JP2965481B2 - Method for producing highly conductive copper alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a highly conductive copper alloy, and more particularly to a method for producing a copper alloy containing at least Ni and P used in the field of electronic materials such as semiconductors which require high conductivity. It relates to a manufacturing method.

[0002]

2. Description of the Related Art A general method for producing a copper alloy by adding another metal to copper is a method in which various metals are charged together with copper into a melting furnace and melted to produce an alloy solution. A batch method was adopted. However, in the method of manufacturing various types of copper alloys in a single furnace in a batch method, the inside of the melting furnace must be cleaned every time the type of the alloy solution is changed, so that a large amount of molten metal is generated. In addition to the necessity, there was a problem in workability. In addition, in this method, continuous production is not possible, and the operation rate of the melting furnace is low, so that there is a problem that productivity is low and manufacturing cost is high. Further, in the melting furnace, it is difficult to uniformly mix copper and the additional element, and contamination due to the previous operation occurs, so that the quality of the resulting alloy solution is poor.

[0003] On the other hand, it is conceivable to melt copper alloys in a shaft furnace which is a continuous melting furnace. However, there are fundamental problems such as non-uniformity of molten metal and furnace contamination. Absent. However, continuity is sufficiently possible for alloying by adding the additional element at a stage prior to casting (such as a continuous casting machine). In particular, the alloy has a low melting point such as Sn and several hundred to several thousand. Application to alloys with low ppm level is conceivable. As a technique for coping with the above-described continuity, a device is provided in which a runner (gutter) is provided upstream of a pool (tundish) and a solid-state alloy component is added through the runner (see Japanese Patent Application Laid-Open No. 63-62829). ) Or a heating furnace (high-frequency furnace) provided between the pool and the runner, and a device for adding the runner to the runner through an additive charging path in the same manner as described above (Japanese Patent Laid-Open No. 63-6 / 1988).
No. 2830) has been proposed.

[0004]

However, in the above prior art, when continuously producing a highly conductive copper alloy, it was difficult to control the content depending on the added element. For example, in the case of a copper alloy containing Ni, the melting point of Ni is 1455
° C, which is much higher than that of copper (1085 ° C).
Even in the case of 30wt% Ni and Cu-50wt% Ni mother alloys, their melting points are 1200 ° C or more and 1300 ° C or more, respectively. Addition cannot be expected. In addition, considering the addition of P, since P is an element having a low density and a low boiling point, it is impossible to add P alone, and generally, shot Cu-P
It is usually added in the form of a master alloy.

[0005] In this regard, in order to realize the precipitation of a fine Ni-P compound required as a highly conductive copper alloy,
If a Cu-Ni mother alloy and a Cu-P mother alloy are used together, the control of the amount ratio of Ni and P is disturbed, and the composition of the precipitate,
The quantity and size fluctuate and the characteristics are not stable. In addition, the amount of Cu to be melted (relative amount of Cu to be added as a master alloy) increases. As a result, the melting temperature of the molten copper is lowered due to the melting of the mother alloy, and extra heat energy is required to ensure the decrease, which hinders the smooth addition of the alloy.

[0006] The main object of the present invention is to propose an advantageous method for producing a homogeneous and highly conductive copper alloy. Another object of the present invention is to produce a high-quality and inexpensive Ni-P-containing highly conductive copper alloy without causing contamination of other pure copper products through high yield and smooth addition of alloying elements. It is in. Still another object of the present invention is to achieve homogeneous addition of a small amount of added components through effective addition immediately before a mold, and to establish a copper alloy production technology that is also advantageous from a thermal viewpoint.

[0007]

Means for Solving the Problems To overcome the above-mentioned problems,
As a means for achieving the above object, the present invention provides:
Each manufacturing method according to the gist configuration described below is proposed. (1) In producing a highly conductive copper alloy by continuously casting a melt of a copper alloy containing Ni and P, molten copper is accommodated in a tundish, and Ni is contained in the molten copper in the tundish. And P is added in the form of a Ni-P compound, followed by continuous casting. However, as the Ni-P compound,
A Ni-P master alloy or a compound of a Ni-P master alloy and a metal having a melting point lower than the molten copper temperature is used. (2) In producing a highly conductive copper alloy by continuously casting a melt of a Ni-P-containing copper alloy, molten copper is contained in a tundish, and a Ni-P compound and Zr are contained in the tundish. , Mg or Si and a copper mother alloy with an active metal surrounded by copper, In, Sn, Cd or Pb
Low melting point metal consisting of Zn, Sb, Al or A
g is added intermittently or continuously in a state of either a melt or a wire or a shot, and then continuously cast, followed by continuous casting. . (3) At least 0.1-2.0 wt% Ni and 0.02-0.4 wt% P
And 0.03 to 3.0 wt% of one or more low-melting metals selected from In, Sn, Cd and Pb, and if necessary, at least one of Zn, Sb, Al and Ag. 0.03 to 3.0 of additional components consisting of seeds
In producing a highly conductive copper alloy containing wt% and the balance substantially consisting of Cu, Ni and P are Ni-P
Use a copper tube, copper strip or copper foil surrounding the mother alloy, use a melt for low-melting metals, and
For other additional components, use those in the form of lines or shots, and add each by intermittently or continuously charging or supplying them in a tundish,
Then, a method for producing a highly conductive copper alloy, which is continuously cast. (4) Preferably, the Ni-P master alloy has a component composition containing 5 to 25 wt% of P and the balance of Ni.

[0008]

One of the features of the present invention is that when a copper alloy melt is adjusted prior to continuous casting, a predetermined copper melt is mixed with a Ni phosphorus compound (Ni-P master alloy) or (Ni-P master alloy + By using a metal having a melting point lower than the molten copper temperature) and supplying it into a tundish for continuous casting,
The present invention has a configuration in which an iP-containing high-conductivity copper alloy ingot is manufactured.

Another feature of the method for producing a highly conductive copper alloy according to the present invention is that the addition of each component element to the tundish is performed in accordance with the characteristics of each element, as follows. To do with It was mainly studied from the viewpoint of thermoeconomics and homogeneous alloying.

(1) Method of charging Ni-P master alloy In the present invention, Ni and P are used in the form of a Ni-P master alloy. That is, an ingot of a Ni-P compound having a brittle composition is manufactured, crushed and classified, and a predetermined amount is filled in a copper tube via a packing machine, and a tube-shaped product is manufactured using a copper strip. The material filled while filling or surrounded by copper foil is intermittently injected into the tundish directly and at regular intervals using a constant pitch injection machine. Alternatively, instead of the ingot pulverized material, it may be charged in the form of a shot, but it is preferable to use a material surrounded by copper. (2) Supply method of low melting point metal In, Sn, Cd, Pb, etc. (all mp = 350 ° C.)
In the case of (below), these metal ingots are melted in a melting furnace, and the melt is added to the melt by controlling it at a constant flow rate through a flow control valve and flowing it directly into a tundish with a pipe. I do. However, in the case where strict content control is required, for example, in the case of addition in a small amount, it is preferable to continuously feed in the form of a line. That is, the processed wire is added from a bobbin to a gutter or directly into a tundish using a constant speed roller. (3) Other metal supply methods For Zn, Sb, Al and Ag (mp = 350-1000 ° C), these metals were processed into wires or shots, and a constant-speed roller was fed from a bobbin. Use or classify and add into gutter or directly into tundish using metering belt feeder.

In this respect, conventionally, Ni is expressed by Cu − (1
5wt%) In the form of Ni master alloy, P is Cu-(15wt%)
A method of supplying these ingots to a melting furnace in the form of a P master alloy (≒ 1000 ° C.), and a method of supplying a low melting point metal such as Sn (mp: 232 ° C.) to a melting furnace or a gutter in the form of a wire rod. The supply (addition) is performed continuously, and the position of the supply (addition) is a melting furnace, a heating furnace upstream of the tundish, or a runner (gutter) upstream thereof. That is, as long as the conventional method is followed, the heating means is always provided on the downstream side of the addition position, so that the shortage of heat is hardly a problem. Therefore, in the case of low melting point metal, wire, Ni and P
In each case, the form of a master alloy with Cu is sufficient.

However, when adding to a non-heating type tundish directly connected to a continuous casting machine as in the present invention, sufficient thermal compensation cannot be performed as in the prior art.
It is necessary to devise the form of addition of each alloy component from the viewpoint of energy saving.

Therefore, in the present invention, the above-described addition means is adopted according to the added components. That is, Ni and P are not Cu master alloys but are in the form of Ni—P master alloys. First, use of excess copper (in the case of Cu—Ni, Cu—P master alloys) Second, the heat of dissolution is made unnecessary, and second, as is clear from the phase diagram shown in FIG. 1, the low melting point of the Ni—P eutectic alloy (≒
(880 ° C) to ensure rapid uniform diffusion into the molten copper to achieve high quality, and furthermore, to reduce the superheat of the molten copper (Super Heat) to stabilize the quality. And cost reduction.

For low-melting metals including Sn, Pb and, in some cases, Zn, by flowing them directly into a tundish or a gutter in a molten state, wasteful consumption of heat energy and molten copper Try to prevent the temperature from dropping.

[0015] And other, mainly mp = 35
Metals (Sb, Al, Ag, etc.) at 0 to 1000 ° C are processed and supplied in the form of linear or shot as before.

According to the method of the present invention, pure copper, in particular, an acid-free copper-based copper alloy can be manufactured by realizing high productivity and low cost at the same time by employing the above structure. Especially,
Since it is added and supplied in a tundish just before the continuous mold, there is no opportunity for molten copper contamination, and it is easy to switch to OFC operation.

[0017]

FIG. 2 shows a main part of a continuous molten copper casting apparatus used for carrying out the production method of the present invention. In order to manufacture a copper alloy by this apparatus, first, molten copper 1 from a melting furnace (not shown) is supplied into a tundish 3 through a gutter 2, and the molten copper 1 is continuously fed through a pouring nozzle 4. Continuous casting is performed in the water-cooled mold 5 of the casting machine. Then, the copper slab that has started to solidify in the continuous casting mold 5 passes through a water-cooled secondary cooling zone, reaches the pinch roll while being dropped, is pulled out, and is further cut into a predetermined length to be cut into copper. A slab (cake) is obtained.

An example in which a copper alloy having the following composition was produced using the above-described apparatus will be described. A. Cast molten copper 1.0 wt% Ni-0.2 wt% P copper alloy 0.32 wt% Ni-0.08 wt% P-0.1 wt% In copper alloy 0.2 wt% Ni-0.05 wt% P-2.0 wt% Sn copper alloy 1.0 wt% Ni -0.2 wt% P-1.0 wt% Zn copper alloy 0.32 wt% Ni-0.08 wt% P-0.1 wt% Ag copper alloy

B. Continuous casting (1) Electrolytic copper is melted at 10 T / H in a low frequency induction furnace, and the molten copper is transferred to a tundish 3 through a gutter 2 (temperature 1180 ° C., O ₂
Then, the cake having a cross section of 178 mm x 635 mm was continuously cast at a pulling speed of 165 mm / min. At this time, according to the method of the present invention, the inlet 6 on the upper part of the tundish 3
A 20 wt% P Ni-P mother alloy (copper alloy) ingot was pulverized and placed in a copper tube in an amount of 57 g (hereinafter referred to as “Ni-P
P powder-containing copper tube ") at 1-second intervals.
When the variation of the component in the length direction of the obtained continuous cast cake was examined, as shown in Table 1, a product sufficiently satisfying the allowable range was obtained. Moreover, almost no casting defects or surface defects were observed. (2) In continuous casting under the same conditions as in (1) above, “Ni-P powder-containing copper tube” containing 91 g of Ni-P alloy powder was charged at intervals of 5 seconds, and In was melted in another melting furnace 7. While maintaining the melt at a temperature of 200 ° C and a pumping pressure of 0.8 kg / cm ² ,
Tundish 3 at a rate of 180 g / min through flow regulating valve 8
Then, the copper alloy was prepared and continuously cast, and as shown in Table 1, there was no problem in quality and workability, and smooth casting was possible. (3) At the time of continuous casting under the same conditions as in (1) above, a “Ni-P powder-containing copper tube” containing 57 g of Ni-P alloy powder was charged at intervals of 5 seconds, and was further melted in another furnace. At a temperature of 300
C., while maintaining the pumping pressure 1 kg / cm ² , the copper alloy was poured into the tundish 3 at a rate of 3.6 kg / min through the flow regulating valve 8 to adjust the copper alloy, and then continuously cast.
As shown in Table 1, there was no particular problem in quality and workability, and smooth casting was possible. (4) During continuous casting under the same conditions as in (1) above, “Ni-P powder-containing copper tube” containing 57 g of Ni-P alloy powder was charged at 1-second intervals, and a Zn wire of 10 mmφ was pinched from the input port. The above-mentioned copper alloy was adjusted by throwing into a tundish 3 at a speed of 3.2 m / min by a roll, and then continuously cast.
There was no problem in both quality and workability, and smooth casting was achieved. (5) During continuous casting under the same conditions as in (1) above, “Ni-P powder-containing copper tube” containing 91 g of Ni-P alloy powder was charged at 5-second intervals, and a 3 mmφ Ag wire was pinched from the inlet. The above-mentioned copper alloy was adjusted by charging into the tundish 3 at a speed of 2.3 m / min by a roll, and then continuously cast.
There was no problem in both quality and workability, and smooth casting was achieved.

[0020]

[Table 1]

[0021]

As described above, according to the present invention, a high-purity Ni, P-containing highly conductive copper alloy can be produced at high productivity and at low cost through smooth continuous casting.
In particular, since the Ni-P-containing copper alloy can be added by directly supplying the tundish without increasing the superheat degree of the molten copper, the contamination of the molten copper is small, and an energy-saving operation is possible. .

[Brief description of the drawings]

FIG. 1 is a state diagram of a Ni—P alloy.

FIG. 2 is a partial schematic view of a continuous casting apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molten copper 2 Gutter 3 Tundish 4 Pouring nozzle 5 Continuous casting mold 6 Input port 7 Melting furnace 8 Flow control valve

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B22D 11/10 370 B22D 11/00 C22C 1/02 503 C22C 9/06

Claims (4)

(57) [Claims] In producing a highly conductive copper alloy by continuously casting a melt of a copper alloy containing Ni and P, molten copper is accommodated in a tundish and the molten copper in the tundish is contained in the tundish. , Ni and P in the form of a Ni-P compound, and then continuously cast, followed by continuous casting. In producing a highly conductive copper alloy by continuously casting a melt of a copper alloy containing Ni and P, molten copper is accommodated in a tundish, and Ni-P is contained in the tundish. An active metal copper mother alloy consisting of a P compound, Zr, Mg or Si, surrounded by copper, In, S
a low melting point metal comprising n, Cd or Pb;
Highly conductive copper characterized by adding intermittently or continuously Sb, Al or other metal consisting of Al or Ag in the form of a melt, wire or shot, and then continuously casting. Alloy manufacturing method. 3. At least 0.1 to 2.0 wt% Ni and 0.02 to
0.4 wt% P, and further contains In, Sn, Cd and P
b) at least one low-melting metal selected from 0.03 to 3.
0 wt%, and if necessary, an additive component comprising at least one of Zn, Sb, Al and Ag.
In producing a highly conductive copper alloy containing 0.03 to 3.0 wt% and the balance substantially consisting of Cu, Ni and P were obtained by enclosing a Ni-P master alloy in a copper tube, copper strip or copper foil. For the low melting point metal, use the melt, and for the other additional components, use those in the form of lines or shots, and supply or supply each one intermittently or continuously in the tundish. , And then continuously cast. 4. The Ni—P master alloy according to claim 1, wherein P is 5 to 25 wt.
The method according to any one of claims 1 to 3, wherein a composition having a composition ratio of 0.1% and a balance of Ni is used.