JPS62169352A - Method for providing clad layer of different kind of metal parts on strip shaped metal sheet at specified interval - Google Patents

Abstract

PURPOSE:To provide a clad layer of the different kind of metal parts on the surface of a strip shaped metal sheet at a specified interval continuously with good dimensional accuracy, by passing the metal sheet having metal foil pieces between secondary compressing rolls, and permanently compressing and connecting the metal foil sheet to the strip shaped metal sheet. CONSTITUTION:A strip shaped metal sheet 1 and a strip shaped metal foil 2, which comprises a material different from the sheet 1, are prepared. Recessed cut-out parts 3 having a required size are formed on the one side edge part of the strip shaped metal foil 2 at a specified interval in the longitudinal direction of the strip shaped metal foil 2. The strip shaped metal sheet 1 and the strip shaped metal film 2 are overlapped and guided in primary compressing rolls 5 and 6. The strip shaped metal foil 2 is compressed to the one surface of the strip shaped metal sheet 1 so that the foil 2 can be separated from the sheet 1. The strip shaped metal foil 2 is cut in the longitudinal direction. Thereafter, strip shaped foil pieces 2B, which are aligned on the strip shaped metal sheet 1 at a specified interval, and made to remain and to pass between the secondary compressing rolls. Thus the metal foil pieces 2B are permanently compressed and connected to the strip shaped metal sheet 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for providing dissimilar metal partial cladding layers at regular intervals on a strip-shaped metal sheet, and relates to a method for providing a strip-shaped metal sheet with dissimilar metal partial cladding layers at regular intervals. The metal sheet is used, for example, as a lead frame for mounting an IC (heat collecting circuit).

BACKGROUND OF THE INVENTION Conventionally, a strip metal sheet with an aluminum partial cladding layer used, for example, as a lead frame, has been manufactured by the following method.

As shown in Fig. 9, for example, 4270I (Fe-42w)
A masking synthetic resin sheet (13) having openings (14) at predetermined intervals in the length direction is formed by combining a band-shaped metal sheet (11) made of t%Ni alloy) and a narrower band-shaped aluminum foil (12). ) through rolling and opening (14)
The aluminum foil portion (12A) corresponding to the metal sheet (11) is pressed against the metal sheet (11), and then the synthetic resin sheet (13) and the aluminum foil portion (12A) on the synthetic resin sheet (13) are pressed together.
2B) was peeled off to leave the aluminum foil fragments on the band-shaped metal sheet (11), and then thermal diffusion bonded (
JP-A-59-1080@publication and JP-A-58-130
(See Publication No. 522). However, in this conventional method, when the synthetic resin sheet (13) is peeled off, the aluminum strip 1 (12) is torn as shown by the chain line (1) in Figure 9, so that the final formed aluminum part As shown in FIG. 10, the portion of the clad I (12S) near the periphery becomes gradually thinner toward the outside and is difficult to form a straight line. Therefore, this aluminum partial cladding layer (12
When a lead frame is made using a band-shaped metal sheet (11) having S), the thickness of the aluminum partial cladding layer at the tip of the lead becomes thin, and the bonding strength becomes small when bonding thin aluminum wires. There was a problem.

In addition, there is a known method (Japanese Unexamined Patent Publication No. 59-21487) in which a band-shaped metal sheet is partially brushed in advance. The outline is A゜)
There was a problem that the beam was difficult to form in a straight line.

Furthermore, a method of forming a partial aluminum cladding layer on a band-shaped metal sheet by an etching method or a polishing method is known (see Japanese Patent Laid-Open No. 1078/1983). The strip-shaped aluminum foil is etched non-uniformly not only in the thickness direction but also in the lateral direction, and the contour of the formed aluminum partial cladding layer is not straight, the dimensional accuracy is reduced, and the etching solution is There was a problem in that a washing process and a drying process were required, making the work extremely troublesome. Further, according to the latter grinding method, there is a problem that chips are generated and if the removal thereof is insufficient, the surface of the flaky aluminum partial cladding layer is easily damaged and uneven portions are formed.

OBJECT OF THE INVENTION The object of the present invention is to solve the above-mentioned problems, and to apply a partial cladding layer of dissimilar metals on the surface of a band-shaped metal sheet in a continuous manner with high precision and at regular intervals so that the peripheral edge of the cladding layer is straight. There is no need to use a resin sheet for masking as in the past, or to perform the troublesome etching process or grinding process.
We are trying to provide a method that does not cause troubles caused by single cutting or powder.

Structure of the Invention In order to achieve the above-mentioned object, the method of the first invention of the present invention first prepares a band-shaped metal sheet and a band-shaped metal foil made of a material different from the band-shaped metal sheet. At least one edge of the foil has an approximately I"-shaped notch of the required size. The strip-shaped metal foil is formed at predetermined intervals in the length direction of the strip-shaped metal sheet, and the strip-shaped metal foil and the strip-shaped metal foil are stacked and guided to a primary pressure welding roll to form a strip-shaped metal foil on at least one side of the strip-shaped metal sheet. Then, the band-shaped metal foil is cut in the length direction so as to form a cutting line that passes through the side edges of all the notches or slightly inside the side edges, and then By peeling off and removing the metal foil strips other than the approximately rectangular metal foil fragments that alternately exist, metal tube fragments arranged at predetermined intervals are left on the strip metal sheet, and then the metal sheet adjacent to the metal tube fragments is removed. is passed between rolls for secondary pressure welding, and as a result, the metal foil fragments are finally welded to the strip-shaped metal sheet.The method is characterized in that cladding layers of dissimilar metal parts are provided at regular intervals on the strip-shaped metal sheet. The main point is how to

Next, in the method of the second aspect of the present invention, a band-shaped metal sheet and a band-shaped metal foil made of a material different from the sheet are prepared, and a pair of front and rear parallel to each other extending in the width direction of the band-shaped metal foil is provided. At least one row of approximately opening-shaped or approximately opening-shaped cuts are formed at predetermined intervals in the length direction of the strip-shaped metal foil, and the strip-shaped metal sheet and the strip-shaped metal foil are overlapped and rolled for primary pressure welding. The strip-shaped metal foil is pressed against at least one side of the strip-shaped metal sheet to the extent that it can be peeled off from the sheet, and then the strip-shaped metal foil is attached to the edges on the same side of the cut (12) or the edges on the same side. After cutting in the length direction so as to form a cutting line that passes through the slightly inner parts, by peeling and removing the gold Er foil strips other than the approximately rectangular metal foil pieces that alternate with the notches, One piece of metal fLli 11g arranged in parallel at predetermined intervals is left on the band-shaped metal sheet, and then the metal sheet on which the metal foil fragments are placed is passed between rolls for secondary pressure welding, and as a result, the metal foil fragments are bonded to the band-shaped metal sheet. The gist of this invention is a method of providing partial cladding layers of dissimilar metals at regular intervals on a band-shaped metal sheet, which is characterized in that the metal sheets are brought into full pressure contact with each other.

In the above, as the band-shaped metal sheet, for example, 42 alloy (Fe-Ni alloy), iron, phosphor bronze, etc. are used. Further, as the band-shaped metal foil, high-purity aluminum with a purity of 99 wt% or more, aluminum alloy, gold, or the like is used. The metal sheet is provided with a dissimilar metal partial cladding layer on one or both sides thereof. - A pair of pressure contact rolls with smooth surfaces are used as the next and secondary pressure contact rolls.

The strip-shaped metal foil is formed with approximately opening-shaped notches having a required size on at least one side edge thereof at predetermined intervals in the length direction of the strip-shaped metal foil, or A pair of front and rear cuts parallel to each other extending in the width direction, or cuts having a substantially opening shape or a substantially mesh shape when viewed from a plane are formed in at least one row at predetermined intervals in the length direction of the band-shaped base B foil.

Note that the term "cut" as used herein includes a linear cut with no width at the top and a slit with a slight width.

The primary pressure welding of a strip-shaped metal sheet and a strip-shaped metal foil is carried out by temporarily welding them together by guiding them to a secondary pressure welding roll and rolling them, and the rolling reduction ratio at this time is usually 7 to 15%. is preferable.

Immediately after the next pressure welding, necessary cutting lines are continuously or intermittently inserted into the strip of metal foil, and the strip of metal foil is peeled off while being wound into a coil, leaving approximately rectangular pieces of the metal foil.

Here, since the strip-shaped metal foil is provided with notches or cuts having a predetermined size at a constant pitch, when stacking the strip-shaped metal foil (2) on the strip-shaped metal sheet (1), , the strip metal foil (2) does not tear even when sufficient tension is applied, the position of the metal foil fragment (2A) with respect to the strip metal sheet (1) is extremely accurate, and the strip metal foil (2) is continuous. The metal foil pieces formed after peeling off the metal foil strips have extremely high dimensional accuracy because they are sharply cut to a depth of 1" corresponding to the thickness of the metal foil using the required discontinuous cutting lines. and are arranged at a constant pitch U'.

After peeling and removing the metal foil strip, main pressure welding is performed by guiding the strip metal sheet I having the metal foil pieces to a secondary pressure welding roll and rolling it, at a rolling reduction rate of 5 to 20.
% is preferable.

After secondary pressure welding, the band-shaped metal sheet usually has gold WA foil pieces]
- is heated in a vacuum or inert gas atmosphere to diffusion bond the metal sheet and the gold fX foil piece.

Diffusion bonding after secondary pressure bonding is performed in a vacuum or inert gas atmosphere to prevent oxidation of the metal sheet and metal foil pieces, but in the former case, the degree of vacuum is 10-3 to 10"-'Torr is preferable. In the latter case, it is carried out in an atmosphere of a chemically inert gas such as nitrogen gas or argon gas. In either case, the heat treatment is about 300 to 50 Carry it out for 30-60 minutes at a temperature of 0'C.
Allow interdiffusion of the A foil pieces to take place in 1 minute.

Example Next, embodiments of the invention will be described based on the drawings.

Example 1 In FIGS. 1 to 4 showing the embodiment of the first invention of the present invention, first, a belt-shaped metal sheet (1) made of 42A and a 99.99wt purity sheet made of a different material. A band-shaped metal foil (2) made of % aluminum foil was prepared. Here, the thickness of the band-shaped metal sheet (1) is 0.32 m1
The strip metal foil (2) has a thickness of 12q and a width of 151I1m.

Notches (3) having a width of 5 mm and a cutout of 12 mm were formed at intervals of in+++ on the negative side edge of the band-shaped metal foil (2) in the length direction by punching. Then, the notch (3) of the strip metal foil (2) and the protruding metal foil portion (2b) existing between the strip metal foil (1) and the strip metal foil (2) The sheets (1) are stacked in the center of the width, guided to the next pressure welding rolls (5) and (6), and applied to one side of the band-shaped metal sheet (1).
The 41-shield metal foil (2) was cold-pressed to the extent that it could be peeled off. At this time, the reduction ratio by the secondary pressure welding roll (5) (G) was 12.degree. 5%.

After the first pressure welding, the strip metal foil (2) is cut into all the notches (3
) is cut in the longitudinal direction to form a cutting line (4) that passes slightly inside the side edge of the metal foil strip (28), and the metal present at the intersection with the notch (3) is cut. By separating the metal foil strips (2B) into foil pieces (2B) and then peeling and removing the metal foil strips (2^), the metal foil strips (2B) of regular size are left at predetermined intervals on the strip metal sheet (1). I forced it.

Next, the metal sheet (1) having the metal foil fragments (28) is passed between secondary pressure welding rolls, so that the metal foil fragments (2B) are coldly subjected to main pressure welding to the band-shaped metal sheet (1). Ta. At this time, the rolling reduction rate by the secondary pressure welding roll is 1
087%, the thickness of the final band-shaped metal sheet (1) is 0.25 mm, the size of the metal foil pieces (2B) is 5 mm square, and the pitch between the metal foil pieces (2B) is It was set to 15 mm.

Finally, place the metal foil fragment (2B) on the right side of the metal strip (1) in a vacuum (10'Torr) at 45) (°C).
Heat the metal sheet (1) and metal foil pieces (2) for 30 minutes.
B) was diffusion bonded, thereby providing aluminum partial cladding layers (2S) at regular intervals on the band-shaped metal sheet (1) as shown in FIG.

The strip-shaped metal sheet (1) with the aluminum partial cladding layer (2S) obtained by the above method had very precise dimensional accuracy and could be used for example as a lead frame for IC mounting. .

In addition, as shown in FIG. 5, approximately ``C''-shaped notches (3) having the required size are formed on the left and right edges of the band-shaped metal foil (2).
) may be provided at predetermined intervals ( ); in this case, the band-shaped metal foil (2) is placed on the wide band-shaped metal sheet (1), -
After the next press contact, the metal foil (2) is cut to form cutting lines (4H4) on both the left and right sides, thereby forming two rows of metal foil pieces (2B) at predetermined intervals.

Example 2 FIGS. 6 to 8 show the method of the second invention of this invention.

First, in FIG. 6, a pair of front and rear cuts (11) and (12) parallel to each other extending in the width direction are made in navy blue on the negative side edge of the same strip-shaped metal foil (2) as in the first embodiment. Formed in a row at predetermined intervals in the length direction of the metal foil (2),
The band-shaped metal sheet (1) and the band-shaped metal cylinder (2) are stacked and guided to the above-mentioned secondary pressure welding rolls (5) and (6), and the band-shaped metal foil (2) is sheeted on at least one side of the band-shaped metal sheet (1). (1) is pressed to the extent that it can be peeled off, and then the band-shaped metal foil (2) is intermittently formed with cutting lines (4) passing through the ends on the same side of the cuts (11) and (12). After cutting in the length direction as shown in FIG.
By peeling off and removing the other metal foil strips (28), the gold f arranged at predetermined intervals on the strip metal sheet (1) is removed.
! A foil fragment (2B) was allowed to remain. Then, the metal sheet (1) having the metal foil fragments (2B) is similarly passed between the secondary pressure rolls, and as a result, the metal foil fragments (2B) are
After this was brought into contact with the band-shaped metal sheet (1) under actual pressure, it was heated to avoid diffusion bonding.

In addition, as shown in FIG. 7, approximately mouth-shaped cuts (13) are provided at predetermined intervals in the length direction in the center of the width of the strip metal foil (2), and the ends on the same side of the cuts (13) are The cutting line (4) passing through the parts may be cut so as to be continuous in the length direction. In this case, the strip metal foil (2) includes metal foil pieces (2B) spaced apart from each other at predetermined intervals, and two metal strip pieces (2A).
) (28).

In addition, the above-mentioned cut may be substantially in the shape of a mouth.

Furthermore, as shown in FIG. 8, a pair of front and rear cuts (11) and (12) extending in the width direction and parallel to each other is provided in the center of the width of the strip base F4 foil (2), and these cuts ( 1
1) (12) may be similarly cut using cutting lines (4) that are interrupted.

In addition, in the above Example 2, the band-shaped metal sheet (1)
One row of the aluminum partial cladding layer (2S) is provided in the band-shaped metal foil (2), but by providing two or more rows of the above-mentioned set of cuts (11) and (12) and the approximately opening-shaped or approximately opening-shaped cuts (13) in the strip metal foil (2). , aluminum partial clad M
(23) can also be provided in two or more rows.

Further, a band-shaped metal sheet (2S) having dissimilar metal partial cladding layers (2S) at regular intervals obtained by the method of the present invention (
1) is applicable not only to IC lead frames but also to other uses.

Effects of the Invention As described above, in the method of the first invention, a band-shaped metal sheet (1) and a band-shaped metal foil (2) made of a different material are prepared, and a band-shaped metal foil (2) is prepared. Approximately mouth-shaped notches (3) having a required size are formed at predetermined intervals in the length direction of the metal strip 11i (2) on at least one side edge of the metal sheet (1) and the metal foil strip. (2) and guide it to the primary pressure welding rolls (5) and (6), and apply the strip metal foil (2) to at least b side of the strip metal sheet (1).
1) to the extent that it can be peeled off, and then the band-shaped metal tube (2) is cut along the cutting line (4) (4) passing through the side edges of all the notches (3) or slightly inside the side edges. After cutting in the length direction to form a metal foil strip, the metal foil strips (2A) other than the substantially rectangular metal foil fragments (2B) that are alternately present with the notches (3) are peeled off and removed. Metal foil pieces (2) arranged at predetermined intervals J3 on the sheet (1)
B) is allowed to remain, and then the metal sheet (1) having the metal foil pieces (2B) is passed between rolls for secondary pressure welding,
As a result, the metal foil fragment (2B) is brought into full pressure contact with the strip-shaped fully bent sheet (1), and the method of the second invention of the present invention also includes applying pressure to the strip-shaped metal foil (2) in the width direction thereof. A pair of front and rear cuts extending parallel to each other (11) (12)
At least one row of substantially mouth-shaped or substantially mouth-shaped cuts (13) are formed at predetermined intervals in the length direction of the strip metal foil (2) when viewed from the set or plane of the strip metal sheet (1) and the strip metal foil (2). 2) and rolls for primary pressure welding (5) (6).
) and press the band-shaped metal foil (2) onto at least one side of the band-shaped metal sheet (1) to the extent that it can be peeled off against the sheet h (1). ) (12) After cutting in the length direction so as to form a cutting line (4) that passes through the ends of the body side or slightly inside the ends of the same side, make a notch (3). By peeling and removing the metal foil strips (2A) other than the substantially rectangular metal foil fragments (2B) that are present alternately with the metal foil strips (2B), the metal foil strips (2A) are arranged at predetermined intervals on the strip metal sheet (1).
B) remains, and the metal sheet (1) having the metal foil fragment (2B) is brought into secondary pressure contact.According to the method of the present invention, when the band-shaped metal foil is stacked on the band-shaped metal sheet (1), J: Even if sufficient tension is applied, the strip metal foil (2) will not break, and the position of the metal foil fragment (2A) with respect to the strip metal sheet h (1) will be extremely accurate, and the strip metal foil (2) will not break. ) is sharply cut by a required cutting line, continuous or discontinuous, so that a dissimilar metal partial cladding layer (2S) is formed on the surface of the band-shaped metal sheet (1).
can be continuously provided with good dimensional viscosity and at a constant pitch so that the peripheral edge is straight, and in addition, a resin sheet can be used for masking as in the past,
Further, there is no need to perform a troublesome etching process or a grinding process, making the work extremely easy, and furthermore, there is no problem caused by chips generated by the grinding.

[Brief explanation of drawings]

FIG. 1 is a partial plan view showing the implementation steps of the method of the present invention;
FIG. 2 is a perspective view of the same portion, and FIG. 3 is a partially enlarged plan view of a band-shaped metal foil having a notch in the first embodiment of the present invention.
FIG. 4 is a partially enlarged plan view of a band-shaped metal sheet having a dissimilar metal partial cladding layer obtained by the method of the present invention; FIG. 5 is a partially enlarged plan view showing a modified example of a band-shaped metal foil having a notch; 6 to 8 are partially enlarged plan views showing three examples of the band-shaped metal foil on the right side of the cuts in the second embodiment of the present invention, and FIG. 9 is a partially enlarged sectional view showing the implementation process of the conventional method. FIG. 10 is a side view showing a product obtained by a conventional method. (1)...Band-shaped metal sheet, (2)...Band-shaped metal foil, (2A)...Metal foil strip, (2B)...Metal foil fragment, (2S)...Different metal part Cladding layer, (3)
... Notch, (4) ... Cutting line, (5) (6) ...
・-Next pressure welding roll, (11) (12) (13)...
Cuts, above Patent applicant Showa Aluminum Co., Ltd. 114 indications 1985 Patent application No. 298833 23 Title of the invention Method 3 of providing dissimilar metal partial cladding layers at regular intervals on a band-shaped metal trunk, Amendment case and Relationships Patent Applicant Address 6-224 Kaiyama-cho, Sakai City Name Showa Aluminum Co., Ltd. t [4, Agent 6, Subject of amendment Full text of the specification and Figures 9 and 10 of the drawings. 7. hli correct description of contents (amendment) 1. Name of the invention Method for providing dissimilar metal partial cladding layers at regular intervals on a band-shaped metal sheet 2. Claims (1) A band-shaped metal sheet (1); A band-shaped metal foil (2) made of a different material is prepared, and a band-shaped metal foil (2) is prepared.
Approximately opening-shaped notches (3) having a required size are formed at predetermined intervals in the length direction of the strip-shaped metal foil (2) on at least one side edge of the strip-shaped metal sheet (1). At least one side of the strip metal sheet (1) is coated with the metal foil (2) and guided to the primary pressure welding rolls (5) (8) to the extent that the strip metal foil (2) can be peeled off from the sheet (I). Then press the strip metal foil (2) onto all the notches (
After cutting in the length direction to obtain the cutting line (4) (4) passing through the side edge of 3) or slightly inside the side edge,
Approximately rectangular metal foil pieces (2) alternating with notches (3)
By peeling and removing the metal foil strips (2A) other than B), the metal foil pieces (2B) arranged at predetermined intervals remain on the strip metal sheet (1), and then the metal foil pieces (2B) are left on the strip metal sheet (1).
2B) is passed between rolls for secondary pressure welding, and as a result, the metal foil fragments (2B) are brought into main pressure contact with the strip metal sheet (1). A method of providing partial cladding layers of dissimilar metals at regular intervals. (2) Prepare a band-shaped metal sheet (1) and a band-shaped metal foil (2) made of a different material, and place the band-shaped metal foil (
2), a pair of front and rear cuts (11) and (12) parallel to each other extending in the width direction or a cut (13) approximately in the shape of an opening or approximately in the shape of an opening when viewed from a plane are formed on the band-shaped metal foil (2).
) are formed in at least one row at predetermined intervals in the length direction, and the band-shaped metal sheet (1) and the band-shaped metal foil (2) are overlapped and guided to the primary pressure welding rolls (5) and (8) to form the band-shaped metal sheet. At least one side of (1) is covered with a sheet of metal foil (2) (
1> to the extent that it can be peeled off, and then the band-shaped metal foil (2) is attached to the above-mentioned cuts (11) (12) (1).
After cutting in the length direction to obtain a cutting line (4) that passes through the ends on the same side or slightly inside the ends on the same side of 3), cut out lines that alternate with the notches (3). By peeling and removing the metal foil strips (2 people) other than the rectangular metal foil fragments (2B), the metal foil strips (2B) arranged at predetermined intervals remain on the strip metal sheet (1), and then The metal sheet (1) with the metal foil pieces (2B) is passed between the secondary pressure rolls, so that the metal foil pieces (2B)
) is brought into full pressure contact with a band-shaped metal sheet (1). 3. Detailed Description of the Invention Industrial Field of Application The present invention relates to a method for providing partial cladding layers of dissimilar metals at regular intervals on a strip-shaped metal sheet, and relates to a method for providing dissimilar metal partial cladding layers on a strip-shaped metal sheet at regular intervals. The metal sheet is used, for example, as a lead frame for mounting an IC (heat collecting circuit). BACKGROUND OF THE INVENTION Conventionally, a strip metal sheet with an aluminum partial cladding layer used, for example, as a lead frame, has been manufactured by the following method. That is, as shown in FIG. 9, 42 alloy (Fe-4
A masking synthetic resin sheet (23) having openings (24) at predetermined intervals in the length direction is made of a band-shaped metal sheet (21) made of a 2w1% Ni alloy) and a narrower band-shaped aluminum foil (22). ) and roll it through the opening (2
The aluminum foil portion (22A) corresponding to 4) is pressed onto the metal sheet (21), and then the synthetic resin sheet (23)
Then, the aluminum foil portion (22B) on the synthetic resin sheet (23) was peeled off to leave the aluminum foil fragments on the band-shaped metal sheet (21), and then thermal diffusion bonding was performed (Japanese Unexamined Patent Publication No. 59-1080) and JP-A-58-1
(See Publication No. 30522). However, in this conventional method, when the synthetic resin sheet (23) is peeled off, the strip-shaped aluminum foil (22) is torn as shown by the chain line (1) in FIG. As shown in FIG. 10, the portion of (228) near the periphery becomes gradually thinner toward the outside, making it difficult to form a straight line. Therefore, this aluminum partial cladding layer (22S
), the thickness of the aluminum partial cladding layer at the tip of the lead will be thinner, and the bonding strength will be lower when thin aluminum wires are bonded. There was a problem. Furthermore, conventionally, there has been a method of partially brushing a band-shaped metal sheet in advance (Japanese Unexamined Patent Publication No. 59-21
487) is known, but when the aluminum foil is peeled off and removed after pressure bonding, the outline of the aluminum foil fragments remaining on the band-shaped metal sheet is difficult to form into alpha rays. A method of forming an aluminum partial cladding layer on a band-shaped metal sheet by a polishing method or a polishing method is known (see Japanese Patent Laid-Open No. 1078/1984). However, according to the former etching method, the band-shaped aluminum foil is It is etched non-uniformly not only in the thickness direction but also in the lateral direction, and the contour of the formed aluminum partial cladding layer is not straight, resulting in a decrease in dimensional accuracy, and furthermore, the process of cleaning the etching solution and drying process is difficult. In addition, the latter method generates chips, and if they are not removed sufficiently, they can damage the surface of the aluminum partial cladding layer. OBJECTS OF THE INVENTION The object of the present invention is to solve the above-mentioned problems and to provide a metal partial cladding layer of a different type on the surface of a band-shaped metal sheet so that its peripheral edge is straight. They can be provided continuously at regular intervals with high dimensional accuracy, and there is no need to use resin sheets for masking or to carry out troublesome etching or grinding processes as in the past. Furthermore, it is an object of the present invention to provide a method in which troubles do not occur due to chips generated during grinding. The method involves preparing a band-shaped metal sheet and a band-shaped metal foil made of a different material, and cutting a substantially opening-shaped notch with a desired size into at least one side edge of the band-shaped metal foil over the length of the band-shaped metal foil. Formed at predetermined intervals in the horizontal direction,
The band-shaped metal sheet and the band-shaped metal foil are stacked and guided to a roll for primary pressure welding, and the band-shaped metal foil is pressed onto at least one side of the band-shaped metal sheet to the extent that it can be peeled from the sheet. After cutting in the length direction to obtain a cutting line that passes through the side edge of the notch or a portion slightly inside the side edge, peel off and remove the metal foil strips other than the approximately rectangular metal foil pieces that alternate with the notch. By doing this, the metal foil fragments arranged at predetermined intervals remain on the strip-shaped metal sheet, and then the metal sheet having the metal foil fragments is passed between rolls for secondary pressure welding, and as a result, the metal foil fragments are bonded to the strip-shaped metal sheet. The gist of this invention is a method of providing partial cladding layers of dissimilar metals at regular intervals on a band-shaped metal sheet, which is characterized in that the metal sheets are brought into full pressure contact with each other. Next, in the method of the second aspect of the present invention, a band-shaped metal sheet and a band-shaped metal foil made of a material different from the sheet are prepared, and a pair of front and rear parallel to each other extending in the width direction of the band-shaped metal foil is provided. At least one row of approximately opening-shaped or approximately opening-shaped cuts are formed at predetermined intervals in the length direction of the strip-shaped metal foil, and the strip-shaped metal sheet and the strip-shaped metal foil are overlapped and rolled for primary pressure welding. The strip-shaped metal foil is pressed onto at least one side of the strip-shaped metal sheet to the extent that it can be peeled off from the sheet, and then the strip-shaped metal foil is attached to the edges of the same side of the above-mentioned cut or slightly inside the edges of the same side. After cutting in the length direction so as to obtain a cutting line that passes through the parts, the metal foil strips other than the approximately rectangular metal foil fragments that alternate with the notches are peeled off and removed to form a predetermined shape on the strip metal sheet. c1 The metal foil fragments lined up at intervals remain, and then the metal sheet having the metal foil fragments is passed between the holes for secondary pressure welding, and as a result, the metal foil fragments are brought into main pressure contact with the band-shaped metal sheet. The gist is a method of providing dissimilar metal partial cladding layers at regular intervals on a band-shaped metal sheet. In the above, as the band-shaped metal sheet, for example, 42 alloy (Fe-Ni alloy), iron, phosphor bronze, etc. are used. Further, as the band-shaped metal foil, high-purity aluminum with a purity of 99 wt% or more, aluminum alloy, gold, or the like is used. A metal sheet has a dissimilar metal partial cladding layer on one or both sides. - A pair of pressure rolls, both of which have smooth surfaces, are used as the next and secondary pressure rolls. The strip-shaped metal foil is formed with approximately opening-shaped notches of a required size on at least one side edge thereof at predetermined intervals in the length direction of the strip-shaped metal foil. A pair of front and rear cuts parallel to each other extending in the width direction, or cuts having a substantially mouth shape or a substantially mouth shape when viewed from a plane are formed in at least one row at predetermined intervals in the length direction of the strip-shaped metal foil. Note that the term "cut" as used herein includes a linear cut with almost no width and a slit having a certain width. In the primary pressure welding of a strip metal sheet and a strip metal foil, temporary pressure bonding is carried out by stacking them on a secondary pressure welding roll and rolling them, and the rolling reduction ratio at this time is usually 3 to 15%. preferable. Immediately after the next pressure welding, necessary cutting lines are continuously or intermittently inserted into the strip of metal foil, and the strip of metal foil is peeled off while being wound into a coil, leaving approximately rectangular pieces of the metal foil. Here, since the band-shaped metal foil is only provided with notches or cuts having a predetermined size at a constant pitch, when stacking the band-shaped metal foil on the band-shaped metal sheet, even if sufficient tension is applied, the band-shaped metal There is no tearing of the foil, the position of the foil pieces relative to the sheet metal strip is very precise, and the foil strips are sharpened to a depth corresponding to the thickness of the foil by the desired continuous or discontinuous cutting line. Since they are cut, the metal foil pieces formed after peeling off the metal foil strip have extremely high dimensional accuracy and are arranged at a constant pitch. After peeling off and removing the metal foil strip, the main pressure welding is performed by guiding the strip metal sheet containing the metal foil fragments to a secondary pressure welding roll and rolling it at a reduction rate of 5 to 20%.
It is preferable that After the secondary pressure bonding, the strip-shaped metal sheet having the metal foil pieces is usually heated in a vacuum or an inert gas atmosphere to diffusion bond the metal sheet and the metal foil pieces. Diffusion bonding after secondary pressure welding is performed in a vacuum or inert gas atmosphere to prevent oxidation of the metal sheets and metal foil pieces, or in the former case, the degree of vacuum is 10-3 to 10 −' Torr is preferable. In the latter case, it is carried out in an atmosphere of a chemically inert gas such as nitrogen gas or argon gas. The heat treatment is carried out in each case at a temperature of about 300°C to 0°C for 30 to 60 minutes to ensure sufficient interdiffusion of the strip metal sheet and the metal foil pieces. Embodiments of the present invention will be described based on the drawings.Example 1 In FIGS. 1 to 4 showing the embodiment of the first invention of the present invention, first, a belt-shaped metal sheet (1) made of 4270I, and A band-shaped metal foil (2) made of aluminum foil with a purity of 99.99vt% and made of a different material was prepared.Here, the thickness of the band-shaped metal sheet (1) was 0.32 mm.
The strip metal foil (2) has a thickness of 12 μm and a width of 15 m [++]. Notches (3) having a width of 5 m [11 mm] and a length of 12 mm were formed at intervals of r4 mm at the negative side edge of the strip-shaped metal foil (2) in the length direction by punching. And these band-shaped metal sheet (1) and band-shaped metal foil <2>
and, the protruding metal foil portion (2b) existing between the notches (3) of the band-shaped metal foil (2) is the band-shaped metal sheet (1).
The strip-shaped metal foil (2) is placed on one side of the strip-shaped metal sheet (1) and cooled to the extent that it can be peeled off, using the next pressure welding roll (5) (G). Pressure contact was made. At this time, the rolling reduction ratio by the secondary pressure welding roll (5) (B) was 12°5%. After the primary pressure welding, cut the strip metal foil (2) into all the notches 3.
) is cut in the length direction to obtain a cutting line (4) passing slightly inside the side edge of the metal foil strip (2 pieces) and a metal foil piece (3) that alternate with the notch (3). (2B) and then peeled and removed the metal foil strip (2A) to leave metal fragment cylinders (2B) lined up at predetermined intervals on the strip metal sheet (1). The metal sheet (1) having the foil fragment (2B) was passed between secondary pressure welding rolls to bring the metal foil fragment (2B) to the strip-shaped metal sheet (1) in a cold manner. At this time, The rolling reduction rate by the secondary pressure welding roll is 1
0.7%, the final thickness of the strip metal sheet (1) is 0.2511101, and the metal foil fragment (2B
) was 5 mm square, and the pitch between the metal foil pieces (2B) was 15 mm. And finally, the strip metal sheet (1) with the metal foil pieces (2B) is placed in a vacuum (10”” Torr), 45)
(Heating at ℃ for 30 minutes to diffusion bond the metal sheet (1) and the metal foil pieces (2B), thereby forming aluminum partial cladding on the strip metal sheet (1) at regular intervals, as shown in Figure 4. The strip metal sheet (1) with the aluminum partial cladding layer (2S) obtained by the above method has very precise dimensional accuracy and is advantageous, for example, as a lead frame for IC mounting. Furthermore, as shown in Fig. 5, approximately opening-shaped notches (3) of the required size were provided at predetermined intervals on the left and right edges of the band-shaped metal foil (2). In this case, after the strip-shaped metal foil (2) is pressure-welded to the wide strip-shaped metal sheet (1), the metal foil ( 2) by cutting the metal foil pieces (2B
) can be formed in two rows at predetermined intervals. Example 2 FIGS. 6 to 8 show the method of the second invention of this invention. First, in FIG. 6, a pair of front and rear cuts (11) and (12) extending in the width direction and parallel to each other are cut into a band on the negative side edge of the same band-shaped metal foil (2) as in the first embodiment. Formed in a row at predetermined intervals in the length direction of the metal foil (2),
The band-shaped metal sheet (1) and the band-shaped metal foil (2) are stacked and guided to the above-mentioned secondary pressure welding roll (5) (G), and the band-shaped metal foil (2) is sheeted on at least one side of the band-shaped metal sheet (1). (1) is pressed to the extent that it can be peeled off, and then the band-shaped metal foil (2) is intermittently formed with a cutting line (4) passing through the ends on the same side of the cuts (11) and (12). After cutting in the length direction as follows, cut [”l (11) (
By peeling and removing the metal foil strips (2A) other than the substantially rectangular metal foil fragments (2B) surrounded by 12) and the cutting line (4), the metal foil strips (2A) are placed on the strip metal sheet (1) at predetermined intervals. The lined metal foil fragments (2B) were allowed to remain. Then, the metal sheet (2B) having the metal foil fragments (2B) is similarly passed between the secondary pressure welding rolls, and as a result, the metal foil fragments (
2B) to the band-shaped metal sheet (1),
Diffusion bonding was performed by heating. Further, as shown in FIG. 7, approximately opening-shaped cuts (13) are provided at predetermined intervals in the length direction in the center of the width of the strip metal foil (2), and the ends on the same side of the cuts (13) are The cutting line (4) passing through the parts may be cut so as to be continuous in the length direction. In this case, the strip metal foil (2) includes metal foil pieces (2B) at predetermined intervals and two metal strip pieces (2A).
) (2A). In addition, the above-mentioned cut may be substantially in the shape of a mouth. Furthermore, as shown in FIG. 8, a pair of front and rear cuts (11) and (12) extending in the width direction and parallel to each other is provided at the center of the width of the strip metal foil (2), and these cuts (u
) (t2) may be cut in the same way using the cutting line (4). In addition, in the above-mentioned Example 2, the belt-shaped metal sheet (1
) is provided in one row on the aluminum partial cladding layer (2S), but two or more rows of the above-mentioned set of cuts (11) and (12) and approximately opening-shaped or approximately opening-shaped cuts (13) are provided on the strip metal foil (2). Accordingly, two or more rows of aluminum partial cladding layers (2S) can be provided. Further, a band-shaped metal sheet (2S) having dissimilar metal partial cladding layers (2S) at regular intervals obtained by the method of the present invention (
1) is applicable not only to IC lead frames but also to other uses. Effects of the Invention As described above, in the method of the first invention, a band-shaped metal sheet (1) and a band-shaped metal foil (2) made of a different material are prepared, and a band-shaped metal foil (2) is prepared. substantially opening-shaped notches (3) of a required size are formed at predetermined intervals in the length direction of the strip-shaped metal foil (2) on at least one side edge of the strip-shaped metal foil (2);
The band-shaped metal sheet (1) and the band-shaped metal foil (2) are overlapped and guided to the primary pressure welding roll (5> (6), and the band-shaped metal sheet (
At least one side of the sheet (1) is coated with a band-shaped metal foil (2).
) to the extent that it can be peeled off, and then cut lines (4) (4) passing through the side edges of all the notches (3) or slightly inside the side edges of the strip metal foil (2) are obtained. After cutting in the length direction as shown in FIG.
1) Leave the metal foil fragments (2B) lined up at predetermined intervals on the top, and then pass the metal sheet (1) having the metal foil fragments (2B) between secondary pressure welding rolls, so that the metal foil The fragment (2B) is brought into full pressure contact with the band-shaped metal sheet (1), and the method of the second invention of the present invention includes:
A pair of parallel front and rear cuts (11) (L2) extending in the width direction of the strip metal foil (2) or a cut (13) approximately in the shape of an opening or approximately in the shape of an opening when viewed from a plane.
are formed in at least one row at predetermined intervals in the length direction of the strip-shaped metal foil (2), and the strip-shaped metal sheet (1) and the strip-shaped metal foil (2) are stacked and rolled into rolls (5) and (8) for primary pressure welding. The strip-shaped metal foil (2) is pressed against at least one side of the strip-shaped metal sheet (1) to the extent that it can be peeled off from the sheet (1), and then the strip-shaped metal foil (2) is attached to the cut line (11).
(12) After cutting in the length direction to obtain a cutting line (4) that passes through the ends on the same side of (13) or slightly inside the ends on the same side, cut it alternately with the notch (3). Metal foil strips (2B) other than the approximately rectangular metal foil fragments (2B) present in
By peeling off and removing the metal sheet (1)
The metal foil fragments (2B) arranged at predetermined intervals are left on the top, and the metal sheet (1
), and according to the method of the present invention, when stacking the strip metal foil on the strip metal sheet (1), even if sufficient tension is applied, the strip metal foil (2) will not tear. Metal foil fragment (
The positions of the two people are extremely accurate, and the strip metal foil (2) is sharply cut along the required continuous or discontinuous cutting line, so that the surface of the strip metal sheet (1) is covered with dissimilar metal parts. The layers (2S) can be continuously provided with good dimensional accuracy and at a constant pitch so that the peripheral edges are straight, and there is no need to use a resin sheet for masking or the hassle of conventional methods. There is no need to perform a detailed etching process or grinding process, making the work extremely easy, and furthermore, there is no problem caused by chips generated by the grinding. 4. Brief description of the drawings FIG. 1 is a partial plan view showing the implementation steps of the method of the present invention;
FIG. 2 is a perspective view of the same portion, and FIG. 3 is a partially enlarged plan view of a band-shaped metal foil having a notch in the first embodiment of the present invention.
FIG. 4 is a partially enlarged plan view of a band-shaped metal sheet having a dissimilar metal partial cladding layer obtained by the method of the present invention; FIG. 5 is a partially enlarged plan view showing a modified example of a band-shaped metal foil having a notch; 6 to 8 are partially enlarged plan views showing three examples of the band-shaped metal foil having cuts in the second embodiment of the present invention, FIG. 9 is a partially enlarged cross-sectional view showing the implementation process of the conventional method, and FIG. FIG. 10 is a side view showing a product obtained by a conventional method. (1)...Band-shaped metal sheet, (2)...Band-shaped metal foil, (2 people)...Metal foil strip, (2B)...Metal foil fragment, (2S)...Different metal Partial cladding layer, (3)
... Notch, (4) ... Cutting line, (5) (13)
...-Next pressure welding roll, (11) (+2) (13)・
...cut. Applicant for the above patents: Showa Aluminum Co., Ltd. '21 Figure 10

Claims (2)

[Claims] (1) Prepare a band-shaped metal sheet (1) and a band-shaped metal foil (2) made of a different material, and prepare a band-shaped metal foil (2).
Approximately ■-shaped notches (3) having a required size are formed at predetermined intervals in the length direction of the strip metal foil (2) on at least one side edge of the strip metal sheet (1) and the strip metal foil (2). Foil (2
) and are guided to the primary pressure welding rolls (5) and (6), and a strip metal foil (2) is applied to at least one side of the strip metal sheet (1).
) is pressed against the sheet (1) to the extent that it can be peeled off, and then the band-shaped metal foil (2) is cut along the cutting line (4) passing through the side edges of all the notches (3) or slightly inside the side edges.
After cutting in the length direction to form (4), approximately rectangular metal foil pieces (2B) that alternate with notches (3)
By peeling off and removing the other metal foil strips (2A), metal foil pieces (2B) arranged at predetermined intervals remain on the strip metal sheet (1), and then metal foil pieces (2B) are removed.
) is passed between rollers for secondary pressure welding, and as a result, the metal foil fragment (2B) is brought into main pressure contact with the strip metal sheet (1). A method of providing partial cladding layers of dissimilar metals at intervals. (2) Prepare a band-shaped metal sheet (1) and a band-shaped metal foil (2) made of a different material, and prepare a band-shaped metal foil (2).
Then, a pair of front and rear cuts (11) and (12) parallel to each other extending in the width direction or a cut (13) in the shape of approximately The strip-shaped metal sheet (1) and the strip-shaped metal foil (2) are formed in at least one row at predetermined intervals in the direction of
) with a strip of metal foil (2) on at least one side of the sheet (1).
Then, the band-shaped metal foil (2) is pressed against the edges of the cuts (11, 12, and 13) on the same side or slightly inside the edges on the same side. After cutting in the length direction to form cutting lines (4), peel and remove the metal foil strips (2A) other than the approximately rectangular metal foil pieces (2B) that alternate with the notches (3). By doing so, the metal foil pieces (2B) arranged at predetermined intervals remain on the band-shaped metal sheet (1), and then the metal sheet (1) having the metal foil pieces (2B) is passed between the rolls for secondary pressure welding. A method for providing partial cladding layers of dissimilar metals at regular intervals on a strip-shaped metal sheet, characterized in that the metal foil fragment (2B) is brought into full pressure contact with the strip-shaped metal sheet (1).