KR20080012627A - Inkjet print head and manufacturing method of the same - Google Patents

Abstract

An inkjet print head and a manufacturing method thereof are provided to improve printing efficiency by preventing foreign materials generated in a dicing process from entering an inkjet print head or adhering to a pad unit. An inkjet print head includes a substrate(111), a nozzle unit formed on the substrate and spraying ink droplets, a pad unit(271) formed on the substrate so as to couple the nozzle unit electrically, a cut-off unit(279) formed between a dicing line and the pad unit, and a protection member(400) covering the nozzle unit, the pad unit and a cut-off unit.

Description

Inkjet print head and manufacturing method thereof {Inkjet print head and manufacturing method of the same}

1 is a perspective view showing the main part of an ink jet image forming apparatus having an ink jet print head of the present invention.

FIG. 2 is a perspective view of the inkjet print head cartridge shown in FIG. 1.

FIG. 3 is a plan view illustrating an inkjet printhead corresponding to part A of FIG. 2.

4 is a side cross-sectional view of the cut line II ′ of FIG. 3 showing a vertical structure of the inkjet print head of the present invention.

5 is a perspective view schematically showing a dicing process of the inkjet print head of the present invention.

FIG. 6 is a side cross-sectional view of the inkjet print head of the II-II ′ cutting line of FIG. 5.

<Explanation of symbols for the main parts of the drawings>

111 substrate 112 insulation layer

113 Heater 114 Electrode

115 ... Protective Layer

116.Anti-cavitation layer

120 chamber chamber 122 ink chamber

126 Ink feed hole 130 Nozzle floor

132 ... Nozzle 161C, 161M, 161Y, 161K ... Nozzle Row

211 Driving means 212 Platen

215a, 215b ... feed roller 252 ... inkjet printhead cartridge

255 ... body 256 ... ink channel unit

Ink ejection 260 Inkjet print head

270 ... FPC (flexible printed circuit) 271 ... pad part

279.Block 310 ... wafer

320 ... dicing cutter 400 ... protective member

C-C '... dicing line

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet printhead and a method of manufacturing the same, and more particularly, to an inkjet printhead and a method of manufacturing the same, which can prevent contamination of the inkjet printhead by foreign matters generated in a unit chip cutting process.

In general, an inkjet printer prints an image of a predetermined color by ejecting a small droplet of ink from an inkjet print head to a desired position on a print medium. Such inkjet printers include inkjet print heads for injecting ink onto a print medium, and inkjet print heads are classified into two types, a shuttle method and an array method.

The shuttle type inkjet print head ejects ink while being reciprocated in a direction perpendicular to a conveying direction (hereinafter referred to as a sub-scanning direction) of the print medium (hereinafter referred to as a main scanning direction). The array type print head has a nozzle row in which nozzles for ejecting ink are arranged in the main scanning direction by the width length of the print medium. Like the shuttle type print head, the nozzle rows are arranged by swath width along the sub-scanning direction. Ink jetting to the first swath is performed at a time while the printing medium and the array type print head are stopped. When the ink ejection to the first swath is completed, the print medium is moved by a swath width, and ink ejection is performed at a time with respect to the second swath. An inkjet printer employing an array-type printhead ejects ink while only the print media is transferred while the printhead is fixed, thereby enabling high-speed printing.

In such an array-type inkjet printhead as well as a shuttle-type inkjet printhead, the number of nozzles is increasing exponentially while the size of the nozzles is reduced for high quality and high speed printing. In general, an inkjet printhead includes a plurality of nozzles for ejecting ink, an ink chamber filled with ink, a heater for providing ink output, and a pad portion for applying driving power or a control signal to the inkjet printhead. Equipped.

The inkjet print head is manufactured by using a MEMS process according to an increase in the nozzle density, and a large amount of particles (dice) is used in a dicing process in which a plurality of wafers in which the inkjet print head is formed are cut into unit chips. particles occur. Most of these particles are washed out with coolant and separated to the outside. However, some of the particles are introduced into nozzles, ink chambers, etc. as foreign matters, which may cause contamination that prevents ink from being discharged, or may be attached to pads, causing malfunction of the inkjet print head.

SUMMARY OF THE INVENTION The present invention has been made in an effort to improve the above-described problems, and provides an inkjet print head and a method of manufacturing the same, which can prevent foreign substances generated in the dicing process from entering the inkjet print head or being attached to the pad part. will be.

In order to achieve the above object, the inkjet printhead of the present invention,

An inkjet printhead comprising a substrate and a nozzle portion formed on the substrate to eject ink droplets, the inkjet printhead comprising:

A pad portion formed on the substrate for electrical connection of the nozzle portion;

A blocking portion formed between a dicing line of the inkjet print head and the pad portion;

A protective member detachable before and after dicing cutting out the plurality of inkjet print heads formed on the wafer into unit chips, the protective member covering the nozzle portion, the pad portion, and the blocking portion; It includes, and the foreign matter generated during the dicing is characterized in that blocked by the protective member and the blocking unit.

Here, the nozzle portion and the blocking portion is preferably formed to be substantially the same height. In one embodiment, the height difference between the nozzle unit and the blocking unit is within 20 μm.

It is preferable that the said protective member is an adhesive tape provided with at least one material of PVC, PET, an ultraviolet curable resin, and an ultraviolet curable resin.

Preferably, the pad portion is formed at a height lower than that of the nozzle portion and the blocking portion. Thus, the protective member may contact the nozzle portion and the blocking portion and be spaced apart from the pad portion when attached to the inkjet print head.

On the other hand, the manufacturing method of the inkjet print head of the present invention,

A method of manufacturing an inkjet printhead comprising a dicing process of cutting a plurality of inkjet printheads formed on a wafer into unit chips, wherein the protection member is pre-attached on the wafer and the inkjet along a dicing line. By providing a blocking portion on the substrate of the print head, foreign matters generated during the dicing is blocked by the protective member and the blocking portion.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention. Embodiments of the invention are not limited to what is shown in the accompanying drawings, it is to be understood that various modifications can be made within the scope of the same invention.

1 is a perspective view showing the main part of an ink jet image forming apparatus having an ink jet print head of the present invention. FIG. 1 shows an inkjet image forming apparatus of a line printing method in which the nozzles 132 are arranged at least as wide as the width of the printing medium P to print line by line. The printing medium P is conveyed in the x direction (hereinafter referred to as sub-scanning direction), which is its longitudinal direction, and the y direction (hereinafter referred to as main scanning direction) is the width direction of the printing medium P.

The inkjet image forming apparatus includes an inkjet printhead cartridge 252 to which the array type inkjet printhead 260 is mounted and fixed to the inkjet image forming apparatus, and between the inkjet printhead 260 and the printing medium P. Platen 212 for guiding print medium P conveyed by providing a gap, feed rollers 215a and 215b for conveying print medium P toward inkjet print head cartridge 252, and Driving means 211 for driving feed rollers 215a and 215b is provided. Although not shown, a shuttle type inkjet print head is of course possible as an embodiment of the present invention.

FIG. 2 is a perspective view of the inkjet print head cartridge shown in FIG. 1. FIG. 3 is a plan view illustrating an inkjet printhead corresponding to part A of FIG. 2. 4 is a side cross-sectional view of the cut line II ′ of FIG. 3 showing a vertical structure of the inkjet print head of the present invention.

2 to 4 together, the inkjet printhead cartridge 252 is a body 255 having an ink tank (not shown) for storing ink for each color, and the inkjet printhead 260 is printed One or more ink ejecting portions 257 mounted along the width direction of the medium P, and an ink channel unit 256 for supplying the ink stored in the ink tank to the inkjet print head 260. The main scanning direction length of the ink ejecting portion 257 corresponds at least to the width size of the print medium P, and the print data is simultaneously printed in the main scanning direction.

For color printing, for example, four types of nozzle rows 161C, each for spraying ink of cyan, magenta, yellow, and black colors, respectively, may be used. 161M, 161Y, and 161K are provided in the inkjet print head 260. The ink channel unit 256 forms an ink passage from the ink tank to the back of the inkjet print head 260. In one embodiment, the ink channel unit 256 is formed by injection molding a liquid crystal polymer (LCP) material to improve thermal stability, durability, and productivity.

The inkjet print head 260 is connected to a controller (not shown) of the inkjet image forming apparatus through a flexible printed circuit (FPC) 270, receives a driving signal, and receives power for ink jetting. The inkjet print head 260 has a pad part 271 electrically connected to the FPC 270 to receive a driving power or a control signal. A blocking portion 279 is formed between the dicing line C-C ′ and the pad portion 271 extending along the edge of the inkjet print head 260 to block foreign substances generated during dicing.

The illustrated inkjet print heads 260 are spaced apart at predetermined intervals along the main and sub-scanning directions and arranged in zigzag form. Although not shown, an embodiment in which one or a plurality of inkjet print heads 260 are arranged in a straight line along the y axis over at least a length corresponding to the width of the print medium P is possible. That is, the inkjet print head 260 of the present invention is not affected by the arrangement, and can be applied to all types of inkjet printheads including the shuttle method as well as the shuttle method.

When the inkjet print heads 260 are arranged in a zigzag as shown in the drawing, the controller (not shown) detects the x-axis deviation of each of the inkjet printheads 260 and the transfer amount of the print medium P, thereby providing different inkjet prints. The ink ejection positions of the nozzle rows 161C, 161M, 161Y, and 161K located in the head 260 are synchronized in the x-axis direction. For example, the black nozzle rows 161K formed on the different inkjet printheads 260 are not positioned on the same straight line along the y-axis direction, but the x-axis deviation of the inkjet printhead 260 and the print medium ( By synchronizing the ink jetting positions in the x-axis direction based on the feed amount of P), the ink dots printed on the printing medium P can be formed on the same straight line parallel to the y-axis. The nozzle pitch ΔP, which is the distance between neighboring nozzles 132, determines the resolution of the inkjet image forming apparatus. Assuming that the nozzle pitch ΔP is 1/600 inch, the printing resolution of the inkjet image forming apparatus is 600 dots per inch (dpi).

Hereinafter, the vertical structure of the inkjet print head 260 will be described. The inkjet print head 260 of the present invention includes a substrate 111 having a heater 113 and an electrode 114 formed thereon, a chamber layer 120 having an ink chamber 122 formed thereon, and being stacked on the substrate 111. And a nozzle layer 130 having a nozzle 132 formed on the chamber layer 120. Generally, a silicon material is used as the substrate 111.

An insulating layer 112 is formed on the upper surface of the substrate 111 to insulate and insulate between the substrate 111 and the heater 113 formed thereon. The insulating layer 112 may be generally made of silicon oxide (SiO ₂ ). On the upper surface of the insulating layer 112, a heater 113 for heating bubbles in the ink chamber 122 to generate bubbles is formed in a predetermined shape. Electrodes 114 for electrically applying the current to the heater 113 are formed on both upper surfaces of the heater 113. The electrode 114 may be made of a metal having good electrical conductivity, for example, aluminum (Al). In order to protect the electrode 114 from ink, a passivation layer 115 may be formed to cover the electrode 114. The protective layer 115 may generally be made of silicon nitride (SiN _x ). An anti-cavitation layer 116 is formed on the passivation layer 115. The cavitation prevention layer 116 is to protect the heater 113 and the electrode 114 from the cavitation force (cavitation force) generated when the bubbles disappear, mainly made of tantalum (Ta).

A chamber layer 120 having an ink chamber 122 filled with ink to be discharged is stacked on the substrate 111 on which the heater 113, the electrode 114, and the protective layer 115 are formed. The chamber layer 120 may be made of a polymer. Here, the ink chamber 122 is positioned above the heat generating portion of the heater 113. Accordingly, the heat generating portion of the heater 113 is located at the bottom surface of the ink chamber 122 and is in direct contact with the ink in the ink chamber 122.

The nozzle layer 130 having the nozzle 132 through which ink in the ink chamber 122 is discharged is stacked on the chamber layer 120. The nozzle layer 130 may be made of a polymer. Here, the nozzle 132 may be formed at a position corresponding to the center of the ink chamber 122. In the illustrated embodiment, the top-shooting inkjet print head 260 has been described as an example, but is not limited thereto, and an inkjet printhead of the side-shooting or back-shooting method is also possible.

5 is a perspective view schematically showing a dicing process of the inkjet print head of the present invention. FIG. 6 is a side cross-sectional view of the inkjet print head of the II-II ′ cutting line of FIG. 5. 5 and 6, a blocking unit and a protection member for blocking foreign substances generated during the dicing process will be described.

In the present invention, the nozzle unit is used as a term to refer to both the chamber layer 120 filled with ink and the nozzle layer 130 for spraying the ink filled therein. The nozzle unit is formed on the substrate 111 to perform a function of ejecting ink droplets. Ink is filled in the ink chamber 122 through the back of the inkjet print head 260 and the ink feed hole 126, and then ejected from the nozzle 132 by the expansion force of the bubbles generated by the heater (see FIG. 4, 113). A pad part 271 for applying a driving power and a control signal for the operation of the nozzle part is formed on the substrate 111.

The inkjet print head 260 is manufactured using a MEMS process as its size is downsized, and a plurality of inkjet print heads 260 formed on the wafer 310 have a dicing line C-C 'in a dicing process. Along the unit chip is cut. Although the inkjet print head 260 is arranged in FIG. 5 so that the pad part 271 faces, the order and shape of arranging the inkjet print head 260 on the wafer 310 are not limited to those illustrated.

In the dicing process by the dicing cutter 320, a large amount of foreign matter is generated, and the foreign matter starts to diffuse in the space 330 as shown in FIG. 6 and is attached to the pad part 271 to attach the pad part 271. ) May affect the electrification characteristics of the c) or may flow into the nozzle 132, the ink chamber 122, and the ink feed hole 126 to prevent the ejection of the ink.

In order to prevent the scattering of foreign matter, a blocking unit 279 and a protecting member 400 are provided. The protection member 400 is attached onto the wafer 310 before the dicing process to cover the nozzle portion, the pad portion 271, and the blocking portion 279. In one embodiment, the protective member 400 is preferably an adhesive tape formed of at least one of PVC, PET, Teflon resin, and ultraviolet curable resin. When the dicing process is completed, the protection member 400 is removed to open the pad part 271 and the nozzle part. However, the protection member 400 alone cannot reliably block the flow of foreign matter diffused from the dicing line C-C 'toward the pad portion 271.

As a countermeasure against this, a blocking part 279 is provided between the nozzle part and the dicing line C-C 'to block the movement of foreign matter diffused from the space of the reference numeral 330 to the pad part 271 and the nozzle part. In order to make the adhesion of the protection member 400 uniform and to improve the sealing property against foreign matter, the nozzle part and the blocking part 279 are preferably formed at substantially the same height. In one embodiment, the height difference between the nozzle portion and the blocking portion 279 is preferably within 20 μm.

As a result of the experiment, the movement of foreign matter is blocked by the blocking unit 279 as a result of attaching a protective member 400 made of a relatively stretchable PVC material and a nearly elastic PET material on the wafer 310 and performing a dicing process. Could observe. When the protective member 400 includes a general adhesive, external force is applied to detach the protective member 400. When the protective member 400 is made of an ultraviolet curable resin, the protective member 400 is attached to or removed from the wafer 310 depending on whether or not the ultraviolet light is irradiated. When the protection member 400 is made of a foamed resin, the amount of bubble generation changes with the addition of a predetermined gas or heat and is attached to and removed from the wafer 310.

When using a flexible PVC protective member 400, the protective member 400 is stuck to the pad portion 271, so that the protective member 400 may not be properly removed and the electrical conductivity of the pad portion 271 may be affected. There is. In order to prevent this, the pad part 271 is preferably formed at a height lower than that of the nozzle part and the blocking part 279. At this time, when the protection member 400 is attached to the wafer 310, the protection member 400 is in contact with the nozzle unit and the blocking unit 279 and is spaced apart from the pad unit 271.

In the manufacturing method of the inkjet print head 260 composed of various processes, the protective member 400 is previously attached to the wafer 310 on which the nozzle portion, the pad portion 271 and the blocking portion 279 are formed, and dicing. By performing the process, foreign matters can be prevented from contaminating the nozzle unit and the pad unit 271. Here, the blocking portion 279 is preferably formed on the substrate 111 at the same height as the nozzle portion along the dicing line C-C '. After the dicing process is completed, the protection member 400 is removed by external force, ultraviolet rays or heat, or the like, and the nozzle unit and the pad unit 271 are opened to the outside.

As described above, according to the inkjet printhead of the present invention and a method of manufacturing the same, contamination of foreign matter generated in the dicing process into the nozzle unit or adhered to the pad unit is prevented by the blocking unit and the protection member, thereby preventing the The failure rate can be reduced in malfunction and wafer fabrication processes.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and various modifications and equivalent other embodiments are possible to those skilled in the art. Will understand. Therefore, the true technical protection scope of the present invention will be defined by the claims below.

Claims (6)

An inkjet printhead comprising a substrate and a nozzle portion formed on the substrate to eject ink droplets, the inkjet printhead comprising: A pad portion formed on the substrate for electrical connection of the nozzle portion; A blocking portion formed between a dicing line of the inkjet print head and the pad portion; A protective member detachable before and after dicing cutting out the plurality of inkjet print heads formed on the wafer into unit chips, the protective member covering the nozzle portion, the pad portion, and the blocking portion; Including; The foreign matter generated during the dicing is blocked by the protective member and the blocking portion, the inkjet print head. The method of claim 1, And the nozzle portion and the blocking portion are formed at substantially the same height. The method of claim 1, The protective member is an inkjet print head, characterized in that the adhesive tape is made of at least one of PVC, PET, Teflon resin, UV curable resin. The method according to any one of claims 1 to 3, And the pad part is formed at a lower height than the nozzle part and the blocking part. The method of claim 4, wherein And the protective member is in contact with the nozzle part and the blocking part when attached to the inkjet print head and spaced apart from the pad part. In the manufacturing method of an inkjet printhead comprising a dicing step of cutting a plurality of inkjet printheads formed on a wafer into unit chips, The protective member is pre-attached on the wafer and provided with a blocking portion on the substrate of the inkjet print head along a dicing line, so that foreign matters generated during the dicing are blocked by the protective member and the blocking portion. Method for producing an inkjet print head.

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