JP2013189021A - Recording head and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a force in the horizontal direction of an FPC applied to a contact point between a land and a bump when the FPC expands and contracts.SOLUTION: A reinforcing member 67 is provided on the whole periphery of an actuator unit 21 in plan view. More specifically, the reinforcing member 67 is provided outside a plurality of dummy lands 59 and in a contour of the actuator unit 21 in plan view. The reinforcing member 67 is interposed between the outer peripheral portion of the actuator unit 21 and a solder resist 61, and is fixed to the both, respectively.

Description

  The present invention relates to a recording head included in a recording apparatus that performs recording on a recording medium by discharging a liquid.

  As described in Patent Document 1, a recording head including an actuator unit and a flat flexible substrate (FPC) fixed to the actuator unit is known. In such a recording head, the actuator unit has a piezoelectric layer straddling a number of pressure chambers, a number of individual electrodes and a number of bumps provided on the surface of the piezoelectric layer. Each of the multiple individual electrodes is disposed so as to face each pressure chamber, and is electrically connected to each bump. The FPC supplies a drive signal to the actuator unit, and is provided with a large number of lands and a plurality of wirings connected to the large numbers of lands. The actuator unit and the FPC are fixed to each other by joining a number of bumps provided on the actuator unit and a number of lands provided on the FPC to each other.

JP 2007-168360 A

  Since the FPC and the actuator unit have different coefficients of thermal expansion, the FPC may expand and contract more greatly than the actuator unit due to, for example, a change in the operating temperature of the recording head or a temperature change due to natural cooling after the heating process during manufacturing. is there. According to the above-described technique, since the FPC and the actuator unit are fixed by the contact between the land and the bump, for example, when expansion or contraction occurs, each contact between the land and the bump is a force inward in the horizontal direction of the FPC. Will receive. As a result, stress concentrates on the contact points between the lands and the bumps, and there has been a problem of substantial reliability such as destruction of the contact points in some cases.

  A main object of the present invention is to provide a recording head capable of reducing the force inward or outward of the FPC applied to the contact point between the land and the bump when the FPC expands and contracts.

  The recording head of the present invention includes a flow path unit that discharges liquid, an actuator unit that applies discharge energy to the liquid in the flow path unit, and a flat plate that is fixed to the actuator unit and supplies a drive signal to the actuator unit. A flexible substrate, a plurality of contacts provided in an outline of the actuator unit in a plan view, and electrically connecting the actuator unit and the flat flexible substrate, and at least a part of an outer peripheral portion of the actuator unit And a reinforcing member that fixes the flat flexible substrate.

  According to the above configuration, at least a part of the outer peripheral portion of the actuator unit and the flat flexible substrate are fixed by the reinforcing member. Therefore, when the flat flexible substrate expands and contracts due to a temperature change, the force in the horizontal direction of the flat flexible substrate applied to the plurality of contacts can be reduced by the reinforcing member. Therefore, reliable electrical connection to the actuator unit can be maintained.

  Moreover, it is preferable that the said reinforcement part is all the outer peripheral parts of the said actuator unit.

  In addition, the actuator unit has a polygonal shape in plan view, and the flat flexible substrate has an unfixed portion that extends beyond the actuator unit and is not fixed to the actuator unit. And the said outer peripheral part along all sides other than one side nearest to the said non-fixed part among the sides of the said actuator unit may be sufficient as the said reinforcement part.

  The recording head of the present invention preferably includes a plurality of dummy contacts having a shape similar to that of the plurality of contacts and provided closer to the non-fixed portion than the plurality of contacts.

  The actuator unit includes a surface A facing the flat flexible substrate, a plurality of individual electrodes arranged on the surface A, and a plurality of electrically connected to the individual electrodes while being supplied with the drive signal. And a plurality of dummy bumps that have the same shape as the plurality of bumps and that are not supplied with the drive signal, and the flat flexible substrate has a surface B facing the actuator unit, the surface B A plurality of lands arranged on the bumps and bonded to the bumps, and a plurality of dummy lands having the same shape as the plurality of lands and bonded to the dummy bumps, The bumps and the lands are included, respectively, and the plurality of dummy contacts include the dummy bumps and the dummy lands, respectively. It may be.

  Further, the flat flexible substrate has a plurality of wirings respectively connected to the lands, and an insulating wiring coating layer that covers the plurality of wirings, and the reinforcing member includes the reinforcing portion and It may be provided so as to be interposed between the wiring covering layers.

  Further, the flat flexible substrate has a plurality of wirings respectively connected to the lands, and an insulating wiring coating layer that covers the plurality of wirings, and the reinforcing member includes the wiring coating layer It may be provided in a recess provided in.

  In addition, the flat flexible substrate has an insulating land coating layer that covers at least the plurality of lands except for joint portions with the plurality of bumps, and in the in-plane direction of the surface B, The land coating layer may be in contact with the wiring coating layer.

  The land coating layer is a thermosetting adhesive, covers the plurality of contacts and the plurality of dummy contacts over the entire circumference, and connects the surface A and the surface B. Is preferred.

  The reinforcing member is preferably a thermosetting adhesive.

  In the recording head manufacturing method of the present invention, an actuator unit that applies discharge energy to the liquid in the flow path unit is fixed to the flow path unit that discharges the liquid, and the actuator unit is driven to the actuator unit. A flat flexible substrate for supplying a signal is fixed, and is provided within a contour of the actuator unit in plan view, and has a plurality of contacts for electrically connecting the actuator unit and the flat flexible substrate. A method for manufacturing a head, comprising: a thermosetting adhesive in a semi-cured state at a position corresponding to the reinforcing portion that is at least a part of the outer peripheral portion of the actuator unit or the reinforcing portion in the flat flexible substrate. A reinforcing member forming step for forming the reinforcing member, and the flat flexible substrate and the reinforcing member are in contact with each other And, by curing by heating said reinforcing member in a state where said reinforcing member and the reinforcing portion are in contact, and a fixing step of fixing the said actuator unit and said flat flexible substrate.

  Moreover, it is preferable that the said reinforcement part is all the outer peripheral parts of the said actuator unit.

  In addition, the actuator unit has a polygonal shape in plan view, and the flat flexible substrate has an unfixed portion that extends beyond the actuator unit and is not fixed to the actuator unit. And the said outer peripheral part along all sides other than one side nearest to the said non-fixed part among the sides of the said actuator unit may be sufficient as the said reinforcement part.

  Further, in the fixing step, the plurality of contacts and a plurality of dummy contacts having the same shape as the plurality of contacts are arranged such that the plurality of dummy contacts are closer to the non-fixed portion than the plurality of contacts. It is preferable to form.

  The actuator unit has a surface A facing the flat flexible substrate, a plurality of individual electrodes disposed on the surface A, and a plurality of bumps supplied with the drive signal and electrically connected to the individual electrodes. And a plurality of dummy bumps having the same shape as the plurality of bumps and not supplied with the drive signal, and the flat flexible substrate is disposed on the surface B and the surface B facing the actuator unit. A plurality of lands that are respectively bonded to the bumps, and a plurality of dummy lands that have the same shape as the plurality of lands and are bonded to the dummy bumps. Each of the plurality of dummy contacts includes the dummy bump and the dummy land, respectively. Ri, in the fixing step, the bumps and the lands are bonded respectively, and the dummy bumps and dummy lands to be bonded respectively, may be fixed to the actuator unit and the flat flexible substrate.

  Further, the flat flexible substrate has a plurality of wirings respectively connected to the lands, and an insulating wiring coating layer that covers the plurality of wirings. In the reinforcing member forming step, the wiring The reinforcing member is formed in a position corresponding to the reinforcing portion of the actuator unit in the covering layer, or in the reinforcing portion, and in the fixing step, the wiring covering layer and the reinforcing member are in contact with each other, and The actuator unit and the flat flexible substrate may be fixed by curing the reinforcing member by heating in a state where the reinforcing member and the reinforcing portion are in contact with each other.

  Further, the flat flexible substrate includes an insulating land coating layer that is in contact with the wiring coating layer and coats at least the land with respect to the in-plane direction of the surface B. In the fixing step, The actuator unit and the flat flexible substrate may be fixed such that the plurality of bumps penetrate the land coating layer and are bonded to the plurality of lands.

  Further, the reinforcing member and the land covering layer are the same resin, and in the reinforcing member forming step, at the same time as forming the land covering layer, at a position corresponding to the reinforcing portion in the flat flexible substrate. The reinforcing member is preferably formed in the provided recess.

  According to the present invention, at least a part of the outer peripheral portion of the actuator unit and the flat flexible substrate are fixed by the reinforcing member. Therefore, when the flat flexible substrate expands and contracts due to a temperature change, the force in the horizontal direction of the flat flexible substrate applied to the plurality of contacts can be reduced by the reinforcing member. Therefore, reliable electrical connection to the actuator unit can be maintained.

1 is a cross-sectional view of an inkjet printer according to an embodiment of the present invention. It is sectional drawing along the transversal direction of the inkjet head shown in FIG. FIG. 3 is a plan view of the head main body shown in FIG. 2. It is an enlarged view of the area | region enclosed with the dashed-dotted line shown in FIG. It is the VV sectional view taken on the line shown in FIG. It is a figure for demonstrating the actuator unit shown in FIG. FIG. 3 is a plan view illustrating a mounting surface of the COF driver IC illustrated in FIG. 2. It is the figure which added the reinforcement member which concerns on one Embodiment of this invention to FIG. It is the IX-IX sectional view taken on the line shown in FIG. FIG. 3 is a block diagram for explaining a process until a COF shown in FIG. 2 is joined to an actuator unit. It is a figure for demonstrating each process shown in FIG. It is sectional drawing which showed COF, the reinforcement member, and actuator unit of the inkjet printer which concerns on another embodiment of this invention. It is a figure for demonstrating the process until it joins COF shown in FIG. 12 to an actuator unit.

As shown in FIG. 1, an inkjet printer 101 according to an embodiment of the present invention has a rectangular parallelepiped housing 1a. In addition, a paper discharge unit 31 is provided at the top of the housing 1a. Furthermore, the inside of the housing 1a can be divided into three spaces A, B, and C in order from the top. The spaces A and B are spaces in which a sheet conveyance path that continues to the paper discharge unit 31 is configured. In the space A, paper conveyance and image formation on the paper are performed. In the space B, paper is fed. In the space C, an ink supply source is stored, and ink is supplied here.

  In the space A, four inkjet heads 1, a transport unit 20 for transporting paper, a guide unit for guiding paper, and the like are arranged. In the upper part of the space A, a controller that controls the operation of the entire printer including these mechanisms is arranged.

  The four heads 1 are long line heads in the main scanning direction and have a substantially rectangular parallelepiped outer shape. The heads 1 are arranged at a predetermined pitch in the sub-scanning direction, and are supported by the housing 1a by the head frame 3. The head 1 includes a flow path unit 9, four actuator units 17 and a reservoir unit 71. Magenta, cyan, yellow, and black inks are ejected from the lower surfaces (ejection surfaces 2a) of the four heads 1, respectively. A more specific configuration of the head 1 will be described later.

  As shown in FIG. 1, the conveyance unit 20 includes a belt roller 6, 7 and an endless conveyance belt 8 wound between the rollers 6, 7, and a nip roller 4 disposed outside the conveyance belt 8. And a peeling plate 5, and a platen 19 and a tension roller 10 disposed inside the conveyor belt 8. The belt roller 7 is a driving roller, and is rotated clockwise in FIG. 1 by a transport motor (not shown). At this time, the conveyor belt 8 travels along the thick arrow. The belt roller 6 is a driven roller and rotates clockwise in FIG. 1 as the conveyance belt 8 travels. The nip roller 4 is disposed so as to face the belt roller 6 and presses the paper P supplied from the preceding guide portion against the outer peripheral surface 8 a of the transport belt 8. The peeling plate 5 is disposed so as to face the belt roller 7, and peels the paper P from the outer peripheral surface 8a and guides the paper P to the subsequent guide portion. The platen 19 is disposed to face the four heads 1 and supports the upper loop of the conveyor belt 8 from the inside. Thereby, a predetermined interval suitable for image formation is formed between the outer peripheral surface 8a and the ejection surface 2a of the head 1. The tension roller 10 urges the lower loop downward. This eliminates the slack of the conveyor belt.

  The guide portions are arranged on both sides with the transport unit 20 in between. The upstream guide portion includes two guides 27 a and 27 b and a pair of feed rollers 26. The guide unit connects the paper feeding unit 1b (described later) and the transport unit 20. The downstream guide portion has two guides 29 a and 29 b and two pairs of feed rollers 28. The guide unit connects the transport unit 20 and the paper discharge unit 31.

  In the space B, the paper feeding unit 1b is detachably arranged with respect to the housing 1a. The paper feed unit 1 b includes a paper feed tray 23 and a paper feed roller 25. The sheet feed tray 23 is a box that opens upward, and stores a plurality of sheets P. The paper feed roller 25 feeds the uppermost paper P in the paper feed tray 23 and supplies it to the subsequent guide section.

  As described above, the paper transport path from the paper feed unit 1b to the paper discharge unit 31 through the transport unit 20 is formed by the space A and the space B. Based on the print command, the controller feeds a feed roller motor (not shown) of the feed unit 1b, a feed roller motor (not shown) of each guide unit, and a transport motor (not shown) of the transport unit 20. D) etc. The paper P fed from the paper feed tray 23 is supplied to the transport unit 20 by the feed roller 26. When the paper P passes directly below each head 1 in the sub-scanning direction, ink is sequentially ejected from the head 1 and a color image is formed on the paper P. The paper P is peeled off on the right side of the transport belt 8 and further transported upward by the two feed rollers 28. The conveyance of the paper P in each guide portion follows the guides 27a and 27b and the guides 29a and 29b. Further, the paper P is discharged from the upper opening 30 to the paper discharge unit 31.

  Here, the sub-scanning direction is a direction parallel to the transport direction when the paper P is transported in the transport unit 20, and the main scanning direction is a direction parallel to the horizontal plane and perpendicular to the sub-scanning direction. .

  In the space C, the ink tank unit 1c is detachably attached to the housing 1a. The ink tank unit 1c stores four ink tanks 49 side by side. The ink in the ink tank 49 is supplied to the corresponding head 1 via a tube (not shown).

  Next, the inkjet head 1 will be described in detail with reference to FIG. FIG. 2 is a cross-sectional view along the sub-scanning direction that is the width direction of the inkjet head 1. As shown in FIG. 2, the head 1 includes a flow path component member, an electrical component member, and a cover body. The flow path component is a laminate in which an ink flow path is formed, and is filled with ink from the ink tank 49. The electrical component is involved in the ejection of ink in the ink flow path. The cover body mainly protects the electrical component from the outside.

  The flow path component is a laminate of the upper reservoir unit 71 and the lower head body 2. The head body 2 includes an actuator unit 21 that is also an electrical component.

  The reservoir unit 71 is a laminated body of four metal plates 91 to 94, and has a rectangular parallelepiped shape as a whole. On the lower surface of the plate 94, a plurality of convex portions 94a are formed. The tip surface of the convex portion 94a is a joint surface with the flow path unit 9 (described later). The concave portion defined by the convex portion 94 a forms a gap with the flow path unit 9. An ink reservoir 72 is formed inside the reservoir unit 71 to store ink from the ink tank 49. An ink outflow passage 73 communicating with the ink reservoir 72 is formed in the convex portion 94a, and is opened at the front end surface. In the present embodiment, there are ten ink outflow channels 73.

As shown in FIG. 3, the head body 2 includes a flow path unit 9 and an actuator unit 21. Among these, the flow path unit 9 is a laminated body of nine metal plates 122 to 130 as shown in FIG. 5 and has a rectangular parallelepiped shape as a whole. The lower surface of the flow path unit 9 is a discharge surface 2a through which a large number of nozzles 108 are opened. The upper surface of the flow path unit 9 is a joint surface through which a large number of pressure chambers 110 (see FIG. 4) and ten ink supply ports 105a are opened. On the upper surface, the convex portion 94a of the plate 94 is joined corresponding to the ink supply port 105a, and the actuator unit 21 is joined corresponding to the pressure chamber group (collection of the plurality of pressure chambers 110). As a result, the ink supply port 105 a communicates with the ink outflow channel 73 of the reservoir unit 71. The actuator unit 21 seals the openings of the plurality of pressure chambers 110 and is also a wall member of the ink flow path.

Inside the flow path unit 9, as shown in FIG. 4, an ink flow path from the ink supply port 105a to the nozzle 108 is formed. The ink channel includes a manifold channel 105 communicating with the ink supply port, a sub-manifold channel 105a branched from the manifold channel 105, and a plurality of individual ink channels 132 extending from the outlet of the sub-manifold channel 105a to the nozzle 108. It is out. In the individual ink channel 132, the pressure chamber 110 and the sub-manifold channel 105a are connected by a throttle (aperture 112). The pressure chambers 110 of the pressure chamber group are arranged in a matrix as shown in FIGS. 3 and 4 and occupy a trapezoidal area similar to the actuator unit 21.

  The actuator unit 21 is a seed-like member having a substantially trapezoidal shape in plan view, and is a laminate of three piezoelectric sheets 141 to 143. The piezoelectric sheets 141 to 143 are made of a lead zirconate titanate (PZT) ferroelectric ceramic material. The four actuator units 21 are arranged in a zigzag pattern in two rows in the main scanning direction, and are joined to the upper surface of the flow path unit 9. The parallel sides of the trapezoid are along the main scanning direction. The actuator unit 21 is disposed between the ink supply ports 105 b from both sides in the main scanning direction, and is accommodated in a gap formed by the lower surface of the plate 94 and the upper surface of the flow path unit 9. The actuator unit 21 is deformed by a drive signal from a driver IC 52 described later, and applies pressure to the ink in the pressure chamber 110.

  The electrical component includes a control board 54 and a COF 50 in addition to the actuator unit 21 described above. The control board 54 has a plurality of electronic components mounted thereon, and outputs print data. The COF 50 is a flat flexible board on which a driver IC 52 is mounted in the middle. One end of the COF 50 is connected to the connector 54 a of the control board 54, and the other end is joined to the upper surface of the actuator unit 21. When print data is output from the control board 54, a drive signal for the actuator unit 21 is output from the driver IC 52.

  The cover body is a box composed of a metal side cover 53 and a resin head cover 55, and is fixed to the flow path unit 9 at the lower end of the side cover 53. In the space formed by the cover body and the flow path unit 9, a reservoir unit 71 and an electrical component are accommodated. As a result, intrusion of ink mist from the outside can be prevented, so that an electrical failure does not occur in the electrical component. The side cover 53 is made of aluminum with good heat dissipation. As shown in FIG. 2, the side cover 53 is thermally connected to the driver IC 52 via the heat dissipation sheet 81. A sponge 82 is fixed to the side surface of the reservoir unit 71, and the driver IC 52 is biased by the side cover 53.

  Next, the actuator unit 21 will be described in detail. As shown in FIG. 3 and FIG. 4, the four actuator units 21 are more specifically hexagons with trapezoidal sharp corners cut off, and short sides and long sides parallel to the longitudinal direction of the flow path unit 9. And two oblique sides facing each other and two short sides parallel to the short direction. Each of the two short sides is connected to one end of the oblique side and one end of the long side, and is very short as compared to the oblique side. Therefore, it can be said that the actuator unit 21 has a substantially trapezoidal shape. As a result, the actuator unit 21 that is likely to occur during manufacture of the head 1 is not damaged. In the two adjacent actuator units 21, the two oblique sides facing each other overlap each other in the width direction (sub-scanning direction) of the flow path unit 9.

  As shown in FIG. 6A, the actuator unit 21 has the lower surface of the lowermost piezoelectric sheet 143 fixed to the flow path unit 9. An individual electrode 135 facing the pressure chamber 110 is formed on the upper surface (surface 21a) of the piezoelectric sheet 141. Between the piezoelectric sheet 141 and the lower piezoelectric sheet 142, a common electrode 134 extending over the entire surface of the sheet is interposed.

  As shown in FIG. 6B, the individual electrode 135 as a whole has a substantially rhombus outer shape and is similar to the pressure chamber 110. The individual electrode 135 is composed of this rhombus portion, a lead portion connected to one acute angle portion of the rhombus portion, and an individual bump 136 disposed at the tip portion thereof. In the plan view, the diamond-shaped portion is included in the pressure chamber 110. The lead portion extends in the long axis direction of the rhombus portion and has a tip portion outside the pressure chamber 110. Therefore, the individual bump 136 does not overlap the pressure chamber 110 in plan view. The individual bump 136 is electrically connected to the individual electrode 135. Each individual bump 136 is bonded to each land 58 of the COF 50 described later, and a drive signal from the driver IC 52 is supplied. Therefore, the joint portion between the individual bump 136 and the land 58 forms a contact C that electrically connects the actuator unit 21 and the COF 50 to each other. In addition to the individual electrode individual bumps 136, the common electrode individual bumps 136 electrically connected to the common electrode 134 are formed on the surface 21a. The individual bump 136 for the common electrode also forms a contact point with the land 58 of the COF 50.

  A plurality of dummy bumps 137 are provided on the surface 21a of the piezoelectric sheet 141 along the outer periphery of the actuator unit 21 (see FIG. 9). Each dummy bump 137 has the same shape as the individual bump 136 and surrounds the individual bump 136. The dummy bump 137 is provided between the outermost individual bump 136 and a reinforcing member 67 described later in plan view. Note that the dummy bump 137 is composed only of a bump portion and does not have a rhombus portion or a lead-out portion. Each dummy bump 137 is bonded to each dummy land 59 of the COF 50 described later, but a drive signal from the driver IC 52 is not supplied. Accordingly, the dummy bump 137 and the dummy land 59 constitute a dummy contact C ′ that physically connects the actuator unit 21 and the COF 50 but does not electrically connect them.

  The contacts C are arranged on the surface 21a so as to correspond to the pressure chambers 110, respectively, and occupy a trapezoidal area like the pressure chamber group. In a plan view, the contacts C are arranged at equal intervals in the trapezoidal region and constitute a plurality of rows extending in the main scanning direction. The dummy contact C ′ is provided along the outer edge of the trapezoidal region and has the same arrangement rule as the contact C. The dummy contact C 'has the same positional relationship with respect to the adjacent contact C as the positional relationship between the contacts C. Furthermore, there is a strip-shaped blank portion between the dummy contact C 'and the outer edge of the surface 21a, and all the contacts C and the dummy contacts C' are surrounded.

  Note that a ground potential is applied to the common electrode 134 via a contact C for the common electrode. On the other hand, the individual electrode 135 is electrically connected to each output terminal of the driver IC 52 via the contact C for the individual electrode, and a drive signal is selectively supplied.

Here, the piezoelectric sheet 141 is polarized in the thickness direction. When the individual electrode 135 has a potential different from that of the common electrode 134, an electric field is generated in the polarization direction, and the electric field application portion (active portion) of the piezoelectric sheet 141 is distorted by the piezoelectric effect. The active part is displaced in at least one vibration mode selected from d ₃₁ , d ₃₃ , and d ₁₅ . In the present embodiment, the active portion is displaced in the d ₃₁ vibration mode. On the other hand, the piezoelectric sheets 142 and 143 are not spontaneously displaced even at the portion corresponding to the individual electrode 135 (inactive portion). Such a combination portion functions as a so-called unimorph type piezoelectric actuator, and the actuator unit 21 has the same number of actuators as the pressure chambers 110.

  Here, a driving method of the actuator unit 21 will be described. For example, if the polarization direction is the same as the electric field application direction, the active portion contracts in a direction (plane direction) perpendicular to the polarization direction. On the other hand, the two lower piezoelectric sheets 142 and 143 do not shrink because the electric field does not affect them. At this time, there is a difference in distortion in the planar direction between the active portion and the inactive portion, so that the entire piezoelectric sheets 141 to 143 are deformed so as to protrude toward the pressure chamber 110 (unimorph deformation). Thereby, pressure (discharge energy) is applied to the ink in the pressure chamber 110, and ink droplets are discharged from the nozzles 108.

  In the present embodiment, a predetermined potential is applied to the individual electrode 135 in advance, and the individual electrode 135 is once set to the ground potential every time there is an ejection request, and then the individual electrode 135 is again set to the predetermined potential at a predetermined timing. A drive signal for applying a potential is output from the driver IC 52. In this case, the piezoelectric sheets 141 to 143 return to the original state at the timing when the individual electrode 135 becomes the ground potential, and the individual ink flow from the sub-manifold channel 105a with the increase in pressure chamber volume (pressure decrease) at this time. Ink is drawn into the path 132. Thereafter, the piezoelectric sheets 141 to 143 are deformed so as to protrude toward the pressure chamber 110 at a timing when a predetermined potential is applied to the individual electrode 135 again, and the pressure chamber volume at this time decreases (increases in pressure). Ink is ejected from the nozzle 108.

  Next, the COF 50 will be described in detail with reference to FIGS. In addition, in FIG. 7, the length of the longitudinal direction of COF50 is drawn short. Further, the outer shape of the actuator unit 21 to which the COF 50 is fixed is indicated by a broken line. As shown in FIG. 7, the COF 50 includes a fixed portion 50 a that is fixed to the actuator unit 21 in the vicinity of one end thereof, and a non-fixed portion 50 b that is not fixed to the actuator unit 21. The non-fixed portion 50b extends beyond the long side (lower bottom) portion of the actuator unit 21, and the tip in the extending direction serves as the terminal 50c.

  As shown in FIG. 9, the COF 50 has a film-like substrate 51. In the fixed portion 50 a, a plurality of lands 58 and a plurality of dummy lands 59 are provided on the surface 51 a of the base material 51. Both of these have the same shape (circular shape). The plurality of lands 58 are respectively provided at positions facing the plurality of individual bumps 136, and are joined to each other to form a contact C. The plurality of lands 58 are connected to a plurality of output wirings 57a. The plurality of dummy lands 59 are provided at positions facing the plurality of dummy bumps 137, and are joined to each other to form dummy contacts C '. None of the dummy lands 59 is connected to the output wiring 57a.

  A driver IC 52 is mounted on the non-fixed portion 50b of the COF 50 between the fixed portion 50a and the terminal 50c. An output wiring 57a extending from the land 58 is connected to an output terminal (not shown) of the driver IC 52, and a control wiring extending from a terminal of the terminal 50c is connected to a control terminal (not shown) of the driver IC 52. 57b are connected to each other.

  The dummy lands 59 arranged along the long side of the actuator unit 21 are arranged at equal intervals at the boundary between the group of lands 58 and the non-fixed portion 50b in plan view. As shown in FIGS. 7 and 8, a plurality of output wirings 57 a led out to the non-fixed portion 50 b are disposed between the two adjacent dummy lands 59 at the boundary portion. The output wiring 57a is bundled in plural at the boundary portion and in the vicinity thereof.

  The COF 50 includes a solder resist 61 that is a layer covering the plurality of output wirings 57a and the control wiring 57b. The solder resist 61 is made of a thermosetting epoxy resin and has an insulating property. The solder resist 61 covers the entire base material 51 except for a portion where the plurality of lands 58 and dummy lands 59 are formed and a portion where the driver IC 52 is mounted. The thickness is thinner than the height of the individual bump 136 and the dummy bump 137. Therefore, a gap is formed between the solder resist 61 and the surface 21 a of the actuator unit 21. This gap enables free unimorph deformation of the actuator unit 21.

  As shown in FIG. 9, the COF 50 has a contact cover layer 60a and a dummy contact cover layer 60b covering the contact C and the dummy contact C '. The contact cover layer 60a covers the entire circumference of the contact cover layer 60a except for the joint portion between the individual bump 136 and the land 58. The dummy contact cover layer 60b also covers the entire circumference of the dummy contact cover layer 60b except for the joint portion between the dummy bump 137 and the dummy land 59. Each of the cover layers 60a and 60b is made of an epoxy-based thermosetting resin different from the solder resist 61 and has high electrical insulation. Each of the cover layers 60 a and 60 b extends from the surface 51 a near the base end portion of the land 58 and the dummy land 59 to the surface 21 a near the base end portion of the individual bump 136 and the dummy bump 137, and fixes the COF 50 to the actuator unit 21. . As shown in FIG. 9, the individual lands 58 and the dummy lands 59 are thinner than the solder resist 61, and the contact C and the dummy contact C ′ have the individual bumps 136 and the dummy bumps 137 in the COF 50 (respective cover layers 60a and 60b) in the thickness direction. It is configured by entering inside. At this time, electrical connection is made by contact between the individual bumps 136 and the tips of the lands 58, and physical connection is made by the spread of the cover layers 60a and 60b.

  As shown in FIG. 8, the reinforcing member 67 is provided over the entire circumference of the belt-like outer peripheral portion of the actuator unit 21 in plan view. More specifically, the reinforcing member 67 is provided in the outline of the actuator unit 21 from the outside of the plurality of dummy lands 59 and is provided along this outline. Further, as shown in FIG. 9, the reinforcing member 67 is interposed between the outer peripheral portion of the actuator unit 21 and the solder resist 61, and is fixed to both of them. The reinforcing member 67 is made of the same material as the cover layers 60a and 60b. Note that a portion of the actuator unit 21 that is fixed to the reinforcing member 67, that is, the entire outer peripheral portion of the actuator unit 21 is referred to as a reinforcing portion 69.

  Next, the manufacturing process of the inkjet head 1 and the process of manufacturing the COF 50 and fixing it to the actuator unit 21 will be described with reference to FIGS. 10 and 11.

  First, the head body 2 is manufactured. The manufacture of the head body 2 includes a process of creating the flow path unit 9, a process of creating the actuator unit 21, and a process of fixing both. The creation process of the flow path unit includes creation of the plates 122 to 130 by etching and fixing of the plates 122 to 130 with a thermosetting adhesive. The production process of the actuator unit 21 includes a process of forming the individual electrodes 135 on the surface 21 a and a process of forming the individual bumps 136 and the dummy bumps 137. A thermosetting adhesive is used for both fixing steps. In the step of forming the individual bumps 136 and the dummy bumps 137, the bumps 136 and 137 are formed at a height of about 50 μm from the surface 21a. This height is larger than the thickness of solder resist 61 (described later).

Next, a process for manufacturing the COF 50 will be described. As shown in FIG. 11A, first, a plurality of lands 58 and dummy lands 59, a plurality of wirings including an output wiring 57a and a control wiring 57b, and a driver IC 52 are mounted on the surface 51a of the sheet material 51. Forming mounting lands. Then, a pattern of the photo-developing solder resist 61 is formed on the surface 51a so as to cover the output wiring 57a and the control wiring 57b by using a photolithography technique. The pattern forming procedure proceeds in the order of solder resist coating, pre-curing of this coating layer (80 ° C., 25 minutes), exposure with a mask pattern, development, and post-curing of a patterned coating film (150 ° C., 1 hour). In the application of solder resist, the coating film is each land 58,
The wirings 57a and 57b including 59 are covered. However, in the patterned coating film, on the lands 58 and 59, the lands 58 and 59 are exposed at the central portion except the peripheral edge. In addition, as the photographic development type solder resist 61, an epoxy resin, an acrylic resin, a polyimide resin, or the like can be used. Here, an epoxy resin is used.

  Next, as shown in FIG. 11 (b), a thermosetting epoxy resin is filled in the recesses having the lands 58 and the dummy lands 59 as the bottom surfaces by a printing method, and the contact cover layer 60a and the dummy contact cover layer are formed. 60b is formed (cover layer printing). At this time, the contact cover layer 60a and the dummy contact cover layer 60b are in contact with the solder resist 61 in the in-plane direction of the surface 51a. Further, since the thermosetting epoxy resin has a high viscosity, the concave portion does not flow out even if it is not cured.

  Next, as shown in FIG. 11C, a reinforcing member 67 is formed by screen printing at a position facing the outer periphery of the actuator unit 21 of the fixed portion 50a (reinforcing member printing). The reinforcing member 67 has a shape that exactly follows the contour of the actuator unit 21 and is formed in a trapezoidal band shape. The material is a thermosetting epoxy resin, which is the same as each cover layer 60a, 60b. Note that the screen plate used at this time has a recess on the bottom surface at a position facing the contact cover layer 60a and the dummy contact cover layer 60b. This is to prevent the thermosetting epoxy resin filled as the cover layers 60a and 60b from being transferred to the screen plate. Thereafter, a heat treatment for semi-curing the contact cover layer 60a, the dummy contact cover layer 60b, and the reinforcing member 67 is performed, for example, at 100 ° C. for 10 minutes (cover layer / reinforcing member semi-cured). Thereafter, the driver IC 52 is mounted on the mounting land. Thereby, the preparation of the COF 50 is completed.

  Then, as shown in FIG. 11 (d), the surface 21 a of the actuator unit 21 and the surface 51 a of the COF 50 are fixed. At the time of fixing, both are arranged opposite to each other with a predetermined rear relationship, and are pressurized so as to approach each other. With respect to the vertical direction, the COF 50 is disposed above. At this time, the individual bump 136 penetrates the contact cover layer 60a, and the dummy bump 137 penetrates the dummy cover layer 60b. The individual bump 136 contacts the individual land 58 by pushing the contact cover layer 60a. On the other hand, the dummy bump 137 pushes away the dummy cover layer 60 b and comes into contact with the dummy land 59. Further, the reinforcing member 67 on the surface 51 a contacts the reinforcing portion 69 of the actuator unit 21. Even in this pressurized state, the solder resist 61 is separated from the surface 21a. In this state, for example, by performing a heat treatment at 200 ° C. for 3 minutes, the contact cover layer 60a, the dummy contact cover layer 60b, and the reinforcing member 67 are cured. During the curing, the cover layers 60a and 60b are temporarily reduced in viscosity and spread from the respective contact portions to the surface 21a. Thereby, each contact part is coat | covered with a thermosetting epoxy resin over the perimeter. When the heating is further continued, the individual bump 136 and the land 58 are bonded to each other (contact C), the dummy bump 137 and the dummy land 59 are bonded to each other (dummy contact C ′), and the reinforcing member 67 is solder resist. 61 and the actuator unit 21 are fixed. As a result, the actuator unit 21 and the COF 50 are fixed to each other (pressure heating joining).

  At this stage, apart from the head main body 2 described above, the reservoir unit 71, the control board 54, the covers 53, 55, and the like are prepared through respective manufacturing processes. Subsequently, following the above-described head body 2 creation step and COF 50 joining step, the reservoir unit 71 is joined. In this joining step, the convex portion 94 a of the reservoir unit 71 is bonded to the upper surface of the flow path unit 9. At this time, the ink outflow channel 73 of the reservoir unit 71 and the ink supply port 105b of the channel unit 9 are communicated with each other. After the reservoir unit 71 is assembled, the control board 54 is fixed to the upper surface of the reservoir unit 71. Both are fastened with screws (not shown). Further, the actuator unit 21 and the control board 54 are electrically connected. At this time, the terminal 50 c of the COF 50 is inserted into the connector 54 a of the control board 50. Subsequently, the cover body is fixed to the flow path unit 9. In the cover body fixing step, the driver IC 52 is arranged between the side cover 53 and the side surface of the reservoir unit 71 so as to be urged toward the side cover 53 by the sponge 82. Further, the boundary between the upper surface of the flow path unit 9 and the side cover 53 and the boundary between the covers 53 and 55 are sealed with silicon resin. Thus, the creation of the head 1 is completed.

According to the embodiment described above, the reinforcing portion 69 of the actuator unit 21, that is, the entire outer peripheral portion and the COF 50 are fixed by the reinforcing member 67. Therefore, when the COF 50 expands and contracts due to a temperature change, the force inward in the horizontal direction of the COF 50 applied to the plurality of contacts C, that is, the plurality of lands 58 and the plurality of bumps 136 can be reduced by the reinforcing member 67. Therefore, reliable electrical connection of the COF 50 to the actuator unit 21 can be maintained. In particular, the solder resist 61 having a thermal expansion coefficient larger than that of the base material 51 tends to shrink greatly during natural cooling after being completely cured. Therefore, if the reinforcing member 67 is not provided, the stress from the surroundings cannot be offset. A large stress is applied to the contact C on the outer periphery inward of the actuator unit 21 at room temperature. However, since the reinforcing member 67 is provided as in the present embodiment, the stress applied to the contact C on the outermost periphery is reduced, and the breakage is suppressed.

  Further, when the COF 50 expands and contracts by forming the plurality of dummy contacts C ′, that is, the plurality of dummy lands 59 and the plurality of dummy bumps 137, a plurality of forces inwardly applied to the contact C in the horizontal direction of the COF 50 are applied. This can be reduced by the dummy contact C ′. Therefore, reliable electrical connection to the actuator unit 21 can be maintained.

  When the COF 50 expands and contracts, the plurality of output wirings 57a are pulled by the solder resist 61, thereby pulling the contact cover layer 60a and the dummy contact cover layer 60b joined to the solder resist 61 in the in-plane direction of the surface 51a. . According to the present embodiment, the direct force inward in the horizontal direction of the COF 50 applied to the contact C can be reduced by pulling the contact cover layer 60a and the dummy contact cover layer 60b as described above. Therefore, reliable electrical connection to the actuator unit 21 can be maintained.

  Further, since the contact cover layer 60a and the dummy contact cover layer 60b connect the actuator unit 21 and the COF 50 at the contact C and the dummy contact C ′, when the COF 50 expands and contracts, the in-plane direction of the surface 51a therebetween. Even if the expansion / contraction difference occurs, it is difficult to exert a force directly on each contact C. Thereby, a stable electrical connection at each contact C can be maintained.

  Further, since the reinforcing member 67 is a thermosetting epoxy resin, the reinforcing portion 69 of the actuator unit 21 and the COF 50 can be reliably fixed.

  In addition, it is possible to provide a recording head in which the reinforcing portion 69 of the actuator unit 21 and the COF 50 are fixed by the reinforcing member 67. Therefore, when the COF 50 expands and contracts due to a temperature change, the force inward in the horizontal direction of the COF 50 applied to the plurality of contacts C can be reduced by the reinforcing member 67. Therefore, reliable electrical connection to the actuator unit 21 can be maintained.

  Further, it is possible to provide a recording head in which a plurality of dummy contacts C ′ are formed. Therefore, when the COF 50 expands and contracts, the force toward the inner side in the horizontal direction of the COF 50 applied to the contact C can be reduced by the plurality of dummy contacts C ′. Therefore, reliable electrical connection to the actuator unit 21 can be maintained.

  When the COF 50 expands and contracts, the plurality of output wirings 57a are pulled by the solder resist 61, thereby pulling the contact cover layer 60a and the dummy contact cover layer 60b joined to the solder resist 61 in the in-plane direction of the surface 51a. Accordingly, it is possible to provide a recording head that can reduce the force applied to the contact C inward of the COF 50 in the horizontal direction. Therefore, reliable electrical connection to the actuator unit 21 can be maintained.

  Next, with reference to FIGS. 12 and 13, a modified example in which the above-described embodiment is modified will be described. However, components having the same configuration as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted as appropriate.

  A COF 150 shown in FIG. 12 has a solder resist 161 instead of the solder resist 61. The solder resist 161 has a groove 161 a provided at a position corresponding to the reinforcing portion 69 (other than one side closest to the non-fixed portion) of the actuator unit 21. In this modification, the reinforcing member 67 is provided so as to be embedded in the groove 161a. The reinforcing member 67 is fixed to the solder resist 161 in the groove 161a, and the surface thereof is fixed to the reinforcing portion 69 of the actuator unit 21, thereby fixing the COF 50 and the actuator unit 21 to each other. The COF 150 is inclined from the vicinity of the plurality of dummy contacts C 'to the portion where the groove 161a is formed. In addition, although the same thermosetting resin is used for the solder resist 161 and the reinforcement member 67 for the formation, the kind differs. Thereby, both can be identified.

  Next, the process of manufacturing the COF 150 and fixing it to the actuator unit 21 will be described with reference to FIG.

  Similar to the above-described embodiment, the head body 2 is manufactured. Next, the COF 150 is manufactured. As shown in FIG. 13A, first, a plurality of lands 58 and dummy lands 59, a plurality of wirings including an output wiring 57a and a control wiring 57b, and a driver IC 52 are mounted on the surface 51a of the sheet material 51. Forming mounting lands. Then, the output wiring 57a and the control wiring 57b are covered with a photographic development type solder resist 161 by using a photolithography technique. The solder resist 161 is made of the same epoxy resin as the solder resist 61. The formation procedure is the same. At this time, in the fixed portion, the pattern of the solder resist 161 is formed in addition to the formation portion of the land 58 and the dummy land 59 and avoiding the position facing the reinforcing portion 69. A circular recess is formed in a portion corresponding to each land 58, 59, and a groove 161a along the contour of the actuator unit 21 is formed in a portion corresponding to the reinforcing portion 69. In the present embodiment, the groove 161a is not formed in the contour portion adjacent to the non-fixed portion of the COF 150. In the trapezoidal outline, the groove 161a is formed along the short side (upper base) and the oblique side (land, wiring, solder resist formation).

  Next, as shown in FIG. 13B, a thermosetting epoxy resin is applied to the entire surface using a squeegee, thereby thermosetting the recesses and grooves 161a with the plurality of lands 58 and dummy lands 59 as bottom surfaces. Fill with functional resin. Thereby, the contact cover layer 60a, the dummy contact cover layer 60b, and the reinforcing member 67 are formed (cover layer / reinforcing member printing). At this time, the contact cover layer 60a and the dummy contact cover layer 60b are in contact with the solder resist 161 in the in-plane direction of the surface 51a. Thereafter, a heat treatment for semi-curing the contact cover layer 60a, the dummy contact cover layer 60b, and the reinforcing member 67 is performed (cover layer / reinforcing member semi-cured). Then, the driver IC 52 is mounted on the mounting land. Thereby, the COF 50 is completed.

  And as shown in FIG.13 (c), the surface 21a of the actuator unit 21 and the surface 51a of COF150 are made to oppose, and it pressurizes so that it may mutually approach. As a result, the individual bumps 136 and the dummy bumps 137 pass through the contact cover layer 60a and the dummy contact cover layer 60b, respectively, and come into contact with the land 58 and the dummy land 59, respectively, and the reinforcing member 67 is attached to the reinforcing portion 69 of the actuator unit 21. Contact. At this time, a part of the reinforcing member 67 also contacts the side surface of the actuator unit 21. By performing the heat treatment in this state, the contact cover layer 60a, the dummy contact cover layer 60b, and the reinforcing member 67 are hardened in the same manner as in the above-described embodiment. At this time, the individual bump 136 and the land 58 are joined to each other (contact C), the dummy bump 137 and the dummy land 59 are joined to each other (dummy contact C ′), and the reinforcing member 67 is connected to the solder resist 161 and the actuator. It is fixed to both units 21. As a result, the actuator unit 21 and the COF 150 are fixed to each other (pressure heating joining).

  According to the modification described above, the reinforcing member 67 can be formed simultaneously with the formation of the contact cover layer 60a and the dummy contact cover layer 60b. Therefore, in addition to the advantage obtained by the embodiment described with reference to FIGS. 1 to 11, the advantage that the recording head can be easily manufactured is obtained.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. In the above-described embodiment, the reinforcing portion 69 fixed to the reinforcing member 67 is the entire outer peripheral portion of the actuator unit 21, but the reinforcing portion 69 may be at least a part of the outer peripheral portion of the actuator unit. For example, the reinforcing portion 69 may be an outer peripheral portion along at least one side of the actuator unit 21. Moreover, the outer peripheral part along all sides other than one side nearest to the non-fixed part 50b among the sides of the actuator unit 21 may be sufficient.

  In the above-described embodiment, the dummy contact C ′ is provided, but the dummy contact C ′ may not be provided. A dummy contact C ′ may be provided along at least one side of the actuator unit 21. For example, when the reinforcing portion is an outer peripheral portion along all sides other than the one closest to the non-fixed portion 50b among the sides of the actuator unit 21, the dummy contact C ′ along the one side closest to the non-fixed portion 50b. It is desirable to provide

  In the above-described embodiment, the dummy bump 137 and the dummy land 59 constituting the dummy contact C ′ may be in a form of physically connecting the actuator unit 21 and the COF 50, and may be connected to the common electrode 134. .

  In the above-described modification, the thermosetting epoxy resin filled in the groove 161 a is bonded to the side surface of the actuator unit 21 and the reinforcing portion 69. At this time, the COF 150 is bent toward the reinforcing portion 69 and joined. However, a reinforcing bump may be formed on the surface of the actuator unit 21 corresponding to the reinforcing portion 69 so as to face the groove 161a. The reinforcing bumps have the same height as the bumps 136 and 137 from the surface. The material may be the same as or different from the bumps 136 and 137. The reinforcing bump only needs to be able to penetrate the resin in the groove 161a when the contact points C and C 'are formed. From the viewpoint of simplifying the manufacturing process, the material is preferably the same as the bumps 136 and 137.

1 Inkjet head 9 Flow path unit 21 Actuator unit 50 COF
58 Land 59 Dummy land 61 Solder resist 69 Reinforcement part 67 Reinforcement member 101 Inkjet printer 136 Individual bump 137 Dummy bump C Contact C 'Dummy contact

The present invention relates to a recording head included in a recording apparatus that performs recording on a recording medium by discharging a liquid, and a method for manufacturing the recording head.

SUMMARY OF THE INVENTION A main object of the present invention is to provide a recording head and a method for manufacturing the same that can reduce the force inward or outward of the FPC applied to the contact points between lands and bumps when the FPC expands and contracts. It is.

The recording head of the present invention includes a flow path unit that discharges liquid, an actuator unit that applies discharge energy to the liquid in the flow path unit, and has a polygonal shape in plan view, and the actuator unit. A flat flexible substrate that is fixed to the actuator unit and supplies a drive signal to the actuator unit, and extends beyond the actuator unit, and has a non-fixed portion that is not fixed to the actuator unit ; In view, there are a plurality of contacts that are provided within the outline of the actuator unit and electrically connect the actuator unit and the flat flexible substrate, and a reinforcing part that is at least a part of the outer periphery of the actuator unit. before one of the sides of the actuator unit Te And a reinforcing member for fixing the reinforcing portion and the flat flexible substrate is the outer peripheral portion along all sides except one side closest to the non-fixed portions.

According to said structure, the outer peripheral part and flat flexible board | substrate along all sides except one side nearest to the said non-fixed part among the sides of an actuator unit are fixed by a reinforcement member. Therefore, when the flat flexible substrate expands and contracts due to a temperature change, the force in the horizontal direction of the flat flexible substrate applied to the plurality of contacts can be reduced by the reinforcing member. Therefore, reliable electrical connection to the actuator unit can be maintained.

According to the recording head manufacturing method of the present invention, an actuator unit that applies discharge energy to the liquid in the flow path unit is fixed to the flow path unit that discharges the liquid. A flat type flexible substrate for supplying a driving signal to the actuator unit, the flat flexible substrate extending beyond the actuator unit and not fixed to the actuator unit. A method of manufacturing a recording head, wherein a flexible substrate is fixed, and is provided in the outline of the actuator unit in a plan view, and has a plurality of contacts that electrically connect the actuator unit and the flat flexible substrate. And at least the outer periphery of the actuator unit The outer peripheral portion in which reinforcing portions along all sides except one side closest to said non-fixed portion of the sides of the actuator unit A is part reinforcing portion, or the reinforcement in the flat flexible substrate A reinforcing member forming step for forming a reinforcing member made of a thermosetting adhesive in a semi-cured state at a position corresponding to the portion, the flat flexible substrate and the reinforcing member are in contact, and the reinforcing member and the And a fixing step of fixing the actuator unit and the flat flexible substrate by curing the reinforcing member by heating in a state where the reinforcing portion is in contact.

According to the present invention, the outer peripheral portion along all sides other than one side closest to the non-fixed portion of the sides of the actuator unit and the flat flexible substrate are fixed by the reinforcing member. Therefore, when the flat flexible substrate expands and contracts due to a temperature change, the force in the horizontal direction of the flat flexible substrate applied to the plurality of contacts can be reduced by the reinforcing member. Therefore, reliable electrical connection to the actuator unit can be maintained.

Claims (18)

A flow path unit for discharging liquid;
An actuator unit for applying discharge energy to the liquid in the flow path unit;
A flat flexible substrate fixed to the actuator unit and supplying a drive signal to the actuator unit;
In a plan view, provided in the outline of the actuator unit, a plurality of contacts for electrically connecting the actuator unit and the flat flexible substrate;
A recording head comprising: a reinforcing portion that is at least a part of an outer peripheral portion of the actuator unit; and a reinforcing member that fixes the flat flexible substrate.   The recording head according to claim 1, wherein the reinforcing portion is an entire outer peripheral portion of the actuator unit. The actuator unit has a polygonal shape in plan view;
The flat flexible substrate has an unfixed portion that extends beyond the actuator unit and is not fixed to the actuator unit;
The recording head according to claim 1, wherein the reinforcing portion is the outer peripheral portion along all sides other than one side closest to the non-fixed portion among the sides of the actuator unit.   The recording head according to claim 3, further comprising: a plurality of dummy contacts having a shape similar to that of the plurality of contacts and provided closer to the non-fixed portion than the plurality of contacts. . The actuator unit has a surface A facing the flat flexible substrate, a plurality of individual electrodes arranged on the surface A, a plurality of bumps to which the drive signal is supplied and electrically connected to the individual electrodes. And having a plurality of dummy bumps having the same shape as the plurality of bumps and not supplied with the drive signal,
The flat flexible substrate has a surface B facing the actuator unit, a plurality of lands disposed on the surface B and bonded to the bumps, and a shape similar to the plurality of lands. It has a plurality of bonded dummy lands,
The plurality of contacts each include the bump and the land,
The recording head according to claim 4, wherein the plurality of dummy contacts include the dummy bumps and the dummy lands, respectively. The flat flexible substrate has a plurality of wirings respectively connected to the lands, and an insulating wiring coating layer that covers the plurality of wirings,
The recording head according to claim 5, wherein the reinforcing member is provided so as to be interposed between the reinforcing portion and the wiring covering layer. The flat flexible substrate has a plurality of wirings respectively connected to the lands, and an insulating wiring coating layer that covers the plurality of wirings,
The recording head according to claim 5, wherein the reinforcing member is provided in a recess provided in the wiring coating layer. The flat flexible substrate has an insulating land coating layer that covers at least the plurality of lands except for joint portions with the plurality of bumps,
The recording head according to claim 5, wherein the land coating layer is in contact with the wiring coating layer in the in-plane direction of the surface B.   The land covering layer is a thermosetting adhesive, and covers the plurality of contacts and the plurality of dummy contacts over the entire circumference, and connects the surface A and the surface B. The recording head according to claim 8.   The recording head according to claim 1, wherein the reinforcing member is a thermosetting adhesive. An actuator unit that applies discharge energy to the liquid in the flow path unit is fixed to the flow path unit that discharges the liquid, and a flat flexible substrate that supplies a drive signal to the actuator unit is fixed to the actuator unit. A method of manufacturing a recording head having a plurality of contacts provided in an outline of the actuator unit in a plan view and electrically connecting the actuator unit and the flat flexible substrate,
A reinforcing member that forms a reinforcing member made of a thermosetting adhesive in a semi-cured state at a position corresponding to the reinforcing portion in at least a part of the outer peripheral portion of the actuator unit or the flat flexible substrate. Forming process;
By curing the reinforcing member by heating in a state where the flat flexible substrate and the reinforcing member are in contact with each other, and the reinforcing member and the reinforcing portion are in contact, the actuator unit and the flat flexible substrate are provided. A recording head manufacturing method comprising: a fixing step of fixing the substrate.   The method of manufacturing a recording head according to claim 11, wherein the reinforcing portion is the entire outer peripheral portion of the actuator unit. The actuator unit has a polygonal shape in plan view;
The flat flexible substrate has an unfixed portion that extends beyond the actuator unit and is not fixed to the actuator unit;
The method of manufacturing a recording head according to claim 11, wherein the reinforcing portion is the outer peripheral portion along all sides other than one side closest to the non-fixed portion of the sides of the actuator unit.   In the fixing step, the plurality of contacts and a plurality of dummy contacts having the same shape as the plurality of contacts are formed such that the plurality of dummy contacts are closer to the non-fixed portion than the plurality of contacts. The method of manufacturing a recording head according to claim 13. The actuator unit includes a surface A facing the flat flexible substrate, a plurality of individual electrodes disposed on the surface A, a plurality of bumps supplied with the drive signal and electrically connected to the individual electrodes, and , Having a plurality of dummy bumps having the same shape as the plurality of bumps and not supplied with the drive signal,
The flat flexible substrate has a surface B facing the actuator unit, a plurality of lands disposed on the surface B and bonded to the bumps, and a shape similar to the plurality of lands. It has a plurality of bonded dummy lands,
The plurality of contacts each include the bump and the land,
The plurality of dummy contacts each include the dummy bump and the dummy land,
The fixing unit includes fixing the actuator unit and the flat flexible substrate so that the bump and the land are bonded to each other, and the dummy bump and the dummy land are bonded to each other. Item 15. A method for manufacturing a recording head according to Item 14. The flat flexible substrate has a plurality of wirings respectively connected to the lands, and an insulating wiring coating layer that covers the plurality of wirings,
In the reinforcing member forming step, the reinforcing member is formed at a position corresponding to the reinforcing portion of the actuator unit in the wiring covering layer, or at the reinforcing portion,
In the fixing step, in the state where the wiring covering layer and the reinforcing member are in contact with each other, and the reinforcing member and the reinforcing portion are in contact with each other, The method of manufacturing a recording head according to claim 15, wherein the flat flexible substrate is fixed. The flat flexible substrate includes an insulating land coating layer that is in contact with the wiring coating layer and covers at least the land with respect to the in-plane direction of the surface B,
17. The fixing unit includes fixing the actuator unit and the flat flexible substrate so that the plurality of bumps penetrate the land coating layer and are bonded to the plurality of lands. The recording head manufacturing method as described in 2. above. The reinforcing member and the land covering layer are the same resin,
The reinforcing member is formed in a recess provided at a position corresponding to the reinforcing portion in the flat flexible substrate simultaneously with forming the land covering layer in the reinforcing member forming step. Item 18. A method for manufacturing a recording head according to Item 17.