JP5914976B2 - Nozzle substrate, droplet discharge head, and droplet discharge apparatus - Google Patents

Description

  The present invention relates to a droplet discharge head such as an ink jet printer and a droplet discharge device, and more particularly to a nozzle substrate in which nozzle holes are formed.

  Conventionally, as described in, for example, Patent Document 1, in the manufacture of a nozzle substrate that is a discharge portion of a droplet discharge head, a silicon substrate is formed with two stages of nozzle holes and chip separation grooves, and then silicon. There has been known a method in which a substrate is bonded to a support substrate with a tape, a surface opposite to a nozzle hole forming surface is ground, and nozzle holes are penetrated and chips are separated.

JP 2006-159661 A

  However, in the nozzle substrate described in Patent Document 1 in which two stages of nozzle holes and chip separation grooves are formed at the same time, there is no step on the outer peripheral side surface of the chip, or an unintended step is formed, and the divided chips are handled. At this time, the droplet protective film on the outer peripheral surface of the chip is easily peeled off. For this reason, there is a problem that when the peeled film adheres to the chip surface, it hinders chip adhesion, and when it adheres to the nozzle hole, it disturbs droplet discharge.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A nozzle substrate according to this application example includes a first nozzle hole opened on a droplet discharge surface side, and the first nozzle hole communicating with the first nozzle hole and opened on the opposite side to the droplet discharge surface side. A nozzle hole in which a second nozzle hole having a larger cross-sectional area than one nozzle hole is continuous, and a chip outer peripheral side opposite to the liquid droplet ejection surface is located inside the chip outer peripheral side of the liquid droplet ejection surface. It has an outer peripheral side surface and a droplet protective film formed on the outer peripheral side surface of the chip.

According to this application example, when the droplet protective film is formed from the droplet discharge surface side, a shadow portion formed by a step on the outer peripheral surface of the chip becomes large, so the liquid on the outer peripheral surface of the chip opposite to the droplet discharge surface side is increased. By reducing the area and thickness of the droplet protective film, it is possible to reduce peeling of the droplet protective film that adheres to the chip surface and the nozzle hole and interferes with adhesion and droplet discharge.
In addition, the manufacturing yield of the nozzle substrate and the droplet discharge head can be improved.

  Application Example 2 In the nozzle substrate according to the application example described above, the depth a of the chip outer peripheral surface on the opposite side to the droplet discharge surface and the second nozzle hole opened on the opposite side to the droplet discharge surface The depth b is preferably a> b.

According to this application example, when the droplet protective film is formed from the droplet discharge surface side, a shadow portion due to a step on the outer peripheral surface of the chip approaches the droplet discharge surface, so that the outer periphery of the chip on the side opposite to the droplet discharge surface. This has the effect of reducing the thickness of the droplet protective film formed on the side surface. For this reason, when handling the divided chips, the droplet protective film on the outer peripheral side surface of the chip is difficult to peel off, thereby preventing the droplets from adhering to the chip surface and the nozzle holes and preventing adhesion and droplet discharge. Film peeling can be reduced.
In addition, the manufacturing yield of the nozzle substrate and the droplet discharge head can be improved.

  [Application Example 3] In the nozzle substrate according to the application example described above, a stepped portion is formed in which the outer peripheral side surface of the chip on the side opposite to the droplet discharge surface is inside the outer peripheral surface of the chip on the droplet discharge surface side, It is preferable that the width of the step portion is larger than the thickness of the droplet protective film.

According to this application example, the tip outer peripheral side opposite to the droplet discharge surface side is inside the chip outer peripheral side on the droplet discharge surface side, and the step width is larger than the droplet protective film thickness. It has the effect of reducing the thickness of the droplet protective film formed on the outer peripheral side of the chip on the side opposite to the droplet ejection surface. Therefore, the droplet protective film on the outer peripheral side of the chip is difficult to peel off when handling divided chips. As a result, it is possible to reduce the peeling of the droplet protective film that adheres to the chip surface and the nozzle hole and hinders adhesion and droplet discharge.
In addition, the manufacturing yield of the nozzle substrate and the droplet discharge head can be improved.

  Application Example 4 A droplet discharge head according to this application example includes the nozzle substrate according to the application example described above in a droplet discharge unit.

  According to this application example, the droplet discharge head is provided with the nozzle substrate that reduces the peeling of the droplet protective film, and a droplet discharge head capable of stable droplet discharge can be provided.

  Application Example 5 A droplet discharge device according to this application example includes the droplet discharge head according to the above application example.

  According to this application example, the droplet discharge device is provided with the droplet discharge head capable of stably discharging the droplet, and a droplet discharge device with stable printing quality can be provided.

FIG. 3 is a top view of the nozzle substrate according to the first embodiment when viewed from the droplet discharge surface side. Sectional drawing of the nozzle board | substrate AA part of FIG. FIG. 5 is a process diagram illustrating a method for manufacturing a nozzle substrate according to the first embodiment. FIG. 5 is a process diagram illustrating a method for manufacturing a nozzle substrate according to the first embodiment. FIG. 5 is a process diagram illustrating a method for manufacturing a nozzle substrate according to the first embodiment. FIG. 4 is a schematic cross-sectional view illustrating a configuration of a droplet discharge head according to a second embodiment. FIG. 4 is an exemplary view of a droplet discharge device according to a third embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the scale of each layer and each member is made different from the actual scale so that each layer and each member can be recognized.

(Embodiment 1)
FIG. 1 is a top view of the nozzle substrate 1 according to the first embodiment as viewed from the droplet discharge surface side. As shown in FIG. 1, a plurality of nozzle holes 10 are linearly arranged on the surface of the nozzle substrate 1. Reference numeral 13 denotes a pin alignment hole when the droplet discharge head is assembled, and reference numeral 14 denotes a chip outer peripheral portion.
FIG. 2 is a cross-sectional view of the nozzle substrate AA portion of FIG. As shown in FIG. 2, the chip outer peripheral side surface 14a opposite to the droplet discharge surface side has a stepped structure that is inside the chip outer peripheral side surface 14b on the droplet discharge surface side. The droplet protective film 11 is formed on the chip outer peripheral surfaces 14a and 14b. Here, the droplet protective film 11 refers to a film including an oxide film formed on the outer periphery of the nozzle substrate and a water-repellent film formed on the surface thereof.

In the nozzle substrate 1, the depth a of the chip outer peripheral side opposite to the droplet discharge surface and the depth b of the second nozzle hole opened to the opposite side of the droplet discharge surface are such that a> b. Is formed.
With this structure, when forming a droplet protective film from the droplet discharge surface side, the shadow portion due to the step on the chip outer peripheral surface approaches the droplet discharge surface, so that the chip outer peripheral surface on the side opposite to the droplet discharge surface This has the effect of reducing the thickness of the droplet protective film formed on the substrate. For this reason, when handling the divided chips, the droplet protective film on the outer peripheral side surface of the chip is difficult to peel off, thereby preventing the droplets from adhering to the chip surface and the nozzle holes and preventing adhesion and droplet discharge. Film peeling can be reduced.

  Further, in the nozzle substrate 1, the chip outer peripheral side opposite to the droplet discharge surface is inside the chip outer peripheral side on the droplet discharge surface side to form a stepped portion, and the width W of the stepped portion is the thickness of the droplet protective film. It is formed several tens of times larger than that.

3 to 5 are process diagrams showing a method for manufacturing a nozzle substrate. Based on this, the manufacturing method of the nozzle substrate will be described.
As shown in FIG. 3A, a single crystal silicon substrate (hereinafter referred to as a nozzle substrate 1) is first prepared, and a thermal oxide film 15 is formed on both sides of the nozzle substrate 1 to a thickness of about 0.5 μm.

  As shown in FIG. 3B, patterning is performed to remove portions of the thermal oxide film 15 that become the second nozzle holes 10b and the chip outer peripheral side surface 14b.

As shown in FIG. 3C, a resist film 16 having a thickness of 2.0 μm is formed on the adhesion surface side of the nozzle substrate 1, and the resist film 16 in portions that become the first nozzle holes 10a and the chip outer peripheral side surface 14a is removed. Patterning is performed.
Here, patterning is performed so that the chip outer peripheral side surface 14a on the side opposite to the droplet discharge surface side is several μm inside the chip outer peripheral side surface 14b on the droplet discharge surface side. By setting the thickness to several μm, which is several tens of times the droplet protective film thickness, the droplet protective film thickness formed on the outer peripheral side surface of the chip opposite to the droplet discharge surface side is thin and the area is small. . Accordingly, it is possible to reduce peeling of the droplet protective film on the outer peripheral side surface of the chip.

  As shown in FIG. 3D, by anisotropic dry etching, the portions that become the first nozzle hole 10a and the chip outer peripheral side surface 14a are etched to a predetermined depth, and the resist film 16 is removed.

As shown in FIG. 4E, using the pattern of the thermal oxide film 15 as a mask, the portions that become the second nozzle hole 10b and the chip outer peripheral side surface 14b are etched to a predetermined depth by anisotropic dry etching.
Here, a structure in which the depth a of the chip outer peripheral side surface 14a is deeper than the depth b of the second nozzle hole 10b using the difference in etching opening area can be obtained. As a result, when forming the droplet protective film from the droplet discharge surface side, the shadow portion becomes the film formation side, the droplet protective film thickness formed on the chip outer peripheral side surface 14a is thin, and the area is small. Become. Accordingly, it is possible to reduce peeling of the droplet protective film on the outer peripheral side surface of the chip.
As shown in FIG. 4F, the thermal oxide film 15 is peeled off, and an oxide film 11a having a thickness of 0.1 μm as a droplet protective film is formed by thermal oxidation.
As shown in FIG. 4G, a support substrate 17 is bonded to the nozzle substrate 1 using a support tape 17a, and is ground and polished until a predetermined plate thickness is obtained. To penetrate.
As shown in FIG. 4 (H), after forming an oxide film by plasma CVD from the droplet discharge surface side, a silane coupling agent is dip coated, and a water repellent film 11b as a droplet protective film is formed on the droplet discharge surface. Form.
As shown in FIG. 5 (I), a support tape 18a and a support substrate 18 are attached to a droplet discharge surface via a water-repellent protective tape 18c, and the support substrate 17 on the adhesion surface side is peeled off. Alternatively, the water repellent film in the nozzle hole is hydrophilized by argon plasma treatment.
As shown in FIG. 5J, finally, the support substrate 18 is peeled off to complete the nozzle substrate 1.

As described above, according to the nozzle substrate 1 according to the present embodiment, the following effects can be obtained.
The chip outer peripheral side surface 14a opposite to the droplet discharge surface side is formed on the chip outer peripheral side surface 14a opposite to the droplet discharge surface side by a step structure that is inside the chip outer peripheral side surface 14b on the droplet discharge surface side. The droplet protective film 11 is thin and has a small area. As a result, when the divided chips are handled, the droplet protective film is hardly peeled off from the outer peripheral side surface of the chip, the amount of peeling is reduced, and the yield is improved.

(Embodiment 2)
FIG. 6 is a schematic cross-sectional view illustrating a configuration of a droplet discharge head including the nozzle substrate described in the first embodiment.

  The droplet discharge head 100 is configured by bonding a nozzle substrate 1, a flow path forming substrate 50, an elastic film 60, and a protective substrate 70. A piezoelectric element 80 is disposed on the elastic film 60 with an insulator film 65 interposed therebetween.

  In this embodiment, the flow path forming substrate 50 is made of a silicon single crystal substrate having a crystal plane orientation (110) in the plate thickness direction, and an elastic film 60 is formed on one surface thereof. The flow path forming substrate 50 is provided with a plurality of pressure generating chambers 52 that are partitioned by a plurality of partition walls. In addition, an ink supply path 54 and a communication path 55 are partitioned by a partition wall on the end side of the pressure generating chamber 52 of the flow path forming substrate 50. In addition, a communication portion 53 that forms part of a reservoir 90 that serves as a common ink chamber (liquid chamber) for each pressure generating chamber 52 is formed at one end of the communication passage 55. That is, the flow path forming substrate 50 is provided with a liquid flow path including a pressure generation chamber 52, a communication portion 53, an ink supply path 54, and a communication path 55.

  Further, on the opening surface side of the flow path forming substrate 50, the nozzle substrate 1 in which the nozzle holes 10 communicating with the vicinity of the end portion of each pressure generating chamber 52 on the side opposite to the ink supply path 54 is formed is adhesive or It is fixed by a heat welding film or the like.

  On the other hand, an elastic film 60 is formed on the side opposite to the opening surface of the flow path forming substrate 50, and an insulator film 65 is laminated on the elastic film 60. On the insulator film 65, a lower electrode film 81, a piezoelectric layer 82, and an upper electrode film 83 are laminated to form a piezoelectric element 80.

  Each upper electrode film 83 that is an individual electrode of the piezoelectric element 80 is connected to a lead electrode 85 that is drawn from the vicinity of the end on the ink supply path 54 side and extends to the insulator film 65. Yes.

  Further, on the flow path forming substrate 50 on which the piezoelectric element 80 is formed, a protective substrate 70 having a piezoelectric element holding portion 72 having a space that does not hinder the movement of the piezoelectric element 80 in a region facing the piezoelectric element 80. Are joined by an adhesive 75.

  In addition, the protective substrate 70 is provided with a reservoir portion 71 in a region facing the communication portion 53, and this reservoir portion 71 is communicated with the communication portion 53 of the flow path forming substrate 50 so that each of the pressure generating chambers 52. A reservoir 90 serving as a common ink chamber is configured. A through hole 73 that penetrates the protective substrate 70 in the thickness direction is provided in a region between the piezoelectric element holding portion 72 and the reservoir portion 71 of the protective substrate 70, and the lower electrode film 81 is provided in the through hole 73. And the tip of the lead electrode 85 are exposed.

  A drive circuit (not shown) for driving the piezoelectric element 80 is fixed on the protective substrate 70, and the drive circuit and the lead electrode 85 are electrically connected via a connection wiring.

  A compliance substrate 95 including a sealing film 96 and a fixed plate 97 is bonded onto the protective substrate 70. Here, the sealing film 96 is sealed on one surface of the reservoir portion 71 by the sealing film 96. The fixing plate 97 is made of a hard material such as metal. Since the region of the fixing plate 97 facing the reservoir 90 is an opening 98 that is completely removed in the thickness direction, one surface of the reservoir 90 is sealed only with a flexible sealing film 96. Has been.

  In the liquid droplet ejection head 100 of this embodiment, after taking in ink from an external ink supply means (not shown) and filling the interior from the reservoir 90 to the nozzle hole 10, according to the recording signal from the drive circuit, A voltage is applied between the lower electrode film 81 and the upper electrode film 83 corresponding to the pressure generation chamber 52. Along with this, the elastic film 60, the insulator film 65, the lower electrode film 81, and the piezoelectric layer 82 are bent and deformed, the pressure in each pressure generating chamber 52 is increased, and ink droplets are ejected from the nozzle holes 10 of the nozzle substrate 1. To do.

  As described above, the droplet discharge head 100 of the present embodiment includes the nozzle substrate 1 described in the first embodiment, and can provide a droplet discharge head capable of stable droplet discharge.

(Embodiment 3)
FIG. 7 is a view showing a droplet discharge device of this embodiment. For example, the ink jet recording apparatus 300 can be exemplified as the droplet discharge apparatus.
The ink jet recording apparatus 300 includes the nozzle substrate described in the first embodiment, and can provide a droplet discharge apparatus with stable print quality.

  DESCRIPTION OF SYMBOLS 1 ... Nozzle substrate, 10 ... Nozzle hole, 10a ... 1st nozzle hole, 10b ... 2nd nozzle hole, 11 ... Droplet protective film, 11a ... Oxide film, 11b ... Water-repellent film, 14 ... Chip outer peripheral part, 14a, 14b ... chip outer peripheral side, 17, 18 ... support substrate, 100 ... droplet discharge head, 300 ... ink jet recording apparatus.

Claims (5)

A nozzle hole opened in the droplet discharge surface;
A chip outer peripheral side opposite to the liquid droplet discharging surface, which is inside the chip outer peripheral side on the liquid droplet discharging surface side;
A droplet protective film composed of an oxide film and a water repellent film provided on the outer peripheral side surface of the chip opposite to the droplet discharge surface and the droplet discharge surface;
A nozzle substrate , wherein an oxide film provided on a chip outer peripheral side opposite to the droplet discharge surface is thinner than an oxide film provided on the droplet discharge surface . The nozzle substrate according to claim 1,
The nozzle hole has a first nozzle hole opened on the droplet discharge surface side and a first nozzle hole communicating with the first nozzle hole and having a larger cross-sectional area than the first nozzle hole opened on the opposite side to the droplet discharge surface. 2 nozzle holes,
The depth a of the chip outer peripheral side opposite to the droplet discharge surface and the second nozzle hole depth b opened to the opposite side of the droplet discharge surface are:
a> b,
A nozzle substrate characterized by: The nozzle substrate according to claim 1,
The chip outer peripheral side opposite to the droplet discharge surface is inside the chip outer peripheral side on the droplet discharge surface side to form a stepped portion, and the width of the stepped portion is larger than the thickness of the droplet protective film Nozzle substrate characterized by.   A droplet discharge head comprising the nozzle substrate according to any one of claims 1 to 3 in a droplet discharge portion.   A droplet discharge device comprising the droplet discharge head according to claim 4.

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