JP6560548B2 - Breaker and safety circuit equipped with it. - Google Patents

Description

  The present invention relates to a small breaker or the like built in a secondary battery pack or the like of an electric device.

  Conventionally, a breaker is used as a protection device (safety circuit) for secondary batteries and motors of various electric devices. When the temperature of the secondary battery during charging / discharging rises excessively, or when an abnormality occurs such as when an overcurrent flows through a motor or the like equipped in a device such as an automobile or home appliance, Cut off current to protect secondary batteries and motors. Breakers used as such protective devices operate accurately following temperature changes (having good temperature characteristics) and have stable resistance when energized to ensure the safety of the equipment. It is required to be.

  The breaker is provided with a thermally responsive element that operates according to a temperature change and conducts or cuts off a current. Patent Document 1 discloses a breaker to which a bimetal is applied as a thermally responsive element. Bimetal is an element that is formed by laminating two types of plate-like metal materials having different coefficients of thermal expansion, and controls the conduction state of the contact by changing the shape in accordance with a temperature change. The breaker shown in the same document is a case in which parts such as a fixed piece, a movable piece, a thermally responsive element, and a PTC thermistor are housed in a case, and terminals of the fixed piece and the movable piece are connected to an electric circuit of an electric device. Used. In the breaker disclosed in Patent Document 1, the fixed piece is incorporated into the case body (resin base) by insert molding (see paragraph (0031) and the like of the same document).

WO2011 / 105175 gazette

  The breaker disclosed in Patent Document 1 has terminals on the fixed piece and the movable piece. The fixed piece and the movable piece are formed, for example, by pressing a metal plate mainly composed of phosphor bronze (see paragraphs (0031) and (0032) of the same document). The terminal is connected to a plate-shaped lead extending from the secondary battery or the circuit board. Conventionally, resistance welding is usually applied to the connection between the terminal and the lead.

  In recent years, with the aim of improving production efficiency, a form in which a breaker is directly mounted on a secondary battery or a printed circuit board has been studied, and furthermore, connection between a breaker terminal and a land formed on the circuit board The use of reflow soldering is being studied. In connecting conductors by soldering, the penetration of molten solder, that is, so-called wettability (infiltration) of solder becomes a problem. When the wettability of the solder deteriorates, the solder does not sufficiently penetrate between the terminal and the land, and the electrical resistance between the two increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a breaker that can easily and satisfactorily infiltrate solder between a terminal and a land.

  In order to achieve the above object, the present invention provides a current interrupting means for interrupting a current in response to a temperature change, a case for accommodating the current interrupting means, and one end portion accommodated in the case for the current interrupting. And a plurality of terminal pieces, the other end portions of which are exposed to the outside of the case, and at least one of the plurality of terminal pieces is selected from a group of gold and silver A metal plating layer including at least one of the two is provided on the other end portion.

  In the breaker according to the present invention, the current interrupting means is provided with a fixed contact fixed to the case, and a movable contact that is movable toward and away from the fixed contact, and the fixed contact is fixed to the fixed contact. A plurality of terminals, each having a movable piece that presses and contacts the contact; and a thermally responsive element that operates the movable piece so that the movable contact is separated from the fixed contact by being deformed as the temperature changes. Preferably, the piece includes a first terminal piece provided with the fixed contact, and the plating layer is continuously formed from the one end portion to the other end portion of the first terminal piece.

  In the breaker according to the present invention, it is preferable that the plating layer is formed in a region including the fixed contact.

  In the breaker according to the present invention, the first terminal piece is made of a plate metal having a first surface provided with the fixed contact and a second surface opposite to the first surface, and the plating The layer is preferably formed on the first surface and the second surface.

  In the breaker according to the present invention, it is preferable that a thickness of the plating layer formed on the first surface is larger than a thickness of the plating layer formed on the second surface.

  In the breaker according to the present invention, it is desirable that the one end portion and the other end portion of the first terminal piece are arranged stepwise in the thickness direction of the first terminal piece.

  In the breaker according to the present invention, the plurality of terminal pieces include a second terminal piece connected to the movable piece, and the plating layer is accommodated in the case among the second terminal pieces. It is desirable to form continuously from the area | region to the area | region which protrudes outside the said case.

  In the breaker according to the present invention, the second terminal piece includes a third surface provided with a connection portion connected to the movable piece, a fourth surface opposite to the third surface, and the third surface. It is preferable that the metal layer is formed of a plate-like metal having a side end surface extending from the surface to the fourth surface, and the plating layer is formed on the third surface, the fourth surface, and the side end surface.

  In the breaker according to the present invention, the current interrupting means further includes a positive temperature coefficient thermistor that connects the first terminal piece and the second terminal piece, and the first terminal piece is provided at the one end. It is desirable to have a support part that abuts and supports a positive temperature coefficient thermistor, and the fixed contact and the support part are arranged in steps in the thickness direction of the first terminal piece.

  In the breaker according to the present invention, the plating layer is preferably formed so as to avoid the support portion.

  A safety circuit for an electric device according to the present invention includes the breaker.

  The breaker of this invention is equipped with the electric current interruption means which interrupts | blocks an electric current according to a temperature change, the case which accommodates an electric current interruption means, and a some terminal piece. Each terminal piece has one end housed inside the case and the other end exposed to the outside of the case. And the one end part of each terminal piece is connected with the electric current interruption means. The other end can be connected to an external circuit such as a secondary battery or a circuit board.

  At least one of the plurality of terminal pieces has a metal plating layer at the other end. The plating layer contains at least one selected from the group of gold and silver. Gold and silver are excellent in the wettability of solder, and the molten solder easily penetrates into every corner of the connection site. Thereby, the electrical resistance between the terminal and the land is reduced, and the voltage drop and heat generation due to the provision of the circuit breaker are reduced. Moreover, since gold and silver have low resistivity, voltage drop and heat generation at the terminals are further reduced.

The side view which shows schematic structure of the breaker by one Embodiment of this invention with a circuit board. The assembly perspective view which shows the structure inside the said breaker. Sectional drawing which shows the said breaker in a normal charge or discharge state. Sectional drawing which shows the said breaker in the overcharge state or the time of abnormality. The perspective view which shows the structure of the 1st terminal piece of the said breaker. The perspective view which shows the structure of the 2nd terminal piece of the said breaker. The perspective view which shows the manufacturing process of the 1st terminal piece of the said breaker in time series. The perspective view which shows the manufacturing process of the 2nd terminal piece of the said breaker in time series. The top view which shows the structure of the secondary battery pack provided with the said breaker of this invention. The circuit diagram of the safety circuit provided with the said breaker of this invention.

  A breaker according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of the breaker. The breaker 1 includes a current interrupting means 10 that interrupts an electric current according to a temperature change, a case 7 that houses the current interrupting means 10, and a plurality of terminal pieces 100.

  The breaker 1 of the present embodiment is configured to be mountable on the surface of the printed circuit board 400. Lands 401 are formed in a pattern on the surface of the printed circuit board 400. The terminal piece 100 is electrically connected to the land 401. Solder 402 is used for connection between the terminal piece 100 and the land 401. In this embodiment, for example, reflow soldering is applied.

  Each terminal piece 100 has one end 101 and the other end 102. The one end 101 is housed inside the case 7 and is electrically connected to the current interrupting means 10. The other end 102 is exposed to the outside of the case 7 and can be electrically connected to a land 401 that is an external circuit of the breaker 1.

  A plating layer 103 is formed on the surface of the other end portion 102 of the terminal piece 100. The plating layer 103 is made of a metal excellent in solder wettability, for example, a metal containing gold, silver, or tin. Since the plating layer 103 made of such a metal is formed on the surface of the other end portion 102, the molten solder easily penetrates into every corner of the connection portion between the other end portion 102 and the land 401. Thereby, the electrical resistance between the terminal strip 100 and the land 401 is reduced, and voltage drop and heat generation due to the circuit breaker 1 being provided are reduced. Moreover, it is possible to suppress the formation of spherical so-called solder balls around the lands 401 due to the excessive molten solder, and it is possible to suppress a short circuit of the circuit due to the solder balls.

  As the plating layer 103, a metal including at least one selected from the group of gold and silver among the above metals can be applied. Since gold and silver have low electrical resistivity, voltage drop and heat generation in the terminal strip 100 are further reduced. For example, when the plating layer 103 is made of a metal including gold, an oxide film is hardly formed on the surface, and the electrical resistance between the terminal piece 100 and the land 401 can be reduced. Moreover, when the plating layer 103 is comprised with the metal containing silver, the electrical resistance of the terminal piece 100 can be reduced.

  2 to 4 show the internal configuration of the breaker 1. The current interrupting means 10 includes a fixed contact 21, a movable piece 4, a thermally responsive element 5, and a PTC (Positive Temperature Coefficient) thermistor 6. The fixed contact 21 is fixed to the case 7. A movable contact 41 is provided at the distal end of the movable piece 4 so as to be movable toward and away from the fixed contact 21. The movable piece 4 presses the movable contact 41 against the fixed contact 21 to make contact. The thermally responsive element 5 is deformed as the temperature changes, thereby operating the movable piece 4 so that the movable contact 41 is separated from the fixed contact 21. The PTC thermistor 6 conducts the movable piece 4 and the first terminal piece 2 through the thermally responsive element 5.

  The case 7 includes a case main body (first case) 71, a lid member (second case) 81 attached to the upper surface of the case main body 71, and the like.

  The terminal piece 100 of this embodiment includes a first terminal piece 2 and a second terminal piece 3. The first terminal piece 2 and the second terminal piece 3 are formed, for example, by pressing a metal plate mainly composed of copper or the like (in addition, a metal plate such as copper-titanium alloy, white or brass). The case body 71 is embedded by insert molding.

  A support portion 23 that supports the fixed contact 21 and the PTC thermistor 6 is formed at one end 101 of the first terminal piece 2. The PTC thermistor 6 is placed on the convex protrusions (dwelling) 24 formed at three places on the support portion 23 of the first terminal piece 2 and supported by the protrusions 24.

  The fixed contact 21 is formed, for example, at a position facing the movable contact 41 by plating or the like such as a metal such as silver or gold, and is exposed from a part of the opening 73a formed inside the case main body 71. The support portion 23 is exposed from an opening 73 d formed inside the case main body 71.

  In the present application, unless otherwise specified, in the first terminal piece 2, the side on which the fixed contact 21 is formed (that is, the upper side in FIG. 1) is described as the front side, and the opposite side is described as the back side. The same applies to other parts, for example, the movable piece 4 and the thermally responsive element 5.

  One end 101 of the second terminal piece 3 is connected to the movable piece 4. The one end portion 101 is exposed from an opening 73 b provided inside the case body 71 and includes a connection portion 33 that is electrically connected to the movable piece 4.

  The movable piece 4 is formed in an arm shape symmetrical to the center line in the longitudinal direction by pressing a plate-like metal material. As a material of the movable piece 4, a material mainly composed of copper or the like equivalent to the first terminal piece 2 is preferable. In addition, a conductive elastic material such as copper-titanium alloy, white or brass may be used.

  A movable contact 41 is formed at the tip of the movable piece 4. The movable contact 41 is formed of the same material as the fixed contact 21 and is joined to the tip of the movable piece 4 by a technique such as clad or crimping in addition to welding.

  A connecting portion 42 that is electrically connected to the second terminal piece 3 is formed at the tip of the movable piece 4. The connection part 33 of the second terminal piece 3 and the connection part 42 of the movable piece 4 are fixed by welding, for example.

  The movable piece 4 has an elastic portion 43 between the movable contact 41 and the connection portion 42. The elastic portion 43 extends from the connection portion 42 to the movable contact 41 side. The movable piece 4 is fixed by being fixed to the connection portion 33 of the second terminal piece 3 at the connection portion 42, and the elastic contact 43 is elastically deformed, whereby the movable contact 41 formed at the tip thereof is fixed contact 21. The first terminal piece 2 and the movable piece 4 can be energized. Since the movable piece 4 and the second terminal piece 3 are electrically connected, the first terminal piece 2 and the second terminal piece 3 can be energized.

  The movable piece 4 is curved or bent at the elastic portion 43 by pressing. The degree of bending or bending is not particularly limited as long as the thermally responsive element 5 can be accommodated, and may be appropriately set in consideration of the elastic force at the operating temperature and the return temperature, the pressing force of the contact point, and the like. In addition, a pair of protrusions (contact portions) 44 a and 44 b are formed on the back surface of the elastic portion 43 so as to face the thermally responsive element 5. The protrusions 44a and 44b and the thermally responsive element 5 come into contact with each other, and the deformation of the thermally responsive element 5 is transmitted to the elastic portion 43 through the protrusions 44a and 44b (see FIGS. 2 to 4).

  The thermally responsive element 5 has an initial shape curved in an arc shape, and is formed by laminating thin plate materials having different thermal expansion coefficients. When the operating temperature is reached due to overheating, the curved shape of the thermally responsive element 5 is reversely warped with a snap motion, and is restored when the temperature falls below the return temperature due to cooling. The initial shape of the thermoresponsive element 5 can be formed by pressing. As long as the elastic portion 43 of the movable piece 4 is pushed up by the reverse warping operation of the thermal response element 5 at a desired temperature and returns to the original state by the elastic force of the elastic portion 43, the material and shape of the thermal response element 5 are particularly limited. Although not intended, a rectangular shape is desirable from the viewpoint of productivity and efficiency of reverse warping operation, and it is desirable that the rectangular shape is close to a square in order to efficiently push up the elastic portion 43 while being small. Examples of the material of the thermally responsive element 5 include, for example, white, brass, and stainless steel including copper-nickel-manganese alloy or nickel-chromium-iron alloy on the high expansion side and iron-nickel alloy on the low expansion side. A laminate of two types of materials having different coefficients of thermal expansion made of various alloys such as steel is used in combination according to the required conditions.

  The PTC thermistor 6 is disposed between the first terminal piece 2 and the thermally responsive element 5. In other words, the support portion 23 of the first terminal piece 2 is located directly below the thermally responsive element 5 with the PTC thermistor 6 interposed therebetween. When the energization of the first terminal piece 2 and the movable piece 4 is interrupted by the reverse warping operation of the thermal response element 5, the current flowing through the PTC thermistor 6 increases. As long as the PTC thermistor 6 is a positive temperature coefficient thermistor that limits the current by increasing the resistance value as the temperature rises, the type of operation current, operation voltage, operation temperature, return temperature, etc. can be selected as necessary. The material and shape are not particularly limited as long as these properties are not impaired. In the present embodiment, a ceramic sintered body containing barium titanate, strontium titanate or calcium titanate is used. In addition to the ceramic sintered body, a so-called polymer PTC in which conductive particles such as carbon are contained in a polymer may be used.

  The case main body 71 and the lid member 81 constituting the case 7 are formed of a thermoplastic resin such as flame retardant polyamide, polyphenylene sulfide (PPS), liquid crystal polymer (LCP), polybutylene terephthalate (PBT) having excellent heat resistance. Has been. A material other than the resin may be applied as long as characteristics equal to or higher than those of the above-described resin can be obtained.

  The case main body 71 is formed with a housing recess 73 for housing the movable piece 4, the thermally responsive element 5, the PTC thermistor 6 and the like. The housing recess 73 has openings 73 a and 73 b for housing the movable piece 4, an opening 73 c for housing the movable piece 4 and the thermally responsive element 5, an opening 73 d for housing the PTC thermistor 6, and the like. doing. Note that the movable piece 4 incorporated in the case main body 71 and the edge of the thermal response element 5 are brought into contact with each other by a frame formed inside the accommodation recess 73 and are guided when the thermal response element 5 is reversely warped. .

  As shown in FIG. 3, the cover piece 9 is embedded in the lid member 81 by insert molding. The cover piece 9 is formed by pressing a metal plate mainly composed of copper or the like, or a metal plate such as stainless steel. As shown in FIGS. 3 and 4, the cover piece 9 abuts on the surface of the movable piece 4 as appropriate to restrict the movement of the movable piece 4, and the lid member 81 and thus the rigidity of the case 7 as the casing Contributes to downsizing of breaker 1 while increasing strength. Resin is disposed on the outer surface side of the cover piece 9.

  As shown in FIG. 2, the openings 73a, 73b, 73c and the like of the case main body 71 that accommodates the first terminal piece 2, the second terminal piece 3, the movable piece 4, the thermally responsive element 5, the PTC thermistor 6, and the like are closed. As described above, the lid member 81 is attached to the case main body 71. The case main body 71 and the lid member 81 are joined by, for example, ultrasonic welding.

  FIG. 3 shows the operation of the breaker 1 in a normal charge or discharge state. In a normal charging or discharging state, the thermal responsive element 5 maintains the initial shape (before reverse warping), the fixed contact 21 and the movable contact 41 are in contact, and the breaker 1 is connected through the elastic portion 43 of the movable piece 4. The first terminal piece 2 and the second terminal piece 3 are electrically connected. The elastic part 43 of the movable piece 4 and the thermal responsive element 5 are in contact, and the movable piece 4, the thermal responsive element 5, the PTC thermistor 6 and the first terminal piece 2 are electrically connected as a circuit. However, since the resistance of the PTC thermistor 6 is overwhelmingly larger than the resistance of the movable piece 4, the current flowing through the PTC thermistor 6 is substantially larger than the amount flowing through the fixed contact 21 and the movable contact 41. It can be ignored.

  FIG. 4 shows the operation of the breaker 1 in an overcharged state or an abnormality. When a high temperature state occurs due to overcharging or abnormality, the thermally responsive element 5 that has reached the operating temperature is warped in reverse, the elastic portion 43 of the movable piece 4 is pushed up, and the fixed contact 21 and the movable contact 41 are separated. At this time, the current flowing between the fixed contact 21 and the movable contact 41 is interrupted, and a slight leakage current flows through the thermal actuator 5 and the PTC thermistor 6. Since the PTC thermistor 6 continues to generate heat as long as such a leakage current flows, the resistance value is drastically increased while maintaining the thermally actuated element 5 in the reverse warping state, so that the current is a path between the fixed contact 21 and the movable contact 41. There is only the above-described slight leakage current (which constitutes a self-holding circuit). This leakage current can be used for other functions of the safety device.

  When the overcharge state is canceled or the abnormal state is resolved, the heat generation of the PTC thermistor 6 is also stopped, and the thermal actuator 5 returns to the return temperature and is restored to the original initial shape. Then, the movable contact 41 and the fixed contact 21 come into contact again by the elastic force of the elastic portion 43 of the movable piece 4, the circuit is released from the interruption state, and returns to the conduction state shown in FIG. 4.

  5A shows the first terminal piece 2 viewed from the front side, and FIG. 5B shows the first terminal piece 2 viewed from the back side. In FIG. 5, the region where the plating layer 103 is formed is indicated by hatching. In the first terminal piece 2, the plating layer 103 is continuously formed from the one end 101 accommodated in the case 7 to the other end 102 protruding to the outside of the case 7. Thereby, when forming the plating layer 103 in the 1st terminal piece 2, it becomes unnecessary to perform a masking process etc. from the one end part 101 of the 1st terminal piece 2 to the other end part 102, and the productivity of the breaker 1 is improved.

  The plating layer 103 is formed in a region including the fixed contact 21 on the front side of the first terminal piece 2. Thereby, the fixed contact 21 is comprised by the plating layer 103 which consists of a metal containing gold | metal | money or silver, and the contact resistance between the movable contacts 41 is reduced.

  The 1st terminal piece 2 consists of a plate-shaped metal which has the 1st surface 2a in which the fixed contact 21 was provided, and the 2nd surface 2b on the opposite side to the 1st surface 2a. The first surface 2 a is disposed on the front side of the first terminal piece 2, and the second surface 2 b is disposed on the back side of the first terminal piece 2.

  In the present embodiment, the plating layer 103 is formed on the first surface 2 a and the second surface 2 b of the first terminal piece 2. The fixed contact 21 is constituted by the plating layer 103 a formed on the first surface 2 a of the one end 101 of the first terminal piece 2.

  On the other hand, the plating layer 103b formed on the second surface 2b of the other end 102 of the first terminal piece 2 is coated with paste solder 402 when the breaker 1 is mounted on the printed circuit board 400. It is placed on the land 401 and brought into contact with the solder 402. Therefore, when the solder 402 is melted, it easily penetrates into every corner of the connecting portion between the other end 102 and the land 401. Thereby, the electrical resistance between the 1st terminal piece 2 and the land 401 is reduced, and the voltage drop and heat_generation | fever by having provided the breaker 1 in the circuit are reduced.

  In FIG. 5, the plating layer 103a formed on the first surface 2a of the first terminal piece 2 is shown by dark hatching, and the plating layer 103b formed on the second surface 2b is shown by thin hatching. The thickness of the plating layer 103a is larger than the thickness of the plating layer 103b. For example, the thickness of the plating layer 103a is preferably 1 to 5 μm, and the thickness of the plating layer 103b is preferably 0.1 to 0.5 μm. By setting the thickness of the plating layer 103a within the above range, the thickness of the fixed contact 21 can be sufficiently secured, and the influence of arc discharge when the movable contact 41 operates can be suppressed. On the other hand, the plating layer 103b having a thickness within the above range can provide sufficient solder wettability.

  One end portion 101 of the first terminal piece 2 on which the fixed contact 21 is formed and the other end portion 102 connected to the land 401 of the printed circuit board 400 are arranged stepwise in the thickness direction of the first terminal piece 2. ing. Such a first terminal piece 2 increases the degree of freedom in the layout of the fixed contacts 21. For example, in FIGS. 3 and 4, by appropriately setting the height of the fixed contact 21, the contact pressure between the fixed contact 21 and the movable contact 41 is optimized, and the temperature characteristics of the breaker 1 are appropriately set. sell.

  On the other hand, in the one end portion 101 of the first terminal piece 2, the fixed contact 21 and the support portion 23 are arranged stepwise in the thickness direction of the first terminal piece 2. According to the first terminal piece 2 as described above, the PTC thermistor 6 and the like can be easily accommodated in the stepped region between the fixed contact 21 and the support portion 23 while appropriately setting the height of the fixed contact 21 as described above. It is possible to reduce the height of the breaker 1.

  In the present embodiment, the plating layer 103 a is formed so as to avoid the support portion 23.

  If the plating layer 103a is formed on the support portion 23, the thickness of the plating layer 103a may vary between manufacturing lots of the first terminal pieces 2 or within the manufacturing lot. Such a variation in the thickness of the plating layer 103a affects the posture of the PTC thermistor 6, and as a result, in the conductive state shown in FIG. 3 or the cut-off state shown in FIG. There is a risk of changing the posture of the person. As a result, the contact pressure between the fixed contact 21 and the movable contact 41 in the conductive state and the distance between the fixed contact 21 and the movable contact 41 in the cut-off state vary, which may affect the conductive resistance and temperature characteristics of the breaker 1. There is.

  On the other hand, in the present embodiment, since the plating layer 103a is not formed on the surface of the support portion 23, the PTC thermistor 6 and the thermal response in the current interruption state between the production lots of the first terminal pieces 2 or within the production lots. The postures of the element 5 and the movable piece 4 are stable. Therefore, the breaker 1 having a low conduction resistance and excellent temperature characteristics can be easily manufactured. As shown in FIG. 5A, in the first terminal piece 2 in which the protrusion 24 is provided on the support portion 23, the plating layer 103 may be formed avoiding the protrusion 24. .

  FIG. 6A shows the second terminal piece 3 viewed from the front side, and FIG. 6B shows the second terminal piece 3 viewed from the back side. In FIG. 6, the region where the plating layer 103 is formed is indicated by hatching. Also in the second terminal piece 3, the plating layer 103 is continuously formed from the one end 101 accommodated inside the case 7 to the other end 102 protruding to the outside of the case 7. Thereby, when forming the plating layer 103 in the 2nd terminal piece 3, it becomes unnecessary to perform a masking process etc. from the one end part 101 of the 2nd terminal piece 3 to the other end part 102, and the productivity of the breaker 1 is improved.

  The second terminal piece 3 includes a third surface 3c provided with a connection portion 33 connected to the movable piece 4, a fourth surface 3d opposite to the third surface 3c, and a third surface to a fourth surface. It consists of a plate-shaped metal which has the side end surface 3e which reaches 3d. The third surface 3 c is disposed on the front side of the second terminal piece 3, and the fourth surface 3 d is disposed on the back side of the second terminal piece 3.

  In the present embodiment, the plating layer 103 is continuously formed on the third surface 3c, the fourth surface 3d, and the side end surface 3e of the second terminal piece 3.

  The plating layer 103 c formed on the third surface 3 c of the one end portion 101 of the second terminal piece 3 is brought into contact with the connecting portion 42 of the movable piece 4. The contact resistance between the second terminal piece 3 and the movable piece 4 is reduced by the plating layer 103c made of a metal containing gold or silver, and voltage drop and heat generation due to the circuit breaker 1 being provided are reduced.

  The plating layer 103 d formed on the fourth surface 3 d of the other end portion 102 of the second terminal piece 3 has a land 401 to which paste solder 402 is applied when the breaker 1 is mounted on the printed circuit board 400. It is placed on and brought into contact with the solder 402. When the solder 402 is melted, it easily penetrates into every corner of the connecting portion between the other end 102 and the land 401. Thereby, the electrical resistance between the 2nd terminal piece 3 and the land 401 is reduced, and the voltage drop and heat_generation | fever by having provided the circuit breaker 1 are reduced.

  A part of the melted solder 402 wraps around the plating layer 103e formed on the side end surface 3e of the other end 102 of the second terminal piece 3 to form a so-called fillet 403 (see FIG. 1). Thereby, while joining of the 2nd terminal piece 3 and the land 401 is strengthened, the electrical resistance between both is further reduced.

  FIG. 7 shows the manufacturing process of the first terminal piece 2 in time series. FIG. 7A shows a flat metal plate 200 that is a base material of the first terminal piece 2. As already described, the metal plate 200 contains copper or the like as a main component.

  FIG. 7B shows a plating process for forming the plating layers 103 a and 103 b on the metal plate 200. In this step, the plating layer 103a is formed on the surface of the metal plate 200 on the front side. As already described, the thickness of the plating layer 103a is 1 to 5 μm. Such a plating layer 103a can be formed in a short time by, for example, a technique of “electrolytic plating”.

  The plating layer 103 a is formed in the region 201 corresponding to the one end 101 of the first terminal piece 2. In forming the plating layer 103a, a masking means 600 indicated by a two-dot chain line in the drawing is used in combination. For example, the region 223 where the support portion 23 of the first terminal piece 2 is formed is masked by the masking means 600, and the plating layer 103 a is not formed in the region 223.

  The edge region 225 opposite to the region 223 across the region 201 is also masked by the masking means 600, and the plating layer 103a is not formed. In addition, this edge area | region 225 is provided for conveyance of the metal plate 200 and the 1st terminal piece 2, for example, and is cut | disconnected after the case main body 71 and the cover member 81 are welded. By not forming the plating layer 103 a in the edge region 225, it is possible to reduce the manufacturing cost of the first terminal piece 2 and thus the breaker 1.

  In the present embodiment, the plating layer 103 a is continuously formed from the region 201 corresponding to the one end portion 101 of the first terminal piece 2 to the region 202 corresponding to the other end portion 102. For this reason, the masking means 600 is not required from the region 201 to the region 202, the plating process can be simplified, and the manufacturing cost of the first terminal piece 2 and thus the breaker 1 can be reduced.

  On the other hand, a plating layer 103b is formed on the back surface of the metal plate 200. The thickness of the plating layer 103b is 0.1 to 0.5 μm. Such a plating layer 103b can be formed with high accuracy by, for example, a technique of “electroless plating”.

  In the plating step shown in FIG. 7B, the plating layer 103 a and the like are formed on the flat metal plate 200. Therefore, the region 224 can be accurately and reliably masked using the simple masking means 600, and the formation of the plating layer 103a on the surface of the support portion 23 can be avoided.

  FIG.7 (c) has shown the 1st terminal piece 2 shape | molded through the press process after the plating process. By the pressing process, the metal plate 200 is punched into a necessary shape, and step bent portions 26 and 27 bent in a step shape are formed, and the first terminal piece 2 is formed.

  By the way, in the pressing process, particularly large stress is applied to the surfaces of the step bent portions 26 and 27. Therefore, for example, when general tin is used for the plating layer 103a as a metal material that improves the wettability of solder, a part of the plating layer 103a may be peeled off from the metal plate 200 due to stress in the pressing process. A peeling piece generated by peeling off a part of the plating layer 103a is confined in the housing recess 73 after the breaker 1 is assembled.

  Tin has a higher electrical resistivity than metals such as gold, silver and copper. For this reason, when the peeling piece of tin described above moves in the housing recess 73 and is positioned between the fixed contact 21 and the movable contact 41, the resistance value between the contacts in the conductive state may increase, and The fixed contact 21 and the movable contact 41 may be damaged by the peeling piece.

  In the present invention, gold or silver used as the metal material of the plating layer 103a has high peel strength, and there is little possibility that a part of the plating layer 103a is peeled off from the metal plate 200 due to stress in the pressing process. Also, since gold or silver has a low electrical resistivity and a high melting point, even if the gold or silver peeling piece is located between the fixed contact 21 and the movable contact 41, the fixed contact 21 and the movable contact 41 There is very little risk of welding.

  FIG. 8 shows the manufacturing process of the second terminal piece 3 in time series. FIG. 8A shows a flat metal plate 300 that is a base material of the second terminal piece 3. As already described, the metal plate 300 contains copper or the like as a main component.

  FIG. 8B shows the second terminal piece 3 formed from the metal plate 300 through a pressing process. In the present embodiment, a pressing process is performed prior to the plating process, and the second terminal piece 3 having the step-bending portion 36 is formed.

  In the plating step shown in FIG. 8C, plating layers 103 c, 103 d, 103 e and the like are formed on the second terminal piece 3. The thickness of the plating layers 103c, 103d, and 103e is 0.1 to 0.5 μm. Such plating layers 103c, 103d, and 103e can be formed with high accuracy by, for example, a method of “electroless plating”.

  In the present embodiment, the plating layers 103 c, 103 d, and 103 e are continuously formed from one end 101 to the other end 102 of the second terminal piece 3. Therefore, no masking means is required from one end 101 to the other end 102, the plating process can be simplified, and the manufacturing cost of the second terminal piece 3 and hence the breaker 1 can be reduced. Similar to the first terminal piece 2, a region where the plating layers 103 c, 103 d, 103 e and the like are not formed may be provided in the tip region of the other end 102.

  As described above, according to the breaker 1 of the present embodiment, at least one of the plurality of terminal pieces 100 has the metal plating layer 103 at the other end portion 102. The plating layer 103 includes at least one selected from the group of gold and silver. Gold and silver are excellent in the wettability of solder, and the molten solder easily penetrates into every corner of the connection site. Thereby, the contact resistance between the terminal strip 100 and the land 401 is reduced, and voltage drop and heat generation due to the circuit breaker 1 being provided are reduced. Moreover, since gold and silver have low resistivity, voltage drop and heat generation in the terminal strip 100 are further reduced.

  The present invention is not limited to the configuration of the above-described embodiment, and at least the current interrupting means 10 that interrupts the current according to the temperature change, the case 7 that houses the current interrupting means 10, and the one end 101 is the case 7. In the breaker 1 having a plurality of terminal pieces 100 that are housed inside and connected to the current interrupting means 10 and the other end portion 102 is exposed to the outside of the case 7, less of the plurality of terminal pieces 100. Alternatively, the other end 102 may have a metal plating layer 103 containing at least one selected from the group of gold and silver.

  Therefore, when the terminal piece 100 is composed of the first terminal piece 2 and the second terminal piece 3, the plating layer 103 may be formed on at least one of the first terminal piece 2 and the second terminal piece 3. . In this case, the above-described effects can be obtained with any one of the terminal pieces.

  In the present embodiment, the terminal piece 100 is configured by the pair of first terminal pieces 2 and second terminal pieces 3, but another terminal piece may be added to the breaker 1. In this case, the plating layer 103 may be formed on the other end portion 102 of the added terminal piece.

  The case 7 may be sealed with resin or the like by secondary insert molding or the like. In this case, the other end 102 of the terminal strip 100 only needs to be exposed from the resin formed on the outside of the case 7 so as to be fixed to the land 401 such as the printed circuit board 400 and to be conductive.

  Further, the terminal piece 100 is not limited to a form protruding outward from the case 7, and may be a form constituting a part of the outer surface of the case 7.

  Moreover, the joining method of the case main body 71 and the lid member 81 is not limited to ultrasonic welding, and can be appropriately applied as long as both are firmly joined. For example, a liquid or gel adhesive may be applied, filled, and cured to bond them together. Further, the case 7 is not limited to the form constituted by the case main body 71 and the lid member 81, but may be constituted by two or more parts.

  Alternatively, the movable piece 4 and the thermally responsive element 5 may be integrally formed by forming the movable piece 4 from a laminated metal such as bimetal or trimetal. In this case, the configuration of the breaker is simplified and the size can be reduced.

  In the present embodiment, the self-holding circuit using the PTC thermistor 6 is provided, but the present invention can be applied even in a form in which such a configuration is omitted.

  Further, the shapes of the first terminal piece 2, the second terminal piece 3, the movable piece 4, the thermally responsive element 5, the PTC thermistor 6, the housing recess 73, etc. are not limited to those shown in FIG. It is.

  Moreover, you may apply this invention to the form by which the 2nd terminal piece 3 and the movable piece 4 are integrally formed as shown by the said patent document 1. FIG. In this case, the integrated second terminal piece 3 and movable piece 4 are sandwiched and welded between the case body 71 and the lid member 81 after the plating layer 103 is formed.

  In the present embodiment, the step bent portion 27 shown in FIG. 7 is exposed to the outside of the case 7, but may be embedded in the case 7, similarly to the step bent portion 26.

  Further, the breaker 1 of the present invention can be widely applied to secondary battery packs, safety circuits for electric devices, and the like. FIG. 9 shows a secondary battery pack 500. The secondary battery pack 500 includes a secondary battery 501 and a breaker 1 provided in the output terminal circuit of the secondary battery 501. FIG. 10 shows a safety circuit 502 for electrical equipment. The safety circuit 502 includes the breaker 1 in series in the output circuit of the secondary battery 501. According to the secondary battery pack 500 or the safety circuit 502 including the breaker 1, the secondary battery pack 500 or the safety circuit 502 that can ensure a good current interruption operation can be manufactured.

DESCRIPTION OF SYMBOLS 1 Breaker 2 1st terminal piece 2a 1st surface 2b 2nd surface 21 Fixed contact 3 2nd terminal piece 3c 3rd surface 3d 4th surface 3e Side end surface 4 Movable piece 41 Movable contact 5 Thermal response element 6 PTC thermistor (positive Characteristic thermistor)
7 Case 71 Case body 100 Terminal piece 101 One end 102 Other end 103 Plating layer 501 Secondary battery 502 Safety circuit

Claims (9)

Current interrupting means for interrupting current according to temperature change;
A case housing the current interrupting means;
In a breaker including a plurality of terminal pieces, one end of which is housed inside the case and connected to the current interrupting means, and the other end is exposed to the outside of the case,
One also less of the plurality of terminal pieces is tin, the plating layer of a metal containing at least one selected from the group of gold and silver, possess the other end,
The current interrupting means is
A fixed contact fixed to the case, a movable contact that moves so as to be movable toward and away from the fixed contact, a movable piece that presses the movable contact against the fixed contact, and a temperature change are provided. A thermally responsive element that operates the movable piece so that the movable contact is separated from the fixed contact by being deformed along with it,
The plurality of terminal pieces include a first terminal piece provided with the fixed contact,
The first terminal piece is made of a plate-like metal having a first surface provided with the fixed contact and a second surface opposite to the first surface,
The plating layer is formed on the first surface and the second surface,
The breaker characterized in that the thickness of the plating layer formed on the first surface is larger than the thickness of the plating layer formed on the second surface . Current interrupting means for interrupting current according to temperature change;
A case housing the current interrupting means;
In a breaker including a plurality of terminal pieces, one end of which is housed inside the case and connected to the current interrupting means, and the other end is exposed to the outside of the case,
At least one of the plurality of terminal pieces has a metal plating layer including at least one selected from the group of tin, gold, and silver at the other end,
The current interrupting means is
A fixed contact fixed to the case, a movable contact that moves so as to be movable toward and away from the fixed contact, a movable piece that presses the movable contact against the fixed contact, and a temperature change are provided. A thermoresponsive element that operates the movable piece so that the movable contact is separated from the fixed contact by being deformed , and a positive temperature coefficient thermistor that connects the first terminal piece and the second terminal piece. Have
The plurality of terminal pieces include a first terminal piece provided with the fixed contact,
The first terminal piece has a support part that contacts and supports the positive temperature coefficient thermistor at the one end part,
The said plating layer is a breaker characterized by being formed avoiding the said support part. The breaker according to claim 2, wherein the fixed contact and the support portion are arranged stepwise in a thickness direction of the first terminal piece. The said plating layer is a breaker in any one of Claim 1 thru | or 3 currently formed from the said one end part of the said 1st terminal piece to the said other end part . The breaker according to any one of claims 1 to 4, wherein the plating layer is formed in a region including the fixed contact . The breaker according to any one of claims 1 to 5, wherein the one end portion and the other end portion of the first terminal piece are arranged stepwise in a thickness direction of the first terminal piece. The plurality of terminal pieces include a second terminal piece connected to the movable piece,
The plating layer, of the second terminal strip, from inside the accommodation area of the case according to any one of claims 1 to 6 are successively formed over the region which projects outside the casing breaker. The second terminal piece includes a third surface provided with a connecting portion connected to the movable piece, a fourth surface opposite to the third surface, and the third surface to the fourth surface. A plate-like metal having side end faces,
The breaker according to claim 7, wherein the plating layer is formed on the third surface, the fourth surface, and the side end surface. A safety circuit for electrical equipment, comprising the breaker according to any one of claims 1 to 8.

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