JPH11330113A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a highly reliabile semiconductor device at a low cost while holding its miniaturized shape in a semiconductor device manufacturing device for encapsulating a semiconductor element loaded on a substrate by resin. SOLUTION: This manufacturing method for manufacturing a BGA-type semiconductor device, e.g. has a junction process for jointing dam parts 35 integrally formed on a dam sheet 31A via connection parts 33 to a device substrate 34 on which semiconductor elements 38 divided into pieces are previously loaded, a resin applying process for applying bonding resin 39 to the inside of a recessed part formed by the dam parts 35 and the substrate 34 and a cutting process for cutting the connection parts 33 to form a semiconductor device as a single piece.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device in which a semiconductor element mounted on a substrate is sealed with a resin. In recent years, the miniaturization of electronic devices such as mobile phones has been rapidly progressing, and accordingly, there has been an increasing demand for miniaturization of semiconductor devices mounted in the electronic devices.

On the other hand, electronic equipment is required to have high reliability and low cost, and therefore, it is necessary for a semiconductor device and a manufacturing method for manufacturing the same to meet these requirements.

[0003]

2. Description of the Related Art FIGS. 7 to 13 are views for explaining a conventional method of manufacturing a semiconductor device. In the following description, as a semiconductor device, a semiconductor element mounted on a circuit board (hereinafter, referred to as a device side substrate) is sealed with a resin, and a ball grid electrode (BGA) having a ball electrode on a lower surface.
The method of manufacturing the ay) type semiconductor devices 10A to 10D will be described as an example.

FIG. 7 is a view for explaining a method of manufacturing a semiconductor device according to a first conventional example. In the manufacturing method shown in the figure, first, at a plurality of predetermined positions (only one is shown in the figure) of the resin substrate 1 having a multilayer wiring substrate structure made of glass-epoxy.
Then, a plurality of device substrates 4 are formed by forming the groove portions 2 while leaving the connecting portions 3. Therefore, the formed device substrate 4 is configured to be supported on the resin substrate 1 by the connecting portion 3.

Subsequently, a bare chip-shaped semiconductor element (not shown) is mounted on the upper part of the device substrate 4, and the semiconductor element is sealed with a molding resin 5. FIG. 7A shows a resin substrate 1 in which a mold resin 5 is formed on a device substrate 4. Device substrate 4 as described above
After the mold resin 5 is formed, a process of cutting the device substrate 4 from the resin substrate 1 is performed. This cutout processing is performed using the router 6 as shown in FIG. The router 6 cuts the resin substrate 1 by rotation to form a processing groove 7, and forms the processing groove 7 on the entire outer periphery of the apparatus substrate 4 along the groove 2 formed in advance. I do.

Accordingly, the connection portion 3 is removed by forming the processing groove 7 on the entire outer periphery of the device substrate 4, the device substrate 4 is separated from the resin substrate 1, and the semiconductor device shown in FIG. 10A is manufactured. After or before the device substrate 4 is separated from the resin substrate 1, a process of arranging ball electrodes (for example, solder bumps) on the lower surface of the device substrate 4 (ball arranging process) is performed. The description of the ball arrangement processing is omitted. The same applies to each conventional example described below.

FIG. 8 is a view for explaining a method of manufacturing a semiconductor device according to a second conventional example. In FIG. 8,
The same components as those of the first conventional example shown in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted. In the manufacturing method shown in FIG. 8, as shown in FIG. 8A, the groove 2, the connecting portion 3, and the device substrate 4 are formed in the resin substrate 1, and the semiconductor element 8 is mounted on the device substrate 4. I do. In this conventional example, subsequently, as shown in FIG. 8B, a potting resin 9 is formed by potting a resin on the device substrate 4, and the semiconductor element 8 is sealed with a resin.

Subsequently, the resin substrate 1 on which the potting resin 9 is formed is mounted on a punching device 14 (described in detail later) shown in FIG. 10, and the connecting portion 3 is cut by punching. As a result, the device substrate 4 is separated from the resin substrate 1, and the semiconductor device 10B shown in FIG. 8C is manufactured. FIG. 9 is a view illustrating a method of manufacturing a semiconductor device according to a third conventional example. In FIG. 8, the same components as those of the first conventional example shown in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted.

[0009] The manufacturing method shown in FIG.
The processing up to the state shown in FIG. 8A in the conventional example is the same processing. However, in the prior art, after the semiconductor element 8 is mounted on the device substrate 4 or from the beginning, a frame-shaped dam 13 is disposed on the upper portion of the device substrate 4 and the potting resin 9 is placed thereon.
Is potted in the dam 13. FIG. 9A shows a state in which the potting resin 9 is provided in the dam 13. Since the height of the dam 13 is high enough to seal the semiconductor element 8, the semiconductor element 8 is resin-sealed by disposing the potting resin 9 in the dam 13. .

When the semiconductor element 8 is sealed with the potting resin 9, the resin substrate 1 is mounted on a punching device 14 shown in FIG.
Is disconnected. As a result, the device substrate 4 becomes the resin substrate 1
And the semiconductor device 10C shown in FIG. 9B is manufactured. FIG. 10 shows a punching device 14 used in the second and third conventional examples. The punching device 14 is roughly composed of a holding jig 15, a die 16, a punch 17, and the like. In order to cut the connecting portion 3 using the punching device 14, the resin substrate 1 is placed at a predetermined position on the die 16, and the resin substrate 1 is pressed toward the die 16 by the holding jig 15.

A pressing spring 19 is provided above the holding jig 15, and the holding jig 15 is pressed toward the die 16 by the spring force of the pressing spring 19. This allows
The resin substrate 1 is held between the holding jig 15 and the die 16. In addition, the resin substrate 1 is
The punch 17 is provided at a position facing the connecting portion 3 in a state where the punch 17 is mounted. The punch 17 is provided with a recess 18 provided in the die 16 by a hydraulic device (not shown).
It is configured to move downward. Therefore, punch 1
The connecting portion 3 is sheared by 7. This allows
The device substrate 4 is separated from the resin substrate 1 as described above, and the semiconductor devices 10B and 10B shown in FIGS.
C can be manufactured.

FIG. 11 is a view for explaining a method of manufacturing a semiconductor device according to a fourth conventional example. In FIG. 11, the same components as those of the first conventional example shown in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted.
In the manufacturing method shown in FIG. 11, the counterbore 20 is located at the mounting position of the semiconductor element 8 on the device substrate 4 formed on the resin substrate 1.
(Recess), and the semiconductor element 8 is formed in the counterbore 20.
With. Subsequently, the semiconductor element 8 is resin-sealed with the potting resin 9 as shown in FIG.

When the semiconductor element 8 is sealed with the potting resin 9, the resin substrate 1 is mounted on the punching device 14, and the connecting portion 3 is punched.
Is disconnected. As a result, the device substrate 4 becomes the resin substrate 1
Then, the semiconductor device 10C shown in FIG. 11B is manufactured. FIG. 12 is a view illustrating a method of manufacturing a semiconductor device according to a fifth conventional example. In FIG. 12, the same components as those of the first conventional example shown in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted.

The manufacturing method shown in FIG. 12 is a so-called push-back method. In the pushback method, first, the device substrate 4 is punched from the resin substrate 1 and then returned by inserting the device substrate 4 again into a punched hole 23 formed in the resin substrate 1 by punching. Perform other semiconductor manufacturing steps such as stopping.

[0015]

However, in each of the above-mentioned conventional examples, the following problems have occurred. In the manufacturing method according to the first conventional example shown in FIG. 7, since the router 6 cuts the resin substrate 1 to form the processing groove 7, the cutting is performed at a position closer to the mold resin 5 than the surface where the mold resin 5 is prevented from peeling. Processing cannot be performed, and as shown in FIG. 7 (C), a portion where the apparatus substrate 4 extends in a flange shape by an amount indicated by an arrow L1 on the outer peripheral portion of the mold resin 5 (hereinafter, this portion is cut). Is called). Therefore, there is a problem that the size of the manufactured semiconductor device 10A cannot be reduced.

In the manufacturing method according to the second conventional example shown in FIG. 8, when the potting resin 9 is formed, the potted resin flows into the groove 2 and the liquid dripping portion 11 is formed. As shown in FIG. 8C, when the liquid dripping portion 11 occurs, the outer shape of the semiconductor device 10B substantially increases, and the semiconductor device 10B manufactured in the conventional example also increases in size. Problems arise.

Further, in the manufacturing method according to the third conventional example shown in FIG. 9, the dam 13 is provided to suppress the generation of the liquid dripping portion 11 generated in the second conventional example. However, by disposing the dam 13 above the device substrate 4,
As shown in FIG. 9B, when the connecting portion 3 is cut, the convex portion 12 is formed, and the outer shape of the semiconductor device 10C is substantially increased. However, there is a problem that the size is increased. The formation of the convex portion 12 is the same in the semiconductor device 10B according to the second conventional example described above with reference to FIG.

Here, the reason why the convex portion 12 occurs in the second and third conventional examples will be described. As described with reference to FIG. 10, the cutting of the connecting portion 3 is performed using the punching device 14. In this punching device 14, a plurality of (in the second and third conventional cases, four for one device substrate 4) connecting portions 3 can be cut simultaneously and collectively,
The cutting process can be performed efficiently, and the semiconductor device 10
B, 10C can be reduced in cost.

However, in the configuration in which the projections such as the potting resin 9 or the dam 13 are provided on the apparatus substrate 4,
When pressing the resin substrate 1 with the holding jig 15 constituting the punching device 14, it is necessary to press the resin substrate 1 outside the position where the potting resin 9 or the dam 13 is provided. Further, since the holding jig 15 needs to hold the punch 17 for cutting the connecting portion 3 so as to be movable in the vertical direction, a certain thickness is provided inside the position where the punch 17 is provided (that is, the cutting position). Required.

For this reason, a certain distance (hereinafter referred to as "holding allowance") indicated by an arrow L2 in FIG. 10 is required between the potting resin 9 or the dam 13 and the actual cutting position. Since the press allowance L2 remains on the apparatus substrate 4 even after the connection portion 3 is cut, the protrusion 12 is formed. That is, in the configuration in which the connecting portion 3 is provided on the resin substrate 1 and the potting resin 9 or the dam 13 is provided on the upper portion of the device substrate 4, the convex portion 12 is inevitably generated, and the semiconductor device 1
The size of 0B and 10C is increased.

On the other hand, in the manufacturing method according to the fourth conventional example shown in FIG. 11, since the concave counterbore portion 20 has the same function as the dam 13, the generation of the liquid dripping portion 11 can be suppressed. . Further, since there is no component protruding above the substrate for apparatus 4, the holding jig 15 constituting the punching device 14 can press on the substrate for apparatus 4, as shown in FIG. The projections 12 are not formed on the manufactured semiconductor device 10D, and the size can be reduced.

However, as in the second to fourth conventional examples described above, the resin substrate 1 having the multilayer wiring board structure is punched by the punching device 14 to cut the connecting portion 3 in a shearing manner. As shown in FIG. 13, there is a possibility that a peeling portion 22 is generated on the cut surface 21. As described above, when the peeled portion 22 is generated on the cut surface 21, in the resin substrate 1 having the multilayer wiring board structure in which the internal wiring is formed for each layer, there is a possibility that the internal wiring is cut due to delamination.
There is a problem that the reliability of the manufactured semiconductor devices 10B to 10D is reduced.

Further, in the manufacturing method according to the fifth conventional example shown in FIG. 12, although the generation of the liquid dripping portion 11 and the convex portion 12 can be suppressed by using the pushback method, the apparatus substrate 4 is formed in the punched hole 23. After returning, the device substrate 4
Is held by the resin substrate 1 only by the fitting force with the inner peripheral portion of the punched hole 23. Therefore, when heat is applied at the time of the resin molding or potting process performed thereafter, or when an impact is applied during the transportation,
There is a problem that the device substrate 4 may be detached from the resin substrate 1. Further, as described in the fourth embodiment, there is a possibility that a peeled portion 22 may be generated on the cut surface 21 at the time of punching.
There is also a problem that the reliability of 10D is reduced.

The present invention has been made in view of the above points, and has as its object to provide a method of manufacturing a semiconductor device capable of manufacturing a highly reliable semiconductor device at a low cost while reducing the size.

[0025]

The above-mentioned object can be attained by taking the following means. In the method for manufacturing a semiconductor device according to the first aspect of the present invention, a dam is formed integrally with a dam sheet via a connecting portion on a substrate on which a semiconductor element singulated in advance is mounted or a substrate before mounting. A joining step of joining parts, a resin disposing step of disposing a resin in a concave portion formed by the dam part and the substrate, and a cutting step of cutting the connecting part into individual semiconductor devices. It is characterized by having.

According to a second aspect of the present invention, in the method of manufacturing a semiconductor device according to the first aspect, the dam sheet and the substrate are made of the same material. Further, in the invention according to claim 3, in the method for manufacturing a semiconductor device according to claim 1 or 2,
In the cutting step, the connecting portion is cut by punching.

Each of the means described above operates as follows.
According to the first aspect of the invention, the substrate used in the bonding step is basically singulated in advance. Since this substrate is singulated before the resin disposing step, the singulation of the substrate is not restricted by the resin or dam, and therefore, a cutting margin (see L1 shown in FIG. 7C) is provided. There is no need to do so, and the substrate can be downsized. In addition, although it was assumed that the individual pieces were basically divided into individual pieces in the above, a method of cutting only the substrate side after joining to the dam sheet in a continuous state is included.

Further, since the dam portion is formed integrally with the dam sheet via the connecting portion, by performing the joining step, the substrate is joined to the dam portion (that is, the dam sheet). Becomes In the subsequent resin disposing step, in order to dispose the resin in the concave portion formed by the dam portion and the substrate,
It is possible to prevent the liquid from dripping out of the substrate outside of the substrate, which can also reduce the size of the manufactured semiconductor device.

In the cutting step, the connecting portion formed on the dam sheet is cut to singulate the semiconductor device. Therefore, even if the cutting process is performed, the substrate is not affected at all,
Therefore, peeling does not occur on the substrate. Therefore, the internal wiring of the substrate is not damaged, and the reliability of the manufactured semiconductor device can be improved.

According to the second aspect of the present invention, since the dam sheet and the substrate are made of the same material, even if heat is applied in the resin disposing step after joining the substrate to the dam sheet, Since the coefficient of thermal expansion of the dam sheet and that of the substrate are equal, peeling does not occur, and the generation of liquid dripping can be reliably prevented.

Further, according to the third aspect of the present invention, by cutting the connecting portions by punching in the cutting step, a plurality of connecting portions supporting the substrate can be cut at a time. The manufacturing efficiency of the semiconductor device can be improved as compared with a configuration in which the connecting portion is cut.

[0032]

Next, embodiments of the present invention will be described with reference to the drawings. 1 to 5 are views for explaining a method of manufacturing a semiconductor device according to one embodiment of the present invention, and particularly show a bonding step, a resin disposing step, and a cutting step in a semiconductor manufacturing step. I have.

In the following description, the semiconductor device is B
GA (Ball Grid Array) type semiconductor device 30 (FIG. 5)
) Will be described as an example. Further, the present embodiment is characterized by the above-described bonding step, resin disposing step, and cutting step, and other manufacturing steps for manufacturing the semiconductor device 30 are well known. Only the resin disposing step and the cutting step will be described.

FIGS. 1 and 2 show the joining process.
In this joining step, a process of joining the dam portion formed on the dam sheet 31A to the device substrate 34 which has been individually separated (hereinafter, referred to as “individualized”) is performed. The device substrate 34 is a multilayer wiring substrate made of, for example, glass-epoxy, and has a semiconductor element 38 mounted on the upper surface thereof. After a plurality of the device substrates 34 are formed on a resin substrate (not shown), the devices 34 are singulated using a router, for example. That is, the device substrate 34 is configured to be singulated in advance before performing the bonding process.

As described above, in the present embodiment, the apparatus substrate 34 is singulated before performing the above-described steps (joining step, resin disposing step, cutting step). No resin or dam is provided on the device substrate 34. For this reason, it is not necessary to provide a cutting margin (see L1 shown in FIG. 7C) when cutting or grinding the device substrate 34 for singulation, and thus the size of the device substrate 34 can be reduced. it can.

The apparatus substrate 34 is singulated using a cutting or grinding means such as a router. At this time, since the cutting or grinding direction is set to be different from the laminating direction of each layer constituting the device substrate 34, a peeled portion does not occur at the cutting position or the grinding position. Therefore, the device substrate 34 maintains high reliability.

On the other hand, the dam sheet 31A is a flat plate member made of glass-epoxy, the same as the material of the device substrate 34, and the connecting portion 33 is provided at a plurality of predetermined positions (only one is shown in the figure). A plurality of dam portions 35 are formed by forming the groove portions 32 while leaving them. The dam 35 has a rectangular frame shape having an opening 36 in the center,
The outer shape is configured to be substantially equal to the outer shape of the device substrate 34 described above. Also, the dam 35
Dam seat 31 is provided by a plurality of (four in the figure) connecting portions 33.
A.

The above-mentioned substrate 34 for the device is made of the dam sheet 3.
It is joined to the lower part of the dam part 35 formed in 1A using an adhesive. At this time, the adhesive used is the dam sheet 3
A glass-epoxy substrate, which is a base material of the substrate 1A and the device substrate 34, is selected to have substantially the same thermal expansion coefficient. FIG. 2 shows a state in which the dam sheet 31A is joined to the device substrate 34. As shown in FIG.
The dam sheet 31A is joined to the
The device substrate 34 cooperates to form a recess 41, and a semiconductor element 38 is provided at the bottom of the recess 41.

After the above-described joining step is completed, a resin disposing step is subsequently performed. FIG. 3 is a view for explaining the resin disposing step, and is a cross-sectional view along the line AA in FIG. As shown in the figure, in the resin disposing step, a sealing resin is potted using a nozzle 40 into a concave portion 41 formed by the dam portion 35 and the device substrate 34.
Thereby, as shown in FIG. 4, the potting resin 39 is formed in the concave portion 41.

At this time, since the height of the dam portion 35 is high enough to seal the semiconductor element 38, the potting resin 39 is provided in the dam portion 35 to make the semiconductor The element 38 has a configuration reliably protected by the potting resin 39. Further, by providing the dam portion 35, it is possible to prevent the liquid dripping portion from being generated on the outer periphery of the device substrate 34 during the potting, and thus it is possible to prevent the outer shape of the semiconductor device 30 from being substantially increased. This can prevent the semiconductor device 30 to be manufactured from being enlarged.

In this embodiment, since the dam sheet 31A and the substrate 34 for the device are made of the same material as described above, even if heat is applied when the potting resin 39 is provided, the dam sheet 31A and the device substrate 34 are not. Since the thermal expansion coefficients of the device substrates 34 are equal to each other, there is no occurrence of separation between them, and this can also prevent liquid dripping.

When the resin disposing step is completed, a cutting step is subsequently performed. In this cutting step, the connecting portion 33 formed on the dam sheet 31A is cut to separate the device substrate 34 (semiconductor device 30). Thus, the semiconductor device 30 shown in FIG. 30 is manufactured. This singulation process is performed by the punching device 1 described above with reference to FIG.
4 is performed. Specifically, the dam sheet 31A to which the device substrate 34 is bonded is placed at a predetermined position on the die 16, and the dam sheet 31A is pressed toward the die 16 by the holding jig 15.

At this time, the potting resin 39 is
5 is arranged so as to be flush with the upper surface of the dam 5.
There is no protrusion on the upper part of 5, so that the pressing jig 15 can press the upper part of the dam part 35. This makes it possible to set the cutting position by the punch 17 to a position near the dam portion 35, and it is not necessary to provide the pressing margin L2 (see FIG. 10) in the connecting portion 33. As a result, no protrusion (see FIGS. 8C and 9B) is formed at the outer peripheral position of the dam 35 after the connecting portion 33 is cut, and the semiconductor device 30 to be manufactured is downsized. Can be achieved.

The connecting portion 3 is formed by using the punching device 14.
By cutting three, a plurality (four in this embodiment)
The provided connecting portions 33 can be cut at a time, and the efficiency of the cutting process can be improved as compared with a configuration in which the connecting portions 33 are cut one by one. Further, the cutting using the punching device 14 is a cutting in the shearing direction with respect to the dam sheet 31A. However, the dam sheet 31A has only the function of supporting the device substrate 34, and has no internal wiring. . Therefore, even if peeling or the like occurs on the cut surface obtained by cutting the connecting portion 33, this does not adversely affect the device substrate 34, and the reliability of the manufactured semiconductor device 30 can be maintained.

The configuration of the dam sheet is not limited to the configuration of the dam sheet 31A having the configuration shown in FIGS. 1 to 4, but may be changed as appropriate in accordance with the required strength of the dam portion 35 to be supported. For example, FIG. 6 (A),
Dam seats 31B, 31 having a configuration as shown in FIG.
It is also possible to set C.

[0046]

According to the present invention as described above, the following various effects can be realized. According to the first aspect of the present invention, no resin or dam is provided when the substrate is divided into individual pieces, so that it is not necessary to provide a cutting margin, so that the size of the substrate, that is, the size of the semiconductor device is reduced. be able to.

Further, since the resin is provided in the concave portion formed by the dam portion and the substrate, it is possible to prevent the liquid from dripping out of the substrate outside the substrate, and the semiconductor manufactured by this is also provided. The size of the device can be reduced. Further, in the cutting step, since the connecting portion formed on the dam sheet is cut into individual semiconductor devices, peeling of the substrate does not occur at the time of cutting. Therefore, it is possible to prevent the internal wiring of the substrate from being damaged, and to improve the reliability of the manufactured semiconductor device.

According to the second aspect of the present invention, even if heat is applied in the resin disposing step after the substrate is joined to the dam sheet, the dam sheet and the substrate have the same coefficient of thermal expansion, so that peeling occurs. The occurrence of the liquid dripping portion can be reliably prevented. Further, according to the third aspect of the present invention, a plurality of connecting portions supporting the substrate can be cut at a time, and the manufacturing efficiency of the semiconductor device is improved as compared with a configuration in which the connecting portions are cut one by one. be able to.

[Brief description of the drawings]

FIG. 1 is a view for explaining a method for manufacturing a semiconductor device according to one embodiment of the present invention, and is a view for explaining a bonding step (part 1).

FIG. 2 is a view for explaining a method for manufacturing a semiconductor device according to one embodiment of the present invention, and is a view for explaining a bonding step (part 2).

FIG. 3 is a diagram for explaining a method of manufacturing a semiconductor device according to one embodiment of the present invention, and is a diagram for explaining a resin disposing step (part 1).

FIG. 4 is a diagram for explaining a method of manufacturing a semiconductor device according to one embodiment of the present invention, and is a diagram for explaining a resin disposing step (part 2).

FIG. 5 is a diagram showing a semiconductor device manufactured by a method for manufacturing a semiconductor device according to one embodiment of the present invention;

FIG. 6 is a view for explaining a modified example of a dam sheet.

FIG. 7 is a view illustrating a method of manufacturing the semiconductor device according to the first conventional example.

FIG. 8 is a view illustrating a method of manufacturing a semiconductor device according to a second conventional example.

FIG. 9 is a view illustrating a method of manufacturing a semiconductor device according to a third conventional example.

FIG. 10 is a view for explaining a punching device for cutting a connecting portion.

FIG. 11 is a view illustrating a method of manufacturing a semiconductor device according to a fourth conventional example.

FIG. 12 is a view illustrating a method of manufacturing a semiconductor device according to a fifth conventional example.

FIG. 13 is a diagram for explaining a problem that occurs when a connecting portion formed on a resin substrate is cut by a punching device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 30 Semiconductor device 31A-31C Dam sheet 32 Groove part 33 Connecting part 34 Device board 35 Dam part 36 Opening 38 Semiconductor element 39 Potting resin

Claims (3)

[Claims] A joining step of joining a dam portion integrally formed on a dam sheet with a connecting portion to a substrate on which a semiconductor element singulated in advance is mounted or a substrate before mounting; A resin arranging step of arranging a resin in a concave portion formed by the substrate and the substrate; and a cutting step of cutting the connecting part into individual semiconductor devices. Production method. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the dam sheet and the substrate are made of the same material. 3. The method of manufacturing a semiconductor device according to claim 1, wherein in the cutting step, the connecting portion is cut by punching.