JP2009073035A - Recording head and ink jet recording apparatus provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a barrier portion between an ILB pad and a TAB lead,
Improving the non-contact reliability of leads and HB edges without significantly increasing the barrier height.
The top surface of the barrier portion is inclined so that the TAB substrate side is higher than the pad side.
[Selection] Figure 1

Description

  The present invention relates to an ink jet recording apparatus that performs recording on a recording medium by discharging ink. More specifically, the present invention relates to a recording head and an ink jet recording apparatus that improve electrical connection reliability by providing a barrier member having an inclined upper surface on a recording element substrate of the recording head.

  The ink jet recording technique is attracting attention as a quiet recording method with a low running cost. In recent years, further improvement in image quality has been demanded from the market, and the graininess in an image has been reduced by reducing the volume of a recording droplet.

  However, the smaller the droplet volume to be ejected, the more easily affected by the airflow around the recording head. In other words, the flying droplets pushed by the air current are bent although the flying direction is slight, and the variation in the landing position on the recording medium such as paper increases. This variation causes image quality deterioration such as density unevenness. If the distance between the recording head and the recording medium can be shortened, the landing point position deviation can be reduced even when the recording droplets are bent in the same flight direction. Accordingly, attempts have been made to reduce the distance between the recording head and the recording medium.

  Patent Document 1 discloses a recording element substrate and a TAB (Tape Automated Bonding) member, and discloses a configuration in which a lead portion extending from the TAB member is connected to a pad on the recording element substrate. . Here, a barrier member made of an insulating material is provided on the recording element substrate so that the lead portion does not contact the surface of the recording element substrate.

  FIG. 9 is a schematic diagram showing the configuration of a recording element substrate and a TAB member of a conventional recording head. In FIG. 9, the distal end portion of the electrode terminal H2304 that is electrically connected to the wiring portion (not shown) of the electric wiring tape H2300 is electrically connected at the position directly above the electrode portion H2104. After the electrical wiring tape H2300 and the recording element substrate H2110 are electrically connected, they are bonded and fixed to the recording element substrate H2100. The electric wiring tape H2300 is bonded and fixed to the ink storage member H1500 with an adhesive.

  FIG. 10 is a diagram illustrating a state in which the surface H2107 from which ink is ejected is close to the recording medium side in order to reduce the distance between the conventional recording head and the recording medium. In FIG. 10, since the height of the electrode portion H2104 is higher than the height of the portion of the electrode terminal H2304 connected to the electrical wiring sheet H2300, the electrode terminal H2304 contacts the ridge line A of the recording element substrate H2110.

  FIG. 11 is a schematic diagram showing a state in which a barrier member H2111 is provided between the electrode portion H2104 and the ridge line A of the recording element substrate H2100 in order to prevent the electrode terminal H2304 from contacting the recording element substrate H2100. In the configuration in which the barrier member H2111 is provided, the electrode terminal H2304 hardly comes into contact with the surface of the recording element substrate even when the recording element substrate is brought close to the recording medium direction. Accordingly, the distance between the ink ejection surface of the recording head and the recording medium can be reduced.

  Incidentally, the recording element substrate includes a nozzle member having a function of holding and foaming the recording liquid on the recording element. The thickness of the nozzle member shape is extremely thin, and the portion from which the recording liquid is discharged requires an accuracy on the order of microns, and is thus formed by a photolithographic method. The nozzle member is formed by applying an epoxy resin material by a spin coating method or the like and removing unnecessary portions after patterning.

  In addition, since the barrier member provided on the recording element substrate is required to have the same high accuracy, it is similarly formed by a photolithography method. Since the partition member also plays an important role in preventing the electrode terminal from contacting the recording element substrate, its height is important.

Patent Document 2 discloses a configuration in which the height variation of the nozzle portion is reduced by surrounding the periphery of the nozzle member to be provided on the recording element substrate with a mold material in advance. In the spin coat application method using centrifugal force, the applied adhesive tends to be thick at the outer periphery. Here, the mold material prevents unnecessary movement of the adhesive and stabilizes the adhesive film thickness.
Japanese translation of publication 2005-506917 Japanese Patent No. 3459703

  However, the electrode member of the TAB member does not contact the edge portion of the recording element substrate due to the barrier member, and may contact depending on the surrounding related dimensions. There is a variation in the height of the barrier member, which increases the contact rate between the lead portion and the recording element substrate. In order to reduce the contact rate, if the height of the barrier member is made extremely high, the contact hardly occurs. However, the height of the electrode terminal which rides on the barrier member is increased accordingly, and the height of the sealing material covering the electrode terminal is increased. Eventually, the distance between the recording head and the recording medium cannot be reduced.

  Therefore, the problem is to improve the reliability of contact prevention without increasing the height of the barrier member.

  In order to achieve the above object, a recording head of the present invention is electrically connected to a recording element substrate having a plurality of ejection openings for ejecting ink, a pad provided on the recording element substrate for receiving electrical energy, and the pad. It is composed of an electrode terminal extended from the flexible member and an insulating barrier member provided between the recording element substrate end and the pad, and the height of the pad side of the top surface of the barrier member is on the side opposite to the pad. It is characterized by being inclined so as to be lower.

  As described above, according to the present invention, it is possible to reduce the probability that the electrode terminal of the TAB member contacts the edge of the Si substrate end without increasing the height of the barrier member.

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

  1 to 8 are explanatory views for explaining an ink jet recording head or an ink jet recording apparatus as an embodiment of the liquid ejecting head or the liquid ejecting apparatus according to the present invention. Hereinafter, each component will be described with reference to these drawings.

  FIG. 2 is a schematic diagram showing a schematic configuration of the ink jet recording apparatus according to the present embodiment, and the operation thereof will be described below.

  The ink jet recording apparatus shown in FIG. 2 repeats the reciprocating movement (main scanning) of the first recording head H1000 and the second recording head H1001 and the conveyance (sub scanning) of the recording medium 108 at a predetermined pitch. In synchronization with these movements, ink is selectively ejected from the first recording head H1000 and the second recording head H1001 and adhered to the recording medium 108, thereby forming a character, symbol, image, or the like. It is a recording device.

  The first recording head H1000 and the second recording head H1001 are slidably supported by the guide shaft 103, and can be attached to and detached from the carriage 102 that is reciprocated along the guide shaft 103 by driving means such as a motor (not shown). It is mounted on. The recording medium 108 faces the ink ejection surfaces of the first recording head H1000 and the second recording head H1001 by the conveyance roller 109. And it is conveyed in the direction (for example, the direction of arrow A which is an orthogonal direction) which cross | intersects the moving direction of the carriage 102 so that the distance with an ink discharge surface may be maintained constant. The first recording head H1000 and the second recording head H1001 adopt a so-called cartridge system and are detachable from the carriage 102 described above. Accordingly, when the filled ink is consumed and lost, the recording head can be replaced.

  The recording head of this embodiment is of an ink tank integrated type, and includes a first recording head H1000 filled with black ink as shown in FIGS. 3A and 3B, and a plurality of colors. The second recording head H1001 is filled with ink.

  Hereinafter, the configuration of the first recording head H1000 will be described in detail by taking the first recording head H1000 as an example.

  Each of the first recording heads H1000 is a recording head using an electrothermal transducer that generates thermal energy for causing film boiling to occur in ink in accordance with an electrical signal. The recording head is disposed so that the electrothermal transducer as a recording element and the ink discharge port face each other. In this embodiment, these recording heads are recording element substrates that discharge ink (an embodiment of a liquid discharge member that includes a discharge port for discharging liquid and discharges liquid using supplied power). In the above description, the ink tank that holds and stores the ink supplied to the recording element substrate is described as an integral unit. However, even if the recording head is structured separately from the ink tank, I do not care.

  FIG. 4 is an exploded perspective view of the first recording head H1000. The first recording head H1000 includes a first recording element substrate H1100, an electric wiring tape H1300 as an electric wiring member, and an ink storage member H1500.

  FIG. 5 is a perspective view illustrating a configuration of the first recording element substrate H1100, partially broken away. The first recording element substrate H1100 is obtained by, for example, forming a long groove-like through-hole ink supply port H1102 as an ink flow path on a Si substrate H1110 having a thickness of 0.2 mm to 1 mm. The first recording element substrate H1100 is connected to the ink storage member H1500 (FIG. 4) so that the ink supply port 1102 of the first recording element substrate H1100 communicates with the ink supply port H1200 (FIG. 4) of the ink storage member H1500. On the other hand, it is bonded and fixed with high positional accuracy.

  On the Si substrate H1110, the electrothermal conversion elements H1103 are arranged side by side on both sides of the ink supply port H1102, and an electric wiring (not shown) made of Al or the like for supplying electric power to the electrothermal conversion elements H1103. Is formed.

  The Si substrate H1110 has electrode portions H1104 for supplying electric power to the electric wiring and supplying an electric signal for driving the electrothermal conversion element H1103, at both ends of the row of the electrothermal conversion elements H1103. It is arranged along the side part located on the side. A bump H1105 made of Au or the like is formed on each electrode portion H1104. Further, a barrier member H1111 is provided between the electrode portion H1104 and the end portion of the Si substrate H1110.

  In this embodiment, the bump H1105 made of Au or the like is formed on the electrode portion H1104. However, the bump shape may not necessarily be a bump shape, and the electrode portion H1104 may be plated with Au or the like.

  FIG. 6A to FIG. 6E show one method of forming the barrier member H1111 of the present invention, and are schematic cross-sectional views in the direction orthogonal to the barrier member in FIG.

  The outline of the forming method is that a mold member that can be dissolved is provided in advance at a predetermined distance from the position where the barrier member is to be formed, a photocurable resin is formed thereon, and finally the mold material is removed.

  Next, the formation method will be described in detail with reference to FIGS.

  First, a photoreactive positive resist material is applied on a Si substrate H1110 on which a heater and an ink supply port are formed, and a mold member K0001 that can be dissolved later is formed around the barrier member by a photolithography process (FIG. 6 ( a)).

Further, a resin H1212 that is a photoreactive negative resist serving as a barrier member is applied onto the Si substrate H1110 and the mold member K0001 by a method such as spin coating. At this time, the thickness of the resin H1212 is thicker on the mold member K001, and is thinner between the mold member and the mold member than in a portion where there is no mold member. (Fig. 6 (b))
The barrier member resin H1212 can be selectively cured by light. In the present embodiment, the distance from the portion to be cured to the mold member K0001 is cured by irradiating light only to a place separated by predetermined distances L1 and L2 (FIG. 6C). Here, in the case of the relationship of L1 <L2, the upper surface of the resin H1212 is an inclined surface. In this embodiment, the dimensions of L1 and L2 are L1 = 0.01 mm and L2 = 0.08 mm.

  Next, the uncured portion H1213 of the resin H1212 that has not been exposed to light in FIG. 6C is washed away with the developer (FIG. 6D).

  Here, since the barrier member H1111 is not in the middle of the two mold materials K0001 but close to the Si substrate end portion side, the upper surface is not flat and has a dimension of T1> T2. This is a reverse utilization of the fact that the nozzle member resin surface applied in the vicinity of the mold member K0001 becomes an inclined surface instead of a flat surface.

  Here, FIG. 7A is an arrow view of FIG. The mold material K0001 is disposed so as to sandwich the barrier member H1111. The length of the mold material K0001 is substantially the same as that of the barrier member H1111. In the present embodiment, the mold material K0001 has a linear shape. However, if a desired shape is obtained, even if it is surrounded as shown in FIG. 7B, it is partially missing as shown in FIG. 7C. Any other configuration may be used.

  Next, the mold member K0001 is dissolved with a removing liquid, and the formation of the barrier member H1111 is completed. (FIG. 6 (e)).

  In addition, the present inventor has discovered that the presence of the mold member K0001 reduces the height dimension variation of the barrier member H1111 compared to the case without the mold member K0001.

  In this embodiment, the barrier member H1111 forming step is performed in the same step as the nozzle member forming, but this is not always necessary. In this embodiment, a photoreactive positive resist is used for the mold member, but a negative resist may be used. Similarly, in this embodiment, a photoreactive negative resist is used for the barrier member, but a positive resist may be used.

  Incidentally, although the mold member K0001 is provided in FIG. 7, there are other effects of arranging the mold member. The effect will be described with reference to FIG.

  FIG. 8A is a view showing a Si wafer state before cutting the Si substrate H1110. Here, the line drawn in a lattice shape is a cutting line S0001, and the line is cut with a disc-shaped grindstone having a thickness of about 0.06 mm along this line. The rectangular chip piece after cutting becomes the Si substrate H1110.

  FIG. 8B is an enlarged view of a C portion shown in FIG. In addition, electrode portions H1104 are disposed at both ends in the longitudinal direction of the Si substrate H1110. Here, the mold member K0002 is provided on the cutting line S0001 described above, and the mold member K0003 is provided on the electrode portion H1104.

  By providing the mold member K0002 on the cutting line S0001, when the resin H1212 is applied onto the FIG. 8A by a method such as spin coating using centrifugal force, the film thickness of the entire wafer becomes more uniform. There is. Here, since necessary members such as nozzle members for ejecting ink are arranged without waste on the chip, the space for arranging the mold members tends to be insufficient, but the cutting line S0001 is lost at the time of cutting. Therefore, it can be arranged. In this embodiment, the width of the mold member K0002 is set to 0.05 mm, which is a width equal to or smaller than the cutting width.

  In FIG. 6C, when the uncured portion K0001 of the resin H1212 that has not been exposed to light is washed away with the developer, the metal film on the surface of the electrode portion H1104 may be corroded. By providing the mold member K0003 on the electrode portion H1104 and protecting the metal film, there is an effect of preventing this corrosion.

  Therefore, if the mold member described with reference to FIGS. 7A, 7B, and 7C is provided at a position where the above-described effects can be obtained, the quality of the recording head can be improved.

  In FIG. 4, an electric wiring tape H1300 forms an electric signal path for applying an electric signal for ejecting ink to the first recording element substrate H1100, and a copper foil is formed on a polyimide base substrate. This wiring pattern is formed. Further, an opening H1303 for incorporating the first recording element substrate H1100 is formed, and an electrode terminal H1304 connected to the electrode portion H1104 of the first recording element substrate H1100 is formed near the edge of the opening. Is formed. Further, an external signal input terminal H1302 for receiving an electrical signal from the main unit is formed on the electrical wiring tape H1300, and the external signal input terminal H1302 and the electrode terminal H1304 are connected by a continuous copper foil wiring pattern. ing.

  FIG. 1 shows the electrical connection between the electrical wiring tape H1300 and the first recording element substrate H1100. The tip end portion of the electrode terminal H1304 that is electrically connected to the wiring portion (not shown) of the electric wiring tape H1300 is electrically connected immediately above the electrode portion H1104. The connection is performed by applying a load and vibration while applying heat to weld the Au layer on the surface of the electrode terminal H1304 and the Au of the bump H1105 on the electrode portion H1104.

  After the electrical wiring tape H1300 and the first recording element substrate H1100 are electrically connected, the ink supply port H1102 (FIG. 5) of the first recording element substrate H1100 is the ink supply port H1200 (FIG. 4) of the ink storage member H1500. Adhesive fixation is performed so as to communicate with

  Next, the back surface of the electric wiring tape H1300 is bonded and fixed to the ink storage member H1500 with an adhesive. Further, the unbonded portion of the electric wiring tape H1300 is bent, and the first recording element substrate H1100 is fixed to the side surface substantially perpendicular to the surface bonded to the ink storage member H1500 with an adhesive or the like.

  Since the height of the electrode part H2104 is higher than the height of the part connected to the electric wiring sheet H1300 of the electrode terminal H2304, the electrode terminal H1304 is bent as shown in FIG.

  At this time, the presence of the barrier member H1111 makes it difficult for the electrode terminal H1304 to contact the ridgeline A at the end of the Si substrate H1110.

  Here, the top surface of the barrier member H1111 is inclined so as to become higher from the electrode portion H1104 side toward the electric wiring sheet H1300 side, and has a dimensional relationship of T1> T2. This inclination changes the trajectory of bending of the electrode terminal H1304 and makes it difficult to make contact with the ridgeline A at the end of the Si substrate H1110.

  In this embodiment, the W1 dimension is 0.04 mm, the W2 dimension is 0.06 mm, the T2 dimension is 0.020 mm, and the T1 dimension is 0.022 mm. By this inclination, the contact ratio of the lead H1211 to the edge line A at the end of the Si substrate H1110 was reduced from about 0.1% to about 0.02%.

  By the way, if the W2 dimension can be set to 0 (zero), the electrode terminal H1304 theoretically does not come into contact with the ridge line A at the end of the Si substrate H1110. In this case, due to variation in the cutting position when cutting the Si substrate, the barrier member The resin constituting H1111 may be cut. In that case, resin adheres to the cutting blade, and it becomes easy to cause chipping of the Si base during subsequent cutting. Therefore, an interval that does not contact the cutting blade is necessary.

  In the first recording element H1100 configured as described above, the ink supplied from the ink flow path H1102 (FIG. 5) is caused by the pressure of the bubbles generated by the heat generation of each electrothermal conversion element H1103 (FIG. 5). It discharges from the discharge outlet 1107 (FIG. 5) facing each electrothermal conversion element H1103 (FIG. 5). Compared to the conventional recording head, the upper surface of the nozzle member H1106 provided with the ejection port H1107 (FIG. 5) is closer to the recording medium, so that the variation in the landing point position of the ink droplets becomes smaller and the print quality is improved.

  In this embodiment, the serial type ink jet recording apparatus has been described. However, a line type ink jet recording apparatus in which the recording head does not move in a direction orthogonal to the moving direction of the recording medium can naturally obtain the same effect. .

FIG. 3 is a schematic cross-sectional view illustrating a barrier member of a recording head that is an embodiment of the present invention. 1 is a schematic diagram illustrating an overall configuration of an ink jet recording apparatus that is an embodiment of the present invention. It is a perspective view for demonstrating the recording head shown in FIG. FIG. 4 is an exploded perspective view of the recording head shown in FIG. 3. FIG. 2 is a perspective view showing a part of a first recording element substrate constituting the recording head shown in FIG. It is a cross-sectional schematic diagram explaining the process of forming the barrier member shown in FIG. It is the arrow line view seen from the B direction of the cross-sectional schematic diagram shown in FIG. It is a schematic diagram which shows the layout of the mold member which produces another effect. FIG. 9 is a schematic diagram illustrating a conventional recording head. FIG. 9 is a schematic diagram illustrating a state in which an ink ejection surface is close to a recording medium in a conventional recording head. FIG. 9 is a schematic diagram illustrating a state in which an ink ejection surface is close to a recording medium in a recording head including a conventional barrier member.

Explanation of symbols

H1100 Si substrate H1111 Barrier member H1300 Electrical wiring tape K0001 Mold material

Claims (2)

A recording element substrate having a plurality of ejection openings for ejecting ink;
A pad provided on the recording element substrate for receiving electrical energy;
A lead extending from a flexible member electrically connected to the pad;
An insulating barrier member provided between the end of the recording element substrate and the pad;
In the recording head constituted by
A recording head characterized in that the height of the upper surface of the barrier member on the pad side is inclined to be lower than that on the non-pad side.   An ink jet recording apparatus comprising the recording head according to claim 1.

Images