JPH06344575A - Liquid injecting head and liquid injecting device - Google Patents

Abstract

PURPOSE:To compactly and favorally carry out the electrical connection between respective element substrates in a head made long by arranging a plurality of element substrates each constituted by forming a functional element and an electrothermal converter on the same substrate. CONSTITUTION:A plurality of element substrates 11 are provided on the upper surface of the aluminum base plate 10 of a recording head so as to be aligned with one end of a base plate 10 and arranged so as to be made same in emitting direction and a PCB substrate 16 having wiring patterns 17 or signal terminals 19 for performing the dispatching and receiving of signals with the outside is arranged. The element substrates 11 and the PCB substrate 16 are electrically connected through the pads 15 and bonding wires 18 on the element substrates. Each of the element substrates is constituted by forming a plurality of electrothermal conversion elements and the function elements corresponding thereto on the same substrate. A liquid chamber member 12 having nozzles 13 formed thereto and an ink supply pipe 14 are formed on each of the element substrates 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid jet recording head and a recording apparatus, and more particularly, an electrothermal conversion element and a functional element such as a driving transistor and a shift register are formed on the same substrate. The present invention relates to an inkjet recording head and a recording device using the element substrate.
In the following description, the recording ink is used as the liquid, but the liquid is not limited to this.

[0002]

2. Description of the Related Art FIG. 10 is a perspective view of a conventional ink jet recording head using a head substrate.

A liquid chamber member 82 through which ink flows and a supply pipe 84 for supplying ink are sequentially formed on an element substrate 33 provided with an electrothermal conversion element (not shown) for ejecting ink. A recording head. The pad 85 formed on the element substrate 33 and the wiring pattern 87 formed on the wiring substrate 32 such as an IC substrate or a PCB substrate are electrically connected via a bonding wire 38.

In such an ink jet recording head, a signal from the outside is a wiring pattern 8 which is a signal line.
7 to the substrate side pad 85 through the bonding wire 38. The ink communicates with the liquid chamber member 82 via the supply pipe 84, and the electrothermal conversion element is driven by an external signal thereof, the thermal energy generated at this time causes the ink to fire, and the pressure at the time of firing fires the nozzle 8
Ink jets from 3.

FIG. 11 shows an example of a recording head substrate used in such an ink jet recording head. The head substrate has an aluminum plate base 41, and each of the bases 41 has a base 41. , An electrothermal transducing element substrate 44 having electrothermal transducing elements arranged in an array, a transistor array 46, a latch 47 and a shift register 48.
An IC substrate 43 in which functional elements such as are formed on the same substrate, an input signal terminal 49 for inputting an external signal, an output signal terminal 50 for outputting a signal to the outside,
And a PCB in which each of the power supply terminals 51 is arranged
The substrate 42 is arranged at a predetermined position.

Using the head substrate having the above structure,
A conventional ink jet recording head is constructed as shown in the side view of the head in FIG.

On the electrothermal conversion element substrate 44, a liquid chamber 52 in which ink flows and a pipe 53 for supplying ink.
And are formed in order. Electrothermal conversion element substrate 44, I
The C substrate 43 and the PCB substrate 42 are electrically connected to each other via bonding wires 45, and ink is ejected by selectively energizing the elements of the electrothermal conversion element substrate 44.

In the recording head having the above structure, the number of wires for electrically connecting the element substrate to the outside is proportional to the number of elements of the electrothermal conversion element, and generally wire bonding of several hundreds is performed. . The wire bonding at such a large number of points becomes a factor of increasing the occurrence of defective mounting, resulting in a decrease in product yield and an increase in cost. Therefore, as disclosed in JP-A-57-72867 and JP-A-57-72868, an electrothermal conversion element and a functional element such as a driving transistor are incorporated on the same substrate. Recording heads have been developed in recent years.

FIG. 13 is a schematic structural diagram of a head substrate using an element substrate in which such a functional element and an electrothermal converting element are formed on the same substrate.

The recording head substrate shown in FIG. 13 constructed in view of the above problem has the aluminum plate base 31 as described above. An electrothermal conversion element 34 and an electrothermal conversion element 34 arranged in an array are provided on the base 31, respectively.
A functional element for driving the device, that is, an element substrate 33 in which a transistor array 35, a latch 36 and a shift register 37 are formed on the same substrate, and an input signal terminal 39 for inputting a signal from the outside, to the outside. An output signal terminal 40 for outputting a signal and a PCB board 32 on which a power supply terminal 41 is formed are arranged at predetermined positions. Then, the element substrate 33 and the PCB substrate 3
2 is electrically connected via a bonding wire 38.

In the above structure, an image signal is input to the input signal terminal 39 on the PCB substrate 32 from the outside, the image signal is transferred to the shift register 37 and then stored in the latch 36. The transistor array 35 is switched based on this image signal, and the current flowing through the electrothermal conversion element 34 connected to the transistor 37 is controlled.
At this time, the electric current is supplied to the electric conversion element 34 from the outside through the power supply terminal 41. In the figure, GND
Terminals are not shown.

By using the element substrate in which the functional element and the electrothermal conversion element as described above are formed on the same substrate, the yield reduction caused by mounting defects due to hundreds of wire bondings is greatly reduced. It became possible to prevent it. However, since functional elements such as transistors and shift registers are formed on the same substrate as the electrothermal conversion element, the yield of the substrate process is the product of the functional element and the electrothermal conversion element. Therefore, the head becomes long, and the number of transistors corresponding to the number of electrothermal conversion elements,
As the number of bits of the shift register and the latch increases, the yield of the substrate process decreases, which is a big problem.

Various studies have been conducted on the device yield, and it is known that the yield can be simulated by an exponential function such as the Poisson model. However, according to these simulations, for example, the number of bits is doubled. By doing so, it is known that the initial yield of 80% falls to 50% or less.

From this point of view, when a long head is formed using an element substrate having functional elements such as shift registers and latches, a long element substrate is not formed by one substrate, A long head was created by arranging multiple small element substrates.

FIG. 14 shows an example of such a long substrate.

Here, an example is shown in which three element substrates 1003 are arranged side by side to form a long head, and reference numeral 1005 indicates a region where an electrothermal converter is provided in each element substrate.
The individual element substrates 1003 are arranged on the respective electrode pads 1004.
Are connected by wire bonding or the like.

FIG. 15 shows the arrangement of each element on the element substrate which constitutes the long head substrate shown in FIG.

Reference numeral 1025 denotes an area in which functional elements such as latches and shift registers for converting serial image data input to the element substrate into parallel signals corresponding to each electrothermal converter are arranged. Reference numeral 1015 is a functional element for controlling energization to the electrothermal converter, and a voltage is applied from the common electrode 1014 on the voltage supply side to the electrothermal converter 1005 selected by the control functional element 1015. It

In such a long head substrate,
A signal is transmitted through each element substrate by connecting each pad of each element substrate described above by wire bonding or the like.

[0020]

However, in the mode in which the element substrates are connected to each other as described above, there are the following problems to be solved.

The element substrates are electrically connected to each other by wire bonding or the like. However, when connecting with a wire made of a material such as Au, a large force acts on the substrates when connecting one end portion of the wire. Therefore, when both sides to which the wires are connected are element substrates, the element substrate may be damaged.

On the other hand, it is desired in the development of the head not only to increase the length of the head but also to downsize the head and arrange the nozzles at a high density. For this reason, it is necessary to narrow the distance between the element substrates and arrange the element substrates so as to correspond to the nozzle pitch. However, when connecting by wire bonding, the distance between the connection points is at least about 300 μm.
It is difficult to arrange the element substrates densely so as to arrange the electrothermal converters at a pitch of 70 μm.

If the pads are not provided at the ends of the element substrate for making this connection, the element substrate may be upsized or the elements on the element substrate may be damaged. The present invention has been made to solve the above problems,
In a head in which a plurality of element substrates each having a functional element and an electrothermal converter formed on the same substrate are arranged side by side to increase the length,
An object of the present invention is to provide a liquid ejecting head and a liquid ejecting apparatus that can make electrical connection between respective element substrates compactly and satisfactorily.

[0024]

In order to achieve the above object, a liquid jet head of the present invention has an electrothermal converter for generating thermal energy for ejecting a liquid and an electrothermal converter for driving the electrothermal converter. The element substrate includes a plurality of element substrates each having a functional element formed on the same substrate, and a wiring board provided with wirings for the functional element to input and output signals to and from the outside. The electrical connection is made so that the output signal from the device is input to the adjacent element substrate via the wiring substrate.

In the liquid jet head, the liquid is ink, and the functional element receives a serial image signal from the outside of the substrate and outputs it as a parallel image signal to the electrothermal converter side. What is characterized by a functional element, the plurality of element substrates and the wiring board are arranged on the base, the height of the surface for electrical connection between the element substrate and the wiring board, It may be the same or the element substrate may be higher.

A liquid ejecting apparatus which has any one of the above liquid ejecting heads and a recording medium conveying means and ejects liquid to perform recording also belongs to the present invention.

[0027]

In the present invention configured as described above, the liquid jet head is divided into a plurality of element substrates, and each element substrate is arranged on the same base, so that the functional element and the electrothermal conversion element are arranged on the same substrate. It is possible to deal with the increase in the number of nozzles of the recording head and the colorization without lowering the yield of the element substrate on which the ink is formed.

Furthermore, by connecting the element substrates to each other via the wiring substrate on the same base as those, it becomes possible to make the bonding direction unidirectional in the wire bonding, and the work efficiency at the time of wire connection is improved. Can be achieved. Further, since the output signal from the element substrate of the previous stage is connected via the wiring board so as to be the input signal to the element substrate of the next stage, the adverse effect on the element substrate during wire bonding is reduced.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. Further, in the following description, an ink jet recording head and an ink jet recording apparatus will be taken as examples of the liquid ejecting head and the liquid ejecting apparatus.

FIG. 1 is a perspective view showing the schematic construction of an embodiment of the liquid jet head of the present invention.

The ink jet recording head of this embodiment is
As shown in FIG. 1, it has an aluminum plate base support 10, and on the upper surface of the aluminum plate base 10, a plurality of element substrates 11 are aligned with one end of the base 10 and the discharge direction is The PCB boards 16 are arranged so as to be the same, and the wiring patterns 17 and the signal terminals 19 for exchanging signals with the outside are formed. The element substrate 11 and the PCB substrate 16 which is a wiring substrate are the element substrate 1
It is electrically connected to the pad 15 on 1 through the bonding wire 18. The element substrate 11 is formed by forming a plurality of electrothermal conversion elements and functional elements corresponding thereto on the same substrate. The nozzle 1 is provided on the element substrate 11.
The liquid chamber member 12 in which 3 is formed and the supply pipe 14 for supplying ink are formed in this order. The ink is supplied into the liquid chamber through the supply pipe 14, the functional element and the electrothermal conversion element of the element substrate 11 are driven through the signal terminal 19 of the PCB board 16, and the electrothermal conversion element generates heat energy. As a result, the ink expands and is ejected from the nozzle 13.

FIG. 2 is a schematic configuration diagram showing the configuration of a head substrate used in one embodiment of the liquid jet head of the present invention.

The recording head substrate shown in FIG. 2 has an aluminum plate base 101 on which electrothermal conversion elements 104 arranged in an array and the electrothermal conversion elements 104 are driven. Functional elements, namely, a plurality of element substrates 103 in which a transistor array 105, a latch 106 and a shift register 107 are formed on the same substrate, an input signal terminal 110 for inputting a signal from the outside, and a signal to the outside. Output signal terminal 112, power supply terminal 113 and wiring pattern 11 for outputting
1 and the PCB substrate 102 on which they are formed are respectively arranged at predetermined positions. Then, the element substrate 103 and P
The CB substrate 102 is electrically connected via a bonding wire 108.

In the above structure, an image signal is input from the outside to the input signal terminals 109 and 110 on the PCB substrate 102, and the image signal is transferred via the bonding wire 108.
After being transferred to the shift register 107, the latch 106
Stored in. The transistor array 105 is switched based on this image signal, and the current flowing through the electrothermal conversion element 104 connected to the transistor is controlled. At this time, the electric current is supplied to the electrothermal converting element 104 from the outside through the power supply terminal 113. Also,
The functional elements of each element substrate 103 are connected to the PCB substrate 10
2 through the wiring pattern 111 on the element substrate 1 of the previous stage
It is connected so that the output signal from 03 becomes an input signal to the element substrate 103 of the next stage. In this way, the shift registers 107 of each element substrate 103 are serially connected. Of course, it is also possible to input image signals such as print data in parallel for each functional element for driving each electrothermal conversion element, but this type of connection increases the signal lines, so here is the advantage in mounting. Considering that the serial connection is made. In the figure, other than the functional element for driving the electrothermal conversion element, for example, a temperature sensor or the like is not shown. Also, the GND terminal is not shown,
Obviously, these can be arranged by the usual layout design.

As described above, in the present invention, the adjacent element substrates are connected to each other through the wiring pattern 111 on the PCB substrate 102.

Therefore, it is possible to connect the element substrate and the wire on the side where no load is applied to the substrate and to connect the wire and the PCB substrate on the side where the load is applied. There is no danger of hurt.

Further, since it is not necessary to provide electrical connection pads on both ends of the element substrate, the element substrate can be downsized, and a plurality of element substrates can be arranged while maintaining the heating resistor pitch on the element substrate. And can be electrically connected.

In particular, in the element substrate having a data conversion function element such as a shift register or a latch which receives serial image data from the outside and converts it into parallel data corresponding to this electrothermal converter on the electrothermal converter side, As described in the explanation column, it is preferable to directly connect the element substrates to each other in terms of data transfer, but as described above,
By intentionally connecting via a PCB board, the above-mentioned effects can be obtained.

Further, in the present invention, the height of the pads for electrically connecting the PCB substrate and each element substrate is made equal, but the height of the pads of the PCB substrate and the element substrate is equal, or the height of the pad of the element substrate is equal. It should be higher. However, it is desirable that this height difference is also 1.7 mm or less.

Next, the arrangement of the element substrate on the base will be described. FIG. 3 is a diagram showing arrangement dimensions of an element substrate included in an embodiment of the liquid jet head of the present invention.

Similar to the above, as shown in FIG.
A plurality of element substrates 123 and a PCB substrate 112 are arranged on the substrate 1. In each element substrate 123, the array length from the first nozzle to the nth nozzle is L ₁ , and the element substrate 1
The interval between the two 23 is defined as the end nozzle interval, and is L ₂ .

Next, the operation for printing using the above recording head will be described.

FIG. 4 is a schematic diagram showing a printing operation when an embodiment of the liquid jet head of the present invention is used.

As shown in FIG. 4, the ink jet recording head is scanned with the feeding direction of the printing paper 151 as the main scanning direction (Y direction), and the X direction orthogonal to this direction as the sub scanning direction. Here, the element substrate on the aluminum plate base is arranged in the Y direction. In a monochrome printer, when the arrangement and scanning direction are set as shown in FIG.
By setting the relationship between the dimensions L ₁ and L ₂ shown in ( ₁ ) to L ₁ = L ₂ and the paper feed amount to L ₁ (= L ₂ ), all nozzles can be driven, and the print processing capability is improved.

Also, in the case of a color printer using several kinds of ink, it is not necessary to match L ₁ and L ₂ .

Here, by arranging several element substrates on the base so that the value of L ₂ is the same as the nozzle pitch, all nozzles of the ink jet recording head composed of each element substrate have the same pitch. Become. Therefore, since complicated control is not required for feeding the paper, higher speed printing is possible.

FIG. 5 is a diagram showing the arrangement dimensions of the element substrate when an embodiment of the liquid jet head of the present invention is used as a color printer.

As shown in FIG. 5, a plurality of bases 141 are provided.
The element substrate 143 and the PCB substrate 142 of
In the case of a color printer, between the arrangement of the element boards
Distance L ₃, L_FourAnd nozzle array length L₁, L₂Each is different
Both are possible.

It is conceivable that an electrical inspection pattern is provided in addition to the configuration shown in FIG. FIG. 6 shows FIG.
It is a schematic block diagram which shows the structure which provided the electrical inspection pattern in the board | substrate for heads shown in FIG.

As shown in FIG. 6, in addition to the structure shown in FIG. 2 described above, a wiring pattern 11 formed on the PCB substrate 102 for serially connecting the functional elements 103 to each other.
1 is provided with an electrical inspection pattern 174.
By providing such an electric test pattern 174, a large number of element substrates 103 are serially connected,
When a functional element becomes defective, it is possible to inspect which element is defective. Then, the number of defective products can be reduced by inspecting the mounting head and correcting the defective blocks by exchanging them.

Next, another embodiment will be described.

FIG. 7 is a perspective view showing the schematic construction of another embodiment of the liquid jet head of the present invention.

In the ink jet recording head of this embodiment, as shown in FIG. 7, a plurality of element substrates 183 and a PCB substrate 184 are arranged at predetermined positions on a base 180, and the PCB substrate 184 and each element substrate are arranged. What is 183?
It is electrically connected by a bonding wire 185. A liquid chamber member 186 is formed on each substrate element 183, and a nozzle opening 182 for ejecting ink is formed on the upper surface of the liquid chamber member 186. This structure is a so-called side shooter structure.

The ink is supplied to the liquid chamber member 186 by providing a hole that penetrates the base 180 and the liquid chamber member 186 in the element substrate 183 and through an ink tank provided in the base 186 through the hole.

In each of the above-described embodiments, each element substrate and PCB are
Although the configuration is shown in which the substrate and the substrate are connected by wire bonding, the present invention is not limited to this, and the connection may be performed by wireless bonding such as a TAB method using a film or by crimping a conductive member. Any method can be used as long as the physical connection is satisfied.

Further, in each of the above-described embodiments, the shift register is formed as a functional element on the substrate to form the element substrate. However, the present invention is not limited to the element substrate, and the same yield improvement can be achieved by the diode matrix substrate. Can be expected. The diode matrix substrate will be described below.

FIG. 8 is a schematic diagram showing another modification of the element substrate included in the liquid jet head of the present invention.

On the diode matrix substrate,
As shown in FIG. 8, an electrothermal conversion element 191 and a diode 192 connected in series to each of the N segments (S) are configured in parallel with the M blocks (B). The electric currents flowing in the respective electrothermal conversion elements 191 are
It is controlled by arbitrarily switching the energization between the block M and the segment N. Even a recording head having such a diode matrix substrate can be manufactured without lowering the yield of the substrate process as in the present embodiment.

FIG. 9 shows several tens of semiconductors according to the present invention.
Recording element corresponding to chip, functional element, and drive collection
By providing a product circuit structurally inside the upper surface of the same substrate,
A full line liquid jet recording device
Cyan, yellow, magenta on line recorder
High-quality full color with black and black
-It is a recording device. Reference numerals 201A and 201B indicate
Recording medium R in sub-scanning direction V _SIt was provided to carry the paper
The roller pair as a conveyance means is shown. Reference numeral 202B
K, 202Y, 202M and 202C are respectively
A black block in which nozzles are arranged over the entire width of the recording medium R
Black, yellow, magenta and cyan.
It shows a recording device of the line type, black, yellow
-, Magenta, and cyan in this order from the upstream side in the recording medium transport direction.
Are arranged to form a recording device assembly. Code 20
Reference numeral 0 indicates a discharge recovery means, which will be described in the discharge recovery process.
Instead of the recording medium R, the recording device assembly faces the recording device assembly.
Cap, ink absorber, wiping blade, etc.

In the above embodiments, it was explained that each functional element and the electrothermal converter were provided on the element substrate, but the term "on the substrate" here means the surface of the substrate, the surface of the substrate and the surface of the substrate. It indicates the inside and so on.

[0061]

As described above, according to the present invention, the ink jet recording head which is a liquid jet head is divided into a plurality of element substrates, and each element substrate is arranged on the same base, so that the functional elements are formed on the same substrate. Further, it is possible to cope with the increase in the number of nozzles of the recording head and the colorization without lowering the yield of the recording head substrate on which the electrothermal conversion element is formed, and the cost of the recording head can be reduced.

Further, by connecting the element substrates to each other via the wiring substrate on the same base as those, it is possible to make the bonding direction unidirectional without the need to connect the chips to each other in wire bonding. Work efficiency can be improved when connecting wires. In addition, the output signal from the element board at the previous stage is connected via the circuit board so as to be the input signal to the element board at the next stage, so that adverse effects on the element board during wire bonding can be prevented. You can In addition, miniaturization of the element substrate and the head can be achieved, and high-density nozzle arrangement in a long head can be achieved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of an embodiment of a liquid jet head of the present invention.

FIG. 2 is a schematic configuration diagram showing a configuration of a head substrate used in an embodiment of the liquid jet head of the present invention.

FIG. 3 is a diagram showing arrangement dimensions of an element substrate included in an embodiment of the liquid jet head of the present invention.

FIG. 4 is a schematic diagram showing a printing operation when an embodiment of the liquid jet head of the present invention is used.

FIG. 5 is a diagram showing arrangement dimensions of an element substrate when an embodiment of the liquid jet head of the present invention is used as a color printer.

6 is a schematic configuration diagram showing a configuration in which an electrical inspection pattern is provided on the head substrate shown in FIG.

FIG. 7 is a perspective view showing a schematic configuration of another embodiment of the liquid jet head of the present invention.

FIG. 8 is a schematic configuration diagram showing another modification of the element substrate included in the liquid jet head of the present invention.

FIG. 9 is a diagram showing a recording apparatus using the liquid jet head of the present invention.

FIG. 10 is a schematic view showing a liquid jet head.

FIG. 11 is a schematic diagram showing a configuration of a recording head substrate.

FIG. 12 is a side view of the recording head.

FIG. 13 is a diagram showing a structure of a head substrate.

FIG. 14 is a diagram for explaining a form of a head in which a plurality of element substrates are connected.

FIG. 15 is a diagram illustrating an element substrate.

[Explanation of symbols]

10, 101, 121, 141, 180 Base 11, 103, 123, 143, 183 Element substrate 12, 186 Liquid chamber member 13 Nozzle 14 Supply pipe 15 Pad 16, 102, 122, 142, 184 PCB substrate 17, 111 Wiring Patterns 18, 108, 185 Bonding wire 19 Signal terminal 104, 191 Electrothermal conversion element 105 Transistor array 106 Latch 107 Shift register 108 Bonding wire 109, 110 Input signal terminal 112 Output signal terminal 113 Power supply terminal 150 Ink jet recording head 151 Printing paper 174 Electrical inspection pattern 182 Nozzle opening 192 Diode 200 Ejection recovery means 201A, 201B Roller pair 202C, 202M, 202Y, 202Bk Recording device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B41J 29/00 C

Claims (5)

[Claims] 1. A plurality of element substrates in which an electrothermal converter that generates thermal energy for ejecting a liquid and a functional element for driving the electrothermal converter are formed on the same substrate, The functional element has a wiring board provided with wiring for inputting / outputting signals to / from the outside, and an output signal from the element board is input to an adjacent element board via the wiring board. The liquid ejecting head is characterized by being electrically connected as described above. 2. The liquid jet head according to claim 1, wherein the liquid is ink. 3. The functional element is a functional element which receives a serial image signal from the outside of the substrate and outputs it as a parallel image signal to the electrothermal converter side.
The liquid jet head according to item 1. 4. The plurality of element substrates and the wiring substrate,
The liquid jet head according to claim 1, wherein the liquid jet head is arranged on the base and has the same height or a higher height on the surface for electrically connecting the element substrate and the wiring substrate. . 5. A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1 and a recording medium transporting means, and ejecting liquid to perform recording.