JP4325550B2 - Bonding structure and bonding method of bus bar for electronic device and connection terminal - Google Patents

Description

The present invention relates to a bonding structure between a bus bar for an electronic device and a connection terminal, and a method for bonding the connection terminal to the bus bar for an electronic device. The present invention also relates to a method of joining a connection terminal to the bus bar for electronic equipment.

  In recent years, the advancement of electronics has been remarkable. For example, in the case of car electronics, the number of electronic devices and CPUs mounted in automobiles has increased dramatically. For this reason, when the automobile wire harness is branched and connected to various electrical components, an electrical connection box (junction block) is employed in order to concentrate the branch connection portions and perform wiring rationally and economically. .

  Conventionally, a desired connection is made by joining connection terminals (tab terminals) of electronic components that are separately manufactured to bus bars that are stamped into various shapes by pressing or the like and have various circuit patterns formed thereon. There is known an electric junction box that is configured to be smaller and higher in density by configuring the above circuit.

  In such an electrical junction box, if soldering is used when joining the bus bar and the connection terminal, cracks may occur in the joint and the mechanical strength may be reduced. A technique of welding using a heat source having a high energy density is known. However, the material of the bus bar is copper or a copper alloy, and its thermal conductivity is high. For this reason, for example, laser welding requires high-power laser irradiation, which may lead to problems such as high equipment costs and poor welding quality due to spattering.

  Therefore, while providing a rod-shaped protrusion having a small cross-sectional area on the connection terminal, a through hole is formed in the bus bar through which the rod-shaped protrusion can be inserted, and the rod-shaped protrusion of the rod-shaped protrusion is inserted in the through hole. A technique is known in which a bus bar and a connection terminal are joined by irradiating a laser beam toward the distal end portion to melt the distal end portion of the rod-shaped protrusion (see, for example, Patent Document 1).

  According to this technique, since the laser beam is irradiated to the low heat capacity shaped rod-shaped protrusion provided on the connection terminal, even if the material is copper or copper alloy having high thermal conductivity, the melting point or more is exceeded. Can be easily heated to melt the tip of the rod-like protrusion, so that welding by low-power laser irradiation becomes possible.

  Also, using a burring process, a burring portion protruding in a tapered cylindrical shape with the through hole as a central hole is provided, and a bar-like protrusion portion of a connection terminal is inserted into the through-hole to burring the tip end portion of the rod-like protrusion portion. There is also known a technique for joining the bus bar and the connection terminal by irradiating the tip of the rod-like projection with laser light in a state of protruding from the protruding tip of the part to melt the tip. For example, see Patent Document 2).

According to this technique, the burring portion protruding in a tapered cylindrical shape serves as a guide when the rod-shaped protrusion of the connection terminal is inserted into the through hole of the bus bar, so that the insertion operation can be performed smoothly and easily. .
JP 2002-25639 A Japanese Patent Laid-Open No. 7-241020

  However, in the above-described prior art, it is necessary to separately provide a bar-shaped protrusion only for joining to the burring portion on the connection terminal, which causes a problem that the number of processes is increased and the cost is increased.

  On the other hand, when the connecting rod-shaped protrusions are not provided on the connection terminals, there are the following problems particularly when connecting the connection terminals of a plurality of electronic components to the bus bar. That is, the connection terminals of each electronic component have different diameters, materials, etc., and the heat input conditions for the connection terminals are greatly different for each terminal. For this reason, in order to join the connection terminals of a plurality of electronic components to the bus bar with the technique of joining the burring part and the connection terminal by heating and melting the connection terminal as in the above-described conventional technology, as shown below The joining method must also be changed for each connection terminal of each electronic component. Therefore, it is necessary to prepare different welding machines for each joining method, resulting in high cost of electronic equipment and complicated manufacturing processes.

  For example, when the connection terminal is made of a copper-based material, the copper-based material has a high thermal conductivity and a high reflectance of the laser beam, so that the copper-based connection terminal having a particularly large wire diameter will be melted by irradiation with the laser beam. If so, a considerable amount of power is required and the efficiency becomes extremely low. Moreover, even if it is going to join a copper-type connection terminal to a bus bar which consists of copper-type materials by resistance welding, since the difference of the resistance value between both members is small, it cannot join favorably. For this reason, copper-based connecting terminals having a wire diameter of φ2 mm or more are joined to a bus bar made of a copper-based material by plasma welding, and copper-based connecting terminals having a wire diameter of less than φ2 mm are joined by TIG welding. On the other hand, when the connection terminal is made of an iron-based material, when the wire diameter is 2 mm or more, laser welding or plasma welding is performed (if the wire diameter is 2 mm or more, it becomes difficult to generate Joule heat by resistance welding. ), If the wire diameter is less than 2 mm, it was joined to a bus bar made of a copper-based material by resistance welding.

  On the other hand, for an electronic device including a bus bar to which a connection terminal of an electronic component is bonded, for example, when performing a vibration test, the bonding strength at the bonding portion between the connection terminal and the bus bar is higher than the base material strength of the connection terminal. Needed. For this reason, if the wire diameter of the connection terminal is increased, the bonding strength between the connection terminal and the bus bar is required to be higher than the bonding strength between the connection terminal having a thin wire diameter and the bus bar. Therefore, it is necessary to employ a welding method that can secure high joint strength for joining the connection terminal having a large wire diameter and the bus bar.

The present invention has been made in view of the above circumstances, and even when a plurality of connection terminals having different materials and wire diameters are welded to a bus bar, a rod-shaped protrusion or the like only for joining is used as the connection terminal. Without having to be provided separately, and without changing the welding method (welding machine) for each connection terminal, each connection terminal can be well welded to the electronic device bus bar and the connection structure of the connection terminal and the electronic device bus bar. Providing a connection terminal joining method is a technical problem to be solved.

The joint structure of the bus bar for electronic equipment and the connection terminal of the present invention that solves the above-mentioned problems is integrally raised from the main body portion so as to have a main body portion made of a copper-based material and an insertion hole, and protrudes into a cylindrical shape. with each said insertion hole of the electronic device bus bar to have a plurality of cylindrical projections each having a front-end-side molten bond to the protruding tip side, the material and at least one of a plurality of different connection terminals of the wire diameter In the inserted state, each tip side melted portion is melted preferentially over each connection terminal by a high energy density heating source , and each tip side melted portion is melted with molten metal. Covering each tip surface of the connection terminal, each cylindrical projection and each connection terminal are welded to each other, and are connected to the electronic device bus bar and the connection terminal , each tip surface of each of the connection terminals is And each insertion hole Each projecting tip surface of each cylindrical projection portion in the vicinity of each tip side melted portion after each terminal is inserted and before each tip end side melted portion is melted. Are arranged at positions where the protrusions protrude, and the cylindrical protrusions protrude in accordance with the material and wire diameter of the connection terminals so that the joint strength with the connection terminals to be welded is a predetermined value or more. The lengths of the melted portions on the front end side are respectively adjusted by adjusting the heights.

  Here, the front end side melted portion refers to a portion on the projecting front end side of the cylindrical projection, which is heated and melted by a high energy density heating source to become a molten metal.

The electronic device bus bar and the connection structure of the connection terminal are preferentially heated and melted at the tip-side melted portion of the cylindrical protrusion rather than the connection terminal inserted into the insertion hole of the cylindrical protrusion. The following effects are exhibited. That is, in the joint structure of the connection terminal and the electronic device for the bus bar, the front-end-side molten bond of the tubular projecting portion is heated and melted by the heat source of high energy density, molten metal connection terminals The front-end-side molten bond is melted And is solidified by being buried in a gap between the cylindrical projection and the connection terminal inserted into the insertion hole (is melted and welded to each other, or the connection terminal has a higher melting point than the bus bar). In the case of a material, it is brazed with a copper-based metal of a bus bar material), thereby joining the cylindrical protrusion and the connection terminal. At this time, the larger the amount of melting (amount of molten metal) of the cylindrical projection heated / melted by the heating source, in other words, the longer the length of the tip-side molten portion heated / melted by the heating source, the larger the bonding area. If it is large, the joint strength at the joint becomes high. For this reason, if the length of the front end side melted part is adjusted appropriately, an appropriate joint area can be secured at the joint part between the cylindrical projection and the front end side melted part, and therefore a desired joint strength can be obtained. Can be obtained.

In the joining structure of the bus bar for electronic equipment and the connection terminal according to the present invention, the length of the front end side melted portion is adjusted by adjusting the protruding height of the cylindrical projection according to the material and wire diameter of the connection terminal to be joined. It has been adjusted. That is, if the connection terminal material is difficult to be joined to the cylindrical projection, or if the connection terminal has a large wire diameter and a higher bonding strength is required, the cylindrical projection is accordingly provided. The length of the melted part at the tip side of the part is increased. In this way, in each cylindrical projection, the projection height of the cylindrical projection is adjusted in advance according to the material and wire diameter of the connecting terminal to be joined, and the length of the tip side melted portion is adjusted appropriately. After that, by reliably heating and melting the tip side melted portion, it is possible to secure an appropriate joint area according to the connection terminal joined to the cylindrical projection and obtain a desired joint strength. It becomes possible.

Therefore, according to the joining structure of the bus bar for an electronic device and the connection terminal of the present invention, each tip side melt of each cylindrical protrusion is employed without employing a different welding method (welder) depending on the connection terminal to be joined. Only by adopting a single welding method (welding machine) using a high energy density heating source that can reliably heat and melt the part, each cylindrical projection and each connection terminal can be satisfactorily It becomes possible to join.

Moreover, in the joining structure of the bus bar for electronic equipment and the connection terminal of the present invention, each cylindrical projection and each connection terminal can be satisfactorily joined by heating and melting each tip side melted portion of each cylindrical projection. Therefore, it is not necessary to separately provide the conventional bar-shaped protrusions for securing the bonding property on the bonding terminal side. Therefore, it is possible to avoid an increase in the number of processes and an increase in cost due to the provision of the bar-shaped protrusions separately on the connection terminals.

In a preferred embodiment, each of the tubular projecting portion is in a state before each of said after each said connection terminal is inserted into the insertion hole and each said front-end-side molten bond is melted, the tubular projections And the minimum clearance at the position where the clearance between each connection terminal is minimum is set to 0.05 to 0.4 mm. In a preferred embodiment, the connection terminal is made of an iron-based material.

In this electronic device bus bar and connection terminal joining structure , since the minimum gap between the cylindrical projection and the connection terminal inserted into the insertion hole is set within a predetermined range, it is connected to the cylindrical projection. It is possible to reliably obtain a desired bonding strength by appropriately filling the gap between the terminal and the molten portion in which the tip side melted portion of the cylindrical projection is heated and melted. Further, if the minimum gap between the cylindrical projection and the connection terminal is set within the predetermined range, the gap between the cylindrical projection and the connection terminal is caused by the molten metal that is heated and melted at the distal end side melting portion. As a result, the appropriate range of the amount of heat input from the heating source suitable for obtaining the desired bonding strength to the front end side melted portion is expanded, and the productivity is improved. Further, since the tip melting portion is heated and melted, it is possible to suppress the occurrence of spatter even when the connection terminal is made of an iron-based material.

Such a joining structure of the bus bar for electronic equipment and the connection terminal according to the present invention is obtained by applying the joining method of the connection terminal to the bus bar for electronic equipment according to claims 4 to 7, so that a rod-like protrusion for joining, etc. Can be satisfactorily joined to the respective cylindrical projections without separately providing the connection terminals or changing the joining method for each connection terminal.

That is, in the method for joining a connection terminal to the bus bar for electronic equipment according to the present invention that solves the above problem, each connection terminal is inserted into each insertion hole of each cylindrical projection, set placing each respective said front end surface to a position where each of said protruding end surface of each cylindrical protrusion than near a and the tip end surface of each of said front-end-side molten bond of each cylindrical protrusion protruding And, by irradiating each tip-side melted portion of each cylindrical protrusion with laser light as the heating source, each tip-side melted portion is preferentially melted over each of the connection terminals, A bonding step of covering each tip surface of each connection terminal with a molten metal in which each tip side melted portion is melted , and joining each cylindrical projection and each connection terminal. It is what.

In this method of joining the connection terminal to the bus bar for electronic equipment, the tip side melted portion of the cylindrical projection is heated and melted preferentially over the connection terminal by using laser light as a high energy density heating source. In this joining method, first, in the setting step, each connection terminal is inserted into each insertion hole of each cylindrical projection, and each tip surface of each connection terminal is connected to each tip side melted portion of each cylindrical projection. and in the vicinity than the tip face each said projecting distal edge face of the cylindrical projections are arranged at a position protruding in. At this time, preferably after the connection terminal is inserted into the insertion hole and before the tip- side melted portion is melted, the minimum at the position where the gap between the cylindrical projection and the connection terminal is minimized. The inner diameter of the insertion hole of the cylindrical projection is set in advance according to the wire diameter of the connection terminal so that the gap is 0.05 to 0.4 mm. And a laser beam is irradiated to each front end side fusion part of each cylindrical projection part at a joining process, respectively. When the tip-side melted part is heated and melted by laser light irradiation, the molten metal melted by the tip-side melted part covers the tip end surface of the connection terminal and is connected to the cylindrical projection and its insertion hole. Each cylindrical protrusion and each connection terminal are joined by being buried in a gap between the terminals and solidifying.

Therefore, according to the joining method of the connection terminal to the bus bar for electronic equipment according to the present invention , each tip side of each cylindrical protrusion is employed without employing a different welding method (welding machine) depending on the connection terminal to be joined. Only by adopting laser welding that irradiates laser light toward each tip side melted part under irradiation conditions that can reliably heat and melt the melted part, each cylindrical protrusion and each connection terminal Can be bonded satisfactorily.

  In this method of joining the connection terminal to the bus bar for electronic equipment, a lower position than the protruding tip surface of the cylindrical projection (the protruding tip surface of the tip-side melted portion heated and melted by laser light irradiation) in the setting step Since the tip surface of the connection terminal is set to the laser beam, it is difficult to irradiate the tip surface of the connection terminal with the laser beam irradiated toward the tip-side melted portion. For this reason, the energy of the laser beam irradiated for heating and melting the front end side melting portion can be efficiently used for heating and melting the front end side melting portion. In addition, when the connection terminal is made of an iron-based material, when the connection terminal is heated and melted by laser light irradiation, spatter due to boiling of low-boiling additive components and impurities contained in the iron-based material may occur. However, according to this bonding method, it is possible to suppress the occurrence of such sputtering.

  In a preferred aspect of the method for joining the connection terminal to the bus bar for electronic equipment according to the present invention, in the joining step, the laser light is obliquely irradiated with respect to the protruding direction of the cylindrical protrusion.

  In the joining method of the connection terminal to the bus bar for electronic equipment, in the joining process, in order to irradiate the laser beam obliquely with respect to the protruding direction of the cylindrical projecting portion, toward the tip side melt portion of the cylindrical projecting portion It is difficult for this laser beam to be applied to the tip surface of the connection terminal. For this reason, the energy of the laser beam can be efficiently used to heat and melt the front end side melting portion, and the occurrence of the spatter can be effectively suppressed.

  In a preferred aspect of the method for joining the connection terminal to the bus bar for electronic equipment according to the present invention, in the joining step, the laser light whose energy density is higher in the outer peripheral portion than in the central portion is used as the cylindrical protrusion. Irradiate vertically along the protruding direction of the part.

  In this method of joining the connection terminals to the bus bar for electronic equipment, in the joining process, the laser light whose energy density is higher in the outer peripheral portion than in the central portion is vertically irradiated along the protruding direction of the cylindrical protrusion. For this reason, the energy of the laser beam irradiated for heating and melting the tip side melting portion can be efficiently used for heating and melting the tip side melting portion. In addition, since the tip surface of the connection terminal is irradiated with laser light having a low energy density, it is possible to suppress the occurrence of spatter due to the boiling of the low-boiling additive component in the connection terminal made of an iron-based material.

  In a preferred aspect of the method for joining the connection terminal to the bus bar for electronic equipment according to the present invention, in the joining step, the energy density is high at the projecting tip position of the cylindrical protrusion and low at the tip position of the connection terminal. The laser beam whose focal position is controlled so as to be vertically irradiated is vertically irradiated along the protruding direction of the cylindrical protrusion.

  In this method of joining the connection terminal to the bus bar for electronic equipment, the focal position control is performed in the joining process so that the energy density is high at the protruding tip position of the cylindrical protrusion and low at the tip position of the connection terminal. In order to irradiate the laser beam vertically along the protruding direction of the cylindrical projection, by appropriately controlling the focal position, the energy of the laser beam irradiated for heating and melting the tip side melted portion is adjusted. By efficiently heating and melting the tip side melted part while heating and melting the tip side melted part, while the low boiling point additive component in the connection terminal made of iron-based material boils Sputtering can be reliably prevented.

Therefore, according to the joining structure of the bus bar for electronic equipment and the connection terminal and the joining method of the connection terminal to the bus bar for electronic equipment according to the present invention, a plurality of connection terminals having different materials and wire diameters are welded to the bus bar. Even so, without connecting the rod-shaped projections only for joining to the connection terminals, and without changing the welding method or welding machine for each connection terminal, each cylindrical projection and each connection terminal are connected. It becomes possible to weld well.

  The bus bar for an electronic device according to the present invention includes a main body portion made of a copper-based material, and is integrally raised from the main body portion so as to have an insertion hole and protrudes in a cylindrical shape, and at the front end side of each protrusion And a plurality of cylindrical protrusions each having

  In this bus bar for electronic equipment, a main body portion and a plurality of cylindrical protrusions are integrally formed from a copper-based material such as a flat plate shape by pressing or the like. The copper-based material is not particularly limited, and a copper alloy such as copper or brass can be used.

  In this bus bar for electronic equipment, each connection terminal of a plurality of electronic components is joined to each cylindrical projection. The type of the electronic component, the material of the connection terminal, and the wire diameter are not particularly limited, and a connection terminal made of a copper-based material or an iron-based material can be joined.

  Each cylindrical protrusion protrudes integrally from a predetermined position of the main body so as to have an insertion hole, and protrudes in a cylindrical shape having a predetermined protruding height and thickness. As described above, in the bus bar for electronic equipment according to the present invention having a plurality of cylindrical protrusions, each of the cylinders is inserted in a state where a plurality of connection terminals having different materials and wire diameters are inserted into the respective insertion holes. Each tip-side melted portion of the cylindrical projection is melted by a high energy density heating source, whereby each cylindrical projection and each connection terminal are welded.

  The plurality of connection terminals having at least one of material and wire diameter different from each other means that at least one of all connection terminals bonded to the bus bar for electronic equipment of the present invention is the remaining connection terminals. Means that at least one of the material and the wire diameter is different from each other. In addition, in the case of one electronic component having a plurality of connection terminals, and the material and wire diameter of each connection terminal are the same, in each cylindrical protrusion to which each connection terminal is joined, The protrusion height, the wall thickness, and the inner diameter of the insertion hole are the same size.

  Each insertion hole of each cylindrical protrusion has a gap between the inner peripheral surface of each cylindrical protrusion and the outer peripheral surface of each connection terminal, depending on the wire diameter of the connection terminal inserted and joined to the insertion hole. Each is formed with a predetermined hole diameter so that a predetermined gap can be formed. That is, the insertion hole is made of a molten metal having a hole diameter larger than the wire diameter of the connection terminal by a predetermined amount so that the connection terminal can be easily inserted, and a molten portion in which the molten portion at the tip side of the cylindrical projection is heated and melted. The hole diameter is set such that the gap can be appropriately filled and desired bonding strength can be exhibited. In addition, if the gap is relatively large with respect to the amount of molten metal heated and melted by the molten portion at the distal end side of the cylindrical protrusion, the gap cannot be filled with molten metal, so that the desired bonding strength can be obtained. Can't get.

Here, the cylindrical projection has a gap between the cylindrical projection and the connection terminal in a state after the connection terminal is inserted into the insertion hole and before the distal end side fusion portion is melted. The minimum gap at the minimum position is preferably set to 0.05 to 0.4 mm, and more preferably set to 0.05 to 0.2 mm. The gap between the cylindrical projection and the connection terminal is one side between the cylindrical projection and the connection terminal when the connection terminal is inserted in the center of the insertion hole of the cylindrical projection. It means a gap. If the minimum gap between the cylindrical projection and the connection terminal inserted into the insertion hole is set within the predetermined range, the gap between the cylindrical projection and the connection terminal is set to the same cylindrical projection. It is possible to reliably obtain the desired bonding strength by appropriately filling the molten portion of the tip side with the molten metal heated and melted. Further, if the minimum gap between the cylindrical projection and the connection terminal is set within the predetermined range, the gap between the cylindrical projection and the connection terminal is caused by the molten metal that is heated and melted at the distal end side melting portion. As a result, the appropriate range of the amount of heat input from the heating source suitable for obtaining the desired bonding strength to the front end side melted portion is expanded, and the productivity is improved. If the gap between the cylindrical projection and the connection terminal is too large, molten metal may be burned out due to the connection terminal being biased in the insertion hole, or the gap may be filled appropriately due to insufficient molten metal. This makes it difficult to generate a bonding failure. On the other hand, if the gap between the cylindrical projection and the connection terminal is too small, the insertion property of the connection terminal into the insertion hole of the cylindrical projection will be lowered, and the molten metal will flow down in the gap due to capillary action. There is a tendency to cause poor bonding.

  In the bus bar for electronic equipment of the present invention, each cylindrical protrusion has a protruding height corresponding to the material and wire diameter of each connection terminal so that the bonding strength with each connection terminal to be welded is a predetermined value or more. The length of the front end side melted part is adjusted by adjusting each of the above. If the wire diameter of the connection terminal joined to the cylindrical protrusion increases, the joint strength required for the joint also increases accordingly. For this reason, if the wire diameter of the connecting terminal to be joined is increased, the protruding height of the cylindrical protrusion is set higher accordingly, and the length of the distal end side melted portion is set longer. Moreover, when the material of the connection terminal to be joined and the material of the bus bar for electronic equipment are different, it is difficult to weld compared to the case of the same type. For this reason, when the material of the connection terminal to be joined and the material of the bus bar for electronic equipment are different, the protruding height of the cylindrical protrusion is set higher than that of the same type, and the tip side melts. The length of the part is set longer.

  Here, if the thickness of the cylindrical projection is too thick, it becomes difficult to heat and melt the molten portion on the tip side of this cylindrical projection, while if it is too thin, it is inserted into the insertion hole of this cylindrical projection. It becomes difficult to obtain a desired joint strength by appropriately filling the gap between the formed connection terminal and the cylindrical projection with the molten metal melted by the melted portion on the tip side. For this reason, the thickness of each cylindrical projection is the gap between the cylindrical projection and the connection terminal inserted into the insertion hole by the molten metal melted by the molten portion at the tip side of the cylindrical projection. Is appropriately filled so that a desired bonding strength can be obtained, and the tip side melted portion can be reliably heated and melted.

  In the bus bar for electronic equipment of the present invention configured as described above, in the state where the connection terminal is inserted into the insertion hole of the cylindrical projection, the melting portion on the tip side of the cylindrical projection has priority over the connection terminal. Heated and melted. At this time, as a heating source for heating and melting the tip side melting portion of the cylindrical projection, a high energy density heating source capable of reliably heating and melting each tip side melting portion of each cylindrical projection is used. If there is no particular limitation, laser, plasma or TIG can be used. However, it is preferable to use laser irradiation from the viewpoint of improving productivity and downsizing of equipment.

That is, the method for joining the connection terminal to the bus bar for electrical equipment of the present invention, which can be suitably employed to form the joint structure of the bus bar for electrical equipment and the connection terminal of the present invention, includes a setting process and a joining process. In this joining step, the tip side melted portion of the cylindrical projection is heated and melted by the laser beam.

In the setting step, each of the connection terminals is inserted into each of the insertion holes of each of the cylindrical projections, and each tip surface of each of the connection terminals is located in the vicinity of each of the tip side melt portions of each of the cylindrical projections. Respectively. At this time, the tip surface of the connection terminal does not protrude beyond the protruding tip surface of the cylindrical projection (the protruding tip surface of the tip-side melted portion), and the tip surface of the connection terminal is lower than the protruding tip surface of the cylindrical projection. Ru is set in position. If it carries out like this, it will become easy to preferentially heat and fuse the tip side fusion part of a cylindrical projection part rather than a connection terminal by irradiation of a laser beam in a joining process. In addition, since it becomes difficult to irradiate the distal end surface of the connection terminal with the laser beam irradiated toward the distal end side melting portion, the energy of the laser beam irradiated for heating and melting the distal end side melting portion is changed to the distal end side. It can be used efficiently for heating and melting the melting portion, and it is possible to suppress the occurrence of spatter when the connection terminal is made of an iron-based material.

In the joining step, each of the cylindrical projections and each connection terminal are melted by irradiating each of the cylindrical projections with a laser beam as a heating source toward each of the distal projections. And are respectively joined. At this time, the length and thickness of each front end side melted portion of each cylindrical projection portion can be surely heated and melted without excess or deficiency by irradiation with laser light. Accordingly, the laser light irradiation conditions are set appropriately in advance. It should be noted that excessive melting of the front end side melted portion by laser light irradiation is allowed within a range in which a desired bonding strength can be obtained. When the tip side melted portion is heated and melted by laser light irradiation in this way, the molten metal melted by the tip side melted portion covers the tip end surface of the connection terminal and is inserted into the cylindrical projection and its insertion hole. Each cylindrical protrusion and each connection terminal are joined by being buried in a gap between the connection terminals and solidifying.

In this joining step, it is preferable to irradiate the laser beam obliquely with respect to the protruding direction of the cylindrical protrusion toward the tip-side melted portion of the cylindrical protrusion. More to obliquely irradiate the laser beam toward the outer surface of the front-end-side molten bond, since hardly laser beam is irradiated on the tip surface of the connecting terminal Kunar, thereby heating and melting the front-end-side molten bond energy of the laser beam Therefore, it is possible to efficiently use the spatter and effectively suppress the occurrence of the sputtering.

  Therefore, when the connection terminal is made of an iron-based material, in order to suppress the generation of spatter, in the joining process, the laser beam is directed toward the tip side melted portion in the protruding direction of the cylindrical protruding portion. It is preferable to irradiate obliquely.

  Further, in this joining step, the laser light whose energy density is higher in the outer peripheral portion than in the central portion is directed toward the melted portion on the distal end side of the cylindrical protruding portion along the protruding direction of the cylindrical protruding portion. Vertical irradiation is preferred. In order to make the energy density of the outer peripheral part higher than the energy density of the central part in the laser beam to be irradiated, for example, a condensing lens having such a ring-shaped energy distribution can be used. At this time, it is preferable to reduce the energy density of the central portion as much as possible in order to more reliably suppress the sputtering when the connection terminal is made of an iron-based material. A circular masking member may be arranged on the optical axis of the laser beam vertically irradiated along the protruding direction of the cylindrical protrusion to block only the central portion of the laser beam.

  Therefore, when the connection terminal is made of an iron-based material, in order to suppress the occurrence of spatter, the laser beam whose energy density is higher in the outer peripheral part than in the central part is used to suppress the occurrence of sputtering. It is preferable to irradiate perpendicularly along the protruding direction of the cylindrical protrusion toward the melting part.

Further, in the joining process, the focus position is controlled so that the energy density of the laser light to be irradiated becomes higher at the protruding tip position of the cylindrical projection and lower at the tip position of the connection terminal. It is preferable that the controlled laser beam is irradiated vertically along the protruding direction of the cylindrical protrusion . This focal position control can be performed, for example, by translating a condensing lens arranged on the optical axis of the laser beam vertically irradiated along the protruding direction of the cylindrical protrusion in the optical axis direction. By vertically irradiating the laser beam whose focal position is controlled in this way, the energy of the laser beam irradiated to heat and melt the tip-side melted portion can be efficiently used to heat and melt the tip-side melted portion. In addition, while the tip-side melted portion can be reliably heated and melted, it is possible to reliably prevent the occurrence of spatter when the connection terminal is made of an iron-based material.

  Therefore, when the connection terminal is made of an iron-based material, the energy density of the laser beam to be irradiated is increased at the protruding tip position of the cylindrical protrusion in the joining process in order to suppress the occurrence of spatter, and the connection terminal It is preferable that the focal position is controlled to be low at the tip position, and the laser light subjected to the focal position control in this way is vertically irradiated along the protruding direction of the cylindrical protrusion.

Hereinafter, specific examples of the joining structure of the bus bar for electrical equipment and the connection terminal and the joining method of the connection terminal to the bus bar for electrical equipment according to the present invention will be described with reference to the drawings.

Example 1
This embodiment embodies the invention according to claim 1, 2, 3, 4 or 5.

  As shown in FIGS. 1 and 2, the electronic device bus bar 1 is integrally raised from the main body 2 so as to have a main body 2 made of copper and first to third insertion holes 3 </ b> A to 3 </ b> C. It has six first to third cylindrical protrusions 5A to 5C, each protruding in a tapered cylindrical shape and having first to third distal end side melting portions 4A to 4C on the protruding distal end side. This bus bar 1 for electronic devices is formed by integrally forming a main body 2 and six first to third cylindrical protrusions 5A to 5C by drawing a copper plate. At the lower end of each insertion hole 3A to 3C of each cylindrical projection 5A to 5C, a tapered (conical side surface) introduction guide portion 6 that inclines in a direction in which the hole diameter gradually decreases upward from the lower end. Each is provided.

  The six cylindrical protrusions 5A to 5C are two, and there are three pairs, and the first cylindrical protrusions 5A and 5A forming the first set and the second cylindrical protrusion forming the second set. The parts 5B and 5B and the third cylindrical protrusions 5C and 5C forming the third set are provided. In addition, a pair of cylindrical projection part which comprises each group has the same shape and magnitude | size (a hole diameter, a protrusion height, thickness, etc. of an insertion hole), respectively. A pair of first connection terminals 7A and 7A extending from the first electronic component (diode) A are joined to the first cylindrical protrusions 5A and 5A forming the first set, respectively. A pair of second connection terminals 7B and 7B extending from the second electronic component (capacitor) B are joined to the second cylindrical protrusions 5B and 5B forming the second set, respectively. A pair of third connection terminals 7C and 7C extending from the third electronic component (coil) C are joined to the third cylindrical protrusions 5C and 5C forming the third set, respectively.

  Here, the first connection terminals 7A and 7A are made of copper and have a wire diameter of φ1.2 mm. The first cylindrical protrusions 5A and 5A to which the first connection terminals 7A and 7A are respectively joined have a minimum hole diameter (hole diameter at the upper end position of the first insertion hole 3A) of the first insertion holes 3A and 3A. The diameter is φ1.4 mm, which is a predetermined amount larger than the wire diameter of the first connection terminal 7A. That is, the minimum gap (the upper end position of the first insertion hole 3A) between the first cylindrical protrusion 5A and the first connection terminal 7A in a state where the first connection terminal 7A is inserted in the center of the first insertion hole 3A. (One-side clearance at the protruding tip position of the first cylindrical protrusion 5A) is 0.1 mm. The protruding heights of the first cylindrical protrusions 5A and 5A are 2 mm, and the lengths of the first tip side melted parts 4A and 4A of the first cylindrical protrusions 5A and 5A are 2 mm. Yes. The thickness of the first cylindrical projections 5A and 5A is such that the first cylindrical projections 5A and the first insertion holes are made of molten metal obtained by melting the first tip side melted part 4A of the first cylindrical projections 5A. The gap between the first connecting terminal 7A inserted in 3A can be appropriately filled to obtain a desired bonding strength, and the first tip side melted portion 4A can be reliably heated and bonded in a bonding process described later. It is adjusted so that it can be melted.

  The second connection terminals 7B and 7B are made of soft iron and have a wire diameter of φ0.8 mm. The second cylindrical projections 5B and 5B to which the second connection terminals 7B and 7B are respectively joined have a minimum hole diameter (hole diameter at the upper end position of the second insertion hole 3B) of the second insertion holes 3B and 3B. It is set to φ1.0 mm which is a predetermined amount larger than the wire diameter of the second connection terminal 7B. That is, the minimum gap between the second cylindrical projection 5B and the second connection terminal 7B in the state where the second connection terminal 7B is inserted at the center of the second insertion hole 3B (the upper end position of the second insertion hole 3B). (One-side clearance at the protruding tip position of the second cylindrical protrusion 5B) is 0.1 mm. The thickness of the second cylindrical projections 5B and 5B is such that the second cylindrical projection 5B and the second insertion hole are made of molten metal melted by the second tip side molten portion 4B of the second cylindrical projection 5B. The gap between the second connection terminal 7B inserted into the 3B and the second connection terminal 7B can be appropriately filled to obtain a desired bonding strength, and the second tip side melted portion 4B can be reliably heated and bonded in the bonding process described later. It is adjusted so that it can be melted.

  The third connection terminals 7C and 7C are made of copper and have a wire diameter of φ2.4 mm. The third cylindrical projections 5C and 5C to which the third connection terminals 7C and 7C are joined respectively have the minimum hole diameters (hole diameters at the upper end position of the third insertion hole 3) of the third insertion holes 3C and 3C. The diameter is 2.6 mm, which is a predetermined amount larger than the wire diameter of the third connection terminal 7C. That is, the minimum gap (the upper end position of the third insertion hole 3C) between the third cylindrical protrusion 5C and the third connection terminal 7C in a state where the third connection terminal 7C is inserted into the center of the third insertion hole 3C. (One-side clearance at the protruding tip position of the third cylindrical protrusion 5C) is 0.1 mm. The thickness of the third cylindrical protrusions 5C and 5C is such that the third cylindrical protrusion 5C and the third insertion hole are formed by the molten metal melted by the third distal end side molten part 4C of the third cylindrical protrusion 5C. A gap between the third connection terminal 7C inserted in the 3C and the third connection terminal 7C can be appropriately filled to obtain a desired bonding strength, and the third tip side melted portion 4C can be reliably heated and bonded in a bonding process described later. It is adjusted so that it can be melted.

  The first to third connection terminals 7A to 7C of the first to third electronic components A to C are joined to the electronic device bus bar 1 having the above-described configuration using laser welding as follows. .

<Set process>
First, the first to third electronic components A to C are held by holding the first to third electronic components A to C on a component holding jig (not shown) with the first to third connection terminals 7A to 7C facing upward. Was arranged at a predetermined position (see FIG. 1). Then, by lowering the electronic device bus bar 1 from above the first to third electronic components A to C, the first to third insertion holes 3A to 3C of the first to third cylindrical protrusions 5A to 5C are changed to the first. 1st-3rd connecting terminal 7A-7C is inserted, respectively, and each 1st-3rd cylindrical projection part 5A-5C 1st-3rd front end side is made into each front end surface of 1st-3rd connecting terminal 7A-7C. It was made to position in the vicinity of the fusion | melting part 4A-4C, respectively. Specifically, the tip surfaces of the first to third connection terminals 7A to 7C are connected to the projecting tip surfaces of the first to third cylindrical protrusions 5A to 5C (of the first to third tip side melting portions 4A to 4C, respectively). It was set at a position lower by a predetermined amount (about 0.5 to 1.5 mm) than the protruding front end surface (see FIG. 2).

  In this setting step, since the introduction guide portions 6 are provided on the first to third cylindrical protrusions 5A to 5C, the first to third connection terminals 7A to 7C are provided along the introduction guide portion 6. Since it is guided and inserted into the first to third insertion holes 3A to 3C, the insertion operation becomes easy.

<Joint process>
Then, using a laser irradiation device (not shown), the laser beam 8 is directed toward the outer surface of the first tip-side melted portion 4A of the first cylindrical protruding portion 5A, and the protruding direction of the first cylindrical protruding portion 5A. Was obliquely irradiated (see FIG. 2). At this time, in the present example, the oblique irradiation was performed so that the outer edge corner portion of the protruding front end surface of the first front end side fusion portion 4A was irradiated with the laser beam 8. In this way, if the outer edge corner of the first tip-side melted portion 4A is irradiated with laser, the first tip-side melted portion 4A can be easily heated and melted by the heat accumulation effect of the edge portion. Then, by obliquely irradiating the laser beam 8 with respect to the first tip side melted portion 4A, the entire first tip side melted portion 4A is melted, and the first tip side melted portion 4A is melted by the molten metal for the first connection. The front surface of the terminal 7A is covered and the gap between the first cylindrical protrusion 5A and the first connection terminal 7A is filled, and in this state, the molten metal is solidified to form the brazing portion 9, and the first cylinder The protrusion 5A and the first connection terminal 7A were integrally joined (see FIG. 3). In addition, the laser beam 8 was not directly irradiated to the first connection terminal 7A by the oblique irradiation of the laser beam 8 with respect to the first distal end side fusion portion 4A. Next, similarly, the other second cylindrical projection 5A and the second connection terminal 7A were integrally joined.

  Similarly, the second cylindrical protrusions 5B and 5B and the second connection terminals 7B and 7B were integrally joined by laser welding. Further, similarly, the third cylindrical protrusions 5C and 5C and the third connection terminals 7C and 7C are integrally joined.

  The laser irradiation device is disposed on the optical axis of the laser oscillator and the laser beam emitted from the laser oscillator so that the focal position and irradiation direction (irradiation angle) of the laser beam can be arbitrarily controlled. A predetermined optical system element is provided with a mirror scanning device.

  Further, the irradiation conditions such as the laser output and the irradiation time during laser welding are such that the entire first tip side melting portions 4A to 4C of the first to third cylindrical projections 5A to 5C are heated and melted without excess or deficiency. It was preset for every 1st-3rd cylindrical projection part 5A-5C so that it could be made.

  As described above, in the present embodiment, the first to third cylindrical protrusions 5A to 5C are adjusted by adjusting the protruding height of the first to third connection terminals 7A to 7C according to the material and the wire diameter of the first to third connection terminals 7A to 7C. -The length of 3rd front end side fusion | melting part 4A-4C is each adjusted. And the 1st-3rd front end side fusion | melting part 4A-4C is reliably heated and fuse | melted preferentially by the oblique irradiation of the laser beam 8. FIG. For this reason, it is possible to ensure appropriate joining areas corresponding to the first to third connection terminals 7A to 7C joined to the first to third cylindrical protrusions 5A to 5C, respectively, and the first to third cylinders. It becomes possible to join the projections 5A to 5C and the first to third connection terminals 7A to 7C with a desired joining strength.

  Therefore, according to the present embodiment, without adopting a different welding method (welding machine) according to the first to third connection terminals 7A to 7C to be joined, and for securing the joining property on the joining terminal side. The first to third connection terminals 7A to 7C and the first to third cylindrical protrusions 5A to 5C having different wire diameters and materials can be satisfactorily joined without separately providing the conventional rod-like protrusions. Can do.

  In the present embodiment, since the minimum gap between the first to third cylindrical protrusions 5A to 5C and the first to third connection terminals 7A to 7C is set within a predetermined range, The gap between the first to third cylindrical protrusions 5A to 5C and the first to third connection terminals 7A to 7C is appropriately filled with the molten metal in which the third tip side molten portions 4A to 4C are heated and melted. Thus, a desired bonding strength can be reliably obtained.

  Furthermore, in the present embodiment, in the setting step, the front end surfaces of the first to third connection terminals 7A to 7C are set at positions lower than the protruding front end surfaces of the first to third cylindrical protrusions 5A to 5C. At the same time, the laser beam 8 is obliquely irradiated with respect to the protruding directions of the first to third cylindrical protrusions 5A to 5C toward the first to third tip-side melted parts 4A to 4C in the joining step. Therefore, the laser beam 8 is not directly irradiated to the first to third connection terminals 7A to 7C, and the laser is irradiated to heat and melt the first to third tip side melting portions 4A to 4C. The energy of the light 8 can be used efficiently. In addition, it is possible to effectively suppress the occurrence of sputtering when the first to third connection terminals 7A to 7C are made of an iron-based material.

(Example 2)
This embodiment embodies the invention according to claim 1, 2, 3, 4 or 6.

  That is, in this embodiment, as shown in FIG. 4, in the joining step, the energy density of the laser beam is higher in the outer peripheral portion than in the central portion through a condenser lens (not shown) (the energy in the central portion). The laser beam 8 having a ring-shaped energy distribution such that the density is almost zero is applied to the projecting tip surfaces (first to third tip side melting portions 4A to 4C) of the first to third cylindrical projections 5A to 5C. Of the first to third cylindrical projections 5A to 5C so that the center of the laser beam 8 coincides with the center of the first to third connection terminals 7A to 7C. Each was irradiated vertically.

  Therefore, according to this embodiment, the energy of the laser beam 8 irradiated for heating and melting the first to third tip side melting portions 4A to 4C can be efficiently used. Moreover, since the laser beam 8 with a low energy density is irradiated to the front end surfaces of the first to third connection terminals 7A to 7C, the first to third connection terminals 7A to 7C are made of an iron-based material. Sputtering can be effectively suppressed.

  Other configurations and operational effects are the same as those of the first embodiment.

(Example 3)
This embodiment embodies the invention according to claim 1, 2, 3, 4 or 7.

  That is, in this embodiment, as shown in FIG. 5, in the joining step, the energy density is increased at the protruding tip positions of the first to third cylindrical protrusions 5A to 5c, and the first to third connections are made. The laser light 8 that has been subjected to the focal position control so as to be lowered at the respective tip positions of the terminals 7A to 7C is adjusted so that the center of the laser light 8 coincides with the centers of the first to third connection terminals 7A to 7C. Vertical irradiation was performed along the protruding directions of the first to third cylindrical protrusions 5A to 5C.

  Therefore, according to the present Example, the energy of the laser beam 8 irradiated in order to heat and melt the 1st-3rd front end side fusion | melting parts 4A-4C can be utilized efficiently. Moreover, since the laser beam 8 with a low energy density is irradiated to the front end surfaces of the first to third connection terminals 7A to 7C, the first to third connection terminals 7A to 7C are made of an iron-based material. Sputtering can be effectively suppressed.

  Other configurations and operational effects are the same as those of the first embodiment.

(Evaluation of minimum clearance)
In the first embodiment, the size of the minimum gap between the first cylindrical protrusion 5A and the first connection terminal 7A is 0.4, 0.3, 0.2, 0.1, 0.05. The joint strength at the joint portion between the first cylindrical protrusion 5A and the first connection terminal 7A was evaluated.

  The result is shown in FIG. In FIG. 6, the vertical axis represents the laser heat input amount based on the appropriate value A of the laser heat input amount (J) to the first tip side melted portion 4 </ b> A. For example, a point of A + 20 indicates that the laser heat input is 20 J greater than the appropriate value A, and a point of A-20 indicates that the laser heat input is 20 J smaller than the appropriate value A.

As can be seen from FIG. 6, the first cylindrical projection 5A and the first cylindrical protrusion 5A are inserted into the first insertion hole 3A and before the first distal end side melting portion 4A is melted. If the minimum gap between the first connecting terminal 7A is set to be 0.05 to 0.4 mm, the first tip side melting portion 4A is heated and melted with at least an appropriate value A of laser heat input. The first cylindrical protrusion 5A and the first connection terminal 7A can be satisfactorily joined.

  Further, as shown in FIG. 6, if the minimum gap between the first cylindrical projection 5A and the first connection terminal 7A is set to 0.05 to 0.2 mm, the first suitable for obtaining a desired bonding strength. It can be seen that the appropriate range of the laser heat input to the 1 tip side melted part 4A is expanded to 60 J or more, and the productivity is improved. For example, if the minimum gap between the first cylindrical protrusion 5A and the first connection terminal 7A is set to 0.2 mm, the laser within a wide appropriate range of 60 J of the appropriate value A-20 to the appropriate value A + 40. Heating the first tip-side melted part 4A with an amount of heat input makes it possible to obtain a desired bonding strength. If the same minimum gap is set to 0.1 mm, an appropriate value A-40 to an appropriate value A + 40 of 80 J If the first tip-side molten portion 4A is heated with a laser heat input within a considerably wide appropriate range, a desired bonding strength can be obtained, and if the minimum gap is set to 0.05 mm, an appropriate value A-40 A desired bonding strength can be obtained by heating the first front end-side melted portion 4A with a laser heat input within a wide appropriate range of 60J of the appropriate value A + 20. In addition, when the minimum gap is 0.05 mm, it is considered that the joining failure occurs with the laser heat input of the appropriate value A + 40 because the molten metal flows down due to the capillary phenomenon. On the other hand, when the minimum gap is 0.3 mm or more, the appropriate range of the laser heat input amount is narrowed to 20 J or less, and the productivity is reduced accordingly.

It is explanatory drawing which concerns on Example 1 of this invention, and typically demonstrates a mode that the connection terminal of an electronic component is set to the cylindrical projection part of the bus bar for electronic devices, and the laser welding is performed. It is a fragmentary sectional view which shows typically a mode that it concerns on Example 1 of this invention and the laser welding is performed at a joining process. FIG. 4 is a partial cross-sectional view schematically showing a state after performing laser welding in the joining process according to Example 1 of the present invention. It is a fragmentary sectional view which shows typically a mode that it concerns on Example 2 of this invention and the laser welding is performed at a joining process. It is a fragmentary sectional view which shows typically a mode that it concerns on Example 3 of this invention, and the laser welding is performed at a joining process. It is explanatory drawing explaining the relationship between the minimum clearance gap (one side clearance gap) between 5 A of 1st cylindrical projection parts, and the 1st connection terminal, and the appropriate range of a laser heat input.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electronic equipment bus bar 2 ... Main-body part 3A-3C ... 1st-3rd insertion hole 4A-4C ... 1st-3rd front end side fusion | melting part 5A-5C ... 1st-3rd cylindrical projection part 7A-7C ... 1st-3rd connection terminal AC ... 1st-3rd electronic component 8 ... Laser beam

Claims (7)

A main body portion made of a copper-based material, and a plurality of cylindrical protrusion portions each integrally protruding from the main body portion so as to have an insertion hole and projecting into a cylindrical shape, and having a distal end side melted portion on each projecting distal end side; each said insertion hole of the electronic device for busbars have a, in a state in which the material and at least one of different plurality of connection terminals of the wire diameter is inserted respectively, heating the distal-end-side molten bond is high energy density Cover each tip surface of each connection terminal with a molten metal that is melted preferentially over each connection terminal by a source , and each tip side melted portion is melted, and each cylindrical projection and each connection terminal And a connection structure of a bus bar for electronic equipment and a connection terminal to be welded,
Each distal end surface of each connection terminal is in the vicinity of each distal end side melted portion in a state after each connection terminal is inserted into each insertion hole and before each distal end side melted portion is melted. And each is arranged at a position where each projecting tip surface of each cylindrical projection protrudes from each tip surface,
Each of the cylindrical protrusions is adjusted in projecting height according to the material and wire diameter of each connection terminal so that the joint strength with each connection terminal to be welded is a predetermined value or more. The length of each said front end side fusion | melting part is adjusted , The joining structure of the bus bar for electronic devices, and a connection terminal characterized by the above-mentioned. Each said tubular projecting portion is in a state before each of said after each said connection terminal is inserted into the insertion hole and each said front-end-side molten bond is melted, the said connecting terminals and each of the tubular projections The joint structure of the bus bar for electronic devices and the connection terminal according to claim 1, wherein a minimum gap at a position where a gap between the bus bar and the connection terminal is 0.05 to 0.4 mm is set. The said connection terminal consists of iron-type materials, The joining structure of the bus bar for electronic devices and a connection terminal of Claim 1 or 2 characterized by the above-mentioned. A joining method for forming a joint structure between the bus bar for electronic equipment and the connection terminal according to any one of claims 1 to 3,
The connection terminals are inserted into the insertion holes of the cylindrical projections, and the distal end surfaces of the connection terminals are arranged near the distal end-side melted portions of the cylindrical projections and A setting step of disposing each protruding tip surface of each of the cylindrical protrusions from the tip surface at a position where it protrudes;
By irradiating laser light as the heating source toward the tip side melted portions of the cylindrical projections, the tip side melt portions are preferentially melted over the connection terminals, And a joining step of covering each tip surface of each connection terminal with a molten metal whose tip side melted portion is melted and joining each cylindrical projection and each connection terminal. A method for joining connection terminals to bus bars for electronic devices. 5. The method of joining connection terminals to a bus bar for electronic equipment according to claim 4 , wherein, in the joining step, the laser beam is obliquely irradiated with respect to a protruding direction of the cylindrical protrusion. 5. The electron according to claim 4 , wherein, in the joining step, the laser beam having an energy density higher in the outer peripheral portion than in the central portion is vertically irradiated along a protruding direction of the cylindrical protrusion. A method of joining connection terminals to a bus bar for equipment. In the joining step, the laser beam whose focal position has been controlled so that the energy density is increased at the protruding tip position of the cylindrical projection and lowered at the tip position of the connection terminal, 5. The method of bonding a connection terminal to a bus bar for electronic equipment according to claim 4, wherein vertical irradiation is performed along the protruding direction.

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