JPH0664170A - Ink jet printer and its printing head - Google Patents

Abstract

PURPOSE: To prevent the corrosion of an orifice plate by ink and the peel and strain thereof during use by forming a plurality of the orifices of a nozzle member to a flexible insulating tape containing a conductor and arranging heating elements in close vicinity of the respective orifices. CONSTITUTION: A polymer tape 104 is sent to a laser treatment chamber and cut off by laser in the pattern prescribed by a single or a plurality of masks 108 by using laser radiation 110 generated by an F2, ArF, KrCl or XeCl type excimer laser 112. Next, after the laser cut-off stage, the polymer tape 104 is advanced by one stage and this process is repeated. A time necessary for forming a single pattern on the tape is several sec as a whole. As a result, a nozzle member made of as polymer cut off by laser has light resistance to the corrosion by aq. ink and is fundamentally water-repellent and relatively low in elastic modulus and, therefore, a tendency such that the peel of the nozzle member and a barrier wall layer is generated by the stress incorporated between the nozzle member and a lower substrate or the barrier wall layer is reduced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention generally relates to inkjet
More particularly, it relates to nozzles or orifice members and other components for print cartridges used in ink jet printers.

[0002]

BACKGROUND OF THE INVENTION Thermal ink jet print cartridges operate by rapidly heating a small amount of ink to evaporate the ink and expel it through an orifice to impinge on a recording medium such as paper. . When a large number of orifices are arranged in a pattern, the ejection of ink from each orifice in the proper order causes a mark or other image on the paper when the printhead is moved relative to the paper. It is printed. Generally, the paper is shifted each time the print head moves with respect to the paper. The thermal ink jet printer operates quickly and quietly because only the ink hits the paper. The printing performance of these printers is high, and they can be made small and portable.

In one example design, a printhead comprises the following parts: That is, 1) an ink reservoir and an ink conduit for supplying ink to an evaporation point in the vicinity of the orifice, 2) an orifice plate in which individual orifices are formed in a required pattern, and 3) a wall of the ink conduit. A series of thin film heaters, one on each substrate, one under each orifice. Each heater is equipped with a thin film resistor and a suitable wire. To print a single dot of ink, current from an external power supply is conducted to the selected heater. The heater is resistively heated, which in turn heats an adjacent thin layer of ink, causing it to explode and vaporize, resulting in a drop of ink being ejected onto the paper through its associated orifice.

An example of a conventional print cartridge is 1985.
No. 4,500,895, entitled "Disposable Inkjet Head," issued on February 19, and assigned to the present applicant.

In such a printer, the printing performance depends on the physical characteristics of the orifice in the printing head mounted on the printing cartridge. For example, the shape of the orifice in the printhead affects the size, trajectory and velocity of ink drop ejection. In addition, the shape of the orifices in the printhead affects the flow of ink supplied to the vaporization chamber and, in some cases, the manner in which ink is ejected from adjacent orifices. Orifice plates for inkjet printers are made of nickel and are often manufactured by an electroforming process using a lithograph. An example of a suitable lithographic electroforming process is U.S. Pat. No. 4,773,971 issued September 27, 1988 to Lam et al.
No. "Thin film mandrel". In such a process, the orifices in the orifice plate are formed by plating nickel around the dielectric disk.

There are several drawbacks to such an electroforming process for forming an orifice plate for an inkjet printhead. One is that this process requires precise equilibration of parameters such as stress and plate thickness, disk diameter and plating rate. Another drawback is that such electroforming processes inherently have limited design options with respect to nozzle shape and size.

Ink corrosion can be a problem when using electroformed orifice plates and other components of printheads for ink jet printers. In general, the corrosion resistance of such orifice plates depends on two parameters. That is, the chemical composition of the ink and the formation of a hydroxide layer on the electroplated nickel surface of the orifice plate. Without the hydroxide layer, nickel can be corroded by the ink. This tendency is particularly strong in the case of water-based inks that are widely used in inkjet printers. Corrosion of the orifice plate can be minimized by applying gold plating, but such plating is expensive.

Yet another drawback of electroformed orifice plates for ink jet printers is that the finished printhead tends to peel during use. Normally,
Delamination originates from the formation of a small gap between the orifice plate and its substrate, often due to the difference in coefficient of thermal expansion between the orifice plate and its substrate. Delamination is further enhanced by the interaction of the printhead material and the ink. For example, the material in an inkjet printhead may swell upon prolonged exposure to aqueous ink, which may change the shape of the internal structure of the printhead.

Even if the peeling of the orifice plate is partial,
The print result may be distorted. For example, partial detachment of the orifice plate usually results in a slow or extremely irregular drop ejection rate. In addition, partial delamination can result in the accumulation of bubbles, which can impede ink drop ejection.

[0010]

A novel nozzle member for an ink jet print cartridge and a method of forming the nozzle member are disclosed below. In the preferred embodiment, nozzles or orifices are formed in a flexible tape having conductor traces formed therein. In the preferred method, the nozzle or orifice is formed by an excimer laser ablation scheme. A frequency doubled YAG laser may be used instead of the excimer laser.

The nozzle member having the resulting orifices and conductor traces is then mounted on a substrate containing heating elements corresponding to each orifice. The conductor trace formed on the back surface of the nozzle member is connected to the electrode on the substrate and supplies an excitation signal to the heating element. The separate layer or barrier layer formed on the nozzle member comprises an evaporation chamber, an enclosure for each orifice, and an ink passage in liquid communication between the ink supply and the evaporation chamber. Excitation of the heating element on the substrate vaporizes the ink in the corresponding evaporation chamber, and the vaporized ink is ejected through the orifice of the nozzle member.

By forming the orifices on the flexible circuit, the disadvantages of conventional electroformed orifice plates are eliminated. Further, the orifices are formed in alignment with the conductor traces of the nozzle member and the heating elements such that the array of electrodes on the substrate corresponds to the ends of the conductor traces.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, reference numeral 10 generally indicates an inkjet print cartridge incorporating a printhead according to one embodiment of the present invention. The inkjet print cartridge 10 includes an ink reservoir 12 and a print head 14, and the print head 14 is formed using an automatic tape joining method (TAB). The printhead 14 (hereinafter referred to as the "TAB head assembly 14") has two rows of vertical offset holes or orifices 1 formed in the flexible polymer tape 18 by, for example, laser ablation.
7 is provided with a nozzle member 16. Tape 18 can be purchased from Kapton ™, commercially available from 3M Corporation. Another suitable tape may be Upilex ™ or similar tape.

Conductive traces 36 are formed on the backside of tape 18 by conventional photolithographic etching and / or plating processes. These conductive traces terminate in large contact pads 20 designed to interface with the printer. Print cartridge 10
Is designed to be mounted within the printer such that contact pads 20 on the surface of the tape 18 contact the electrodes of the printer and send an externally generated excitation signal to the printhead.

In the various embodiments shown, the traces are formed on the backside of tape 18 (opposite the side facing the recording medium). In order to access these traces from the surface of the tape 18, holes (lines) must be formed through the front of the tape 18 to expose the ends of the traces. The exposed trace ends are then plated, for example with gold, to form the contact pads 20 shown on the surface of the tape 18.

Windows 22 and 24 extend through the tape 18 and are utilized to facilitate bonding of the electrodes on the heater resistor, including the silicon substrate, to the other ends of the conductive traces. The windows 22 and 24 are padded to protect the traces and the underlying portion of the substrate.

In the print cartridge 10 of FIG. 1, the tape 18 is bent at the back edge of the "cartridge" of the print cartridge and extends for about half the length of the back wall of the cartridge mouth.
This flap portion of tape 18 is necessary to route the conductive traces connected to the substrate electrodes through the window 22 at the remote end. FIG. 2 is a front view of the TAB head assembly 14 of FIG. 1 before removal from the print cartridge and filling windows 22 and 24 within the TAB head assembly 14. T
A silicon substrate 28 (shown in FIG. 3) containing a plurality of individually excitable thin film resistors is fixed to the back surface of the AB head assembly 14. Each resistor has a single orifice 1
7. The contact pad (s) 20 located approximately after 7 and
When selectively excited by a single pulse or a plurality of pulses applied sequentially or simultaneously to the two, it functions as a resistive heater. The orifices 17 and conductive traces may be of any size, number and pattern and are shown in several shapes to simplify and clarify the features of the present invention. The relative dimensions of each shape have been significantly modified for clarity.

The orifice pattern of tape 18 shown in FIG. 2 is formed using a masking process in conjunction with a step and repeat laser or other etching means. This will be easily understood by the expert reading this specification. FIG. 12, which will be described in detail later, shows the above steps in supplementary detail.

FIG. 3 illustrates the backside of the TAB head assembly of FIG. 2 showing a silicon die or substrate 28 attached to the backside of tape 18 and further includes a substrate 28 including ink lines and evaporation chambers. Formed on the barrier layer 30
Is shown. FIG. 6 illustrates the barrier layer 30 in more detail, which will be described below. Shown along the edge of the barrier layer 30 is the inlet of an ink conduit 32 which receives ink from the ink reservoir 12 (FIG. 1). Conductive traces 36 formed on the backside of tape 18 are also shown in FIG. 3, where trace 36 is on contact pad 20 (FIG. 2) on the opposite side of tape 18.
Ends with. The windows 22 and 24 allow access to the ends of the trace 36 and substrate electrodes from the opposite side of the tape 18 to facilitate bonding.

FIG. 4 is a cross-sectional view taken along the line AA of FIG. 3, showing the connection between the ends of the conductive traces 36 and the electrodes 40 formed on the substrate 30. As shown in FIG. 4, the portion 42 of the barrier layer 30 is utilized to insulate the ends of the conductive traces 36 from the substrate 28. Also shown in FIG. 4 is a side view of tape 18, barrier layer 30, windows 22 and 24, and the inlets of various ink conduits 32. The manner in which ink drops 46 are ejected from the orifice holes associated with each ink conduit 32 is shown.

The back side of the TAB assembly 14 of FIG. 3 surrounds the substrate 28 as shown in FIG. 5 and is adhered to the ink reservoir 12 by an adhesive seal that forms an ink leak stop between the back surface of the tape 18 and the ink reservoir 12. Is sealed against the ink opening.

FIG. 5 is a side view of a cross section taken along line BB of FIG. 1, which shows a part of an adhesive seal 50 surrounding the substrate 28, a barrier layer 30 including an ink conduit and evaporation chambers 54 and 56. The substrate 28 is adhesively secured to the central portion of the tape 18 by a thin adhesive layer 52 on the top surface of the substrate. A part of the plastic body of the print head cartridge 10 is also shown. Thin film resistors 58 and 60 are shown within evaporation chamber 54, respectively. FIG. 5 also illustrates how ink flows from the ink reservoir 12 through the central slot 64 formed in the print cartridge 10 and around the edges of the substrate 28 to evaporation chambers 54 and 56. Resistors 58 and 6
When 0 and 0 are excited, some of the ink in the evaporation chambers 54, 56 is ejected, which is ejected ink drops 66 and 68.
Indicated by.

FIG. 6 is a front plan view of a silicon substrate 28 secured to the backside of tape 18 of FIG. 2 to form TAB head assembly 14. On the silicon substrate 28, the thin film resistors 70 in two columns shown in FIG. 6 are formed by using the conventional photolithography technique, and the thin film resistors 70 are exposed through the evaporation chamber 72 formed in the barrier layer 30. In one embodiment,
The length of the substrate 28 is about 1/2 inch, and with 300 heater resistors 70, 6 per inch.
A resolution of 00 dots is possible. Also formed on the substrate 28 are electrodes 74 for connecting to the conductive traces 36 (shown in dotted lines) formed on the back surface of the tape 18 in FIG.

Demultiplexer 78, shown in phantom in FIG. 6, is also formed on substrate 28 for demultiplexing the multiplexed incoming signal applied to electrode 74 and distributing the signal to various thin film resistors 70. Has been done. The demultiplexer 78 allows the use of a much smaller number of electrodes 74 than the thin film resistors 70. Demachixplexer 78
May be any decoder for decoding the encoded signal applied to electrode 74.

A barrier layer 30 is also formed on the surface of the substrate 28 using conventional photolithographic techniques, which is the evaporation chamber 7
2 and the ink conduit 80 may be a photoresist layer or other polymer body formed therein. Portion 42 of barrier layer 30 has conductive traces 3 as described above in connection with FIG.
Insulate 6 from the underlying substrate 28.

The tape 1 whose upper surface of the barrier layer 30 is shown in FIG.
A thin adhesive layer 84, such as an uncured photoresist layer, is added to the top surface of the barrier layer 30 for adhesive fixing to the back surface of 8. A separate adhesive layer is not required if the upper surface of the barrier layer 30 could be the adhesive surface in that way.
The resulting substrate structure is then positioned against the backside of tape 18 such that resistor 70 is aligned with the ends of conductive traces 36. This alignment step also necessarily aligns the electrodes 74 and the ends of the conductive traces 36. The trace 36 is then joined to the electrode 74. The aligned and bonded substrate / tape structure is then heated and at the same time pressure is applied to cure the adhesive layer 84 and secure the substrate structure to the backside of the tape 18.

FIG. 7 is an enlarged view of a single evaporation chamber 72, thin film resistor 70 and orifice 17 after the substrate structure of FIG. 6 is fixed to the back surface of the tape 18 via the thin adhesive layer 84. . The side edges of the substrate 28 are shown as edges 86. In operation, ink passes from the ink reservoir 12 of FIG. 1 around the side edges 86 of the substrate 28 and into the associated evaporation chamber 7.
It flows to 2. When the thin film resistor 70 is energized, the adjacent thin layer of ink overheats causing explosive evaporation, which results in ink drops being ejected through the orifice 17. The evaporation chamber 72 is then refilled by capillarity. In the preferred embodiment, the barrier layer 30 has a thickness of about 1 mil, the substrate 20 has a thickness of about 20 mils, and the tape 18 has a thickness of about 2 mils.

FIG. 8 illustrates one ink ejection chamber of the TAB head assembly 14 in accordance with one embodiment of the present invention.
It is a side view of the cross section along the CC line of FIG. This cross-sectional view shows a laser ablated polymer nozzle member 90 laminated to the barrier layer 30, which may be the same nozzle as shown in FIG. When the thin film resistor 70 on the substrate 28 is excited, a part of the ink droplet in the evaporation chamber 72 is evaporated and the ink droplet 91 is ejected through the orifice 17.

FIG. 9 is a cross-sectional side view of another embodiment of an ink ejection chamber using a laser ablated nozzle member 92 of polymer. As in the previous embodiment, the evaporation chamber 7
2 is surrounded by the nozzle member 92, the base 28, and the barrier layer 30. However, unlike the previous embodiment, the heater resistor 94 is not on the substrate 28, but rather on the nozzle member 9
2 is attached to the lower surface. This further simplifies the structure of the print head. Electrical signals are sent to the resistors by conductive traces (as shown in FIG. 3) formed on the bottom surface of the nozzle member 92.

The various evaporation chambers described here are also formed by laser ablation similarly to the formation of the nozzle member. More specifically, the evaporation chamber of the selected structure places a lithographic mask on top of a polymer layer, such as a polymer tape, and then laser beam ablate areas of the polymer layer not covered by the lithographic mask. Can be formed. In practice, the polymer layers, including the evaporation chamber, can be combined and formed near a single piece of the nozzle member, or integrally formed.

FIG. 10 is a cross-sectional side view showing a nozzle member 96 having a laser-removed orifice formed in one polymer layer and having an ink conduit, and an evaporation chamber 98. As shown in FIG. 10, the formation of the evaporation chamber as an integral part of the nozzle member by laser ablation has a substantially flat bottom if the optical energy density of the incident laser beam is constant over the entire ablated region. It is significantly facilitated by the properties of laser ablation which form a recessed chamber. The depth of such a chamber is determined by the number of laser irradiations and the energy density of each irradiation. If a resistor, such as resistor 70 of FIG. 10, is formed on the nozzle member itself, the substrate 28 may also be removed.

FIG. 11 shows the back surface of the nozzle member 96 of FIG. 10 before the base is mounted thereon. Evaporation chamber 98, ink conduit 99, and ink manifold 100 are formed over a portion of the thickness of nozzle member 96, while an orifice, such as orifice 17 in FIG. 2, extends over the entire thickness of the nozzle member. Is formed. Ink from the ink reservoir is a substrate (not shown) attached to the back surface of the nozzle member 96.
Flow around the sides of the ink and then the ink manifold 10
0, and then flows into the ink conduit 99 and the evaporation chamber 98. The window 22 used for joining as described above
And 24 are also shown. Multiple lithographic masks may be utilized to form the pattern of orifices and ink passages within a single nozzle member 96.

FIG. 12 illustrates a method of forming either the TAB head assembly 14 embodiment of FIG. 3 or the TAB head assembly formed using the nozzle member 96 of FIG. The first material is Kapton ™ or Upilex ™ type polymer tape 104,
Tape 104 may be any suitable polymer film that can be used in the procedure described below. Such a thin film may be made of Teflon, polyimide, polymethylmethacrylate, polycarbonate, polyester, polyamide, polyethylene terephthalate, or a mixture thereof.

Tape 104 is typically formed as a long strip on reel 105. Sprocket holes 106 along the sides of tape 104 are utilized to transport tape 104 accurately and safely. Alternatively, the sprocket hole 106 may be omitted, and another type of fixing means may be provided for transfer.

In the preferred embodiment, tape 104 is preloaded with conductive copper traces 36 formed using conventional photolithographic and metal deposition processes, as shown in FIG. The particular pattern of conductive traces will depend on the desired method for delivering electrical signals to the electrodes formed on the silicon die that are subsequently attached to tape 104.

In the preferred process, the tape 104 is sent to a laser processing chamber where it is F2, ArF, KrCL or XeCL.
Laser ablation 110 using laser radiation 110 generated by an excimer laser 112 in the form of a pattern in a pattern defined by one or more masks 108.
Laser radiation utilizing masking is indicated by arrow 114.

In the preferred embodiment, such a mask 1
Reference numeral 08 denotes, for example, the orifice pattern forming mask 108.
In the case of, the plurality of orifices are surrounded, and in the case of the evaporation chamber forming mask 108, the plurality of evaporation chambers are surrounded, and all the shapes to be cut off with respect to the region where the tape 104 extends are determined. Alternatively, patterns such as orifice patterns, evaporation chamber patterns or other patterns may be juxtaposed on a common mask substrate that is significantly larger than the laser beam. Next, such a pattern is continuously irradiated with a laser beam. The masking material used in such masks is preferably a material that is highly reflective at the laser wavelength, consisting of, for example, a multilayer dielectric or a metal such as aluminum.

The orifice pattern defined by the mask or masks 108 is shown schematically in FIG. Multiple masks 108 may be used to form the stepped orifice taper as shown in FIGS.

In one embodiment, the separate mask 108 is shown in FIG.
And the patterns of windows 22, 24 shown in FIG. 3 are established, but in the preferred embodiment, tape 104 is shown in FIG.
The windows 22 and 24 are formed by using the conventional photolithographic method before the process shown in FIG. In the embodiment of FIGS. 10 and 11 in which the nozzle member also includes an evaporation chamber, a single or multiple masks 108 are used to form the orifice and are formed over a portion of the thickness of tape 104. , Another mask 108 and laser energy density would be used to form the ink lines and manifolds. The laser system for this purpose further includes a beam transmission optical system, an alignment optical system, a highly accurate and high speed mask reciprocating system, and a processing chamber including a mechanism for processing and positioning the tape 104. It has and. In the preferred embodiment, the laser system uses a projection mask structure, which includes mask 108 and tape 104.
A precision lens 115 sandwiched between and projects the excimer laser beam on the tape 104 with an image of the pattern determined on the mask 108. The masked laser radiation exiting lens 115 is indicated by arrow 116. Such a projection type mask structure has an advantage that the accuracy of the orifice size is high because the mask is physically separated from the nozzle member. In the cutting process, soot is naturally generated, discharged, and moved about 1 cm from the nozzle member to be cut. If the mask is in contact with or in the vicinity of the nozzle member, soot formation on the mask tends to distort the excised shape and reduce dimensional accuracy. In the preferred embodiment, the projection lens is 2 cm from the nozzle member to be ablated.
Since they are separated by the distance described above, the formation of soot on the nozzle member or the mask is avoided.

The cutting method is known as a method for producing a structure having a tapered wall. That is, the taper is a tapered structure in which the diameter of the orifice is large on the surface on which the laser enters and is small on the exit surface of the laser. For energy densities less than 2 Joules per square centimeter, the taper angle varies significantly with the density of the optical energy incident on the nozzle member. If the energy density is not controlled, the taper angle of the formed orifice will change significantly, resulting in a large change in exit orifice diameter. Such changes undesirably change the volume and velocity of the ejected ink drops, which in turn reduces print performance. In the preferred embodiment, the light energy of the ablating laser beam is accurately monitored and controlled to achieve a constant taper angle and a highly reproducible exit diameter. In addition to the printing performance benefits of a constant orifice exit diameter, the taper also benefits the operation of the orifice. This is because the taper has the function of increasing the ejection speed, providing a more precisely focused ink ejection, and providing other advantages. The taper angle may range from 5 to 15 degrees with respect to the axis of the orifice. The process of the preferred embodiment described herein allows for rapid and accurate manufacture without the need to rock the laser beam relative to the nozzle member. This step provides an accurate exit diameter even when the laser beam is incident on the entrance surface of the nozzle member rather than the exit surface.

After the laser ablation step, the polymer tape 104 is advanced one step and the process is repeated. This is called a step and repeat process. The total time required to form a single pattern on the tape 104 can be several seconds. As mentioned above, a single mask pattern can surround the extended group of ablated shapes to reduce processing time per nozzle member.

The laser ablation process has unique advantages over other types of laser cutting methods that form precision orifices, evaporation chambers and ink lines. In the laser ablation scheme, intense, short pulses of ultraviolet light are absorbed within less than about 1 micrometer of the surface of a thin surface layer of material. Preferred pulse energies are greater than or equal to about 100 millijoules per square cm, and pulse durations are less than about 1 microsecond. In these conditions, intense UV light optically breaks the chemical bonds of the material. Furthermore, the absorbed UV energy is concentrated in a small volume of material so as to rapidly heat the decomposed debris and release these debris from the surface of the material. These steps occur so quickly that there is no time for heat to transfer to the surrounding material. as a result,
The surrounding area is not melted or otherwise damaged and the contours of the ablated structure can accurately reproduce the shape of the incident beam with an accuracy of about 1 micrometer. Moreover, laser ablation can also form a chamber with a substantially flat bottom surface that forms a grooved plane in the layer, provided that the light energy is constant over the entire area to be ablated. The depth of such a chamber is determined by the number of laser irradiations and the energy density of each irradiation.

The laser ablation process also has many advantages over conventional lithographic electroforming processes for forming nozzle members for inkjet printheads. For example, laser ablation processes are generally cheaper and easier than conventional lithographic electroforming processes. Further, by employing a laser ablation process, the polymeric nozzle member has a significantly larger size (ie, a nozzle member having a larger surface area).
With this, it becomes possible to manufacture a member having a nozzle shape that cannot be realized by the conventional electroforming process. More specifically, uniquely shaped nozzles can be produced by controlling the exposure intensity, or by performing multiple exposures to redirect the laser beam between each exposure. . Examples of various nozzle geometries are assigned to the assignee of the present application and are hereby incorporated by reference in copending application Ser. No. 07 / 658,726 "at least one stepped opening extending through a polymeric material. Method of photoablation and nozzle plate with stepped openings ". Further, it is possible to form a nozzle having a precise shape without performing the strict process control necessary for the electroforming process.

Another advantage of forming the nozzle member by laser ablation of the polymer material is that the orifice or nozzle can be easily manufactured with a larger nozzle length (L) and nozzle diameter (D) ratio than previously. In the preferred embodiment, the L / D ratio is 1 or greater. One of the advantages of extending the nozzle length compared to its diameter is that the orifice-resistor positioning in the evaporation chamber does not have to be very precise.

In use, laser ablated polymer nozzle members for ink jet printers exhibit superior properties to conventional electroformed orifice plates. For example, laser ablated polymer nozzle members are highly resistant to corrosion by aqueous inks and are essentially anaerobic. Furthermore, the relatively low modulus of elasticity of laser ablated polymer nozzle members reduces the tendency for built-in stress between the nozzle member and the underlying substrate or barrier layer to cause delamination of the nozzle member and barrier layer. . Further, the laser ablated polymer nozzle member can be easily attached to or formed integrally with the polymer substrate.

Although an excimer laser is used in the preferred embodiment, another ultraviolet light source with approximately the same light wavelength and energy density may be used to perform the ablation process. The wavelength of such an ultraviolet light source is preferably 150 nm to 400 nm in order to enhance the absorption of the tape to be cut off. Furthermore, to achieve a rapid release of the ablated material with little heating of the surrounding ablated material, the energy density is greater than about 100 millijoules per square cm and the pulse length is less than about 1 microsecond. Would be necessary.

As will be understood by experts in this field,
Many other processes for forming patterns on tape 104 can also be used. These other steps include chemical etching, stamping, reactive ion etching,
There are methods such as casting or forging of a pattern formed by ion beam milling and light.

The next stage in the process is the cleaning stage, where the laser ablated portion of tape 104 is placed at cleaning station 117. Cleaning station 117
Dust from laser ablation is removed by standard industrial means.

The tape 104 is then sent to the next station. This is an optical alignment station 118 incorporated into a conventional automatic TAB bonder such as the internal lead bonder commercially available from Shinkawa Corporation under model number IL-20. The splicing device has the same method and / or as used to produce the orifice.
The alignment (target) pattern on the nozzle member manufactured in step and the target pattern on the substrate manufactured in the same method and / or step used to manufacture the resistor are pre-programmed. In the preferred embodiment, the material of the nozzle member is translucent so that the target pattern on the substrate can be viewed through the nozzle member. The bonder then automatically positions the silicon die 120 with respect to the nozzle member so as to align the two target patterns. Shinkawa's TAB joining device has such an aligning function. Such self-alignment of the target pattern of the nozzle member and the target pattern of the substrate not only allows for precise alignment of the orifice and resistor, but also allows the electrodes on the die 120 to end the conductive traces formed on the tape 104. It can be aligned with the department. This is because the traces and orifices are aligned within the tape 104 and the substrate electrodes and heating resistors are aligned within the substrate. Therefore, when the two target patterns are aligned, all the patterns on the tape 104 and silicon die 120 are aligned with each other.

As described above, the alignment of the silicon die 120 with respect to the tape 104 is automatically performed only by using a commercially available device. Such a centering function is obtained by integrally forming the conduction trace and the nozzle member. Such integration not only reduces the cost of assembling the printhead, but also reduces the cost of material for the printhead.

The automatic TAB bonder then utilizes an interlocking bond scheme to press the ends of the conductive traces down through the window formed in tape 104 and to the associated substrate electrode. The bonding apparatus then heats and welds the ends of the traces to the associated electrodes, for example, by thermal compression bonding. A side view of one embodiment of the resulting structure is shown in FIG. Other types of bonding methods such as ultrasonic bonding, conductive epoxies, solder paste or other known means may be utilized.

The tape 104 is then advanced to the heating and compression station 122. As described above in connection with FIGS. 6 and 7, there is an adhesion layer 84 on the top surface of the barrier layer 30 formed on the silicon substrate. After the bonding step described above, the silicon die 120 is pressed against the tape 104 and heated to cure the adhesive layer 84 and the die 120 is physically bonded to the tape 104.

After that, the tape 104 is advanced,
If necessary, it is wound on the take-up reel 124. Tape 1
04 can be later cut to separate the individual TAB printhead assemblies from each other.

The resulting TAB head assembly is then placed on the print cartridge 10 to secure the nozzle member to the print cartridge.
Adhesive seals are formed to seal the perimeter of the substrate between the nozzle member and the ink reservoir from ink leakage and enclose traces extending from the substrate to isolate the traces from the ink.

The peripheral points of the flexible TAB head assembly are then secured to the plastic print cartridge 10 by a conventional fusion-type bonding process, and the polymer tape 18 is attached to the print cartridge 10 as shown in FIG. It is made to be almost flush with the surface.

The foregoing has described the principles, preferred embodiments, and modes of operation of the present invention. However, the invention is not limited to the particular embodiments described above. For example, the invention described above can be used in combination with a non-thermal ink jet printer, and can also be used in a thermal ink jet printer. It will therefore be appreciated that many modifications can be made by the expert in these embodiments without departing from the scope of the invention as set forth in the following claims.

[0057]

As described above, the present invention has the following advantages. (1) The manufacturing process of the orifice is so rapid that heat does not conduct to the surrounding material, so that the surrounding area is not melted or otherwise damaged and the ablated structure has a contour of about 1 The shape of the incident light beam can be accurately reproduced with the accuracy of micrometers. Moreover, laser ablation can also form a chamber with a substantially flat bottom surface that forms a grooved plane in the layer, provided that the light energy is constant over the entire area to be ablated. (2) Generally cheaper than the conventional lithographic electroforming process,
It's easy. Furthermore, by adopting a laser ablation process, the polymer nozzle member has a significantly larger size,
It becomes possible to manufacture it as a member having a nozzle shape that cannot be realized by the conventional electroforming process. Further, it is possible to form a nozzle having a precise shape without performing the strict process control necessary for the electroforming process. (3) By cutting the polymer material with a laser, an orifice or nozzle can be easily manufactured with a larger nozzle length (L) and nozzle diameter (D) ratio than before, and as a result, positioning of the orifice-resistor in the evaporation chamber. Although not so strict. (4) The laser ablated polymer nozzle member is highly resistant to corrosion by water-based ink and is basically anaerobic. Furthermore, the relatively low modulus of elasticity of laser ablated polymer nozzle members reduces the tendency for built-in stress between the nozzle member and the underlying substrate or barrier layer to cause delamination of the nozzle member and barrier layer. . Further, the laser ablated polymer nozzle member can be easily attached to or formed integrally with the polymer substrate.

[Brief description of drawings]

FIG. 1 is a perspective view of an ink cartridge according to an embodiment of the present invention.

FIG. 2 is a front view of a nozzle member.

FIG. 3 is a rear view of the nozzle member with a substrate on which a heating element is mounted attached.

4 is a cross-sectional view taken along the line AA of FIG.

5 is a cross-sectional view taken along the line BB of FIG.

FIG. 6 is a perspective view of a bottom surface side of a substrate on which a heating element is mounted.

FIG. 7 is an enlarged perspective view of an orifice portion of the print head, showing a main portion cut away.

8 is a cross-sectional view taken along the line DD of FIG.

9 is a corresponding cross-sectional view of FIG. 8 showing an embodiment in which a heating element is arranged on a nozzle member.

FIG. 10 is a corresponding cross-sectional view of FIG. 8 showing still another embodiment of the nozzle member.

FIG. 11 is a perspective view showing the back surface side of the tape on which an ink passage and an evaporation chamber are formed.

FIG. 12 is a perspective view showing a manufacturing process of the print head.

[Explanation of symbols]

 10: Ink cartridge 12: Ink reservoir 14: Print head 17: Orifice 18: Flexible polymer tape 20: Contact pad 22, 24: Window 28: Substrate 30: Barrier layer 32: Ink channel 36: Conductive trace 40, 74 : Electrode 70: Heating resistor 78: Demultiplexer 90: Adhesive seal 92, 94: Evaporating chamber

Front Page Continuation (72) Inventor Sai Tai Lam, Pleasant Kamp Drive, 3861, California, USA 3861 (72) Inventor, Paul H. Mackleland, Monmouth Cover Road, Oregon, USA 20225 (72) Inventor, William J. Lloyd Pigeon Peau Box, Michigan, USA 843 (72) Inventor Winslope Dee Childers San Diego Occult Court, California 17015, California

Claims (2)

[Claims] 1. An ink jet printer comprising a nozzle member made of an insulating material and having an upper surface facing a recording medium, the nozzle member having a plurality of orifices and conducting wires. 2. An ink jet device comprising: a step of forming a plurality of orifices of a nozzle member on a flexible insulating tape including a conductive wire; and a step of positioning a heating element in the vicinity of each orifice. Method for molding print head of printer.