JP2012043690A - Connection member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection member and a connection method of low connection resistance without using solder.SOLUTION: A connection member 1 connects a lead wire for supplying a current to a defogger 2 equipped with a plurality of heating wires 2c and a bus bar 2b for supplying a current to the plurality of heating wires 2c. The connection member 1 comprises a metal plate 10 to which the lead wire is connected, a conductive member 12 having one end abutting against a conductive plate and the other end abutting against the bus bar and connecting the conductive plate electrically with the bus bar, and a holding member 11 which holds the conductive member 12 in such a state that one end is abutting against the conductive plate and the other end is abutting against the bus bar 2b. The conductive member 12 is arranged on the bus bar 2b so that the longitudinal direction is substantially perpendicular to the longitudinal direction of the bus bar 2b.

Description

  The present invention relates to a connection member and a connection method with an electrode formed on a glass surface, and particularly relates to a connection member with an electrode formed on a window glass of a vehicle.

  A window glass for an automobile, particularly a rear glass, is provided with a defogger for removing fogging of the glass due to condensation, and an antenna for receiving AM, FM, TV, and the like. The defogger or antenna is manufactured by forming a fired body of a silver paste mainly composed of silver (Ag) on the rear glass surface. The defogger or antenna is connected to a lead wire from the vehicle body. Conventionally, the fired body and the lead wire are connected using solder containing lead.

  However, the solder containing lead (Pb) needs to remove the lead contained when it is processed as waste, which takes time and cost. In recent years, regulations regarding the use of lead-containing solder have been studied in various countries, such as the ELV (Discarded Vehicle) Directive and the WHEE & RoHS (Waste Electrical and Electronic Equipment) Directive in Europe, and the situation in which solder containing lead cannot be used. It is becoming.

  From such a problem, a solder containing no lead has been proposed (see, for example, Patent Documents 1 and 2). Further, there has been proposed a method of mechanically connecting a fired body and a lead wire without performing soldering (see, for example, Patent Document 3). In this proposal, a conductive elastic member is provided on the vehicle body side, and the rear glass is attached to the vehicle body so that the conductive elastic member provided on the vehicle body and the antenna formed on the rear glass are in contact with each other. Further, an electrically conductive member having elasticity is disposed in a casing (casing) provided so as to cover at least a part of the fired body formed on the rear glass so as to press the fired body. Has been proposed (see, for example, Patent Document 4).

JP 2000-326088 A JP 2000-141078 A JP-A-10-56317 International Publication No. 2004/049511 Pamphlet

  However, when connecting the fired body and the lead wire using the lead-free solder described in Patent Documents 1 and 2, the silver contained in the fired body is diffused and dissolved in tin (Sn) contained in the solder. Therefore, the solder does not spread in the fired body. For this reason, the contact area between the solder and the fired body becomes small, and sufficient bonding strength cannot be obtained. Further, when soldering, the strength of the glass may be reduced due to thermal shock.

  Moreover, in the method of patent document 3 which connects a sintered body and a lead wire mechanically without performing soldering, and the method of patent document 4 which connects an electroconductive member and a lead wire, in a connection location, Since the resistance is high, there is no problem when supplying low power (low current) like an antenna, but when high power (high current) is supplied like a defogger, there is a problem that heat is generated at the connection location.

  The present invention has been made in response to the above-described circumstances, and an object thereof is to provide a connection member that does not use solder and has low connection resistance.

  The connecting member of the present invention is a connecting member for connecting a lead wire for supplying a current to a defogger provided with a plurality of heating wires and a bus bar for supplying electricity to the plurality of heating wires. The conductive plate to be connected, one end to the conductive plate, the other end abuts to the bus bar, electrically connecting the conductive plate and the bus bar, the conductive member, one end to the conductive plate, the other end A holding member that holds the bus bar in contact with the bus bar, and the conductive member is disposed on the bus bar so that the longitudinal direction is substantially perpendicular to the longitudinal direction of the bus bar. .

  According to the connecting member of the present invention, the conductive plate to which the lead wire is connected, the conductive member that contacts one end of the conductive plate and the bus bar with one end abutting the conductive plate and the other end to the bus bar, and conductive A holding member that holds the member in a state where one end is in contact with the conductive plate and the other end is in contact with the bus bar, and the conductive member has a longitudinal direction substantially orthogonal to the longitudinal direction of the bus bar. Since it is disposed on the bus bar, it is not necessary to use solder for connection to the lead wire, and the connection resistance can be reduced.

It is the figure which showed an example of arrangement | positioning of a connection member. It is a figure which shows the structure of the connection member which concerns on one Embodiment of this invention. It is a side view explaining the preparation process of the connection member in an Example. It is the figure which showed arrangement | positioning of the connection member in each example of an Example. It is the figure which showed the result of the energization heat_generation | fever test in each example of an Example.

Hereinafter, the present invention will be described in detail with reference to the drawings.
Fig.1 (a) is the figure which showed an example of arrangement | positioning of the connection member 1 which concerns on this embodiment. FIG.1 (b) is an enlarged view of the area | region A of Fig.1 (a).

  The defogger 2 includes two bus bars 2a and 2b formed at both ends of the glass surface of the vehicle, and a plurality of heating wires 2c connecting the bus bars 2a and 2b. This defogger is produced by forming a fired body of a silver paste containing silver (Ag) as a main component on a glass surface.

  Connection members 1 for connecting lead wires from a vehicle (not shown) are arranged at substantially the center of the bus bars 2a and 2b. In addition, the connection member 1 is arrange | positioned so that the longitudinal direction of bus-bar 2a, 2b and the longitudinal direction of the connection member 1 may respectively become substantially perpendicular | vertical. The reason why the connecting member 1 is arranged so that the longitudinal direction of the bus bars 2a and 2b and the longitudinal direction of the connecting member 1 are substantially perpendicular will be described later. In this embodiment, a positive lead wire is connected to the connecting member 1 disposed on the bus bar 2a, and a negative lead wire is connected to the connecting member 1 disposed on the bus bar 2b. Shall.

  In the defogger 2, when electric power is supplied from a vehicle (not shown) via a lead wire, a current flows from the connecting member 1 arranged on the bus bar 2a to the connecting member 1 arranged on the bus bar 2b (the flow of electrons is And vice versa). When a current flows between the bus bars 2a and 2b, the heating wire 2c is heated to warm the glass of the vehicle. As a result, frost and cloudiness formed on the glass surface are removed.

  FIG. 2A is a top view of the connection member 1. FIG. 2B is a bottom view of the connection member 1. FIG.2 (c) is sectional drawing in line segment AA of FIG.2 (b). A metal plate 10 for connecting a lead wire for power supply, a holding member 11 that covers at least a part of the metal plate 10 and holds the metal plate 10, and penetrates from the lower surface of the holding member 11 to the metal plate 10. A conductive member 12 that is disposed in the hole 11a and electrically connects the metal plate 10 and a fired body formed on a glass surface, which will be described later, and a lower surface of the holding member 11, and connects the connection member 1 to the fired body or Two adhesive layers 13 and 14 fixed to the glass surface are provided.

  The metal plate 10 is made of a low resistance metal such as copper (Cu), iron (Fe), etc., and one end side not covered with the holding member 11 is processed into a predetermined shape defined by JIS-D5403, etc. Lead wires can be connected.

  The holding member 11 is made of an insulating material. The material is not particularly limited as long as it has insulating properties, but is determined in consideration of durability and adhesiveness with the adhesive material forming the adhesive layers 13 and 14. For example, a polyamide resin is mentioned. Further, the manufacturing method may be cutting or injection molding, and is not particularly limited.

  The conductive member 12 is made of an elastic rubber having conductivity. The conductive member 12 has a function of transmitting a current from the metal plate 10 to the bus bar 2a or the bus bar 2b formed on the glass plate. The height of the conductive member 12 is set to be longer than the distance obtained by adding the depth of the hole 11 a provided in the holding member 11 and the thickness of the adhesive layer 13 or the adhesive layer 14. By doing in this way, the electrically-conductive member 12 is pressed by the bus-bar 2a, 2b formed on the glass plate, a contact resistance can be suppressed and required electroconductivity can be ensured. The conductive member 12 is preferably pressed onto the bus bars 2a and 2b with a pressure of 0.2 MPa or more, and more preferably pressed with a pressure of 1.0 MPa or more.

  The conductive member 12 has a rectangular bottom surface 12a facing the bus bar 2a or 2b, and the longitudinal direction of the bottom surface 12a is substantially orthogonal to the longitudinal direction of the bus bars 2a and 2b, that is, the direction of current flow. Are disposed on the bus bars 2a and 2b. Here, “substantially orthogonal” is a concept that includes a state that is not exactly orthogonal, and, as will be described below, within a range in which a temperature rise at the contact portion between the lower surface 12a of the conductive member 12 and the bus bar 2a or 2b can be suppressed. Thus, it is assumed to include a state shifted from a state orthogonal to the longitudinal direction of the bus bars 2a and 2b.

  The arrangement of the conductive member 12 on the bus bars 2a and 2b so that the longitudinal direction of the lower surface 12a of the conductive member 12 is substantially orthogonal to the longitudinal direction of the bus bars 2a and 2b, that is, the current direction will be described in detail in an example described later. As described above, when the long sides of the conductive rubber are orthogonal to the current application direction, the temperature rise can be suppressed more than when the short sides are orthogonal. This is presumably because the electron flow in the vicinity of the conductive rubber can be diffused to suppress the concentration of electrons.

  The conductive member 12 includes various conductive rubbers such as EC-100A (W200) (trade name) manufactured by Shin-Etsu Silicone, dot connector (trade name) manufactured by POLYMATEC, and high conductive rubber manufactured by Asahi Rubber. GB-Matrix (trade name) manufactured by Shin-Etsu Silicone Co., Ltd. can be used. When using a dot connector, it has a structure in which conductive particles contained inside are arranged in a specific direction, so contact resistance is small compared to conductive rubber containing conductive particles randomly, and it is sufficient even at low loads High conductivity can be ensured.

  Examples of the adhesive layers 13 and 14 include a double-sided pressure-sensitive adhesive (double-sided tape), a thermosetting adhesive, and a thermoplastic adhesive. The adhesive layers 13 and 14 are selected so as to exhibit sufficient durability even when used in a situation where the external environment changes drastically, such as temperature and ultraviolet rays.

  Next, the present invention will be described in more detail by giving specific examples with reference to FIGS. Note that the present invention is not limited to these examples. In the following examples, a test was conducted on heat generation when a current was passed by changing the contact size and arrangement (direction) of the conductive rubber (conductive member) to the bus bar. Hereinafter, Examples 1 to 4 will be described. Examples 2 and 4 are examples, and examples 1 and 3 are comparative examples.

(Example 1)
(1) Production of glass plate with silver printing (production of bus bars 2a, 2b)
A silver paste containing silver (Ag) as a main component on one side of a 3.5 mm thick glass substrate 21 cut out to a size of 100 × 100 mm is 90 × 90 mm so that the center is the same as the center of the glass substrate. A silver print 22 printed in size (hereinafter referred to as silver printing) and fired was used as a bus bar. The thickness of the silver print 22 is about 7 μm. Further, a coaxial cable 23 was soldered as a lead wire to the central portion B of any one of the four sides of the silver print 22 formed on the glass substrate 21. The length and cross-sectional area of the coaxial cable 23 are about 400 mm and 3 mm ² (AV-3), respectively.

(2) Production of connecting member (i) Production of conductive rubber (production of conductive member 12)
Conductive silicone rubber processed product EC-100A (W200) (trade name, manufactured by Shin-Etsu Silicone Co., Ltd.) cut into a size of 20 × 10 mm was used as conductive rubber 24 (conductive member 12).

(Ii) Fabrication of connector (production of metal plate 10)
A galvanized SS (steal structure) material having a width of 10 mm is prepared, and the SS material is bent so that the length of one surface is 20 mm and the length of the other surface is 10 mm. (Metal plate 10). The coaxial cable 26 was soldered as a lead wire on the other surface. The length and cross-sectional area of the coaxial cable 26 are about 400 mm and 3 mm ² (AV-3), respectively.

(3) Disposition of Conductive Rubber The conductive rubber 24 of (2) was disposed on the glass substrate 21 on which the silver printing 22 of (1) was performed as shown in FIG. Specifically, the long side of the conductive rubber 24 is arranged so that the side close to the soldering point is parallel to the silver printing side at a position 45 mm from the soldered silver printing side.

(4) Connector Arrangement One surface of the connector 25 produced in (2) (ii) was stacked on the conductive rubber 24 so as not to protrude from the conductive rubber 24.

(5) Arrangement of load plate and weight In order to apply pressure to the conductive rubber 24 and the connector 25, the load plate 28 and the weights 27a and 27b were arranged on the connector 25. As the load plate 28, an acrylic plate of 300 × 100 × 4 mm was used. This acrylic plate (load plate 28) was placed on the conductive rubber 24 so that the longitudinal direction of the conductive rubber and the longitudinal direction of the acrylic plate were parallel. In addition, a hole for passing the coaxial cable 26 as a lead wire is provided at the center of the acrylic plate (load plate 28).

  Next, cylindrical weights 27a and 27b having a diameter of 100 mm and a height of 30 mm provided with a hole having a diameter of 20 mm in the center were placed on the acrylic plate. The weights 27a and 27b were arranged so as to be symmetric with respect to a hole for passing a lead wire provided on the acrylic plate. In addition, Fuji prescale extremely low pressure pressure sensitive paper (product name, manufactured by Fuji Film Co., Ltd.) is laid under the conductive rubber 24, and the two weights 27a and 27b are in a symmetrical balance position. It was confirmed in advance that a uniform load was applied.

The weights of the weights 27a and 27b were 2 kg (4 kg in total). For this reason, a force of about 40 N is applied to the conductive rubber. When the conductive member 12 is disposed on the bus bars 2a and 2b as in the embodiment, the lower surface 12a of the conductive member 12 is brought into contact with the bus bars 2a and 2b using an adhesive as described in FIG. However, when urethane is used as the adhesive, it has an adhesive force of 3 MPa or more even in an 80 ° C. atmosphere when energized, so the required adhesion area is 40 (N) / 3 (MPa = N / mm ² ). ≈13.3 (mm ² ), and there is no problem if an adhesive area of about 5 mm × 2 mm can be secured. In Example 1, a force of 40 N is applied to the conductive rubber. However, in practice, sufficient conductivity can be ensured by applying a pressure of 0.2 MPa or more to the conductive rubber.

(Example 2)
In this example 2, as shown in FIG. 4B, the conductive rubber is arranged at a position where the short side of the conductive rubber is close to the soldering point at a position 45 mm from the soldered silver printed side. The glass plate was placed on the same silver plate as in Example 1 (1) so as to be parallel to the sides. Since the conditions other than the arrangement of the conductive rubber are the same as in Example 1, the description is omitted.

(Example 3)
In Example 3, eight conductive rubbers cut out to a size of 2.5 × 2.5 mm are conductive on a long side of a rectangle having a length and width of 20 × 10 mm as shown in FIG. Four rubbers were arranged at equal intervals. Specifically, four conductive rubbers are arranged at equal intervals on the inner side sharing one long side where conductive rubber is arranged in Example 1, and two conductive rubbers at both ends are arranged with conductive rubber in Example 1. Shared vertices. The remaining four conductive rubbers are arranged at equal intervals on the inner side sharing the other long side where the conductive rubber is arranged in Example 1, and the two conductive rubbers at both ends are the apexes where the conductive rubber is arranged in Example 1 To share. Since the conditions other than the arrangement of the conductive rubber are the same as in Example 1, the description is omitted.

(Example 4)
In this example 3, as shown in FIG. 4 (d), 8 conductive rubbers cut into a size of 2.5 × 2.5 mm are electrically conductive on the long side of a rectangle having a vertical and horizontal length of 10 × 20 mm. Four rubbers were arranged at equal intervals. Specifically, four conductive rubbers are arranged at equal intervals on the inner side sharing one long side where the conductive rubber is arranged in Example 2, and two conductive rubbers at both ends are arranged in Example 2. Shared vertices. The remaining four conductive rubbers are arranged at equal intervals on the inner side sharing the other long side where the conductive rubber is arranged in Example 2, and the two conductive rubbers at both ends are the apexes where the conductive rubber is arranged in Example 2 To share. Since the conditions other than the arrangement of the conductive rubber are the same as in Example 1, the description is omitted.

(Energization test)
The coaxial cable, which is a lead wire prepared as described above, was connected to a constant current source, and 30 A was energized for 1 hour to measure the temperature change. The measurement is 5 seconds using a data logger (trade name, manufactured by Keyence Corporation) with a K thermocouple fixed at a point C 10 mm away from the conductive rubber on the extension of the side near the soldering point on the conductive rubber and silver printing. The temperature was measured every time.

  FIG. 5 shows the measurement results. The vertical axis | shaft of FIG. 5 has shown the temperature measured with a thermocouple. Further, the horizontal axis in FIG. 5 indicates the elapsed time from the start of energization. From the comparison between Example 1 and Example 2 in FIG. 5 and the comparison between Example 3 and Example 4, when the long side of the conductive rubber is orthogonal to the current application direction, the temperature is higher than when the short side is orthogonal. It can be seen that the rise can be suppressed. This is presumably because the electron flow in the vicinity of the conductive rubber can be diffused to suppress the concentration of electrons.

  From the comparison between Example 1 and Example 3, the maximum temperature rises by reducing the contact area between the conductive rubber and the silver printing, but from the comparison between Example 3 and Example 2, the contact between the conductive rubber and the silver printing. It can be seen that even if the area is reduced, temperature rise can be suppressed by making the long sides of the conductive rubber perpendicular to the direction of current application.

  The connection member and the connection method of the present invention can be used for connection in places where the use of solder is restricted, and is particularly suitable for supplying power to a defogger formed on the glass surface of an automobile.

  DESCRIPTION OF SYMBOLS 1 ... Connection member, 2 ... Defogger, 2a, 2b ... Bus bar, 10 ... Metal plate, 11 ... Holding member, 12 ... Conductive member, 13, 14 ... Adhesive layer, 21 ... Glass substrate, 22 ... Silver printing, 23 ... Coaxial Cable, 24 ... conductive rubber, 25 ... connector, 26 ... coaxial cable, 27 ... weight, 28 ... load plate.

Claims (4)

A connecting member for connecting a plurality of heating wires and a lead wire for supplying a current to a defogger having a bus bar for supplying electricity to the plurality of heating wires;
A conductive plate to which the lead wire is connected;
One end is in contact with the conductive plate, the other end is in contact with the bus bar, and a conductive member that electrically connects the conductive plate and the bus bar,
A holding member for holding the conductive member in a state in which the one end is in contact with the conductive plate and the other end is in contact with the bus bar;
Comprising
The connecting member, wherein the conductive member is disposed on the bus bar so that the longitudinal direction of the conductive member is substantially orthogonal to the longitudinal direction of the bus bar on the surface in contact with the bus bar. The connection member according to claim 1, wherein a contact area between the conductive member and the bus bar is 200 mm ² or less. The holding member is
The connection member according to claim 1 or 2, wherein the other end of the conductive member is held in a state of being pressed onto the bus bar with a pressure of 0.2 MPa or more.   The connecting member according to any one of claims 1 to 3, wherein the conductive member is an anisotropic conductive member having conductivity in a direction from the one end to the other end.

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