JP2003064413A - Method and device for heating metal bar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the heat treatment of a metal bar at a low cost. SOLUTION: Two metal bars 2A and 2B of different materials are allowed to travel parallel to each other, and guided to an annealing furnace 12 at a specified speed via a first accumulator 8. The metal bars are individually wound around heating rolls 14 and 15 by about one half turn in a heating chamber 12a of the annealing furnace 12. Heating is performed through direct heat transfer so that the temperature of the metal bars is substantially equal to the temperature of the outer circumferential surfaces of the heating rolls by using a heating means such as an electric heater. The metal bars are gradually cooled until they are wound by winding rolls Aa and Ba via a second accumulator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a method for heating a metal strip for annealing and heating a band-shaped metal material having conductivity which is used for a conductive component such as a lead frame. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, lead frame materials have been used as electronic parts used as conductive terminals for electric products and electronic products.
There is a terminal connector etc., for example, a metal strip used for manufacturing a conductive component having high conductivity and thermal conductivity such as a lead frame is manufactured by rolling a metal block having high conductivity etc. There is. When a sheet-shaped or strip-shaped deformed metal strip having a substantially convex cross section as shown in FIG. 4 is manufactured by rolling a metal ingot, the metal strip becomes hard by rolling and is less likely to be plastically deformed. It is difficult to use as a conductive terminal such as a frame. Therefore, after thinning the thickness of the metal strip by rolling, it is annealed in an annealing furnace and cooled over time to soften it and reduce its hardness to impart plasticity and remove stress and strain due to rolling. Is manufactured in this way. The metal strip thus obtained is manufactured as a conductive component such as a lead frame by punching or the like. When manufacturing such a metal strip, the composition of the metal strip differs due to the required characteristics such as electrical conductivity and thermal conductivity depending on the type and application of the electronic component used as the lead frame. It was necessary to manufacture different metal ingots according to the material of the metal strip and to perform rolling under unique pressure conditions. Therefore, also in the subsequent annealing process, the annealing treatment is individually performed using the annealing furnace provided with a separate line according to the type of the metal strip.

[0003]

However, in the conventional apparatus for heating a metal strip, one line having one annealing furnace is required for heat-treating one type of metal strip, and thus a plurality of types of metal strips are required. Since a plurality of annealing furnaces and lines are required to heat treat the metal strip at the same time, there is a drawback that the cost becomes high. Alternatively, in order to heat-treat a plurality of types of metal strips in one line, the metal strips must be sequentially treated one by one, which requires a long processing time. In view of such circumstances, it is an object of the present invention to provide a heating method and a heating device for a metal strip that can heat-treat a plurality of metal strips at a relatively low cost and in a short processing time. .

[0004]

A method for heating a metal strip according to the present invention comprises heating a plurality of metal strips made of the same or different materials and heating the metal strips in one heating furnace. It is characterized in that the metal strip that has been treated and then heat-treated is conveyed from the heating furnace. When heat-treating a plurality of metal strips, regardless of the material of the metal strips, they can be treated at the same time in the same heating furnace, and the equipment and running costs are low and efficient treatment is possible.

The method for heating a metal strip according to the present invention is
While running a plurality of rolled metal strips made of the same or different materials, each of these metal strips is rapidly heat-treated in one heating furnace, and then the metal strips are gradually cooled. Is characterized by. Although the thickness of the metal strip can be set to an appropriate thickness by rolling, there is a drawback that the hardness increases, and when annealing a plurality of rolled metal strips, the material of the metal strip Regardless of whether they are the same or different, the cost can be reduced and the treatment can be performed efficiently by using the same heating furnace at a time. Further, the hardness can be reduced to facilitate the plastic deformation and the strain and internal stress due to the rolling can be removed. Further, the plurality of metal strips may be fed through one accumulator for adjusting the traveling speed provided on at least one side before and after the heating furnace. The traveling speed can be adjusted at low cost by simultaneously traveling a plurality of metal strips with a single accumulator.

The metal strip heating device according to the present invention comprises a traveling mechanism for traveling a plurality of metal strips made of the same or different materials, and one heating furnace for heating each metal strip to an appropriate temperature. It is characterized by When heat-treating a plurality of metal strips, it is possible to perform heat treatment at the same time in the same heating furnace regardless of the material of the metal strips, and it is possible to perform heat treatment efficiently with low equipment cost and running cost.

Further, the traveling mechanism further comprises an accumulator which is arranged on at least one side before and after the heating furnace to adjust the traveling speed of the metal strip, and the metal strip is gradually heated in the heating furnace and then gradually heated. It is characterized by being cooled. The thickness of the metal strip can be set to an appropriate thickness by rolling, but there is a drawback that the hardness increases, and when annealing a plurality of rolled metal strips, the metal strip material Heat treatment can be performed at a low cost and efficiently by performing heat treatment at the same time in the same heating furnace regardless of the difference, and further, the hardness can be reduced to facilitate plastic deformation, and distortion and internal stress due to rolling can be removed. Further, the heating furnace may be provided with a plurality of heating rolls or an induction furnace for respectively heating the plurality of metal strips. If the metal strips are individually heated by a plurality of heating rolls, the temperature can be individually set according to the material of each metal strip, and more precise heat treatment can be performed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A heating apparatus for a metal strip according to an embodiment of the present invention will be described below with reference to FIGS. 1 is a schematic configuration diagram showing a line of a heating device according to an embodiment, FIG. 2 is a partial plan view showing a metal strip wound around a part of a roll in a first accumulator of the heating device shown in FIG. 1, and FIG. It is a partial side view which shows arrangement | positioning of the heating roll in an annealing furnace. In the heating device 1 according to the embodiment of the present invention shown in FIG. 1, the strip-shaped metal strip 2 manufactured by rolling has, for example, a vertical cross-section as shown in FIG. However, the cross-sectional shape of the metal strip 2 is not limited to such an irregular shape, and another appropriate irregular shape or a flat plate shape can be used. This metal strip 2 is formed in a convex cross section by providing thin side portions 2b, 2b on both sides of a thick central portion 2a.
The thin side parts 2b, 2b are processed into a lead frame or the like by punching after annealing by the heating device 1. Here, as the metal strip 2, two types of strips having different materials, for example, Cu-Fe-P alloy and Cu-
Heat treatment is applied to a strip made of P alloy, and Cu-F
One strip 2 made of an e-P alloy is a metal strip 2A,
The other strip 2 made of a Cu-P alloy is referred to as a metal strip 2B. And one of the strips 2A is a set of feeding rolls A
1 and A2, and the other strip 2B is wound around another set of feeding rolls B1 and B2.

In the heating device 1, two lines AA and BB are arranged as a traveling mechanism so that the two metal strips 2A and 2B are separately conveyed and wound by two winding rolls Aa and Ba. Have been established. The strip-shaped metal strips 2A, 2B are respectively fed in parallel from the feeding rolls A1, B1 of one set of feeding rolls A1, A2, B1, B2 onto the lines AA, BB, respectively. When all the metal strips 2A and 2B from the rolls A1 and B1 are fed out, the rear end of the metal strips 2A and B2 is welded to the leading ends of the other delivery rolls A2 and B2, respectively.
A and 2B are continuously fed out. The metal strips 2A and 2B delivered from the delivery rolls A1 and B1 are guided and conveyed while being wound by the feed rolls 5 and 6 along the respective lines AA and BB for about half a turn, and then to the first accumulator 8. Will be sent.

In the first accumulator 8, for example, as a set of upper and lower rolls, a plurality of upper rolls 9a, 9b ... And a plurality of lower rolls 10a, 10b. The upper rolls 9a, 9b ... And the lower rolls 10a, 10b ... which are arranged and are opposed to each other are arranged so that the distances between the upper rolls 9a, 9b ... Moreover, the upper rolls 9a, 9b, ... And the lower rolls 10a, 10b, ... Which face each other are vertically displaceable with respect to each other in order to adjust the distance between each pair of the upper roll and the lower roll that face each other. Before and after the accumulator 8, the conveying speed of the metal strips 2A, 2B on the downstream side is constant with respect to the fluctuation of the tension (conveying speed) of the metal strips 2A, 2B on the upstream side, that is, the feeding rolls A1, B1 ... The position is adjusted to control, for example, 10 to 15 m / min. The plurality of upper rolls 9a, 9b ... And the plurality of lower rolls 10a, 10b ... are, for example, as shown in FIG. Each of the lower rolls is wound around about half a turn and is sequentially fed to the other lower or upper roll that faces the lower roll (only the upper roll 9a is shown in the figure). Therefore, the metal strips 2A and 2B are simultaneously stretched around the upper and lower rolls 9a, 9b ... 10a, 10b ... so that the traveling speed of the first accumulator 8 can be adjusted simultaneously. The speeds of the metal strips 2A and 2B may be adjusted individually by separate upper and lower roll groups.

A single annealing furnace 12 is provided downstream of the first accumulator 8 as a heating furnace.
In the heating chamber 12a of the two heating rolls 14 for heating the metal strips 2A, 2B on the respective lines AA, BB,
For example, as shown in FIG. 3, 15 are arranged so as to be displaced in the vertical direction. The heating rolls 14 and 15 are integrally formed concentrically with the mutually parallel rotating shafts 16 and 17, and transmit the driving force to the rotating shafts 16 and 17 via drive belts 18 and 19 that transmit the rotating force of a drive motor (not shown). It is configured.
Moreover, since the heating rolls 14 and 15 are expanded in diameter with respect to the rotary shafts 16 and 17, they are arranged so as to be offset from each other in the longitudinal direction of the rotary shafts 16 and 17, so that the storage space such as the furnace width is set small. The finished annealing furnace 12 is downsized. An inert gas such as nitrogen or argon, a reducing gas such as hydrogen or carbon monoxide, or a mixed gas thereof is supplied into the heating chamber 12a of the annealing furnace 12 to maintain an additive or reducing atmosphere, The oxide film of the metal strips 2A and 2B is removed. Further, the heating chamber 12a of the annealing furnace 12 is provided with the metal strips 2A and 2A.
Sealing means (not shown) is provided at the entrance and exit of B to hermetically close the heating chamber 12a. A cooling chamber 13 for cooling the metal strips 2A and 2B that has passed through the heating chamber 12a is provided in the annealing furnace 12.

Inside the heating rolls 14 and 15, heating means (not shown) by electric heat or combustion heat is provided, and the temperature of the outer peripheral surface of the heating rolls 14 and 15 is annealed to the metal strips 2A and 2B by this heating means. It is heated to a temperature (for example, about 840 ° C.). The heating roll is made of metal strip 2A, 2
According to the method of contacting with B and heating, the heat transfer effect is 5 times or more as compared with the ordinary heating furnace, and not only the rapid heating that is difficult in the ordinary heating furnace is possible, Since the heat is evenly distributed over the entire area of the metal strips 2A and 2B, uniform heating is possible.
It is easy to accurately adjust the tension applied to B. In the heating chamber 12a, an auxiliary heating means such as a burner or a high frequency induction heating device may be provided. Although the material of the heating rolls 14 and 15 is not limited, it is generally preferable that the heating rolls 14 and 15 are formed of a metal having excellent heat resistance, and the outer peripheral surface thereof is mirror-finished so as to be in close contact with the metal strips 2A and 2B. It is preferable. The outer diameter and width of the heating rolls 14 and 15 are not particularly limited, but are generally 50 to 100 cm in consideration of the ease of heating, the thickness of the metal strip to be treated, and the traveling speed.
The width is set to about 60 to 90 cm, and the width is set to about 150 mm, for example.

The rotation speed of the heating rolls 14 and 15 is not limited, but the metal strip 2 set by the first accumulator 8 is used.
It is preferable that the traveling speed of A and 2B is set to be slightly higher than 10 to 15 m / min.
It is good to make it about 1 to 10% faster. This is heating roll 1
In the process in which the metal strips contact the outer circumferences of Nos. 4 and 15 and the temperature rises, the metal strips gradually thermally expand, and there is a risk of peeling between the heating roll and the metal strips due to slack. Is. When peeling occurs, heat conduction from the heating roll to the metal strip is hindered and the temperature of the metal strip becomes non-uniform. In the illustrated example, the metal strip 2A,
2B has a central angle of about 180 on the outer peripheral surfaces of the heating rolls 14 and 15.
The metal strips 2A, 2B are wound by an angle of .degree., And the other ends of the metal strips 2A, 2B are extended downward. As a result, the metal strips 2A and 2B come into close contact with the heating rolls 14 and 15 in a wide range, and are rapidly heated by direct heat conduction until the temperature becomes substantially equal to the outer peripheral surface temperature of the heating rolls, so that the line speed is high. However, the metal strip can be heated uniformly and with high accuracy. In addition, the heating method by contacting the rolls is not only low in heating cost because the thermal efficiency is several times higher than that of the vapor phase heating method, but also the metal strips 2A and 2B are applied to the metal strips 2A and 2B by the heating rolls 14 and 15 in the heating process. Since the tension can be adjusted uniformly, even a strip material having a different shape can be uniformly heated to a high temperature. Therefore, it is particularly suitable for annealing and heating to 800 ° C. or higher.

A second accumulator 20 is arranged on the downstream side of the annealing furnace 12 in the lines AA and BB, and a winding roll Aa for winding the annealed metal strips 2A and 2B, respectively, on the downstream side. , Ba are provided. The second accumulator 20 has substantially the same configuration as the first accumulator 8 and includes a plurality of upper rolls 9a and 9b.
... and a plurality of lower rolls 10a, 10b ... are sequentially arranged in the horizontal direction so as to be offset by their outer diameters, and the distance between the upper rolls 9a, 9b ... And the lower rolls 10a, 10b. The upper rolls 9a, 9b facing each other are arranged so as to become smaller toward the front in the direction.
, And the lower rolls 10a, 10b, respectively, are vertically displaceable with respect to each other in order to adjust the distance between the upper roll and the lower roll facing each other. In the second accumulator 20, before and after that, the traveling speed (tension) of the metal strips 2A, 2B on the upstream side, that is, on the side of the annealing furnace 12, etc. is kept constant, and on the downstream side, the winding rolls Aa, Ba are wound. The distance between the upper roll and the lower roll is increased / decreased so that the transport speed of the metal strips 2A, 2B decreases as the outer diameter increases. This prevents excessive tension from being applied to the metal strips 2A and 2B as the winding diameter increases.

The heating device 1 according to the present embodiment has the above-mentioned structure. Next, the annealing method will be described with reference to FIG. Each set of feeding rolls A1, A2 and B
1 and B2 are, for example, Cu-F having an irregular shape with a convex cross section.
Two kinds of metal strips 2A and 2B made of e-P alloy and Cu-P alloy, which are different in material, are wound, and the metal strips 2A and 2B have their wall thickness changed by the rolling process in the previous process. The hardness is increasing. Then, the metal strips 2A and 2B of different material types are respectively delivered from the respective one of the delivery rolls A1 and B1, and are delivered to the first accumulator 8 in parallel, for example, via the delivery rollers 5 and 6. Here, after all the metal strips 2A, 2B of the respective one of the delivery rolls A1, B1 have been delivered, the rear end thereof is welded to the tip of the metal strips 2A, 2B of the other delivery rolls A2, B2. Connect each other to each other, and further perform continuous feeding.

In the first accumulator 8, as shown in FIG. 2, two metal strips 2A and 2B are wound around each roll between a plurality of upper and lower rolls 9a. Run in parallel. First accumulator 8
Of the metal strips 2A, 2B on the upstream side of the feeding roll A1,
The traveling speed changes according to the change in the outer diameter of A2, B1, B2, and the metal strips 2A, 2B on the downstream side, that is, the delivery side, are adjusted by adjusting the distance between the upper and lower rollers 9a, 10a ,. The traveling speed is controlled to be constant at, for example, 10 to 15 m / min. Then, the metal strips 2A, 2B are made to travel upward through the transport rollers 25, 26 and sent into the heating chamber 12a of the single annealing furnace 12, where the metal strips 2A, 2B are respectively.
The linear bottom surface of the convex cross section is closely attached to the heating rolls 14 and 15, and one metal strip 2A is wound around the heating roll 14 and the other metal strip 2B is wound around the heating roll 15 for about a half turn, respectively, and is moved downward. Sent to. Here, each metal strip 2A, 2B
In a reducing atmosphere such as argon gas, for example (84
Directly receives heat conduction by the heating rolls 14 and 15 that are heated to about 0 ° C), and rapidly and uniformly at 800 ° C with high accuracy.
Is heated to the desired temperature above. Thereby, a plurality of metal strips 2A and 2B having different materials can be annealed at a time. The heating temperatures of the heating rolls 14 and 15 may differ depending on the materials of the metal strips 2A and 2B. In this case, the heating temperatures of the strips 2A and 2B also have different values.

After that, the respective metal strips 2A and 2B are annealed in the annealing furnace 1.
In the process of passing through the cooling chamber 13 inside 2, it is gradually cooled over time, and the temperature is lowered at, for example, 10 ° C./second for about 30 seconds. In this process, the metal strips 2A and 2B become soft materials that are easily plastically deformed due to the decreased hardness increased in the rolling process, and at the same time, the strain and internal stress caused by rolling can be removed. Further, the second accumulator 20 keeps the traveling speed of the metal strips 2A and 2B on the upstream side constant, and the feed rollers 27 and 28 on the downstream side.
The traveling speed is controlled in accordance with the change in the winding outer diameter when being wound by the winding rolls Aa and Ba via the. Each of the metal strips 2A thus annealed is
2B is wound on the winding rolls Ab and Bb, respectively.

As described above, according to the present embodiment, a plurality of types of deformed metal strips 2A, 2B are connected to a plurality of lines AA,
BB using single annealing furnace 12 and each single first and second
It can be processed together by accumulators 8 and 20,
Heat treatment cost can be reduced and efficient treatment can be performed.

In the above embodiment, the two metal strips 2A and 2B are introduced into the annealing furnace 12, but three or more strips may be used. Although the heating roll is used as the heating means of the heating furnace, the heating means is not limited to this, and various heating means such as an induction furnace can be adopted, and various heat transfer methods such as gas phase heating can be used in addition to direct heating. it can. Further, although the annealing treatment is performed as the heat treatment, it goes without saying that the heating apparatus and method of the present invention are not limited to this and can be used for various heat treatments. Moreover, in the above-mentioned embodiment, the metal strip 2
As A and 2B, those having different shapes of convex cross-sections were used, but the present invention is not limited to this, and it is possible to perform heat treatment of flat metal sheets and other various shapes. Further, the plurality of metal strips to be heat-treated are not necessarily different materials, and a large number of metal strips can be efficiently heat-treated by simultaneously transporting and heat-treating a plurality of strips of the same material.

[0020]

The method for heating a metal strip according to the present invention is a method in which a plurality of metal strips made of the same or different materials are run, and each of these metal strips is heat-treated in one heating furnace. Since the heat-treated metal strips are transported from the heating furnace, multiple metal strips can be processed at the same time in the same heating furnace regardless of the material of the metal strips, and the equipment and running cost are low. Can be processed efficiently.

The method for heating a metal strip according to the present invention is
While running a plurality of rolled metal strips made of the same or different materials, each of these metal strips is rapidly heat-treated in one heating furnace, and then the metal strips are gradually cooled. , When annealing multiple rolled metal strips, the cost can be reduced and the efficiency can be improved by performing the treatment at the same time in the same heating furnace regardless of the material of the metal strips. The reduced hardness can be reduced to facilitate plastic deformation, and strain and internal stress due to rolling can be removed. Further, since the plurality of metal strips are fed through one accumulator for adjusting the traveling speed provided on at least one side before and after the heating furnace, the plurality of metal strips can be simultaneously traveled by a single accumulator. The traveling speed can be adjusted at low cost.

The metal strip heating apparatus according to the present invention comprises a traveling mechanism for traveling a plurality of metal strips made of the same or different materials, and one heating furnace for heating each metal strip to an appropriate temperature. Therefore, regardless of the difference in the material of the metal strip, the same heating furnace can perform the treatment at a time, and the equipment cost and running cost are low, and the treatment can be performed efficiently. Further, the traveling mechanism further includes an accumulator disposed on at least one side before and after the heating furnace to adjust the traveling speed of the metal strip, and the metal strip is rapidly heated in the heating furnace and then gradually cooled. As a result, equipment costs and running costs are reduced. Further, since the heating furnace is provided with a plurality of heating rolls or induction furnaces for heating a plurality of metal strips, if the metal strips are individually heated by a plurality of heating rolls, the individual metal strips can be heated. The temperature can be set according to the material, and more precise heat treatment can be performed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a line of a heating device according to an embodiment of the present invention.

FIG. 2 is a partial plan view showing a metal strip wound around a part of the rolls in the first accumulator shown in FIG.

FIG. 3 is a partial side view showing the arrangement of heating rolls in an annealing furnace.

FIG. 4 is a perspective view including a vertical cross section of a metal strip.

[Explanation of symbols] 1 heating device 2A, 2B metal strip 8 First accumulator 12 Annealing furnace (heating furnace) 20 Second accumulator A1, A2, B1, B2 feeding roll Aa, Ba winding roll

Claims (6)

[Claims] 1. A plurality of metal strips made of the same or different materials are run, each of these metal strips is heat-treated in one heating furnace, and then the heat-treated metal strip is removed from the heating furnace. A method for heating a metal strip, which is characterized by being transported. 2. A plurality of rolled metal strips made of the same or different material are run, and these strips are rapidly heat-treated in one heating furnace, and then the strips are gradually heated. A method for heating a metal strip, which is characterized in that it is cooled. 3. A plurality of metal strips are fed through one accumulator for adjusting the traveling speed, which is provided on at least one side in front of and behind the heating furnace. The heating method for the described metal strip. 4. A metal strip heating device comprising a traveling mechanism for traveling a plurality of metal strips made of the same or different materials, and one heating furnace for heating each of the metal strips to an appropriate temperature. 5. The traveling mechanism further comprises one accumulator arranged on at least one of the front and rear sides of the heating furnace for adjusting the traveling speed of the metal strip.
The metal strip heating device according to claim 4, wherein the metal strip is rapidly heated in a heating furnace and then gradually cooled. 6. The metal strip according to claim 4 or 5, wherein the heating furnace is provided with a plurality of heating rolls or an induction furnace for respectively heating a plurality of metal strips. Heating device.