JP4455577B2 - Inkjet recording head - Google Patents

Description

  The present invention relates to an ink jet recording head that performs recording by ejecting ink droplets from an ink ejection port.

  Confirmation of the operation of the transistor portion formed on the substrate of the ink jet recording head is performed by measuring the resistance of the transistor portion or the like. Such an operation check needs to be performed before the nozzle forming member is formed on the substrate.

  The resistance measurement of the transistor portion can also be performed using an electrical connection terminal provided on the ink jet recording head substrate and connected to the recording apparatus main body. However, since the electrical connection terminal is connected to an energy generating element provided on the ink jet recording head substrate, when the measurement is performed using the electrical connection terminal, the resistance of only the transistor portion cannot be measured. In order to directly measure the transistor portion, it is necessary to provide a test terminal separate from the electrical connection terminal before and after the transistor portion.

  FIG. 10 is a diagram showing a wiring structure in which test terminals are provided before and after the transistor portion formed on the substrate of the ink jet recording head.

  During normal ink ejection driving, the energy generating element is heated by passing a current from the terminal 1 (power supply) toward the terminal 2 (GND), whereby the ink is foamed and ejected from the ink ejection port. At this time, it is necessary to measure whether or not the resistance value of the transistor portion, which is a driving element of the energy generating element, is a predetermined value, and determine whether or not the driving is normally performed. According to the configuration shown in FIG. 10, by measuring the resistance value between the test terminal A and the test terminal B, the resistance value of the transistor can be directly measured to determine whether the driving operation is good or bad. Patent Document 1 discloses that a test terminal separate from an electrical connection terminal connected to the recording apparatus main body is provided.

The test terminal 105 is disposed under the nozzle forming member 106 as shown in FIG. Thereby, the test terminal 105 is protected from ink. Further, the periphery of the test terminal 105 may be sealed with a thermosetting sealing material as disclosed in Patent Document 2.
JP 07-323549 A JP-A-2005-132102

  However, the conventional techniques described above have the following problems.

  FIG. 12 is a schematic diagram showing a state in which a nozzle forming member in a conventional ink jet recording head is peeled off from a substrate. In FIG. 12, reference numeral 101 denotes a substrate having an energy generating element (not shown), reference numeral 102 denotes an electrical connection terminal to which a wiring board electrically connected to the recording apparatus body is joined, and reference numeral 103 denotes an electrical connection to the recording apparatus body. The wiring board connected to is shown. Further, reference numeral 104 denotes a lead connecting the wiring substrate 103 and the electrical connection terminal 102, reference numeral 5 denotes a test terminal provided on the substrate 101, which is a separate test terminal from the electrical connection terminal 102, and reference numeral 106 denotes a nozzle forming member. Yes. Further, reference numeral 100 denotes an ink supply member or an ink supply auxiliary member, and reference numeral 201 denotes a sealing material.

  As shown in FIG. 12A, the substrate 101 on which the nozzle forming member 106 is formed has an ink supply member or an ink supply auxiliary member in a state where the electrical connection terminals 102 and the leads 104 of the wiring substrate 103 are joined. 100 is affixed. In this state, as shown in FIG. 12B, in order to protect the leads 104 and the electrical connection terminals 102 from ink, a sealing material 201 is applied so as to seal them. Since the sealing material 201 is a thermosetting sealing material, it is heated in the state shown in FIG.

  Then, as shown in FIG. 12C, the ink supply member or the ink supply auxiliary member 100 is thermally expanded in the direction indicated by the arrow. When the sealing material 201 is cured in this state, and then shrinkage due to cooling starts, the sealing material 201 is pressed in the direction of the arrow by the member 100 as shown in FIG. The substrate 101 and the nozzle forming member 106 are pressed in the direction of the arrow shown. Then, as shown in FIG. 12E, the sealing material 201 peels off the nozzle forming member 106 from the substrate 101, and as a result, the test terminal 105 is exposed. If the test terminal 105 is exposed and ink enters the exposed portion, an electrical failure may occur.

  The test terminals 105 are often arranged in the outer peripheral area of the substrate 101. This is because if the test terminal 105 is arranged at the center of the substrate 101, other necessary electrical wiring such as an energy generating element must be routed around the test terminal 105, and the size of the substrate 101 is required. This is because it becomes larger than that. Therefore, even if the nozzle forming member 106 is peeled off in a small area around the nozzle forming member 106, the peeling area may reach the test terminal 105 and the test terminal 105 may be exposed. .

  Accordingly, an object of the present invention is to provide an ink jet recording head capable of preventing exposure of test terminals on a substrate covered with a nozzle forming member.

The ink jet recording head of the present invention includes a substrate on which an energy generating element that generates ink discharge energy for discharging ink droplets from an ink discharge port and a drive element that drives the energy generating element are provided. Furthermore, the ink jet recording head of the present invention includes a nozzle forming member that is provided on the substrate and forms the ink discharge port and an ink flow path communicating with the ink discharge port on the substrate. A plurality of test terminals for inspecting the drive element are provided in the outer peripheral area of the substrate. It said nozzle forming member comprises a recess previous SL plurality of test terminals are formed on opposite portions formed region and a through hole which is formed in a portion opposed to the plurality of test terminals of the recess, The inside of the recess is sealed with a sealing material.

  ADVANTAGE OF THE INVENTION According to this invention, the inkjet recording head which can prevent the test terminal on the board | substrate covered with the nozzle formation member being exposed can be provided.

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

  FIG. 1 is a schematic perspective view showing the shape of a nozzle forming member in an ink jet recording head according to an embodiment of the present invention.

  In FIG. 1, the ink jet recording head of this embodiment has a substrate 1 having an energy generating element (not shown) and a driving element (not shown) composed of a transistor or the like for driving the energy generating element. On the substrate 1, there are formed electrical connection terminals 2 to which a wiring substrate 3 electrically connected to terminals (not shown) on the recording apparatus main body side is electrically connected. The electrical connection terminals 2 and the wiring board 3 are connected by leads 4. A test terminal 5 separate from the electrical connection terminal 2 is formed on the substrate 1. The test terminal 5 is a terminal used for inspection for confirming the operation of the drive element (not shown). Further, on the substrate 1, a nozzle forming member 6 is formed on the substrate 1 to form an ink flow path (not shown) and an ink discharge port 6a communicating therewith.

  In the nozzle forming member 6, a concave portion 6 b that forms a gap between the substrate 1 and the nozzle forming member 6 is formed at a portion facing the region where the test terminal 5 is formed on the substrate 1. For this reason, the nozzle forming member 6 in this portion is thinner than the other regions, and has a hook-like shape protruding above the region where the test terminals 5 on the substrate 1 are formed.

  The nozzle forming member 6 in the present embodiment can be manufactured as follows. First, in the process of applying the mold material forming the ink flow path on the substrate 1, the mold material is also applied to the region on the substrate 1 where the test terminals 5 are formed. Thereafter, the mold material is patterned so as to leave the portion forming the ink flow path and the portion forming the recess 6b of the mold material, and removing the other portions of the mold material. Thereafter, the nozzle forming member 6 is formed on the substrate 1 on which the mold material is formed as described above. Further, the nozzle forming member 6 is formed with an ink discharge port 6a communicating with the ink flow path. Finally, the mold material is removed using an etching solution. The mold material forming the ink flow path on the substrate 1 is removed to the outside of the nozzle forming member 6 through the ink discharge ports 6a and the like. The mold material that forms the recess 6b is also removed during this removal step. As a result, the nozzle forming member 6 is formed with a recess 6b that forms a gap between the substrate 1 and the nozzle forming member 6.

  When a thermosetting sealing material 20 (see FIG. 2) is applied to the substrate 1 provided with such a nozzle forming member 6, the sealing material 20 flows into the recess 6b and seals the test terminal 5. .

  FIG. 2 is a schematic cross-sectional view of the vicinity of the test terminals of the ink jet recording head shown in FIG. As shown in FIG. 2, the sealing material 20 applied between the substrate 1 on which the nozzle forming member 6 is configured and the ink supply member or the ink supply auxiliary member 10 flows into the recess 6 b, and the test terminal 5 is sealed.

  In the inkjet recording head of this embodiment, the test terminals 5 on the substrate 1 are sealed with a sealing material 20 that seals between the substrate 1 and the member 10. When the shrinkage is started by cooling after the sealing material 20 is heated and cured, a force that the member 10 presses the sealing material 20 in the left direction in the figure is generated. However, even in this case, since the sealing material 20 remains in a state of covering the test terminals 5, the test terminals 5 are not exposed and ink does not adhere to the test terminals 5. Even if a part of the nozzle forming member 6 is peeled off from the substrate 1 by such pressing force, the test terminal 5 is not exposed in the configuration of the present embodiment.

  Further, the surface of the ridge-like portion of the nozzle forming member 6 that protrudes above the region where the test terminals 5 are formed on the substrate 1 is the surface of the region where the ink discharge ports 6a of the nozzle forming member 6 are formed. The same surface as the (ink discharge port forming surface) is formed. Therefore, when the ink discharge port forming surface of the ink jet recording head is wiped with a wiping blade (not shown), the ridge-shaped portion of the nozzle forming member 6 does not deteriorate its wiping performance.

  In this embodiment, the sealing material 20 that seals and protects the test terminal 5 is applied between the substrate 1 and the member 10 and is a thermosetting sealing used for protecting the cut end surface of the substrate 1. An example using wood was shown. However, the sealing material applicable to the sealing of the test terminal 5 is not limited to this, and a thermosetting sealing material for protecting the electrical connection portion between the electrical connection terminal 2 and the lead 4 may be used. Good. However, it is desirable to use a sealing material having a viscosity capable of flowing into the recess 6b between the substrate 1 and the nozzle forming member 6.

  Subsequently, some modified examples of the present embodiment will be described.

<First Modification>
FIG. 3 is a schematic cross-sectional view of the vicinity of a test terminal according to a first modification of the ink jet recording head shown in FIG.

  In this modification, the through-hole 6c is formed in the portion where the recess 6b of the nozzle forming member 6 is formed. The through-hole 6c can be formed in the same manner as the ink discharge port 6a in the step of forming the ink discharge port 6a in the nozzle forming member 6. The sealing material 20 that has flowed into the recess 6 b also flows into the through-hole 6 c and is held by the meniscus force at the opening surface at the outermost surface of the nozzle forming member 6.

  When the sealing material 20 flows into the recess 6b, if the sealing material 20 embeds air and air bubbles are present in the sealing material 20, the ability of the sealing material 20 to protect the test terminals 5 decreases. There is a concern that bubbles in the sealing material sealing material 20 may burst during the thermosetting of the sealing material sealing material 20. On the other hand, by forming the through-hole 6c in the nozzle forming member 6 as in this modified example, bubbles remaining in the recess 6b when the sealing material 20 flows into the recess 6b are removed. It can be discharged to the outside. Therefore, the sealing material 20 can be surely flowed into the recess 6b.

<Second Modification>
FIG. 4 is a schematic perspective view showing the shape of a nozzle forming member according to a second modification of the ink jet recording head shown in FIG.

  When the sealing material 20 flows into the recess 6b, if the sealing material 20 embeds air and air bubbles are present in the sealing material 20, the ability of the sealing material 20 to protect the test terminals 5 decreases. There is a concern that bubbles in the sealing material sealing material 20 may burst during the thermosetting of the sealing material sealing material 20. This is as described above.

  On the other hand, in the second modification shown in FIG. 4A, the corner of the side wall forming the recess 6b of the nozzle forming member 6 is formed in a chamfered shape or an arc shape. Thereby, the inflow property of the sealing material flowing into the recess 6b is improved, and it is possible to prevent bubbles from remaining in the corners at the back of the recess 6b. Further, similarly to the configuration shown in FIG. 3, the through hole 6 c may be formed in the portion of the nozzle forming member 6 where the recess 6 b is formed.

  In the example shown in FIG. 4 (a), all the corners of the side wall forming the recess 6b of the nozzle forming member 6 are formed in a chamfered shape or an arc shape, but all the corners are as such. It may not be formed. For example, as shown in FIG. 4B, a configuration in which a chamfered shape or a circular arc shape is formed only at the corner of the back of the recess 6b may be used.

<Third Modification>
FIG. 5 is a schematic perspective view showing the shape of a nozzle forming member according to a third modification of the ink jet recording head shown in FIG.

  The portion of the nozzle forming member 6 where the recess 6b is formed has a small thickness, and there is a concern that the nozzle forming member 6 may be damaged when the substrate 1 is cut, washed and separated. Therefore, it is desirable to reinforce the portion of the nozzle forming member 6 where the recess 6b is formed.

  In this modification, a columnar or wall-shaped reinforcing portion 6 d that is in contact with the substrate 1 is formed on the back surface of the portion where the recess 6 b of the nozzle forming member 6 is formed. The reinforcing portion 6 d is in contact with the substrate 1 in a region other than the test terminals 5 on the substrate 1. The reinforcing portion 6d supports the portion of the nozzle forming member 6 where the concave portion 6b is formed, and prevents the hook-shaped portion from being damaged when the substrate 1 is cut, washed, separated, or the like.

  In particular, by providing the reinforcing portion 6d at the corner of the bowl-shaped portion as shown in FIG. 5, it is possible to suppress the reinforcing portion 6d from hindering when the sealing material flows into the recess 6b.

(Other embodiments)
Hereinafter, an example of an ink jet recording head using an electrical wiring member having flying leads for electrical connection will be described.

  An ink jet recording head H1000, which will be described later, is a bubble jet (registered trademark) ink jet that uses an electrothermal transducer as an energy generating element that generates thermal energy for causing film boiling in ink in response to an electrical signal. It is a recording head. The ink jet recording head H1000 is a so-called side shooter type ink jet recording head arranged so that the electrothermal transducer and the ink discharge port face each other.

  6 is a perspective view of the ink jet recording head H1000, and FIG. 7 is an exploded perspective view of the ink jet recording head H1000. The ink jet recording head H1000 includes a recording element substrate H1100 having energy generating elements, an electric wiring member H1300 having flying leads, and an ink supply holding member H1500. Further, the ink jet recording head H1000 includes a filter H1700, an ink absorber H1600, a lid member H1900, and a seal member H1800.

(1) Recording element substrate H1100 having energy generating elements
FIG. 8 is a diagram for explaining the configuration of the recording element substrate H1100 having energy generating elements, and is a partially broken perspective view. The recording element substrate H1100 is, for example, an Si substrate H1110 having a thickness of 0.5 mm to 1 mm. It is formed by the method.

  In the Si substrate H1110, electrothermal conversion elements H1103 as energy generating elements are arranged side by side on both sides of the ink supply port H1102, and Al or the like that supplies electric power to the electrothermal conversion element H1103 is arranged. An electric wiring (not shown) made of is formed. These electrothermal conversion elements H1103 and electrical wiring can be formed by using an existing film forming technique. The electrothermal conversion elements H1103 in each column are arranged in a staggered manner. In other words, the positions of the ejection ports in each row are slightly shifted so as not to line up in a direction orthogonal to the row direction.

  In the recording element substrate H1100, the ink supplied from the ink flow path H1102 is ejected from the ejection port 1107 facing the electrothermal conversion elements H1103 by the pressure of the bubbles generated by the heat generated by the electrothermal conversion elements H1103.

(2) Electric wiring member H1300 having flying leads
The electrical wiring member H1300 having flying leads forms an electrical signal path for applying an electrical signal for ejecting ink to the recording element substrate H1100, and a wiring pattern of copper foil on a polyimide base substrate. It is comprised by forming. Further, an opening H1303 for incorporating the recording element substrate H1100 is formed, and a flying lead portion H1304 connected to the electrical connection terminal portion H1104 of the recording element substrate H1100 is formed near the edge of the opening. Yes. Further, the electric wiring member H1300 is formed with an external signal input terminal H1302 for receiving an electric signal from the main unit, and the external signal input terminal H1302 and the flying lead portion H1304 are a continuous copper foil wiring pattern. It is connected.

  The electrical connection between the electrical wiring member H1300 and the recording element substrate H1100 is made as follows. For example, the bump H1105 formed on the electrical connection terminal portion H1104 of the recording element substrate H1100 and the flying lead portion H1304 of the electrical wiring member H1300 corresponding to the electrical connection terminal portion H1104 are electrically joined in the positional relationship shown in FIG. It is made by that.

(3) Ink supply holding member H1500
The ink supply holding member H1500 is formed by, for example, resin molding. As the resin material, it is desirable to use a resin material mixed with 5 to 40% of glass filler in order to improve the shape rigidity. As shown in FIG. 7, the ink supply holding member H1500 has an absorber H1600 for holding ink therein and generating negative pressure. Thus, the ink supply function is realized by forming an ink flow path for guiding the ink to the recording element substrate H1100. As the ink absorber H1600, a compressed PP fiber is used. Alternatively, a compressed urethane fiber may be used.

  A filter for preventing dust from entering the inside of the substrate H1100 having an energy generating element at a boundary portion between a portion where ink is supplied from the ink absorber H1600 located upstream of the ink flow path and the ink flow path H1700 is joined by welding. The filter H1700 may be a metal mesh type made of stainless steel, but is preferably a metal fiber sintered type made of stainless steel.

  An ink supply port H1200 for supplying black ink to the recording element substrate H1100 is formed in the downstream portion of the ink flow path. The recording element substrate H1100 is adhesively fixed to the ink supply holding member H1500 with high positional accuracy so that the ink supply port 1102 of the recording element substrate H1100 communicates with the ink supply port H1200 of the ink supply holding member H1500. The first adhesive used for the bonding is desirably a low viscosity, low curing temperature, cured in a short time, and has a relatively high hardness after curing and ink resistance. As this 1st adhesive agent, there exists a thermosetting adhesive agent which has an epoxy resin as a main component, for example. When this thermosetting adhesive is used, the thickness of the adhesive layer is desirably about 50 μm.

  In addition, a part of the back surface of the electric wiring member H1300 is bonded and fixed to the plane around the bonding surface of the recording element substrate H1100 by the second adhesive. The electrical connection portion between the recording element substrate H1100 and the electrical wiring member H1300 is sealed with a first sealant H1307 and a second sealant H1308 (see FIG. 9), whereby the electrical connection portion is corroded by ink. And protects against external impacts. The first sealant H1307 mainly seals the back side of the connecting portion between the flying lead portion H1302 of the electric wiring member H1300 and the bump H1105 of the recording element substrate H1100 and the outer peripheral portion of the recording element substrate H1100. Yes. The 2nd sealing agent H1308 has sealed the front side of the above-mentioned connection part. The unbonded portion of the electric wiring member H1300 is bent and fixed to the side surface of the ink supply holding member H1500 that is substantially perpendicular to the bonding surface of the recording element substrate H1100 by heat caulking or bonding.

  The ink supply holding member H1500 corresponds to the member 10 shown in FIGS. A member 10 shown in FIG. 2 and the like represents a portion on which the recording element substrate H1100 of the ink supply holding member H1500 is mounted.

(4) Lid member H1900
The lid member H1900 seals the inside of the ink supply holding member H1500 by being welded to the upper opening of the ink supply holding member H1500. The lid member H1900 is provided with a narrow opening H1910 for releasing pressure fluctuation inside the ink supply holding member H1500 and a fine groove H1920 communicating with the narrow opening H1910. Most of the narrow opening H1910 and the fine groove H1920 are covered with a seal member H1800, and one end of the fine groove H1920 is opened to form an air communication opening H1924. The lid member H1900 has an engaging portion H1930 for fixing the ink jet recording head H1000 to the ink jet recording apparatus.

It is a typical perspective view which shows the shape of the nozzle formation member in the inkjet recording head which concerns on one Embodiment of this invention. FIG. 2 is a schematic cross-sectional view in the vicinity of a test terminal of the ink jet recording head shown in FIG. 1. It is a cross-sectional schematic diagram of the test terminal vicinity which concerns on the 1st modification of the inkjet recording head shown in FIG. It is a typical perspective view which shows the shape of the nozzle formation member which concerns on the 2nd modification of the inkjet recording head shown in FIG. It is a typical perspective view which shows the shape of the nozzle formation member which concerns on the 3rd modification of the inkjet recording head shown in FIG. It is a perspective view of the inkjet recording head which concerns on other embodiment of this invention. It is a disassembled perspective view of the inkjet recording head which concerns on other embodiment of this invention. FIG. 8 is a perspective view showing the recording element substrate shown in FIG. 7 in a partially broken state. FIG. 7 is a partial cross-sectional view of the ink jet recording head shown in FIG. 6 and the like. It is a figure which shows the wiring structure by which the test terminal was provided before and behind the transistor part comprised on the board | substrate of an inkjet recording head. It is a typical perspective view which shows the shape of the nozzle formation member in the conventional inkjet recording head. It is a schematic diagram which shows a mode that the nozzle formation member in the conventional inkjet recording head peels from a board | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 5 Test terminal 6 Nozzle formation member 6a Ink discharge port 6b Recessed part 20 Sealing material

Claims (7)

A substrate provided with an energy generating element for generating ink discharge energy for discharging ink droplets from the ink discharge port and a drive element for driving the energy generating element, and provided on the substrate, and the ink discharger on the substrate. In an ink jet recording head having an outlet and a nozzle forming member that forms an ink flow path communicating with the ink discharge port,
A plurality of test terminals for inspecting the driving element is provided in the outer peripheral region of the substrate,
It said nozzle forming member comprises a recess previous SL plurality of test terminals are formed on opposite portions formed region and a through hole which is formed in a portion opposed to the plurality of test terminals of the recess, An ink jet recording head, wherein the inside of the recess is sealed with a sealing material.   2. The ink jet recording head according to claim 1, wherein a surface of the nozzle forming member in a region where the ink discharge port is formed and a surface of a portion where the recess is formed are flush with each other. At least one corner portion is formed in the chamfered shape or arc shape, the ink jet recording head according to claim 1 or 2 of the side walls forming the recess of the nozzle formation member. Wherein the said portions which the recess is formed in the nozzle forming member, prior Symbol plurality of test terminals are reinforcing portion in contact with the substrate is provided in the region other than the region provided, of claims 1 to 3 The inkjet recording head according to any one of the above. Said ink jet recording head is adhesively fixed on the ink supply member or the ink supply assisting member made of a resin material, the ink jet recording head according to any one of claims 1 to 4. The cut end surface of the substrate is protected by a thermosetting first sealing material,
Wherein the sealing material the first sealing material is used, the ink jet recording head according to any one of claims 1 to 5. The board is provided with an electrical connection terminal connected to a wiring board, and the electrical connection terminal is protected by a thermosetting second sealing material,
Wherein the sealing member and the second sealing material is used, the ink jet recording head according to any one of claims 1 to 6.

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