TWI736111B - Method and system for measuring a parameter - Google Patents

Abstract

A droplet measurement system (DMS) is used in concern with an industrial printer used to fabricate a thin film layer of a flat panel electronic device. A clear tape serves as a printing substrate to receive droplets from hundreds of nozzles simultaneously, while an optics system photographs the deposited droplets through the tape (i.e., through a side opposite the printhead). This permits immediate image analysis of deposited droplets, for parameters such as per-nozzle volume, landing position and other characteristics, without having to substantially reposition the DMS or printhead. The tape can then be advanced and used for a new measurement. By providing such a high degree of concurrency, the described system permits rapid measurement and update of droplet parameters for printers that use hundreds or thousands of nozzles, to provide a real-time understanding of per-nozzle expected droplet parameters, in a manner that can be factored into print planning.

Description

System and method for measuring parameters

The invention relates to the rapid measurement of droplet parameters in an industrial printing system.

More and more industrial processes are turning to seeking printing systems for manufacturing product laminates. These printing systems deposit a fluid, which is then cured or hardened to form a permanent laminate of a particular product. These processes are particularly useful for microelectronic products or products with quasi-electronic structure arrays. For example, these printing processes are increasingly being used to manufacture thin-film electronic displays and solar panels with a wide variety of applications. In addition to the type of fluid ("ink") used, the typical feature of the aforementioned printing system is the use of thousands of printing nozzles on one or more print heads, which are designed to have a placement close to micrometer resolution. The capacity of individual droplets of approximately uniform size. This precise control of both the volume and position of the deposited droplets contributes to the high-quality and high-resolution, small-size products and reduced manufacturing costs of the end product. For example, in one application, which means the manufacture of organic light emitting diode (OLED) displays, the ability to accurately deposit ink helps to produce smaller and thinner at a lower cost. , And a better-resolution display. Note that when the term "ink" is used to denote a deposition fluid, the deposition fluid is essentially colorless and is deposited into a structure that will "build" a permanent stack of a device to a thickness, meaning That is, in terms of the meaning of the ink used in traditional graphic printing applications, the color of the fluid itself is usually not important.

Not surprisingly, in these applications, the quality control depends on the uniformity of the deposited ink droplets, in terms of size (droplet volume) and precise position, or at least understand that it is For permanent laminates that consistently meet the quality standards for laminate alignment accuracy and/or laminate homogeneity, the variation of these characteristics is important. Please note that in an industrial printing system, the droplet uniformity of any particular nozzle has the potential to change over time, whether it is due to statistical variation, nozzle age changes, clogging, ink viscosity or composition variation, temperature, Or other factors may happen.

What is needed is a droplet measurement system that is adjusted to be used with an industrial printing process. Ideally, it can be used on-site with a printing system used by an industrial production equipment. Ideally, this droplet measurement system will provide fast measurement of one or more droplet parameters, easy maintenance, and provide input that can be used to adjust printing, thereby facilitating precise quality control for use in industrial product manufacturing processes. Among. The present invention addresses these needs and provides other related advantages.

According to one aspect of the present invention, a system for measuring parameters related to droplets ejected from a plurality of nozzles of a printing head is disclosed. The system includes: a film with a first surface and a second surface, the first surface will be positioned near the print head to provide a substrate to receive ink droplets from the plurality of nozzles; an image capturing subsystem, Positioned to shoot an image through the second side of the film, the image represents ink droplets received from nozzles located at respective positions of the nozzles, and the image capturing subsystem is used to generate an output signal to deliver the captured image To an image processing system; and a mechanism for advancing the film to position a brand new part of the film for a subsequent image capturing process, wherein the droplets from the plurality of nozzles of the printing head are received in the first part of the film Above the surface, the advancement of the film does not require repositioning of the print head or the imaging subsystem.

According to one aspect of the present invention, a method for measuring droplet parameters is to measure a parameter related to droplets ejected from a plurality of nozzles of a printing head. The method includes: providing a film having a first surface and a second surface, and positioning the first surface near the printing head to provide a substrate to receive ink droplets from the plurality of nozzles; using an image capturing device Shoot through the second side of the film An image representing ink droplets received from nozzles located at respective positions of the nozzles, and correspondingly generating an output signal to deliver the captured image to an image processing system; and advancing the film to capture a subsequent image The program locates a brand new part of the film, in which droplets from a plurality of nozzles of the print head are received on the first surface of the film in a way that does not require repositioning of the print head or the imaging device .

According to one aspect of the present invention, an apparatus includes: a printer for receiving a first substrate, the printer having a print head, the print head contains a plurality of nozzles, the plurality of nozzles are used to eject an ink on On the first substrate, the ink contains a liquid that will be hardened on the first substrate to form a permanent stack of an electronic device thereon, the permanent stack of the electronic device having A thickness; and a system for measuring a parameter related to the droplets ejected by the plurality of nozzles of the print head. The system includes: a film having a first surface and a second surface, the first surface will be positioned near the print head to provide a second substrate to receive ink droplets from the plurality of nozzles; an image capturing sub The system is positioned to shoot an image through the second surface of the film. The image represents ink droplets received from nozzles located at respective positions of the nozzles. The image capturing subsystem is used to generate an output signal to capture the image. The image is sent to an image processing system; and a mechanism for advancing the film to position a brand new part of the film for a subsequent image capturing process, wherein the droplets from the plurality of nozzles of the print head are received in the film Above the first surface, the advancement of the film does not require the repositioning of the print head or the imaging subsystem.

101: Flow Chart

103-123: Steps

201: Droplet measurement system

203: Measurement window

205: Arrow

207: Reel

209: Vacuum port

211: winch

213: Chassis

301: Droplet measurement system

303: Inspection Window

305: Optical components

307: Camera

309: Light Source

311: stepping motor

313: Direction indicator arrow

315: winch

317: UV curing rod

319: Interface and Control Panel

321: Film Rolling Motor

323: Film winding motor

403: Vacuum port

405: Film tape supply reel

407: Film tape storage reel

409: Frame and Optical Chamber

411: Direction indicator arrow

412: Direction indicator arrow

415: Direction indicator arrow

501: Method of performing droplet measurement

503-533: Steps and related items

551: sample image

571: sample image

601: Different implementation levels

603: Non-transitory machine readable media

605: Computer

607: storage media

609: Manufacturing Device

611: Semi-finished flat panel device array

613: Portable Digital Device

615: TV display screen

617: Solar Panel

621: Multi-chamber manufacturing equipment

623: Conveying Module

625: printing module

627: Processing Module

629: Input load lock

631: delivery chamber

633: Environmental Buffer Chamber

635: Gas Hood

636: delivery chamber

637: output load lock

639: Nitrogen accumulation buffer

641: curing chamber

701: droplet measurement system

703: Print head assembly

705A: Print head

705B: print head

707: Nozzle

708: Three-dimensional coordinate system

709: Chassis

711A: mobile system

711B: Optical recovery under the plane

711C: Under-plane light source supply

713: Dimensional Plane

715: measurement area

717: light source

719: Optical delivery optics

721: Light Sensor

723: Reply Optics

725: Focusing lens

727: Non-imaging device

731: Droplet measurement process

733-753: Steps and related items

781: method

783-797: Steps and related items

801: Typical configuration in industrial manufacturing equipment

803: Printed closed chamber

805: Second Closed Environment

807: print head assembly

809: Arrow

811: Sliding Rod

813: substrate

815: Floating Platform

817: Droplet measurement system

819: park position

821: Arrow

823: Dimension Reference

825: Y axis

857: Transfer Direction

865: nozzle

867: Nozzle interval

901: Chart

1001: Flow chart

1003-1013: Steps and related items

Figure 1 is a flowchart illustrating the technique used to measure a droplet parameter.

Figure 2 is a close-up perspective view of a droplet measurement system.

Figure 3 is a cross-sectional view of a droplet measurement system.

Figure 4A is another perspective view of a droplet measuring system.

Fig. 4B is a perspective view of the 4A droplet measurement system taken from the commanding height of the arrow B-B in Fig. 4A.

FIG. 5A is a flowchart related to the image processing technology used in an embodiment.

Fig. 5B represents a sample shot of a sample of liquid droplets deposited on a medium, followed by gray-scale conversion.

FIG. 5C is the filtering (for example, gradient processing) of the captured image of FIG. 5B.

FIG. 6A is an exemplary schematic diagram showing the production level of related product manufacturing; the technology disclosed herein can, but is not limited to, be implemented at any level in the drawn level.

Figure 6B shows a manufacturing facility in plan view.

Figure 7A is an illustrative depiction of the use of a droplet measurement system.

Fig. 7B is a flow chart of droplet measurement.

Figure 7C is a flow chart related to droplet verification.

Figure 8A is a cross-sectional depiction of a component in an industrial printer located inside a printing room.

Fig. 8B is a cross-sectional depiction of the industrial printer of Fig. 8A taken along the line B-B in Fig. 8A.

Figure 9 is a schematic diagram showing a comparison of the measured droplet position relative to one of the respective expected positions.

Figure 10 is a flow chart about the calculation of droplet volume.

The subject matter defined by the listed claims can be better understood by referring to the following detailed descriptions. The review of these descriptions should be carried out in accordance with the attached drawings. The descriptions of these one or more specific embodiments are listed below to allow people to construct and use various implementations of the technologies listed in the claims, but they are not intended to limit the scope of the listed patents. Rather, it explains its application. Without being limited to the foregoing, the present disclosure provides some different examples of a droplet measurement system that optically measures or images a plurality of droplets on a medium, and uses image processing to identify those used in industrial manufacturing One of the parameter values of the various nozzles of the print head. These various technologies can be implemented as a droplet measurement system, a printing press or manufacturing equipment, or software for executing the technology, in the form of a computer, printing press, or other device that runs the software, or by Produced by these technologies A form of electronic or other device (for example, a tablet device or other consumer terminal device). Although it provides specific examples, the principles described herein can also be applied to other methods, devices, and systems.

In one embodiment, a droplet measurement system receives ink droplets from various nozzles of one or more print heads, and then uses optical analysis to measure the various droplets associated with and/or the various printhead nozzles that produced the droplets A value of one of the parameters. More specifically, as will be described below, some embodiments use a deposition tape in the service tray of the printer for test printing with inks from various nozzles at the same time. In an advantageous embodiment, this belt can be any medium that can receive ink droplets, and in the noteworthy embodiments described below, it includes a transparent film that has been specially treated to hold wet ink droplets. Much like photographic paper. And, in one embodiment, the system is applied to an industrial manufacturing facility, where the droplets to be deposited are transparent or translucent (for example, representing a material that will be deposited and cured to form a panel An encapsulation layer of a device (such as a display or solar panel, or the light-emitting element of this device). This transparency makes it possible to capture images in groups of one or more droplets for a group of multiple nozzles; in an alternative embodiment, droplet deposition can be combined with the film and the imaging nozzle position (located behind the film) The separation from each other provides an extremely fast measurement of droplet position offset (relative to the ideal droplet position) and/or volume and/or timing error associated with droplet deposition.

In one embodiment, for measurement, one or more print heads are parked in an inspection station, for example, when a substrate is loaded or unloaded into the printer (so it is in the printer/manufacturing When the equipment is used for other purposes). When the print head is parked, it is incorporated into the droplet measurement system in a manner that is aligned at a specific position with respect to one or more print heads to bring the deposition medium (for example, the above-mentioned transparent film) into the one or more print heads. Near the print head. It then causes nozzles from one or more print heads (e.g., a window or sub-array containing a subset of all nozzles) to eject a drop or a series of droplets (e.g., 2, 5, 10, etc.), Make the droplets fall on the medium close to a desired position of the specific nozzle. here During or after this period, the film is imaged from the side of the film opposite to the printing head, effectively passing through the transparent film; in other words, the film is accurately positioned at a normal deposition distance relative to the nozzle being measured (for example, , <1.0 mm), and by firing multiple nozzles at the same time (or shortly thereafter) to measure the nozzles, and then by shooting an image through the other side of the film, the resulting shot image is then image processed And get the droplet parameter value.

The following is an annotation of some of the advantages of the features of the various embodiments described so far. First, the optical processing of the deposited droplets that pass through the transparent film is particularly suitable for extremely large print heads with hundreds to thousands of nozzles, which means that the optical processing can be performed immediately without additional mobile printing. Head, droplet measurement system, or other components. Second, the droplet measurement system can be configured to measure droplets from multiple nozzles at the same time; for example, it is possible to eject droplets from hundreds of nozzles and measure them at the same time. When compared to systems that optically image individual droplets in flight (e.g., one drop at a time), such simultaneity can greatly facilitate thousands of print head nozzles (e.g., as used in some industrial manufacturing (Applicable) droplet measurement between. For systems that rely on droplet parameters to dynamically update measurements, in order to combine droplets in a way that reduces variation or compensates for variations that produce accurate target volumes, this simultaneity may be important because it does not require any impact on printing time or manufacturing. There is a significant interruption in output. For a droplet measurement system that connects one or more parked print heads in a repair station, this provides easy access to any of the thousands of print nozzles that can be used in some industrial processes And accurate access. Moreover, the deposited film strip or its treatment can be specially adjusted to match the chemical properties of a specific ink to be tested (that is, its properties can be more conveniently and accurately determined by optical mechanisms). It should be obvious that the technology provides enhanced accuracy and lower cost for the manufacture of products, for example, especially for price-sensitive consumer products such as flat-panel high-definition televisions ("HDTV").

In at least one of the designs described below, the above-mentioned droplet measurement system utilizes a roll-to-roll mechanism to load a transparent film, which allows the film to be placed on an imaging area like a roll of film. Advance to allow intermittent replacement of film rolls used for measurement. In addition, the droplet measurement system can also advantageously use a vacuum system that tightly adheres to the portion of the film tape being deposited to form a flat and precise positional relationship with each other, simulating an online deposition surface. The droplet measurement system can also optionally include a curing station to cure/air-dry the ink, so that after the measurement, additional ink is prohibited from spreading to any other part of the system; please note that this is wrong in some embodiments It is necessary, for example, that the thin film can also be selected or processed to have properties such that the ink droplets are immediately fixed once they are deposited. In addition, as mentioned above, the droplet measurement system can be selectively loaded on a three-dimensional movable carrier, in other words, to engage a parked print head from below along a vertical (V) axis, and Move along the x (and optionally y) axis as needed to reach different nozzles and different print heads. This allows a "large" print head assembly (for example, one with thousands of nozzles) to be connected to a printing plane (for example, in an overhaul carriage) under the aforementioned droplet measurement system and used When measuring the parameters of the nozzles of different groups, the parameters remain fixed. A hypothetical deposition process advances a roll of film tape so that a window of unused film tape is adjacent to the selected print head. These print heads are then controlled so that all nozzles eject a specific amount of ink, which are then fixed to the Above the film tape; at the same time, a coaxial camera from below (for example, located in a housing or cabinet of the droplet measurement system) and the image sensor parallel to image all deposited droplets (similarly, by passing through the The image shooting of the opposite side of the film strip makes the film and the droplet measurement system basically do not need to be moved or repositioned for analysis). If necessary, the camera (or image capturing optics) can be set to be able to move relative to the droplet measurement system, for example, to provide scanning activities between nozzles in a certain range, focus adjustment, or other assistance as needed .

The output of an image processing system then provides droplet parameter data suitable for verifying nozzles or otherwise planning printing. Immediately after any specific measurement iteration step, the film tape and the droplet measurement system are each pushed into place, the used film tape is cured and/or rolled up, and then the process is repeated immediately or at a later time as needed Click repeat. In the design where the film tape cannot be reused once it is printed, a used film tape roll (or a film tape cassette, which has a place for new and used film tape) The used reels and winches) can be recycled or replaced periodically on a module basis. Note that in an envisaged application, one of the manufacturing mechanisms is used continuously (for example, to print a stack of OLED TV screens, or to manufacture one of one or more flat-panel devices in other ways), when a previous The substrate is unloaded, the print head is parked to accept the aforementioned droplet measurement, and as long as a new subsequent substrate is ready, the measurement progress is stored, the print head returns to the active printing job, etc.; when the subsequent substrate is completed , The print head returns to the inspection station again (when a new substrate is loaded) to start the measurement where the system previously stopped. In this way, repeated measurements can be collected for nozzles and used on a scrolling basis to establish a statistical distribution for each printing nozzle or nozzle waveform combination through many measurements (e.g., as in the patent application in the priority statement). As mentioned, these patent applications are incorporated herein by reference), using a moving measurement window, which advances cyclically through all the printing nozzle sets to continuously update the measurement data.

Note that all the process steps listed above (and below) can be implemented in a variety of ways. For example, in one embodiment, with special-purpose hardware or general-purpose hardware configured to operate as a special-purpose machine, these steps are performed by one or more computers or other types of machines (such as A printer or one or more manufacturing devices) execute. For example, in a contemplated design, one or more operations can be performed by one or more of these machines, which are stored on non-transitory machine-readable media such as firmware or Actions under software command control. The way these instructions are written or designed to have a specific structure (structural characteristics), so that when the instructions are finally executed, they will cause one or more general-purpose machines (for example, processors, computers, or other machines) to behave It can be like a special-purpose machine with the necessary structure to perform the descriptive tasks on the input operands to take actions or produce output in other ways. "Non-transitory machine-readable medium" means any tangible (meaning physical) storage medium, no matter how data is stored on it, including but not limited to random access memory, hard disk memory, optical Memory, floppy disks or CDs, server storage devices, volatile memory, and other tangible mechanisms in which commands can be later retrieved by a machine. The machine-readable medium may be in a stand-alone form (for example, a program disc) or implemented as part of a larger mechanism, such as a laptop computer, Portable devices, servers, networks, printers, or other device sets consisting of one or more devices. These instructions can be implemented in different formats, for example, implemented as metadata that effectively invokes a specific action when called, implemented as Java code or script, implemented as a code written in a specific programming language (For example, implemented as C++ program code), implemented as a specific processor instruction set, or implemented in some other form; these instructions can also be executed by the same processor or different processors, depending on the embodiment. In the entire content of this disclosure, various processes will be described, any of which can basically be implemented as instructions stored on a non-transitory machine-readable medium, and any of them can use a "3D" "Print" or other printing procedures to manufacture products. Depending on the product design, these products can be manufactured in a form that can be sold, or as a preliminary step for other printing, curing, manufacturing or other processing steps, which will eventually produce finished products for sale, distribution, and export Or import. Depending on the implementation, the instructions on the non-transitory machine-readable medium can be executed by a single computer, while in other cases, they can be stored and/or executed on a distributed basis, for example, using one or Multiple servers, network client devices, or specific application devices. Each function described can be implemented as part of a combined program or implemented as an independent module, stored together on a single media (for example, a single floppy disk), or stored on multiple separate storage devices .

In addition, it should be noted that the term "transparent" is a relative term when used in conjunction with a film or film tape, meaning that it means that it is photographed through a second side of the film tape and deposited on one of the first side of the film tape. The image of the droplet above. Strictly speaking, this does not mean that the film tape must be colorless, or that, for this issue, it can be transparent to visible light. In one embodiment, the film strip is colorless and has a high visible light transmittance, and the visible light is used to capture the image of the droplets from the respective nozzles, wherein the droplets are deposited in such a way that the respective nozzles The droplets are arranged in an array on the first side of the film strip (that is, located at respective positions related to respective nozzles). In another embodiment, the film strip has a certain degree of color, for example, it is optimized to a specific ink to enhance the image capturing properties of the ink. In yet another embodiment, it uses radiation instead of visible light to capture the droplet properties.

From the description of this article, various other features will be obvious to those familiar with the relevant technology. Having introduced the features of some embodiments, the following disclosure will turn to provide further details on selected embodiments.

Figure 1 shows a flowchart 101 that illustrates some of the techniques described herein. As shown above, it is necessary to measure the values of the droplet parameters of the droplets produced by many nozzles at the same time. In order to perform this action as quickly as possible, the embodiments disclosed herein rely on receiving an image capture of the deposition surface of one of these droplets (that is, a rapid capture of the droplets that collectively represent the many nozzles), and capture from this image Image processing for calculating one or more required parameters relative to the plurality of nozzles. As indicated by reference number 103, one or more print heads under analysis cause a range of nozzles or an array of nozzles to eject, thereby depositing one or more droplets each. For example, it may be that a hypothetical print head has two thousand nozzles, and these nozzles are scheduled to be measured in groups of one hundred nozzles at the same time. For each measurement iteration step, the print head and/or the droplet measurement system are aligned, and the window or group of one hundred nozzles to be measured is identified and causes them to eject a controlled amount of ink approximately simultaneously In one embodiment, the above-mentioned deposition may be a single droplet per nozzle, while in other embodiments, each nozzle can be controlled to eject a larger number of droplets, for example, 2, 5, 10, 12, 20, or other number of droplets. Note that in some conceived designs (for example, OLED applications), the droplet size is usually quite small, including picoliter (pL) size droplets with a diameter coefficient of ten microns or less, which is close to micron precision. Deposition.

As described in the patent application incorporated herein by reference in the priority statement, depending on the application, it may be necessary to measure the position of the deposited droplet, the droplet velocity, the droplet volume, the nozzle warpage, or the amount of each nozzle. Or multiple other parameters. In short, in one embodiment, for each deposited droplet, the droplet quality of each nozzle can be expected to be of importance; that is, if one nozzle is relative to the others If it is at a stop position (nozzle warpage) or a droplet trajectory that deviates from the normal track or an inaccurate droplet volume, this may cause unevenness on a deposited film. This unevenness may cause quality defects on precision products such as display devices. For nozzles to understand this deficiency one by one The trap makes it possible to achieve: Nozzle Pass/Fail: It can identify nozzles that are not working or have other bad characteristics and screen them out of the printing operation. The printing method of software planning can use a different nozzle to deposit a liquid. Drops on a predetermined area; the emission time is relieved: the positional defects in the scanning direction can be corrected by changing the nozzle drive pulses related to the timing or voltage, for example, to make the nozzles erupt earlier or later, or with a larger Or a lower velocity injection; in addition, it is also possible to use alternating drive pulse shapes, as disclosed in the patent application incorporated herein by reference in the priority statement.

Planar droplet combination: The difference between the detected nozzles can be accepted and deliberately used to calculate the droplet combination according to the respective expected values to achieve an accurate result, for example, within a specific tolerance; For example, if a nozzle is measured and judged to produce the expected 9.89 picoliters (pL) droplets, a second nozzle is measured and judged to produce the expected 10.11pL droplets, and it is expected to produce the total If the ink volume of 20.00pL is at a specific target position, the two nozzles can be specially designated and planned to print to deposit this special droplet combination; please note that the result that can be obtained is different from that of simply averaging the difference without considering System for specific filling volume or filling tolerance (for example, target volume ±0.50%); and pre-screening of drive waveforms: As shown in the patent application incorporated herein by reference in the priority statement, it is possible to pre-screen each nozzle Programmable driving waveforms (for example, a selection from sixteen pre-selected driving waveforms) for inventory use during printing, which selects each waveform to achieve a specific deposition characteristic, accuracy, and desired result.

Please note that the droplet parameters may vary from day to day, or even different for each deposition, for example, depending on ink quality, temperature, nozzle age (for example, clogging), and other factors. In order to ensure printing accuracy, therefore, in some embodiments, it may be necessary to re-measure these values from time to time. It should also be noted that each deposited droplet may be slightly different, even from a single nozzle; therefore, in one embodiment, each nozzle (or nozzle waveform combination or pairing) is measured more than once, Instead, the total number of measurements is accumulated multiple times, and an average value or other statistical parameters (for example, a spread measure) can be calculated from it to provide a high degree of confidence in the relevant expected value of the droplet parameter. Spend. For example, it can measure "24" droplets from each nozzle-waveform pair to obtain the average value of volume, velocity, warpage (position orthogonal to the scanning direction), etc. (and thus obtain these items One of the expected values), where the number of measurements n (n=24) helps reduce the uncertainty due to measurement errors or statistical variations. It can be based on a scrolling basis (for example, all measurements are stored, and the 6 latest measurements for each nozzle every two hours replace the 6 oldest measurements) or on a one-time basis (for example, during startup Re-measure all nozzles at once) update the total number of specific measurements. Those familiar with the relevant technology will envision many variations. For example, a nozzle can be measured to determine a desired value, and if the measured (expected) value lies outside the ±5% zone of an ideal value, the nozzle will be lost Qualifications for use; many permutations and variations are clearly possible.

However, it should be clearly visible that in a printing system that uses thousands of nozzles (for example, tens of thousands or more nozzles, each with multiple available "pre-screened" drive waveforms), each The measurement of the expected droplet parameters of a nozzle can take a lot of time; in an industrial manufacturing environment, this is usually unacceptable. In other words, if it is to be commercially viable, the manufacturing output and cost required for the production of the product Must be located at an acceptable consumer price point, and this usually means that the printing process produces as many products as possible, has as much accuracy as possible (and less product waste), and has as little as possible Downtime. The technology disclosed in this article enables far more rapid measurement, and thus more feasible measurement becomes possible.

Returning to FIG. 1, in order to achieve this effect, the droplet measurement technique proposed in the present disclosure also captures droplets from many nozzles at a time, refer to 105. In other words, in contrast to systems that "one at a time" imaging droplets in flight, the embodiments proposed in this disclosure rely on simultaneity to measure as many nozzles as possible at the same time. Therefore, image capture can be used to effectively obtain an image containing many droplets from a large nozzle array, for example, droplets deposited in multiple rows and rows, which can be quickly processed by an image processing system with software. In one embodiment, a shot image can represent dozens of nozzles, and maybe The droplets of hundreds of nozzles (or more) are all measured simultaneously. Figure 1 shows the various options that can promote this goal in the dashed box. For example, (a) shoot an image through the deposition surface on the opposite side of the print head (107), which helps speed measurement, (b) a In the shooting image, both the droplet and the nozzle are shot at the same time (109), which assists the measurement of the position shift, warpage, or velocity of the droplet from each nozzle. (c) Simultaneously ) Nozzle droplets are photographed (111), for example, forty or more nozzles are actually measured at a time, and (d) instead of taking one droplet for each nozzle, it measures one droplet at the same time (for example, , 5 or more) a collection of droplets. Please note that in the latter case, the image processing software can detect the volume of a pooled deposition (for example, the volume), or the range of the droplet position near the expected position, and can identify individual droplets at a time from a single shot image. Average value, or other statistical parameters such as distribution (distance). Please note that depending on the embodiment, it may be necessary to measure a standard in advance and store it in the system; for example, when the ink droplets are fixed in the deposition medium (that is, the film tape), it may be difficult to detect. Measure the volume of the droplet; this judgment can be based on the treatment of the droplet diameter, the color (or gray scale) value of a deposited droplet, or the way to make a judgment, and use these values to compare with a calibration standard to produce an accurate Numerical estimation of.

As indicated by reference numerals 115 and 117, the system (for example, using an image processor running appropriate software) then calculates the measured value and stores it in memory (for example, such as in an available hard drive Random access memory). In one embodiment, these values are stored individually (that is, each measurement of each parameter to be measured for each nozzle is stored once), while in another embodiment, they can be stored as a Represents a mixture distribution (for example, as an average value of a specific parameter of a specific nozzle, total number of measurements, standard deviation, etc.) to be stored. With reference to numbers 119, 121, and 123, as previously mentioned, the measured values can be optionally used to calculate a statistical distribution, to perform nozzle qualification/verification, and to perform "smart combinations", among which are The print scan is planned to match droplets with expected characteristics in a certain desired way.

Figures 2 to 4B are used to depict an embodiment of a modularized droplet measurement system.

Figure 2 shows a close-up view of a first such system 201. This view depicts a measurement window 203 (for example, a glass-covered viewing window) through which images are taken along a vector denoted by reference numeral 205. An optical detector, such as a camera, is located in the system 201 and takes pictures through the window 203 in the direction of the arrow 205. During operation, a transparent film tape from the reel 207 is pushed above the window, and a set of vacuum ports 209 are closely attached to the window. Immediately after each measurement, the film tape can be pushed in the direction of the winch 211 and accumulated in a waste reel (not shown in the figure) held in a chassis 213 of the droplet measurement system. Please note that the depicted system is modular and moves in the form of a unit, for example, to position the measurement window 203 (and the related measurement area defined by this window) in close proximity to any print head nozzles to be measured , It is a "standard deposition depth" relative to a nozzle plate of the printing head. In an alternative embodiment, the droplet measuring system 201 can be connected in a three-dimensional form, so that the system can be arranged adjacent to other sets of nozzles, and the deposition height can be changed according to needs.

FIG. 3 shows an internal cross-sectional view of one of the droplet measurement system 301. This system similarly includes a viewing window 303 through which images are taken, and an optical system including an optical component 305, a camera 307, and a light source 309. A stepping motor 311 selectively advances the optical assembly 305 linearly with respect to the viewing window 303, that is, back and forth in the direction indicated by the arrow 313. Please note that in this specification, "camera" can optionally refer to any type of light sensor, which means that it is possible to use a simple line sensor including individual optical sensors, and for example , "Sweep" the line sensor back and forth to use the stepping motor 311 to image the entire inspection window 303. In other embodiments, the camera uses any conventional mechanism, for example, a commercial photosensitive camera, a charge couple device array, an ultraviolet or other invisible light radiation imaging device, or other methods to photograph the representative inspection An image of a pixel array of a region. Please note that camera movement (ie, scanning movement) is not necessary for all embodiments. In the depicted embodiment, the optical component 305 also includes a beam splitter inside, which allows light from the light source to pass (for example, upwards to the inspection window 303), but uses a beam splitter in the direction of the camera 307 The mirror deflects the returning (reflected) light. It should Obviously, the light from the light source passes through the inspection window, passes through the transparent film belt, reflects from the print head (not shown in Figure 3), and returns to pass through the transparent film belt again, and accepts any focusing or other optical actions, and is photographed and processed. For analysis. A captured image thus provides a visible indication of the position of each measured nozzle (for example, this image is taken from the reflection of the nozzle plate) and also shows the stack of any deposited droplets (which are transparent but distinguishable from the film) cover. In other words, in the envisaged manufacturing process (especially for OLED display manufacturing, for example, for an encapsulation layer), the deposition material is semi-transparent, so it does not block the image capture of the nozzle plate. FIG. 3 also shows a winch 315 for transporting the transparent film tape, and a UV curing rod 317 for curing any deposited ink to prevent the deposited ink from being transferred to any other system components. Figure 3 also shows an interface and control board 319 for the control of various system components and control for image capture; this interface and control board 319 also control the transport of the film tape, for example, by controlling the respective Film rolling motors 321 and 323 used for film storage and supply rolls (this is not separately indicated in the figure). Depending on the embodiment, the image processing may be performed locally on the interface and control board 319, or, alternatively, performed in a processor located in a manufacturing facility or on a remote computer.

4A and 4B show a perspective view of the droplet measurement system 301 of FIG. 3. Fig. 4B represents a perspective view of the back side of the unit relative to Fig. 4A, that is, a view from the commanding height provided by the arrow B-B in Fig. 4A. More specifically, these drawings show the inspection window 303, the vacuum port 403, the UV curing rod 317, a film tape supply reel 405 and a receiving reel 407, and a frame and optical chamber 409 (which contains Interface and control board 319, as previously described). During operation, it supplies the unused film tape in the direction indicated by the arrow 411, and adheres tightly to the inspection window 303, as mentioned previously. From this point on, the film is pushed down on the winch 315 along the arrow 412 toward the UV curing rod 317 for the purpose previously described. The operation of the aforementioned UV curing rod is controlled by the interface and control board 319, using on-board firmware or software stored in a non-transitory machine-readable medium. Finally, after curing, the film is pushed onto the storage reel 407 substantially as indicated by the arrow 415. It should be clearly visible that the entire unit is modular, providing ease of removal and maintenance, for example, removing one of the transparent deposition film tapes to complete the storage reel 407, and replacing the supply The reel 405 should have a brand new feed.

FIG. 5A presents a flowchart associated with an embodiment 501 of a method for performing droplet measurement. As mentioned earlier, it may be necessary to perform on-site measurements, which means that measurements are performed directly in a manufacturing facility to dynamically update the value of one or more droplet parameters for process, age, temperature, or other factors. For this purpose, it is advantageous to perform measurements in a maintenance station of a printing press, for example, when a new substrate is being loaded, unloaded, cured after deposition, or other idle periods relative to actual printing. With reference to reference numeral 503, one or more print heads (eg, loaded into a common print head assembly) are advanced to the repair station and "parked" for maintenance operations. This maintenance action may include various calibrations, print head replacement, nozzle cleaning, or other quality processing, droplet measurement as conceived in the present disclosure, or other uses. As will be explained more fully below, for OLED display manufacturing applications (and the manufacturing of certain other devices, such as solar panels), it may want to perform printing in a controlled environment; therefore, in many applications In this case, the "parking" position will be located in a second controlled environment chamber, for example, in a chamber that can be operated externally (for example, for print head replacement) without the need to connect the entire manufacturing facility or printing machine to one In the location of an uncontrolled environment. That is to say, this second chamber is manufactured in a preferred embodiment to have a small size relative to any closed space for printing, for example, occupying 2% or less of the volume of the entire printing chamber Space to minimize leakage (if any). Once the print head is parked, it is sealed in this second controlled environment, and the aforementioned droplet measurement system ("DMU", stands for droplet measurement unit) is selectively engaged to perform the measurement (505). As noted in the optional process block 507, if the printing is moving the window for one of the nozzles (for example, where different nozzle sets are used between printing rounds as mentioned previously when the substrate is loaded or unloaded) Measurement or re-measurement) is performed on an intermittent basis, and the system captures the initial address to locate the DMU and shoot the selected subset of nozzles. Please note that this process can use an alignment procedure to identify the corner nozzles of each print head (for example, update when a print head is replaced, so that the system is calibrated to "know" the approximate position of each nozzle). This alignment procedure can be imaged by connecting the aforementioned DMU (and its camera), And thereby find the corner nozzles of each array, and use an approximate location addressing and search program (for example, spiral search algorithm) to execute, for example, as the previously cited US Patent No. 14/340403 As mentioned in the application. The system is very precise in controlling the position of the throwing position, for example, to a precision of about one micron, and usually the recalibration of the positioning of the droplet measurement system by the print head is not necessary unless a system component is manually replaced (for example, , DMU or a print head is removed or repaired). When a transparent film strip (that is, the droplet deposition surface for testing) is positioned, refer to reference number 509, the system controls the print head nozzles under inspection to deposit a controlled number of droplets (rapidly and continuously, if every If each nozzle is scheduled to measure multiple droplets). At the same time, the image capture system in the DMU images the deposited ink and the nozzle position (for example, through the transparent film tape and ink to capture the light reflected by the print head). Please note that, as indicated by reference numeral 511, in one embodiment, the image capturing is performed in color to be able to identify the ink concentration in any deposited ink droplet (for example, when it is translucent, it will depend on the material or thickness Give subtle color properties). As indicated by reference number 511, a captured image can be filtered (for example, for color, intensity, gamma, or one or more other required parameters) to produce a filtered image; next After this filtering action (or as part of this filtering action), the captured image is converted to grayscale, refer to 513. Please note that multiple images can also be generated from this process according to individual filters. For example, a first image representing a nozzle and a second image representing a deposited droplet; obviously, there are many transformations. The image processing software then uses the output grayscale image(s) to identify nozzles, ink droplets, position differences between nozzles and ink droplets, droplet volume, droplet diameter, droplet shape, and/or any Other required parameters (515/517). It should be obvious that measuring all the above items is not necessary in all embodiments. For example, in a system that calculates the volume of a droplet, it may not need to image the nozzle itself, or analyze the shape or position of the droplet. On the contrary, in this embodiment (if the spreading range of multiple droplets is being analyzed), it is important to determine the deviation value of the droplet position or perform color analysis to calculate the volume correctly. The parameters measured will basically depend on the implementation and the desired result. As indicated by number 517, no matter what parameter is measured, the system will calculate One or more measured values, or the offset of a parameter, for example, using an optional criterion 519, as previously described. The offset or value of a parameter can be calculated for the position of the droplet or nozzle, the timing of the droplet, or the volume of the droplet, or any combination of these items, as indicated by the reference number 521. The system then updates one of the local or remote DMU storage information repository (523), and it then stores the position for the next measurement iteration step and advances the membrane tape, referring to the optional process 525. The process is thus completed and ready for another measurement iteration step (which can be executed immediately or at a later point in time, for example, following a subsequent round of substrate operations).

Please note that, as marked with reference numbers 529 to 533, the calculation of parameters and/or any positional offset can optionally be performed by one or more processors running appropriate software (instructions stored on a processor-readable medium) These processors usually store image data in the processor’s accessible memory, isolate the individual image data of each nozzle, calculate the parameters from the individual image data, and also store the parameters of each nozzle for processing The device can access the memory.

Figures 5B and 5C show sample images 551 and 571, respectively. The first of these, image 551, represents a photograph taken from a subset of approximately 40 nozzles of a printing head. Note how the nozzles are slightly staggered from row to row to provide a choice of tight pitch variation in an intersecting scan axis (for example, a droplet scheduled to be sprayed to a specific substrate position can be selected from any The nozzle row printing, in some embodiments, provides better than, that is, less than twenty microns of deposition accuracy). Figure 5B represents a color image, which can then be filtered and/or converted into a grayscale format as appropriate. It is also a grayscale image after this filtering or conversion action (because color is usually not used or not allowed in patent applications). figure). Please note that in this embodiment, the nozzles are not separately imaged or depicted, although this may be the case in other embodiments. The second image 571 (FIG. 5C) represents the image of FIG. 5B after filtering and gradient processing to identify the droplet diameter. In other words, FIG. 5C shows a white circle corresponding to the diameter of the droplet, with a clearly distinguishable droplet boundary. Image processing calculates a center of gravity (for example, by calculating the horizontal maximum diameter and vertical maximum diameter of these "circles" and by taking the middle right-angled coordinate points along each diameter (medial Cartesian coordinate point), so that each droplet is associated with a specific xy rectangular coordinate position). This position can then be compared with the nozzle position to determine the offset. The system recognizes the offset variation between nozzles for printing planning. These photos can also represent droplet volume processing; for example, image processing software can calculate the diameter and/or area and/or associated color of each droplet, and compare this with a factory-defined standard or a field-defined standard Compare to calculate the size and density, and thus calculate the volume. Almost any required droplet parameter can be measured in this way.

The above describes a specific droplet measurement system, and the following will describe its application to manufacturing and to an industrial manufacturing equipment/printing machine. In the following description, an exemplary system for performing this printing will be described, more specifically, applied to the production of solar panels and/or display devices that can be used in electronic devices (for example, smart phones). , Smart watches, tablets, computers, TVs, monitors, or other forms of displays). The manufacturing technology provided by the present disclosure is not limited to this specific scope. For example, it can be applied to any 3D printing application and to a wide range of other forms of products.

Figure 6A depicts a number of different implementation levels, collectively labeled with reference number 601; each of these levels represents a possible independent implementation of the technology described herein. First, the technology as introduced in this disclosure can take the form of instructions stored in a non-transitory machine-readable medium, as represented by the graphic 603 (for example, the executable used to control a computer or a printer). Instructions or software). For example, the disclosed technology can be implemented as software that is adjusted to enable a manufacturing device (or an included printer) to measure one or more droplet parameters using the optical measurement technology disclosed herein. Second, according to the computer icon 605, these technologies can also be selectively implemented as part of a computer or network, for example, within a company that designs or manufactures components for sale or use in other products. Third, as the example of using a storage media graphic 607, the previously introduced technology can take the form of a stored printer control command. For example, when enabled, it will cause a printer to perform a method that relies on droplet measurement and related planning. (For example, scan path planning or nozzle qualification verification, as described in this article) One or more laminates in a component are made in a way. Please note that the printer command can be sent directly to a printer, for example, via a LAN or WAN; in this context, the depicted storage media graphics can represent (but not limited to) internal RAM, or a servo RAM, portable devices, laptops, other forms of computers or RAM that can be accessed by a printer, or portable media such as pen drives. Fourth, as shown by the same manufacturing device icon 609, the technology introduced above can be implemented as a part of a manufacturing facility or machine, or presented as such a facility or machine (for example, as a droplet measurement system based on the technology disclosed herein). , As a manufacturing method, as a software used to control a droplet measurement system, etc.) In the form of a printing press. It should be noted that the special depiction of the manufacturing device 609 represents an exemplary printer device described below in conjunction with FIGS. 6B, 7A, and 7B. The technology introduced above can also be implemented as a complete or partially complete manufacturing component or a component in a manufacturing component (for example, manufactured according to a patent process); for example, in FIG. 6A, some of these components are depicted In the form of an array 611 of semi-finished tablet devices, it will be separated and sold to be included in the terminal consumer products. The depicted device may have, for example, one or more encapsulation laminates or other laminates manufactured by the method described above. The technology introduced above can also be implemented in the form of the above-mentioned terminal consumer products, for example, in the form of a portable digital device 613 (for example, an electronic tablet device or a smart phone), a TV display screen 615 (for example, an OLED TV ), solar panels 617, or other types of devices.

FIG. 6B shows a conceived multi-chamber manufacturing equipment 621 that can be used to apply the technology disclosed herein. In summary, the depicted device 621 includes some general modules or subsystems, including a conveying module 623, a printing module 625, and a processing module 627. Each module maintains a controlled environment, for example, so that printing can be performed by the printing module 625 in a first controlled environment, and other processes, such as other deposition procedures such as the deposition of an inorganic encapsulation layer Or a curing process (for example, for printed materials) can be executed in a second controlled environment. The device 621 uses one or more mechanical loaders to move a substrate between modules without exposing the substrate to an uncontrolled environment. Within any specific module, it may use other substrate handling systems and/or specific devices and control systems, Adapt to the processing that the module is scheduled to execute.

Various embodiments of the delivery module 623 may include an input load lock (loadlock) 629 (that is, a chamber that provides buffering between different environments while maintaining a controlled environment), and a delivery chamber 631 (which also has A loader to transport a substrate), and an environmental buffer chamber 633. Within the printing module 625, it is possible to use other substrate loading and unloading mechanisms, such as a floating table (flotation table) for stable support of a substrate during a printing process. In addition, an xyz transfer system, such as a split shaft or overhead transfer system, can be used for precise positioning of at least one print head relative to the substrate, and a y-axis transfer system is provided for the substrate to be transported through the printing module 625. It is also possible to use multiple inks for printing in the printing chamber. For example, using separate print head assemblies enables, for example, two different types of deposition processes to be executed in a printing module located in a controlled environment . The printing module 625 may include a gas hood 635 that houses an inkjet printing system, is equipped with a device for introducing an inert gas environment (for example, nitrogen), and is controlled in other ways for environmental regulation (for example, temperature and pressure). Gas environment, gas composition and dust content.

Various embodiments of a processing module 627 may include, for example, a conveying chamber 636; the conveying chamber also includes a loader for conveying a substrate. In addition, the processing module may also include an output load lock 637, a nitrogen accumulation buffer 639, and a curing chamber 641. In some applications, the curing chamber can be used to cure, bake or dry a monomer film into a uniform polymer film; for example, two specially conceived procedures include a heating procedure and a UV radiation curing procedure .

In one application, the device 621 is configured for mass production of liquid crystal display screens or OLED display screens. For example, on a single large substrate, an array containing, for example, eight screens is manufactured at a time. These screens can be used in televisions and as display screens for other forms of electronic devices. In a second application, the device can be used in mass production of solar panels in almost the same way.

The printing module 625 can be advantageously used in such applications where the organic encapsulation laminate is deposited Among them, these organic encapsulation laminates help protect the sensitive components of the OLED display device. For example, the depicted device 621 can be loaded into a substrate and can be controlled to move the substrate back and forth between the chambers in a manner that is not interrupted by exposure to an uncontrolled environment during the encapsulation process . The substrate can be loaded via the input loading lock 629. A loading and unloading device located in the conveying module 623 can move the substrate from the input loading lock 629 to the printing module 625, and immediately after a printing process is completed, the substrate can be moved to the processing module 627 for curing. Through repeated deposition of subsequent laminates, each of the controlled thickness, the pooled encapsulation, or other laminate thickness can be established to suit any desired application. Please also note that the aforementioned technology is not limited to the encapsulation process or OLED manufacturing, and it can use many different types of tools. For example, the configuration of the device 621 can be changed to place the modules 623, 625, and 627 in different parallel positions; in addition, it can also use more, fewer, or different modules.

Although Figure 6B provides an example of a set of joined chambers or manufacturing components, many other possibilities clearly exist. The technique described above can be used with the device depicted in FIG. 6B, or even used to control a process performed by any other type of deposition equipment.

Figures 7A to 7C are used to generally introduce the techniques and structures used for nozzle-by-nozzle droplet measurement and verification.

More specifically, FIG. 7A provides an exemplary view depicting a droplet measurement system 701 and a relatively large print head assembly 703; the print head assembly has multiple print heads (705A/705B), each with a large number of individual nozzles ( For example, 707), where there are hundreds of nozzles. An ink supply (not shown in the figure) fluidly communicates with each nozzle (for example, nozzle 707), and a piezoelectric sensor (also not shown in the figure) is used under the control of a nozzle-by-nozzle electric control signal Jet ink droplets. The nozzle design maintains a slightly negative ink pressure at each nozzle (for example, nozzle 707) to avoid flooding of the nozzle plate. The electrical signal of a specific nozzle is used to activate the corresponding piezoelectric sensor to The specific nozzle is pressurized, and thereby droplets are ejected from the specific nozzle. In one embodiment, the control signal of each nozzle is normal The lower is at zero volts, and a positive pulse or signal level used for a specific nozzle at a specific voltage is used to eject droplets of the nozzle (one drop per pulse); in another embodiment, after cutting Modified different pulses (or other more complex waveforms) can be used between each nozzle. However, with the example provided in FIG. 7A, it should be assumed that it needs to measure the volume of a droplet produced by a specific nozzle or a specific nozzle set (for example, nozzle 707), in which a droplet is deposited from the printing head toward the carrier. A box 709 of the film is ejected downward (that is, in the direction "h" representing the height of the z-axis relative to a three-dimensional coordinate system 708). As mentioned earlier, for embodiments using existing droplet deposition from many nozzles, a target surface is advantageously fixed to a known position relative to the print head (for example, so that it knows which deposited droplets belong to Which nozzle). The size of the aforementioned "h" is usually on the order of one millimeter or less, and there are thousands of nozzles (e.g., 10,000 Nozzles) in which the deposition surface is incrementally changed or advanced to multiple windows where many droplets (for example, tens to hundreds) will be simultaneously imaged and measured. Therefore, in order to accurately measure the droplets optically from each nozzle, it uses specific techniques in the disclosed embodiments to appropriately position the droplet measurement system 701, the print head assembly 703, or both relative to each other. Components for optical measurement.

In one embodiment, these techniques use a combination of the following items: (a) At least part of the xy movement system (711A) of the optical system (for example, within the dimensional plane 713) to accurately locate a measurement area 715, which The measurement area 715 is provided by any nozzle or nozzle set system that generates droplets for optical calibration/measurement in close proximity, and (b) under-plane optical recovery (711B) (for example, allowing the next to any nozzle The measurement area is easy to deploy, even under the surface area of a large print head). Therefore, in an exemplary environment with approximately 10,000 or more printing nozzles, this movement system can be located at, for example, approximately 10,000 discrete positions near the discharge path of each individual nozzle in the print head assembly. In, at least part of the optical system is positioned. The optical device is usually adjusted to position so that the precise focus is maintained on the measurement area to capture the deposited droplets on a transparent film or other deposition medium, as described above. Please note that the diameter of a typical droplet can be on the order of microns, so optical placement is usually It is quite precise and challenging in terms of the relative positioning of the print head assembly and the measurement optics/measurement area. In some embodiments, in order to assist this positioning, optical devices (mirrors, horns, etc.) are used to adjust the orientation of a light capture path for sensing under the dimensional plane 713 originating from the measurement area 715 , So that the measuring optics can be placed close to the measuring area without disturbing the relative positioning between the optical system and the printing head. This enables it to perform effective position control in a way that is not limited to the millimeter-level deposition height h of each droplet for deposition and imaging, or a large x and y width occupied by the inspected print head. Alternatively, different light beams incident from different angles can be used to image a thin film or deposition surface from below, or it can also use a coaxial imaging system with a beam splitter. It can also use other optical measurement techniques. Among the optional features of these systems, the mobile system 711A is selectively and advantageously manufactured as an xyz transport system, which allows the droplet measurement system to selectively and without moving the print head assembly during droplet measurement. Joining and separation. In short, the idea is that in an industrial manufacturing facility with one or more large print head assemblies, in order to maximize the normal operation time of production, each print head assembly will be "parked" from time to time. The maintenance station can perform one or more maintenance functions; considering the huge scale of the number of print heads and nozzles, it may be desirable to perform multiple maintenance functions on different parts of the print head at one time. For this purpose, in this embodiment, it is advantageous to move the measuring/calibration device around the printing head instead of moving the printing head around the devices. [This thus also allows the addition of other non-optical maintenance procedures, for example, for other nozzles if necessary. ] In order to facilitate these actions, the print head assembly can be selectively "parked", as described above, in conjunction with the system to designate a specific group or range of nozzles, which are intended to be the protagonists of optical calibration. Once the print head assembly or a specific print head is stationary, the movement system 711A is added to move at least part of the optical system relative to the "parked" print head assembly, and accurately position the measurement area 715 to a suitable detection The position of the droplets ejected from a group of individual nozzles; using a z-axis movement allows them to selectively engage light recovery optics from quite below the plane of the print head, which alternatively or additionally contributes to optical alignment other than Other maintenance actions. Or in other words, using an xyz moving system makes the droplet measurement system selective Ground bonding is independent of other testing or testing devices used in a maintenance station environment. For example, in this system, one or more print heads in a print head assembly can also be selectively replaced while the print heads are parked. Please note that this structure is not necessary for all embodiments; other alternatives are also possible, such as where only the print head assembly moves (or one of the print heads moves) and the measurement assembly is stationary, or there is no need to park the print head. Component.

In summary, the optical device used for droplet measurement will include a light source 717, a selective set of light projection optics 719 (which directs light from the light source 717 to the measurement area 715 as required), one or more light sources. The sensor 721 and a set of return optics 723 that direct the light used to measure the droplet(s) from the measurement area 715 to the one or more light sensors 721. The moving system 711A selectively moves any one or more of these components and the chassis 709 together in a way that allows the light of the post-droplet measurement to be directed from the measurement area 715 to a position below the plane (for example, moves together with the imaging area). ). In one embodiment, the light projection optics 719 and/or the light recovery optics 723 use mirrors, which guide and control back and forth between the measurement areas 715 along a vertical dimension parallel to the direction of droplet travel. The light and the moving system that moves each element 709, 717, 719, 721, and 723 becomes an integrated system during the droplet measurement; this setting method has the advantage that the focus does not need to be recalibrated relative to the measurement area 715. As marked by the reference number 711C, the light projection optics are also selectively used to supply source light from a position below the dimensional plane 713 of the measurement area, for example, with the light source 717 and the light sensor(s) Both 721 guide/collect light from below the measurement area, as outlined in the figure. As indicated by reference numerals 725 and 727, the optical system may optionally include a lens for focusing purposes and a photodetector (for example, for non-imaging technology that does not rely on processing a multi-pixel "image"). Please also note that at any point during the "parking" of the print head assembly, the selective use of z-motion control for the chassis allows the optical system to be selectively joined and separated, and facilitates the measurement area near the nozzles of any group The precise positioning of the 715. The parking of the print head assembly 703 and the xyz movement of the optical system 701 are not necessary for all embodiments. Other permutations and combinations are also possible.

Figure 7B provides a flow of a procedure associated with some embodiments of droplet measurement. This program flow is generally labeled as 731 in FIG. 7B. More specifically, as indicated by reference number 733, in this special procedure, the print head assembly is first parked, for example, at a maintenance station (not shown in the figure) of a printing press or deposition equipment middle. A droplet measuring device then engages (735) the print head assembly, for example, by selectively engaging part or all of a droplet measuring system, by moving from below a deposition plane into one of the droplet measuring system An optical system can simultaneously measure the position of droplets from many nozzles. With reference to 737, the movement of one or more optical system components relative to a parked print head can be selectively performed in the x, y, and z dimensions.

As stated in the patent application incorporated herein by reference in the priority statement, even a single nozzle and related nozzles emit driving waveforms (that is, the pulse or signal level(s) used to eject a droplet) ) Can also produce a slightly different droplet volume, trajectory, and velocity between each droplet. According to the teachings herein, in one embodiment, the aforementioned droplet measurement system, as indicated by reference number 739, selectively obtains n measurements per droplet of a required parameter to derive the expected properties of the parameter Statistical credibility. In one embodiment, the measured parameter may be volume, but for other embodiments, the measured parameter may be flight speed, flight trajectory, nozzle position error (for example, nozzle warpage) or other parameters, or more A combination of one of these parameters. In one embodiment, "n" can vary with each nozzle, but in another embodiment, "n" can be a fixed number of measurements (for example, "24") that each nozzle is scheduled to perform; In yet another embodiment, "n" represents a minimum number of measurements, so that more measurements can be performed to dynamically adjust the measurement statistical properties of the parameter or increase the reliability. Obviously, there may be many variations. In conjunction with the previously described system, a measurement total can be established immediately (that is, by performing multiple droplet measurements on a particular nozzle array during a single measurement iteration step, in other words, without moving the droplet measurement system to one Different nozzle sets), or by taking a single measurement and establishing a total number of measurements through later measurements (for example, when the measurement is performed continuously through a circular range of nozzles over time).

For the example provided in FIG. 7B, it should be assumed that the droplet volume is being measured in order to obtain an accurate average value representing one of the expected droplet volumes from a specific nozzle and a tight confidence interval. This facilitates selective planning of droplet combinations (using multiple nozzles and/or drive waveforms), while reliably maintaining the distribution of mixed ink filling in a target area near a desired target (that is, relative to the droplet average的mix). As marked in optional process blocks 741 and 743, the conceived optical measurement process ideally facilitates the one-time real-time or near real-time measurement and calculation of the volume (or other required parameters) of many nozzles, for example, using a transparent film And shooting below the deposition plane (that is, from the opposite side of the film used for deposition); with this rapid measurement, it becomes possible to update the volume measurement frequently and dynamically, for example, to compensate for the ink properties (including viscosity and composition materials) , Temperature, nozzle clogging or aging, and other factors change over time. Based on this, for example, for a print head assembly containing 10,000 nozzles, it is expected that the huge total number of measurements for each of the thousands of nozzles can be obtained within a few minutes, so that it can be executed frequently and dynamically. Droplet measurement. As mentioned earlier, in an alternative embodiment, droplet measurement (or measurement of other parameters such as trajectory and/or velocity) can be performed as a periodic intermittent procedure, based on a schedule or between the substrate In between (for example, when the substrate is being loaded or unloaded) into the droplet measurement system, or stacked under other components and/or other print head maintenance procedures, to effectively collect a lot of data in many measurement intervals Points (and thus establish a statistical distribution representing one of each nozzle). Please note that for embodiments that allow alternate nozzle drive waveforms to be used in a manner specific to each nozzle, this rapid measurement system facilitates scan path adjustment, nozzle pass/fail verification, and various nozzle waveform pairings. The programmatic droplet combinations of the droplets are the same as those mentioned in the patent application incorporated by reference in the previous content and priority statement in this article. With reference to numbers 745 and 747, by measuring the expected droplet volume to an accuracy better than 0.01pL, it becomes possible to plan very precise droplet usage, in which droplet usage can also be planned (in ideal Case) to 0.01pL resolution, and the measurement error in one embodiment is effectively reduced to provide 3σ (or other statistical values, such as 4σ , 5σ , 6σ , Etc.) credibility. The same holds for the position and/or velocity of the droplet and/or the warpage of the nozzle. For example, by measuring the expected position to an accuracy better than one micron (or another distance value), it becomes possible to provide very accurate deposition; the expected position can be measured to a specific rectangular coordinate point and standard Within a certain range of the difference (or, for example, the 4σ , 5σ , and 6σ deviations near this point). Once adequate measurements have been taken for various droplets, the fill involving the combination of these droplets can be evaluated and used to plan printing in the most efficient way possible (748). As indicated by the dividing line 749, the execution of droplet measurement can be intermittently switched back and forth between the current "online" printing procedure and the "offline" measurement and calibration procedure; please note that in order to minimize the downtime of the manufacturing system, these Measurements are usually performed when, for example, the printing press during substrate loading and unloading is assigned to other programs. With reference to reference numeral 751, in one embodiment, the transparent film or film tape can be specially selected (or treated) to optimize the droplet properties of the particular ink under analysis (that is, the specific chemical or fluid properties of the ink). ) For the purpose of auxiliary image shooting and/or analysis. For example, in some applications, the ink will be cured later by an ultraviolet light curing process to be converted into a monomer of a polymer; in order to assist the trapping of droplets, the transparent film It can be selected to have physical, color, absorption, fixation, curing, or other properties to enhance the predictive conditions for analyzing this material by the image capturing system. Finally, referring to reference numeral 753, the thin film (film tape) or the droplet measurement system as a whole (or both) can be designed for modular replacement to minimize the downtime of the measurement system and the printing system.

During printing, the nozzle (and nozzle waveform) measurement can be performed on a scroll basis, advancing through a certain range of nozzles, and each interruption occurs between substrate printing actions. Regardless of whether it is engaged to re-measure all nozzles, or based on this scrolling basis, the same basic procedure of Fig. 7B can be used to perform the measurement. To achieve this goal, when adding a droplet measuring device for a new measurement (immediately after the previous measurement or immediately after a substrate printing action), the system software loads an indicator that indicates the next one scheduled to be measured. Nozzle group (for example, for a second print head, "the nozzle window at nozzle 2,312 in the upper left corner"). In the case of initial measurement (for example, in response to the installation of a new print head, or a recent start-up, or a periodic procedure such as a daily measurement procedure), the above The indicator will point to the first nozzle of a print head, for example, "Nozzle 2,001". This nozzle is associated with a specific imaging grid to access or search from memory. The system uses the provided address to advance the droplet measurement system (for example, the measurement area previously described) to a position corresponding to the expected nozzle position. Please note that in a typical system, the mechanical throw positioning associated with this movement is quite accurate, in other words, to a resolution of approximately micrometers. At this time, the system selectively searches for the nozzle position near the expected micron resolution position, and finds the nozzle and its position center within a tiny micron distance from the estimated grid position based on the image analysis of the print head. For example, a zigzag, spiral, or other search pattern can be used to search for an expected position for a nozzle or reference point that has a specific positional relationship relative to the desired set. A typical spacing distance between nozzles can be on the order of 250 microns, while the nozzle diameter can be on the order of 10 to 20 microns.

Figure 7C provides a flow chart for nozzle qualification verification. In one embodiment, droplet measurement is performed to generate a statistical model for any one and/or each of droplet volume, velocity, and trajectory for each nozzle and each waveform applied to any particular nozzle (For example, distribution profile and average). Therefore, for example, if there are two choices of waveforms for twelve nozzles, there are up to 24 waveform-nozzle combinations or pairs; in one embodiment, for each nozzle or waveform-nozzle pairing The number of measurements performed for each parameter (for example, volume) is sufficient to develop a robust statistical model. Please note that despite the planning, a specific nozzle or nozzle-waveform pairing may conceptually produce an abnormally broad distribution, or an average value that is too off-track and should be specially processed. This applied special processing is conceptually depicted in FIG. 7C in an embodiment.

More specifically, it uses the reference number 781 to generally indicate a method. The data generated by the droplet measuring device is stored in the memory 785 for later use. During the application of method 781, this data is recalled from memory, and the data for each nozzle or nozzle-waveform pair is extracted and processed individually (783). In one embodiment, it establishes a normal random distribution for each variable subject to qualification verification, which is defined by an average value, standard deviation, and the number of measured droplets (n), or uses an equivalent value. Please note that it can use other distribution formats (for example, Student's-T, Poisson, etc.). The measured parameter is compared with one or more ranges (787) to determine whether the relevant drop can be actually used. In one embodiment, at least one range is applied to disqualify the droplet from being used (for example, if the droplet has a volume that is too large or too small relative to the desired target, the nozzle or nozzle-wave pair can be excluded Short-term use). To provide an example, if 10.00pL droplets are required, nozzles or nozzle-waveform pairs that are connected to the average droplet value exceeding this target, for example, 1.5% (for example, <9.85pL or >10.15pL), can be excluded. It can also use or alternatively use range, standard deviation, variance, or other deviation measures. For example, if a droplet statistical model with a narrow square cloth is desired (for example, an average value of 3σ<1.005%), droplets whose measured values do not meet this criterion can be excluded. It is also possible to use a sophisticated/complex standard that takes into account multiple factors. For example, an abnormal average combined with a very narrow deviation may be acceptable. For example, if deviation (e.g., 3 σ) deviates from the measured (e.g., abnormal) average μ is within 1.005%, then it can be used A related droplet. For example, if you want to use a droplet with a 3 sigma volume within 10.00pL±0.1pL, you can exclude generating a nozzle-waveform pair with an average value of 9.96pL with a value of ±0.8pL 3 sigma, but produces A nozzle-waveform pair with a mean value of ±0.3pL 3 sigma of 9.93pL may be acceptable. Obviously, there are many possibilities based on any required rejection/exception criterion (789). Please note that this same type of processing can be applied to the flight angle and velocity of each droplet, which means that it is expected that the flight angle and velocity of each nozzle-waveform pair will show a statistical distribution, and depends on the derivation from the droplet measurement According to the measurement and statistical model of the device, some droplets can be eliminated. For example, a droplet whose average velocity or flight trajectory deviates from the normal value by 5%, or the variation of velocity outside a specific target, can be assumed to be excluded from use. Different ranges and/or evaluation criteria can be applied to each droplet parameter 785 measured and provided by the storage.

Note that depending on the rejection/abnormality criterion 789, the droplet (and nozzle-waveform combination) can be handled and treated in different ways. For example, it can reject a feature that does not meet a required standard. Do not drop (791), as described above. Or, it may selectively perform more measurements for the next measurement iteration step of a particular nozzle-waveform pair; for example, if a statistical distribution is too wide, it may be specifically for that particular nozzle-waveform pair Perform more measurements to improve the tightness of this statistical distribution through more measurements (for example, the variance and standard deviation depend on the number of data points measured). With reference to 793, it is also possible to adjust a nozzle drive waveform, for example, to use a higher or lower voltage level (for example, to provide a larger or smaller speed or a more consistent flight angle), or to reshape A waveform is generated to adjust the nozzle-wave pair in accordance with one of the specified standards. With reference to numeral 794, the timing of the waveform can also be adjusted (for example, to compensate for an abnormal average velocity associated with a particular nozzle-waveform pair). For example (as mentioned earlier), a slow drop can be ejected at an earlier point relative to other nozzles, while a fast drop can be ejected slower in time to compensate for the faster flight time . Many such alternatives are possible. Finally, referring to reference number 795, any adjusted parameter (for example, eruption time, waveform voltage level or shape) can be stored, and, optionally, if desired, the adjusted parameter can be applied to re-measurement One or more associated droplets. After each nozzle-waveform pair (modified or otherwise processed) is qualified (passed or failed), the method then proceeds to the next nozzle-waveform pair, reference numeral 797.

The aforementioned mechanism can also be used to measure nozzle warpage (and of course to verify the qualification of the nozzle based on this). In other words, for example, if it is assumed that a group of deposited droplets originate from a single common precise nozzle position, but are clustered off-center in a direction orthogonal to the scanning movement of the print head substrate, the nozzles involved may be located at the same position. The nozzles on the column or the same row are offset. Such abnormal deviations may lead to deviations from the idealized droplet ejection, which can be taken into consideration when planning the precise combination of droplets. In other words, any such "warping" or individual nozzle deviations are stored and used To verify the pass/fail of the nozzles or as part of the printing scan plan, as mentioned earlier, let the printing system use the differences of each individual nozzle in a planned way instead of trying to average out the differences . In a selective variation, the same technique can be used to determine the scanning direction along the print head (i.e., The irregular nozzle spacing of the fast printing axis), although for the depicted embodiment, any such error is included in the correction for the droplet velocity deviation (for example, any such spacing error can be adjusted by the nozzle velocity The correction to be adjusted, for example, due to a small change in the driving waveform for that particular nozzle). In order to determine the warping across the scan axis of a nozzle that produces a cluster of droplets, the individual orbits are actually drawn (or mathematically transformed in other ways) relative to the other measurement orbits of the same nozzle and used for identification. One of the specific nozzles averages the position across the scan axis. This position can deviate from an expected position of the nozzle, which may be evidence of nozzle warpage.

As mentioned above and as the meaning implies in this description, one embodiment establishes a statistical distribution of each nozzle for each measured parameter, for example, for volume, velocity, trajectory, nozzle warpage, and possibly other parameters . As part of such statistical procedures, individual measurements can be discarded or used to identify errors. To cite some examples, if a droplet measurement is found to have a value that has been removed from other measurements of the same nozzle so far, then the measurement can represent an eruption or measurement error; in one embodiment, if it deviates To a point exceeding a statistical error parameter, the system discards this measurement. If no droplets are seen at all, this may be evidence that the droplet measurement system is at the wrong nozzle (wrong position), or has an error in the ejection waveform or a nozzle failure under inspection. It can use an error handling procedure to make appropriate adjustments, including taking any new or further measurements as needed.

Please note that although Figures 7A to 7C are not individually called, they basically perform the depicted measurement procedure for each available candidate waveform used with each nozzle. For example, if each nozzle has four different piezoelectric drive waveforms to choose from, the measurement procedure may generally be repeated 4 times for each group of nozzles; The 24 droplets of the waveform establish a statistical distribution, then a nozzle can have 96 such measurements (24 for each of the four waveforms), and each measurement is used to obtain each droplet velocity, trajectory, and volume. One is the statistical average value and the deviation value of the estimated nozzle position (for example, for evaluating nozzle warpage). In a contemplated embodiment, any Any number of waveforms can be shaped or generated in other ways, and the system measures the droplet parameters associated with one or more preselected waveforms and stores these parameters for subsequent use in printing and/or printing planning. These parameters can also be used to determine whether to maintain (and store) the waveform for printing (for example, as part of a set of pre-selected allowable waveforms), or to select a different waveform and measure multiple of the waveform parameter.

Through the use of precise mechanical systems and droplet measurement technology, the disclosed method allows extremely high accuracy measurement of individual nozzle characteristics, including the average of each of the aforementioned parameters (for example, volume, velocity, trajectory, nozzle position, and other parameters) Droplet measurement. It should be appreciated that the described technology promotes a high degree of consistency in the manufacturing process, especially the manufacturing process of OLED devices, and therefore enhances reliability. By providing control efficiency, especially with regard to the speed of droplet measurement, and stacking these measurements in other system programs in a way that is calculated to reduce overall system downtime, the teachings presented above help to provide a better Fast and less expensive manufacturing process, designed to provide flexibility and accuracy in the production process.

FIG. 8A shows a cross-sectional view of a typical configuration in an industrial manufacturing facility (for example, associated with a printer in the facility) 801. More specifically, it can be seen that printing is performed in a printing closed chamber 803, so that the surrounding environment can be controlled ("controlled environment"); this control is usually performed to eliminate unacceptable dust particles, Or, printing is performed in other ways in the presence of a specific gas composition (for example, nitrogen, inert gas, etc.). In summary, a substrate 813 is generally introduced into the printer using an environmental buffer chamber (not shown in the figure) and transported to a floating support table 815 using a mechanical loader, which also passes through one or more of the substrates The detection of fiducial points (the fiducial points used to detect the precise substrate position and a camera or other optical detector are not shown in FIG. 8A) are appropriately aligned with the substrate for printing. Printing is performed using a print head assembly 807, which moves back and forth along a traveler 811 in the direction of a "slow printing axis" (as depicted by arrow 809). The print head assembly 807 is depicted as a single object, but it can be a complex assembly that carries multiple print heads (e.g., 6, 10, or other numbers), each with hundreds to thousands of print nozzles (e.g., Each has two thousand nozzles). The print head assembly 807 deposits a liquid ink to a precise thickness at a precise position on the substrate 813, where the ink contains a material, This material will form a permanent stack of one or more products intended to be manufactured on the substrate 813. For example, the material can be an organic or inorganic material, a conductor or insulator, a plastic, a metal, or some other types of materials. In a typical application, the substrate 813 is more than one meter wide and several meters long, and is used to manufacture multiple OLED displays arranged in an array on the substrate at the same time; each stack is deposited across all such "substrates" "Panel" (meaning across multiple such displays in manufacturing) is part of an integrated printing process in which individual displays are finally cut from the substrate through other processes. Each printing process can deposit a different ink to a specific thickness, for example, conductors, insulators, light-emitting elements, semiconductor materials, encapsulation, etc., using printing instructions specific to a particular laminate. In an assembly line process, there may be multiple printers, which are arranged at different positions or used in continuous different deposition processes. For OLED materials, an ink is deposited for a particular layer, and after deposition, the substrate is removed from the chamber and pushed into a curing chamber (not shown in the figure), where the deposited ink can be cured and dried , Be heated or otherwise treated to add durability to the deposited material. Please note that the depicted configuration represents a "separation axis" printing machine, which means that the floating table 815 and the associated loader (not shown in the figure) are along a dimension near the lower right corner of the figure, as seen at 823. In the direction of Y-axis 825, push the substrate into and out of the graphic page.

In order to perform droplet measurement, the print head assembly 807 is selectively advanced outside a normal printing area to reach a point where it can be parked in a repair station, in general, associated with a second Closed environment 805. This second environment is optional, but it is conducive to allow detection, print head replacement, and other types of maintenance, without adding vents to the closed printing chamber 803. In order to park the print head assembly 807, the assembly is moved to a position that appears to be roughly on the left side of the figure, and then pushed vertically to seal the print head assembly 807 in a chamber that serves as the second enclosed environment , As depicted by dotted line position 819. In this "parked" position, the droplet measurement system 817 can be controlled (for example, in three dimensions) to selectively move a measurement area, simulating a substrate deposition height adjacent to any desired nozzle area.

Please note that, as mentioned above, in a typical application, it is intended to keep the manufacturing equipment 801 "online" and in use as much as possible. For this purpose, it is not to perform droplet measurement when the device 801 can be used for printing (but for product manufacturing). In one embodiment, measurement and printing are alternated "ping-pong", that is, every time The next time a substrate (e.g., 813) is loaded or unloaded, the print head assembly 807 is advanced to the repair station and calibrated locally (e.g., for printing nozzles and/or printing nozzles) during a time interval of the printing operation. One of the waveforms is a rolling subset), so as to build a set of robust measurements for each nozzle in a way of accumulating the total number of statistical measurements, update to the latest state, and perform maintenance, as previously described. Please note that any of these features can be considered selective and not all necessary for the implementation of the revealing technique.

FIG. 8B provides a plan view of the substrate and printer taken along the line B-B of FIG. 8A during the deposition process. The printed closed chamber is also generally designated by reference number 803, and the second closed environment for droplet measurement is generally designated by reference number 805. In the printing enclosed chamber, the substrate to be printed thereon is also generally indicated by the reference number 813, and the support table used to transport the substrate is generally indicated as the reference number 815. In summary, any xy coordinate of the substrate is reached by a combination of movement, including the movement of the substrate in the x and y dimensions of the support table (for example, using a floating support, as indicated by reference numeral 857), and using a movement along a The movement of the “slow axis” of the one or more printing heads 807 of the sliding rod 811 in the x-dimension is generally indicated by the arrow 809. As mentioned earlier, the floating table and substrate handling infrastructure are used to move the substrate along one or more "fast axes" during printing as needed. It can be seen that the print head has a plurality of nozzles 865, and each nozzle is controlled by a spray pattern derived from a printed image (for example, when the print head moves from left to right and from right to right along the "slow axis" When moving to the left, printing of rows corresponding to the grid points of the printer is caused; please note that although only some printing nozzles are depicted in the figure, they actually contain hundreds to thousands of such nozzles, configured as Many rows and columns. With the relative movement between one or more print heads and the substrate provided in the fast axis (ie, y axis) direction, printing basically presents a web area of one of a plurality of individual columns following the grid points of the printer. It can also selectively rotate or adjust the print head group in other ways To change the effective nozzle interval, refer to number 867. Please note that multiple such print heads can be used together, and the x-dimension, y-dimension, and/or z-dimension offset relative to each other can be adjusted as needed (see the axis legend in FIG. 8B). The printing operation continues until the entire target area (and any boundary areas) has been printed with ink as required, where the vertical component of the depicted transfer direction 857 represents the relative print head assembly/substrate movement. After the deposition of the necessary amount of ink, the substrate is completed, such as by using ultraviolet (UV) or other curing or hardening procedures to form a permanent laminate from liquid ink. As mentioned earlier, when the substrate is loaded or unloaded for printing, the print head is advanced to an inspection station and sealed to a second enclosed environment 805. In practice, this second closed environment is set as a subset of the printing closed chamber 803 as described above, so that it can replace a printing head without adding ventilation holes for the printing closed chamber at all. Within the second enclosed environment 805, the droplet measuring system 817 (visible in the dashed line under the sliding rod 811) is selectively engaged (similarly, it is advantageous to use the entire droplet measuring system of one of the enclosures Sexual three-dimensional connection) for the measurement as described earlier.

Figure 9 provides a graph illustrating the measured droplet position relative to the expected position of the droplet for each of the many nozzles. More specifically, the chart is generally indicated by reference numeral 901, and shows a group of approximately 40 nozzles. It should be assumed that the chart 901 represents image data. For example, after the processing described above with reference to FIGS. 6A to 6C, the droplet position (meaning, such as position 904) is measured relative to a corresponding expected position (ie, position 904). That is, such as location 903). Compared with Figure 9, some features should be noted. First, the nozzles appear to be arranged in slightly staggered rows of nozzles, as shown in icon 905; this feature allows extremely precise droplet spacing, for example, when manufacturing tolerances allow the nozzles to be positioned at a span of hundreds of microns apart In the scanning direction, the slight staggering between the rows allows alternate nozzles to be used (for example, the nozzles corresponding to the position 907 corresponding to the nozzles corresponding to the position 906), which allows extremely tight droplet placement, for example, in Within 20 microns or less of any predetermined position on a substrate. Second, the chart 901 indirectly emphasizes the benefits provided by the position calibration of the droplet measurement system relative to a print head. For example, it is important for the system to know exactly which nozzle corresponds to the position 903 and the expected position 904. Able to test any The quantity data (and any nozzle qualification verification or adjustment) is matched to the correct nozzle. Through image processing, it can determine the precise position offset of each nozzle, which is included in the influence factors of nozzle qualification verification and printing planning. Finally, please note again that the use of a transparent film not only allows image capture of deposited droplets, but also allows image capture of nozzles (for example, shooting through the transparent film), which helps the performance of distance analysis by software. This is not necessary for all embodiments. For example, the software can easily infer the nozzle position relative to the shot image and calculate the position offset based on the understanding of how the image shot through the film corresponds to the position of the nozzle plate. . In the background of FIG. 9, the reference numeral 904 represents the image nozzle position in one embodiment, where any deviation between the measurement position 903 and the position 904 represents droplet velocity and/or warpage. And, although Figure 9 represents the droplet position offset relative to the expected droplet position, a similar analysis can also be used to measure the droplet volume, for example, by changing the droplet color (e.g., grayscale value) ), droplet diameter, or other characteristics of the captured image are compared with a standard, and then the droplet volume is calculated from it. Through the use of repeated additional measurements for each nozzle or nozzle-waveform pairing, the system can easily establish the distribution of any required droplet parameters based on the basis of each nozzle or each nozzle waveform.

Figure 10 shows a flow chart 1001 for determining the droplet volume from a captured image. Reference numeral 1003 represents that one of the shot images of the droplets generated by a nozzle array is first captured from the memory. This image is then optionally filtered to exactly segment the droplets of interest (for example, with different color intensities depending on the thickness or concentration of the ink on the deposition medium), refer to 1005. Please note that these filtered images can be one of the first, second, third, or other examples of filtering actions performed to measure a specific parameter from a single image (for example, other examples can be used to target the droplet velocity , Position, nozzle position, etc. to calculate distance, position, offset, etc.). With reference to 1007, any color hue is then processed to correlate the hue with the ink thickness or density; for example, if the deposited ink has a slightly reddish hue, a "redder" part of the image will usually represent a greater thickness . Please note that for the embodiment where multiple droplets are deposited from each nozzle at a time, there may be multiple visible droplets overlapping, and the thickness processing 1007 is The preferred embodiment takes this into consideration and divides any individual droplets; however, this is not necessary for all embodiments. For example, if it knows that five droplets have been deposited, for example, the overall volume is calculated. Dividing by five may be enough. With reference to reference numeral 1009, the droplet radius is then calculated (or pooled ink coverage) as described earlier and used in conjunction with the derived thickness value to calculate the total deposited ink. It is important that the transparent film used as a deposition surface holds the deposited ink under ideal conditions and may therefore be different from an actual deposition surface used in actual printing (for example, a glass substrate); therefore, as indicated by the reference number 1008 Depicted, a storage standard specific to the deposition material is captured and used in conjunction with thickness processing, volume calculation 1011, or both to obtain the correct droplet volume estimate. Finally, the measurement data is stored, refer to the number 1013, and any calculated per-nozzle or per-nozzle waveform distribution (for example, average value and deviation) are updated for use in printing or scanning planning. Please note that similar comparisons calculated for a standard and original value (or offset) can be applied to many other parameters besides volume, depending on suitability for a particular application.

Realizing from the aforementioned various technologies and considerations, a process can be executed to quickly mass produce products with low system costs. By providing fast and repeatable printing technology, it is believed that printing can be substantially improved, for example, by reducing the printing time of each layer to a fraction of the time required before the aforementioned technology was used. Going back to the example of a large HD TV monitor again, it is believed that for a large substrate (for example, the 8.5 generation substrate, approximately 220cm x 250cm), each color component stack can be printed accurately and reliably, in one hundred and eighty seconds or Within a shorter time, or even within ninety seconds or less, represents a substantial process improvement. Improving the efficiency and quality of printing has paved the way for huge cost reductions in the production of large HD TV displays, thereby achieving lower end-consumer costs. As mentioned earlier, display manufacturing (especially OLED manufacturing) is an application of the technologies described in this article. These technologies can be applied to numerous processes, computers, printers, software, manufacturing equipment, and terminal devices. Limited to the display panel.

In the foregoing description and the accompanying drawings, specific terms and schematic symbols are used to provide Have a thorough understanding of one of the disclosed embodiments. In some examples, the terms and symbols may imply specific details that are not necessary when implementing these embodiments. The terms "exemplary" and "embodiment" are used to indicate an example, not a preference or a necessary item.

As shown above, various modifications and changes can be made to the embodiments proposed herein, which do not deviate from the broader spirit and scope of the present disclosure. For example, the features or features of any embodiment can be applied in combination with any other embodiment, at least where it is practical, or replace its equivalent features or features. Therefore, for example, not all features are shown in each figure. For example, a feature or technique shown in an embodiment according to a figure should be assumed to be selectively adopted as any other figure. An element in a formula or embodiment, or a combination thereof, even if it is not specifically pointed out in the specification. Therefore, the description and drawings should be interpreted as having an illustrative rather than a restrictive meaning.

101: Flow Chart

103-123: Steps

Claims (20)

A system for measuring a parameter related to the ejection of droplets by a number of nozzles of a print head on a film having a first side and a second side, the first side being positioned To the vicinity of the print head to receive ink droplets from the nozzles, the system includes: a platform for supporting the film on the second surface of the film, the platform including a measurement area and adjacent A plurality of vacuum ports in the measurement area, the vacuum ports are arranged in an area, the area has a length less than a length of the measurement area, the platform has a length greater than a width of the film; a suction Mechanism for adhering the second surface of the film to the platform when receiving several droplets on the first surface of the film; an image capturing subsystem which is positioned to capture the first surface deposited on the film An image of several droplets on one side, and an output signal representing the captured image is generated to an image processing system; and a mechanism to advance the film without repositioning the print head or the image capturing subsystem. For example, the system described in claim 1 further includes the image processing system. The image processing system includes at least one processor and a number of instructions stored on a machine-readable medium. When the number of instructions is executed At this time, the at least one processor: receives the signal representing the captured image from the image capturing subsystem; stores data representing the received signal in the memory accessible by the processor; processes the stored data so as to The stored parts of the data are individually associated with the nozzles of the print head; the parameter for each associated nozzle is calculated; and the processor accessible memory is stored for each associated nozzle Of the parameter. The system described in item 2 of the scope of the patent application, wherein the parameter of each nozzle includes an average value of a number of droplets generated by the nozzle. The system described in item 2 of the scope of patent application, wherein the parameter of each nozzle includes a statistical separation value for the number of droplets produced by the nozzle. The system described in item 2 of the scope of patent application, wherein the parameter of each nozzle includes a desired volume for the number of droplets produced by the nozzle. The system described in item 5 of the scope of patent application, wherein the expected volume is expressed in a unit with a resolution less than one picoliter. The system described in item 2 of the scope of patent application, wherein the parameter of each nozzle includes a desired droplet trajectory for the plurality of droplets generated by the nozzle. The system described in the first item of the patent application, wherein the film is a film tape, the film tape is provided on a supply reel and collected on a take-up reel, and the mechanism includes a motor so as to After the image has been shot, advance the take-up reel. The system described in item 8 of the patent application, wherein the system defines a film path extending along the film, and the system further includes a film path along the film path between the platform and the take-up reel A curing mechanism for curing the received ink droplets. The system described in item 1 of the scope of patent application, wherein the image capturing subsystem includes a high-resolution, high-speed digital camera and an electronically actuated focusing mechanism. The system described in item 1 of the scope of patent application, wherein the print head is a component of a printing machine, and the system further includes the printing machine, the film, the image capturing subsystem, and the film advancing the One of the institutions is a gas hood. A method of measuring a parameter related to the ejection of droplets by a plurality of nozzles of a printing head. The method includes: positioning a film having a first side and a second side near the printing head On a platform, the membrane has a width less than a length of the platform, the platform has a measurement area and a plurality of vacuum ports adjacent to the measurement area, the plurality of vacuum ports are arranged in an area, the area Has less than A length of a length of the measuring area; by applying suction to the second surface of the film through the vacuum ports to adhere the film to the platform; eject several from the plurality of nozzles of the print head Droplets onto the first surface of the film; use an image shooting mechanism to capture an image of the ink droplets on the first surface of the film; output one of the images representing the plurality of droplets Signal to an image processing system; and advancing the film without repositioning the print head or the image capturing mechanism. The method described in item 12 of the scope of patent application further includes using the image processing system to receive the signal representing the image; converting the signal to data representing the image; storing the image in a processor accessible memory Data, process the stored data, in order to associate several parts of the stored data with the nozzles of the print head, calculate the parameter for each associated nozzle, and be accessible to the processor This parameter is stored in the memory for each associated nozzle. The method described in item 13 of the scope of patent application, wherein the parameter for each nozzle includes an average value of a number of droplets generated by the nozzle. The method described in item 13 of the scope of patent application, wherein the parameter for each nozzle includes a statistical separation value for the number of droplets produced by the nozzle. The method described in item 13 of the scope of patent application, wherein the parameter for each nozzle includes a desired volume for the number of droplets produced by the nozzle. The method described in item 16 of the scope of patent application, wherein the desired volume is expressed in a unit with a resolution less than one picoliter. The method described in item 13 of the scope of patent application, wherein the parameter for each nozzle includes a desired droplet trajectory for the plurality of droplets produced by the nozzle. The method described in claim 12, wherein the film is a film tape, and advancing the film includes using a motor to advance a take-up reel for collecting the film tape from a supply reel. The method described in item 12 of the scope of patent application further includes controlling the operating gas environment of one of the printing head, the film, and the image capturing subsystem.

Images