JPH0234442B2 - INDAKUTANSUSOSHINOKEISEIHOHO - 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 a single 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. . FIG. 5 shows that the winding 21 is applied to the winding portion of the drum-shaped core 20, which has lead wires 26, 26 protruding from the bottom surface of the flange 23, and the 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 elements and chip inductance elements, the insulation coating material of the windings melts due to the soldering temperature during mounting, which may lead to a defective rearrangement. Further, in chip inductance elements, a large amount of solder tends to adhere to the silver electrodes, and the amount is not constant, so there is a risk that the solder may be stuck in an inclined state.

(d) Means for Solving the Problems The present invention has been made in view of the above problems, and after soldering other circuit elements, an inductance element is formed directly on an insulating substrate using an ultrasonic bonding device with an insulated winding. This completely eliminates the drawbacks of the conventional method.

(E) Effect According to the present invention, attention is paid to the fact that the insulated winding can be ultrasonically bonded directly onto the conductive path after other circuit elements are soldered, and the inductance is created by winding the bonding wire using an ultrasonic bonding device. Since the element is formed, the inductance element can be formed without undergoing heat treatment.

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

The first step of the present invention consists in forming conductive paths 2, 2' on a circuit board 1 and soldering desired circuit elements 3 (see FIG. 1A).

The circuit board 1 functions as a supporting board, and uses a ceramic board, a printed board made of glass epoxy resin, etc., an aluminum board whose surface is alumite-treated, or the like. After a copper foil is attached to the entire surface of one main surface of the circuit board 1, the copper foil is selectively etched to form conductive paths 2, 2' in a desired pattern. The conductive paths 2, 2' are preferably formed not only as pads for connecting the windings of the inductance element, but also as conductive paths 2 necessary for forming a hybrid integrated circuit.

The circuit elements 3 are circuit parts necessary for forming a hybrid integrated circuit, and specifically include an IC chip, a transistor chip, a chip capacitor, a chip resistor, and the like.

In this process, the conductive path 2 to which the circuit element 3 is soldered
After selectively screen-printing solder cream thereon, the circuit elements 3 are placed in a predetermined position, and the entire circuit board 1 is heated in a heating furnace or on a hot plate to be fixed by the solder layer 4.

The second step of the present invention is to place the winding frame 5 on the circuit board 1.
(See Figure 1 B).

The winding frame 5 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. The shape of the winding frame 5 may be the cylindrical shape shown in the figure, but it may also be a rod shape or an I-shape. The winding frame 5 is fixedly arranged on the circuit board 1 in the vicinity of the conductive paths 2, 2' by means of an adhesive 6.

The third step of the present invention consists in ultrasonically bonding one end of the winding 7 onto one conductive path 2 using an ultrasonic bonding device (see FIG. 1C).

The insulated winding used in the present invention is as shown in FIG.
It is formed of a thin copper wire 8 of 50 to 800 μΦ and an insulating coating 9 made of urethane or fluorinated ethylene covering its surface. The insulating coating 9 is made by passing the copper magnetic wire 8 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, it is composed of a table 10, a capillary chip 11, an ultrasonic vibration source 12, a clamp 13, a reel 14, and an insulated winding 7. 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 11 is fixed to the electrode of a transistor etc. placed on the table 10 by applying ultrasonic vibrations of 20K to 60KHz. The rear capillary chip 11 is moved and the other end of the thin aluminum bonding 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 7 is stored on the reel 14 for forming an inductance element.
Second, ultrasonic vibration sources have slightly more power than those used for assembling semiconductor devices. Thirdly, table 10
is provided with an XY-axis moving device 15 and a Z-axis moving device 16, and has a structure that allows the table 10 to be freely moved in the X, Y, and Z directions. Fourth, table 1
0 is equipped with a rotating device 17 and rotates the table 10.
You can rotate around any XY coordinate.

In this process, the circuit board 1 is fixed on the table 10 of the ultrasonic bonding apparatus using vacuum suction force, and one conductive path 2 is connected to the capillary chip 1.
The table 10 is moved by the XY axis moving device 15 so that it is directly below the table 10. Next, capillary chip 1
1 is lowered and one end of the insulating winding 7 is fixed to one conductive path 2 by ultrasonic vibration. Since the insulating winding 7 is made of thin copper wire with a circular cross section, the energy of ultrasonic vibration is concentrated at the point of contact with the conductive path 2, causing the insulating coating 9
is torn and the thin copper wire is exposed. Ultrasonic bonding can be realized by bonding the thin copper wire and the copper conductive path 2 of the same material.

The fourth step of the present invention consists in rotating the circuit board 1 and winding the insulated winding 7 around the winding frame 5 (see FIG. 1D).

In this step, the insulating winding 7 is wound around the winding frame 5 by a predetermined number of turns, thereby forming an inductance element having a desired value. Since one end of the insulated winding 7 was fixed to one conductive path 2 in the previous step, the circuit board 1 is moved by the XY axis moving device 15 so that the insulated winding 7 is entangled with the winding frame 5. Subsequently, the XY axis moving device 15 is used to move the winding frame 5 so that the center of rotation is set at or near the center. Thereafter, the rotating device 17 of the ultrasonic bonding device is operated to rotate the winding frame 5, and the insulating winding 7 fed from the reel 14 is evenly wound around the winding frame 5 by a predetermined number of turns. . In order to wind the insulated winding 7 around the winding frame 5 to a uniform thickness, the Z-axis moving device 16 is used to move the table up and down to move the position of the winding frame 5 up and down, thereby achieving uniform winding. can be realized. Furthermore, in the present invention, by rotating the winding frame 5, the insulating winding 7 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 7 can be wound on either an E-type or an I-type winding frame 5. That is, in the I-shaped winding frame 5, the height of the capillary tip 11 may be arranged so as to correspond to the I-shaped winding frame 5. Further, in the case of an E-shaped core, the capillary chip 11 may be placed in the E-shaped gap.

The fifth step of the present invention consists in ultrasonically bonding the other end of the insulated winding 7 to another conductive path 2' (see FIG. 1E).

In this step, the table 10 of the ultrasonic bonding apparatus is moved by the XY axis moving device 15 to bring the capillary chip 11 onto another conductive path 2'.
Subsequently, the capillary chip 11 is lowered and brought into contact with another conductive path 2', and ultrasonic vibrations are applied to the other end of the insulating winding 7 to perform ultrasonic bonding. Note that the insulated winding 7 is cut using a cutter or the like when the capillary chip 11 is raised.

As detailed above, according to the present invention, the circuit board 1
In addition to the conventional circuit elements 3 such as ICs, transistors, chip capacitors, or chip resistors, an inductance element can also be incorporated, making it possible to eliminate the need for almost any external components. Further, since the inductance element is assembled after the soldering heating process is completed, short circuits due to heating of the insulated winding 7 will not occur at all.

(G) Effects of the Invention The first effect of the present invention is that since the inductance element is formed after the soldering of the circuit element 3 is completed, the inductance element has the advantage that it can be formed without going through a heating process. As a result, shortening of the insulated winding of the inductance element can be completely prevented.

The second effect of the present invention is that it is possible to incorporate an inductance element with an arbitrary value into the linear circuit board 1, so that all the circuit elements of the LCR can be integrated on the circuit board 1. A wide range of circuits can be realized on the top.

The third effect of the present invention is that the inductance element
The advantage is that it can be formed directly on the circuit board 1. That is, in the present invention, the inductance element can be formed using the winding frame 5, the insulated winding 7, and a minimum number of parts, so that it is possible to obtain an inductance element that is extremely small and inexpensive compared to conventional chip inductances.

A fourth effect of the present invention is that inductance elements can be continuously formed at arbitrary positions on the circuit board 1. That is, the table 10 of the ultrasonic bonding device may be moved by the XY axis moving device 15, and the process of forming the inductance element may be repeated.

A fifth effect of the present invention is that the inductance element can be set to an arbitrary value. That is, the number of turns of the insulated winding 7 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 sixth effect of the present invention is that the inductance element can be automatically formed by adding pattern recognition and programmable memory to the ultrasonic bonding apparatus.

[Brief explanation of drawings]

1A to 1E 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 the circuit board, 2 and 2' are the conductive paths, 3 is the circuit element, 5 is the winding frame, 7 is the insulated winding, 10 is the table, 11 is the capillary chip,
14 is a reel, and 17 is a rotating device.

Claims (1)

[Claims] 1. In a method for forming an inductance element that is directly incorporated on a circuit board, after soldering the circuit element onto a desired conductive path of the circuit board, an insulated winding stored in a reel is supplied using an ultrasonic bonding device. 1. A method for forming an inductance element, which comprises incorporating an inductance element which is ultrasonically bonded onto a conductive surface and wound into a coil.