TWI296574B - Ink jet head structure and method of fabricating ink jet head - Google Patents

Description

1296574 V. INSTRUCTION DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention is applied to printing related products, and the technical field belongs to a semi-conductor process, a microelectromechanical system, and an inkjet printing (inkjet). Printing technology [previous technology] Inkjet printing head is one of the most important components in printing technology and system, printing speed and printing resolution, etc., all by the number of nozzles of inkjet printing head, inkjet microflow The size of the knot and the resolution of the structure are determined. Generally, it is a thermal bubble inkjet manufactured by a semiconductor process. The inkjet actuator used is a heater with the highest resolution and microflow size. The finest, HP (Hewlett Packard, HP), Cano η and Lexmark inkjet printers all use thermal bubble printheads, and now have a structural resolution of 1 2〇〇npi

(nozzles per inch), nozzle hole diameter 10um, ink droplet size 2 pL (pi co 1 i ter) products 〇Η P nozzle ink microfluidic structure is divided into two categories: the first is the spring photo method used in most products The flow path is made of the photosensitive material 12 2, and the electroformed orifice sheet is attached: firstly, the lithography method is used to align, expose, and develop the flow on the ink jet wafer 1 1 微 by the lithography method. The film 132 is further bonded to the metal orifice sheet 124 formed by electroforming (usually electroformed nickel and then gold plated, platinum or palladium) [1], and the wafer is aligned one by one to complete the inkjet. Unit 1 〇〇, this

Page 6 1296574 Description (2) "~' ""~ The inkjet unit 1 Ο Ο section is shown as the first figure: prior art one. The advantage of this method is that the orifice sheet can be independently produced and inspected, the yield is easy to monitor, and the cost of the electroformed orifice sheet material is low, but since the Hekong sheet is taken one by one, the price of the matching automatic equipment is high. And the production capacity is limited; and because electroforming is istropical deposition, the orifice 13 is volcanic cone-shaped (as shown in the first figure), and the maximum print head resolution is only 60 Onpi. The second type is to use the lithography method to make the flow channel, but the orifice film is changed to laser or excimer laser aperture p〇lyimide orifice film.岔 Perforation, so HP's such orifices are combined with tab (tape _r automatic bonding) [2], making it cost-effective.

Lexmark is a perforated orifice 224 using a laser perforation. The maximum difference from HP is the flow passage 2 3 2 by laser hot chisel, and combined with the injection hole 230 to two post-alignment laser hot chisel holes. The sheet 22 is formed [3], and the ink jet unit 200 is completed. The ink jet unit 200 is schematically illustrated as a second figure: prior art 2. Since the alignment accuracy of the subsequent orifice is not as good as the lithography of the alignment apparatus (a 1 igner), the method needs to define a lithography on the inkjet wafer or wafer 210. The area of the firing chamber or the bubble chamber is to avoid the heating resistance 2 2 2 when the orifice sheet is aligned. Therefore, the laser flow micro-flow structure of the L e X mark needs one layer more than HP. And one more match. The on-flow microfluidic structure is divided into two types: sidesh ο 〇t and orthomorphic (fr ο nt shoot, HP and Lexmark). The side shot type is only used for 3 0 0 np i The low-order head product, ortho-beam, J is divided into optical perforations to make nozzles, and the lithography method (1 i thography) is used to make the flow channel [4] [5]. Lithography

Page 7 1296574 • V. INSTRUCTIONS (3) Manufactured with a first photosensitive material (hole, coated with a second material, or defined by a Thunder and a first material to form a flow path Spray hole. This = f spray hole, the output before removal is much better than the HP, Lexmark one-to-one bit eight, ancient,, and 晶圆 wafer process, the film will affect the yield, and the second material is in the mouth but the first The coverage rate of a material is the key to this method. ...Structural strength, another method of lithographic photoresist and plasma etching of the first material "fi 1 "7 Ί i pomelo wear The method of making the inkjet head micro-muscle structure [6], [7] is characterized in that the flow path 332 is first made on the .310 with the photosensitive material 322, and then the pressure head is used...p day ( Laminating a solid layer material 328 on the flow channel layer, and then coating the nozzle layer photoresist 3 2 4 by lithography on the solid layer and defining the nozzle hole 3 3 0 by lithography, and finally applying voltage Plasma etching, reactive ion etching (RIE) or inductive couple plasma etching (IC) P), the solid layer 3 2 8 is left over the orifice layer 3 2 4 to penetrate the solid layer orifice 3 3 4 to form a complete orifice and microfluidic structure 300, the inkjet unit 3 〇 The cross-section is shown in the third figure: prior art 3. Because three layers of photoresist or polymer materials need to be stacked, and then one of the solid layers is engraved, which is referred to herein as “stack etching.” The advantage of this method is also the wafer process. The output is high, but RIE and ICI^ semiconductor-grade precision vacuum reactive gas equipment are required, and the etching uniformity of r丨E or 丨CP is limited, and the orifice diameter is easily affected.

Page 8 1 129 574, invention description (4) = 1, month will be proposed _ lithography method to make the inkjet microfluidic structure of the flow channel and the orifice material to the preferred embodiment is on the inkjet thermal resistance wafer The flow path is formed by exposure and development of the photosensitive material 2, and the injection hole is also formed on the other substrate by the photosensitive material t=light development, and then the two are aligned and bonded, and the injection hole is separated from the original sprayed soil plate, that is, A complete inkjet microfluidic structure. The gossip horse Japanese yen process, the production capacity is far more than HP and Lexmark's one-by-one positional paste to the 'and the alignment fits only the general wafer alignment exposure machine, no need for orifice alignment bonding machine, RIE Or a high-priced vacuum reactive gas device such as I CP is a simple and low-cost microfluidic structure fabrication method. [Embodiment] First, an orifice substrate 5 is produced. In order to avoid the edge effect of thick film photoresist coating, a larger substrate than the inkjet wafer may be used, or an edge beam removed (EBR) may be used to remove the wafer or Thicker photoresist at the edge of the substrate. After cleaning and baking, a separation layer 5 4 (released iayer) is applied to match the nozzle layer photoresist, and the separation layer is selected as L i R r s e r i e s non-photosensitive photoresist material of M i c r 〇 C h e m . After L 0 R coating baking, the nozzle layer photoresist is applied, and the thickness of the photoresist is about 20 to 7 5 um, depending on the size of the ink droplets and the aperture diameter of the nozzle. Fuji Durimide 7000- is used here. Wei ries photosensitive polyimide, or MicroChem SU8 3000-series, soft bake, exposure, development to form the orifice 30, as shown in the fourth figure (A) and (B) .

Page 9 1296574

Further, an ink jet head wafer 1 having an ink jet driving element or a thermal resistance element 12 is formed into a flow path wafer 20. The flow channel layer 22 can be selected from TOK PR-1 〇〇-series, MicroChem SU8 solid film photoresist, or liquid photosensitive resin (resin) or p〇ly i rai de material, and the thickness of the photoresist is ink. Drop size orifice diameter requirements, preferably 10~35um. The flow channel 32 is formed by coating or laminating, exposing, developing, and then etched through the wafer by sandblasting, laser ablation or etching. Make an ink tank 4 〇 (inks丨〇t) connected to the ink reservoir, and complete the flow path rounding 20. The fifth figure (A) is the upper view of the flow path and the thermal resistance element, along the figure _' The cross section is shown in Fig. 5(B). Here, the alignment device (a 1 igner ) of the lithography process is used to align the above-mentioned orifice substrate 50 and the runner wafer 20 with the alignment machine. The pressure or vacuum makes it align and fit, as shown in the sixth figure. In order to make the orifice layer and the runner layer adhere when they are aligned, the surface of the orifice layer or the runner layer can be coated before the alignment. The adhesive material or the adhesive material; in order to reinforce the adhesion of the spray hole layer and the flow channel layer after the alignment, the above-mentioned aligned orifice substrate and the inkjet head flow channel wafer may be heated and pressurized To further promote the fit. Immerse the orifice substrate together with the inkjet head flow channel wafer in a TMAH (tetra methyl ammonium hyperoxide) solution to dissolve the previous The LOR separation layer 54 separates the orifice layer from the substrate 52 and adheres to the flow channel layer 22 to form the microfluidic structure 70 of the present invention, as shown in FIG.

Page 10 1 129 574 V. INSTRUCTIONS (6) The above-described embodiments are one of the methods for reaching the cost case, the steps up to the cost case, the process parameters, the materials selected for the separation layer, the orifice layer and the runner layer. Not limited to this. References: [1] US patent 47 9 1 43 6.

[2]US patent 5305018..

[3] James M. Mrvos, e t. a 1., 丨, Measurement of modulus changes of a phenolic adhesive using nano -dentation for an inkjet printhead nozzle plate"CM Hong and S Wagner, "Inkjet Printed Copper Source/Dra In Metallization for Amorphous Silicon Thin-Film Transistors", in Proceeding of IS&T NIP-17, p. 387, 2001.

[4] US patent 5948290.

[5] US patent 6390606. [6] US patent 6773094 [7] US patent 6364455.

Page 11 1296574 «Simple description of the description [Simplified description of the drawings] The first figure shows a schematic cross-sectional view of the inkjet microfluidic structure of the prior art. 2 is a schematic cross-sectional view of the inkjet microfluidic structure of the prior art. The third figure is a schematic cross-sectional view of the inkjet microfluidic structure of the prior art III. Figure 4 (a) is a schematic cross-sectional view showing the steps of fabricating the orifice substrate of the present invention. FIG. 4(B) is a schematic cross-sectional view showing the second step of the fabrication of the orifice substrate of the present invention. Figure 5 (a) is a schematic top view of the flow channel wafer of the present invention. Figure 5 (b) Schematic diagram of the flow channel wafer of the present invention. Fig. 6 is a cross-sectional view showing the alignment of the orifice substrate of the present invention and the flow channel wafer. Figure 7 is a schematic cross-sectional view showing the ink jet microfluidic structure of the present invention after the orifice substrate is separated. [Description of main component symbols] 1 〇 inkjet driving device wafer 1 2 inkjet driving device, 20 channel wafer or wafer of the invention 2 2 channel layer 2 4 orifice layer • orifice 3 2 runner 4 0 ink tank 50 0 The orifice substrate 5 2 of the present invention is used to make a substrate for the orifice

Page 12 1296574 Simple Description 5 4 Separation Layer 7 0 Inkjet Microfluidic Structure of the Invention 1 0 0 Prior Art 1 Inkjet Microfluidic Structure 1 1 0 Prior Art 1 Inkjet Driving Element Wafer or Wafer 1 1 2 prior art inkjet driving element 1 2 2 prior art one channel layer 1 2 4 prior art one orifice layer 1 3 0 prior art one orifice 1 3 2 prior art one channel _ 0 Prior art inkjet microfluidic structure 2 1 0 prior art inkjet driving component wafer or wafer 2 1 2 prior art 2 inkjet driving component 224 prior art 2 orifice layer 2 2 6 prior art 2 Photosensitive material defining a bubble chamber 2 3 0 prior art orifice 2 2 2 prior art 2 flow channel 3 0 prior art three inkjet microfluidic structure 3 1 0 prior art three inkjet drive component wafer or Wafer 3 1 2 Prior Art 3 Inkjet Drive Element A 2 Prior Art 3 Channel Layer 3 24 Prior Art 3 orifice layer 3 2 8 Prior Art 3 Solid Layer 3 3 0 Prior Art 3 orifice 3 3 2 prior art three flow channels

Page 13 1296574 • Brief description of the diagram 3 3 4 Solid state orifices of the prior art 3 3 0 0 ink tank ΙΙΙΗΗΙ page 14

Claims (1)

1296574 VI. Patent application scope:: The micro-flow structure of the ink head contains at least the following items: Wang Xiyi thermal resistance element for heating liquid; ^ ^, layer is p.....Μ Φί bottle; heat a flow stop, a flow path of the liquid flow, is formed on the wafer of the thermal resistance element, and is formed by making the layer a to 16 and A · ^; at least one The nozzle hole for discharging the liquid, the nozzle hole layer forming the nozzle hole is formed on the other substrate, and the nozzle hole layer substrate is attached to the flow channel layer wafer, and then the orifice layer is separated from the substrate. Forming the microfluidic structure. The ink jet head microfluidic structure according to the first aspect of the invention, wherein the thermal resistance element is formed on a wafer. The ink jet head microfluidic structure according to the first aspect of the invention, wherein the channel layer is formed by using a photosensitive material, and after exposure and development, the photosensitive material is removed by development to form a flow path. 40%: The inkjet head microfluidic structure described in the first paragraph of the patent dry circumference is used for straight-line use ^ / ;::=: The pore layer is formed by using a photosensitive material to form a region after exposure and development. Spray hole. After that, the photosensitive material 5啧:: the substrate of the ink jet head microfluidic structure Α φ layer described in the first paragraph of the patent, the surface of which has a material for separating the orifice layer from the substrate: (: a method of fabricating a microfluidic structure, Containing at least 6 · One type of inkjet display is shown on page 15 1296574. 6. The patent application scope uses a wafer on which at least one heat resistance for heating liquid is formed. On the wafer, at least one layer of photosensitive material is covered. To define at least a first-class track; using a substrate having a surface for separating; on the substrate, covering at least one layer of photosensitive material to define at least one orifice; and the aforementioned wafer with a runner and a substrate having a nozzle The substrate is bonded to the wafer, and the substrate is separated by the surface to separate the material from the material forming the nozzle to form a microfluidic structure. The method for fabricating the microfluidic structure of the inkjet head is to use a photosensitive material for forming a flow path, first covering the photosensitive material on the wafer on which the thermal resistance is formed, exposing and developing, and forming a region removed by development 8. A method for producing a microfluidic structure of an ink jet head according to the sixth aspect of the patent, in which a photosensitive material is used for forming an orifice, for exposure and development, and a region to be removed by development forms an orifice. The ink head microfluidic structure comprises at least the following items: at least one spray hole for discharging the liquid, the spray hole layer forming the spray hole is formed on a substrate, and is defined by using at least one photosensitive material; at least one is provided a flow channel for liquid flow, the flow channel layer forming the flow channel is formed on the substrate having the orifice layer, and is defined by using at least one layer of photosensitive material Page 16 1295574 6. The patent application scope is formed; at least one thermal resistance element for heating the liquid is formed on the wafer; after the substrate having the orifice layer and the flow channel layer is attached to the thermal resistance wafer, The orifice layer is separated from the substrate to form the present microfluidic structure. 10. The ink jet head microfluidic structure according to claim 9, wherein the substrate for the orifice layer and the flow channel layer has a material on the surface for separating the orifice layer from the substrate. 11. The ink jet head microfluidic structure according to claim 9, wherein the orifice layer for forming the orifice is formed by using a photosensitive material, and after exposure and development, the photosensitive material is developed and removed to form an orifice. 12. The ink jet head microfluidic structure according to claim 9, wherein the flow path layer for forming the flow path is a photosensitive material, and after the exposure and development, the photosensitive material is developed and removed to form a flow path. 13. A method of fabricating an ink jet head microfluidic structure comprising at least the following item i: using a substrate having a surface for separation thereon; and covering at least one layer of photosensitive material on the substrate to define at least one orifice; The substrate is further covered with at least one layer of photosensitive material to define at least a first-class track; Page 17 cs 1296574 *-6. The patent application scope uses a wafer, and the wafer has at least one thermal resistance for heating the liquid; the substrate with the nozzle and the flow channel is aligned with the wafer; The substrate which is bonded to the wafer is aligned, and the substrate is separated from the material forming the orifice by the material for separation, thereby forming a microfluidic structure. 14. The method for producing a microfluidic structure of an ink jet head according to the above-mentioned Patent Document No. 13, which is to use a photosensitive material for forming an orifice, to expose the development, and to form an orifice by the region where the development is removed. 15. The method of producing a microfluidic structure of an ink jet head according to the above-mentioned Patent Document No. 13, which is to form a flow path by using a photosensitive material for forming a flow path for exposure development and a region to be removed by development. Page 18