JPH02140906A - Connection structure of lead wire - Google Patents

Abstract

PURPOSE:To enable a lead wire to be connected to an electrode easily and positively by placing the lead wire on the insulating film and then pressing a heating tool which is heated to a high temperature on both the lead wire and the insulation film. CONSTITUTION:A lead wire W1 with coating is allowed to be in contact with an electrode 6 of a base 5, the pressing surface 1c of a heater chip 1 heated to a high temperature is pressed against the lead wire W1. At this time, the coating of the lead wire W1 is melted due to high temperature, thus allowing the part contact with the press surface 1c and the periphery to be exposed. Also, the exposed part is softened while it is directly in contact with the electrode 6 due to heating of the heater chip 1, is deformed flatly being equal to the shape of the pressing surface 1c, and the deformed exposure part and the electrode 6 are subject to contact bonding. Thus, a lead wire can be connected easily and securely without removing the coating of the lead wire W1 previously.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lead wire connection structure, and more particularly to a lead wire connection structure in which the lead wire is thermocompressed and connected to the electrode of a small electronic component.

Small electronic components such as bobbins with windings, transformers, various types of chip fills, and other inductance components involve terminal connections of the windings during the manufacturing process.

If this electronic component is a chip coil 4 as shown in FIG. 8, the terminals 8, 8 protruding from the back surface of the insulating substrate 7 are coated! l
Generally, lead wires Wl and Wl drawn out from W are connected. Specifically, the lead wire W1 with the insulating coating still attached is wound around the terminal 8 and temporarily fixed, and the lead wire W1 is immersed in a solder bath.
The film was evaporated and the leads and iWl were connected by soldering.

By the way, these types of electronic components have become smaller and smaller in recent years.
Although there is a trend toward chipping, the terminals 8 protruding outward from the insulating substrate 7 have been an obstacle to chipping. Therefore, as shown in FIG. 9, a film-like electrode 6 is formed on the back surface of the base 5 of the chip coil 4, and the lead wire w
1 is connected. As a method for connecting the lead wires, a conventionally well-known solder connection method, or when the lead wires are bare wires, a welding method, an induction heating method, etc. are employed. In the induction heating method, as shown in FIG. 10, a pair of positive and negative electrode rods 9 and 10 are pressed from above the lead wire W1 that is in contact with the electrode 6, and the electrode rods 9 and 10 are energized. As a result, the positive electric fence rod 9
- A current flows through the lead wire w1 - the electrode 6 - the negative electrode rod 10,
Induction heating occurs between the electrode 6 and the lead wire, and their contact surfaces become molten and connected.

Problems to be Solved by the Invention However, the former solder connection method (see Figure 8) is unsuitable for chip-type electronic components, which are suitable for relatively large electronic components, and requires a high degree of soldering when used. There was a problem that processing technology was required.

On the other hand, the latter welding method and induction heating method are limited to bare lead wires, and when connecting covered lead wires, it is necessary to peel off the coating on the lead wires in advance, which requires a large amount of work in the manufacturing process. Including peeling work increases the number of steps and is inferior to mass production.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a lead wire connection structure that can easily and reliably connect a lead wire to an electrode of an electronic component or the like.

Means for Solving the Problems In order to solve the above problems, the first invention is to bring a lead wire having an insulating coating into contact with an electrode of an electronic component, and press a heating jig heated to a high temperature onto the lead wire. and a lead wire is thermocompression bonded to the electrode. Moreover, the second invention forms a lead wire suppression surface with a required slope on a heating jig, heats the heating jig at a high temperature, and brings the lead wire suppression surface into contact with an electrode of an electronic component. It is characterized in that the lead wire is thermocompression bonded to the electrode by pressing it onto the lead wire, and the excess lead wire is cut off.

According to the first invention, when connecting a lead wire to an electrode of an electronic component, the lead wire is held in contact with the electrode while being covered. Then, the heating jig is heated to a high temperature and applied to the lead wire to apply pressure. Then, the coating of the lead wire melts due to the high heat, creating an exposed part, and this exposed part softens and deforms to the same shape as the suppressing surface of the heating jig, thereby anchoring the exposed part of the lead wire to the electrode. Due to the effect, it will be bonded by thermocompression.

Further, according to the second invention, when connecting a lead wire to an electrode of an electronic component, the lead wire is held in contact with the electrode. Then, the heating jig is heated to a high temperature and applied to the lead wire to apply pressure. As a result, the suppressed portion of the lead wire is softened and deformed, and the lead wire is heated and compressed against the electrode. At this time, the upper side of the lead wire is deformed into a shape equal to the lead wire suppression surface of the heating jig with the required slope, and the suppressed part of the lead wire has an inclined surface, with a thick part and a thin part. part is formed. After this, when tension is applied to the lead wire, the lead wire is easily cut at the thin portion. Note that in the second invention as well, it is not necessary to peel off the insulating coating of the node wire in advance, but the insulation coating of the node wire is melted by the pressure of the heating jig, and the lead wire is exposed.

Embodiments Hereinafter, embodiments of a lead wire connection structure according to the present invention will be described based on the accompanying drawings.

[Refer to Embodiment 1 and FIGS. 1 to 3] The heating jig used in this Embodiment has a lead wire w1 of a covered winding W that can be completely wound around the chip coil 4 shown in FIG. 10. The heater chip 1 is made of a metal material with excellent thermal conductivity and is formed into a substantially Y shape. This heater chip 1 is heated as a whole to a temperature range of 350° to 400° by connecting an electric heater or the like on the upper end side. The lower end side 1b is a rectangular parallelepiped, that is, the width L1 is slightly larger than the outer diameter of the lead heath, and the vertical width L
2 is set to a length that can pressurize and deform the node line W1 by a required length. Further, the bottom surface is flat and serves as a lead wire suppression surface IC that is in flush contact with the lead wire W1.

The node wire w1 is a lead-out portion of a covered winding made of a polyurethane copper wire that is completely wound around the body of a chip coil made of a magnetic ceramic, and is connected to an electrode 6 provided on the base 5 as described below. Moreover, this electrode 6 is made of Ag,
It is formed in the form of a film on the back surface of the base 5 of the chip coil using Ag-Pd, Cu, solder, or the like.

Next, a method for connecting the lead wires will be explained.

First, as shown in FIG. 1, the node wire W1 is brought into contact with the electrode 6 of the base 5 with the coating still attached. Then, the heater chip 1 is heated to a high temperature of 350 to 400° C., and the pressing surface 1c is pressed onto the lead wire w1. At this time, the coating of the lead wire W1 is melted by high heat, and the contact portion of the pressing surface IC and its surroundings are exposed. Further, due to the heating action of the heater chip 1, this exposed portion is softened while in direct contact with the electrode 6, and deformed into a flat shape equal to the shape of the pressing surface 1c, and as shown in FIG. The electrode 6 is bonded by thermocompression. Further, the other lead wire (not shown) is similarly thermocompressed to another electrode (not shown), thereby connecting both ends of the covered winding to the pair of electrodes 6.

[Second Embodiment, See FIG. 4] As shown in FIG. 4, the heater chip 1 may be provided with inclined surfaces 1d and ld at both ends of the suppressing surface 1c. As a result, when the lead wire W1 is connected to the electrode 6 as described above, the exposed deformed portion of the lead wire 1 is drawn out at a gentle angle having an inclined surface Wla equal to the inclined surface 1d.

Therefore, when some tension is applied to the lead wire, disconnection from the connection portion is minimized.

[Third embodiment, see FIGS. 5 to 7] In the third embodiment, the heater chip 1 used as a heating jig has a bottom surface, which is a lead wire suppression surface 1c, inclined at a gentle angle θ. The connection method and the like are the same as in the first embodiment.

That is, the lead wire suppressing surface 1c of the heater chip 1 heated to a high temperature is pressed against the top of the lead wire brought into contact with the electrode 6 to apply pressure. As a result, the lead wire W1 is thermocompressed to the electrode 6 as shown in FIG. 6 in the same manner as in the first embodiment, but the exposed deformed portion of the lead wire w1 is equal to the inclination angle θ of the suppressing surface 1c, and one side It becomes an inclined plane from one side to the other.

Therefore, when tension is applied to the lead wire W1 after the connection portion, the thin portion W1b is easily cut. Moreover, the remaining portion is fixed to the electrode 6 with a wide joint surface, and the lead heath is firmly connected to the electrode 6 due to the anchor effect of the copper.

According to the lead wire connection structure in each of the embodiments described above, even if it is an electronic component such as the small chip coil 4 shown in FIG. 9 where it is not appropriate to provide the terminal 8, the lead wire w1 can be attached to the electrode 6 with an insulating coating. It can be connected as is without having to peel it off. In addition, since the terminals of the winding can be easily processed in this way, special winding methods such as aligned winding using spindle winding, which is difficult with conventional chip coils, can be easily employed. That is, in the case of a chip coil, by thermocompressing one end of the lead 1iW1 to the electrode 6 in advance, the lower base 5 or upper base 5' of the chip fill is chucked to rotate the chip coil itself, and the body It can be wound around. Therefore, highly accurate winding processing is possible, and a highly reliable chip coil can be manufactured.

As detailed above, according to the lead wire connection structure according to the first invention, a heating jig heated to a high temperature is pressed onto the lead wire having an insulating coating brought into contact with the electrode. This allows the lead wire to be thermocompression bonded to the electrode. Therefore, instead of soldering, which is widely used in the past, connection can be performed with the lead wires covered, and the process is extremely simple.

Furthermore, the heating jig may have a simple structure, and since it is only necessary to heat the wire to a high temperature during connection, there is no need for incidental equipment required for conventional welding methods, induction heating methods, etc.

Furthermore, when making connections, it is only necessary to hold the lead wires in contact with the electrodes, so it is possible to connect many lead wires at the same time, making it easier to connect multiple leads, which leads to improved productivity. There is also.

Further, according to the lead wire connection structure according to the second invention,
Since the heating jig is formed with a lead wire suppression surface having a required inclination angle, the connection portion of the lead wire thermocompressed to the electrode has a difference in wall thickness (thinner part) corresponding to the lead wire suppression surface. Therefore, when cutting the lead wire from the connecting portion, the thin portion can be easily cut by applying tension to the lead wire to be cut.

[Brief explanation of the drawing]

1 and 2 are front views of the first embodiment of the present invention when the lead wires are connected, and FIG. 3 is a perspective view of the first embodiment of the present invention showing the state in which the lead wires are connected to the electrodes. FIG. 4 is a perspective view showing a connection state of lead wires in a second embodiment in which the shape of the heating jig is changed. FIG. 5 is a front view when the lead wires are connected in the third embodiment, and FIGS. 6 and 7 are perspective views showing the state in which the lead wires are connected to the electrodes in the third embodiment. Figures 8 to 10 show the conventional node wire connection structure, Figure 8 is a front view of the chip coil with terminals, and Figure 9 is the back side of the chip coil with lead wires connected by solder connection. A side perspective view and FIG. 10 are perspective views showing a state in which lead wires are connected by an induction heating method. 1... Heating jig, IC... Lead wire suppression surface, 4...
・Electronic parts (chip coil), 6... electrode, Ken 1...
・Lead wire, Wlb...Thin wall part.

Claims (2)

[Claims] 1. A lead wire characterized in that a lead wire having an insulating coating is brought into contact with an electrode of an electronic component, a heating jig heated to a high temperature is pressed onto the lead wire, and the lead wire is thermocompression bonded to the electrode. connection structure. 2. Forming a lead wire pressing surface with a required inclination on a heating jig, heating this heating jig to a high temperature, and pressing the lead wire pressing surface onto a lead wire that is in contact with an electrode of an electronic component. A lead wire connection structure characterized in that the lead wire is thermocompression bonded to the electrode and the excess lead wire is cut.