JP2008044316A - Liquid ejection recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid ejection recording head which prevents a sealant from dispersing onto a nozzle plate surface, and holds down the width and height of the sealant. <P>SOLUTION: The recording head has a recording element 110, an electric wiring board 130, and an electric joint 140 for electrically jointing the recording element and the electric wiring board. The electric wiring board has a device hole 134 positioned to the recording element in order to expose a discharge port row of the recording element; an auxiliary aperture 135 formed near the device hole and positioned to the recording element so as to expose the electric connection portion; a slit 136 formed so as to be connected to the device hole, and extending from a side of the device hole, opposed to the auxiliary aperture, along a side portion of the auxiliary aperture; a separating band 130a partitioning the device hole from the auxiliary aperture; a first sealing material 121 filled in a lower portion of the separating band; and a second sealing material 122 for sealing the electric joint. The separating band is formed like the U shape between the device hole, the slit, and the auxiliary aperture. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid discharge recording head mounted on a recording apparatus that performs recording by discharging a liquid such as ink.

  A liquid discharge type recording apparatus such as an ink jet printer is a so-called non-impact recording type recording apparatus, which is capable of high-speed recording and recording on various recording media, and hardly generates noise during recording. Have For this reason, the liquid discharge recording head is widely used as a recording apparatus such as a printer, a word processor, a facsimile machine, and a copying machine.

  FIG. 5 is a perspective view showing a main part of a liquid discharge recording head according to a conventional example. FIG. 4A is a perspective view showing a discharge surface, and FIG. 4B is a perspective view seen from the opposite side of FIG.

  As shown in FIG. 5A, a recording head 1001, which is a liquid discharge recording head, includes one or a plurality of recording elements 1100, an electric wiring board 1300, a support member 1500 connected to an ink tank (not shown), and the like. It is composed of The recording element 1100 heats ink by an electrothermal transducer that is a heating resistor, and ejects ink droplets by the action of film boiling. The electrical wiring board 1300 is composed of a base film 1307, an adhesive layer 1308, and wiring 1309 (see FIG. 8B), and applies a drive signal or the like from a recording apparatus main body (not shown) to the recording element 1100. . The support member 1500 includes an ink flow path for supplying ink from the ink tank to the recording element 1100. As illustrated in FIG. 5B, the support member 1500 includes a filter 1504 and a seal rubber 1505 at the connection portion.

  As shown in the exploded perspective view of FIG. 6, the recording element 1100 is fixed to the support member 1500 by an adhesive 1501, and an ejection port array (not shown) of the recording element 1100 is connected to an ink supply port (not shown) of the support member 1500. Connected). The recording element 1100 is electrically connected to the electric wiring board 1300. The electrical wiring board 1300 has an opening 1303 into which the recording element 1100 is incorporated. The electric wiring board 1300 is connected to the support member 1500 so that the inner leads 1302 of the electric wiring board 1300 are connected to the electrode portions 1103 (see FIG. 7B) of the recording element 1100 that is bonded and fixed to the support member 1500. Is positioned. Thereafter, the electric wiring board 1300 is fixed to the support member 1500 with an adhesive 1502. The electrical wiring board 1300 has an external signal input terminal 1301 to which a drive signal or the like from the apparatus main body is input. The bent surface of the electric wiring board 1300 provided with the external signal input terminal 1301 is bonded and fixed to the side surface of the support member 1500 with an adhesive 1503.

  FIG. 7 is a conceptual diagram showing the process of assembling the recording head. FIG. 4A is a perspective view of the recording head, and FIG. 4B is a partially enlarged perspective view of a portion surrounded by a circle C5 in FIG. A main surface of the recording element 1100 is provided with a nozzle plate 1102 including an ejection port array 1101 and an electrode portion 1103. These are incorporated in the opening 1303 of the electric wiring board 1300. An inner lead 1302 is also disposed in the opening 1303. Gold bumps 1104 are formed on the electrode portions 1103, and the inner leads 1302 and the electrode portions 1103 are electrically connected via the bumps 1104 by a TAB (Tape Automated Bonding) mounting technique (see Patent Document 1).

  8A and 8B are diagrams showing a sealing portion of the recording head, in which FIG. 8A is a partially enlarged perspective view of the sealing portion at one end of the recording element, and FIG. 8B is a line AA in FIG. It is a fragmentary sectional view in alignment with. As shown in FIG. 8A, the periphery of the side surface of the recording element 1100 is sealed with a sealant 1201. Furthermore, the electrical connection portion 1400 including the inner lead 1302 is sealed with a sealant 1202, and the electrical connection portion 1400 is protected from ink corrosion and external force (see Patent Document 2).

The sealant 1201 filled around the side surface of the recording element 1100 cannot be directly applied to the back surface of the electrical connection portion 1400 as shown in FIG. Therefore, as the sealant 1201, an elastic sealant that has low viscosity and does not apply stress to the recording element 1100 is used so as to penetrate the back surface of the electrical connection portion. On the other hand, the sealing material 1202 that seals the front side of the electrical connection portion 1400 needs high viscosity and rigidity against external force so as not to spread on the surface of the nozzle plate 1102 including the discharge port array 1101. Therefore, a sealant having different characteristics from the sealant 1201 is used. In order to prevent the sealant from spreading to the nozzle plate surface, an interruption portion may be provided on the nozzle plate surface (see Patent Document 3).
Japanese Patent Laid-Open No. 10-000776 JP 2001-130001 A JP 08-080442 A

The sealing width L ₇ on the distal end side of the inner lead 1302 needs to have a width that takes into consideration the performance of the sealing agent coating apparatus and the sealing performance of the sealing agent. However, when the sealing width L ₇ is large, the distance between the nozzle plate 1102 and the electrode portion 1103 (bump 1104) increases, which causes an increase in the size of the recording element 1100.

Further, in order to securely seal the electrical connection portion with the sealant 1202 having high viscosity and poor fluidity, the sealant 1202 is overlapped by a distance L ₁ from the edge of the opening 1303, and further the base It was necessary to apply a height H ₁ on the film 1307. The technique described in Patent Document 3 also requires the height H _{1 in the same} manner in terms of sealing the base film of the electric wiring board. In the recording apparatus, an interval of, for example, about 2 mm is provided between the recording head 1001 and a recording medium such as recording paper so that they do not contact each other. However, as the height of the sealant 1202 on the electric wiring board 1300 is larger, it is necessary to increase the distance between the nozzle plate 1102 and the recording medium, resulting in a decrease in image performance.

  The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and can easily suppress the width and height of the sealant while preventing the sealant from diffusing to the nozzle plate surface. It is an object to provide a simple liquid discharge recording head. Specifically, an object is to provide an improved sealing structure for an electrical connection between a recording element and an electrical wiring board.

  The liquid discharge recording head of the present invention includes a recording element having an ejection port array for discharging a liquid, an electric wiring substrate that supplies electric energy to the recording element, and an electric that electrically connects the recording element and the electric wiring substrate. And a connecting portion. The electrical wiring board is provided close to the device hole, which is positioned with respect to the recording element so as to expose the ejection port array of the recording element, and to the recording element so as to expose the electrical connection portion. A positioned auxiliary opening. The electrical wiring board is also provided in connection with the device hole, and includes a slit extending along the side of the auxiliary opening from a side facing the auxiliary opening of the device hole, and a separation band that partitions the device hole and the auxiliary opening. Have. The electrical wiring board further includes a first sealing material filled below the separation band and a second sealing material that seals the electrical connection portion. The separation band is formed in a substantially U shape between the device hole, the slit, and the auxiliary opening.

  Thus, according to the present invention, it is possible to provide a liquid discharge recording head that can easily suppress the width and height of the sealant while preventing the sealant from diffusing to the nozzle plate surface. That is, it is possible to provide an improved sealing structure for the electrical connection between the recording element and the electrical wiring board.

The liquid discharge recording head of the present invention is applied not only to a general printing apparatus but also to a recording apparatus such as a copying machine, a facsimile machine, a word processor, and an industrial recording apparatus combined with various processing apparatuses. be able to. Hereinafter, an embodiment of a recording head of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a recording head according to an embodiment of the present invention. FIG. 4A is a perspective view showing the main part, and FIG. 4B is a partially enlarged perspective view of a portion surrounded by a rectangular range C ₁ in FIG. FIG. 2 is an exploded perspective view of the recording head of FIG. 3A and 3B are diagrams showing a state of the recording head of FIG. 1 before sealing with a sealant. FIG. 3A is a perspective view thereof, and FIG. 3B is a circle C ₂ in FIG. It is a partial expansion perspective view of the part enclosed by. FIG. 4 is a partial cross-sectional view of the recording head of FIG. 1 taken along the line BB of FIG.

  The liquid discharge recording head (hereinafter referred to as the recording head 100) of the present embodiment uses an electrothermal transducer provided in the recording element 110 to cause film boiling to occur in response to an electrical signal in the liquid ink and perform recording. An ink jet side shooter type recording head.

  The liquid ejection recording head 100 electrically connects a recording element 110 having an ejection port array 111 that ejects liquid, an electrical wiring substrate 130 that supplies electrical energy to the recording element 110, and the recording element 110 and the electrical wiring substrate 130. And an electrical connection portion 140 connected to the.

  The recording element 110 has a silicon substrate. An ink supply port (not shown) is opened in the shape of a long hole in the center of the substrate, and an electrothermal converter (not shown) made up of a plurality of heating resistors on both sides of the ink supply port on the substrate. Are arranged at almost equal intervals. The substrate on which such a heating resistor is formed is called a heater board 110a (see FIG. 4). Wiring (not shown) for supplying power to the heating resistor is provided on the main surface (the surface facing the recording medium) of the heater board 110a which is the main body of the recording element 110. As shown in FIG. It is connected to electrode portions 113 installed at both ends of the element 110. A nozzle plate 112 having a protective film and a discharge port array 111 is formed on the heater board 110a. The heating resistor heats the ink by a drive signal from the apparatus main body, and discharges ink droplets from the discharge port array 111 by the action of film boiling.

  The surface of the nozzle plate 112 is water repellent. The thickness of the nozzle plate 112 is various, for example, 25 μm or 75 μm. In the case of the recording head 100 having a plurality of recording elements 110 as shown in FIG. 1, recording elements 110 having different thicknesses of the nozzle plate 112 are used. .

  The electrical wiring board 130 has a device hole 134 and a pair of auxiliary openings 135. The device hole 134 is formed larger than the nozzle plate 112 and is positioned with respect to the recording element 110 so as to expose the nozzle plate 112 (discharge port array 111) of the recording element 110. The pair of auxiliary openings 135 is provided on both sides of the device hole 134 in the vicinity of the device hole 134 and is positioned with respect to the recording element 110 so as to expose the electrical connection portion 140. The electrical wiring board 130 further includes a slit 136 that is connected to the device hole 134 and extends from the side 161 facing the auxiliary opening 135 of the device hole 134 along the side portion 162 of the auxiliary opening 135. The device hole 134 and the auxiliary opening 135 are partitioned by a separation band 130a which is a separation means extending in parallel with the electrical connection portion 140, and are arranged independently of each other. As a result, the separation band 130 a is formed in a substantially U shape between the device hole 134, the slit 136, and the auxiliary opening 135. The electrical wiring board 130 further has an external signal input terminal 131 connected to an external wiring (not shown).

  The side surface of the recording element 110 in the device hole 134 and the lower side of the separation band 130 a are filled with the first sealing material 121. The auxiliary opening 135 is sealed with the second sealing material 122 from the surface side of the electrical wiring board 130 in order to protect the electrical connection portion 140.

  The electrical wiring board 130 receives an inner lead as an electrical connecting means for supplying a drive signal supplied from the main body of the recording apparatus having a conveying means for conveying the recording medium so as to face the recording head 100 through an external signal input terminal 131. This is transmitted to the recording element 110 by 132. As the electrical wiring board 130, for example, a TAB tape is used. As shown in FIG. 4, the electric wiring board 130 has a laminated structure in which wirings 139 connected to the inner leads 132 are laminated on the base film 137 via an adhesive 138. The thickness of each material is, for example, 50 μm for the base film 137, 20 μm for the adhesive 138, and 25 μm for the wiring 139. A device hole 134 for exposing the nozzle plate 112 and an auxiliary opening 135 for exposing the electrical connection portion 140 are formed in the base film 137 and separated by a separation band 130a which is a part thereof.

The width L ₂ of the separation band 130a is preferably as narrow as possible since the size of the recording element 110 increases as the width increases. In the present embodiment, the width L ₂ of the separation band 130a is set to 0.35 mm in consideration of the processing accuracy of the mold for punching the device hole 134 and the auxiliary opening 135 and the rigidity of the material of the base film 137. By making the distance L ₃ from the separation band 130a to the tip of the inner lead 132 as small as possible, the size of the recording element 110 can be reduced. In the present embodiment, the distance L _{3 is set} to 0.1 mm in consideration of the processing accuracy of the TAB tape.

  It is desirable that the slit 136 extending from the device hole 134 extends as long as possible in order to improve the mobility of the separation band 130a. The mobility of the separation band 130a is enhanced as follows. As described above, the separation band 130a is formed in a substantially U-shape. Specifically, the separation band 130a has a main portion 130b extending adjacent to the device hole 134 and a connecting portion 130c extending on both sides of the main portion 130b. The connecting portion 130 c is formed only by providing the slit 136. The main part 130b is supported at the tip of a connecting part 130c having the function of a cantilever or an arm. As a result, the main part 130b becomes easy to move in the vertical direction by the deformation of the connecting part 130c.

  In the present embodiment, the slit 136 is formed up to the position of the base line of the lead group of the inner lead 132 provided in the auxiliary opening 135 (the side of the auxiliary opening 135 far from the device hole 134) 163. However, the slit 136 does not need to extend to the position of the line 163 as long as the purpose of enhancing the deformability of the separation band 130a is achieved.

  As shown in FIGS. 2 and 4, the recording element 110 is fixed to the support member 150 with an adhesive 151, and the electrical wiring board 130 is fixed to the support member 150 with adhesives 152 and 153. An ink channel (not shown) for supplying ink from an ink tank (not shown) to the recording element 110 is formed in the support member 150, and a filter and a seal rubber are provided at the connection position with the ink tank on the upper surface. Is provided. The recording element 110 is incorporated in the recess 157 of the support member 150.

  The recording element 110 is positioned so that the ink supply port (not shown) corresponds to the ink flow path 156 of the support member 150 and is fixed by the adhesive 151. In the recording element 110, the nozzle plate 112 is incorporated in the device hole 134 of the electric wiring board 130 and is electrically connected to the inner lead 132 protruding into the auxiliary opening 135. That is, the electrical wiring board 130 is positioned at a position where the inner lead 132 of the electrical wiring board 130 can be connected to the electrode portion 113 of the recording element 110 fixed to the support member 150 as shown in FIG. In this state, the principal part of the electric wiring board 130 is adhesively fixed to the support member 150 by the adhesive 152 and the bent parts having the external signal input terminals 131 for receiving the drive signals from the apparatus main body are adhesively bonded to the support member 150, respectively. The electrode portion 113 of the recording element 110 that is positioned and fixed and the inner lead 132 of the electric wiring board 130 are electrically connected by the TAB mounting technique via the bump 114 provided on the electrode portion 113, thereby forming the electric connection portion 140. Is done.

  When the electrical wiring board 130 is bonded and fixed to the support member 150, the separation band 130a is deformed by its own weight and contacts (grounds) on the heater board 110a of the recording element 110 by the above-described configuration of the separation band 130a. At this time, in the recording head 100 in which a plurality of recording elements 110 having different thicknesses of the nozzle plate 112 are mounted, the deformed shape of the separation band 130 a is not affected by the thickness of each nozzle plate 112. In the most preferable mode, the separation band 130a contacts the heater board 110a in the same bent shape even with the nozzle plates 112 having different thicknesses.

  Next, the first sealant 121 is filled around the side surface of the recording element 110 from the device hole 134 of the electric wiring board 130. Since the first sealing agent 121 needs to be filled up to the back side of the electrical connection part 140 that cannot be directly applied, a material having a low initial viscosity and good fluidity is used. In this embodiment, NR200C manufactured by Sanyu Rec Co., Ltd., which is a thermosetting sealant, is used. The first sealing agent 121 is heated at 100 ° C. for about 1 to 4 hours, for example, so that a part 121a of the first sealing agent 121 is filled in the entire side surface of the recording element 110 and temporarily cured. At the same time, a portion 121b of the first sealant 121 is filled between the heater board 110a and the separation band 130a by the capillary phenomenon and temporarily cured. As a result, the separation band 130a is lifted from the heater board 110a via the first sealant 121 (121b), and in this state, is adhered and fixed to the main surface of the recording element 110. The separation band 130a functions as a bank (dam) that partitions the nozzle plate 112 and the auxiliary opening 135 (see FIG. 4). Further, the auxiliary opening 135 is surrounded by the general part of the separation band 130a and the electric wiring board 130, and becomes a pit-shaped opening.

  In the present embodiment, since the outer shape of the nozzle plate 112 is slightly smaller than the device hole 134, a step is formed in the vicinity of the separation band 130a. Further, the surface of the nozzle plate 112 is water repellent. These prevent the first sealant 121 (121b) from spreading on the surface of the nozzle plate 112.

  Next, the second sealing agent 122 is filled in the auxiliary openings 135 in the form of pits, and the electrical connection portion 140 is sealed. Since the second sealing agent 122 is filled in a dam-shaped portion having a depth of, for example, about 0.1 mm, a material having a low initial viscosity and a good leveling property may be used similarly to the first sealing agent 121. it can. Thereby, the height of the second sealing agent 122 can be made substantially the same as the surface of the base film 137 of the electric wiring board 130. Since the outer periphery of the second sealant 122 is surrounded by the base film 137, it is difficult to receive external force. For example, the external force at the time of contact received from the wiper blade of the wiping mechanism provided in the recording apparatus main body is reduced.

  In the present embodiment, as with the first sealant 121, NR200C manufactured by San Yulec Co. is used for the second sealant 122. By making the 1st, 2nd 1st sealing agents 121 and 122 into the same material, both adhesiveness can be improved and productivity can be improved. After filling the second sealant 122, the first sealant 121 and the second sealant 122 are completely cured by heating at 150 ° C. for about 3 hours, for example.

  In the recording head of the present embodiment, the sealant is prevented from flowing out to the recording element side by the separation band, not by the viscosity of the sealant itself, so that the width of the sealant is large as in the prior art. There is no increase. Moreover, since the auxiliary opening is surrounded by the raised separation band and becomes concave, it is possible to fill the electrical connection portion with an appropriate amount of the second sealing agent, and the sealing height is suppressed. Thereby, the interval between the recording head and the recording medium conveyed so as to face the recording head by the conveying means (not shown) can be reduced, and the printing quality of the recording apparatus can be improved. In addition, a single type of sealant with good fluidity can seal the periphery of the recording element and the electrical connection portion, thereby improving the coating property and adhesiveness of the sealant and reducing the material cost. Can be planned.

  Further, even in the case of a recording head equipped with a plurality of recording elements having different nozzle plate thicknesses, the deformation of the separation band with respect to the heater board does not depend on the thickness. Therefore, the separation band comes into contact with the heater board of each recording element in the same positional relationship. Therefore, the same amount of sealant flows into the gap between the separation band and the heater board, and the height of the separation band is fixed to the heater board of each recording element having a different nozzle plate thickness. It will never be done. Most preferably, the separation band is fixed at the same height relative to the heater board. As a result, it is possible to prevent the electric wiring board from being damaged or peeled off due to external force at the time of contact received from the wiper blade.

1 is a perspective view of a recording head according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the recording head illustrated in FIG. 1. It is a figure which shows the state before sealing with the sealing agent of the recording head shown in FIG. FIG. 2 is a partial cross-sectional view of the recording head in FIG. 1 taken along line BB in FIG. FIG. 11 is a perspective view illustrating a conventional example of a recording head. FIG. 6 is an exploded perspective view of the recording head shown in FIG. 5. FIG. 6 is a diagram showing a state before the recording head shown in FIG. 5 is sealed. FIG. 6 is a diagram illustrating a sealing portion of the recording head illustrated in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 110 Recording element 111 Discharge port row | line | column 112 Nozzle plate 121 1st sealing agent 122 2nd sealing agent 130 Electric wiring board 130a Separator 134 Device hole 135 Auxiliary opening 136 Slit 140 Electrical connection part

Claims (3)

A recording element having an ejection port array for ejecting liquid;
An electrical wiring board for supplying electrical energy to the recording element;
An electrical connection for electrically connecting the recording element and the electrical wiring board;
Have
The electrical wiring board is:
A device hole positioned with respect to the recording element so as to expose the discharge port array of the recording element;
An auxiliary opening provided in proximity to the device hole and positioned relative to the recording element to expose the electrical connection;
A slit that is connected to the device hole and extends along a side of the auxiliary opening from a side of the device hole that faces the auxiliary opening;
A separation band that partitions the device hole and the auxiliary opening;
A first sealing material filled below the separation band;
A second sealing material for sealing the electrical connection portion;
Have
The separation band is formed in a substantially U-shape between the device hole, the slit, and the auxiliary opening.
Liquid discharge recording head. A plurality of the recording elements are provided,
Each recording element has a nozzle plate having the ejection port array on the surface facing the recording medium,
The thickness of the nozzle plate is different between some of the recording elements and the other recording elements.
The liquid discharge recording head according to claim 1.   The liquid discharge recording head according to claim 1, wherein the first sealing material and the second sealing material are the same sealing agent.

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