A miniature relay and a manufacturing method thereof

Abstract

The present invention discloses a micro relay, comprising an electromagnet layer and a membrane switch layer; the membrane switch layer comprises a TiW-Au adhesion layer, a first insulating layer, a second insulating layer, and a static conductive sheet and a dynamic conductive sheet arranged between the first insulating layer and the second insulating layer, the TiW-Au adhesion layer is formed on the surface of the electromagnet layer by sputtering technology, the first insulating layer is formed on the TiW-Au adhesion layer by sputtering technology, one end of the dynamic conductive sheet is located above the static conductive sheet, and an air bridge is formed between the dynamic conductive sheet and the static conductive sheet. The thickness and volume of the membrane switch layer of the present invention are very small, which effectively reduces the size of the relay; the air bridge replaces the function of the spring in the ordinary relay, so that the balance of the dynamic conductive sheet is better, and the stability of the relay is improved; and the relay can be processed into a patch form for easy integration with other components.

Description

Technical Field

[0001] The invention belongs to the technical field of relays, and in particular relates to a miniature relay and a manufacturing method thereof. Background Art

[0002] A relay is an electrical control device, usually used in automated control circuits. It is actually an "automatic switch" that uses a small current to control the operation of a large current. It plays the role of automatic adjustment, safety protection, and circuit conversion in the circuit. When the relay is working, as long as a certain voltage is applied to both ends of the coil, a certain current will flow through the coil, thereby generating an electromagnetic effect, and the moving armature piece and the static armature piece are attracted together by electromagnetic attraction, thereby forming a conductive circuit; when the coil is powered off, the electromagnetic attraction disappears, the moving armature returns to its original position, the moving armature piece and the static armature piece are separated, and the circuit is disconnected. In the existing technology, a separate construction is used, and the relay is large in size, heavy in weight, and has a high manufacturing cost, which is not conducive to the application of miniaturized equipment. On the other hand, the internal components of the existing relay are not firmly assembled, and are easily moved by collision, which affects the service life of the relay, and there is also the disadvantage of poor balance of the moving conductive piece. Summary of the invention

[0003] The present invention provides a micro relay and a manufacturing method for solving the above problems.

[0004] The technical solution adopted by the present invention is: a micro relay, including an electromagnet layer and a membrane switch layer; the membrane switch layer includes a TiW-Au adhesion layer, a first insulating layer, a second insulating layer, and a static conductive sheet and a dynamic conductive sheet arranged between the first insulating layer and the second insulating layer, the TiW-Au adhesion layer is formed on the surface of the electromagnet layer by sputtering technology, the first insulating layer is formed on the TiW-Au adhesion layer by sputtering technology, one end of the dynamic conductive sheet is located above the static conductive sheet, and an air bridge is formed between the dynamic conductive sheet and the static conductive sheet.

[0005] Furthermore, the dynamic conductive sheet includes a fixed portion and an extension portion, the fixed portion is arranged on the first insulating layer, the static conductive sheet is arranged on the first insulating layer, and the extension portion of the dynamic conductive sheet is located above the static conductive sheet.

[0006] Furthermore, a passivation layer is provided on the second insulating layer, between the fixed portion of the moving conductive sheet and the second insulating layer, between the end of the static conductive sheet away from the moving conductive sheet and the second insulating layer, and in the area on the first insulating layer corresponding to the extending portion of the moving conductive sheet.

[0007] Furthermore, the passivation layer is a silicon oxide passivation layer.

[0008] Furthermore, the electromagnet layer includes a coil and an iron core arranged inside the coil, the height of the iron core is equal to the height of the coil, and the coil is provided with an input end and an output end.

[0009] Furthermore, an isolation layer is arranged around the coil, and isolation through holes are arranged on the isolation layer.

[0010] Furthermore, the electromagnet layer is formed by using a low temperature co-fired ferrite process, and the coil is a vertical spiral coil formed by laminating and sintering microstrip lines.

[0011] The manufacturing method of the micro relay comprises the following steps:

[0012] Step 1, using low temperature co-fired ferrite process to make the electromagnet layer;

[0013] Step 2, forming a TiW-Au adhesion layer on the surface of the electromagnet layer by using a sputtering technique;

[0014] Step 3, sputtering a first insulating layer on the TiW-Au adhesion layer using a sputtering technique;

[0015] Step 4: electroplating a first metal conductive layer on the first insulating layer using micro-electroplating technology to form a static conductive sheet; using spin-coating polyimide, adhesive bonding, and graphic processing technology to make a first sacrificial layer, and electroplating a second metal conductive layer on the first sacrificial layer using micro-electroplating technology to form an armature conductive sheet, that is, a dynamic conductive sheet;

[0016] Step 5, using spin coating polyimide, adhesive bonding, and patterning processing technology to make a second sacrificial layer on the armature conductive sheet, and using sputtering technology to sputter a second insulating layer on the second sacrificial layer;

[0017] Step 6, using plasma etching technology to wash away the first sacrificial layer and the second sacrificial layer to form an air bridge;

[0018] Step seven: grow a silicon oxide film as a passivation layer on the TiW-Au adhesion layer using plasma enhanced chemical vapor deposition and photolithography patterning processes.

[0019] In the step 2, before forming the TiW-Au adhesion layer, the surface of the electromagnet layer is polished to make its surface flatness less than 0.1 μm.

[0020] The beneficial effects of the present invention are:

[0021] The micro relay of the present invention has a coil formed by sintering a microstrip line stack, a TiW-Au adhesion layer formed by sputtering technology, and a static conductive sheet and a dynamic conductive sheet electroplated by micro-electroplating technology, so that the thickness and volume of the electromagnet layer and the membrane switch layer are very small, effectively reducing the size of the relay; the air bridge replaces the function of the spring in the ordinary relay, so that the balance of the dynamic conductive sheet is better, the stability of the relay is improved, and the service life is extended. The micro relay can also be processed into a patch form for easy integration with other components. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the present invention;

[0023] Figure 2 It is a structural schematic diagram of the electromagnet layer of the present invention;

[0024] Figure 3 It is a schematic diagram of the structure of the membrane switch layer of the present invention.

[0025] Figure numerals: 1-electromagnet layer, 2-TiW-A adhesion layer, 3-first insulating layer, 4-static conductive sheet, 5-moving conductive sheet, 51-fixed portion, 52-extension portion, 6-second insulating layer, 7-passivation layer, 8-air bridge, 11-coil, 12-iron core, 13-isolation layer, 14-isolation through hole, 15-input end, 16-output end. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] Reference Figures 1 to 3A micro relay comprises an electromagnet layer 1 and a membrane switch layer; the membrane switch layer comprises a TiW-Au adhesion layer 2, a first insulating layer 3, a second insulating layer 6, and a static conductive sheet 4 and a dynamic conductive sheet 5 arranged between the first insulating layer 3 and the second insulating layer 6, the TiW-Au adhesion layer 2 is formed on the surface of the electromagnet layer 1 by sputtering technology, the first insulating layer 3 is formed on the TiW-Au adhesion layer 2 by sputtering technology, one end of the dynamic conductive sheet 5 is located above the static conductive sheet 4, and an air bridge 8 is formed between the dynamic conductive sheet 5 and the static conductive sheet 4. The dynamic conductive sheet 5 comprises a fixed portion 51 and an extension portion 52, the fixed portion 51 is arranged on the first insulating layer 3, the static conductive sheet 4 is arranged on the first insulating layer 3, and the extension portion 52 of the dynamic conductive sheet 5 is located above the static conductive sheet 4. The electromagnet layer 1 includes a coil 11 and an iron core 12 disposed inside the coil 11 . The height of the iron core 12 is equal to that of the coil 11 . The coil 11 is provided with an input end 15 and an output end 16 .

[0028] The moving conductive sheet 5 is a metal conductor with a memory function. The extension 52 of the moving conductive sheet 5 serves as a moving contact, and one end of the static conductive sheet 4 serves as a static contact. The moving conductive sheet 5 is suspended in the air bridge 8 to replace the function of the spring in an ordinary relay. When a certain voltage is applied to the input end 15 and the output end 16 of the coil 11, a certain current will flow through the coil 11, thereby generating an electromagnetic effect, causing the iron core 12 to generate suction, thereby driving the extension 52 of the moving conductive sheet 5 to move downward and attract one end of the static conductive sheet 4; when the two ends of the coil 11 are powered off, the suction of the iron core 12 disappears, and the moving conductive sheet 5 is released to return to its original position. The purpose of controlling the conduction and disconnection of the circuit is achieved by attracting and releasing the moving conductive sheet 5 and the static conductive sheet 4.

[0029] The TiW-Au adhesion layer 2 of the membrane switch layer is formed by sputtering technology, and the static conductive sheet 4 and the dynamic conductive sheet 5 are electroplated by micro-electroplating technology, so that the thickness and volume of the membrane switch layer are very small, which effectively reduces the size of the relay and improves the stability of the relay. The micro relay can also be processed into a patch form for easy integration with other components.

[0030] A passivation layer 7 is provided on the second insulating layer 6, between the fixed portion 51 of the moving conductive sheet 5 and the second insulating layer 6, between the end of the static conductive sheet 4 away from the moving conductive sheet 5 and the second insulating layer 6, and in the area on the first insulating layer 3 corresponding to the extension portion 52 of the moving conductive sheet 5. The passivation layer 7 is a silicon oxide passivation layer 7. The function of the passivation layer 7 is to protect the moving conductive sheet 5 and the static conductive sheet 4 from oxidation.

[0031] The electromagnet layer 1 is formed by a low temperature co-fired ferrite process (LTCF), and the coil 11 is a vertical spiral coil formed by laminating and sintering a microstrip line, which is small in size and light in weight. An isolation layer 13 is arranged around the coil 11, and an isolation through hole 14 is arranged on the isolation layer 13 to reduce the interference of the external environment on the electromagnetic field of the coil 11.

[0032] The manufacturing method of the micro relay is as follows: firstly, the electromagnet layer 1 is manufactured by using a low temperature co-fired ferrite process (LTCF), and then the thin film process is used to realize the switch of the thin film air bridge 8. Specifically, the surface of the sintered electromagnet layer 1 is polished to make its surface flatness less than 0.1 μm, and then a TiW-Au adhesion layer 2 is formed on the surface of the electromagnet layer 1 by using the sputtering technology; a first insulating layer 3 is sputtered on the TiW-Au adhesion layer 2 by using the sputtering technology; a first metal conductive layer is electroplated on the first insulating layer 3 by using the micro-electroplating technology to form a static conductive sheet 4; a first sacrificial layer is made by using spin coating polyimide, bonding, and patterning processing technology, and a second metal conductive layer is electroplated on the first sacrificial layer by using the micro-electroplating technology to form an armature conductive sheet, that is, a dynamic conductive sheet 5; a second sacrificial layer is made on the armature conductive sheet by using spin coating polyimide, bonding, and patterning processing technology, and a second insulating layer 6 is sputtered on the second sacrificial layer by using the sputtering technology; the first sacrificial layer and the second sacrificial layer are washed away by using the plasma etching technology to form an air bridge 8; a silicon oxide film is grown on the TiW-Au adhesion layer 2 by using plasma enhanced chemical vapor deposition (PECVD) and photolithography patterning process as a passivation layer 7.

Claims

1. A miniature relay, characterized in that: including an electromagnet layer and a membrane switch layer; The membrane switch layer includes a TiW-Au adhesion layer, a first insulating layer, a second insulating layer, and a static conductive sheet and a dynamic conductive sheet arranged between the first insulating layer and the second insulating layer. The TiW-Au adhesion layer is formed on the surface of the electromagnet layer by sputtering technology, and the first insulating layer is formed on the TiW-Au adhesion layer by sputtering technology. One end of the dynamic conductive sheet is located above the static conductive sheet, and an air bridge is formed between the dynamic conductive sheet and the static conductive sheet. The manufacturing method of the micro relay is as follows: Step 1, using low temperature co-fired ferrite process to make the electromagnet layer; Step 2, polishing the surface of the electromagnet layer to make its surface flatness less than 0.1 μm, and then forming a TiW-Au adhesion layer on the surface of the electromagnet layer by using sputtering technology; Step 3, sputtering a first insulating layer on the TiW-Au adhesion layer using a sputtering technique; Step 4: electroplating a first metal conductive layer on the first insulating layer using micro-electroplating technology to form a static conductive sheet; using spin-coating polyimide, adhesive bonding, and graphic processing technology to make a first sacrificial layer, and electroplating a second metal conductive layer on the first sacrificial layer using micro-electroplating technology to form an armature conductive sheet, that is, a dynamic conductive sheet; Step 5, using spin coating polyimide, adhesive bonding, and patterning processing technology to make a second sacrificial layer on the armature conductive sheet, and using sputtering technology to sputter a second insulating layer on the second sacrificial layer; Step 6, using plasma etching technology to wash away the first sacrificial layer and the second sacrificial layer to form an air bridge; Step seven: grow a silicon oxide film as a passivation layer on the TiW-Au adhesion layer using plasma enhanced chemical vapor deposition and photolithography patterning processes.

2. The micro relay according to claim 1, characterized in that: The dynamic conductive sheet includes a fixed portion and an extended portion, the fixed portion is arranged on the first insulating layer, the static conductive sheet is arranged on the first insulating layer, and the extended portion of the dynamic conductive sheet is located above the static conductive sheet.

3. The micro relay according to claim 2, characterized in that: A passivation layer is provided on the second insulating layer, between the fixed portion of the moving conductive sheet and the second insulating layer, between the end of the static conductive sheet away from the moving conductive sheet and the second insulating layer, and in the area on the first insulating layer corresponding to the extending portion of the moving conductive sheet.

4. The micro relay according to claim 3, characterized in that: The passivation layer is a silicon oxide passivation layer.

5. The micro relay according to any one of claims 1 to 4, characterized in that: The electromagnet layer comprises a coil and an iron core arranged inside the coil, the height of the iron core is equal to the height of the coil, and the coil is provided with an input end and an output end.

6. The micro relay according to claim 5, characterized in that: An isolation layer is arranged around the coil, and an isolation through hole is arranged on the isolation layer.

7. The micro relay according to claim 5, characterized in that: The electromagnet layer is formed by using a low temperature co-fired ferrite process, and the coil is a vertical spiral coil formed by laminating and sintering microstrip lines.

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