JPH09118017A - Method for forming nozzle structure of ink-jet print head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a highly automated ink jet printing head. SOLUTION: A composite structure containing a nozzle layer 10 and an adhesive layer 24 is provided and a polymeric sacrifice layer 28 is applied to the adhesive layer. Laser ablation is applied to the coated composite structure to form one or more nozzle 20 to the structure and, subsequently, the sacrifice layer is removed. This sacrifice layer is pref. composed of a water-soluble polymer and most pref. composed of polyvinyl alcohol and water is injected to the sacrifice layer until the sacrifice layer is substantially removed from the adhesive layer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to inkjet printheads and, more particularly, to improved manufacturing techniques for nozzle structures for inkjet printheads.

[0002]

Printheads for ink jet printers are precisely manufactured so that various components cooperate with an integrated ink reservoir to achieve a desired print quality. Despite such precision, printheads with ink reservoirs are discarded when the supply of ink in the reservoir is exhausted. Therefore, there is a need to keep the various components of such an assembly relatively inexpensive, so that the overall cost of printing per page, in which assembly life is a factor, relative to other printer configurations on the market. Will be able to maintain its competitiveness.

In general, the inks and materials used to manufacture the reservoirs and printheads do not make up the largest portion of the manufacturing cost of the printhead assembly. Rather, it is a labor intensive stage in the manufacture of the various components of the printhead itself. Thus, efforts to reduce printhead fabrication costs have the greatest effect on the print cost per page of inkjet printers in which the printhead assembly is used.

1 for reducing the manufacturing cost of the print head
One way is to use highly automated manufacturing techniques. This saves money on highly skilled techniques such as manually performing each stage of manufacturing.
Another way to reduce manufacturing costs is to improve yields across all such automated manufacturing processes. Making printheads at a higher rate reduces the cost per printhead, thereby distributing the manufacturing cost across a larger number of items. Process yields tend to increase as the number of process steps required to make a single part decreases, either reducing the number of process steps required to manufacture a printhead, or producing a complex, low yield. It is desirable to replace the process steps with simpler and higher yield process steps.

Inkjet printheads include: 1) a substrate containing a plurality of resistive elements for exciting components of the ink;
2) Often formed from two or three major components with integrated flow functional structures / nozzle layers for directing the movement of the excited ink. The flow functional structure of the printhead can be included in the nozzle layer or in a separate layer attached to the nozzle layer or substrate. The individual functions, which must cooperate during the printing phase, are included in the above components, which are connected to one another before use. Generally, it is the adhesive that is used to join these components of the printhead together into a unitary structure.

If an adhesive is applied to the one component before the manufacturing stage for one of these components is completed, the adhesive layer is formed during the next various manufacturing stages. May hold debris. Such debris is often difficult to remove, requiring at least an extra process step for removal, increasing the cost of the printhead. Moreover, if such debris is not completely removed, the adhesive bond between the substrate and the nozzle layer can be compromised, resulting in printheads that do not function properly or are expected. It will either not fulfill its useful life.

After the above-mentioned various functional structures are formed on one component as described above, if an adhesive is applied to the one component, the various components are to be used as a bonding surface. Further labor intensive to ensure that the adhesive is located in the parts and that the adhesive is removed from the various parts of the component whose function is suppressed by the presence of the adhesive. Different stages are required. Not only are these extra steps added to the cost of the printhead, but misalignment of the adhesive on the components will reduce product yield from the printhead manufacturing process.

For example, if the adhesive remains in some of the components such as the flow channel for the ink, the proper functioning of that flow channel will be hindered and the printhead will be rendered unusable. Alternatively, if the adhesive does not sufficiently cover the bonding surfaces between the components, these components may separate, allowing ink leakage from the completed assembly. Both of these conditions reduce product yield, which increases the cost of printheads made as described above.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a highly automated method for manufacturing an ink jet print head.

Another object of the present invention is to provide a method of manufacturing an ink jet print head that does not require additional process steps for alignment and removal of adhesive.

A further object of the invention is that the adhesive used to bond the various components together does not attract and hold debris or the like during subsequent process steps.
A method of manufacturing an inkjet printhead is provided.

[0012]

SUMMARY OF THE INVENTION The foregoing and other objects are met by an inkjet printhead according to the present invention.
This is solved by a method of forming a nozzle member. In the present invention, a composite structure comprising a nozzle layer and an adhesive layer is provided, the adhesive layer being coated or coated with a sacrificial polymeric sacrificial layer of polymer. The coated composite structure is laser ablated or laser ablated to form one or more nozzles. After forming the nozzle, the sacrificial layer is removed.

The sacrificial layer is preferably a water soluble polymeric material, such as polyvinyl alcohol, in which substantially all of the sacrificial layer is removed from the adhesive layer by directing a jet of water at the sacrificial layer. Is preferred.

During the critical laser ablation step, the slag and other debris produced by laser ablation of the composite structure often adheres to the sacrificial layer rather than the adhesive layer. Since the sacrificial layer is water-soluble, it can be easily removed by simple water washing techniques, with the result that the debris adhered to it will be carried away with it. In this way, the nozzle structure is free from debris that can cause structural or operational problems without the use of a thorough cleaning process. Moreover, the adhesive can be applied directly to the nozzle structure before the nozzle is manufactured by laser ablation, thus simplifying the manufacturing process.

Further objects and advantages of the present invention will be apparent from the detailed description of the preferred embodiments with reference to the accompanying drawings.

[0016]

1 of the drawings, the main features of a nozzle layer 10 of a printhead composite structure are shown. Nozzle layer 10 is a polymeric material such as polyimide, polyester, fluorocarbon polymer, or polycarbonate, preferably having a thickness of between about 15 and about 200 microns, and most preferably of about 75 microns to about 125 microns. It is the thickness between.

The material from which the nozzle layer 10 is formed can be provided in the form of continuous strips of polymeric material, many nozzle layers of which can be formed in successive or semi-continuous steps. . Sprocket holes or holes 12 may be provided in the strip to aid in handling and positive transfer of the strip of polymeric material through multiple manufacturing steps.

Several important functional structures can be formed in the nozzle layer 10 by various processes described in more detail below. There is an ink distribution channel 14 that receives ink from an ink reservoir (not shown), from which ink is supplied to a plurality of flow channels 16. These flow channels 16 receive ink from the ink distribution channel 14 and supply it to a resistive element (not shown) below the bubble chamber 18.

Exciting one or more resistive elements,
The ink components are vaporized and impart mechanical energy to a portion of the ink to eject the ink through the corresponding nozzles 20 in the nozzle layer 10. The ink exiting the nozzles 20 impinges on the print medium to produce a predetermined pattern of ink spots that result in alphanumeric and graphic images.

The strip material on which the nozzle layer 10 is formed, as shown schematically in FIG.
It is possible to provide it on 2. Ube Company (Japan) and EI duPont de, Wilmington, Del.
Several manufacturers, such as Numours & Co., provide commercially suitable materials for making nozzle layers, either as "UPILEX" or "KAPTON" (trademark), respectively. A more preferred nozzle layer material is formed from a polyimide tape with an adhesive layer 24 thereon, as shown in FIG.

The adhesive layer 24 is preferably any B-staged material that may include thermoplastic polymeric materials. Examples of the thermosetting resin that can be in the B-stage state include phenol resin, resorcinol resin, urea resin, epoxy resin, ethylene urea resin, furan resin,
Includes polyurethane and silicone resin. Suitable polymeric thermoplastic or hot melt materials are ethylene vinyl acetate, ethylene ethyl acrylate, polypropylene,
Includes polystyrene, polyamide, polyester, as well as polyurethane.

In the most preferred embodiment, the adhesive layer 24
Is a laminated "RFLEX R1100" or "RFLEX R100" from Rogers, Inc. of Candler, Arizona.
2 is a phenol butyral adhesive as used in 0 ". The composite structure of nozzle layer 10 and adhesive layer 24 in the position labeled A in FIG. 2 has the cross-sectional morphology shown in FIG. In most applications, the thickness of adhesive layer 24 is between about 1 micron and about 25 microns.

The adhesive layer 24, as shown in FIG.
The sacrificial layer 28 is applied. As the sacrificial layer 28, a thin layer can be applied, and the adhesive layer 24 or the nozzle layer 10 can be applied.
Any polymeric material that can be removed by a solvent that does not interact with it can be used. Water is the preferred solvent and polyvinyl alcohol is just one example of a suitable water-soluble sacrificial layer 28.

Commercially available polyvinyl alcohols that can be used as sacrificial layers include "AIRVOL 165" available from Air Products Inc. and "EM" available from Emulsitone Inc.
S1146 ", including various polyvinyl alcohol resins available from Aldrich. Sacrificial layer 28 is most preferably at least about 1 micron thick and nozzle layer 1
It is preferably applied onto an adhesive layer 24 on a carrier sheet of polyimide forming 0.

Extrusion, roll coating, brush coating, knife coating,
Methods such as spraying, dipping, or other techniques known in the coating or coating industry can be employed to apply sacrificial layer 28 to such composite strips 26.

As shown in FIG. 2, the sacrificial layer 28 may be coated on the composite strip 26 by a coating roller 34 or the like. Composite strip 26 in position B (of FIG. 2)
Has a cross-sectional shape as shown in FIG. 4, and the adhesive layer 24 is disposed between the nozzle layer 10 and the sacrificial layer 28.

Distribution channel 14, flow channel 16, bubble chamber 1 shown in FIG. 1 of nozzle layer 10.
Various functional structures, such as 8, nozzles 20, are preferably formed by laser ablating the composite strip 26 in a predetermined pattern. A laser beam 36 that creates various flow features or flow features in the nozzle layer 10.
Is F2, ArF, KrCl, KrF, or XeCl
It can be generated by a laser 38 such as an excimer laser or a frequency doubled YAG laser.

Laser ablation for the composite structure in FIG. 4 has a power of between about 100 millijoules / square centimeter and about 5,000 millijoules / square centimeter, preferably about 1,500 millijoules / square centimeter. Achieved with the power of. During the laser ablation process, wavelengths between about 150 nanometers and about 400 nanometers, and most preferably about 24 nanometers.
A laser beam having a wavelength of 8 nanometers is applied in a pulsed form that lasts from about 1 nanosecond to about 200 nanoseconds, and most preferably lasts about 20 nanoseconds.

The special functional structure of the nozzle layer 10 is formed by applying a predetermined number of pulses of a laser beam 36 through a mask 40 which is used to precisely position various flow functional structures on the nozzle layer. . As will be made clearer below, many energy pulses are
Fewer energy pulses may be required in the portion of the nozzle 20 in the nozzle layer 10 where material will be removed over a greater transverse depth, resulting in less flow channel 1.
Only some material, such as 6, may be required to be removed from the transverse depth of nozzle layer 10.

The lateral boundaries of the various functional structures in the nozzle layer 10 are defined by a mask 40, which mask 4
0 allows the laser beam 36 to pass through a plurality of holes provided at a plurality of fixed positions in the mask 40,
The laser beam 36 is prohibited from reaching the composite strip 26 at a plurality of other positions of the mask 40. The portions of the mask 40 that allow the laser beam 36 to contact the strip 26 are arranged in a pattern that corresponds to the shape of the various functional structures desired to be formed in the nozzle layer 10.

During the laser ablation process of the composite strip 26 including the sacrificial layer 28, slag and other debris 42 is formed. At least some of these pieces 42 are strips 26
May fall on and adhere. In the present invention, since the upper layer of the strip 26 includes the sacrificial layer 28, these debris 42 will fall and adhere to the sacrificial layer 28 rather than the adhesive layer 24.

If the composite strip 26 did not have the sacrificial layer 28, the debris 42 would fall onto and adhere to the adhesive layer 24. Once attached to adhesive layer 24, debris 42 is difficult to remove, resulting in a product that requires complex cleaning procedures or is unusable. The present invention not only makes it easier to remove these debris 42, but it also increases yield by reducing unusable products.

After laser ablation of the composite strip 26 is complete, the cross-section of the strip 26 at position C, as seen through one of the bubble chambers 18, is as shown in FIG. As can be seen from FIG. 5, the nozzle layer 10
Still includes an adhesive layer 24 protected by a sacrificial layer 28. Debris 42 is shown on the exposed surface of sacrificial layer 28. The relative dimensions of the flow channel 16, bubble chamber 18, and nozzle 20 are also shown in FIG.

If the sacrificial layer 28 is water-soluble, the sacrificial layer 28
And the debris 42 thereon is removed from the water source 46 by the water jet 4
This can be achieved by directing 4 to strip 26. Alternatively, the sacrificial layer 28 can be removed by immersing the strip 26 in water for a time sufficient for the sacrificial layer 28 to dissolve. The temperature of the water used to remove the sacrificial layer 28 ranges from about 20 ° C to about 90 ° C.
A range of ° C is possible. Higher water temperatures tend to reduce the time required to dissolve the sacrificial layer 28 of polyvinyl alcohol. The temperature and type of solvent used to dissolve the sacrificial layer 28 is preferably the sacrificial layer 2.
8 is selected to enhance the dissolution rate of the material selected for use.

The debris 42 and sacrificial layer 28 removed from the adhesive layer are contained in the aqueous waste steam removed from the strip 26. The adhesive-coated composite structure at position D after removal of the sacrificial layer 28 has a cross-sectional morphology as shown in FIG. As can be seen from FIG. 6, this structure includes the nozzle layer 10 and the adhesive layer 24, but prior to the adhesive layer 2
The sacrificial layer 28 applied on the substrate 4 has been removed. The cutting materials 50 of the nozzle layer 10 separated from each other by a cutting blade 56 are then mounted on a silicon heater substrate. Adhesive layer 24 is used to mount nozzle layer 10 on its silicon substrate.

Since the debris 42 formed during the laser ablation of the nozzle layer 10 adheres to the sacrificial layer 28, removal of the sacrificial layer 28 causes such debris 4 formed during the laser ablation process.
Almost all of the two are also removed. Since the water-soluble sacrificial layer 28 is used, the removal of the sacrificial layer 28 and the debris 42 does not require careful and time-consuming operation. Further, the presence of the sacrificial layer 28 during laser ablation effectively prevents debris 42 from contacting and adhering to the adhesive layer 24.
Thus, according to the procedure described above, the adhesive layer 24 may be deposited on the nozzle layer 10 rather than the substrate prior to laser ablation, simplifying the printhead manufacturing process.

Prior to attaching the nozzle layer 10 to a silicon substrate, it is preferable to apply a very thin adhesion promoter to the silicon substrate. Nozzle layer 1 is used as the amount of the adhesion promoter.
The amount should be sufficient to interact with the 0-side adhesive, but should be less than the amount with which it interacts with functional structures such as electrical elements on the substrate side. . Adhesion of the nozzle layer 10 to the silicon substrate is preferably performed by arranging the adhesive layers 24 facing each other on the silicon substrate side, and then the nozzle layer 10 is compressed to the silicon substrate by a heated platen. .

Alternatively, the adhesion promoter can be applied to the exposed surface of the adhesive layer 24 before the sacrificial layer 28 is applied or after the sacrificial layer 28 is removed. Known techniques such as spinning, spraying, roll coating, and brush coating can be used to apply the adhesion promoter to the silicon substrate or the adhesive layer. A particularly suitable adhesion promoter is a reactive silane formulation such as "DOW CORNING Z6032 SILANE" available from Dow Corning, Midland, Mich.

While the preferred embodiment of the present invention is as described above, it is possible to make various changes, rearrangement and replacement of various parts of the present invention without departing from the spirit of the present invention. One of ordinary skill in the art would understand.

[Brief description of the drawings]

FIG. 1 of the nozzle layer in a printhead composite structure,
It is a top view not to scale.

FIG. 2 is a process block diagram showing a manufacturing method of the present invention.

FIG. 3 is a cross-sectional view, not to scale, of a composite structure having a nozzle layer formed therein.

FIG. 4 is a cross-sectional view of the composite structure including a sacrificial layer, not to scale.

FIG. 5 is a cross-sectional view, not to scale, of a nozzle configuration in a composite structure after laser ablation for nozzle formation.

FIG. 6 is a cross-sectional view, not to scale, of the completed composite structure after removal of the sacrificial layer.

[Explanation of symbols]

 10 Nozzle Layer 12 Sprocket Hole 14 Distribution Channel 16 Flow Channel 18 Bubble Chamber 20 Nozzle 22 Reel 24 Adhesive Layer 26 Composite Strip 28 Sacrificial Layer 36 Laser Beam 38 Laser 40 Mask 42 Fragment 44 Water Spray 46 Water Source

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Stephen Robert Complin United States 40515 Kentucky, Lexington, Escondida Way 2201 (72) Inventor Ashok Mercy United States 40515 Kentucky, Lexington, Woodfield Circle 2376 (72) Inventor Gary Raymond Williams United States 40517 Kentucky, Lexington, Pimlico Parkway 3218

Claims (31)

[Claims] 1. A method for manufacturing an inkjet print head / nozzle member, comprising: preparing a composite structure including a nozzle layer and an adhesive layer; applying a polymeric sacrificial layer to the adhesive layer; Laser ablating the composite structure to form one or more nozzles and removing the polymeric sacrificial layer from the composite structure. 2. The method of claim 1, wherein the nozzle layer comprises a polymeric material. 3. The method of claim 2, wherein the nozzle layer is selected from the group consisting of polyimides, polyesters, fluorocarbon polymers, and polycarbonates. 4. The method of claim 1, wherein the nozzle layer is between about 15 microns and about 200 microns thick. 5. The adhesive layer comprises a phenol resin, resorcinol resin, urea resin, epoxy resin, ethylene urea resin, furan resin, polyurethane resin, silicone resin, ethylene vinyl acetate, ethylene ethyl acrylate,
The method of claim 1, wherein the method is selected from the group consisting of polypropylene, polystyrene, polyamide, polyester, polyurethane resin, and acrylic resin. 6. The method of claim 5, wherein the adhesive layer is phenol butyral. 7. The method of claim 1, wherein the sacrificial layer can be dissolved by a solvent that does not interact with and dissolves the adhesive layer and the nozzle layer. 8. The method of claim 7, wherein the sacrificial layer is a water soluble polymer. 9. The method of claim 8, wherein the sacrificial layer is polyvinyl alcohol. 10. The method of claim 8, further comprising removing the sacrificial layer from the composite structure by immersing the composite structure in water for a time sufficient to dissolve the sacrificial layer. the method of. 11. The method further comprises removing the sacrificial layer from the composite structure by directing a jet of water at the sacrificial layer until the sacrificial layer is substantially removed from the adhesive layer. Item 8. The method according to Item 8. 12. The method of claim 1, wherein the polymeric sacrificial layer is between about 1 micron and about 5 microns thick. 13. The method of claim 1, wherein the laser ablation is performed by a laser selected from the group consisting of excimer lasers and frequency doubled YAG lasers. 14. The laser ablation is performed at a power of between about 100 millijoules / square centimeter and about 5,000 millijoules / square centimeter.
The method of claim 1. 15. The method of claim 1, wherein the laser ablation is performed at a wavelength between about 150 nanometers and about 400 nanometers. 16. The method of claim 1, wherein the laser ablation is performed by applying laser energy at a pulsed laser power that lasts from about 1 nanosecond to about 200 nanoseconds. 17. The method of claim 1, wherein the nozzle layer comprises a plurality of nozzles and flow functional structures. 18. The method of claim 1, further comprising applying an adhesion promoter to the adhesive layer prior to applying the sacrificial layer to the adhesive layer. 19. The method of claim 18, wherein the adhesion promoter is a reactive silane formulation. 20. A method for attaching the nozzle member formed by the method according to claim 1 to a silicon substrate, wherein an adhesion promoter is applied to the silicon substrate, and the adhesion layer faces the silicon substrate. And attaching the nozzle member to the silicon substrate by compressing the nozzle member against the silicon substrate by a heated platen. 21. The method of claim 20, wherein the fixative is a reactive silane formulation. 22. A method of forming one or more ink jet nozzles of polymeric material, the method comprising: applying an adhesive layer to the surface of the polymeric material, and applying a sacrificial layer of polymer to the adhesive layer. Thereby forming a three-layer composite and laser ablating one or more holes in the composite. 23. The polymeric material is selected from the group consisting of polyimides, polyesters, fluorocarbon polymers, and polycarbonates.
The method described in. 24. The adhesive layer comprises a phenol resin, a resorcinol resin, a urea resin, an epoxy resin, an ethylene urea resin, a furan resin, a polyurethane resin, a silicone resin,
23. The method of claim 22, selected from the group consisting of ethylene vinyl acetate, ethylene ethyl acrylate, polypropylene, polystyrene, polyamides, polyesters, and polyurethane resins, and acrylic resins. 25. The method of claim 22, wherein the sacrificial layer is polyvinyl alcohol. 26. The method further comprising removing the sacrificial layer from the adhesive layer by directing a jet of water at the sacrificial layer until the sacrificial layer is substantially removed from the adhesive layer. The method according to 25. 27. The method of claim 22, wherein the laser ablation is performed by a laser selected from the group consisting of excimer lasers and frequency doubled YAG lasers. 28. The method of claim 22, further comprising applying an adhesion promoter to the adhesive layer prior to applying the sacrificial layer to the adhesive layer. 29. The method of claim 22, wherein the adhesion promoter is a reactive silane formulation. 30. A method for attaching the polymer material formed by the method according to claim 22 to a silicon substrate, wherein an adhesion promoter is applied to the silicon substrate, and the adhesion layer is formed on the silicon substrate. A method comprising attaching the polymeric material to the silicon substrate by facing and compressing the polymeric material against the silicon substrate by a heated platen. 31. The method of claim 22, wherein the adhesion promoter is a reactive silane formulation.