JPH0976500A - Ink jet recording head and ink jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the deviation of the application of a load to a ball due to the shape of the tip of a capillary by a constitution wherein the bonding surface on the 1st side of an incline, to which a recording head is fixed, is made lower than the bonding surface on the 2nd side, to which a printed-wiring board is fixed. SOLUTION: After the height of a capillary 204 is controlled through the circular motion at its vertical movement so as to be vertically brought into contact with the bonding pad 202 of a printed-wiring board placed on the horizontal surface, the capillary 204 is moved to a bonding pad 201. At that time, a ball 207 formed at the tip of a bonding wire 203 is pushed against the face of the capillary 204. Next, the capillary 204 is lowered so as to being the ball 207 in contact with the bonding pad in order to perform bonding, during which ultrasonic vibration is applied in case of by thermosonic technique. Since the 1st side bonding position is lower than the 2nd side bonding position, the capillary 204 in its circular motion can be brought into contact with the inclined bonding surface at the angle, which is more near normal than that realizing when the 1st side bonding potion is flush with or higher than the 2nd side bonding position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head and an ink jet recording apparatus for recording by ejecting ink, and more particularly, to an improved ink jet recording head for wire bonding to an inclined bond surface. And an inkjet recording apparatus using this recording head. The recording used in the present invention includes printing on cloth, thread, or the like.

[0002]

2. Description of the Related Art The ink jet recording method (liquid jet recording method) is capable of high-speed recording because noise generation at the time of recording is negligibly small.
Moreover, it has recently attracted interest in that recording can be performed without requiring a special process of fixing on so-called plain paper. Among them, the liquid jet recording method described in, for example, Japanese Patent Application Laid-Open No. 54-51837 and German Patent (DOLS) 2843064 makes thermal energy act on liquid to drive liquid droplets. In terms of
It has different characteristics from other liquid jet recording methods. That is, in the recording method disclosed in the above publication, the liquid subjected to the action of thermal energy causes a state change accompanied by a sharp increase in volume, and the action force based on the state change causes an orifice at the tip of the recording head portion. The liquid is ejected more to form flying droplets, and the droplets adhere to the recording member to perform recording. In particular, DOLS No. 284
The liquid jet recording method disclosed in Japanese Patent No. 3064 is so-called drop-on-deman.
d) The recording head is not only applied very effectively to the recording method, but also a recording head having a full line type and a high density multi-orifice can be easily embodied. It has the feature that images can be obtained at high speed.

The recording head portion of the apparatus applied to the above-mentioned recording method communicates with an orifice provided for discharging a liquid, and thermal energy for discharging a droplet acts on the liquid in communication with the orifice. A recording head substrate provided with a liquid discharge part having a liquid flow path whose part is a heat acting part, and an electrothermal converter (heat generating part) as means for generating thermal energy, Consists of. This recording head substrate is fixed by an adhesive on a support (for example, Al) having excellent thermal conductivity. Further, on the support, a printed circuit board for transmitting an electric signal sent from the recording apparatus main body to the recording head board is fixed by an adhesive, and both terminals are electrically connected by wire bonding.

[0004]

Conventionally, although there was a difference in height of the bond surface between the recording head substrate and the printed circuit board due to the difference in thickness between the two substrates, both were fixed on the same horizontal plane, so wire bonding was performed. When performing, such a difference in height of the bond surface did not cause any particular problem. However, when the electrical connection between the recording head substrate provided on the inclined surface of the support and the printed board provided on the horizontal plane is performed by wire bonding, the capillary provided in the bonding device is provided on the horizontal plane. The capillary is positioned vertically on the printed circuit board, and in this case, the capillary moves up and down by making a circular motion around a point fixed to the main body of the device with a radius to the capillary as a radius. .

As a result, the 1st (first) side is 2
When the height is the same as or higher than that on the nd (second) side and the bond surface is inclined, the tip of the capillary is in contact with the bond surface at an acute angle as shown in FIG. The force is concentrated on one side of the ball and the contact area with the bond surface is reduced. For this reason, there is a problem that it is difficult to perform good bonding, such as local thinning and reduction in strength or, in the worst case, peeling. Further, such a tendency is more likely to occur as the face surface angle of the capillary becomes shallower, and there is a limit to the selection of the capillary for bonding to the inclined surface.

Therefore, the present invention solves the above problems in the prior art, and even in a structure having a bond surface on the inclined surface, a capillary with no restriction on the tip shape can be used, and the reliability is high. It is an object of the present invention to provide an inkjet recording head and a recording apparatus having a high yield bonding performance.

[0007]

According to the present invention, in order to achieve the above object, a recording head substrate is fixed to an inclined surface provided on a part of a support, and a printed circuit board is fixed to a horizontal surface of the support. In the ink jet recording head in which the recording head substrate and the printed circuit board are electrically connected by wire bonding, the inclined surface side to which the recording head is fixed is the first (1st) side,
The horizontal surface side to which the printed circuit board is fixed is the second (2
The bond surface on the first (1st) side is lower than the bond surface on the second (2nd) side. Then, by applying the inkjet recording head of the present invention to an inkjet recording apparatus in which the inkjet recording head can be replaced on the carriage, a more effective inkjet recording apparatus can be configured.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the present invention includes a recording head substrate (heater board) fixed to an inclined surface on a support (base plate) partially having an inclined surface, and a support on the support. When connecting the print head for electrical connection between the print head and the printing apparatus, which is fixed to the horizontal surface by adhesive bonding, by wire bonding, the inclined surface side is the 1st side, the horizontal surface side is the 2nd side, and 1s
By ensuring that the bond surface on the t side is at a lower position than the bond surface on the 2nd side, when the ball portion of the wire tip contacts the inclined surface as shown in FIG. Since the contact is made at a more nearly perpendicular angle with respect to the above, there is no uneven distribution of the load on the ball due to the tip shape of the capillary, and it is possible to obtain a recording head that achieves the above-mentioned object of the present invention.

[0009]

EXAMPLES The present invention will be described in detail below with reference to examples. FIG. 1 is a configuration diagram of a recording head which is a feature of the present invention. Here, 100 is a support, 101 is a recording head substrate, 102 is a printed circuit board, 103 is a bonding wire, and 104 is a bonding pad. For example Si
A plurality of electrothermal converters (not shown) for giving foaming energy to at least a recording liquid on a semiconductor substrate, and a plurality of functional elements (not shown) driven in a one-to-one correspondence with each of the plurality of electrothermal converters. ), And a recording head substrate (heater board) 101 having a wiring electrode for electrically connecting the electrothermal converter and the functional element, and wiring for transmitting an electric signal sent from the recording device to the recording head substrate 101. A printed circuit board 102 having (not shown)
The substrate is accurately positioned by die bonding on a support (base plate) 100 made of a material having excellent thermal conductivity such as a substrate, and is bonded by a die bond adhesive 105 with an adhesive thickness of 20 to 40 μm. At this time, an inclination having an arbitrary angle is formed at the place where the recording head substrate is arranged, and wire bonding is performed from the inclined surface (1st) to the horizontal surface (2nd). In this case, as the bonding method, ball stitch bonding using a gold wire (Au) which is generally used is most suitable, but it goes without saying that the ball stitch bonding is not limited to this.

Next, the flow of wire bonding according to this configuration will be described with reference to FIG. First, the capillary 204
Makes a circular motion when it moves up and down, so that the height is adjusted so as to make vertical contact with the bonding pad 202 of the printed circuit board arranged on the horizontal plane, and then the recording head substrate arranged on the inclined surface. Bonding pad 201
Move to. At that time, the bonding wire 2
The ball 207 formed at the tip of 03 is pressed against the face of the capillary 204 (Fig. A).

Next, the capillary 204 descends and the balls 207 come into contact with the bonding pads for bonding. At this time, if the thermosonic method is used, ultrasonic vibration is applied. In this configuration, 1 is placed at a position lower than the 2nd side.
Since there is a bond position on the st side, the capillary 204 that makes a circular motion can contact the inclined bond surface at a more vertical angle (FIG. b).

The ball 207 is the bonding pad 201.
After being bonded to the capillary, the capillary 204 rises to the height of the loop. At this time, since the wire clamp 205 is open, the bonding wire 203 is freely sent out from the tip of the capillary 204 (Fig. C).

Next, the capillary 204 moves to the bond surface on the printed circuit board while sending out the bonding wire 203, and contacts the bond surface vertically (d).
Figure).

After this, the capillary 204 presses the bonding wire 203 against the bonding pad 202 to transform it into a fishtail shape. At this time, if the thermosonic method is used, ultrasonic vibration is applied (e
Figure).

The capillary 204 rises above the bond surface and reaches the wire clamp 20 at the initially set height.
5 is closed and the bonding wire 203 is grasped. However, since the capillary 204 continues to rise, it is cut at the thinnest bond of the bonding wire 203 (Fig. F).

A new ball is formed on the wire tail protruding from the end of the capillary 204 by a hydrogen flame or electronic spark, and the next bonding is performed (FIG. 9G). By repeating this, a series of wire bonding steps is completed.

FIG. 3 shows an example of an ink jet recording head including the recording head structure of FIG. 1 thus constructed.
As shown in FIG. 3, the recording head substrate 301 has a liquid passage wall member 304 for forming a liquid passage 303 communicating with the plurality of ejection ports 302, and a top plate 30 having an ink supply port 305.
6 are attached, and each liquid passage 303 and the ink supply port 305 are connected to each other via a common liquid chamber 307. Further, in each liquid path 303, the recording head substrate 301
A heat generating portion 308 provided in the vicinity of the discharge port 302 and a wiring 309 to the heat generating portion 308 are arranged. Inkjet recording type recording head 3 configured as described above
In FIG. 10, the ink injected from the ink supply port 305 is stored in the internal common liquid chamber 307 and supplied to each liquid path 303, and in this state, the heat generating portion 308 of the recording head substrate 301 is driven to discharge the ink 302. Ink is ejected from. By mounting the recording head 310 having the above-described configuration on the recording apparatus main body and applying a signal to the recording head 310 from the apparatus main body, it is possible to obtain an inkjet recording apparatus capable of high-speed recording and high-quality recording.

Next, an ink jet recording apparatus using the recording head of the present invention will be described with reference to FIG. FIG. 4 shows an inkjet recording apparatus 40 to which the present invention is applied.
It is an external appearance perspective view which shows an example of 0. Recording head 310
Is the carriage 42 that engages with the spiral groove 421 of the lead screw 404 that rotates via the driving force transmission gears 402 and 403 in association with the forward and reverse rotation of the drive motor 401.
With 0, it is reciprocated along the guide 419 in the directions of arrows a and b. A paper pressing plate 40 for the recording paper P that is conveyed onto the platen 406 by a recording medium supply device (not shown).
5 presses the recording paper P against the platen 406 in the carriage movement direction.

Photocouplers 407 and 408 are home position detecting means for confirming the presence of the lever 409 of the carriage 420 in this region and switching the rotation direction of the drive motor 401. Reference numeral 410 denotes a support member that supports a cap member 411 that caps the entire surface of the recording head 410 described above, and 412 denotes the cap member 411.
By suction means for sucking the inside, the suction recovery of the recording head 310 is performed through the cap inner opening 413. Reference numeral 414 is a cleaning blade, and 415 is a moving member that allows this blade to move in the front-rear direction, and these are supported by a main body support plate 416. Cleaning blade 414
Needless to say, a well-known cleaning blade other than this form can be applied to this example.

Reference numeral 417 is a lever through which suction for suction recovery is performed, and a cam 41 that engages with the carriage 420.
8, the drive force from the drive motor 401 is controlled by a known transmission means such as clutch switching. A recording control unit that gives a signal to the heat generating unit 406 provided in the recording head 310 and controls drive of each mechanism described above is provided on the main body side of the apparatus. The recording controller is not shown.

In the ink jet recording apparatus 400 having the above-mentioned structure, the platen 4 is formed by the recording medium feeding apparatus.
The recording head 31 for the recording paper P conveyed on
0 is for recording while reciprocating over the entire width of the recording paper P, and since the recording head 310 is manufactured by the method described above, high-accuracy and high-speed recording is possible. . In the above description, the ink jet type recording head has been described, but the present invention can also be applied to, for example, a thermal head.

The present invention is provided with means for generating thermal energy as energy used to eject ink, particularly in the ink jet recording system (for example, an electrothermal converter or laser light), and the thermal energy A recording head that changes the state of ink
This brings an excellent effect in the recording apparatus. This is because according to such a method, it is possible to achieve higher density and higher definition of recording. Regarding the typical configuration and principle thereof, for example, U.S. Pat. No. 4,723,129 and No. 474.
No. 0796, the present invention is preferably carried out using these basic principles.

This recording method can be applied to both the so-called on-demand type and the continuous type. To briefly explain this recording method, a nucleate boiling phenomenon occurs in the liquid (ink) corresponding to the recorded information in the electrothermal converter arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal for causing a rapid temperature rise that causes a film boiling phenomenon, thermal energy is generated and film boiling is caused on the heat acting surface of the recording head. In this way liquid (ink)
Since it is possible to form bubbles corresponding to the drive signal applied to the electrothermal converter, it is particularly effective for the on-demand recording method. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection port to form at least one droplet.

When the driving signal is formed into a pulse shape, the growth and shrinkage of the bubbles are performed immediately and appropriately, and the ejection of the liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable.
The driving signal in the form of a pulse is disclosed in US Pat.
Those described in 3359 and 4345262 are suitable. It should be noted that US Pat.
If the conditions described in the specification are adopted, more excellent recording can be performed. As the configuration of the recording head, in addition to the combination of the ejection port, the liquid flow passage, and the electrothermal converter (the linear liquid flow passage or the right-angle liquid flow passage) as disclosed in the above-mentioned specifications, US Pat. No. 4,558,333
As disclosed in Japanese Patent No. 4459600 and Japanese Patent No. 4459600, the present invention also includes a structure in which a heat acting portion is arranged in a bending region.

Further, Japanese Patent Application Laid-Open No. 59-123670 discloses a structure in which a common slit is used as a discharge port of an electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy. The present invention is also effective in a configuration based on Japanese Patent Application Laid-Open No. 59-138461, which discloses a configuration in which a hole corresponds to a discharge portion.

Further, as a recording head in which the present invention is effectively used, there is a full line type recording head having a length corresponding to the maximum width of the recording medium which can be recorded by the recording apparatus.
The full line head may be a full line configuration by combining a plurality of recording heads as disclosed in the above specification, or may be a single full line recording head formed integrally. Also, by being adhered to the device body, it is provided integrally with a replaceable chip type recording head that enables electrical connection to the device body and supply of ink from the device body, or the recording head itself. The present invention is also effective when a cartridge type recording head is used.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc. to the recording apparatus of the present invention because the recording apparatus of the present invention can be made more stable. Specific examples thereof include capping means, cleaning means, pressurizing or absorbing means, an electrothermal converter or a heating element other than this, or a preheating means for the recording head for the recording head, and recording means. It is also effective to perform stable recording by adding a means for performing a preliminary ejection mode for performing ejection different from the above.

Further, the recording mode of the recording apparatus is not limited to the mode in which only the mainstream color such as black is recorded, and either the recording head may be integrally formed or a plurality of recording heads may be combined. However, the present invention is also extremely effective for an apparatus provided with at least one of a multicolor of different colors or a full color by color mixing. In the example described above, the description is made using the liquid ink,
In the present invention, an ink that is solid at room temperature or an ink that is in a softened state at room temperature can be used.

In the above-mentioned ink jet apparatus, since the temperature of the ink itself is adjusted within the range of 30 ° C. or higher and 70 ° C. or lower, the viscosity of the ink is generally controlled so that the viscosity of the ink is within the stable ejection range. Any ink may be used as long as the ink is in a liquid state when a signal is applied. In addition, excessive temperature rise of the head or ink due to thermal energy is positively prevented by using it as energy for changing the state of the ink from a solid state to a liquid state, or it is left unattended for the purpose of preventing ink evaporation. An ink that solidifies can also be used.

In any case, the application of thermal energy such as the one in which the ink is liquefied by the application of the thermal energy according to the recording signal and ejected as an ink liquid, or the one which has already started to solidify when it reaches the recording medium. The use of an ink having the property of liquefying for the first time is also applicable to the present invention. Such an ink is disclosed in JP-A-54-56.
No. 847 or Japanese Patent Laid-Open No. 60-71260, so that it faces the electrothermal converter while being held as a liquid or solid in the recesses or through holes of the porous sheet. It may be in any form. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method. Furthermore, as a form of the ink jet recording apparatus of the present invention,
In addition to those used as image output terminals of information processing equipment such as computers, copying machines combined with readers,
Further, it may be in the form of a facsimile device having a transmission / reception function.

[0031]

As described above, according to the present invention, the recording head substrate fixed to the inclined surface provided on a part of the support and the printed circuit board fixed to the horizontal surface of the support are electrically bonded by wire bonding. When the physical connection is performed, the recording head substrate is set to the 1st side, the printed circuit board is set to the 2nd side, and the bond surface height on the 1st side is always lower than the bond surface height on the 2nd side, so that the wire bonding process in the configuration having the inclined surface It is possible to maintain the reliability of the ink jet recording head and the recording device without lowering the yield of. Further, according to this configuration, there is an advantage that a wide range of capillaries can be selected without being limited by the shape of the tip of the capillary. Furthermore, by applying the recording head of the present invention to an inkjet recording apparatus in which the recording head can be replaced on the carriage, a more effective inkjet recording apparatus can be realized.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a recording head according to an embodiment of the invention.

FIG. 2 is a diagram illustrating a flow of a wire bonding process in the present invention.

FIG. 3 is a perspective view showing a recording head of the present invention.

FIG. 4 is a perspective view showing a recording apparatus using the recording head of the present invention.

FIG. 5 shows a bond surface on the inclined surface side (1st) as a horizontal surface (2
It is a figure which shows the situation of bonding when providing in a position higher than the bond surface of the (nd) side.

[Explanation of symbols]

 100 Support 101 Recording Head Substrate 102 Printed Circuit Board 103 Bonding Wire 104 Bonding Pad 105 Die Bon Adhesive 201 Bonding Pad (1st Side) 202 Bonding Pad (2nd Side) 203 Bonding Wire 204 Capillary 205 Wire Clamp 206 Electron Spark Electrode 207 Ball 301 Recording head substrate 302 Discharge port 303 Liquid path 304 Liquid path wall member 305 Ink supply port 306 Top plate 307 Common liquid chamber 308 Heat generating part 309 Wiring 310 Recording head 400 Inkjet recording device 401 Drive motors 402, 403 Driving force transmission gear 404 Lead screw 405 Paper pressing plate 406 Platens 407, 408 Photo coupler 409 Lever 410 Supporting member 411 Cap section 412 suction means 413 cap opening 414 cleaning blade 415 moves member 416 main body support plate 417 lever 418 cams 419 Guide 420 carriage 421 spiral groove 501 bonding Patsu de (傾科 surface) 502 Capillary 503 Bondi signaling wire (ball portion)

Claims (2)

[Claims] 1. A recording head substrate is fixed to an inclined surface provided on a part of a support, a printed circuit board is fixed to a horizontal surface of the support, and the recording head substrate and the printed circuit board are wire-bonded to each other. In an inkjet recording head that is electrically connected, the inclined surface side to which the recording head is fixed is first (1st)
Side, the horizontal surface side to which the printed circuit board is fixed is the second (2nd) side, and the bond surface on the first (1st) side is lower than the bond surface on the second (2nd) side. Inkjet recording head. 2. An inkjet recording device using the inkjet recording head according to claim 1, wherein the inkjet recording head is replaceable on a carriage.