JP2009248154A - Lap laser welding equipment and lap laser welding method - Google Patents

Abstract

Even when a member to be welded is inclined with a simple configuration, a portion to be pressed is made to closely follow the inclination and the member to be welded is brought into close contact and joined by a laser beam.
The lap laser welding apparatus of the present invention pressurizes a plurality of overlapped members to be welded W1 and W2 so that they are brought into close contact with each other, and irradiates a laser beam LB to a welding portion. The nozzle 1 is provided so as to be movable with respect to the welding members W1 and W2 and the laser beam LB is guided therein, and the spherical member 2 held at the tip of the nozzle 1. Is formed with a spherical member holding portion 10 for slidably holding the spherical member 2, and the spherical member 2 includes a laser beam transmitting portion 20 that transmits the laser beam LB guided into the nozzle 1, and A pressurizing portion 21 is formed so as to slightly protrude around the tip opening and presses against and presses against the plurality of overlapped welded members W1 and W2.
[Selection] Figure 1

Description

  The present invention relates to a lap laser welding apparatus and a lap laser welding method, and in particular, a lap laser welding apparatus that pressurizes a plurality of overlapped members to be in close contact with each other and irradiates a laser beam onto a welding site, and a lap laser welding apparatus. The present invention relates to a lap laser welding method in which a plurality of welded members combined are pressed and brought into close contact with each other to irradiate a laser beam onto a welding site and lap weld the overlapped welded members.

  As a member to be welded by lap laser welding, for example, when a pad and a ribbon mounted on a substrate constituting a semiconductor are lap welded, if there is a gap between the pad and the ribbon, A predetermined peel strength cannot be obtained. Therefore, as shown in FIG. 4, generally, the pad W1 and the ribbon W2 on which the front end surface 101 of the nozzle 100 is overlaid are pressurized (see the arrows in FIG. 4), and both W1 and W2 are brought into close contact with each other to eliminate a gap. In this state, the laser beam LB guided into the nozzle 100 is irradiated and bonded.

  By the way, there is a substrate W3 on which the pad W1 is mounted, which is formed of ceramic, and distortion occurs at the time of the formation, and the substrate W3 has a distortion with respect to the H1 surface of the housing H serving as a base on which the substrate W3 is installed. The surface W3b may be inclined (hereinafter, this inclination is referred to as substrate inclination J). The substrate tilt J is allowed to be, for example, a maximum of 1 ° as an error of the substrate W3. Further, in the pad W1 mounted on the substrate W3, the solder S is not evenly interposed, and the pad W1 may be inclined with respect to the surface W3b of the substrate W3 (hereinafter, this inclination is referred to as solder). Inclination K). The solder inclination K of the pad W1 is allowed up to, for example, 3 ° as an error. Therefore, when the substrate inclination J and the solder inclination K are in the same direction, the surface of the pad W1 to which the ribbon W2 is bonded is inclined by 4 ° at the maximum. Furthermore, in addition to these inclinations J and K, the welded members W1 and W2 may be uneven.

  Here, FIG. 6 shows the sensitivity between the pad W1 and the ribbon W2 in order to examine the pressure between the pad W1 and the ribbon W2 (see the arrow in FIG. 6) when the tip 100 is pressurized with the tip surface 101. It is the figure which showed the state which interposed the pressure paper. FIG. 7 shows the impression PM ′ of the pressure-sensitive paper 102 when the tip 100 of the nozzle 100 is pressurized as shown in FIG.

  When the ribbon W2 is superimposed on the surface of the pad W1 and pressed by the tip surface 101 of the nozzle 100 in the state where the inclinations J and K and the unevenness are generated as described above, the conventional nozzle 100 of the nozzle 100 is pressed as shown in FIG. The indentation PM ′ due to the pressurization appears only in a part of the shape of the tip surface 101 of the nozzle 100. Therefore, the ribbon W2 is not pressed with a uniform force on the surface of the pad W1, and between the pad W1 and the ribbon W2. A gap M (FIG. 4) is partially formed in

  FIG. 5 shows a case where the gap M is not generated between the welded members W1 and W2 (0 mm), a case where the gap M is generated at 0.02 mm, and a case where the gap is generated at 0.04 mm. The peel strength of welding is shown respectively. In the example shown in FIG. 5, when the gap between the welded members W1 and W2 is 0.02 mm or more, there is no welding strength in the peeling direction (zero N), that is, the welded members W1 and W2 overlap each other. It will not be welded.

  Patent Document 1 is known as a conventional technique for pressurizing the members to be welded W1 and W2 having such inclinations J and K and unevenness with a uniform force. In Patent Document 1, a laser processing optical system that performs processing such as workpiece cutting and welding is formed by condensing and irradiating laser light output from a laser oscillator, and this laser processing optical system is used as a laser processing head. In the laser processing apparatus, the laser processing head includes a fixed unit that guides laser light from a laser oscillator, and a movable unit that is provided in the fixed unit and includes a condensing optical system that condenses the laser light. An elastic holding means provided between the fixed unit and the movable unit and elastically holding the movable unit, and the movable unit has a contact type work copying mechanism that follows the irregularities of the workpiece processing surface by the elastic holding means. The laser processing device is characterized in that the distance from the condensing optical system to the workpiece processing position is always kept substantially constant by this workpiece copying mechanism. There has been disclosed. In Patent Document 1, in the laser processing apparatus, the contact-type workpiece copying mechanism is provided in a movable unit, and includes an optical torch having a condensing optical system for condensing laser light, and a tip of the optical torch. Contact type machining surface copying nozzle means provided in the section, the contact type machining surface copying nozzle means is configured to press the workpiece machining surface by the elastic holding means and follow the unevenness of the workpiece machining surface, Further, the contact type machining surface copying nozzle means is configured to be held at the tip of the optical torch so as to be tiltable with respect to the laser beam optical axis by a spherical bearing, and to follow the unevenness of the workpiece machining surface. .

  In Patent Document 1, laser light output from a laser oscillator is guided to a laser processing head, and the guided laser light is irradiated to a workpiece such as a workpiece or a sample through a laser processing optical system in the laser processing head. When the workpiece is subjected to laser processing for cutting or welding with a laser beam, the contact processing surface of the movable unit is provided while the contact type workpiece copying mechanism of the laser processing unit is pressed against the workpiece by the elastic holding means. The scanning nozzle means is made to follow the workpiece along the workpiece machining direction, and the laser machining is performed while the distance from the condensing optical system built in the movable unit to the workpiece machining position is always kept substantially constant. A laser processing method is also disclosed.

JP 2000-61669 A

  However, in the laser processing apparatus disclosed in Patent Document 1, the base end portion of the laser processing nozzle is held by the contact-type processing surface copying nozzle means by a spherical bearing, as shown in FIG. Due to the structure, when the tip of the laser processing nozzle is greatly lifted following the inclination of the work surface of the workpiece, the laser beam guided inside the lower unit is irradiated to the inner surface of the laser processing nozzle, and the workpiece is processed. In addition to not being able to perform processing without reaching the surface, there were problems such as damage to the laser processing nozzle and welding of the laser processing nozzle to the workpiece. Further, in Patent Document 1, contact type scanning roller means are provided in front and rear of the laser processing nozzle, and the tip surface of the laser processing nozzle is separated from the processing surface of the workpiece. The laser processing nozzle cannot be raised and raised accurately with respect to the inclination, and the laser beam irradiation part cannot be accurately pressed and brought into close contact with each other. Since the surrounding area is complicated and requires a large installation area, there is a problem in that it cannot be applied when the work surface on which lap welding is performed is relatively small.

  In addition, in Patent Document 1, “contact type machining surface scanning nozzle means 35 is supported on the optical torch 22 of the lower unit 13 through a spherical bearing 41 so as to be rotatable and up and down. It is always supported perpendicularly to the inclination of the processed surface of W. At this time, the optical axis of the laser light changes by an angle change with respect to the workpiece W. 0068) The angle change of the laser machining nozzle 40 in which the optical axis of the laser beam L condensed by the condenser lens 38 provided in the optical torch is raised by the spherical bearing 41 according to the inclination of the machining surface of the workpiece. A specific configuration that only changes is not disclosed.

The present invention has been made in view of the above-described problems. Even when the member to be welded is inclined with respect to the pressurizing direction of the nozzle, the portion to be pressed is surely made to follow the inclination to be welded. A lap laser welding apparatus configured so that members can be brought into close contact with each other, and a portion to be pressed is welded or deformed to a member to be welded by heat, and lap welding with good quality can be performed. The purpose is to provide.
In addition, the present invention has been made in view of the above-described problem, and even when the member to be welded is inclined with respect to the pressurizing direction of the nozzle, the portion to be pressed is made to closely follow the inclination. It is an object of the present invention to provide a lap laser welding method capable of bringing a member to be welded into close contact and thus performing lap welding with certainty.

In order to achieve the above object, the invention according to claim 1 is an overlap laser welding apparatus that pressurizes a plurality of overlapped members to be in close contact with each other and irradiates a laser beam to a welding portion. A spherical member holding portion formed on the inner side of the tip, a nozzle for guiding a laser beam therein, and a spherical member slidably held by the spherical member holding portion of the nozzle, the spherical member Includes a laser beam transmitting portion that transmits the laser beam guided into the nozzle, and a pressurizing portion that is formed around the tip opening of the laser beam transmitting portion and pressurizes the plurality of welded members that are overlapped with each other. It is characterized by having.
In order to achieve the above object, the invention according to the lap laser welding apparatus according to claim 2 is characterized in that, in the invention according to claim 1, the spherical member comprises 20 to 40% by weight of copper and 80 to 60% by weight of tungsten. It is characterized by being an alloy of the following.
Further, in order to achieve the above object, the invention according to claim 3 is directed to irradiating a welding spot with a laser beam in a state in which a plurality of overlapped members to be welded are in close contact with each other, A lap laser welding method for lap welding a plurality of overlapped members to be welded, wherein a spherical member holding portion is formed inside a tip of a nozzle to which a laser beam is guided, and guided into the nozzle. A spherical member having a laser beam transmitting portion that transmits a laser beam, and a pressurizing portion that is formed around a tip opening of the laser beam transmitting portion and pressurizes the plurality of overlapped members to be welded. By slidably holding the member holding portion, an inclination copying mechanism is formed, the welding locations of each of the plurality of welded members are overlapped, and the nozzle is moved in the axial direction. A pressure member of a spherical member held at the tip is brought into contact with the plurality of welded members superimposed to pressurize, and a laser beam guided into the nozzle is welded through the laser beam transmitting portion. And lap welding.

According to the invention relating to the laser welding apparatus of the first aspect, the spherical member holding portion is formed on the inner side of the tip, and the nozzle in which the laser beam is guided and the spherical member holding portion of the nozzle are slidable. A spherical member that is held, and the spherical member includes a laser beam transmitting portion that transmits the laser beam guided in the nozzle, and a plurality of the plurality of the plurality of the overlapped members formed around a tip opening of the laser beam transmitting portion. A pressurizing portion that pressurizes the welded member of the welding member, so that the plurality of superposed welded members can be reliably pressed and brought into close contact with each other, and the welding spot can be reliably overlapped and welded with a laser beam. it can.
According to the invention relating to the laser welding apparatus of claim 2, in the invention of claim 1, the spherical member is made of an alloy of 20 to 40% by weight of copper and 80 to 60% by weight of tungsten. Thus, the spherical member can be lap welded with good welding strength without being welded or deformed to the member to be welded by heat.
According to the invention relating to the lap laser welding method of claim 3, the spherical member holding portion is formed inside the tip of the nozzle to which the laser beam is guided, and the laser beam guided into the nozzle is transmitted. A spherical member having a beam transmitting part and a pressurizing part that is formed around the tip opening of the laser beam transmitting part and pressurizes the overlapped welded member is slidable on the spherical member holding part of the nozzle By holding and configuring an inclination copying mechanism, the welding portion of each of the plurality of overlapped members to be welded is overlapped, and the nozzle is moved in the axial direction so as to be held at the tip thereof. Is pressed against a plurality of members to be welded, and a laser beam guided in the nozzle is irradiated to a welding location through the laser beam transmitting portion, the pressure direction of the nozzle is Even when the member to be welded is tilted, the parts to be pressed can be brought into close contact with each other so as to follow the tilt, so that lap welding can be reliably performed. it can.

(Aspect of the Invention)
In the following, the invention that is claimed to be claimable in the present application (hereinafter referred to as “claimable invention”. The claimable invention is at least the “present invention” to the invention described in the claims. Some aspects of the present invention, including subordinate concept inventions of the present invention, superordinate concepts of the present invention, or inventions of different concepts) will be illustrated and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention. In each of the following items, item (1) corresponds to claim 1, item (2) corresponds to claim 2, and item (6) corresponds to claim 3.

(1) An overlap laser welding apparatus that pressurizes a plurality of overlapped members to be welded to each other and irradiates a laser beam to a welding portion,
A spherical member holding portion is formed inside the tip, a nozzle that guides the laser beam inside,
A spherical member slidably held in the spherical member holding portion of the nozzle,
The spherical member includes a laser beam transmitting portion that transmits a laser beam guided into the nozzle, and a pressurization that pressurizes the plurality of welded members formed around the tip opening of the laser beam transmitting portion. And a lap laser welding apparatus characterized by comprising:

  In the invention of (1), a spherical member holding portion is formed inside the tip of the nozzle to which the laser beam is guided, a laser beam transmitting portion that transmits the laser beam guided in the nozzle, and this laser beam transmission The spherical member formed around the tip opening of the part and having a pressurizing part that pressurizes the plurality of welded members superimposed on each other is overlapped by slidably holding the spherical member holding part of the nozzle Even when a plurality of members to be welded are inclined with respect to the axial direction of the nozzle, the pressurizing portion of the spherical member slides so as to follow the inclination. It is possible to apply pressure to bring them into close contact with each other and to reliably weld the welded portions with a laser beam.

  (2) The lap laser welding apparatus according to (1), wherein the spherical member is an alloy of 20 to 40% by weight of copper and 80 to 60% by weight of tungsten.

  In the invention described in the item (2), in the invention described in the item (1), the spherical member is an alloy of 20 to 40% by weight of copper and 80 to 60% by weight of tungsten. It is possible to perform lap welding with a good welding strength without causing the spherical member to be welded or deformed to the member to be welded by the heat generated by.

  (3) The lap laser welding apparatus according to the item (1) or (2), further including a restricting unit that restricts sliding of the spherical member with respect to the spherical member holding portion.

  In the invention described in the item (3), in the invention described in the item (1) or (2), it is guided into the nozzle by having a regulating means for regulating sliding of the spherical member with respect to the spherical member holding portion. The laser beam is surely transmitted through the laser beam transmitting portion of the spherical member and irradiated to the welded part of the welded member, and the welded part of the welded member is lap welded.

  (4) Any one of the items (1) to (3), wherein a clearance of 0.030 to 0.035 mm in diameter is formed between the spherical member holding portion and the spherical member. The lap laser welding apparatus described in 1.

  In the invention of item (4), in the invention of any one of items (1) to (3), a diameter of 0.030 to 0.035 mm is provided between the spherical member holding portion and the spherical member. By forming the clearance, the spherical member can slide reliably and appropriately with respect to the spherical member holding portion of the nozzle.

  (5) The press-fitting allowance of the spherical member to the tip opening of the spherical member holding part is 0.05 to 0.06 mm in diameter, and any one of the items (1) to (4) is characterized. Lap laser welding equipment.

  In the invention described in the item (5), in the invention described in any one of the items (1) to (4), a pressure allowance of the spherical member with respect to the tip opening of the spherical member holding portion is 0.05 in diameter. By being 0.06 mm, the spherical member can be attached to and detached from the spherical member holding portion of the nozzle.

(6) A lap laser welding method in which a plurality of overlapped members to be welded are pressed and brought into close contact with each other to irradiate a laser beam to a welding location, and the plurality of overlapped members to be welded are lap welded. And
A spherical member holding portion is formed inside the tip of the nozzle to which the laser beam is guided, a laser beam transmitting portion that transmits the laser beam guided into the nozzle, and a periphery of the tip opening of the laser beam transmitting portion. By forming a spherical member having a pressurizing part that pressurizes the plurality of welded members formed and slidably held on the spherical member holding part of the nozzle, a tilt copying mechanism is configured,
Superimposing the welding locations of each of the plurality of members to be welded,
A pressure member of a spherical member that is moved in the axial direction and held at the tip of the nozzle is brought into contact with the plurality of welded members that are overlapped and pressurized,
A lap laser welding method, wherein a laser beam guided into the nozzle is irradiated to a welding portion through the laser beam transmitting portion and lap welding is performed.

  In the invention described in (6), a spherical member holding portion is formed inside the tip of the nozzle to which the laser beam is guided, and a laser beam transmitting portion that transmits the laser beam guided in the nozzle; A spherical member formed around the tip opening of the laser beam transmitting portion and having a pressurizing portion that pressurizes the plurality of overlapped members to be welded is slidably held on the spherical member holding portion of the nozzle. By constructing an inclination copying mechanism, a plurality of welded portions of the plurality of members to be welded are overlapped, and a plurality of pressure members of spherical members that are held at the tips of the nozzles are moved in the axial direction are overlapped. When a laser beam guided in the nozzle is pressed against the member to be welded and irradiated with a laser beam through the laser beam transmitting portion, the overlap is performed in the pressure direction of the nozzle. Even when the welded member is inclined, a plurality of welded members can be brought into close contact with each other by reliably following the inclination of the portion to be pressed, and thus lap welding can be performed reliably. Can do.

  (7) The lap laser welding method according to (6), wherein a spherical member is press-fitted into the tip opening of the spherical member holding portion of the nozzle.

  In the invention described in item (7), in the invention described in item (6), a spherical member is press-fitted into the tip opening of the spherical member holding portion of the nozzle, whereby the spherical member holding portion of the nozzle is pressed. A spherical member can be attached and detached.

First, an embodiment of the lap laser welding apparatus of the present invention will be described in detail based on FIG. 1 and FIG. 2 by the case where a pad and a ribbon mounted on a substrate are spot-welded.
The lap laser welding apparatus of the present invention is generally configured to pressurize a plurality of superposed welded members W1 and W2 so that they are brought into close contact with each other and irradiate a laser beam LB on a welding site. A nozzle 1 is provided so as to be movable at least in the axial direction with respect to the welding members W1 and W2, and a laser beam LB is guided therein, and a spherical member 2 held at the tip of the nozzle 1 is provided. A spherical member holding portion 10 for slidably holding the spherical member 2 is formed inside the tip of the nozzle 1. The spherical member 2 includes a laser beam transmitting portion 20 that transmits the laser beam LB guided into the nozzle 1 and a plurality of overlapped objects formed so as to slightly protrude around the tip opening of the laser beam transmitting portion 20. And a pressurizing portion 21 that presses against the welding members W1 and W2. The spherical member 2 is made of an alloy of 20 to 40% by weight of copper and 80 to 60% by weight of tungsten. Furthermore, it has the control means 3 which controls the sliding of the spherical member 2 with respect to the spherical member holding | maintenance part 10 of the nozzle 1. FIG.

  A pad W1, which is one of the members to be welded, is soldered onto a substrate W3 made of ceramic. The substrate W3 is positioned and fixed on the housing H when the pad W1 and the ribbon W2 are overlap-welded. The upper surface H1 of the housing H is processed in parallel with the lower surface H2 of the housing H in the case of this product (that is, the upper surface H1 of the housing H is parallel to the upper surface of the welding table 4). Therefore, in the case of this product, the upper surface H1 of the housing H for positioning and fixing the substrate W3 becomes a reference surface with inclinations J and K described later. However, when the upper surface H1 of the housing H is not processed parallel to the lower surface H2, the welding table 4 that positions and supports the housing H serves as a reference surface. The substrate W3 may have a substrate inclination J in which the upper surface (front surface) W3b soldered to the pad W1 is inclined with respect to the reference surface due to distortion during molding. The substrate inclination J is allowed to be 1 ° at maximum as an error. Further, the pad W1 soldered on the substrate W3 does not spread the solder S uniformly between the substrate W3 and the pad W1, and a solder inclination K is generated that is inclined with respect to the surface W3b of the substrate W3. There is a case. This solder inclination K is allowed up to 3 ° as an error. Therefore, the inclination of the surface of the pad W1 for spot welding the ribbon W2 with respect to the reference plane is inclined by 4 ° at the maximum.

  On the other hand, the ribbon W2 is made of, for example, tin plated on the surface of a thin strip-shaped copper, and a portion W2a spot-welded with the pad W1 is formed by bending the vicinity of the tip, and the portion W2a is formed as a pad. It is supported so as to be substantially parallel to the upper surface of W1. The ribbon W2 has a tin-plated surface so that it can easily absorb the laser beam LB, and is melted and joined to the pad W1 by the thermal energy.

  The nozzle 1 is supported so as to be movable to an arbitrary position by, for example, an arm of a robot so as to be able to move and pressurize a predetermined welding location of the overlapped welded members W1 and W2 in the axial direction. . The nozzle 1 is formed in a hollow, substantially cylindrical shape having a circular shape, and is guided so that a laser beam LB output from the laser oscillation device and condensed at a predetermined focal point is irradiated toward the tip. The nozzle 1 can be made of alumina-dispersed copper, for example. Further, the nozzle 1 can be configured so that an inert gas or a reactive gas, an assist gas, a shield gas, or the like can be supplied into the nozzle 1 and ejected toward the welding location as required. Since the type of the laser oscillation device, the mode of the laser beam LB to be output, the transmission time, the output, and the like are appropriately selected according to the types and thicknesses of the members to be welded W1, W2, the present invention is particularly limited. Never happen. A spherical member holding portion 10 is formed inside the tip of the nozzle 1. The inner diameter of the opening 10a of the spherical member holding part 10 is slightly smaller than the outer diameter of the spherical member 2, and a predetermined press-fitting allowance is formed. Further, the inner peripheral side wall 30 in the lower part of FIG. 1 from the opening 10a constitutes a restricting means 3 that restricts the sliding of the spherical member 2, as will be described later.

  The spherical member 2 is formed in a substantially spherical shape so that it can slide so as to rotate within the spherical member holding portion 10 of the nozzle 1, but the portion exposed from the tip of the nozzle 1 is cylindrical. A pressurizing portion 21 is formed that slightly protrudes and abuts against the welded member W2 whose front end surface is superimposed. And the laser beam transmission part 20 is formed by the hole drilling so that the pressurization part 21 may penetrate to the opposite side from the center. The laser beam transmitting portion 20 may be a spherical member such as a cylindrical transparent glass member as long as it can irradiate the laser beam LB from the nozzle 1 toward the welded members W1 and W2. The hole formed in 2 is not limited. The inner diameter of the laser beam transmitting portion 20 is such that the laser beam guided in the nozzle 1 does not interfere with the laser beam LB when the spherical member 2 slides in the spherical member holding portion 10 of the nozzle 1 as will be described later. It is set according to the diameter of LB, the allowable sliding range of the spherical member 2 with respect to the spherical member holding portion 10 of the nozzle 1, and the like. As will be described later, the outer peripheral side wall 31 of the pressurizing portion 21 that slightly protrudes in a cylindrical shape allows the spherical member 2 to slide along with the inner peripheral side wall 30 below in FIG. 1 from the opening 10a of the spherical member holding portion 10. A regulating means 3 for regulating is configured.

  In this embodiment, the difference between the inner diameter of the spherical member holding portion 10 and the outer diameter of the spherical member 2 (ie, clearance) is set to about 0.030 to 0.035 mm in diameter. The surface of the spherical member 2 is formed with a roughness of Ra 0.4 or less. Due to the clearance and the surface roughness, the spherical member 2 is brought into contact with the inner peripheral side wall 30 of the spherical member holding unit 10 without being affected by expansion due to heat during welding. Within the restricted range, it can slide freely in all directions within the spherical member holding portion 10 without causing seizure according to the inclination of the pad W1 on which the ribbon W2 is superimposed. Therefore, even when the pad W1 is inclined with respect to the reference plane, when the nozzle 1 is moved in the axial direction (vertical direction in the drawing) and pressurized, the pressurizing unit 21 follows the inclination. Is configured to follow the inclination.

  Further, in this embodiment, the difference between the inner diameter of the opening 10a of the spherical member holding portion 10 and the outer diameter of the spherical member 2 is set to about 0.05 to 0.06 mm in diameter. ing. By this press-fitting allowance, the spherical member 2 can be incorporated and securely held in the spherical member holding portion 10 of the nozzle 1, and the spherical member 2 can be reliably held from within the spherical member holding portion 10 of the nozzle 1 as necessary. Can be removed and replaced.

  Here, the material which comprises the spherical member 2 is demonstrated. FIG. 2 is a chart showing the evaluation of welding, deformation, and welding strength with a member to be welded when experiments are performed by molding the spherical member 2 with various materials. Due to the thermal energy of the laser beam LB during welding, the pressure member 21 of the spherical member 2 is not welded to the ribbon W2 plated with tin as a member to be welded or deformed by pressurization and has a predetermined strength. It was found that the only material that could be welded with was an alloy of copper and tungsten. Therefore, in the present invention, the spherical member 2 is composed of an alloy of 20 to 40% by weight of copper and 80 to 60% by weight of tungsten.

Next, one embodiment of the lap laser welding method of the present invention will be described in detail together with the operation thereof, depending on the case of using the lap laser welding apparatus configured as described above. In addition, the same code | symbol is attached | subjected about the part which overlaps with embodiment of the overlap laser welding apparatus mentioned above, or the equivalent part, and the description is abbreviate | omitted.
The lap laser welding method according to the present invention generally includes a plurality of overlapped welded members by irradiating a welding spot with a laser beam LB in a state in which the overlapped welded members W1 and W2 are pressed and brought into close contact with each other. The members W1 and W2 are lap welded, and the spherical member holding portion 10 is formed inside the tip of the nozzle 1 to which the laser beam LB is guided, and the laser beam LB guided in the nozzle 1 is transmitted. A spherical member 2 having a laser beam transmitting portion 20 to be pressed and a pressurizing portion 21 for pressing a plurality of welded members W1 and W2 formed and overlapped around the tip opening of the laser beam transmitting portion 20 is formed. Then, the spherical member 2 is slidably held on the spherical member holding portion 10 of the nozzle 1 to constitute an inclination copying mechanism. Then, a plurality of members to be welded in which the welded portions of the plurality of members to be welded W1 and W2 are overlapped, and the pressure member 21 of the spherical member 2 held at the tip of the nozzle 1 is moved in the axial direction are overlapped. The laser beam LB guided into the nozzle 1 is converted into the laser beam of the spherical member 2 in a state in which the gap M between the welded portions of the welded members W1 and W2 is eliminated by abutting against W1 and W2. Irradiation is applied to the welded part through the transmission part 20 and lap welding is performed.

  When spot welding the ribbon W2 to the pad W1 soldered on the substrate W3, the substrate W3 is fixed on the housing H, and the housing H is positioned and fixed on the welding table 4, and the spot of the ribbon W2 is fixed. The portion W2a to be welded is superimposed on the upper surface of the pad W1. At this time, as described above, the upper surface of the pad W2 may be inclined with respect to the upper surface H1 of the housing H or the upper surface of the welding table 4 as a reference surface due to the solder inclination K, the substrate inclination J, or the like.

  Next, the arm of the robot is driven so that the axial direction of the nozzle 1 is perpendicular to the upper surface of the housing H or the upper surface of the welding table 4 and corresponds to the welding location. Moved in the vertical direction with respect to the upper surface or the upper surface of the welding table 4, the pressurizing portion 21 protruding from the tip of the nozzle 1 of the spherical member 2 is brought into contact with the welding portion of the ribbon W 2 and placed on the welding table 4. The pressure is applied between the housing H and the pressurizing unit 21 so as to eliminate the gap M at the welded portion between the pad W1 and the ribbon W2 on the substrate W3, that is, the two W1 and W2 are brought into close contact with each other. At this time, since the spherical member 2 is held by the spherical member holding portion 10 of the nozzle 1 to form a copying mechanism, the pad W1 is relative to the upper surface H1 of the housing H or the upper surface of the welding table 4 as a reference surface. Even if it is inclined, by moving the nozzle 1 in the axial direction and applying pressure (see the arrow in FIG. 1), the spherical member 2 is held by the spherical member holding portion 10 of the nozzle 1 according to the inclination of the pad W1. Will slide inside. Therefore, as in the case shown in FIG. 6, when the pressure between the pad W1 and the ribbon W2 is examined by interposing the pressure sensitive paper 102 (see reference numeral 102 in FIG. 6) between the pad W1 and the ribbon W2, As shown in FIG. 3, since the impression PM according to the shape of the pressurizing portion 21 appeared on the pressure sensitive paper, it was proved that the periphery of the welded portion was uniformly pressurized over the entire circumference. Therefore, it is ensured that the ribbon W2 is in close contact with the surface of the pad W1 at the welding location. Note that the pressure applied to the pressurizing portion 21 of the spherical member 2 by driving the robot can be set to a strength at which the ribbon W2 can sufficiently adhere to the pad W1, for example, as 2 kgf. Further, the base end side of the nozzle 1 is supported so as to be movable in the axial direction, the movement in the direction in which the nozzle 1 extends (down in FIG. 1) is restricted, and the direction in which the nozzle 1 extends is attached. It is also possible to provide a spring to be urged and to obtain a desired pressure of the pressure member 21 of the spherical member 2 such as 2 kgf by the urging force of the spring.

  When the laser beam LB is output in this state, the laser beam LB is guided inside the nozzle 1 and irradiated onto the ribbon W2 through the laser beam transmitting portion 20 of the spherical member 2, and the welded portion between the ribbon W2 and the pad W1 is detected. It is melted and joined by the thermal energy of the laser beam LB. At this time, for example, assuming that the diameter of the laser beam LB is about 0.63 mm at a predetermined position in the nozzle 1 and is condensed to about 0.60 mm on the surface of the ribbon W2, the inner diameter of the nozzle 1 is The inner diameter of the laser beam transmitting portion 20 of the spherical member 2 is 1.8 mm and 1.6 mm. When the pad W1 is inclined with respect to the reference plane at an angle greater than an assumed angle, the outer peripheral side wall 31 of the pressure member 21 of the spherical member 2 is the inner peripheral side wall of the opening 10a of the spherical member holding unit 10. The sliding of the spherical member 2 with respect to the spherical member holding portion 10 is restricted. Therefore, the spherical member 2 is prevented from sliding so as to rotate excessively in the spherical member holding portion 10 and the laser beam transmitting portion 20 is prevented from interfering with the laser beam LB.

  The present invention is not limited to the above-described embodiment, and a plurality of members to be welded can be formed by the laser beam LB in addition to the case where the pad W1 soldered on the substrate W3 and the ribbon W2 are joined. Any lap welding can be applied.

It is principal part sectional drawing shown in order to demonstrate one Embodiment of the overlap laser welding apparatus of this invention. It is a graph which shows evaluation with welding with a to-be-welded member, a deformation | transformation, and welding strength at the time of experimenting by shape | molding a spherical member with various materials, respectively. In the case of this invention, it is an impression of a pressurizing part when a pressure sensitive paper is interposed between a pad and a ribbon. It is principal part sectional drawing shown in order to demonstrate the conventional overlap laser welding apparatus. It is the chart shown in order to demonstrate the relationship between the clearance gap between to-be-welded members, and peeling strength. FIG. 5 is a cross-sectional view of an essential part for explaining a state in which pressure-sensitive paper is interposed between a pad and a ribbon in order to investigate a state of pressurization by a nozzle in the conventional lap laser welding apparatus shown in FIG. 4. . FIG. 5 is an indentation on the tip surface of the nozzle when pressure is applied with a pressure-sensitive paper interposed between the pad and the ribbon in the case of the conventional technique shown in FIG. 4.

Explanation of symbols

W1: pad (member to be welded), W2: ribbon (member to be welded), LB: laser beam, 1: nozzle, 2: spherical member, 3: regulating means, 10: spherical member holding portion, 20: laser beam transmitting portion , 21: Pressurizing part

Claims (3)

A lap laser welding apparatus that pressurizes a plurality of overlapped members to be welded to closely contact each other and irradiates a welding spot with a laser beam,
A spherical member holding portion is formed inside the tip, a nozzle that guides the laser beam inside,
A spherical member slidably held in the spherical member holding portion of the nozzle,
The spherical member includes a laser beam transmitting portion that transmits a laser beam guided into the nozzle, and a pressurization that pressurizes the plurality of welded members formed around the tip opening of the laser beam transmitting portion. And a lap laser welding apparatus characterized by comprising:   The lap laser welding apparatus according to claim 1, wherein the spherical member is an alloy of 20 to 40% by weight of copper and 80 to 60% by weight of tungsten. A lap laser welding method in which a plurality of members to be welded are pressurized and irradiated with a laser beam in a state of being in close contact with each other, and the plurality of members to be welded are lap welded.
A spherical member holding portion is formed inside the tip of the nozzle to which the laser beam is guided, a laser beam transmitting portion that transmits the laser beam guided into the nozzle, and a periphery of the tip opening of the laser beam transmitting portion. By forming a spherical member having a pressurizing part that pressurizes the plurality of welded members formed and slidably held on the spherical member holding part of the nozzle, a tilt copying mechanism is configured,
Superimposing the welding locations of each of the plurality of members to be welded,
A pressure member of a spherical member that is moved in the axial direction and held at the tip of the nozzle is brought into contact with the plurality of welded members that are overlapped and pressurized,
A lap laser welding method, wherein a laser beam guided into the nozzle is irradiated to a welding portion through the laser beam transmitting portion and lap welding is performed.

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