JPS5886992A - Manufacture of clad band - Google Patents

Abstract

PURPOSE:To prevent lubricating oil from going into a press-contacting part, and to prevent bulging of a clad band, by dividing the cold rolling press-contact into 2 stages, rolling the first stage by low draft without using lubricating oil for rolling, and rolling the second stage by high draft by using lubricating oil. CONSTITUTION:As for draft of rolling press-contact, which uses no lubricating oil for rolling, of the first stage, rolling is executed by selecting usually 8%- maximum 25%, usually up to 15% draft in order to avoid the fact that lubricating oil permeates the junction surrace in the second stage. Subsequently, since rolling press-contact of the second stage uses lubricating oil, high draft is adopted, that of >=10% or >= maximum 30% is selected, and rolling is executed. Subsequently, an aluminum stripe clad band is junctioned completely and its thickness is set to a desired value, by executing the diffusion annealing treatment and finishing cold rolling.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing metal clad materials, particularly aluminum striped clad strips.

BACKGROUND ART Striped cladding of aluminum or aluminum alloy (hereinafter referred to as "aluminum") on various metal base materials is used as a material for electronic components such as lead frames of ICs and LSIs.

Hitherto, the production of aluminum striped clad strips has been carried out in a conventional manner. In other words, the parts of the base material strips to be clad (and if possible, the mating surfaces of the aluminum strips) are cleaned by polishing with a wire brush or the like in advance, then stacked on top of each other, and then cold rolled. After thorough pressure bonding, diffusion annealing treatment is performed to heat the parts to a temperature of 300 to 600°C for a short time to complete the bond. after that,
Finish to the specified thickness by cold rolling.

However, when using cladding material on glass (including ceramics) sealing alloy base materials, which is an important application of aluminum striped clad strips, heating to temperatures of around 500℃ or higher is required for sealing. At that time, fine blisters occur in the aluminum cladding, causing partial peeling. This often reduces the acceptance rate of the final product, so there is a need to provide cladding bands free of these defects.

According to the present inventors, the cause of the above-mentioned blisters is as follows:
Lubricating oil used to prevent seizure during cold rolling crimping may scatter or permeate between the base material and the aluminum ram strip, partially interfering with rolling crimping and causing damage to that area. It remains in the water and decomposes and vaporizes and expands during subsequent heating. However, until now, there have been no effective measures to prevent blisters.

The present invention has been made with the intention of overcoming such problems, and involves manufacturing an aluminum stripe clad strip by cladding aluminum strips in a stripe shape onto a base material by cold rolling and bonding. In this method, cold rolling crimping is divided into two stages, in which rolling lubricating oil is not used in the first stage, and rolling lubricating oil is applied to the joint surface between aluminum and base metal during rolling crimping in the second stage. In the second stage, rolling crimping is performed at a low rolling reduction rate that does not cause penetration, to avoid seizure to the rolling rolls, and in the second stage, rolling crimping is performed using rolling lubricating oil at a high rolling reduction rate that provides sufficient bonding. This provides an aluminum cladding that does not blister even when subsequently heated.

The rolling reduction ratio for rolling crimping without using rolling lubricating oil in the first stage is:
In order to prevent the lubricating oil from seeping into the joint surface in the second stage, it is usually necessary to set it to 8 inches or more. On the other hand, if the rolling reduction is increased, seizure will occur on the rolls, so to avoid this, the rolling reduction must be selected within a maximum of 25%, usually up to 15 inches. The optimum value varies somewhat depending on the combination of cladding materials, but can be found around 10%.

Since the second stage of rolling crimping uses lubricating oil, a high rolling reduction rate should be adopted to further strengthen the bond that has been formed in the first stage. Although the limit varies depending on the thickness of the cladding band to be manufactured, choose a reduction rate of at least 10%, preferably 30% or more.〇 Completely join the aluminum stripe cladding band. In order to obtain a desired thickness and a desired thickness, it may be necessary to perform diffusion annealing and finish cold rolling even in the method of the present invention. Of course, the conditions may be in accordance with known techniques.

It has been confirmed as follows that in the aluminum striped clad strip produced according to the method of the present invention, the adhesion between the base material and aluminum is improved on average. i.e. diffusion annealing. When examining the dark coloring caused by the Fe-Alized food produced by diffusion by corroding the clad wood with caustic powder to remove the aluminum, the conventional material had strong shading and was strongly adhered to the surface. It can be seen that while there are some areas where the adhesive is weakly adhered or not adhered at all, according to the present invention, an average adhesion is achieved which is dark and pale over the entire surface.

Example 1 The base material was 42-inch Ni-F, which is known as a glass sealing alloy.
A strip of 0.341111% thick and 25 m wide of e is made of pure aluminum (JIS 1070 equivalent) as a cladding material.
A strip with a thickness of 10 μm and a width of 4.6+ m was used. After polishing the part in contact with the aluminum base material with a wire brush and cleaning it, the aluminum strips were stacked and passed through cold rolling rolls, and rolling lubricant was applied. Reduction rate 11 without using
%, the first stage of rolling crimping was carried out so that the plate thickness was 0.31 cm, then the second stage of rolling crimping was carried out using lubricating oil at a rolling reduction of 13 cm. The board was bound to a thickness of 0.27cm.

For comparison, we also prepared a clad strip made of the same plate thickness of 027 m as above, which was made by one-stage cold rolling and crimping at a rolling reduction of 20% using rolling lubricating oil as in the past.

These clad strips were held in a furnace in a non-oxidizing atmosphere at 550 DEG C. for 30 seconds to perform diffuse bright annealing, and then finish rolled to a thickness of 0.25 mm.

After holding the resulting product in a furnace at 530°C for 6 minutes, they examined it using a magnifying glass to see if any minute blisters had formed on the aluminum parts. The product according to the present invention had no blisters, whereas the comparative example had 11 blisters/blisters.
10 c+I blisters were observed.

11-L Kovar alloy (29%Ni-16%Co -
An aluminum alloy (JIS 2
The first stage of rolling crimping is a combination of strips with a thickness of 15 μm and a width of 4.6 m (equivalent to 014), and is rolled to a thickness of 0.41 m at a rolling reduction rate of 9% without using rolling lubricating oil. Then, the second stage of rolling crimping was performed using lubricating oil at a reduction rate of 34 inches and a plate thickness of 0.
It was rolled to 27cm.

In the comparative example, using rolling lubricating oil, rolling and crimping is performed at a rolling reduction rate of 40% to a thickness of 0.27 m.

As in Example 1, the product was subjected to diffuse bright annealing at 550° C. for 30 seconds and then finished rolled to a thickness of 0.25 m.

Each clad zone was subjected to a heating test at 530°C for 6 minutes to examine the occurrence of fine 7 cracks. No blisters were found in the sample according to the present invention, but 21 blisters/10 crI were observed in the comparative example.

Patent applicant: Daido Steel Co., Ltd.

Claims (3)

[Claims] (1) In the method of producing an aluminum stripe clad strip by cladding strips of aluminum or aluminum alloy on a base material in the form of a cysteine by cold rolling crimping, the cold rolling crimping is divided into two stages, and the In the first stage, no rolling lubricant is used, and the rolling lubricant is applied to the rolling rolls at a low rolling reduction rate as long as the rolling lubricant does not seep into the joint surface between the aluminum or aluminum alloy and the base metal during rolling crimping in the second stage. A manufacturing method characterized in that rolling crimping is performed while avoiding seizure, and in the second stage, rolling crimping is performed using rolling lubricating oil at a high rolling reduction ratio that provides sufficient bonding. (2) The rolling reduction ratio of the first stage rolling crimping is 8 to 25 inches, preferably 8 to 15 inches, and the rolling reduction ratio of the second stage rolling crimping is 1
The method according to claim 1, wherein the content is 0% or more, preferably 30% or more. (3) The manufacturing method according to claim 1, in which diffusion annealing and finish rolling are sequentially performed after rolling crimping. (4) The manufacturing method according to claim 1, wherein the base material is a glass sealing alloy.