JPH0418027B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] 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. [Prior art] Copper alloy is generally used for semiconductor lead materials.
Conventionally, after hot rolling, desired dimensions were 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 equipment parts, and there has been a demand for flat materials with even higher strength and less distortion. 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 isodirectionality during processing. [Problems to be solved by the invention] The material subjected to finish skin rolling has poor formability,
In particular, it has the disadvantage of poor bending workability. In other words, anisotropy of springback occurs during bending depending on the direction, and as in the lead frame of PLCC etc.
If a device with leads protruding in different directions is bent at a different angle, the position may shift when it is mounted on a board, or some parts may not touch the board, significantly reducing the reliability of the semiconductor. [Means for Solving the Problems] In view of this, the present invention has been made as a result of various studies and has developed a copper-based lead material for semiconductors that has less distortion, is flat, has an excellent shape, and has less anisotropy during bending. A manufacturing method was developed. That is, in the manufacturing method of the present invention, after finish-pass rolling the copper alloy for the lead, low-temperature annealing is performed at a temperature of 150 to 600°C for 5 to 300 minutes, or continuous annealing is performed at a temperature of 300 to 800°C for 10 seconds to 5 minutes. After annealing, the elongation rate is 0.3.
It is characterized by being straightened by a tension leveler of less than %. [Function] The present invention improves the anisotropy by subjecting the lead copper alloy to finish conditioning rolling, and then releasing the strain accumulated in the grain boundaries due to conditioning rolling by low-temperature annealing or continuous annealing. Further, after low-temperature annealing or continuous annealing, a tension leveler is applied without applying much strain to remove curling curls in the coil. However, low-temperature annealing for 5 to 300 minutes at a temperature of 150 to 600 degrees Celsius after finish skin-pass rolling is because even if annealing is performed for more than 300 minutes at a temperature below 150 degrees Celsius, strain accumulated at the grain boundaries will occur. is not released, the anisotropy is large, and the strength of the material decreases at temperatures above 600°C. Further, if annealing is performed for less than 5 minutes, the entire material will not be sufficiently strain-relieved, and if annealing is performed for more than 300 minutes, the effect will be saturated and the cost will increase, making it unsuitable for industrial use. In addition, instead of the low-temperature annealing described above, continuous annealing at a temperature of 300 to 800°C for 10 seconds to 5 minutes is not effective because strain relief is insufficient at temperatures below 300°C and the anisotropy is large.
At temperatures above 800°C, the strength decreases.
Moreover, if the time is less than 10 seconds, the strain will not be released, and if it is more than 5 minutes, the productivity will drop significantly, making it unsuitable for industrial use. Next, after each of the above annealing processes, a tension leveler with an elongation rate of less than 0.3% is applied because an elongation of 0.3% or more causes anisotropy during bending. [Example] An alloy consisting of 0.1wt% Sn, 0.15wt% Cr, and the balance Cu is melted and cast according to a conventional method, and the ingot is faceted and then hot rolled. Copper alloy strips with a thickness of 0.2 mm were manufactured by finishing chamber rolling with repeated annealing. 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 examined, and the results are also listed in Table 1. Also, the conventional method, i.e.
The results of measuring the tensile strength and bending workability of an alloy ingot consisting of 0.1wt% Sn, 0.15wt% Cr, and the balance Cu were hot-rolled and then finished by chamber rolling with repeated cold rolling and annealing. Also listed in the table. The bending workability was determined by taking samples parallel and perpendicular to the rolling direction, bending both samples to 90° using the V-block method according to JIS Z 2248, measuring the angle of both samples, and calculating the difference in angle. Absolute values are shown.

【table】

〔Effect of the invention〕

As described above, according to the method of the present invention, a copper alloy with improved shape and bending workability can be produced,
This can be used as lead material for semiconductors to make them thinner.
This has significant industrial effects, such as enabling miniaturization.

Claims (1)

[Claims] 1 After finishing and temper rolling the lead copper alloy,
Low-temperature annealing is performed at a temperature of 150-600°C for 5-300 minutes, or continuous annealing is performed at a temperature of 300-800°C for 10 seconds-5 minutes, and then adjusted with a tension leveler with an elongation rate of less than 0.3%. A method for manufacturing a copper-based lead material for semiconductors, which is characterized by its ability to be repaired.