KR930006292B1 - Cupper alloy for electronic articles and its making process - Google Patents

Abstract

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Description

Copper alloy for electronic device and manufacturing method thereof

1 to 3 are each a process diagram showing a manufacturing method of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to copper alloys for electronic devices used in lead frame materials, connectors, and the like of integrated circuits, and methods of manufacturing the same. Materials used for electronic devices are required to be more excellent in corrosion resistance and heat resistance in addition to high strength and high conductivity in accordance with miniaturization of components and high reliability.

Conventionally, as an example of a lead frame material of an integrated circuit, it is largely divided into an iron-based alloy (Fe-42% Ni) and a copper-based material, but in recent years, a change has been made to a copper-based material to remove heat from heat generation due to high integration. . However, on the other hand, as the miniaturization progresses, the material itself is also thinned and insufficient in the strength level of the conventional copper alloy. Therefore, 42 alloys are still used in the GFP (Q uard Feat Package) type IC package.

Among these trends, a material having a strength equivalent to 42 alloys, that is, a strength equivalent to 70 kgf / mm 2 in tensile strength, and an electrical conductivity of 30% or more is required as a standard that can satisfy a wide range of demands.

On the other hand, some of the connectors and the like are desired to have a higher spring characteristic for thinning the material by miniaturization, and have higher electrical conductivity than phosphor bronze and higher strength levels.

Conventional copper alloys for electronic devices include CDA (Copper Development Association) C19400 alloys and high-conductivity types such as Cu-0.1% Sn and Cu-0.1% Fe (tensile strength is about 50kgf / mm2 or less, but the electrical conductivity is 60% IACS or more). ) Or high-strength type such as phosphor bronze (strength level is 42 alloy, but electrical conductivity is less than 20% IACS), and high-strength materials include expensive beryllium copper alloy.

However, in terms of electrical conductivity, strength level, and price, which are required in fields such as lead frames and connectors, there is a single piece, which is not a satisfactory situation.

An object of the present invention is to solve the above problems, to provide a copper alloy for an electronic device having excellent properties in both strength and electrical conductivity and a method of manufacturing the same.

The object of the present invention is achieved by the following copper alloy for electronic equipment. In other words,

(1) Copper alloys for electronic equipment containing 1.0-8% nickel, 0.1-0.8% phosphorus and 0.06-1% silicon by weight, with the remainder being copper and unavoidable impurities.

In other words, the inevitable impurities here do not industrially have 100% purity such as Cu, Ni, P, Si, and Zn used as raw materials, but are mixed with trace amounts of impurities. For this reason, the substance which mixes without intentional addition is shown.

(2) Copper alloys for electronic equipment containing 1.0 to 8% nickel, 0.1 to 0.8% phosphorus and 0.06 to 1% silicon, the remainder being copper and unavoidable impurities, and oxygen content of 20 ppm or less.

(3) Copper alloys for electronic equipment containing 1.0 to 8% nickel, 0.1 to 0.8% phosphorus, 0.06 to 1% silicon and 0.03 to 0.5% zinc, with the remainder being copper and unavoidable impurities.

(4) For electronic devices with 1.0% to 8% nickel, 0.1% to 0.8% phosphorus, 0.06% to 1% silicon and 0.03% to 0.5% zinc, the remainder being copper and unavoidable impurities, and oxygen content of 20ppm or less Achieved by copper alloy.

Moreover, the objective of this invention is achieved by the following manufacturing method of the copper alloy for electronic devices. In other words,

(5) A copper alloy containing 1.0 to 8% nickel, 0.1 to 0.8% phosphorus, and 0.06 to 1% silicon by weight, the remainder being copper and unavoidable impurities, before Copper alloy for electronic devices that performs at least one time heating in the temperature range or quench in water or oil, and then at least one time heating process in the temperature range of 350 ~ 500 ℃ for at least one time regardless of cold processing. Manufacturing method.

(6) A copper alloy containing 1.0 to 8% nickel, 0.1 to 0.8% phosphorus, and 0.06 to 1% silicon by weight, the remainder being copper and unavoidable impurities, before the final finish rolling at 750-950 ° C. A method of manufacturing a copper alloy for an electronic device which is heated at a temperature range for at least 1 minute and then gradually cooled at 4 ° C / min or less.

(7) A copper alloy containing 1.0-8% nickel by weight, 0.1-0.8% phosphorus, 0.06-1% silicon by weight, and the remainder being copper and unavoidable impurities, before the final finishing rolling at 750-950 ° C. After heating for 1 minute or more in the temperature range, to 500 ℃ to cool at 1 ℃ / min or more, 500 to 350 ℃ is maintained for at least 1 hour or more, the manufacturing method of the copper alloy for electronic devices.

(8) Final finishing of a copper alloy containing 1.0 to 8% nickel, 0.1 to 0.8% phosphorus, 0.06 to 1% silicon, 0.03 to 0.5% zinc, and the remainder being copper and unavoidable impurities in weight percent Process of quenching in water or oil by heating at least 1 minute in the temperature range of 750 ~ 950 ℃ before rolling and then heating at least 10 minutes in the temperature range of 350 ~ 500 ℃ regardless of cold processing. A method of manufacturing a copper alloy for an electronic device that is executed more than once.

(9) Final finishing copper alloy containing 1.0-8% nickel, 0.1-0.8% phosphorus, 0.06-1% silicon, 0.73-0.5% zinc, the remainder being copper and unavoidable impurities in weight percent A method for producing a copper alloy for electronic equipment, which is heated at a temperature range of 750 ° C. to 950 ° C. for at least 1 minute, and then gradually cooled at 4 ° C./min or less before rolling.

(l0) wt% 1.0-8% nickel, 0.1-0.8% phosphorus, 0,06-1% silicon, 0.03-0.5% zinc, the remainder being copper and inevitable impurities After heating the copper alloy for 1 minute or more in the temperature range of 750 ~ 950 ℃ before final finishing rolling, it is cooled to 1 ℃ / min up to 500 ℃, and maintained or gradually cooled at least 1 hour between 570 ~ 350 ℃. It is achieved by a method for producing a copper alloy.

Next, the reason for the addition of the alloy component constituting the copper alloy for an electronic device of the present invention and the reason for limiting the composition range will be described.

Nickel, phosphorus, and silicon are within a range in which their elements efficiently form intermetallic compounds to improve the strength and lower the conductivity, and the lower limit of nickel is less than this and the intermetallic compound is less and the strength is less improved. This is because, if it exceeds 8%, the improvement of the strength level is less effective than the compounding amount, and there is a tendency that the electrical conductivity is lowered and the heat resistance of the solder plating is lowered along with the decrease in workability. The relationship between the ranges of nickel, phosphorus and silicon amounts is that when Ni: P is about 5: 1 and Ni: Si is about 4: 1 by weight, the level of strength and electrical conductivity is the best, and this is an intermetallic compound. It is almost equivalent to Ni ₅ P ₂ or Ni ₂ Si. Therefore, the amounts of phosphorus and silicon ranged from this weight ratio.

Zinc, an additive element, is effective in suppressing the deterioration of reliability such as peeling of the solder layer in a high temperature environment after lead crystal or solder plating, and the lower limit is 0.03% of the minimum required amount. 0.5% was set.

As for the oxygen content, the upper limit was set to 20 ppm as a range in which the occurrence of plating swelling was not recognized by the heating test (450 ° C. × 5 min) after Ag plating in the evaluation of Ag plating adhesion to the material.

Next, a manufacturing method is demonstrated with reference to drawings.

1 is a process chart showing the manufacturing methods (5) and (8). In the manufacturing method (5), cold working is performed on copper alloy (W) containing 1.0-8% nickel, 7.01-0.8% phosphorus, 0.06-1% silicon by weight, and the remainder being copper and unavoidable impurities. And the heat treatment was repeated, and in the manufacturing method (8), 1.0 to 8% nickel, 0.1 to 0.7% phosphorus, 0.06 to 1% silicon, 0.03 to 0.5% zinc, Cold processing and heat treatment are repeated for copper alloy (W) which is made of copper and unavoidable impurities. At this time, before final finishing rolling, it heats more than 1 minute at the temperature of 750-950 degreeC in process (A), and then quenches in water or oil in process (B). The cooled product is subjected to cold working in step (C) or not, and in step (D), at a temperature range of 350-500 ° C. for 10 minutes or more, and if necessary, cold working in step (E). To produce a copper alloy for electronic devices. The heat treatment as the step (D) and the cold working as the step (E) to be carried out as necessary may be performed two or more times.

2 is a process chart showing the manufacturing methods (6) and (9). In the manufacturing method (6), cold work is performed on copper alloy (W) containing 1.0-8% nickel by weight, 0.01-0.8% phosphorus, 7.06-1% silicon, and the remainder being copper and unavoidable impurities. And heat treatment was repeated, and in the manufacturing method (9), 1.0 to 8% nickel, 0.1 to 0.8% phosphorus, 0.06 to 1% silicon, 0.03 to 0.5% zinc, Cold processing and heat treatment are repeated for copper alloy (W) which is made of copper and unavoidable impurities. At this time, before the final finishing rolling (A) step is heated at a temperature of 750 ~ 950 ℃ for 1 minute or more. Subsequently, in step (B2), the copper alloy is gradually cooled at a cooling rate of 4 ° C./min or less.

3 is a process chart showing the manufacturing method of the manufacturing method (7) and (10). In the manufacturing method (7), cold work is performed on copper alloy (W) containing 1.0-8% nickel by weight, 0.1-0.8% phosphorus, 0.06-1% silicon, and the remainder being copper and inevitable impurities. And heat treatment was repeated, and in the manufacturing method (10), 1.0 to 8% nickel, 0.1 to 0.8% phosphorus, 0.06 to 0.1% silicon, 0.03 to 0.5% zinc, Cold processing and heat treatment are repeated for copper alloy (W) which is made of copper and unavoidable impurities. At this time, before the final finish rolling (A) step is heated for 1 minute or more at a temperature of 750 ~ 950 ℃. The heat treated product was cooled to 500 ° C. or more at 1 ° C./min or more in the step (B ₃ ), and then maintained or gradually cooled to a predetermined temperature for at least 1 hour in the temperature range of 500 to 350 ° C. in the step (C 3). Manufacture copper alloys for electronic devices.

Hereinafter, an embodiment of the present invention will be described.

First, in order to manufacture Sample Nos. 1 to 11, each component was dissolved in a high frequency electric furnace, poured into a casting mold having a thickness of 20 mm, the surface was cut, repeated cold rolling and heat treatment, and the final 50% cold working was performed. To a plate shape having a thickness of 0.25 mm. The heat treatment before final finishing rolling was performed at 800 ° C. for 30 minutes, then quenched in water, and then baked again at 450 ° C. for 2 hours.

Table 1 shows examples of various properties of the material of the present invention and the comparative material.

TABLE 1

1) The time until fracture was measured by ammonia stress corrosion resistance test.

[Exam conditions ]

Bending stress: 30kfg / ㎠, Test temperature: 40 ℃

Atmosphere: A commercially available ammonia reagent grade 1 is diluted with the same amount of water and placed in the bottom of the desiccator dryer, exposing the sample to the reagent atmosphere.

2) The sample was immersed in the molten 9/1 solder, and after soldering, the sample was kept at a high temperature of 150 DEG C. Then, the time until the peeling or the like occurred by closely bending the soldered portion was measured.

3) After 8-micrometer-thick Ag plating was performed, heating was performed at 350 ° C. for 5 minutes, and the presence or absence of swelling due to peeling of the plating was examined.

As a result of Table 1, compared with the composition composed only of Cu-Ni-P, a higher strength level is obtained when Si is added, and the higher the amount of Ni, P, and Si blended, the more significant the improvement in strength is.

However, on the other hand, the fall of electric conductivity is recognized as a compounding quantity is great. For this reason, the quantity of Ni, P, and Si was determined in the said range by the relationship of these intensity | strength and electrical conductivity.

Regarding the O ₂ content, the swelling of the plating was recognized in the heating test after Ag plating for samples No. 7 and No. 10 exceeding 20 ppm, so the upper limit was set to 20 ppm.

It is recognized that the heat resistance of the solder decreases as the content of Ni, P, and Si increases, but as a result of comparing the samples No. 5 and No. 11, No. 11 containing 0.15% of Zn improved the solder heat resistance. Therefore, the improvement effect by Zn is recognized. On the other hand, in sample No. 9 having a high Zn content, stress corrosion cracking easily occurred, so the content of Zn was limited to 0.03-0.5%.

Stress corrosion cracking is the cracking of alloying materials caused by the joint action of stress and corrosion, and when the material is prone to corrosion due to stress under tensile stress and its material is in a unique corrosive environment. , This crack occurs. Such cracking becomes a practical problem for austenitic stainless steels, copper alloys (mainly brass) when ammonia is present in a liquid containing chlorine ions, and strong aluminum alloys in a humid atmosphere.

Since the copper alloy of the present invention contains nickel, phosphorus and silicon, it has high strength level and excellent electrical conductivity, which is very effective for miniaturization of electronic component parts, and is not limited to the lead frame material of the integrated circuit. It is not only applicable to a wide range of applications such as switches and switches, but also useful as an inexpensive copper alloy.

In addition, since the copper alloy containing zinc has little decrease in heat resistance, the strength level can be further increased.

Next, the Example of the manufacturing method of this invention is described.

Based on the Cu-Ni-P-Si alloy and the Cu-Ni-P-Si-Zn alloy of the component ratio shown in Table 2, the copper alloy for electronic devices was manufactured by the manufacturing method of this invention and a comparative example.

In order to manufacture Sample Nos. 12 to 23, each component was dissolved in a high frequency electric furnace, poured into a casting mold having a thickness of 20 mm, and the surface was shaved, followed by cold rolling and heat treatment, followed by cold working at the final 50%. It finished in the plate shape of 0.25 mm.

The conditions such as heat treatment are as shown in Table 1, and Sample No. 12, Sample No. 14, Sample No. 17 and Sample No. 18 were 0.5 mm thick and heated at 800 ° C. for 30 minutes, and then After quenching and cold working to a thickness of 0.25 mm, the mixture was heated at 450 ° C. for 2 hours and then slowly cooled in a furnace. Sample No. 13 was heated and quenched in the same manner as Sample No. 12, and then heated at 450 ° C. for 2 hours, gradually cooled in a furnace, and cold worked to a thickness of 0.25 mm.

Sample Ne.15 and Sample No. 27 were heated similarly to Sample No. 12, and then gradually cooled in a furnace such that the maximum value of the cooling rate was 2.5 ° C./minute, and cold worked to 0.25 mm in thickness. Sample No. 16 was heated in the same manner as Sample No. 12, and then cooled to 450 ° C. for 30 minutes, held at 450 ° C. for 2 hours in this state, gradually cooled in a furnace, and cold worked to a thickness of 0.25 mm. Sample No. 19 was heated for 30 minutes after heating 1.5 mm thick for 30 minutes, cold working to 0.5 mm thick, then heating at 450 ° C. for 2 hours, and slowly cooling in a furnace to cold working 0.25 mm.

As a comparative example, Sample No. 22 was 0.5 mm thick, heated at 700 ° C. for 1 hour, quenched in water, and cold worked to 0.25 mm thick. In addition, sample No. 23 was heated at 450 ° C. for 2 hours after heating, quenching, and cold working similarly to sample No. 22, and was gradually cooled in the furnace.

Table 2 shows the results obtained by measuring the tensile strength and the electrical conductivity of the sample obtained as described above.

TABLE 2

From the results in Table 2, it is clear that the strength higher than the samples No. 22 and No. 23 of the comparative example is obtained by adopting the production method according to the present invention. Moreover, in the comparative example of the Example of sample No.12,13,15,16, it shows that the manufacturing method (5) is more excellent in intensity | strength among manufacturing methods (5)-(7).

In addition, heating at 150 to 450 ° C. for at least 3 minutes as a distortion freezing bake to remove the internal distortion during rolling after the final rolling is more effective for improving the spring characteristics and workability.

According to the present invention, by performing specific heat treatment on a Cu-Ni-P-Si alloy and a Cu-Ni-P-Si-Zn alloy, a copper alloy for electronic devices having both high strength and high conductivity can be obtained. Very useful for miniaturization.

Claims (10)

A copper alloy for electronic equipment containing 1.0-8% nickel, 0.1-0.8% phosphorus and 0.06-1% silicon by weight, with the remainder being copper and inevitable impurities. A copper alloy for electronic equipment containing 1.0-8% nickel, 0.1-0.8% phosphorus and 0.06-1% silicon by weight, the remainder being copper and unavoidable impurities, and having an oxygen content of 20 ppm or less. A copper alloy for electronic equipment containing 1.0 to 8% by weight, 0.1 to 0.8% phosphorus, 0.06 to 1% silicon, and 0.03 to 0.5% zinc, and the remainder being copper and unavoidable impurities. Electromagnetic characterized by containing 1.0 to 8% by weight of nickel, 0.1 to 0.8% of phosphorus, 0.06 to 1% of silicon and 0.03 to 0.5% of zinc, the remainder being copper and unavoidable impurities, and oxygen content of 20 ppm or less Copper alloy for use. A copper alloy containing 1.0-8% nickel by weight, 0.1-0.8% phosphorus and 0.06-1% silicon by weight, the remainder being copper and unavoidable impurities, in the temperature range of 750-950 ° C. before final finishing rolling. A method of manufacturing a copper alloy for an electronic device, characterized by performing a step of quenching in water or oil by heating for 1 minute or more, and then heating for 10 minutes or more in a temperature range of 350 to 500 ° C. A copper alloy containing 1.0-8% nickel by weight, 0.1-0.8% phosphorus and 0.06-1% silicon by weight, with the remainder being copper and unavoidable impurities, at 750-950 ° C and temperature range before final finishing rolling A method of producing a copper alloy for electronic equipment, characterized by heating at least 1 minute and then gradually cooling at 4 ° C / minute or less. A copper alloy containing 1.0-8% by weight, nickel, 0.1-0.8% phosphorus and 0.06-1% silicon by weight, the remainder being copper and unavoidable impurities, in the temperature range of 750-950 ° C. before final finishing rolling. After heating for 1 minute or more, it cools to 1 degree-C / min or more to 500 degreeC, and maintains or cools gradually at least 1 hour between 500-350 degreeC, The manufacturing method of the copper alloy for electronic devices. A copper alloy containing 1.0 to 8% nickel, 0.1 to 0.8% phosphorus, 0.06 to 1% silicon, 0.03 to 0.5% zinc, the remainder being copper and inevitable impurities, by weight 750 before final finishing rolling Manufacture of copper alloy for electronic equipment, characterized in that the step of quenching in water or oil by heating at least 1 minute in the temperature range of ~ 950 ℃ and then heating at least 10 minutes in the temperature range of 350 ~ 500 ℃. Way. A copper alloy containing 1.0 to 8% nickel, 0.1 to 0.8% phosphorus, 0.06 to 1% silicon, 0.03 to 0.5% zinc, the remainder being copper and inevitable impurities, by weight 750 before final finishing rolling A method of manufacturing a copper alloy for an electronic device, characterized by heating at least 1 minute in a temperature range of ˜950 ° C. and then gradually cooling at 4 ° C./min or less. A copper alloy containing 1.0 to 8% nickel, 0.1 to 0.8% phosphorus, 0.06 to 1% silicon, 0.03 to 0.5% zinc, the remainder being copper and inevitable impurities, by weight 750 before final finishing rolling After heating for 1 minute or more in the temperature range of ~ 950 ℃, to 500 ℃ to cool at 1 ℃ / min or more, 500 ~ 350 ℃ to maintain or gradually cool the copper alloy for electronic equipment, characterized in that for at least 1 hour Way.

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