A method for preparing conductive electrodes of a piezoelectric ceramic driver of a printer head

Abstract

The application discloses a kind of preparation methods of piezoelectric ceramic driver conductive electrode of ink-jet printer nozzle, it is related to electrode preparation technical field, specifically including the following steps: driver workpiece cleaning;Driver workpiece preheating;Piezoelectric ceramic driver conductive electrode of ink-jet printer nozzle is pasted on driver workpiece with photosensitive dry film;To the workpiece with photosensitive dry film well pasted heating baking (pre-baking);Natural cooling after pre-baking;Workpiece photosensitive film exposure;Workpiece photosensitive film exposure after heating baking (post-baking);Natural cooling after post-baking;Workpiece photosensitive film development;Workpiece photosensitive film development after heating baking (firm film);Workpiece vacuum metal-plating conductive film;Workpiece photosensitive film stripping;Check.The preparation method of the application realizes the preparation of piezoelectric ceramic driver conductive electrode of ink-jet printer nozzle using photosensitive dry film technology, which can be applied to other irregular or non-planar workpiece fine line processing and manufacturing, with better effect and stronger applicability.

Description

Technical Field

[0001] This invention relates to the field of conductive electrode preparation technology, and in particular to a method for preparing a conductive electrode for a piezoelectric ceramic driver of a printer printhead. Background Technology

[0002] With the development of digital inkjet printing and 3D printing technologies, research on piezoelectric inkjet printers is increasing both domestically and internationally. Piezoelectric inkjet printing resolution is getting higher and higher, and the geometric dimensions of ink channels and their piezoelectric drive mechanisms are getting smaller and smaller. The mass production process technology of micron-level microelectromechanical systems (MEMS) has become a bottleneck for development. Domestic research and application of this technology is almost non-existent. In particular, the inkjet head, which is the core component of inkjet printers, has long been completely dependent on imports. The piezoelectric ceramic actuator is the core component of the inkjet head, and the fabrication of its conductive electrodes is the core technology among the core technologies of inkjet printers.

[0003] The piezoelectric ceramic actuator of an inkjet printer printhead requires the fabrication of fine conductive electrodes with a linewidth of approximately 60 micrometers (the electrode specifications vary depending on the printhead). Generally, the fabrication of these fine electrodes employs semiconductor planar lithography. Semiconductor planar lithography utilizes the photosensitive properties of photoresist to transfer patterns designed on a photomask onto a substrate through processes such as exposure, development, and etching. This technique is widely used for the fabrication of fine patterns on planar substrate materials, such as in the fabrication of large-scale integrated circuits and surface acoustic wave devices.

[0004] The area where the conductive electrodes of the piezoelectric ceramic driver in an inkjet printer printhead need to be fabricated is non-planar, and these conductive electrodes must be reliably connected to the conductive layer inside the inkjet nozzle. When applying photoresist using traditional semiconductor photolithography, the photoresist can flow into the inkjet nozzle, causing blockage and preventing reliable connection between the conductive electrodes and the electrodes inside the nozzle. After repeated experiments, no suitable process has been found to completely remove the photoresist from the inkjet nozzle; therefore, a more suitable fine patterning technique must be found. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a method for preparing conductive electrodes for a printer printhead piezoelectric ceramic driver.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for preparing a conductive electrode for a piezoelectric ceramic actuator in a printer printhead, based on photosensitive dry film technology, includes the following steps:

[0008] S1: Driver workpiece cleaning, cleaning the driver workpiece to be processed;

[0009] S2: Preheat the driver workpiece, cut a piece of photosensitive dry film larger than the stretcher ring, peel off the PE film layer of the photosensitive dry film with transparent tape, then place the peeled PE film side up on the table, place the stretcher ring flat on the dry film, roll up the four sides of the photosensitive dry film and fix it to the stretcher ring with transparent tape; heat the hot plate, place the cleaned and dried driver workpiece on the hot plate for preheating;

[0010] S3: Film application process. Peel off the PE film layer of the photosensitive dry film, and stick it with the adhesive film facing down onto the preheated workpiece. Use an electric iron to press and heat the photosensitive dry film to make it adhere tightly to the workpiece. After it is firmly adhered, let it cool naturally, and then peel off the PET film. At this time, the photosensitive adhesive film has been transferred to the driver workpiece. Remove the excess photosensitive adhesive film from the edges of the driver workpiece.

[0011] S4: Exposure process. Under a microscope, align the electrode pattern on the photomask with the area of ​​the driver workpiece where the electrode needs to be made, press it in a vacuum device, and then expose it under ultraviolet light in an exposure machine.

[0012] S5: Post-baking treatment, the driver workpiece is placed on a hot plate for baking, and then naturally cooled after baking;

[0013] S6: Development process, develop with developer, then rinse and dry the developed driver workpiece.

[0014] S7: Drying and hardening treatment, place the inspected and qualified driver workpieces on a preheated hot plate for baking;

[0015] S8: Coating process, loading the driver workpiece into a vacuum coating machine to coat a conductive metal film;

[0016] S9: Peeling process. Immerse the driver workpiece in the peeling solution, and then use an ultrasonic cleaner to clean the adhesive film and the conductive metal on the adhesive film.

[0017] Preferably, in step S1, the specific method for cleaning the driver workpiece is as follows: the driver workpiece is ultrasonically cleaned for 15 minutes, then wiped with degreased cotton in heated and flowing deionized water, and after wiping, it is directly placed in a 100°C oven or hot plate to bake for more than 30 minutes before use.

[0018] Furthermore: In step S2, the temperature of the hot plate is 60°C when the driver workpiece is preheated, and the preheating time is controlled to be more than 5 minutes.

[0019] A further preferred embodiment: In step S3, the specific steps of the film application process are as follows:

[0020] S31: Lay the dry film adhesive side down on the driver workpiece, secured with a bandage;

[0021] S32: Check the drive workpiece and the adhesive film for particles or other contaminants. If there are particles or contaminants, peel off the adhesive film, move it, and re-attach it to the drive workpiece. Repeat this step until the adhesive film is flat and smooth on the drive workpiece.

[0022] S33: Place a silicone sheet, slightly larger than the actuator workpiece, onto the actuator workpiece that has been covered with adhesive film;

[0023] S34: Place a preheated iron on the driver workpiece and hold it for 30 seconds (make sure the contact surface between the iron and the driver workpiece is flat). Then, use the iron to hold the workpiece in the areas without inkjet holes at both ends for another 10 seconds to ensure that the dry film adheres tightly to both ends so that the PET film can be peeled off.

[0024] S35: Place the driver workpiece with the film applied on it under the deion fan for cooling, and peel off the PET film. At this time, the photoresist film has been transferred to the driver workpiece.

[0025] S36: Use scissors to cut off the excess adhesive film from the edge of the driver workpiece, or place the driver workpiece on a hot plate at 60°C and heat it to apply the excess adhesive film to the side of the driver workpiece.

[0026] As a preferred embodiment of the present invention: in step S4, the exposure energy is controlled at 50 mJ / cm. 2 .

[0027] As a further preferred embodiment of the present invention: in step S5, the hot plate baking temperature is controlled at 60°C, the baking time is controlled at 15 minutes, and the natural cooling time is controlled at 15 minutes.

[0028] As a further embodiment of the present invention: In step S6, the specific method of development treatment is as follows: heat the prepared developing solution to 30°C, develop for 30 seconds, rinse the developed driver workpiece with deionized water, and then dry the driver workpiece with clean compressed air or nitrogen.

[0029] After development, the integrity of the adhesive strip on the driver workpiece and the cleanliness of the development are checked under a microscope. Defective products need to be reworked.

[0030] Based on the aforementioned scheme: In step S7, the specific method for drying and hardening the film is as follows: Place the qualified driver workpiece on a preheated 60°C hot plate and bake for 30 minutes.

[0031] Based on the aforementioned scheme, the preferred embodiment is that in step S8, the coating thickness is controlled within the required range (e.g., 1 μm).

[0032] A further optimized version of the aforementioned scheme is as follows: in step S9, the soaking time is controlled at 2 hours and the ultrasonic cleaning time is controlled at 15 minutes.

[0033] The beneficial effects of this invention are as follows:

[0034] 1. The preparation method of the present invention uses photosensitive dry film technology to prepare the conductive electrode of the piezoelectric ceramic driver of the printer nozzle, which can be extended to the fine line processing of other irregular or non-planar workpieces, with better effect and wider applicability.

[0035] 2. The preparation method of the present invention uses photosensitive dry film technology. The thickness of fine lines made by photosensitive dry film fine line processing technology can reach more than 3 micrometers, while the thickness of lines processed by semiconductor planar liquid photosensitive adhesive technology is difficult to reach more than 1 micrometer. Attached Figure Description

[0036] Figure 1 This is a flowchart illustrating a method for preparing a conductive electrode for a printer printhead piezoelectric ceramic driver, as proposed in this invention. Detailed Implementation

[0037] The technical solution of this patent will be further described in detail below with reference to specific embodiments.

[0038] Example 1:

[0039] A method for preparing a conductive electrode for a piezoelectric ceramic actuator in a printer printhead, based on photosensitive dry film technology, includes the following steps:

[0040] S1: Driver workpiece cleaning, cleaning the driver workpiece to be processed;

[0041] S2: Preheat the driver workpiece. Cut a piece of dry film larger than the size of the dicing ring. First, peel off the PE film layer of the dry film with transparent tape. Then, place the side with the PE film layer peeled off face up on the table. Place the ring flat on the dry film. Finally, roll up the four sides of the dry film and fix it to the ring with transparent tape. Heat the hot plate and place the cleaned and dried driver workpiece on the hot plate for preheating.

[0042] S3: Film application process. Apply the dry film adhesive side, which is fixed with a bandage, to the driver workpiece. Place a silicone sheet, slightly larger than the driver workpiece, on the driver workpiece with the adhesive film already applied. Press and heat to ensure that the dry film at both ends adheres tightly so that the PET film can be peeled off. After cooling, peel off the PET film. At this time, the photoresist film has been transferred to the driver workpiece. Trim off the excess adhesive film at the edge of the driver workpiece, or heat the driver workpiece through a hot plate to apply the excess adhesive film to the side of the driver workpiece.

[0043] S4: Exposure process. Under a microscope, align the electrode pattern on the photomask with the area of ​​the driver workpiece where the electrode needs to be made, press it in a vacuum device, and then expose it under ultraviolet light in an exposure machine.

[0044] S5: Post-baking treatment, the driver workpiece is placed on a hot plate for baking, and then naturally cooled after baking;

[0045] S6: Development process, develop with developer, then rinse and dry the developed driver workpiece.

[0046] S7: Drying and hardening treatment, place the inspected and qualified driver workpieces on a preheated hot plate for baking;

[0047] S8: Coating process, loading the driver workpiece into a vacuum coating machine to coat a 1-micron thick aluminum film;

[0048] S9: Peeling process: Immerse the driver workpiece in acetone solution, and then use an ultrasonic cleaner to clean the adhesive film and the aluminum film on the adhesive film.

[0049] In step S1, the specific method for cleaning the driver workpiece is as follows: ultrasonically clean the driver workpiece with acetone for 15 minutes, then wipe it with degreased cotton under heated and flowing deionized water, and after wiping, place it directly into a 100°C oven or hot plate to bake for more than 30 minutes before use.

[0050] In step S2, the temperature of the hot plate is 60°C during the preheating of the driver workpiece, and the preheating time is controlled to be more than 5 minutes.

[0051] In step S3, the specific steps of the film application process are as follows:

[0052] S31: Lay the dry film adhesive side down on the driver workpiece, secured with a bandage;

[0053] S32: Check the drive workpiece and the adhesive film for particles or other contaminants. If there are particles or contaminants, peel off the adhesive film, move it, and re-attach it to the drive workpiece. Repeat this step until the adhesive film is flat and smooth on the drive workpiece.

[0054] S33: Place a silicone sheet, slightly larger than the actuator workpiece, onto the actuator workpiece that has been covered with adhesive film;

[0055] S34: Place a preheated iron on the silk setting on the driver workpiece and hold for 30 seconds (ensure the contact surface between the iron and the driver workpiece is flat). Then, use the iron to hold the workpiece in the areas without inkjet holes at both ends for another 10 seconds to ensure the dry film adheres tightly to both ends so that the PET film can be peeled off.

[0056] S35: Place the driver workpiece with the film applied under a deion fan to cool for more than 10 minutes, then peel off the PET film. At this time, the photoresist film has been transferred to the driver workpiece.

[0057] S36: Use scissors to cut off the excess adhesive film from the edge of the driver workpiece, or place the driver workpiece on a hot plate at 60°C and heat it to apply the excess adhesive film to the side of the driver workpiece.

[0058] In step S4, the exposure energy is controlled at 50 mJ / cm. 2 .

[0059] In step S5, the hot plate baking temperature is controlled at 60°C, the baking time is controlled at 15 minutes, and the natural cooling time is controlled at 15 minutes.

[0060] In step S6, the specific method of development is as follows: heat the prepared developing solution to 30°C, develop for 30 seconds, rinse the developed driver workpiece with deionized water, and then dry the driver workpiece with clean compressed air or nitrogen.

[0061] After development, the integrity of the adhesive strip on the driver workpiece and the cleanliness of the development are checked under a microscope. Defective products need to be reworked.

[0062] In step S7, the specific method for drying and hardening the film is as follows: place the qualified driver workpiece on a preheated hot plate at 60°C and bake for 30 minutes.

[0063] In step S8, the coating thickness is controlled at 1 micrometer.

[0064] In step S9, the soaking time is controlled at 2 hours and the ultrasonic cleaning time is controlled at 15 minutes.

[0065] Before ultrasonic stripping, the driver workpiece should be fully immersed in the stripping solution. This will allow for quick and thorough stripping during ultrasonic stripping, thus improving the stripping efficiency.

[0066] In step S3, the temperature of the hot plate and the electric iron should not be too high when applying the film, otherwise the dry film will wrinkle; the preheating temperature of the driver workpiece must be guaranteed when applying the film, otherwise the dry film will not adhere firmly to the driver workpiece and there will be local air bubbles; the electric iron should be placed horizontally when heating, otherwise the film will not adhere tightly to the edges of the driver workpiece, resulting in air bubbles.

[0067] In step S4, the exposure energy must be sufficient; otherwise, a sol will form after development. If the exposure is insufficient, the film will nearly dissolve after development. Experiments have shown that 50 mJ / cm² is optimal. 2 It is the lowest exposure energy.

[0068] Dry film is sensitive to the temperature of the developer solution; if the developer solution temperature is below 26℃, the development will not be clean.

[0069] The hardening time must be guaranteed. Appropriately increasing the hardening time can make the edges of the conductive electrodes steeper. A hardening time of 30 minutes is the best for experimental results.

[0070] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a conductive electrode for a piezoelectric ceramic driver in an inkjet printer printhead, characterized in that, Based on photosensitive dry film technology, the following steps are included: S1: Driver workpiece cleaning, cleaning the driver workpiece to be processed; S2: Preheating the driver workpiece: Heat the hot plate and place the cleaned and dried driver workpiece on the hot plate for preheating. S3: Film application process. Peel off the PE film layer of the dry film, stick the adhesive film down onto the preheated workpiece, and use an electric iron to press and heat the dry film to make the dry film adhere tightly to the workpiece. After it is firmly adhered, let it cool naturally, and then peel off the PET film. At this time, the photoresist film has been transferred to the driver workpiece. Remove the excess adhesive film from the edge of the driver workpiece. S4: Pre-baking treatment, place the driver workpiece with the photosensitive adhesive film attached on a hot plate for baking, and then let it cool naturally after baking; S5: Exposure process. Under a microscope, align the electrode pattern on the photomask with the area of ​​the driver workpiece where the electrode needs to be made, press it in a vacuum device, and then expose it under an exposure machine. S6: Post-baking treatment, the exposed driver workpiece is placed on a hot plate for baking, and then naturally cooled after baking; S7: Development process: The driver workpiece after post-drying is developed with a developing solution. After development, the driver workpiece is rinsed clean and dried. S8: Drying and curing film treatment: Place the inspected and qualified driver workpiece on a preheated hot plate to bake and cure the adhesive film. S9: Coating process, loading the driver workpiece into a vacuum coating machine to coat it with a conductive metal film; S10: Peeling process, immerse the driver workpiece in the peeling solution, and then peel off the photosensitive film using an ultrasonic cleaner.

2. The method for preparing the conductive electrode of a printer printhead piezoelectric ceramic actuator according to claim 1, characterized in that, In step S1, the specific method for cleaning the driver workpiece is as follows: ultrasonically clean the driver workpiece for 15 minutes, then wipe it under heated and flowing deionized water, and after wiping, put it directly into an oven or hot plate to bake for more than 20 minutes before use.

3. The method for preparing the conductive electrode of a printer printhead piezoelectric ceramic actuator according to claim 1, characterized in that, In step S2, the temperature of the hot plate is 60°C when the driver workpiece is preheated, and the preheating time is controlled to be more than 5 minutes.

4. A method for preparing a conductive electrode for a printer printhead piezoelectric ceramic actuator according to any one of claims 1-3, characterized in that, In step S3, the specific steps of the film application process are as follows: S31: Lay the dry film adhesive side of the bandage fixed on the driver workpiece with the bandage side facing down; S32: Check the side light for particles or other contaminants between the driver workpiece and the adhesive film. If there are particles or contaminants, peel off the adhesive film, move it, and re-attach it to the driver workpiece. Repeat this step until the adhesive film is flat and smooth on the driver workpiece. S33: Place a silicone sheet, slightly larger than the actuator workpiece, onto the actuator workpiece that has been covered with adhesive film; S34: Place an iron preheated to the silk setting on the driver workpiece and hold for 30 seconds. Then, use the iron to hold the area without inkjet holes at both ends of the driver workpiece for another 10 seconds to make the dry film adhere tightly to both ends so that the PET film can be peeled off. S35: Place the driver workpiece with the film applied under a deion fan to cool for more than 10 minutes, then peel off the PET film. At this time, the photoresist film has been transferred to the driver workpiece. S36: Use scissors to cut off the excess adhesive film from the edge of the driver workpiece, or place the driver workpiece on a hot plate at 60°C and heat it to apply the excess adhesive film to the side of the driver workpiece.

5. The method for preparing the conductive electrode of the piezoelectric ceramic actuator for a printer printhead according to claim 4, characterized in that, In step S5, the exposure energy is controlled at 50 mJ / cm. 2 .

6. The method for preparing the conductive electrode of the piezoelectric ceramic driver for a printer printhead according to claim 4, characterized in that, In step S5, the hot plate baking temperature is controlled at 60°C, the baking time is controlled at 15 minutes, and the natural cooling time is controlled at 15 minutes.

7. The method for preparing the conductive electrode of the piezoelectric ceramic actuator for a printer printhead according to claim 4, characterized in that, In step S7, the specific method of development is as follows: heat the prepared developer to 30°C, develop for 30 seconds, rinse the developed driver workpiece with deionized water, and then dry the driver workpiece with clean compressed air or nitrogen.

8. The method for preparing the conductive electrode of the piezoelectric ceramic actuator for a printer printhead according to claim 4, characterized in that, In step S8, the specific method for drying and hardening the film is as follows: place the qualified driver workpiece on a preheated hot plate at 60°C and bake for 30 minutes.

9. A method for preparing a conductive electrode for a printer printhead piezoelectric ceramic actuator according to claim 4, characterized in that, In step S9, the thickness of the conductive metal film is controlled according to the required value.

10. A method for preparing a conductive electrode for a printer printhead piezoelectric ceramic actuator according to claim 4, characterized in that, In step S10, the soaking time is controlled at 2 hours and the ultrasonic cleaning time is controlled at 15 minutes.

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