JPH0363802B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method for forming an inductance element, and particularly to a method for forming an inductance element by winding an insulated winding using an ultrasonic bonding device.

(b) Prior Art Recently, with the progress of chip components, hybrid integrated circuits of electronic circuits have been significantly developed. By accommodating a semiconductor integrated circuit and its external components such as capacitors, resistors, and coils in one package, hybrid integrated circuits can greatly reduce the number of parts in electronic devices, simplify assembly, and facilitate maintenance and inspection. This has the advantage of making it easier.

However, with regard to inductance elements, miniaturization of chips is far behind. This is because coils formed by winding a conductor have unresolved problems in the heat resistance of the insulator that covers the conductor and the connection between the conductor and external terminals in the solder dip when mounted on a board as a chip component. Because there is.

Examples of conventional small inductance elements include those shown in FIGS. 4 and 5 (see, for example, Japanese Patent Laid-Open No. 57-92807). FIG. 4 shows a magnetic material, for example, a drum-shaped core 20 with a winding 21,
The winding terminals 22, 22 are connected to both end flanges 23 of the core 20,
It is a small inductance element formed by bending the surface of silver electrodes 24, 24 formed on the end faces of 23, and then electrically connecting the winding terminals, electrodes, and lead wires 26, 26 via solders 25, 25. . In FIG. 5, a winding 21 is applied to the winding portion of a drum-shaped core 20, which has lead wires 26, 26 protruding from the bottom surface of the flange 23, and winding ends 22, 22 are connected to the lead wires 2, 26, respectively.
6 and 26 and connected by solders 25 and 25. Both small inductance elements have lead wires 26, 26 and solder 2
5.25, and cannot be miniaturized like chip resistors and chip capacitors.

Therefore, a chip inductance element shown in FIG. 6 has been proposed in Japanese Patent Laid-Open No. 59-43513. In FIG. 6, a winding 21 is applied to a drum-shaped core 20, and silver electrodes 24, 2 are spaced apart on the bottom surface of the flange 23 of the core 20.
4, and the silver electrodes 24, 24 are connected to the silver electrodes 24, 24 by bending the ends of the windings to the surface of the silver electrodes 24, 24.
It is connected to the. Such a chip inductance element is fixed to a desired electrode using solder 25, 25 on the silver electrodes 24, 24.

(c) Problems to be Solved by the Invention However, in the above-mentioned small inductance element and chip inductance element, after winding the winding 21 around the drum-shaped core 20 by a predetermined number of turns, the ends of the winding are connected to the silver electrodes 24, 24. It is necessary to solder to the inductance element, and it is necessary to adopt a formation method that is no different from that of ordinary inductance elements. For this reason, when manufacturing small inductance elements and chip inductance elements, there is a drawback that the cost increases due to miniaturization.

(d) Means for Solving the Problems The present invention has been made in view of the above points, and completely eliminates the drawbacks of the conventional method by directly forming an inductance element on an insulating substrate using an ultrasonic bonding device for an insulated winding. It is intended to be removed.

(e) Effects According to the present invention, focusing on the fact that the insulated winding can be ultrasonic bonded directly onto the conductive path, an inductance element is formed by directly winding the bonding wire with an ultrasonic bonding device.

(F) Embodiment An embodiment of the present invention will be described in detail with reference to FIGS. 1A to 1D.

The first step of the present invention is to form a conductive path 2 on an insulating substrate 1.
The main purpose is to form the winding frame 3 and arrange the winding frame 3 (see FIG. 1A). The insulating substrate 1 acts as a supporting substrate,
A ceramic substrate, a printed circuit board made of glass epoxy resin, etc., an aluminum substrate whose surface is alumite-treated, etc. are used. After pasting copper foil over the entire surface of one main surface of the insulating substrate 1, the copper foil is selectively etched to form conductive paths 2 in a desired pattern.
form. It is desirable that the conductive path 2 not only be used as a pad for connecting the windings of the inductance element, but also as a conductive path necessary for forming a hybrid integrated circuit.

The winding frame 3 has the role of winding the winding wire forming the inductance element, and may be made of a magnetic material such as ferrite or an insulating material such as plastic depending on the reactance value of the inductance element to be formed. Note that the shape of the winding frame 3 may be the cylindrical shape shown in the figure, but it may also be rod-shaped or I-shaped. The winding frame 3 is fixedly arranged on the insulating substrate 1 close to the conductive path 2 by means of an adhesive 4.

The second step of the present invention consists in ultrasonically bonding one end of the winding 5 contained in the reel 12 onto one conductive path 2 using an ultrasonic bonding device (see FIG. 1B).

The insulated winding used in the present invention is as shown in FIG.
It is formed of a thin copper wire 6 of 50 to 800 μΦ and an insulating coating 7 made of urethane or fluorinated ethylene covering its surface. The insulation coating 7 is made by passing the thin copper wire 6 through a urethane or fluorinated ethylene solution to a thickness of 10 to 50 μm.
It is deposited thickly (on average 20μ thick) and insulates each winding that forms the inductance element.

The ultrasonic bonding device used in the present invention is the third
As shown in the figure, a table 8, a capillary chip 9, an ultrasonic vibration source 10, a clamp 11, a reel 1
2 and an insulated winding 5. Such ultrasonic bonding equipment is known and widely used in the assembly of semiconductor devices. Briefly explaining the operation, one end of the thin aluminum bonding wire led out from the central hole of the capillary chip 9 is fixed to the electrode of a transistor etc. placed on the table 8 by applying ultrasonic vibrations of 20K to 60KHz.
Thereafter, the capillary tip 9 is moved and the other end of the thin aluminum wire is fixed to the other lead by applying ultrasonic vibration. The ultrasonic bonding apparatus used in the present invention has several improvements over those used for assembling such semiconductor devices. First, an insulated winding 5 is stored on the reel 12 for forming an inductance element. Second, ultrasonic vibration sources have slightly more power than those used for assembling semiconductor devices. Thirdly, table 8 has XY
An axis moving device 13 and a Z-axis moving device 14 are provided,
The structure is such that the table 8 can be freely moved in the X, Y, and Z directions. Fourthly, the table 8 is provided with a rotation device 15, which allows the table 8 to be rotated around arbitrary XY coordinates.

In this process, the insulating substrate 1 is fixed on the table 8 of the ultrasonic bonding device using vacuum suction, and the table 8 is moved in the XY axes so that the first conductive path 2 is directly below the capillary chip 9. Device 13
to move it. Subsequently, the capillary chip 9 is lowered and one end of the insulating winding 5 is fixed to one conductive path 2 by ultrasonic vibration. Since the insulating winding 5 uses a thin copper wire with a circular cross section, the energy of the ultrasonic vibration is concentrated at the point of contact with the conductive path 2, and the insulating coating 7 is torn, exposing the thin copper wire. Ultrasonic bonding can be realized by bonding the thin copper wire and the copper conductive path 2 of the same material.

The third step of the present invention consists in winding the insulated winding 5 fed from the reel 12 around the winding frame 3 (see FIG. 1C).

In this step, the insulated winding 5 is wound around the winding frame 3 by a predetermined number of turns, thereby forming an inductance element having a desired value. Since one end of the insulated winding 5 was fixed to one conductive path 2 in the previous step, the insulated substrate 1 is moved by the XY axis moving device 13 so that the insulated winding 5 is entangled with the winding frame 3. Subsequently, the XY axis moving device 13 is used to move the winding frame 3 so that the center of rotation is set at or near the center. Thereafter, the rotating device 15 of the ultrasonic bonding device is operated to rotate the winding frame 3, and the insulated winding 5 fed from the reel 12 is evenly wound around the winding frame 3 by a predetermined number of turns. . In order to wind the insulated winding 5 around the winding frame 3 to a uniform thickness, the Z-axis moving device 14 is used to move the table up and down to move the position of the winding frame 3 up and down, thereby achieving uniform winding. can be realized. Furthermore, in the present invention, by rotating the winding frame 3, the insulating winding 5 can be wound with a constant tension, and even if the number of turns is large, it can be set completely arbitrarily.

The advantage of the present invention is that the insulated winding 5 can be wound on either an E-type or an I-type winding frame 3. That is, in the I-shaped winding frame 3, the height of the capillary tip 9 may be arranged so as to correspond to the I-shaped winding frame 3. Further, in the case of an E-shaped core, the capillary chip 9 may be placed in the E-shaped gap.

The fourth step of the invention consists in ultrasonically bonding the other end of the insulated winding 5 to another conductive path 2 (see FIG. 1D).

In this step, the table 8 of the ultrasonic bonding device is moved by the XY axis moving device 13 to bring the capillary chip 9 onto another conductive path 2. Subsequently, the capillary chip 9 is lowered and brought into contact with another conductive path 2, and ultrasonic vibration is applied to the other end of the insulating winding 5 for ultrasonic bonding. Note that the insulated winding 5 is cut using a cutter or the like when the capillary chip 9 is raised.

The process detailed above is a process for forming one inductance element, and by repeating this process, a plurality of inductance elements can be formed. That is, after forming the first inductance element at the first position, the table 8 is
A second inductance element can be similarly formed at a second position by moving with the axis moving device 13. Further, the plurality of inductance elements can be formed to have any value by controlling the rotation speed of the table 8, and are useful in tuner circuits and the like.

(G) Effects of the Invention The first effect of the invention is that the inductance element can be formed directly on the insulating substrate 1. That is, in the present invention, since the inductance element can be formed using the minimum number of components including the winding frame 3 and the insulated winding 5, it is possible to obtain an inductance element that is extremely small and inexpensive compared to conventional chip inductances.

The second effect of the present invention is that since the inductance element is formed by winding the insulated winding 5 fed from the reel 12 of the ultrasonic bonding device, an arbitrary number of turns can be realized and a value of a wide width can be obtained. An inductance element can be formed. Furthermore, since the insulated winding 5 is continuously supplied from the reel 12, the inductance element can be formed continuously.

A third effect of the present invention is that inductance elements can be continuously formed at arbitrary positions on the insulating substrate 1. That is, the table 8 of the ultrasonic bonding device may be moved by the XY axis moving device 13, and the process of forming the inductance element may be repeated.

A fourth effect of the present invention is that the inductance element can be set to any value. That is, the number of turns of the insulated winding 5 may be programmed in the process of forming each inductance element. As a result, it is extremely useful in tuner circuits that require various types of inductance.

A fifth effect of the present invention is that a heating process is not required in the process of forming the inductance element. That is, in the present invention, since the connection between the insulating winding 5 and the conductive path 2 is carried out by ultrasonic bonding, there is no possibility that the insulating coating 7 will melt due to heating and generate a reasyot.

A sixth effect of the present invention is that by adding pattern recognition and programmable memory to the ultrasonic bonding apparatus, the inductance element can be automatically formed as long as the insulating winding 5 is supplied from the reel 12. .

[Brief explanation of drawings]

FIGS. 1A to 1D are cross-sectional views explaining the method of forming an inductance element according to the present invention, FIG. 2 is a cross-sectional view explaining the insulated winding used in the present invention, and FIG. A block diagram illustrating an ultrasonic bonding apparatus and FIGS. 4 to 6 are cross-sectional views illustrating conventional small inductance elements and chip inductance elements. Explanation of the main drawing numbers, 1 is an insulated substrate, 2 is a conductive path,
3 is a winding frame body, 5 is an insulated winding, 9 is a capillary chip, and 15 is a rotating device.

Claims (1)

[Claims] 1. In a method for forming an inductance element that is directly incorporated on a circuit board, an insulated winding is built into a reel of an ultrasonic bonding device, and one cut end of the insulated winding is attached to one of the inductance elements provided on the circuit board. After ultrasonic bonding to the conductive path, the insulated winding is fed from the reel and wound to form an inductance element, and then the insulated winding is ultrasonically bonded to another conductive path on the circuit board. A method for forming an inductance element, comprising bonding and cutting the insulated winding.