CN201522974U - An electromagnetic bistable micro-relay - Google Patents

Abstract

The utility model relates to a bistable electromagnetic micro-relay, which belongs to the technical field of manufacturing. It adopts a structure in which the driving coil system, electrode system, contact system and its magnetic core and iron core are fabricated on a semiconductor silicon substrate, and then mounted and combined with a permanent magnet. The driving coil system is composed of a driving coil, a wire and a wire connecting the center electrodes of the two planar driving coils. The contact system consists of two pairs of static contacts, a torsion beam, a support, and a rotating shaft, and is distributed in the center of the chip. The magnetic core and the iron core are silicon cups coated with permalloy layers on the three etched surfaces on the back of the silicon substrate. The relay adopts an integrated basic structure, which overcomes the disadvantages of poor reliability and low structural precision of the split structure. The utility model has the advantages of simple process, low cost, simple structure and high reliability.

Description

An electromagnetic bistable micro-relay

technical field

The utility model relates to a bistable relay based on microelectromechanical system (MEMS) technology, which is driven by electromagnetic force and maintained in a stable state by permanent magnetic force, in particular to an electromagnetic bistable micro relay, which belongs to the field of manufacturing technology.

technical background

As a basic electrical component, relays are widely used in automatic control systems, power protection systems, electrical systems, communication systems, and instrumentation.

Conventional relays fall into two broad categories: electromechanical relays and solid state relays. Electromechanical relays are realized based on the pull-in and disconnection of metal electrodes. This kind of relay has almost perfect electrical properties, that is, small closing resistance, large conduction current, large open-circuit resistance, and small leakage current. However, due to mechanical contact, Its response speed is slow and its working life is relatively short. Solid state relays are based on the coupling of phototransistors and light emitting diodes. This relay has insulation properties comparable to electromechanical relays and can provide a compressive strength of 1500V. However, solid state relays are far inferior to electromechanical relays in terms of insertion loss and load current. Therefore, solid state relays are mainly used in occasions that require extremely high reliability or require miniaturization. In addition, the price of solid-state relays is about three times that of electromechanical relays. Therefore, relays whose performance and price are between electromechanical relays and solid-state relays, especially miniaturized relays with comparable performance to electromechanical relays, have great market demand. Therefore, in recent years, many researchers in the field of relays have turned their attention to micro-electromechanical systems (MEMS) technology, which represents the direction of miniaturization and integration.

From the perspective of working principle, relays based on micro-electromechanical technology mainly include electrostatic type, electromagnetic type, thermomechanical type, thermomagnetic type, etc. Their main advantages are: small size, low power consumption, fast response, high isolation, Strong load capacity etc. The main research direction is concentrated on relays driven by static electricity and electromagnetic. Among them, the further development of electrostatic relays is limited due to their high driving voltage, while electromagnetic driving is characterized by low driving voltage, large torque generation, long life, and low driving signal. The characteristics of isolation and transmission signals have become the direction of research and development of micro-relays. At present, the biggest dilemma of electromagnetic relays is that the structure is complex, the process is difficult to realize, and the electromagnetic field intensity generated by the planar coil is small.

Utility model content

The purpose of the utility model is to design and develop a micro-electromagnetic relay based on the advantages of the traditional relay and to overcome the shortcomings of the existing MEMS relay. Each structure (except the permanent magnet (1)) is integrated and manufactured on a silicon substrate, the magnetic circuit tends to be closed and the electromagnetic field strength is high, and it has the characteristics of high reliability, simple structure and manufacturing process, and low processing cost.

In order to achieve the above object, the utility model adopts the following technical solutions: the device includes a silicon substrate, a magnetic core system etched on the lower surface of the silicon substrate, a drive coil system made on the silicon substrate, and a drive coil system. Contact system arranged on top of the system.

The magnetic core system includes an iron core and two magnetic cores, the center of the iron core coincides with the center of the silicon substrate, and the two magnetic cores are opposite to the iron core along the direction of the centerline of the silicon substrate Symmetrically distributed, the iron core is a silicon cup with a triangular cross-sectional shape etched on the lower surface of the silicon substrate, and a permalloy layer is plated on the silicon cup to form an iron core. The structure of the two magnetic cores and the iron core The structure is the same, and the magnetic core and the iron core are also connected by a permalloy layer; an insulating protective layer is arranged under the iron core and the magnetic core, and a permanent magnet is pasted under the protective layer.

The drive coil system includes two planarly arranged drive coils, wires connecting the drive coils and two pairs of load electrodes. A wire connected to the drive coil is made on the upper surface of the silicon substrate. The two terminals of the wire are respectively located directly above the two coil cores. The entire wire is in a "U" shape structure. A Two layers of insulating layer, two planar coils and two pairs of load terminals are made on the insulating layer, the central terminal of the planar coil is directly above the terminal of the wire, and conducts with the wire terminal, and the two pairs of load terminals are distributed symmetrically on both sides of the two drive coils;

The contact system includes two pairs of static contacts, a support, a torsion beam and a rotating shaft. An insulating layer is made on the coil, and the coil electrodes and two pairs of load terminals are exposed. Two pairs of static contacts, supports, torsion beams and rotating shafts are made on the insulating layer. The torsion beams, supports and rotating shafts are electroplated. The permalloy layer forms a "ten"-shaped structure, the center of the cross structure coincides with the center of the silicon substrate, the torsion beam and the rotating shaft have the same thickness, the support is connected to both ends of the rotating shaft, and the thickness difference between the support and the static contact and the rotating shaft Forming the working gap of the relay, the two ends of the torsion beam with two pairs of static contacts symmetrically arranged are connected with the two pairs of load electrodes one by one. When the torsion beam rotates, its ends can contact with the static contacts.

The utility model has the advantages of high manufacturing reliability, large driving torque, simple process, simple structure, low manufacturing cost and the like.

Description of drawings

Figure 1 Structural sectional view of the bistable electromagnetic micro-relay

Figure 2 Structural diagram of driving coil system and electrode system

Figure 3 Contact system structure diagram

In the figure: 1. Permanent magnet; 2. Magnetic core; 3. Protective layer; 4. Magnetic circuit; 5. Silicon substrate; 6. Static contact; 7. Iron core; 8. Support; 9. Coil; 10. Insulation layer; 11, torsion beam; 12, wire; 13, coil electrode; 14, rotating shaft; 15, load terminal.

Detailed ways

The utility model is further described in conjunction with Fig. 1-Fig. 3:

The structure of the present embodiment is shown in Figure 1, including the silicon substrate 5, the magnetic core iron core system etched on the lower surface of the silicon substrate 5, the driving coil system made on the silicon substrate, and the upper part of the driving coil system. Arranged contact system. Magnetic core The core system includes one core 7 and two magnetic cores 2 . The driving coil system includes two planarly arranged driving coils 9 , wires 12 connecting the driving coils and two pairs of loading electrodes 5 . The contact system includes two pairs of static contacts 6 , a support 8 , a torsion beam 11 and a rotating shaft 14 . The specific positional relationship of each part is as follows:

As shown in Figure 1, the magnetic core system includes an iron core 7 and two magnetic cores 2, the center of the iron core coincides with the center of the silicon substrate, and the two magnetic cores are opposite to the iron core 7 along the direction of the centerline of the silicon substrate Symmetrically distributed, the iron core 7 is a silicon cup with a triangular cross-sectional shape etched on the lower surface of the silicon substrate, and the silicon cup is coated with a permalloy layer to form the iron core 7. The structure of the two magnetic cores 2 and the iron core 7 The structure is the same, and the magnetic core 2 and the iron core 7 are also connected by a permalloy layer. A protective layer 3 for insulation is arranged under the iron core and the magnetic core, and a permanent magnet 1 is bonded under the protective layer 3 .

The structure of the drive coil system is as shown in Figure 2. On the other side of the silicon substrate 5, a lead 12 connected to the drive coil 9 is made. Above, and conduct with the central electrode of driving coil, whole wire 12 becomes " U " font structure, make one deck insulating layer 10 above two terminals of removing wire 12, wire 12 is insulated from driving coil 9. Two planar coils 9 and four load terminals 15 are fabricated on the insulating layer 10 , the central terminal of the planar coil 9 is directly above the terminals of the wire 12 , and the load terminals 15 are symmetrically distributed on both sides of the coil 9 .

The structure of the contact system is shown in Fig. 1 and Fig. 3. An insulating layer 10 is made on the top of the coil 9 to insulate the driving coil 9 from the upper layer structure, and the coil electrodes 13 and four load terminals 15 are exposed. Four load terminals 15 make up the electrode system. On the top of the coil insulating layer 10, a static contact 6, a support 8, a torsion beam 11 and a rotating shaft 14 are sequentially fabricated. The torsion beam 11, the support 8 and the rotation shaft 14 are electroplated permalloy layers, forming a "ten" shape structure, the center of the cross is located in the center of the silicon substrate 5, the torsion beam 11 and the rotation shaft 14 have the same thickness, the support 8 and Both ends of the rotating shaft 14 are connected, and the thickness difference between the support 8 and the static contact 6 and the rotating shaft 14 forms the working gap of the relay. Two pairs of static contacts 6 are symmetrically arranged at both ends of the torsion beam 11, and are connected to two pairs of load electrodes 15 in one-to-one correspondence. When the torsion beam 11 rotates, its ends can be in contact with the static contacts.

The working principle of this embodiment is as follows:

In the working process of the bistable relay, a load is applied to two pairs of static contacts, and a rectangular pulse is applied to both ends of the two driving coils in series. When a positive pulse is applied to the two coils in series, the two instantaneous Two driving coils generate an opposite electromagnetic field, which magnetizes the torsion beam in one direction, and the magnetized torsion beam is subjected to a clockwise torque in the combined field of the electromagnetic field and the permanent magnetic field. Then, under the action of the torque, the torsion beam rotates clockwise Rotate clockwise, so that one end of the torsion beam on the left is in contact with the static contact on the corresponding side, the loaded load on the left is turned on, the left side is in a closed state and the other side is in an open state and this state is maintained by a permanent magnet ; Conversely, applying a reverse pulse to its drive coil causes the torsion beam to be subjected to counterclockwise torque, and then the torsion beam rotates counterclockwise, the load on the right side is turned on and is in a closed state, and the left side is in a disconnected state, which is held by a permanent magnet this state.

The structure of the bistable electromagnetic micro-relay is shown in Figure 1. The center terminal center of the coil and the terminal center of the wire must be aligned up and down with the center of the coil core; the silicon cup etching remaining thickness of the coil core and iron core is about 50 microns.

The structure of the contact system is shown in Figure 3. The length of the torsion beam should exceed the outer side of the coil center terminal by about 100 microns, so that the driving torque on the torsion beam can be larger; the left and right sides of the torsion beam are respectively connected to the corresponding static contacts. The dots are aligned left and right; the distance between pairs of stationary contacts is approximately 200 microns.

Claims (1)

1. electromagnetism bistable micro-relay is characterized in that: comprise silicon substrate (5), at magnetic core iron core system, the drive coil system that makes on silicon substrate of the lower surface etching of silicon substrate (5) and the contact system of arranging on drive coil system top;

Described magnetic core iron core system comprises an iron core (7) and two magnetic cores (2), the center of described iron core overlaps with the center of silicon substrate, described two magnetic cores are symmetrically distributed with respect to iron core (7) along the direction of silicon substrate center line, described iron core (7) is leg-of-mutton silicon cup for the lower surface at silicon substrate etches cross sectional shape, on silicon cup, be coated with permalloy layer and form iron core (7), the structure of two magnetic cores (2) is identical with the structure of iron core (7), also connects by permalloy layer between magnetic core (2) and the iron core (7); Below iron core and magnetic core, be provided with the protective layer (3) of insulating effect, below protective layer (3), be fitted with permanent magnet (1);

Described drive coil system comprise two floor plan drive coil (9), connect lead (12) and two pairs of load electrodes (5) of drive coil; Be manufactured with the lead (12) of a connection drive coil (9) at the upper surface of silicon substrate (5), two terminals of lead (12) lay respectively at two coil magnetic cores (2) directly over, whole lead (12) becomes " U " font structure, be manufactured with a layer insulating (10) above the terminal at two that remove lead (12), on insulating barrier (10), be manufactured with two planar coils (9) and two pairs of load terminals (15)), the center terminal of planar coil (9) be in lead (12) terminal directly over, and be conducted with conductor terminal, two pairs of load terminals (15) are symmetrically distributed in the both sides of two drive coils (9) respectively;

Described contact system comprises two pairs of fixed contacts (6), bearing (8), torsion beam (11) and rotating shaft (14); On coil (9), be manufactured with insulating barrier (10), and expose coil electrode (13) and two pairs of load terminals (15), on insulating barrier (10), be manufactured with two pairs of fixed contacts (6), bearing (8), torsion beam (11) and rotating shaft (14), torsion beam (11), bearing (8) and rotating shaft (14) permalloy layer for electroplating, become " ten " font structure, the center of cross structure overlaps with the center of silicon substrate (5), torsion beam (11) has identical thickness with rotating shaft (14), bearing (8) is connected with rotating shaft (14) two ends, bearing (8) and fixed contact (6) and rotating shaft (14) thickness difference form the working clearance of relay, the two ends of the torsion beam (11) of two pairs of fixed contacts (6) symmetric arrangement, and connect one to one with two pairs of load electrodes (15), its end can contact with fixed contact when torsion beam (11) was rotated.

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