CN114771102B - Piezoelectric ink-jet printer nozzle and preparation method thereof - Google Patents

Abstract

The invention relates to a piezoelectric ink-jet printer nozzle and a preparation method thereof, wherein the piezoelectric ink-jet printer nozzle comprises a glass substrate and a silicon substrate which are mutually bonded, a liquid spraying passage is formed between the glass substrate and the silicon substrate, the liquid spraying passage comprises a liquid inlet channel, a liquid inlet liquid storage tank, a flow limiting channel, a liquid spraying liquid storage tank and a nozzle which are sequentially distributed along the flow direction of liquid inlet, the back surface of the liquid spraying liquid storage tank is a vibrating surface, a piezoelectric layer is arranged outside the vibrating surface, and the piezoelectric layer is connected with a driving circuit and used for driving the vibrating surface to vibrate; the nozzle both sides are equipped with the cutting driving piece respectively, and the ink droplet that reaches the maximum value with the ink droplet speed of cutting nozzle department through delay circuit control cutting driving piece drive nozzle's both sides. The invention utilizes the time delay circuit and the cutting driving piece to cut the ink drop when the speed of extruding the ink drop at the nozzle reaches the maximum value to obtain the ink drop with the maximum speed, thereby avoiding the formation of a long tail column in the ink jet process and preventing the ink drop from being broken to form satellite drops in the ejection process.

Description

Piezoelectric ink-jet printer nozzle and preparation method thereof

Technical Field

The invention belongs to the technical field of ink-jet printer nozzles, and particularly relates to a piezoelectric ink-jet printer nozzle and a preparation method thereof.

Background

In the ink drop ejection process of various existing printing technologies, ink drops are easy to form long tail columns, satellite ink drops are likely to be formed after breakage due to the instability of Rayleigh-Purabot, the satellite ink drops with high enough speed can catch up with main ink drops and be fused into one ink drop, the satellite ink drops with low enough speed cannot be fused with the main ink drops, the main ink drops can reach a substrate after being ejected to the substrate, and the accuracy of printed images is affected.

At present, for a nozzle of a piezoelectric ink-jet printer, the process of breaking a long tail into a main ink drop and a satellite ink drop is mainly influenced by the viscosity and the tension of the ink drop and the applied voltage pulse; the generation of satellite ink droplets can be suppressed by setting appropriate voltage pulses, but the voltage pulses are related to the velocity and volume of the ink droplets, and the volume and velocity of ejected ink droplets are inevitably limited when designing voltage pulse signals to suppress satellite ink droplets.

Disclosure of Invention

Based on the above defects in the prior art, the present invention aims to provide a piezoelectric inkjet printer head and a method for manufacturing the same.

In order to realize the purpose, the invention adopts the following technical scheme:

a piezoelectric type ink jet printer nozzle comprises a glass substrate and a silicon substrate which are bonded with each other, a liquid spraying passage is formed between the glass substrate and the silicon substrate and comprises a liquid inlet channel, a liquid inlet liquid storage tank, a current limiting channel, a liquid spraying liquid storage tank and a nozzle which are sequentially distributed along the flow direction of liquid inlet, the back of the liquid spraying liquid storage tank is a vibrating surface, a piezoelectric layer is arranged outside the vibrating surface, and the piezoelectric layer is connected with a driving circuit and used for driving the vibrating surface to vibrate;

and the two sides of the nozzle are respectively provided with a cutting driving part, and the cutting driving parts are controlled by a delay circuit to drive the two sides of the nozzle so as to cut the ink drops with the maximum ink drop speed at the nozzle.

Preferably, the liquid inlet liquid storage tank, the flow limiting channel and the liquid spray liquid storage tank of the liquid spray passage are positioned on the glass substrate;

the liquid inlet channel and the nozzle of the liquid spraying passage are positioned on the silicon substrate.

Preferably, the liquid inlet and storage tank, the flow limiting channel and the liquid spray storage tank of the liquid spray passage are distributed along the bonding surface of the glass substrate and the silicon substrate, and the openings of the liquid inlet and storage tank, the flow limiting channel and the liquid spray storage tank face the bonding surface.

Preferably, the piezoelectric layer includes a first electrode layer, a first PZT piezoelectric layer, and a second electrode layer stacked in sequence, and the first electrode layer is disposed on the vibration surface.

Preferably, the first PZT piezoelectric layer wraps one side of the first electrode layer, and the lead wires are respectively led out from two sides of the piezoelectric layer.

Preferably, the silicon substrate has cutting driving member mounting grooves respectively formed at both sides of the nozzle.

As preferred scheme, the cutting driving piece includes along cutting driving piece mounting groove from inside to outside third electrode layer, second PZT piezoelectric layer and the fourth electrode layer of establishing of stacking in proper order, and the both sides of second PZT piezoelectric layer parcel fourth electrode layer.

Preferably, the delay circuit comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a JFETQ1, an NMOS tube Q2 and a PMOS tube Q3, one end of the resistor R1 is used for inputting a pulse signal, the other end of the resistor R1 is connected with a grid of the JFETQ1 and the resistor R2, and the other end of the resistor R2 is grounded; one end of the resistor R3 is connected with +5V, and the other end of the resistor R3 is connected with the grid electrode of the NMOS tube Q2, the grid electrode of the PMOS tube Q3 and the source electrode of the JFETQ 1; the capacitor C1 is connected with the resistor R4 in parallel, one end of the capacitor C1 is connected with the drain electrode of the JFETQ1, and the other end of the capacitor C is grounded; the source electrode and the substrate of the PMOS tube Q3 are connected with +5V, and the drain electrode of the PMOS tube Q3 is connected with the substrate and the output of the NMOS tube Q2; the source electrode of the NMOS tube Q2 is grounded with the substrate;

and simultaneously, an input signal connected with the second electrode layer of the piezoelectric layer is used as an input signal of the time delay circuit, and an output signal of the time delay circuit is connected with the third electrode layer of the cutting driving piece. The delay circuit can convert an input trapezoidal wave signal into a square wave signal generated by delay, and the delay time can be changed by adjusting the resistor R4.

Preferably, the liquid spraying passages are distributed in a plurality of rows and in an array.

The invention also provides a preparation method of the piezoelectric ink-jet printer nozzle, which comprises the following steps:

s1, selecting a glass substrate, and sequentially processing a first electrode layer, a first PZT piezoelectric layer and a second electrode layer on the front surface of the glass substrate; then, etching a liquid inlet storage tank, a flow-limiting channel and a liquid spray storage tank on the back of the glass substrate by adopting a metal sputtering process;

s2, selecting a silicon substrate, and etching a cutting driving piece mounting groove in the back of the silicon substrate by adopting a reactive ion etching process; then, oxidizing the whole silicon substrate by adopting a high-temperature oxidation process, and then sequentially processing a third electrode layer, a second PZT piezoelectric layer and a fourth electrode layer in the cutting driving piece mounting groove; then etching a liquid inlet channel and a nozzle opening on the back of the silicon substrate; etching the oxide layer on the front surface of the silicon substrate by adopting a reactive ion etching process;

and S3, rinsing the silicon substrate and the glass substrate by using a BOE solution, and then bonding the glass substrate and the silicon substrate.

Compared with the prior art, the invention has the following technical effects:

the invention utilizes the time delay circuit and the cutting driving piece to cut the ink drop when the speed of extruding the ink drop at the nozzle reaches the maximum value to obtain the ink drop with the maximum speed, thereby avoiding the formation of a long tail column in the ink jet process and preventing the ink drop from being broken to form satellite drops in the ejection process; the speed and the formation of the ink drop are controlled through an external structure, the limitation on input voltage pulse and the size of the spray head can be avoided, the size of the spray head can be further reduced under the permission of the process, the arrangement density of the spray head is improved, the speed of ink drop ejection is improved, the pulse holding time is shortened, and the effect of high-speed printing is achieved.

Drawings

FIG. 1 is a schematic plan view of a piezoelectric type ink jet printer head according to embodiment 1 of the present invention;

FIG. 2 is a schematic view of the overall structure of a piezoelectric ink jet printer head according to embodiment 1 of the present invention;

FIG. 3 is a schematic view showing a partial structure of a glass substrate of a head of a piezoelectric ink jet printer according to embodiment 1 of the present invention;

FIG. 4 is a schematic view showing a partial structure of a silicon substrate of a head for a piezoelectric type ink jet printer according to embodiment 1 of the present invention;

FIG. 5 is a schematic view showing the connection of electrode leads of a piezoelectric layer of a piezoelectric type ink jet printer head according to embodiment 1 of the present invention;

FIG. 6 is a schematic view showing the connection of electrode leads of a cutting driving member of a piezoelectric type ink jet printer head according to embodiment 1 of the present invention;

FIG. 7 is a circuit diagram of a delay circuit of a piezoelectric type ink jet printer head according to embodiment 1 of the present invention;

FIG. 8 is a waveform diagram showing the input and output of the delay circuit of the piezo ink jet printer head according to embodiment 1 of the present invention;

fig. 9 is a flow chart of a manufacturing process of the piezoelectric inkjet printer head according to embodiment 1 of the present invention.

Wherein: 1. a glass substrate; 11. a first electrode layer; a PZT piezoelectric layer; 13. a second electrode layer; 14. an ink droplet reservoir; 15. an ink droplet flow-limiting tube; 16. a vibrating plate; 2. a silicon substrate; 21. a third electrode layer; PZT push-in layer; 23. a fourth electrode layer; 24. a nozzle; 25. a liquid inlet pipe.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention, the following description will explain the embodiments of the present invention with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

Example 1:

as shown in fig. 1 to 6, the piezoelectric inkjet printer head of the present embodiment includes a glass substrate 1 and a silicon substrate 2 bonded to each other, an array type liquid ejection path is formed between the glass substrate 1 and the silicon substrate 2, and the liquid ejection path includes a liquid inlet channel 25, a liquid inlet reservoir 14, a flow limiting channel 15, a liquid ejection reservoir 14, and a nozzle 24, which are sequentially distributed along a liquid inlet flow direction.

Wherein, the liquid inlet reservoir 14, the flow-limiting channel 15 and the liquid spray reservoir 14 of the liquid spray passage are positioned on the glass substrate 1, and the liquid inlet channel 25 and the nozzle 24 of the liquid spray passage are positioned on the silicon substrate 2. In addition, the liquid inlet channels of all liquid spraying channels in the array type liquid spraying channels share the same liquid inlet channel, and the liquid inlet liquid storage tanks 14 of all liquid spraying channels are combined into a large liquid inlet liquid storage tank; the restricted passage 15, the spray reservoir 14 and the nozzle 24 are provided independently of each other.

The liquid inlet liquid storage tank 14, the flow limiting channel 15 and the liquid spray storage tank 14 of the liquid spray passage are distributed along the bonding surface of the glass substrate 1 and the silicon substrate 2, and the openings of the liquid inlet liquid storage tank 14, the flow limiting channel 15 and the liquid spray storage tank are all towards the bonding surface.

The structures of the glass substrate 1 and the silicon substrate 2 which are oppositely distributed up and down are combined to form a liquid spraying passage after being bonded.

The back of the liquid spraying liquid storage tank 14 is a vibration surface, and a piezoelectric layer is arranged outside the vibration surface and is connected with a driving circuit for driving the vibration surface to vibrate. Specifically, the piezoelectric layer includes a first electrode layer 11, a PZT piezoelectric layer 12, and a second electrode layer 13 stacked in this order, and the first electrode layer 11 is disposed on the vibration surface. As shown in fig. 5, the PZT piezoelectric layer 12 of the piezoelectric layer covers one side of the first electrode layer 11, and the lead wires are led out from two sides of the piezoelectric layer, i.e. from two sides of the first electrode layer 11 and the second electrode layer 13, respectively, so as to avoid short circuit.

In this embodiment, the cutting driving members are respectively disposed on the back surface of the bonding surface of the silicon substrate 2 corresponding to the two sides of the nozzle, and the cutting driving members are driven by the delay circuit to cut the ink droplet with the maximum speed at the nozzle. Wherein the silicon substrate 2 has cutting driving member mounting grooves respectively at both sides of the nozzle for mounting the cutting driving member. Specifically, the cutting driving member includes a third electrode layer 21, a PZT piezoelectric layer 22, and a fourth electrode layer 23 stacked in sequence from inside to outside along the cutting driving member mounting groove, as shown in fig. 6, the PZT piezoelectric layer 22 wraps the two sides of the fourth electrode layer 23, and the lead wires are connected out from one side of the third electrode layer 21 and the lower side of the fourth electrode layer 23, so as to avoid short circuit.

In addition, as shown in fig. 7, the delay circuit of the present embodiment includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a jfet Q1, an NMOS transistor Q2, and a PMOS transistor Q3, one end of the resistor R1 is used for inputting a pulse signal, the other end is connected to the gate of the jfet Q1 and the resistor R2, and the other end of the resistor R2 is grounded; one end of the resistor R3 is connected with +5V, and the other end of the resistor R3 is connected with the grid electrode of the NMOS tube Q2, the grid electrode of the PMOS tube Q3 and the source electrode of the JFETQ 1; the capacitor C1 is connected with the resistor R4 in parallel, one end of the capacitor C1 is connected with the drain electrode of the JFETQ1, and the other end of the capacitor C is grounded; the source electrode and the substrate of the PMOS tube Q3 are connected with +5V, and the drain electrode of the PMOS tube Q3 is connected with the substrate and the output of the NMOS tube Q2; the source electrode of the NMOS tube Q2 is grounded with the substrate; the input signal of the second electrode layer connected with the piezoelectric layer is simultaneously used as the input signal of the time delay circuit, and the output signal of the time delay circuit is connected with the third electrode layer of the cutting driving piece.

R1, R2, R3, R4, C1 and Q1 of the delay circuit form a switch, when the conduction voltage is not reached, a high level is output at a source electrode of Q1, a low level is output after the conduction voltage is reached, the R1 and the R2 are used for dividing voltage to control the voltage of a grid electrode of the Q1, the C1 enables the Q1 to be in short circuit to output the low level when the conduction voltage is reached, and the R3 and the R4 control the starting voltage of the Q1 by controlling leakage current. Inputting a trapezoidal pulse, and outputting a low level by a source electrode of Q1 when the rising edge of the pulse reaches a starting voltage; when the falling edge of the pulse reaches the start voltage, the source of Q1 outputs high level, and at the same time, the trapezoidal pulse is converted into a square wave pulse, as shown in fig. 8. Q2 and Q3 form an inverter to invert the square wave signal output by the source of Q1, so that a trapezoidal pulse is input, when the rising edge of the pulse reaches the starting voltage, the circuit outputs high level, and when the falling edge of the pulse reaches the starting voltage, the circuit outputs low level. The time delay circuit can adjust the time delay of the square wave signal by adjusting the resistor R4.

When the circuit is manufactured, a proper resistor R4 is selected according to an input trapezoidal wave signal to obtain the desired time delay, in the embodiment, a signal with pulse rising time of 150 mus, pulse holding time of 100 mus, pulse falling time of 150 microseconds and maximum pulse voltage of 5V is adopted, the PZT piezoelectric layer 22 works through the pulse, the nozzle 24 is pushed to extrude and cut ink drops, satellite-free ink drop generation is achieved, and printing quality of a printer is improved.

As shown in fig. 9, the method for manufacturing a piezoelectric inkjet printer head according to this embodiment includes the steps of:

s1, selecting a 4inch glass substrate 1, preparing a first electrode layer 11 on the front surface of the glass substrate by adopting metal sputtering and photoetching processes,

s2, depositing a PZT piezoelectric layer 12 right above a first electrode layer 11 of the glass substrate 1 by adopting a photoetching process and a PECVD process;

s3, preparing a second electrode layer 13 on the PZT piezoelectric layer 12 of the glass substrate 1 by adopting a photoetching process and a metal sputtering process;

s4, transferring the pattern of the flow limiting channel 15 to the back of the glass substrate 1 by adopting a photoetching process, and etching to prepare the flow limiting channel 15 by adopting a reactive ion etching process;

s5, transferring the pattern of the ink droplet liquid storage tank 14 to the back of the glass substrate 1 by adopting a photoetching process, and etching to prepare the ink droplet liquid storage tank 14 by adopting a reactive ion etching process; (glass substrate partial completion)

S6, selecting a 4inch silicon substrate 2, transferring a propulsion groove pattern to the back of the silicon substrate 2 by adopting a photoetching process, and etching to prepare a propulsion groove by adopting a reactive ion etching process;

s7, oxidizing the whole silicon substrate by adopting a high-temperature oxidation process;

s8, preparing a third electrode 21 on the back surface of the silicon substrate 2 by adopting a photoetching process and a metal sputtering process;

s9, depositing a PZT piezoelectric layer 22 outside the third electrode layer 21 on the back of the silicon substrate by adopting a photoetching process and a PECVD process;

s10, preparing a fourth electrode layer 23 outside the PZT piezoelectric layer 22 on the back surface of the silicon substrate 2 by adopting a photoetching process and a metal sputtering process;

s11, transferring the patterns of the liquid inlet channel 25 and the nozzle opening 24 to the back surface of the silicon substrate 1 by adopting a photoetching process, and etching to prepare the liquid inlet channel 25 and the nozzle opening 24 by adopting a deep reactive ion etching process;

s12, etching an oxide layer on the front side of the silicon substrate 2 by adopting a reactive ion etching process;

s13, rinsing the front surface of the silicon substrate 2 and the glass substrate 1 by using BOE solution, and completing two-piece bonding by using a silicon-glass bonding process.

When the ink jet printer is used, when printing information is transmitted to the printer, the driving circuit generates trapezoidal wave signals on the first electrode layer 11 and the second electrode layer 13, square wave signals are generated on the third electrode layer 21 and the fourth electrode layer 23 through the delay circuit, the PZT piezoelectric layer 12 deforms when a rising edge signal of the trapezoidal wave comes, the vibration plate is pushed to vibrate, ink is sprayed out from the nozzle 24, when the ink droplet speed reaches the maximum value at 100 mu s, the rising edge of the square wave signal comes, the PZT piezoelectric layer 22 deforms, the nozzle 24 is squeezed to cut the ink droplet, and the small enough liquid droplet is generated and the generation of satellite liquid droplets is avoided; when the falling edge of the trapezoidal wave comes, the PZT piezoelectric layer 12 contracts to push the vibration surface to vibrate, ink is supplemented from the liquid inlet liquid storage tank 14 through the current limiting channel 15, the PZT piezoelectric layer 22 contracts when the falling edge of the trapezoidal wave comes, the nozzle 24 is opened, and the ink at the nozzle 24 is recovered.

The piezoelectric type ink jet printer shower nozzle of this embodiment has increased the cutting driving piece by delay circuit control on the basis of traditional ink jet printer shower nozzle, has avoided the ink droplet to produce long tail post in the injection process, can increase the speed of ink droplet simultaneously, reduce the volume of ink droplet, has solved because of shower nozzle size undersize leads to the unable spun problem of ink droplet, can further reduce the shower nozzle size under the circumstances that technology allows, makes the range of shower nozzle inseparabler.

Example 2:

the piezoelectric ink jet printer head of the present embodiment is different from that of embodiment 1 in that:

the number of the liquid spraying passages in the array type liquid spraying passages is not limited to the 5 passages shown in the figure in the embodiment 1, and the number can be adjusted according to the actual application requirement;

other structures can refer to embodiment 1.

The foregoing has outlined rather broadly the preferred embodiments and principles of the present invention and it will be appreciated that those skilled in the art may devise variations of the present invention that are within the spirit and scope of the appended claims.

Claims (6)

1. The piezoelectric type ink-jet printer nozzle is characterized by comprising a glass substrate and a silicon substrate which are bonded with each other, wherein a liquid spraying passage is formed between the glass substrate and the silicon substrate and comprises a liquid inlet channel, a liquid inlet liquid storage tank, a current limiting channel, a liquid spraying liquid storage tank and a nozzle which are sequentially distributed along the flow direction of liquid inlet;

the two sides of the nozzle are respectively provided with a cutting driving part, and the cutting driving parts are controlled by a delay circuit to drive the two sides of the nozzle so as to cut the ink drops with the maximum ink drop speed at the nozzle;

the piezoelectric layer comprises a first electrode layer, a first PZT piezoelectric layer and a second electrode layer which are sequentially stacked, and the first electrode layer is arranged on the vibration surface;

the silicon substrate is provided with cutting driving piece mounting grooves which are respectively positioned at two sides of the nozzle;

the cutting driving part comprises a third electrode layer, a second PZT piezoelectric layer and a fourth electrode layer which are sequentially stacked from inside to outside along the cutting driving part mounting groove, and the second PZT piezoelectric layer wraps the two sides of the fourth electrode layer;

the time delay circuit comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a JFETQ1, an NMOS tube Q2 and a PMOS tube Q3, one end of the resistor R1 is used for inputting pulse signals, the other end of the resistor R1 is connected with a grid electrode of the JFETQ1 and the resistor R2, and the other end of the resistor R2 is grounded; one end of the resistor R3 is connected with +5V, and the other end of the resistor R3 is connected with the grid electrode of the NMOS tube Q2, the grid electrode of the PMOS tube Q3 and the source electrode of the JFETQ 1; the capacitor C1 is connected with the resistor R4 in parallel, one end of the capacitor C1 is connected with the drain electrode of the JFETQ1, and the other end of the capacitor C is grounded; the source electrode and the substrate of the PMOS tube Q3 are connected with +5V, and the drain electrode of the PMOS tube Q3 is connected with the substrate and the output of the NMOS tube Q2; the source electrode of the NMOS tube Q2 is grounded with the substrate;

the input signal of the second electrode layer connected with the piezoelectric layer is simultaneously used as the input signal of the time delay circuit, and the output signal of the time delay circuit is connected with the third electrode layer of the cutting driving piece.

2. The piezoelectric ink jet printer head according to claim 1, wherein the liquid inlet reservoir, the liquid restricting passage, and the liquid reservoir of the liquid ejection passage are provided on a glass substrate;

the liquid inlet channel and the nozzle of the liquid spraying passage are positioned on the silicon substrate.

3. The piezoelectric ink jet printer head according to claim 2, wherein the liquid inlet reservoir, the flow restricting passage, and the liquid reservoir of the liquid ejection passage are distributed along a bonding surface of the glass substrate and the silicon substrate, and each opening is directed toward the bonding surface.

4. The piezo ink jet printer head of claim 1 wherein said first PZT piezoelectric layer is wrapped around one side of said first electrode layer and leads are routed from both sides of said first PZT piezoelectric layer.

5. The piezoelectric ink jet printer head according to any one of claims 1 to 4 wherein said liquid ejection passages are plural and arranged in an array.

6. The method of claim 1, wherein the method comprises the steps of:

s1, selecting a glass substrate, and sequentially processing a first electrode layer, a first PZT piezoelectric layer and a second electrode layer on the front surface of the glass substrate; then, etching a liquid inlet liquid storage tank, a flow limiting channel and a liquid spraying liquid storage tank on the back of the glass substrate by adopting a metal sputtering process;

s2, selecting a silicon substrate, and etching a cutting driving piece mounting groove on the back of the silicon substrate by adopting a reactive ion etching process; then, oxidizing the whole silicon substrate by adopting a high-temperature oxidation process, and then sequentially processing a third electrode layer, a second PZT piezoelectric layer and a fourth electrode layer in the cutting driving piece mounting groove; then etching a liquid inlet channel and a nozzle opening on the back of the silicon substrate; etching the oxide layer on the front surface of the silicon substrate by adopting a reactive ion etching process;

and S3, rinsing the silicon substrate and the glass substrate by using a BOE solution, and then bonding the glass substrate and the silicon substrate.

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