Precise positioning, calibration, and measurement in printing and manufacturing systems

Abstract

This disclosure provides a high-precision measurement system for rapidly and accurately determining the height of a deposition source relative to a target substrate. In one embodiment, a camera and a high-precision sensor are installed in each of the two transport paths of an industrial printer. These cameras are used to separate recordings between the transport axes and to accurately determine the positions of the high-precision sensors based on their x and y positions. One of the high-precision sensors is used to measure the height of the deposition source, while the other sensor measures the height of the target substrate. The relative z-axis positions between these sensors are identified to provide accurate z-coordinate identification for both the source and the target substrate. The disclosed embodiment enables dynamic, real-time, and high-precision height measurement with micrometer or sub-micrometer accuracy.

Description

[0001] This application claims the benefit of U.S. Patent Application No. 15 / 851419, filed December 21, 2017, entitled "Precise Position Alignment, Calibration, and Measurement in Printing and Manufacturing Systems," with David C. Darrow as the first inventor; and, like the aforementioned U.S. Patent Application, U.S. Provisional Patent Application No. 62 / 459402, filed February 15, 2017, with David C. Darrow as the first inventor, also entitled "Precise Position Alignment, Calibration, and Measurement in Printing and Manufacturing Systems." Each of these prior applications is incorporated herein by reference. This application also incorporates by reference the following documents: (1) U.S. Patent No. 9,352,561 (USSN 14 / 340403), filed July 24, 2014, entitled “Technique for Measuring and Controlling Printed Ink Droplets to Ensure Liquid Deposition Within Precise Tolerances”, with Nahid Harjee as the first inventor; (2) U.S. Patent Publication No. 20,150,981,53 (USSN 14 / 788609), filed June 30, 2015, entitled “Technique for Array Printing of Permanent Layers with Increased Speed ​​and Accuracy”, with Michael Baker as the first inventor; and (3) U.S. Patent No. 8,995,022, filed August 12, 2014, entitled “Preparation of Ink-Based Layers Using Halftone Thickness Control”, with Eliyahu Vronsky as the first inventor. Background Technology

[0002] Printing presses are widely used in industrial fabrication processes where liquid is printed onto a substrate, then cured, dried, or otherwise treated to transform this "ink" into a finished layer of a specifically predetermined thickness, imparting structural, electrical, optical, or other properties to the manufactured product. Some of these fabrication processes require extremely high precision, such as positioning the deposited material with accuracy down to the micrometer level. As an example, a "room-sized" industrial inkjet printer might be used to print liquid droplets onto substrates exceeding 1 meter in length and width, depositing specific layers of millions of individual "pixels" that will form part of a high-definition (HD) smartphone display. Each layer produced in this way has stringent volume specifications (e.g., "50 picoliters per pixel"), and failure to adhere to these specifications can lead to defects in the finished product. This process is also used to deposit other large-scale layers for encapsulating and covering many such microelectronic or optical components, where very constant thickness is also required (and therefore, volume control per unit area). Depending on the specific product being manufactured, processing can be carried out on a single large substrate to form one or more products; for example, a single large substrate can be used to make a large electronic display (e.g., a huge HD TV screen) or many smaller products (e.g., "one hundred" smartphone HD displays) that are arranged and cut from an array of substrates during the manufacturing process.

[0003] To provide the high precision required by many designs, printing presses and other types of precision manufacturing equipment undergo rigorous calibration and alignment procedures designed to ensure that material deposition occurs precisely when needed. As an example, split-axis printing presses are typically characterized by a “y-axis” transport system that moves the substrate and an “x-axis” transport system that moves the print head (or other components, such as one or more inspection tools, UV lamps for curing, or other types of objects). Typically, these different transport paths are painstakingly and manually calibrated relative to the printing press’s reference frame, often based on the operator’s subjective judgment; once each substrate is loaded, it must also typically be individually aligned to the printing press’s position reference system. Over time, due to offsets from various sources, these transport paths and position reference systems typically require recalibration and realignment; typically, the manufacturing equipment must be taken offline, and physical intervention is required for this, again necessitating laborious and typically highly human-intensive procedures. The example of the split-axis printing machine is merely an illustrative case, illustrating some of the challenges involved in achieving precision in the fabrication of microstructured products; downtime and the need for manual operation limit product output, but these are often unavoidable, i.e., even a “micrometer deviation” from the intended position in the fabrication can result in an invalid or low-quality product.

[0004] Depending on the application, precise measurement and calibration of additional dimensions, such as the height of the deposition source above the substrate (e.g., typically the "z-axis"), are also crucial. Manufacturing equipment of this type typically operates to deposit as quickly as possible (while maintaining accuracy); for split-axis printing presses, deposition is typically performed "on-the-go," meaning ink droplets are ejected while the printhead and substrate move relative to each other, thus translating height errors into positional errors in droplet attachment locations. Height errors are not insignificant; for example, some industrial printing systems have a dozen or more printheads supporting thousands of nozzles in total, each producing picoliter droplets with pre-defined attachment locations. Considering that each printhead may have nozzles at slightly different heights or with uneven (off-level) ejection plates, it is conceivable that variations in nozzle z-axis height can hinder precise control over droplet attachment locations. For instance, in such systems, the height distance error of each nozzle often translates directly into droplet attachment location errors, which are typically 20% or more of the height distance of the droplets produced from that nozzle.

[0005] There is a need for technologies to improve the calibration capabilities of manufacturing systems. Ideally, such technologies would facilitate more precise calibration, thereby elevating these systems to very high accuracy. Ideally, these technologies would be performed faster or even fully automated, substantially reducing the time and effort required for calibration. In industrial printing systems, these types of improvements would improve manufacturing system uptime, thereby increasing production volume and reducing overall manufacturing costs. This invention addresses these needs and provides further related advantages. Attached Figure Description

[0006] Figure 1A The diagram illustrates a production process in the form of an assembly line, where a series of substrates 105 will have one or more layers of material deposited thereon by a deposition apparatus 103 to form part of a precision electrical structure. It should be noted that although only one deposition apparatus 103 is shown, in practice, multiple apparatuses may be used (e.g., located before or after this process to perform other processing or deposit other types of materials, structures, or films). Once processed, each substrate (such as substrate 107) will be used to form part of one or more electronic products (e.g., a mobile phone 109, an HDTV 111, a solar panel 113, or other structures, by way of non-limiting examples).

[0007] Figure 1B It is a deposition device (such as one that can be used as a deposition equipment). Figure 1AA schematic plan view of an arrangement or configuration of a deposition apparatus. The printing module 125 is used to deposit a liquid (i.e., "ink") that is different from photocopy ink, which will be processed (e.g., by processing module 127) to form a thin film, which will become one of the multiple layers of the precision electrical structure shown in FIG1.

[0008] Figure 1C This shows printing press 151 in Figure 1B A plan view of the basic operations within the printing module of the printer; this printer exemplarily illustrates a "split-axis" mechanical system. As shown, a first conveying system (e.g., "clamping" system 159) conveys the substrate 157 along the "y-axis" direction as indicated by a first double arrow 161, while a second conveying system conveys the print head 165 along the "x-axis" direction as indicated by a second double arrow 169.

[0009] Figure 1D The fabrication of an exemplary substrate 181 and four supported electronic products (183) is illustrated, each electronic product having multiple micron-level or smaller electrical, optical, or other structures (not shown individually). The substrate moves back and forth along its longitudinal axis while a printhead 191 moves between such "scans" (i.e., as indicated by arrow 195) to print ink "strips" over the surface of the exemplary substrate 181.

[0010] Figure 2A An embodiment of a mechanism and technique for providing precise positioning in a split-axis system, such as a split-axis printing press, is shown.

[0011] Figure 2B Another implementation of the mechanism and technology for providing precise positioning in a split-axis system is shown.

[0012] Figure 3A This is a flowchart illustrating techniques used for position alignment and calibration in manufacturing equipment.

[0013] Figure 3B This is a flowchart of a technique used for position alignment and calibration in split-axis printing presses.

[0014] Figure 4A This is a flowchart 401 illustrating an operation method for depositing materials to form layers of electronic products using an inkjet printer.

[0015] Figure 4B An embodiment of mechanical and electromechanical components for providing improved precision position calibration and alignment in a split-axis system is shown.

[0016] Figure 4C It shows the combination Figure 4C The flowchart shows the components used in a technique to provide automatic and / or dynamic position determination in a split-axis preparation and / or printing system.

[0017] Figure 5A This is a perspective view of one embodiment of the clamping system and support table (chuck), wherein the clamp can move on the support table.

[0018] Figure 5B This is a perspective view of the camera assembly used in conjunction with the printhead assembly.

[0019] Figure 5C yes Figure 5A and Figure 5B A close-up perspective view of the calipers used by the camera in the middle component.

[0020] Figure 5D This is a close-up perspective view of a calibration standard or "gauge block" used for laser height measurement in one embodiment.

[0021] Figure 5E It is a close-up perspective view of the alignment plate or target mounted on the fixture system or printhead assembly.

[0022] The subject matter of the invention as defined by the enumerated claims can be better understood by referring to the following detailed description, which should be understood in conjunction with the accompanying drawings. The description below of one or more specific embodiments of the various technical implementations set forth in the claims is not intended to limit the enumerated claims, but rather to illustrate their application. Without limiting the foregoing, this disclosure provides examples of several different techniques for position determination, calibration, and alignment of position sensing systems for precision manufacturing. Such techniques can be applied as part of an integrated, repeatable printing process in the automated preparation of films for one or more products on a substrate. These various techniques can be implemented as software for performing these techniques, in the form of a computer, printing press, or other apparatus or a combination thereof running such software, in the form of an industrial printing and / or manufacturing system (or elements of such a system), as manufacturing equipment, or in the form of electronic or other devices (e.g., having one or more layers produced according to the described techniques) prepared as a result of using these techniques. While specific examples are given, the principles described herein can also be applied to other methods, apparatus, and systems. Detailed Implementation

[0023] A. Introduction

[0024] This disclosure provides improved techniques for calibrating and aligning components of manufacturing equipment and / or printers for precise position measurement in one or more dimensions and for the associative fabrication of one or more layers of electronic products. More specifically, the apparatus, methods, devices, and systems disclosed herein provide improved accuracy and speed in the calibration and alignment positioning systems of manufacturing systems and / or printers, thereby facilitating the deposition or processing of structures in manufactured products with micron-level or finer precision. The techniques disclosed herein provide far faster, highly automated, and repeatable calibration and alignment processes, thereby reducing system downtime and substantially increasing manufacturing throughput. In one embodiment, these techniques provide an improved and highly accurate dynamic means of measuring the precise height (e.g., “z-axis” height) of the deposition source above the substrate, thereby further improving the positional accuracy of the deposited material. By providing such precision, the disclosed techniques contribute to the realization of smaller, denser, and more reliable devices, further reinforcing the trend towards smaller, more reliable, and fully functional electronic products. The disclosed techniques also provide further related advantages.

[0025] In one embodiment, the disclosed technology is presented as an improved approach to an alignment split-axis transport system. Imaging systems or other sensors mounted on each transport path are aligned with each other (and / or with a common reference frame, such as a manufacturing chuck), and a position feedback system is used for each transport path to provide precise positional accuracy to the drive system, thereby enabling micrometer-level or better positional identification. Advantageously, the disclosed technology may also optionally facilitate micrometer-level or better height determination (e.g., z-axis determination) between the deposition substrate and the deposition material source, thereby further enhancing positional accuracy.

[0026] In a second embodiment, the disclosed technology provides a precise z-axis height calibration and / or position determination system, i.e., a system that can be used without human intervention in the manufacturing equipment. This system optionally uses z-axis sensors above and below the deposition plane to identify a common reference frame and precisely measure the absolute position of the deposition source above the substrate. In one implementation, a first sensor above the substrate measures the absolute height of the sensor relative to the substrate, while a second type of sensor below the substrate measures the height difference between the first sensor and the deposition source (e.g., one or more printheads of a printing press). These techniques can be automated and widely used for various purposes, such as adjusting printhead level and / or height, and otherwise adjusting printing or system parameters to eliminate potential sources of error.

[0027] Alternatively, the components of these various technologies can be used in any desired combination or arrangement.

[0028] Note that height determination is crucial in printing systems, particularly those with interchangeable and / or multiple printheads. Specifically, in precision manufacturing systems, the height between the nozzle orifice (e.g., the printhead ejection plate) and the substrate surface can deviate by tens of micrometers or more due to various factors. Since droplet ejection is typically performed using relative movement between the printhead and the substrate, this deviation results in errors of tens of micrometers or more at the droplet attachment site, thus reducing the desired placement accuracy. A significant advantage of some of the techniques presented herein is that this error can be corrected by providing a more accurate and rapid determination of the nozzle height relative to the substrate surface, enabling more precise droplet placement (as mentioned above, which facilitates manufacturing advantages). It should be noted that, given an understanding of height and height variations, various techniques can be used in such systems to reduce errors; for example, the printhead can be adjusted manually or automatically in height or level; furthermore, in some embodiments, errors can be compensated for in software, for example, by adjusting pre-planned printing parameters such as nozzle timing, droplet velocity, droplet waveform, and even which of the multiple nozzles on the printhead are used to print each droplet. Based on an understanding of the height and / or position provided by the described alignment and calibration, as well as height measurement techniques, this document discloses various techniques for reducing any errors in nozzle position, nozzle-to-substrate height, substrate position error, scaling error, product tilt error (“shear”), etc. The described techniques are important for achieving fine-grained positional accuracy at the microscopic level (e.g., reaching resolutions of tens of micrometers or better) to allow for precise feature preparation and / or deposition of the deposited material.

[0029] In one implementation, at least one optical component is used for alignment and calibration of at least two different transport path directions to provide micron- or quasi-micron-resolution x, y position accuracy relative to the substrate and / or manufacturing chuck; for example, such a component may include one or more cameras that generate high-resolution digital images for calibrating each transport path to a common reference point. Optionally, a position feedback system (imaging or non-imaging) is also used to enable transport path-driven calibration in each transport axis direction, thereby providing micron- or quasi-micron-resolution position accuracy covering each transport path direction (e.g., in a split-axis system, such as the exemplary printing system described below, two transport paths are optically aligned to an origin, and a position feedback system is used for each transport path to ensure accurate transport path advancement). Optionally, a second component is also used for z-axis calibration and position sensing; and to identify any positional offset of such a second component relative to the calibrated x, y positions, thereby enabling Z-height determination at any point relative to the manufacturing substrate chuck. In one embodiment, because the deposition source may be at a different height (or misaligned) relative to the second component, the height can be derived through a suitable process, for example, by (a) measuring the height difference between the first z-axis measurement system above the manufacturing surface, (b) using a second z-axis measurement system below the manufacturing surface to measure any height difference between the first z-axis measurement system and the deposition material source (e.g., the printhead or a specific printhead nozzle), and (c) calibrating the first z-axis height determination system to match it or “zero” it to a known coordinate reference system. As implicitly illustrated, this capability, along with the ability to repeatedly measure height non-invasively during system operation, provides dynamic height measurements with far-reaching implications; for example, when the printhead or other manufacturing tooling is changed, the deposition source height can be measured immediately, automatically, and dynamically, thereby substantially improving system uptime. The fact that these measurements can be automatically correlated to a precise coordinate system also reduces errors due to operator subjectivity, thus providing far more accurate results.

[0030] Precise information about the height between the deposition source and the substrate surface can be used to correct the deposition position with high accuracy. As mentioned earlier, various errors / deviations will reduce this by changing the height, alignment, or level of the source (e.g., printhead), changing the substrate height or position, changing the source drive signal (e.g., nozzle drive signal) to change the jetting speed (i.e., thereby calibrating the attachment position), changing the jetting time (i.e., thereby also calibrating the attachment position to compensate for the error), changing which source is used for deposition (e.g., using a different nozzle that provides an alternative attachment position closer to the desired position), and / or potentially changing other deposition and / or mechanical parameters in software or otherwise.

[0031] An example of a manufacturing system that can benefit from the described technology is an industrial fabrication system that relies on an inkjet printer to deposit liquid droplets onto a substrate (e.g., depositing organic materials that cannot be easily deposited using other fabrication processes). Droplets, ejected one by one from thousands of parallel nozzles (one of multiple printheads), adhere to the substrate and fuse together to form a continuous liquid coating or liquid film. However, the liquid has adhesive properties, causing the coating thickness to vary locally depending on the droplet concentration and / or other forms of volume control (see content incorporated by way of previously cited referenced patents and publications). The film can provide a “blanket” of liquid coverage over a larger area relative to the electronic microstructure (e.g., it can provide an encapsulation layer, barrier layer, smoothing layer, dielectric layer, or other layers spanning multiple such microstructures), or be contained within a fluidic dam to form, for example, a layer for forming a single pixel or a light-emitting structure, where multiple such structures are fabricated simultaneously on the same layer. For example, the aforementioned manufacturing system could be used to print the same organic light-emitting layer on each of the millions of pixels that will form an HDTV in a single deposition process; in such a fabrication process, there can be millions of corresponding microsopic wells, and it is generally desirable to deposit precise amounts of liquid precisely within these wells. Regardless of the type of layer being manufactured, the continuous liquid coating is processed after printing and stabilization to cure, dry, harden, solidify, stabilize, or otherwise treat the deposited liquid coating, thereby converting it into a permanent or semi-permanent form (e.g., a treated layer). Considering the precise accuracy required to deposit precise amounts of ink at the microscopic level or to ensure uniform layer or specific edge profile distribution, the described alignment, calibration, and measurement techniques provide powerful tools to facilitate very precise droplet placement and provide very precise deposition control. These and other examples will be discussed further below.

[0032] Before moving on to other topics, it is helpful to first introduce some of the terminology used in this article.

[0033] Specifically, this disclosure will use various expressions for "ink". Unlike coloring liquids used in graphic applications, which are generally absorbed into a support medium and convey image information through their color (hue) and brightness, the "ink" discussed in this disclosure, typically deposited by a printing press, usually does not have significant color or image properties in itself; instead, the liquid carries materials that, once deposited and processed, will provide the desired layer thickness and structural elements that provide desired structural, optical, electrical, and / or other properties. While many materials can theoretically be deposited using this process, in several conceivable applications, "ink" is essentially a liquid monomer that, after deposition, will be converted into a polymer (i.e., into a plastic with desired conductivity, optical, or other properties). In a particular application where the deposited layer forms part of an organic light-emitting diode ("OLED") display, the deposited layer can contribute color and image information through electromagnetic actuation, but crucially, the liquid itself is not deposited for the purpose of transferring the liquid's inherent color to the substrate as part of a predefined image, but rather for the purpose of constructing a structure. In typical applications, the liquid is deposited in the form of discrete droplets diffused to a certain limit, fused together, and provides a “blanket” cover (i.e., typically without pores or gaps in the cover) within at least the defined area of ​​the fluid well.

[0034] Specifically, conceivable implementations may also include devices containing instructions stored in a non-transient machine-readable medium. This instruction logic can be written or designed in a structured (architectural) manner such that, when the instructions are ultimately executed, one or more general-purpose machines (e.g., processors, computers, or other machines) behave as special-purpose machines, capable of performing described tasks on input operands according to these instructions to take specific actions or otherwise produce specific outputs. For example, the techniques described herein can be implemented as control software stored on a non-transient machine-readable medium that, when executed, causes one or more processors and / or other devices to perform the calibration, alignment, and positioning functions described herein. As used herein, “non-transient” machine-readable or processor-accessible “medium” or “storage device” refers to any tangible (i.e., physical) storage medium, regardless of the technology used to store data on that medium, including but not limited to random access memory, hard disk storage, optical storage, floppy disks or CDs, server storage devices, volatile memory, non-volatile memory, computer internal memory, removable storage devices, and other tangible mechanisms in which the instructions can subsequently be retrieved by the machine. The medium or memory may be a standalone device (e.g., a program disk or solid-state device) or implemented as part of a larger mechanism, such as a laptop, portable device, server, network, printing press, or an additional suite of one or more devices. These instructions may be implemented in different formats, such as as metadata that effectively triggers an action when invoked, as Java code or a script, as code written in a specific programming language (e.g., as C++ code), as a processor-specific instruction set, or in some other form; these instructions may also be executed by the same processor or different processors or processor cores, depending on the implementation. Throughout this disclosure, various processes will be described, any of which may be implemented as instructions stored on a non-transient machine-readable medium, and any of which may be used to prepare products. Specifically, depending on the product design, such products may be prepared in a commercially viable form or as a preparatory step for other printing, curing, manufacturing, or other processing steps, ultimately forming finished products for sale, wholesale, export, or import, wherein these finished products are incorporated into the prepared layers. Again, to cite an example already mentioned, the use of a conceivable implementation method to manufacture the layers of an electronic display screen. Alternatively, other layers may be added by other processes without impairing (or substantially altering) the layers prepared according to the precise processes described herein; and the resulting display screen may also be combined with other components (e.g., thereby forming a working television or other electronic device) without substantially altering the layers prepared according to the precise processes described herein.Furthermore, depending on the specific implementation, the instructions or methods described herein may be executed by a single computer, and in other cases, may be distributed for storage and / or execution, for example, using one or more servers, web clients, or dedicated devices. Each function mentioned herein with reference to several different figures may be implemented as part of a combined program or as a separate module, or stored together on a single medium (e.g., a single floppy disk) or on multiple separate storage devices. The same applies to error calibration information generated according to the process described herein, indicating that a pre-printed template or "recipe" can be modified to incorporate positional errors or feedback and stored on a non-transient machine-readable medium for current or subsequent use on the same machine or on one or more other machines; for example, such data may be generated using a first machine and then stored for transfer to a printing press or manufacturing equipment, for example, by downloading via the Internet (or other networks) or by manual transfer (e.g., via a transfer medium such as a portable drive) for use on another machine. As used herein, "raster" or "scan path" refers to the progression of movement of the print head or camera relative to the substrate; that is, in all embodiments, it need not be linear or continuous. As used herein, the terms “hardening,” “solidifying,” “processing,” and / or “rendering” refer to the process of applying deposited ink to transform it from a liquid form into a permanent or semi-permanent structure (e.g., relative to a temporary structure such as a temporary mask) of a manufactured object. Throughout this disclosure, various processes will be described, any of which may be implemented as instruction logic (e.g., as instructions stored on a non-transient machine-readable medium or other software logic), as hardware logic, or a combination of both, depending on the implementation or specific design. As used herein, “module” refers to a structure dedicated to a specific function; for example, when used in an instruction context (e.g., computer code), a “first module” for performing a first specific function and a “second module” for performing a second specific function refer to mutually exclusive sets of code. When used in a mechanical or electromechanical context (e.g., a “cryptographic module”), the term module refers to a set of dedicated elements that may include hardware and / or software. In all cases, the term "module" is used to refer to a specific structure for performing a function or operation, which should be understood by those skilled in the art to which this invention pertains as a conventional structure used in a particular prior art (e.g., a software module or hardware module), rather than as a general space-occupying device or "means" of "any structure" (e.g., "a team of oxen") for performing the cited function.

[0035] Furthermore, this document references detection mechanisms and alignment marks or reference points, which are located on each substrate or as part of the printing press plate or transport path or as part of the printhead. In several embodiments, the detection mechanism is an optical detection structure that uses an array of sensors (e.g., a camera) to detect identifiable shapes or patterns on the substrate (and / or physical structures within the printing press). Other embodiments are not based on sensor "arrays"; for example, line sensors may be used to sense reference points as the substrate is loaded into or advanced within the printing press. Note that some embodiments are based on patterns (e.g., simple alignment guides, lines, or marks), while others are based on more complex and identifiable features (including shapes of any previously deposited layer geometry on the substrate or physical features within the printing press or printhead), each of which can be a "reference point." In addition to using visible light, other embodiments may rely on ultraviolet or other invisible light, magnetic, radio frequency, or other forms of detection of substrate details relative to the desired printing position. It should also be noted that the various embodiments described herein involve one or more printheads or printhead assemblies; however, it should be understood that the printing systems described herein can typically be used with one or more printheads, whether modular or otherwise mounted. In a conceivable application, for example, an industrial printing press may have three printhead assemblies (each assembly is sometimes referred to as an “ink bar” mount), each assembly or mount having three separate printheads with a mechanical mounting system that allows for positional and / or rotational adjustments such that the components of the printhead (e.g., printhead assembly) and / or the printhead assembly and / or its nozzles can be precisely aligned with the desired grid system; other configurations with one or more printheads are also possible. Generally, the terms “film” or “coat” used herein refer to the original deposited material (e.g., liquid), while “layer” is generally used to refer to post-processed structures, such as those that have been converted to a solidified, hardened, polymerized, or other permanent or semi-permanent form. Generally, the “x-axis” and “y-axis” will be used to refer to the plane of deposition, while the “z-axis” will refer to the direction perpendicular to that plane; however, it should be understood that these references can refer to any corresponding degree of freedom of motion. The following text will define a number of other terms or use them in a manner that is obvious in the context.

[0036] In the following discussion, we will first refer to Figure 1A-1D This paper explains the basic configuration of a split-axis industrial printing press, and then discusses some challenges related to precise droplet placement and how this split-axis industrial printing press uses innovative structures to solve these challenges. Figure 2A-2B The discussion will proceed by illustrating the structures of the first and second embodiments, respectively. Figures 3A-3BThe discussion will proceed by illustrating exemplary operational steps or methods for each of these embodiments. Generally, embodiments for performing x and y position calibration and alignment will be described first, followed by an additional description of z-axis measurement. Figures 4A-4C The accompanying figures will describe a high-resolution measurement that provides an absolute z-axis (i.e., height) measurement, and an implementation utilizing the coordinate system of the manufacturing equipment. Further, more detailed embodiments will be described in the following figures. Such a design can be implemented in a printing system that deposits organic materials for preparing light-emitting product layers, including, for example, an "active" layer that facilitates light emission and a passive layer that encapsulates sensitive electronic components; such a manufacturing equipment can be used, for example, to fabricate "OLED" televisions and other displays.

[0037] B. Exemplary scenario - including a split-axis system for a printing press.

[0038] Figure 1A An overview of the manufacturing process is provided by reference numeral 101 in the accompanying figure; this figure also illustrates some possible individual embodiments of the techniques described herein. As seen on the left side of the figure, a series of substrates 105 are to be processed, each substrate having a layer deposited thereon, wherein the deposition process, by means of the techniques described herein, makes the manufacturing process more accurate and / or faster compared to not employing these techniques. Figure 1A The right side shows one of a series of substrates 107 currently in finished form, which is ready to be cut into multiple products (as indicated by the dashed portion of substrate 107). For example, the finished substrate 107 can be used to form one or more mobile phone displays 109, HDTV displays 111, or solar panels 113.

[0039] To form the layer in question, manufacturing equipment 103 is used to deposit, prepare, and / or process the material. As will be further discussed below, in one embodiment, the manufacturing equipment may include a printer (119) that prints material in the form of microdroplets of dispersed liquid, wherein the microdroplets are diffused in a limited manner to form a continuous liquid coating (at least locally), and wherein the manufacturing equipment or another device then processes the liquid coating to convert the material into a permanent or semi-permanent form. In one example, the liquid is an organic material (e.g., a monomer) that is cured, dried, baked, or otherwise treated to change the form and / or physical properties of the organic material to a form in which it will remain as a layer of the finished device; a contemplated manufacturing process may use an ultraviolet (“UV”) lamp to convert the monomer into a polymer, substantially converting it into a conductive, electroactive, luminescent, or other form of plastic. The techniques disclosed herein are not limited to these types of materials. In addition, it should be noted that there may be prior processing steps (e.g., there may be an existing lower layer surface geometry consisting of microstructures on the substrate 105) and / or subsequent processing steps (e.g., other layers and / or treatments that may be applied after the layers are completed, and / or films produced by the manufacturing equipment 103). Figure 1A A first computer icon 115 and an associated non-transient machine-readable medium icon 117 are also shown to indicate that the manufacturing equipment can be controlled by one or more processors under the action of control instruction logic; for example, such software and / or processors can control or command the calibration, alignment and measurement techniques described herein. Figure 1A A second non-transient machine-readable medium icon 118 is also shown, representing the deposition on each substrate 105 in a series, performed according to instructions of a predefined printing process or “specification,” such as a general design expected to be applied to each substrate 105 in a sequence. The techniques described herein can be used to adjust printing press components and / or printing process parameters for more accurate printing according to a general specification, or can be used to convert or adjust the specification itself (e.g., potentially on a substrate-by-substrate basis), thereby adjusting individual printing actions (e.g., jet signals applied to nozzles) according to the calibrations, alignments, and measurements described herein; despite such errors or deviations, subsequent processes effectively adjust the design to reduce such errors / deviations and produce the desired printing results.

[0040] Therefore, the techniques introduced in this disclosure may optionally take the form of instructions stored on a non-transient machine-readable medium 117 (e.g., control software). According to computer icon 115, these techniques may also optionally be implemented as part of a computer or network, for example, as part of a computer system used by a company manufacturing the product. Third, as with the manufacturing equipment indicated by reference numeral 103, the previously described techniques may take the form of manufacturing equipment or its components, for example, a position measurement system for manufacturing equipment, or a printing press controlled according to position signals and / or calibration generated using the techniques described herein. Fourth, the techniques described herein may take the form of corrective "specifications" (e.g., printing press control instructions corrected to reduce alignment, scaling, tilting, or other errors). Finally, the techniques described above may also be embodied in the manufactured product or the manufactured item itself; for example, in… Figure 1A In this document, several such components are shown in the form of an array 107 of semi-finished flat panel devices, which will be separated and sold for incorporation into final consumer products. The described devices may have one or more light-emitting layers, encapsulation layers, or other layers, for example, prepared according to the methods described above. For example, the techniques described herein may be embodied in the form of improved digital devices 109 / 111 / 113 (e.g., electronic tablets or mobile phones, television displays, solar panels) or other types of devices.

[0041] Figure 1B A contemplated multi-chamber manufacturing apparatus 121 is illustrated for use with the techniques disclosed herein. Generally, the illustrated apparatus 121 comprises several general modules, or a subsystem comprising a transfer module 123, a printing module 125, and a processing module 127. In this example, each module maintains a controlled environment relative to ambient air. This controlled environment may be the same throughout the manufacturing apparatus 121, or it may differ for each chamber. The transfer module 123 is used for loading and unloading substrates, or exchanging these substrates with other manufacturing equipment. Each received substrate may be printed by the printing module 125 in a first controlled atmosphere, and (if desired) other processing may be performed by the processing module 127 in a first or second controlled atmosphere, such as another deposition step (e.g., for the printed material) or a curing, drying, or baking process. The manufacturing apparatus 121 uses one or more mechanical handling devices to move substrates between modules without exposing the substrates to an uncontrolled atmosphere (i.e., to ambient air that may contain contaminants such as particulates, moisture). Within any given module, other substrate handling systems and / or specific devices and control systems suitable for the processing performed by that module may be used. Within the printing module 125, mechanical processing may include (in a controlled atmosphere) the use of a floating stage, fixtures, and alignment / fine-tuning error calibration mechanisms as described above and below. In some embodiments, other types of deposition equipment (besides a printing press) may be used.

[0042] Various embodiments of the transfer module 123 may include an input loading lock chamber 129 (i.e., a chamber that provides a buffer between different environments while maintaining a controlled atmosphere), a transfer chamber 131 (also having a carrier for transferring substrates), and an atmosphere buffer chamber 133. Within the printing module 125, as mentioned, a floating stage can be used to stably support the substrate during the printing process. Furthermore, an xyz-motion system, such as a split-axis or gantry-type motion system, can be used for precise positioning of at least one printhead relative to the substrate, and to provide electrically driven transport of the substrate along the y-axis of the printing module 125, and electrically driven transport of one or more printheads along the x and z axes. Various inks can also be used for printing within the printing chamber, for example, using individual printheads or printhead assemblies, to perform two different types of deposition processes, for example, within the printing module in a controlled atmosphere. The printing module 125 may include a gas-sealed chamber 135 housing an inkjet printing system, having components for introducing an inert gas (e.g., nitrogen or a rare gas) and additionally controlling the atmosphere, gas composition, and particulate matter presence for environmental conditioning (e.g., temperature and pressure).

[0043] Various embodiments of processing module 127 may include, for example, a transfer chamber 136; this transfer chamber also has a carrier for transferring substrates. Furthermore, the processing module may also include an output loading lock chamber 137 for exchanging substrates with another manufacturing device or for additional unloading of substrates, a nitrogen stacking buffer 139, and a curing chamber 141. In some applications, the curing chamber may be used to cure monomer films to convert them into homogeneous polymer films; in other applications, the curing chamber may be replaced by a drying oven or other processing chambers. For example, two particularly desirable processes include a heating process and a UV curing process.

[0044] In one application, manufacturing equipment 121 is suitable for mass production of liquid crystal displays or OLED displays, for example, fabricating an array of eight screens at once on a single large substrate. These screens can be used for televisions and displays as displays for other forms of electronic devices. In a second application, the equipment can be used to mass produce solar panels or other electronic devices in almost the same manner. In the process of an exemplary assembly line, each of a series of substrates is fed in through an input loading lock chamber 129 to be mechanically pushed into a transfer chamber 131. If appropriate, the substrate is then transferred to a printing module, where a liquid coating is deposited with very precise positional parameters in a manner already described herein. After a settling time that allows microdroplets to fuse and form a locally uniform liquid coating, the substrate is moved to a processing module 127, where it is transferred separately to an appropriate chamber (e.g., a curing chamber 141) for appropriate curing or other processes to complete the layer, which is then conveyed out through an output loading lock chamber 137. Note that the individual modules within these modules can be interchanged, omitted, or changed depending on the configuration; that is, regardless of the process, the manufacturing equipment deposits at least some material used to “build” the desired layer of the finished product. As previously mentioned, in conventional processes, deposition parameters may be precise, requiring each “pixel-level” droplet to be placed at a specific location on the substrate, accurate to 1 or a few micrometers. For specific desired purposes, the droplet size and / or placement may sometimes be intentionally altered; see the aforementioned patents and patent applications incorporated by reference.

[0045] By repeatedly depositing subsequent layers, each controlled thickness of a light-emitting layer, electronic microstructure element layer, or blanket layer (e.g., encapsulation) can be constructed to suit any desired application. In one embodiment, one or more layers may be different, but a series of microlayers (e.g., each less than 20 micrometers thick) can also be fabricated to construct a more aggregated thicker layer. The modular nature of the fabrication equipment can be used to tailor the fabrication equipment for a variety of different applications; for example, as noted, one application may use a baking chamber, as the “printed” liquid coating can be processed by baking to make it a permanent or semi-permanent structure. In different embodiments, it may be desirable to use UV light to cure the deposited layers and perform similar processing. Therefore, it is apparent that the configuration of equipment 121 can be changed to place various modules 123, 125, and 127 in different adjacent locations, or to use additional, fewer, or different modules, largely depending on the type and design of the product being manufactured, the desired deposition material, the specific type of layer to be formed, the end product application, and other potential factors. As each substrate in the series is processed, the next substrate in the series is then introduced and processed in almost the same manner.

[0046] Although Figure 1B This provides one example of a set of connected chambers or fabrication elements, but clearly many other possibilities exist. The techniques described above can also be combined with... Figure 1B The apparatus shown is used in conjunction with, or can in fact control, any preparation process performed by any other type of deposition equipment.

[0047] Figure 1C A top view of a split-axis printing press 151 is shown. This printing press can be used as a non-limiting example of manufacturing equipment. Note that this drawing is not to scale and uses conventional parts to aid in the discussion of basic mechanisms and concepts; for example, the print head 165 typically has more than the five described nozzles 167, possibly thousands or even tens of thousands of nozzles, to print the widest possible strips on the substrate 157 beneath it with the greatest possible precision and speed. Similarly, only general details and components are shown to illustrate the operating principles. In the scenario of assembling a line, it is generally desirable to achieve printing on panels that may be several meters long by several meters wide in less than 60-90 seconds, i.e., to keep the cost of the production process as low as possible without sacrificing print quality.

[0048] The printing press includes a printhead assembly 165 for depositing ink onto a substrate 157. As previously mentioned, during the manufacturing process, ink is typically viscous, causing it to spread only within a limited area. Once any processing is performed to convert the liquid coating into a permanent or semi-permanent structure, the maintained thickness will become the layer thickness. The thickness of the layer produced by depositing liquid ink depends on the volume of ink applied, for example, the density and / or volume of droplets deposited at the predetermined location. The ink has one or more materials that will form part of the finished layer, which may be formed as monomers, polymers, or materials carried by solvents or other delivery media. In one embodiment, these materials are organic. After ink deposition, the ink is dried, cured, hardened, or otherwise treated to form a permanent or semi-permanent layer; for example, some applications use an ultraviolet (UV) curing process to convert liquid monomers into solid polymers, while other processes dry the ink to remove solvents and leave the delivered material in the desired location. Other processes are also possible. Note that there are many other features that distinguish the illustrated printing process from conventional graphic and text applications; for example, as described elsewhere in this document, one implementation uses a manufacturing apparatus that encloses the printer 151 in a gas chamber so that printing can be performed in the presence of a controlled atmosphere to exclude moisture and other unwanted particles.

[0049] Further as Figure 1CAs can be seen, roughly indicated by double arrows 169, the print head 165 moves back and forth along the "x-axis" dimension on the support rod or guide 155 relative to the support table or chuck 153. A dimensional illustration 163 is provided in the figure to explain the orientation of the axis. It should also be noted that the print head 165 in this figure is shown in dashed lines to indicate that it is obscured by the support rod 155, i.e., it is facing downwards toward the substrate 157 to eject ink droplets that fall under gravity from the corresponding nozzles 167 and adhere to a predictable, planned position on the top surface of the substrate 157. Although only a single printhead 165 and a single row of nozzles 167 are shown in the figures, it should be recognized that there are typically multiple printheads, each with hundreds or thousands of nozzles; the printheads are typically staggered relative to their “x-axis” position to provide an effective spacing of approximately tens of micrometers between the nozzles, and in some embodiments, the printheads are mounted on a moving assembly that allows one or more of the following actions: (a) generating power to rotate the printhead to change the effective “span-scan” spacing, (b) generating power to adjust the height of the printhead above the substrate (or more precisely, relative to the printhead support bracket or “ink bar” base for a set of printheads), (c) generating power or manually leveling the printhead, i.e., aligning the nozzle orifice plate with the receiving substrate, and / or (d) module exchange with the printhead or “ink bar” base, and potentially other actions. Note that in a typical graphic press, as indicated by reference numeral 169, the substrate (e.g., paper) is slowly advanced along the "y-axis" as the printhead moves back and forth. Unlike such graphic presses, in industrial presses, the substrate transport along the "y-axis," in the direction indicated by double arrow 161, is typically a rapid axial movement, while the printhead usually only changes position between scans (relative movement between the substrate and the printhead). Therefore, in this example, the "y-axis" is referred to as the rapid axis or the "in-scan" dimension, while the "x-axis" is referred to as the "slow axis" or the "cross-scan" dimension. In this example, each printhead present at any given moment typically deposits the same ink (even if there may be multiple printheads), with the aim of simultaneously providing a microscopic cross-scan spacing for depositing droplets and covering the widest possible stripe to enable fewer scans and faster fabrication / printing of each product layer. The substrate is typically an ultrathin glass plate, and the support stage or chuck 153 is usually a floating stage that supports each substrate on an air (or other atmospheric gas) cushion; in the illustrated system, the vacuum clamp 159 engages the substrate along an edge as it is introduced and moves the substrate back and forth along the y-axis during printing. The clamp travels along a track or path ( Figure 1C(Not shown in the diagram) operates and provides one transfer axis in the illustrated split-axis system, while the rod or guide 155 provides another transfer axis. As should be apparent from this example, any desired printing position can be obtained on the substrate 157 by using the jig 159 to move the substrate along the y-axis in the inner dimension of the scan, and also by moving the printhead 165 across the scan dimension (i.e., along the x-axis), where each movement is finely controlled.

[0050] It is equally apparent that, given that the distance between the scanning nozzles is on the micrometer scale, even a tiny calibration error could theoretically lead to ink droplets being placed in the wrong position on the substrate. Therefore, to precisely control droplet placement in such systems, the calibration techniques described herein are used to ensure that droplets are accurately placed in a predetermined position, with an error no greater than a few micrometers and ideally much smaller. As with many other descriptions herein, this type of system (printer / splitter) is merely representative, and the details described above should be considered as a presentation of details of alternative implementations in order to understand one possible approach.

[0051] Figure 1D The diagram illustrates a series of individual substrates 181 moving through a printing press, with multiple dashed boxes representing individual panel products 183, as shown in the specific design example; the accompanying drawing in this example shows exactly four such panel products. Each substrate (in a series of substrates) is as follows: Figure 1DThe substrate 181, as shown in the figure, has a plurality of alignment marks 187 in one embodiment. In the illustrated embodiment, three (or more) such alignment marks 187 are used for the entire substrate, thereby enabling the measurement of positional offset and / or rotational error of the substrate relative to the manufacturing equipment (e.g., relative to a chuck, a split-axis transport path, or another reference frame). Other errors, such as tilt errors (e.g., a non-linear spindle axis relative to the printing press axis) and / or proportional errors between the substrate and the printed image (i.e., in the x-dimensional, y-dimensional, or both), can also be detected. One or more camera assemblies 185 are used to image the alignment marks in order to detect these various errors. In one anticipated implementation, a single camera assembly is used (e.g., mounted on the printhead assembly). As mentioned, the split-axis system allows the printhead to be placed anywhere on the substrate by coordinating the drive of two transport systems, and the camera assembly in this embodiment is not different in that the press's transport mechanism (e.g., a carrier and / or an air-floating mechanism) moves the substrate and the camera to sequentially position each alignment mark in the field of view of the camera assembly. In one embodiment, the assembly includes both a high-resolution camera and a low-resolution camera, while in other embodiments, a single camera or different types of sensors (e.g., a motionless light sensor) may be used to detect the actual position of the substrate relative to the press reference frame. The camera assembly in this example, as intended, may be mounted on a printhead carriage or a printhead assembly or a second printhead assembly, or it may be mounted on different carriages (bridges or guides), depending on the specific implementation. In the dual-camera assembly, low-magnification and high-magnification images are captured separately. The low-magnification image is used for coarse positioning as a reference for high-resolution magnification, while the high-magnification image is used to identify the precise reference position according to the printing press coordinate system. Relative to Figure 1D These different structures are used to detect the relationship between each individual substrate and the coordinate system of the fabrication system, so that substrate alignment, orientation, position, skew and size can be standardized and deposition can be taken into account, thereby ensuring that material is precisely deposited at the exact same location on each substrate (i.e., relative to the alignment mark) during subsequent fabrication.

[0052] Considering the structure just discussed, in a anticipated implementation, the camera assembly can be integrated with the printhead assembly (i.e., the printhead holder mentioned above) to simultaneously calibrate the position reference system of the manufacturing equipment (i.e., position calibration and effective alignment of the two transport paths before the substrate is introduced), and then, as combined... Figure 1DThe position of each individual substrate reference point is detected to align each substrate with the printing press coordinate system, or to adjust printing parameters to align with the actual position / or orientation / skew and / or size of each substrate. Like the other components described, the camera assembly can also be a modular unit interchangeable with other modules in the printing press maintenance station, such as the ink bar holder cited above; however, in one embodiment, the camera used in the printhead transport path is fabricated as an integral, permanent part of the printhead assembly.

[0053] In a typical implementation, printing is performed to deposit a given layer of material immediately across the entire substrate (i.e., a single printing step provides one layer for the substrate of multiple products in each scan or group of scans). It should be noted that this deposition can be performed within a single pixel well. Figure 1D (Not shown in the diagram, meaning there are typically millions of such wells), in order to deposit a luminescent layer within these wells, or to deposit a barrier or protective layer, such as a barrier or encapsulation layer, on a "blanket" base. Problems exist with either deposition process. Figure 1D Both images show two illustrative scans 189 and 191 of the printhead along the longitudinal axis of the substrate; in split-axis printing presses, the substrate typically moves back and forth (e.g., along...). Figure 1D The arrow direction shown and Figure 1C The direction of the double arrow 161 in the figure), while the printing press advances the print head between scans in position (i.e., in the "x-axis" direction or the vertical direction relative to the drawing). It should be noted that although the scan path is shown as linear, this is not necessary in any implementation. Furthermore, although the scan paths (e.g., 189 and 191) are shown as adjacent and opposite in the coverage area, this is not necessary in any implementation (e.g., if necessary, the print head is applied relative to the base of the printed strip). Finally, it should also be noted that any given scan path typically traverses the entire printable length of the substrate in order to print one layer for (possibly) multiple products in a single scan. Each pass is determined by the nozzle jetting according to the "printed image" or nozzle bitmap, with the aim of ensuring that each droplet in each scan is precisely deposited in the position that should be located relative to the substrate and / or product / panel boundary. As shown, during the first scan 189, the substrate 181 is advanced relative to the printing press in the "fast axis" or "in-scan" direction (i.e., Figure 1C The printhead assembly moves along the y-axis and is placed in the first position 193. During the second scan 191, the substrate moves in the opposite direction to the "fast axis" or "in-scan" direction, and the printhead assembly is repositioned in the "slow axis" or "across scan" direction (as shown by arrow 195) to position 194, thereby completing the strip indicated by numeral 191.

[0054] Once all printing is complete on the layer or film being discussed, the next step is to transfer the substrate and wet ink (i.e., the deposited liquid that has settled onto the liquid coating) to cure or process the deposited liquid into a permanent or semi-permanent layer. For example, briefly returning to... Figure 1B The substrate may contain "ink" applied in printing module 125 and then conveyed to curing chamber 141 without disrupting the controlled atmosphere until the treated layer is formed (i.e., this process advantageously suppresses moisture, oxygen, or particulate contamination). In different embodiments, ultraviolet scanners or other processing mechanisms may be used in situ, for example, in a split-axis traveler in substantially the same manner as the one or more printhead / camera assemblies described above.

[0055] C. First implementation - Calibration, alignment and position sensing in a split-axis system.

[0056] Figure 2A This is an illustrative diagram of the split-axis system 201, which uses precise calibration, alignment, and / or sensing as described above. It should be noted that actual implementations may differ slightly from those shown (e.g., the printhead 223 is typically oriented "downward" towards the image, spraying droplets towards the image rather than as depicted in the diagram; furthermore, the heights shown are for entering and exiting the image, not as illustrated, and the sensor 229 is oriented upwards towards the image exit); nevertheless, the examples shown rely on this diagram for the purpose of explanation and reader understanding.

[0057] The split-axis system has a first transport path 203 (e.g., for transporting the printhead assembly 205 in the direction indicated by double arrow 207) and a second transport path 209 (e.g., for transporting the fixture 211 in the direction indicated by double arrow 213). Note that double arrows 207 and 213 represent reciprocating motion (e.g., reversal of the scan path direction, such as...). Figure 1D The stripes formed by the interactive scanning paths shown are 189 and 191, and these types of systems typically have basic translational inertia when moving their components. For this and other reasons, each transport path, indicated by reference numerals 215 and 219, also uses a position feedback system. That is, the bridges or guides used to support the printhead assembly are characterized by having position markers to aid in precise position determination; these markers typically take the form of adhesive strips with markings spaced at intervals of one or several micrometers (i.e., as indicated by the “ruler” marking 215). Sensors 217 on the printhead assembly 205 image, optically detect, or otherwise sense these markers and provide feedback based on the actual position of the printhead assembly, thus allowing electronic control or drive systems ( Figure 2A(Not shown) precisely positions the printhead carriage despite the effects of inertia, jitter, or other sources of error. Similarly, the second transport path (e.g., a guide provided by the printing press support or chuck 231) is typically also equipped with a similar set of position markers, such as marked adhesive tape 219, again indicated by scale markings that provide position information; these markers are similarly imaged and detected or sensed by sensors 221 on the fixture 211, and similarly, this feedback system allows the electronic control or drive system ( Figure 2A (Not shown) Precision positioning fixture, despite the effects of translational inertia, jitter and other potential sources of error.

[0058] The system presents a challenge in linking or aligning these two paths and their associated systems; that is, the first and second transport paths need to be associated with each other, thereby, for example, defining a coordinate system and directly associating it with the printable location.

[0059] To this end, a reference of some type is provided that can be reached and detected by each of the printhead assembly 205 and the fixture 211. This reference is shown as numeral 235 in the figures. This reference is located using a first sensor 227 associated with the first transport path and a second sensor 229 associated with the second transport path, respectively, to establish coordinate points common to each transport path. The printhead 223 can then be positioned at any specific coordinate position relative to the printable area of ​​the printing press, based on the position of the feedback system for each position of each transport path (e.g., indicated by the alignment tape or "ruler" illustrations 215 and 219). Note again, Figure 2AFor ease of illustration and interpretation, the printhead 223 and sensor 227 typically face downwards as they enter the drawing page to image the reference 235, while sensor 229 typically faces upwards as it leaves the drawing page to approach the reference 235 from below. Therefore, in this embodiment, the clamp 211 can only move in the vertical (“y-axis”) direction, while the printhead assembly 205 can only move in the horizontal direction. To facilitate positioning and identification of the reference 235, in one embodiment it is directly connected to either the clamp 211 or the printhead assembly 205, i.e., positioned in a known location relative to either sensor 111 or sensor 229. In this case, the reference 235 is coupled to the printhead assembly 205, as shown by dashed line 237. For example, as will be discussed in the embodiments below, the reference can take the form of an optical reticle, where sensors 227 and 229 are each cameras. In such a system, the carriages or components moving along each transport path are adjusted until they coincide with the overlay image rendering datum lines for each transport path. A position feedback system is then used to normalize the position of each transport path; this position marking identifies a common coordinate point (e.g., the “origin” of the coordinate system), to which the x, y transport system is calibrated so that the position feedback provides a unit of advance relative to that origin. The datum lines can be optical attachments, which can then optionally be removed after this calibration. Note that various alternatives exist for finding the common reference point (e.g., sensors 227 and 229 can be configured as cooperative elements of the sensing system to allow for precise alignment between them, and, as implied by this statement, various different types of sensors and / or positioning methods can be used to perform this cooperative positioning). Through the described cooperative positioning, a complete x, y coordinate reference system for the printing press / manufacturing equipment can be established.

[0060] When printing begins, substrate 239 is introduced into system 201 and engaged by vacuum element 225 of fixture 211. As shown, substrate 239 may have undesired translational offsets and / or rotational errors, as well as potential other errors such as tilt and / or scaling errors; therefore, it is generally necessary to correct or at least take this error into account so that the droplets from the printhead can be precisely placed in the intended position relative to the substrate and / or any product prepared thereon. Note that there are many mechanisms available for calibrating this error. For example, the substrate can be repositioned using mechanical handling devices; or, as described by reference in incorporated patents and patent publications (see, for example, U.S. Patent Publication No. 20150298153), printing parameters can be adjusted so that nozzle allocation, jetting time, print grid definition, scan path position, and / or other parameters are adjusted in software to match substrate errors, thereby substantially allowing fine virtual calibration of substrate alignment, orientation, skew, and / or dimensional errors. Regardless of the mechanism employed, for calibration, errors in substrate position, scale, and / or tilt are first identified, in this case using alignment mark 243 (i.e., another reference). Given that the substrate in typical applications is often transparent glass, this error detection can be performed by controlling two transport paths to locate and image the reference 243 using sensor 227; since the position of the reference 243 in the press coordinate system can now be measured, image processing techniques (recognition of the reference 243) can be used to couple the position learned from the position feedback system of each transport path to accurately determine the coordinates of the substrate (i.e., the reference) relative to the press. As cited above, using complex or multiple references, the image processing system can also identify other misalignments, such as errors in substrate rotation orientation. By performing layer deposition (for all layers of the desired device) relative to the substrate reference (e.g., 243), accurate layer registration can be achieved even with substrate position and / or orientation errors, as well as other errors such as substrate edge non-straightness, tilt, and / or scale errors.

[0061] It should be noted that each of these different procedures described can be performed with operator involvement, or (especially with the aid of the techniques described herein) can be fully automated under processor control. For example, in one implementation, the operator observes the images provided by each camera and manually engages each transport system to manually align the trajectories imaged by each camera, thereby establishing a common coordinate point. Advantageously, in one embodiment, this alignment operation is performed entirely by image processing software, which, for example, uses image processing, search algorithms, and associated electronic control for each transport path; the image processing software causes one or more processors to detect deviations between trajectories aligned with the trajectories and / or images produced by the cameras, thereby driving the transport motion system to reduce / eliminate these deviations, reading position data from feedback systems 215 / 219, and “zeroing” the system to the common reference point. Image data from each camera is stored in the frame-capturing circuitry of each camera, and the definition information of the common coordinate point is stored in processor-accessible non-transient memory for use during position sensing.

[0062] Once the substrate position and / or printing parameters have been calibrated based on the measured position and / or orientation errors derived from one or more substrate references 243, the substrate can be advanced by a jig as required for printing, for example, by moving back and forth in the scan direction as indicated by double arrows 241.

[0063] However, if the height of the printhead 223 (and each nozzle of the printhead) above the substrate is not carefully controlled, Figure 2A The system shown may also produce errors. This can be explained relative to the height indicators “h0”, “h1”, and “h2” shown in the attached figure next to the printhead 223, relative to the ejected droplets, and relative to the droplet apparent velocity indicator “V”. Note that these are also drawn only to aid explanation, i.e., where the substrate moves along the “rapid axis” in the direction of the double arrow 241, the droplets and the substrate move relative to each other, and the droplets are ejected from below the printhead toward the substrate and the drawing page. During scanning, as the ejected droplets fall, the continuous movement of the substrate means that the position of the droplets adhering to the substrate depends on factors such as (a) the substrate velocity, (b) the droplet ejection velocity, and (c) the distance or height between the printhead and the substrate; a height deviation at a given constant velocity can therefore be directly translated into a deviation in the droplet attachment position on the substrate. In practice, the deviation in the attachment position is typically about one-fifth of the height deviation; for example, if the typical height of the printhead nozzle above the substrate is 2 mm, and the height error and / or deviation is about 100 micrometers, this deviation will translate into a difference of about 20 micrometers at the expected droplet attachment position. Note that if the altitude is unknown or the effective altitude deviation is large, the error will be much greater.

[0064] To address this potential source of error, in one embodiment, the height of the deposition source above the substrate is also calibrated, measured, and controlled during the deposition process. In one embodiment, this calibration is performed using sensors 227 and 229 and a reference for the alignment system (e.g., caliper 235). (Followed by...) Figure 4A In another embodiment (described in -C), another sensor system (i.e., an absolute position sensor) can be used to measure the height. In the case of the illustrated system, the difference between the height of the printhead assembly and the camera may not be accurately known. Therefore, it is advantageous to measure both heights "h0" and "h1" simultaneously, so that height "h2" can be easily derived from height "h0" measured using sensor 227 (i.e., according to "h2" = "h0" - "h1"). In printing press embodiments, for some implementations it may be sufficient to simply "know" a height of the printhead (e.g., if the level control of the printhead nozzle plate can achieve reasonable accuracy), while in other embodiments it may be desirable to measure the absolute height of each nozzle orifice of each printhead, i.e., thereby enabling precise knowledge or reduction of the apparent droplet velocity difference between nozzles. It should also be noted that, as discussed by reference in incorporated patents and patent publications (e.g., particularly U.S. Patent No. 9,352,561), each nozzle may exhibit errors in nozzle position (“nozzle bow”), droplet ejection volume, droplet trajectory, and / or droplet velocity due to manufacturing process angles, and these errors may exhibit statistical bias. Therefore, in a contemplated implementation, each nozzle may have a statistical model designed for the droplets (i.e., as discussed in U.S. Patent No. 9,352,561), wherein the measured height of each nozzle is taken as a factor into account in the expected droplet attachment location, in order to design a precise expectation of where the droplets from each nozzle will attach relative to the nozzle height and the process angles affecting the specific nozzle. As previously described, such information can be used to calibrate deviations from the desired height depending on the specific implementation, for example, by adjusting the printhead height (in one embodiment, the printhead, printhead holder, or “ink bar” has an electronically driven z-axis motor) or adjusting the droplet velocity, ejection time, substrate position, nozzle for deposition, droplet timing, cross-scan spacing, and / or other printing parameters.

[0065] Figure 2B Further details regarding height calibration and related measurements are provided in one implementation method. More specifically, Figure 2BSystem 251 is shown, which also shows printhead carrier 205 and clamp 211. In this figure, the clamp rides in and out of the drawing page (i.e., riding on support guide 261, as indicated by the dimension legend), while the printhead carrier 205 rides back and forth parallel to the x-axis, as indicated by reference numeral 207. As before, the printhead carrier uses position reference 215 (shown as scale markings), while the clamp uses position reference 219 (which travels in and out of the drawing page and is sensed by sensor 221 as the clamp moves). The datum line (i.e., the reference for linking the coordinate references of the sub-axis) is shown as being located in the xy plane and is indicated by reference numeral 255; this datum line is fixed in place by a mechanical base (i.e., an "L-shaped rod" or equivalent), thereby placing it directly within the optical path 259 of camera 253. In one embodiment, the base may be a movable base that can be adjusted once (or infrequently) and allows for manual or automatic coupling and decoupling as needed, maintaining a consistent position repeatably and accurately relative to the field of view of camera 253. The camera includes an electronic autofocus system that allows adjustment of the camera's focal length (represented by conical optical path 259) to accurately image the datum line—in this case, the datum line may be a set of crosshairs on a transparent plate. Again, note that multiple items are shown in this figure for illustrative purposes, and specific implementation details may vary.

[0066] The distance between the camera and the reticle is calculated by adjusting the camera's focal length to obtain a precise focal length, which is accompanied by a specific focal length length (or "focal depth"); the height ("h4") is calculated directly by the processor based on the focal length length or focal depth (operated with the assistance of image processing software).

[0067] Similar to the printhead assembly, the fixture 211 also mounts a camera 263 (however, facing upwards) to locate and image the mark from below; similarly, the image produced by the camera is focused (according to the illustrated optical cone 265), and a processor calculates, based on the focal length and a height “h5” from the second focal length, to derive the height from this second camera to the mark. Therefore, the distance between the cameras (in the absence of a substrate, i.e., during calibration) is obtained by summing these two heights, which are also calculated by a software-controlled processor.

[0068] Similarly, before the substrate is introduced, the printhead carrier is transported in such a manner that the printhead 223 (i.e., the alignment mark or feature at the bottom of the printhead) can be imaged by the lower camera 263; similarly, focusing is performed and used to obtain a new focal length and associated height “h6”, which represents the height of the printhead above the upper (second) camera. Therefore, the height “h1” of the printhead (or a specific feature on it) relative to the upper camera 253 can be determined by calculating the value “h1” = (“h4” + “h5”) - “h6”, and stored in processor-accessible memory for future use.

[0069] When printing is required, remove (manual, mechanical, or machine-operated) the marking 255 and the associated base, and introduce the substrate 239 into the system. Similar to the height determination process described above, a downward-facing printhead assembly camera is used to locate the position, this time by imaging features on the substrate (e.g., Figure 2A The system aligns the substrate with the marker 243 and then identifies the appropriate focus of the camera to perform a processor calculation of the distance "h7" between the camera and the substrate based on the new focal length. However, the deposition source (i.e., the printhead or any specific nozzle thereof) may not be at the same height as h7 and may differ from that value by tens of micrometers. To address this, the stored value "h1" is retrieved from processor-accessible memory and subtracted from the newly calculated height "h7" to obtain the actual measured height "h2" at which the droplet is expected to fall before impacting the substrate.

[0070] Note that this system and associated calculations can be performed with or without operator involvement. That is, in one embodiment, the focus points of various cameras are displayed on a monitor, and the electronic focusing system is controlled by the operator until a clear image is displayed. Alternatively, the focusing system can be automatically controlled by software using known image processing techniques to achieve correct focus and obtain the focal length and associated height; in some embodiments, this method is preferred to speed up the process and eliminate potential human error.

[0071] Note that the system just described can be used to perform many measurements. For example, an upward-facing camera mounted by a fixture can be used to measure the height of each printhead nozzle orifice plate above the upward-facing camera to detect height deviations between printheads and / or the tilt / level of each individual printhead. The upward-facing camera can also be used (through image processing) to identify the xy position of each nozzle and correct for errors in that position (see, for example, the teachings of the patents and publications incorporated herein by reference).

[0072] The illustrated implementation is applicable to many calibration procedures, but it can still be subject to uncertainty that limits the achievable accuracy and resolution of height measurements—for example, temperature variations, the refractive index of caliber 255, and the difficulty of objectively setting precise camera focus, even when performed with the aid of machine control, are all potential sources of error. Furthermore, the required precise focusing can be time-consuming, especially when performed by an operator. Finally, while the described system can easily measure the height of a deliberately provided substrate reference, dynamically measuring the height at arbitrary locations on the substrate can be difficult (i.e., due to the difficulty or dependence on image processing and variable focus relative to potentially unknown features). For all these reasons, several conceivable implementations advantageously utilize the following combined... Figure 4A The implementation described in -C offers even faster and more powerful calibration, alignment, and measurement, particularly when applied to altitude measurement. This system decouples altitude measurement from the image focusing methods cited above, but still uses a reciprocal altitude measurement system to obtain results with even higher accuracy and speed. The following will combine... Figures 4A-4C This will be discussed further.

[0073] Figure 3A and 3B Flowcharts 301 and 341 are provided, which correspond to the methods and steps mentioned above. Figure 2A and Figure 2B The exemplary operational associations described.

[0074] like Figure 3AAs shown, the first method is presented in the form of a flowchart, denoted by reference numeral 301. Step 302 may begin by performing a set of alignment steps to connect one or more axes of the manufacturing apparatus 302 for depositing material from a deposition source. For example, relative to the aforementioned split-axis system, calibration may be performed on one or more motion systems to connect these systems in one or more of the x-axis, y-axis, and z-axis dimensions. In one embodiment, it is assumed that the x and y-axis transport structures require calibration, but other dimensions may also be calibrated using the described techniques. Step 303 involves first moving each component in one of the two different transport paths to a predetermined position, for example, to a predetermined starting point where the two transport paths are expected to intersect. Each transport component on each path has an integrated sensor, which is then used to identify a common reference frame (reference numeral 304); if necessary, a search algorithm may be optionally used (step 305) according to reference numeral 305 to precisely locate the reference point after coarse alignment. Alternatively, according to reference numeral 309, position feedback can be obtained for each transport path or multiple axes to measure the track or guide position at a common point; as indicated by reference numeral 310, this feedback can optionally be provided by alignment marks associated with each transport path. Alternatively, as indicated by reference numerals 311, 312, and 313, the alignment process may include independent alignment of each sensor to a midpoint (e.g., a fixed reference point associated with the manufacturing stage or a datum as described above), alignment of one sensor to another (e.g., by mounting a datum by one of the sensors, or conversely, using imaging techniques to locate the other sensors), or coaxial optical alignment (e.g., images generated by each of the two sensors are overlaid until they are aligned to define a common optical axis. Other techniques are also possible. At the point where alignment is achieved, the position of the components on each respective transport path is used to establish a coordinate system for deposition / manufacturing, that is, aligning the transport paths with the common axis (reference numeral 315). Next, reference numeral 316 is performed to connect additional axes together or align them with each other, or to align the additional axes with the desired existing coordinate system (e.g., z-axis height or another dimension or set of dimensions). Once the desired or required number of alignment steps have been performed, the system is in a calibrated state (reference numeral 317).

[0075] Reference numeral 318 indicates an offline / online process separator, meaning that steps above this line are typically performed offline during the fabrication process, while steps below it are typically performed online. For example, as shown in reference numeral 321, steps below the separator can be performed online for each new substrate, which is introduced into the manufacturing equipment as part of an assembly line-type procedure (reference numeral 322). With the introduction of each substrate 322, a transfer mechanism is used to detect one or more substrate reference points (reference numeral 323), allowing a single substrate (or the product on it) to align with the printer's coordinate system and the intended formulation information. This enables the extraction of calibration or offset information (reference numeral 325). For example, once the substrate's position, orientation, size, and / or offset errors are identified, this calibration and offset information can be stored and / or used to calibrate the substrate's position / orientation or otherwise adjust printing parameters (reference numeral 326). Finally, with the calibration strategy employed, a subsequent manufacturing process, such as printing (reference numeral 327), is performed to precisely deposit material in the desired location, which is relevant to precision manufacturing processes. As indicated by reference numeral 328, the method can then be continued (e.g., applying post-printing processing steps to complete the layer of deposited material).

[0076] Figure 3BA flowchart of the alignment procedure 341 is shown in more detail. As shown in step 343, in one embodiment, the printhead (PH) camera is first placed in a maintenance compartment or service position (e.g., a "second volume" or enclosed chamber adjacent to the first volume or enclosed chamber where printing is performed), and the marker is manually or mechanically mounted onto the PH camera. It should be noted that this is not necessary for all embodiments; that is, in different embodiments, the marker may be mounted in place or may be mechanically pivoted or engaged to move to a suitable position at any point in time. Regardless of the specific engagement mechanism, once the marker is in place, the PH camera is then moved to a position ready for coaxial optical alignment with the second (clamp) camera assembly. A PH camera is engaged to image / sensor a tread (345), wherein the camera and / or tread position is adjusted (reference numeral 347) so that the tread is approximately centered, thus clearly positioned within the PH camera's field of view, and then the focus is adjusted (reference numeral 351); as previously described, focus determination allows for the measurement of the tread's height relative to the PH camera (reference numeral 356). A second (clamp) camera assembly is then moved to a designated position (reference numeral 357) and used for imaging the tread below (reference numeral 359); as previously described, the tread may be a set of crosshairs on a transparent plate, preferably having approximately the same refractive index as the atmosphere to be printed / manufactured. The clamp camera assembly (i.e., clamp position and / or PH camera position) is then adjusted (reference numeral 361) so that the images generated by each camera assembly precisely overlap (e.g., as determined by the operator or image processing software). At this location, adjust the focus of the clamp camera assembly according to label 361 to allow the height of the datum line relative to the clamp camera assembly to be derived from the focal length. As previously mentioned, this allows the vertical (z-axis distance) between the PH camera and the clamp camera assembly to be identified. It should be noted that... Figure 3B Several options related to these procedures are highlighted; for example, in one embodiment, the height determination process is coaxial for the PH camera and the clamp camera assembly (reference numeral 346); and, in one embodiment, each of the PH camera and the clamp camera assembly includes two cameras, for example, a low-resolution camera for approximate location of the tracing lines and a high-precision camera for improving alignment accuracy and focus determination (348 / 362). As noted, the operator can provide system control for alignment and / or focusing purposes, for example, by viewing images on one or more monitors (reference numerals 352 / 364) and responsively controlling the system and / or focus; in another embodiment, such adjustments can be performed and controlled automatically by software (reference numerals 353 / 365).

[0077] According to step 369, if the distance between the cameras is identified (i.e., as...), Figure 2BThe image is then taken as “h4” + “h5” (marked in Figure 2b), and then the print head itself is imaged using the jig camera assembly, or for example, an image is taken at a reference point on the print head; again, according to step 372, focus adjustment 371 is performed or other techniques are used to measure the height from the jig camera assembly to the print head (i.e., measuring “h6” in Figure 2b). The processor / software then calculates the height difference “h1” between the print head and the PH camera (i.e., by measuring the distance between the cameras “h4” + “h5”, subtracting the value of “h6” from it, and storing the result). Such measurements can be performed if necessary, for example, by adjusting multiple print heads to the same height, or by having a horizontal lower plate (i.e., a nozzle orifice plate); the jig camera assembly can also be used to perform other measurements, such as calibrating the position of each nozzle as needed.

[0078] During the printing process, when a new substrate is introduced, the system performs step 373 to use the PH camera to find a visual reference (substrate reference point) for this new substrate, and performs focus adjustment 374 again to identify the resulting focal length, and uses this focal length to determine the vertical distance "h7" (reference 376) between the PH camera and the substrate at this location. Upon identifying this distance, the processor executes step 378 to calculate the vertical distance between the print head and the substrate by subtracting the previously stored value "h1" from the value of "h7" (i.e., the previously stored value "h1" equals "h4" + "h5" - "h6"). As described differently by way of a set of calibration results (381), possible responses to the identified height include automatic or manual (a) adjusting the printhead height or level (383), (b) adjusting the drive voltage to increase or decrease the droplet velocity (384), (c) adjusting the timing of the nozzle emission trigger (385), i.e., ensuring that the droplets are ejected earlier or later with their own effective trajectory to reach the desired attachment location, and / or (d) adjusting which nozzles will be used for printing (386), i.e., using droplets from other nozzles to simulate the desired location. Other techniques, as previously mentioned, may also be used.

[0079] Reflecting on the described operation, a set of alignment techniques can be used to co-locate two or more transport systems relative to a common reference point. Optionally, a position feedback system is used to enable the manufacturing apparatus to position the deposition material source and / or substrate to deposit material at any given location on the deposition substrate as needed. A height calibration system (optionally relying on the same elements used in the system for aligning the two transport systems) can then be used to calibrate the height of the deposition source relative to the deposition substrate; finally, the substrate position, source height, and / or deposition details can be adjusted to provide more precise control over the precise deposition point of the deposited material. In various embodiments, the system performing alignment between transport paths and the system performing source height calibration can be independent of each other and used independently, and this system can be used independently with other types of calibration systems.

[0080] D. Second implementation – accuracy in source height determination and dynamic measurement.

[0081] As mentioned above, refer to Figures 2A-3B The described implementation method can be applied to various implementations, but may still be an unexpected source of error. Figures 4A-4C This is intended to introduce an alternative implementation that provides more accurate and faster height measurement as well as dynamic height measurement.

[0082] According to reference numeral 403, the manufacturing equipment is first initialized before the substrate is introduced; as part of this initialization process, an automated calibration routine 405 is run, entirely under the control of software and at least one processor, which performs the calibration and alignment steps as described above and below. These steps allow the system to associate its transport axis with a reference frame, thereby enabling the deposition source and substrate to be transported relative to each other, allowing material to be deposited at any desired location on the substrate. In embodiments where elements such as markers are attached and removed as described above, or in embodiments with camera assemblies attached to and removed from the printhead carriage, the system is optionally controlled to transfer the printhead carriage to a maintenance compartment, where appropriate tools are automatically replaced with variable tool mounts under automated machine control. Similarly, not all embodiments require the use of a maintenance compartment or the transfer of the printhead carriage to a maintenance compartment; in other embodiments, the associated tools may be engaged in situ or permanently mounted in a manner that does not interfere with in-line printing. Each tool (and printhead carriage) is equipped with an electronic, magnetic, and / or mechanical interface, allowing selection of an appropriate interface as an implementation option. For this purpose, in one embodiment, a motion support is employed that provides magnetic engagement of the marking or other suitable tool in a highly reliable and repeatable manner, for example, within the micrometer range. To engage the tool, the printhead holder may optionally mechanically or otherwise engage the tool (marking) precisely in the correct position with tool-magnetically-settling to a predetermined position with a maximum micrometer deviation. Optical alignment between the transport axes is then performed using the tool as described in the preceding embodiments, for example, by moving one or two transport paths to positions in the respective camera images with aligned coaxial markings, and defining a common coordinate point using position information / position feedback information for each transport axis, thereby establishing the xy coordinate system for printing / preparation / processing. As described below, this calibration step then uses a separate set of laser sensors to very quickly measure the z-axis height of the printhead and / or one or more features associated with the printhead. Several steps are performed using these lasers / sensors, including (a) identifying the approximate xy laser measurement position coordinates of each laser / sensor using a camera, (b) establishing the precise xy coordinate position of each laser / sensor using a target (e.g., a hole or protrusion), (c) measuring the printhead height or levelness of each printhead (and optionally each nozzle), (d) measuring the standard height of the printhead (discussed below), and (e) periodically recalibrating the lasers / sensors relative to each other, or relative to their xy positions, to account for drift factors for accuracy. These different operations will be discussed below.Optionally, as described above, one or more of these procedures may also utilize one or more tools that engage and disengage mechanically or otherwise as appropriate. Again, note that as part of the automatic calibration routine, several other system measurements may optionally be performed, such as measuring the position of each nozzle, measuring and / or comparing the height of the printhead relative to other printheads, etc. Also note that in one embodiment, the automatic calibration routine (405) runs once during initial system installation; in another embodiment, it runs on an intermittent basis (e.g., on a periodic basis, such as daily or hourly). In yet another embodiment, the calibration routine runs in response to system events, such as each time a printhead or “ink bar” is replaced, or on a specific (e.g., operator-triggered) basis, the calibration routine is in response to a power-up, or in response to a periodic quality test run by software that returns a fixed target of deviation greater than a threshold amount. It also note that the exemplary system may have multiple different calibration routines employing various combinations or subsets of the above-described measurement procedures related to the design or calibration events. Regardless of the calibration option used, an initial (offline) automatic calibration sequence is typically planned to prepare the system to receive a range of substrates.

[0083] In assembly line-type processes, each substrate in a series typically receives the exact same manufacturing design pattern or "recipe," and the system attempts to correctly align / position it using reference points present on each substrate. A single layer is formed using a given manufacturing process, typically micrometer thick (e.g., between 1 and 20 micrometers). For example, in the case of OLED display manufacturing processes, materials can be used to construct layers that facilitate the operation of individual light-emitting elements, including but not limited to an anode layer, hole injection layer ("HIL"), hole transport layer ("HTL"), emission or light-emitting layer ("EML"), electron transport layer ("ETL"), electron injection layer ("EIL"), and cathode layer. Additional layers, such as hole blocking layers, electron blocking layers, polarizers, blocking layers, undercoating layers, and other materials, can also be fabricated or alternatively manufactured. The design of the light-emitting elements can limit the area of ​​one or more of these layers to create a single light-emitting element for a single pixel (e.g., a single red, green, or blue light-emitting element), while one or more of these layers can be deposited to create a "blanket" coverage over multiple such elements (e.g., providing a common barrier, encapsulation layer, or electrode, or other types of layers). In operation, applying a forward bias voltage (anode-positive relative to cathode-positive) results in hole injection from the anode layer and electron injection from the cathode layer. The recombination of these electrons and holes leads to the formation of excited states in the emitter layer material, which subsequently emits photons to return to the ground state. In the case of a "bottom-emitting" structure, light passes through a transparent anode layer formed beneath the hole injection layer. For example, a common anode material can be indium tin oxide (ITO). In bottom-emitting structures, the cathode layer is typically reflective and opaque. Common bottom-emitting cathode materials include aluminum (Al) and silver (Ag), which are typically thicker than 100 nm. In top-emitting structures, emitted light exits the device through the cathode layer, and for optimal performance, the anode layer is highly reflective, and the cathode layer is highly transparent. Commonly used reflective anode structures have a single-layer structure comprising a transparent conductive layer (e.g., ITO) formed on a highly reflective metal (e.g., Ag or Al) and provide efficient hole injection. Commonly used transparent top-emitting cathode (PEC) materials that provide good electron injection include Mg:Ag (approximately 10⁻¹⁵ nm, atomic ratio approximately 10:1), ITO, and Ag (10⁻¹⁵ nm). The high-work-function (HIL) layer is typically a transparent material that readily accepts holes from the anode layer and injects them into the high-transfer (HTL) layer. The HTL is another transparent layer that transfers holes received from the HIL layer to the electron transfer layer (EML). Electrons are supplied from the cathode layer to the electron injection layer (EIL). After electron injection into the electron transfer layer, electrons are then injected from the electron transfer layer into the EML, where electrons and holes recombine with light emission. The emission color depends on the EML layer material and, for full-color displays, is typically red, green, or blue.The emission intensity is controlled by the electron-hole recombination rate, which depends on the driving voltage applied to the device.

[0084] To establish the desired layer during system operation, the substrate is sequentially introduced into the manufacturing equipment. For organic material deposition, the manufacturing equipment may include a printer that deposits a liquid film in a controlled environment. Figure 4A In this context, reference numeral 407 refers to layer printing and / or fabrication in a first controlled environment, while reference numeral 409 refers to subsequent processing in a first or second controlled environment, i.e., environments maintained to protect the deposited sensitive materials from decomposition due to exposure to oxygen, moisture, and other contaminants until the materials are cured or otherwise processed to be permanent or semi-permanent. Upon introduction, the substrate is first aligned with the printing press reference system, as described elsewhere herein, and optionally, height measurements are performed to calibrate variations in each substrate, according to reference numeral 411. For example, misaligned substrates can be repositioned using mechanical carriers or fine position sensors that can be used to adjust substrate position and / or orientation; additionally, printing formulations or printing parameters can be adjusted using software to calibrate the printing and match XYZ positional misalignments. Optionally, factors of height variation can be incorporated into the deposition parameters (including substrate position and / or printhead height and / or software parameters and nozzle control), followed by responsive adjustments for specific substrates (according to reference numerals 413 / 414) to provide more precise printing control. As with the online processing shown in reference numerals 415 and 416, in one embodiment, this adjustment is performed automatically before printing begins, while in another embodiment, the height is dynamically measured and used dynamically for calibration. Printing is then performed according to the desired parameters, as shown in reference numeral 417. After printing, as shown in reference numeral 424, the deposited film (e.g., a continuous liquid coating) is treated, for example, by drying or curing. In one embodiment, this step can be performed directly by a tool carried by the printhead conveyor mechanism, such as a conveyed ultraviolet light source; in other embodiments, such processing is performed in different chambers (e.g., containing the same or different atmospheric contents, as described above).

[0085] As indicated by reference numerals 420 and 421, deposition can be performed in a controlled environment for any of these layers, meaning the atmosphere is controlled in some way to exclude unwanted substances or particles. In this case, the printing press is completely enclosed in a gas chamber and controlled to perform printing under such controlled conditions. In one embodiment, the atmospheric content differs from normal air, for example, containing an increased amount of nitrogen or inert gas relative to the ambient atmosphere. Alternatively, the automated calibration, alignment, and measurement techniques described herein are performed within the controlled atmosphere (i.e., based on automation without operator intervention). Reference numerals 425, 426, 427, 428, and 429 represent a number of other processing options, such as using two different controlled atmospheres (425) (e.g., one for printing and one for processing), using liquid ink in the deposition (printing) process (426), being able to deposit on substrates with a basic geometry (e.g., a deposition structure) or curves or other contours (427), encapsulation and / or printing that can expose selected layers in portions of the substrate, such as electrodes (428), and optional program controls to adjust printing parameters in layer boundary areas, such as printing specific edge contours (e.g., this is particularly useful for modifying the edges of encapsulation or other “blanket” layers), 429; these techniques can also be combined with other optional techniques.

[0086] Once the desired layer has been processed into a permanent or semi-permanent form, the particular substrate can be sent back to the printing press or connected manufacturing equipment to receive additional layers (or processing), or it can be removed from the controlled environment for further processing or finishing, as shown in reference numeral 431.

[0087] As previously mentioned, in precision environments, particularly for pixel fabrication (e.g., precisely positioning picoliter-sized droplets within fluid "wells" that are micrometer-scale (e.g., tens of micrometers wide and long) containing planned quantities of deposited liquid such as 50 picoliters), the droplets must be transported within the well without significant variation. Therefore, accurate height calibration and (static or dynamic) measurement and calibration of height variations can be critical. For example, in systems where the height variation of a nozzle or printhead relative to other nozzles or printheads is tens to hundreds of micrometers, the resulting positional error can be approximately 20% or more of the height error or variation; unacceptable for many applications. To address this issue, Figure 4B An alternative height calibration and measurement system 441 based on the use of high-precision sensors is shown. Such systems generally offer higher accuracy, are more suitable for fully automated control, and are capable of performing rapid and very fast measurements to provide dynamic interpretations of highly varying conditions. Figure 4BIt contains several components, including a printhead (PH) camera assembly 443, a fixture camera assembly 445, a printhead 455, a printhead assembly fixing reference block 471, a printhead laser sensor 461, a fixture laser sensor 463, and a gauge block 467 (for calibration).

[0088] Figure 4B The operation of the various components shown is as follows: First, the PH camera 443 and the clamp camera assembly 445 are each optically aligned in the manner described above. That is, each camera is used to image trajectories (451 / 451') along its respective optical paths 449 and 450. The labels 451 and 451' may refer to the same common reference mark (e.g., a common trajectories) or to their respective reference marks (e.g., having a known positional relationship). However, unlike some of the embodiments described above, the precise focus and precise focal length of the optical paths 449 / 450 are not closely related to the calibration result. That is, as previously described, the digital image output of each camera is sent to the frame receiver for comparison, but the image processing software only identifies the overlap of the positions of the trajectories (e.g., crosshairs) from each image and adjusts the two transmission paths until their respective positions are aligned (e.g., fixing the trajectories to the PH camera 443 and moving the clamp camera assembly 445 to center the trajectories in their field of view). It should be noted that each of the depicted cameras includes a coaxial light source 447 and a beam splitter 448 for guiding light from the light source to illuminate the tracing line and providing backlighting to the image sensor within cameras 443 / 445. As previously described, each camera assembly may optionally also have dual low and high resolution imaging capabilities and an electronically controlled autofocus mechanism controlled by image processing software (or other software) to obtain a sharp image of the tracing line. As previously described, the image processing software detects the correct positional alignment of the cameras, and the measurement system, after capturing the precise position of each transport path corresponding to this alignment, is zeroed out or otherwise defines the origin of the coordinate system.

[0089] Once xy alignment is complete, the transport system of the control manufacturing equipment is moved according to the xy coordinates to move the PH camera 443 to approximately “locate” the z-axis high-precision sensor 463 of the fixture, and conversely, the transport system is also moved so that the fixture camera assembly 445 “locates” the z-axis high-precision sensor 461 of the printhead assembly according to the xy coordinates. As described above, in this embodiment, each high-precision sensor may be a laser sensor for measuring distance, for example, oriented to measure height. To perform the positioning function, imaging can be performed in this way by both the camera and the associated z-axis laser sensor, and a detectable height profile (hole or protrusion or other detectable height feature) represented by an alignment feature is positioned by the respective camera. For example, in one embodiment, a low-resolution camera or image from the fixture camera assembly 445 is used to search for and locate identifiable holes or protrusions (e.g., those mounted to the printhead assembly, although they may be mounted at any location that can be imaged by the fixture camera assembly and the z-axis laser sensor 463 of the fixture) through automatic image processing. Once the feature is located and centered, a high-resolution camera or image from the same camera assembly (e.g., a jig camera assembly) can be used to more accurately identify the location of the identifiable feature or protrusion, and the image processing software then stores its xy coordinates. Since the printer's coordinate system has been established, the z-axis laser sensor 463 of the jig is used to roughly position the jig at this location, where the identifiable hole or protrusion can be scanned, and its precise midpoint determined. A precise xy coordinate point is associated with this location, and based on the difference between the xy coordinate position determined by the identifiable hole's camera and the xy coordinates of the center point of the identifiable hole or protrusion provided by the z-axis laser sensor, the precise xy distance between the jig's z-axis laser sensor 463 and the jig camera assembly 445 is derived and stored for use in various calibrations. Conversely, the same procedure is performed using the PH camera 443 and the printhead's z-axis laser sensor 461 to locate common features or protrusions and to find and store the precise relative xy distance between the printhead's z-axis laser sensor 461 and the printhead's camera assembly 445. This distance can then be used for calibration to assist in dynamic measurements and other measurements as described above. For example, during operation, to measure the height of any part of the substrate, the conveyor system of the manufacturing equipment is simply driven to position the printhead's z-axis laser sensor 461 at any desired point on the substrate to obtain a height reading; conversely, as needed (i.e., typically in an offline procedure or between substrates), the system can position the jig's z-axis laser sensor 463 to image any desired features associated with the printhead.

[0090] It should be noted that although a laser sensor has been described, any high-precision sensor can be used, provided that appropriate adjustments are made according to the sensing technology discussed, which is within the capabilities of those skilled in the art. Referring to the examples of laser-based sensors discussed above, a suitable sensor for the aforementioned purposes is a laser sensor supplied by Micro-Epsilon Corporation, which has offices in Raleigh, North Carolina. A suitable sensor can measure height variations within a range of 3 millimeters or less and has sub-micron measurement accuracy.

[0091] It should be noted that, Figure 4B The right side shows that each laser sensor 461 / 463 uses a beam pointing at angles 464 / 465 to detect height (“h9” / “h”). 10 In this regard, the aforementioned sensor preferably operates using a reflectance measurement method, for example, since deposition is to be performed on a glass or transparent substrate in one embodiment, "head-on" measurement may introduce undesirable reflection noise caused by the refractive index of the imaging material. To address this issue, each sensing laser is preferably a type of light guided at an angle (e.g., "a") that minimizes backscattering and undesirable reflections. Figure 4B The right side also shows a gauge block 467 for calibration; gauge block 467 typically has a body that can be mounted to the system and a tongue 469 with a precisely known thickness (“h8”). In this regard, as previously mentioned, certain tools (e.g., by manual engagement and / or hinged and / or machine engagement, or mounted in a fixed position that does not interfere with online manufacturing) can be selectively used for specific calibration purposes during offline calibration; gauge block 467 is one such tool. In one embodiment, the tool is also mounted at a known location relative to the printing press support or chuck, for example, permanently outside the substrate transport path (e.g., at an xy position still reachable by both laser sensors 461 / 463), or in a location that can be selectively machine engaged and disengaged, for example, by another moving bracket. In this regard, the precise thickness is a known value, such as “1.00 micrometers”, and is placed at a location that can be sensed by each laser sensor. As part of the calibration procedure, each laser is continuously driven to the appropriate position via software and used to measure the height between the laser sensor and the corresponding side of the tongue, for example, to measure heights "h9" and "h". 10 Since the thickness of the tongue, "h8", is precisely known, the calibration software can immediately calculate the distance between the two laser sensors, for example, "h9" + "h". 10 +1.00 micrometers (this is similar to) Figure 2BThe calculation of "h4" + "h4" differs in that it can be performed almost immediately once the laser sensor is driven to the correct position; in fact, as with the other measurements described herein, these measurements are preferably performed very closely and continuously to minimize the possibility of temperature or other factors affecting the measurement. It should also be noted that because this measurement scheme does not rely on achieving "precise focusing" (i.e., which may be subjective, time-consuming, or subject to error), it is generally more accurate than the schemes discussed above.

[0092] Many of the measurements performed thereafter are similar to those discussed earlier. For example, a laser sensor using a fixture is used to image the perforated plate 457 running on the bottom of the printhead 455, and a height measurement is formed (e.g., Figure 2B The difference between "h6" and "h9" is that the measurement is now taken from the laser sensor 463 of the fixture. However, since the distance between the laser sensors is precisely known, the calibration software can immediately calculate the height difference between the printhead orifice plate 457 and the printhead laser sensor 461, i.e., by subtracting the height of the printhead orifice plate 457 from the distance between the sensors, i.e., from "h9" + "h9". 10 The value obtained is +1.00 micrometers. This value can then be stored and used as before, for example, to enable precise measurement of the height of the printhead aperture plate 457 above the substrate 459 at any point in time (e.g., dynamically, during printing, on an automated basis): simply by using the printhead laser sensor 461 to measure the substrate at the desired xy coordinate point, and by subtracting the stored height difference between the printhead aperture plate 457 and the printhead laser sensor 461. Again, because dynamic focusing is not used for height measurement, and because the sensor employed is a precision device and provides instantaneous readings, the measurement is instantaneous.

[0093] Figure 4BThe image also shows a fixed reference block 471 for the printhead assembly and an associated reference point 472. In short, these objects can be optionally used to provide a fixed reference point relative to the printhead assembly; advantageously, during the initialization of gauge block 467 and / or other offline calibrations, the distance from the fixture's laser sensor 463 to the reference point 472 is also measured and stored by the fixture's laser sensor 463. This measured and stored value can be used to provide a shortcut for processing in subsequent measurements. For example, in inkjet-based manufacturing equipment, the printhead and / or ink bar may be frequently replaced or changed, each potentially presenting new height differences and potential error factors that should be measured and incorporated into considerations for printing, press adjustments, or printing process adjustments. Using the fixed reference block 471 and the associated reference point, a second, simplified calibration procedure can be used. For example, instead of repeating all the steps mentioned above; during replacement, the height difference can be derived by imaging both the fixture's laser sensor 463 and the reference point 472 for each new printhead orifice. This height difference can then be used to immediately derive the new printhead height by referencing the difference relative to a reference point (and the previous printhead height difference relative to the reference point). Therefore, without gauge blocks or other measurements, the system can immediately derive the new printhead height value based on a shortened calibration sequence, thereby further improving equipment uptime. It should be noted that not all implementations require this optional technique.

[0094] Figure 4C Method 471 is shown, characterized by some of the measurements and other steps described above. First, as indicated by reference numeral 473, the two transport paths are aligned with a common reference point, for example, using the aforementioned print head and jig camera, as well as a datum line. Reference numeral 475, with a coordinate system established, the system searches for the xy coordinates of a first high-precision sensor, for example, a first laser. With this information known, then relative to a standard (e.g., ... Figure 4B The high-precision sensor (labeled 477) is precisely positioned in block 467 and used to acquire height measurements relative to the standard. The system also searches for the xy coordinates of a second high-precision sensor (e.g., a second laser, mounted relative to a different transmission path) according to label 478. With this information known, then relative to the standard (e.g., ... Figure 4B The second high-precision sensor is precisely positioned in block 467 and used to acquire height measurements relative to the standard, as indicated by reference numeral 480. Based on these measurements, a processor operating with the support of calibration software then calculates the height difference between the two high-precision sensors (e.g., from the first laser to the second laser), step 481, thereby enabling the height measurements from the two high-precision sensors to be precisely correlated with each other; as previously stated, this can be done according to the formula "h total= "h8" + "h9" + "h 10 "And obtain (483). As previously noted, alternatively, a fixed reference such as reference 472 may also be provided and measured, and the obtained measured height is then stored for future use, as shown in reference numerals 485, 487 and 488. As shown in reference numeral 491, one of the high-precision sensors (e.g., associated with a transfer axis such as a clamp, or another sensor such as a camera) is then used to locate the source, and a second high-precision sensor is used to measure the distance between it and the deposition source (as shown in reference numeral 492). Thus, the height difference (493) presented by the source can be determined, for example, relative to the distance between the two sensors or relative to the fixed reference. As desired, then according to reference numeral 495, the first high-precision sensor is used (e.g., dynamically or otherwise) to measure the height relative to the deposition target (e.g., substrate); finally, as shown in 497, the system measures and stores the height difference between the source and the deposition target, and takes appropriate calibration / adjustment measures, i.e., as shown in reference numeral 498."

[0095] Reflecting again on some of the components and structures discussed earlier, in one embodiment, z-axis measurement can be performed immediately with greater precision than in the previously discussed embodiments. Optionally, the preparation system is preferably calibrated to identify an xy or similar coordinate system. High-precision sensors associated with each transport path are then engaged and used to measure the height difference between two high-precision sensors. These two sensors can be used through a series of measurements, or by selectively using certain features, as described above, to quickly and accurately measure the height difference between the deposition source and the target (e.g., or between the tool and the target) in the preparation system. This process can be fully automated to avoid potentially subjective or time-consuming steps and potential limitations on resolution in determining the correct focus. When combined with optional xy-coordinate calibration and alignment schemes, and with precise identification of sensor positions relative to xy-coordinates, the disclosed technique allows for automatic and accurate z-axis measurement on an instantaneous and dynamic basis, and can be used to measure any part of the deposition target (or other preparation or manufacturing equipment components).

[0096] Figures 5A-5E This is used to provide some additional information about more detailed implementation methods.

[0097] first, Figure 5AA portion of manufacturing apparatus 501 is shown, including a vacuum boom 503 (for engaging a substrate) and a printing press support table or chuck 505. The vacuum boom forms part of a fixture in which the fixture (e.g., fixture frame 506) and the vacuum boom 503 move back and forth in the general direction of the double arrow 507 to transfer the substrate. The vacuum boom is hinged to the fixture frame 506 by a set of linear transducers (only one 509 is shown in the figure), which linearly throw the vacuum boom and the substrate in the direction of the double arrow 510; the common-mode drive of these transducers can linearly offset the substrate in the direction of the double arrow 510, while the differential-mode drive of these transducers can rotate the substrate about a floating pivot point 511 (e.g., this can be used to perform selective substrate position calibration as described above). The manufacturing apparatus 501 shown also shows an upward-facing camera or fixture camera assembly, which includes a camera 513, a light source 515, and an associated heat sink 517. The light source and the aforementioned beam splitter (not shown, but mounted in the camera's optical path approximately at optical axis position 521) are used to direct light from the light source upward through the hole 523 in the fixture frame for the purpose of providing optical measurements as described above. The fixture frame 506 also mounts a high-precision sensor 525, such as the previously mentioned laser sensor from Micro-Epsilon, which is oriented upwards and measures the height of an object through the hole block 527. This hole block can be used to selectively attach (mechanically or otherwise) a gauge block 528, for example, a magnetic plate forming part of a motion support for the purposes mentioned above. Notably, the fixture frame 506 is also shown to be equipped with a calibration block 529, which provides identifiable holes / protrusions 530 for passing through the printhead camera ( Figure 5A (not shown in the image) and through a high-precision sensor mounted on the print head ( Figure 5A (Not shown in the image) is used for imaging. As previously described, the calibration block and associated reference features (reference points) are used to accurately identify the position of the high-precision sensor mounted on the printhead relative to the camera mounted on the printhead in xy coordinates.

[0098] Figure 5B A camera assembly 541 mounted on a printhead holder (not shown) is shown. This assembly includes a downward-facing camera 543 and a light source 545, along with an associated heat sink 547. As previously described, a beam splitter in the camera's optical path (approximately located at 549) directs light from the light source downwards through a lens 551 and receives the returning image light sensed by the camera 543. A motion support 553 is also shown, comprising a permanently mounted "L-shaped rod" 554 that provides a height-repeatable connection to a removable bracket 555, which in turn carries a reticle 556 mounted on the lens, as described above. During calibration, the camera images the reticle (while...). Figure 5A The upward-facing camera 513 in the assembly images the same datum 556 from below. As previously described, the motion support allows for highly repeatable attachment and detachment of the lens assembly of the datum for purposes such as defining the xy coordinate system and other measurement tasks. In one embodiment, the position of the datum relative to the imaging target can be calibrated occasionally using the adjusting bolt 557, either by an operator or by performing electronic actuation (in one embodiment). Figure 5B Also shown is calibration block 558, which provides another identifiable hole / protrusion 559 for use with the camera of the clamping system (i.e., via...). Figure 5A The camera 513) and the high-precision sensor mounted on the fixture (i.e. Figure 5A Imaging is performed using a high-precision sensor 525. As previously described, the calibration block and associated reference points are used to accurately identify the position of the high-precision sensor mounted on the fixture relative to the camera mounted on the fixture in xy coordinates.

[0099] Figure 5C A close-up perspective view of the lens assembly 561 providing the gradation lines, also shown in... Figure 5B The component includes the aforementioned bracket 555, which also provides a portion of a motion support for rapid and precise (e.g., manual or machine-based) attachment and removal, or other positioning / engagement, of the grading lens. The component also includes an optical lens 563 that carries the grading line 556, whose precise positioning is achieved through manual adjustment of the alignment / mounting bolt 567 without frequent fine-tuning. As described above, the grading line (component) is advantageously designed for rapid (e.g., machine-based) attachment and removal, or other automated positioning / engagement, to provide a fully automated calibration and measurement process.

[0100] Figure 5D A close-up view of gauge block 581 is provided. This block is visible as consisting of a body 583, which similarly provides a half-motion support suitable for simple and repeatable attachment and detachment and / or other selective engagement or use. More specifically, this component is selectively engaged to place tongue 585 directly into the optical path of a precision height sensor of the clamp, for example, for... Figure 5A The reciprocating memory of the motion support formed by the hole block 527 is selectively attached and detached. Of course, many design alternatives also exist. Figure 5D Two clamping screws 587 on the tongue are also shown. Although in Figure 5D Not shown, but the motion support has an adjustable slide that can be used to provide infrequent manual fine-tuning of the precise tongue position relative to the gauge block mounted via the clamp frame.

[0101] at last, Figure 5E An example of reference block 591 is shown, which is used to provide a calibration block for various cameras and high-precision sensors. In this particular example, the calibration block can be entirely made by... Figure 5A The device indicated by the Chinese reference number 529 ( Figure 4B The design of calibration block 472 is similar. The calibration block is "L-shaped" and includes mounting plate and target plate portions 592 and 593, the latter providing a calibration reference for the xy distance between the camera and the associated high-precision sensor. A polished metal plate (e.g., stainless steel or other surface) is used to provide a highly reflective surface for imaging through the precision sensor. In short, as previously described, the protrusion / hole (in this case, the hole) is first imaged by a lower-resolution camera, then by a higher-resolution camera, and finally by a high-precision sensor associated with one of the given transmission axes; the position from the position feedback system associated with the transmission axis is read at the center position of this hole 595 detected by the camera and its associated high-precision sensor. These positions are then used to calculate the xy offset between the two measuring devices. It should be noted that, advantageously, hole 595 does not represent the entire hole passing through the target plate portion, which could lead to inconsistent sensor readings (i.e., noise) – instead, all that is necessary is that the target plate portion provides a target that provides clear high-precision sensor signal identification in a manner that allows for the identification of the hole position and hole center. As shown in reference numerals 597 and 598, the target plate portion may provide additional variable-sized holes for additional calibration functions.

[0102] By providing calibration and measurement references in the manner described, Figures 5A-5E The components presented provide an efficient and highly accurate method for determining multi-axis (e.g., x, y, and z) position calibration and measurement in high-precision manufacturing systems. As previously described, this provides finer control over deposition parameters, such as the desired landing location of the deposited material. In one embodiment, these techniques can be used to facilitate precise droplet placement in industrial split-axis printing systems.

[0103] It should be noted that the described techniques offer a wide range of options. First, it should be noted that while several implementations based on printing presses (e.g., inkjet printers) have been described, the techniques described herein are not limited to this; to provide an example, the described techniques can be applied to manufacturing systems that do not include printing presses (e.g., where precise position control is additionally required). The teachings described herein can be applied to any type of manufacturing or manufacturing equipment, including, for example, positioning tools, processing devices, deposition sources, inspection equipment, and similar devices where high precision is desired or required. The techniques described herein are also not limited to split-axis systems; for example, while the aforementioned implementations are characterized by separate transport mechanisms in the x and y dimensions, the techniques described herein can be applied to other types of positional articulation systems (e.g., relying on universal joints or other nonlinear transport paths, or systems providing transport across multiple dimensions), or where different degrees of freedom exist. Third, while the described techniques have been presented in the context of assembly line processes, their application is not limited to this environment; for example, they can be implemented in any type of manufacturing system, positioning system, non-industrial printing press, or potentially other types of systems or devices.

[0104] Without limiting the foregoing, in one embodiment, the manufacturing process or manufacturing equipment or printing press is adjusted offline; in different embodiments, adjustments can be made for each substrate or each product to calibrate deviations or deformations. In yet another embodiment, measurements can be taken dynamically and used for real-time adjustments. Clearly, many variations exist without departing from the inventive principles described herein.

[0105] Specific terms and reference numerals have been set forth in the foregoing description and accompanying drawings to provide a thorough understanding of the disclosed embodiments. In some cases, these terms and reference numerals may imply specific details not required for implementing these embodiments. The terms "exemplary" and "implementation" are used to indicate an example, not a preference or requirement.

[0106] As noted, various modifications and alterations can be made to the embodiments provided herein without departing from the broader spirit and scope of this disclosure. For example, at least in practice, features or aspects of any embodiment can be combined with or substituted for corresponding features or aspects of any other embodiment. Thus, for example, not all features are shown in every drawing, and features or techniques shown according to an embodiment of one drawing should be assumed to be optional elements or combinations thereof that can be used as features of any other drawing or embodiment, even if not specifically mentioned in the specification. Accordingly, the specification and drawings should be regarded as illustrative rather than restrictive.

Claims

1. An apparatus for manufacturing a layer of an electronic product on a substrate, the apparatus comprising: A printing press, which has a print head; The conveying mechanism includes a base support and a clamp. Markers that can be used as visual alignment markers; A first sensor is coupled to the printhead and detects the markings; A second sensor, coupled to the clamp, detects the markings. The printing head and the fixture are arranged in the following positional relationship: the first sensor and the second sensor face each other in the height direction, and the mark is located between the first sensor and the second sensor; and The processor is configured as The first sensor is controlled to detect a first height from the first sensor to the substrate disposed on the substrate support; The first and second sensors are controlled under the stated positional relationship to detect a second height, which is the sum of the height of the first sensor from the mark and the height of the second sensor from the mark. Control the second sensor to detect a third height from the second sensor to the printhead; and The height from the printhead to the substrate is calculated based on the first height, the second height, and the third height.

2. The device of claim 1, wherein the first sensor is in a fixed position relative to the printhead.

3. The device of claim 1, wherein the first sensor is a camera, and the processor is configured to detect a first height and a second height by moving the first sensor until the mark or substrate target is in focus and measuring the distance between the mark or target and the focal length of the first sensor.

4. The device of claim 1, wherein the conveying mechanism further comprises a first support guide extending along a first direction, a second support guide extending along a second direction, a conveying carriage for conveying the printhead assembly along the first support guide, the printhead assembly moving the printhead along the first support guide, the clamp moving along the second support guide, the second sensor being a camera, and the processor further configured to... Use a camera to capture images of the print head and the first sensor, and Based on the position of the printhead assembly, the position of the fixture along the second support guide during image capture, and the position of the ejector orifice or the first sensor in the captured image, the relative positions of at least one ejector orifice of the printhead and the first sensor are identified; and Based on the identified relative position, adjust the jetting parameters of at least two nozzles on the printhead.

5. The device of claim 1, wherein the second sensor is a camera, and the processor is configured to detect the second height and the third height by moving the second sensor until the mark or printhead target is in focus, and measuring the distance between the mark or target and the focal length of the second sensor.

6. The device of claim 1, wherein the clamp comprises a frame and a vacuum rod, and the second sensor is coupled to the frame.

7. The device of claim 1, wherein the third height is the height from the second sensor to the nozzle plate of the printhead, and the processor is further configured to calculate a fourth height from the first sensor to the nozzle plate and store the fourth height in a computer system.

8. The device of claim 1, wherein the processor is further configured to control the first sensor to detect the position of the second sensor, and to control the second sensor to detect the position of the first sensor.

Images