JP2018118386A - Liquid discharge head and liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid discharge head, which can suppress the effect of stress caused by contraction of a sealing material and prevent liquid such as ink from entering a groove part between a side wall near a long side of a recording element substrate and an inner wall of a supporting member.SOLUTION: The liquid discharge head has: a substrate, in which are provided an energy generating element for discharging liquid through a discharge port and a supply port for supplying the liquid to be discharged to a flow path communicating with the discharge port and which has an opening extending in one direction, which has long sides along an extending direction of the supply port and short sides crossing the long sides; a support member having a recessed part for supporting the substrate formed; an electric connection part provided along the short side of the substrate; and a sealing material for sealing the electric connection part. At a position corresponding to a side closer to the center side of the substrate than the electric connection part in the recessed part of the support member, near the long side of the substrate, is arranged a wall member, and at the long side part and at the short side part of the substrate, in the recessed part of the support member, is arranged the sealing material.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a liquid discharge head and a liquid discharge apparatus, and more particularly to an application range of a sealing material used for protecting an electrical connection portion in the liquid discharge head.

  As a configuration example of a liquid discharge head for discharging a liquid such as ink, an energy generation element such as an electrothermal conversion element disposed in a pressure chamber communicating with the discharge port and the discharge port is provided on a substrate. What is provided with the element substrate which is said is known. In this type of liquid ejection head, the support member supports the element substrate disposed in the recess. Further, the liquid discharge head is provided with a contact for receiving an electric signal and electric power used for driving the electrothermal conversion element from the main body of the liquid discharge apparatus. This electrical connection between the contact portion and the recording element substrate is made possible by connecting the inner leads exposed from the electrical wiring member to connection terminals provided on the recording element substrate.

  The sealing material covers the electrical connection portion between the inner lead and the connection terminal, and protects the electrical connection portion from ink or the like. Regarding the application range of this sealing material, Patent Document 1 discloses that the sealing material includes a side wall that forms a concave portion of the support substrate and a side portion on the long side where the connection terminal of the recording element substrate is not provided. It is described that the wall member is formed so as not to flow into the groove portion therebetween. This suppresses the recording element substrate from being affected by the stress due to the shrinkage of the sealing material that may occur when the sealing material is cured at a high temperature and returned to room temperature, or when the environmental temperature changes. it can.

JP 2012-143896 A

  However, as in Patent Document 1, when the sealing material is not applied to the groove between the long side wall of the element substrate and the inner wall of the support member, ink enters the groove and the element substrate is exposed to the ink. May be. Then, dissolution of the element substrate by ink occurs, which affects the life of the element substrate. In addition, the groove on the long side of the element substrate where the sealing material is not disposed may become an ink reservoir, and in that case, there may be a problem that the device or an image to be recorded is soiled by a liquid such as ink.

  The present invention is capable of suppressing the influence of stress due to shrinkage of the sealing material, and does not allow liquid such as ink to enter the groove between the long side wall of the recording element substrate and the inner wall of the support member, and An object is to provide a liquid ejection device.

  In order to achieve the above object, the present invention provides an energy generating element for discharging liquid from a discharge port, and a supply port for supplying a liquid for discharge to a flow path communicating with the discharge port, A supply port having an opening extending in one direction, a substrate having a long side along the extending direction of the supply port and a short side intersecting the long side, and supporting the substrate A liquid discharge head, comprising: a support member having a concave portion formed thereon; an electrical connection portion provided along the short side of the substrate; and a sealing material covering the electrical connection portion, wherein the substrate A wall member is disposed at a position corresponding to a center side of the substrate from the electrical connection portion in the concave portion of the support member on the long side of the long side, and the long side of the substrate in the concave portion of the support member The sealing material is arranged on the side part and the short side part. It is characterized in.

  According to the above configuration, in the liquid ejection head, the influence of the stress due to the shrinkage of the sealing material can be suppressed, and the groove portion between the long side wall of the recording element substrate and the inner wall of the support member can be used. It is possible to prevent intrusion.

(A) And (b) is a figure which shows the liquid discharge head which concerns on one Embodiment of this invention. (A) And (b) is a figure which shows the surface side in which the discharge port of each element substrate which comprises a liquid discharge head was each arrange | positioned, and the back surface side. (A) And (b) is a figure which shows the structure of the element substrate of the liquid discharge head which concerns on 1st Embodiment of this invention. It is a figure explaining the position reference | standard of the wall member which concerns on 1st Embodiment. It is a figure which shows the relationship between the position of a wall member and the largest principal stress which acts on the end of a supply port by shrinkage | contraction of a sealing material based on 1st Embodiment. It is a figure which shows the relationship between the width | variety of a wall member and the largest principal stress which acts on the edge of a supply port based on 1st Embodiment. It is a figure which shows the relationship between the largest principal stress which acts on the edge G of the space | interval G of a wall member and a board | substrate based on 1st Embodiment, and a supply port. (A) And (b) is a figure which shows the structure of the element substrate of the liquid discharge head which concerns on 2nd Embodiment of this invention. It is a figure which shows the relationship between the position of a wall member and the largest principal stress which acts on the end of a supply port by shrinkage | contraction of a sealing material based on 2nd Embodiment. It is a figure for demonstrating the effect of the wall member of 2nd Embodiment.

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

  1A and 1B are views showing a liquid discharge head 100 according to an embodiment of the present invention. FIG. 1A is a perspective view of the liquid discharge head 100 viewed from the discharge port surface side, and FIG. 1B is an exploded perspective view of the liquid discharge head 100. FIGS. 2A and 2B are views showing the surface side of the element substrate 101 constituting the liquid discharge head 100 where the discharge ports are provided and the back side thereof.

  The liquid ejection head 100 is formed by attaching a recording element substrate (simply referred to as an element substrate) to a case member that constitutes the ink containing portion 103. The electrical wiring member 102 and the element substrate 101 are electrically connected by connecting the inner leads 109 of the electrical wiring member 102 and the connection terminals 107 of the element substrate 101. Further, the contact portion 108 of the electric wiring member 102 is connected to a connector pin in the carriage of the apparatus main body. Thereby, it is possible to exchange electric signals and supply power between the liquid discharge head 100 and the apparatus main body.

  Ink inside the ink container 103 is held as liquid. Then, the ink is guided to the element substrate 101 through the ink supply channel 106 communicated with the ink containing portion 103, and the ink is ejected from the ejection port 104 provided in the element substrate 101. The present embodiment relates to a configuration in which the liquid ejection head 100 and the ink storage unit 103 are integrated, but a system in which the ink storage unit 103 can be attached to and detached from the liquid ejection head 100 may be used.

  The electric wiring member 102 is a flexible wiring member, and a contact portion 108, an electric wiring (not shown) sandwiched between resin films, and an inner lead 109 which is a lead wiring exposed from the end surface of the resin film are formed. Has been. As an example of such an electric wiring member 102 having flexibility, a TAB (Tape Automated Bonding) type tape can be cited. The contact portion 108 is composed of a plurality of contact pads, and comes into contact with a connector pin (not shown) on the recording apparatus main body when the liquid ejection head 100 is mounted on a carriage (not shown) of the recording apparatus main body. And electrical connection is made.

  The element substrate 101 is formed by a substrate 117 and a nozzle plate 116 in which the discharge ports 104 are formed. Among these, an electrothermal conversion element (not shown) is provided on the substrate 117 as an energy generating element that generates energy used to eject ink. Further, the substrate 117 has a plurality of wirings connected to the electrothermal conversion element and a plurality of connection terminals 107 connecting the wirings and the electrical wiring member 102. By connecting the inner lead 109 of the electric wiring member 102 to the connection terminal 107 by bonding, an electric signal and electric power can be supplied from the electric wiring member 102 to the element substrate 101. A region where the inner lead 109 is bonded to the connection terminal 107 is defined as an electrode portion. This electrode portion is disposed at the end portion on the short side of the substrate 117. The sealing material 110 is applied to the end portion of the substrate 117, so that these connection terminal portions can be covered and protected from a liquid such as ink.

  The substrate 117 of the element substrate 101 has an ink supply port 105 formed of a long groove-shaped through-hole. The ink supply port 105 has an elongated opening extending in one direction, and is formed inside the electrode portion of the substrate 117. In this embodiment, the shape of the ink supply port is a quadrangular pyramid created by anisotropic etching or the like, but it may be a rectangular parallelepiped. Ink is supplied from the ink supply channel 106 on the ink container 103 side to the channel formed by the nozzle plate 116 formed on the substrate 117 via the ink supply port 105. Ink can be discharged from the corresponding discharge port 104 by driving the electrothermal conversion element provided in the flow path.

  The support member 111, which is a part of the casing of the liquid discharge head 100, and the element substrate 101 are joined by applying an adhesive to the support member 111 and then aligning the element substrate 101. In addition, the electric wiring member 102 is bonded and fixed to the support member 111 with an adhesive different from the adhesive used when the element substrate is bonded. The support member 111 is formed by resin molding, and the resin material (modified polyphenylene ether) used in the present embodiment is mixed with 35% by mass of a glass filler in order to improve rigidity. The support member 111 has a shape (concave portion 113) in which a portion where the element substrate 101 is arranged is recessed from a portion where the surrounding electric wiring member 102 is bonded and fixed. This is because the inner leads 109 of the electric wiring member 102 and the connection terminals 107 of the element substrate 101 are made substantially the same height to improve the reliability of the electric connection portions of both.

(First embodiment)
3A and 3B are views showing the configuration of the element substrate 101 of the liquid ejection head according to the first embodiment of the present invention, and FIG. 3B is a cross-sectional view taken along the line IIIb-IIIb in FIG. It is. As shown in these drawings, the element substrate 101 of this embodiment includes a substrate 117 having a long side along the extending direction of the supply port 105 and a short side intersecting the long side. Further, in addition to the electrode portion which is an end portion on the short side of the substrate 117, a sealing material 110 is formed in a groove portion between a side portion on the long side of the substrate 117 and an inner wall portion forming a concave portion of the support member 111. Is filled. However, wall members 119 are arranged at four locations of the groove corresponding to the long side of the substrate 117. The position of the wall member 119 with the end of the supply port 105 as the reference of the distance is P, the width of the wall member 119 in the long side direction of the substrate 117 is W, and the distance G between the wall member 119 and the substrate 117 is G. At this time, in this embodiment, as will be described later, W is set to 1 mm, P is set to 0.5 mm, and G is set to 0.13 mm. The height of the upper surface of the wall member is the same height as the position where the upper surfaces of the element substrate 101 and the support member 111 are continuous. In the present embodiment, the wall member is resin-molded integrally with the support member, but the wall member may be formed by bonding with an adhesive or the like. Further, the material may be different from that of the support member.

  An example of the specification of the element substrate 101 in which the arrangement and shape of the wall member 119 are determined as described above is as follows. The sealing material is a thermosetting type mainly composed of an epoxy resin and cured at 100 ° C. for 1 hour. The sealing material 110 has a linear expansion coefficient of about 20 ppm to 40 ppm and a Young's modulus of about 4 GPa to 8 GPa. In this embodiment, the linear expansion coefficient is about 30 ppm and the Young's modulus is about 6 GPa. The support member 111 is made of alumina and has a linear expansion coefficient of about 7 ppm and a Young's modulus of about 320 GPa. The substrate 117 is made of silicon and has a linear expansion coefficient of about 3 ppm and a Young's modulus of about 170 GPa. Is.

  In order to evaluate the resistance against cracking of the element substrate of the liquid discharge head having the above-described specification, the evaluation was made to cool the entire liquid discharge head to −25 ° C. The larger the temperature difference from the cure curing temperature, the more the sealing material shrinks, and the deformation of the element substrate increases. In the evaluation environment of −25 ° C., the liquid discharge head provided with the wall member according to the present embodiment is less susceptible to cracking of the element substrate than the conventional liquid discharge head without the wall member. confirmed. For quantitative evaluation, the maximum principal stress at the end 118 of the element substrate supply port was measured. The starting point of the crack is the edge of the supply port, and the higher the maximum principal stress at this point, the easier it is to crack. The maximum principal stress was measured by Raman shift by Raman spectroscopy. The maximum principal stress of the element substrate without the wall member of the conventional example is 100 MPa, whereas the maximum principal stress of the element substrate 101 of the present embodiment with the wall member is reduced to 20 MPa and 20%. Although it has been confirmed that the maximum principal stress is reduced to about 70%, there is a sufficient effect for suppressing cracking of the element substrate, but in the present embodiment, the effect of being reduced to 20% is shown.

  When the liquid discharge head is cooled from the cure temperature, the sealing material contracts, and a crack starting from the end edge of the supply port 105 may occur. Here, since the sealing material contracts as the linear expansion coefficient of the sealing material increases, cracking is likely to occur. In addition, as the Young's modulus of the sealing material is larger, the stress at the time of contraction is not relaxed, the force for pulling the element substrate is increased, and the chip is easily broken. On the other hand, it is thought that it is sufficient to use a sealing material having physical properties that do not easily cause chip cracking, but it is necessary to control the viscosity from the point of applicability of the sealing material. There are restrictions on physical properties. This embodiment can prevent a crack by determining the shape and arrangement | positioning of a wall member as mentioned above, without receiving such a restriction | limiting.

  Below, the consideration matter and preferable range in determining each of the position of the wall member 119 which concerns on this embodiment, the width | variety, and the space | interval with the board | substrate 117 mentioned above are demonstrated.

<Position of wall member>
By arranging the wall member, there is no sealing material at the place where the wall member is arranged. For this reason, the stress which an element substrate receives by shrinking | contracting a sealing material is reduced, and it is suppressed that an element substrate deform | transforms and a crack generate | occur | produces. However, if the wall member is disposed over the entire side of the long side of the substrate 117, it may adversely affect wiping. Wiping is an operation of wiping the surface on which the discharge port is provided with a wiper and wiping off ink or dust adhering to the surface of the discharge port. For example, if the wall member exists over the entire side of the long side of the substrate 117, the wiper may hit the wall member during the wiping operation, and the wiping effect may be reduced. In order to reduce the influence on the wiping, it is preferable that the wall member is disposed not in the whole area of the side portion of the substrate but in a minimum necessary place. Moreover, in order to reduce as much as possible that it hits the wall member during wiping, the upper surface position of the wall member is preferably equal to or lower than the upper surface position of the substrate.

  In view of this, several liquid discharge heads having different wall member positions were prepared, and evaluation of cracks in the element substrate was performed by changing the temperature of the entire liquid discharge head as described above. The width W of the wall member on the long side of the substrate 117 is 1.0 mm, the distance G between the wall member and the substrate is 0.13 mm, and a sealing material is filled between the wall member and the substrate. FIG. 4 is a view for explaining the position reference of the wall member according to the present embodiment. In the present embodiment, the position at which the center position of the wall member 119 and the end of the supply port 105 of the substrate 117 coincide with each other as a reference 0, and the outside of the supply port 105 in the longitudinal direction of the supply port 105 is minus and the center side is plus. Yes.

  FIG. 5 is a diagram showing the relationship between the position of the wall member and the maximum principal stress acting on the end of the supply port due to the shrinkage of the sealing material according to the present embodiment. In FIG. 5, the solid line indicates the above relationship, and the broken line indicates the maximum principal stress acting on the end of the supply port when there is no wall member. As shown in FIG. 5, when the center position P of the wall member 119 is about 0.5 mm, the maximum principal stress becomes a minimum value. Further, the center position P of the wall member 119 is in the range of about −0.5 mm to about 2.0 mm, which is about 70% of the maximum principal stress acting when there is no wall member. As described above, when the maximum principal stress acting on the end of the supply port 105 is about 70% or less when there is no wall member, cracking of the element substrate can be effectively suppressed.

  As described above, by disposing the wall member 119 in the vicinity of the end 118 of the supply port 105, deformation of the substrate in the vicinity of the end 118 of the supply port can be suppressed. Specifically, the wall member 119 is preferably arranged on the inner side in the longitudinal direction of the element substrate 101 than the connection terminal 107 of the element substrate 101. Particularly, when the wall member 119 is extended in the short direction of the element substrate 101, the wall member 119 is arranged so that the end 118 of the supply port 105 is located in the region (including the boundary) of the wall member 119. Is more preferable.

<Width of wall member>
Several liquid discharge heads having different width W (length) in the direction along the long side of the substrate of the wall member were created, and the evaluation for cracking of the element substrate was the same as the examination of the position of the wall member. Went in the way. The center position P of the wall member 119 is set to +0.5 mm, the gap G between the wall member 119 and the substrate 117 is set to 0.13 mm, and a sealing material is filled between the wall member 119 and the substrate 117.

  FIG. 6 is a diagram illustrating a relationship between the width W of the wall member and the maximum principal stress acting on the end of the supply port according to the present embodiment. As shown in FIG. 6, when the width W of the wall member 119 is 1.5 mm or more, the maximum principal stress becomes substantially zero. On the other hand, as the width W is reduced, the maximum principal stress increases. Therefore, the width W of the wall member 119 is preferably as large as possible from the viewpoint of reducing the maximum principal stress. However, the width W is 1.5 mm or less (the lower limit is 0 mm) from the viewpoint of the influence of the wall member on the wiping described above. ) Is preferable. Furthermore, it is more preferable that the lower limit is 0.25 mm, which is the width W that is about 70% of the maximum principal stress when there is no wall member.

<Space between substrate and wall member>
The gap G between the substrate 117 and the wall member 119 is changed, and several liquid discharge heads in which a groove with the gap G is filled with a sealing material are created, and evaluation for cracks in the element substrate is performed in the same manner as described above. It was. In this evaluation, the center position P of the wall member 119 was +0.5 mm, and the width W of the wall member 119 was 1.0 mm.

  FIG. 7 is a diagram showing the relationship between the wall member-to-substrate gap G and the maximum principal stress acting on the end of the supply port according to the present embodiment. As shown in FIG. 7, when the distance G between the substrate 117 and the wall member 119 is 1 mm or more, the effect of reducing the maximum principal stress by the wall member is almost lost. This is because as the gap G increases, the sealing material increases and the shrinkage of the sealing material increases. Therefore, the distance G between the substrate 117 and the wall member 119 is preferably 1 mm or less. In particular, about 0.4 mm or less, which is the range of the gap G that is about 70% or less of the maximum principal stress when there is no wall member, is further preferable.

(Second Embodiment)
FIGS. 8A and 8B are views showing the configuration of the element substrate of the liquid ejection head according to the first embodiment of the present invention. FIG. 8A is a front view of the element substrate 101, and FIG. 8B is a cross-sectional view taken along the line VIIIb-VIIIb in FIG.

  The present embodiment is different from the first embodiment described above in that a gap S with a predetermined interval is provided between the wall member 120 and the recess bottom surface of the support member 111 as shown in FIG. It is. The gap 110 is also filled with the sealing material 110. The wall member 120 is formed integrally with the support member 111, but may be formed by bonding the support member 111 with an adhesive or the like.

  As described above, since there is a space S between the bottom surface of the concave portion of the support member and the wall member 120, the degree of freedom in the manufacturing process of the liquid discharge head is increased, and the process can be simplified. That is, in the case where there is no gap between the bottom surface of the recess of the support member 111 and the wall member, it is necessary to fill the sealing material in either the long side or the short side of the element substrate, which increases the number of steps. On the other hand, when there is a gap S between the bottom surface of the concave portion of the support member 111 and the wall member 120 as in this embodiment, for example, even if the sealing material 110 is filled from the long side of the substrate 117, the gap It is possible to fill the short side through S.

  In this embodiment, the thickness T of the wall member 120 is half that of the substrate 117, and the upper surface of the wall member 120 is disposed so as to coincide with the upper surface of the element substrate. The width (length) of the wall member 120 in the direction along the long side of the substrate 117 is 1.0 mm, and the distance between the wall member 120 and the substrate 117 is 0.13 mm, which is the same as in the first embodiment.

  Several liquid discharge heads in which the position of the wall member 120 was changed were created, and the same evaluation as in the first embodiment was performed. FIG. 9 shows this result, and the relationship between the maximum principal stress acting on the end 118 of the supply port 105 that can be a starting point of cracking of the element substrate due to shrinkage of the sealing material and the position of the center of the wall member 120. It is a figure shown by. The position of the wall member 120 is near the end of the supply port, and the maximum principal stress takes a minimum value. With respect to the center position of the wall member 120, when the position of the end 118 of the supply port 105 is set to the reference 0, the range of −0.5 mm to 2.0 mm is the maximum principal stress with respect to the liquid ejection head without the wall member 120. Is about 70%, and chip cracking due to this main stress can be effectively suppressed.

  FIGS. 10A to 10C are diagrams for explaining the action and effect of suppressing cracking of the element substrate by the wall member according to the embodiment of the present invention described above. As shown in FIG. 10A, in the element substrate 101 having no wall member, as shown in FIG. While the three surfaces are connected, the surface indicated by E is not in contact with any member. In this case, when the sealing material 110 contracts due to a temperature change, a rotational force in the direction shown in FIG. 10C acts on the substrate 117. Here, it has been found that the resistance to cracking is low when an outward tensile force on the long side is applied to a single substrate. For this reason, it becomes easy to generate | occur | produce a crack on the basis of the end of the supply port 105 with the said rotational force. On the other hand, according to the first and second embodiments of the present invention described above, the presence of the wall members (119, 120) can limit the amount of rotation of the substrate 117 by the wall members. . As a result, the substrate can be prevented from cracking. This is the same even when there is a gap S between the wall member and the support member recess as in the second embodiment. In addition, as described above, since the wall member exists in the vicinity of the end 118 of the supply port 105, there is no sealing member there. Thereby, the rotation does not occur at the place, and the rotation of the substrate 117 in the vicinity of the end 118 of the supply port 105 can be suppressed.

DESCRIPTION OF SYMBOLS 100 Liquid discharge head 101 Element board | substrate 104 Discharge port 105 Ink supply port 107 Connection terminal 109 Inner lead 110 Sealing material 111 Support member 116 Nozzle plate 117 Substrate 118 End of supply port 119, 120 Wall member

Claims (8)

An energy generating element for discharging liquid from the discharge port, and a supply port for supplying the discharge liquid to the flow path communicating with the discharge port, the supply having an opening extending in one direction A substrate having a long side along the extending direction of the supply port and a short side intersecting the long side, a support member having a recess for supporting the substrate, A liquid discharge head having an electrical connection portion provided along the short side of the substrate, and a sealing material covering the electrical connection portion,
A wall member is disposed at a position corresponding to a center side of the substrate from the electrical connection portion in the concave portion of the support member on the long side of the substrate, and the substrate of the substrate in the concave portion of the support member A liquid discharge head, wherein the sealing material is disposed on a side portion on a long side and a side portion on a short side.   The liquid discharge head according to claim 1, wherein the position of the upper surface of the wall member is equal to or lower than the position of the upper surface of the substrate.   The liquid discharge head according to claim 1, wherein a distance between the wall member and the substrate is 0.4 mm or less.   The liquid discharge head according to claim 3, wherein a sealing material is disposed in the groove having the gap between the wall member and the substrate.   The wall member has the wall at a position in a range of −0.5 mm to +2.0 mm, where an end in the extending direction of the supply port of the substrate is a distance reference 0 and a center side of the substrate is +. 5. The liquid ejection head according to claim 1, wherein the member is disposed so that a center of the extending direction of the member is located.   The liquid ejection head according to claim 1, wherein a width of the wall member in the extending direction is 1.5 mm or less.   The clearance gap is provided between the said wall member and the bottom face of the said recessed part of the said supporting member, The said sealing material is distribute | arranged to the said clearance gap, The any one of Claim 1 thru | or 6 characterized by the above-mentioned. Liquid discharge head.   A liquid discharge apparatus comprising the liquid discharge head according to claim 1.