Patent Publication Number: US-8534804-B2

Title: Ink-jet head and method of manufacturing ink-jet head

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2011-054384, filed on Mar. 11, 2011, the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to an ink-jet head and a method of manufacturing the ink-jet head. 
     BACKGROUND 
     An ink-jet head comprises a substrate and a piezoelectric member mounted on the substrate. The piezoelectric member comprises a plurality of groove-like pressure chambers to be supplied with ink. Electrodes are disposed in the pressure chambers, individually, and are connected individually to a plurality of electrical traces on the substrate. A driver IC for controlling the ink-jet head is connected to the electrical traces. If the driver IC applies voltage to the electrodes in the pressure chambers through the electrical traces, the piezoelectric member undergoes a shear-mode deformation such that the ink in the pressure chambers can be ejected. 
     To prevent corrosion of electrically conductive portions or a short circuit, an insulating film is formed on the electrodes in the pressure chambers and the electrical traces on the substrate. In forming the insulating film, those portions to which the driver IC is connected are masked with, for example, grease. 
     After the insulating film is formed, that part of it located on the grease is removed. The driver IC is connected to the electrical traces exposed by the masking. On the other hand, the electrical traces are left exposed between the driver IC and an end portion of the insulating film. Thus, exposed parts of the electrical traces may be degraded. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view showing an ink-jet head according to a first embodiment; 
         FIG. 2  is a sectional view of the ink-jet head of the first embodiment taken along line F 2 -F 2  of  FIG. 1 ; 
         FIG. 3  is a sectional view of the ink-jet head of the first embodiment taken along line F 3 -F 3  of  FIG. 1 ; 
         FIG. 4  is a perspective view showing an ink-jet head according to a second embodiment; and 
         FIG. 5  is a sectional view of the ink-jet head of the second embodiment taken along line F 5 -F 5  of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION 
     In general, according to one embodiment, an ink-jet head includes a main body, a plurality of electrodes, a plurality of electrically conductive portions, an insulating film, an adhesive, a frame member, a lid member, an electronic component and a protective agent. The main body includes a plurality of pressure chambers. The electrodes are disposed in the pressure chambers, individually. The electrically conductive portions are disposed on the main body and connected to the electrodes, individually. The insulating film covers the electrodes and a part of the electrically conductive portions. The adhesive covers an end portion of the insulating film. The frame member inside which an ink chamber communicating with the pressure chambers is defined is located on the end portion of the insulating film and attached to the main body by the adhesive. The lid member is mounted on the frame member and closes the ink chamber. The electronic component is connected to the electrically conductive portions. The protective agent covers the electrically conductive portions between the electronic component and the frame member. 
     A first embodiment will now be described with reference to  FIGS. 1 to 3 .  FIG. 1  is an exploded perspective view showing an ink-jet head  1 .  FIG. 2  is a partial sectional view of the head  1  taken along line F 2 -F 2  of  FIG. 1 .  FIG. 3  is a partial sectional view of the head  1  taken along line F 3 -F 3  of  FIG. 1 . 
     As shown in  FIG. 1 , the ink-jet head  1  of the first embodiment is of a so-called end-shooter type. The head  1  comprises a main body  10 , frame member  11 , lid member  12 , nozzle plate  13 , and driver IC  14 . The driver IC  14  is an example of an electronic component. 
     The main body  10  comprises a substrate  21  and piezoelectric member  22 . The substrate  21  is in the form of a rectangular plate. The substrate  21  comprises a notch portion  24  ranging from an upper surface  21   a  to a front surface  21   b  of the substrate  21 . 
     The piezoelectric member  22  is formed by affixing two piezoelectric plates of, for example, lead zirconate titanate (PZT) together such that their polarization directions are opposite. The piezoelectric member  22  is attached to the notch portion  24  of the substrate  21 . 
     The main body  10  comprises a plurality of pressure chambers  27  into which ink is introduced. The pressure chambers  27 , each in the form of a groove, are arranged side by side and parallel to one another. These chambers  27  are located ranging from the substrate  21  to the piezoelectric member  22 . The pressure chambers  27  open in the upper surface  21   a  of the substrate  21  and upper and front surfaces  22   a  and  22   b  of the piezoelectric member  22 . 
     As shown in  FIG. 2 , column portions  28  are formed individually between the pressure chambers  27 . The column portions  28  divide the pressure chambers  27  and form side surfaces of the pressure chambers  27 , individually. 
     Electrodes  31  are disposed in the pressure chambers  27 , individually. Each electrode  31  covers the side and bottom surfaces of its corresponding pressure chamber  27 . Although each electrode  31  is formed of, for example, a thin nickel film, it may alternatively be formed of a gold or copper film, for example. Each electrode  31  is, for example, 2 to 5 μm thick. The column portions  28 , having the electrodes  31  formed on their opposite side surfaces, are used as driving elements. 
     As shown in  FIG. 1 , a plurality of electrical traces  33  are arranged on the upper surface  21   a  of the substrate  21 . Each electrical trace  33  is an example of an electrically conductive portion. The electrical traces  33  are formed by, for example, laser-patterning a thin nickel film formed on the upper surface  21   a  of the substrate  21 . Each electrical trace  33  is, for example, 2 to 5 μm thick. The electrical traces  33  individually extend from the rear end of the upper surface  21   a  of the substrate  21 . One end of each electrical trace  33  is connected to its corresponding electrode  31 . 
     As shown in  FIG. 3 , an insulating film  35 , which is electrically insulating and resistant to ink, is disposed on the main body  10 . The insulating film  35  (not shown in  FIG. 1 ) covers the electrodes  31 , part of the electrical traces  33 , part of the upper surface  21   a  of the substrate  21 , and upper surface  22   a  of the piezoelectric member  22 . The insulating film  35  may be configured to cover some other portion or portions, such as the front surface  21   b  of the substrate  21 . The insulating film  35  is, for example, 3 to 10 μm thick. The electrodes  31  are protected by the insulating film  35  from ink introduced into the pressure chambers  27 . 
     The insulating film  35  is cut at the rear part of the upper surface  21   a  of the substrate  21 . Thus, each electrical trace  33  comprises an exposed portion  33   a  that is exposed by virtue of not being covered by the insulating film  35 . The exposed portion  33   a  defines that part of the electrical trace  33  which is not covered by the insulating film  35 , and can be covered by some member other than the insulating film  35 . 
     The insulating film  35  consists mainly of, for example, a para-xylene polymer. Specifically, a para-xylylene polymer, such as Parylene-C (poly-chloro-para-xylylene), Parylene-N (poly-para-xylylene), or Parylene-D (poly-dichloro-para-xylylene), is available as this polymer material. Alternatively, the insulating film  35  may be formed using some other material, such as polyimide. 
     The frame member  11  is attached to the main body  10  using an adhesive  38 . A beam portion  11   a  on the rear side of the frame member  11  is located on an end portion  35   a  of the insulating film  35  where the insulating film  35  is cut. As shown in  FIG. 3 , the end portion  35   a  of the insulating film  35  is located below the transverse central part of the beam portion  11   a  of the frame member  11 . 
     The adhesive  38  is sandwiched between the main body  10  and frame member  11 . The adhesive  38  is, for example, 30 μm thick. For example, the adhesive  38  is an epoxy-resin adhesive, which is resistant to ink and thermosetting. Alternatively, the adhesive  38  may be, for example, a silicone or acrylic adhesive. The resistance of the adhesive to ink implies that the adhesive strength can be kept at 50 kg/cm 2  even when the adhesive is immersed in ink for an assumed period of use of 6 to 12 months. 
     The adhesive  38  covers and seals the end portion  35   a  of the insulating film  35 . A difference in level produced by the electrical traces  33  and insulating film  35  is made up for by the adhesive  38 . 
     The lid member  12  is mounted on the frame member  11 . As shown in  FIG. 1 , the lid member  12  comprises two ink supply ports  41 . The frame member  11  and lid member  12 , thus combined together, close the pressure chambers  27  from the side of the upper surface  21   a  of the substrate  21 . 
     As shown in  FIG. 3 , an ink chamber  42  to be supplied with ink is defined inside the frame member  11  and lid member  12 . The lid member  12  closes the ink chamber  42  by being mounted on the frame member  11 . The ink supply ports  41  open into the ink chamber  42  and are connected to an ink tank. The ink chamber  42  communicates with the pressure chambers  27 . The ink introduced into the ink chamber  42  through the ink supply ports  41  is delivered to the pressure chambers  27 . 
     The nozzle plate  13  is formed of a rectangular film of polyimide. The nozzle plate  13  may be formed from a material other than polyimide that can undergo laser micro-processing. The nozzle plate  13  is mounted on the main body  10 , frame member  11 , and lid member  12 . As shown in  FIG. 1 , the nozzle plate  13  closes the pressure chambers  27  from the side of the front surface  22   b  of the piezoelectric member  22 . 
     The nozzle plate  13  comprises a plurality of nozzles  45 . The nozzles  45 , which correspond to the pressure chambers  27 , individually, are arranged side by side and longitudinally relative to the nozzle plate  13 . The nozzles  45  open into the pressure chambers  27 , individually. 
     As shown in  FIG. 3 , the driver IC  14  is connected to the respective exposed portions  33   a  of the electrical traces  33 . The driver IC  14  is a flexible printed circuit board for controlling the ink-jet head  1 . The driver IC  14  is thermocompressively bonded to the electrical traces  33  by an anisotropic conductive film (ACF)  48 . Alternatively, the driver IC  14  may be connected to the electrical traces  33  by some other means than the ACF  48 , such as an anisotropic conductive paste (ACP), nonconductive film (NCF), or nonconductive paste (NCP). The driver IC  14  is, for example, 35 μm thick. Likewise, the ACF  48  is 35 μm thick, for example. 
     Based on a signal input from a controller of an ink-jet printer, the driver IC  14  applies a voltage to the electrodes  31  through the electrical traces  33 . The column portions  28  to which the voltage is applied through the electrodes  31  undergo a shear-mode deformation, thereby pressurizing the ink introduced into the pressure chambers  27 . The pressurized ink is ejected from the corresponding nozzles  45 . 
     A protective agent  51  is disposed ranging from the frame member  11  to the driver IC  14 . An illustration of the protective agent  51  is omitted in  FIG. 1 . The protective agent  51  covers the exposed portions  33   a  of the electrical traces  33  between the frame member  11  and driver IC  14 . 
     The protective agent  51 , like the adhesive  38 , for example, is an epoxy-resin adhesive resistant to ink and thermosetting. Alternatively, the protective agent  51  may be, for example, a silicone or acrylic adhesive. Further, the protective agent  51  may be an adhesive of a type different from the adhesive  38 . 
     The protective agent  51  adheres to the side surfaces of the frame member  11 . Further, the protective agent  51  adheres to the driver IC  14  such that it covers a part of the IC. Thus, the protective agent  51 , along with the ACF  48 , secures the driver IC  14  to the main body  10 . 
     The following is a description of an example of a method of manufacturing the ink-jet head  1  constructed in this manner. First, two piezoelectric plates are affixed to each other with, for example, a thermosetting adhesive, thereby forming the piezoelectric member  22 . This piezoelectric member  22  is attached to the notch portion  24  of the substrate  21  with, for example, a thermosetting adhesive, thereby forming the main body  10 . 
     Then, the pressure chambers  27  are formed in the main body  10 . The pressure chambers  27  are defined by cutting the main body  10  by means of, for example, a diamond wheel of a dicing saw, which is used to cut IC wafers. 
     Subsequently, the electrodes  31  are formed in the pressure chambers  27 , individually, and at the same time, the electrical traces  33  are formed on the upper surface  21   a  of the substrate  21 . The electrodes  31  and electrical traces  33  are formed by, for example, electroless plating. Then, patterning is performed by, for example, laser irradiation, whereupon the thin nickel film is removed from regions other than the electrodes  31  and electrical traces  33 . 
     Then, the insulating film  35  is formed by chemical vapor deposition (CVD). When this is done, the rear part of the upper surface  21   a  of the substrate  21  and other portions that are not covered by the insulating film  35  are protected with a masking tape, e.g., a polyimide tape. The masking tape is removed after the insulating film  35  is formed. Thus, the respective exposed portions  33   a  of the electrical traces  33  are formed that are exposed by virtue of not being covered by the insulating film  35 . 
     After the insulating film  35  is formed, the frame member  11  is attached to the main body  10  with the adhesive  38 . The adhesive  38  is applied to the frame member  11  by, for example, screen printing. The frame member  11  is bonded to the main body  10  so that its beam portion  11   a  is located above the end portion  35   a  of the insulating film  35 . The end portion  35   a  of the insulating film  35  is covered by the adhesive  38 . The lid member  12  is attached to the frame member  11  on the main body  10  with a thermosetting adhesive. 
     Then, the nozzle plate  13  that has not yet had the nozzles  45  formed in it is attached to the main body  10  with a thermosetting adhesive. An ink-repellent film is previously formed on the nozzle plate  13  by means of, for example, a bar coater. The nozzles  45  are formed by applying an excimer laser beam to the nozzle plate  13  mounted on the main body  10 . 
     Subsequently, the driver IC  14  is thermocompressively bonded to the exposed portions  33   a  of the electrical traces  33  with the ACF  48 . The driver IC  14  is electrically connected to the electrical traces  33  through the ACF  48 . 
     Then, the protective agent  51  is applied between the driver IC  14  and frame member  11  by means of, for example, a dispenser. The respective exposed portions  33   a  of the electrical traces  33  between the frame member  11  and driver IC  14  are covered by the protective agent  51 . 
     Thus, manufacturing processes for the ink-jet head  1  shown in  FIG. 1  are accomplished. The thermosetting adhesive used in the manufacturing processes for the ink-jet head  1  may be either thermally cured every time one member is mounted or thermally cured at a time in a stage. 
     According to the ink-jet head  1  constructed in this manner, the end portion  35   a  of the insulating film  35  is covered by the adhesive  38 . Therefore, the insulating film  35  is prevented from starting to peel off at the end portion  35   a , or the ink from the end portion  35   a  is prevented from penetrating between the insulating film  35  and electrical traces  33 . Since the adhesive  38  seals the end portion  35   a  of the insulating film  35 , moreover, the ink is prevented from adhering to the end portion  35   a.    
     The protective agent  51  covers the exposed portions  33   a  of the electrical traces  33  between the driver IC  14  and frame member  11 . Thus, the ink is prevented from adhering to the exposed portions  33   a  even if it is introduced to the vicinity of the driver IC  14  as it leaks from an ink supply tube or creeps up during maintenance, for example. Consequently, the ink is prevented from corroding the electrical traces  33  or causing a short circuit. The conductive electrical traces  33  are protected in this way. 
     The protective agent  51  is an ink-resistant adhesive. Therefore, the exposed portions  33   a  of the electrical traces  33  between the driver IC  14  and frame member  11  are easily covered by applying the protective agent  51  by means of the dispenser. Since the protective agent  51  is an adhesive of the same type as the adhesive  38 , moreover, an increase in the manufacturing cost of the ink-jet head  1  is suppressed. 
     The protective agent  51  adheres to the driver IC  14 . Thus, the protective agent  51 , along with the ACF  48 , secures the driver IC  14  to the main body  10 , thereby preventing the driver IC from separating from the electrical traces  33 . 
     A second embodiment of the ink-jet head will now be described with reference to  FIGS. 4 and 5 . In the description of the embodiments to follow, like reference numbers are used to designate those constituent parts which have the same functions as their counterparts in the ink-jet head  1  of the first embodiment. Further, a description of some or all of those parts may be omitted. 
       FIG. 4  is a cutaway perspective view showing an ink-jet head  1 A according to the second embodiment. An illustration of an insulating film  35  is omitted in  FIG. 4 .  FIG. 5  is a partial sectional view of the ink-jet head  1 A taken along line F 5 -F 5  of  FIG. 4 . 
     As shown in  FIG. 4 , the ink-jet head  1 A of the second embodiment is of a so-called side-shooter type. The head  1 A comprises a substrate  61 , a pair of piezoelectric members  62 , frame member  63 , nozzle plate  13 , a plurality of driver ICs  14 , and manifold  64 . As shown in  FIG. 5 , an ink chamber  66  to be supplied with ink is defined inside the substrate  61 , frame member  63 , and nozzle plate  13 . The ink chamber  66  is closed by the substrate  61  and nozzle plate  13 . The pair of piezoelectric members  62  are located within the ink chamber  66 . 
     The substrate  61  is a rectangular plate of a ceramic, such as alumina. The substrate  61  has a flat first surface  61   a  and a second surface  61   b  on the opposite side to it. The second surface  61   b  is attached to the manifold  64 . As shown in  FIG. 4 , the substrate  61  comprises a plurality of ink supply ports  73  and a plurality of ink discharge ports  74 . 
     The ink supply ports  73  are disposed in the central part of the substrate  61  such that they are arranged longitudinally relative to the substrate  61 . The ink supply ports  73  individually open into the ink chamber  66 . When the substrate  61  is attached to the manifold  64 , the ink supply ports  73  are connected to an ink tank through the manifold  64 . Ink in the ink tank is introduced into the ink chamber  66  through the ink supply ports  73 . 
     The ink discharge ports  74  are arranged in two rows such that they sandwich the ink supply ports  73  between them. The ink discharge ports  74  individually open into the ink chamber  66 . When the substrate  61  is attached to the manifold  64 , the ink discharge ports  74  are individually connected to the ink tank through the manifold  64 . The ink in the ink chamber  66  is recovered into the ink tank through the ink discharge ports  74 . 
     The pair of piezoelectric members  62  are individually mounted on the first surface  61   a  of the substrate  61  and extend longitudinally relative to the substrate  61  and parallel to each other. The piezoelectric members  62  are individually disposed between the ink supply ports  73  and ink discharge ports  74 . 
     Each of the piezoelectric members  62  is formed by affixing two piezoelectric plates of, for example, PZT together such that their polarization directions are opposite. Each piezoelectric member  62  is in the form of a bar having a trapezoidal cross-section. 
     Each piezoelectric member  62  comprises a plurality of pressure chambers  77  that communicate with the ink chamber  66 . The pressure chambers  77  are grooves that extend across the piezoelectric member  62 . As shown in  FIG. 5 , electrodes  31  are disposed in the pressure chambers  77 , individually. Each electrode  31  is formed on the side and bottom surfaces of its corresponding pressure chamber  77 . 
     A plurality of electrical traces  33  are arranged on the first surface  61   a  of the substrate  61 . The electrical traces  33  are located ranging from side edges  61   c  of the substrate  61  to the piezoelectric members  62  and connected to the electrodes  31 , individually. 
     The insulating film  35 , which is electrically insulating and resistant to ink, is disposed on the substrate  61  and piezoelectric members  62 . The insulating film  35  covers the electrodes  31 , part of the electrical traces  33 , part of the first surface  61   a  of the substrate  61 , second surface  61   b  of the substrate  61 , and piezoelectric members  62 . The insulating film  35  may be configured to cover some other portion or portions. The electrodes  31  are protected by the insulating film  35  from ink introduced into the pressure chambers  77 . Further, the electrical traces  33  are protected by the insulating film  35  from ink introduced into the ink chamber  66 . 
     The insulating film  35  is cut in regions around the side edges  61   c  of the substrate  61 . Thus, each electrical trace  33  comprises an exposed portion  33   a  that is exposed by virtue of not being covered by the insulating film  35 . 
     The frame member  63  is attached to the first surface  61   a  of the substrate  61  using an adhesive  38 . The frame member  63  surrounds the pair of piezoelectric members  62 , ink supply ports  73 , and ink discharge ports  74 . 
     A beam portion  63   a  of the frame member  63  is located on an end portion  35   a  of the insulating film  35  where the insulating film  35  is cut. As shown in  FIG. 5 , the end portion  35   a  of the insulating film  35  is located below the transverse central part of the beam portion  63   a  of the frame member  63 . 
     The adhesive  38  is sandwiched between the substrate  61  and frame member  63 . For example, the adhesive  38  is an epoxy-resin adhesive, which is resistant to ink and thermosetting. Alternatively, the adhesive  38  may be, for example, a silicone or acrylic adhesive. 
     The adhesive  38  covers and seals the end portion  35   a  of the insulating film  35 . A difference in level produced by the electrical traces  33  and insulating film  35  is made up for by the adhesive  38 . 
     The nozzle plate  13  is mounted on the frame member  63 . The nozzle plate  13  comprises a plurality of nozzles  45 . The nozzles  45 , which correspond to the pressure chambers  77 , individually, are arranged side by side and open into the pressure chambers  77 , individually. 
     The driver ICs  14  are connected to the respective exposed portions  33   a  of the electrical traces  33 . The driver ICs  14  are flexible printed circuit boards for controlling the ink-jet head  1 A. The driver ICs  14  are thermocompressively bonded to the electrical traces  33  by an ACF  48 . Alternatively, the driver ICs  14  may be connected to the electrical traces  33  by some other means than the ACF  48 , such as an ACP, NCF, or NCP. 
     Based on a signal input from a controller of an ink-jet printer, the driver ICs  14  apply voltage to the electrodes  31  through the electrical traces  33 . The piezoelectric members  62  supplied with voltage through the electrodes  31  undergo a shear-mode deformation, thereby pressurizing the ink introduced into the pressure chambers  77 . The pressurized ink is ejected from the corresponding nozzles  45 . 
     A protective agent  51  is disposed ranging from the frame member  63  to the driver ICs  14 . The protective agent  51  covers the exposed portions  33   a  of the electrical traces  33  between the frame member  63  and driver ICs  14 . 
     The protective agent  51 , like the adhesive  38 , for example, is an epoxy-resin adhesive resistant to ink and thermosetting. Alternatively, the protective agent  51  may be, for example, a silicone or acrylic adhesive. Further, the protective agent  51  may be an adhesive of a type different from the adhesive  38 . 
     The protective agent  51  adheres to the side surfaces of the frame member  63 . Further, the protective agent  51  adheres to the driver ICs  14  such that it covers a part of each IC  14 . Thus, the protective agent  51 , along with the ACF  48 , secures the driver ICs  14  to the substrate  61 . 
     The following is a description of an example of a method of manufacturing the ink-jet head  1 A constructed in this manner. First, the ink supply and discharge ports  73  and  74  are formed by press forming in the substrate  61 , which is an unfired ceramic sheet (ceramic green sheet). Thereafter, the substrate  61  is fired. 
     Then, the pair of piezoelectric members  62  are attached to the substrate  61  with, for example, a thermosetting adhesive. The piezoelectric members  62  are positioned on the substrate  61  by means of a jig and mounted on the substrate. Subsequently, the respective corner portions of the piezoelectric members  62  are, so to speak, tapered. Thereupon, the cross-section of each piezoelectric member  62  becomes trapezoidal. 
     Then, the pressure chambers  77  are formed in the piezoelectric members  62 . The pressure chambers  77  are defined by means of, for example, a diamond wheel of a dicing saw, which is used to cut IC wafers. 
     Subsequently, the electrodes  31  are formed in the pressure chambers  77 , individually, and at the same time, the electrical traces  33  are formed on the first surface  61   a  of the substrate  61 . The electrodes  31  and electrical traces  33  are formed from, for example, a thin nickel film by electroless plating. Then, patterning is performed by laser irradiation, whereupon the thin nickel film is removed from regions other than the electrodes  31  and electrical traces  33 . 
     Then, the insulating film  35  is formed by CVD. When this is done, the regions around the side edges  61   c  of the first surface  61   a  of the substrate  61  and other portions that are not covered by the insulating film  35  are protected with a masking tape, e.g., a polyimide tape. The masking tape is removed after the insulating film  35  is formed. Thus, the respective exposed portions  33   a  of the electrical traces  33  are formed that are exposed by virtue of not being covered by the insulating film  35 . 
     After the insulating film  35  is formed, the frame member  63  is attached to the substrate  61  with the adhesive  38 . The adhesive  38  is applied to the frame member  63  by, for example, screen printing. The frame member  63  is bonded to the substrate  61  so that its beam portion  63   a  is located above the end portion  35   a  of the insulating film  35 . The end portion  35   a  of the insulating film  35  is covered by the adhesive  38 . 
     Then, the nozzle plate  13  that has not yet had the nozzles  45  formed in it is affixed to the piezoelectric members  62  and frame member  63 . An ink-repellent film is previously formed on the nozzle plate  13  by means of, for example, a bar coater. The nozzles  45  are formed by applying an excimer laser beam to the nozzle plate  13  mounted on the frame member  63 . 
     Subsequently, the driver ICs  14  are thermocompressively bonded to the exposed portions  33   a  of the electrical traces  33  with the ACF  48 . The driver ICs  14  are electrically connected to the electrical traces  33  through the ACF  48 . 
     Then, the protective agent  51  is applied between the driver ICs  14  and frame member  63  by means of, for example, a dispenser. The respective exposed portions  33   a  of the electrical traces  33  between the frame member  63  and driver ICs  14  are covered by the protective agent  51 . 
     Finally, the second surface  61   b  of the substrate  61  is attached to the manifold  64 , whereupon manufacturing processes for the ink-jet head  1 A shown in  FIG. 4  are accomplished. The thermosetting adhesive used in the manufacturing processes for the ink-jet head  1 A may be either thermally cured every time one member is mounted or thermally cured at a time in a stage. 
     According to the ink-jet head  1 A constructed in this manner, the end portion  35   a  of the insulating film  35  is covered by the adhesive  38 . Therefore, the insulating film  35  is prevented from starting to peel off at the end portion  35   a , or the ink from the end portion  35   a  is prevented from penetrating between the insulating film  35  and electrical traces  33 . Since the adhesive  38  seals the end portion  35   a  of the insulating film  35 , moreover, the ink is prevented from adhering to the end portion  35   a.    
     The protective agent  51  covers the exposed portions  33   a  of the electrical traces  33  between the driver ICs  14  and frame member  63 . Thus, the ink is prevented from adhering to the exposed portions  33   a  even if it is introduced to the vicinity of the driver ICs  14  as it leaks from an ink supply tube or creeps up during maintenance, for example. Consequently, the ink is prevented from corroding the electrical traces  33  or causing a short circuit. The conductive electrical traces  33  are protected in this way. 
     The protective agent  51  is an ink-resistant adhesive. Therefore, the exposed portions  33   a  of the electrical traces  33  between the driver ICs  14  and frame member  63  are easily covered. Since the protective agent  51  is an adhesive of the same type as the adhesive  38 , moreover, an increase in the manufacturing cost of the ink-jet head  1 A is suppressed. 
     The protective agent  51  adheres to the driver ICs  14 . Thus, the protective agent  51 , along with the ACF  48 , secures the driver ICs  14  to the main body  10 , thereby preventing the driver ICs from separating from the electrical traces  33 . 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.