KR20060015993A - Encapsulant to protect the interconnection of the ink cartridge head and the ink cartridge with the same - Google Patents

Abstract

The present invention relates to an encapsulant for protecting an ink cartridge head joint, and an ink cartridge employing the same, wherein the pad is electrically connected to the ink ejection means of the ink cartridge and is applied to the joint portion of the conductive trace of the flexible circuit board to apply the joint portion. In the encapsulant to form a bead, the encapsulant provides an encapsulant, characterized in that it comprises a plurality of glass beads.

According to the present invention, not only the rigidity of the beads positioned at the junction between the pad and the conductive trace can be improved, but also the diffusion of ink into the beads can be prevented due to the water repellency of the glass beads, thereby improving the life of the product. have.

Ink cartridges, heads, beads, encapsulants, glass beads.

Description

Encapsulant to protect the interconnection of the ink cartridge head and the ink cartridge with the same}

1 is a perspective view showing a conventional ink cartridge.

2 is a cross-sectional view taken along the line a-a in FIG. 1.

3 is an equivalent to FIG. 2 showing an embodiment of the ink cartridge according to the present invention.

4 is a cross-sectional view illustrating glass beads in the embodiment illustrated in FIG. 3.

FIG. 5 is a photograph showing the bonding portion of the pad and the conductive trace in the ink cartridge. FIG.

FIG. 6 is a photograph showing a state in which a certain period has elapsed after the application of ink to the joint shown in FIG. 5.

<Explanation of symbols for main parts of the drawings>

100... Case 102. Ink supply,

104. Ink supply pipe, 110... Flexible circuit board,

112. Connection terminal 114. Conductive traces,

120... Head, 122... Ink feed hole,                 

124. Nozzle 126... Heating means,

128... Pad 130... Sealant,

140. Bead, 150... Glass Beads.

The present invention relates to an encapsulant for protecting an ink cartridge head joint and an ink cartridge employing the same, and more particularly, to be installed in the ink cartridge to be applied to protect the joint between the head for ejecting ink and the flexible circuit board. An encapsulant and an ink cartridge employing the same.

An inkjet printer is an image forming apparatus which injects ink stored in an ink cartridge into the surface of a print medium in the form of fine ink droplets through ink ejection means to perform a printing operation. As the ink ejection means, a head including a thermal transfer inkjet method or a piezoelectric element is generally used. The thermal transfer inkjet method incorporates a heating means in the head to heat ink at a pressure of an ink drop generated by heating the ink. The piezoelectric method is a method of discharging ink using a pressure generated by deformation of the piezoelectric element by embedding a piezoelectric element.

1 shows a conventional thermal inkjet ink cartridge. The ink cartridge includes a case 100 having a storage space for storing ink, and inside the case 100 (Fig. 1 is shown in an upside down state for ease of understanding). An ink supply section 102 having an ink supply passage is located. In addition, a flexible circuit board 110 is attached to the side and top surfaces of the ink supply unit 102. The flexible circuit board 110 has a connection terminal 112 connected to a main body of the printer on one side thereof. A plurality of conductive traces 114 connected to the connection terminal 112 are inserted into the flexible circuit board 110.

On the other hand, a head 120 as an ink ejecting means is mounted on an upper surface of the ink supply part 102, and the head 120 is connected to the conductive trace 114. Accordingly, the head 120 is electrically connected to a controller (not shown) mounted on the printer body through the conductive trace 114 and the connection terminal 112.

Referring to FIG. 2, details of the attachment portion of the head 120 are shown. An ink supply pipe 104 is formed inside the ink supply unit 102, and a head 120 is attached to an upper portion thereof. An ink feed hole 122 is formed in the head 120 to communicate with the ink supply pipe 104, and nozzles 124 are formed at upper ends of the ink feed hole 122, and the nozzle ( The heating means 126 is arranged under the 124. The heating means 126 is connected to the pad 128 installed on the head surface through a circuit board formed inside the head 120.

The pad 128 is attached by the end of the conductive trace 114 and the tape automated bonding (TAB) bonder to receive power from the printer body. The head 120 is attached by the ink supply unit 102 and the sealant 130. Here, a bead 140 made of an encapsulant is formed around the junction to protect the junction of the conductive trace 114 and the pad 128. The bead 140 is generally made of a thermosetting polymer resin or a UV curing agent, and the like is applied around the junction using a dispenser or the like and then cured by heat or UV.

In general, inks include low molecular weight water, diluents, additives to increase the solubility of dyes, surfactants and the like. Such water-soluble materials generally cause corrosion of the member when contacted with aluminum, silicon nitride, amorphous silicon, etc., which constitute the pad, and thus, an inorganic protective layer 142 may be formed on the upper portion of the bead 140 to block it. ) Is applied. The inorganic layer 142 is formed by a general thin film deposition process, depositing a metal such as tantalum, platinum or gold to a thickness of 0.05 ~ 0.1㎛, or tantalum containing nickel, nickel, titanium, aluminum, Alloys such as tungsten, palladium, copper and the like are formed by depositing to a thickness of 0.01 ~ 0.02㎛. In addition, inorganic films such as nitride, oxide, carbide, boride, and fluoride may be deposited to a thickness of 0.1 μm to 0.5 μm.

However, the above structure has the following problems.

(1) A protective layer made of a metal layer or an inorganic layer does not have high chemical resistance to ink.

(2) The protective layer composed of a metal layer or an inorganic layer does not have ductility enough to cover the irregular surface of the bead of the encapsulant evenly.

(3) The protective layer made of the metal layer or the inorganic layer has little adhesion with the surface of the bead made of the encapsulating agent.

(4) The encapsulating agent has a network structure, so that the encapsulating agent is easily peeled off due to the small scale expansion and contraction of the polymer with the change of temperature and humidity.

(5) The inorganic protective layer is easily broken by external force applied by wiping or the like.

(6) Not only is the self stress caused by the relatively thick protective layer thick, but also the deformation and breakage caused by self stress on the irregular encapsulant surface is accelerated.

(7) A broken piece of protective layer is a sufficient factor to cause clogging of the nozzle.

(8) In case of using metal layer, it may cause conductive trace and short circuit.

(9) Since PVD or CVD is used as the deposition process, it is difficult to selectively deposit only a desired portion with the cartridge assembled.

The present invention has been made to overcome the disadvantages of the prior art as described above, it is a technical problem to provide an encapsulating agent that can improve the rigidity and durability of the beads without forming a separate protective layer.

Another object of the present invention is to provide an ink cartridge having beads having a higher rigidity and durability than those of the related art, and having a bead that can be selectively formed only on an intended portion.

In order to achieve the above technical problem, the present invention, an encapsulant is formed on the junction of the pad and electrically connected to the ink ejection means of the ink cartridge and the conductive trace of the flexible circuit board to form a bead for applying the junction The encapsulating agent provides encapsulating agent, characterized in that it comprises a plurality of glass beads.

That is, the present invention is to improve the rigidity and durability of the beads by mixing the glass beads, which acts as aggregate to reinforce the strength in the reinforced concrete, to the encapsulant forming the beads. Here, glass beads are meant to be very small beads made of glass, and have a diameter of several to several tens of micrometers. After mixing the glass beads in a liquid UV curing agent or a thermosetting polymer and the like, using a dispenser or the like to the bonding portion and curing the glass beads, the glass beads are uniformly mixed with the inside and the surface of the beads. To harden.

Here, the glass beads disposed inside the beads increase the strength and durability of the beads, and the glass beads disposed on the surface of the beads reduce the surface area of the beads exposed to the outside, so that the surface of the beads is corroded by ink or the like. Will be prevented. Preferably, the glass beads may have a fluorine-based polymer coating film on the surface. Since the fluorine-based polymer coating film has water repellency, even when ink is applied to the surface of the beads, it is possible to reduce the wetness of the beads due to the ink. This can reduce the contact area and the contact time with the ink, thereby preventing the ink from diffusing into the beads.

Preferably, the glass beads may have a diameter of 5 ~ 500㎛.

The present invention also includes a head having a pad externally connected to the ink jetting means; A cartridge case having a head seat to which the head is bonded; An ink cartridge attached to the cartridge case, the ink cartridge comprising a flexible circuit board electrically connected to the pad of the head by conductive traces, wherein the ink cartridge comprises: It provides an ink cartridge comprising a bead cured by applying an encapsulant including a glass bead of.

That is, by applying the encapsulant including the glass beads to the junction of the conductive trace and the pad of the head as described above to configure the beads, the strength and durability of the beads can be improved, so that the performance of the ink cartridge can be stably maintained.

Preferably, the glass beads may have a fluorine-based polymer coating film on the surface, the glass beads may have a diameter of 5 ~ 500㎛.

Hereinafter, embodiments of the encapsulant and ink cartridge according to the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals are assigned to the same parts as the above-mentioned parts, and redundant description thereof will be omitted.                     

3 illustrates a state in which the bead 140 is formed by using the encapsulant according to the present invention in the head portion of the ink cartridge shown in FIG. 2. That is, the pad 128 electrically connected to the heating means 126 formed in the head 120 is connected to the conductive trace 114 inserted between the flexible circuit boards 110. ) And the conductive trace 114 is coated with a mixture of an encapsulant and glass beads 150 made of a liquid UV curing agent or a thermosetting polymer and then cured to form the beads 140.

Here, the encapsulating agent is an epoxy-based, polyimide-based or polyacrylate-based polymer. Meanwhile, as shown in FIG. 4, the glass bead 150 has a form in which a coating layer 150b made of a fluorine-based polymer is formed on a surface of a glass sphere 150a having a diameter of 5 to 500 μm. Teflon may be used as the fluorine-based polymer. Therefore, since the glass beads 150 positioned on the surface of the beads 140 have water repellency, even when ink is attached to the surfaces of the beads 140 without forming a protective layer made of a metal or an inorganic material. The contact area can be minimized to prevent the ink from encapsulating the bead encapsulant.

FIG. 5 is a photograph of a junction between the conductive trace 114 and the pad 128. In Fig. 5, since the ink does not penetrate into the beads, no corrosion of the surface of the pad is observed. Meanwhile, FIG. 6 is a photograph showing the bonding state of the pad and the conductive trace in which ink is deposited on the surface of the head, that is, a predetermined time (about 4 weeks) has elapsed in a general printing environment. In this case, it can be seen that the ink is diffused into the encapsulant and the corrosion occurs in the portion indicated by the dotted line. This corrosion breaks the electrical connection between the pad and the conductive traces, rendering the head inoperable.

However, when the encapsulant including glass beads having a fluorine coating layer according to the present invention is used, the pad does not corrode even after long-term use because it minimizes the contact area between the ink and the beads. That is, on a typical hydrophilic surface (bead surface), water tends to minimize the contact angle, so it spreads widely, but on a water-repellent surface such as a fluorine coating layer, water particles are more attractive to water particles than mutual attraction to the surface. This is because the contact angle becomes very large, that is, the contact area becomes very low. As a result, not only the contact area and the contact time as described above can be reduced, but also the cleaning of the inkjet printer head such as wiping is advantageous. In other words, the wiping on the water repellent surface is sufficient wiping even with a relatively low contact force.

According to the present invention having the configuration as described above, not only can the rigidity of the bead located at the junction between the pad and the conductive trace be improved, but also the ink can be prevented from being diffused into the bead due to the water repellency of the glass bead. It can improve the lifespan.

In addition, since there is no need to form a separate protective layer as in the prior art, the process can be simplified, thereby contributing to productivity improvement. In addition, even with changes in the environment such as temperature and humidity, it is possible to ensure the numerical stability of the beads due to the addition of glass beads, the conventional protective layer is easily broken by an external force such as wiping, in the present invention, the protective layer Since it does not exist, the setting of the wiping force is more free.

In addition, unlike the inorganic protective layer, since no thin film fragments are generated during breakage, no clogging of the nozzle is caused, and since the glass beads have insulation, electrical synthesis can be prevented even if broken. In addition, since the conventional inorganic protective layer is formed through a deposition process such as PVD and CVD, it is difficult to deposit only a desired portion in advance in the state where the ink cartridge is assembled, but in the case of the present invention, the liquid mixture is dispensed into the required portion. It can be easily formed by coating with, etc. has the advantage of easy manufacturing.

Claims (6)

An encapsulant which is applied to a joint of a pad electrically connected to an ink ejecting means of an ink cartridge and a conductive trace of a flexible circuit board to form a bead that applies the joint. The encapsulating agent comprises a plurality of glass beads (glass bead). The method of claim 1, The glass bead is characterized in that the encapsulating agent having a fluorine-based polymer coating film on the surface. The method of claim 1, The glass bead is encapsulating agent, characterized in that having a diameter of 5 ~ 500㎛. A head having a pad externally connected to the ink jetting means; A cartridge case having a head seat to which the head is bonded; An ink cartridge attached to the cartridge case, the ink cartridge comprising a flexible circuit board electrically connected to the pad of the head by conductive traces. And a bead cured by applying an encapsulant including a plurality of glass beads on top of a portion where the conductive trace of the flexible circuit board and the pad of the head are joined. The method of claim 4, wherein The glass bead is an ink cartridge, characterized in that the surface has a fluorine-based polymer coating film. The method of claim 4, wherein The glass bead is ink cartridge, characterized in that having a diameter of 5 ~ 500㎛.

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