JP2006289895A - Inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording head excellently suppressing a temperature rise in a recording element substrate even if the head has a structure using a first plate where a through-hole or a notch is provided. <P>SOLUTION: The inkjet recording head 50 comprises: the first plate 10 supporting the recording element substrate 32; and a second palte 20 fixed on the first plate, and the through-hole 15 is provided on the first plate 10. A heat receiving body 40 is arranged on the exposed surface A<SB>15</SB>of the second plate 20, which is produced because the through-hole 15 is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ink jet recording head that performs recording by discharging ink.

  FIG. 8 shows a configuration of an ink jet recording head (hereinafter also simply referred to as “recording head”) disclosed in Patent Document 1, for example.

  As shown in FIG. 8, the ink jet recording head 650 includes a recording element substrate 631 and 632 each having a function of ejecting ink, and a first plate that supports the two recording element substrates 631 and 632 on a support surface 613. 610, a second plate 620 bonded and fixed on the support surface 613, and a wiring tape 660 for transmitting an external electric pulse to each of the recording element substrates 631 and 632, and ink is illustrated in the Z-axis. The ink is discharged upward in the direction.

  Although not shown in detail, each of the recording element substrates 631 and 632 has a plurality of heaters (electrothermal conversion elements) for applying ejection energy to the ink, ejection ports from which the ink is ejected, and the like. In addition to the electrothermal conversion element, for example, a piezo element or the like can be used as a recording element that generates ejection energy.

The first support plate 610 is made of a ceramic material such as alumina (Al ₂ O ₃ ), for example, from the viewpoints of ink resistance, heat resistance, and bondability with the recording element substrate. In the first support plate 610, a plurality of ink supply ports (not shown) are formed so as to open to the support surface 613, and in a state where the recording element substrates 631 and 632 are arranged, These ink supply ports communicate with a predetermined ink flow path (not shown) on the recording element side.

  The second plate 620 is made of a ceramic material like the first plate, and has two openings 625 and 626 corresponding to the recording element substrates 631 and 632, respectively.

  The wiring tape 660 is connected at its other end (not shown) to a predetermined electrical connection (not shown) on the recording apparatus side, while the tip end shown is on the upper surface of the second plate 620. It is designed to be bonded and fixed. Inner leads (not shown) are drawn from the inner peripheral edges of the openings 665 and 666 of the wiring tape 660, and electric pulses are transmitted to the recording element substrates 631 and 632 by using the inner leads. It has become.

  Incidentally, the first plate 610 made of the above-described ceramic material is usually produced by pressure firing using a mold. In this case, the mold clamping force of the mold increases in proportion to the projected area of the first plate. Therefore, in order to reduce the mold clamping force, a part of the first plate 610 includes a through hole. Or a notch part etc. may be provided.

  FIG. 9 shows an example in which a through hole 615 is formed in the first plate 610A. By providing the through hole 615 in this manner, the projected area of the first support plate 610A is reduced, and as a result, the clamping force can be reduced.

  On the other hand, in manufacturing the recording head 650 having the above-described configuration, the wiring tape 660 is attached to the upper surface of the second plate 620 by using a thermosetting adhesive (which is made of a thermosetting resin and functions as an adhesive). It is done to be fixed by bonding. That is, the wiring tape 660 is brought into close contact with the upper surface of the second plate while an uncured thermosetting adhesive is interposed, and heat is applied from the upper surface side of the wiring tape 660 in this state. The heat applied to the wiring tape 660 is transferred from the wiring tape to the uncured thermosetting adhesive, thereby curing the adhesive.

In order to fix the wiring tape 660, not only the thermosetting adhesive but also a method using other adhesives can be considered. However, from the viewpoint of ink resistance, heat resistance, adhesive strength, manufacturing cost, etc. A curable adhesive is advantageous.
JP 2002-19119 A

  As described above, when the wiring tape 660 is bonded and fixed using a thermosetting adhesive, it is necessary to consider a problem in the thermocompression bonding process (heating process) for curing the adhesive. That is, there is no particular problem in the case of the first plate 610 having no through hole as shown in FIG. 8, but the through hole 615 is provided in the case of the plate 610A as shown in FIG. For this reason, the lower surface of the second plate 620 is partially exposed at the through hole 615. In other words, in this region, the second plate 620 is not in contact with the first plate 610 but in contact with the air.

  When the above heating process is performed on such a configuration, the heat distribution in the adhesive layer becomes non-uniform, and a thermosetting adhesive is formed in a region corresponding to the through hole 615 and other regions. A difference occurs in the degree of curing. That is, in the region where the second plate 620 and the first plate 610A are in contact with each other, heat escapes to the inside of the first plate 610A, so that the adhesive is not easily heated. On the other hand, since the heat hardly escapes in a region where the second plate and the first plate are not in contact with each other, the adhesive is easily heated. As a result of such non-uniform heating, a difference occurs in the degree of curing of the adhesive, and a difference in the degree of curing means that the adhesive strength varies.

  By the way, in the recording head configured as described above, the first plate 610 also has a function as a heat radiating member of the recording element substrates 631 and 632 that become high temperature during operation. When paying attention to this point, there is a possibility that the following adverse effects are caused by providing a through hole in the first plate. That is, the fact that the through hole is provided in the first plate means that the amount of heat received by the first plate is reduced by that amount, so that the heat dissipation effect by the first plate is reduced. Become. If the heat dissipation effect decreases, the recording element substrate naturally becomes higher in temperature, and an excessive increase in the temperature of the recording element substrate causes the ejection operation to become unstable.

  The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and the object thereof is to record even if the first plate provided with a through hole or a notch is used. An object of the present invention is to provide an ink jet recording head capable of satisfactorily suppressing an increase in temperature of an element substrate.

  In order to achieve the above object, an ink jet recording head of the present invention has a first plate for supporting a recording element substrate having a recording element that generates energy for ejecting ink on a support surface, and exposing the recording element substrate. In the ink jet recording head having the second plate and the second plate fixed to the support surface, a through hole or a notch is formed in the first plate. Thus, an exposed surface is formed on the first surface of the second plate, and a heat receiving body that receives heat from the second plate is disposed on the exposed surface. To do.

  According to the ink jet recording head of the present invention, since the heat receiving body is disposed on the exposed surface of the second plate even in the configuration using the first plate provided with the through hole or the notch, the recording is performed. It is possible to satisfactorily suppress the temperature rise of the element substrate.

Hereinafter, the present invention will be described with reference to some embodiments.
(First embodiment)
FIG. 1 is an exploded perspective view showing the configuration of the ink jet recording head of this embodiment. FIG. 2 is a cross-sectional view taken along the cutting line AA in the completed state of the recording head of FIG. 1, and FIG. 3 shows the positional relationship between the through holes of the first plate and the heat receiving bodies disposed therein. FIG. The recording head 50 of the present embodiment is mainly characterized in that the heat receiving body 40 is added to the configuration of the conventional recording head described above, and the other structural portions are those shown in FIGS. It is the same. Therefore, in FIGS. 1 to 3, structural parts having the same functions are denoted by reference numerals corresponding to FIGS. 8 and 9, and redundant descriptions are omitted.

  The ink jet recording head 50 is bonded and fixed on the supporting surface 13 with two recording element substrates (only the recording element substrate 32 is shown), the first plate 10 that supports these recording element substrates on the supporting surface 13, and the like. A second plate 20; a wiring tape 60 (see FIG. 2) affixed as a wiring member on the second plate 20; and a heat receiving body 40 disposed on the exposed surface A15 of the second plate 20. ing. In addition, since the mounting structure of the two recording element substrates is the same, one recording element substrate 32 will be described below as an example.

  The recording element substrate 32 has a color configuration, and is arranged so that one surface thereof is in surface contact with the support surface 13 of the first plate 10. As a result, heat generated by the recording element substrate 32 during operation is transmitted into the first plate 10.

Corresponding to the through hole 15 formed in the first plate 10, an exposed surface A ₁₅ is partially formed on the lower surface of the second plate 20 in the figure. The second plate 20 has two openings 25 and 26 corresponding to the respective recording element substrates, as in the conventional configuration. For bonding the first plate 10 and the second plate 20, for example, a thermosetting resin such as an epoxy resin is used.

The heat receiving body 40 is made of, for example, aluminum, and is disposed on the exposed surface A ₁₅ of the second plate 20 with the metal paste 45 interposed, and the maximum area surface is substantially larger than the exposed surface A ₁₅ . It is in a state of surface contact.

Aluminum has the advantage of being inexpensive and lightweight. In the present embodiment, the heat receiving body 40 has a rectangular parallelepiped shape, but the present invention is not limited to this. However, as described later, considering that the heat conducting member 40 is a member for receiving heat from the second plate 20, as described above, the maximum area surface is in surface contact with the exposed surface A ₁₅ It is preferable. In particular, in the case where the heat receiving body 40 has a rectangular parallelepiped shape, it is preferable from the viewpoint of heat transfer efficiency that the maximum area surface is brought into contact.

  The metal paste 45 is obtained, for example, by mixing metal fine particles in a resin material that functions as an adhesive, and its thermal conductivity is a normal thermosetting resin (that does not contain metal fine particles). It is higher compared. By interposing such a metal paste 45, heat transfer from the second plate 20 to the heat receiving body 40 is improved.

  As shown in FIG. 3, the heat receiving body 40 is disposed substantially at the center of the through hole 15, and a gap is secured between the side edge wall of the heat receiving body 40 and the inner peripheral wall of the through hole 15. In addition, such arrangement | positioning does not limit this invention, and the arrangement | positioning of the heat receiving body 40 can be variously changed so that it may mention later as 2nd Embodiment.

  Next, the heat transfer behavior in the recording head 50 having such a configuration will be described with reference to FIG. The types of heat in the recording head of the present embodiment include heat when the wiring tape 60 is thermocompression-bonded on the second plate 20 and heat generated by the recording element substrate 32. These will be described in order.

  When the wiring tape 60 is thermocompression bonded, heat is applied to the wiring tape 60 with an uncured thermosetting adhesive layer (not shown) interposed between the wiring tape 60 and the second plate 20. Is added. The heat applied to the wiring tape 60 is transferred to the adhesive layer, and is also transferred to the second plate 20 through the adhesive layer.

In the region B of FIG. 4, since the members of the first plate 10 are present, the heat of the second plate 20 is further transferred into the first plate 10. On the other hand, in the region A, although the member of the first plate 10 does not exist, the heat receiving body 40 is arranged instead, so that the heat of the second plate is transmitted into the heat receiving body 40. Conventionally, in the region A, since the entire exposed surface A ₁₅ remains exposed, heat transfer from the second plate 20 is greatly different between the region A and the region B. On the other hand, in the present embodiment, in the region A, the heat of the second plate 20 is transmitted to the heat receiving body 40. Therefore, heat transfer is substantially the same in both areas A and B.

  This means that the heat distribution in the second plate 20 is made uniform, and further means the heat distribution in the adhesive layer is made uniform. And since the heat distribution of the adhesive layer is made uniform in this way, the difference in the degree of curing of the adhesive is finally suppressed, and consequently the adhesive strength is less likely to vary.

  In the conventional configuration without the heat receiving body 40, when the regions A and B were compared, the adhesive layer in the region A tended to harden faster. For such a configuration, if an adhesive layer is formed well in the region A, the heating in the region B becomes insufficient, and the adhesive layer may not be sufficiently cured in the region B. . On the contrary, if the adhesive layer is formed and used well in the region B, the heating in the region A becomes more than necessary. If heating is more than necessary, other problems such as elongation or breakage of the wiring tape 60 may occur. In the conventional configuration, since the heat distribution becomes non-uniform in this way, the thermocompression bonding condition has a small margin. However, according to the present embodiment, the advantage that the margin of the thermocompression bonding condition can be increased. There is.

  Next, the heat transfer behavior from the recording element substrate 32 will be described. When the recording element substrate 32 is operated, the recording element substrate itself has heat, and this heat is transferred into the first plate 10. Here, since the first plate 10 and the second plate 20 are in contact with each other, the heat transferred to the first plate 10 is also transferred to the second plate 20. The heat transmitted to the second plate 20 is transmitted to the heat receiving body 40 in the region A.

  According to the present embodiment, the heat generated in the recording element substrate 32 is transmitted to the heat receiving body 40 as described above, and the apparent heat capacity of the first plate 10 is increased. Therefore, even though the through hole 15 is formed, the heat from the recording element substrate can be sufficiently received. For this reason, it is possible to suppress heat from being accumulated in the recording element substrate, and as a result, the temperature of the recording element substrate is hardly increased.

  If attention is paid to the uniform heat distribution as described above, the size of the heat receiving body 40 is preferably determined so that the heat distribution is uniform in consideration of the thermal conductivity and the like of the heat receiving body. Further, when paying attention to the point that heat from the recording element substrate is stored and dissipated, it is preferable that the size of the heat receiving body 40 is made as large as possible. Although aluminum has been described as an example of the material of the heat receiving body 40, a metal material other than aluminum, a ceramic material, or, in some cases, a plastic material may be used. The ceramic material may be silicon carbide or the same ceramic material as the first plate 10.

The metal paste 45 is not necessarily limited to functioning as an adhesive, and other fillers can be used instead. However, if the heat receiving body 40 is disposed so as to be in surface contact with the exposed surface A ₁₅ , it is possible to omit the metal paste. However, as described above, it is preferable that some kind of filler material including a metal paste is provided in order to improve the thermal conductivity.

  Moreover, although the wiring tape 60 is usually affixed on the 2nd plate 20 with a thermosetting adhesive agent normally, it is not restricted to this. In addition to the thermosetting resin adhesive, for example, the wiring tape 60 can be attached with an ultraviolet curable adhesive. In this case, since the thermocompression bonding process as described above is eliminated in the first place, the above effect of uniform heat distribution during thermocompression bonding cannot be obtained. However, another effect by the heat receiving body 40 of suppressing the temperature rise of the recording element substrate is ensured.

(Second Embodiment)
In the first embodiment, as shown in FIG. 3, the heat receiving body 40 is arranged at the center of the through hole 15. However, the heat receiving body 40 is not limited to this, and the heat receiving body 40 is configured as shown in FIGS. 5 and 6, for example. It may be arranged.

  In the ink jet recording head 51 shown in FIGS. 5 and 6, the heat receiving body 40 is arranged so that one of the peripheral walls thereof is in contact with one of the inner peripheral walls of the through hole 15. More specifically, the heat receiving body 40 is disposed so as to be in contact with the inner peripheral wall closest to the recording element substrate 32 among the four inner peripheral walls of the through hole 15.

  Between both members, as in the first embodiment, a metal paste 45b is filled in order to improve heat conduction. In FIG. 5, the metal paste is divided into reference numerals 45a and 45b, but both the metal pastes 45a and 45b may be the same material or different materials. For example, if the metal paste 45b itself functions as an adhesive and can fix the heat receiving body 40, the metal paste 45a on the upper surface side may be omitted.

  In the recording head 51 of the present embodiment configured as described above, the heat receiving body 40 is in contact with not only the second plate 20 but also the first plate 10, and therefore the heat receiving body 40 and the first plate 10. Heat is exchanged with each other. This means that the heat distribution of the adhesive layer can be made more uniform when the wiring tape is thermocompression bonded.

  Further, when the recording element substrate is operated, it means that the heat of the recording element substrate can be transmitted to the heat receiving body 40 more efficiently. In the first embodiment, the heat from the recording element substrate is transferred to the heat receiving body 40 only through the second plate 20. In the present embodiment, the heat is transferred from the first plate 10. Since it is directly transmitted to the heat receiving body 40, it is more efficient.

The distance L shown in FIG. 5 is the shortest distance between the heat receiving body 40 and the recording element substrate 32, and the thickness t ₁₀ is the thickness of the first plate 10. If a more specific example is shown regarding the distance L and the thickness t ₁₀ , it is preferable that the distance L has a dimension of the thickness t ₁₀ or less.

The results of experiments conducted on two recording heads manufactured by changing the relationship between the distance L and the thickness t ₁₀ will be described for reference. One recording head has a distance L = 4 mm and a thickness t ₁₀ = 4 mm (Example 1), and the other recording head has a distance L = 1 mm and a thickness t ₁₀ = 4 mm (Example 2). In either case, a metal paste having a thermal conductivity of 50 W / m · K is used, and an adhesive (epoxy resin adhesive) for bonding the first plate and the second plate is thermally conductive. A degree = 0.1 W / m · K was used.

  The recording heads of each example thus produced were actually printed solid (color secondary printing), and then the temperature of the recording element substrate of each recording head was measured. As a result, it was confirmed that Example 1 having a shorter distance L was 8 ° C. lower.

(Third embodiment)
In the first and second embodiments, the configuration in which the through hole 15 is provided in the first plate 10 has been described. However, the present invention is not limited to this, and as shown in FIG. A notch 15A may be provided. Even if the cutout portion 15A is provided in place of the through-hole 15, it is the same in terms of the effect of reducing the projected area of the first plate, and thereby the advantage that the mold clamping force of the mold can be reduced. Is obtained.

  By the way, in actually manufacturing the recording head, the first plate 10A may be disposed on a predetermined support 5 as indicated by a broken line in FIG. The advantage of the notch 15A compared to the through hole 15 is that the inside of the notch 15A is not sealed even if the first plate 10A is arranged on the support 5 as described above. That is, in the case of the through hole 15, the space inside the through hole may be sealed by disposing the plate on the support 5, but this is not the case at the notch 15 </ b> A, and it is exposed to the outside. The state as it was done is kept. This means that no heat is trapped inside. Therefore, if the heat receiving body 40 is arranged in the cutout portion 15A, the heat receiving body 40 is radiated more favorably, and as a result, the temperature rise of the recording element substrate is more effectively suppressed. Will be.

  In the present invention, the configurations of the first to third embodiments described above can be used in appropriate combination. In addition, the ink jet recording head is not limited to having two recording element substrates, and may have only one of the recording element substrates. As a material of the second plate 20, for example, a metal material can be selected in addition to the ceramic material.

  Further, the heat receiving body may be formed larger than those shown in FIGS. 3 and 6 and may be fitted into the through hole, for example. Even in this case, it is preferable that a filler such as a metal paste is filled between the peripheral wall of the heat receiving body and the inner peripheral wall of the through hole. In addition, although not particularly described in the above description, if the heat receiving body itself is further brought into contact with another member (for example, the support 5), the heat dissipation efficiency of the heat receiving body itself is further improved.

  Of course, the ink jet recording head of the present invention can be used by being mounted on a recording apparatus having a general configuration. The recording apparatus includes, for example, a mechanism for transporting a recording medium such as paper, a carriage on which a recording head is mounted, and a mechanism for reciprocating the carriage in a direction crossing the transport path of the recording medium. There may be. In this type of recording apparatus, a sheet is transported in a predetermined speed pattern, and a recording head equipped with a recording head is reciprocated and scanned in accordance with the sheet, and at that time, a recording liquid is supplied from the recording head according to desired recording information. Recording is performed by discharging. As described above, according to the recording apparatus that performs recording by mounting the recording head of the present invention, the advantage of the recording head of the present invention, that is, the temperature of the recording element substrate hardly rises and thus a stable ejection operation is performed. Benefits are gained.

1 is an exploded perspective view illustrating a configuration of an ink jet recording head according to a first embodiment. FIG. 2 is a cross-sectional view taken along a cutting line AA in the completed state of the recording head of FIG. 1. It is a top view which shows the positional relationship of the through-hole of a 1st plate, and the heat receiving body arrange | positioned in the inside. FIG. 2 is a diagram for explaining heat transfer behavior in the recording head of FIG. 1. It is sectional drawing which shows the structure of the inkjet recording head of 2nd Embodiment. It is a top view which shows the positional relationship of the through-hole of a 1st plate, and the heat receiving body arrange | positioned in the inside. It is a figure which shows the structure of the inkjet recording head of 3rd Embodiment. It is a disassembled perspective view which shows the structure of the conventional inkjet recording head. It is a perspective view which shows the structure of the other conventional inkjet recording head.

Explanation of symbols

10,10A first plate 13 supporting surface 15 through holes 15A cutout portion 20 second plate 32 the printing element substrate 40 heat conducting member 45, 45a, 45b metal paste 50, 51 ink jet recording head 60 wiring tape A ₁₅ exposed surface

Claims (6)

A recording element substrate having a recording element that generates energy for ejecting ink; a first plate that supports the recording element substrate by a supporting surface; an opening for exposing the recording element substrate; In an inkjet recording head having a second plate fixed to a support surface,
By forming a through hole or a notch in the first plate, an exposed surface is formed on the first surface of the second plate, and the second surface has the second surface. An ink jet recording head, wherein a heat receiving body for receiving heat from the plate is disposed.   The ink jet recording head according to claim 1, wherein the heat receiving body substantially contacts the exposed surface with a filler interposed.   The inkjet recording head according to claim 1, wherein a part of the heat receiving member is also in contact with the first plate.   The wiring member for transmitting an electric pulse to the recording element substrate is attached to a second surface opposite to the first surface of the second plate with a thermosetting adhesive. The inkjet recording head according to any one of 1 to 3.   The heat receiving body is made of any one of a metal material, a ceramic material, and a plastic material, and one surface thereof is in surface contact with the exposed surface. 2. An ink jet recording head according to item 1. A recording apparatus that performs recording by mounting the ink jet recording head according to claim 1.

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