CN118315519A - Composite bonding wire and preparation method thereof - Google Patents

Abstract

The invention provides a composite bonding wire and a preparation method thereof, and relates to the technical field of semiconductor and LED packaging. Specifically: the bonding wire comprises a main body section and a bonding section which is in diffusion connection with at least one side of the main body section; the main body section comprises at least one of silver and silver-based alloy, copper and copper-based alloy; the bonding segment comprises at least one element of gold, silver, palladium or bismuth. The invention can effectively solve the technical problems that the bonding wire is easy to have ageing defect at the interface and the cost of the precious metal of the bonding wire raw material is high, and the preparation process can be completed through the working procedures of alloy ingot preparation, diffusion connection, multipass rolling, laser cutting and the like; the bonding wire product has strong designability, simple and feasible preparation process and good application prospect in the aspects of semiconductor packaging, LED packaging and the like.

Description

A composite bonding wire and a method for preparing the same

Technical Field

The present invention relates to the technical field of semiconductor and LED packaging, and in particular to a composite bonding wire and a preparation method thereof.

Background technique

Bonding wire is the core material for semiconductor and LED packaging. It is a component that connects pins and silicon wafers or two terminals and transmits electrical signals. It is used in integrated circuit systems such as automobile transportation, aerospace and electronic communications. With the development trend of high performance, multi-function, miniaturization and portability of electronic devices, electronic packaging technology has put forward higher requirements on the performance of bonding wire materials.

At present, the main bonding wires used in the packaging field are gold wire, silver wire, copper wire, aluminum wire and their alloy wires, and the main material on the pad is aluminum. For gold wire, after bonding, as the electronic device works, gold and aluminum at the bonding interface will form intermetallic compounds, such as Au ₄ Al, and this intermetallic compound is easily corroded by halogen, resulting in bonding failure. As for silver bonding wire, silver is easily sulfided in the air, so it is less used. At present, silver alloy wire is mainly used in semiconductor packaging in the market. In addition, the use of gold wire, silver wire and their alloy wires results in high packaging costs and is difficult to invest in batches. The process of aluminum wire is mature, the price is low, and the variety is rich. However, due to the large difference in the thermal expansion coefficient of aluminum and the thermal expansion coefficient of silicon chips, heat will accumulate in the package body during a long power cycle, causing the module temperature to rise, generating and accumulating thermal stress, which is easy to cause the bonding wire to break or the bonding contact surface to fall off, and ultimately leading to the overall failure of the module. Although copper wire is cheap, it is very hard and can easily damage the substrate during bonding. In addition, inert gas protection is required during bonding to prevent copper oxidation from causing poor connections such as cold solder joints at the bonding interface, which can seriously affect product quality and reliability.

Therefore, it can be seen that bonding wires of a single texture type have different types of defects; in view of the current high cost of semiconductor and LED bonding materials, severe aging of the bonding interface and other problems, it is urgent to develop new bonding wire preparation methods.

In view of this, the present invention is proposed.

Summary of the invention

The first purpose of the present invention is to provide a composite bonding wire, which is mainly used to solve the technical problems that aging defects are prone to occur at the interface of the bonding wire and the high cost of precious metals as raw materials of the bonding wire. The present invention provides a bonding wire with a segment structure including a bonding segment and a main segment, and different metal materials are used in different segments, which can effectively solve the above technical problems.

The second purpose of the present invention is to provide a method for preparing the composite bonding wire, which is completed through processes such as alloy ingot preparation, ultrasonic impact, diffusion connection, multi-pass rolling and laser cutting; the method is simple and easy to implement, has good customizability, and is suitable for mass promotion.

In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

A composite bonding wire comprises a main body segment and a bonding segment diffusely connected to at least one end of the main body segment;

The main body segment comprises at least one of silver and silver-based alloys, copper and copper-based alloys;

The bonding segment includes at least one element of gold, silver, palladium or bismuth.

The method for preparing the composite bonding wire comprises the following steps:

(1) independently smelting and casting the metal materials of the main section and the bonding section to obtain a main section ingot and a bonding section ingot;

(2) placing the bonding segment ingot on at least one side of the main segment ingot, placing the pressed and fixed ingot in a vacuum environment for heat preservation treatment, and obtaining a composite ingot;

(3) rolling the composite ingot, wherein the rolling is performed 2 to 20 times to obtain an alloy strip;

(4) The alloy wires are subjected to annealing treatment in sequence to obtain bonding wires.

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

(1) The bonding wire described in the present invention includes a main body section and a bonding section which are connected by diffusion bonding, which can not only greatly reduce the raw material cost of the bonding wire, but also ensure that the bonding wire will not damage the integrated circuit substrate, and also solve the problem of aging failure at the bonding interface.

(2) The bonding wires described in the present invention are of fixed size and can be customized to controllable specifications according to demand, which can greatly reduce the problem of product waste caused by cutting during the preparation process.

(3) The bonding wire manufacturing method of the present invention has strong process applicability and can be used to manufacture bonding wires for semiconductor packaging, as well as bonding wires for LED packaging and other application fields.

BRIEF DESCRIPTION OF THE DRAWINGS

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 use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 provides a schematic diagram of a bonding wire product;

FIG2 provides a schematic diagram of a bonding wire product;

FIG3 provides a schematic diagram of rolling in a bonding wire preparation process;

FIG4 provides a schematic diagram of rolling in a bonding wire preparation process;

FIG5 is a schematic diagram of a slitting line setting in a bonding wire preparation process.

Detailed ways

The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be appreciated by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work, all belong to the scope of protection of the present invention. If the specific conditions are not indicated in the embodiments, they are carried out according to the normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be purchased commercially.

A first aspect of the present invention is to provide a composite bonding wire.

A composite bonding wire comprises a main body segment and a bonding segment diffusely connected to at least one side of the main body segment; the main body segment comprises at least one of silver and silver-based alloys, copper and copper-based alloys; the bonding segment comprises at least one element of gold, silver, palladium or bismuth.

As a preferred embodiment, the bonding wire can adopt a three-section composite structure of bonding section-main section-bonding section, as shown in FIG1 ; or a two-section structure of main section-bonding section can be adopted, and the overall structure conforms to the structure of wire products of bonding wire products, as shown in FIG2 .

As a preferred embodiment, when one end of the main body segment is connected to the bonding segment, the ratio of the length of the bonding segment to the length of the main body segment is 1/6 to 1/3; or, when the two ends of the main body segment are respectively connected to the bonding segments, the ratio of the length of each bonding segment to the length of the main body segment is 1/6 to 1/3. In the present invention, by limiting the length ratio of the bonding segment to the main body segment, the bonding performance of the bonding wire can be guaranteed while reducing the cost of metal raw materials, and a more convenient packaging bonding operation can be achieved.

As a preferred embodiment, the cross-section of the bonding wire is square, and the long side length of the square is ≤1 mm; it should be noted that the cross-section refers to the cross-section obtained by vertically cutting at any point on the bonding wire, which is parallel to the diffusion connection interface between the main section and the bonding section.

As an optional implementation, the specifications of the square can be adjusted according to the application scenario or market demand, and the length and width specifications of the square mean the side width or height specifications of the bonding wire. The side length of the square includes but is not limited to 20μm, 23μm, 25μm, 30μm, 35μm, 38μm, 50μm, 100μm, etc.

As a more preferred embodiment, the length of the long side of the square is 16 μm to 70 μm; when the bonding segments are diffusely connected at one end and both ends of the main segment, the technical personnel in this field should adaptively adjust the parameter specifications of the cross-section according to the number of the bonding segments.

As a preferred embodiment, at least one of the metal elements in the main segment is the same as the metal element in the bonding segment.

As a preferred embodiment, for the raw material components of the main body segment: the purity of the silver is ≥99.99%, and the purity of the copper is ≥99.99%;

The silver content of the silver-based alloy is ≥ 99.95%, and the silver-based alloy includes at least one of trace elements such as Au, Mg, Pd or Cu in addition to silver;

The copper content in the copper-based alloy is ≥99.90%, and the copper-based alloy includes at least one of trace elements such as Au, Ag, Ce or Mg in addition to silver.

As a preferred embodiment, the bonding segment includes at least one of gold, gold-palladium alloy, silver-gold-palladium alloy or silver-bismuth alloy.

As a more preferred embodiment, with respect to the raw material components of the bonding segment: the purity of the gold is ≥99.99%;

The gold content in the gold-palladium alloy is ≥90.00%, and the palladium content in the gold-palladium alloy is 1% to 10%;

The silver content in the silver-gold-palladium alloy is ≥90.00%, the palladium content in the silver-gold-palladium alloy is 1% to 10%, and the gold content in the silver-gold-palladium alloy is ≥1.00%;

The silver content in the silver-bismuth alloy is ≥ 90.00%, and the bismuth content in the silver-bismuth alloy is 1% to 10%;

The above alloys may also contain trace amounts of impurity components such as Au, Ag, Cu, Mg, etc. These impurities are usually inevitably doped during the smelting process; and the impurity content is ≤0.01%.

In the present invention, the main segment uses a metal with high conductivity and relatively low cost as the raw material, while the bonding segment uses a metal material with low hardness and not easy to oxidize; by designing the structure and raw materials of the bonding wire, on the one hand, it can suppress or solve the defect of easy aging of the bonding interface, and on the other hand, it can effectively reduce the high cost problem of the bonding wire.

As a preferred embodiment, the length of the bonding wire is the distance between the bonding points between the electronic component terminals and the target device; that is, technicians in this field can customize the length of the bonding wire according to the application scenario of the bonding wire without any technical limitations.

The second aspect of the present invention is to provide a method for preparing the bonding wire. The method for preparing the bonding wire comprises the following steps: (1) independently smelting and casting the metal materials of the main section and the bonding section to obtain a main section ingot and a bonding section ingot; (2) arranging the bonding section ingot on at least one side of the main section ingot, placing the pressed and fixed ingot in a vacuum environment for heat preservation treatment to obtain a composite ingot; (3) rolling the composite ingot, and obtaining an alloy strip after rolling for 2 to 20 times; (4) annealing the alloy wire in sequence to obtain a bonding wire.

As a preferred embodiment, in step (1), the metal materials of the main segment and the bonding segment are vacuum melted respectively, and a uniform metal melt is obtained accordingly; the temperature of the vacuum melting is determined according to the melting point of the metal raw materials used in each structural segment.

As a preferred embodiment, in step (1), the length and width of the main segment ingot and the bonding segment ingot are the same; as a more preferred embodiment, the molten metal of the main segment and the bonding segment can be cast using molds of the same specifications to ensure that the length and width of the two ingots remain consistent; and ingots of different heights can be obtained by controlling the volume of the molten metal during the casting process.

As a preferred embodiment, in step (1), the height of the main section ingot is 1 mm to 4 mm, including but not limited to one of 1, 1.5, 2, 2.5, 3, 3.5, 4 (mm) or a numerical range consisting of any two of them.

As a preferred embodiment, in step (1), the height of the bonding segment ingot is 1 mm to 3 mm, including but not limited to one of 1, 1.5, 2, 2.5, 3 (mm) or a numerical range consisting of any two of them; when the bonding segment ingots are provided on both sides of the main segment ingot, the height of each bonding segment ingot is independently selected from 1 mm to 3 mm.

As a preferred embodiment, after step (1), it also includes: independently performing at least one of ultrasonic impact treatment, polishing treatment or pickling treatment on the surfaces to be composited of the main section ingot and the bonding section ingot; as a more preferred embodiment, independently performing ultrasonic impact treatment, polishing treatment and pickling treatment on the surfaces to be composited of the main section ingot and the bonding section ingot in sequence.

In the present invention, ultrasonic impact is used to impact the surface of the alloy ingot to be composited. On the one hand, the surface of the alloy ingot can be cleaned to ensure that no impurities are introduced during diffusion welding; on the other hand, ultrasonic impact is used to realize plastic deformation energy storage and surface grain refinement, refine the grains on the surface of the alloy ingot, and reduce the diffusion welding temperature (by about 10°C to 50°C), so as to achieve a more solid diffusion welding effect.

As a more preferred embodiment, the ultrasonic output amplitude of the ultrasonic impact treatment is 20 μm to 60 μm, and the time of the ultrasonic impact treatment is 30 min to 50 min.

As a more preferred embodiment, the polishing operation method can be carried out according to conventional operations in the field, such as grinding the surface of the alloy ingot with a polishing machine, a sanding machine, etc., or rubbing with a polishing pad, a grinding disc, etc. The present invention does not limit the operation of the polishing treatment; the roughness of the metal surface after the polishing treatment Ra is less than 0.1μm.

As a more preferred embodiment, the oxide film on the surface of the ingot is removed by the pickling treatment; the time of the pickling treatment is 30s to 60s, the acid used in the pickling treatment includes but is not limited to hydrochloric acid, sulfuric acid, nitric acid, etc., and the concentration of the acid used in the pickling treatment is 4mol/L to 6mol/L.

As a preferred embodiment, before step (2), it also includes: grinding the bonding segment ingot and the main segment ingot until they are smooth to facilitate diffusion fusion at the interface in subsequent steps; the grinding includes any one of mechanical polishing, chemical polishing, electrochemical polishing, sand blasting, etc., but it should be noted that the limitation on the ingot height should be determined based on the height after grinding.

As a preferred embodiment, in step (2), local plastic deformation occurs on the surface of the ingot of the main segment and the bonding segment in contact with each other due to the action of temperature and pressure, and mutual diffusion occurs between atoms, thereby forming a diffusion segment alloy at the interface contact to achieve diffusion connection between segments; in the present invention, the fixed pressure can be performed by a press, and the pressure value of the pressure is 100MPa to 500MPa, including but not limited to one of 100, 150, 200, 250, 300, 350, 400, 450, 500 (MPa) or a numerical range composed of any two of them.

As a preferred embodiment, in step (2), the temperature of the insulation treatment is not lower than 200°C; and the temperature of the insulation treatment is lower than the melting point of the main section ingot and the bonding section ingot; the insulation time of the insulation treatment is 3h to 10h, including but not limited to 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10 (h) or a numerical range composed of any two of them.

As a more preferred embodiment, in step (2), the heat preservation treatment is carried out under vacuum conditions.

As a preferred embodiment, in step (3), the rolling includes: placing the diffusion interface close to the roller and rolling in parallel to the rolling direction. Figures 3 and 4 show schematic diagrams of the rolling process in two cases, respectively. The precursor product obtained after several rollings is shown in Figure 5.

As a preferred embodiment, in step (3), the rolling is carried out through multiple passes, and the specific number of rolling passes is determined according to the thickness of the composite ingot and the preset diameter of the bonding wire product, and an alloy strip with a thickness of less than 1 mm is obtained; in some conventional implementation methods, the rolling includes but is not limited to 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 times, etc.

As a preferred embodiment, in step (3), the deformation amount of each rolling is 10% to 30%, wherein the deformation amount is the conventional definition in the art: that is, the ratio of the thickness difference before and after rolling to the thickness before rolling; as an optional embodiment, the deformation amount of each rolling includes but is not limited to 10%, 12%, 14%, 15%, 16%, 18%, 20%, 22%, 24%, 25%, 26%, 28%, 30% or a numerical range consisting of any two of them.

As a preferred embodiment, in step (4), the annealing temperature is 200°C to 500°C, including but not limited to one of 200, 250, 300, 350, 400, 450, 500 (°C) or a numerical range consisting of any two of them; the annealing time is 120min to 180min, including but not limited to one of 120, 130, 140, 150, 160, 170, 180 (min) or a numerical range consisting of any two of them.

As a preferred embodiment, in step (4), the annealing treatment is performed under a vacuum state.

As a preferred embodiment, in step (4), the annealing treatment further includes a trimming treatment, wherein the trimming treatment is performed by laser cutting to obtain a bonding wire product with a specific length and width requirement; or, the annealing treatment further includes setting a slitting line, so that during use, a number of independent bonding wire products can be obtained by a simple separation operation. A schematic diagram of a slitting line is shown in FIG5 .

As a more preferred embodiment, after step (4), the trimming residue is mechanically separated and used for remelting ingots and solder alloys; wherein the residue containing diffusing elements is mainly used for the preparation of solder alloys.

Example 1

(1) Alloy ingot preparation

The pure copper raw material for the main part of the bonding wire and the gold-palladium alloy (3wt.% palladium) for the bonding part are melted in a vacuum melting furnace to obtain liquid metals with uniform composition; then they are cast in rectangular molds of the same size (the length and width of the mold are 20cm*1cm), and the volume of the liquid metal used for the bonding part is smaller than the liquid metal used for the main part of the bonding wire. Then they are cooled and solidified at room temperature to obtain a main section ingot with a thickness of 4mm and a bonding section ingot with a thickness of 3mm.

(2) Surface treatment

The surfaces of the copper ingot and the gold-palladium ingot to be composited were treated by ultrasonic impact equipment, the ultrasonic output amplitude was set to 40 μm, and the impact time was set to 40 min; after the ultrasonic impact was completed, the surfaces were polished smooth (Ra < 0.1 μm), and then the surfaces were pickled with hydrochloric acid solution (5 mol/L) for 40 s, and then the residual acid was washed away and dried.

(3) Diffusion bonding

The copper ingot is placed on one side of the gold-palladium ingot, with the surfaces of the same size and larger area fitting tightly together, and fixed with a fixture and a pressure of 300 MPa. The fixed metal ingot is then placed in a vacuum diffusion furnace for high-temperature diffusion connection. The insulation time is 3 hours, and the vacuum furnace temperature is 900°C.

(4) Multi-pass rolling

The ingot after diffusion is rolled on the rolling mill, with the diffusion interface close to the roller and parallel to the rolling direction. After multiple rolling passes, the deformation of the alloy is about 40% during each rolling pass, and an alloy strip with a certain width and a thickness of 1mm is obtained. After rolling, the alloy strip is placed in a vacuum furnace again for annealing to eliminate residual stress. The annealing temperature is 200°C and the annealing time is 180 minutes.

(5) Laser cutting

The alloy strip after annealing is cut and trimmed by a laser cutting machine to obtain a composite bonding wire with a length of 20 mm and a thickness of 1 mm.

Example 2

It is basically the same as Example 1, except that:

In step (1), the gold-palladium alloy is replaced with a silver-gold-palladium alloy (5 wt.% palladium, 2 wt.% gold);

In step (3), the holding time is 5 h and the vacuum furnace temperature is 850° C.;

In step (4), the deformation of the alloy is about 30% in each rolling process, and an alloy strip with a certain width and a thickness of 0.5 mm is obtained.

Example 3

It is basically the same as Example 2, except that:

In step (1), pure copper is replaced by pure silver, and gold-palladium alloy is replaced by silver-gold-palladium alloy (6wt.% palladium, 2wt.% gold);

In step (3), silver-gold-palladium ingots are placed on both sides of the copper ingot;

In step (4), the deformation of the alloy during each rolling process is about 50%, and an alloy strip with a certain width and a thickness of 0.05 mm is obtained; the annealing temperature is 250° C.;

In step (5), the bonding wire length is 10 mm.

Example 4

It is basically the same as Example 1, except that:

In step (1), pure copper is replaced by a silver-based alloy (Ag-4Pd), and gold-palladium alloy is replaced by a silver-bismuth alloy (5wt.% bismuth); at the same time, during casting, the volume of the liquid metal used for the bonding part is larger than the liquid metal used for the main body of the bonding wire, and then cooled and solidified at room temperature to obtain a main body section ingot with a thickness of 3 mm and a bonding section ingot with a thickness of 5 mm;

In step (3), a pressure of 500 MPa is applied.

Example 5

It is basically the same as Example 1, except that:

In step (1), pure copper is replaced by copper-based alloy (Cu-3Pd), and gold-palladium alloy is replaced by pure gold; at the same time, the volume of liquid metal cast for the bonding part is larger than the liquid metal used for the main body of the bonding wire during casting, and then cooled and solidified at room temperature to obtain a main body section ingot with a thickness of 1 mm and a bonding section ingot with a thickness of 3 mm;

In step (3), a pressure of 100 MPa is applied.

Comparative Example: 4N pure gold bonding wire, the specifications are consistent with those of Example 1.

Test example: Aging resistance test

A single bonding wire is inserted into the splitter of the bonding machine, and a bonding point is formed on the aluminum substrate using the bonding machine. It is then placed in a temperature shock test chamber for a thermal shock test. -55 to 150°C is selected as the thermal shock condition, the cycle period is 1h/week, and it stays at the extreme temperature for 30min. The experiment is terminated after 600 cycles.

The bonding point was dissected and its microstructure was analyzed. The growth depth of the intermediate compound at the bonding point interface was observed under a metallographic microscope and a scanning electron microscope to measure the degree of aging. The test results are shown in Table 1 below.

Table 1

Growth depth (μm) Example 1 3 Example 2 2 Example 3 1 Example 4 1 Example 5 5 Comparative Example 7

Although the present invention has been illustrated and described with specific embodiments, it should be appreciated that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Those skilled in the art should understand that the technical solutions described in the above embodiments may be modified, or some or all of the technical features thereof may be replaced by equivalents without departing from the spirit and scope of the present invention. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. Therefore, this means that all such replacements and modifications within the scope of the present invention are included in the appended claims.

Claims (10)

1. A composite bond wire, wherein the bond wire comprises a body segment, and a bond segment diffusion bonded to at least one end of the body segment;

the main body section comprises at least one of silver and silver-based alloy, copper and copper-based alloy;

the bonding segment comprises at least one element of gold, silver, palladium or bismuth.

2. The composite bond wire of claim 1 wherein when the bond segment is attached to one end of the body segment, the ratio of the length of the bond segment to the length of the body segment is 1/6 to 1/3;

or when the two ends of the main body section are respectively connected with the bonding sections, the ratio of the length of each bonding section to the length of the main body section is 1/6-1/3.

3. The composite bonding wire according to claim 1, wherein the bonding wire has a square cross section, and the length of the long side of the square is less than or equal to 1mm;

Preferably, the length of the long side of the square is 16-70 μm.

4. The composite bond wire of claim 1 wherein at least one of the metallic elements in the body segment is the same as the metallic element in the bond segment.

5. The composite bonding wire according to claim 1, wherein the silver content in the silver-based alloy is not less than 99.95%, and the copper content in the copper-based alloy is not less than 99.90%;

And/or the bonding section comprises at least one of gold, gold-palladium alloy, silver-gold-palladium alloy or silver-bismuth alloy; the content of gold in the gold-palladium alloy is more than or equal to 99.00%; the silver content in the silver-gold-palladium alloy or the silver-bismuth alloy is more than or equal to 99.00 percent.

6. The method of manufacturing a composite bond wire according to any one of claims 1 to 5, comprising the steps of:

(1) Independently smelting and casting the metal materials of the main body section and the bonding section to obtain a main body section cast ingot and a bonding section cast ingot;

(2) Arranging the bonding section cast ingot on at least one side of the main body section cast ingot, and placing the cast ingot subjected to pressure application and fixation in a vacuum environment for heat preservation treatment to obtain a composite ingot;

(3) Rolling the composite ingot for 2-20 times to obtain an alloy belt;

(4) And annealing the alloy strip in sequence to obtain the bonding wire.

7. The method of manufacturing a composite bond wire of claim 6, further comprising, after step (1): independently performing at least one of ultrasonic impact treatment, polishing treatment or pickling treatment on the surfaces to be compounded of the main body section ingot and the bonding section ingot;

preferably, the ultrasonic output amplitude of the ultrasonic impact treatment is 20-60 μm, and the ultrasonic impact treatment time is 30-50 min.

8. The method of manufacturing a composite bonding wire according to claim 6, wherein in the step (2), the temperature of the heat-retaining treatment is not lower than 200 ℃; the temperature of the heat preservation treatment is less than the melting points of the main body section cast ingot and the bonding section cast ingot; the heat preservation time of the heat preservation treatment is 3-10 h;

preferably, the pressure value of the pressing is 100MPa to 500MPa.

9. The method of manufacturing a composite bond wire according to claim 6, wherein in step (3), the rolling includes: the diffusion interface is tightly clung to a roller and is parallel to the rolling direction for rolling;

preferably, the deformation amount per rolling is 10% to 30%.

10. The method of manufacturing a composite bonding wire according to claim 6, wherein in the step (4), the annealing treatment is performed at a temperature of 200 ℃ to 500 ℃ for 120min to 180min;

Preferably, in step (4), the annealing treatment is followed by a cutting treatment, the cutting treatment being performed by a laser; or setting a parting line after the annealing treatment in the step (4);

more preferably, the cut surplus material is mechanically separated and used for remelting the ingot and the solder alloy.