JPS6259672B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an inkjet recording head that performs recording by forming flying droplets.

The inkjet recording head used in the inkjet recording method that performs recording by forming flying droplets is formed as a part of the ejection orifice, ink flow path, and ink flow path, and uses the energy to form the flying droplets to transfer the ink. In the so-called multi-orifice type recording head, which has a working part, a plurality of ink channels, and ejection orifices provided one-to-one in the ink channels, a common ink supply chamber is further provided. These are precisely and accurately processed and manufactured using micro-machining.

The precision and accuracy of ink flow path formation during the manufacturing of this recording head is determined by the droplet generation efficiency, energy consumption rate, stability and uniformity of droplet generation, and the durability of the head itself. In particular, in the case of high-density multi-orifice type recording heads, precise and accurate ultra-fine processing technology is required for the manufacturing method, and furthermore, from the point of view of mass production, cost is reduced. Good yield is required in terms of reduction.

However, conventional methods such as methods for forming ink channels by grinding a glass plate, methods for forming ink channels by etching photosensitive glass, etc. do not necessarily satisfy the above points. This has led to deterioration in the characteristics of manufactured recording heads, increased costs due to poor yields, and decreased feasibility of achieving higher density multi-orifice recording heads.

For example, in a recording head made by the former conventional method, the inner wall surface of the ink flow path is rough, and the inner surface provides a large resistance to sudden pressure changes for ejecting droplets. It requires a lot of energy for grinding, so the energy saving rate is poor, the glass chips and cracks occur during grinding, and the manufacturing yield is poor.
This has a large impact on the stability and uniformity of droplet ejection.
If the latter conventional method is used, there may be disadvantages such as a limit to the precision of microfabrication of photosensitive glass and high material costs. Furthermore, common shortcomings of these conventional methods include a grooved substrate with ink channel grooves formed thereon, and active elements for the formation of flying droplets such as piezoelectric elements and heating elements that generate energy that acts on the ink. The problem is that it is difficult to align the cover plate when bonding it to the cover plate, which is attached to the cover plate.

Therefore, the development of an inkjet recording head having a structure that solves these problems is eagerly awaited.

The present invention has been made in view of the above points, and an object of the present invention is to provide an inkjet recording head that is inexpensive, compact, and highly reliable.

Another object of the present invention is to provide an inkjet recording head having a configuration in which the ink flow path is finely machined with high accuracy and high yield.

In the inkjet recording head of the present invention, along the ink channel groove formed by the cured layer of photosensitive resin,
The ink channel is formed by providing a cover member over the ink channel groove of the base body in which the active element for ejecting liquid is provided.

The inkjet recording head configured as described above solves the problems of conventional methods during manufacturing.Furthermore, since the ink flow path wall surface is smooth, the liquid flows smoothly, and the liquid flows smoothly. Loss of energy during ejection is hardly a problem, and it has extremely excellent droplet generation efficiency, energy saving rate, and stability and uniformity of droplet generation.

The present invention will be specifically described below with reference to the drawings.

FIGS. 1a, 1b and 1c are schematic illustrations for explaining the structure and assembly of the inkjet recording head of the present invention.

At predetermined positions on the substrate 101, which is obtained by forming ceramics such as alumina, metal, plastics, etc., active elements such as heating elements, piezoelectric elements, etc., are installed as energy sources that provide energy to the liquid (ink) to generate droplets. 102 are fixedly installed in a predetermined number (in the figure, there are three active elements). Although not shown, electrodes for inputting electrical signals to the active element 102 may be provided in advance according to a predetermined procedure and method, or may be provided at the same time as the installation of the active element 102. Alternatively, it may be provided after the grooves are formed, which will be described later.

A photosensitive composition layer 104 having a predetermined thickness is provided on the surface of the substrate 101 on which the active element 102 is provided by an appropriate method such as a coating method or a laminating method.

Thereafter, the ink channel grooves 1 which form ink channels such as the orifice section 105, the action section 106, the ink supply channel section 107, and the ink discharge channel section 108 are formed by means of commonly used photolithography.
Form 03. Next, a top cover 109 is bonded to the active element 102 side of the substrate 101 provided with the ink channel grooves 103, thereby manufacturing the inkjet recording head of the present invention. Therefore, first of all, there is no need for accurate alignment between the substrate 101 and the top lid 109 as in the conventional method, and the inner wall surface of the ink flow path to be formed is smooth and the liquid flows smoothly, which does not interfere with droplet ejection. It has the advantages of not causing any problems, and is easy to perform high-density microfabrication, making it possible to produce high-density multi-orifice recording heads with high characteristics at low cost and with good yield. The recording head has excellent droplet ejection efficiency, energy consumption rate, stable and uniform droplet ejection properties, and also has the advantage of being compact and inexpensive.

The photosensitive composition used in the present invention includes many photosensitive materials such as photosensitive resins and photoresists that are commonly used in the field of phosphorography. Examples of these photosensitive materials include diazoresin, P-diazoquinone, photopolymerizable photopolymers using a vinyl monomer and a polymerization initiator, and dimerized photopolymers using polyvinyl cinnamate and a sensitizer. , a mixture of orthonaphthoquinone diazide and volac type phenolic resin, a mixture of polyvinyl alcohol and diazo resin, a polyether type photopolymer obtained by copolymerizing 4-glycidyl ethylene oxide with benzophenone or glycidyl chalcone, N,N-dimethylmethacrylamide and For example, copolymers with acrylamide benzophenone, unsaturated polyester photosensitive resins (e.g. APR (Asahi Kasei), Tevista (Teijin), Sonne (Kansai Paint), etc.), unsaturated urethane oligomer photosensitive resins, bifunctional acrylics. Photosensitive compositions in which a photopolymerization initiator and a polymer are mixed in a monomer, dichromic acid photoresists, non-chromium water-soluble photoresists, polyvinyl cinnamate photoresists, cyclized rubber-azide photoresists, etc. Can be mentioned.

In addition, photosensitive compositions commercially available under trade names such as DuPont's 110-manent photopolymer coating, RISTON, Soldermask 730S, 740S, 730FR, 740FR, and SMI can also be effectively used in the present invention.

The orifice diameter that provides the desired resolution of the photosensitive composition,
If the density is lower than the ink flow path (especially nozzle) density, only that portion may be cut using a cutting machine (for example, a grinding machine for silicon wafer cutting).

[Brief explanation of the drawing]

1A, 1B and 1C are schematic assembly process diagrams for explaining the assembly of one preferred embodiment of the recording head of the present invention. 101...Substrate, 102...Active element, 103
... Ink channel groove, 104 ... Photosensitive composition layer, 105 ... Orifice, 106 ... Working part,
107... Ink supply path section, 108... Ink discharge path section, 109... Upper lid.

Claims (1)

[Scope of Claims] 1. A lid member is provided along an ink channel groove formed of a cured layer of photosensitive resin over the ink channel groove of a base body in which an active element for ejecting liquid is provided. An inkjet recording head that forms an ink flow path. 2. The inkjet recording head according to claim 1, wherein the ink flow path is composed of an orifice section, an ink discharge section, an action section, and an ink supply path section. 3. The inkjet recording head according to claim 2, wherein the active element is provided at the action portion position. 4. The inkjet recording head according to claim 3, wherein the active element is a piezoelectric element. 5. The inkjet recording head according to claim 3, wherein the active element is a heat generating element.