JP5465195B2 - Ultrasonic bonding method - Google Patents

Description

  The present invention relates to an ultrasonic bonding method, and more particularly to an ultrasonic bonding method performed when members are bonded to each other at both opposing portions of a workpiece having a narrow portion.

  In some cases, the members are joined to each other at both opposing portions of the narrow portion of the metal or plastic processed material having the narrow portion. For example, when the processed material is a metal processed material and it is a battery, in manufacturing the battery, an electrode unit in which a positive and negative electrode sheet made of a metal foil such as aluminum and a separator are laminated is placed in an opposing state. There is a step of joining positive and negative current collecting terminals made of copper to each electrode unit.

  Conventionally, such bonding is performed by ultrasonic waves in a state where the horn or the horn is integrally processed, attached to the horn by means of silver brazing, screwing or the like, and pressurized by a bonding tip that vibrates ultrasonically in a desired vibration mode. This is done by applying vibration to the joint.

  In this case, stable bonding is possible by appropriately setting the pressure value and the vibration amplitude value of the horn or the bonding tip. In general, it is possible to increase the ultrasonic energy per unit time supplied to the joint by increasing both or either of the pressure value and the vibration amplitude value. It is known that the time required for ultrasonic vibration can be shortened.

  In addition, when ultrasonic vibration is applied by the horn itself in the above-mentioned joining, if it is made to enter into a narrow part with a considerably narrow interval, the thickness of the bowl-shaped tip part thereof is considerably reduced. In such a case, the tip portion is bent at the time of pressurization, which causes poor bonding. For this reason, ultrasonic vibration is often applied by a joining tip that is attached to the horn by the above-described means and has a processed surface protruding from the tip of the horn.

  Then, specifically, for example, as shown in FIG. 6, the thickness of the bowl-shaped tip portion 100a of the horn 100 is set to a thickness that does not cause bending when being pressed, and the tip portion of the horn. The processing surface 101a is attached to a flat portion on one side (lower side in the illustrated example) of 100a, and the joining chip 101 protruding from the tip portion 100a of the horn is attached. Is inserted into the narrow portion, and the joining chip 101 is used to join one side of the opposing portion first, and after that, the other side is joined. Reference numeral 102 denotes a narrow portion of the battery, which is a portion of the electrode units 103 and 103 in an opposed state. Reference numerals 104 and 104 denote positive and negative current collecting terminals. The spacing S between the opposing electrode units 103, 103 is about 5 mm. Reference numerals 103a and 103a denote clips made of a conductive material, which are put together by sandwiching the end portions of the electrode units 103 and 103, respectively.

  However, in the case of such a conventional configuration, both opposing portions of the narrow portion 102, that is, the electrode units 103 and 103 must be joined separately, which is problematic in terms of work efficiency. Further, in order to obtain a vibration mode suitable for bonding of the machining surface 101a, A (distance in which the machining surface 101a protrudes from the lower flat portion at the tip portion 100a of the horn) and B (of the machining surface 101a) shown in FIG. Since there is a limit on the dimension of the distance from the tip to the attachment position of the joining tip 101 to the lower flat portion of the tip portion 100a of the horn, only a limited portion on the open side 102a in the narrow portion 102 is joined. I can't. That is, it is not possible to perform the rear joining in the narrow portion 102. Further, since the joining chip 101 is supported in a cantilevered manner on the tip portion 100a of the horn and is in a state of projecting obliquely downward, either or both of the dimensions A and B are excessive. Then, the processed surface 101a does not vibrate evenly as a whole, so that there arises a problem that the bonding becomes unstable or non-uniform. In addition, when the overhanging length becomes longer, the difference in vibration amplitude between the tip portion 100a of the horn and the processed surface 101a at the time of joining increases, and accordingly, the vibration stress generated between the tip portion 100a of the horn and the processed surface 101a also increases. Therefore, the vibration amplitude value of the processed surface 101a that can be used for joining is limited to about 1/5 compared to the case where the overhang length is very small. As a result, there arises a problem that the bonding time becomes long or the bonding quality is not stable.

  The present invention has been made in view of the above points, and when performing the joining of members at each of the opposing portions of the narrow portion where the interval between the opposing portions is narrow, without performing separately as in the past, It is possible to increase the efficiency of the work by joining both opposing parts at the same time, and in addition, it is possible to join any part from the open side part to the back part of the narrow part, and the whole joined part In addition, the portion corresponding to the dimension A in FIG. 6 of the joining tip attached to the tip of the horn can be made smaller, and the joining between the tip of the horn and the processed surface of the joining tip can be performed. By reducing the vibration amplitude difference at the time, it is possible to increase the ultrasonic energy per unit time supplied to the joint, and consequently shorten the time of ultrasonic vibration required for joining With it, it is intended to provide an ultrasonic bonding method without so as to obtain a wider bonding area.

  In order to solve the above-mentioned problems, the present invention forms the tip of the horn into a predetermined thick hook shape so that the shape of the horn enters between the opposing portions of the narrow narrow portion. Attach a joining tip with the projection distance from the flat part of the processed surface as small as possible within the required range to both flat parts of the tip part, and when pressurizing from one side if the horn thickness is small The main element is to prevent the horn from being bent by simultaneously applying pressure to the horn from both sides with two anvils. It is.

  Thus, the gist of the present invention is that the tip end portion is formed in a bowl shape with a predetermined thickness, and the protruding distance of the processed surface from the flat portion is made as small as possible within the required range on both flat portions. The horn with the joined chip attached is positioned at the center of the narrow portion of the workpiece to which the member is joined at each of the opposing portions, and is attached to the horn on the outside of the opposing portions of the narrow portion. An anvil facing the bonded tip is disposed, and ultrasonic vibration is applied by the horn in a state in which each of the opposed portions of the narrow portion is sandwiched between the horn and the anvil with a predetermined pressure, The ultrasonic bonding method is characterized in that members are bonded to each other at both opposing portions of the narrow portion.

  Further, in the above method, both the anvils may be movable in the direction of contacting and separating from the horn and may be pressurized at the same pressure at the same time.

  Further, in the above method, one of the opposing anvils may be movable in a direction in which the anvil is moved toward and away from the horn, and the other anvil may be fixed.

  Moreover, a battery can be mentioned as a processed material in the said method.

  According to the present invention, when the members are joined to each other in the opposing portions of the narrow portion where the interval between the opposing portions is narrow, the opposing portions are joined at the same time without separately performing the conventional methods. Work efficiency can be improved. In addition, it can be joined at any part from the open side part to the back part of the narrow part, and the joined part can be joined uniformly throughout. Further, the bonding tip attached to the horn-shaped tip of the horn is made as small as possible within the required range of the processed surface from the flat portion of the horn tip, and the tip of the horn and the bonding tip are connected. By reducing the difference in vibration amplitude at the time of joining between processed surfaces, it is possible to increase the ultrasonic energy per unit time supplied to the joint, resulting in a reduction in the time of ultrasonic vibration required for joining. In addition to this, a wider bonding area can be obtained.

It is a schematic explanatory drawing of the ultrasonic joining method concerning a 1st embodiment of the present invention. It is a side view of the horn used in the embodiment. It is an expansion perspective view of the front-end | tip part of the same horn. It is an enlarged plan view of the tip portion of the horn. It is a schematic explanatory drawing of the ultrasonic bonding method which concerns on 2nd Embodiment of this invention. It is a schematic explanatory drawing of the conventional ultrasonic bonding method.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  In the figure, reference numeral 1 denotes a horn for ultrasonic vibration. A tip 1a is formed in a bowl shape with a predetermined thickness, and bonded chips 2 and 2 are attached to both flat portions, respectively. In addition, each of the joining tips 2 and 2 has a projection distance A ′ from the flat portion of the tip of the horn of the processed surface 2a as small as possible within a required range. Moreover, attachment of the joining chips 2 and 2 to the tip portion 1a of the horn is performed by appropriate means such as integral processing, silver brazing, and screwing. Further, a large number of fine irregularities are provided on the processed surface 2a of the joining chips 2 and 2. Note that the ultrasonic bonding apparatus including the horn 1 is the same as that conventionally known, so that the description thereof is omitted.

  Reference numeral 3 denotes a narrow portion in the metal workpiece, and in this embodiment, the portion of the electrode units 4 and 4 in an opposing state that constitutes the battery. The electrode units 4 and 4 are formed by laminating positive and negative electrode sheets made of a metal foil such as aluminum and a separator. Reference numerals 4a and 4a denote clips made of a conductive material, which are put together by sandwiching the end portions of the electrode units 4 and 4, respectively. Reference numerals 5 and 5 denote positive and negative current collecting terminals made of copper, which are joined to the electrode units 4 and 4 respectively. In the present embodiment, the distance S between the opposing electrode units 4 and 4 is 5 mm, and the thickness W of the tip 1a of the horn 1 is 4 mm. Further, the protruding distance A ′ from the flat portion at the tip of the horn of the processed surface 2a of each joining chip 2, 2 is 0.2 mm.

  Reference numerals 6 and 6 denote anvils, both of which are movable in the direction of contact with and away from the horn 1 and simultaneously pressurized with the same pressure. In addition, a large number of irregularities are provided on the contact surfaces of the anvils 6 and 6 with the processed material. In addition, what is necessary is just to employ | adopt a conventionally well-known appropriate mechanism in order to move this anvil 6 and 6. FIG.

  In the ultrasonic bonding method according to the present embodiment, the horn 1 is positioned at the center between the opposing electrode units 4 and 4, and the current collecting terminals 5 and 5 superposed on the electrode units 4 and 4 and their outer surfaces. The anvils 6 and 6 are arranged on the outer sides of the horns 1 and 2 so as to face the joining tips 2 and 2 attached to the horn 1, and the anvils 6 and 6 are moved simultaneously so that the horn 1 and the anvils 6 and 6 are moved. The electrode units 4, 4 and the current collector terminals 5, 5 are sandwiched at a predetermined pressure with each other, and in this state, ultrasonic vibration is applied by the horn 1, 4 is joined to the current collecting terminals 5 and 5.

  Thus, in the present embodiment, as described above, in order to allow the shape of the horn 1 to enter the narrow narrow portion 3, between the opposing portions of the electrode units 4, 4 in the present embodiment, the tip portion 1 a is set to a predetermined value. The joining tips 2 and 2 are formed in a thick bowl shape, and the projection distance A ′ of the processing surface 2a from the flat portion is made as small as possible within the required range at both flat portions of the bowl-shaped tip. If the thickness of the horn 1 is small, the horn 1 is bent when pressed from one side and cannot be completely joined together. The main element is that the horn 1 is prevented from being bent by being simultaneously pressurized.

  Thereby, in the narrow portion 3 where the interval between the opposing portions is narrow, in this embodiment, the members are bonded to each other, and in this embodiment, the electrode unit 4 and the current collecting terminal 5 are joined together. In addition, it is possible to improve the efficiency of the work by jointly processing both opposing portions without performing them separately as in the prior art. In addition, it is possible to join at any part from the open side part to the back side of the narrow part 3 and to join the joint part uniformly. Further, the bonding tip 2 to be attached to the bowl-shaped tip portion 1a of the horn is made to have a projection distance A ′ from the flat portion of the tip of the horn on the processed surface 2a as small as possible within the required range, and the tip of the horn. By reducing the vibration amplitude difference at the time of joining between the part 1a and the processed surface 2a of the joining chip 2, it is possible to increase the ultrasonic energy per unit time supplied to the joining part, and as a result, the joining is required. The ultrasonic vibration time can be shortened and a wider bonding area can be obtained.

  Next, an ultrasonic bonding method according to the second embodiment of the present invention shown in FIG. 5 will be described.

  In the present embodiment, one of the anvils 6 and 6 facing each other is movable in the direction in which the horn 1 is brought into contact with and separated from the horn 1 and the other anvil 6 is fixed. In addition, since the other structure is the same as that of the said 1st Embodiment, the same code | symbol is attached | subjected to the same member and detailed description is abbreviate | omitted.

  In this embodiment, the horn 1 and the anvils 6 and 6 are moved by moving the movable anvil 6 toward the fixed anvil 6 while the horn 1 is positioned between the opposing electrode units 4 and 4. Each of the electrode units 4 and 4 and the current collecting terminals 5 and 5 is sandwiched between each of them at a predetermined pressure, and in this state, ultrasonic vibration is applied by the horn 1 to collect the current at the electrode units 4 and 4. The electric terminals 5 and 5 are joined.

  Thereby, this embodiment also has the same effect as the first embodiment.

  Moreover, in the above embodiment, although the metal processed material was shown as a processed material, it can implement similarly to a plastic processed material.

DESCRIPTION OF SYMBOLS 1 Horn 1a Horn tip part 2, 2 Joining chip 3 Narrow part of work material 4, 4 Electrode unit 5, 5 Current collecting terminal 6, 6 Anvil

Claims (4)

  A horn having a tip portion formed in a bowl shape with a predetermined thickness and a bonding tip with a projection distance from the flat portion of the processing surface made as small as possible within the required range is attached to both flat portions. In each of the above, the anvil facing the joining tip attached to the horn is disposed outside each of the opposing portions of the narrow portion, and the anvil facing the joining tip is disposed on the outside of each of the opposing portions of the narrow portion. Ultrasonic vibration is applied by the horn in a state where the opposing portions of the narrow portion are sandwiched with a predetermined pressure between the horn and the anvil, and the members are joined to each other at the opposing portions of the narrow portion. An ultrasonic bonding method, characterized in that:   2. The ultrasonic bonding method according to claim 1, wherein both the anvils are movable in a direction in which the anvil is brought into contact with and separated from the horn, and the pressure is simultaneously applied at the same pressure.   The ultrasonic bonding method according to claim 1, wherein one of the opposing anvils is movable in a direction in which the anvil is moved toward and away from the horn, and the other anvil is fixed. The ultrasonic bonding method according to claim 1, wherein the processed material is a battery.

Images