JP2004090354A - Wiring board of inkjet recording head, and inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To fully connect terminals at both ends, to increase the connecting strength of ends, and to arrange an alignment mark and a connecting land without enlarging an outline. <P>SOLUTION: The wiring board 11b of the inkjet recording head 3 which records by jetting recording liquid drops from nozzle openings has a plurality of terminals 112 arranged for electrical connection, and the alignment mark 110' for registration and electrical connection. The wiring board includes an outermost terminal 111' with a broad part 111a at an end of an arrangement of the terminals 112. The alignment mark 110' and the broad part 111a of the outermost terminal 111' are arranged in parallel to each other with respect to a direction orthogonal to a direction of the arrangement of the terminals 112. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wiring substrate of an ink jet recording head that performs recording by discharging a recording liquid from a discharge port, and to an ink jet recording head.
[0002]
[Prior art]
Among the conventional recording methods, an ink jet recording method in which ink is ejected from an ejection port to perform recording on a recording medium has been widely adopted in recent years because a quiet, high-density, and high-speed recording operation is possible. ing.
[0003]
A general recording apparatus employing this method includes an ink jet recording head for discharging ink for recording an image on a recording medium, and a transport device for the recording medium.
[0004]
Ink jet recording heads use an electromechanical transducer element such as a piezo element or an electrothermal transducer element such as a heating resistor in a nozzle communicating with the ejection port to eject ink droplets from the ejection port. And those using electromagnetic wave mechanical transducer elements of radio waves or lasers, and electromagnetic wave heat transducer elements.
[0005]
Among them, an ink jet recording head using an element for ejecting ink droplets by using thermal energy can perform high-resolution recording because nozzles can be arranged at a high density.
[0006]
In particular, ink jet recording heads using electrothermal transducer elements as thermal energy generating elements are easier to miniaturize than those using electromechanical transducer elements. By applying the advantages of IC technology and micro-fabrication technology, which are significantly improved in performance, and making full use of their advantages, it is possible to provide high-density mounting easily and at low cost.
[0007]
A general ink jet recording head supplies electricity necessary for discharging ink to a recording element substrate provided with an electrothermal transducer element for discharging ink from a printer main body via a wiring substrate.
[0008]
The wiring board is an electrical path connecting the printer main body and the recording element board provided with the electrothermal transducer elements.
[0009]
Examples of the wiring substrate include a flexible wiring substrate such as a TAB film and a solid wiring substrate such as a printed circuit board. The former is a recording element substrate having an electrothermal transducer element because it is easily deformable. The contact surface with the printer main body can be provided on different planes, and the latter is advantageous in that it is relatively inexpensive, allows multilayer wiring, and allows any wiring design with a small area.
[0010]
Also, the former and the latter are often used in combination.
[0011]
In such a case, a flexible wiring board such as a TAB film is used for electrical connection with the recording element substrate having the electrothermal transducer element, and a solid wiring board such as a printed board is used for electrical connection with the printer body. Is typically used to electrically connect both with an anisotropic conductive film or the like.
[0012]
An example of an ink jet recording head integrated with an ink tank will be described with reference to FIG. 4 and FIG.
[0013]
FIG. 4 is a diagram of an example of an ink jet recording head in which a recording element unit is exploded and illustrated, and FIG. 5 is a diagram of an example of an ink jet recording head.
[0014]
Reference numeral 10 denotes a recording element substrate having an electrothermal transducer element, 11a denotes one of wiring boards, for example, a flexible wiring board such as an electric wiring tape or a TAB film, and 11b denotes one of wiring boards. A printed circuit board 112 has connection lands as terminals for electrical connection, H1002 a printing element unit, H1003 an ink supply unit, H1104 a nozzle row, H1200 a first plate, H1201 an ink supply port, and H1400. Is a second plate, and H2000 is a tank holder for holding the ink tank.
[0015]
Generally, as shown in FIG. 4, the ink jet recording head includes a recording element unit H1002, an ink supply unit H1003, a tank holder H2000, and the like.
[0016]
The recording element unit H1002 for discharging ink includes the recording element substrate 10, the flexible wiring substrate 11a, the printed substrate 11b, a first plate H1200, a second plate H1400, and the like.
[0017]
The printing element substrate 10 includes a nozzle row H1104, which is a row of nozzles for discharging ink, an electrothermal transducer element (not shown) for discharging ink from the nozzle row H1104, and an electrothermal transducer element connected to the flexible wiring board 11a. An electrode unit (not shown) for connection is provided.
[0018]
The flexible wiring board 11a is, for example, a TAB film. The TAB film is a laminate of a base film, copper foil wiring, and a cover film for protecting the wiring.
[0019]
The copper foil wiring has traces of a predetermined shape connecting the recording element substrate 10 and the printed circuit board 11b. In addition, on two sides of the device hole corresponding to the electrode portion of the recording element, inner leads (not shown) whose surfaces are not plated with Au extend as connection terminals.
[0020]
The flexible wiring board 11a is adhered and fixed to the surface of the second plate H1400 via a thermosetting epoxy resin adhesive layer or the like, and an inner lead (not shown) extending at one end is provided with an electrode portion (not shown) of the recording element substrate 10. (Not shown).
[0021]
The other end is electrically connected to the printed board 11b.
[0022]
The printed circuit board 11b has one end electrically connected to the electric wiring tape H1300 and the other end electrically connected to the printer main body.
[0023]
In this way, the recording element substrate 10 provided with the electrothermal transducer elements is electrically connected to a printer body (not shown) via the flexible wiring board 11a and the printed board 11b, which are wiring boards.
[0024]
Further, by joining the first plate H1200 and the second plate H1400 and joining the recording element substrate 10 in accordance with the ink supply port H1201 of the first plate H1200, as shown in FIG. The unit H1002 can be assembled.
[0025]
Next, the connection between the flexible wiring board and the printed board will be described with reference to FIG.
[0026]
FIG. 6 is a schematic view showing the periphery of an end portion of a conventional printed circuit board.
[0027]
Reference numeral 110 denotes an alignment mark, 111 denotes an outermost terminal located at the end of the row of the connection lands 112, 113 denotes a solder resist coating, and 114 denotes an end of the printed board 11b.
[0028]
The printed circuit board 11b is connected to the flexible electric wiring 11a by thermocompression bonding using an anisotropic conductive film after the electrode portion (not shown) of the recording element substrate 10 and the flexible wiring substrate 11a are electrically connected by bonding. Is done.
[0029]
First, an anisotropic conductive film is temporarily bonded on the connection land 112 of the printed board 11b.
[0030]
Next, alignment is performed using the alignment mark provided on the flexible electric wiring 11a side in advance and the alignment mark 110 on the printed circuit board 11b.
[0031]
At this time, since the periphery of the connection land of the printed board 11b is not covered with the resist unlike the solder resist covering portion 113, the connection land is made of a transparent glass epoxy or the like so that it can be clearly recognized.
[0032]
Therefore, the alignment mark 110 can be recognized by the transmitted light from the back surface, and the alignment can be performed.
[0033]
In order to accurately align the flexible wiring board 11a and the connection lands 112 having a narrow pitch with respect to the vertical position, the horizontal position, the angle, and the like, the alignment marks 110 are provided at both ends of the connection lands 112 (one in FIG. Is omitted).
[0034]
After alignment using the alignment mark 110, thermocompression bonding between the flexible wiring board 11a and the printed board 11b is performed.
[0035]
Thermocompression bonding is performed at a pressure and temperature sufficient for connection.
[0036]
In this way, the flexible wiring board 11a and the printed board 11b are electrically connected.
[0037]
[Problems to be solved by the invention]
However, the above configuration has several problems.
[0038]
First, both ends of the printed board 11b are easily released by force due to deformation due to pressure or the like, and a crimping failure often occurs at the outermost terminals 111 at both ends of the printed board 11b.
[0039]
In addition, when the end 114 of the flexible wiring board 11a or the printed board 11b, or the end 114 of the flexible wiring board 11a and the printed board 11b does not have sufficient bonding strength, the connection is separated from the end 114. Sometimes.
[0040]
In other words, the outermost terminals of the connection lands 112 are disadvantageous for crimping because the force easily escapes during thermocompression bonding with the TAB film, and if the connection strength at the end is weak, the connection is peeled off from the end after manufacturing or the like. There is fear.
[0041]
In addition, when electrically connecting the flexible wiring board 11a such as a TAB film and the printed board 11b to each other, as described above, it is general that both are connected by an anisotropic conductive film. The alignment of the printed circuit board 11b with the printed circuit board 11b is performed by using alignment marks 110 prepared at both ends of a terminal for connecting the two.
[0042]
Accordingly, although it is advantageous to keep the outer shape of the wiring board as small as possible, it is advantageous for miniaturization and cost reduction, a dimensional margin for the alignment mark 110 is required, and a portion where the connection land 112 is not arranged is required. Due to this, the outer shape became larger.
[0043]
The present invention has been made in view of the above problems, and the object thereof is to make it possible to sufficiently connect the terminals at both ends and to increase the connection strength at the ends. Another object of the present invention is to provide a wiring substrate of an ink jet recording head and an ink jet recording head, in which alignment marks and connection lands can be arranged without increasing the outer shape.
[0044]
[Means for Solving the Problems]
The present invention has achieved the above object by the following technical configuration.
[0045]
(1) A wiring substrate of an ink jet recording head for performing recording by discharging recording liquid droplets from an opening of a nozzle, for aligning a plurality of terminals arranged for electric connection with each other for electric connection. An alignment mark, and having an outermost terminal having a wide portion at an end of the arrangement of the terminals, wherein the alignment mark and the wide portion of the outermost terminal are arranged in a direction orthogonal to a direction in which the terminals are arranged. A wiring substrate for an ink jet recording head, which is provided side by side.
[0046]
(2) The wiring board of the ink jet recording head according to (1), wherein the wide portion of the outermost terminal is disposed on an end side of the substrate with respect to the alignment mark.
[0047]
(3) An ink jet recording head comprising the wiring substrate of the ink jet recording head according to the above (1) or (2).
[0048]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0049]
(Example 1)
First, an ink jet recording apparatus that supplies ink to an ink jet recording head using an ink supply tube will be described with reference to FIG.
[0050]
FIG. 1 is a schematic configuration diagram of an ink jet recording apparatus provided with an ink jet recording head to which the present invention can be applied.
[0051]
1 is an ink jet recording apparatus which is a liquid ejecting apparatus, 2 is a carriage, 3 is an ink jet recording head which is a print cartridge, 4 is a guide shaft, 5 is a platen board, 6 is an ink tank, 7 is an ink supply tube, and P is It is a recording medium.
[0052]
In the inkjet recording apparatus 1 shown in FIG. 1, an inkjet recording head 3 having a recording element substrate 10 (not shown in FIG. 1) provided with a plurality of sets of nozzles (liquid ejection ports) is detachably mounted on a carriage 2. The carriage 2 is mounted on the guide shaft 4 so as to be slidable and driven by a driving unit (not shown) to move the inkjet recording head 3 in the main scanning direction.
[0053]
A platen board 5 for holding a recording medium P such as printing paper is disposed at a lower position facing the ink jet recording head 3, and the recording medium P held by the platen board 5 is a feed roller serving as medium conveying means. (Not shown), the paper is sequentially conveyed in the sub-scanning direction.
[0054]
A plurality of ink tanks 6 are arranged on one side of the frame, and are connected to the ink jet recording head 3 via an ink supply tube 7.
[0055]
As shown in FIG. 1, four ink tanks 6 are arranged, and each ink tank 6 contains ink of a different color (for example, four color inks of black, yellow, magenta, and cyan). I have.
[0056]
The ink is supplied to each nozzle (liquid ejection port) of the recording element substrate 10 of the ink jet recording head 3 via an ink supply tube 7 connected to each ink tank 6.
[0057]
Next, the configuration of an ink jet recording head that supplies ink with an ink needle will be described with reference to FIG.
[0058]
FIG. 2 is a diagram showing a configuration of an ink jet recording head to which the present invention can be applied.
[0059]
3a is a main body of the ink jet recording head 3 ', 12 is a sub-tank, 12a is an ink flow path, 12b is an ink inflow groove, 12c is a filter, 13 is an ink inflow member, 13a is a flat plate portion, and 14 is a cylindrical shape. Projecting portion, 14a is a hole, 14b is a needle tip avoiding shape that is a cutout, 15 is an interconnecting member, 15a is a small hole, 16 is a closed thin film, 17 is a guide boss hole, 18a is an inclined surface, and 18b is a lock. Plane.
[0060]
As shown in FIG. 2, the ink jet recording head 3 'detachably mounted on the carriage 2 has a plurality of sets of nozzles (liquid discharge ports) not shown, a liquid flow path not shown, and a liquid flow path not shown. A recording element substrate 10 including a recording element (not shown) (for example, an electrothermal transducer element) and configured to discharge ink droplets from a plurality of sets of nozzles (not shown) in accordance with recording data; A sub-tank 12 for temporarily storing liquid in communication with the element substrate 10, an ink flow path 12 a for supplying ink stored in the sub-tank 12 to the recording element substrate 10, and an ink flow path for flowing ink into the sub-tank 12. A main body 3a having an ink inflow groove 12b formed therein, and an ink inflow member 13 for receiving ink supplied from the ink tank 6 and flowing the ink into the sub tank 12. Is composed of an external electric signal flexible wiring board 11a to be input to the recording element substrate 10, the printed circuit board 11b ', etc., a filter 12c is disposed between the sub-tank 12 and the ink flow path 12a.
[0061]
The ink inflow member 13 includes a flat plate portion 13a for forming an ink flow path covering one surface of the ink inflow groove 12b through which ink flows into the sub-tank 12, and a plurality (four in this embodiment) arranged in a line. ), And a flat plate portion 13a is joined to one surface of the main body portion 3a of the ink jet recording head 3 'by vibration welding (ultrasonic welding) or the like to be integrated with the ink jet recording head 3'. Have been.
[0062]
Each of the plurality of cylindrical protrusions 14 has a hole 14a larger than the outer diameter of the ink needle formed at the distal end thereof so that the ink needle of the needle holding member can be inserted therein, and a lower portion around the hole 14a. Is formed with a needle tip avoiding shape 14b partially cut away.
[0063]
By forming the needle tip avoiding shape 14b, when the inkjet recording head 3 'is detached from the carriage 2, it is possible to avoid the tip end surface of the protrusion 14 from coming into contact with the tip of the ink needle. By doing so, it is possible to reduce the amount of movement (avoidance amount) of the needle holding member that holds the ink needle, which contributes to downsizing of the carriage 2 and eventually downsizing of the ink jet recording apparatus 1.
[0064]
A cylindrical interconnecting member 15 formed of rubber, soft resin, or the like is fitted inside each of the cylindrical protrusions 14. The interconnecting member 15 has an outer diameter of the ink needle at one end. A small hole 15a having a smaller diameter is formed, and a taper is provided on the side of the small hole 15a into which the ink needle is inserted.
[0065]
Further, a closing thin film 16 is disposed at the back of the small hole 15a when viewed from the direction of inserting the ink needle, and the closing thin film 16 has one or a plurality of slits 16a in a range corresponding to the inner diameter of the small hole 15a. It is cut.
[0066]
By configuring the interconnecting member 15 in this manner, when the ink needle is connected to the interconnecting member 15, the ink needle passes through the small hole 15a of the interconnecting member 15 while expanding and further closing. The slit of the thin film 16 is inserted by pushing it out.
[0067]
When the ink needle is inserted into the small hole 15a, airtightness is secured by surface contact between the outer surface of the ink needle and the inner surface of the small hole 15a.
[0068]
Here, the length of the small hole 15a is preferably 1 mm or more so as to maintain the surface contact with the ink needle.
[0069]
Further, by providing the closing thin film 16 having a slit cut therein, when the ink needle is separated from the interconnecting member 15, the slit of the closing thin film 16 returns to its original state by elastic force and closes. The ink temporarily stored in the sub-tank 12 in the main body portion 3a can maintain a meniscus at the nozzle (liquid discharge port), prevent the ink from flowing out from the nozzle (liquid discharge port), and prevent the outflow and drying of the ink. Intrusion of dust from the outside can be prevented, and leakage of ink can be prevented even when the inkjet recording head 3 'is detached from the carriage 2 or the like.
[0070]
Here, since the thickness of the closing thin film 16 greatly affects the insertion force of the ink needle and the reliability of maintaining the meniscus, in this embodiment, by setting the thickness to 0.2 mm or more and 1 mm or less, both thicknesses are reduced. I was able to satisfy the function.
[0071]
In addition, in the slit cut into the closing thin film 16, there is a concern that the end of the slit may be cracked when the ink needle is inserted or removed. There is no concern about cracks or the like by setting the range to the inside diameter.
[0072]
By providing a taper on the side of the small hole 15a where the ink needle is inserted, the tip of the ink needle can always be guided into the small hole 15a when the ink needle is inserted. Ink leakage due to the resulting deformation of the interconnect member 15 can be eliminated.
[0073]
As shown in FIG. 2, the ink inflow member 13 has a plurality of (two in the present embodiment) guide boss holes 17 for guiding and positioning the ink needle when inserting the interconnecting member 15. And corresponds to a guide boss provided on a needle holding member (not shown).
[0074]
The upper surface of the left and right side walls of the main body 3a of the ink jet recording head 3 'is provided on the carriage 2 in accordance with the rotation of a head set lever (not shown) when the ink jet recording head 3' is mounted on the carriage 2. An inclined surface 18a and a lock surface 18b formed with an arbitrary inclination angle to be engaged with a set plate or the like of a head set lever (not shown) are provided so as to be moved to a predetermined mounting position and positioned.
[0075]
The ink jet recording head 3 'is a flexible wiring board for applying an electric signal for discharging ink to a recording element substrate 10 composed of a plurality of nozzles (liquid discharge ports), liquid flow paths, recording elements and the like. 11a and a printed circuit board 11b 'located above the flexible wiring board 11a and including an external signal input terminal (not shown) for receiving an electric signal from a printer body (not shown). It is positioned and fixed on the surface opposite to the ink inflow member 13.
[0076]
In this embodiment, the flexible wiring board 11a uses a TAB film.
[0077]
The TAB film is formed by patterning copper wiring on a film based on polyimide or aramid resin, and further covering the film with a cover film or a solder resist made of the same material as the base film.
[0078]
The flexible wiring substrate 11a is connected to the recording element substrate 10 via inner leads (not shown) by metal bonding such as bonding.
[0079]
For connection between the flexible wiring board 11a and the printed board 11b 'including the external signal input terminal, an anisotropic conductive film in which Ni particles or the like are dispersed in a B-stage epoxy resin is used.
[0080]
On the other hand, the printed board 11b 'is a multilayer printed board made of glass epoxy in this embodiment.
[0081]
The printed board 11b 'includes a connection land portion 112 for connecting to the flexible wiring board 11a via an anisotropic conductive film, and an external signal input terminal (not shown).
[0082]
Next, the connection between the flexible electric wiring 11a and the printed circuit board 11b 'in this embodiment will be described with reference to FIG.
[0083]
FIG. 3 is a schematic view showing the periphery of an end of a printed circuit board according to the present invention.
[0084]
The configuration of the printed circuit board according to the present embodiment is the same as the configuration described with reference to FIG. 6 in the related art, except for the outermost terminals and the alignment marks. Detailed description is omitted.
[0085]
11b 'is a printed circuit board in this embodiment, 110' is an alignment mark in this embodiment, 111 'is an outermost terminal in this embodiment, and 111a is a wide portion.
[0086]
In this embodiment, only the portion of the outermost terminal 111 'on the end 114 side of the printed circuit board 11b' is a wide portion 111a, and the alignment mark 110 'and the wide portion 111a of the outermost terminal 111' are terminals. The connection lands 112 are arranged in a direction orthogonal to the direction in which the connection lands 112 are arranged.
[0087]
This makes it possible to increase the bonding area of the outermost terminal 111 'of the printed board 11b'.
[0088]
Further, only the portion on the end 114 side of the outermost terminal 111 'is made to be the wide portion 111a, so that the vicinity of the end 114 (corner) which is a trigger for peeling of the flexible wiring board 11a and the printed board 11b' is obtained. Since the wide portion 111a of the connection land 112 can be arranged, it is possible to increase the bonding strength near the end 114 (corner).
[0089]
In addition, by arranging the wide portion 111a and the alignment mark 110 'in a direction orthogonal to the direction in which the connection lands 112 are arranged, there is no need for a dimensional margin for the alignment mark 110' on the printed circuit board 11b '. They can be arranged at both ends of the connection land 112 without increasing the outer shape of the substrate 11b '.
[0090]
As described above, in this embodiment, only the portion of the outermost terminal 111 ′ on the end 114 side of the printed circuit board 11 b ′ is the wide portion 111 a, and the alignment mark 110 ′ and the wide portion 111 a of the outermost terminal 111 ′ are Are arranged side by side in a direction orthogonal to the direction in which the connection lands 112 as terminals are arranged, so that the bonding area of the outermost terminal 111 'is increased, and the bonding near the end 114 (corner) of the printed board 11b' The strength can be increased, and the alignment mark 110 'and the connection land 112 can be arranged without increasing the outer shape.
[0091]
In this embodiment, the printer board 11b 'has been described. However, the present invention is not limited to this. For example, the present invention is applicable to any wiring board such as a flexible wiring board 11a that performs terminal alignment using alignment marks. If applicable.
[0092]
Furthermore, in the present embodiment, an ink jet recording head of a type separated from an ink tank for supplying ink with an ink supply tube or an ink needle has been described, but the present invention is not limited to this, The present invention is applicable to any type of ink jet recording head using a wiring substrate, such as an ink jet recording head integrated with an ink tank described in the art.
[0093]
【The invention's effect】
As described above, according to the present invention, the terminals at both ends can be sufficiently connected, the connection strength at the ends can be increased, and the alignment mark and the connection land can be formed without increasing the outer shape. Can be provided, and a wiring board of an ink jet recording head and an ink jet recording head can be provided.
[0094]
That is, it is possible to improve the connection reliability between the printed circuit board and a flexible wiring board such as a TAB film without increasing the outer size of the printed circuit board, and to reduce the size of the inkjet recording head and the size of the inkjet recording apparatus. Cost reduction.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an inkjet recording apparatus including an inkjet recording head to which the present invention can be applied.
FIG. 2 is a diagram illustrating a configuration of an inkjet recording head to which the present invention can be applied.
FIG. 3 is a schematic view showing the periphery of an end portion of a printed circuit board according to the present invention.
FIG. 4 is a diagram illustrating an example of an ink jet recording head in which a recording element unit is exploded and illustrated.
FIG. 5 is a diagram illustrating an example of an inkjet recording head.
FIG. 6 is a schematic view showing the periphery of an end portion of a conventional printed circuit board.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ink-jet recording apparatus 2 Carriage 3 Ink-jet recording head 4 Guide shaft 5 Platen board 6 Ink tank 7 Ink supply tube 10 Recording element substrate 11a Flexible electric wiring 11b Printed circuit board 12 Sub-tank 13 Ink inflow member 13a Plate portion 14 Projection 14a Hole 14b Needle tip avoidance shape 15 Interconnection member 15a Small hole 16 Closed thin film 17 Guide boss hole 18a Inclined surface 18b Lock surface 110 Alignment mark 111 Outermost terminal 112 Connection land 113 Solder resist coating portion 114 End

Claims (3)

A wiring substrate of an ink jet recording head that performs recording by discharging recording droplets from nozzle openings,
Multiple terminals arranged for making electrical connections,
And an alignment mark for making an electrical connection by adjusting the position.
An outermost terminal having a wide portion at an end of the arrangement of the terminals,
A wiring board for an ink jet recording head, wherein the alignment mark and a wide portion of the outermost terminal are arranged in a direction orthogonal to a direction in which the terminals are arranged. 2. The wiring board according to claim 1, wherein the wide part of the outermost terminal is disposed on an end side of the substrate with respect to the alignment mark. An ink jet recording head comprising the wiring substrate of the ink jet recording head according to claim 1.

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