JP2017170709A - Inkjet recording head and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such the concern about reliability in ink resistant electrical implementation part in an encapsulation material for an electric connection part in an ink jet recording head in view of variation in ink property and long-term reliability.SOLUTION: The encapsulation material for encapsulating the electric connection part includes: an epoxy resin; an acid anhydride; a hardening accelerator; and a filler, where a hardening agent is trialkyl tetrahydrophthalic anhydride.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid discharge head that discharges liquid such as ink.

  In a recording method using a liquid discharge head typified by an ink jet recording head, thermal energy or vibration energy is applied to a liquid such as ink, and ink is discharged as fine droplets from a discharge port to form an image on a recording medium. Is. As a method of manufacturing such an ink jet head, there is a method disclosed in Patent Document 1.

  As a method for manufacturing this type of liquid discharge head, first, a discharge energy generating element and a wiring conductor for supplying power to the discharge energy generating element are provided on a silicon substrate. Then, after providing a protective film on the wiring conductor, the ink flow path and the ink discharge port are patterned with a resist. Next, a through hole (ink supply port) for supplying ink from the back surface side of the silicon substrate to the ejection energy generating element portion is opened in the silicon substrate.

  Then, the recording element substrate is attached to a support plate such as alumina, and the recording element substrate and the electric wiring member are electrically joined.

  Next, a peripheral sealing material is applied to protect the side surface of the recording element substrate from ink and dust. After the surrounding sealing material is cured, an inner lead bonding (ILB) sealing material (electrical connection portion sealing material) for sealing the electrical connection portion is applied from above.

  The functions required for the two sealing materials, the peripheral sealing material for sealing the periphery of the recording element substrate and the electrical connection portion sealing material used here, are as follows.

  As the surrounding sealing material, it is required to flow in a gap of a width of less than 1 mm formed between the portion on the support plate and the recording element substrate in a short time and be quickly filled. In addition, it is required to protect the recording element substrate from ink and other factors.

  As the electrical connection portion sealing material, not only the electrical connection portion is sealed, but also the contact with the paper or the like by rubbing with a blade or wiper for cleaning the ink discharge port arrangement surface or paper jam. It is required that the stopper does not peel off.

  Patent Document 2 describes a method for applying two kinds of sealing materials, that is, a peripheral sealing material (lead lower region) and an electrical connection portion sealing material (lead upper region). Here, the hardness after curing of the electrical connection portion sealing material is made higher than the height after curing of the surrounding sealing agent, and the main agent and the curing agent of the electrical connection portion sealing material and the surrounding sealing material are used. The method of making it the same is described.

  By this method, even if the surrounding sealing material and the electrical connection portion sealing material are cured at the same time, there is no contention (curing inhibition) between the two sealing agents due to the difference in curing speed.

JP 2002-019120 A JP 2005-132102 A

  Since the surrounding sealing material (lower lead region) flows under the lead, a low-viscosity material is used, and as a result, the filler content is lower than that of the electrical connection sealing material (lead upper region). . As a filling amount of the filler, it is desirable to make the filling amount as high as possible in consideration of flowability. If the filler becomes highly filled, the linear expansion coefficient decreases, the super expansion coefficient of the recording element substrate becomes close, the reliability increases, and the resistance to ink increases as the filler increases.

  However, in recent years, IJ head ink has been used that has a stronger attack on the sealing material, such as a polar solvent, due to the supply of higher speed and higher image quality. If work such as wiping the discharge mist or the surface of the discharge port with a blade is performed, the ink may adhere to the sealing material, and if used for many years, the ink may gradually soak into the sealing material and affect the electrical mounting area. is there.

  The IJ head has been used for various industrial applications such as printing from offices, and long-term reliability has been demanded.

  The object of the present invention is to solve the above problems. In other words, not only is the ink resistance improved by adding fillers, but also the ink resistance of the resin component is improved, and by improving the ink resistance as a sealing material, it is possible to improve the reliability of the electrical connection part for a longer period of time. It is to provide a recording head.

In order to achieve the above object, an ink jet recording head according to claim 1 of the present invention includes:
A substrate including a discharge energy generating element that generates energy used to discharge a liquid; a flow path member formed on the substrate that forms a flow path for supplying a liquid; and the discharge energy generating element. A liquid discharge head comprising: an electrical wiring member for transmitting a signal for driving; and an electrical connection part for electrically connecting the substrate and the electrical wiring member, and sealing the electrical connection part The sealing material is composed of at least an epoxy resin, an acid anhydride, a curing catalyst or a curing accelerator, and a filler.
The curing agent is trialkyltetrahydrophthalic anhydride.

An ink jet recording head according to claim 2 of the present invention includes:
The inkjet recording head according to claim 1, wherein
The epoxy resin is a dicyclopentadiene type epoxy.

An ink jet recording head according to claim 3 of the present invention is
In the inkjet recording head according to claim 2 or 3,
2-ethylhexyl glycidyl ether is added as a reactive diluent to the sealing material.

  According to the ink jet recording head of the present invention, the reliability of the long-term electrical connection portion is remarkably improved by improving the ink resistance of the sealing material for the electrical mounting portion.

Schematic diagram showing the configuration of the liquid ejection head Schematic diagram showing the sealing process of the present invention

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1A is a schematic view of the ink-jet recording head as viewed from the direction in which ink is ejected. FIG.1 (b) is a figure of the AA cross section in Fig.1 (a).

  Two ink supply ports 16 are provided on one recording element substrate 1, four rows of discharge port arrays in which the discharge ports 3 are arranged are arranged, two ink supply ports are filled with the same type of ink, and ink is discharged. It is something to be made.

  Since the electrical connection portion sealing material (lead upper region) 11 has a function of protecting the lead 6, it requires a high elastic modulus (high hardness). Therefore, the filler such as silica is highly filled. Further, in order to leave the sealing material on the upper part of the lead, it is necessary to impart thixotropy. In addition, it is necessary to impart thixotropy after having a certain fluidity.

  Since the peripheral sealing material (lead lower region sealing material) 13 must flow to the lead lower region and the periphery, low viscosity and low thixotropy are required.

  Typically, the electrical connection portion sealing material (lead upper region) and the peripheral sealing material (lead lower region sealing material) have compositions as shown in Table 1.

  As described above, the electrical connection portion sealing material has a composition in which a filler is highly filled in consideration of fluidity and a thixotropic agent is added. On the other hand, although the surrounding sealing material depends on the structure of the head, the filler filling amount is low in order to reduce the viscosity.

  The sealing material according to the present invention used for such a part comprises at least an epoxy resin, an acid anhydride, a curing catalyst or a curing accelerator, and a filler, and the curing agent is trialkyltetrahydrophthalic anhydride, The epoxy resin is suitably used as a material having excellent ink resistance by adding dicyclopentadiene type epoxy and further adding 2-ethylhexyl glycidyl ether as a reactive diluent.

  Ink resistance can be improved by using trialkyltetrahydrophthalic anhydride as a curing agent.

As trialkyltetrahydrophthalic anhydride,
Methylbutenyltetrahydrophthalic anhydride YH306 (trade name, manufactured by Mitsubishi Chemical Corporation)
Examples include 3,4-dimethyl-6- (2-methyl-1-propenyl) -4-cyclohexene-1,2-dicarboxylic anhydride YH307 (trade name, manufactured by Mitsubishi Chemical Corporation).

  Epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, compounds obtained by adding alkylene oxide to these, epoxy novolac resin, bisphenol A novolac diglycidyl ether, bisphenol F novolac diglycidyl ether. The glycidyl ether type epoxy resin, glycidyl amine type epoxy resin, alicyclic epoxy resin, etc., and since there are many liquid curing agents, solid epoxy can also be used. For example, biphenyl skeleton, naphthalene skeleton, cresol Examples thereof include epoxy resins having a novolak skeleton, a trisphenolmethane skeleton, a dicyclopentadiene skeleton, a phenol biphenylene skeleton, and the like. These epoxy resins may be used alone or in combination of two or more. Among these, it is preferable to use an epoxy resin having a dicyclopentadiene skeleton as the epoxy resin from the viewpoint of suppressing electrical performance deterioration due to moisture absorption and water absorption by the ink.

  Although not limited to the case of using a solid epoxy, in the case of an application site such as under a lead, if a low viscosity is necessary, a reactive diluent can be used as is conventionally used.

  Among the reactive diluents, 2-ethylhexyl glycidyl ether having a long alkyl chain has an alkyl chain, and thus has a high affinity with a curing agent and deteriorates performance as a resin composition against moisture absorption and water absorption. There is nothing.

  Examples of the curing catalyst include tertiary amines, boron trifluoride amine complexes, and cationic polymerization catalysts. One of these curing catalysts may be used, or two or more thereof may be used in combination.

  Examples of the curing accelerator include imidazole, tetraethylammonium bromide, tetraphenylphosphonium bromide, 1,8-diaza-bicyclo- (5,4,0) -undecene-7, 2-ethylhexanoate and the like. These curing accelerators may be used alone or in combination of two or more.

  As a sealing material, it is preferable that a silane coupling agent is included from a viewpoint of adhesion | attachment with a filler and a viscosity fall. Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-aminopropyltrimethoxysilane. Etc.

  Table 2 shows the resin composition (no filler) in the method of the present invention and the comparative example and the weight change rate after 10 hours of ink immersion pressure cooker at 121 ° C.

  The effect on the resin content was confirmed. In this example, the weight change rate is about 1/3 of the comparative example.

  In Example 3, the epoxy resin also has the lowest weight change rate due to low water absorption. In Example 4, a reactive diluent is used, but the rate of weight change is almost the same as in Example 3, and no performance degradation due to the reactive diluent, which is normally observed, is observed. The actual sealing material contains a filler for the purpose of lowering the ink resistance and CTE for improving electrical characteristics. Examples of the filler include glass, titanium oxide, alumina, aluminum hydroxide, magnesium hydroxide, talc, mica, silica, and the like. Among these, as the filler, fused silica having a small linear expansion coefficient is preferable. The shape of the filler is preferably spherical from the viewpoint of increasing the filling rate. Furthermore, it is preferable that the filler from which a particle size differs is contained from a viewpoint which can perform close-packing.

Here, the sealing material of Table 1 will be described.
Example 8 (lead lower region), Example 9 (lead upper region)
Example 10 (lead lower region), Example 11 (lead upper region)
Comparative Example 12 (lower lead region) and Comparative Example 13 (lead upper region)
Comparative example 14 (lower lead region), comparative example 15 (lead upper region), comparative example 7,
In each case, a sealing material is obtained by adding a filler and a thixotropic agent.

  As shown in FIG. 2A, the peripheral sealing materials (lower lead regions) of Examples 8 and 10 and Comparative Examples 12 and 14 shown in Table 1 are respectively shown in FIG. Coating was performed as shown in (b). At this time, since it cannot be applied directly to the lower part of the lead 6 by a dispenser because of space, it was applied to the lateral region of the lead part and a sealing agent was poured into the lower part of the lead.

  Next, Examples 9 and 11 and Comparative Examples 13 and 15 of the electrical connection portion sealing material (lead upper region) were applied as shown in FIG. 1, and heat-cured at 150 ° C. for 3 hours.

  With respect to the recording element unit 10 thus produced, the sealing material portion was immersed in ink and stored at 60 ° C. for two months.

  When the resistance between the wirings was confirmed, no change in resistance was observed in the example, but it was confirmed that the resistance value was slightly lowered in the comparative example.

As described above, in the present invention, the sealing material that seals the electrical connection portion includes at least an epoxy resin, an acid anhydride, a curing catalyst or a curing accelerator, and a filler.
The curing agent is trialkyltetrahydrophthalic anhydride. The epoxy resin is a dicyclopentadiene type epoxy. By adding 2-ethylhexyl glycidyl ether as a reactive diluent to the sealing material, Thus, the swelling of the sealing material can be lowered, and the reliability of the electrical connection portion can be obtained for a longer period.

1 recording element substrate, 2 discharge energy generating element, 3 discharge port, 5 electric wiring member,
6 Lead, 7 Support member, 8 Horizontal circumference sealing part, 10 Recording element unit,
11 Electrical connection part sealing material (on-lead area sealing material),
13 Surrounding sealing material (Lead lower area sealing material)

Claims (3)

A substrate including a discharge energy generating element that generates energy used to discharge a liquid; a flow path member formed on the substrate that forms a flow path for supplying a liquid; and the discharge energy generating element. A liquid discharge head comprising: an electrical wiring member for transmitting a signal for driving; and an electrical connection part for electrically connecting the substrate and the electrical wiring member, and sealing the electrical connection part An ink jet recording head, wherein the sealing material comprises at least an epoxy resin, an acid anhydride, a curing accelerator, and a filler, and the curing agent is trialkyltetrahydrophthalic anhydride. 2. The ink jet recording head according to claim 1, wherein the epoxy resin is a dicyclopentadiene type epoxy. The inkjet recording head according to claim 1, wherein 2-ethylhexyl glycidyl ether is used as the reactive diluent.