TW576799B - Fabricating process of an inkjet print head - Google Patents

Abstract

A fabricating process of an inkjet print head is described. A master mold with a plurality of notches whereon is provided. A material layer is formed to cover the master mold and fill the notches whereon for manufacturing an ink chamber layer and a vibrating layer as an integrative unit. Then, at least an actuator is disposed on the vibrating layer and the master mold is removed. Finally, disposing a nozzle plate on the ink chamber layer to form at least an ink chamber. The ink chamber comprises the vibrating layer, the ink chamber layer and the nozzle plate with at least an ink inlet and the ink inlet connects through the ink chamber. By manufacturing the ink chamber layer and the vibrating layer as an integrative unit, the jointing ability between the ink chamber layer and the vibrating layer can be enhanced and the fabricating process of the inkjet print head can be simplified.

Description

576799 V. Description of the invention α) [Technical field to which the invention belongs] The present invention relates to a process of an inkjet printhead (Inkjetprinthead), and in particular relates to a method of manufacturing an ink chamber layer (Ink chamber) by an integral molding method. layer) and vibrating layer process. [Previous technology] In recent years, driven by the high-tech industry, all electronics-related industries have flourished. Taking the printer as an example, in just a few years, the printing technology has improved from the early striker printing and monochrome laser printing to the current color inkjet printing and color laser printing. , And even print technologies such as thermal transfer printing. Most of the inkjet printers currently on the market use thermal bubble and piezoelectric inkjet print heads to spread ink onto the surface of the paper and complete the output of text or patterns. Print jobs. Among them, the bubble-type printing technology uses a heater (h e a t e r) to instantaneously vaporize the ink, so that high-pressure bubbles are generated to push the ink, and the ink is ejected from the nozzle holes. In addition, the piezoelectric printing technology uses a piezoelectric material that can deform due to the application of voltage to instantly squeeze the ink located in the ink chamber to eject the ink from the ink jet. ejection. FIG. 1 is a schematic cross-sectional view of a conventional piezoelectric inkjet print head. Please refer to FIG. 1. The piezoelectric inkjet print head 100 is mainly composed of a vibration layer 110, an ink cavity layer 120, a nozzle plate 130 and at least an actuator 140. (Only one is shown). Among them, Mo

11159twf.ptd Page 6 576799 V. Description of the invention (2) The cavity layer 1 2 0 is arranged between the vibration layer 1 1 0 and the orifice plate 1 3 0, and the vibration layer 1 1 0 and the ink cavity layer 1 2 0 And the nozzle hole sheet 130 constitutes at least one ink cavity 150 (only one is shown). The actuating element 1 40 is disposed on the vibration layer 1 10, and its position corresponds to the position of the ink cavity 150. The function of the actuating element 1 40 is to directly or indirectly provide the force of instantaneously pushing the ink. . In addition, the nozzle hole sheet 130 has a plurality of nozzle holes 1 32 (only one of which is shown), and communicates with the ink chamber 120, and the function of the nozzle hole 1 32 is to let the actuated element The ink that was squeezed instantaneously at 1 40 was ejected from the ink chamber 150 outside the inkjet print head 100. It is worth noting that since the vibration layer 110 and the ink cavity layer 120 in the conventional piezoelectric inkjet print head 100 are made of a single material layer, they are co-fired or adhered at high temperature. The method is to join the vibration layer 110 and the ink cavity layer 120. Among them, when the material of the vibrating layer 110 and the ink cavity layer 120 is ceramics, the vibrating layer 110 and the ink cavity layer 120 are joined by high temperature co-firing. In addition, when the piezoelectric layer (not shown) in the actuating element 140 is made of piezoelectric ceramics, the piezoelectric layer is subjected to a sintering step so that the piezoelectric layer has piezoelectric characteristics. Therefore, it can be seen from the above that when the materials of the vibration layer 1 10, the ink cavity layer 120 and the piezoelectric layer are ceramics, the vibration layer 1 110, the ink cavity layer 120, and the piezoelectric layer are usually processed. Co-firing at high temperature to achieve the purpose of joining the vibration layer 110 and the ink cavity layer 120 together and the piezoelectric layer to have piezoelectric characteristics. However, joining the vibration layer 110 and the ink cavity layer 120 in a high-temperature co-firing manner will result in a difference in the volume shrinkage rate after the high temperature co-firing. The relative position is shifted, resulting in misalignment between the actuating element 1 40 disposed on the vibration layer 1 10 and the ink chamber 150.

11159twf.ptd Page 7 576799 V. Description of the invention (3) The problem of accuracy leads to a decrease in the yield of the inkjet print head 100, and reduces the print quality of the inkjet print head 100. In addition, the vibrating layer 110 and the ink cavity layer 120 are bonded in an adhesive manner, and the selection of the adhesive, the adhesive parameters, and the adhesive strength are very high, and the vibrating layer 1 110 and the adhesive layer are bonded in an adhesive manner. The ink cavity layer 1 2 0 needs to be aligned by a high-precision alignment system to avoid inaccurate alignment between the actuating element 1 4 0 and the ink cavity 1 5 0 disposed on the vibration layer 1 1 0 This problem will increase the complexity of the entire process. In addition, because the ink's constituents mainly include dye (dye), pigment (pigment), solvent (solvent), etc., the ink is very easy to invade #adhesive glue, so that the vibration layer 1 10 and the ink cavity layer 1 2 0 There is a gap between them, which causes the ink to penetrate through the gap (that is, the situation of ink leakage), which reduces the printing quality of the inkjet print head 1000. [Summary of the Invention] Therefore, the object of the present invention is to provide an inkjet print head manufacturing process, in which the ink cavity layer and the vibration layer of the inkjet print head are integrally formed during the manufacturing process, so as to improve the ink cavity layer. The adhesiveness with the vibrating layer can effectively solve the problem of penetration between the conventional ink cavity layer and the vibrating layer and reduce the complexity of manufacturing the inkjet print head. Another object of the present invention is to provide a process of inkjet print head, which is to make a master mold by means of exposure, development and electroplating, etc., for integrally forming the ink cavity layer and vibration of the inkjet print head on the master mold. Floor. Based on the above objectives, the present invention proposes a process for manufacturing an inkjet print head. First, a master mold is provided. The master mold has a plurality of openings and is recessed in the master mold.

11159twf.ptd Page 8 576799 V. Description of the invention (4) A surface is then formed with a material layer which fills these openings and covers the surface of the master mold with these openings, which fills in these openings. The local material layer constitutes a patterned ink cavity layer, and the local material layer covering the surface of the master mold constitutes a vibration layer. Then, at least a moving element is connected to the vibration layer, then the master mold is removed, and finally a The orifice plate is above the ink cavity layer, so that the vibration layer, the patterned ink cavity layer and the orifice plate form at least one ink cavity, wherein the orifice plate has at least one orifice and communicates with the ink cavity. 0 According to the present invention According to a preferred embodiment of the present invention, the above-mentioned master mold is manufactured by first providing a substrate, and then forming a patterned photoresist layer on the substrate to form an opening of the master mold. The method for forming the patterned photoresist layer includes exposure and development, and the substrate is, for example, a silicon substrate, and the material of the patterned photoresist layer is, for example, an epoxide. According to a preferred embodiment of the present invention, the above-mentioned master mold is manufactured by first providing a substrate, then forming a patterned photoresist layer on the substrate, and then forming a conductor layer without covering the patterned photoresist. On the substrate of the layer, the photoresist layer is finally removed to form an opening of the master mold. The method for forming a patterned photoresist layer includes exposure and development, and the substrate is, for example, a silicon substrate or a metal substrate. The material of the patterned photoresist layer is, for example, polymethyl methacrylate (P MM A) o In addition, when the substrate is made of metal, for example, the aforementioned conductive layer is directly formed on the substrate by electroplating, and when the substrate is made of non-metallic material (such as silicon substrate), then Before the patterned photoresist layer is formed on the substrate, a seed layer is first formed (seed 1 ayer).

11159twf.ptd Page 9 576799 V. Description of the invention (5) The above-mentioned conductor layer is formed on the substrate by electroplating. According to a preferred embodiment of the present invention, the above-mentioned actuating element is manufactured by first forming an electrode layer on the vibration layer, then forming a piezoelectric layer on the lower electrode layer, and finally forming an upper electrode layer on the pressure electrode. On the floor. Among them, the method of connecting the actuator and the vibration layer is, for example, a high-temperature sintering method. In addition, the material of the piezoelectric layer is, for example, piezoelectric ceramics, and the materials of the material layers constituting the vibration layer and the ink chamber layer are, for example, ceramics, polymers, or metals. When the piezoelectric layer is made of piezoelectric ceramics, a step of sintering the piezoelectric layer is further performed to make the piezoelectric layer have piezoelectric characteristics. The invention is to provide a master mold for integrally forming the ink cavity layer and the vibration layer of the inkjet print head on the master mold. Since the ink cavity layer and the vibration layer are integrally formed during the manufacturing process, the ink cavity layer and the The vibrating layer has good jointability, and can effectively solve the problem of penetration between the conventional ink cavity layer and the vibrating layer, and reduce the complexity of manufacturing the inkjet print head. In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below and described in detail in conjunction with the accompanying drawings. As follows: [Embodiment] Please refer to it in order Figures 2A to 2E are cross-sectional flowcharts of a piezoelectric inkjet print head according to a preferred embodiment of the present invention. As shown in FIG. 2A, a master mold 200 is provided first, and the master mold 200 has a plurality of openings 202, which are recessed on one surface of the master mold 200. Next, as shown in FIG. 2B, a material layer 2 10 is formed, and the material layer 2 10 fills the openings 2 2 and covers the surface of the female mold 2 0 2 having the openings 2 2. Among them, the part that fills these openings 2 2

11159twf.ptd Page 10 576799 V. Description of the invention (6) The material layer 2 1 0 constitutes a patterned ink cavity layer 2 2 0, and a part of the material layer 2 1 0 covering the surface of the master mold 2 0 0 A vibration layer 2 3 0 is formed. In addition, the material constituting the material layer 2 10 of the patterned ink cavity layer 2 2 0 and the vibration layer 2 3 0 is, for example, a ceramic, a polymer, or a metal. As shown in FIG. 2C, at least the moving element 2 4 0 (four are shown in this figure) is then disposed on the vibration layer 2 3 0. In addition, the step of manufacturing the actuating element 240 is to first form an electrode layer 2 42 on the vibration layer 2 30, then form a piezoelectric layer 244 on the lower electrode layer 242, and finally form an upper electrode layer 246. The piezoelectric electrode layer 244 is made of piezoelectric ceramic. It is worth noting that if the material of the piezoelectric layer 2 4 4 is a piezoelectric ceramic, it needs to further perform a step of sintering the piezoelectric layer 244 to make the piezoelectric layer 244 have piezoelectric characteristics (that is, the applied voltage will correspondingly produce deformation. characteristic). As shown in FIG. 2D, the master mold 200 is then removed. At this time, the patterned ink cavity layer 220 and the vibration layer 230 are integrally formed. In addition, the material of the master mold 200 and the aforementioned material layer 2 10 may be selected with a low adhesion, so as to smoothly remove the master mold 200. In addition, the above-mentioned steps of high-temperature sintering and demolding do not limit their sequence. If the master mold 200, the actuating element 2 40, and the aforementioned material layer 2 1 0 are first subjected to high-temperature sintering, and then the demolding step is performed, The material of mold 2 0 0 needs to choose heat-resistant material. As shown in FIG. 2E, after removing the master mold 200, an orifice plate 250 is then disposed on the patterned ink cavity layer 220 to make the vibration layer 230, the patterned ink cavity layer 220, and the orifice The sheet 250 constitutes at least one ink cavity 260 (four are shown in this figure), and the nozzle hole sheet 250 has at least one spray hole 252 (four are shown in this figure), and communicates with the ink cavity 260. Of inkjet print head

11159twf.ptd Page 11 576799 V. Description of Invention (7) Production. Therefore, by applying a voltage between the upper electrode layer 246 and the lower electrode layer 2 4 2, the piezoelectric layer 2 4 4 is subjected to a voltage difference, and a corresponding deformation is caused to instantaneously move the vibration layer 2 3 0, and then directly or indirectly. Press the ink within the ink chamber 260 instantly, so that part of the ink close to the nozzle hole 2 5 2 will be ejected from the nozzle hole 2 5 2. Therefore, it can be known from the foregoing that the present invention is to provide a master mold for integrally forming the ink cavity layer and the vibration layer in an inkjet print head on the master mold. The manufacture of the master mold will be described below. Detailed description. Please refer to FIGS. 3A to 3C in sequence, which is a cross-sectional flowchart of a master mold according to a preferred embodiment of the present invention. First, as shown in FIG. 3A, a substrate 300 is provided, for example, a Shi Xi substrate. Next, as shown in FIG. 3B, a photoresist layer 3 1 0 (Photo-Resist (PR)), such as an epoxide (e ρ ο X y), is formed on the substrate 300 in a comprehensive manner, and The photoresist 310 layer is patterned using processes such as exposure and development to form a plurality of openings 3 1 2. In this embodiment, a patterned photomask 3 2 0 is disposed above the photoresist layer 3 1 0 for exposure. The light irradiated is, for example, ultraviolet light (UV-1 ight), and the photoresist layer is exposed. After the partial area of 310, for example, a negative-type developing solution is used to remove the remaining unexposed areas on the photoresist layer 3 10 to form a plurality of openings 3 1 2 to fill the areas shown in FIG. 2B. The material layer 210 forms an ink cavity layer 220 and a vibration layer 230 as a whole. Please refer to FIGS. 4A to 4E in sequence, which is a cross-sectional flowchart of a mother mold according to another preferred embodiment of the present invention. First, as shown in FIG. 4A, a substrate 400 is provided, such as a silicon substrate or a metal substrate. Next, as shown in Figure 4B

11159twf.ptd Page 12 576799 5. The description of the invention (8) shows that a photoresist layer 410 (PR), such as polymethyl acrylate (PMMA), is comprehensively formed on the substrate 400, and exposure is performed by using And developing processes, patterning the photoresist layer 410. In this embodiment, a patterned photomask 4 2 0 is arranged above the photoresist layer 4 1 0 for exposure. The irradiated light is, for example, X-ray (X-1 ight), and the photoresist layer 4 is exposed. After a local area of 10, for example, a negative-type developing solution is used to remove the remaining unexposed areas on the photoresist layer 4 10. As shown in FIG. 4D, after removing the unexposed areas on the photoresist layer 410, a conductor layer 4 3 0 is formed on the substrate 4 0 which does not cover the patterned photo resist layer 4 1 0. It is worth noting that when the substrate 400 is made of a metal material, for example, the conductive layer 4 3 0 described above is directly formed on the substrate 400 by electroplating, and when the substrate is made of a non-metal material (such as Silicon substrate), before forming the patterned photoresist layer 410 on the substrate 400, a plating seed layer (not shown) is formed on the substrate 400, and then, for example, electroplating In this way, the above-mentioned conductive layer 430 is formed on the substrate 400. Finally, as shown in FIG. 4E, the patterned photoresist layer 4 1 0 is removed to form a plurality of openings 4 4 0, which are used to fill the material layer 2 1 0 shown in FIG. 2 B to be integrated. An ink cavity layer 220 and a vibration layer 230 are formed. In summary, the main feature of the inkjet print head manufacturing process of the present invention is to provide a master mold, and integrally mold the master mold to form the ink cavity layer and the vibration layer of the inkjet print head. It is worth noting that because the ink cavity layer and the vibration layer of the inkjet printhead® are integrally formed, the adhesion between the ink cavity layer and the vibration layer is better, and it is not necessary to co-fire or adhere at high temperature as in conventional techniques Way to join separately

1 Γ159rwf. Ptd Page 13 576799 V. Description of the invention (9) The position of the vibrating layer and the ink chamber is fixed, and it will not occur in between. In addition, the layer will be better, so the printing quality between the ink chamber layers of the hair will not be good. The master mold is used in the moving layer, and although the master mold is to limit the scope of the present invention, the protective range is regarded as the rear layer, so the alignment is not allowed due to the gap caused by the bright inkjet printing. The vibration layer of the present invention And the problem between the ink chamber layer and the actuator element on the vibration layer and the ink chamber is indeed a problem. The process of forming the ink cavity layer and the vibrating head of the inkjet print head by volume molding can be simplified, and the vibration layer and the case of ink leakage, so it can be maintained. The invention is made by exposure, development, and plating. The ink cavity layer and the vibration of the inkjet print head that are integrally formed on the master mold can be reused, thereby reducing the cost of the process. The Ming has disclosed the above with a preferred embodiment, but it is not useful. Anyone skilled in this art can make some changes and retouch without departing from the essence of the present invention. Therefore, the scope of the patent application attached to the present invention is defined Whichever comes first.

11159twf.ptd Page 14 576799 Brief description of the drawings Figure 1 is a schematic cross-sectional view of a conventional piezoelectric inkjet print head; Figures 2 A to 2 E are piezoelectric ink jets according to a preferred embodiment of the present invention Sectional flow chart of the print head; Figs. 3A to 3C are cross-sectional flow charts of a master mold according to a preferred embodiment of the present invention; and Figs. 4A to 4E are another preferred embodiment of the present invention. Sectional flow chart of the master mold. [Illustration of Graphical Indication] 100 Piezoelectric inkjet print head 110 Vibration layer 120 Ink cavity layer 130 Nozzle piece 132 Nozzle 140 Actuating element 150 Ink cavity 200 Female mold 202 Open U 21 0 Material layer 220 Ink cavity layer 230 Vibrating layer 240 Actuating element 242 Lower electrode layer 244 Piezoelectric layer 246 Upper electrode layer

11159twf.ptd Page 15 576799 Brief description of the drawings 250 252 260 300 310 3 12 320 430 Nozzle sheet Nozzle Ink cavity 400 410 440 420 Conductive layer substrate Photoresist layer opening Photomask

11159twf.ptd Page 16

Claims (1)

576799 VI. Scope of Patent Application 1. A process of inkjet print head, including the following steps: Provide a master mold, the master mold has a plurality of openings, which are recessed on one surface of the master mold; forming a material layer, the material The layer fills the openings and covers the surface of the master mold, wherein a part of the material layer filled in the openings forms a patterned ink cavity layer, and a part of the surface of the master mold covers The material layer constitutes a vibrating layer; at least a uniform moving element is disposed on the vibrating layer; the master mold is removed; and an orifice plate is disposed on a side of the ink cavity layer farther from the vibrating layer so that the vibrating layer The patterned ink cavity layer and the spray hole sheet form at least one ink_water cavity, wherein the spray hole sheet has at least one spray hole, and the spray hole is in communication with the ink cavity. 2. The process of the inkjet print head described in item 1 of the scope of patent application, wherein the production of the master mold includes the following steps: providing a substrate; and forming a patterned photoresist layer on the substrate to These openings are formed. 3. The process of the inkjet print head described in item 2 of the scope of patent application, wherein the method of forming the patterned photoresist layer includes exposure and development. 4. The process of the inkjet print head as described in item 2 of the scope of patent application, wherein the substrate comprises a Shixi substrate. 5. The process of the inkjet print head described in item 2 of the scope of patent application, wherein the material of the patterned photoresist layer includes an epoxide. 6. The process of inkjet print head as described in item 1 of the patent application scope, which 11159twf.ptd Page 17 576799 6. The production of the master mold in the scope of patent application includes the following steps: providing a substrate; forming a patterned photoresist layer on the substrate; forming a conductor layer without covering the pattern Patterning the photoresist layer on the substrate; and removing the patterned photoresist layer to form the openings. 7. The process of inkjet print head as described in item 6 of the scope of patent application, wherein the substrate comprises one of a stone substrate and a metal substrate. 8. The process of inkjet print head as described in item 6 of the scope of patent application, wherein the material of the pattern photoresist layer includes polymethyl methacrylate. 9. The process of inkjet print head described in item 6 of the scope of patent application, wherein the method of forming the conductor layer includes electroplating. 10. The process of the inkjet print head described in item 6 of the patent application scope, wherein before the step of forming the patterned photoresist layer on the substrate, it further comprises forming a plating seed layer by electroplating. On the substrate. 1 1. For example, the process of the inkjet print head described in item 1 of the scope of the patent application, wherein the material of the material layer includes ceramics, high molecular polymers and metals-1 2. In the manufacturing process of the inkjet print head, the manufacturing of the actuating element includes the following steps: forming a lower electrode layer on the vibration layer; forming a piezoelectric layer on the lower electrode layer; and forming an upper electrode layer on the pressure On the electrode layer. 1 3. According to the process of inkjet print head described in item 12 of the scope of patent application, 11159twf. Pid Page 18 576799 6. Scope of patent application Where the material of the piezoelectric layer includes piezoelectric ceramics. 14. The process of the inkjet print head described in item 13 of the scope of patent application, wherein before the step of arranging the nozzle plate on the side of the ink cavity layer farther from the vibration layer, the method further includes The electrical layer is sintered. 11159twf.ptd Page 19