KR101029239B1 - Variable passive device tuning inductance and capacitance simulataneously and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a variable passive element.

The variable passive device according to the present invention is formed so as to be spaced apart from the bottom electrode portion on the insulating substrate, the bottom electrode portion formed on the insulating substrate, the bottom electrode portion, the metal layer constituting the capacitor together with the bottom electrode portion, opposing the metal layer on the metal layer A spiral inductor formed to be spaced apart from each other, and a heat driving part formed between the insulating substrate and the metal layer to support the metal layer spaced apart from the bottom electrode part and the spiral inductor, and moving the metal layer in a vertical direction with respect to the insulating substrate in response to a temperature change. The inductance and the capacitance are simultaneously variable as the metal layer is moved.

According to the present invention, since the inductance and the capacitance can be simultaneously changed as a single device, the required area can be minimized compared to the method of separately manufacturing the variable inductor and the variable capacitor, thereby reducing the manufacturing cost. In addition, since the variable capacitor and the variable inductor operate as one drive circuit, the drive circuit can be integrated.

MEMS, Variable Passive Components, Variable Inductors, Variable Capacitors

Description

VARIABLE PASSIVE DEVICE TUNING INDUCTANCE AND CAPACITANCE SIMULATANEOUSLY AND MANUFACTURING METHOD THEREOF}

The present invention relates to a variable passive element. More specifically, the present invention relates to a microelectromechanical system (MEMS) variable passive device and a method of manufacturing the same, which simultaneously increase or decrease inductance and capacitance.

Currently, with the development of micro-machining techniques, microelectromechanical system variable capacitors and variable capacitors can be substituted for silicon-based variable capacitors and variable inductors, such as varactor diodes used for frequency tuning. Inductors are widely studied.

The driving principle of the variable capacitor used in the conventional integrated circuit can be largely classified into three ways. These methods include varying the overlapping area of two metal layers of a capacitor, changing the dielectric constant between two metal layers of a capacitor, and varying the distance between two metal layers of a capacitor. .

The driving principle of a variable inductor used in a conventional integrated circuit can be largely classified into three methods. Such methods include a method of varying the length of an inductor using a switching element, a method of varying a distance between two conductors constituting the inductor, and a method of changing a distance between an insulator and an inductor and an electrically insulated and adjacent metal layer. .

A variable capacitor and a variable inductor driven by using this method are devices capable of varying only one capacitance or inductance. In an application such as a matching network, a capacitive load or an inductive load may be used. load) has the limit of matching only one.

It is also used in voltage controlled oscillators and variable filters in order to increase the variable range of the center frequency in the application of voltage controlled oscillators (VCOs) to frequency variable elements such as LC-tanks and tunable filters. It is desirable that the capacitance and inductance of the capacitor and the inductor change simultaneously.

Accordingly, in the related art, a method of fabricating and integrating a variable capacitor and a variable inductor element in order to simultaneously change capacitance and inductance has been proposed. However, this method has a problem of occupying a large area because the variable inductor and the variable capacitor are made separately on the circuit board.

In addition, a method of driving a variable passive device fabricated by integrating a variable capacitor and a variable inductor is generally a method of discontinuously changing capacitance or inductance by using a switching element and a continuous capacitance or by using a continuously moving driver. There are two ways to change the inductance. However, the continuously variable variable capacitor and the variable inductor have a great difficulty in simultaneously changing the capacitance and the inductance because the two variable methods are different.

In addition, since the driving circuits of the driver for changing each variable capacitor and variable inductor must be present, the circuit becomes complicated and the system becomes large.

In order to solve this problem, an object of the present invention is to provide an integrated variable passive element capable of simultaneously varying inductance and capacitance in one driving scheme.

In addition, another object of the present invention is to provide a method for manufacturing a variable passive device.

The variable passive device according to the present invention is formed so as to be spaced apart from the bottom electrode portion on the insulating substrate, the bottom electrode portion formed on the insulating substrate, the bottom electrode portion, the metal layer constituting the capacitor together with the bottom electrode portion, opposing the metal layer on the metal layer A spiral inductor formed to be spaced apart from each other, and a heat driving part formed between the insulating substrate and the metal layer to support the metal layer spaced apart from the bottom electrode part and the spiral inductor, and moving the metal layer in a vertical direction with respect to the insulating substrate in response to a temperature change. The inductance and the capacitance are simultaneously variable as the metal layer is moved.

It is preferable to further include a support for supporting the spiral inductor from the insulating substrate so as to face away from the metal layer.

Bottom electrode,

It is preferable to include a first bottom electrode and a second bottom electrode formed on the insulating substrate spaced apart.

Thermal drive unit,

A plurality of unit heat driving units respectively formed between the insulating substrate and the metal layer;

Each unit heat drive unit,

One side is fixed to the insulating substrate, the other side is connected to the metal layer, and formed on the first driving unit formed of an insulating material, the first driving unit formed on the first driving unit, the second driving unit and the second driving unit insulated from the metal layer, respectively It includes a lead connected by

Preferably, the second drive unit is made of a material different from the coefficient of thermal expansion of the first drive unit.

Thermal drive unit,

A plurality of unit heat driving units respectively formed between the insulating substrate and the metal layer;

Each unit heat drive unit,

A first driver having one side fixed to the insulating substrate, a second driver formed on the first driver, a connection part connected between the other side of the first driver and a metal layer and formed of an insulating material, and conductive wires electrically connected to both ends of the second driver, respectively Includes wealth,

Preferably, the first drive unit and the second drive unit are made of a material having a different thermal expansion coefficient.

The variable passive device according to the present invention is formed so as to be spaced apart from the bottom electrode portion on the insulating substrate, the bottom electrode portion formed on the insulating substrate, the bottom electrode portion, the metal layer constituting the capacitor together with the bottom electrode portion, opposing the metal layer on the metal layer A spiral inductor formed to be spaced apart from each other, and an electrostatic drive unit formed between the insulating substrate and the metal layer to support the metal layer spaced apart from the bottom electrode part and the spiral inductor, and to control the separation distance between the metal layer and the bottom electrode part and the separation distance between the metal layer and the spiral inductor. It includes, the metal layer is moved in the vertical direction with respect to the insulating substrate in accordance with the voltage difference with the bottom electrode, characterized in that the inductance and capacitance is simultaneously changed as the metal layer is moved.

It is preferable to further include a support for supporting the spiral inductor from the insulating substrate so as to face away from the metal layer.

The electrostatic drive unit,

It includes a plurality of unit electrostatic driving unit respectively formed between the insulating substrate and the metal layer,

The unit electrostatic driving unit is electrically connected to each of the metal layers,

The metal layer is applied with a voltage through the electrostatic driving unit, it is preferable to move the position by the electrostatic force generated in accordance with the voltage difference with the bottom electrode.

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Method for manufacturing a variable passive device according to the present invention comprises the steps of (a) forming a bottom electrode portion on the insulating substrate, (b) forming a sacrificial layer on the insulating substrate and the bottom electrode portion, so that a portion of the insulating substrate is exposed (C) depositing and patterning an insulating material on a portion of the insulating substrate and the sacrificial layer to form a first drive layer, (d) a thermal expansion coefficient different from the coefficient of thermal expansion of the first drive layer on the first drive layer Depositing a material having a coefficient to form a second driving layer, and patterning the second driving layer to form a plurality of thermal driving parts including a plurality of thermal driving parts including the first driving layer and the second driving layer, e) depositing a metal material on the insulating substrate and patterning the metal material on the first driving layer located above the bottom electrode part by patterning the metal material so as not to contact with the second driving layer. Sang Forming a first photoresist, spaced apart the helical inductor from the metal layer, and patterning the pattern to form a support for supporting on the insulating substrate, (g) depositing and patterning a metal material on the patterned first photoresist Forming a support, (h) forming a second photoresist on the first photoresist, and patterning a pattern of the spiral inductor, and (i) depositing a metal material on the patterned second photoresist. And patterning to form a spiral inductor, and (j) sequentially removing the second photoresist, the first photoresist, and the sacrificial layer through an etching process.

 (a) step,

It is preferable to form a second bottom electrode part including a first bottom electrode and a second bottom electrode spaced apart from each other on an insulating substrate.

According to the present invention, since the inductance and the capacitance can be simultaneously changed as a single device, the required area can be minimized compared to the method of separately manufacturing the variable inductor and the variable capacitor, thereby reducing the manufacturing cost.

In addition, since the variable capacitor and the variable inductor operate as one drive circuit, the drive circuit can be integrated.

In addition, in applications such as matching networks, both capacitive and inductive loads can be matched, providing flexibility in circuit design and optimization.

Also, when used in a frequency variable element such as an LC-tank and a variable filter of a voltage controlled oscillator, the center frequency variable range can be improved as compared with the case of using only one element of a variable capacitor or a variable inductor.

1. Variable Passive Device Using Thermal Drive Method

Hereinafter, with reference to the accompanying drawings will be described in detail a variable passive device according to a first embodiment of the present invention.

1-1. Configuration of Variable Passive Devices Using Thermal Drive Method

1A is a top view illustrating a configuration of a variable passive device according to a first embodiment of the present invention. FIG. 1B is a cross-sectional view of the variable passive element illustrated in FIG. 1A in the direction of AA ′. FIG. 1C is a cross-sectional view illustrating the variable passive element illustrated in FIG. 1A in a direction BB ′.

1A to 1C, the variable passive device according to the first embodiment of the present invention may include an insulating substrate 100, a bottom electrode 110, a metal layer 120, a spiral inductor 130, and a support 131. And a heat driver 140.

As the insulating substrate 100, a glass substrate, a ceramic substrate, a silicon substrate, or the like having insulating properties and formed flat with high accuracy may be used. When the insulating substrate 100 is formed of a conductive material such as a silicon substrate, an insulating layer such as silicon oxide is preferably formed on the upper surface.

As shown in FIG. 1B, the bottom electrode unit 110 includes a first bottom electrode 110a and a second bottom electrode 110b spaced apart from each other on the insulating substrate 100. The first bottom electrode 110a and the second bottom electrode 110b together with the metal layer 120 spaced apart from each other form a capacitor.

The quality factor, one of the important figure of merit of a variable capacitor, is greatly influenced by the resistance component in the path through which a high frequency signal flows. Therefore, it is preferable that a high frequency signal does not flow through the heat driver 140 having a relatively high resistance component. Accordingly, in order to prevent the high frequency signal from flowing to the column driver 140 having a high resistance component, the bottom electrode 110 is separated into two and formed as the first bottom electrode 110a and the second bottom electrode 110b. It is preferable to configure the variable capacitor together with the metal layer 120 electrically insulated therefrom so that a high frequency signal does not flow through the column driver 140. Therefore, the high frequency signal enters through the first bottom electrode 110a of the variable capacitor and exits through the second bottom electrode 110b via the metal layer 120. By such a configuration, the high-frequency signal does not flow to the relatively high column driver 140, thereby increasing the quality factor of the variable capacitor. In addition, the capacitance between the first bottom electrode 110a and the metal layer 120 and the capacitance between the metal layer 120 and the second bottom electrode 110b may be represented by a series connection of capacitances.

The metal layer 120 is positioned on the top of the bottom electrode part 110 and is spaced apart from the bottom electrode part 110 at a predetermined distance. The metal layer 120 together with the bottom electrode 110 constitutes a variable capacitor.

The spiral inductor 130 is positioned above the metal layer 120, and faces the metal layer 120 and is spaced apart from each other by a predetermined distance. The inductor according to the first embodiment of the present invention is not limited to an inductor formed in a spiral form, and may be used as an inductor manufactured in a planar form having various shapes.

In addition, the spiral inductor 130 may include a support part 131 supporting the spiral inductor 130 on the insulating substrate 100 to be spaced apart from the metal layer 120. As shown in FIG. 1C, the support 130 may include a first pillar 131a and a second pillar 131b formed between both ends of the spiral inductor 130 and the insulating substrate 100. The first pillar 131a and the second pillar 131b may be electrically connected to both ends of the spiral inductor 130 to be used as current supply paths.

As illustrated in FIG. 1A, the column driver 140 may include a plurality of unit column drivers 140a, 140b, 140c, and 140d formed between the insulating substrate 100 and the metal layer 120.

Each of the unit column drivers 140a, 140b, 140c, and 140d may have a metal layer 120 positioned between the bottom electrode 110 and the spiral inductor 130 and spaced apart from the bottom electrode 110 and the spiral inductor 130, respectively. It may be formed between the insulating substrate 100 and the metal layer 120.

In addition, each of the unit column drivers 140a, 140b, 140c, and 140d may include a first driver 141 and a second driver 143 formed on the first driver 141, as shown in FIG. 1B. Can be.

As shown in FIG. 1B, one side of the first driver 141 is fixed to the insulating substrate 100, and the other side thereof is connected to the metal layer 120. Here, when the first driver 141 is made of an insulating material, the first driver 141 extends to be connected to the first driver of another unit column driver, as shown in FIG. 1B, and a metal layer on the extended part thereof. It may be formed to support the (120). That is, as shown in FIG. 1D, a second driving unit 143 is formed on the first driving unit 141, and the other side of the first driving unit 141 extends in the direction of the metal layer 120, and the metal layer 120 It may take a connected form. Accordingly, the second driver 143 and the metal layer 120 to which the current is applied may be thermally / electrically insulated from each other.

In addition, when the first driving unit 141 is not made of an insulating material, as shown in FIG. 1F, a separate connection unit 142 connecting the other side of the first driving unit 141 to the metal layer 120. May be formed. In this case, the connection part 142 is formed of an insulating material, and physically connects the first sphere eastern part 141 and the second driving part 143 to the metal layer 120, and serves to thermally and electrically insulate.

In addition, as shown in FIG. 1A, the thermal driver 140 is connected to the conductive part 150 to receive a current for driving the thermal driver 140. The conductive part 150 is electrically connected to both ends of the second driving part 143 configured in the thermal driving parts 140a, 140b, 140c, and 140d, and electrically connects the unit thermal driving parts 140a, 140b, 140c, and 140d with each other. It is preferred that it is formed to

The first driving unit 141 and the second driving unit 142 are preferably formed of different materials having different thermal expansion coefficients according to temperature change. Accordingly, the first driver 141 and the second driver 143 perpendicular to the insulating substrate 100 with the metal layer 120 connected to the first driver 141 by using a stress gradient according to temperature change. It moves the position in the direction (up and down).

For example, when the thermal expansion rate of the material constituting the first driver 141 is greater than the thermal expansion rate of the material constituting the second driver 143, as the temperature of the thermal driver 140 increases due to the supply of current. As shown in FIG. 1G, since the first driving unit 141 having a relatively high thermal expansion coefficient expands more than the second driving unit 143, the first driving unit 141 is bent toward the second driving unit 143. . Accordingly, the metal layers 120 connected to the first driver 141 are moved in the direction toward the spiral inductor 130. At this time, the distance between the spiral inductor 130 and the metal layer 120 is reduced, and at the same time the distance between the metal layer 120 and the bottom electrode 110 is increased. Thereafter, when the amount of current supplied decreases to decrease the temperature of the heat driver, the first driver 141 and the second driver 143 are returned to their original positions. At this time, the separation distance between the spiral inductor 130 and the metal layer 120 increases, and at the same time, the separation distance between the metal layer 120 and the bottom electrode part 110 decreases. Accordingly, the separation distance between the spiral inductor 130 and the metal layer 120 and the separation distance between the metal layer 120 and the bottom electrode 110 can be simultaneously changed.

On the contrary, when the thermal expansion rate of the material constituting the second driving unit 143 is greater than the thermal expansion rate of the material constituting the first driving unit 141, as the temperature of the thermal driving unit 140 increases due to the supply of current, Since the second driving unit 143 having a relatively high thermal expansion is expanded more than the first driving unit 141, the second driving unit 143 is bent toward the first driving unit 141. Accordingly, the metal layers 120 connected to the first driving unit 141 are moved in the direction toward the bottom electrode unit 110. At this time, the separation distance between the spiral inductor 130 and the metal layer 120 increases, and at the same time, the separation distance between the metal layer 120 and the bottom electrode part 110 decreases. Thereafter, when the amount of current supplied decreases so that the temperature of the thermal driver decreases, the first driver 141 and the second driver 143 return to their original positions. At this time, the distance between the spiral inductor 130 and the metal layer 120 is reduced, and at the same time the distance between the metal layer 120 and the bottom electrode 110 is increased. Accordingly, the separation distance between the spiral inductor 130 and the metal layer 120 and the separation distance between the metal layer 120 and the bottom electrode 110 can be simultaneously changed.

1-2. Driving Principle of Variable Passive Device Using Thermal Drive Method

In the variable passive device according to the first embodiment of the present invention, the inductance and the capacitance can be simultaneously increased or decreased. Hereinafter, a driving principle in which the variable passive device according to the first embodiment of the present invention can simultaneously vary inductance and capacitance will be described.

In addition, the driving principle of the variable passive device according to the first embodiment to be described below is the same as the driving principle that the variable passive device according to the second and third embodiments described later simultaneously vary inductance and capacitance.

2A to 2F are diagrams for explaining a driving principle in which the variable passive device according to the first embodiment of the present invention can simultaneously vary inductance and capacitance.

Prior to the description, as shown in FIG. 2A, in the initial state in which the column driver 140a is not driven, the distance between the spiral inductor 130 and the metal layer 120 is minimized, thereby increasing the inductance value of the spiral inductor 130. It is assumed that the minimum (Lmin), the separation distance between the metal layer 120 and the bottom electrode (110a, 110b) is the maximum, the series capacitance value is the minimum (Cmin = C1 / / C1).

First, the driving principle of the variable passive element whose capacitance value is variable will be described.

2B and 2C are diagrams for explaining the principle that the variable passive element varies capacitance.

As shown in FIG. 2B, when the metal layer 120 is moved in the direction of the bottom electrode parts 110a and 110b by driving the column driver 140a, the spiral inductor 130 is spaced apart from the metal layer 120. The distance is increased. At the same time, the separation distance between the metal layer 120 and the bottom electrode parts 110a and 110b is reduced. At this time, as the separation distance between the metal layer 120 and the bottom electrode parts 110a and 110b decreases, the series capacitance value of the metal layer 120 and the bottom electrode parts 110a and 110b increases (Ctuned = C2 // C2). do.

Next, as shown in FIG. 2C, when the metal layer 120 is moved in the helical inductor 130 direction by the driving of the column driver 140a, the space between the metal layer 120 and the bottom electrode parts 110a and 110b is separated. The distance is increased. At this time, as the separation distance between the metal layer 120 and the bottom electrode parts 110a and 110b increases, the series capacitance values of the metal layer 120 and the bottom electrode parts 110a and 110b decrease again (Cmin = C1 // C1). Done.

Next, the driving principle of the variable passive element whose inductance value is variable will be described.

2D and 2E are diagrams for explaining the principle that the variable passive element varies inductance value.

First, as shown in FIG. 2D, when a current is applied to the spiral inductor 130, a magnetic field 131 is formed around the spiral inductor 130 by the applied current. At this time, the magnetic field 131 generated around the spiral inductor 130 generates electromotive force in the metal layer 120 existing on the lower surface of the spiral inductor 130. As a result, an induction magnetic field 121 in a direction opposite to the direction of the magnetic field 131 formed around the spiral inductor 130 is formed in the metal layer 120. Therefore, as the metal layer 120 is positioned closer to the spiral inductor 130, the amount of the magnetic field 131 focused on the spiral inductor 131 is reduced by the induction magnetic field 121 formed in the metal layer 120, thereby reducing the inductance. Done. Therefore, when the distance between the metal layer 120 and the spiral inductor 130 is minimum, the inductance value of the spiral inductor 130 is also minimum (Lmin).

Next, in the initial state of the variable passive element illustrated in FIG. 2D, when the metal layer 120 is moved in the direction of the bottom electrode portions 110a and 110b by driving the column driver 140a as shown in FIG. 2E. The distance between the spiral inductor 130 and the metal layer 120 increases, and the distance between the metal layer 120 and the bottom electrode parts 110a and 110b decreases. In this case, as the separation distance between the metal layer 120 and the spiral inductor 130 increases, the influence of the induced magnetic field 121 formed on the metal layer 120 decreases, so that the inductance of the spiral inductor 130 increases (Ltuned). do.

In summary, as shown in FIG. 2F, when the metal layer 120 is moved in the direction of the bottom electrode parts 110a and 110b by driving the column driver 140a, the bottom electrode part 110a, The separation distance between 110b) and the metal layer 120 is reduced, thereby increasing the series capacitance value C2 // C2. At the same time, the separation distance between the metal layer 120 and the spiral inductor 130 is increased, thereby also increasing the inductance value of the spiral inductor 130 (Ltuned). After the heat driver 140a is returned to its original state, the metal layer 120 is also moved to the spiral inductor 130 again. As a result, the separation distance between the bottom electrode parts 110a and 110b and the metal layer 120 is increased, thereby decreasing the series capacitance value. At the same time, the separation distance between the metal layer 120 and the spiral inductor 130 is reduced, thereby reducing the inductance value of the spiral inductor 130.

3A is an electron micrograph showing a variable passive device actually manufactured according to the first embodiment of the present invention. 3B is an optical photomicrograph illustrating a variable passive element when a voltage of 0 V is applied through the lead of the variable passive element according to the first embodiment of the present invention. 3C is an optical photomicrograph illustrating a variable passive element when a voltage of 2 V is applied through a lead portion of the variable passive element according to the first embodiment of the present invention. FIG. 3D is an optical micrograph showing a variable passive element when a voltage of 4 V is applied through a lead portion of the variable passive element according to the first embodiment of the present invention. FIG. 3E is an optical micrograph showing a variable passive element when a 6V voltage is applied through the lead of the variable passive element according to the first embodiment of the present invention.

3B to 3E, as the driving voltage applied through the conductive part of the variable passive element is increased, the amount of current flowing through the column driving part is increased, which causes the metal layer to move in the direction of the bottom electrode part. It can be seen that the separation distance between the negative portion and the metal layer gradually decreased, and the separation distance between the spiral inductor and the metal layer gradually increased.

FIG. 4A is a graph illustrating a change in inductance value of the variable passive device as the driving voltage applied through the lead of the variable passive device shown in FIGS. 3B to 3E is increased. FIG. 4B is a graph illustrating a change in capacitance value of the variable passive element as the driving voltage applied through the lead portion of the variable passive element shown in FIGS. 3B to 3E is increased.

As shown in FIGS. 3B to 3E, the separation distance between the spiral inductor and the metal layer gradually increases as the driving voltage applied to the column driver through the lead increases. As can be seen, the inductance of the spiral inductor is increased. At the same time, the separation distance between the bottom electrode portion and the metal layer gradually decreases, and as a result, the capacitance between the metal layer and the bottom electrode portion is increased as shown in FIG. 4B.

5 is a view illustrating a variable capacitor formed by omitting a spiral inductor in a variable passive device according to a first embodiment of the present invention. 6 is a view illustrating a variable inductor formed by omitting a bottom electrode part in a variable passive device according to a first embodiment of the present invention.

5 and 6, the variable passive element according to the first embodiment of the present invention can be used as a variable capacitor or as a variable inductor according to its use.

1-3. Method of Manufacturing Variable Passive Device Using Thermal Drive Method

Hereinafter, a method of manufacturing a variable passive device according to a first embodiment of the present invention will be described in detail with reference to the accompanying drawings.

7A to 7G are views for explaining a method of manufacturing a variable passive device according to a first embodiment of the present invention.

1) step (a)

First, as shown in FIG. 7A, the bottom electrode parts 110a and 110b are formed on the insulating substrate 100.

As the insulating substrate 100, a silicon, glass, or plastic substrate may be used. When a conductive material such as silicon is used as the substrate forming material, it is preferable to form an insulating layer on the substrate before forming the bottom electrode portions 110a and 110b. In this case, the insulating layer may be thermal oxidation, low pressure chemical vapor deposition (LPCVD), plasma enhanced chemical vapor deposition (PECVD), or atmospheric pressure chemical vapor deposition (Atmospheric Pressure Chemical Vapor Deposition). , APCVD) or the like.

The bottom electrode parts 110a and 110b may be formed of gold (Au), copper (Cu), or the like having high conductivity, in order to increase the quality factor of the variable capacitor, and may be formed of the first bottom electrode 110a and the first electrode. 2 is preferably formed by separating the bottom electrode (110b). The bottom electrode parts 110a and 110b may be formed using a sputtering deposition method or a thermal evaporation method.

2) step (b)

Next, as shown in FIG. 7B, the sacrificial layer 111 is formed on the insulating substrate 100 and the bottom electrode parts 110a and 110b. The sacrificial layer 111 may be formed using a sputtering deposition method, a thermal deposition method, a plating method, or the like. The initial distance between the bottom electrode parts 110a and 110b and the metal layer 120 may be determined according to the thickness of the deposited sacrificial layer 111. As the constituent material of the sacrificial layer 111, a polymer or a metal material may be used, and a material having an etch selectivity and materials forming the structure of the variable passive device may be used.

Thereafter, the sacrificial layer 111 is patterned so that a part of the insulating substrate 100 is exposed to form the thermal driver 140 on the insulating substrate 100.

3) step (c)

Next, in order to form the first driving layer 141 as shown in FIG. 7C, an insulating material is deposited and patterned on a portion of the insulating substrate 100 from which the sacrificial layer 111 is removed and on the sacrificial layer 111. do. The insulating material constituting the first driving layer 141 is preferably a material such as silicon oxide, silicon nitride, or the like for thermal and electrical insulation between the thermal driving unit 140a and the metal layer 120. The insulating material constituting the first driving layer 141 may be formed using low pressure chemical vapor deposition, plasma chemical vapor deposition, or atmospheric pressure chemical vapor deposition.

Thereafter, a portion of the insulating substrate 100 and an insulating material deposited on the sacrificial layer 111 are patterned to form the first driver 141.

4) step (d)

As shown in FIG. 7D, a material for forming the second driving layer 143 is deposited, and the first seed layer 121 is formed. Here, the process of forming the first seed layer 121 is a process necessary for the plating process for forming the metal layer 120, and the metal layer 120 is not formed through the plating process but is formed through a sputtering deposition method or a thermal deposition method. Can be omitted. The second driver 143 and the first seed layer 121 may be formed using a sputtering deposition method and a thermal deposition method, respectively.

The material deposited to form the second driving layer 143 preferably has a thermal expansion coefficient different from that of the first driving layer 141. In addition, the second driving layer 143 may be the first driving layer 141 so that the first driving layer 141 and the second driving layer 143 may be bent in a vertical direction with respect to the insulating substrate 100 as the temperature changes. It is preferably formed by selecting a material having a stress gradient with ().

As illustrated in FIGS. 1A and 1B, the material deposited to form the second driving layer 143 includes a plurality of thermal driving units 140a including the first driving layer 141 and the second driving layer 143. Patterned to form dogs.

5) step (e)

As shown in FIG. 7E, a metal material is deposited on the insulating substrate 100 and patterned so as not to be contacted with the second driving layer 143. The patterned metal material is formed of the metal layer 120 on the first driving layer 141 positioned on the bottom electrode parts 110a and 110b. Here, as the metal material forming the metal layer 120, a metal material such as gold and copper having high conductivity may be used for high quality factor of the variable capacitor and the variable inductor. The metal layer 120 may be formed through a sputtering deposition method, a thermal deposition method or a plating method.

6) step (f)

As shown in FIG. 7F, the first photoresist 123 is formed thick so that the metal layer 120 is completely covered. An initial separation distance between the spiral inductor 130 and the metal layer 120 may be determined according to the thickness of the first photoresist 123. Subsequently, the spiral inductor 130 is spaced apart from the metal layer 120 and patterned to form a pattern of a support portion (not shown) indicated on the insulating substrate 100. In this case, the first photoresist 123 may be patterned to form a pattern of a support part (not shown) which is formed perpendicular to the insulating substrate 100 by using an etching process.

7) step (g)

A support part capable of depositing and patterning a metal material on the patterned first photoresist 123 through step (f) described above and connected to both sides of the subsequent spiral inductor 130 to support the spiral inductor 130 ( Not shown). The support portion (not shown) may be formed through a plating process. Thereafter, the second seed layer 131 may be formed on the first photoresist 123. The second seed layer 131 is a process necessary for the plating process for forming the spiral inductor 130. The second seed layer 131 may be formed through a sputtering deposition method and a thermal deposition method.

8) step (h)

As shown in FIG. 7F, the second photoresist 133 is formed on the second seed layer 131 formed through the first photoresist 123 or (g). Thereafter, the second photoresist 133 is patterned to form a pattern of the spiral inductor 130.

9) (i) step

Thereafter, a metal material is deposited and patterned on the patterned second photoresist 133 through step (h) to form a spiral inductor 130. The spiral inductor 130 may be formed through a plating process.

10) step (i)

Finally, as shown in FIG. 7G through the wet etching process and the dry etching process, the second passive photoresist 133, the first photoresist 123, and the sacrificial layer 111 may be sequentially removed to remove the variable passive device. Form.

2. Variable Passive Device Using Electrostatic Drive

Hereinafter, with reference to the accompanying drawings will be described in detail a variable passive device according to a second embodiment of the present invention.

2-1. Configuration of Variable Passive Device Using Electrostatic Drive Method

8A is a top view illustrating a configuration of a variable passive device according to a second embodiment of the present invention. FIG. 8B is a cross-sectional view of the variable passive element illustrated in FIG. 8A in a direction A-A '. FIG. 8C is a cross-sectional view illustrating the variable passive element illustrated in FIG. 8A in a direction BB ′.

8A to 8C, the variable passive device according to the second exemplary embodiment of the present invention may include an insulating substrate 800, a bottom electrode 810, a metal layer 820, a spiral inductor 830, and an electrostatic driving unit ( 840).

As the insulating substrate 800, a glass substrate, a ceramic substrate, a silicon substrate, or the like having insulating properties and formed flat with high accuracy may be used. When the insulating substrate 800 is conductive like a silicon substrate, an insulating layer such as a silicon oxide film is preferably formed on the upper surface.

The bottom electrode part 810 is formed on the insulating substrate 800.

The metal layer 820 is positioned above the bottom electrode part 810 and is spaced apart from the bottom electrode part 810 by a predetermined distance. The metal layer 820 together with the bottom electrode 810 constitutes a variable capacitor.

The spiral inductor 830 is positioned above the metal layer 820 and is spaced apart from the metal layer 820 by a predetermined distance. The inductor according to the second embodiment of the present invention is not limited to the inductor formed in a spiral form, and may be used as the inductor having a planar shape having various forms.

In addition, as illustrated in FIG. 8A or 8C, the spiral inductor 830 may include a support part 831 supporting the spiral inductor 830 on the insulating substrate 800 to be spaced apart from the metal layer 820. . The support part 830 may include a first pillar 831a and a second pillar 831b respectively formed between both ends of the spiral inductor 830 and the insulating substrate 800. The first pillar 831a and the second pillar 831b may be electrically connected to both ends of the spiral inductor 830 to be used as a current supply path.

The electrostatic driving unit 840 includes a plurality of unit electrostatic driving units 840a, 840b, 840c, and 840d. Each of the unit electrostatic driving units 840a, 840b, 840c, and 840d is formed such that one side thereof is electrically connected to the metal layer 820, and the other side thereof is fixed to the insulating substrate 800. The unit electrostatic driving units 840a, 840b, 840c, and 840d are respectively formed between the insulating substrate 800 and the metal layer 820 so that the metal layer 820 is between the bottom electrode portion 810 and the spiral inductor 830. The 810 and the spiral inductor 830 serve to support each other at a predetermined distance from each other.

Hereinafter, the mechanical driving principle of the variable passive element according to the second embodiment of the present invention will be described.

The variable passive device according to the second embodiment of the present invention is mechanically operated using an electrostatic driving method.

First, as shown in FIG. 8B, the metal layer 820 receives a driving voltage through the electrostatic driving units 840a and 840b. At this time, when the applied voltage increases, the voltage difference between the bottom electrode portion 810 and the metal layer 820 increases, and the electrostatic force generated between the bottom electrode portion 810 and the metal layer 820 increases. At this time, the electrostatic force generated is an electrostatic attraction, and as the electrostatic attraction increases, the metal layer 820 moves in the direction of the bottom electrode part 810. Accordingly, the separation distance between the metal layer 820 and the bottom electrode portion 810 is reduced. At the same time, as the distance between the metal layer 820 and the bottom electrode 810 decreases, the distance between the metal layer 820 and the spiral inductor 830 increases.

On the contrary, when the voltage applied to the metal layer 820 through the electrostatic driving units 840a and 840b is reduced, the voltage difference between the metal layer 820 and the bottom electrode part 810 is reduced, so the metal layer 820 and the bottom electrode part are reduced. The electrostatic force between 810 is reduced. In this case, the metal layer 820 moves to its original position. At this time, the metal layer 820 is moved in the direction of the spiral inductor 830, and thus the separation distance between the metal layer 820 and the spiral inductor 830 is reduced, so that the metal layer 820 and the bottom electrode 810 The separation distance will increase.

As such, when the metal layer 820 moves in the vertical direction (up and down) with respect to the insulating substrate 800, the separation distance between the metal layer 820 and the bottom electrode part 810, the metal layer 820, and the spiral inductor 830. ) May be controlled by the electrostatic driver 840 connected to the metal layer 820. Therefore, the electrostatic driving unit 840 is preferably formed to have an elastic force and a restoring force.

2-2. Driving Principle of Variable Passive Device Using Electrostatic Driving Method

The variable passive device according to the second embodiment of the present invention can increase or decrease inductance and capacitance at the same time.

The driving principle that the variable passive device according to the second embodiment of the present invention can simultaneously vary the inductance and the capacitance may include a separation distance between the metal layer 820 and the bottom electrode 810, and the metal layer 820 and the spiral inductor 830. The variation of the separation distance between the two and the same, and the principle that the more specific inductance and capacitance are variable at the same time is the same as the principle that the variable passive element according to the first embodiment of the present invention described above simultaneously inductance and capacitance.

3. Variable Passive Device Using Comb Electrode

Hereinafter, with reference to the accompanying drawings will be described in detail a variable passive device according to a third embodiment of the present invention.

3-1. Structure of Variable Passive Device Using Comb Electrode

9A is a top view illustrating a configuration of a variable passive device according to a third embodiment of the present invention. FIG. 9B is a diagram illustrating a structure of a solenoid inductor in the variable passive device illustrated in FIG. 9A. FIG. 9C is a cross-sectional view of the variable passive element BB ′ shown in FIG. 9A.

9A to 9C, the variable passive device according to the third exemplary embodiment of the present invention may include an insulating substrate 900, a solenoid inductor 910, a fixed comb electrode 920, and a floating comb electrode 930. ).

As the insulating substrate 900, a glass substrate, a ceramic substrate, a silicon substrate, or the like having insulating properties and formed flat with high accuracy may be used. When the insulating substrate 900 is conductive like a silicon substrate, an insulating layer such as a silicon oxide film is preferably formed on the upper surface.

As illustrated in FIG. 9B, the solenoid inductor 910 is formed on the insulating substrate 900 and includes a first coil part 910a, a second coil part 910b, and a third coil part 910c. It may be made in the form of a solenoid. The solenoid type inductor 910 according to the third exemplary embodiment of the present invention is not limited to the solenoid type formed of the first to third coil parts 910a, 910b, and 910c, as shown in FIGS. 9A and 9B. In addition, common solenoid type inductors can be used.

The fixed comb electrode part 920 is fixed on the insulating substrate 900 and includes a plurality of comb electrodes formed in the direction of the solenoid type inductor 910.

The floating comb electrode part 930 is positioned between the solenoid type inductor 910 and the fixed comb electrode part 920 and is formed to be movable in the direction of the solenoid type inductor 910 and the fixed comb electrode part 920.

The flow comb electrode part 930 includes a plurality of first flow comb electrodes 931a, a plurality of second flow comb electrodes 931b, a support part 933, and an elastic part 935.

The first flow comb electrodes 931a are positioned between the coil and the coil of the solenoid inductor 910. That is, the first flow comb electrodes 931a are positioned between the coil and the coil of the solenoid inductor 910 so that the central cross-sectional area of the solenoid inductor 910 and some cross-sectional areas of the first flow comb electrodes 931a overlap. It is. The second flow comb electrodes 931b are positioned between the comb electrode and the comb electrode of the fixed comb electrode unit 920. That is, the second flow comb electrodes 931b are connected to the comb electrode of the fixed comb electrode 920 so that the cross-sectional area of the comb electrode of the fixed comb electrode 920 and some cross-sectional areas of the second flow comb electrodes 931b overlap with each other. It is located between comb electrodes.

A support part 933 is formed between the first flow comb electrodes 931a and the second flow comb electrodes 931b, so that the first flow comb electrodes 931a and the second flow comb electrodes 931b are respectively formed. It is fixed by the support part 933. The second flow comb electrodes 931b together with the fixed comb portion 920 constitute a plurality of capacitors, and the second flow comb electrodes 931b have a driving voltage for mechanical driving of the flow comb electrode 930. Is approved.

The elastic part 935 is formed such that the support part 933 is connected to the insulating substrate 900. The elastic part 935 has a first elastic means 935a connecting between one side of the support part 933 and the insulating substrate 900, and a second connecting part between the other side of the support part 933 and the insulating substrate 900. It may be composed of an elastic means (935b). In addition, the first flow comb electrodes 931a, the second flow comb electrodes 931b, and the support part 933 may be spaced apart from the insulating substrate 900 by a connection with the elastic part 935. The elastic portion 935 can be used as an elastic portion according to the third embodiment of the present invention, as long as it is a structure capable of mechanical spring operation.

3-2. Driving principle of variable passive element using comb electrode

Hereinafter, the driving principle of the variable passive element according to the third embodiment of the present invention will be described.

First, when a current is applied to the solenoid inductor 910, a magnetic field focused on the center cross-sectional area of the solenoid inductor 910 is formed. In this case, an induction magnetic field opposite to the direction of the magnetic field focused on the central cross-sectional area of the solenoid inductor 910 is generated in the first flow comb electrode 931a between the coil and the coil of the solenoid inductor 910. This induced magnetic field reduces the strength of the magnetic field focused on the central cross-sectional area of the solenoid inductor 910. Therefore, when the overlapping area between the solenoid type inductor 910 and the first flow comb electrode 931a is reduced, the inductance of the solenoid type inductor 910 increases, and conversely, when the overlapping area is increased, the solenoid type inductor 910 Inductance is reduced. Accordingly, the inductance of the variable passive element may be determined according to the overlapping area between the center cross-sectional area of the solenoid inductor 910 and the first flow comb electrode 931a.

In addition, the capacitance of the variable passive element increases in proportion to the overlapping area between the second flow comb electrode 931b and the fixed comb electrode unit 920. Therefore, as the area overlapping between the second flow comb electrode 931b and the fixed comb electrode unit 920 increases, the capacitance increases.

9A and 9C, it is assumed that the initial position of the floating comb electrode part 930 is further biased to the solenoid inductor 910.

First, when a driving voltage is applied to the second flow comb electrode 931b and the applied voltage is increased, an electrostatic force is generated between the second flow comb electrode 931b and the fixed comb electrode 920. In this case, the electrostatic force is an electrostatic attraction, and as shown in FIG. 9D, the flow comb electrode part 930 moves in the direction of the fixed comb electrode part 920. Accordingly, as shown in FIG. 9E, the area where the center cross-sectional area of the solenoid inductor 910 and the first flow comb electrode 931a overlap is reduced, thereby increasing the inductance of the solenoid inductor 910. do. At the same time, while the overlapping area between the second flow comb electrode 931b and the fixed comb electrode part 920 increases, the capacitance of the capacitor including the second flow comb electrode 931b and the fixed comb electrode part 920 also increases. Done.

On the contrary, when the intensity of the voltage applied to the second flow comb electrode 931b is reduced, the electrostatic force generated between the second flow comb electrode 931b and the fixed comb electrode unit 920 is weakened, thereby the flow comb electrode The unit 930 gradually returns to its original position. Accordingly, the area where the center cross-sectional area of the solenoid type inductor 910 overlaps with the first flow comb electrode 931a increases again, thereby decreasing the inductance of the solenoid type inductor 910. At the same time, the overlapping area between the second flow comb electrode 931b and the fixed comb electrode part 920 is reduced, and thus the capacitance of the capacitor including the second flow comb electrode 931b and the fixed comb electrode part 920 is also reduced. Decreases together.

Therefore, as the position of the floating comb electrode 930 moves in the horizontal direction, the inductance and the capacitance may increase or decrease at the same time.

According to the present invention, since the inductance and the capacitance can be simultaneously changed as a single device, the required area can be minimized compared to the method of separately manufacturing the variable inductor and the variable capacitor, thereby reducing the manufacturing cost.

In addition, since the variable capacitor and the variable inductor operate as one drive circuit, the drive circuit can be integrated.

In addition, in applications such as matching networks, both capacitive and inductive loads can be matched, providing flexibility in circuit design and optimization.

In addition, when used in a frequency variable element such as an LC-tank and a variable filter of a voltage controlled oscillator, the center frequency variable range can be improved compared to the case of using only one element of a variable capacitor or a variable inductor.

As described above, those skilled in the art to which the present invention pertains will understand that the present invention may be implemented in other specific forms without changing the technical spirit or essential features.

Therefore, the embodiments described above are to be understood in all respects as illustrative and not restrictive, and the scope of the present invention is indicated by the following claims rather than the above description, and the meaning and scope of the claims And all changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

1A to 1G show a variable passive element according to a first embodiment of the present invention.

2A to 2F illustrate a driving principle of a variable passive device according to an embodiment of the present invention.

3A is an electron micrograph showing a variable passive device according to a first embodiment of the present invention.

3b to 3e are optical micrographs showing the operation of the variable passive device according to the applied voltage.

Figure 4a is a graph showing the change in inductance of the variable passive device according to the first embodiment of the present invention.

4B is a graph showing capacitance variation of the variable passive device according to the first embodiment of the present invention.

5 is a view showing a variable capacitor in a variable passive device according to a first embodiment of the present invention.

6 illustrates a variable inductor in a variable passive device according to a first embodiment of the present invention.

7A to 7G illustrate a method of manufacturing a variable passive device according to a first embodiment of the present invention.

8A-8C illustrate a variable passive element according to a second embodiment of the present invention.

9A to 9E illustrate a variable passive device according to a third embodiment of the present invention.

********** Explanation of symbols for the main parts of the drawings **********

100, 800, 900: insulation board

110, 810: bottom electrode portion

120, 820: metal layer

130 and 830: spiral inductors

140: thermal drive unit

840: electrostatic drive unit

910: Solenoid Inductor

920: fixed comb electrode unit

930: the floating comb electrode

Claims (13)

Insulating substrate; A bottom electrode formed on the insulating substrate; A metal layer formed on the bottom electrode portion to be spaced apart from the bottom electrode portion and forming a capacitor together with the bottom electrode portion; A spiral inductor formed on the metal layer to be spaced apart from the metal layer; And A heat driving part formed between the insulating substrate and the metal layer to support the metal layer so as to be spaced apart from the bottom electrode part and the spiral inductor, and to move the metal layer in a vertical direction with respect to the insulating substrate in response to a temperature change; , Variable passive device characterized in that the inductance and capacitance is changed at the same time as the metal layer is moved. The method of claim 1, And a support for supporting the spiral inductor from the insulating substrate so as to be spaced apart from the metal layer. The method of claim 1, The bottom electrode portion, A variable passive device comprising a first bottom electrode and a second bottom electrode formed on the insulating substrate spaced apart. The method of claim 1, The heat drive unit, A plurality of unit heat driving units respectively formed between the insulating substrate and the metal layer; Each of the unit heat driver, A first driver having one side fixed to the insulating substrate and the other side connected to the metal layer and including an insulating material; A second driver formed on the first driver and insulated from the metal layer; And A conductive wire part electrically connected to both ends of the second driving part; And the second driver is made of a material different from the coefficient of thermal expansion of the first driver. The method of claim 1, The heat drive unit, A plurality of unit heat driving units respectively formed between the insulating substrate and the metal layer; Each of the unit heat driver, A first driver having one side fixed to the insulating substrate; A second driver formed on the first driver; A connection part connecting between the other side of the first driving part and the metal layer and formed of an insulating material; And A conductive wire part electrically connected to both ends of the second driving part; And the first driving unit and the second driving unit are made of a material having a different thermal expansion coefficient. Insulating substrate; A bottom electrode formed on the insulating substrate; A metal layer formed on the bottom electrode portion to be spaced apart from the bottom electrode portion and forming a capacitor together with the bottom electrode portion; A spiral inductor formed on the metal layer to be spaced apart from the metal layer; And Is formed between the insulating substrate and the metal layer to support the metal layer to be spaced apart from the bottom electrode portion and the spiral inductor, and to control the separation distance of the metal layer and the bottom electrode portion and the separation distance of the metal layer and the spiral inductor. Including an electrostatic drive unit, The metal layer is moved in a vertical direction with respect to the insulating substrate according to the voltage difference with the bottom electrode, Variable passive device, characterized in that the inductance and capacitance is simultaneously changed as the metal layer is moved. The method of claim 6, And a support for supporting the spiral inductor from the insulating substrate so as to be spaced apart from the metal layer. The method of claim 6, The electrostatic drive unit, A plurality of unit electrostatic driving units respectively formed between the insulating substrate and the metal layer, The unit electrostatic driving units are electrically connected to the metal layers, respectively. The metal layer is applied to the voltage through the electrostatic driving unit, the variable passive element is moved by the electrostatic force generated in accordance with the voltage difference with the bottom electrode. delete delete delete A method of manufacturing the variable passive device of claim 1, (a) forming the bottom electrode part on an insulating substrate; (b) forming a sacrificial layer on the insulating substrate and the bottom electrode portion, and patterning the sacrificial layer to expose a portion of the insulating substrate; (c) depositing and patterning an insulating material on a portion of the insulating substrate and the sacrificial layer to form a first driving layer; (d) depositing a material having a thermal expansion coefficient different from the thermal expansion coefficient of the first driving layer on the first driving layer to form a second driving layer, and the heat composed of the first driving layer and the second driving layer Patterning the second driving layer to form a plurality of driving units to form the plurality of column driving units; (e) depositing a metal material on the insulating substrate and patterning the metal material so as not to contact the second driving layer so as to be in contact with the second driving layer to form the metal layer on the first driving layer located above the bottom electrode part; (f) forming a first photoresist on the insulating substrate so that the metal layer is covered, spaced apart the spiral inductor from the metal layer, and patterning a pattern of a support for supporting the insulating substrate; (g) depositing and patterning a metal material on the patterned first photoresist to form the support; (h) forming a second photoresist on the first photoresist and patterning the pattern of the spiral inductor to be formed; (i) depositing and patterning a metal material on the patterned second photoresist to form the spiral inductor; And (j) sequentially removing the second photoresist, the first photoresist, and the sacrificial layer through an etching process Method of manufacturing a variable passive device comprising a. The method of claim 12, In step (a), And forming the second bottom electrode part including a first bottom electrode and a second bottom electrode spaced apart from each other on the insulating substrate.

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