JPS63112003A - Production of copper lead material for semiconductor - Google Patents

Abstract

PURPOSE:To reduce the thickness and size of a product by subjecting a copper alloy material for leads to finish temper rolling, then to low temp. annealing or continuous annealing respectively at and for a specific temp. and time and straightening the material at a prescribed elongation rate at need. CONSTITUTION:The copper alloy material for leads of semiconductors is subjected to the finish temper rolling, then to the low temp. annealing for 5-300min at 150-600 deg.C. The copper alloy material is otherwise subjected to the continuous annealing for 10sec-5min at 300-800 deg.C. Said material is subjected to straightening with a tension leveler or roller leveler at <0.3% elongation rate. Since the strains accumulated at the grain boundaries by the temper rolling are relieved by the low temp. or continuous annealing, the anisotropy of the copper alloy material for leads is improved. The shape and bending workability thereof are, therefore, improved and the thickness and size of the product are reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a copper-based lead material for semiconductors, and particularly provides a lead material with excellent moldability.

[Conventional technology]

Copper alloy is generally used for semiconductor lead materials, and conventionally, after hot rolling, 1q of desired dimensions have been obtained by finish temper rolling, which involves repeating cold rolling and annealing. In recent years, lead materials for semiconductors have become thinner due to the miniaturization and higher integration of electronic device parts, and flat materials with even higher strength and less distortion are now required. Furthermore, recently there has been a shift from a mounting method with leads in two directions to a mounting method with leads in four directions, and lead materials are now required to have better moldability and isotropy during processing.

[Problem that the invention seeks to solve]

Materials subjected to finish temper rolling inevitably have the disadvantage of poor formability, especially poor bending workability. In other words, springback anisotropy occurs during bending depending on the direction, and in lead frames such as PLCC where leads come out in four directions, if the angle is different when bent, the position may shift when mounting on the board. The reliability of semiconductors is significantly reduced because some parts do not stick to the substrate.

(Means for Solving the Problems) In view of this, the present invention has been developed as a result of various studies to create a copper-based lead material for semiconductors that has less distortion, is flat, that is, has an excellent shape, and has less anisotropy during bending. A manufacturing method was developed.

That is, one of the manufacturing methods of the present invention is to finish-pass-roll the copper alloy for the lead, and then perform low-temperature annealing at a temperature of 150 to 600°C for 5 to 300 minutes, or perform low-temperature annealing at a temperature of 300 to 800°C for 10 seconds. One is characterized by performing continuous annealing for ~5 minutes, and the other is by performing low temperature annealing at a temperature of 150 to 600°C for 5 to 300 minutes after finish-pass rolling the copper alloy for the lead. , or at a temperature of 300 to 800°C for 10 seconds to 5
It is characterized by carrying out continuous annealing for several minutes, and then realigning it with a tension leveler or roller leveler with an elongation rate of less than 0.3%.

[Function] The present invention is to improve the anisotropy by finish-pass-rolling a copper alloy for leads, and then releasing the strain accumulated in the grain boundaries due to the temper-rolling by low-temperature annealing or continuous annealing. Furthermore, after low-temperature annealing or continuous annealing, the winding irregularities in the coil can be removed by applying a tension leveler without necessarily applying strain.

However, performing low-temperature annealing for 5 to 300 minutes at a temperature of 150 to Boo ℃ after finish skin-pass rolling is because even if annealing is performed for more than 300 minutes at a temperature of less than 150 ℃, the strain accumulated at the grain boundaries will be reduced. No release, large anisotropy, 600℃
If the temperature exceeds 100%, the strength of the material will decrease. Also 5
If it is less than 300 minutes, sufficient amount will not be taken over the entire material, and
This is because annealing for more than a minute will saturate the effect and increase the cost, making it unsuitable for industrial use.

In addition, instead of the above-mentioned low-temperature annealing, continuous annealing at a temperature of 300 to 800°C for 10 seconds to 5 minutes is recommended because at temperatures below 300°C, strain relief is insufficient and anisotropy is large; Strength decreases at high temperatures. In addition, if it takes less than 10 seconds, the strain will not be released, and if it takes more than 5 minutes, the productivity will drop significantly, making it unsuitable for industrial use.

Next, after each of the above annealing steps, a tension leveler with an elongation rate of less than 0.3% is applied because an elongation rate of 0.3% or more causes anisotropy during bending.

Note that instead of the tension leveler, it is possible to use various straightening devices used in industry, such as a normal roller leveler that does not apply tension to the strip. Furthermore, the leveler may be applied either to the wide strip material during the manufacturing process or after it has been slit to the final sheet width.

〔Example〕

An alloy consisting of 3NO, iwt%, CrO, 15wt%, and the balance CU is melted and cast according to a conventional method, and the ingot is face-faced and then hot rolled, followed by finishing tempering by repeating cold rolling and annealing. A copper alloy strip with a thickness of 0.2 m was produced by rolling. These copper alloy strips were subjected to annealing, a tension leveler, etc. as shown in Table 1, and the tensile strength and bending workability of these materials were investigated, and the results are also listed in Table 1.

In addition, the conventional method, namely Sn0.1wt%, Oro, 15w
Table 1 also shows the measurement results of tensile strength and bending workability of an alloy ingot consisting of t% and the balance Cu, which was finished by hot rolling and then temper rolling, which involves repeating cold rolling and annealing. For bending workability, samples were taken parallel and perpendicular to the rolling direction, and JIS Z 2248 was used for both samples.
After bending the sample to 90' using the V-block method similar to the above, the angles of both samples were measured, and the absolute value of the angular difference was shown.

As is clear from Table 1, the methods of the present invention Nα1 to Nα1
The materials produced by the conventional method Nα18 to Nα19
It can be seen that the bending workability is far superior to that of the material made by

On the other hand, comparative method Nα11 in which the elongation rate of the tension leveler exceeds 0.3%. Comparative method Nα12 in which the temperature of low-temperature annealing is less than 150°C. Comparative method Nα13 where the holding time of low temperature annealing is less than 5 minutes. Comparative method Nα15 in which the continuous annealing temperature is less than 300° C. and comparative method Nα16 in which the continuous annealing holding time is less than 10 seconds are both inferior in bending workability. Furthermore, it can be seen that both Comparative Method Nα14, in which the temperature of low-temperature annealing exceeds 600°C, and Comparative Method Nα17, in which the temperature of continuous annealing exceeds 800°C, have a significant decrease in strength.

〔Effect of the invention〕

As described above, according to the method of the present invention, it is possible to produce a copper alloy with improved shape and bending workability, and this can be used in semiconductor lead materials to make them thinner and more compact. This has a remarkable effect.

Claims (2)

[Claims] (1) After finishing and temper rolling the copper alloy for leads, 150
A method for producing a copper-based lead material for semiconductors, characterized by performing low-temperature annealing at a temperature of ~600°C for 5 to 300 minutes, or performing continuous annealing at a temperature of 300 to 800°C for 10 seconds to 5 minutes. (2) After finish-pass rolling the copper alloy for the lead, 150
Low-temperature annealing at a temperature of ~600°C for 5 to 300 minutes or continuous annealing at a temperature of 300 to 800°C for 10 seconds to 5 minutes, followed by a tension leveler or roller with an elongation of less than 0.3%. A method for manufacturing copper-based lead materials for semiconductors, which is characterized by straightening with a leveler.