JP2007307833A - Inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure a higher reliability for the sealing structure of the mounting section of an inkjet head which is connected with a wiring substrate by bonding while reducing the manufacturing cost by decreasing the number of parts. <P>SOLUTION: In the sealigng structure of the mounting section of the inkjet head which is connected with the wiring substrate by bonding, an inner lead of the wiring substrate is completely coated with a base film of the wiring substrate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inkjet head that performs recording by discharging a recording liquid from an ejection port, and a method for manufacturing the same.

  Among conventional recording methods, an ink jet recording method that performs recording on a recording medium by ejecting ink from an ejection port has been widely adopted in recent years because it can perform a recording operation at a high density and at a high speed. ing.

  A general recording apparatus that employs this method includes an inkjet head that ejects ink for recording an image on a recording medium, and a conveying apparatus for the recording medium.

  The inkjet head uses an electromechanical transducer element such as a piezo element or an electrothermal transducer element such as a heating resistor in a nozzle communicating with the ejection port in order to eject ink droplets from the ejection port. And those using electromagnetic wave mechanical transducer elements or electromagnetic heat transducer elements of radio waves or lasers. Among them, an ink jet recording apparatus that discharges ink droplets using thermal energy can perform high-resolution recording because the nozzles can be arranged at high density.

  In particular, an ink jet head using an electrothermal transducer element as a thermal energy generating element is easier to miniaturize than an inkjet head using an electromechanical transducer element, and further advances and reliability in recent semiconductor manufacturing fields. By applying IC technology and micro-machining technology, which are remarkably improved, and making full use of their advantages, high-density mounting can be easily provided at low cost.

  A wiring board whose base material is made of glass / epoxy or the like for transmitting an electrical signal sent from the recording apparatus main body to a heater board (hereinafter referred to as HB) provided with a conversion portion of such a conversion body is an inkjet head. It is arranged as a part. The wiring board is provided with contact pads that are in contact with and electrically connected to the flexible wiring board of the recording apparatus main body. The HB and the wiring board are connected to each other through a TAB tape wired from the inner lead to the outer lead. Specifically, the HB and TAB tape are connected by bonding gold bumps formed on the HB pads and inner leads formed on the TAB tape by bonding. Further, the TAB tape and the wiring board are connected by interposing the ACF tape between the respective pads and performing a thermal load process using the ACF.

  In addition, cover sealing is essential for each electrical connection portion in order to prevent corrosion due to ink from the outside, short circuit, and the like, and it is necessary to use different sealing agents depending on the material and application of the sealing portion.

  As a sealing technique used for the connecting portion between the HB and the TAB tape of the above-described inkjet head, two sealing agents having different properties are used above and below the inner lead as a boundary.

  Also, the sealing process is complicated, and after the lower sealant is applied, it is cured by applying heat curing, and then the upper sealant is applied and then heated again to complete.

For example, Patent Document 1 can be cited as a conventional example.
JP 2004-351754 A

  The reason why such a complicated sealing process is performed will be described below.

  In the lower sealing, an item “low viscosity and want to have elasticity after curing” is required. As described above, a plurality of HBs are arranged as described above, but the gaps between the arrangements are very small, and therefore, it is required that the flow does not flow by capillary force unless the type has a low viscosity. In addition, since HB is made of silicon, it has a character that is very vulnerable to thermal shock, and it must be a sealing agent that has elasticity even after thermosetting.

  On the other hand, in the upper sealing, an item of “high viscosity and does not want to have elasticity after curing” is required. In this case, since the sealant must be applied only on the inner lead portion, if the viscosity is low, it may flow out to an excessive point. In order to provide durability to the blade for removing ink adhering to the vicinity of the nozzle provided in the recording main body, it must be a sealing agent having as little elasticity as possible after curing. .

  For both of these reasons, two types of sealants having contradictory properties are used, but as described above, the sealing process is complicated, and the sealants having different properties are continuously used. For this reason, the heat curing conditions and the like are very severe. In addition, when the cured state is unstable, the two types of sealants may not be completely cured due to the mutual compatibility, sometimes leading to an electrical short due to the penetration of ink etc. from the outside There are also problems that cannot be avoided under curing conditions and the like, and alternative techniques are desired.

  Therefore, in view of the above problems, the object of the present invention is that the inner lead portion can be reliably sealed, there is no influence on the electrical connection portion due to environmental changes, and the sealing process can be simplified. The present invention provides a highly reliable sealing structure and sealing means that satisfy all of the problems that lead to an improvement in productivity.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a nozzle that communicates with an opening that discharges liquid droplets, a liquid storage unit that stores liquid supplied to the nozzle, and the liquid storage unit from outside. A mounting portion in an ink jet head having a liquid introducing portion for introducing a liquid into the inner lead, after the ink jet configuration has positioned and arranged a plurality of HBs on an alumina chip plate. Inkjet recording is performed by positioning and bonding a TAB provided with the HB to the HB and bonding the TAB inner leads in a one-to-one relationship with bumps on a pad provided on the HB in advance. In the head, the TAB base film completely covers the upper part of the inner lead, and the inner lead bonding part Sealing structure is preferable.

  Moreover, in order to achieve the said objective, it is preferable that the 2nd aspect of this invention fills the sealing agent in the lower part of the said base film.

  In order to achieve the above object, in the third aspect of the present invention, the base film is preferably a polyimide resin.

  In order to achieve the above object, according to a fifth aspect of the present invention, there is provided a nozzle communicating with an opening for discharging a droplet, a liquid storage part for storing a liquid supplied to the nozzle, and the liquid from the outside. A mounting structure in an ink jet head having a liquid introduction section for introducing a liquid into a storage section, wherein the inkjet configuration has a plurality of HBs positioned and arranged on an alumina chip plate; The TAB with the inner leads is positioned and bonded to the HB, and the TAB inner leads are bonded one-to-one with the bumps on the pads previously provided on the HB to conduct the TAB. In an ink jet recording head, an inner lead bonder in which the TAB base film completely covers the upper part of the inner lead. Wherein the sealing method of the portion, the manufacturing method of the ink jet head is preferred.

  As described above, according to the sealing structure and the sealing method of the inkjet head of the present invention, compared to the technique using two types of sealing agents having different compositions up and down with the conventional inner lead as a boundary, The inner lead can be completely covered with one kind of sealant, and the reliability with respect to the ingress of ink or the like from the outside is dramatically improved.

  In addition, with the conventional sealant applied on the inner lead, cracks may occur during curing, or it may be scraped off or worn by the blade of the main body, but by using the cover member of the present invention, the strength can be increased. From this point of view, the reliability of the main body blade is improved.

  In addition, since a TAB base film is used without using a high-viscosity sealant, the convex portion of the face surface does not occur, and the distance between the paper and the head can be reduced, which is advantageous for the landing of ink droplets. In addition, there is no wiping left behind by the blade of the main body.

  In terms of cost, the use of a TAB base film reduces the number of parts, and the process requires only one application of sealant and one heat cure, reducing tact time and reducing costs. It becomes.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, an example of an ink jet recording apparatus using an ink jet head to which the head of the present invention is applied will be described.

  FIG. 1 is a perspective view showing a schematic configuration of an ink jet recording apparatus according to an embodiment of the present invention.

  The ink jet recording apparatus shown in FIG. 1 repeats the reciprocating movement (main scanning) of the ink jet head 201 and the conveyance (sub scanning) of recording sheets S such as general recording paper, special paper, and OHP film at a predetermined pitch. This is a serial type ink jet printer that forms characters, symbols, images, and the like by selectively ejecting ink from the ink jet head 201 and making it adhere to the recording sheet S while synchronizing with these movements.

  In FIG. 1, an inkjet head 201 is detachably mounted on a carriage 202 that is slidably supported by two guide rails and reciprocated along the guide rails by a driving means such as a motor (not shown). The recording sheet S is opposed to the ink ejection surface of the inkjet head 201 by the conveying roller 203 and crosses the moving direction of the carriage 202 so as to maintain a constant distance from the ink ejection surface (for example, It is conveyed in the direction of arrow A, which is a direction orthogonal to each other.

  The inkjet head 201 has a plurality of nozzle rows for ejecting inks of different colors. A plurality of independent main tanks 204 are detachably attached to the ink supply unit 205 in accordance with the color of ink ejected from the inkjet head 201. The ink supply unit 205 and the inkjet head 201 are connected to each other by a plurality of ink supply tubes 206 corresponding to the colors of the ink, and the main tank 204 is mounted on the ink supply unit 205 so that the ink is stored in the main tank 204. Each color ink can be independently supplied to each nozzle row of the inkjet head 201.

  A recovery unit 207 is disposed so as to face the ink ejection surface of the inkjet head 201 in a non-recording area that is within the reciprocating range of the inkjet head 201 and outside the passing range of the recording sheet S. Yes.

  The appearance of the inkjet head 201 used in the ink supply method described above is as shown in FIG. 2, for example. FIG. 2 shows an external view of the ink jet head 201 as viewed obliquely from below. FIG. 2 shows an inkjet head 201 in which a plurality of nozzles are arranged. The ejection port 210 is an opening of the nozzle 201g, and a row composed of the plurality of ejection ports is parallel to the carriage movement direction B. A plurality are arranged.

  Next, a detailed configuration of the inkjet head will be described along each step with reference to FIGS. 3 and 4.

  First, FIG. 3-a is a macula pasting process.

  After the adhesive 223 is applied to the alumina chip plate 221, the same alumina pillow 222 is positioned and pasted, and heat is applied from above to complete the adhesive.

  Subsequently, FIG. 3B shows a chip mounting process.

  A plurality of HBs 224 are positioned and attached to the previously completed chip plate connection. Here, the four HB 224 are pasted into one and three sheets. The adhesive 225 in this case is previously applied to the back surface of the HB 224 by a transfer method.

  Subsequently, FIG. 3C shows a TAB bonding process and a bonding process.

  After the adhesive 227 is applied to the previously completed chip mount unit, the TAB 226 is positioned and pasted, and the adhesive 227 is cured by applying heat from above.

  Thereafter, the inner leads (not shown) of the TAB 226 are bonded one-to-one with gold bumps (not shown) provided in advance on the pads of the terminals on the HB 224.

  Subsequently, FIG. 3D illustrates a cover sealing process of the bonding portion.

  This is performed in order to prevent the entry of external force or ink from the outside.

  First, the sealing agent (1) 228 is injected. In this case, it is necessary to make sure to wrap around the HBs 224 arranged in advance. In particular, since the gap between the HBs 224 is very small, a sealant with better flowability is preferable. After the injection is completely completed, the sealant (1) 228 is cured by applying heat curing.

  Next, a sealant (2) 229 is applied over the inner lead. In this case, since it is difficult to flow out to an extra portion, a sealant having a higher viscosity is preferable. After the application is completely completed, heat curing is performed again to cure the sealant (2) 229, and the chip unit 220 is completed.

  Subsequently, FIG. 4A shows a chip unit bonding step.

  After the adhesive is applied to the sub tank unit 232 made of mold, the previously completed chip unit 220 is positioned and pasted, and the adhesive is cured by applying heat curing.

  Subsequently, FIG. 4B is a PWB bonding process.

  Here, a wiring board (hereinafter referred to as PWB) 231 for receiving an electrical signal transmitted from the main body is electrically connected to the TAB 226. Both TAB 226 and PWB 231 are provided with connection pads in the same shape, and in the present invention, connection is performed by thermocompression bonding via an ACF tape.

  Thereafter, the PWB 231 is lifted and fixed to the sub tank unit 232 by heat caulking or the like, and the above-described inkjet head 201 is completed.

  The configuration of the conventional head has been described in detail above. Next, FIGS. 5 and 6 that best illustrate the present invention will be described. FIG. 5 shows the structure of the TAB used in the present invention, and FIG. 6 shows an alternative process using the TAB and corresponding to the bonding process and cover sealing process shown in FIGS.

  First, TAB 226 will be described. The inner lead 226d is completely covered with the base film 226a. Subsequently, the adhesive surface between the base film 226a and the inner lead 226d is peeled off with a solvent or a sharp blade. The peeled portion is up to the cover film 226c. Through the above steps, the TAB 226 shown in FIG. 5 can be formed.

  Next, FIG. 6 showing an alternative process corresponding to the bonding process and cover sealing process of FIGS.

  First, as shown in FIG. 6A, the base film 226a of the TAB 226 is fixed with a pressing jig 241 so that it does not interfere with the used cavity 240 during bonding. Next, the inner lead 226a is bonded, and the fixing 241 of the presser is released. The base film 226a returns to its original shape with elasticity and covers the inner lead 226a.

  Next, as shown in FIG. 6B, a sealant with good flowability is poured into the entire periphery of the HB 224 including the inside of the base film 226a. Here, it is possible to use the sealing agent (1) 228 for lower sealing which has been conventionally used.

  Other than this, there is no limitation if there is a sealant with good flowability.

  The sealant with good flowability instantaneously flows inside the base films 226a and HB224 by capillary force, and it becomes possible to completely fill the periphery of the HB and the lead portion with one kind of sealant. In this state, the chip unit 220 is completed by applying heat curing.

  In the present invention, unlike the prior art, the inner lead 226a can be completely covered with only one type of sealing agent, and the reliability with respect to the penetration of ink or the like from the outside is improved.

  Moreover, since the sealing agent application process and the heat curing process are each performed once, it contributes to tact improvement in the process.

1 is a schematic configuration diagram of an ink jet recording apparatus of the present invention. It is an external view of the inkjet head of the inkjet recording apparatus of this invention. It is the schematic model explaining the mounting process of the inkjet head in a prior art example. It is the schematic model explaining the assembly process of the inkjet head. It is a schematic block diagram of TAB of this invention. It is the schematic model explaining a part of inkjet head mounting process of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 201 Inkjet head 201a Connector insertion port 202 Carriage 203 Conveyance roller 204 Main tank 205 Ink supply unit 206 Ink supply tube 207 Recovery unit 210 Discharge port 213 Protection cap positioning boss 215 Hook part 220 Chip unit 221 Chip plate 222 Macula 223 Adhesive 224 HB
225 Adhesive 226 TAB
226a Base film 226b Adhesive 226c Cover film 226d Inner lead 227 Adhesive 228 Sealant (1)
229 Sealant (2)
231 PWB
232 Sub tank unit 240 Capillary 241 Holding jig 242 Stud bump

Claims (4)

Mounting in an inkjet head having a nozzle communicating with an opening for discharging droplets, a liquid storage part for storing liquid supplied to the nozzle, and a liquid introduction part for introducing liquid into the liquid storage part from the outside Part sealing structure,
In the inkjet configuration, after a plurality of HBs were positioned and arranged on an alumina chip plate, a TAB having an inner lead was positioned and bonded to the HB, and was previously provided on the HB. In an inkjet recording head that conducts conduction by bonding a TAB inner lead in a one-to-one relationship with a bump on a pad,
An ink jet head characterized by a sealing structure of an inner lead bonding portion in which a TAB base film completely covers an upper portion of an inner lead.   2. The ink jet head according to claim 1, wherein the base film is filled with a lower sealant.   The inkjet head according to claim 1, wherein the base film is made of a polyimide resin. Mounting in an inkjet head having a nozzle communicating with an opening for discharging droplets, a liquid storage part for storing liquid supplied to the nozzle, and a liquid introduction part for introducing liquid into the liquid storage part from the outside Part sealing structure,
In the inkjet configuration, after a plurality of HBs were positioned and arranged on an alumina chip plate, a TAB having an inner lead was positioned and bonded to the HB, and was previously provided on the HB. In an inkjet recording head that conducts conduction by bonding a TAB inner lead in a one-to-one relationship with a bump on a pad,
A method of manufacturing an ink-jet head, comprising: a method of sealing an inner lead bonding portion, wherein a TAB base film completely covers an upper portion of an inner lead.

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