KR100339394B1 - microswitches and production method using electrostatic force - Google Patents

Abstract

The present invention is to provide a micro switch and a manufacturing process using the electrostatic force to increase the yield using dry etching processes (dry etching processes), a ground plane formed at a predetermined interval on the substrate, A lower electrode formed with a predetermined distance between the ground planes, an upper electrode formed at an arbitrary distance on the lower electrode and moving up and down by an electrostatic force with the lower electrode, and fixed to the ground plane and having elasticity; It consists of a hinge supporting the upper electrode, is driven using a low voltage, high yield because of the dry etching treatment, high current transfer is possible because of the use of an electroplated metallic film It can also be used for power.

Description

Microswitches and production method using electrostatic force

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electronic systems, and more particularly, to a micro switch driven using electrostatic force and a method of manufacturing the same.

Current electronic systems are becoming smaller and lighter, and many switches are used to control electrical signals such as closing, restoring, and switching of electric circuits.

The most commonly used switches are semiconductor switch such as FET (Field Effect Transistor) or PIN diode.

However, the semiconductor switches have disadvantages such as high power loss when they are operated, and incomplete isolation.

In order to make up for the shortcomings of such semiconductor switches, many studies of micromechanical switches have been conducted recently.

The micro switch according to the related art described above has the following problems.

First, there is a problem that the yield is low because the driving voltage is large during operation, and is manufactured using wet etching processes.

Second, the thickness of the metallic film used is so small that it cannot be used for power applications.

Therefore, the present invention has been made to solve the above problems, the low-voltage driving is possible, and the purpose is to increase the yield using dry etching processes (dry etching processes).

Still another object of the present invention is to enable high current transfer using a plated metal film to facilitate use in power applications.

1 is a configuration diagram of four types of micro switches according to the present invention;

2 (a) is a schematic diagram of a resistive switch configuration according to the present invention

(b) is a capacitive switch configuration according to the present invention

3 is a hinge configuration according to the present invention

4 is a configuration diagram of the connection between the upper electrode and the hinge according to the present invention

5 is a manufacturing process diagram according to the first embodiment of the micro switch using the electrostatic force according to the present invention;

6 is a cross-sectional view of the switch formed through the process of FIG. 5 with the hinge of FIG.

7 is a manufacturing process diagram according to the second embodiment of the micro switch using the electrostatic force according to the present invention;

8 is a manufacturing process diagram according to the second embodiment of the micro switch using the electrostatic force according to the present invention;

* Explanation of symbols for main parts of the drawings

10 lower electrode 13 insulating film

20: ground plane 30: hinge

40: upper electrode 50: substrate

60, 61: seed layer

70, 71, 72, 73: photoresist or the polyimide

Features of the micro-switch and manufacturing method using the electrostatic force according to the present invention for achieving the above object is a ground plane formed with a predetermined distance on the substrate, a lower electrode formed with a predetermined distance between the ground plane, and The upper electrode is formed at an arbitrary distance on the lower electrode and moves up and down by an electrostatic force with the lower electrode, and a hinge fixed to the ground plane and having elasticity to support the upper electrode.

Another feature of the present invention is to form a plurality of molds on a substrate, the process of depositing a first metal (metals) in the formed plurality of molds to form a lower electrode and a ground plane, coating and patterning the sacrificial layer on the front surface Forming a plurality of via molds and depositing a second metal in the plurality of via molds; coating a seed layer on the second metal and forming a mold to form third metals in the mold Forming a hinge to form a hinge, and forming a plurality of molds for forming a scalpel of the upper electrode on the hinge, and depositing fourth metals in the plurality of molds to form an upper electrode having a mass. It includes a step of selectively etching the sacrificial layer and the seed layer.

Another feature of the present invention is to form a pattern after coating an insulating film on the ground plane in the case of a capacitive switch, and a plurality of ground planes in the case of a resistive switch.

The operation according to the characteristics of the present invention can be driven using a low voltage, high yield due to dry etching processes, and high current transfer due to the use of an electroplated metallic film. This can be used for power.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

A preferred embodiment of the micro switch and the manufacturing method using the electrostatic force according to the present invention will be described with reference to the accompanying drawings.

1 is a configuration diagram of four types of microswitches according to the present invention. Referring to FIG. 1, a ground plane 20 formed at a predetermined interval on a substrate is formed at a predetermined distance from the ground plane 20. A lower electrode 10 used as a signal line, an upper electrode 40 formed at an arbitrary distance on the lower electrode 10, and moved up and down by an electrostatic force, the ground plane 20 and the upper electrode 40. The hinge 30 is configured to support the upper electrode 40 with elasticity.

The upper electrode 40, the hinge 30, and the ground plane 20 configured as described above are electrically connected to each other.

Accordingly, when a driving voltage is applied to the ground plane 20 and the lower electrode 10, current flows through the ground plane 20 and the hinge 30, and at this time, the lower electrode 10. Electrostatic force is generated between the upper electrode 40 and the upper electrode 40 so that the upper electrode 40 having a predetermined distance from the lower electrode 10 moves in the up and down direction of the lower electrode 10.

The structure of the switch shown in FIGS. 1 a, b, c, and d is a bridge type that the hinge 30 symmetrically holds with respect to the upper electrode 40.

However, such a bridge type structure can be modified through the switch manufacturing process.

That is, unless one of the hinges 30 symmetrical with respect to the upper electrode 40 is made, the switch may be a cantilever type and driven at a lower voltage than the switch of the bridge type.

As described above, the characteristics of the switch vary depending on the number of hinges 30. Accordingly, the switch according to the present invention includes one, two, or a plurality of hinges.

Referring to FIG. 1D, the signal lines and the lower electrode 10 are divided in structure, and unlike the switches shown in FIGS. 1A, 1B and 3C, the signal line is not used as the lower electrode 10.

2 is a configuration diagram of a lower electrode according to the present invention, FIG. 2 (a) is a resistive switch configuration, and FIG. 2 (b) is a capacitive switch configuration.

The resistive switch shown in FIG. 2 (a) connects the first signal line 11 and the second signal line 12 in which the upper electrode 40, which is moved when the switch is turned on, is disconnected, thereby connecting the first signal line 11 to the first signal line 11. The flow of current in the second signal line 12 is controlled.

In the capacitive switch shown in FIG. 2B, the first signal line 11 and the second signal line 12 are connected to each other, and an insulator 13 is formed on the first and second signal lines 11 and 12. It is.

Thus, when the switch is turned on, the upper electrode 40, which is moved, is grounded with the insulator 13 so as to change impedance between the first and second signal lines 11 and 12, so that the first signal line 11 and the first signal line 11 and 12 are moved. 2 Controls the flow of current in the signal line 12.

3 is a configuration of the hinge according to the present invention, Figure 3 (a) is a general structure and Figure 3 (b) (c) is a structure modified from the shape of Figure 3 (a).

As shown in (b) and (c) of FIG. 3, the shape of the hinge 30 may be changed into an 'L' shape or a zigzag shape to support the movement of the upper electrode 40. By reducing residual stresses, a low driving voltage can be obtained.

And Figure 4 is a connection diagram of the upper electrode and the hinge according to the invention, Figure 4 (a) is a configuration diagram without the mass (mass) in the upper electrode 40, Figure 4 (b) (c) (d) is a configuration diagram in which a mass is placed on the upper electrode 40, and a hinge diagram 30 is connected to each position of the mass.

As shown in FIG. 4 (b) (c) (d), the upper electrode 40 has a mass so that the upper electrode 40 and the lower electrode 10 are grounded due to switching. The upper electrode 40 moves uniformly without bending, so that the change in impedance can be changed linearly with respect to the applied voltage.

The switch proposed in the present invention uses electroplating, and various metals such as Au, Cu, Ni, and NiFe are used.

When described in detail with reference to the accompanying drawings, a micro switch and a manufacturing process using an electrostatic force according to the present invention configured as follows.

First embodiment

5 is a process diagram illustrating a manufacturing process according to the first embodiment of the micro switch using the electrostatic force according to the present invention. As shown in FIG. 5A, the seed layer 60 is formed to be electrically connected to the substrate 50.

After coating and curing a polyimide 70 on a substrate on which the seed layer 60 is formed, a plurality of molds 10 and 20 are formed by using a patterned aluminum (Al) mask and dry etching. ).

Subsequently, the aluminum mask is removed and metals having high conductivity, such as Au or Cu, are deposited using electroplating in the formed molds 10 and 20.

The pattern formed as described above forms the lower electrode 10 and the ground plane 20.

In this case, when the structure of the switch is a capacitive switch, the insulating layer 13 is formed on the lower electrodes 10 connected to each other so that the switching is performed using the impedance change in the lower electrode 10.

Thus, as shown in FIG. 5B, the insulating film 13 is coated on the entire surface and patterned so that the insulating film 13 remains only on the lower electrode 10.

In this case, the insulating layer 13 uses a polymer, silicon nitride, silicon oxide, or a ferroelectric material having a high dielectric constant.

And when the structure of the switch is a resistive switch, as shown in the configuration shown in Figure 8 of the metal deposited by the electroplating to form a metal corresponding to the lower electrode 10, respectively, the separated lower electrode 10 is later The connection is made via the upper electrode 40 to be produced.

Therefore, the insulating film 13 necessary for the capacitive switch is not necessary for the resistive switch.

Subsequently, a photoresist 71 or a polyimide 71 is coated on the entire surface, as shown in FIG. 5C, and then cured and the photoresist 71 on the ground plane 21. ) Or the polyimide 71 is selectively etched to form a via mold 21 at a portion corresponding to the ground plane 21.

In this case, the photoresist 71 forms the via mold 21 through a photolithography process, and the polyimide 71 forms the via mold 21 using a dry etching process. ).

Au or Cu is deposited using the electroplating into the via mold 21 formed as described above.

Subsequently, a thin seed layer 61 is coated on the front surface as shown in FIG. 5 d, and then a photoresist 72 or a polyimide 72 is coated on the front surface.

The photoresist 72 or polyimide 72 of the seed layer 61 may be selectively etched and cured to form a mold for the hinge 30.

Then, as shown in FIG. 5E, a hinge 30 is formed by depositing Ni, NiFe alloys, Au, Cu, Ag, Al, etc. using electroplating in the formed mold.

In this case, the hinge 30 may be formed by patterning the deposited metal by sputtering or evaporation.

Subsequently, as illustrated in FIG. 5F, a plurality of molds are formed on the hinge 30 using the photoresist 73 to form upper electrodes, and metals having high conductivity are deposited in the plurality of molds. An upper electrode 40 having a mass is formed.

Finally, the photoresist 70, 71, 72, 73, the polyimide 70, 71, 72, 73, and seed layers 60, 61 are removed as shown in FIG. 5 g. By selectively etching, a switch is fabricated.

In this case, the photoresist is etched using a dry etching treatment, and the polyimide is etched using a dry etching treatment or acetone.

6 illustrates a cross-sectional view of a switch formed through the process of FIG. 5 with the hinge of FIG. 3C.

Second embodiment

7 is a flowchart illustrating a manufacturing process according to the second embodiment of the micro switch using the electrostatic force according to the present invention. Referring to FIG. 7, the lower electrode 10 and the ground plane 20 are formed in the first embodiment. 5a to 5c, the descriptions thereof are the same, and will be omitted.

The characteristics of the resistive switch and the capacitive switch are also the same.

Subsequently, as shown in FIG. 7D, the seed layer 61 is coated on the entire surface, a photoresist is coated on the seed layer 61, and then selectively etched to form a mold 72a on the lower electrode 10. 20) forms via mold 72b.

As shown in FIG. 7E, metals having high conductivity are deposited in the via mold 72b and the mold 72a to form the upper electrode 40.

Subsequently, the photoresist is coated on the upper electrode 40 and then selectively etched to form a mold 73a.

As shown in FIG. 7F, the hinge 30 is formed by depositing metals having high conductivity such as Ni, NiFe plywood, Au, Cu, Ag, and Al using electroplating in the mold 73a.

In this case, the hinge 30 may be formed by patterning the deposited metal by sputtering or evaporation.

And finally, the photoresist 70, 71, 72, 73, the polyimide 70, 71, 72, 73, and seed layers 60, 61, as shown in FIG. 7 g. By selectively etching, a switch is fabricated.

In this case, the photoresist is etched using a dry etching treatment, and the polyimide is etched using a dry etching treatment or acetone.

Third embodiment

8 is a process chart showing a manufacturing process according to the third embodiment of the micro switch using the electrostatic force according to the present invention, the first and second embodiments are a manufacturing process diagram of the capacitive switch, the third embodiment of the resistive switch It is a manufacturing process chart.

Therefore, referring to FIG. 8, the manufacturing process is the same as the first embodiment, and the difference is as follows.

In the process of FIG. 5A according to the first embodiment, the lower electrode 10 formed as one is formed by separating a plurality of lower electrodes 10 as shown in FIG. 8A.

And the insulating film 13 formed in FIGS. 5B-5G according to 1st Example was not deposited.

In addition, the manufacturing process according to the second embodiment may also be manufactured by the manufacturing process as described above.

Micro switch and manufacturing process using the electrostatic force according to the present invention as described above has the following effects.

First, it is driven using a low voltage, and the yield is high because it uses a dry etching process, and because of the use of an electroplated metallic film, high current can be transmitted and used for power.

Second, it can be used for military purposes in high frequency bands or in wireless communications systems, phase shifters, antenna tuners, receivers, transmitters, commercials such as phased array antennas, and the like.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (18)

A ground plane formed on the substrate at a predetermined interval; A lower electrode formed with a predetermined distance between the ground planes, An upper electrode formed at an arbitrary distance on the lower electrode and moving up and down by an electrostatic force with the lower electrode; And a hinge fixed to the ground plane and configured to have any one of I, L, and zigzag shapes to support the upper electrode with elasticity. The method of claim 1, Micro switch using the electrostatic force, characterized in that the lower electrode is used as a signal line delete The method of claim 1, The hinge is a micro switch using an electrostatic force, characterized in that formed in plurality. The method of claim 1, The upper electrode is a micro switch using an electrostatic force, characterized in that it has a mass (mass) structure to move uniformly without bending by switching. Forming a plurality of molds on a substrate and depositing first metals in the formed plurality of molds to form a lower electrode and a ground plane, Coating and patterning a sacrificial layer on the entire surface to form a plurality of via molds and depositing a second metal in the plurality of via molds; Coating a seed layer on the second metal and forming a mold to deposit a third metal in the mold by electroplating to form a hinge; Forming a plurality of molds for forming a scalpel of the upper electrode on the hinge, and depositing fourth metals by electroplating in the plurality of molds to form an upper electrode having a mass; And selectively etching the sacrificial layer and the seed layer using a dry etching process. The method of claim 6, The micro switch manufacturing method using the electrostatic force, characterized in that for forming a seed layer electrically connected to the substrate. The method of claim 6, The micro switch manufacturing method using the electrostatic force, characterized in that for dry etching the sacrificial layer (dry etching). The method of claim 6, The sacrificial layer using a photoresist or polyimide of any one of the micro switch manufacturing method using the electrostatic force, characterized in that. The method of claim 6, In the case of a capacitive switch, the step of forming the lower electrode and the ground plane further comprises the step of patterning after coating the insulating film on the ground plane micro-switch manufacturing method using the electrostatic force. The method of claim 9, The insulating film is a method of manufacturing a micro switch using an electrostatic force, characterized in that any one of a polymer, silicon nitride, silicon oxide, or a ferroelectric material. The method of claim 6, In the case of a resistive switch, a micro switch manufacturing method using an electrostatic force, characterized in that the plurality of ground planes are formed in the process of forming the lower electrode and the ground plane. The method of claim 6, The first to fourth metal is any one selected from Ag, Al, Au, Cu, Ni, NiFe alloy (alloy) of the micro switch manufacturing method using an electrostatic force, characterized in that. delete The method of claim 6, In the etching process, the polyimide of the sacrificial layer using a dry etching process (dry etching process), and the photoresist is removed using a dry etching process or acetone, characterized in that the micro switch manufacturing method using the electrostatic force. Forming a plurality of molds on a substrate, and depositing first metals for forming a lower electrode and a ground plane in the formed plurality of molds, Coating and patterning a sacrificial layer on the entire surface to form a plurality of via molds and depositing a second metal in the plurality of via molds; A seed layer is coated on the second metal, a sacrificial layer is coated on the seed layer, and a pattern is formed to form a mold on the lower electrode and a via mold on the ground plane, thereby forming a third metal for forming an upper electrode in the mold. metals) process, Forming a mold on the upper electrode by using a photoresist, and depositing fourth metals for forming a hinge in the mold; And selectively etching the sacrificial layer and the seed layer. The method of claim 15, In the case of a capacitive switch, the step of forming the lower electrode and the ground plane further comprises the step of patterning after coating the insulating film on the ground plane micro-switch manufacturing method using the electrostatic force. The method of claim 15, In the case of a resistive switch, a micro switch manufacturing method using an electrostatic force, characterized in that the plurality of ground planes are formed in the process of forming the lower electrode and the ground plane.