TWI478818B - Molded ink manifold with polymer coating - Google Patents

Description

Molded ink manifold with polymer coating

This invention relates to printers, and more particularly to inkjet printers.

Applicants have developed a wide range of printers that use a pagewidth printhead instead of a conventional reciprocating printhead design. The page width design increases the print rate because the print head does not have to traverse the page to rewind to deposit a list of images. The page width print head simply deposits ink on the medium because it moves at high speed. These printheads have been able to perform full color 1600 dpi printing at a rate of about 60 pages per minute, which is not available with conventional inkjet printers.

Printing at this rate will quickly consume ink, which can cause problems with enough ink to supply the print head. Not only is the flow rate high, but the page width printhead must distribute ink along its entire length as compared to feeding the ink to a relatively small reciprocating print head.

A circuit-integrated printhead is typically attached to the ink manifold using a viscous film. It is desirable to optimize this attachment process to provide a printhead assembly that prevents minimal ink leakage.

In a first aspect, the present invention provides a printhead assembly comprising: a molded ink manifold having a plurality of ink outlets defined within a manifold bonding surface;

One or more print head integrated circuits, each of the print head integrated circuits having one or more ink inlets defined within the print head bond surface;

An adhesive film sandwiched between the manifold bonding surface and the one or more printhead bonding surfaces, the film having a plurality of ink supply apertures defined therein, each ink supply aperture being aligned with the ink outlet and the ink inlet,

Wherein at least the manifold bonding surface comprises a polymeric coating that plugs a gap within the molded ink manifold.

The first aspect of the printhead assembly advantageously minimizes ink leakage by plugging the micromolded slits within the molded ink manifold.

Optionally, the gaps are useless gaps created by the molding process used to fabricate the ink manifold. Even with high tolerance molding tools, some useless microscopic gaps are often inevitable.

Optionally, the manifold bonding surface is substantially flat because the polymer coating plugs the gaps. The flat manifold bonding surface advantageously minimizes ink leakage through the molding gaps within the bonding surface.

Optionally, the molded ink manifold is coated with the polymer coating as a whole. Therefore, all the slits in the molded ink manifold (including the internal slits between the respective ink supply flow paths) can be plugged.

Optionally, the polymeric coating is selected from the group of polymers consisting of polyimide, polyester, epoxy, polytetrafluoroethylene, decane, and liquid crystal polymers. The polymer coating is typically different than the polymer used to form the molded ink manifold.

Optionally, the polymeric coating comprises an inorganic or organic additive for providing one or more of the following characteristics, including wettability, adhesive strength, and scratch resistance. Thus, in addition to the primary function of the polymeric coating to plug the gap, the polymeric coating can advantageously have a variety of functions, such as the ruthenium particles can be incorporated into the polymeric coating to improve durability, scratch resistance, And wettability, etc.

Optionally, the polymer coating is applied to the molded ink manifold by dipping, spray coating, or spin coating.

Optionally, the plurality of print head integrated circuits are contiguously end to end along the longitudinal extent of the ink supply manifold. The present applicant has described this configuration for manufacturing a printhead in the cross-reference patent and patent application incorporated by reference.

Optionally, the complex print head integrated circuit defines a pagewidth printhead.

Optionally, an ink supply channel extending longitudinally along the printhead bonding surface defines a plurality of ink inlets. Optionally, the plurality of ink supply apertures are aligned with an ink supply channel, each of the plurality of ink supply apertures being longitudinally spaced along the ink supply channel.

In a second aspect, a page width printer is provided comprising a stationary print head assembly as described above.

In a third aspect, a molded ink manifold for an inkjet printhead having a manifold bonding surface for attaching one or more printhead integrated circuits is provided, Each of the print head integration circuits receives ink from one or more ink outlets defined in the bonding surface, wherein at least the manifold bonding surface comprises a polymer coating that is plugged A gap in the molded ink manifold.

In a fourth aspect, a method of making a printhead assembly is provided, the method comprising the steps of:

(a) providing a molded ink manifold having a manifold bonding surface for attaching one or more printhead integrated circuits, the bonding surface having a plurality of ink outlets defined therein, The bonding surface has a plurality of slits created by a molding process;

(b) coating at least the manifold bonding surface with a polymer coating, thereby plugging the gaps; and

(c) bonding one or more print head integrated circuits to the manifold bonding surface.

Optionally, the manifold bonding surface is substantially flat because the polymer coating plugs the gaps.

Optionally, the coating step coats the molded ink manifold as a whole with the polymer coating.

Optionally, the polymeric coating plugs an internal gap defined between each of the ink supply channels within the ink manifold.

Optionally, the polymeric coating is selected from the group of polymers consisting of polyimide, polyester, epoxy, polytetrafluoroethylene, decane, and liquid crystal polymers.

Optionally, the polymeric coating comprises an inorganic or organic additive for providing one or more of the following characteristics, including wettability, adhesive strength, and scratch resistance.

Optionally, the coating step comprises: dipping, spray coating, or spin coating.

Optionally, the coating step utilizes a polymer coating solution comprising an organic solvent.

Optionally, the coating step is controlled to provide a polymeric coating having a predetermined thickness. The thickness of the polymer coating can be controlled by parameters such as the immersion time and the viscosity of the polymer.

Optionally, the combining step comprises:

Bonding an adhesive film to the manifold interface; and

The print head integrated circuit is bonded to the adhesive film.

Optionally, the adhesive film is a laminated film comprising a central polymeric film sandwiched between the first and second adhesive layers.

In a fifth aspect, a combined printhead assembly is provided, comprising one or more printhead integrated circuits coupled to a manifold bond surface of a molded ink supply manifold, wherein the The tube bonding surface comprises a polymeric coating that plugs a plurality of slits within the molded ink manifold.

summary

Fig. 1 shows a printer 2 embodying the present invention. The main body 4 of the printer is supported on the rear media feed tray 14, and on the front pivoting surface 6. Figure 1 shows the pivoting face 6 closed so that the display screen 8 is in its upright viewing position. The control button 10 extends from the side of the screen 8 to facilitate operator input while viewing the screen. For printing, a single sheet is withdrawn from the stack 12 of feed trays 14 and fed through a printhead (hidden in the printer). The printed sheet 16 is conveyed through the printed media exit slot 18.

Figure 2 shows the pivoting front 6 open to reveal the interior of the printer 2. The front of the printer is opened, exposing the print head 匣 96 set inside. The print head 匣 96 is fixedly positioned by the 匣 engaging cam 20. The cam 20 pushes the print head 匣 96 downward to ensure that the ink coupler (described later) is fully engaged and the print head integrated circuits (ICs) (described later) are correctly positioned adjacent to the paper feed path. The cam 20 is manually actuated by the release lever 24. The front 6 cannot be closed, and therefore the printer cannot operate until the release lever 24 is pushed down to fully engage the cam. The pivoting face 6 is closed to engage the printer contact 22 with the splicing point 104.

Figure 3 shows that the pivoting face 6 of the printer 2 is open and the printhead 匣 96 is removed. Since the pivoting face 6 is inclined forward, the user can pull the release lever 24 upward to release the engagement of the cam 20. This allows the handle 26 on the catch 96 to be pulled up. The upstream ink coupler 112A and the downstream ink coupler 112B are detached from the catheter 142 of the printer, as will be described in more detail below. Perform the reverse steps to install unused new ones. The new raft is shipped and sold in an unfilled state, so in order to prepare the printer for printing, the active jet system (described below) uses a downstream pump to fill the enamel and print head with ink.

In Figure 4, the outer casing of the printer 2 has been removed to reveal its interior. The large ink tank 60 has four separate reservoirs for all four different inks. The ink tank 60 itself is a replaceable cassette that is coupled upstream of the printer of the switching valve 66 (see Figure 6). There is also a sump 92 for pump 62 to draw ink from 匣96. The printer jet system is described in detail with reference to FIG. Briefly, ink flows from tank 60 through upstream ink line 84 to switching valve 66 and onto printer tube 142. As shown in FIG. 5, when a crucible 96 is provided, the pump 62 (driven by Marlon 196) can draw ink into the liquid crystal polymer (LCP) module 64 (see FIG. 6, FIG. 17-20), so that the print head The integrated circuit 68 (again with reference to Fig. 6, Fig. 17-20) is filled by capillary action. The ink extracted by the pump 62 is fed to the sump 92, which is housed in the ink tank 60.

Because of the number of contacts used, all of the connector forces between the contact 104 and the printer contacts 22 are relatively high. In the illustrated embodiment, the total contact force is 45 Newtons, which is sufficient to deflect the 匣 deflection. Referring briefly to Figure 30, the internal construction of the chassis module 100 is shown. The bearing surface 28 shown in Figure 3 is shown schematically in Figure 30. The compression load acting on the splicing point 104 of the printer joint is represented by an arrow, and likewise the reaction force at the support surface 28 is represented by an arrow. To maintain the structural integrity of the crucible 96, the chassis module 100 has a structural member 30 that extends in the plane of the connector force. In order to maintain the reaction force acting in the plane of the connector force, the chassis also has contact ribs 32 that press against the support surface 28. This keeps the load on the structural member 30 fully compressed to maximize the stiffness of the crucible and minimize any flexibility.

Print engine pipeline

The print engine pipeline is a reference for the printer to process print data that is received from an external source and output to the printhead for printing. The printing engine pipeline is described in detail in the USSN 11/014,769 (RRC 001 US) filed on Dec. 20, 2004, which is incorporated herein by reference.

Jet system

Conventional printers rely on the construction and components of the printheads, cartridges, and ink lines to avoid jet problems. Some common jet problems are unfilled or dry nozzles, bubble products of the exhaust, and color mixing due to cross-contamination. The optimized design of the printer components to avoid these problems is a passive method of jet control. In general, the nozzle actuator itself is the only active component for improving these drawbacks, but this is often insufficient and/or wasted a lot of ink when attempting to improve these problems. This problem is more severe in page width printheads because of the length and complexity of the ink conduits that are supplied to the printhead integrated circuit.

The applicant has solved this problem by developing an active jet system for printers. A number of such systems are described in detail in USSN 11/677,049, the disclosure of which is hereby incorporated by reference. Figure 6 shows one of the single pump embodiments of an active flow system that is suitable for use with the printheads described herein.

The flow-through structure shown in Figure 6 is a single ink line for only one color. The color printer has a separate line (and of course an isolated ink tank 60) for each color of ink. As shown in FIG. 6, this configuration has a single pump 62 downstream of the LCP module 64 and an on-off valve 66 upstream of the LCP module 64. The LCP module supports the print head integrated circuit 68 by a viscous integrated circuit attachment film 174 (see Fig. 25). Whenever the power to the printer is turned off, the on-off valve 66 isolates the ink in the ink tank 60 from the printhead integrated circuit 68. This prevents any color mixing at the print head integrated circuit 68 from reaching the ink tank 60 during non-action. These issues are discussed in more detail in the cross-referenced USSN 11/677049 (our case number is SBF 006US).

The ink tank 60 has a discharge bubble point pressure regulator 72 for maintaining a relatively constant hydrostatic negative pressure within the ink at the nozzle. The bubble point pressure regulator in the ink reservoir is more widely described in co-pending USSN 11/640355 (our case number RMC007US), which is hereby incorporated by reference. For the purposes of this description, however, regulator 72 is shown as a bubble outlet 74 that is immersed in the ink of canister 60 and vented to the atmosphere by a sealed conduit 76 that extends to air inlet 78. When the print head integrated circuit 68 consumes ink, the pressure within the can 60 drops until the pressure differential at the bubble outlet 74 draws air into the can. This air forms bubbles in the ink which rise to the head space of the can. This pressure differential is the bubble point pressure and will depend on the diameter (or smallest dimension) of the bubble outlet 74 and the Laplace pressure of the ink meniscus at the outlet. This Laplace pressure will prevent air from entering.

The bubble point regulator uses the bubble point pressure to keep the hydrostatic pressure at the outlet substantially constant (slight fluctuations when the convex meniscus of the air forms bubbles and rises to the head space inside the ink tank). This bubble point pressure is required to generate bubbles at the bubble outlet 74 immersed in the ink. If the hydrostatic pressure at the outlet is at the bubble point, the hydrostatic pressure profile within the ink tank is also known regardless of how much ink has been consumed in the tank. When the ink level drops to the exit, the pressure at the surface of the ink in the can decreases toward the bubble point pressure. Of course, once the outlet 74 is exposed, the head space is connected to the atmosphere and the negative pressure disappears. The ink tank should be refilled or replaced (if the ink tank is in the 匣 type) before the ink level reaches the bubble exit 74.

The ink tank 60 can be a refillable fixed reservoir, a replaceable crucible, or a refillable crucible (as disclosed in RRC001 US incorporated by reference). In order to prevent particulate deposits, the outlet 80 of the ink tank 60 has a thick filter 82. The system also uses a thin filter at the coupling to the print head cartridge. Because the filter has a limited life, it is particularly convenient for the user to replace the filter by simply replacing the ink cartridge or the print head cartridge. If the filter is a separate consumable item, it depends on the user's diligence to replace it regularly.

When the bubble outlet 74 is at the bubble point pressure and the switching valve 66 is open, the hydrostatic pressure at the nozzle is also constant and less than atmospheric pressure. However, if the switching valve 66 has been closed for a period of time, air bubbles from the exhaust may be formed in the LCP module 64 or the printhead IC 68, which changes the pressure at the nozzle. Similarly, the pressure in the ink line 84 downstream of the switching valve 66 can be varied due to the expansion and contraction of the bubble due to daily temperature changes. Similarly, during non-action, the pressure within the ink tank changes due to dissolved gases that escape from the solution.

The downstream ink line 86 from the LCP 64 to the pump 62 can include an ink sensor 88 that is coupled to an electronic controller 90 for the pump. The sensor 88 senses the presence of ink in the downstream ink line 86. In another embodiment, the system can be provided with an inductor 88 and the pump 62 can be constructed to operate for each different job for a suitable period of time. This may adversely affect operating costs by increasing ink waste.

Pump 62 is fed into tank sump 92 (when pumping in the forward direction). The sump 92 is physically positioned within the printer at a lower position than the printhead IC 68. This allows the ink column within the downstream ink line 86 to be suspended at the LCP 64 during standby, thereby creating a hydrostatic negative pressure at the printhead LCP 64. The negative pressure at the nozzle draws the ink meniscus inward and inhibits pigment mixing. Of course, the peristaltic pump 62 needs to be stopped in an open state to provide fluid communication between the LCP 64 and the ink outlets within the sump 92.

During non-actuation, there is a pressure differential between the ink lines of different pigments. Furthermore, paper dust or other particulates on the nozzle plate will draw ink from one nozzle capillary to the other. By the slight differential pressure between each ink line, pigment mixing occurs when the printer is not operating. The on-off valve 66 isolates the ink tank 60 from the nozzles of the printhead IC 68 to prevent the mixing of the pigments from extending up to the ink tank 60. Once the ink in the ink tank is contaminated with different pigments, it cannot be recovered and must be replaced.

The cover 94 is a printhead maintenance station that seals the nozzle during standby to avoid dehydration of the printhead IC 68, and the cover 94 shields the nozzle plate from paper dust and other particulates. The cover 94 is also constructed to wipe the nozzle plate to remove dried ink and other contaminants. When the ink solvent (usually water) evaporates, the print head IC 68 dehydrates and increases the viscosity of the ink. If the ink viscosity is too high, it is difficult for the ink jet actuator to eject ink droplets. In the event of a leak in the cover seal, the dewatered nozzle is a problem when the printer is turned off after the power is turned off or during standby.

The above problems are not uncommon during the operational life of the printer, and they can be effectively improved by the relatively simple jet structure shown in FIG. The jet structure also allows the user to initially fill the printer, stop filling the printer before removing the jet structure, or restore the printer to a known print ready state using a simple troubleshooting protocol. . An example of several of these conditions is described in detail in the above-referenced USSN 11/677049 (our case number SBF006US).

Print head 匣

The print head 96 is shown in Figures 7-16A. Figure 7 shows the 匣96 in its combination and intact morphology. The block of the crucible is wrapped between the crucible base 100 and the base cover 102. The window of the base 100 exposes the splicing points 104 that receive material from the print engine controller in the printer.

Figures 8 and 9 show that the 匣 96 is snapped onto the protective cover 98. The protective cover 98 prevents damage contact to the electrical contacts 104 and the printhead IC 68 (see Figure 10). The user can grasp the top of the cymbal 96 and remove the protective cover 98 before installing it into the printer.

Figure 10 shows the underside and back of the printhead 96 (relative to the paper feed direction). The printhead contact 104 is a conductive pad on the flexible printed circuit board 108 that surrounds the curved support surface (discussed below in the description of the LCP module) to the print head A row of wires on one side of IC 68 is bonded 110. The other side of the printhead IC 68 is a paper mask 106 to prevent direct contact with the media substrate.

Figure 11 shows the underside and front side of the print head cartridge 96. The front side of the crucible has two ink couplers 112A, 112B at the two ends, each ink coupler having four helium valves 114. When the crucible is disposed within the printer, the ink couplers 112A, 112B engage a mating ink supply interface (described in more detail below). The ink supply interface has a printer conduit 142 that engages and opens the helium valve 114. One of the ink couplers 112A is the upstream ink coupler, and the other is the downstream coupler 112B. The upstream coupler 112A establishes fluid communication between the printhead IC 68 and the ink supply source 60 (see Figure 6), while the downstream coupler 112B is coupled to the sump 92 (see Figure 6).

Figure 12 shows various views of the print head cartridge 96. The plan view of 匣96 also shows the position of the cross-sectional view shown in Figures 14, 15, and 16.

FIG. 13 is an exploded perspective view of the crucible 96. The LCP module 64 is attached to the underside of the crucible base 100. The flexible printed circuit board 108 is attached to the underside of the LCP module 64 and surrounds one side to expose the print head contacts 104. An inlet manifold and filter 116 and outlet manifold 118 are attached to the top of the base 100. The inlet manifold and filter 116 are coupled to the LCP inlet 122 by a resilient connector 120, and similarly, the LCP outlet 124 is coupled to the outlet manifold 118 by another set of resilient connectors 120. The base cover 102 covers the inlet and outlet manifolds within the base 100 from the top, and a removable protective sleeve 98 snaps over the bottom to protect the contacts 104 and the printhead IC (see Figure 11).

Inlet and filter manifold

14 is an enlarged view along line 14-14 of FIG. 12 showing the fluid path through one of the helium valves 114 to the LCP module 64 of the upstream coupler 112A. The helium valve 114 has an elastomeric sleeve 126 that is biased into a state of sealing engagement with the fixed valve member 128. The printer tube 142 (see FIG. 16) opens the helium valve 114 by compressing the elastomeric sleeve 126 away from the fixed valve member 128 and allowing ink to flow up the top of the inlet and filter manifold 116 to the top channel 138. The top channel 138 is conductive to the upstream filter chamber 132. The upstream filter chamber 132 has a wall portion defined by the filter membrane 130. The ink passes through the filter membrane 130 into the downstream filter chamber 134 and out to the LCP inlet 122. The filtered ink is fed from the LCP inlet 122 along the LCP main channel 136 to a printhead IC (not shown).

Specific construction features and advantages of the inlet and filter manifold 116 will now be described with reference to FIG. The exploded perspective view of Figure 15 is best suited to illustrate the compact design of the inlet and filter manifold 116. There are many aspects of design to help achieve this pocket form. First, the helium valves are placed together, which is achieved by the conventional structure of the self-sealing ink valve. Previous designs also used an elastic member to bias into sealing engagement with the stationary member, but the resilient member is not in a solid shape (the ink flows around it) or the diaphragm (the ink flows through the diaphragm).

In the 匣 coupler, the 匣 valve is easily opened automatically during installation, which is most easily and inexpensively provided by the coupler. In the coupler, one valve has an elastic member that is engaged by the rigid member on the other valve. If the elastic member is in the form of a diaphragm, it often abuts against the central rigid member under tension. This provides an efficient seal and requires relatively low tolerances. However, this also requires a wide surrounding installation of the elastic element. The width of the elastomer is a compromise between the desired coupling force, the integrity of the seal, and the material properties of the elastomer used.

As clearly shown in Fig. 16, the helium valve 114 of the present invention uses an elastic sleeve 126 that is pressed against the fixed valve member 128 under residual pressure to seal. When the crucible is disposed within the printer and the catheter end 148 of the printer valve 142 further compresses the sleeve 126, the valve 114 is opened. The collar 146 releases the seal of the fixed valve member 128 to connect the LCP 64 into the printer jet system (see Figure 6) via the upstream and downstream ink couplers 112A, 112B. The side walls of the sleeve are constructed to protrude outwardly because the inward deformation causes a flow barrier. As shown in Figure 16, the sleeve 126 has a line of relatively fragile portions around the midsection thereof to facilitate and guide the buckling step. This reduction will force the force required to engage the printer and ensure that the sleeve is deflected outward.

When the coupler is constructed to uncouple the printer from the printer, there is no dripping. When pulled from the printer phase, the elastic sleeve 126 pushes the collar 146 to press against the fixed valve member 128 to seal it. Once the sleeve 126 has sealed the valve member 128 (by thereby sealing the heel side of the coupler), the seal collar 146 and the weir rise together, which releases the seal of the collar 146 and the catheter tip 148. When the seal is broken, the gap between the collar and the end 148 of the conduit forms an ink meniscus. The shape of the end of the fixed valve member 128 guides the meniscus toward the middle of its bottom surface rather than forming a point. In the middle of the circular bottom of the fixed valve member 128, the meniscus is forced to separate from the now almost horizontal bottom surface. In order to obtain the lowest possible energy state, the surface tension drives the meniscus out of the fixed valve member 128. The bias that minimizes the surface area of the meniscus is strong, so the separation is complete and there is little, if any, ink remaining on the helium valve 114. Any residual ink is not sufficient to form droplets that will drip or stain before discarding the crucible.

When a new cassette is placed in the printer, air within the conduit 150 is entrained into the ink stream 152 and absorbed by the crucible. In view of this, the inlet manifold and filter assembly have a high bubble tolerance. Referring back to Figure 15, the ink flows through the top of the fixed valve member 128 and into the top channel 138. As the highest point of the inlet manifold 116, the top channel captures (collects) bubbles. However, the bubbles will still flow into the filter inlet 158. In this case, the filter assembly itself can tolerate air bubbles.

The bubbles on the upstream side of the filter membrane 130 affect the flow rate, and the bubbles effectively reduce the wetted surface area on the dirty side of the filter membrane 130. The filter membrane has a long rectangular shape so that even a significant amount of air bubbles are drawn into the dirty side of the filter, retaining a sufficiently large wet surface area to filter the ink at the desired flow rate. This is important for the high rate operation provided by the present invention.

When bubbles in the upstream filter chamber 132 cannot traverse the filter membrane 130, bubbles caused by heating to remove the gas may generate bubbles in the downstream filter chamber 134. The filter outlet 156 is located at the bottom of the downstream filter chamber 134 and is diagonally opposite the inlet 158 in the upstream filter chamber 132 to minimize the effect of air bubbles on the convection rate in either chamber.

The filter film 130 for each pigment is erected and closely juxtaposed. The dividing wall 162 partially defines an upstream filter chamber 132 on one side and partially defines a downstream filter chamber 134 that abuts the pigment on the other side. Because the filter chamber is thin (due to pocket design), the filter membrane 130 can be pushed against the opposing walls of the downstream filter chamber 134. This effectively reduces the surface of the filter membrane 130, so it is not conducive to maximizing the flow rate. To prevent this, the opposing wall of the downstream filter chamber 134 has a series of spaced ribs 160 to keep the membrane 130 and wall apart.

The filter inlet and outlet are placed in diagonally opposite corners to help remove air from the system during the initial fill of the system.

In order to reduce the risk of particles contaminating the print head, the filter film 130 is first welded to the downstream side of the first partition wall before the next partition wall 162 is welded to the first partition wall. In this manner, any filter film 130 that is broken during the welding process is on the "dirty" side of the filter membrane 130.

LCP Module / Flexible Printed Circuit Board / Print Head IC

17-33 show an LCP module 64, a flexible printed circuit board 108, and a printhead IC 68 assembly. 17 is a bottom perspective view of the LCP module 64 with the flexible printed circuit board 108 and the printhead IC 68 attached. The LCP module 64 is secured to the crucible base 100 via countersunk holes 166,168. The apertures 168 are elliptical apertures to accommodate mismatch in thermal expansion coefficient without having to bend the LCP. The print head IC 68 is disposed end to end along a line along the longitudinal direction of the LCP module 64. The flexible printed circuit board 108 is wire bonded to an edge of the printhead IC 68. The flexible printed circuit board 108 is also secured to the LCP module at the edge of the printhead IC and at the edge of the splicing point 104. The edges of the flexible printed circuit board are secured to hold the flexible printed circuit board tightly against the curved support surface 170 (see Figure 19). This ensures that the flexible printed circuit board does not bend tighter than a particular minimum radius, thereby reducing the risk of breaking through the conductive tracks of the flexible printed circuit board.

Figure 18 is an enlarged plan view of the insertion block A shown in Figure 17. It shows the wires joining the contacts 164 along the sides of the flexible printed circuit board 108, and the lines of the printhead IC68.

19 is an exploded perspective view of an LCP module/flexible printed circuit board/printhead IC assembly showing the underside of each component. Figure 20 is another exploded perspective view showing the upper side of each component this time. The LCP module 64 has a liquid crystal polymer (LCP) channel module 176 sealed to its underside. The printhead IC 68 is attached to the underside of the channel module 176 by a viscous IC attachment film 174. On the upper side of the LCP channel module 176 is the LCP main channel 184. These are connected to the ink inlet 122 and the ink outlet 124 in the LCP module 64. At the bottom of the LCP main channel 184 is an ink supply flow path 182 that is connected to the printhead IC 68. The viscous IC attachment film 174 has a series of laser drill supply holes 186 such that the attachment side of each of the print head ICs 68 is in fluid communication with the ink supply flow path 182. The structural features of the viscous IC attachment film will be described in detail below with reference to FIGS. 31 to 33.

The LCP module 64 has a recess 178 for receiving the electronic component 180 in the drive circuit on the flexible printed circuit board 108. For optimum electrical efficiency and operation, the bond point 104 on the flexible printed circuit board 108 should be close to the printhead IC 68. However, in order to keep the paper path adjacent to the printhead straight rather than curved or curved, the splicing point 104 needs to be on the side of the cymbal 96. The conductive path within the flexible printed circuit board is referred to as the trajectory. When a flexible printed circuit board has to be bent around a corner, the trajectory can crack and break the connection. In order to solve this problem, the trajectory needs to be forked before the bend, and then rejoined after the bend. If the branches of the bifurcation segment are cracked, the other branches remain connected. Unfortunately, splitting the track into two and then combining them increases the electromagnetic interference problem, which creates noise in the circuit.

Widening the trajectory is not an effective solution because the wider trajectory does not significantly increase the ability to prevent cracking. Once cracks begin to appear within the trajectory, the cracks propagate relatively quickly and easily throughout the width. Careful control of the bend radius can be more effective in minimizing trajectory cracks, which minimizes the number of traces across the bend of the flexible printed circuit board.

The page width printhead presents additional complexity because large array nozzles must be fired in a relatively short time. Many nozzles are fired at one time, causing the system to withstand large current loads. This can result in a high level of inductance through the circuit, which can cause a voltage dip, and a voltage dip is detrimental to the operation. To avoid this problem, the flexible printed circuit board has a series of capacitors that discharge during the nozzle firing sequence to release the current load on the remaining circuitry. Because the paper path through the printhead IC needs to be straight, the conventional approach is to attach the capacitor to a flexible printed circuit board near the junction on the side of the crucible. Unfortunately, the capacitors create additional tracks that increase the risk of cracking in the curved sections of the flexible printed circuit board.

The above problem can be solved by mounting the capacitor 180 (see Fig. 20) in close proximity to the print head IC 68 to reduce the chance of trajectory cracking. The paper path can be kept linear by accommodating capacitors and other components within the recesses of the LCP module 64. The printhead IC 68 and paper mask 172 are mounted to the front face of the crucible 96 (relative to the feed direction), and the relatively flat surface of the flexible printed circuit board 108 downstream thereof minimizes the risk of jamming.

Isolating the contacts from the remaining components of the flexible printed circuit board minimizes the number of tracks that extend through the curved sections. This increases reliability as it reduces the chance of cracking. Setting the circuit components next to the printhead IC means that a wider edge is required, which is not conducive to pocket design. However, the advantages offered by this structure are more important than any disadvantage of being slightly wider. First, the contacts can be larger because there are no traces from the components passing between and around the contacts. Because of the large contacts, the connection is more reliable and more capable of handling manufacturing inaccuracies between the contacts on the splicing and printer sides. This problem is particularly important in this case because it relies on the user to accurately insert 匣 to match the joint.

Second, the wire is bonded to the edge of the flexible printed circuit board on the side of the printhead IC without residual stress and does not try to peel away from the bend radius. The flexible printed circuit board is fixed to the support structure at the capacitor and other components, so it is easier to form a wire connection to the printhead IC during manufacturing, and is less prone to be produced when it is not used to secure the flexible printed circuit board. crack.

Third, the capacitance is closer to the nozzle of the print head IC, so the electromagnetic interference generated by the discharge capacitor is minimized.

21 is an enlarged view of the lower side of the print head cartridge 96 showing the flexible printed circuit board 108 and the print head IC 68. The wire bond contacts 164 of the flexible printed circuit board 108 are parallel to the pads of the print head IC 68 on the underside of the viscous IC attachment film 174. Figure 22 shows the removal of the printhead IC 68 and the flexible printed circuit board of Figure 21 to reveal the supply aperture 186. The holes are arranged in four longitudinal columns, each column conveying a particular color of ink, and each column is aligned with a single channel behind each of the print head ICs.

Figure 23 shows the underside of the LCP channel module 176 with the viscous IC attachment film 174 removed. This exposed ink supply flow path 182 is coupled to an LCP main channel 184 (see FIG. 20) formed in the other side of the channel module 176. It will be appreciated that when the viscous IC attachment film 174 is adhered to the location, it partially defines the supply flow channel 182. It should also be appreciated that the attachment film must be accurately positioned because the individual supply flow paths 182 must be aligned with the supply holes 186 of the laser drilled through film 174.

Figure 24 shows the underside of the LCP module with the LCP channel module removed, which exposes the blind pockets 200 of the array. When filling the crucible with ink, the blind pocket 200 contains air to dampen any pressure pulses. This is discussed in more detail below.

Print head IC attachment film

Laser resection film

Referring briefly to Figures 31 through 33, the viscous IC attachment film is described in more detail. The membrane 174 is drilled through the laser and wound onto a spool 198 for convenient incorporation into the print head cartridge 96. For handling and storage, film 174 has a second protective lining (typically polyethylene terephthalate (PET) lining) on either side; one of which is the existing lining 188B, which is attached prior to laser perforation Attached to the membrane; another protective lining is a replacement lining 192 that replaces the existing lining 188A after the drilling operation.

In the section of the laser-drilled film 174 of Figure 32, some of the existing lining 188B is removed to expose the supply aperture 186. The replacement lining 192 on the other side of the membrane replaces the existing lining 188A after the laser has drilled the supply aperture 186.

Figures 33A through 33C show in detail how the film 174 can be made by shot cutting. Figure 33A shows in detail the laminated construction of the film prior to laser drilling. The central web 190 is typically a polyimide film and provides the strength required for lamination. The web 190 is sandwiched between the first and second adhesive layers 194A and 194B, and the adhesive layer is typically an epoxy layer. The first adhesive layer 194A is used to bond to the liquid crystal polymer channel module 176. The second adhesive layer 194B is for bonding to the print head integrated circuit 68. The melting point temperature of the first adhesive layer 194A is typically at least 10 ° C lower than the melting temperature of the second adhesive layer 194B. As described in more detail below, this difference in melting temperature improves the control of the printhead integrated circuit attachment process and, as a result, improves the effectiveness of the film 174 in use.

To store and process the film, each of the adhesive layers 194A and 194B is covered with a liner 188A and 188B, respectively. The thickness of the central web 190 is typically from 20 to 100 microns (typically about 50 microns). The thickness of each of the adhesive layers 194A and 194B is typically from 10 to 50 microns (typically about 25 microns).

Referring to Figure 33B, laser drilling is performed from the side of the film defined by the lining 188A. Hole 186 drills through first lining 188A, epoxy layers 194A and 194B, and central web 190. The aperture 186 terminates somewhere within the lining 188B, so the gusset 188B can be thicker than the gusset 188A (eg, the gusset 188A can be 10-20 microns thick and the gusset 188B can be 30-100 microns thick).

The apertured backing 188A on the laser entry side is then removed and replaced with a replacement liner 192 to provide the film package shown in Figure 33C. The film package is then wrapped around a roll 198 (see Figure 31) for storage and handling prior to attachment. When the print head is combined, the appropriate length is pulled from the roll 198, the liner is removed, and the film 174 is attached to the underside of the liquid crystal polymer channel film set 176 such that the holes 186 are aligned to the correct ink supply stream. Road 182 (see Figure 25).

Laser drilling is a standard method for defining pores within a polymer film. The problem with laser drilling is the deposition of charcoal-containing soot 197 in and around the drilling location (see Figures 33B and 33C). The soot around the protective lining can be easily handled because the lining is often replaced after laser drilling. However, the soot 197 deposited in and around the actual supply aperture 186 has potential problems. During bonding, the soot can be displaced as the film is compressed between the liquid crystal polymer channel film set 176 and the printhead integrated circuit 68. Any displaced soot 197 represents a means. Particles can enter the ink supply system by this means and potentially block the nozzles within the printhead integrated circuit 68. Moreover, soot is very fast and cannot be removed by conventional ultrasonic and/or isopropyl alcohol (IPA) washing techniques.

From the analysis of the laser-drilled film 174, the Applicant has observed that the soot 197 is typically present on the laser entry side of the film 174 (i.e., the epoxy layer 194A and the central web 190), but typically does not appear in the film. The laser exit side of 174 (i.e., epoxy layer 194B).

Double-removal of the membrane by laser

In U.S. Patent Application Serial No. U.S. Application Serial No. Serial No. No. No. No. No. No. No. No. No. No. No. , including soot deposition 197 on the laser entry side of the membrane. The starting point for dual pass laser ablation is the film shown in Figure 33A.

In a first step, the first aperture 185 is a laser drilled from the side of the film defined by the lining 188A. Hole 185 drills through lining 188A, epoxy layers 194A and 194B, and central web 190. Hole 185 terminates somewhere within lining 188B. The first aperture 185 is smaller in size than the desired ink supply aperture 186. Each length and width dimension of the first aperture 185 is typically about 10 microns smaller than the length and width dimension of the desired ink supply aperture 186. As can be seen in Figure 34A, the first aperture 185 has soot 197 deposited on the first lining 188A, the first epoxy layer 194A, and the central web 190.

In the second step, the first hole 185 is bored (stretched) by laser drilling to provide an ink supply hole 186 having a desired size. The drilled enlarged process produces very little soot, and the resulting ink supply aperture 186 thus has a clean sidewall as shown in Figure 34B.

Finally, and referring to Figure 34C, the first liner 188A is replaced with a replacement liner 192 to provide a film package. The film package is pre-wound onto the roll 198 and is subsequently used to attach the printhead integrated circuit 68 to the liquid crystal polymer channel film set 176. If you wish. The second lining 188B can also be replaced at this stage.

Comparing the films shown in Figures 33C and 34C, it is understood that the dual laser ablation method has a cleaner ink supply aperture 186 than the membrane 174 provided by a simple laser ablation method. Therefore, the film is more suitable for attaching the print head integrated circuit 68 to the liquid crystal polymer channel film group 176 without contaminating the ink by unwanted soot deposition.

Print head integrated circuit attachment process

Improvement of mold attachment film 174

Referring to Figures 19 and 20, it is understood that the print head integrated circuit attachment process is an important stage in the manufacture of print heads. In the integrated circuit attachment process, the first adhesive surface of the laser drilled film 174 is initially adhered to the lower side of the liquid crystal polymer channel film group 176, and then the print head integrated circuit 68 is bonded. To the opposite second surface of the membrane 174. The film 174 has epoxy resin layers 194A and 194B on each side, and the adhesive layer is melted and bonded under application of heat and pressure.

Because the liquid crystal polymer channel film set 176 has very poor thermal conductivity, application heat must be provided via the second surface of the film 174 during each bonding process that does not contact the liquid crystal polymer channel module.

From the standpoint of the positioning of each of the print head integrated circuits 68 and the supply of ink to the printhead integrated circuit, the control of the process is important for optimized print head performance. A typical sequence of steps for attaching a print head integrated circuit, as shown in Figures 35A-D, using a prior art film 174 (as described in US Application No. US 2007/0206056, incorporated herein by reference). In the longitudinal section. Referring to Figure 35A, the film 174 is initially aligned with the liquid crystal polymer pass-through module 176 such that the ink supply holes 186 are properly aligned with the ink outlets defined in the manifold bonding surface 175. As described above, the ink outlet takes the form of an ink supply flow path 182. The first adhesive layer 194A faces the manifold bonding surface 175, while the protective backing 188B protects the opposite side of the film.

Referring to Figure 35B, film 174 is bonded to manifold bonding surface 175 by application of heat and pressure to heating block 302. The silicone rubber pad 300 separates the heating block 302 from the film backing 188B to prevent any damage to the film 174 during bonding. During bonding, the first epoxy layer 194A is heated to its melting temperature and bonded to the bonding surface 175 of the liquid crystal polymer channel module 176.

As shown in Figure 35C, the liner 188B is then removed from the film 174 to reveal the second epoxy layer 194B. Next, the print head integrated circuit 68 aligns the film 174 that is prepared for the second bonding step. Figure 35C illustrates some of the problems that are typically shown in the first bonding step. Since the epoxy layers 194A and 194B in the prior art film are the same, both layers are melted during the first bonding step. Melting of the second epoxy layer 194B is a problem for a number of reasons. First, some epoxy adhesive 199 is extruded from the second epoxy layer 194B and arranged along the laser-drilled ink supply holes 186. This reduces the area of the ink supply aperture 186, thereby increasing the resistance to ink flow within the finished printhead assembly. In some cases, the ink supply aperture 186 may also become completely blocked during the bonding process, which is a highly undesirable situation.

Figure 36B shows an actual photograph of one of the ink supply holes 186 suffering from the problem of "extruding" the epoxy. The outer peripheral wall 310 shows the original dimensions of the laser drilling holes 186. The light colored material 312 in the surrounding wall 310 is an adhesive that is squeezed into the ink supply aperture 186 during bonding to the liquid crystal polymer channel module 176. Finally, the central black area defined by the surrounding wall 314 shows the effective cross-sectional area of the ink supply aperture 186 after bonding. In this example, the original ink supply aperture 186 for laser drilling is 400 microns by 130 microns. These dimensions were reduced to 340 microns x 80 microns after bonding and extruding the epoxy. In addition to the significant problem of increasing ink flow resistance, the ambiguous edges of the ink supply aperture 186 are a problem for the second bonding step because the printhead integrated circuit 68 must accurately align the ink supply apertures 186. In automated printhead manufacturing, a particular alignment device uses optical components to position the center of mass of each ink supply aperture 186. When the edge of each ink supply hole 186 is blurred by the extruded epoxy resin, it is difficult to determine the optical position of each center of mass. As a result, alignment errors are more likely to occur.

A second problem with the molten second epoxy layer 194B is that the film 174 loses some of its overall structural integrity. As a result, the film 174 tends to bulge or sag into the ink supply flow path 182 defined in the liquid crystal polymer channel module 176. Figure 35C illustrates the depressed portion 198 of the film 174 after the first bonding step. The applicant in this case created the term “tenting” to describe this phenomenon. Since the bonding surface 195 of the second adhesive layer 194B loses its flatness, "tenting" is particularly a problem. The "flattening" problem of the epoxy resin causes a change in the thickness in the second adhesive layer 194B, so that the flatness of the loss is further deteriorated. The combination of the "bump" and the thickness variation in the second adhesive layer 194B reduces the contact area of the bonding surface 195 and causes problems in the second bonding step.

In a second bonding step, shown in Figure 35D, each of the print head integrated circuits 68 is heated to about 250 ° C and then accurately positioned on the second adhesive layer 194B. The print head integrated circuit 68 accurately aligns the film 174, ensuring that the ink supply channel 218 is disposed above its corresponding ink supply aperture 186; the channel 218 and the nozzle 69 are in fluid communication. In Figure 35D, which is a longitudinal section, an ink supply channel 218 is shown, although (as can be appreciated from Figure 25), each of the column header circuits 68 can have multiple columns of ink supply channels.

Since the epoxy resin is "extruded", the thickness of the second adhesive layer 194B having an original thickness of about 25 μm may be reduced to 5 to 10 μm in some regions. Such a large change in thickness in the second adhesive layer 194B causes a skew displacement of the print head integrated circuit in which one end of the print head integrated circuit 68 rises relative to the other end. This situation is clearly undesirable and can affect print quality. Another problem with the uneven bonding surface 195 is that a relatively long bonding time of about 5 seconds is typically required, and each column of the integrated head circuit 68 needs to be pressed relatively far into the second adhesive layer 194B.

The most important issue associated with the "bumping" printhead assembly within the adhesive film 174 is that the seal provided by the film may not be perfect. The applicant of the present application has developed a leak test to determine the efficiency of the seal provided by the inner membrane 174 of the printhead assembly. In this test, the print head assembly was first immersed in ink at 90 ° C for one week. After the ink was soaked and rinsed, a pigment channel of the print head assembly was filled with 10 kPa of air and the rate of air leakage from the pigment channel was measured. Leakage may be generated by air (via membrane 174) being transported to other pigment channels within the printhead, or because air is directly lost to the atmosphere. In this test, a typical print head assembly made using the integrated circuit attachment film described in U.S. Publication No. US 2007/0206056 has a leak rate of about 300 cubic millimeters per minute or more.

In view of the above problems, Applicants have developed an improved print head integrated circuit attachment process that minimizes such problems. The modified column head circuit attachment process is described in U.S. Patent Application Serial No. 12/049,373 filed on Jan. 17, 2008, which is incorporated herein by reference. The improved in-line integrated circuit attach process is substantially the same as the above described steps associated with Figures 35A-D. However, the design of the membrane 174 reduces the problems associated with the first bonding step and equally reduces the associated problems associated with the second bonding step. The membrane 174 still contains a central elastomeric web 190 sandwiched between the first and second adhesive layers 194A and 194B. (For convenience, the corresponding parts of film 174 have the same symbols as described above). However, the first and second epoxy layers 194A and 194B in the film differ from the previous film design. In particular, the melting temperature of the epoxy resin layer 194A is at least 10 ° C lower than the melting temperature of the second epoxy resin layer 194B. The difference in melting temperature is usually at least 20 ° C or at least 30 ° C. For example, the melting temperature of the first epoxy resin layer 194A may be in the range of 80 to 130 ° C, and the melting temperature of the second epoxy resin layer 194B may be in the range of 140 to 180 °C. Those skilled in the art can easily select an adhesive film (e.g., an epoxy film) that satisfies these criteria. The adhesive film suitable for use in the laminated film 174 is a Hitachi DF-XL9 epoxy resin film (having a melting temperature of about 120 ° C) and a Hitachi DF-470 epoxy resin film (having A melting temperature of about 160 ° C).

Accordingly, the first bonding step (illustrated in FIG. 35B) can be controlled such that the second adhesive layer 194B does not melt during bonding of the first adhesive layer 194A to the bonding surface 195 of the liquid crystal polymer channel module 176. The temperature of the heating block 302 generally matches the melting temperature of the first adhesive layer 194A. Therefore, the "extrusion" of the first adhesive layer is minimized or completely eliminated. Furthermore, during the combined process, there is little or no "bumping".

Referring to Figure 37A, a bonded liquid crystal polymer/membrane assembly using film 174 is shown. Referring to the assembly shown in Fig. 35C, it can be seen that "bumping" has not occurred in the film 174, and the second adhesive layer 194B has uniform flatness and thickness. FIG. 36A shows an actual photograph of an ink supply aperture 186 after bonding to the liquid crystal polymer channel module 176 using the film 174. Compared with the ink supply hole shown in Fig. 36B, the definition of the ink supply hole 186 is greatly improved, and it can be seen that the "extruding" epoxy resin does not occur. Therefore, the ink flow resistance through the hole shown in Fig. 36A is not disadvantageously increased, and the optical position of the center of mass of the hole can be performed with a minimum error.

Furthermore, since the problems associated with the first bonding step have been minimized, the associated problems associated with the second bonding step are also minimized. As shown in FIG. 37A, the second adhesive layer 194B has a flat bonding surface 195 with minimal thickness variation. Therefore, the displacement and bonding of the print head integrated circuit are greatly improved, so that a relatively short bonding time of about 1 second can be used. The flat bonding surface 195 shown in Fig. 37A also means that the print head integrated circuit 68 does not have to be pressed far into the second adhesive layer 194B to provide sufficient bonding strength, and the attachment process is less likely to cause skew. The print head integrated circuit 68.

Referring to Figure 37B, the printhead assembly produced by the improved printhead integrated circuit attachment step has an excellent seal around each ink supply aperture 186, primarily because there is no "bump" and epoxy "squeezing" The relationship of "out". In the Applicant's leak test described above, the print head assembly shown in Figure 37B exhibits a significant 3000 fold improvement over the print head assembly shown in Figure 35D. After immersion in ink at 90 ° C for one week, when 10 kPa of air was poured, the leak rate of the print head assembly shown in Fig. 37B was measured to be about 0.1 mm 3 per minute.

Improvement of liquid crystal polymer channel module 176

As described above, the integrated circuit attachment process involves bonding the first adhesive surface of the laser drilled film 174 to the underside of the liquid crystal polymer channel module 176. Printhead integrated circuit 68 is then bonded to the opposite second adhesive surface of film 174. While the above improvements in film 174 help minimize leakage from the bond between liquid crystal polymer channel module 176 and printhead integrated circuit 68, the molding within liquid crystal polymer channel module 176 is irregular, still It will provide an undesired source of ink leakage. In particular, micro-molding gaps (eg, cracks, grooves, scores, holes, etc.) within the liquid crystal polymer channel module 176 are sealed between the liquid crystal polymer channel module 176 and the printhead integrated circuit 68. negative effect. These molded gaps are a potential source of ink leakage.

As shown in FIG. 38, the molding slits 350 (exaggerated for clarity) may occur at the bonding surface of the liquid crystal polymer channel module 176 and/or between the respective ink supply channels 182. In either of the two conditions, ink leakage and/or pigment mixing may occur if the slit 350 is not plugged or sealed by the integrated circuit attachment process.

FIG. 39 shows a process in which a liquid crystal polymer channel module 176 is coated with a polymer coating 352. Prior to attaching any of the print head integrated circuits 68, the entire liquid crystal polymer module 64 (including the liquid crystal polymer channel module 176 sealed on its underside) is immersed in the polymer coating solution 354. This produces a coated liquid crystal polymer channel module in which all of the slits 350 are plugged by the polymer coating 352. The surface gap is plugged with a polymeric coating 352 that improves the contour of the bonding surface 175 that is bonded to one side of the adhesive film 174. In particular, by minimizing surface irregularities, the results shown in FIG. 40 have been combined with the printhead assembly to provide an improved seal between the liquid crystal polymer channel module 176 and the adhesive film 174.

Furthermore, the internal gaps in the liquid crystal polymer channel module 176 are plugged to minimize mutual contamination between the pigments in the liquid crystal polymer channel module 176.

The polymer coating 352 can be applied using any suitable process, such as dipping, spray coating, or spin coating. As shown in FIG. 39, the liquid crystal polymer module 64 is entirely immersed in a polymer coating solution including a polymer dispersed or dissolved in a suitable solvent such as an organic solvent. The polymer can be hardened when dried, heated, or exposed to ultraviolet light.

The polymeric coating can include any suitable polymer, such as polyimine, polyester (such as PET), epoxy, polyene (such as polyethylene, polypropylene, polytetrafluoroethylene), oxime (such as Polydimethyl siloxane, or a liquid crystal polymer. Combinations and/or copolymers of the various polymers can also be used as suitable coating polymers. The polymeric coating typically comprises a different polymeric material than the liquid crystal polymer channel module 176.

Further, the optional polymer coating 352, or polymer coating 352, can include additives to provide a liquid crystal polymer channel module 176 having desired surface characteristics. For example, the polymeric coating can include an adhesive additive to improve bonding to film 174. Alternatively (or in addition), the polymeric coating may include additives to improve the surface characteristics of the ink supply flow path, such as to increase wettability. Alternatively (or in addition), the polymeric coating may include additives to improve the overall durability of the liquid crystal polymer channel module 176, such as scratch resistant additives such as ruthenium particles.

Promote ink supply to the end of the print head IC

25 shows a printhead IC 68 that overlaps the ink supply aperture 186 that penetrates the viscous IC attachment film 174, which overlaps the ink supply channel 182 in the underside of the LCP channel module 176. Adjacent printhead ICs 68 are disposed end-to-end on the bottom of the LCP channel module 176 by attachment film 174. At the junction of each adjacent printhead IC 68, one of the ICs 68 has a "drop triangle" 206 portion of the array of nozzles. The nozzles are displaced from corresponding columns in the remaining nozzle array 220, which allows the printing edge of one of the printhead ICs to continue printing adjacent to the printhead IC. By displacing the drop triangles 206 of the nozzles, the spacing between adjacent nozzles remains the same regardless of whether each nozzle is on the same IC or on either side of the junction on a different IC. This requires a relatively precise positioning of the adjacent printhead IC 68 and the use of the reference mark 204 to achieve this goal. This process can be time consuming, but avoids producing artificial results in the printed images.

Unfortunately, some of the nozzles may lack ink at the end of the printhead IC 68 relative to the nozzle blocks in the remaining array 220. For example, the nozzle 222 can be supplied by the ink of the two ink supply holes. The ink supply holes 224 are the closest. However, if there is an obstacle or a particularly large demand from the nozzle to the left side of the hole 224, the supply hole 226 is also close to the nozzle 222, so that these nozzles are less likely to be unfilled due to lack of ink.

In contrast, if the ink supply hole 216 is not for the "extra" ink supply hole 210 provided at the junction between the adjacent ICs 68, the nozzle 214 at the end of the print head IC 68 is only fluid with the ink supply hole 216. Connected. "With additional ink supply holes 210", i.e., no nozzles are too far away from the ink supply holes so that the nozzles are at risk of lacking ink.

Both of the ink supply holes 208, 210 are fed by a common ink supply flow path 212. The ink supply flow path 212 has the ability to supply two holes because the supply hole 208 has only the nozzle to the left side thereof, and the supply hole 210 has only the nozzle to the right side thereof. Therefore, the total flow rate through the supply flow path 212 is approximately equal to the supply flow path fed only to one hole.

Figure 25 also illustrates the inconsistency between the number of channels (pigments) in the ink supply (four channels) and the five channels 218 in the printhead IC 68. The third and fourth passages 218 behind the print head IC 68 are supplied by the same ink supply holes 186. These supply holes are slightly enlarged to provide a distance between the two channels 218.

The reason for this is that the printhead IC 68 is fabricated for use in a wide range of printer and printhead configurations. These can have five pigment channels - cyan, magenta, yellow, black, and infrared pigments - but other printers (such as this design) can only be four-channel printers, while the rest Still only three channels (cyan CC, magenta MM, and yellow Y). In view of this, a single pigment channel can be fed to two of the printhead IC channels. A Print Engine Controller (PEC) microprocessor can easily adapt this to the printed material that is sent to the printhead IC. Furthermore, supplying the same pigment to the two nozzle rows in the IC provides the status of redundant nozzles for dead nozzle compensation.

Pressure pulse

When the ink flowing into the print head suddenly stops, a sharp peak of ink pressure is generated, which occurs at the end of the printing job or at the end of a page. Due to the high rate of the custodian, the pagewidth printhead requires a high flow rate to supply ink during the job. Thus, the ink mass to the nozzle within the ink line is relatively large and moves at a significant rate.

Suddenly ending the printing job, or simply at the end of the printed page, requires that this relatively fast flowing relatively high volume ink be stopped immediately. But suddenly taking ink momentum will increase the shock wave in the ink line. The LCP module 64 (see Figure 19) has a special stiffness and the LCP module 64 provides little flexibility when the ink column in the line is stationary. Since there is no compliance in the ink line, the shock wave can exceed the Laplace pressure (the pressure provided by the surface tension of the ink at the nozzle opening, which is used to retain the ink in the nozzle chamber) and flood the printhead IC 68 The front surface. If the nozzle is submerged, the ink may not be ejected, and the artificial result appears in the printing.

When the nozzle emissivity matches the resonant frequency of the ink line, a resonance pulse is generated in the ink. Moreover, because of the rigid configuration of the ink line, most of the nozzles for one color are simultaneously emitted, producing standard or resonant pulses within the ink line. This can cause the nozzle to flood (or be submerged), or conversely, if the Laplace pressure is exceeded, the nozzle is not filled because of the pressure drop after the peak.

To address this issue, the LCP module 64 incorporates a pulsation damper to remove pressure peaks from the ink line. The damper can be a closed gas volume that can be compressed by the ink. In another embodiment, the damper can be a compliant section of the ink line that elastically flexes and absorbs pressure pulses.

To minimize design complexity and preserve pocket form, the present invention uses a compressible gas volume to dampen pressure pulses. With a small volume of gas, it is possible to use a gas compression to dampen the pressure pulse. This retains a pocket design while avoiding any nozzle flooding caused by transient peaks in ink pressure.

As shown in Figures 24 and 26, the pulsation damper is not a single gas volume for pulse compression within the ink, but rather an array of pockets 200 distributed along the length of the LCP module 64. A pressure pulse that moves past an elongated printhead (e.g., a pagewidth printhead) can be damped at any point within the ink flow line. But when the pulse passes through the nozzle in the printhead IC, the pulse will flood the nozzle regardless of whether the pulse is later dissipated at the damper. By incorporating multiple pulsation dampers into the ink supply conduit and in close proximity to the nozzle array, any pressure spikes are damped at locations where they can cause unwanted flooding.

In Figure 26, it can be seen that the air damming pockets 200 are arranged in four rows, each column of holes being located directly above the LCP main channel 184 within the LCP channel module 176. Any pressure pulse in the ink within the main channel 184 acts directly on the air within the pocket 200 and dissipates quickly.

Print head fill

The fill 匣 is now described with particular reference to the LCP channel module 176 shown in FIG. The ink fills the LCP channel module 176 by the suction applied to the main channel outlet 232 from the pump of the fluidic system (see Figure 6). The main channel 184 is filled with ink, and then the ink supply flow path 182 and the print head IC 68 are self-filled by capillary action.

Main channel 184 is relatively long and thin. Again, if the air pockets 200 are used to damp pressure pulses within the ink, the air pockets 200 must remain unfilled. This may be problematic for the filling process, where the pockets 200 can be easily filled by capillary action during filling, or the main channel 184 may not be fully filled due to trapped air. To ensure that the LCP channel module 176 is fully filled, the main channel 184 has a dam 228 at the downstream end prior to the outlet 232. To ensure that the air pockets 200 within the LCP module 64 are not filled, the air pockets 200 have openings and the openings have sharp upstream edges to direct the ink meniscus to not travel up the walls of the pockets.

These aspects of the crucible are described in detail with reference to Figs. 28A, 28B and 29A to 29C. These figures schematically illustrate the filling process. Figures 28A, 28B show the problems that may occur if there are no dams in the main channel, while Figures 29A through 29C show the function of the dams 228.

28A, 28B are cross-sectional views through one of the main channels 184 of the LCP channel module 176 and the inner air pockets 200 of the channels. Ink 238 is pumped through inlet 230 and flows along the floor of main channel 184. It should be noted that the advancing meniscus and the bottom surface of the channel 184 have a steep contact angle which causes the front end of the ink stream 238 to be slightly spherical. When the ink reaches the end of the channel 184, the ink level rises and the ball front contacts the top of the channel before the remaining ink stream. As shown in Figure 28B, the channel 184 is not fully filled and the air is now trapped. This air bag retains and interferes with the job of the print head. The ink damping characteristics are altered and the air can be an ink barrier.

In Figs. 29A to 29C, the passage 184 has a dam 228 at the downstream end. As shown in Figure 29A, ink stream 238 collects behind the dam 228 and rises toward the top of the channel. The dam 228 has a sharp edge 240 at the top as a fixed point for the meniscus. The advancing meniscus is pinned (attached) to the anchor 240 so that when the ink level is above the top edge, the ink does not simply flow through the dam 228 immediately.

As shown in Figure 29B, the protruding meniscus causes the ink to rise until the ink fills the channel 184 to the top. Since the ink seals the pockets into separate air pockets, the protruding ink meniscus at the dam 228 exits the sharp top edge 240 and fills the end of the channel 184 and the ink outlet 232 (see Figure 29C). The sharp top edge 240 is precisely positioned such that the ink meniscus protrudes until the ink fills the top of the channel 184, but does not allow the ink to bulge too much so that the ink contacts a portion of the end air pocket 242. If the meniscus contacts and is fixed to the inside of the end air pocket portion 242, the end air pocket portion 242 may be filled with ink. Accordingly, the height of the dam and its position under the pocket are tightly controlled. The curved downstream surface of the dam 228 ensures that no further anchor points allow the ink meniscus to span the gap to the pocket 242.

Another mechanism by which the LCP is used to keep the pockets 200 unfilled is the upstream and downstream edges of the pocket openings. As shown in Figures 28A, 28B and 29A through 29C, all of the upstream edges have curved transition faces 234 and the downstream edges 236 are sharp. The ink meniscus that advances along the top of the channel 184 can be nailed to the sharp upstream edge and then moved upward into the cavity by capillary action. The transition surface at the upstream edge (especially the curved transition surface 234) removes the strong anchor points provided by the sharp edges.

Similarly, Applicants' efforts have found that if the pockets 200 have been disadvantageously filled with some ink, the sharp downstream edge 236 can facilitate removal of the fill. If the printer is impacted, shaken, or tilted, or the jet system must flow back for any reason, the pocket 200 may be completely or partially filled. The sharp downstream edge 236 helps pull the meniscus back to the natural anchor point (i.e., the sharp corner) as the ink flows in its normal direction. In this manner, the management of the meniscus of the moving ink through the LCP channel module 176 is a mechanism for properly filling the crucible.

The invention has been described herein by way of example only. Variations and modifications of the spirit and scope of the broad inventive concept will be apparent to those skilled in the art. Accordingly, the embodiments described and illustrated in the drawings are only to be considered as illustrative and not restrictive.

2. . . Printer

4. . . main body

6. . . Pivoting surface

8. . . Display screen

10. . . Control button

12. . . Media stack

14. . . Feed tray

16. . . Printed sheet

18. . . Exit slot

20. . . Cam

twenty two. . . contact

twenty four. . . Release lever

26. . . handle

28. . . Bearing surface

30. . . Structural component

32. . . Contact rib

60. . . Ink tank

62. . . Pump

64. . . Liquid crystal polymer (LCP) module

66. . . Shut off valve

68. . . Print head integrated circuit (IC)

69. . . nozzle

72. . . Regulator

74. . . Bubble outlet

76. . . Sealed catheter

78. . . Air inlet

80. . . Export

82. . . filter

84. . . Upstream ink line

86. . . Downstream ink line

88. . . sensor

90. . . Electronic controller

92. . . Storage tank

94. . . Cover

96. . . (print head)匣

98. . . protective case

100. . .匣 base (chassis module)

102. . . Base cover

104. . . Contact point

104. . . Contact point

106. . . Paper mask

108. . . Flexible printed circuit board

110. . . Wire bonding

112A. . . Upstream ink coupler

112B. . . Downstream ink coupler

114. . .匣 valve

116. . . Inlet manifold and filter

118. . . Export manifold

120. . . Elastic connector

122. . . Liquid crystal polymer (LCP) inlet (ink inlet)

124. . . Liquid crystal polymer (LCP) outlet (ink outlet)

126. . . Elastic sleeve

128. . . Fixed valve member

130. . . Filter membrane

132. . . Upstream filter chamber

134. . . Downstream filter chamber

136. . . Liquid crystal polymer (LCP) channel

138. . . Top channel

142. . . Catheter (printer valve)

146. . . Collar

148. . . End of catheter

150. . . catheter

152. . . Ink flow

156. . . Filter outlet

158. . . Filter inlet

160. . . Spacer

162. . . Partition wall

164‧‧‧Wire joints

166‧‧‧ countersink

168‧‧‧ countersink

170‧‧‧arc support surface

172‧‧‧paper mask

174‧‧‧Adhesive film (adhesive integrated circuit (IC) attachment film)

175‧‧‧Management joint surface

176‧‧‧Liquid Crystal Polymer (LCP) Channel Module

178‧‧‧ recess

180‧‧‧Electronic components

182‧‧‧Ink supply runner

184‧‧‧Liquid Crystal Polymer (LCP) main channel

185‧‧‧ first hole

186‧‧‧ (desired ink supply hole), (laser drilling) supply hole

188A‧‧‧ Existing lining

188B‧‧‧ Existing lining

190‧‧‧Central web

192‧‧‧Replacement lining

194A‧‧‧First adhesive layer

194B‧‧‧Second adhesive layer

195‧‧‧ bonding surface

196‧‧‧Motor

197‧‧‧ ash

198‧‧‧Roll (sag)

199. . . Epoxy resin adhesive

200. . . Cave

204. . . Benchmark mark

206. . . Drop triangle

208. . . (ink) supply hole

210. . . (ink) supply hole

212. . . (ink) supply flow path

214. . . nozzle

216. . . (ink) supply hole

218. . . aisle

220. . . Nozzle array

222. . . nozzle

224. . . (ink) supply hole

226. . . (ink) supply hole

228. . . dam

230. . . Entrance

232. . . Main channel exit

234. . . Curved transition surface

236. . . Downstream edge

238. . . Ink (flow)

240. . . Sharp edge

300. . . pad

302. . . Heating block

310. . . (outer) surrounding wall

312. . . Light color material

314. . . Surrounding wall

350. . . (molding) gap

352. . . (polymer) coating

Embodiments of the present invention are described by way of example only with reference to the drawings. The figure is:

Figure 1 is a side front perspective view of a printer embodying the present invention;

Figure 2 shows the printer of Figure 1 with the front in the open position;

Figure 3 shows the printer of Figure 2, and removes the print head;

Figure 4 shows the printer of Figure 3, and the outer casing is removed;

Figure 5 shows the printer of Figure 3, and the outer casing is removed, but the print head 安装 is installed;

Figure 6 is a schematic representation of a printer jet system;

Figure 7 is a front upper perspective view of the print head cartridge;

Figure 8 is a front upper perspective view of the print head cartridge in its protective cover;

Figure 9 is a front upper perspective view of the print head cartridge with its protective cover removed;

Figure 10 is a front lower perspective view of the print head cartridge;

Figure 11 is a rear lower perspective view of the print head cartridge;

Figure 12 shows a view of each side of the print head;

Figure 13 is an exploded perspective view of the print head cartridge;

Figure 14 is a transverse section through the ink inlet coupler of the print head cartridge;

Figure 15 is an exploded perspective view of the ink inlet and filter assembly;

Figure 16 is a cross-sectional view of a weir valve engaged with a printer valve;

Figure 17 is a perspective view of the LCP module and the flexible PCB;

Figure 18 is an enlarged plan view of the insertion block A shown in Figure 17;

Figure 19 is a bottom exploded perspective view of the LCP module/flexible printed circuit board/printing head IC assembly;

20 is an upper perspective exploded view of an LCP module/flexible printed circuit board/printing head IC assembly;

21 is an enlarged view of the underside of the LCP module/flexible printed circuit board/printing head IC assembly;

Figure 22 is an enlarged view showing the print head IC and the flexible printed circuit board of Figure 21 removed;

Figure 23 shows an enlarged view of the print head IC attachment film of Figure 22;

Figure 24 is an enlarged view showing the removal of the LCP channel film group of Figure 23;

Figure 25 shows the printhead IC having back channels and nozzles that overlap the ink supply flow path;

Figure 26 is a horizontal enlarged perspective view of an LCP module/flexible printed circuit board/printing head IC assembly;

Figure 27 is a plan view of the LCP channel module;

28A and 28B are schematic cross-sectional views showing the filling of the LCP channel module without a dam;

29A, 29B, and 29C are schematic cross-sectional views of the LCP channel module filled with a dam;

Figure 30 is a horizontal enlarged perspective view of the position of the LCP module having contact force and reaction force;

Figure 31 shows a reel of an IC attachment film;

Figure 32 shows a cross section of the IC attachment film between the linings;

33A-C are partial cross-sectional views showing stages of a conventional laser drilling attachment film;

34A-C are partial cross-sectional views showing stages of a dual laser drilling attachment film;

35A-D are longitudinal cross-sectional views of the illustrated printhead integrated circuit attachment process;

36A and 36B are photographs of ink supply holes in two different attachment films after the first bonding step;

37A and 37B are longitudinal cross-sectional views of the illustrated printhead integrated circuit attachment process;

Figure 38 is a schematic illustration of a printhead integrated circuit having an exaggerated gap in a molded ink manifold;

Figure 39 is a schematic illustration of a process for applying a polymeric coating to a molded ink manifold;

Figure 40 shows schematically a printhead assembly having a jammed gap.

68. . . Print head integrated circuit (IC)

174. . . Viscous integrated circuit (IC) attachment film

176. . . Liquid crystal polymer (LCP) channel module

352. . . (polymer) coating

Claims (20)

A printhead assembly comprising: a molded ink manifold having a plurality of ink outlets defined within a manifold bonding surface; one or more printhead integrated circuits, each of the printhead integrated circuits having a Or more ink inlets defined within the printhead bonding surface; and an adhesive film sandwiched between the manifold bonding surface and the one or more printhead bonding surfaces, the film having a defined therein A plurality of ink supply apertures, each ink supply aperture being aligned with the ink outlet and the ink inlet, wherein at least the manifold bonding surface comprises a polymeric coating that plugs a gap within the molded ink manifold. The print head assembly of claim 1, wherein the gaps are useless gaps created by a molding process for making the ink manifold. The printhead assembly of claim 1, wherein the manifold bond surface is substantially flat because the polymer coating plugs the gaps. The printhead assembly of claim 1, wherein the molded ink manifold is coated with the polymer coating. The printhead assembly of claim 1, wherein the polymer coating plugs an internal gap defined between respective ink supply channels within the ink manifold. The print head assembly of claim 1, wherein the polymer coating is selected from the group consisting of polyimine, polyester, epoxy, polytetrafluoroethylene. Composition of ethylene, alkane, and liquid crystal polymer. The print head assembly of claim 1, wherein the polymer coating comprises an inorganic or organic additive for providing one or more of the following characteristics, including wettability, adhesion Agent bonding strength, and scratch resistance. The printhead assembly of claim 1, wherein the polymer coating is applied to the molded ink manifold by dipping, spray coating, or spin coating. The printhead assembly of claim 1, comprising a plurality of print head integrated circuits that are contiguously end to end along a longitudinal extent of the ink supply manifold. The printhead assembly of claim 9, wherein the plurality of printhead integrated circuits define a pagewidth printhead. The print head assembly of claim 10, wherein the plurality of ink inlets defined by the ink supply passages extending longitudinally along the print head bonding surface, and wherein the plurality of ink supply holes are aligned with one ink supply A channel, each of the plurality of ink supply holes, is longitudinally spaced along the ink supply channel. A page width printer comprising a stationary print head assembly as described in claim 1 of the patent application. A molded ink manifold for an inkjet printhead having a manifold bonding surface for attaching one or more printhead integrated circuits, each of the printhead integrated circuits One receiving ink from one or more ink outlets defined within the bonding surface, wherein at least the manifold bonding surface comprises a polymeric coating that is plugged within the molded ink manifold The gap. A molded ink manifold for an ink jet print head according to claim 13 wherein the gap is a useless gap created by a molding process for fabricating the ink manifold. The printhead assembly of claim 13 wherein the manifold bond surface is substantially flat because the polymer coating plugs the gaps. A molded ink manifold for an ink jet print head according to claim 13 wherein the molded ink manifold is entirely coated with the polymer coating. A molded ink manifold for an ink jet print head according to claim 13 wherein the polymeric coating plugs an internal gap defined between respective ink supply channels within the ink manifold. The molded ink manifold for an ink jet print head according to claim 13, wherein the polymer coating is selected from the group consisting of polyimine, polyester, Epoxy resin, polytetrafluoroethylene, decane, and liquid crystal polymer. A molded ink manifold for an ink jet print head according to claim 13 wherein the polymer coating comprises an inorganic or organic additive for providing one or more of the following characteristics, Characteristics include wettability, adhesive strength, and scratch resistance. A molded ink manifold for an ink jet print head according to claim 13 wherein the polymer coating is applied to the molded ink by dipping, spray coating, or spin coating. tube.