JP6811123B2 - Seam welding equipment and seam welding method - Google Patents

Description

The present invention relates to a seam welding apparatus that welds a lid to a container of a circuit element such as an IC or a crystal oscillator.

The sealing work of circuit elements such as ICs and crystal oscillators is performed as a final manufacturing process after housing these circuit elements in a package and performing wiring and test adjustment work. Sealing methods include resin sealing and airtight sealing.
The airtight sealing method is a method in which an element is housed and fixed in a metal or ceramic package and covered with a lid in a dry inert gas atmosphere to completely seal the element. According to this airtight sealing method, impurities such as moisture do not enter, and since the sealing is performed by local heating, the influence of thermal stress is small and high sealing reliability can be obtained as compared with resin sealing.

There is a seam welding device that welds a lid to a package using a seam welding method, which is one of the airtight sealing methods. In this seam welding apparatus, a disk-shaped roller electrode is used to apply a pressure to a work while passing an electric current, and the Joule heat generated melts the work to obtain a joint.
FIG. 5 is a diagram illustrating a sealing operation by a seam welding device. The seam welding apparatus includes disk-shaped roller electrodes 10a and 10b, conductive shafts 11a and 11b that feed the roller electrodes 10a and 10b, electrode holders 12a and 12b that feed the conductive shafts 11a and 11b, and electrode holders 12a, It is provided with electrode holding arms 13a and 13b for holding 12b. In FIG. 5, 14 is a chip such as an IC or a crystal oscillator, 15 is a for example ceramic package for accommodating the chip 14, and 16 is a metal lid (lid).

In this seam welding device, the roller electrodes 10a and 10b are brought into contact with the lid 16 under a predetermined pressure. Then, while moving the tray (not shown) on which the package 15 is placed or the electrode holding arms 13a and 13b, the power supply block 12a, the conductive shaft 11a, the roller electrode 10a, the lid 16, the roller electrode 10b, the conductive shaft 11b, and the power supply block 12b are referred to. The lid 16 is welded to the package 15 by passing an electric current through the path.

Then, when the welding of the two sides of the lid 16 is completed in the state shown in FIG. 6 (A), the roller electrodes 10a and 10b are once moved upward to adjust the electrode spacing, and the package 15 is shown in FIG. 5 (B). After rotating 90 ° in the horizontal plane, the roller electrodes 10a and 10b are lowered again to weld the other two sides of the lid 16.

In the seam welding apparatus as described above, in order to ensure the required airtightness, it is necessary to strengthen and stabilize the welding of the four corners of the lid 16 having a substantially quadrangular plan view. Therefore, as shown in FIG. 7, the roller electrodes 10a and 10b are moved within a long range in which the start and end of welding are extended from the actual length of the lid 16 to perform welding. That is, welding must be started at a position protruding from the corner of the lid 16 and finished at a position protruding from another corner in the traveling direction of the roller electrodes 10a and 10b. Usually, this protruding part is called an overlap.

In recent years, as shown in FIG. 8, a manufacturing method in which a large number of packages 15 are placed on a tray 17 in a matrix and seam welding of individual packages 15 is performed has appeared with the demand of the times. In such a method, since the distance between the packages is short, if the above-mentioned overlap exists, the roller electrode during welding of one package 15 comes into contact with another adjacent package 15. There was a problem.

Therefore, the applicant has proposed to realize a seam welding apparatus with zero overlap and reduce the possibility that the roller electrode during welding comes into contact with another package (see Patent Document 1). However, with the recent miniaturization of packages (for example, about 1 mm × 1 mm), the distance between packages is narrowed, and even when the overlap is set to 0, the roller electrodes during welding come into contact with another package. The possibilities have increased. In order to avoid contact, it is necessary to keep the distance between the packages, so there is a problem that the packages cannot be arranged at high density on the tray.

JP-A-2007-175717

The present invention has been made to solve the above problems, and reduces the possibility that the roller electrodes during welding come into contact with another package even when the packages to be welded are arranged at high density. It is an object of the present invention to provide a seam welding apparatus and a seam welding method capable of performing seam welding.

The seam welding apparatus of the present invention includes a drive mechanism for moving the pair of roller electrodes with respect to a work to be welded, which comprises a pair of roller electrodes and a package and a lid placed on the package. A power source for supplying a welding current to a pair of roller electrodes, a first control unit for controlling the drive mechanism, and a second control unit for controlling the power supply are provided, and the first control unit is welded. At the start, the pair of roller electrodes are brought into contact with the first position of the two sides closer to the center than the two corners at one end of the two opposite sides of the lid, and this contact state is stopped by the first stop. After maintaining the time, the pair of roller electrodes are moved while being in contact with the two sides, and the 1 is placed at the second position of the two sides closer to the center than the two corners at the other ends of the two sides. When the pair of roller electrodes arrives, the pair of roller electrodes is stopped, and after the second stop time, the pair of roller electrodes is raised, and the second control unit performs the first stop time. The pair of roller electrodes are moved, and a welding current individually determined for each of the second stop times is supplied from the power source to the pair of roller electrodes. is there.

Further, the seam welding apparatus of the present invention includes a pair of roller electrodes and a drive mechanism for moving the pair of roller electrodes with respect to a work to be welded including a package and a lid placed on the package. The first control unit includes a power source for supplying a welding current to the pair of roller electrodes, a first control unit for controlling the drive mechanism, and a second control unit for controlling the power supply. At the start of welding, the pair of roller electrodes are brought into contact with the first position of the two sides closer to the center than the two corners at one end of the two opposite sides of the lid, and the pair of roller electrodes are brought into contact with each other. While in contact with the two sides, they are sequentially moved at a first speed, a second speed faster than the first speed, and a third speed slower than the second speed, and are located at the other ends of the two sides. When the pair of roller electrodes reaches the second position on the two sides closer to the center than the two corners, the pair of roller electrodes is raised, and the second control unit uses the first control unit. It is characterized in that welding currents individually determined for each of the speed period, the second speed period, and the third speed period are supplied from the power source to the pair of roller electrodes. is there.

Further, in the seam welding method of the present invention, with respect to a work to be welded composed of a package and a lid placed on the package, two corner portions at one ends of two opposing sides of the lid at the start of welding. During the first step of bringing the pair of roller electrodes into contact with the first position of the two sides closer to the center and the first stop time, the first welding current is applied from the power source to the pair of roller electrodes. During the movement of the pair of roller electrodes, the third step of moving the pair of roller electrodes while contacting the two sides, and the movement of the pair of roller electrodes after the first stop time. At the fourth step of supplying the second welding current from the power source to the pair of roller electrodes, and at the second position of the two sides closer to the center than the two corners at the other ends of the two sides. During the fifth step of stopping the pair of roller electrodes when the pair of roller electrodes arrives and the second stop time, a third welding current is applied from the power source to the pair of roller electrodes. It is characterized by including a sixth step of supplying and a seventh step of raising the pair of roller electrodes after the second stop time.

Further, in the seam welding method of the present invention, with respect to a work to be welded composed of a package and a lid placed on the package, two corner portions at one ends of two opposing sides of the lid at the start of welding. The first step of bringing the pair of roller electrodes into contact with the first position of the two sides closer to the center, and the first step of moving the pair of roller electrodes at the first speed while contacting the two sides. The second step, the third step of supplying the first welding current from the power source to the pair of roller electrodes during the period of the first speed, and the pair of roller electrodes being brought into contact with the two sides. However, a fourth step of moving at a second speed higher than the first speed and a second welding current being supplied from the power source to the pair of roller electrodes during the period of the second speed. During the period of the fifth step, the sixth step of moving the pair of roller electrodes at a third speed slower than the second speed while contacting the two sides, and the third speed. The seventh step of supplying a third welding current from the power source to the pair of roller electrodes and the second position of the two sides closer to the center than the two corners at the other ends of the two sides. It is characterized by including an eighth step of raising the pair of roller electrodes when the pair of roller electrodes arrives.

According to the present invention, the roller electrode is stopped at a position close to the corner of the lid for a predetermined time to allow a welding current to flow, or the roller electrode is stopped at a position near the corner of the lid at a slow speed different from other positions. Since the welding current is passed while moving the lid, the corners of the lid, which must be strongly welded, can be reliably welded. Further, in the present invention, by setting the first position at the start of welding and the second position at the end of welding at positions closer to the center than the corners of the lid, the package to be welded is raised on the tray. Even in the case of the density arrangement, it is possible to reduce the possibility that the roller electrode during welding one package comes into contact with another adjacent package.

It is a block diagram which shows the electrical connection relation of the seam welding apparatus which concerns on 1st Example of this invention. It is a side view and a plan view which show the welding profile at the time of seam welding of 1st Example of this invention, and the positional relationship of a package, a lid, and a roller electrode. It is a flowchart explaining the operation of the seam welding apparatus which concerns on 1st Embodiment of this invention. It is a flowchart explaining the operation of the seam welding apparatus which concerns on 2nd Embodiment of this invention. It is a figure explaining the sealing work by the conventional seam welding apparatus. It is a top view explaining the sealing work by a conventional seam welding apparatus. It is a figure explaining the overlap of welding in the conventional seam welding apparatus. It is a top view which shows the state which the package to be welded is arranged at high density on a tray.

[First Example]
Hereinafter, examples of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an electrical connection relationship of the seam welding apparatus according to the first embodiment of the present invention. Also in this embodiment, the configuration of the electrode portion of the seam welding apparatus is the same as that of the conventional one, and thus the reference numerals in FIG.

The seam welding device includes a drive mechanism 1 for driving the electrode section, a power supply 2 for supplying current to the roller electrodes 10a and 10b, a control section 3 for controlling the entire seam welding device, and a program of the control section 3 and a seam welding device. It is provided with a storage unit 4 that stores information on the operation of the seam welding device in advance, and an operation unit 5 for the user to give an instruction to the seam welding apparatus. The control unit 3 includes a drive mechanism control unit 30 that controls the drive mechanism 1 and a power supply control unit 30 that controls the power supply 2.

FIG. 2 (A) is a view showing a welding profile at the time of seam welding of this embodiment, and FIG. 2 (B) is a side view showing a positional relationship between a package, a lid (lid), and a roller electrode corresponding to FIG. 2 (A). 2 (C) is a plan view showing the positional relationship between the package, the lid, and the roller electrode corresponding to FIG. 2 (A).

In seam welding, it is necessary to intermittently apply a welding current while the roller electrodes 10a and 10b are rotationally moving on the lid 16 (during welding). FIG. 2 (A) shows this situation. In FIG. 2A, the horizontal axis represents the welding time, and the vertical axis represents the welding current flowing through the roller electrodes 10a and 10b. In FIG. 2A, WT is a time in which a welding current is passed with a 1-pulse energization waveform, and CT is a time in which a welding current is not passed with a 1-pulse energization waveform.

MHC is a parameter for setting the magnitude of welding current during seam welding, which is set according to the amount of melting. UHC, DHC1, DHC2, UPL, DWL1, DWL2 are parameters of the welding current in consideration of the welding quality of the corners of the lid 16. UHC is a parameter that sets the welding current at the start of seam welding. DHC1 and DHC2 are parameters for setting the welding current at the end of seam welding. UPL is a parameter that sets the moving distance of the roller electrodes 10a and 10b while increasing the welding current from UHC to MHC. DWL1 is a parameter for setting the moving distance of the roller electrodes 10a and 10b while reducing the welding current from MHC to DHC1. DWL2 is a parameter for setting the moving distance of the roller electrodes 10a and 10b while reducing the welding current from DHC1 to DHC2.

FIG. 2B shows that the overlap in this embodiment is negative, that is, the positions of the roller electrodes 10a and 10b at the start and end of welding are inside the corners of the lid 16.

In this embodiment, there are the following parameters as other parameters. Specifically, the stop time SST at the position at the start of welding of the roller electrodes 10a and 10b, the stop time EST of the roller electrodes 10a and 10b at the position at the end of welding, and the moving speed WS of the roller electrodes 10a and 10b are is there. Further, as another parameters, the moving speed SSP of the roller electrodes 10a and 10b at the start of welding, the distance SSL for seam welding at the moving speed SSP, the moving speed ESP of the roller electrodes 10a and 10b at the end of welding, and the like. There is a distance ESL for seam welding at a moving speed ESP. Note that SSP and ESP have slower speeds than WS (SSP, ESP <WS).
Each of the above parameters is preset by the user and stored in the storage unit 4.

Next, the operation of the seam welding apparatus of this embodiment will be described with reference to FIG. Prior to welding, the drive mechanism control unit 30 and the power supply control unit 30 of the control unit 3 read out the above-mentioned various parameters from the storage unit 4 (step S1 in FIG. 3). Then, the drive mechanism control unit 30 controls a transport mechanism (not shown) to mount the lid 16 on the package 15 and adjust the position and angle of the lid 16 so that the lid 16 is accurately mounted on the package 15. (Step S2 in FIG. 3) Since such transfer and positioning of the lid 16 is a well-known technique, detailed description thereof will be omitted.

Next, the drive mechanism control unit 30 controls the drive mechanism 1 to place the roller electrodes 10a and 10b at predetermined positions at the start of welding, specifically, at the edge position closer to the center than the corner portion of the lid 16. The roller electrodes 10a and 10b are moved down to the position (a position in FIGS. 2B and 2C), and the roller electrodes 10a and 10b are brought into contact with the lid 16 under a predetermined pressure (FIG. 2B). 3 steps S3).

Then, the power supply control unit 30 has the electrode holder 12a, the conductive shaft 11a, the roller electrode 10a, the lid 16, the roller electrode 10b, the conductive shaft 11b, and the electrode from the power supply 2 in a state where the roller electrodes 10a and 10b are in contact with the lid 16. A current is passed through a path called the holder 12b. As is well known, the columnar conductive shafts 11a and 11b are inserted and supported by the through holes of the electrode holders 12a and 12b, respectively, and rotate by sliding friction. The roller electrodes 10a and 10b are attached to one ends of the conductive shafts 11a and 11b. The electrode holders 12a and 12b function as bearings for the conductive shafts 11a and 11b, and at the same time serve to supply an electric current to the conductive shafts 11a and 11b.

The power supply control unit 30 stops the roller electrodes 10a and 10c at the positions at the start of welding during the stop time SST, and causes the welding current set by the parameter UHC to flow (step S4 in FIG. 3). That is, a constant welding current flows at the position at the start of welding.

After the stop time SST elapses, the drive mechanism control unit 30 and the power supply control unit 30 control the drive mechanism 1 to move the roller electrodes 10a and 10b at a speed WS along the X direction of FIG. 2C. However, a pulsed welding current is passed from the power source 2 through the above path. The power supply control unit 30 increases the pulsed welding current from UHC to MHC while the roller electrodes 10a and 10b move by the movement distance set by the parameter UPL (step S5 in FIG. 3).

After the roller electrodes 10a and 10b have moved by the movement distance set by the parameter UPL, the power supply control unit 30 applies a pulsed welding current set by the parameter MHC (step S6 in FIG. 3). Then, the power supply control unit 30 moves the roller electrodes 10a and 10b by the moving distance D determined by the distance L between the position at the start of welding and the position at the end of welding and the parameters UPL, DWL1 and DWL2, and then the parameter DWL1. While the roller electrodes 10a and 10b move by the moving distance set in step 1, the pulsed welding current is reduced from MHC to DHC1 (step S7 in FIG. 3). The moving distance D is D = L-UPL-DWL1-DWL2.

The power supply control unit 30 has a pulse shape from DHC1 to DHC2 while the roller electrodes 10a and 10b move by the movement distance set by the parameter DWL1 and then the roller electrodes 10a and 10b move by the movement distance set by the parameter DWL2. (FIG. 3, step S8). In this way, as shown in FIG. 2C, the roller electrodes 10a and 10b move while rotating on the lid 16, so that the two sides of the lid 16 in the X direction are welded to the package 15.

When the roller electrodes 10a and 10b move by the movement distance set by the parameter DWL2 and the roller electrodes 10a and 10b reach a predetermined position at the end of welding, the drive mechanism control unit 30 and the power supply control unit 30 are roller electrodes. The movements of 10a and 10b are stopped, and the welding current set by the parameter DHC2 is passed during the stop time EST (step S9 in FIG. 3). That is, a constant welding current flows at the position at the end of welding.

After the stop time EST has elapsed, the power supply control unit 30 stops the power supply from the power supply 2 and stops the flow of the welding current (step S10 in FIG. 3).
Subsequently, the drive mechanism control unit 30 and the power supply control unit 30 control the drive mechanism 1 to raise the roller electrodes 10a and 10b (step S11 in FIG. 3), and set the mounting table (not shown) of the package 15 at 90 degrees. After rotating (step S12 in FIG. 3), the processes of steps S13 to S21 are performed.

The processing of steps S13 to S21 is the same as the processing of steps S3 to S11 except that the welding target is the two sides of the lid 16 in the Y direction, and thus the description thereof will be omitted. In this way, the two sides of the lid 16 in the Y direction are welded to the package 15.

Since the sizes of the package 15 and the lid 16 are various, the position at the start of welding, the position at the end of welding, the distance L between the position at the start of welding and the position at the end of welding, and the parameters SST, EST, MHC. , UHC, DHC1, DHC2, UPL, DWL1, DWL2 may be set individually for each of the X direction and the Y direction of the lid 16.

In this way, seam welding of one work (package 15 and lid 16) is completed, and airtight sealing can be realized. After that, the airtightly sealed package 15 is conveyed to a predetermined place by a separately provided conveying means. Then, the next package 15 is seam welded in the same procedure as above. In this way, seam welding of the package 15 is performed one after another.

In this embodiment, the roller electrodes 10a and 10b are stopped at a position close to the corner of the lid 16 for a predetermined time to allow a welding current to flow, so that the corner of the lid 16 that must be strongly welded can be reliably welded. .. Further, in this embodiment, by setting the overlap value to a negative value, even when the packages 15 to be welded are arranged at high density on the tray, the roller electrodes 10a during welding of one package 15 The possibility that the 10b will come into contact with another adjacent package 15 can be reduced. Therefore, in this embodiment, the package 15 can be arranged at high density on the tray.

[Second Example]
Next, a second embodiment of the present invention will be described. In this embodiment, a case of a seam welding method in which the roller electrodes 10a and 10b are welded while moving a predetermined distance at a predetermined moving speed at the start of seam welding and the end of seam welding will be described. In the first embodiment, the moving speed WS of the roller electrodes 10a and 10b was set to be constant, but in this embodiment, the moving speed of the roller electrodes 10a and 10b is not kept constant during the seam welding time. , At the start of seam welding and at the end of seam welding, seam welding is performed at a slower moving speed than at other times. Also in this embodiment, the configuration of the seam welding apparatus is the same as that in the first embodiment, and thus the reference numerals of FIGS. 1 and 5 will be used for description.

The operation of the seam welding apparatus of this embodiment will be described with reference to FIG. Prior to welding, the drive mechanism control unit 30 and the power supply control unit 30 read various parameters from the storage unit 4 (step S1 in FIG. 4). In this embodiment, the parameters SSP, SSL, ESP, and ESL are used instead of the parameters SST and EST. The processes of steps S2 and S3 of FIG. 4 are as described in the first embodiment.

The drive mechanism control unit 30 and the power supply control unit 30 control the drive mechanism 1 to move the roller electrodes 10a and 10b in a state where the roller electrodes 10a and 10b are in contact with the lid 16, while moving the roller electrodes 10a and 10b from the power supply 2 to the electrode holder. A welding current is passed through a path of 12a, a conductive shaft 11a, a roller electrode 10a, a lid 16, a roller electrode 10b, a conductive shaft 11b, and an electrode holder 12b. At this time, the drive mechanism control unit 30 and the power supply control unit 30 flow the welding current set by the parameter UHC while moving the roller electrodes 10a and 10b at the movement speed set by the parameter SSP (FIG. 4 step S4a). ).

The drive mechanism control unit 30 and the power supply control unit 30 move the roller electrodes 10a and 10b at a speed WS along the X direction of the lid 16 after the roller electrodes 10a and 10b have moved by the movement distance set by the parameter SSL. While doing so, a pulsed welding current is passed from the power supply 2 through the above path. The power supply control unit 30 increases the pulsed welding current from UHC to MHC while the roller electrodes 10a and 10b move by the movement distance set by the parameter UPL (step S5 in FIG. 4).

The processing of steps S5 to S8 is the same as that of the first embodiment. However, in this embodiment, the moving distance D during the period in which the pulsed welding current set by the parameter MHC is passed is D = L-SSL-UPL-DWL1-DWL2-ESL.

The drive mechanism control unit 30 and the power supply control unit 30 change the moving speed of the roller electrodes 10a and 10b from WS to ESP after the roller electrodes 10a and 10b have moved by the moving distance set by the parameter DWL2, and the speed ESP. While moving the roller electrodes 10a and 10b, the welding current set by the parameter DHC2 is passed (step S9a in FIG. 4).

When the roller electrodes 10a and 10b move by the movement distance set by the parameter ESL and the roller electrodes 10a and 10b reach a predetermined position at the end of welding, the drive mechanism control unit 30 and the power supply control unit 30 are roller electrodes. The movement of the 10a and 10b is stopped, and the power supply from the power source 2 is stopped (step S10a in FIG. 4).

The processes of steps S11 and S12 of FIG. 4 are as described in the first embodiment. The processing of steps S13, S14a, S15 to S18, S19a, S20a, and S21 of FIG. 4 is performed in steps S3, S4a, S5 to S8, S9a, except that the welding target is the two sides of the lid 16 in the Y direction. Since it is the same as the processing of S10a and S11, the description thereof will be omitted. In this way, the two sides of the lid 16 in the Y direction are welded to the package 15.

Similar to the first embodiment, the position at the start of welding, the position at the end of welding, the distance L between the position at the start of welding and the position at the end of welding, and the parameters SSP, SSL, ESP, ESL, MHC. , UHC, DHC1, DHC2, UPL, DWL1, DWL2 may be set individually for each of the X direction and the Y direction of the lid 16.

In this embodiment, a welding current is applied while moving the roller electrodes 10a and 10b at a slow speed different from other positions at a position close to the corner of the lid 16, so that the corner of the lid 16 must be welded strongly. Welding can be done reliably. Further, in this embodiment, by setting the overlap value to a negative value, even when the packages 15 to be welded are arranged at high density on the tray, the roller electrodes 10a during welding of one package 15 The possibility that the 10b will come into contact with another adjacent package 15 can be reduced.

In the first and second embodiments, the roller electrodes 10a and 10b are brought into contact with the lid 16 and a welding current is applied for a very short time to perform temporary attachment before performing the processing after step S3. May be good.

The control unit 3 and the storage unit 4 described in the first and second embodiments are realized by a computer provided with a CPU (Central Processing Unit), a storage device, and an interface, and a program for controlling these hardware resources. be able to. The CPU executes the processes described in the first and second embodiments according to the program stored in the storage device.

The present invention can be applied to seam welding.

1 ... Drive mechanism, 2 ... Power supply, 3 ... Control unit, 4 ... Storage unit, 5 ... Operation unit, 10a, 10b ... Roller electrode, 15 ... Package, 16 ... Lid, 30 ... Drive mechanism control unit, 31 ... Power supply control Department.

Claims (4)

With a pair of roller electrodes,
A drive mechanism that moves the pair of roller electrodes with respect to the work to be welded, which consists of a package and a lid placed on the package.
A power supply that supplies welding current to the pair of roller electrodes,
A first control unit that controls the drive mechanism,
A second control unit for controlling the power supply is provided.
At the start of welding, the first control unit brings the pair of roller electrodes into contact with the first positions of the two sides closer to the center than the two corners at one ends of the two opposite sides of the lid. After maintaining this contact state for the first stop time, the pair of roller electrodes are moved while being in contact with the two sides, and the 2 is closer to the center than the two corners at the other ends of the two sides. When the pair of roller electrodes reaches the second position on the side, the pair of roller electrodes is stopped, and after the second stop time, the pair of roller electrodes is raised.
The second control unit outputs a welding current individually determined for each of the first stop time, the period during which the pair of roller electrodes are moving, and the second stop time from the power source. A seam welding device characterized in that it is supplied to a pair of roller electrodes. With a pair of roller electrodes,
A drive mechanism that moves the pair of roller electrodes with respect to the work to be welded, which consists of a package and a lid placed on the package.
A power supply that supplies welding current to the pair of roller electrodes,
A first control unit that controls the drive mechanism,
A second control unit for controlling the power supply is provided.
At the start of welding, the first control unit brings the pair of roller electrodes into contact with the first position of the two sides closer to the center than the two corners at one end of the two opposite sides of the lid. The pair of roller electrodes are sequentially moved at a first speed, a second speed faster than the first speed, and a third speed slower than the second speed while contacting the two sides. When the pair of roller electrodes reaches the second position of the two sides closer to the center than the two corners at the other ends of the two sides, the pair of roller electrodes is raised.
The second control unit applies a welding current individually determined for each of the first speed period, the second speed period, and the third speed period from the power source to the pair of rollers. A seam welding device characterized in that it is supplied to an electrode. With respect to the workpiece to be welded consisting of the package and the lid placed on the package, the second side of the two sides closer to the center than the two corners at one ends of the two opposite sides of the lid at the start of welding. The first step of bringing a pair of roller electrodes into contact with position 1 and
A second step of supplying a first welding current from the power source to the pair of roller electrodes during the first downtime,
After the first stop time, a third step of moving the pair of roller electrodes while contacting the two sides, and
A fourth step of supplying a second welding current from the power source to the pair of roller electrodes during the movement of the pair of roller electrodes.
A fifth step of stopping the pair of roller electrodes when the pair of roller electrodes reaches the second position of the two sides closer to the center than the two corners at the other ends of the two sides. When,
A sixth step of supplying a third welding current from the power source to the pair of roller electrodes during the second downtime.
A seam welding method comprising a seventh step of raising the pair of roller electrodes after the second stop time. With respect to the workpiece to be welded consisting of the package and the lid placed on the package, the second side of the two sides closer to the center than the two corners at one ends of the two opposite sides of the lid at the start of welding. The first step of bringing a pair of roller electrodes into contact with position 1 and
A second step of moving the pair of roller electrodes at the first speed while contacting the two sides, and
A third step of supplying a first welding current from the power source to the pair of roller electrodes during the period of the first speed.
A fourth step of moving the pair of roller electrodes at a second speed faster than the first speed while contacting the two sides.
A fifth step of supplying a second welding current from the power source to the pair of roller electrodes during the period of the second speed.
A sixth step of moving the pair of roller electrodes at a third speed slower than the second speed while contacting the two sides.
A seventh step of supplying a third welding current from the power source to the pair of roller electrodes during the period of the third speed.
An eighth step of raising the pair of roller electrodes when the pair of roller electrodes reaches the second position of the two sides closer to the center than the two corners at the other ends of the two sides. A seam welding method comprising and.

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