JPS62156089A - Production of partial clad material - Google Patents

Abstract

PURPOSE:To easily manufacture the partial clad material having high dimensional accuracy and positional accuracy by forming the projecting part in a spot shape on the rolling roll for a coating material in case of rolling by overlapping the coating material of dissimilar metal on a base material. CONSTITUTION:The belt like coating material 2 of dissimilar metal is overlapped on a base material 1 and rolled with a pair of rolling roll 3, 4. In this case the rolling roll 3 at the base metal 1 side is taken as a flat roll and the rolling roll 4 at the coating material 2 side is taken as the stepping roll having plural projecting parts 5. The rolling is performed at the prescribed rolling reduction rate by turning the rolling rolls 3, 4 in the arrow mark direction by applying optimum tension Tf, Tb respectively to the front part and rear part of the base metal 1. The excessive coating material 2'' is easily separated with its shearing in good accuracy by the slit effect due to the rolling reduction of the projecting part 5 because of the projecting part 5 of the rolling roll 4 being composed with the corner part having sharp edge and the coating material 2' located on the projecting part 5 only is fitted and coated on the base metal 1. In this way the partial clad material 6 having a spot like coating material 2' is easily obtd.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a partial cladding material in which coating materials made of different metals are adhesively coated in spots at desired positions on a strip-shaped metal base material in the longitudinal direction thereof by rolling. The present invention relates to a manufacturing method.

[Prior art and problems] With the development of the semiconductor and electronic component industries, partially cladding materials manufactured by the above method are being actively used as electronic component materials, mainly for IC lead frames and various contact materials. . In this case, noble metals such as gold, silver, and aluminum are used as the covering material for the partial clad material from a functional standpoint. Therefore, from an economic point of view, a covering material is partially provided as a partial cladding material in such a structure in order to save precious metals.

In addition to the method of adhering by rolling (cladding method), there are other industrial methods for partially providing the covering material, such as vapor deposition method and plating method. In the vapor deposition method and the plating method, the covering material is partially provided by using a mechanical or chemical mask, so it can be said that the dimensional accuracy and positional accuracy of the covering material in products made of partially clad materials are generally high.

However, the vapor deposition method requires very expensive equipment to create an atmosphere and has low productivity, while the plating method requires very complicated management of the plating solution and the coating. There is a problem that there is a limit to the thickness of the material, and some metals such as aluminum cannot be plated.

In contrast to such vapor deposition and plating methods, the cladding method has the advantage of being extremely economical and easy to manufacture in terms of equipment and manufacturing management, as well as being highly productive. . However, when comparing products produced by each method, the cladding method has the disadvantage that it is difficult to ensure and adjust the dimensional accuracy and positional accuracy of the covering material. Disadvantages of the Ladd method include that during rolling, especially when the coating material is as thin as several tens of microns, it tends to wobble during introduction and undergoes plastic deformation during rolling, as well as the use of a fixed mask as in vapor deposition and plating methods. The main reason is that it cannot be done.

In recent years, electronic component materials such as IC lead frames are required to have higher and higher precision not only in the size and shape of the lead frame but also in the size and positional accuracy of the covering material due to the remarkable progress in miniaturization of devices and higher integration of devices. It has become so. For this reason, one of the major technical challenges in recent cladding methods is to improve the dimensional accuracy and positional accuracy of the covering material.

[Object of the Invention] The present invention was made to solve the above problems, and its purpose is to manufacture a partial cladding material that can improve the dimensional and positional accuracy of the covering material with respect to the base material. The purpose is to provide a method.

[Summary of the Invention] That is, the present invention provides a method for manufacturing a partial cladding material in which a coating material made of different metals is adhesively coated in spots at intervals on a strip-shaped metal base material by rolling. A wide band-shaped covering material including spot-like covering portions of the material is prepared, and when the base material and the band-shaped covering material are overlapped and rolled by a pair of rolling rolls, the rolling rolls are rolled. As at least the rolling roll on the side that covers the band-shaped coating material, a stepped irregular roll whose tip surface has a plurality of convex portions having the same shape as the spot-shaped coating portion at intervals on the circumference of the roll. The base material and the covering material are bonded by rolling at the convex portion of the stepped irregularly shaped roll, and then the non-adhered portion of the covering material that has come off from the convex portion is removed, thereby causing spora of the covering material on the base material 1 to 1. This makes it easier to adjust the size and positional accuracy of the shaped covered portion, and improves these.

In the present invention, the metals used for the base material and the coating material are not particularly limited, and various metals or combinations of metals may be used depending on the intended use of the product. Further, the rolling reduction rate during rolling differs depending on the type of inkstone used for the base material and covering material.

When considering an IC lead frame as a product, the base material for the cladding material is mainly 4270I (Fe-4
2% N1 alloy), Invar, Kovar, stainless steel, or other iron-based alloys, or copper-based alloys are used, and as the coating material, A or an alloy of A, Ag, or an AI1 alloy is mainly used. When such a base material and coating material are a combination of an iron-based alloy and an AI or Al alloy, the practical rolling reduction range is 2 to 70%. Here, if the rolling reduction exceeds the appropriate range, if it is too small, the adhesion will be insufficient, and if it is too large, waves will occur at the edges of the covering material, making the plate shape unstable.

Furthermore, when considering contact materials as products, there are many types of contact materials depending on their use, but the base materials for the cladding materials are, for example, the above-mentioned iron-based alloys and copper-based alloys, and the coating materials include AU or Au alloys, AQ or A(j alloys or Cu or CU alloys are used.

In rolling, the base material and the covering material are bonded, but in order to further increase the bonding strength, in the present invention, diffusion heating or finishing hot rolling with a slight deformation rate is performed in the next step. It can be carried out.

[Example] Next, an example of the method for manufacturing a partial cladding material of the present invention will be described with reference to the accompanying drawings.

Figure 1 shows the manufacturing state of the partial cladding material.
The base material 1 is 427 with a thickness of 1.0# and a width of 50mm.
0 is used. On the other hand, the band-shaped covering material 2 supplied together with the base material 1 is made of Al having a thickness of 20 um and a width of 50 m.
Foil is used. The base material 1 and the covering material 2 are overlapped and in this state are led to a pair of rolling rolls 3.4 and rolled.

The rolling roll 3 on the base material 1 side is a flat roll with a diameter of 80 m, and the rolling roll on the coating material 2 side is also a roll with a maximum diameter of 80 #, but has a plurality of convex portions 5 at intervals on its circumference. It is a stepped roll. The shape of the tip end face of each convex portion 5 of the stepped roll 4 is a 5 mm square, which is the same shape as the spot-shaped covered portion of the covering material 2- in the partial cladding material 6.

The height of the convex portion 5 is determined according to the thickness of the covering material 2. Furthermore, what is important about the shape of the convex portion 5 is that its edges have sharp corners.

As a result, the slit effect described later can be expected.

In FIG. 1, the base material 1 and the covering material 2 are bonded together by rotating the rolling rolls 3 and 4 in the directions of the arrows and rolling with a rolling reduction of 40%.

At this time, a moderate tension T is applied to the front and rear of the base material 1.
If f and Tb are added to the rolling operation, the rolling operation becomes easier and an improvement in the rolling speed can be expected. In this example, rolling was performed with Tf and Tb set at 35% of the breaking strength of base material 1.

As shown in FIG. 2, the adhesion status of the base material 1 and the covering material 2 is as shown in FIG.
As a result, only the covering material 2- located on the convex portion 5 is adhesively coated onto the base material 1. When the covering material is thin such as foil, such shearing is largely recognized as a slit effect due to the reduction of the convex portion. In FIG. 1, after rolling, the excess shearing material 2'' separated as described above is removed, thereby forming a spot-shaped covering material 2 with a desired size and shape at a desired position on the base material 1. Although not shown, after the process shown in FIG. 1, the partial cladding material 6 is diffused and heated at a temperature of 400°C to ensure sufficient adhesive strength between the base material 1 and the covering material 2-. I have to.

In this embodiment, the cladding material 2' has a square shape and only one side has been manufactured. However, the shape of the sheathing material 2' is not limited to a square, and may be rectangular, circular, or oval. Furthermore, the covering material 2- can be provided not only on one side of the base material 1 but also on both sides. When manufacturing a double-sided partial cladding material using the present invention, rolling may be performed by arranging stepped rolls 4 having convex portions on both sides of the base material 1, respectively.

FIG. 3 shows a modification of the present invention, in which the stepped roll 4 has a convex portion 5.
A groove 7 is provided on both sides of the groove. By providing this groove 7, it is easy to remove the excess coating material that has been sheared away from the position of the convex portion 5. Further, the stepped roll 4 has a structure that restrains both ends of the base material. According to this, lateral wobbling of the base material 1 can be reliably prevented, so that the positional accuracy of the covering material with respect to the base material 1 can be further improved.

[Effects of the Invention] As described above, according to the present invention, when a base material and a band-shaped covering material having a width wider than planned are superimposed on the base material and are guided to a pair of rolling rolls and rolled, At least the rolling roll on the side facing the band-shaped coating material is a stepped roll having a plurality of convex portions having the same shape as the spot-shaped coating portion on the tip surface at intervals around the roll circumference. By performing rolling using irregularly shaped rolls, there is no need to use a covering material with exact dimensions and shape from the beginning as the covering material to be introduced into the pair of rolling rolls, and the base can be easily removed by using the protrusions of the stepped rolls during rolling. Since the dimensions and position of the sheathing material with respect to the material are determined, it is extremely easy to adjust the dimensions and position of the sheathing material with respect to the base material, and moreover, it reliably improves the dimension and positional accuracy of the sheathing material with respect to the base material, As in the case of the steaming method and the plating method, the cladding method has the effect of easily obtaining a spot-shaped partially clad material with excellent dimensions and shape.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the method for manufacturing a partially clad material of the present invention, and FIGS. 2 and 3 are cross-sectional views showing rolling conditions using rolling rolls, respectively. 1...Base material. 2... Band-shaped covering material. 2'...Spot-like covering material. 2"...Excess covering material. 3...Flat roll. 4...Stepped roll. 5...Convex part. 6...Partial cladding material. 7...Concave groove.

Claims (2)

[Claims] (1) In a method for manufacturing a partial cladding material, in which a coating material made of a different metal is adhesively coated in spots at intervals on a strip-shaped metal base material by rolling, the base material and the spot-shaped coating portions of the coating material are coated. A wide band-shaped coating material is prepared, and when the base material and the band-shaped coating material are overlapped and rolled by a pair of rolling rolls, at least the band-shaped coating material is rolled as the pair of rolling rolls. As the rolling roll on the side facing A method for manufacturing a partial cladding material, which comprises rolling and bonding a base material and a covering material in the convex portion of a irregularly shaped roll, and then removing a non-bonded portion of the covering material that has come off the convex portion. (2) The method for manufacturing a partial cladding material according to claim 1, wherein the base material is made of an Fe-based alloy, and the covering material is made of Al or an Al alloy.