Alignment of diced substrates

Abstract

The alignment of the present invention for cut substrates relates to a tool for supporting a workpiece during a printing operation, comprising a support tower having a base and a head, wherein, in use, the head is vertically located above the base and is movable relative to the base in a horizontal plane, the head having a first support surface and a second support surface located at an upper end thereof, each of the first support surface and the second support surface being suitable for supporting a corresponding workpiece thereon, wherein, in use, the first support surface is movable relative to the second support surface in a vertical direction between a printing configuration and a pre-printing configuration, wherein in the printing configuration, the first support surface and the second support surface are substantially coplanar in the horizontal plane, and in the pre-printing configuration, the first support surface and the second support surface are spaced apart in the vertical direction.

Description

Technical Field

[0001] The present invention relates to a tool, a printing press and a method for aligning a workpiece prior to a printing operation. Background Art

[0002] Industrial screen printers typically apply a conductive print medium (e.g., solder paste or conductive ink) to a planar workpiece (e.g., a circuit board) through a pattern of holes in a printing screen (sometimes called a foil or stencil) using an angled blade or squeegee. In cases where the pattern area is relatively small relative to the screen area, more than one pattern may be included within the screen, allowing more than one board area or more than one board to be printed simultaneously using the same screen. Alternatively, more than one relatively small screen may be used within the same printer to enable more than one board area or more than one board to be printed simultaneously using the respective screens. While such simultaneous printing is clearly more efficient than sequential printing, these techniques also present some problems.

[0003] i) Printing on more than one area of ​​the board

[0004] As mentioned above, multiple patterns or arrays of patterns can be printed onto corresponding areas of a single board or panel in a single printing operation to produce multiple printed circuit boards (PCBs) that can then be physically separated. Conceptually and technically, the technology is simple, i.e., a panel with multiple boards is loaded into the printing press, properly aligned, and all boards of the panel are printed simultaneously. However, with any circuit board, there is a risk that at least some of the boards will be defective, which in turn may result in defective PCBs. This situation is as follows Figure 1Figure 1 shows three panels 1, 2, and 3, each with a 4×1 array of panels A through D. While the leftmost panel 1 is completely defect-free, the adjacent panel 2 has defective panels 2A, and the rightmost panel 3 has defective panels 3B. Pre-screening the boards for defects and rejecting the entire panel if a panel is found to be defective is inefficient. Printing patterns onto identified defective panels and rejecting the isolated defective panels after the printing process is also inefficient and problematic. Current approaches to this problem involve identifying defective panels before the printing process begins and separating panels with similar defects into batches—for example, the first batch has no defects, the leftmost panel in the second batch has defects, the second left panel in the third batch has defects, and so on. Each batch can then use a dedicated screen. For example, a screen with all four hole patterns would be used for the first batch, while a screen with only three hole patterns would be used for each of the remaining batches. For the 4×1 array described here, this would result in each panel being printed using five different screens on one side. Since each panel is typically printed on both sides, this can result in ten different settings being used for a single panel type, rather than the optimal two (i.e., one for each side). Furthermore, the printing efficiency for batches two through five is only 75%. Furthermore, if two or more panels are defective, additional measures must be taken.

[0005] ii) Printing of multiple boards

[0006] One solution to this problem is to pre-separate or "slice" the individual boards before the printing process. Here, any defective boards can be identified and immediately rejected before printing, allowing only the defect-free boards to be printed. While this process is relatively effective, it also presents some challenges. In particular, it is difficult to support and align the relatively small boards for simultaneous (or continuous) printing.

[0007] Various methods have been developed to overcome these problems. For example, GB 2484373A describes a method in which the individual plates are positioned individually, but this only allows sequential printing of one substrate at a time. JP 2009248551 describes a method in which the position of each plate is checked individually and each plate is repositioned in turn using a repositioning arm. Although this technique allows all plates of a panel to be printed simultaneously, additional equipment (i.e., a positioning arm) is required and moving the positioning arm between the workpieces is time consuming. WO2014 / 166956 describes an alternative device in which all plates can be aligned simultaneously using a reference roll and then printed simultaneously. This solution works well, but is not suitable if the position of the input unprinted plates is too far from their correct position.

[0008] EP 3693168 A1 describes a workpiece support assembly that is capable of supporting and individually aligning a plurality of relatively small workpieces (often referred to as "sliced" workpieces). Figure 2 An example of such an assembly 4 is shown schematically, comprising a 2×4 array of individual support “towers” ​​5. The top of each tower 5 has a support surface 6 on which a workpiece (not shown) can be supported during the printing operation. In addition, each tower 5 can be individually actuated to move in orthogonal directions X and Y, which are generally located in a horizontal plane, and to rotate about an orthogonal Z axis, which generally extends in a vertical direction to provide a so-called θ correction. As described in EP3693168A1, this movement can be advantageously provided by using a parallel motion drive system within each tower. Of course, other arrays of larger or smaller sizes can also be used. This system, published by ASM under the name “MASS”, provides a very fast and accurate printing solution. In an extension of the MASS methodology, GB2596517A describes how to use such an apparatus to print a plurality of slit substrates, the spacing of which along the transport direction is less than the spacing of the individual support towers. Furthermore, in a further extension of the MASS methodology, GB 2117575.7 describes how to use such an apparatus to print a plurality of slit substrates, which are arranged at a pitch orthogonal to the transport direction, which pitch is smaller than the pitch of the individual support towers.

[0009] However, the problem is that even using the methodologies described in GB2596517A and GB2117575.7, there is a lower limit to the pitch of the printable array of diced workpieces. That is, if the workpieces or the pitches are so small that more than one workpiece is located on the upper support surface of a single support tower, then the MASS system is not applicable. Summary of the Invention

[0010] The present invention aims to overcome this problem and enable a support tower tooling system (e.g., MASS) to be used with all currently used arrays of diced workpieces. In particular, the present invention aims to provide an apparatus and methodology for aligning diced workpieces with the aperture pattern of a patterned printing screen using such a support tower tooling system while the workpieces are in a printing press and prior to the printing operation. Thus, the present invention enables the use of "MASS-type" tooling to print diced workpieces contained in all standard carrier trays (e.g., "JEDEC" trays).

[0011] According to the invention, this object is achieved by providing each support tower with a plurality of support surfaces, each of said plurality of support surfaces being arranged in a pre-printing configuration with a different height profile, whereby raising the or each support tower brings the individual workpieces into staggered contact from below, allowing them to be individually aligned.

[0012] According to a first aspect of the present invention, there is provided a tool for supporting a workpiece during a printing operation, comprising:

[0013] a support tower having a base and a head, the head being located vertically above the base and being movable relative to the base in a horizontal plane in use,

[0014] The head has a first support surface and a second support surface at an upper end thereof, each of the first support surface and the second support surface being adapted to support a corresponding workpiece thereon,

[0015] Wherein, in use, the first supporting surface is capable of relative movement along a vertical direction relative to the second supporting surface between a printing configuration and a pre-printing configuration, wherein in the printing configuration, the first supporting surface and the second supporting surface are substantially coplanar in the horizontal plane, and in the pre-printing configuration, the first supporting surface and the second supporting surface are spaced apart along the vertical direction.

[0016] According to a second aspect of the present invention, there is provided a printing press for printing a workpiece at a printing position within the printing press, comprising:

[0017] a transport system configured to transport the workpiece into the printing press and to the printing position, and then out of the printing press after the printing operation is completed;

[0018] a printing screen support for holding the patterned printing screen above the printing position;

[0019] a tooling table located below the printing position, the tooling table being drivable toward and away from the printing position; and

[0020] The tooling according to the first aspect is installed on the tooling table.

[0021] According to a third aspect of the present invention, there is provided a method for aligning a workpiece prior to a printing operation, comprising the steps of:

[0022] i) providing a tooling within the printing press below a printing position of the printing press, the tooling comprising at least one support tower, the support tower having at least a first support surface and a second support surface at an upper end thereof, each of the at least first support surface and the second support surface being adapted to support a corresponding workpiece thereon, the first support surface being higher than the second support surface;

[0023] ii) transporting the workpieces to a printing position so that they are located on respective support surfaces of the tooling;

[0024] iii) moving the upper end of the support tower in the horizontal plane to align the first support surface with the corresponding workpiece thereon;

[0025] iv) lifting the tooling so that the first supporting surface is in supporting contact with the corresponding workpiece thereon;

[0026] v) moving the upper end of the support tower in the horizontal plane so that the second support surface is aligned with a corresponding workpiece thereon;

[0027] vi) raising the tooling so that the second support surface is in supporting contact with a corresponding workpiece thereon; and

[0028] vii) moving the upper end of the support tower within the horizontal plane such that the workpieces supported on the respective first and second support surfaces are aligned for the printing operation.

[0029] Further particular aspects and features of the present invention are set out in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The invention will now be described with reference to the accompanying drawings (not to scale), in which:

[0031] Figure 1 Three panels are shown schematically, with four plates on each panel;

[0032] Figure 2 A known multi-tower support system is schematically shown;

[0033] Figures 3A to 9A Schematically shows a top view of an alignment method according to the present invention;

[0034] Figures 3B to 9B Schematically shows the corresponding Figures 3A to 9A side views of the method steps shown;

[0035] Figure 10 schematically illustrates a side view of a printing apparatus during a printing operation;

[0036] Figure 11 Schematically shows Figure 10 a side view of the printing apparatus after the printing operation is shown;

[0037] 12A and 12B schematically illustrate a top view and a side view, respectively, of a tool according to another embodiment of the present invention;

[0038] Figure 13 schematically shows a perspective view of a tool according to another embodiment of the present invention;

[0039] 14A to 14Ea top view schematically illustrating sequential steps in another exemplary method for aligning a workpiece; and

[0040] Figure 15 A side view schematically shows another embodiment of the present invention.

[0041] Description of reference numerals:

[0042] 1, 2, 3-Panel

[0043] 1A to 3D-Board

[0044] 4-Workpiece support assembly

[0045] 5-Tower

[0046] 6-Support surface

[0047] 10, 110-carrying device

[0048] 11, 11A to 11D - Unprinted workpieces

[0049] 12-Workbench

[0050] 13-Upper surface of the workbench

[0051] 14, 114, 140-Tooling

[0052] 15, 16, 115, 116, 117, 145A to 145H - Support towers

[0053] 17, 18-Base

[0054] 19, 20, 119, 120, 121 - head

[0055] 21A to 21D - Support

[0056] 22A, 22C, 122A, 122C, 122E, 222A, 222B - first support surface

[0057] 22B, 22D, 122B, 122D, 122F, 222C - Second support surface

[0058] 23-Workpiece reference point

[0059] 24-Hoarding

[0060] 25-Printing Screen

[0061] 26-Camera

[0062] 27-Scraper

[0063] 28-Printing press

[0064] 29, 129, 149, 229 - Assembly units

[0065] 300-base plate. DETAILED DESCRIPTION

[0066] Figures 3A to 9B The alignment method according to the invention is schematically illustrated.

[0067] Figure 3A and Figure 3B The initial stage of the method is shown, wherein the printing press (28, see Figure 4B ) is transported to the printing position by a conveyor system (not shown) of the printer 28. As is well known in the art, such a conveyor system may typically include a plurality of conveyor belts (not shown) on which the carrier 10 may rest directly, which are configured to move the carrier 10 loaded with the unprinted workpiece 11 from the input end to the printer 28 in a horizontal plane along the X direction shown, and then to the printing position and, after the printing operation is completed, to the output end of the printer 28, in which a printing medium such as solder paste is delivered to the upper surface of the workpiece. Although not shown in these figures, the carrier 10 can be transported to other parts of the production line as needed, for example, to a placement machine, an inspection machine, or a reflow oven. As will be understood by those skilled in the art, the printer 28 (including its conveyor system) is controlled by a control system running complex software via a suitably programmed processor, computer, or similar device.

[0068] like Figure 3A As shown, in this example, the carrier 10 is loaded with four unprinted, cut workpieces 11, labeled 11A to 11D. It should be noted that, although for the sake of clarity, Figure 3A The misalignment shown is exaggerated, but the workpieces 11 may not be well aligned in the carrier 10. Each workpiece 11 is provided with at least one workpiece reference point 23 at a fixed and predetermined position, which is a graphic symbol that can be easily recognized by an optical sensor.

[0069] The printer 28 includes a table 12 having an upper table surface 13 that is flat and aligned in the horizontal (X, Y) plane as shown. The table 12 can be driven by a drive mechanism (not shown) in a vertical direction (i.e., parallel and antiparallel to the Z axis as shown). In particular, the table 12 can be driven between at least a lowest position, in which the upper table surface 13 is at a height Z0 as shown, and a highest position, in which the upper table surface 13 is at a height ZP as shown. This range includes intermediate heights ZA and ZB as shown. The height difference between ZB and ZA is greater than the thickness of the workpiece 11.

[0070] The tooling 14 is mounted on the upper surface 13 of the tooling table for vertical movement with the tooling table 12. In the illustrated example, the tooling includes two support towers 15, 16 that project upward from an assembly unit 29. Assembly unit 29 includes control circuitry for controlling the movement of support towers 15, 16, as described in detail below. These support towers 15, 16 are of the aforementioned "MASS" type, including respective bases 17, 18 and heads 19, 20 positioned vertically above the bases 17, 18. Each head 19, 20 is movable relative to the respective base 17, 18 in a horizontal (X, Y) plane. As MASS-type towers, each base 17, 18 includes a drive (not shown) for driving the respective head relative to the base 17, 18 in the horizontal plane. In this embodiment, the drive is operable to drive the respective head 19, 20 in orthogonal directions X and Y in the horizontal plane and to rotate the respective head 19, 20 about a vertical axis parallel to the illustrated Z axis. Advantageously, the actuators may be parallel kinematic actuators to provide such motion while maintaining compact dimensions, as described in EP 3693168A1. The support towers 15, 16 are provided with vacuum connections so that the respective heads 19, 20 can be selectively provided with at least a partial vacuum by a separately provided vacuum pump (not shown) located elsewhere in the printing press 28. Each head 19, 20 is equipped with first and second supports arranged in a linear array, the head 19 being provided with supports 21A, 21B and the head 20 being provided with supports 21C, 21D. Each support 21A to 21D is provided at its upper end with a respective support surface 22A to 22D, each of these support surfaces being adapted to support a single respective workpiece 11A to 11D thereon. Each support surface 22A to 22D is provided with at least one opening (not shown) for selectively providing at least partial vacuum to the workpieces 11A to 11D when the workpieces 11A to 11D are supported thereon to anchor the workpieces to the respective support surfaces. The vacuum supply to each opening comes from the respective head 19, 20. Optionally, the opening may comprise a gauze-type material. As another option, the support surfaces 22A to 22D may optionally comprise a sintered material through which a vacuum may be provided. For each support tower 15, 16, in use, the first of the support surfaces (i.e., support surfaces 22A, 22C) may only move in a vertical direction (parallel to the Z axis) relative to the second of the support surfaces (i.e., support surfaces 22B, 22D). As shown in the figure, the first support surfaces 22A, 22C are in a pre-printing configuration, wherein the first support surfaces (22A, 22C) and the second support surfaces (22B, 22D) are spaced apart in a vertical direction (parallel to the Z axis), that is, in the vertical direction, the first support surfaces 22A, 22C are higher than the second support surfaces 22B, 22D by a distance ZB to ZA.The first support surface 22A, 22C can be moved downwardly to a printing configuration (see. Figure 9B ), in which configuration the first support surfaces 22A, 22C are substantially coplanar with the second support surfaces 22B, 22D in the horizontal (X, Y) plane. Figure 3A In the top view, it can be seen more clearly that the shape and size of each support surface 22A to 22D are selected to be substantially consistent with the shape and size of the workpiece 11, so as to provide sufficient support for the workpiece 11. For the sake of clarity, in all top views, for example Figure 3A , support surfaces 22A to 22D are shown in dashed lines. Also for the sake of clarity, the enclosure (24, see FIG. 24 ) that would otherwise be present in the printing press 28 has been omitted. Figure 4B ). Similarly, in all top views, i.e., Figures 3A to 9A The enclosure 24 is omitted.

[0071] like Figure 4A and Figure 4B As shown, the carrier device 10 is transported to a printing position where the unprinted workpieces 11A to 11D are located on the corresponding support surfaces 22A to 22D. Figure 4A It can be seen that the workpieces 11A to 11D are misaligned with their underlying support surfaces 22A to 22D. Figure 4B The relative positioning of the components within the printing press 28 is more clearly shown. In the printing position, the carrier 10 is located below a panel 24 that is rigidly fixed to a vertically drivable track (not shown) within the printing press 28. As is well known in the art, the panel is a flat plate with holes formed therein to receive the corresponding cut workpieces 11. The top surface of the panel 24 is arranged to be coplanar with the upper surface of the workpiece 11 during the printing operation to prevent the scraper (27, see Figure 10 ) exerts undue stress on the workpiece 11. Above the enclosure 24 is a printing screen or stencil 25, which is rigidly fixed within the printing press 28 and is formed with apertures corresponding to the desired target print pattern for the workpiece 11. During the printing operation, the scraper (27, see Figure 10 ) across the top of the printing screen 25, forcing the printing medium through the orifice and onto the workpiece 11. In the pre-printing configuration shown, and with the table top 13 at height Z0, there is sufficient space between the enclosure 24 and the printing screen 25 for positioning the camera 26 of the camera system. At this stage of the method, the camera 26 is positioned over each workpiece 11A to 11D in turn to capture each corresponding workpiece reference point 23 (see Figure 3A). The camera 26 may be mounted, for example, on a movable hanger (not shown) or arm so as to be movable on the carrier 10. In an alternative embodiment (not shown), a camera system may be used that is capable of simultaneously capturing the workpiece reference points 23 of more than one workpiece 11A to 11D. In any case, the data associated with the captured reference points is transmitted to the control system and processed to determine the position of each workpiece 11A to 11D in the horizontal (X, Y) plane and its orientation about a vertical axis parallel to the Z axis, which is referred to as its θ rotation. Figure 10 As shown, after all workpiece reference points 23 are captured, the camera 26 is moved to a retracted position horizontally spaced apart from the carrier 10 so as not to interfere with subsequent movement of the tooling table 12 .

[0072] like Figure 5A In the top view shown, each support tower 15, 16 is independently driven (i.e., the head 19, 20 is independently driven relative to its base 17, 18) so that the corresponding lower first support surface 22A, 22C is aligned with the corresponding upper workpiece 11A, 11C using the workpiece position determined in the previous step. It should be understood that by using appropriate encoders in each support tower 15, 16, the position of each support tower 15, 16 can be accurately controlled and determined. It should also be understood that since the amount of movement of the head 17, 18 is very small, Figure 5B The displacement of the heads 17, 18 and the supports 21A to 21D cannot be discerned.

[0073] like Figure 6A and Figure 6B As shown, once the first support surfaces 22A, 22C are aligned with the workpieces 11A, 11C, the tooling table 12 can be raised so that the first support surfaces 22A, 22C contact the respective workpieces 11A, 11C and lift them out of engagement with the carrier 10. This corresponds to raising the tooling table upper surface 13 to a height ZA as shown. At least a partial vacuum is applied to the first support surfaces 22A, 22C to securely adhere the respective workpieces 11A, 11C thereto. The at least partial vacuum is applied until the printing operation is complete.

[0074] Then, if Figure 7A and Figure 7B As shown, each support tower 15, 16 is driven independently (i.e., the heads 19, 20 are driven independently relative to their bases 17, 18) so that the corresponding lower second support surface 22B, 22D is aligned with the corresponding upper workpiece 11B, 11D using the previously determined workpiece position. Figure 7B The displacement of the heads 17, 18 and the supports 21A to 21D cannot be discerned.

[0075] like Figure 8A and Figure 8B As shown, once the second support surfaces 22B, 22D are aligned with the workpieces 11B, 11D, the worktable 12 is further raised, bringing the second support surfaces 22B, 22D into contact with the respective workpieces 11B, 11D and lifting them out of engagement with the carrier 10. This corresponds to raising the worktable upper surface 13 to a height ZB as shown. At least a partial vacuum is applied to the second support surfaces 22B, 22D to securely adhere the respective workpieces 11B, 11D thereto. The at least partial vacuum is applied until the printing operation is complete. During this raising, the first support surfaces 22A, 22C are maintained at a constant absolute height, rather than moving upward with the worktable 12. As a result, the first support surfaces 22A, 22C move relatively closer to the second support surfaces 22B, 22D during the raising process, until all support surfaces 22A to 22D are substantially coplanar in the horizontal plane, at which point the first support surfaces 22A, 22C are in the printing configuration. There are various ways to move the first support surfaces 22A, 22C to the printing configuration. For example, each first support surface 22A, 22C can be driven between its printing configuration and its pre-printing configuration. This can be achieved by providing a Z-axis drive within each first support member 21A, 21C or support tower, in particular within the respective head 19, 20, which is operable to drive the respective first support surface 22A, 22C downward relative to the respective second support surface 22B, 22D. However, a simpler solution is to restrict each first support surface 22A, 22C from rising further with the workbench 12 once the workbench upper surface 13 passes the height ZA. This can be achieved, for example, by resiliently biasing each first support surface 22A, 22C to the pre-printing configuration (i.e., to its maximum vertical height), for example by connecting each first support surface 22A, 22C to its respective head 19, 20 via a compression spring (not shown). A protrusion (not shown) may be provided at each first support surface 22A, 22C for abutting against an external stopper (not explicitly shown), such that when the protrusion abuts against the external stopper, the first support surfaces 22A, 22C are prevented from lifting during the lifting of the support towers 15, 16. In a preferred embodiment, the stopper may comprise at least a portion of the shroud 24, i.e., a member specifically for abutting against the protrusion is provided on the shroud, or the protrusion is sized to abut against a "normal" shroud itself, without any additional member provided for this purpose.

[0076] Then, if Figure 9A and Figure 9BAs shown, each support tower 15, 16 is driven independently (i.e., the heads 19, 20 are driven independently relative to their bases 17, 18) so that all support surfaces 22A to 22D are correctly aligned with the respective workpieces 11A to 11D they support, i.e., with the printing screen (25, see Figure 4B ) of the hole pattern. Since the movement of the heads 17 and 18 is very small, Figure 9B The displacement of the heads 17 and 18 cannot be discerned.

[0077] At the end of the previous step, the alignment method is complete. All workpieces 11A to 11D can now be printed in a single printing operation. Figure 10 As shown, once all workpieces 11A to 11D are correctly aligned, the table 12 is further raised to its printing height, at which point the table upper surface 13 is at height ZP. As is well known in the art, the raising of the table 12 causes the carrier 10 and the enclosure 24 to also be raised. When the table 12 is fully raised to the printing height, the workpieces 11A to 11D and the enclosure 24 are pressed against the underside of the printing screen 25, and the upper sides of the workpieces 11A to 11D are coplanar with the upper surface of the enclosure 24. Since the enclosure 24 is raised together with the table 12, the first support surfaces 22A, 22C will maintain their printing configuration throughout the raising process. The camera 26 is shown in a retracted position, in which it does not interfere with the raising of the table 12. Once the tooling table 12 is raised to its printing height, a squeegee 27 may be drawn across the upper surface of the printing screen 25 to force the printing medium through the apertures of the printing screen 25 and onto the workpieces 11A to 11D, as is known per se in the art.

[0078] After the printing operation is completed, the tooling table 12 is lowered so that the upper surface 13 of the tooling table returns to the height Z0 , and the printed workpiece is returned to the carrier 10 . Figure 11 This position is shown in the side view shown.

[0079] The transport system can then transport the loaded carrier 10 in the indicated positive direction X to the output of the printing press and thus to other modules of the production line as required.

[0080] The above example shows a simple embodiment of the invention, however the invention is not limited to this particular embodiment. In particular, the arrangement of the support tower and the support surface on the support tower are very flexible.

[0081] As an example, Figures 12A and 12B schematically illustrate a tool 114 in top and side views, respectively, suitable for printing a batch of six workpieces 111A to 111F arranged in a 3×2 matrix array on a carrier 110. This is achieved using three support towers 115, 116, and 117 mounted on an assembly unit 129, each of which is of the MASS type as previously described. Each respective head 119, 120, and 121 of each support tower 115, 116, and 117 carries first and second support surfaces arranged in a linear array for positioning beneath the respective workpieces 111A to 111F during use. In the pre-printing configuration, the first support surfaces 122A, 122C, and 122E are at a higher elevation than the second support surfaces 122B, 122D, and 122F. The operation of the tool 114 is the same as previously described.

[0082] Figure 13 A perspective view of a tooling 140 is schematically shown, comprising eight MASS-type support towers 145A to 145H arranged in a 4×2 array on an assembly unit 149. Each support tower 145A to 145H bears on its top four support surfaces 142A to 142D arranged in a 2×2 square matrix. Of these support surfaces, 142A to 142C may be considered "first support surfaces," similar to the first support surfaces 22A and 22C of the first embodiment. During use, the tooling 140 is movable relative to support surface 142D (i.e., the "second support surface") in a vertical direction between a printing configuration and a pre-printing configuration. In the printing configuration, the first and second support surfaces are substantially coplanar in the horizontal plane. In the pre-printing configuration, the first and second support surfaces are spaced apart in the vertical direction. In its pre-printing configuration shown, support surfaces 142A through 142D are vertically spaced apart, with support surface 142A being the highest, followed by 142B, then 142C, with support surface 142D being the lowest support surface of the support tower. The operation of tooling 140 is very similar to that previously described. The workpiece (not shown) positioned above is aligned as follows:

[0083] i) Capture the reference point information of the workpiece;

[0084] ii) the support surface 142A moves in a horizontal plane to align with the corresponding workpiece above it;

[0085] iii) raising the tooling table (not shown) to height ZA so that the support surface 142A engages its workpiece, applying vacuum, and raising the workpiece out of engagement with the carrier (not shown);

[0086] iv) moving the support surface 142B in a horizontal plane to align with the corresponding workpiece above it by movement of the corresponding head;

[0087] v) raising the tooling table to height ZB so that the support surface 142B engages its workpiece, applying vacuum, and raising the workpiece out of engagement with the carrier;

[0088] vi) moving the support surface 142C in a horizontal plane to align with the corresponding workpiece above it by movement of the corresponding head;

[0089] vii) raising the tooling table to height ZC so that the support surface 142C engages its workpiece, applying vacuum, and raising the workpiece out of engagement with the carrier;

[0090] viii) moving the support surface 142D to align with the corresponding workpiece above it through movement of the corresponding head;

[0091] ix) raising the tooling table to height ZD so that the support surface 142D engages its workpiece, applying vacuum, and raising the workpiece out of engagement with the carrier; and

[0092] x) Moving the head of the support tower in a horizontal plane so that the workpiece supported on all support surfaces 142A to 142D is aligned for the printing operation.

[0093] After alignment, the workpiece can be printed in the following ways:

[0094] xi) further raising the workbench to height ZP, thereby bringing the workpiece supported on the support surfaces 142A to 142D to the printing height. During this step, the support surfaces 142A to 142C are brought to their printing configuration so that all support surfaces 142A to 142D are substantially coplanar; and

[0095] xii) Performing a printing operation.

[0096] As previously mentioned, GB 2596517A describes the use of a MASS-type tooling to print multiple slit substrates arranged at a spacing along the conveying direction that is less than the spacing between the individual support towers, while GB 2117575.7 describes the use of this apparatus to print multiple slit substrates arranged at an orthogonal spacing along the conveying direction that is less than the spacing between the individual support towers. Essentially, both methods implement a two-stage process, where workpieces located in non-adjacent rows or columns of a carrier array are printed in a first printing operation, followed by printing of workpieces located in alternate rows or columns of the carrier array in a second printing operation.

[0097] This methodology is fully compatible with the methodology of the present invention. For example, 14A to 14EA schematic top view of sequential steps of a method for aligning 27 workpieces 211 arranged in a 9×3 matrix array (e.g., a JEDEC 31mm 9×3 tray) in a carrier 210 using a tool 214 including three support towers 215, 216, 217 mounted on an assembly unit 229 is shown. For convenience, each column of workpieces is labeled "1" through "9." Each support tower 215, 216, 217 includes a head that carries three support surfaces 222 arranged in a linear array, each corresponding to the size of a workpiece 211 and spaced apart at a spacing equal to the spacing between adjacent workpieces 211 in a column of the carrier 210 (i.e., the distance in the Y direction between each workpiece aligned in the X direction). Support surfaces 222A and 222B can be considered "first support surfaces," similar to first support surfaces 22A and 22C of the first embodiment. During use, they can be moved vertically relative to support surface 222C (i.e., "second support surface") between a printing configuration and a pre-printing configuration. In the printing configuration, the first and second support surfaces are substantially coplanar in the horizontal plane, while in the pre-printing configuration, the first and second support surfaces are vertically spaced apart. In the illustrated pre-printing configuration, support surfaces 222A through 222C are vertically spaced apart, with support surface 222A being the highest, followed by support surface 222B, and support surface 222C being the lowest support surface of the support tower. The tooling 214 can be operated in a manner very similar to that described previously, and therefore this aspect will not be described in further detail. It can be seen that the spacing between adjacent columns of workpieces 211 in the carrier 210 (i.e., the distance in the X direction between each column of three workpieces aligned in the Y direction) is less than the spacing between adjacent support towers 215, 216, and 217.

[0098] exist Figure 14A In the illustrated step, the carrier 210 and its unprinted and misaligned workpiece 211 are shown before being transported to a printing position above a tooling 214 .

[0099] exist Figure 14B In the subsequent steps shown, the carrier 210 with the unprinted and misaligned workpieces 211 is shown transported to the printing position so that the workpieces 211 in its rightmost column "1" are positioned on the respective support surfaces 222A to 222C of the support tower 217, while the workpieces 211 in column "4" are positioned on the respective support surfaces 222A to 222C of the support tower 216, and the workpieces 211 in column "7" are positioned on the respective support surfaces 222A to 222C of the support tower 215. Once in this position, the workpieces in these columns are aligned as previously described and then printed as previously described.

[0100] exist Figure 14CIn the subsequent steps shown, the carrier 210 with the unprinted and misaligned workpieces 211 is shown to have been transported in the X direction at a pitch so that the workpieces 211 in the second rightmost column "2" are located on the corresponding support surfaces 222A to 222C of the support tower 217, while the workpieces 211 in column "5" are located on the corresponding support surfaces 222A to 222C of the support tower 216, and the workpieces 211 in column "8" are located on the corresponding support surfaces 222A to 222C of the support tower 215. Once in this position, the workpieces in these columns are aligned as previously described and then printed as previously described.

[0101] exist Figure 14D In the subsequent steps shown, the carrier 210 with the unprinted and misaligned workpieces 211 is shown to have been transported in the X direction at a pitch so that the workpieces 211 in the third rightmost column "3" are located on the corresponding support surfaces 222A to 222C of the support tower 217, while the workpieces 211 in column "6" are located on the corresponding support surfaces 222A to 222C of the support tower 216, and the workpieces 211 in column "9" are located on the corresponding support surfaces 222A to 222C of the support tower 215. Once in this position, the workpieces in these columns are aligned as previously described and then printed as previously described.

[0102] Finally, if Figure 14E As shown, the carrier 210 on which all workpieces have been aligned and printed is transported away from the printing position along the X direction and transported to other modules of the production line as needed.

[0103] Figure 15 A side view of another embodiment of the present invention is shown as an example. Figure 5A 、 5B The arrangement shown is very similar except that, as shown, the datum plate 300 is parallel to and vertically above the enclosure 24. If a MASS type fixture is not used, datum plates are used in some configurations of certain printing presses to actively align the slit workpieces. For example, an exemplary datum system using two adjacent datum plates is fully described in US2021 / 0070033A1, which describes aligning the workpieces by sliding at least one datum plate in a horizontal plane to contact the edges of the slit workpieces and cause them to align correctly. Figure 15 In the illustrated embodiment, the stopper comprises at least a portion of the reference plate 300, i.e., a member is provided on the reference plate specifically for abutting the protrusion, or the protrusion is sized to abut against a "normal" reference plate itself, without any additional member for this purpose. As will be understood by those skilled in the art, such a reference plate is retracted from the printing position before the printing operation begins.

[0104] The above embodiments are merely exemplary, and other possibilities and alternatives within the scope of the present invention will be apparent to those skilled in the art.

Claims

1. A tool for supporting a workpiece during a printing operation, comprising: a support tower having a base and a head, wherein, in use, the head is located vertically above the base and is movable relative to the base in a horizontal plane, The head has a first support surface and a second support surface at an upper end thereof, each of the first support surface and the second support surface being adapted to support a corresponding workpiece thereon, Wherein, in use, the first supporting surface is capable of relative movement along a vertical direction relative to the second supporting surface between a printing configuration and a pre-printing configuration, wherein in the printing configuration, the first supporting surface and the second supporting surface are substantially coplanar in the horizontal plane, and in the pre-printing configuration, the first supporting surface and the second supporting surface are spaced apart along the vertical direction.

2. The tooling according to claim 1, wherein: The head comprises at least one additional supporting surface, and wherein, in a respective pre-printing configuration, the first supporting surface and the second supporting surface and each additional supporting surface are spaced apart along the vertical direction.

3. The tooling according to claim 2, wherein: The first and second support surfaces and each additional support surface are arranged in a linear array on the head.

4. The tooling according to claim 2, wherein: The first support surface, the second support surface, and each additional support surface are arranged on the head in a two-dimensional matrix array.

5. The tooling according to claim 1, wherein: The support tower includes a drive for driving the head relative to the base in the horizontal plane.

6. The tooling according to claim 5, wherein: The drive is operable to drive the head in orthogonal directions X and Y within the horizontal plane and is operable to rotate the head about a vertical axis.

7. The tooling according to claim 1, wherein: The first support surface is resiliently biased toward the pre-printing configuration.

8. The tooling according to claim 1, wherein: The first support surface includes a protrusion for abutting an external stop, such that when the protrusion abuts the external stop, lifting of the first support surface is prevented during raising of the support tower.

9. The tooling according to any one of claims 1 to 6, wherein: The first support surface is drivable between a printing configuration and a pre-printing configuration thereof.

10. A printing press for printing a workpiece at a printing position within the printing press, comprising: a transport system configured to transport the workpiece into the printing press and to the printing position, and then out of the printing press after the printing operation is completed; a printing screen support for holding the patterned printing screen above the printing position; a tooling table located below the printing position, capable of being driven toward and away from the printing position; as well as The tooling according to claim 1, which is mounted on the tooling table.

11. The printing press according to claim 10, wherein: The transport system is configured to transport a carrier into the printing press and to the printing position, and then transport it out of the printing press after the printing operation is completed, the carrier being adapted to carry a plurality of workpieces. 12 . The printing press according to claim 10 , comprising a stopper disposed to abut against the first supporting surface to limit a vertical position of the first supporting surface during upward driving of the workbench.

13. The printing press according to claim 12, wherein: The stopper comprises at least a portion of a surrounding plate, the surrounding plate comprises at least one hole, and the at least one hole is located above the corresponding workpiece in the printing position.

14. The printing press according to claim 12, wherein: The limiting member includes at least a portion of a reference plate.

15. The printing press of claim 10, comprising a camera system for determining the orientation of a workpiece that has been delivered to the printing position.

16. The printing press according to claim 15, wherein The camera system comprises a camera positioned, in use, at a vertical height between the conveyor system and the printing screen.

17. The printing press according to claim 16, wherein: The camera is drivable in the horizontal plane to be positioned over each workpiece and to scan each workpiece sequentially.

18. A method for aligning a workpiece prior to a printing operation, comprising the steps of: i) providing a tooling within a printing press below a printing position of the printing press, the tooling comprising at least one support tower, the support tower having at least a first support surface and a second support surface at an upper end thereof, each of the at least first support surface and the second support surface being adapted to support a respective workpiece thereon, the first support surface being higher than the second support surface; ii) transporting the workpieces to a printing position so that they are positioned on corresponding support surfaces of the tooling; iii) moving the upper end of the support tower in a horizontal plane to align the first support surface with a corresponding workpiece located thereon; iv) raising the tooling so that the first support surface is in supporting contact with a corresponding workpiece located thereon; v) moving the upper end of the support tower within the horizontal plane to align the second support surface with a corresponding workpiece positioned thereon; vi) raising the tool so that the second support surface is in supporting contact with a corresponding workpiece located thereon; and vii) moving the upper end of the support tower within the horizontal plane to align the workpiece supported on the respective first and second support surfaces for the printing operation.

19. The method according to claim 18, further comprising the steps of: viii) raising the tooling to bring the workpiece supported on the respective first and second support surfaces to a printing height.

20. The method of claim 18, further comprising the step of determining the orientation of each workpiece at the printing location within the horizontal plane.

21. The method according to claim 20, wherein Prior to step iii), the orientation of all workpieces at the printing position in the horizontal plane is determined.

22. The method according to claim 20, wherein The orientation of the first workpiece on the respective first support surface in the horizontal plane is determined before step iii), and the orientation of the second workpiece on the respective second support surface in the horizontal plane is determined before step v).

Images