RU2758986C1 - Method for manufacturing induction coils and induction coil - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, to the manufacture of spiral inductors for high-power radio equipment. In the manufacture of spiral inductors consisting of one or more layers and rows, the coils are first connected sequentially from the first layer to the last one, then from the inner row to the outer. The shape and structure of the frame are made of a thermoplastic dielectric with a low tangent of the dielectric loss angle and are formed during the laying of the wire as a result of heating the thermoplastic dielectric to a viscous state. The wire feed and the laying process are provided by a positioning device.

EFFECT: increase in the stability of the parameters of the inductor under mechanical vibrations, an increase in electrical strength at a high level of supplied power, a reduction in the cost of manufacturing and structural strength of inductors of large dimensions, an increase in Q-factor.

9 cl, 6 dwg

Description

The invention relates to the field of radio engineering, namely to spiral inductance coils, and can be used in high-power radio equipment.

In modern radio equipment, it becomes necessary to use inductance coils that meet the requirements: a high level of operating voltage and a level of permissible currents, a high value of the quality factor. Spiral coils of inductance allow at the same time to obtain a large value of inductance in a small volume and have a low level of parasitic capacitance. Spiral inductors are made, as a rule, in metallization layers on ceramic, silicon and other substrates.

A known method of manufacturing a high-quality spiral inductance coil according to the invention [EP0915513A1], in which a flat spiral inductance coil is located above the substrate and separated from it by an air gap using a bracket. The disadvantages are: extremely small possible dimensions due to the structural complexity and limited bearing capacity of the bracket, low figure of merit.

There is a known method of manufacturing an inductor, presented in the invention [RU2377033], which consists in placing the winding wire on a flat dielectric frame made of a solid dielectric. The frame is made in the form of radially located petals with gaps. The number of petals is odd. The winding is made in the form of a flat spiral, with each turn of the spiral alternately going around all the petals, from turn to turn the wire goes around one or the other side of each petal. The disadvantages are: instability of parameters due to possible vibrations of the structure during operation due to the presence of an air gap in the area of the wire transition between the petals, the technological complexity of production.

Also, the disadvantage of these inventions is the limitation on the magnitude of the inductance of the flat structure.

Known methods of manufacturing spiral inductance coils from several layers and turns on a dielectric frame, for example [RU2120148]. The disadvantages are: the technological and constructive complexity of manufacturing the frame, low electrical strength and low stability of parameters due to the presence of an air gap between the turns.

A known method of manufacturing a high-quality spiral inductor according to the invention [US5446311A], which consists in the formation of a multilayer spiral inductor at several levels of metallization in a silicon substrate. The disadvantage is the low figure of merit due to large losses in the silicon substrate.

There is a method of manufacturing a high-quality spiral inductor according to the invention [US6650220B2], which consists in the layer-by-layer formation of coaxial spiral coils connected in parallel on metallized layers separated by silicon-based dielectric layers with metallized vias. The disadvantage is the low figure of merit due to large losses in the silicon substrate.

There is a method of manufacturing a high-quality inductor [CN1377071A], which consists in forming a multilayer spiral inductance coil from a conductor located in a dielectric substrate, connected in several layers, and creating an air gap between the turns at the stage of forming each layer. The disadvantage is the reduced dielectric strength due to the presence of an air gap.

There is a known method of manufacturing a high-quality spiral inductance coil according to the invention [US5610433A], which consists in forming a spiral inductance coil from several layers and rows in a dielectric substrate, in which first turns are connected in series from the first layer to the last, then from the inner row to the outer, the connections between layers are carried out by vias.

The general disadvantages of the above inventions and similar solutions are: high resistivity of a thin conductive layer, a strong dependence of the parameters on the heating of the dielectric substrate at a high level of supplied power, the high cost of manufacturing large inductance coils for low, medium and high frequencies.

The technical result of the invention is a high stability of the parameters of the inductance coil during mechanical vibrations, high dielectric strength at a high level of supplied power, low manufacturing cost and structural strength of large-size inductance coils, high quality factor.

The specified technical result is achieved by the fact that in the method of manufacturing spiral inductance coils consisting of one or more layers and rows, in which the turns are first connected in series from the first layer to the last, then from the inner row to the outer, according to the claimed invention, the shape and design the frames are made of a thermoplastic dielectric with a low tangent of the dielectric loss angle and are formed in the process of laying the wire as a result of heating the thermoplastic dielectric to a viscous-flow state and feeding it into the zone of laying the wire with subsequent sintering, and the wire feed and the laying process are provided by a positioning device.

The essence of the invention is illustrated by drawings, where:

FIG. 1 - Explanation of the principle of forming an inductor.

FIG. 2 - Structural drawing of a nozzle forming a coating of a thermoplastic dielectric wire.

FIG. 3 - Explanation of different options for coil formation.

FIG. 4 - Explanation of the process of laying the inductor on the substrate.

FIG. 5 - Explanation of vertical stacking methods.

FIG. 6 - Appearance of a high-quality inductor.

The most common thermoplastic dielectrics in the radio engineering industry are hydrocarbon polymers. The table below shows the physical and technical characteristics of some of them [Bogoroditskiy NP, Pasynkov VV, Tareev BM. Electrical materials. 7th ed., Rev. and add. - L .: Energoatomizdat. Leningrad. branch, 1985].

Low dielectric constant means low turn-to-turn capacitance, low dielectric loss tangent means low losses due to the effect of proximity of conductors, together with high breakdown voltage, this means the ability to work with stable parameters at a high input power (up to several kilowatts).

Hydrocarbon polymers have high resistance to the action of solutions of alkalis, acids, mechanical strength, hygroscopicity. The frame of the inductor coil, formed from this material, is a monolithic product with high stability of parameters in a wide range of changes in climatic (humidity, salinity, temperature, pressure, dust) and mechanical (linear acceleration, vibration and shock effects) operating factors.

As an example, the following is the process of forming a skeleton using an extrusion unit.

The process of forming an inductor in the general case consists of several stages:

- heating the thermoplastic dielectric in the melting chamber of the extrusion unit to the temperature of the viscous-flow state and feeding it by the screw into the nozzle;

- feeding the winding wire into the nozzle, forming a coating of the winding wire from a thermoplastic dielectric after passing the winding wire through the nozzle of the extrusion unit;

- the formation of turns of the inductance coil by a winding wire with a thermoplastic dielectric heated to the temperature of the viscous-flow state, which is necessary for strong sintering of the laid turn to the already laid ones;

- laying of subsequent layers and turns of the inductor.

- расстояние между проводами намотки по рядам, b - расстояние между проводами намотки по слоям, N - количество слоев, М - количество рядов. Сначала происходит укладка первого (нижнего) слоя первого ряда (фиг. 1-а), затем происходит укладка последующих слоев первого ряда (фиг. 1-b), далее происходит переход на первый (нижний) слой второго ряда (фиг. 1-c), далее, аналогично первому ряду, происходит укладка последующих слоев, и рядов. На фиг. 1-d показана катушка, состоящая из N слоев и М рядов.FIG. 1, in section, the stages of coil formation are shown in succession with the horizontal arrangement of the winding machine table, where it is indicated: 1 - winding wire, 2 - polyethylene coating, 3 - winding table, 4 - axis of rotation of the winding table,

is the distance between the winding wires in rows, b is the distance between the winding wires in layers, N is the number of layers, M is the number of rows. First, the first (lower) layer of the first row is laid (Fig. 1-a), then the subsequent layers of the first row are laid (Fig. 1-b), then there is a transition to the first (lower) layer of the second row (Fig. 1-c ), then, similarly to the first row, the subsequent layers and rows are laid. FIG. 1-d shows a coil with N layers and M rows.

FIG. 2 shows a part of the extrusion unit, explaining the principle of forming a polyethylene sheath of the winding wire, where it is indicated: 5 - auger, 6 - a zone for feeding granular polyethylene, 7 - a cooling device for the upper part of an extrusion unit, 8 - a nozzle heating device, 9 - a zone for feeding a winding wire into nozzle, 10 - exit zone of the winding wire from the nozzle, 11 - nozzle, V - feed speed of the winding wire, W - screw rotation speed.

The winding table rotates about its own axis of rotation at a given speed. The extrusion unit with a nozzle and a winding wire feed device moves relative to the winding table in several coordinates (horizontally and vertically).

и по слоям b (фиг. 1).Coating of the winding wire with polyethylene is carried out in the nozzle of the extruder, through which the winding wire passes (Fig. 2). Granular polyethylene from the feeding zone 6 is fed by the screw 5 to the heating area. At a given temperature T, the polyethylene is melted and fed by the screw 5 to the nozzle, through which the winding wire passes at a certain speed V. Depending on the wire diameter, the size of the nozzle outlet, the temperature of the viscous-flow state of the polyethylene T, the wire feed speed V and the rotation speed of the screw W, the thickness of the polyethylene coating can be adjusted, and, accordingly, the distance between the winding wires along the rows

and on layers b (Fig. 1).

Laying can be done immediately after the wire leaves the nozzle in a polyethylene coating (Fig. 3-a), in this case, the newly laid turns are quickly sintered to the already laid turns without additional heating.

For the manufacture of inductors, a wire can be used already in an insulating sheath made of thermoplastic dielectric. In this case (Fig. 3-b), immediately before laying, a local heating of the thermoplastic dielectric is carried out in the heating zone 13 to the temperature of the viscous-flow state G, sufficient for strong sintering of the laid turns to those already laid. Heating can be carried out, for example, with a stream of hot air 12 (Fig. 3-b).

и по слоям b (фиг. 1), в процессе укладки могут быть достигнуты стабильные значения расстояний

и b по всей катушке индуктивности. От выбора соотношений диаметра провода намотки к расстояниям

и b будут зависеть величина добротности и значение частоты собственного резонанса.When choosing the optimal temperature for heating the thermoplastic dielectric in the extruder and the speed of laying the wire, taking into account the distances between the winding wires in rows

and along the layers b (Fig. 1), during the laying process, stable values of the distances can be achieved

and b across the entire inductor. From the choice of the ratio of the diameter of the winding wire to the distances

and b the value of the quality factor and the value of the natural resonance frequency will depend.

The process of laying the inductor coil can be carried out on a thermoplastic dielectric substrate 14 (Fig. 4), which gives the resulting product additional structural rigidity. This method is preferable for single-layer coils, since it allows the turns to be fixed when the thermoplastic dielectric cools down without deforming the frame shape.

The process of forming the inductor may differ from the above example. Laying can take place with a stationary base and a moving device for positioning the wire, which has several axes (degrees of freedom). The laying table can have not only a horizontal position, but also a vertical one. In this case, the stacking of the multilayer inductor can be done in two ways. Or even and odd rows are stacked from the first layer to the last (Fig. 5-a). Or the odd rows are stacked from the first to the last layer, and the even ones - from the last to the first (Fig. 5-b).

Litz wire can be selected as the winding wire. It is known that in the ranges of medium and short waves, the use of litz wire leads to a significant decrease in the resistance to alternating current, which makes it possible to increase the Q-factor of the inductor [M. Bartoli, N. Noferi, A. Reatti, M.K. Kazimierczuk 'Modeling litz-wire winding losses in high-frequency power inductors' PESC Record. 27th Annual IEEE Power Electronics Specialists Conference, 23-27 June 1996, R.P. Wojda, M.K. Kazimierczuk 'Winding resistance of litz-wire and multi-strand inductors' IET Power Electronics, Volume: 5, Issue: 2, Feb. 2012].

FIG. 6 shows an example of an inductor manufactured according to the claimed invention.

Claims (9)

1. A method of manufacturing spiral inductance coils, consisting of one or more layers and rows, in which first turns are connected in series from the first layer to the last, then from the inner row to the outer, characterized in that the shape and structure of the frame are made of a thermoplastic dielectric with low tangent of the angle of dielectric losses and are formed in the process of laying the wire as a result of heating the thermoplastic dielectric to a viscous-flow state and feeding it into the zone of laying the wire with subsequent sintering, and the wire feed and the laying process are provided by a positioning device. 2. The method according to claim 1, characterized in that a hot air flow is supplied to the laying zone to warm up to the required temperature of the viscous-flow state of the thermoplastic dielectric. 3. The method according to claim 1, characterized in that the heating, dosage and supply of the thermoplastic dielectric is carried out in the extruder, and the device for positioning the laid wire is aligned with the nozzle of the extruder. 4. The method according to claim 1, characterized in that the inductance coil is laid on a fixed thermoplastic dielectric substrate. 5. A method according to claim 1, characterized in that a stacking table is used to position the wire in the process of placing the coil. 6. A method of manufacturing spiral inductance coils consisting of one or more layers and rows, characterized in that the shape and structure of the frame are made of a thermoplastic dielectric with a low tangent of the dielectric loss angle and are formed in the process of laying a wire with insulation from a thermoplastic dielectric into a coil with a local by heating the insulation of the wire to a viscous-flowing state at the place of laying the wire of the inductor with subsequent sintering of the dielectric, and the supply of the wire and the process of laying are provided by a positioning device. 7. The method according to claim 6, characterized in that a hot air flow is supplied to the laying zone to warm up to the required temperature of the viscous-flow state of the thermoplastic dielectric. 8. A method according to claim 6, characterized in that the inductance coil is laid on a fixed thermoplastic dielectric substrate. 9. A method according to claim 6, characterized in that a stacking table is used to position the wire during the placement of the coil.

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