A high-platinum alloy bonding wire and its preparation method and application

Abstract

The present application relates to the field of alloy bonding wires, and in particular to a high-platinum alloy bonding wire and its preparation method and application. The high-platinum alloy bonding wire, in terms of mass percentage, includes: Pt5-15%, Cu 0.5-2%, Pd 1-3%, Si 0.01-0.015%, Ce 0.001-0.005%, In 0.001-0.003%, Ni 0.002-0.0025%, Re 0.01-0.015%, Y 0.001-0.005%, and the balance is Ag. The high-platinum alloy bonding prepared in the present application can effectively improve the mechanical properties of the bonding wire, such as elongation and tensile strength, while further greatly ensuring that the bonding wire retains excellent electrical conductivity and oxidation resistance. It has very comprehensive performance, excellent market prospects, and can be used in a variety of fields and environments.

Description

Technical Field

[0001] The present application relates to the field of alloy bonding wires, and in particular to a high-platinum-containing alloy bonding wire and a preparation method and application thereof. Background Art

[0002] Bonding alloy materials are widely used in the integrated circuit packaging industry and the LED industry due to their excellent chemical stability. After years of research and development, the development of bonding wire materials has reached its limit. Nowadays, alloy wire materials with excellent performance and low price have become a research and development trend. Nowadays, because the cost of silver bonding wire and copper bonding wire is much lower than that of gold bonding wire, and the bonding process does not require a protective gas atmosphere, they have become an important alternative to gold bonding wire in more fields and occasions.

[0003] Although the existing silver / copper bonding wire has excellent cost advantages, with the development of high-density, high-speed and miniaturization of electronic packaging, the performance requirements for bonding wires have been further improved, and traditional silver / copper bonding wires have fallen behind the existing demand. Silver bonding wires face technical problems such as low tensile strength and poor high-temperature oxidation resistance, while copper bonding wires also have significant disadvantages such as high hardness and easy oxidation.

[0004] Therefore, in order to solve the above problems, the present application provides a high-platinum alloy bonding wire and a preparation method thereof. The high-platinum alloy bonding wire prepared in the present application can effectively improve the mechanical properties of the bonding wire such as elongation and tensile strength, while further greatly ensuring that the bonding wire retains excellent electrical conductivity and oxidation resistance, has very comprehensive performance, excellent market prospects, and can be applied in a variety of fields and environments. Summary of the invention

[0005] In order to solve the above problems, the first aspect of the present application provides a high-platinum alloy bonding wire, which includes, by mass percentage: Pt 5-15%, Cu 0.5-2%, Pd 1-3%, Si 0.01-0.015%, Ce 0.001-0.005%, In 0.001-0.003%, Ni 0.002-0.0025%, Re 0.01-0.015%, Y 0.001-0.005%, and the balance is Ag.

[0006] As a preferred solution, the mass ratio of Pt, Cu, Pd and Si is (10-14): (0.8-1.25): (1-1.5): (0.01-0.012).

[0007] As a preferred solution, the mass ratio of Pt, Cu, Pd and Si is (12-14): (1-1.2): (1.3-1.5): 0.01.

[0008] As a preferred solution, the mass ratio of Si, Ni, Re and Y is (0.01-0.012):(0.002-0.0022):(0.012-0.014):(0.003-0.005).

[0009] As a preferred solution, the mass ratio of Si, Ni, Re and Y is 0.001:0.0022:0.013:0.004.

[0010] In the present application, the mechanical properties of the alloy bonding wire can be effectively improved by adding Si, Ni, Re and Y doped metals, while ensuring that the bonding wire retains excellent electrical conductivity and oxidation resistance. This is mainly because the Si and Ni metals added in the present application can work together to increase the softening temperature of the bonding wire, and greatly enhance the resistance of Ag to high-temperature oxidation under high temperature conditions, but the addition of the relative content of Si and Ni in the present application will further affect the overall electrical conductivity of the bonding wire, and in the present application, by adding Re and Y, the combined effect of the two can play a significant hindering role in the growth process of Si crystals, preventing the rapid increase of Si phase grains, avoiding the generation of brittle flaky Si phases, which can hinder the Si crystals from forming a continuous phase, thereby affecting the electron flow rate inside the bonding wire; and under the above conditions, the grain size difference ratio inside the mixed phase of Ag and Pt in the bonding wire is further reduced, and the distribution is more uniform and stable, thereby obtaining excellent mechanical properties.

[0011] The second aspect of the present application provides a method for preparing the above-mentioned high-platinum alloy bonding wire, and the preparation method includes the following steps: S1: melting part of Ag with Pt, Cu and Pd under vacuum, and then casting into alloy plate I; melting the remaining Ag and other remaining metal raw materials under vacuum, and then casting into alloy plate ⅠⅠ; S2: stacking and fixing alloy plate Ⅰ and alloy plate ⅠⅠ alternately, and then vacuum continuously casting to melt into bonding wires; S3: subjecting the bonding wire to three-stage wire drawing treatment by controlling the processing deformation amount to obtain bonding wire; S4: annealing the bonding wire, and naturally cooling it to 20-30°C after the annealing treatment is completed; S5: placing the bonding wire on a rewinding machine for winding treatment, and packaging it after completion to obtain the high-platinum alloy bonding wire.

[0012] As a preferred solution, the melting temperature of Ag, Pt, Cu and Pd in ​​S1 is 1700-1900°C.

[0013] As a preferred solution, the melting temperature of Ag, Pt, Cu and Pd in ​​S1 is 1750-1800°C.

[0014] As a preferred solution, the melting temperature of Ag and other remaining metal raw materials in S1 is 1600-2000°C.

[0015] As a preferred solution, the melting temperature of Ag and other remaining metal raw materials in S1 is 1850-1950°C.

[0016] As a preferred solution, the process temperature of the vacuum continuous casting in S2 is 2120-2240°C.

[0017] As a preferred solution, the process temperature of the vacuum continuous casting in S2 is 2200-2240°C.

[0018] In the present application, by combining and superposing two Ag alloys, the dispersion of doped metals and trace metals in the bonding wire can be controlled as much as possible on a macro scale. It can also accelerate the compatibility rate of Ag with Pt and other metals, weaken the mutual repulsion between metal grains, and thus provide a good foundation for the bond wire to be drawn during the smelting stage; on the other hand, by controlling the smelting temperature and the processing deformation of multi-stage wire drawing, a uniform and stable crystal phase can be effectively formed, avoiding the appearance of cracks on the surface of the bonding wire, so that when an external force acts, it can show a more excellent upper limit of strength resistance, and can keep the external force in the bonding wire as a silver streak state, thereby obtaining excellent mechanical properties.

[0019] As a preferred solution, the diameter of the bonding wire is 15 to 20 mm.

[0020] As a preferred scheme, the specific operation of the three-stage wire drawing process is: the bonding wire is drawn once, twice, and three times respectively, the processing deformation amount of the first wire drawing is controlled to be 15-20%, the processing deformation amount of the second wire drawing is controlled to be 10-15%, and the processing deformation amount of the third wire drawing is controlled to be 5-10%, so as to obtain the bonding wire.

[0021] As a preferred solution, the primary wire drawing controls the processing deformation amount to be 16-18%.

[0022] As a preferred solution, the secondary wire drawing controls the processing deformation to be 12-15%.

[0023] As a preferred solution, the three wire drawing processes control the deformation amount to be 6-8%.

[0024] As a preferred solution, the specific operation of the annealing treatment is: annealing the bonding wire in an annealing furnace, the effective annealing length is 600-800 mm, the annealing temperature is 700-1000° C., and the annealing rate is 50-90 m / min.

[0025] As a preferred solution, the annealing temperature is 800-900°C.

[0026] As a preferred solution, the annealing rate is 70-80 m / min.

[0027] As a preferred solution, the winding tension of the rewinding machine is 10 to 25 g.

[0028] As a preferred solution, the winding tension of the rewinding machine is 20-25g.

[0029] As a preferred solution, the winding speed of the rewinding machine is 500-650 rpm.

[0030] As a preferred solution, the winding speed of the rewinding machine is 550-600 rpm.

[0031] The third aspect of the present application provides an application of the above-mentioned high-platinum alloy bonding wire, including the application of the high-platinum alloy bonding wire in the fields of integrated circuits, discrete devices, LED packaging, microelectronic packaging, automotive electronic systems, and communications.

[0032] The beneficial effects of this application are:

[0033] 1. A high-platinum alloy bonding wire prepared in the present application can effectively improve the mechanical properties of the bonding wire, such as elongation and tensile strength, while further greatly ensuring that the bonding wire retains excellent electrical conductivity and antioxidant properties. It has very comprehensive performance, excellent market prospects, and can be used in a variety of fields and environments.

[0034] 2. A high-platinum alloy bonding wire prepared in the present application effectively improves the mechanical properties of the alloy bonding wire by adding Si, Ni, Re and Y doped metals, while ensuring that the bonding wire retains excellent electrical conductivity and oxidation resistance; Si and Ni metals can work together to increase the softening temperature of the bonding wire, and greatly enhance the resistance of Ag to high-temperature oxidation under high temperature conditions, but the addition of the relative content of Si and Ni in the present application will further affect the overall electrical conductivity of the bonding wire, and in the present application, through the addition of Re and Y, the combined effect of the two can play a significant hindering role in the growth process of Si crystals, prevent the rapid increase of Si phase grains, and avoid the formation of brittle flaky Si phases, which can hinder the Si crystals from forming a continuous phase, thereby affecting the electron flow rate inside the bonding wire.

[0035] 3. A high-platinum alloy bonding wire prepared in the present application, through the combined superposition of two Ag alloys, can control the dispersion degree of doped metals and trace metals in the bonding wire as much as possible on a macro scale, can accelerate the compatibility rate of Ag with Pt and other metals, and weaken the mutual repulsion between metal grains, thereby providing a good foundation for the drawn bonding wire in the smelting stage; on the other hand, by controlling the smelting temperature and the processing deformation of multiple sections of wire drawing, a uniform and stable crystal phase can be effectively formed, avoiding the appearance of cracks on the bonding wire surface, thereby showing a more excellent upper limit of strength resistance when external forces act. DETAILED DESCRIPTION

[0036] The following will further explain and demonstrate the technical solutions in the above invention content of this application in the form of specific implementation schemes. The following embodiments are only practical examples used to illustrate and explain the contents of the technical solutions in the specification, and should not limit the scope of the claims to be protected by this application. All technical products based on the technical solutions described in the invention content of this application should be included in the scope to be protected by this application.

[0037] In the following examples, unless otherwise specified, the raw materials are all commercially available products, or can be prepared by methods well known to those skilled in the art.

[0038] Example 1

[0039] Embodiment 1 The first aspect provides a high platinum-containing alloy bonding wire, which comprises, by mass percentage: Pt 12.5%, Cu 1.2%, Pd 1.5%, Si 0.01%, Ce 0.0025%, In 0.0022%, Ni 0.0022%, Re 0.013%, Y 0.004%, and the balance is Ag.

[0040] The second aspect of the present embodiment provides a preparation method for the above-mentioned high-platinum alloy bonding wire, and the preparation method includes the following steps: S1: 50wt% of Ag is melted with Pt, Cu and Pd under vacuum, and then drawn into alloy plate I; the remaining 50wt% of Ag is melted with other remaining metal raw materials under vacuum, and then drawn into alloy plate ⅠⅠ; S2: Alloy plate Ⅰ and alloy plate ⅠⅠ are alternately stacked and fixed, and then vacuum continuously drawn to form bonding wires; S3: The bonding wire is subjected to three-stage wire drawing treatment by controlling the processing deformation amount to obtain a bonding wire; S4: After the bonding wire is annealed, it is naturally cooled to 25°C; S5: The bonding wire is placed on a rewinding machine for winding treatment, and after completion, it is packaged to obtain a high-platinum alloy bonding wire.

[0041] The melting temperature of Ag, Pt, Cu and Pd in ​​S1 is 1750°C.

[0042] The melting temperature of Ag and other remaining metal raw materials in S1 is 1900°C.

[0043] The process temperature of vacuum continuous casting in S2 is 2220°C.

[0044] The diameter of the bonding wire is 20 mm.

[0045] The specific operation of the three-stage wire drawing process is: draw the bonding wire once, twice, and three times respectively, control the processing deformation amount of the first wire drawing to be 16%, the second wire drawing to be 13%, and the third wire drawing to be 8%, to obtain the bonding wire.

[0046] The specific operation of the annealing treatment is: annealing the bonding wire in an annealing furnace, the effective annealing length is 800 mm, the annealing temperature is 850° C., and the annealing rate is 75 m / min.

[0047] The winding tension of the rewinding machine is 25g; the winding speed of the rewinding machine is 600rpm.

[0048] Example 2

[0049] Embodiment 2 The first aspect provides a high platinum-containing alloy bonding wire, which comprises, by mass percentage: Pt 14%, Cu 1%, Pd 1.2%, Si 0.012%, Ce 0.0025%, In 0.002%, Ni 0.002%, Re 0.014%, Y 0.003%, and the balance is Ag.

[0050] The second aspect of the present embodiment provides a preparation method for the above-mentioned high-platinum alloy bonding wire, and the preparation method includes the following steps: S1: 50wt% of Ag is melted with Pt, Cu and Pd under vacuum, and then drawn into alloy plate I; the remaining 50wt% of Ag is melted with other remaining metal raw materials under vacuum, and then drawn into alloy plate ⅠⅠ; S2: Alloy plate Ⅰ and alloy plate ⅠⅠ are alternately stacked and fixed, and then vacuum continuously drawn to form bonding wires; S3: The bonding wire is subjected to three-stage wire drawing treatment by controlling the processing deformation amount to obtain a bonding wire; S4: After the bonding wire is annealed, it is naturally cooled to 25°C; S5: The bonding wire is placed on a rewinding machine for winding treatment, and after completion, it is packaged to obtain a high-platinum alloy bonding wire.

[0051] The melting temperature of Ag, Pt, Cu and Pd in ​​S1 is 1750°C.

[0052] The melting temperature of Ag and other remaining metal raw materials in S1 is 1900°C.

[0053] The process temperature of vacuum continuous casting in S2 is 2220°C.

[0054] The diameter of the bonding wire is 20 mm.

[0055] The specific operation of the three-stage wire drawing process is: draw the bonding wire once, twice, and three times respectively, control the processing deformation amount of the first wire drawing to be 16%, the second wire drawing to be 13%, and the third wire drawing to be 8%, to obtain the bonding wire.

[0056] The specific operation of the annealing treatment is: annealing the bonding wire in an annealing furnace, the effective annealing length is 800 mm, the annealing temperature is 850° C., and the annealing rate is 75 m / min.

[0057] The winding tension of the rewinding machine is 25g; the winding speed of the rewinding machine is 600rpm.

[0058] Example 3

[0059] Embodiment 3 The first aspect provides a high platinum-containing alloy bonding wire, which comprises, by mass percentage: Pt 12.5%, Cu 1.2%, Pd 1.5%, Si 0.01%, Ce 0.0025%, In 0.002%, Ni 0.0022%, Re0.013%, Y 0.004%, and the balance is Ag.

[0060] The second aspect of the present embodiment provides a preparation method for the above-mentioned high-platinum alloy bonding wire, and the preparation method includes the following steps: S1: 50wt% of Ag is melted with Pt, Cu and Pd under vacuum, and then drawn into alloy plate I; the remaining 50wt% of Ag is melted with other remaining metal raw materials under vacuum, and then drawn into alloy plate ⅠⅠ; S2: Alloy plate Ⅰ and alloy plate ⅠⅠ are alternately stacked and fixed, and then vacuum continuously drawn to form bonding wires; S3: The bonding wire is subjected to three-stage wire drawing treatment by controlling the processing deformation amount to obtain a bonding wire; S4: After the bonding wire is annealed, it is naturally cooled to 25°C; S5: The bonding wire is placed on a rewinding machine for winding treatment, and after completion, it is packaged to obtain a high-platinum alloy bonding wire.

[0061] The melting temperature of Ag, Pt, Cu and Pd in ​​S1 is 1800°C.

[0062] The melting temperature of Ag and other remaining metal raw materials in S1 is 2000°C.

[0063] The process temperature of vacuum continuous casting in S2 is 2240°C.

[0064] The diameter of the bonding wire is 20 mm.

[0065] The specific operation of the three-stage wire drawing process is: draw the bonding wire once, twice, and three times respectively, control the processing deformation amount of the first wire drawing to be 18%, the second wire drawing to be 15%, and the third wire drawing to be 10%, to obtain the bonding wire.

[0066] The specific operation of the annealing treatment is: annealing the bonding wire in an annealing furnace, the effective annealing length is 850 mm, the annealing temperature is 900° C., and the annealing rate is 70 m / min.

[0067] The winding tension of the rewinding machine is 20g; the winding speed of the rewinding machine is 550rpm.

[0068] Comparative Example 1

[0069] The specific implementation of this comparative example is basically the same as that of Example 1, except that the high platinum-containing alloy bonding wire includes, by mass percentage, Pt 15%, Cu 1.2%, Pd 1.5%, Si 0.03%, Ce 0.0025%, In0.002%, Ni 0.0022%, Re 0.001%, Y 0.001%, and the balance is Ag.

[0070] Comparative Example 2

[0071] The specific implementation of this comparative example is basically the same as that of Example 1, except that the high platinum-containing alloy bonding wire, in terms of mass percentage, includes: Pt 12.5%, Cu 1.2%, Pd 1.5%, Ce 0.0025%, In 0.002%, Ni0.001%, Re 0.05%, Y 0.005%, and the balance is Ag.

[0072] Comparative Example 3

[0073] The specific implementation of this comparative example is basically the same as that of Example 1, except that the high platinum-containing alloy bonding wire includes, by mass percentage, Pt 12.5%, Cu 1.2%, Pd 1.5%, Si 0.01%, Ce 0.0025%, In0.002%, Ni 0.0022%, Re 0.02%, and the balance is Ag.

[0074] Comparative Example 4

[0075] The specific implementation of this comparative example is basically the same as that of Example 1, except that the specific operation of the annealing treatment is: annealing the bonding wire in an annealing furnace, the effective annealing length is 600 mm, the annealing temperature is 650° C., and the annealing rate is 40 m / min.

[0076] Comparative Example 5

[0077] The specific implementation method of this comparative example is basically the same as that of Example 1, with the only difference being that the specific operation of the three-stage wire drawing process is to draw the bonding wire once, twice, and three times respectively, with the processing deformation amount of the first wire drawing being controlled to be 25%, the processing deformation amount of the second wire drawing being controlled to be 10%, and the processing deformation amount of the third wire drawing being controlled to be 3%, to obtain the bonding wire.

[0078] Performance Evaluation

[0079] Elongation and tensile strength: The bonding wires prepared in the examples and comparative examples were tested for their elongation and tensile strength. The measured values ​​were averaged over 10 tests and recorded in Table 1.

[0080] Durability: The bonding wires prepared in the embodiments and comparative examples were subjected to 500 rounds of hot and cold shocks. The conditions of the hot and cold shocks were as follows: first, they were kept at a high temperature of 100°C for 15 minutes, kept at room temperature for 5 minutes, and kept at a low temperature of -40°C for 15 minutes. If no dead light problem occurred when the LED including the bonding wire was used, it was considered qualified, otherwise it was considered unqualified. 20 samples were tested and the qualified rate of the final test was taken. The qualified rate (%) = number of qualified samples / 20×100%.

[0081] Table 1

[0082] Example Elongation % Tensile strength cN Durability qualified rate % Example 1 12.24 11.54 95 Example 2 11.98 10.87 95 Example 3 12.04 11.22 90 Comparative Example 1 8.74 9.14 70 Comparative Example 2 9.56 8.98 70 Comparative Example 3 8.34 9.01 75 Comparative Example 4 9.01 8.77 70 Comparative Example 5 8.67 8.91 75

[0083] From the examples and comparative examples of the present application and the data results in Table 1, it can be seen that the examples 1 to 3 adopting the necessary technical solutions given in the present application have achieved excellent results in terms of mechanical properties and durability of the bonding wire, and can have good oxidation resistance and conductivity while ensuring the above excellent performance, thereby greatly improving the stability and reliability of the gold alloy bonding wire itself. However, because comparative examples 1 to 5 did not fully adopt the necessary technical solutions described by the applicant, their corresponding test results were significantly worse than those of examples 1 to 3, which better proves the irreplaceable nature of the specific technical solutions of the present application in achieving technical effects and solving technical problems.

Claims

1. A high platinum alloy bonding wire, characterized in that: Calculated by mass percentage, it includes: Pt 5-15%, Cu 0.5-2%, Pd 1-3%, Si 0.01-0.015%, Ce 0.001-0.005%, In 0.001-0.003%, Ni 0.002-0.0025%, Re 0.01-0.015%, Y 0.001-0.005%, and the balance is Ag.

2. The high platinum alloy bonding wire according to claim 1, characterized in that: The mass ratio of Pt, Cu, Pd and Si is (10-14): (0.8-1.25): (1-1.5): (0.01-0.012).

3. The high platinum alloy bonding wire according to claim 2, characterized in that: The mass ratio of Si, Ni, Re and Y is (0.01-0.012):(0.002-0.0022):(0.012-0.014):(0.003-0.005).

4. A method for preparing a high platinum-containing alloy bonding wire according to any one of claims 1 to 3, characterized in that: Preparation method The following steps are involved: S1: melt part of Ag with Pt, Cu and Pd under vacuum, and then draw and cast into alloy plate I; melt the remaining Ag and other remaining metal raw materials under vacuum, and then draw and cast into alloy plate ⅠⅠ; S2: alternately stack and fix alloy plate Ⅰ and alloy plate ⅠⅠ, and then draw and cast them into bonding wires in vacuum; S3: draw the bonding wires in three stages by controlling the processing deformation to obtain bonding wires; S4: annealing the bonding wire, and naturally cooling it to 20-30° C. after the annealing is completed; S5: placing the bonding wire on a rewinding machine for winding, and packaging it after completion to obtain a high-platinum alloy bonding wire.

5. The method for preparing a high platinum-containing alloy bonding wire according to claim 4, characterized in that: The melting temperature of Ag, Pt, Cu and Pd in ​​the S1 is 1700-1900°C.

6. The method for preparing a high platinum-containing alloy bonding wire according to claim 5, characterized in that: The melting temperature of Ag and other remaining metal raw materials in S1 is 1600-2000°C.

7. The method for preparing a high platinum-containing alloy bonding wire according to claim 6, characterized in that: The specific operation of the three-stage wire drawing process is: the bonding wire is drawn once, twice and three times respectively, the deformation amount of the first wire drawing is controlled to be 15-20%, the deformation amount of the second wire drawing is controlled to be 10-15%, and the deformation amount of the third wire drawing is controlled to be 5-10%, so as to obtain the bonding wire.

8. The method for preparing high platinum-containing alloy bonding wire according to claim 7, characterized in that: The specific operation of the annealing treatment is: annealing the bonding wire in an annealing furnace, the effective annealing length is 600-800 mm, the annealing temperature is 700-1000° C., and the annealing rate is 50-90 m / min.

9. The method for preparing a high platinum-containing alloy bonding wire according to claim 8, characterized in that: The winding tension of the rewinding machine is 10-25g; the winding speed is 500-650rpm.

10. Use of the high platinum alloy bonding wire according to any one of claims 1 to 3 in the fields of integrated circuits, discrete devices, LED packaging, microelectronic packaging, automotive electronic systems, and communications.