Copper alloy bonding wire for electronic packaging and preparation method and application thereof

Abstract

The present invention provides a copper alloy bonding wire for electronic packaging, a preparation method and an application thereof, wherein the copper alloy bonding wire comprises the following raw materials by mass fraction: Pd 0.06-0.13%, Ru 0.12-0.17%, Nb 0.14-0.18%, Ca 0.09-0.15%, Sc 0.002-0.004%, Mg 0.004-0.008%, B 0.003-0.006%, In 0.001-0.003%, Al 0.003-0.005%, Li 0.002-0.005%, and the balance is Cu. The copper alloy bonding wire provided by the present invention has excellent tensile force and elongation, moderate hardness, and significant aging resistance and corrosion resistance. It is packaged in combination with epoxy molding compound KH9200-3T, and the product has high reliability, which has a boosting effect on the application and development of domestic epoxy molding compound.

Description

Technical Field

[0001] The invention belongs to the technical field of copper alloy bonding wires, and in particular relates to a copper alloy bonding wire for electronic packaging and a preparation method and application thereof. Background Art

[0002] As integrated circuit and semiconductor device packaging technology develops towards multi-lead, high integration and miniaturization, packaging materials require the use of bonding wires with finer wire diameters and better electrical properties for narrow spacing and long distance bonding. Traditional gold and silver wires have gradually approached their limits in terms of electrical and thermal conductivity. Therefore, the industry is in urgent need of new bonding wire materials with relatively low cost and stable and reliable performance to replace gold and silver bonding wires. In recent years, bonding copper wires have begun to occupy the low-end market of the electronic packaging industry with their low cost and good comprehensive performance. They are mainly used as inner leads in various semiconductor devices such as diodes, triodes, integrated circuits, and large-scale integrated circuits. In the field of high-end products such as leadless packaging and small-pitch pads, bonding copper wires also show good potential for use.

[0003] Although copper wire has excellent mechanical, thermal and electrical properties during bonding, the development of copper wire bonding also faces challenges. In the prior art, in order to improve the problem of easy oxidation during copper wire bonding, some trace elements are usually added to the copper wire, but this practice will increase the hardness of the copper wire. If the copper wire is too hard, it is easy to cause problems such as substrate breakage and cold solder joints. If the copper wire purity is increased to reduce its own hardness, the copper wire purity will be too high, which will reduce its own strength, make it difficult to control the forming, and make the arc height uneven; in addition, the recrystallization temperature of the copper wire will be reduced, and the breaking force and elongation will also decrease with the extension of the use time. The above problems make it very difficult to produce copper alloy bonding wires with excellent comprehensive performance. DIP package, full name: dual in-line package, is a form of electronic component packaging. It is characterized by two rows of parallel metal pins, which can be directly inserted into the circuit board for soldering. DIP package can also be inserted into the DIP socket to facilitate component replacement. The advantages of this package include simple structure and low cost, so it is suitable for small and medium-sized integrated circuits. DIP packaging is widely used and can be found in many electronic devices, such as computers, game consoles, and stereos. DIP packaging has the advantages of small size and easy installation. Epoxy molding compound of Zhongke Chemical New Materials Co., Ltd.: KH9200-3T is a product suitable for dual in-line packaging (DIP). It has the characteristics of partial melting + partial crystallization of silicon powder, high thermal conductivity and low stress balance, low cost and good film forming properties. This product has a large market share, but customers generally respond that this epoxy molding compound is not ideal for packaging with commercially available copper alloy bonding wires, which affects the quality of subsequent products and long-term use effects. Summary of the invention

[0004] The purpose of the present invention is to provide a copper alloy bonding wire for electronic packaging and a preparation method and application thereof, which has excellent tensile strength and elongation, moderate hardness, and significant anti-oxidation effect. It is packaged in combination with epoxy molding compound KH9200-3T, and the product has high reliability.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A copper alloy bonding wire for electronic packaging comprises the following raw materials in mass fraction: Pd 0.06-0.13%, Ru 0.12-0.17%, Nb 0.14-0.18%, Ca 0.09-0.15%, Sc 0.002-0.004%, Mg 0.004-0.008%, B 0.003-0.006%, In 0.001-0.003%, Al 0.003-0.005%, Li 0.002-0.005%, and the balance is Cu.

[0007] Furthermore, the purity of Cu is greater than 99.9995%.

[0008] Furthermore, the purity of any one of Pd, Ru, Nb and Ca is greater than 99.999%.

[0009] Furthermore, the purity of any one of Sc, Mg, B, In, Al, and Li is greater than 99.9%.

[0010] The present invention adds specific contents of Pd, Ru, Nb and Ca to copper, and the obtained copper alloy bonding wire is packaged with epoxy molding compound KH9200-3T, and the aging resistance is significantly better than that of commercially available products. Analysis shows that the epoxy molding compound KH9200-3T mainly includes a resin matrix, a curing agent, a filler and other additives, and the substances released by the epoxy molding compound or the influence on the environmental stress caused by the change of the environment will indirectly or directly affect the performance of the copper alloy bonding wire. The components of the copper alloy bonding wire of the present invention can form a relatively stable interface with KH9200-3T, thereby reducing the reaction activity between the copper bonding wire and the epoxy molding compound.

[0011] The difference between the epoxy molding compound KH9200-3T and most of the same series products of the company is that KH9200-3T is a halogen product and may also contain other substances such as sulfur. The copper alloy bonding wire on the market has poor corrosion resistance when encapsulated with it. The present invention can improve the corrosion resistance of the copper alloy bonding wire and the epoxy molding compound KH9200-3T package by further adding an appropriate amount of trace elements. Analysis shows that under this condition, the oxidation resistance of the bonding copper wire can be improved, thereby reducing the reaction between copper oxide and halogen ions. At the same time, adding trace elements can improve the crystal structure of copper, thereby affecting the chemical reaction activity between it and the metallization layer to which it is welded, improving the growth rate of intermetallic compounds between the welding wire and the metallization layer, and improving the bonding strength, thereby improving the welding reliability.

[0012] The present invention also provides a method for preparing the copper alloy bonding wire for electronic packaging, comprising the following steps:

[0013] (1) After the raw materials are uniformly mixed, they are refined at 1300-1350° C. for 25-40 min under argon protection conditions, and cast into ingots to obtain copper alloy ingots;

[0014] (2) The copper alloy ingot is heated and melted in a nitrogen environment, and after heat preservation, refining and degassing, it is continuously drawn and cast into a copper alloy rod with a diameter of 4-6 mm;

[0015] (3) subjecting the copper alloy rod to homogenization annealing and then cooling to room temperature to obtain a homogenization annealed copper alloy rod;

[0016] (4) Drawing the homogenized annealed copper alloy rod multiple times into a copper alloy bonding wire with a diameter of 0.4-0.8 mm;

[0017] (5) intermediate annealing of the copper alloy bonding wire, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 450-500° C., and the annealing rate is 80-100 m / min;

[0018] (6) drawing the copper alloy bonding wire that has undergone the first intermediate annealing into a copper alloy bonding wire with a diameter of 15 μm to 50 μm;

[0019] (7) final annealing of the 15 μm-50 μm copper alloy bonding wire, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 550-600° C., and the annealing rate is 110-120 m / min;

[0020] (8) Clean and dry the surface to obtain copper alloy bonding wire.

[0021] Furthermore, the homogenization annealing conditions in step (3) are as follows: heating to 600-650°C at a heating rate of 13-15°C / min, keeping the temperature for 5-7h, cooling to 450-500°C at a cooling rate of 10-12°C / min, and keeping the temperature for 10-12h.

[0022] Furthermore, the heating and melting in step (2) is performed using medium frequency induction heating.

[0023] Furthermore, the casting temperature in step (2) is 1100-1200°C.

[0024] Furthermore, the protective atmosphere used in steps (3), (5) and (7) is 95% N2+5% H2, and the gas flow rate is 5-8 L / min.

[0025] The present invention further improves the mechanical properties of the copper alloy bonding wire under the specific element ratio conditions of the present invention through homogenization treatment and multiple annealing. At the same time, the copper alloy bonding wire of the present invention has moderate hardness, which helps to effectively reduce the arc height of the wire.

[0026] The third aspect of the present invention provides the application of the copper alloy bonding wire for electronic packaging.

[0027] Furthermore, the copper alloy bonding wire and the epoxy molding compound KH9200-3T are used for DIP packaging at the same time.

[0028] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0029] 1. The present invention provides a copper alloy bonding wire for electronic packaging, a preparation method and an application thereof, which has excellent tensile strength and elongation, moderate hardness, and significant aging resistance and corrosion resistance. It can be packaged in combination with epoxy molding compound KH9200-3T, and the product has high reliability. The copper alloy bonding wire provided by the present invention has a boosting effect on the application and development of domestic epoxy molding compounds.

[0030] 2. The present invention adds specific contents of Pd, Ru, Nb and Ca to copper, and the obtained copper alloy bonding wire is packaged with epoxy molding compound KH9200-3T, and the aging resistance is significantly better than that of commercially available products. By further adding appropriate amounts of trace elements, the corrosion resistance of the copper alloy bonding wire and epoxy molding compound KH9200-3T packaging can be improved.

[0031] 3. The present invention further improves the mechanical properties of the copper alloy bonding wire under the specific element ratio conditions of the present invention through homogenization treatment and multiple annealing. At the same time, the copper alloy bonding wire of the present invention has a moderate hardness, which helps to effectively reduce the arc height of the wire. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Example 1

[0034] The present embodiment provides a copper alloy bonding wire for electronic packaging, comprising the following raw materials in mass fractions: Pd 0.09%, Ru 0.15%, Nb 0.17%, Ca 0.11%, Sc 0.003%, Mg 0.006%, B 0.004%, In 0.002%, Al 0.004%, Li 0.005%, and the balance is Cu.

[0035] The purity of Cu is greater than 99.9995%. The purity of Pd, Ru, Nb, and Ca is greater than 99.999%. The purity of Sc, Mg, B, In, Al, and Li is greater than 99.9%.

[0036] The method for preparing the copper alloy bonding wire for electronic packaging comprises the following steps:

[0037] (1) After the raw materials are uniformly mixed, they are refined at 1320° C. for 35 min under argon protection conditions, and cast into ingots to obtain copper alloy ingots;

[0038] (2) The copper alloy ingot is heated and melted by medium frequency induction heating in a nitrogen environment, and after heat preservation, refining and degassing, it is continuously drawn and cast into a copper alloy rod with a diameter of 5 mm, and the drawing temperature is 1150°C;

[0039] (3) After homogenizing annealing, the copper alloy rod is cooled to room temperature to obtain a homogenized annealed copper alloy rod; the homogenizing annealing conditions are: heating to 630°C at a heating rate of 14°C / min, keeping the temperature for 6 hours, cooling to 470°C at a cooling rate of 11°C / min, and keeping the temperature for 11 hours;

[0040] (4) The homogenized annealed copper alloy rod is drawn multiple times into a copper alloy bonding wire with a diameter of 0.6 mm;

[0041] (5) intermediate annealing of the copper alloy bonding wire, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 470° C., and the annealing rate is 90 m / min;

[0042] (6) drawing the copper alloy bonding wire that has undergone the first intermediate annealing into a copper alloy bonding wire with a diameter of 20 μm;

[0043] (7) The 20 μm copper alloy bonding wire is subjected to final annealing, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 580° C., and the annealing rate is 115 m / min;

[0044] (8) Clean and dry the surface to obtain copper alloy bonding wire.

[0045] The protective atmosphere used in steps (3), (5) and (7) is 95% N2+5% H2, and the gas flow rate is 6 L / min.

[0046] Example 2

[0047] The present embodiment provides a copper alloy bonding wire for electronic packaging, comprising the following raw materials in mass fractions: Pd 0.06%, Ru 0.12%, Nb 0.14%, Ca 0.09%, Sc 0.002%, Mg 0.004%, B 0.003%, In 0.001%, Al 0.003%, Li 0.002%, and the balance is Cu.

[0048] The purity of Cu is greater than 99.9995%. The purity of Pd, Ru, Nb, and Ca is greater than 99.999%. The purity of Sc, Mg, B, In, Al, and Li is greater than 99.9%.

[0049] The method for preparing the copper alloy bonding wire for electronic packaging comprises the following steps:

[0050] (1) After the raw materials are uniformly mixed, they are refined at 1300° C. for 25 min under argon protection conditions, and cast into ingots to obtain copper alloy ingots;

[0051] (2) The copper alloy ingot is heated and melted by medium frequency induction heating in a nitrogen environment, and after heat preservation, refining and degassing, it is continuously drawn and cast into a copper alloy rod with a diameter of 4 mm at a drawing temperature of 1100°C;

[0052] (3) After homogenizing annealing, the copper alloy rod is cooled to room temperature to obtain a homogenized annealed copper alloy rod; the homogenizing annealing conditions are: heating to 600°C at a heating rate of 13°C / min, keeping the temperature for 5 hours, cooling to 450°C at a cooling rate of 10°C / min, and keeping the temperature for 10 hours;

[0053] (4) Drawing the homogenized annealed copper alloy rod multiple times into a copper alloy bonding wire with a diameter of 0.4 mm;

[0054] (5) intermediate annealing of the copper alloy bonding wire, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 450° C., and the annealing rate is 80 m / min;

[0055] (6) drawing the copper alloy bonding wire that has undergone the first intermediate annealing into a copper alloy bonding wire with a diameter of 20 μm;

[0056] (7) The 20 μm copper alloy bonding wire is subjected to final annealing, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 550° C., and the annealing rate is 110 m / min;

[0057] (8) Clean and dry the surface to obtain copper alloy bonding wire.

[0058] The protective atmosphere used in steps (3), (5) and (7) is 95% N2+5% H2, and the gas flow rate is 5 L / min.

[0059] Example 3

[0060] The present embodiment provides a copper alloy bonding wire for electronic packaging, comprising the following raw materials in mass fractions: Pd 0.13%, Ru 0.17%, Nb 0.18%, Ca 0.15%, Sc 0.004%, Mg 0.008%, B 0.006%, In 0.003%, Al 0.005%, Li 0.005%, and the balance is Cu.

[0061] The purity of Cu is greater than 99.9995%. The purity of Pd, Ru, Nb, and Ca is greater than 99.999%. The purity of Sc, Mg, B, In, Al, and Li is greater than 99.9%.

[0062] The method for preparing the copper alloy bonding wire for electronic packaging comprises the following steps:

[0063] (1) After the raw materials are uniformly mixed, they are refined at 1350° C. for 40 min under argon protection conditions, and cast into ingots to obtain copper alloy ingots;

[0064] (2) The copper alloy ingot is heated and melted by medium frequency induction heating in a nitrogen environment, and after heat preservation, refining and degassing, it is continuously drawn and cast into a copper alloy rod with a diameter of 6 mm at a drawing temperature of 1200°C;

[0065] (3) After homogenizing annealing, the copper alloy rod is cooled to room temperature to obtain a homogenized annealed copper alloy rod; the homogenizing annealing conditions are: heating to 650°C at a heating rate of 15°C / min, keeping the temperature for 7 hours, cooling to 500°C at a cooling rate of 12°C / min, and keeping the temperature for 12 hours;

[0066] (4) The homogenized annealed copper alloy rod is drawn multiple times into a copper alloy bonding wire with a diameter of 0.8 mm;

[0067] (5) intermediate annealing of the copper alloy bonding wire, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 500° C., and the annealing rate is 100 m / min;

[0068] (6) drawing the copper alloy bonding wire that has undergone the first intermediate annealing into a copper alloy bonding wire with a diameter of 20 μm;

[0069] (7) The 20 μm copper alloy bonding wire is subjected to final annealing, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 600° C., and the annealing rate is 120 m / min;

[0070] (8) Clean and dry the surface to obtain copper alloy bonding wire.

[0071] The protective atmosphere used in steps (3), (5) and (7) is 95% N2+5% H2, and the gas flow rate is 8 L / min.

[0072] Example 4

[0073] The present embodiment provides a copper alloy bonding wire for electronic packaging, comprising the following raw materials in mass fractions: Pd 0.06%, Ru 0.17%, Nb 0.14%, Ca 0.15%, Sc 0.002%, Mg 0.008%, B 0.003%, In 0.003%, Al 0.003%, Li 0.005%, and the balance is Cu.

[0074] The purity of Cu is greater than 99.9995%. The purity of Pd, Ru, Nb, and Ca is greater than 99.999%. The purity of Sc, Mg, B, In, Al, and Li is greater than 99.9%.

[0075] The method for preparing the copper alloy bonding wire for electronic packaging comprises the following steps:

[0076] (1) After the raw materials are uniformly mixed, they are refined at 1300° C. for 40 min under argon protection conditions, and cast into ingots to obtain copper alloy ingots;

[0077] (2) The copper alloy ingot is heated and melted by medium frequency induction heating in a nitrogen environment, and after heat preservation, refining and degassing, it is continuously drawn and cast into a copper alloy rod with a diameter of 4 mm at a drawing temperature of 1200°C;

[0078] (3) After homogenizing annealing, the copper alloy rod is cooled to room temperature to obtain a homogenized annealed copper alloy rod; the homogenizing annealing conditions are: heating to 650°C at a heating rate of 13°C / min, keeping the temperature for 5 hours, cooling to 450°C at a cooling rate of 12°C / min, and keeping the temperature for 12 hours;

[0079] (4) Drawing the homogenized annealed copper alloy rod multiple times into a copper alloy bonding wire with a diameter of 0.4 mm;

[0080] (5) intermediate annealing of the copper alloy bonding wire, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 500° C., and the annealing rate is 80 m / min;

[0081] (6) drawing the copper alloy bonding wire that has undergone the first intermediate annealing into a copper alloy bonding wire with a diameter of 20 μm;

[0082] (7) The 20 μm copper alloy bonding wire is subjected to final annealing, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 550° C., and the annealing rate is 120 m / min;

[0083] (8) Clean and dry the surface to obtain copper alloy bonding wire.

[0084] The protective atmosphere used in steps (3), (5) and (7) is 95% N2+5% H2, and the gas flow rate is 5 L / min.

[0085] Example 5

[0086] The present embodiment provides a copper alloy bonding wire for electronic packaging, comprising the following raw materials in mass fractions: Pd 0.08%, Ru 0.13%, Nb 0.17%, Ca 0.10%, Sc 0.003%, Mg 0.005%, B 0.003%, In 0.002%, Al 0.003%, Li 0.005%, and the balance is Cu.

[0087] The purity of Cu is greater than 99.9995%. The purity of Pd, Ru, Nb, and Ca is greater than 99.999%. The purity of Sc, Mg, B, In, Al, and Li is greater than 99.9%.

[0088] The method for preparing the copper alloy bonding wire for electronic packaging comprises the following steps:

[0089] (1) After the raw materials are uniformly mixed, they are refined at 1330° C. for 30 min under argon protection conditions, and cast into ingots to obtain copper alloy ingots;

[0090] (2) The copper alloy ingot is heated and melted by medium frequency induction heating in a nitrogen environment, and after heat preservation, refining and degassing, it is continuously drawn and cast into a copper alloy rod with a diameter of 5 mm at a drawing temperature of 1180°C;

[0091] (3) After homogenizing annealing, the copper alloy rod is cooled to room temperature to obtain a homogenized annealed copper alloy rod; the homogenizing annealing conditions are: heating to 610°C at a heating rate of 13°C / min, keeping the temperature for 5 hours, cooling to 480°C at a cooling rate of 11°C / min, and keeping the temperature for 11 hours;

[0092] (4) The homogenized annealed copper alloy rod is drawn multiple times into a copper alloy bonding wire with a diameter of 0.7 mm;

[0093] (5) intermediate annealing of the copper alloy bonding wire, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 460° C., and the annealing rate is 90 m / min;

[0094] (6) drawing the copper alloy bonding wire that has undergone the first intermediate annealing into a copper alloy bonding wire with a diameter of 20 μm;

[0095] (7) The 20 μm copper alloy bonding wire is subjected to final annealing, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 570° C., and the annealing rate is 115 m / min;

[0096] (8) Clean and dry the surface to obtain copper alloy bonding wire.

[0097] The protective atmosphere used in steps (3), (5) and (7) is 95% N2+5% H2, and the gas flow rate is 7 L / min.

[0098] Comparative Example 1

[0099] The difference between this comparative example and Example 1 is that the ratio of raw materials is different.

[0100] A copper alloy bonding wire for electronic packaging comprises the following raw materials in mass fractions: Pd 0.20%, Ru 0.04%, Nb 0.9%, Ca 0.19%, Sc 0.003%, Mg 0.006%, B 0.004%, In 0.002%, Al 0.004%, Li 0.005%, and the balance is Cu.

[0101] Comparative Example 2

[0102] The difference between this comparative example and Example 1 is that the composition of the raw materials is different.

[0103] A copper alloy bonding wire for electronic packaging comprises the following raw materials in mass fractions: Pd 0.09%, Ru 0.15%, Nb 0.17%, Ca 0.11%, Ti 0.003%, Fe 0.006%, Cr 0.004%, W 0.002%, Ce 0.004%, Ga 0.005%, and the balance is Cu.

[0104] The purity of Ti, Fe, Cr, W, Ce and Ga is greater than 99.9%.

[0105] Comparative Example 3

[0106] The difference between this comparative example and Example 1 is that the preparation method is different.

[0107] The method for preparing the copper alloy bonding wire for electronic packaging comprises the following steps:

[0108] (1) After the raw materials are uniformly mixed, they are refined at 1320° C. for 35 min under argon protection conditions, and cast into ingots to obtain copper alloy ingots;

[0109] (2) The copper alloy ingot is heated and melted by medium frequency induction heating in a nitrogen environment, and after heat preservation, refining and degassing, it is continuously drawn and cast into a copper alloy rod with a diameter of 5 mm, and the drawing temperature is 1150°C;

[0110] (3) The copper alloy rod is drawn multiple times into a copper alloy bonding wire with a diameter of 0.6 mm;

[0111] (4) drawing the copper alloy bonding wire into a copper alloy bonding wire with a diameter of 20 μm;

[0112] (5) The 20 μm copper alloy bonding wire is subjected to final annealing, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 580° C., and the annealing rate is 115 m / min;

[0113] (6) Clean and dry the surface to obtain copper alloy bonding wire.

[0114] The protective atmosphere used in step (5) is 95% N2+5% H2, and the gas flow rate is 6 L / min.

[0115] Performance Testing

[0116] The performance tests were conducted on the bonding wires made of the same alloys in Examples 1-5 and Comparative Examples 1-3.

[0117] 1. Tensile test, sample length is 254mm, test speed is 25.4mm / min, and the breaking load BL and elongation EL are measured. Test equipment: instron3343 tensile testing machine. Vickers hardness tester is used to measure the hardness.

[0118] 2. HAST reliability: For the copper alloy bonding wires of Examples 1-5 and Comparative Examples 1-3, two commercially available high-selling copper alloy bonding wires were used as the control group (Control Group 1: Sichuan Winar Special Electronic Materials Co., Ltd., bonding copper wire, model TW-1, diameter 20μm. Control Group 2: Tanaka Precious Metals Group, bonding copper wire, model: CA-1, diameter 20μm.), they were bonded on the IC chip respectively, and the epoxy molding compound KH9200-3T was used to complete the plastic epoxy resin sealing to obtain the sample. The resistance A0 of the sample in the initial state was measured. The sample was placed at a temperature of 130°C and a relative humidity of 85%, and a HAST test was performed for 168 hours. The tested sample was measured by the DC four-terminal method to measure the solder joint interface resistance A1, and the resistance change rate was calculated: (A1-A0) / A0*100%.

[0119] 5. Aging resistance: The test conditions are: -40℃*30min-100℃*30min (conversion time is less than 20 seconds), which is one round of thermal shock. The test package is DIP in LED package, and the packaging material is epoxy plastic packaging material KH9200-3T. After each 50 cycles of thermal shock, observe whether the packaged sample can still light up, and record the number of aging rounds.

[0120] Table 1 Performance test results

[0121]

[0122]

[0123] The results show that the copper alloy bonding wires of Examples 1-5 have high breaking load BL and elongation EL, suitable hardness, good aging resistance, and are packaged with epoxy molding compound KH9200-3T. The HAST reliability test shows that the resistance change rate is low, indicating that the copper alloy bonding wires prepared in Examples 1-5 have good packaging effect with KH9200-3T materials, while commercially available copper alloy bonding wires are more likely to react or corrode with elements such as chlorine released by KH9200-3T materials, forming more non-conductive layers, resulting in a large increase in resistance, thereby affecting the reliability of the product.

[0124] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A copper alloy bonding wire for electronic packaging, characterized in that: The invention comprises the following raw materials in mass fractions: Pd 0.06-0.13%, Ru 0.12-0.17%, Nb 0.14-0.18%, Ca 0.09-0.15%, Sc 0.002-0.004%, Mg 0.004-0.008%, B 0.003-0.006%, In 0.001-0.003%, Al 0.003-0.005%, Li 0.002-0.005%, and the balance is Cu.

2. The method for preparing the copper alloy bonding wire for electronic packaging according to claim 1, characterized in that: The following steps are involved: (1) After the raw materials are mixed evenly, they are refined at 1300-1350°C for 25-40 minutes under argon protection conditions, and cast into ingots to obtain copper alloy ingots; (2) The copper alloy ingot is heated and melted in a nitrogen environment, and after heat preservation, refining and degassing, it is continuously drawn and cast into a copper alloy rod with a diameter of 4-6 mm; (3) After homogenizing annealing, the copper alloy rod is cooled to room temperature to obtain a homogenizing annealed copper alloy rod; (4) Drawing the homogenized annealed copper alloy rod multiple times into a copper alloy bonding wire with a diameter of 0.4-0.8 mm; (5) The copper alloy bonding wire is subjected to intermediate annealing, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 450-500 ° C, and the annealing rate is 80-100 m / min; (6) Drawing the copper alloy bonding wire after the first intermediate annealing into a copper alloy bonding wire with a diameter of 15 μm-50 μm; (7) Final annealing of 15 μm-50 μm copper alloy bonding wire, the effective length of the annealing furnace is 1000 mm, the annealing temperature is 550-600 ° C, and the annealing rate is 110-120 m / min; (8) Clean and dry the surface to obtain copper alloy bonding wire.

3. The method for preparing the copper alloy bonding wire for electronic packaging according to claim 2, characterized in that: The conditions for homogenization annealing in step (3) are: heating to 600-650°C at a heating rate of 13-15°C / min, keeping the temperature for 5-7h, cooling to 450-500°C at a cooling rate of 10-12°C / min, and keeping the temperature for 10-12h.

4. The method for preparing the copper alloy bonding wire for electronic packaging according to claim 2, characterized in that: The heating and melting in step (2) is performed by medium frequency induction heating.

5. The method for preparing the copper alloy bonding wire for electronic packaging according to claim 2, characterized in that: The casting temperature in step (2) is 1100-1200°C.

6. The method for preparing the copper alloy bonding wire for electronic packaging according to claim 2, characterized in that: The protective atmosphere used in steps (3), (5) and (7) is 95% N2 + 5% H2.

7. The use of the copper alloy bonding wire for electronic packaging according to claim 1, characterized in that: The copper alloy bonding wire and the epoxy molding compound KH9200-3T are used for DIP packaging at the same time.

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