen-free copper strips. The width of the silver-copper composite belt is 200mm, and the thickness of the silver-copper composite belt is 0.1mm; the lengths and the thicknesses of the oxygen-free copper strip and the pure silver strip in the silver-copper composite strip are equal, the width of the pure silver strip is 4.6mm, and the width of the oxygen-free copper strip is 14mm.
The silver-copper composite tape of comparative example 4 was prepared in substantially the same manner as in example 1, except that: the size fit clearance of the pure silver strips adopted in the step (1) and the blind hole groove is 0.5-1 mm.
Comparative example 5
The silver-copper composite strip provided in comparative example 5 was made of the same material composition and dimensions as those in example 1, i.e., composed of pure silver strips and oxygen-free copper strips arranged in sequence in the width direction; the number of the pure silver strips in the silver-copper composite strip is 10, the number of the oxygen-free copper strips is 11, the oxygen-free copper strips are arranged on the outermost side of the composite strip, and a BAg72Cu material layer is formed at the interface of the pure silver strips and the oxygen-free copper strips. The width of the silver-copper composite belt is 200mm, and the thickness of the silver-copper composite belt is 0.1mm; the length and thickness of the oxygen-free copper strip and the pure silver strip in the silver-copper composite belt are equal, the width of the pure silver strip is 4.6mm, and the width of the oxygen-free copper strip is 14mm.
The silver-copper composite tape of comparative example 5 was prepared in substantially the same manner as in example 1, except that: the size fit clearance of the pure silver strips adopted in the step (1) and the blind hole grooves is 0.01-0.04 mm.
Test example 1
In the test example, the differences between the preparation method of the silver-copper composite tape in example 1 of the present invention and the conventional hot-pressing diffusion lamination and mechanical inlay lamination methods were examined, and three silver-copper composite tapes of the same specification were prepared by the three methods, respectively. Then, the appearance and the appearance of the three silver-copper composite belts are compared, and the results are shown in figures 3 to 5.
Fig. 3 is an appearance view of a silver-copper composite tape obtained by conventional hot-press diffusion lamination. As shown in fig. 3, when the silver-copper composite tape with multiple interfaces is prepared by conventional hot-pressing diffusion lamination, multiple silver strips and copper strip interfaces are required to be laminated, and since there are multiple silver-copper interfaces and the pressure of the diffusion pressure head is transferred layer by layer, the phenomenon of inconsistent load transfer due to the change of the contact area between silver and copper is likely to occur, so that the pressure between silver and copper is too large or too small. When the pressure is too high and the 'overpressure' occurs, the situation that the deformation is too large and even the silver material is 'crushed' occurs (see the left picture of fig. 3); and the pressure is insufficient, namely the precise diffusion recombination of silver and copper cannot be effectively realized under the condition of under-pressure (see the right graph of figure 3).
Fig. 4 is an appearance diagram of a silver-copper composite tape obtained by compounding by a traditional mechanical inlaying method. As shown in fig. 4, when the silver-copper composite tape with multiple interfaces is prepared by the conventional mechanical damascene method, multiple silver strips and multiple copper strips need to be compounded, and due to the fact that the multiple interfaces are too many, the multiple interfaces are prone to dislocation in the compounding process, which easily causes slippage and instability of the interface contact area, and the unfavorable compounding condition occurs.
FIG. 5 is an external view of a silver-copper composite tape obtained by the method of example 1 of the present invention. As can be seen from FIG. 5, the silver-copper composite tape prepared by the method of the present invention is not limited by pressure, has no interface instability, and realizes stable and accurate compounding of multiple interfaces.
Test example 2
This test example examines the bonding strength and resistivity of the silver-copper composite tapes of examples 1 to 5 and comparative examples 1 to 5. The composite tapes of examples 1 to 5 and comparative examples 1 to 5 were sampled as test samples, respectively, and the resistivity and the interface bonding strength of the samples were measured, the interface bonding strength being performed in accordance with GB/T228.1, and the transverse tensile strength of the tapes was measured by taking 5mm × 10mm tapes as standard samples (silver at one end and copper at one end). The resistivity test is to measure the resistance of the composite strip with the same dimension and specification by adopting a QJ84 type digital direct current bridge under the experimental environment of 20 ℃. The results of the three tests were averaged separately. The test results are shown in table 1 below.
Table 1 bonding strength and resistivity test results of silver-copper composite tapes of examples and comparative examples
As can be seen from table 1, the mixed solution of comparative example 1, to which no carbon nanotube was added, resulted in a silver-copper composite tape having low interfacial bonding strength and high resistivity, which failed to satisfy the use requirements. The nano graphite powder and the nano cubic boron nitride are respectively added into the mixed solution in the comparative examples 2 and 3, and can be embedded into the brazing seam to play a role of a skeleton, so that the bonding strength of an interface is enhanced, but the conductivity of the materials of the nano graphite powder and the nano cubic boron nitride is poor, so that the resistivity of the composite tape is increased, and the use requirements can not be met. In comparative example 4, the fit clearance between the silver bar and the groove is too large, which is equivalent to that of a brazing seam, and the brazing seam clearance is too large, so that the brazing seam is difficult to fill by brazing filler metal liquid, the interface bonding strength is low, and the electrical resistivity is increased due to too wide brazing seam. In the comparative example 5, the fit clearance between the silver bar and the groove is too small, which is equivalent to the clearance between brazing seams is too small, and in the process of dip brazing, brazing filler metal liquid is difficult to fill into the too narrow brazing seams, so that the interface bonding strength is low, and the use requirement cannot be met.
Comprehensive comparison shows that when the silver-copper composite belt is prepared in the embodiment of the invention, the mixed liquid contains the carbon nano tubes which have good conductivity and can increase the interface bonding strength, the brazing seam gap is moderate, the filling quality of the brazing filler metal liquid is good, and the total application effect ensures that the composite belt not only has high interface bonding strength, but also has small resistivity and good comprehensive quality, and is very suitable for being used as a melt material for a fuse.
In conclusion, the preparation method of the large-size multi-interface silver-copper composite belt provided by the invention can ensure that the number of silver strips and the belt width in the composite belt are not limited by pressure, multiple rolling is not needed, the method is simple, the efficiency is high, the integrated preparation of the large-size multi-interface silver-copper composite belt is really realized, the interface bonding strength of the prepared composite belt is up to 166-170 MPa, and the resistivity is only (1.85-1.88) multiplied by 10 -8 Omega.m, excellent comprehensive quality, and wide application prospect in the field of melt material preparation for large-voltage direct current circuits.
Claims (10)
1. A preparation method of a large-size multi-interface silver-copper composite belt is characterized by comprising the following steps:
(1) Uniformly cutting a preset number of blind hole grooves along the length direction of the oxygen-free copper plate, and brushing soldering flux on the inner walls of the blind hole grooves;
taking pure silver strips with the same quantity and size as the blind hole grooves, and heating the pure silver strips and the oxygen-free copper plate coated with the soldering flux;
melting the BAg72Cu alloy block into molten metal, adding the carbon nano tubes into the molten metal, and uniformly mixing to obtain a mixed solution;
(2) Immersing the heated pure silver strips obtained in the step (1) into the mixed solution, then sequentially embedding the pure silver strips into blind hole grooves of the oxygen-free copper plate obtained after heating, and cooling to obtain a silver-copper composite belt preform;
(3) And cutting the silver-copper composite belt preform to obtain a large-size multi-interface silver-copper composite belt finished product.
2. The method for preparing a large-size, multi-interface silver-copper composite tape according to claim 1, wherein in the step (1), the type of the flux is any one of FB102, FB103, FB104 and FB 302.
3. The method for preparing a large-size multi-interface silver-copper composite tape according to claim 1, wherein in the step (1), the size fit clearance between the pure silver strips and the blind hole grooves is 0.05-0.2 mm.
4. The method for preparing a large-size multi-interface silver-copper composite strip according to claim 1, wherein in the step (1), the temperature of the heat treatment is 780-850 ℃, and the time of the heat treatment is 25-40 min.
5. The method for preparing a large-size multi-interface silver-copper composite strip according to claim 1, wherein in the step (1), the temperature for melting the BAg72Cu alloy block into molten metal is 780-800 ℃; the addition amount of the carbon nano tube is 0.03-0.06% of the mass of the molten metal.
6. The method for preparing a large-sized, multi-interface silver-copper composite strip according to any one of claims 1 to 5, wherein in the step (2), the immersion is carried out by completely immersing the pure silver strip into the molten metal for 8 to 10 seconds.
7. A method for preparing a large size, multi-interface silver-copper composite strip according to any of claims 1 to 5, wherein in step (2), after cooling, the method further comprises the step of mechanically removing excess flux and excess oxygen-free copper.
8. The method for preparing a large-size, multi-interface silver-copper composite tape according to any one of claims 1 to 5, wherein in the step (3), the cutting is performed by using a picosecond laser; the output power of the picosecond laser is 3-5W, the focusing light plate is 4-6 mu m, and the moving speed is 400-600 mm/s.
9. A large-size, multi-interface silver-copper composite tape prepared by the method for preparing a large-size, multi-interface silver-copper composite tape according to any one of claims 1 to 8, wherein the silver-copper composite tape is mainly formed by arranging pure silver strips and oxygen-free copper strips in sequence along the width direction; forming a BAg72Cu material layer at the interface of the pure silver strip and the oxygen-free copper strip; the number of the oxygen-free copper strips is 1 greater than that of the pure silver strips, and the outermost side of the silver-copper composite belt is the oxygen-free copper strips.
10. The large-size, multi-interface silver-copper composite tape according to claim 9, wherein the width of the silver-copper composite tape is not less than 120mm, and the number of pure silver strips in the silver-copper composite tape is not less than 6; the lengths and the thicknesses of the oxygen-free copper strip and the pure silver strip in the silver-copper composite strip are equal; the thickness of the silver-copper composite belt is 0.1-0.3 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211558973.8A CN115846901A (en) | 2022-12-06 | 2022-12-06 | Large-size multi-interface silver-copper composite belt and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211558973.8A CN115846901A (en) | 2022-12-06 | 2022-12-06 | Large-size multi-interface silver-copper composite belt and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115846901A true CN115846901A (en) | 2023-03-28 |
Family
ID=85670454
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211558973.8A Pending CN115846901A (en) | 2022-12-06 | 2022-12-06 | Large-size multi-interface silver-copper composite belt and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115846901A (en) |
-
2022
- 2022-12-06 CN CN202211558973.8A patent/CN115846901A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8198116B2 (en) | Fabrication method for thermoelectric device | |
| JP6041117B1 (en) | Heat dissipation substrate, semiconductor package, semiconductor module, and method of manufacturing heat dissipation substrate | |
| JP2005129529A (en) | Superconducting wire material, its manufacturing method and article using the same | |
| WO1991006128A1 (en) | Process for making electrical connections to high temperature superconductors using a metallic precursor and the product made thereby | |
| CN100503851C (en) | Method for preparing tungsten copper or tungsten silver composite material | |
| JP2001267642A (en) | Method of manufacturing thermoelectric conversion module | |
| CN110064899B (en) | Tungsten-copper-clad electrical contact material and preparation method thereof | |
| CN115846901A (en) | Large-size multi-interface silver-copper composite belt and preparation method thereof | |
| CN112338389B (en) | Laminated strip-shaped self-brazing solder for aluminum copper brazing and preparation method thereof | |
| CN113718250A (en) | Method for manufacturing tungsten-copper electrical contact material | |
| US4493964A (en) | Method of joining electrically conductive members | |
| KR100603021B1 (en) | ??-?? clad bus bar with ??coating and manufacturing methods thereof | |
| JPH09234826A (en) | Metal-ceramic composite base plate and manufacture thereof | |
| CN217799731U (en) | Soldering lug for welding strip, combined welding strip and combined welding strip string | |
| CN111451497B (en) | Parallel fiber reinforced silver graphite strip contact material and preparation method thereof | |
| EP1880426B1 (en) | Method for producing a superconductive element | |
| JPH10144459A (en) | Conductive heating element | |
| CN114628179A (en) | Method for connecting copper-tungsten alloy and copper alloy | |
| FR2568050A1 (en) | IMPLEMENTATION OF OXYGEN-FREE ELECTROLYTIC COPPER, BORON OR LITHIUM DEOXIDE, FOR HOLLOW PROFILES AND METHOD OF MANUFACTURE | |
| CN101281839B (en) | Belt material for fused mass of fuse and manufacturing method thereof | |
| KR100629445B1 (en) | Fabrication methid of titanium clad copper bus-bars | |
| CN115972704A (en) | Punching-free silver-copper composite belt and preparation method thereof | |
| JP2000286466A (en) | Si-ge semiconductor device and manufacture of the same, and thermoelectric conversion module | |
| CN111979444B (en) | Silver solder and preparation method and application thereof | |
| CN109411378A (en) | A kind of preparation method of copper strips winding-type welding column |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |