CN113833634B - Electromagnetic driving MEMS micropump and integrated processing technology of micropump - Google Patents

Abstract

The invention discloses an electromagnetic drive MEMS micropump and an integrated processing technology, comprising a micropump body and a fluid channel, wherein a permanent magnet, an MEMS coil and a soft magnetic iron core are arranged in the fluid channel, and the soft magnetic iron core and the permanent magnet form a double-ring magnetic circuit; the fluid channel is communicated with an inlet and an outlet; the inlet has an inlet accessory channel in communication with the fluid channel and the outlet has an outlet accessory channel in communication with the fluid channel; the connection part of the inlet auxiliary channel and the fluid channel is provided with an inlet check valve, and the connection part of the outlet auxiliary channel and the fluid channel is provided with an outlet check valve; the micropump achieves unidirectional flow of liquid through the inlet check valve and the outlet check valve. The MEMS micropump solves the problem of liquid return of the valveless micropump, the introduction of the check valve can effectively increase the continuity of liquid flow of the pump, the MEMS micropump has stronger performance for a scene needing accurate liquid control, and the micropump is easier to integrate with a microfluidic technology due to the planarization design and the introduction of MEMS integrated processing, so that the MEMS micropump has more purposes.

Description

Electromagnetic driving MEMS micropump and integrated processing technology of micropump

Technical Field

The invention relates to the technical field of micropumps, in particular to an electromagnetic drive MEMS micropump and an integrated processing technology of the micropump.

Background

Micropumps are an important component of the development of modern drug delivery systems, micropower systems, microelectronic system cooling systems, and other microfluidics, and laboratory-on-a-chip (Lab-on-a-chip) technology. The driving modes mainly include piezoelectric, electrostatic, thermal-pneumatic and electromagnetic modes, and electromagnetic modes are widely studied by scientific research and industry due to the characteristics of precise flow control, ultra-low power consumption and the like.

The existing electromagnetic micropump is generally composed of a planar coil or a wound coil, a PDMS film, and permanent magnets, channels and substrates attached thereto. The permanent magnet is attracted or repelled by energizing the coil and a restoring force is provided by the PDMS membrane.

An electromagnetic micropump (design uniplanar technology 2019,25 (Issue): 509-519) in the prior art, from Gidde, pawar, roge, dhamgaye, design uniplanar technology 2019,25, see fig. 1, is shown, in which alternating current is applied to a coil winding 1 and an iron core 2 to generate attractive or repulsive magnetic force to a permanent magnet 3, the permanent magnet 3 drives a PDMS film 4 to squeeze or suck liquid in a channel, a microchannel 5 adopts a valveless design, and the flow resistance of the design fluid flowing through an inlet-outlet is larger than the flow resistance of an outlet-inlet in the design of the microchannel 5, so that the net flow is realized from the inlet pump to the outlet through the pump effect.

In addition, in the prior art, chinese patent application publication No. CN107975463a also proposes a plunger type electromagnetic micropump with a tubular structure of a permanent magnetic unidirectional valve, as shown in fig. 2, the electromagnetic force generated by energizing the wound electromagnetic coils 1 and 2 is utilized to drive the permanent magnetic iron column 3 to reciprocate to drive the fluid in the circular tube flow channel 4 to move, and the unidirectional rectification is realized by the machined spherical unidirectional valve, so as to ensure the unidirectional performance of the pump.

After careful analysis of the two electromagnetic micropump structures disclosed in the prior art, it is not difficult to find that the electromagnetic micropump in the prior art still has the following drawbacks:

1. the winding coil has larger volume, larger manual winding error, cannot accurately control the inductance and is not beneficial to mass production;

2. the integration level of the pump and the micro-channel is poor, and the driving coil of the micro-pump in the form of the PDMS film in FIG. 1 or the plunger type micro-pump in FIG. 2 is outside the channel, so that the characteristic of the pump is changed due to the assembly error;

3. most of valve designs of the existing planar micropump are valveless, and the micropump with the valveless design is low in efficiency, and backflow can cause mixing of liquid after the pump and liquid before the pump, so that the valve is not applicable to liquid supply in chemical, biological and medical experiments. Whereas the micropump structure disclosed in fig. 2 is mainly a typical one-way valve, which has no restoring force, has poor feeding performance under low frequency driving, and is inefficient.

Accordingly, based on the above-mentioned drawbacks of the prior art, a need exists for developing a novel electromagnetic driven MEMS micropump and an integrated processing process of the micropump.

Disclosure of Invention

The invention aims to provide an electromagnetic drive type micropump with high integration and high performance based on an MEMS process and a check valve, so as to overcome the defects of poor integration, large volume and poor valve performance of the micropump in the prior art.

In order to achieve the above object, the present invention provides the following technical solutions:

the electromagnetic driven MEMS micropump of the present invention comprises:

a micropump body;

the fluid channel is formed in the middle of the micropump body, and a permanent magnet is arranged in the fluid channel;

MEMS coils formed on both sides of the fluid channel; and

the soft magnetic iron core and the permanent magnet form a double-ring magnetic circuit;

an inlet and an outlet in communication with the fluid passageway;

the inlet having an inlet accessory channel in communication with the fluid channel and the outlet having an outlet accessory channel in communication with the fluid channel;

an inlet check valve is arranged at the joint of the inlet auxiliary channel and the fluid channel, and an outlet check valve is arranged at the joint of the outlet auxiliary channel and the fluid channel;

the micropump achieves unidirectional flow of liquid through the inlet check valve and the outlet check valve.

Further, the inlet check valve and the outlet check valve are connected with the bent and extended base material spring and are connected with the base plate of the micropump body through the end bump.

The invention discloses an integrated processing technology of an electromagnetic drive MEMS micropump, which uses three wafers for processing, namely a first wafer, a second wafer and a third wafer, and mainly comprises the following steps:

s1, manufacturing a micro pump substrate, namely manufacturing an upper micro pump substrate and a lower micro pump substrate, processing a first wafer to form the upper micro pump substrate, and processing a third wafer to form the lower micro pump substrate;

s2, manufacturing a micropump fluid channel, a soft magnetic iron core and a check valve, processing a second wafer and bonding the second wafer and the first wafer into a first whole at low temperature;

s3, electroplating the soft magnetic iron core;

s4, manufacturing a permanent magnet matrix material;

s5, bonding a third wafer, wherein the third wafer and the first whole are bonded into a whole at low temperature;

s6, manufacturing MEMS coil electroplating;

s7, magnetizing the permanent magnet;

s8, cutting to obtain individual micropump.

Further, the specific steps of manufacturing the micropump substrate in the step S1 are:

s101, cleaning a first wafer and a third wafer by using Prianha solution;

s102, performing thermal oxidation treatment on a first wafer, respectively etching a plurality of parallel coil grooves and vertical through holes according to the positions and the shapes of coil grooves on the bottom surfaces of MEMS coils on two sides and the positions and the shapes of vertical holes, and cleaning by using Prianha solution to obtain a lower substrate;

s103, performing thermal oxidation treatment on the third wafer, respectively etching a plurality of parallel coil grooves, vertical through holes, four lead pad grooves and check valve expansion runner grooves according to the positions and the shapes of the coil grooves on the top surfaces of the MEMS coils on two sides, the positions and the shapes of the lead pad grooves of the MEMS coils, the positions and the shapes of the runners on one side of the check valve close to the permanent magnet, and the positions and the shapes of the vertical holes of the MEMS coils, and cleaning by using Prinaha solution to obtain an upper substrate.

Further, the specific steps of the step S2 are as follows:

s201, cleaning a second wafer by using Prianha solution;

s202, performing thermal oxidation treatment on the second wafer, and etching boss-shaped bonding points and vertical hole grooves according to the positions and the shapes of the connecting bosses of the inlet check valve and the substrate, the shapes of the fluid channels and the positions and the shapes of the vertical holes of the MEMS coil;

s203, cleaning the first wafer and the second wafer by using Prianha solution, and cleaning the first wafer and the second wafer by using an RCA method;

s204, placing one surface of the non-coil groove of the first wafer opposite to the etching surface of the second wafer, and bonding the first wafer and the second wafer at low temperature after aligning the non-coil groove of the first wafer and the etching surface of the second wafer through an alignment mark so as to obtain a first whole;

s205, etching the side of the first integral non-coil groove into an accessory channel, an inlet check valve, an outlet check valve, a soft magnetic iron core groove and a MEMS coil vertical hole respectively according to the position and the shape of the fluid channel, the position and the shape of the inlet check valve, the position and the shape of the MEMS coil vertical hole and the position and the shape of the soft magnetic iron core, and releasing the inlet check valve spring and the outlet check valve spring at the moment.

Further, the specific steps of the step S3 are as follows:

s301, cleaning the first whole by using Prianha solution;

s302, performing a first integral thermal oxidation treatment to form an oxide layer;

s303, sputtering a titanium metal layer on one surface of the cleaned first integral soft magnetic iron core groove according to the position and the shape of the soft magnetic iron core groove;

s304, sputtering or electroless plating the soft magnetic iron core slot sputtered in the step S303 to obtain an iron or nickel metal layer on the titanium metal layer;

s305, protecting the position of the first integral soft-removing magnet core groove and forming a protection layer;

s306, electroplating iron-nickel alloy or iron-cobalt alloy at the position of the soft magnetic iron core slot, and electroplating to the etching depth;

s307, removing the protective layer.

Further, the specific steps of the step S4 are as follows:

s401, protecting the soft magnetic core and forming a protective layer;

s402, etching the first whole electroplated with the iron-cobalt alloy or the iron-nickel alloy in the S306 into a permanent magnet shape at the position of the fluid channel according to the position and the shape of the permanent magnet, and connecting beams around with surrounding matrixes to prepare for subsequent release;

s403, cleaning the first whole obtained in the step S402 by using Prianha solution;

s404, sputtering a titanium metal layer on one surface of the first integral permanent magnet after the cleaning in the step S403 according to the position and the shape of the permanent magnet matrix;

s405, sputtering an iron-nickel metal layer on one surface of the first integral permanent magnet sputtered in the step S404 according to the position and the shape of the permanent magnet matrix;

s406, protecting other positions of the permanent magnet grooves except for the first whole in the step S405 to obtain a protection layer;

s407, injecting Ru-Fe-B into the soft magnetic iron core slot position and the permanent magnet shape to a preset height;

s408, rust prevention is carried out on the Ru-Fe-B permanent magnet sputtering chromium metal layer obtained in the step S407;

s409, releasing the permanent magnet according to the position and the shape of the connection part of the permanent magnet and the matrix.

Further, the specific steps of the step S5 are as follows:

s501, performing thermal oxidation on the third wafer, and forming an oxide layer;

s502, cleaning the first whole by using a Prinanha solution and an RCA method successively;

and S503, placing one surface of the third wafer non-MEMS coil groove opposite to one surface of the first integral non-MEMS coil groove according to the pre-etched alignment mark, aligning the third wafer with the first integral low-temperature bonding after aligning the third wafer non-MEMS coil groove through the alignment mark, and obtaining the integral wafer.

Further, the specific steps of the step S6 are as follows:

s601, cleaning the whole wafer obtained in the step S5 by using Prianha solution, and sputtering a titanium metal layer on the pad surface of the wireless ring;

s602, sputtering or electroless plating a copper metal layer on the whole wafer non-coil pad surface obtained in the step S601;

s603, electroplating copper until the coil grooves and the vertical through holes of the coil-free pad face are covered;

s604, sputtering a titanium metal layer on the surface with the coil pad;

s605, sputtering or electroless plating a copper metal layer on the coil pad surface of the whole wafer obtained in the step S604;

s606, electroplating copper until coil pad coil grooves are covered;

s607, thinning copper to the thickness of the base layer by using a CMP method, and releasing the coil.

Further, the specific steps of the step S7 are as follows:

s701, performing shatter-proof protection on the whole wafer obtained in the step S6;

s702, placing the micropump whole wafer in magnetizing equipment, and magnetizing the permanent magnet according to the magnetizing direction and the magnetizing intensity of the designed permanent magnet;

the specific steps of the step S8 are as follows: and (3) cutting the magnetized micropump whole wafer obtained in the step (S7) into micropump units according to the cutting marks.

In the technical scheme, the electromagnetic drive type MEMS micropump and the integrated processing technology of the micropump provided by the invention have the following beneficial effects:

the MEMS micropump solves the problem of liquid return of the valveless micropump, the introduction of the check valve can effectively increase the continuity of liquid flow of the pump, the MEMS micropump has stronger performance for a scene needing accurate liquid control, and the micropump is easier to integrate with a microfluidic technology due to the planarization design and the introduction of MEMS integrated processing, so that the MEMS micropump has more purposes.

The MEMS micropump of the invention introduces the MEMS three-dimensional coil with more integrated manufacturing potential and beam magnetic energy into the micropump design, and the electromagnetic driving type has remarkable effects on accurate flow control and power consumption reduction. The integrated design makes mass production and variable control easier.

The electromagnetic drive formed by the double MEMS coils and the permanent magnets is finely designed on the magnetic circuit closure, so that the electromagnetic drive can have higher electromagnetic efficiency.

The planar design micropump of the invention is easier to combine with wafers of other microfluidic systems, microelectronic cooling systems and the like, has lower integration difficulty, reduces redundant connection between a driver and an actuator, and improves the reliability and integration level of the whole system.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings may be obtained according to these drawings for a person having ordinary skill in the art.

FIG. 1 is a schematic diagram of a first micropump according to the prior art;

FIG. 2 is a schematic diagram of a second micropump according to the prior art;

FIG. 3 is a schematic structural diagram of an electromagnetic MEMS micropump according to an embodiment of the present invention;

FIG. 4 is an enlarged view of a portion of an inlet check valve of an electromagnetically driven MEMS micropump provided by an embodiment of the present invention;

FIG. 5 is an enlarged view of a portion of an outlet check valve of an electromagnetically driven MEMS micropump provided by an embodiment of the present invention;

FIG. 6 is a schematic process diagram of step 102 of an integrated process for manufacturing an electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of the integrated processing step 103 of the electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 8 is a schematic process diagram of step 202 of an integrated process of an electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of the integrated processing of an electromagnetic driven MEMS micropump according to an embodiment of the present invention, step 204;

FIG. 10 is a schematic process diagram of step 205 of an integrated process for fabricating an electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 11 is a schematic diagram of the integrated processing of an electromagnetic driven MEMS micropump according to an embodiment of the present invention, step 302;

FIG. 12 is a schematic diagram of the integrated processing of the electromagnetic driven MEMS micropump according to an embodiment of the present invention in step 303;

FIG. 13 is a schematic diagram illustrating the processing of step 304 of the integrated processing of an electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 14 is a schematic diagram of the integrated processing of the electromagnetic driven MEMS micropump according to an embodiment of the present invention in step 305;

FIG. 15 is a schematic diagram illustrating the processing of step 306 of the integrated processing process of the electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 16 is a schematic process diagram of step 307 of an integrated process of an electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 17 is a schematic diagram of the integrated processing of an electromagnetic MEMS micropump according to an embodiment of the present invention in step 401;

FIG. 18 is a schematic process diagram of step 402 of an integrated process for fabricating an electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 19 is a schematic diagram of the integrated processing of an electromagnetic driven MEMS micropump according to an embodiment of the present invention at step 404;

FIG. 20 is a schematic process diagram of step 405 of an integrated process of an electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 21 is a schematic process diagram of step 406 of an integrated process of an electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 22 is a schematic diagram illustrating the processing of step 407 of the integrated processing of the electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 23 is a schematic diagram of the integrated processing step 408 of the electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 24 is a schematic diagram illustrating the processing of step 409 of an integrated processing process for an electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 25 is a schematic diagram illustrating the processing of step 501 of the integrated processing of an electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 26 is a schematic diagram of the integrated processing of an electromagnetic driven MEMS micropump according to an embodiment of the present invention at step 503;

FIG. 27 is a schematic diagram illustrating the processing of step 601 of the integrated processing process of the electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 28 is a process schematic of step 602 of an integrated process for manufacturing an electromagnetic driven MEMS micropump according to an embodiment of the present invention;

fig. 29 is a schematic processing diagram of step 603 of the integrated processing process of the electromagnetic driven MEMS micro-pump according to the embodiment of the present invention;

FIG. 30 is a schematic process diagram of step 604 of an integrated process for manufacturing an electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 31 is a schematic diagram illustrating the processing of step 605 of the integrated processing process of the electromagnetic driven MEMS micropump according to an embodiment of the present invention;

FIG. 32 is a schematic diagram of the integrated processing of an electromagnetic driven MEMS micropump according to an embodiment of the present invention at step 606;

fig. 33 is a schematic process diagram of step 607 of an integrated process of an electromagnetic driven MEMS micro-pump according to an embodiment of the present invention.

Reference numerals illustrate:

101. an inlet; 102. an inlet check valve; 103. an inlet auxiliary passage;

201. an outlet; 202. an outlet check valve; 203. an outlet auxiliary passage;

3. a soft magnetic iron core;

4. a fluid channel;

5. a permanent magnet;

6. and a MEMS coil.

Detailed Description

In order to make the technical scheme of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings.

An embodiment one specifically discloses a micro pump structure based on a MEMS three-dimensional coil, which is shown in fig. 3 to 5;

an electromagnetically driven MEMS micropump of the first embodiment, said micropump comprising:

a micropump body;

a fluid channel 4 formed in the middle of the micro pump body, wherein a permanent magnet 5 is arranged in the fluid channel 4;

MEMS coils 6 formed on both sides of the fluid passage 4; and

the soft magnetic core 3, the soft magnetic core 3 and the permanent magnet 5 form a double-ring magnetic circuit;

an inlet 101 and an outlet 201 communicating with the fluid channel 4;

the inlet 101 has an inlet satellite channel 103 in communication with the fluid channel 4 and the outlet 201 has an outlet satellite channel 203 in communication with the fluid channel 4;

the junction of the inlet auxiliary channel 103 and the fluid channel 4 is provided with an inlet check valve 102, and the junction of the outlet auxiliary channel 103 and the fluid channel 4 is provided with an outlet check valve 202;

the micropump achieves unidirectional flow of liquid through the inlet check valve 102 and the outlet check valve 202.

Preferably, the inlet check valve 102 and the outlet check valve 202 of this embodiment are each spring-connected to the base material of the bent extension and connected to the base plate of the micropump body by a tip bump.

The micro pump of the first embodiment is provided with a check valve at the accessory channel of the inlet and the outlet, and MEMS coils 6, soft magnetic cores 3, permanent magnets 5 and corresponding fluid channels 4 are integrated at two sides of the micro pump, wherein the inlet and the outlet are communicated with the fluid channels 4 through the check valve, and the one-way flow of liquid can be realized through the inlet check valve and the outlet check valve.

Referring to fig. 6 to 33, in a second embodiment, the second embodiment is an integrated processing process of the MEMS micro pump disclosed in the first embodiment, specifically:

the invention discloses an integrated processing technology of an electromagnetic drive MEMS micropump, which uses three wafers for processing, namely a first wafer, a second wafer and a third wafer, and mainly comprises the following steps:

s1, manufacturing a micro pump substrate, namely manufacturing an upper micro pump substrate and a lower micro pump substrate, processing a first wafer to form the upper micro pump substrate, and processing a third wafer to form the lower micro pump substrate;

s2, manufacturing a micropump fluid channel, a soft magnetic iron core and a check valve, processing a second wafer and bonding the second wafer and the first wafer into a first whole at low temperature;

s3, electroplating the soft magnetic iron core;

s4, manufacturing a permanent magnet matrix material;

s5, bonding a third wafer, wherein the third wafer and the first whole are bonded into a whole at low temperature;

s6, manufacturing MEMS coil electroplating;

s7, magnetizing the permanent magnet;

s8, cutting to obtain individual micropump.

Referring to fig. 6 to 7, the specific steps of fabricating the micropump substrate in step S1 are as follows:

s101, cleaning a first wafer and a third wafer by using Prianha solution;

s102, performing thermal oxidation treatment on a first wafer, respectively etching a plurality of parallel coil grooves and vertical through holes according to the positions and the shapes of coil grooves on the bottom surfaces of MEMS coils on two sides and the positions and the shapes of vertical holes, and cleaning by using Prianha solution to obtain a lower substrate;

s103, performing thermal oxidation treatment on the third wafer, respectively etching a plurality of parallel coil grooves, vertical through holes, four lead pad grooves and check valve expansion runner grooves according to the positions and the shapes of the coil grooves on the top surfaces of the MEMS coils on two sides, the positions and the shapes of the lead pad grooves of the MEMS coils, the positions and the shapes of the runners on one side of the check valve close to the permanent magnet, and the positions and the shapes of the vertical holes of the MEMS coils, and cleaning by using Prinaha solution to obtain an upper substrate.

Referring to fig. 8 to 10, further, the specific steps of step S2 are as follows:

s201, cleaning a second wafer by using Prianha solution;

s202, performing thermal oxidation treatment on the second wafer, and etching boss-shaped bonding points and vertical hole grooves according to the positions and the shapes of the connecting bosses of the inlet check valve and the substrate, the shapes of the fluid channels and the positions and the shapes of the vertical holes of the MEMS coil;

s203, cleaning the first wafer and the second wafer by using Prianha solution, and cleaning the first wafer and the second wafer by using an RCA method;

s204, placing one surface of the non-coil groove of the first wafer opposite to the etching surface of the second wafer, and bonding the first wafer and the second wafer at low temperature after aligning the non-coil groove of the first wafer and the etching surface of the second wafer through an alignment mark so as to obtain a first whole;

s205, etching the side of the first integral non-coil groove into an accessory channel, an inlet check valve, an outlet check valve, a soft magnetic iron core groove and a MEMS coil vertical hole respectively according to the position and the shape of the fluid channel, the position and the shape of the inlet check valve, the position and the shape of the MEMS coil vertical hole and the position and the shape of the soft magnetic iron core, and releasing the inlet check valve spring and the outlet check valve spring at the moment.

Referring to fig. 11 to 16, further, the specific steps of step S3 are as follows:

s301, cleaning the first whole by using Prianha solution;

s302, performing a first integral thermal oxidation treatment to form an oxide layer;

s303, sputtering a titanium metal layer on one surface of the cleaned first integral soft magnetic iron core groove according to the position and the shape of the soft magnetic iron core groove;

s304, sputtering or electroless plating the soft magnetic iron core slot sputtered in the step S303 to obtain an iron or nickel metal layer on the titanium metal layer;

s305, protecting the position of the first integral soft-removing magnet core groove and forming a protection layer;

s306, electroplating iron-nickel alloy or iron-cobalt alloy at the position of the soft magnetic iron core slot, and electroplating to the etching depth;

s307, removing the protective layer.

Referring to fig. 17 to 24, further, the specific steps of step S4 are as follows:

s401, protecting the soft magnetic core and forming a protective layer;

s402, etching the first whole electroplated with the iron-cobalt alloy or the iron-nickel alloy in the S306 into a permanent magnet shape at the position of the fluid channel according to the position and the shape of the permanent magnet, and connecting beams around with surrounding matrixes to prepare for subsequent release;

s403, cleaning the first whole obtained in the step S402 by using Prianha solution;

s404, sputtering a titanium metal layer on one surface of the first integral permanent magnet after the cleaning in the step S403 according to the position and the shape of the permanent magnet matrix;

s405, sputtering an iron-nickel metal layer on one surface of the first integral permanent magnet sputtered in the step S404 according to the position and the shape of the permanent magnet matrix;

s406, protecting other positions of the permanent magnet grooves except for the first whole in the step S405 to obtain a protection layer;

s407, injecting Ru-Fe-B into the soft magnetic iron core slot position and the permanent magnet shape to a preset height;

s408, rust prevention is carried out on the Ru-Fe-B permanent magnet sputtering chromium metal layer obtained in the step S407;

s409, releasing the permanent magnet according to the position and the shape of the connection part of the permanent magnet and the matrix.

Referring to fig. 25 to 26, further, the specific steps of step S5 are as follows:

s501, performing thermal oxidation on the third wafer, and forming an oxide layer;

s502, cleaning the first whole by using a Prinanha solution and an RCA method successively;

and S503, placing one surface of the third wafer non-MEMS coil groove opposite to one surface of the first integral non-MEMS coil groove according to the pre-etched alignment mark, aligning the third wafer with the first integral low-temperature bonding after aligning the third wafer non-MEMS coil groove through the alignment mark, and obtaining the integral wafer.

Referring to fig. 27 to 33, further, the specific steps of step S6 are as follows:

s601, cleaning the whole wafer obtained in the step S5 by using Prianha solution, and sputtering a titanium metal layer on the pad surface of the wireless ring;

s602, sputtering or electroless plating a copper metal layer on the whole wafer non-coil pad surface obtained in the step S601;

s603, electroplating copper until the coil grooves and the vertical through holes of the coil-free pad face are covered;

s604, sputtering a titanium metal layer on the surface with the coil pad;

s605, sputtering or electroless plating a copper metal layer on the coil pad surface of the whole wafer obtained in the step S604;

s606, electroplating copper until coil pad coil grooves are covered;

s607, thinning copper to the thickness of the base layer by using a CMP method, and releasing the coil.

Further, the specific steps of the step S7 are as follows:

s701, performing shatter-proof protection on the whole wafer obtained in the step S6;

s702, placing the micropump whole wafer in magnetizing equipment, and magnetizing the permanent magnet according to the magnetizing direction and the magnetizing intensity of the designed permanent magnet;

the specific steps of the step S8 are as follows: and (3) cutting the magnetized micropump whole wafer obtained in the step (S7) into micropump units according to the cutting marks.

In the technical scheme, the electromagnetic drive type MEMS micropump and the integrated processing technology of the micropump provided by the invention have the following beneficial effects:

the MEMS micropump solves the problem of liquid return of the valveless micropump, the introduction of the check valve can effectively increase the continuity of liquid flow of the pump, the MEMS micropump has stronger performance for a scene needing accurate liquid control, and the micropump is easier to integrate with a microfluidic technology due to the planarization design and the introduction of MEMS integrated processing, so that the MEMS micropump has more purposes.

The MEMS micropump of the invention introduces the MEMS three-dimensional coil with more integrated manufacturing potential and beam magnetic energy into the micropump design, and the electromagnetic driving type has remarkable effects on accurate flow control and power consumption reduction. The integrated design makes mass production and variable control easier.

The electromagnetic drive formed by the double MEMS coils and the permanent magnets is finely designed on the magnetic circuit closure, so that the electromagnetic drive can have higher electromagnetic efficiency.

The planar design micropump is easier for the wafer joint design of other microfluidic and microelectronic cooling systems, has lower integration difficulty, reduces redundant connection between a driver and an actuator, and improves the reliability and the integration level of the whole system.

While certain exemplary embodiments of the present invention have been described above by way of illustration only, it will be apparent to those of ordinary skill in the art that modifications may be made to the described embodiments in various different ways without departing from the spirit and scope of the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive of the scope of the invention, which is defined by the appended claims.

Claims (8)

1. An electromagnetically driven MEMS micropump, comprising:

a micropump body;

a fluid channel (4) formed in the middle of the micropump body, wherein a permanent magnet (5) is arranged in the fluid channel (4);

MEMS coils (6) formed on both sides of the fluid passage (4); and

the soft magnetic iron core (3), the soft magnetic iron core (3) and the permanent magnet (5) form a double-ring magnetic circuit;

an inlet (101) and an outlet (201) are communicated with the fluid channel (4);

-said inlet (101) having an inlet satellite channel (103) communicating with said fluid channel (4), said outlet (201) having an outlet satellite channel (203) communicating with said fluid channel (4);

an inlet check valve (102) is arranged at the joint of the inlet auxiliary channel (103) and the fluid channel (4), and an outlet check valve (202) is arranged at the joint of the outlet auxiliary channel (203) and the fluid channel (4);

the micropump achieves unidirectional flow of liquid through said inlet check valve (102) and said outlet check valve (202);

the inlet check valve (102) and the outlet check valve (202) are connected with the bent and extended base material spring and are connected with the base plate of the micropump body through the end bump;

the micro pump is processed by three wafers, namely a first wafer, a second wafer and a third wafer, and the integrated processing technology of the electromagnetic driving MEMS micro pump mainly comprises the following steps:

s1, manufacturing a micro pump substrate, namely manufacturing an upper micro pump substrate and a lower micro pump substrate, processing a first wafer to form the upper micro pump substrate, and processing a third wafer to form the lower micro pump substrate;

s2, manufacturing a micropump fluid channel (4), a soft magnet core (3) and a check valve, processing a second wafer and bonding the second wafer and the first wafer into a first whole at low temperature;

s3, electroplating the soft magnetic iron core (3);

s4, manufacturing a matrix material of the permanent magnet (5);

s5, bonding a third wafer, wherein the third wafer and the first whole are bonded into a whole at low temperature;

s6, manufacturing an MEMS coil (6) through electroplating;

s7, magnetizing the permanent magnet (5);

s8, cutting to obtain individual micropump.

2. The electromagnetic MEMS micro-pump according to claim 1, wherein the manufacturing of the micro-pump substrate in step S1 comprises the following steps:

s101, cleaning a first wafer and a third wafer by using Prianha solution;

s102, performing thermal oxidation treatment on a first wafer, respectively etching a plurality of parallel coil grooves and vertical through holes according to the positions and the shapes of coil grooves on the bottom surfaces of MEMS coils (6) on two sides and the positions and the shapes of vertical holes, and cleaning by using Prianha solution to obtain a lower substrate;

s103, performing thermal oxidation treatment on the third wafer, respectively etching a plurality of parallel coil grooves, vertical through holes, four lead pad grooves and check valve expansion runner grooves according to the positions and the shapes of the coil grooves on the top surfaces of the MEMS coils (6) on two sides, the positions and the shapes of the lead pads of the MEMS coils, the positions and the shapes of runners of the check valves close to one side of the permanent magnet (5), and the positions and the shapes of vertical holes of the MEMS coils, and cleaning by using Prinaha solution to obtain an upper substrate.

3. The electromagnetic MEMS micro-pump according to claim 2, wherein the specific steps of step S2 are:

s201, cleaning a second wafer by using Prianha solution;

s202, performing thermal oxidation treatment on the second wafer, and etching boss-shaped bonding points and vertical hole grooves according to the positions and the shapes of the connecting bosses of the inlet check valve and the substrate, the shapes of the fluid channels (4) and the positions and the shapes of the vertical holes of the MEMS coil;

s203, cleaning the first wafer and the second wafer by using Prianha solution, and cleaning the first wafer and the second wafer by using an RCA method;

s204, placing one surface of the non-coil groove of the first wafer opposite to the etching surface of the second wafer, and bonding the first wafer and the second wafer at low temperature after aligning the non-coil groove of the first wafer and the etching surface of the second wafer through an alignment mark so as to obtain a first whole;

s205, etching the auxiliary channel, the inlet check valve (102), the outlet check valve (202), the soft magnetic core groove and the MEMS coil vertical hole on one surface of the first integral non-coil groove according to the position and the shape of the fluid channel (4), the position and the shape of the inlet check valve, the position and the shape of the MEMS coil vertical hole and the position and the shape of the soft magnetic core (3), and releasing the inlet check valve spring and the outlet check valve spring at the moment.

4. The electromagnetic MEMS micro-pump as set forth in claim 3, wherein the specific steps of the step S3 are:

s301, cleaning the first whole by using Prianha solution;

s302, performing a first integral thermal oxidation treatment to form an oxide layer;

s303, sputtering a titanium metal layer on one surface of the cleaned first integral soft magnetic iron core groove according to the position and the shape of the soft magnetic iron core groove;

s304, sputtering or electroless plating the soft magnetic iron core slot sputtered in the step S303 to obtain an iron or nickel metal layer on the titanium metal layer;

s305, protecting the position of the first integral soft-removing magnet core groove and forming a protection layer;

s306, electroplating iron-nickel alloy or iron-cobalt alloy at the position of the soft magnetic iron core slot, and electroplating to the etching depth;

s307, removing the protective layer.

5. The electromagnetic MEMS micro-pump of claim 4, wherein the specific steps of step S4 are:

s401, protecting the soft magnetic core and forming a protective layer;

s402, etching the first whole body which is electroplated with the iron-cobalt alloy or the iron-nickel alloy in S306 into the shape of the permanent magnet (5) at the position of the fluid channel according to the position and the shape of the permanent magnet (5), and connecting beams around the permanent magnet with surrounding matrixes to prepare for subsequent release;

s403, cleaning the first whole obtained in the step S402 by using Prianha solution;

s404, sputtering a titanium metal layer on one surface of the first integral permanent magnet after the cleaning in the step S403 according to the position and the shape of the permanent magnet matrix;

s405, sputtering an iron-nickel metal layer on one surface of the shape of the first integral permanent magnet (5) sputtered in the step S404 according to the position and the shape of the permanent magnet matrix;

s406, protecting other positions of the permanent magnet grooves except for the first whole in the step S405 to obtain a protection layer;

s407, injection molding Ru-Fe-B at the position of the soft magnetic iron core slot and the shape of the permanent magnet (5) to a preset height;

s408, rust prevention is carried out on the Ru-Fe-B permanent magnet sputtering chromium metal layer obtained in the step S407;

s409, releasing the permanent magnet (5) according to the position and the shape of the connection part of the permanent magnet (5) and the matrix.

6. The electromagnetic MEMS micro-pump of claim 5, wherein the specific steps of step S5 are:

s501, performing thermal oxidation on the third wafer, and forming an oxide layer;

s502, cleaning the first whole by using a Prinanha solution and an RCA method successively;

and S503, placing one surface of the third wafer non-MEMS coil groove opposite to one surface of the first integral non-MEMS coil groove according to the pre-etched alignment mark, aligning the third wafer with the first integral low-temperature bonding after aligning the third wafer non-MEMS coil groove through the alignment mark, and obtaining the integral wafer.

7. The electromagnetic MEMS micro-pump of claim 6, wherein the specific steps of step S6 are:

s601, cleaning the whole wafer obtained in the step S5 by using Prianha solution, and sputtering a titanium metal layer on the pad surface of the wireless ring;

s602, sputtering or electroless plating a copper metal layer on the whole wafer non-coil pad surface obtained in the step S601;

s603, electroplating copper until the coil grooves and the vertical through holes of the coil-free pad face are covered;

s604, sputtering a titanium metal layer on the surface with the coil pad;

s605, sputtering or electroless plating a copper metal layer on the coil pad surface of the whole wafer obtained in the step S604;

s606, electroplating copper until coil pad coil grooves are covered;

s607, thinning copper to the thickness of the base layer by using a CMP method, and releasing the coil.

8. The electromagnetic MEMS micro-pump of claim 7, wherein the specific steps of step S7 are:

s701, performing shatter-proof protection on the whole wafer obtained in the step S6;

s702, placing the micropump whole wafer in magnetizing equipment, and magnetizing the permanent magnet (5) according to the magnetizing direction and the magnetizing intensity of the permanent magnet (5);

the specific steps of the step S8 are as follows: and (3) cutting the magnetized micropump whole wafer obtained in the step (S7) into micropump units according to the cutting marks.

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