JP2007320116A - Inkjet recording head, and recording device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording head having a large number of discharging ports which are arranged by a higher density compared with a conventional one, and is excellent in heat radiation property even when a recording element board is a shrunk one. <P>SOLUTION: A foil-form heat-transferring member and the rear surface of a recording element board are connected. The area of the foil-form heat-transferring member which is wider than the area of the rear surface of the recording element board is exposed in an ink flow passage, and comes into contact with an ink. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that performs a recording operation by discharging a recording liquid such as ink, a recording head applied to the ink jet recording apparatus, and a recording element substrate applied to the recording head. The present invention can be applied to an industrial recording apparatus combined with a general printing apparatus, a copying machine, a facsimile having a communication system, and various processing apparatuses having a printing unit.

  The ink jet recording apparatus is a so-called non-impact recording type recording apparatus, and is capable of recording on various recording media at high speed and hardly causes noise during recording. For this reason, the ink jet recording apparatus is widely adopted as an apparatus that bears a recording mechanism such as a printer, a facsimile machine, and a copying machine.

  As a typical ink discharge method in this ink jet recording apparatus, there is a method using an electrothermal conversion element. In this method, a minute droplet is ejected from a minute ejection port to perform recording on a recording medium. In general, an inkjet recording head for forming a droplet, It comprises a supply system that supplies ink and an electric circuit board that supplies electrical energy.

  An ink jet recording head using an electrothermal conversion element is provided with an electrothermal conversion element in a liquid chamber of a recording element substrate, and gives thermal energy to the recording liquid by applying an electric pulse as a recording signal to the recording element substrate. The bubble pressure at the time of foaming (boiling) of the recording liquid caused by the phase change of the liquid is used for discharging the recording droplets. Furthermore, in the case of an ink jet recording head using an electrothermal conversion method, a recording liquid is ejected in parallel to a substrate on which electrothermal conversion elements are arranged (edge shooter) and on a substrate on which electrothermal conversion elements are arranged. There is also a method (side shooter) in which the recording liquid is ejected vertically. The recording element substrate of these ink jet recording heads is fixed to an ink supply supporting member with an adhesive, and supplies ink in a sealed state where the ink supply port of the recording element substrate and the supply hole of the supporting member do not communicate with the outside. To do.

  In recent years, a printer called a photo printer that can express a color space like a photograph at a high speed using a plurality of color inks has been sold. In order to increase the speed, the number of nozzles on the recording element substrate has been increasing. For example, a high-density recording head in which a total of 3072 nozzles are arranged has been developed. Furthermore, the resolution has also increased due to the demand for higher image quality. For example, a recording head capable of recording at a high resolution such as 4800 × 2400 dpi has been developed. Under such circumstances, a recording head for achieving a printer with higher speed and higher resolution is desired. On the other hand, the price of printers has been reduced, and a recording head that realizes high speed and high resolution at a low price is desired.

  Therefore, in the recording element substrate, speeding up by increasing the number of nozzles, high resolution by narrowing the nozzle pitch, and cost reduction are desired at the same time. Since the printing element substrate is manufactured in the same process as a general semiconductor, it is necessary to increase the number of wafers per wafer in order to reduce costs. For this purpose, a method of shrinking the chip size is effective. is there. However, since the bonding area with the above-described support member is reduced in the shrinked recording element substrate, the heat conduction from the recording element substrate to the support member is reduced, and the ink ejection performance is liable to be adversely affected by a significant temperature rise.

As a structure for improving the heat dissipation of the recording element substrate, for example, an ink jet print head of Patent Document 1 has been proposed. As shown in FIG. 7, this ink jet print head has a metal film 116 formed on the upper surface of a glass substrate 115 and a metal film 117 formed on the lower surface. An insulating film 125 and a heating resistor are formed on the metal film 116 on the upper surface. A film 126, a heating resistor 126 a, an individual wiring electrode 127, a common electrode 128, a partition wall 129, and an orifice plate 131 having an ink discharge hole 132 are sequentially stacked, and an ink supply groove 133 and an ink supply hole are formed in the glass substrate 115. 134 is formed to form a head portion. Further, a through hole 123 is formed, a metal film 124 is formed on the inner wall, and the metal films 116 and 117 on both surfaces of the substrate are thermally coupled by the metal film 124. Further, the entire inkjet print head 135 is die bonded to the heat radiating plate 137 with the die bonding agent 136 through the metal film 117 on the lower surface. Heat generated in the printing portion on the upper surface is conducted to the metal films 116, 124, and 117 and is dissipated to the outside through the heat radiating plate 137. However, since the area of the metal film 117 on the lower surface of the recording element substrate that has been shrunk conventionally is reduced, the heat dissipation effect on the heat dissipation plate 137 is reduced.
JP 2002-316419 A

  That is, in the ink jet print head having the structure as shown in FIG. 7, when a recording element substrate shrunk conventionally is used, the contact area with the heat radiating plate is reduced, so that the heat radiation effect is lowered, and the ink is increased due to a significant temperature rise. The discharge performance is likely to be adversely affected. SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording head having a large number of ejection openings arranged at a higher density than in the past and having excellent heat dissipation even with a shrinked recording element substrate. It is in. Furthermore, it is providing the inkjet recording device using the recording head.

  In order to achieve the above object, the ink jet recording head of the present invention has energy generating means for generating energy used for discharging liquid from the discharge port according to an electric signal on the surface, and a drive circuit related to energy generation. It has an element, a logic circuit element, and a heating element, and has a nozzle structure that forms a liquid chamber filled with liquid with an opening on the surface, and a liquid supply port that communicates with the liquid chamber from the back side. Supporting at least one recording element substrate and supplying a liquid to the liquid supply port on the back surface of the recording element substrate, and having a supply hole wider than at least the short side of the recording element substrate A foil-shaped heat transfer member and a back surface of the recording element substrate connected to each other, and a foil having an area larger than the area of the back surface of the recording element substrate Wherein the heat transfer member is in contact with the liquid is exposed to the feed hole of the support member.

  Further, the surface is provided with energy generating means for generating energy used for discharging liquid from the discharge port in response to an electric signal, and has a drive circuit element, a logic circuit element, and a heating element related to energy generation. And a recording element substrate having a nozzle structure constituting a liquid chamber filled with liquid and having a liquid supply port communicating from the back surface to the liquid chamber, and at least one recording element An ink jet recording head having a support member that supports a substrate and supplies a liquid to a liquid supply port on the back surface of the recording element substrate and has a supply hole wider than at least a short side of the recording element substrate. The heat transfer member and the back surface of the recording element substrate are connected, and a foil-like heat transfer member having an area larger than the area of the back surface of the recording element substrate is exposed in the supply hole of the support member and is in contact with the liquid. Characterized in that the plane parallel to the flow path of the foil-like heat transfer member is exposed to the feed hole of the support member is formed. Furthermore, the cross-sectional area of the flow path that is exposed to the supply hole of the support member and parallel to the surface of the foil-like heat transfer member through which the liquid flows is smaller than that of the foil-like heat transfer member that is exposed to the supply hole of the support member. It is smaller than the cross-sectional area of the flow path through which the liquid flows almost vertically.

  It is characterized in that at least a portion of the foil-like heat transfer member exposed in the supply hole of the support member is plated with gold.

  The back surface of the recording element substrate is connected to a foil-like heat transfer member via an adhesive or via an adhesive and a bump.

  The foil-like heat transfer member including the portion exposed in the supply hole of the support member is a part of the wiring of the film-like circuit board, and the film-like circuit board has a plurality of wiring layers. The ink jet recording head according to claim 1.

  A back electrode that is electrically connected to a drive circuit, a logic circuit, and a heating element of the recording element substrate is provided on the back surface of the recording element substrate, and the terminals of the film-like circuit board and the back electrode are electrically connected by bumps.

  Furthermore, the recording apparatus of the present invention is equipped with the ink jet recording head.

  In the present invention configured as described above, even if the recording element substrate has a large number of ejection openings arranged at a higher density than the conventional one and is shrunk, the ink jet recording has excellent heat dissipation. A head can be provided. Furthermore, by mounting the recording head, it is possible to provide an inexpensive and high-performance inkjet recording apparatus.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  A first embodiment of the present invention will be described with reference to the drawings. In FIG. 2, the recording element substrate 1 of the present invention includes energy generating means for generating energy used for discharging liquid from the discharge port in accordance with an electric signal on the surface side, and a drive circuit element related to energy generation. And logic circuit elements and heating elements. The drive circuit element, the logic circuit element, and the heating element are joined to the electrode 14 formed on the surface of the recording element substrate 1 and the lead wire 13 of the film-like wiring board such as the TAB tape 12, and the inkjet recording apparatus via a connector or the like. Connected with. In addition to the electrical connection using the TAB tape 12, a method of connecting the electrodes 14 formed on the surface of the recording element substrate 1 to the terminals of the film-like wiring substrate by wire bonding is also conceivable. The periphery of the recording element substrate 1 is sealed with an adhesive A5.

  1 is a cross-sectional view taken along line AA in FIG. A discharge port 2 is opened on the front surface side of the recording element substrate 1, has a nozzle structure constituting a liquid chamber 3 filled with ink, and communicates with the liquid chamber 3 from the back surface side of the recording element substrate 1. A supply port 4 is provided. The back surface of the recording element substrate 1 is connected to a foil-like heat transfer member 7 via an adhesive A 5 and bumps 6. As shown in FIG. 3, a method of connecting the back surface of the recording element substrate 1 and the foil-like heat transfer member 7 with only the adhesive A5 without using bumps is also conceivable. However, in order to efficiently transfer excess heat generated in the recording element substrate 1 by the foil-like heat transfer member 7, it is more preferable to provide the bumps 6. The bump 6 is formed of gold, solder or the like.

  For the bonding of the back surface of the recording element substrate 1, the bumps 6, and the heat transfer member 7, heat-pressure bonding, ultrasonic bonding, fusion bonding, and the like are suitable. The heat transfer member 7 is further bonded to the support member 9 with an adhesive B8. The support member 9 preferably has a certain level of rigidity in order to support the heat transfer member 7 and the recording element substrate 1, and is formed of a ceramic such as alumina or a resin material, for example. The entire supply hole 10 of the support member 9 communicates with the liquid supply port 4 of the recording element substrate 1, and the whole of the foil-like heat transfer member 7 is exposed in the supply hole 10 of the support member 9. Has been placed. The surface of the foil-like heat transfer member 7 on which the recording element substrate 1 is disposed is covered with a cover 11 to prevent corrosion due to ink or the like. The ink supply path constituted by each component is a sealed space that is not in communication with the outside air except for both ends thereof. Ink supplied from an ink supply source (not shown) passing through the space is supplied to the recording element substrate 1 as indicated by a black arrow in FIG.

  The foil-like heat transfer member 7 is formed of a metal having high heat conductivity, such as aluminum, copper, silver, gold, or the like. Here, when using, for example, aluminum or copper, which is easily corroded with respect to ink, at least a portion exposed to the supply hole 10 of the support member 9 is made of a metal having excellent anti-corrosive properties against ink such as gold. It is preferable to plate.

  In this embodiment, excess heat generated in the recording element substrate 1 in accordance with the printing operation on the recording medium is transferred to the foil-like heat transfer member 7 through the adhesive A 5 and the bumps 6. Since the foil-like heat transfer member 7 is exposed in the supply hole 10 of the support member 9, the heat is further transferred to the ink. The area of the foil-like heat transfer member 7 exposed to the supply hole 10 of the support member 9 and in contact with the ink is larger than the area of the back surface of the recording element substrate 1. By supplementing the area of the back surface of the recording element substrate 1 which has been shrunk and smaller than before with the foil-like heat transfer member 7, excess heat generated in the recording element substrate 1 can be efficiently dissipated to the ink. .

  By letting excess heat generated in the recording element substrate 1 escape to the liquid (ink) having a large heat capacity, an excessive increase in temperature of the recording element substrate 1 is not caused, thereby preventing printing defects.

  FIG. 4 shows a cross-sectional view of the second embodiment of the present invention.

  In order to newly supply ink consumed by the printing operation of the inkjet recording head, an ink flow from the ink supply source toward the recording element substrate 1 is generated as indicated by a black arrow in FIG. In this embodiment, the rectifying unit 15 is provided so that the entire amount of ink directed to the recording element substrate 1 flows in parallel with the foil-like heat transfer member 7 exposed in the supply hole 10. In order to increase the flow velocity at the portion where the ink flows parallel to the foil-like heat transfer member 7, the cross-sectional area of the flow path at the portion is smaller than the portion where the ink flows almost perpendicularly to the foil-like heat transfer member 7. Thus, the size and position of the rectifying unit 15 are adjusted. The rectifying unit 15 may be formed integrally with the support member 9, or a member separate from the support member 9 may be fixed in the supply hole 10 of the support member 9. As in Example 1, when the foil-like heat transfer member 7 is easily corroded with respect to ink, for example, aluminum or copper is used, at least a portion exposed to the supply hole 10 of the support member 9 is made of gold or the like. It is preferable to plate the surface of a metal excellent in corrosion resistance against ink. Further, the periphery of the recording element substrate 1 is sealed with an adhesive A5, and the ink supply path constituted by each component is a sealed space that is not in communication with the outside air except for both ends thereof. ing.

  Excess heat generated in the recording element substrate 1 by the printing operation of the ink jet recording head is transferred to the foil-like heat transfer member 7 through the adhesive A 5 and the bumps 6 on the back surface of the recording element substrate 1. The heat is further transferred from the foil-like heat transfer member 7 to the ink in the supply hole 10 of the support member 9. The area of the foil-like heat transfer member 7 exposed to the supply hole 10 of the support member 9 and in contact with the ink is larger than the area of the back surface of the recording element substrate 1. Therefore, the excess heat generated in the recording element substrate 1 is efficiently radiated to the ink by expanding the area of the back surface of the recording element substrate 1 that has been shrunk and reduced by the foil-like heat transfer member 7. be able to.

  Further, in this embodiment, since the flow of ink parallel to the foil-like heat transfer member 7 is generated by the rectifying unit 15, excess heat generated in the recording element substrate 1 can be effectively radiated to the ink. Compared with Example 1, the heat dissipation efficiency can be further increased. Furthermore, since the cross-sectional area of the flow path through which the ink flows parallel to the foil-like heat transfer member 7 exposed in the supply hole 10 of the support member 9 is reduced, the flow velocity of the ink flowing in other portions Since a faster ink flow occurs, heat can be radiated with high efficiency.

  The ink that has received heat from the foil-like heat transfer member 7 is directly discharged from the recording element substrate 1 to the outside of the recording head, so that heat does not stay in the recording head. Therefore, it is possible to prevent printing defects without causing an excessive temperature rise of the recording element substrate 1.

  FIG. 5 is a top view of the third embodiment of the present invention, and FIG. 6 is a BB cross section of FIG.

  In the present embodiment, the back electrode 18 that is electrically connected to the drive circuit, logic circuit, and heating element of the recording element substrate 1 is provided on the back side of the recording element substrate 1. The back electrode 18 was electrically connected to the terminal 17 of the film-like circuit board 16 disposed between the recording element substrate 1 and the support member 9 by a bump. The bumps that connect the back electrode 18 and the terminal 17 are joined by a method such as heating and pressing, ultrasonic waves, or melting. The terminal 17 of the film-like circuit board 16 is in electrical communication with the wiring 19, and the wiring 19 is connected to the ink jet recording apparatus main body via a connector or the like.

  In this embodiment, a film-like circuit board 16 having a plurality of wiring layers is used, a part of which is a foil-like heat transfer member 7 and the rest is an electric wiring part, whereby the heat transfer part and the electric wiring part are integrated. Formed. The film-like circuit board 16 is provided with a through hole 20, and the foil-like heat transfer member 7 connected to the back surface of the recording element substrate 1 is inserted into the supply hole 10 of the support member 9 through the through hole 20. It is supposed to be exposed. When the film-like circuit board 16 having a plurality of wiring layers is used, it is necessary to provide the through holes 20 in order to form wirings straddling the layers. Although FIG. 6 shows a state in which the through-hole 20 is provided only in the foil-like heat transfer member 7, the through-hole 20 may be provided in either the heat transfer portion or the electrical wiring portion, or may be provided in both. . Further, the area of the foil-like heat transfer member 7 exposed to the supply hole 10 of the support member 9 and in contact with the ink is larger than the area of the back surface of the recording element substrate 1. As in Example 1, when the foil-like heat transfer member 7 is easily corroded with respect to ink, for example, aluminum or copper is used, at least a portion exposed to the supply hole 10 of the support member 9 is made of gold or the like. It is preferable to plate the surface of a metal excellent in corrosion resistance against ink. The periphery of the recording element substrate 1 is sealed with an adhesive A5, and the ink supply path constituted by each component is a sealed space that is not in communication with the outside air except for both ends thereof. . Ink supplied from an ink supply source (not shown) passing through the space is supplied to the recording element substrate 1 as indicated by a black arrow in FIG.

  Excess heat generated in the recording element substrate 1 by the printing operation of the ink jet recording head is transferred to the foil-like heat transfer member 7 through the adhesive A5 and the bumps 6 on the back surface of the recording element substrate 1. The heat is further transferred from the foil-like heat transfer member 7 to the ink in the supply hole 10 of the support member 9. The area of the foil-like heat transfer member 7 exposed to the supply hole 10 of the support member 9 and in contact with the ink is larger than the area of the back surface of the recording element substrate 1. Therefore, the excess heat generated in the recording element substrate 1 is efficiently radiated to the ink by expanding the area of the back surface of the recording element substrate 1 that has been shrunk and reduced by the foil-like heat transfer member 7. be able to.

  In the present embodiment, as in the second embodiment, the flow of ink parallel to the foil-like heat transfer member 7 is generated by the rectifying unit 15, so that excess heat generated in the recording element substrate 1 is effectively radiated to the ink. Therefore, the heat radiation efficiency can be further increased as compared with the first embodiment. Furthermore, since the cross-sectional area of the flow path through which the ink flows parallel to the foil-like heat transfer member 7 exposed in the supply hole 10 of the support member 9 is reduced, the flow velocity of the ink flowing in other portions Since a faster ink flow occurs, heat can be radiated with high efficiency.

  The ink that has received heat from the foil-like heat transfer member 7 is directly discharged from the recording element substrate 1 to the outside of the recording head, so that heat does not stay in the recording head. Therefore, it is possible to prevent printing defects without causing an excessive temperature rise of the recording element substrate 1.

  Furthermore, the heat transfer part and the electric wiring part are integrally formed by using the film-like circuit board 16 having a plurality of wiring layers, a part of which is a foil-like heat transfer member 7 and the rest as an electric wiring part. Thus, the number of parts can be reduced, and an inexpensive and highly functional ink jet recording head can be configured.

1 is a cross-sectional view of a first embodiment of the present invention. FIG. 3 is a partial top view of the first exemplary embodiment of the present invention. FIG. 6 is a cross-sectional view of another form of the first embodiment of the present invention. It is sectional drawing of the 2nd Example of this invention. It is a partial top view of the 3rd example of the present invention. It is sectional drawing of the 3rd Example of this invention. It is the upper side figure and sectional drawing of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording element board | substrate 2 Discharge port 3 Liquid chamber 4 Liquid supply port 5 Adhesive A
6 Bump 7 Foil-like heat transfer member 8 Adhesive B
9 Support member 10 Supply hole 11 Cover 12 TAB
13 Lead wire 14 Electrode 15 Rectification part 16 Film-like circuit board 17 Terminal 18 Back surface electrode 19 Wiring 20 Through hole

Claims (9)

The surface is provided with energy generating means for generating energy used for discharging liquid from the discharge port in response to an electrical signal,
A drive circuit element, a logic circuit element and a heating element involved in the energy generation;
The discharge port is opened on the surface;
Having a nozzle structure constituting a liquid chamber filled with the liquid;
A recording element substrate in which a liquid supply port communicating with the liquid chamber from the back surface is opened;
Supporting at least one recording element substrate;
A support member that supplies the liquid to the liquid supply port on the back surface of the recording element substrate and has a supply hole wider than at least the short side of the recording element substrate;
In an inkjet recording head having
The foil-shaped heat transfer member and the back surface of the recording element substrate are connected,
The ink jet recording head, wherein the foil-like heat transfer member having an area larger than the area of the back surface of the recording element substrate is exposed to the supply hole of the support member and is in contact with the liquid. The surface is provided with energy generating means for generating energy used for discharging liquid from the discharge port in response to an electrical signal,
A drive circuit element, a logic circuit element and a heating element involved in the energy generation;
The discharge port is opened on the surface;
Having a nozzle structure constituting a liquid chamber filled with the liquid;
A recording element substrate in which a liquid supply port communicating with the liquid chamber from the back surface is opened;
Supporting at least one recording element substrate;
A support member that supplies the liquid to the liquid supply port on the back surface of the recording element substrate and has a supply hole wider than at least a short side of the recording element substrate;
In an inkjet recording head having
The foil-shaped heat transfer member and the back surface of the recording element substrate are connected,
The foil-like heat transfer member having an area larger than the area of the back surface of the recording element substrate is exposed to the supply hole of the support member and is in contact with the liquid.
An ink jet recording head, wherein a flow path is formed in parallel with the surface of the foil-like heat transfer member exposed in the supply hole of the support member.   A cross-sectional area of a flow path exposed to the supply hole of the support member and parallel to the surface of the foil-shaped heat transfer member through which the liquid flows is exposed to the supply hole of the support member. The inkjet recording head according to claim 2, wherein the inkjet recording head is smaller than a cross-sectional area of a flow path through which the liquid flows substantially perpendicularly to the heat transfer member.   The inkjet recording according to any one of claims 1 to 3, wherein at least a portion of the foil-like heat transfer member exposed in the supply hole of the support member is plated with gold. head.   5. The ink jet recording head according to claim 1, wherein the back surface of the recording element substrate is connected to the foil-like heat transfer member via an adhesive.   6. The ink jet recording head according to claim 1, wherein the back surface of the recording element substrate is connected to the foil-like heat transfer member via an adhesive and a bump.   The foil-like heat transfer member including a portion exposed to the supply hole of the support member is a part of the wiring of the film-like circuit board, and the film-like circuit board has a plurality of wiring layers. The ink jet recording head according to any one of claims 1 to 6, wherein the ink jet recording head is characterized in that:   The back surface of the recording element substrate is provided with a back electrode that is electrically connected to the drive circuit, logic circuit, and heating element of the recording element substrate, and the terminals of the film-like circuit board and the back electrode are electrically connected by bumps. The ink jet recording head according to claim 1, wherein the ink jet recording head is characterized in that:   A recording apparatus comprising the ink jet recording head according to any one of claims 1 to 8.

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