阅读说明：本技术 一种梁膜式pzt薄膜压电阵列打印头及其制造方法 (Beam film type PZT thin film piezoelectric array printing head and manufacturing method thereof ) 是由 邵金友 杨正杰 王春慧 田洪淼 平鹏祥 严超 王小培 于 2019-09-18 设计创作，主要内容包括：一种梁膜式PZT薄膜压电阵列打印头及其制造方法,打印头包括多个压电喷射单元和设于相邻压电喷射单元之间的分隔梁,分隔梁降低了振动膜之间的机械串扰,并且隔绝了电极之间的电串扰,在提高喷射单元阵列密度与喷射频率的同时有效降低了串扰效应；制造方法先在第一基底上刻蚀出分隔梁,在第一基底上设有分隔梁的一面上生成振动膜,在振动膜上依次沉积下电极、PZT薄膜、上电极；依次刻蚀出上电极图形、PZT薄膜图形、下电极图形并去除光刻胶；在第一基底另一面刻蚀出压力腔室并去除光刻胶；在第二基底上刻蚀出液体流道与喷嘴；将第一基底上设有压力腔室的一面与第二基底上设有液体流道的一面对准键合；本发明打印头减少串扰效应的产生。(A beam film PZT thin film piezoelectric array print head and its manufacturing method, the print head includes multiple piezoelectric jet units and partition beams between adjacent piezoelectric jet units, the partition beams reduce the mechanical crosstalk between the vibrating films and isolate the electric crosstalk between the electrodes, effectively reduce the crosstalk effect while improving the array density and jet frequency of the jet units; the manufacturing method comprises the steps that firstly, a separation beam is etched on a first substrate, a vibration film is generated on one surface, provided with the separation beam, of the first substrate, and a lower electrode, a PZT thin film and an upper electrode are sequentially deposited on the vibration film; etching an upper electrode pattern, a PZT thin film pattern and a lower electrode pattern in sequence and removing the photoresist; etching a pressure chamber on the other surface of the first substrate and removing the photoresist; etching a liquid flow channel and a nozzle on the second substrate; aligning and bonding one surface of the first substrate, which is provided with the pressure chamber, with one surface of the second substrate, which is provided with the liquid flow channel; the print head of the present invention reduces the occurrence of crosstalk effects.)

1. A beam film type PZT thin film piezoelectric array printing head is characterized in that: the piezoelectric jetting device comprises a plurality of piezoelectric jetting units (1) and separating beams (2) arranged between adjacent piezoelectric jetting units (1), wherein each piezoelectric jetting unit (1) consists of a PZT thin film piezoelectric actuator (3) and a nozzle plate, each PZT thin film piezoelectric actuator (3) comprises a first substrate (9) and a pressure chamber (8) formed between the separating beams (2) or a pressure chamber (8) formed between the two separating beams (2), a vibrating membrane (7) is arranged on the upper part of each pressure chamber (8), and a lower electrode (4), a PZT thin film (5) and an upper electrode (6) are sequentially arranged above each vibrating membrane (7);

the nozzle plate comprises a second substrate (11), a liquid flow channel (10) is arranged on the second substrate (11), the upper part of the liquid flow channel (10) corresponds to the pressure chamber (8), and a nozzle (12) is arranged below the liquid flow channel (10);

the second substrate (11) is bonded with the first substrate (9), so that the nozzles (12) and the pressure chambers (8) are in one-to-one correspondence and are communicated with each other;

the polarization direction of the PZT thin film (5) is vertical to the upper electrode (6) and the lower electrode (4);

the height of the separation beam (2) in the beam mode structure is higher than that of the PZT thin film piezoelectric actuator (3).

2. The beam film PZT thin film piezoelectric array printhead of claim 1, wherein: the thickness of the PZT thin film (5) is 1-5 mu m.

3. The beam film PZT thin film piezoelectric array printhead of claim 1, wherein: the vibrating membrane (7) is made of silicon dioxide, silicon nitride, a combination of silicon dioxide and silicon nitride or a combination of silicon dioxide-silicon dioxide.

4. The beam film PZT thin film piezoelectric array printhead of claim 1, wherein: the first substrate (9) and the second substrate (11) are silicon wafers or SOI.

5. A method of fabricating a beam film PZT thin film piezoelectric array printhead as claimed in claim 1, comprising the steps of:

1) providing a silicon substrate as a first base (9), and etching a separation beam (2) on the first base (9);

2) generating a vibrating membrane (7) material on one side of the first substrate (9) on which the separation beam (2) is disposed;

3) sequentially depositing a lower electrode (4), a PZT thin film (5) and an upper electrode (6) on one surface of the first substrate (9) on which the material of the vibrating film (7) is arranged, and carrying out high-temperature annealing;

4) photoetching an upper electrode (6) pattern on one surface of the first substrate (9) on which the upper electrode (6) material is arranged, etching an upper electrode (6) pattern and removing photoresist;

5) photoetching a PZT thin film (5) pattern on one surface of the first substrate (9) on which the upper electrode (6) is arranged, etching a PZT thin film (5) pattern and removing the photoresist;

6) photoetching a lower electrode (4) pattern on one surface of the first substrate (9) on which the PZT thin film (5) is arranged, etching a lower electrode (4) pattern and removing photoresist;

7) photoetching a pressure chamber (8) pattern on the surface, opposite to the upper electrode (6), of the first substrate (9), etching the pressure chamber (8) and removing the photoresist;

8) providing another silicon substrate as a second base (11), and etching the liquid flow channel (10) and the nozzle (12) on the second base (11);

9) aligning and bonding one surface of the first substrate (9) provided with the pressure chamber (8) with one surface of the second substrate (11) provided with the liquid flow channel (10);

10) the upper electrode (6) and the lower electrode (4) are respectively used as an upper polarized electrode and a lower polarized electrode to polarize the PZT thin film (5).

6. The method of manufacturing a beam film PZT thin film piezoelectric array printhead of claim 5, wherein: the method for generating the vibrating membrane (7) material in the step 2) is to generate a silicon dioxide material by a hot dry oxygen method, or generate a silicon nitride material by a PECVD method, or generate a silicon dioxide and silicon nitride combined vibrating membrane material by sputtering.

7. The method of manufacturing a beam film PZT thin film piezoelectric array printhead of claim 5, wherein: the method for depositing the lower electrode (4), the PZT film (5) and the upper electrode (6) in the step 3) is a magnetron sputtering method, the annealing temperature of high-temperature annealing is 550-700 ℃, and the annealing time is 30-120 min.

8. The method of manufacturing a beam film PZT thin film piezoelectric array printhead of claim 5, wherein: the method for etching the separation beam (2), the upper electrode (6), the PZT thin film (5) and the lower electrode (4), the pressure chamber (8), the liquid flow channel (10) and the nozzle (12) in the steps 1), 4), 5), 6), 7) and 8) is ICP dry etching.

9. The method of manufacturing a beam film PZT thin film piezoelectric array printhead of claim 5, wherein: the method for aligning bonding in the step 9) is silicon-silicon bonding or high-molecular middle layer hot-pressing bonding.

10. The method of manufacturing a beam film PZT thin film piezoelectric array printhead of claim 5, wherein: the polarization voltage of the PZT thin film (5) in the step 10) is 20-200V.

Technical Field

The invention belongs to the technical field of piezoelectric type droplet jet printing, and particularly relates to a beam-film type PZT thin film piezoelectric array printing head and a manufacturing method thereof.

Background

The piezoelectric type droplet jet printing technology has very important application in the fields of microelectronic manufacturing and packaging, panel display, cell printing, biomedical engineering, 3D printing and the like, and the research and development of the high-efficiency and high-precision piezoelectric array printing head has important significance for improving the droplet jet printing efficiency and printing precision. The PZT thin film piezoelectric array printhead using PZT piezoelectric thin films as driving elements can theoretically obtain higher operating frequency, higher nozzle array density and more accurate volume of ejected droplets, and has become one of the research and development hotspots of high-efficiency and high-precision piezoelectric array printheads. However, with the increase of the working frequency and the nozzle array density of the PZT thin film piezoelectric array printhead, crosstalk effects such as electrical crosstalk and mechanical crosstalk between adjacent piezoelectric ejection units are seriously aggravated, and thus the printing accuracy and the printing quality are reduced. Reducing the crosstalk effect has become a key to further improve the performance of PZT thin film driven piezoelectric array printheads.

In the prior art, the structural design of completely independent piezoelectric elements for all piezoelectric ejection units in a piezoelectric array printing head has become a common measure for reducing the crosstalk effect, but the method can only reduce the electrical crosstalk effect to a limited extent and cannot effectively reduce the mechanical crosstalk between adjacent ejection units with high density. On the basis, the mechanical crosstalk of the piezoelectric array printing head is reduced by adopting a method of increasing the distance between adjacent jet units or idle part jet units (a plurality of idle jet units which cannot be driven exist between every two simultaneously driven jet units of the printing head), but the method can cause the effective resolution and the effective printing speed of the printing head to be remarkably reduced, and further causes the reduction of the printing precision and the printing efficiency. Optimizing the piezoelectric element control signals of a printhead on the basis of the original structural design of the printhead is also a complementary method for reducing crosstalk effects, for example, chinese patent CN102781671A proposes that selecting drive signals for nozzles, determining time delay and pulse width extension based on adjacent drive signals, and applying the time delay and pulse width extension to the drive signals to reduce crosstalk in a piezoelectric printhead may be effective to some extent, but also obviously introduces complicated drive circuits and drive signal design, and increases design restrictions on the drive signals.

Disclosure of Invention

To overcome the above-mentioned disadvantages of the prior art, it is an object of the present invention to provide a beam film PZT thin film piezoelectric array printhead and a method for manufacturing the same, which can reduce the occurrence of crosstalk.

In order to achieve the purpose, the invention adopts the technical scheme that:

a beam film type PZT thin film piezoelectric array printing head comprises a plurality of piezoelectric jet units 1 and partition beams 2 arranged between the adjacent piezoelectric jet units 1, wherein each piezoelectric jet unit 1 consists of a PZT thin film piezoelectric actuator 3 and a nozzle plate, each PZT thin film piezoelectric actuator 3 comprises a pressure chamber 8 formed between a first substrate 9 and the partition beam 2 or a pressure chamber 8 formed between two partition beams 2, a vibration film 7 is arranged at the upper part of the pressure chamber 8, and a lower electrode 4, a PZT thin film 5 and an upper electrode 6 are sequentially arranged above the vibration film 7;

the nozzle plate comprises a second substrate 11, the second substrate 11 is provided with a liquid flow channel 10, the upper part of the liquid flow channel 10 corresponds to the pressure chamber 8, and a nozzle 12 is arranged below the liquid flow channel 10;

the second substrate 11 and the first substrate 9 are bonded, so that the nozzles 12 correspond to the pressure chambers 8 one by one and are communicated with each other;

the polarization direction of the PZT thin film 5 is vertical to the upper electrode 6 and the lower electrode 4;

the height of the separation beam 2 in the beam mode structure is higher than that of the PZT thin film piezoelectric actuator 3.

The thickness of the PZT thin film 5 is 1-5 μm.

The material of the vibrating membrane 7 is silicon dioxide, silicon nitride, a combination of silicon dioxide and silicon nitride or a combination of silicon dioxide-silicon dioxide.

The first substrate 9 and the second substrate 11 are silicon wafers or SOI.

The manufacturing method of the beam film type PZT thin film piezoelectric array printing head comprises the following steps:

1) providing a silicon substrate as a first base 9, and etching a separation beam 2 on the first base 9;

2) generating a vibrating membrane 7 material on one side of the first substrate 9 on which the separation beam 2 is provided;

3) sequentially depositing a lower electrode 4, a PZT thin film 5 and an upper electrode 6 on one surface of the first substrate 9 on which the material of the vibrating membrane 7 is arranged, and carrying out high-temperature annealing;

4) etching an upper electrode 6 pattern on one surface of the first substrate 9 on which the upper electrode 6 material is arranged, etching the upper electrode 6 pattern, and removing the photoresist;

5) photoetching a PZT thin film 5 pattern on one surface of the first substrate 9 on which the upper electrode 6 is arranged, etching a PZT thin film 5 pattern, and removing the photoresist;

6) photoetching a lower electrode 4 pattern on one surface of the PZT thin film 5 on the first substrate 9, etching a lower electrode 4 pattern and removing photoresist;

7) photoetching a pressure chamber 8 pattern on the first substrate 9 on the surface opposite to the upper electrode 6, etching the pressure chamber 8 and removing the photoresist;

8) providing another silicon substrate as a second base 11, and etching the liquid flow channel 10 and the nozzle 12 on the second base 11;

9) aligning and bonding one surface of the first substrate 9, which is provided with the pressure chamber 8, with one surface of the second substrate 11, which is provided with the liquid flow channel 10;

10) the PZT thin film 5 is polarized by the upper electrode 6 and the lower electrode 4 as an upper polarized electrode and a lower polarized electrode, respectively.

The method for generating the vibrating membrane 7 material in the step 2) is to generate a silicon dioxide material by a thermal dry oxygen method, or generate a silicon nitride material by a PECVD method, or generate a silicon dioxide and silicon nitride combined vibrating membrane material by sputtering.

The method for depositing the lower electrode 4, the PZT thin film 5 and the upper electrode 6 in the step 3) is a magnetron sputtering method, the annealing temperature of high-temperature annealing is 550-700 ℃, and the annealing time is 30-120 min.

The method for etching the separation beam 2, the upper electrode 6 pattern, the PZT thin film 5 pattern and the lower electrode 4 pattern, the pressure chamber 8, the liquid flow channel 10 and the nozzle 12 in the step 1), the step 4), the step 5), the step 6), the step 7) and the step 8) is ICP dry etching.

The method for aligning bonding in the step 9) is silicon-silicon bonding or high-molecular middle layer hot-pressing bonding.

The polarization voltage of the PZT thin film 5 in the step 10) is 20-200V.

Compared with the prior art, the invention has the beneficial effects that:

1. the separation beam 2 arranged between the adjacent piezoelectric jetting units in the beam film type structural design reduces the mechanical crosstalk between the vibrating films 7, isolates the electrical crosstalk between the electrodes, does not relate to a complex drive circuit and drive signal design, and effectively reduces the crosstalk effect while improving the array density and the jetting frequency of the jetting units;

2. the manufacturing steps of the printing head all adopt a standard MEMS process, the high-precision controllable manufacturing of a design structure is realized on the premise of not increasing the manufacturing difficulty, in addition, the height of the separation beam 2 in the beam mode structure is higher than that of the PZT thin film piezoelectric actuator 3, and in the pressurizing process of the bonding process, the separation beam 2 can apply larger bonding pressure to the PZT thin film piezoelectric actuator 3 for protecting, so that the bonding reliability is improved, and the risk of bonding failure in the printing head manufacturing process is reduced.

Drawings

Fig. 1 is a schematic structural diagram of a beam film PZT thin film piezoelectric array printhead according to the present invention.

FIG. 2 is a schematic view showing the polarization direction of the PZT thin film according to the present invention.

Fig. 3 is a schematic view of a method of fabricating a beam film PZT thin film piezoelectric array printhead according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, a beam film type PZT thin film piezoelectric array printhead includes a plurality of piezoelectric jetting units 1 and partition beams 2 disposed between adjacent piezoelectric jetting units 1, each piezoelectric jetting unit 1 is composed of a PZT thin film piezoelectric actuator 3 and a nozzle plate, each PZT thin film piezoelectric actuator 3 includes a pressure chamber 8 formed between a first substrate 9 and a partition beam 2, or a pressure chamber 8 formed between two partition beams 2, a vibration film 7 is disposed on an upper portion of the pressure chamber 8, and a lower electrode 4, a PZT thin film 5, and an upper electrode 6 are sequentially disposed above the vibration film 7;

the nozzle plate comprises a second substrate 11, the second substrate 11 is provided with a liquid flow channel 10, the upper part of the liquid flow channel 10 corresponds to the pressure chamber 8, and a nozzle 12 is arranged below the liquid flow channel 10;

the second substrate 11 and the first substrate 9 are bonded, so that the nozzles 12 correspond to the pressure chambers 8 one by one and are communicated with each other;

referring to fig. 2, the PZT thin film 5 is polarized in a direction perpendicular to the upper electrode 6 and the lower electrode 4.

The height of the separation beam 2 in the beam mode structure is higher than that of the PZT thin film piezoelectric actuator 3.

The thickness of the PZT thin film 5 is 1-5 μm.

The material of the vibrating membrane 7 is silicon dioxide, silicon nitride, a combination of silicon dioxide and silicon nitride or a combination of silicon dioxide-silicon dioxide.

The first substrate 9 and the second substrate 11 are silicon wafers or SOI.

Referring to fig. 3, the method for manufacturing the beam film type PZT thin film piezoelectric array printhead includes the steps of:

1) providing a silicon substrate as a first base 9, and etching a separation beam 2 on the first base 9;

2) generating a vibrating membrane 7 material on one side of the first substrate 9 on which the separation beam 2 is provided;

3) sequentially depositing a lower electrode 4, a PZT thin film 5 and an upper electrode 6 on one surface of the first substrate 9 on which the material of the vibrating membrane 7 is arranged, and carrying out high-temperature annealing;

4) etching an upper electrode 6 pattern on one surface of the first substrate 9 on which the upper electrode 6 material is arranged, etching the upper electrode 6 pattern, and removing the photoresist;

5) photoetching a PZT thin film 5 pattern on one surface of the first substrate 9 on which the upper electrode 6 is arranged, etching a PZT thin film 5 pattern, and removing the photoresist;

6) photoetching a lower electrode 4 pattern on one surface of the PZT thin film 5 on the first substrate 9, etching a lower electrode 4 pattern and removing photoresist;

7) photoetching a pressure chamber 8 pattern on the first substrate 9 on the surface opposite to the upper electrode 6, etching the pressure chamber 8 and removing the photoresist;

8) providing another silicon substrate as a second base 11, and etching the liquid flow channel 10 and the nozzle 12 on the second base 11;

9) aligning and bonding one surface of the first substrate 9, which is provided with the pressure chamber 8, with one surface of the second substrate 11, which is provided with the liquid flow channel 10;

10) the PZT thin film 5 is polarized by the upper electrode 6 and the lower electrode 4 as an upper polarized electrode and a lower polarized electrode, respectively.

The method for generating the vibrating membrane 7 material in the step 2) is to generate a silicon dioxide material by a thermal dry oxygen method, or generate a silicon nitride material by a PECVD method, or generate a silicon dioxide and silicon nitride combined vibrating membrane material by sputtering.

The method for depositing the lower electrode 4, the PZT thin film 5 and the upper electrode 6 in the step 3) is a magnetron sputtering method, the annealing temperature of high-temperature annealing is 550-700 ℃, and the annealing time is 30-120 min.

The method for etching the separation beam 2, the upper electrode 6 pattern, the PZT thin film 5 pattern and the lower electrode 4 pattern, the pressure chamber 8, the liquid flow channel 10 and the nozzle 12 in the step 1), the step 4), the step 5), the step 6), the step 7) and the step 8) is ICP dry etching.

The method for aligning bonding in the step 9) is silicon-silicon bonding or high-molecular middle layer hot-pressing bonding.

The polarization voltage of the PZT thin film 5 in the step 10) is 20-200V.

The foregoing is directed to embodiments of the present application and it is noted that numerous modifications and adaptations may be made by those skilled in the art without departing from the principles of the present application and are intended to be within the scope of the present application.