WO2010035263A1

WO2010035263A1 - System and method for conveyor based printing

Info

Publication number: WO2010035263A1
Application number: PCT/IL2009/000924
Authority: WO
Inventors: Yigal Rozval; Hanan Gothait
Original assignee: Xjet Ltd.
Priority date: 2008-09-25
Filing date: 2009-09-24
Publication date: 2010-04-01
Also published as: TW201021148A

Abstract

A system and method of translating substrates is provided. A plurality of substrates may be translated according to a respective plurality of routes. In some embodiments, a plurality of routes may be associated with a common segment in a processing zone. A plurality of routes may enable translating a plurality of items through a common processing zone. A route may be associated with a plurality of spatial precisions. A route may comprise a first segment from a starting point to an ending point of an operational track and a second segment from an ending point to a starting point of the operational track.

Description

SYSTEM AND METHOD FOR CONVEYOR BASED PRINTING

BACKGROUND OF THE INVENTION

[0001] Conventional conveyor systems are typically designed for transporting goods between various stations, locations or positions. Conventional conveyor systems are also used in processing and/or manufacturing where elements or items used in a manufacturing process are translated or positioned in proximity to a component of a manufacturing system. For example, media such as silicon wafers may be conveyed to a specific location in relation to a printing component so that ink or other substance may be deposited on such wafers. [0002] Among other aspects and for obvious reasons, precision of a printed pattern, loading capacity and speed are of considerable importance in such systems. However, in current systems, precision may be achieved by an alignment system which is not part of the transporting systems. Such alignment system typically relies on patterns located on the printed media, or other attributes of the media in order to control the position of the element being printed, e.g., a silicon wafer.

[0003] Moreover, in many cases, processed elements or items may be required to be translated along more than one direction or axis. However, current systems implement multi- axes movement of elements by integrating several single axis system or components into a single system or device. For example, a system required to translate elements in three orthogonal directions X, Y and Z is assembled from three linear, single axis systems or devices positioned perpendicularly to each other using suitable mechanical fixtures and fittings.

BRIEF DESCRIPTION OF THE DRAWINGS [0004] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanied drawings in which: [0005] Fig. 1 shows an exemplary translation unit according to embodiments of the invention;

[0006] Fig. 2 shows an exemplary translation assembly according to embodiments of the invention; [0007] Fig. 3 depicts an exemplary route of a processed item according to embodiments of the present invention;

[0008] Fig. 4 depicts exemplary routes according to embodiments of the present invention; [0009] Fig. 5 depicts exemplary routes according to embodiments of the present invention;

[0010] Figs. 6 A, 6B and 6C depict exemplary routes according to embodiments of the present invention;

[0011] Fig. 7 shows exemplary printing components according to embodiments of the present invention;

[0012] Fig. 8 shows an exemplary printing system according to embodiments of the present invention; [0013] Figs. 9 A, 9B and 9C show exemplary print head arrangements and print patterns according to embodiments of the present invention; and

[0014] Fig. 10 shows an exemplary printing system and exemplary tray positions according to embodiments of the present invention.

[0015] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0016] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, modules, units and/or circuits have not been described in detail so as not to obscure the invention.

[0017] Embodiments of the invention may be applicable to a variety of printing systems and methods. For example, printing systems and methods such as non-contact inkjet printing or aerosol deposition systems. For the sake of clarity and simplicity, exemplary embodiments and/or references to non-contact material deposition systems will mostly be for the application of fabrication of conducting metal lines for solar cells using an inkjet system.

However, the scope of the invention is not limited by such exemplary embodiments and may be applied to other material deposition or printing systems, such an aerosol jet deposition system or a dispenser and to other applications, such as graphics, press, mass media, packaging, electronics and others.

[0018] Embodiments of the invention may be applicable to the general field of conveyors of the type that transports goods, items or elements in a linear path or route, and in particular to linear conveyors used in a process that requires high degree of precision in positioning of the elements with respect to a processing equipment. Embodiments of the invention are also applicable to and may be used in the general field of printers, particularly of inkjet and aerosol jet printers used in the electronics industry, e.g., the printing or depositing of material on solar cells.

[0019] According to embodiments of the invention, a translation unit may be used to move, relocate, position or translate goods, components, articles, elements or items. For the sake of simplicity, the term "items" or "item" will be used herein to refer to any object being translated by embodiments of the invention. Translation of items may be according to a predefined route, trajectory, coordinates, path, track, lane, course, direction, or according to any applicable parameters that may define a translation in a three dimensional space. For the sake of simplicity, the terms "route" or "path" will be mainly used herein to denote a trajectory in space.

[0020] Translated items or articles may be processed at one or more stations along a route of translation. For example, translated items may be silicon wafers, e.g., semiconductor wafers, glass or a substrate such as wafers used to manufacture photovoltaic (PV) solar cells. A processing of such items may comprise a metallization process and/or depositing or printing conductive and/or insulting material on such items. Accordingly, a processing station along a route may comprise a suitable printing component, device or system that may deposit material on translated items. For example, translation units may be configured to translate one or more substrates according to a scan direction while a material is being deposited on the substrates by a printing component. [0021] In relevant manufacturing environments, translation of processed items may be required or desired to be in more than one direction. For example, while printing or other processing may be done along a first X axis or direction, items may need to travel along a different direction or axis. For example, in order to reach a station where the items are removed from the system, e.g., in order to be packed into shipping boxes or processed by another, geographically distant system items may need to travel in directions other than the X axis direction. According to embodiments of the invention, a linear or other conveyor based system may enable translation in a first direction, e.g., along an X axis related to a three dimensional cartesian coordinates system, where the X, Y and Z axes are orthogonal to one another. According to embodiments of the invention, a mounting unit coupled to the conveyor may enable movement or translation of items mounted thereon in one or more directions other than the direction enabled by the conveyor. For example, conveyor 140 may translate substrates in a first and second directions (e.g., a forward and backward scanning directions) and a mounting unit coupled to conveyor 140 may translate one or more substrates in a third direction, where the third direction is different from the forward scanning direction and the backward scanning direction. Accordingly, a translation unit may be configured to translate one or more substrates in three orthogonal directions.

[0022] According to embodiments of the invention, an item may be translated from a first station or location to a second station or location along or according to a first path, route, shuttle, track, course or direction. The item may further be translated from the second station or location back to the first station along or according to a second, different, path, route course or direction.

[0023] For example, items may be silicon wafers and a processing may comprise depositing conductive material on the items. Items may be loaded, e.g., placed on a mounting unit such as a table or tray coupled to a conveyor, in a first station or location. Such station may be a loading/unloading station. Items may then be translated, along a first segment of a route, to a printing area where material may be deposited on them. After deposition of material, items may be translated, along a second, different segment of the route, back to the loading/unloading station or location where they may be removed from the system.

[0024] Embodiments of the invention may enable various levels or degrees of precision. For example, a resolution or step of translation along an axis or an ability to repeat a route, path or track. According to embodiments of the invention, a conveyor may enable high resolution and precision along a predefined axis, also known as high resolution linear translation, e.g., by employing motorized linear stages. Linear motorized stages may utilize different schemes of motors, bearings and other components as known in the art. The position resolution of a stage measures its smallest incremental movement. Most high resolution linear translation stages are operated in a closed loop mode comprising a position sensor, such as for example optical encoder, that provides feedback to a closed loop control and/or operation. State of the art linear stages with travel distance of up to 2 meters can offer a precision of few microns.

[0025] A mounting unit coupled to a conveyor may enable translation of items in directions other than the direction enabled by the conveyor to which the mounting unit is coupled. A mounting unit may provide other degrees of precision or accuracy of a position or translation in space. For example, while high precision may be required along a first axis, e.g., an axis along which printing is performed, precision requirements may be relaxed when translation in other direction is relevant. For example, moving an item from a printing area to an unloading area may not require precision or accuracy required during the actual printing process. [0026] Reference is made to Fig. 1 showing an exemplary translation unit 100 according to embodiments of the invention. Translation unit 100 may comprise a conveyor 140 that may be, may comprise or may be part of a linear conveyor or other linear motorized stage as known in the art. Conveyor 140 may enable long travel distances with high precision, for example, in a predefined scan direction. For example, a forward scanning direction and a backward scanning direction along the X axis. As shown by the arrow 150, conveyor 140 may translate items along an axis denoted as the X axis. Translation unit 100 may comprise a mounting unit 160. Mounting unit 160 may comprise a tray 110. Tray 110 may be any suitable tray, table, stand, support or platform that may support items translated by translation unit 100. For example, tray 110 may support items 120 that may be silicon wafers. Items 120 may be coupled, fastened or otherwise connected to tray 110 or they may simply be placed on tray 110. Mounting unit 160 may comprise a translation assembly 130. Translation assembly 130 may be coupled to tray 110 and conveyor 140 and may translate, position or move tray 110 in space and/or with respect to conveyor 140. Translation assembly 130 may move, relocate, translate or otherwise position tray 110 in any direction. For example, any one of three directions of a three dimensional cartesian coordinate system as known and referred to in the art. For example, translation assembly 130 may raise, lift or otherwise position tray 110 at various heights with respect to conveyor 140. Such translation may be referred to herein as a translation in or along the Z axis. Translation assembly 130 may move, translate position or reposition tray 110 in a direction orthogonal to both the X axis and Y axis described herein, e.g., along the Y axis. Translation assembly 130 may relocate, translate or move tray 110 in according to a direction that is a combination of a translation in the X, Y and Z direction. Accordingly, translation assembly 130 may move or relocate tray 110 in any direction in a three dimensional space. Translation assembly 130 may rotate tray 110. For example, with respect to a top view, tray 110 may be rotated clockwise or counter clockwise by translation assembly 130. In some embodiments, translation assembly 130 may tilt tray 110. Accordingly, any applicable position of tray 110 in space and/or with respect to conveyor 140 may be assumed.

[0027] Reference is made to Fig. 2 showing an exemplary mounting unit 200 according to embodiments of the invention. As shown, mounting unit 200 may comprise tray 110 described herein. Mounting unit 200 may comprise assemblies 250 and 230, translation components 216 and 217 and a coupling 240. Assembly 250 may couple tray 110 to translation component 216. Assembly 230 may couple translation component 216 to translation component 217. Coupling 240 may couple translation component 217, thus coupling mounting unit 200 to any applicable system or component. For example, coupling 240 may couple translation component 217 to conveyor 140 described herein and mounting unit 200 described herein may be similar to mounting unit 160. For example, when mounting unit 200 is coupled to conveyor 140, items placed on tray 110 may be translated in the Y or Z directions by translation component 217 and 216 respectively as shown and in the X direction by conveyor 140.

[0028] Although an exemplary mounting unit 200 is described herein, embodiments of the invention are not limited by such unit. Any applicable mounting unit may be used. For example, a mounting capable of rotating tray 110 with respect to a given plane or surface may be used. Accordingly, a mounting unit may rotate tray 110 by ninety degrees (90°) in one or more directions, e.g., clockwise or counter clockwise. Other mounting units according to embodiments of the invention may tilt tray 110 or otherwise position tray 110 in any desired position or orientation in space.

[0029] Reference is made to Fig. 3 that depicts an exemplary route of a processed item according to embodiments of the present invention. Of relevance are points 310, 350, 360 and 320 shown. The description herein is with respect to a coordinate system as shown by 305. As shown, tray 110 carrying item 111 may be translated between points 310, 350, 360 and 320. For example, items may be loaded or mounted on tray 110 in point 310 that may be a loading and/or unloading point or station. By a translation in the Y direction, tray 110 may be moved to an positioned in point 350. For example, translation component 217 described herein may shift or translate tray 110 and item 111 placed thereon to point 350. Point or location 350 may be a starting point of a processing track of which point 350 is the ending point. For example, in a printing process, tray 110 may be translated from point 350 to point 360 by a conveyor such as conveyor 140. Such translation may be performed with high precision and accuracy along the X axis. For example, conveyor 140 may be fitted with precision elements as known in the art and may translate tray 110 with high precision. Such precision may be expressed by high resolution with respect to tome, space and the ability to repeat a past track.

[0030] Tray 110 may be translated from point 360 to point 320. For example, upon completing a print process along the track connecting points 350 and 360, tray 110 may be relocated, shifted or translated to point 320. For example, processed item 111 may be unloaded from tray 110 at point 320. Translation in the reverse Y direction from point 360 to point 320 may be performed by translation component 217 as described herein. As shown, the route may include a section from point 320 to point 310. For example, after unloading in point 320, tray 110 may be translated to point 310 that may be a loading station or point. Items may be loaded in point 310 and a route of tray 110 may be repeated as described herein.

[0031] Loading of goods or items at point 310 may be accomplished by an alignment device or system that may comprise a mechanical arm and visualization means such as, for example, a digital camera equipped with an appropriate optical imaging system that may provide feedback information to a control of the mechanical arm. Accordingly, items, elements or substrates may be loaded or unloaded with any suitable precision. Likewise, an arm and/or visualization means described herein may enable an alignment of substrates. For example, after a first scan in a printing zone (e.g., in a forward scanning direction) and before a second scan (e.g., in a backward scanning direction), a tray supporting a number of substrates may be aligned, rotated or otherwise positioned.

[0032] In some embodiments, processing of items may involve a number of passes, also known in the art as a "multi-pass" process. For example, inkjet printing systems may require several or multi-passes over the same printed block in order to achieve a desirable formation of the printed pattern. In such or other embodiments, the unloading of items as described herein may be omitted. Multi-pass processing may require realignment of the items or the mounting tray. For example, a rotation of tray 110 may be performed at point 320 or 360. Accordingly, tray 110 may be rotated at point 320 and a track through points 320, 360 and

350 may be tracked by the rotated tray 110. Alternatively, after being rotated, tray 110 may be carried from point 320 to point 310 and may further repeat the track described herein.

[0033] Reference is made to Fig. 4 that depicts exemplary routes according to embodiments of the present invention. The description herein is with respect to a coordinate system as shown by 405. Embodiments of the invention may comprise a plurality of linear systems. According to embodiments of the invention, a system 400 as shown may comprise two routes that may be tracked by two trays. System 400 may comprise a conveyor (not shown) such as conveyor 140. Such conveyor may translate trays along or in a direction in the X axis shown by coordinate system 405. System 400 may comprise tray 110 carrying item 111 and tray HOA on which item 11 IA may be placed or mounted. Points 410, 450, 460 and 420 may be similar to respective points 310, 350, 360 and 320 described herein with reference to Fig. 3. Accordingly, tray 110 may follow a route described herein with reference to Fig. 3.

[0034] Point or station 410A may be similar to point or station 410, for example, loading and/or unloading of item 11 IA on tray HOA may be done at station 410A. Tray 11OA may then be translated in the reverse Y direction (with respect to coordinate system 405) to point 450. Tray 11 OA may further be translated from point 450 to point 460. Any applicable processing may be performed along the route segment connecting points 450 and 460. For example, while being translated along such segment, item 11 IA may be printed on. As shown, tray 11 OA may be translated from point 460 to point 420A that may be similar to point 420. For example, as described with reference to point 420, point 420A may be an unloading station or it may be a location where a rotation or other positioning of tray 11OA is performed. [0035] According to embodiments of the invention, translation of trays 110 and HOA may be synchronized. For example, a common control may control translation of trays 110 and 11OA such that a single tray is present at point 450, point 460 or the track connecting these points. According to embodiments of the invention, a track followed by a tray such as tray 110 or 11 OA may be cyclic. As shown, possibly after being unloaded or when a rescan is required, tray HlA may be translated from point 420A back to point 410A where new items to be treated may be loaded.

[0036] Reference is made to Fig. 5 that depicts exemplary routes according to embodiments of the present invention. The description herein is with respect to a coordinate system as shown by 505. Embodiments of the invention may involve translating items vertically. Fig. 5 shows system 500 that may implement vertical translation. System 500 may comprise a conveyor and trays 110 and 11OA that may be coupled to the conveyor. At station 510, items may be loaded on and/or unloaded from tray 110 similarly to the way loading or unloading is performed as described herein. Tray 110 may then be translated vertically down to point 550. Form point 550 tray 110 may be translated to point 560 along a linear segment of a route where processing of item 111 may be performed as described. At point 560, tray 110 may be lifted vertically to point 520 where unloading may be performed or an alignment or repositioning, e.g., rotating of tray 110 may be done.

[0037] Similarly, possibly after being loaded with items to be treated or processed, tray 11OA may be lifted vertically from loading station 510A to stating point 550 from where it may begin an operational track to point 560. An operational track may bring items carried on a tray coupled to a conveyor to an appropriate proximity to a processing unit. For example, printheads may be located along the track connecting points 550 and 560. Such printheads may print a pattern on items placed on trays 110 and 11OA. At point 560, tray 11OA may be lowered to point 520A that may be an unloading station as described herein. Alternatively, tray 11OA may be rotated at point 520A or a repositioning or alignment of tray 11OA may be performed. As shown, the upper track through points 510, 550, 560 and 520 may be above the lower track comprising of points 510A, 550, 560 and 520A. Such arrangement may enable utilizing a single printing system to print on items carried by trays traveling separate tracks. Accordingly, production, efficiency or other aspects of the printing system may be improved. At least a pass of trays 110 and 11OA through the segment connecting points 550 and 560 may be synchronized. Such synchronization may ensure that a single tray is placed under a printing system along the route segment connecting points 550 and 560.

[0038] Reference is made to Fig. 6 A that depicts exemplary routes according to embodiments of the present invention. The description herein is with respect to a coordinate system as shown by 605. Embodiments of the invention may involve translating items in any one or in any combination of three orthogonal directions, for example, X, y and Z directions of coordinate system 605. As shown, tray 110 may start a route at point 610 that may be a loading point where items may be loaded on tray 110. Tray 110 may be moved horizontally along the Y axis to point 615. Tray 110 may be then translated vertically downward to point 650 that may be the starting point of an operational track connecting points 650 and 660. Tray 110 may next be translated from point 650 to point 660, as described herein, any applicable processing of item 111 may be performed during a translation of tray 110 between points 650 and 660. At point 660, tray 110 may be raised to point 625 and may further be translated from point 625 to point 620 that may be an unloading or alignment station as described herein. [0039] Similarly, tray HOA in Fig. 6 may be loaded with items at point 610A, translated horizontally to point 615 A, translated vertically from point 615a down to point 650A, translated along the X axis to point 660A, possibly while item 11 IA placed on tray 110a are being treated. From point 660A tray HOA may be lifted, e.g., along the Z axis to point 625 A and from point 625 A tray 11OA may be translated to point 620A where item 11 IA may be removed. Translations described herein may be performed by a movement of a conveyor and/or operation of translation assemblies incorporated in a mounting unit coupled to the conveyor. For example, translation along the X axis may be realized by conveyor 140 and translation along the Y and Z axes may be enabled by translation components 216 and 217 described herein. Tray 11 OA may be translated back to station 610A after unloading of treated items, new items may be loaded at point 610A and the cycle may be repeated. A system may be designed such that trays 110 and 11 OA may share a common track. For example, translation of trays 110 and HOA may be synchronized such that they are brought to a common printing location at different times. Although only two exemplary are shown in Fig. 6, embodiments of the invention are not limited in this regard. Any number of trays may simultaneously track the routes described herein and may further be synchronized such that each tray is in a predefined location, e.g., a printing location, at a different time. [0040] Reference is made to Fig. 6B that depicts exemplary routes according to embodiments of the present invention. The description herein is with respect to a coordinate system as shown by 605. Tray 110 may be loaded with items for processing at point or station 710. Unloading of processed items, elements or substrates may be performed at station or point 710. Tray 110 may then be translated laterally along the Y axis to point 715. From point 715 tray 110 may be translated upward along the Z axis to point 750 that may be a beginning of an operational track. As shown, tray 110 may be translated from point 750 to point 760. A processing of items mounted on tray 110, e.g., item 111 as shown may be performed during a translation from point 750 to point 760. Such translation may also be referred to herein as a scan, e.g., a scan along or in the X axis. Tray 110 may be lowered from point 760 to point 725 and further translated from point 725 to point 720 that may be an unloading station, e.g., a station or post where processed items are removed from tray 110. It will be noted that in some embodiments, loading and unloading of items or substrates may be done in substantially the same point or station. In other embodiments, a loading of substrates may be conducted in a first station, e.g., 710A and an unloading of processed elements or substrates may be conducted in a second, different point or station, e.g., 720A.

[0041] The route or path depicted by points 710A, 715 A, 750A, 760A, 725 A and 720A may be a mirror view of the track or route described herein with respect to points 710, 715A, 750, 760, 725 and 720. Accordingly, tray HOA may be loaded (and when applicable, unloaded) with items in point 710, translated horizontally to point 715 A, translated vertically to point 750A, translated in the X direction by a conveyor to point 760A, down to point 725A and horizontally to point 720A. Tray HOA may be translated from point 720A to point 710A. For example, after unloading of treated items and/or in preparation for another cycle described herein. As discussed herein, an item may be processed a number of times. Accordingly, tray 11 OA may repeat the track through points 710A, 715 A, 750A, 760A, 725 A and 720A a number of times where item 11 IA is treated in some or all of the times the track is followed. The direction according to which tray 11OA follows the described track may be changed, e.g., reversed. Accordingly, tray 11 OA may follow a track through points 720A, 725 A, 760A, 750A, 715 A and 710A in this order. In some embodiments of the invention, a plurality of tracks may be used to translate a plurality of trays carrying items to be processed to a single processing station, track, system or device, for example, the four tracks shown in Figs. 6A and 6B may all be associated with a single printing system. For example, the segments connecting points 650 and 660, 650A and 660A, 750 and 760 and points 750A and 760A may be substantially the same such that trays 110 and HOA may travel substantially a similar or even identical route segment.

[0042] Reference is made to Fig. 6C that depicts exemplary routes according to embodiments of the present invention. The description herein is with respect to a coordinate system as shown by 6030. Rectangle 6020 may be any suitable or applicable processing zone. For example, rectangle 6020 may be a printing zone and may accordingly comprise any suitable printing components. For example, printheads (not shown) described herein may be placed above an area defined by rectangle 6020 and may print or deposit material on items being translated through rectangle 6020, for example, along a segment connecting points 6003 and 6004. For the sake of simplicity and clarity, details related to processing zone 6020 are omitted. For example, a number of parallel tracks such as that shown by the segment connecting points 6003 and 6004 may be present in processing area 6020. Such plurality of tracks may enable, for example, a plurality of conveyors to translate a respective plurality of elements or trays through area 6020 substantially simultaneously. Other elements, such as a printing device or component that are typically present in proximity to area 6020 are also omitted.

[0043] According to some embodiments of the invention, a system may include a plurality of translation units, each associated with a respective route. For example and as shown by Fig. 6C, four routes may be associated with a single printing zone 6020. For example, a first route may be associated with a loading point at point 6001. At such loading point 6001 elements may be loaded and/or unloaded. For example, silicon wafers to be printed on may be loaded or mounted on a tray at point 6001. A loaded tray may be translated from point 6001 to point 6002 along the Y axis. From point 6002, the tray may be lowered to point 6003 along the Z axis. For example, a mounting unit as described with reference to Fig. 2 may perform the Y and Z translations described herein. The tray may then be translated through processing area 6020 by being translated from point 6003 to point 6004. The track through the processing area may herein be referred to as an "operational track" and the direction of translation in an operational track may be referred to herein as a "scan direction". During such translation, printing on elements carried by the tray may be performed. Translation through the processing area may be performed by a conveyor, e.g., conveyor 140 described herein, accordingly, translation through area 6020 may be according to a predefined precision as may be enabled by a conveyor.

[0044] Upon completing an operational track segment of the route, the tray may be translated up along the Z axis from point 6004 to point 6005. The tray may then be translated sideway, in the Y direction to point 6006 and from point 6006 back to loading point 6001 where treated elements may be unloaded. For example, printed wafers may be unloaded at loading point 6001 and new wafers to be printed may be loaded. Accordingly, a route may include three segments or sections. A first segment may be from a loading point to a processing or printing zone (the segment connecting points 6001, 6002 and 6003, a second segment through a processing zone (the segment connecting points 6003 and 6004), and a segment from the processing or printing zone back to the loading point (the segment connecting points 6004, 6005, 6006 and 6001). The segment from a processing zone to a loading point may be referred to herein as a "back track".

[0045] In the same manner, a second route associated with loading point 6007 may include a first segment from the loading point 6007 to the printing zone (the segment connecting points

6007, 6002 and 6003), a segment through a processing zone (the segment connecting points

6003 and 6004), and a back track segment (the segment connecting points 6004, 6005, 6008 and 6007). Likewise, a third route associated with loading point 6009 may include a first segment from the loading point 6009 to the printing zone (the segment connecting points 6009, 6010 and 6003). According to such route, an element or tray may be shifted or translated along the Y axis from point 6009 to point 6010 and then lifted along the Z from point 6010 to point 6003. Such third route may include a segment through a processing zone

(the segment connecting points 6003 and 6004), and a back track segment (the segment connecting points 6004, 6011, 6012 and 6009). Note that such route may include lowering an element upon completion of an operational track (from point 6004 to point 6011).

[0046] Similarly, a fourth route may include a loading point 6013, may include a first segment from the loading point 6013 to the printing zone (the segment connecting points 6013, 6010 and 6003). According to such route, an element or tray may be shifted or translated along the Y axis from point 6013 to point 6010 and then raised along the Z from point 6010 to point 6003. Such fourth route may include a segment through a processing zone (the segment connecting points 6003 and 6004), and a back track segment (the segment connecting points 6004, 6011, 6014 and 6013). Similarly to the third route described herein, the fourth route may also include lowering an element upon completion of an operational track (from point 6004 to point 6011). Routes enabling translation from a loading point through a processing zone and back to the loading point may be referred to herein as "cyclic routes". [0047] According to some embodiments of the invention, a system comprising a plurality of routes, e.g., as shown by Fig. 6C may be realized or implemented by employing a plurality of multi axes motorized translation assemblies. For example, the routes shown in Fig. 6C may be realized by four translation units 100 as shown in Fig. 1. In such implementation, four conveyors 140 may translate trays along the scan axis, e.g., from points 6003 to point 6004. For example, such four conveyors may be placed in parallel along an operational track from point 6003 to point 6004. Respective mounting units capable of translating trays or elements in the Y and Z directions may enable the respective Y and Z translations shown in Fig. 6C. Accordingly, a plurality of routes may be associated with a common printing or processing zone and a common or similar operational track while having different segments for arriving to the processing zone and returning to a respective loading point.

[0048] According to embodiments of the invention, a first line or vector line that is perpendicular to a segment that is common to a number of routes and connecting a predefined point on the common segment with a first segment included in a first route may be at an angle with respect to a second line that is perpendicular to the common segment and connecting the same predefined point on the common segment with a second segment included in a second route. Accordingly, a first segment included in a first route may be located above, below or otherwise in a different spatial location compared to a second segment included in a second route.

[0049] For example and as shown by the angle α between the lines 6050 and 6052, lines connecting a predefined point on a segment common to a number of routes (for example, the operating track as shown by the segment connecting points 6003 and 6004) and respective points on a first and second segments included in a first and second routes may at an angle with respect to each other. Similarly, the angle β between lines 6051 and 6052 exemplifies the spatial divergence of the segment connecting points 6001 and 6006 (included in a first route) with respect to the segment connecting points 6009 and 6012, included in a second route. [0050] According to embodiments of the invention, a route may comprise two segments. A first segment may be common to a number of routes and may typically be an operating track. For example, the segment connecting points 6003 and 6004 may be common to the four routes shown in Fig. 6C. As shown, the segment connecting points 6003 and 6004 may be common to or shared by all four shown routes. As further shown, each route may further include its own, separate segment connecting an end or ending point in the operating track (e.g., point 6004) to a start or starting point of the operating track (e.g., point 6003). For example, the segment starting at point 6004 and connecting points 6005, 6006, 6001, 6002 and ending at point 6003 may be referred to as a segment connecting the end point of the operating track to the starting point of the operating track. In some embodiments, loading and/or unloading may be performed at a point on the segment connecting the start and end points of an operating track or a common segment as described herein.

[0051] According to embodiments of the invention, a loading and/or unloading station or point may be shared by or common to a number of routes. For example, loading and/or unloading of substrates at point 6002 may be done for the top right route shown by points

6001, 6002, 6003, 6004, 6005 and 6006 and for the top left route shown by points 6007,

6002, 6003, 6004, 6005 and 6008. A control unit (not shown) may synchronize translation of elements according to such two routes such that loading or unloading of elements at a common point is enabled. For example, arrival of trays traveling according to different routes to a loading point may be interleaved or otherwise synchronized, for example, by controlling the relevant conveyors or mounting units.

[0052] According to some embodiments, a translation units may configured to translate one or more substrates along at least two different routes. For example, the four routes shown in Fig 6C and described herein may all be realized by a single translation unit. For example, by controlling a conveyor and a mounting unit described herein any one and/or all the four routes may be implemented. For example, to implement the top right route shown by points 6001, 6002, 6003, 6004, 6005 and 6006 a mounting unit may lift a tray and shift it to the right when appropriate and to implement the top left route shown by points 6007, 6002, 6003, 6004, 6005 and 6008 a mounting unit may lift a tray and shift it to the left when appropriate. Similarly, rather then lifting, a tray may be lowered in order to implement the lower routes shown in Fig. 6C. [0053] A system operating according to routes as described herein may offer high productivity by increasing the number of elements translated through a printing zone at a given period of time combined with micron resolution and precision that may be achieved by a spatial precision of a conveyor. Translation units may be configured to synchronize a translation of one or more substrates through a printing zone, hi some embodiments, in addition to loading and/or unloading, alignment or other manipulation of items may be performed, for example, at loading points 6001, 6007, 6009 and 6013. For example, after a printing on wafers has been performed during a first passage or scan, a tray may be rotated at point 6001 and the route through points 6002, 6003, 6004, 6005, 6006 and back to point 6001 may be tracked a second time. Accordingly, multi-pass processing may be realized by embodiments implementing exemplary multiple routes as described herein. In some embodiments, multiple translation units may be synchronized, arbitrated, coordinated or otherwise managed such that at least translation of elements through an operating track, e.g., the segment connecting points 6003 and 6006 in Fig. 6C is such that translated elements do not collide in the operating track, for example, an entrance to an operating track of trays carrying wafers for printing may be interleaved. Other components may be similarly managed. For example, loading and/or unloading arms or industrial robots may be made to operate synchronously such that they do not interfere each other. For example, a loading arm associated with a first route may be controlled such that it does not interfere with a translation of trays according to a second route.

[0054] Reference is made to Fig. 7 that shows exemplary printing components according to embodiments of the present invention. According to embodiments of the invention, a printing component may include a plurality of nozzles that may be mounted on a plurality of printheads. An exemplary printing component may include printheads 770A-C each comprising a number of nozzles. The printing component may be place in proximity to a route segment tracked by a tray carrying items on which printing is to be performed. Printing as referred to herein may comprise any form of deposition of any applicable material on any applicable media. For example, conductive or insulating material may be deposited on silicon wafers such as photovoltaic (PV) cells using nozzles or jets. As shown, an item 780 that may be any media or substrate may be mounted on tray 110. Tray 110 may be translated as described herein such that item 780 is placed under printheads 770 A-C. Tray 110 may be translated while printheads 770A-C deposit material on item 780. [0055] According to embodiments of the invention, a translation unit may maintain substrates substantially stationary in a predefined stations or point for a predefined time interval. For example, tray 110 may be made stationary at predefined points in space or time in order to control a deposition of material by printheads 770A-C. Printing components shown in Fig. 7 may be placed near, above or in any suitable place or position along an operational track as described herein. For example, a component similar to that shown in Fig. 7 may be placed above the segment connecting points 550 and 560 in Fig. 5. Accordingly, material may be deposited on items carried along the route described with reference to Fig. 5 by printheads 770A-C. [0056] Reference is made to Fig. 8 that shows an exemplary printing system 800 according to embodiments of the present invention. System 800 may comprise printheads 870A-C, trays 110 and HOA. The description of Fig. 8 is made with reference to coordinate system 805 showing a scan axis X that may be related to a direction in which items are scanned by a printing component and a cross scan axis Y that is perpendicular or orthogonal to the X axis. As shown, tray 110 may carry items 111 and 112 and tray 110a may carry items 11 IA and 112 A. For example, items 111, 112, H lA and 112A may be wafer of photovoltaic solar cells.

[0057] Wafers or other items to be printed may be loaded at points 810 and 810A on trays 110 and 11OA respectively as described herein. Trays 110 and HOA may then be translated to point 850 where an operational scan may commence. Trays 110 and 11 OA may be translated from point 850 to point 860 passing under printheads 870A-C. While trays 110 and 11OA are under printheads 870A-C, printheads 870- A-C may deposit material on items 111, 112, 11 IA and 112 A. For example, metallization ink may be deposited from selected nozzles in printheads 870 A-C according to a programmed pattern. A passage of trays 110 and 11 OA through the segment connecting points 850 and 860 may be synchronized such that only one tray is present under a given printhead or nozzle at a given time. Precision of the printed pattern may be achieved by high resolution translation that may be made possible by a conveyor to which trays 110 and 11 OA are coupled. Such precision may be crucial, e.g., in order to avoid mis-registration as known in the art. Upon reaching point 860, tray 110 may be translated to station 820 where wafers or other items may be unloaded from tray 110. Similarly, tray HOA may be translated from point 860 to point 820A where unloading may be performed. As described herein, trays 110 and/or 11 OA may be aligned rotated or otherwise repositioned in points 860, 820 and/or 820A. For example, rather than unloading wafers from tray 110, tray 110 may be rotated and another printing scan may be performed for the wafers.

[0058] In some embodiments, passage in proximity to a printing component of multiple trays may be interleaved. For example, while tray 110 is translated between points 850 and 860 and items placed thereon are being scanned by printheads 870 A-C, tray HOA may be located at point 820A where items may be unloaded or it may be located in point or station 810A where items may be loaded onto tray HOA. Enabling a printing on a first set of items while unloading a second set of items may increase productivity as the times when printheads 870 A-C are not actively printing may be reduced. Although only two trays 110 and 11OA are shown, embodiments of the invention are not limited in this regard. Any suitable number of trays may be used and their passage under printheads 870A-C may be synchronized. Accordingly, while a first tray is under printhead 870C a second tray may be under printhead 870A so that two sets of wafers may be printed on at the same time. Similarly, while a first set of wafers or other items are being printed, a second set may be loaded onto a tray or unloaded from a tray.

[0059] Reference is made to Figs. 9A, 9B and 9C that show exemplary print patterns and print head arrangements according to embodiments of the present invention. Fig 9A depicts the metallization pattern of typical solar wafer. Such pattern may comprise narrow parallel finger lines 91 spaced several millimeters to collect the photocurrent generated at the semiconductor layer of the wafer, and orthogonal wider strips 92 of metal called bus bars to conduct this current towards the leads of the wafer, usually there are two to three such bars on the wafer. Preferably finger lines are deposited from arrays of nozzles oriented along the finger lines 93 while the wafer is scanned in parallel as depicted in Fig. 9B. A finger line may be applied from a single column of nozzles depositing simultaneously from several nozzles. Bus bars, on the other hand, may be deposited from arrays of nozzles placed over areas reserved for the bus bars with array of overlapping nozzles 94 as shown by Fig. 9C. In some embodiments, to accommodate for printing orthogonal lines such as the fingers and bars, a tray supporting the wafers or other media may be rotated between print scans.

[0060] Reference is made to Fig. 10 that shows an exemplary printing system 1000 and exemplary tray positions according to embodiments of the present invention, system 1000 may be similar to system 800 described herein. In addition to components and elements described with reference to system 800, system 1000 may comprise two printheads arrays 93 and 94. As shown, printheads in array 93 may be arranged such that rows on nozzles are aligned with the scan direction. As shown, nozzles or printheads in array 94 are arranged such that some overlap between nozzles with respect to the scan direction is achieved. As shown by position A, a tray 110 supporting items 111 may start a scan by being translated under nozzles in printhead array 93. As shown by position B, a printed pattern corresponding to the rows of nozzles may be deposited on the items. For example, the items may be to wafers in a production of solar cells and the pattern shown in position B may be conductive lines to collect the photocurrent generated at the semiconductor layer of the wafer, also known in the art as fingers. As shown by position C, the orientation of the items may be changed, e.g., they may be rotated by ninety degrees. For example, tray 110 carrying the wafers may be rotated. The tray may then be translated under printheads 94 where thicker lines, known as bus lines may be deposited. Such bus lines may collect current from finger lines and conduct the current to a terminal.

[0061] Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed at the same point in time or overlapping points in time. As known in the art, an execution of an executable code segment such as a function, task, sub-task or program may be referred to as execution of the function, program or other component. [0062] Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, "processing," "computing," "calculating," "determining," "establishing", "analyzing", "checking", or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulate and/or transform data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer's registers and/or memories or other information storage medium that may store instructions to perform operations and/or processes.

[0063] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents may occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

Claims

CLAIMS What is claimed is:

1. A system for printing on a plurality of substrates, the system comprising: a printing zone comprising a printing component; a plurality of translation units, each configured to translate a respective one or more substrates according to a respective plurality of different routes, wherein said routes include: a first segment in said printing zone, wherein said first segment is substantially common to said routes, and a respective second segment from an end point of said first segment to a start point of said first segment.

2. The system of claim 1, wherein a first vector line that is perpendicular to said first common segment and connecting a predefined point on said first common segment with said second segment related to a first route, is at an angle with respect to a second vector line that is perpendicular to said first common segment and connecting said predefined point on said first common segment with said second segment related to a second route.

3. The system of claim 1, wherein said plurality of translation units comprise: a linear conveyor to translate one or more substrates in a forward scanning direction and in a backward direction, and a mounting unit coupled to said conveyor to support said one or more substrates and to translate said one or more substrates in a second direction, wherein said second direction is different from said forward scanning direction and said backward direction.

4. The system of claim 1 , wherein at least one of said translation units is configured to translate said one or more substrates in three orthogonal directions.

5. The system of claim 1, wherein said plurality of translation units are configured to synchronize translations of said plurality of respective one or more substrates through said printing zone.

6. The system of claim 3, wherein said conveyor is configured to translate said one or more substrates in said scanning direction according to a predefined precision.

7. The system of claim 3, wherein said plurality of translation units are configured to translate said one or more substrates in said scanning direction while material is being deposited on said one or more substrates by said printing component.

8. The system of claim 1, wherein said translation units are configured to translate said one or more substrates to a plurality of stations, and to maintain said one or more substrates substantially stationary in said stations for a respective predefined time intervals.

9. The system of claim 1, wherein said one or more substrates are a photovoltaic (PV) wafer cell and wherein a metallization process is performed in said printing zone.

10. The system of claim 9, wherein at least one of said plurality of translation units is configured to translate a respective one or more substrates along at least two different routes.

11. A method of printing on a plurality of substrates, the method comprising: translating, by a plurality of translation units, a plurality of one or more substrates according to a respective plurality of different routes, wherein at least some of said routes include: a first segment in a printing zone, wherein said first segment is substantially common to at least some of said routes, and a second segment from an end point of said first segment to a start point of said first segment.

12. The method of claim 11, wherein a first line that is perpendicular to said first common segment and connecting a predefined point on said first common segment with a second segment related to a first route, is at an angle with respect to a second line that is perpendicular to said first common segment and connecting said predefined point on said first common segment with a third segment related to a second route.

13. The method of claim 11, wherein at least some of said one or more translation units comprise: a linear conveyor to translate a one or more substrates in a forward scanning direction and in a backward scanning direction, and a mounting unit coupled to said conveyor to support said one or more substrates and to translate said one or more substrates in a second direction, wherein said second direction is different from said forward scanning direction and said backward scanning direction.

14. The method of claim 11, wherein at least some of said one or more translation units are configured to translate said one or more substrates in three orthogonal directions.

15. The method of claim 11 , wherein said one or more translation units are configured to synchronize a translation of said one or more substrates through said printing zone.

16. The method of claim 13, wherein said conveyor is configured to translate said one or more substrates in said scanning direction according to a predefined precision.

17. The method of claim 13, wherein said one or more translation units are configured to translate said one or more substrates in one of said scanning directions while a material is being deposited on said one or more substrates by said printing component.

18. The method of claim 11, wherein at least some of said one or more translation units are configured to translate said one or more substrates to a plurality of stations, and to maintain said one or more substrates substantially stationary in said stations for a respective predefined time intervals.

19. The method of claim 11, wherein said one or more substrates are a photovoltaic (PV) wafer cell and wherein a metallization process is performed in said printing zone.

20. The method of claim 11, wherein at least some of said one or more translation units are configured to translate a respective some of said substrates along at least two different routes.