Preparation method of copper-phosphorus alloy

Abstract

The invention relates to a preparation method of a copper-phosphorus alloy, in particular to the field of copper-phosphorus alloys, and the preparation method comprises the following steps: carrying out vacuum melting on a copper material, adding a copper-phosphorus intermediate alloy, then carrying out cooling and heating operations for at least three times, and casting to obtain the copper-phosphorus alloy, wherein the cooling and heating operation comprises cooling, first heat preservation, heating and second heat preservation which are carried out in sequence; the initial temperature of cooling ranges from 1200 DEG C to 1300 DEG C; the cooling range is 90 DEG C to 120 DEG C; the temperature rise range is 90 DEG C to 120 DEG C. According to the preparation method provided by the invention, by adopting the designed preparation process and by virtue of specific temperature lowering and raising operation, preparation of the copper-phosphorus alloy cast ingot with uniform phosphorus distribution and uniform grain distribution is realized, and the utilization effect of the copper-phosphorus alloy is favorably improved.

Description

Technical Field

[0001] The invention relates to the field of copper alloys, and in particular to a method for preparing a copper-phosphorus alloy. Background Art

[0002] At present, high-purity copper-phosphorus alloy (P content is 100-600ppm) is the raw material for manufacturing copper-phosphorus alloy anodes for semiconductors, which are mainly used for the wiring of integrated circuit chips. High-purity copper-phosphorus alloy ingots require good uniformity of alloy elements such as phosphorus content and uniform original grains of the ingots.

[0003] For example, CN102485924A discloses a method for preparing a phosphor copper anode for an integrated circuit, which comprises using high-purity graphite as a crucible and a mold material, melting a high-purity copper ingot with a purity of 99.99% or more in a high-vacuum medium-frequency induction melting furnace, adding a phosphor copper intermediate alloy containing 6-16wt.% phosphorus at 1150-1300°C, wherein the weight ratio of the phosphor copper intermediate alloy to the high-purity copper ingot is 1:(50-600), and the mixture is kept at 1150-1300°C for 20-30min, and then allowed to stand for 20min, and then poured into a graphite mold to obtain a phosphor copper alloy ingot; after the ingot riser is cut off from the obtained phosphor copper alloy ingot, the ingot is subjected to multi-directional forging and rolling, and subjected to recrystallization treatment at 300-600°C for 0.5-12h, and then subjected to surface treatment, and mechanically processed into a phosphor copper anode for an integrated circuit.

[0004] For example, CN106381410A discloses a preparation method of a phosphor copper anode for integrated circuits, a smelting furnace and a system thereof, the method comprising the following steps: using grade A electrolytic copper with a copper content of more than 99.99% and a high-phosphorus copper alloy with a single impurity of no more than 0.003% as raw materials; vacuum smelting and continuous casting: using a vacuum smelting furnace to synthesize and pull copper and phosphorus from the grade A electrolytic copper and the high-phosphorus copper alloy to obtain a phosphor copper alloy ingot; microcrystal treatment: performing microcrystal treatment on the phosphor copper alloy ingot under a vacuum state; cold processing and forming: processing and forming the phosphor copper alloy ingot after microcrystal treatment at room temperature to obtain a phosphor copper anode for integrated circuits.

[0005] During the melting and casting process of high-purity copper-phosphorus alloy ingots, P is easy to volatilize and will cause segregation of alloy elements. In addition, there are many specifications according to different requirements for P element content, usually hundreds of ppm. The upper and lower limits of P element content requirements are generally ±50ppm or even smaller. This requirement is inconsistent with the characteristics of P element in the melting and casting process. Therefore, how to accurately control P content, reduce P loss, and improve the original ingot grain is the key. However, the currently used copper-phosphorus alloy preparation process still has the defects of severe phosphorus segregation and uneven ingot grain distribution. Summary of the invention

[0006] In view of the problems existing in the prior art, the object of the present invention is to provide a method for preparing a copper-phosphorus alloy to solve the defects of severe phosphorus segregation and uneven grain distribution of the ingot obtained in the copper-phosphorus alloy preparation process.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for preparing a copper-phosphorus alloy, the preparation method comprising:

[0009] The copper material is vacuum melted, a copper-phosphorus master alloy is added, and then the temperature is lowered and raised for at least 3 times, and the copper-phosphorus alloy is obtained by casting;

[0010] Among them, the temperature reduction and heating operation includes cooling, first heat preservation, heating and second heat preservation in sequence; the starting temperature of the cooling is 1200-1300℃; the range of the cooling is 90℃-120℃; the range of the heating is 90℃-120℃.

[0011] The preparation method provided by the present invention realizes the preparation of copper-phosphorus alloy ingots with uniform phosphorus distribution and uniform grain distribution by adopting a designed preparation process and relying on specific temperature reduction and heating operations, which is beneficial to improving the utilization effect of copper-phosphorus alloys.

[0012] As a preferred technical solution of the present invention, the purity of the copper material is ≥99.99%.

[0013] As a preferred technical solution of the present invention, the absolute vacuum degree of the vacuum melting is ≤0.08Pa.

[0014] As a preferred technical solution of the present invention, the temperature of the vacuum melting is 1100°C-1200°C.

[0015] As a preferred technical solution of the present invention, the vacuum melting time is ≥30 min.

[0016] As a preferred technical solution of the present invention, the first insulation time is 30min-45min.

[0017] As a preferred technical solution of the present invention, the second insulation time is 30min-45min.

[0018] As a preferred technical solution of the present invention, the temperature of the molten metal used in the casting is 1200°C-1300°C.

[0019] As a preferred technical solution of the present invention, the casting method includes semi-continuous casting.

[0020] As a preferred technical solution of the present invention, the casting speed is 10-40 mm / min.

[0021] Compared with the prior art solutions, the present invention has the following beneficial effects:

[0022] The preparation method provided by the present invention realizes the preparation of a high-performance copper-phosphorus alloy by means of a specific temperature reduction and heating process in combination with casting. The phosphorus element of the obtained copper-phosphorus alloy has good uniformity, uniform grain size, and a grain size range of ≤0.13 mm, thereby avoiding the occurrence of uneven grain distribution such as an equiaxed crystal region in the center, a coarse columnar crystal region in the outside, and a fine crystal region in the outermost layer, and significantly reducing shrinkage defects inside the ingot. DETAILED DESCRIPTION

[0023] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0024] This embodiment provides a method for preparing a copper-phosphorus alloy, the preparation method comprising:

[0025] The copper material is vacuum melted, a copper-phosphorus master alloy is added, and then the temperature is lowered and raised for at least 3 times, and the copper-phosphorus alloy is obtained by casting;

[0026] Among them, the temperature reduction and heating operation includes cooling, first heat preservation, heating and second heat preservation in sequence; the starting temperature of the cooling is 1200-1300℃; the range of the cooling is 90℃-120℃; the range of the heating is 90℃-120℃.

[0027] In the present invention, the amount of copper-phosphorus master alloy added is determined based on the phosphorus content of the required copper-phosphorus alloy, which is not required by the present invention.

[0028] In the present invention, the purity of the prepared high-purity copper-phosphorus alloy is ≥99.99%, and the P content is 100-600ppm.

[0029] In the present invention, cooling refers to lowering the temperature to any temperature within the range of 90-120° C. based on the temperature after adding the copper-phosphorus master alloy, and then performing a first heat preservation and a temperature increase;

[0030] Herein, heating refers to raising the temperature to any temperature within the range of 90-120°C based on the temperature of the first insulation.

[0031] In the present invention, the starting temperature of the cooling is 1200-1300°C, for example, it can be 1200°C, 1220°C, 1240°C, 1260°C, 1280°C or 1300°C, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0032] In the present invention, the temperature reduction range is 90°C-120°C, for example, it can be 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0033] In the present invention, the temperature rise range is 90°C-120°C, for example, it can be 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0034] Wherein, the purity of the copper material is ≥99.99%.

[0035] In the present invention, the copper material used can be selected from raw materials such as copper-phosphorus alloy and / or high-purity copper according to the target alloy composition requirements.

[0036] The absolute vacuum degree of the vacuum melting is ≤0.08Pa, for example, it can be 0.08Pa, 0.07Pa, 0.06Pa, 0.05Pa, 0.04Pa, 0.03Pa, 0.02Pa or 0.01Pa, but is not limited to the listed values, and other values ​​not listed within the range also meet the requirements.

[0037] Wherein, the temperature of the vacuum melting is 1100°C-1200°C, for example, it can be 1100°C, 1110°C, 1120°C, 1130°C, 1140°C, 1150°C, 1160°C, 1170°C, 1180°C, 1190°C or 1200°C, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0038] The vacuum melting time is ≥30 min, for example, it can be 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min or 100 min, but is not limited to the listed values, and other values ​​not listed within the range also meet the requirements.

[0039] Among them, the first insulation time is 30min-45min, for example, it can be 30min, 31min, 32min, 33min, 34min, 35min, 36min, 37min, 38min, 39min, 40min, 41min, 42min, 43min, 44min or 45min, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0040] Among them, the second insulation time is 30min-45min, for example, it can be 30min, 31min, 32min, 33min, 34min, 35min, 36min, 37min, 38min, 39min, 40min, 41min, 42min, 43min, 44min or 45min, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0041] Wherein, the casting method includes semi-continuous casting.

[0042] Among them, the temperature of the molten metal used for casting is 1200℃-1300℃, for example, it can be 1200℃, 1210℃, 1220℃, 1230℃, 1240℃, 1250℃, 1260℃, 1270℃, 1280℃, 1290℃ or 1300℃, but is not limited to the listed values, and other unlisted values ​​within this range also meet the requirements.

[0043] The casting speed is 10-40 mm / min, for example, 10 mm / min, 15 mm / min, 20 mm / min, 25 mm / min, 30 mm / min, 35 mm / min or 40 mm / min, but is not limited to the listed values. Other values ​​not listed within the range also meet the requirements.

[0044] Further, in order to illustrate the good performance of the copper-phosphorus alloy obtained by the preparation method provided by the present invention, the following practical examples are used for illustration, as follows:

[0045] Example 1

[0046] This embodiment provides a method for preparing a copper-phosphorus alloy, the preparation method comprising:

[0047] The copper material is vacuum melted, a copper-phosphorus master alloy is added, and then the temperature is lowered and raised three times, and a copper-phosphorus alloy (target phosphorus content is 300 ppm) is obtained by casting;

[0048] The purity of the copper material is 99.99%;

[0049] The absolute vacuum degree of the vacuum melting is 0.02 Pa, the temperature is 1150° C., and the time is 40 min;

[0050] The temperature reduction and heating operation includes cooling, first heat preservation, heating and second heat preservation in sequence; the starting temperature of the cooling is 1250°C; the amplitude of the cooling is 100°C; the time of the first heat preservation is 40 minutes; the amplitude of the heating is 100°C; the time of the second heat preservation is 40 minutes;

[0051] The temperature of the molten metal used in the casting is 1250° C.; the casting method includes semi-continuous casting; and the casting speed of the casting is 20 mm / min.

[0052] Example 2

[0053] This embodiment provides a method for preparing a copper-phosphorus alloy, the preparation method comprising:

[0054] The copper material is vacuum melted, a copper-phosphorus master alloy is added, and then the temperature is lowered and raised three times, and a copper-phosphorus alloy (target phosphorus content is 500ppm) is obtained by casting;

[0055] The purity of the copper material is 99.99%;

[0056] The absolute vacuum degree of the vacuum melting is 0.04 Pa, the temperature is 1180° C., and the time is 30 min;

[0057] The temperature reduction and heating operation includes cooling, first heat preservation, heating and second heat preservation in sequence; the starting temperature of the cooling is 1250°C; the amplitude of the cooling is 110°C; the time of the first heat preservation is 35 minutes; the amplitude of the heating is 110; the time of the second heat preservation is 35 minutes;

[0058] The temperature of the molten metal used in the casting is 1280° C.; the casting method includes semi-continuous casting; and the casting speed of the casting is 30 mm / min.

[0059] Example 3

[0060] This embodiment provides a method for preparing a copper-phosphorus alloy, the preparation method comprising:

[0061] The copper material is vacuum melted, a copper-phosphorus master alloy is added, and then the temperature is lowered and raised four times, and a copper-phosphorus alloy (target phosphorus content is 100 ppm) is obtained by casting;

[0062] The purity of the copper material is 99.99%;

[0063] The absolute vacuum degree of the vacuum melting is 0.05 Pa, the temperature is 1100° C., and the time is 50 min;

[0064] The temperature reduction and heating operation includes cooling, first heat preservation, heating and second heat preservation in sequence; the starting temperature of the cooling is 1200°C; the amplitude of the cooling is 90°C; the time of the first heat preservation is 45 minutes; the amplitude of the heating is 120°C; the time of the second heat preservation is 30 minutes;

[0065] The temperature of the molten metal used in the casting is 1200° C.; the casting method includes semi-continuous casting; and the casting speed of the casting is 10 mm / min.

[0066] Example 4

[0067] This embodiment provides a method for preparing a copper-phosphorus alloy, the preparation method comprising:

[0068] The copper material is vacuum melted, a copper-phosphorus master alloy is added, and then the temperature is lowered and raised three times, and a copper-phosphorus alloy (target phosphorus content is 600 ppm) is obtained by casting;

[0069] The copper material is 99.99%;

[0070] The absolute vacuum degree of the vacuum melting is 0.08 Pa, the temperature is 1200° C., and the time is 30 min;

[0071] The temperature reduction and temperature increase operation includes temperature reduction, first heat preservation, temperature increase and second heat preservation in sequence; the starting temperature of the temperature reduction is 1300°C; the temperature reduction amplitude is 120°C; the first heat preservation time is 30 minutes; the temperature increase amplitude is 90°C; the second heat preservation time is 45 minutes;

[0072] The temperature of the molten metal used in the casting is 1300° C.; the casting method includes semi-continuous casting; and the casting speed is 40 mm / min.

[0073] Example 5

[0074] The only difference from Example 1 is that the temperature of the molten metal used for casting is 1100°C.

[0075] Example 6

[0076] The only difference from Example 1 is that the temperature of the molten metal used for casting is 1380°C.

[0077] Comparative Example 1

[0078] The only difference from Example 1 is that no temperature reduction and heating operation is performed, that is, after melting, the temperature is directly raised to the temperature of the molten metal used for casting for casting.

[0079] Comparative Example 2

[0080] The only difference from Example 1 is that the temperature reduction and heating operation is performed only twice.

[0081] Comparative Example 3

[0082] The only difference from Example 1 is that the temperature is reduced by 200°C.

[0083] Comparative Example 4

[0084] The only difference from Example 1 is that the temperature is reduced by 40°C.

[0085] Comparative Example 5

[0086] The only difference from Example 1 is that the temperature is increased by 200°C.

[0087] Comparative Example 6

[0088] The only difference from Example 1 is that the temperature rise is 40°C.

[0089] The macroscopic grain index (the grain size is measured according to the method for measuring the average grain size of metals in GB 6394-2017, and the range is calculated) and the P distribution results of the copper-phosphorus alloy product obtained in the above embodiment are shown in Table 1 below, wherein the P distribution is the detection of the P element content of the copper-phosphorus alloy product by GMDS. During the detection process, 6 detection points are randomly selected along the length and width directions of the sample to test the P element content, thereby obtaining the uniformity index.

[0090] Table 1

[0091]

[0092]

[0093] As can be seen from Table 1, the preparation method provided by the present invention, by adopting a designed preparation process and with the help of specific temperature reduction and heating operations, achieves the preparation of copper-phosphorus alloy ingots with uniform phosphorus distribution and uniform grain size distribution, which is beneficial to improving the utilization effect of copper-phosphorus alloys.

[0094] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0095] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0096] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing a copper-phosphorus alloy, characterized in that: The preparation method comprises: The copper material is vacuum melted, a copper-phosphorus master alloy is added, and then the temperature is lowered and raised for at least 3 times, and the copper-phosphorus alloy is obtained by casting; Among them, the temperature reduction and heating operation includes cooling, first heat preservation, heating and second heat preservation in sequence; the starting temperature of the cooling is 1200-1300℃; the range of the cooling is 90℃-120℃; the range of the heating is 90℃-120℃.

2. The preparation method according to claim 1, characterized in that The purity of the copper material is ≥99.99%.

3. The preparation method according to claim 1, characterized in that: The absolute vacuum degree of the vacuum melting is ≤0.08Pa.

4. The preparation method according to claim 1, characterized in that: The vacuum melting temperature is 1100°C-1200°C.

5. The preparation method according to claim 1, characterized in that: The vacuum melting time is ≥30 min.

6. The preparation method according to claim 1, characterized in that: The first insulation time is 30 min-45 min.

7. The preparation method according to claim 1, characterized in that: The second insulation time is 30min-45min.

8. The preparation method according to claim 1, characterized in that: The temperature of the molten metal used in the casting is 1200°C-1300°C.

9. The preparation method according to claim 1, characterized in that: The casting method includes semi-continuous casting.

10. The preparation method according to claim 1, characterized in that: The casting speed of the casting is 10-40 mm / min.

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