Reference system for singulating workpieces

Abstract

A method and apparatus for referencing a plurality of singulated workpieces within a printer prior to performing a printing operation such that a single reference plate can be used for both horizontal and vertical referencing operations.

Description

Technical Field

[0001] The present invention relates to a tool for supporting multiple cut-out workpieces during a printing operation, a printer for printing media onto multiple cut-out workpieces during a printing operation, and a method for referencing multiple cut-out workpieces within the printer prior to performing a printing operation. Background Technology

[0002] Industrial screen printing machines typically apply conductive printing media (such as solder paste, silver paste, or conductive ink) to one or more planar workpieces (such as circuit boards) by applying a conductive printing medium through a pattern of holes in a thin planar layer or mask, such as a stencil (which is a patterned solid material, such as stainless steel) or a screen (which is a mesh material coated with an emulsion). This invention is equally applicable to screen printing and stencil printing, and for convenience, the term "stencil" will be used to refer to any such patterned mask throughout this document. The printing medium is applied using a tilting blade or squeegee. The same machine can also be used to print certain non-conductive media (such as glue or other adhesives) onto workpieces.

[0003] When printing multiple individual "cut-to-order" pieces in a single printing operation, each piece needs to be individually supported while allowing alignment within its plane, i.e., horizontal alignment in a standard printing press. Typically, a reference support in the vertical or Z-direction is also required.

[0004] For example, a system for supporting single-piece cutters is known from WO2014 / 166956A1. This system uses multiple towers, each for a single-piece cutter, arranged in an array on top of a vertically movable tool table. Each tower has a head portion at its distal end, which is movable in a horizontal plane relative to the rest of the tower, and this movement is generated during horizontal reference operations by the action of a separate horizontal reference plate (sometimes referred to as an "active surround"). Each tower is also lockably deformable in the Z-direction. To achieve Z-direction reference, a vertical reference operation is performed, wherein the tower is raised by the tool table such that it engages with the underside of a vertical reference plate (sometimes referred to as a "top reference plate" or TRP), deforms, and then locks to a reference Z-height (sometimes referred to as "Z-lock"). Obviously, it is necessary to remove the top reference plate from the tool so that it does not interfere with subsequent printing operations.

[0005] While the system functions well, it also has drawbacks. In particular, it is crucial that the TRP be a large, rigid structure capable of absorbing the combined upward forces from all the towers. For example, each tower can exert an upward force of up to approximately 1 kg. This, in turn, requires relatively large components to move the top reference plate in and out of its reference position above the towers. Furthermore, the Z-axis locking system must maintain each tower under a downward force of approximately 3 to 5 kg due to the pressure exerted by the squeegee during the printing operation. Therefore, these components are large in size and weight, and it is desirable to reduce their size without adversely affecting reliability or accuracy. Summary of the Invention

[0006] This invention seeks to overcome these problems and provide a tool system with significantly reduced weight and size.

[0007] According to the present invention, this objective is achieved in a dual manner: i) A novel Z-axis actuation and locking mechanism is proposed for the tower, which significantly reduces weight, size, and generated Z-axis force; and ii) By utilizing an active surround for top reference, the need for a separate top reference plate is completely eliminated.

[0008] In this way, a single reference board can be used for both horizontal and vertical reference operations.

[0009] According to a first aspect of the invention, a tool is provided for supporting a plurality of cut single workpieces during a printing operation. The tool includes a plurality of towers, each tower extending along an axis and configured to support a corresponding workpiece among the plurality of workpieces in a horizontal orientation. Each tower includes: main body; The head has a supporting surface located at its distal end and configured to support a corresponding workpiece thereon. This supporting surface is displaceable relative to the body in a plane perpendicular to the axis. The main body includes a pneumatic input to receive pressurized air and to provide a lifting force to the head so that the head moves relative to the main body along the axis; and Each tower includes a locking mechanism for selectively locking the head relative to the body.

[0010] According to a second aspect of the invention, a printer is provided for printing printing media onto a plurality of cut single workpieces during a printing operation, comprising the tools of the first aspect.

[0011] According to a third aspect of the invention, a method is provided for referencing a plurality of cut workpieces within a printing press prior to performing a printing operation, the printing press including tools for supporting the cut workpieces thereon and a reference plate having a plurality of reference surfaces movable in a horizontal plane, the method comprising the following steps: i) Supporting the workpiece on the tool in a horizontal orientation; and ii) Perform vertical and horizontal reference operations in any order; The vertical reference operation includes lifting the supported workpiece to contact the underside of the reference plate, and then locking the tool to hold the supported workpiece at a locked vertical distance from the tool base; and The horizontal reference operation involves lifting the supported workpiece into the corresponding hole set in the reference plate and moving the reference surface in the horizontal plane to contact the corresponding supported workpiece.

[0012] Other specific aspects and features of the invention are set forth in the appended claims. Attached Figure Description

[0013] The invention will now be described with reference to the accompanying drawings (not to scale), in which: Figure 1 A cross-sectional side view of a tool located below a reference plate according to an embodiment of the present invention is shown schematically; Figures 2A-2C schematically show cross-sectional side views of the tower at various stages during vertical reference operation; and Figure 3A -3S schematically illustrates a stage in a reference method according to an embodiment of the present invention.

[0014] [Explanation of reference numerals in the attached figures] 1 printer 2 tools 3 lifting platforms 4 towers 5 heads 6 Supporting surfaces 7 main bodies 8 bases 9 air channels 10 air pressure source 11 Reference Board 12 lifting chambers 13 air bearings 14 on board 15 lower board 16 fasteners 17 holes 18 Reference Surfaces HR level reference direction W workpiece. Detailed Implementation

[0015] One embodiment of the present invention is in Figure 1The diagram is schematically shown. A printing press 1 equipped with a tool 2 is shown, which is supported on a lifting platform 3 of the printing press 1. Although not shown for clarity, it should be understood that the tool 2 is therefore located below the printing area of ​​the printing press 1, allowing the stencil to be positioned above the tool, and the scraper of the print head can act on the tool during printing operations. In use (and as is known in the art itself), multiple unprinted workpieces ( Figure 1 The printing press 1 (not shown) can enter the carrier (not shown) to cover the tool 2. Then, the lifting platform 3 can be driven vertically upward (i.e., parallel to the positive Z direction shown) to lift the unprinted workpiece from the carrier and bring it into contact with the template for printing. After the printing operation is completed, the lifting platform 3 can then be lowered to remove the printed workpiece from the template and move it back to the carrier for further transfer from the printing press 1.

[0016] Tool 2 includes a plurality of vertically oriented towers 4, each extending parallel to the Z-axis, wherein each tower 4 is configured to support a corresponding workpiece (not shown) among a plurality of workpieces in a horizontal orientation. Each tower 4 includes a head 5 and a body 7 supporting the head 5, wherein the body is supported on a base 8 of tool 2, which is common to all towers 4. The head 5 has a corresponding support surface 6 at its distal end, which is configured to support the corresponding workpiece thereon. The support surface 6 is displaceable relative to the body 7 in a plane perpendicular to the axis, i.e., parallel to the horizontal XY plane shown. This displaceability can be achieved in various ways. For example, in the aforementioned WO2014 / 166956A1, the support surface 6 is attached to its tower via an elastically deformable material such as rubber or other elastic material. As will be described in more detail below, this displaceability allows the support surface 6 and its corresponding workpiece to be removed from a “neutral” XY position via a reference plate 11 during horizontal reference operation, and then returned to the neutral position after horizontal reference operation when the reference plate 11 is disengaged. For tool 2, the support surface 6 may be connected to its head 5, for example, via an elastically deformable material (not shown), or the head 5 may be connected to the body 7 via an elastically deformable material, or alternative arrangements may be provided (e.g., using a spring instead of an elastically deformable material), which will be apparent to those skilled in the art.

[0017] Furthermore, the head 5 can move relative to the body 7 in a direction parallel to the Z-axis (i.e., vertically). To control this vertical movement of the head 5, the body 7 includes a pneumatic input to receive pressurized air and provide a lifting force to the head 5 to move it vertically upward relative to the body 7. The pressurized air is delivered to the body 7 of each tower 4 via an air passage 9 disposed in the base 8, which is connected to a pressure source 10, such as a pump (not shown). In this way, air can be supplied to each tower 4 to raise each head 5 to contact the underside of the reference plate 11, as... Figure 1 As shown, during vertical reference operation, which will be described in more detail below, each tower 4 also includes a locking mechanism ( Figure 1 (Not shown in the image) for selectively locking the head 5 relative to the body 7. The locking mechanism can be applied to... Figure 1 The positions shown are used to lock the head 5 of each tower 4 in a vertical reference position set by the lower side of the reference plate 11, such that when the tower 4 and the reference plate 11 are moved apart, the head 5 remains in that position, which will be described in more detail below.

[0018] Despite Figure 1 As not shown, each tower may also include means for adhering the workpiece to the support surface 6, such as a vacuum or a relatively low pressure source, which is known in the art itself and therefore need not be described in detail here.

[0019] Figures 2A-2C schematically illustrate cross-sectional side views of the tower 4 at various stages during vertical reference operation, showing a locking mechanism according to an embodiment of the invention. As shown, in this embodiment, the head 5 includes an elongated rod extending along the axis of the tower 4 (i.e., parallel to the Z-axis), the elongated rod having a support surface 6 at its uppermost end. The body 7 includes a sleeve with a central hole sized to slidably receive the rod along the axis. (Source: pneumatic source 10, see...) Figure 1Pressurized air can be selectively introduced into the lifting chamber 12 at the bottom of the sleeve, located below the rod, via a pneumatic port (not shown). An air bearing 13 is disposed in a bore adjacent to the rod, such that when air is supplied to the air bearing via a separate air channel (not shown), friction between the rod and the air bearing is reduced, allowing the rod to slide parallel to its axis relative to the air bearing 13. When no air is supplied to the air bearing 13, the rod is locked relative to the air bearing 13. More specifically, the sleeve is sized such that when no air is supplied to the air bearing 13, the rod is held firmly by the air bearing 13. However, when air is supplied to the air bearing 13, the sleeve deforms slightly outward, allowing the rod to move, thus reducing or essentially eliminating friction in the activated air bearing 13. Therefore, only a very small upward force can be applied via the lifting chamber 12 to lift the head 5. When air is again supplied to the air bearing 13, the sleeve contracts, and the rod is locked relative to the air bearing, and thus locked relative to the sleeve.

[0020] In Figure 2A, the head 5 is at or near its lowest limit of vertical movement relative to the body 7. The workpiece W, supported on the support surface 6, is located below the reference plate 11. Figure 2B shows the same tower 4 after the head 5 has been lifted by applying air to the lifting chamber 12 and the air bearing 13. The head 5 “floats” upward until the workpiece W contacts the underside of the reference plate 11. At this point, the air supply to the air bearing 13 is removed to lock the head 5 relative to the body 7, and optionally, the air supply to the lifting chamber can also be removed. As shown in Figure 2C, the head 5 remains in its locked position when the reference plate 11 is removed from the workpiece W.

[0021] Instead of using a lifting spring (as in known systems), a constant upward force is maintained using lifting pressure by supplying an air source to the lifting chamber 12. This eliminates the need to consider the maximum / minimum spring values ​​during design and further reduces the maximum force that the reference plate must withstand. Therefore, the reference plate 11 can be significantly thinner and thus lighter compared to a conventional top reference plate. As will be described in more detail below, this improvement allows a common, relatively thin reference plate to be used for both vertical and horizontal reference operations.

[0022] Furthermore, the use of conformers as described above can have the additional benefit of eliminating the need for high machining tolerances.

[0023] The design of this tower is flexible. For example, the pole can have a square cross-section, in which case the air bearings can be planar so as to be adjacent to at least two opposite sides of the pole. Alternatively, for example, the pole can have a circular cross-section, in which case the air bearings can be in a ring completely surrounding the pole.

[0024] In an alternative embodiment, it is otherwise very similar to the embodiment shown in Figures 2A-C. The sleeve can be sized such that a gap is maintained between the air bearing 13 and the rod when no air source is supplied to the air bearing 13 (or alternatively during the application of positive air pressure to the air bearing 13), thereby allowing relative movement between them. Subsequently applying negative pressure to the air bearing 13 will cause the air bearing 13 to collapse, locking the rod relative to the air bearing 13.

[0025] In another alternative embodiment, a separate locking component may be provided, which can be actuated when negative pressure is applied.

[0026] Figure 3A -3S schematically illustrates a stage in a reference method according to an embodiment of the present invention. More specifically, Figure 3A -3C shows the tools and reference board before performing any reference. Figures 3D-3J illustrate vertical reference operations. Figure 3K-3P The horizontal reference operation prior to the printing operation is shown. Figure 3Q -3S shows the apparatus after the printing operation. For clarity, these figures only show tool 2 and reference plate 11, and in particular tool 2 is omitted from these figures by the lifting platform supported on it, the carrier on which the workpiece W enters the printer, and the template and print head required to perform the printing operation.

[0027] Figure 3A -3C shows the tool and reference plate before any reference is performed, in sectional side view, top view, and enlarged view, respectively. As shown, the tool 2 includes eight towers 4 arranged in a 4×2 array. Here, the support surface 6 of each tower 4 is connected to its corresponding head 5 via an elastically deformable material (not visible) (such as rubber), as previously described. The reference plate 11 is shown in more detail than before, and it can be seen here that the reference plate 11 includes an upper plate 14 and a lower plate 15 connected by fasteners 16 such that they are constructed to remain parallel and horizontal (i.e., in the XY plane), but can be moved relative to each other in the horizontal (XY) plane. More specifically, the lower plate 15 can be parallel to the horizontal reference direction HR (e.g., ... Figure 3BThe upper plate 14 moves in the direction HR, which is approximately 45° to the X and Y axes. An actuator (not shown) can be configured to move the lower plate 15 in the direction HR and the opposite direction, while the upper plate 14 returns to rest, as is known in the art itself. Holes 17 are formed extending through the reference plate 11, i.e., through the upper plate 14 and the lower plate 15. These holes are arranged and sized such that, after the tool 2 is raised, the workpiece W supported on each tower 4 can be received therein, with sufficient clearance to allow for reasonable misalignment of the workpiece W on the tower 4. Thus, it can be seen that, as the lower plate 15 moves in the direction HR, as shown, the right and lower edges of the holes 17 move inward from the corresponding holes 17, thereby reducing their opening area. These edges thus serve as reference surfaces 18 such that, if the workpiece W is received within the holes 17, when they move in the direction HR, the reference surfaces 18 will contact the workpiece W and push it to the upper left corner of the hole 17, i.e., into the horizontal reference position, as shown. As shown more clearly in Figure 3C, the reference surface 18 is made larger in the Z direction by providing upwardly projecting "L-shaped" walls on the lower plate 15 at the lower part and right-hand side of the hole 17, the "L-shaped" walls extending upward into the hole formed in the upper plate 14. For clarity, in the following discussion, the term "closed" will be used to describe the movement of the lower plate 15 in the direction HR to reduce the opening area of ​​the hole 17, while the term "open" will be used to describe the movement of the lower plate 15 in the opposite direction to HR to increase the opening area of ​​the hole 17.

[0028] Alternatively, at least one of the upper plate 14 and the lower plate 15 may be compliant, or allow for small off-axis translation in the horizontal plane. This compliance can be used to accommodate minute variations in hole size and substrate size.

[0029] Figures 3D-3J illustrate the stages in the vertical reference operation. First, as shown in Figures 3D and 3E, tool 2 is in the lowered state (and also as...). Figure 3A In the case shown, by moving the reference surface 18 in the direction HR, the hole 17 is closed. It should be noted that the workpiece W, visible in Figure 3D, is visible through the hole but is not received within it.

[0030] Then, as shown in Figure 3F, tool 2 is raised to the "pre-reference position" by lifting the lifting platform (not shown) near the reference plate 11.

[0031] Next, as shown in Figures 3G and 3J, the workpieces W are lifted to the reference plate 11 by raising the head 5 of each tower 4 relative to the body 7, i.e., by supplying pneumatic air to the lifting chamber 12 (see Figure 2). Once the workpieces W contact the lower side of the reference plate 11, they are prevented from rising further. As shown in Figures 3G and 3H, this lifting can optionally be performed sequentially. In Figure 3G, only the leftmost workpiece W is lifted; however, in Figure 3H, the two leftmost workpieces W have been lifted until all supported workpieces W have been lifted. This sequential lifting can be controlled by appropriate control of the air pressure source of the tower 4, such as using pneumatic logic, series air supply, or other control devices known per se. Sequential lifting may help reduce the maximum upward surge received by the reference plate 11. Figure 3I As shown, the workpieces W contact the lower side of the reference plate 11; more specifically, they contact the lower side of the lower plate 15 near the reference surface 18 of the closing hole 17. This contact is used to vertically reference the workpieces W. When all workpieces W are referenced in this way, the locking mechanisms of all towers 4 are engaged, for example by removing the air supply to the air bearing 13 (see Figure 2) or by applying negative pressure to it. Then, as... Figure 3J As shown, tool 2 can be lowered by the movement of the lifting platform, so that the workpiece W no longer contacts the reference plate 11.

[0032] Figure 3K-3P This illustrates the stages of subsequent horizontal reference operations following the printing operation. For example... Figure 3K As shown, the reference surface 18 is moved to open the hole 17. Then, as shown in Figures 3L and 3M, the tool 2 is raised toward the reference plate 11, so that the workpiece W approaches and is subsequently received in the hole 17. Due to the previous vertical reference, they protrude from above the reference plate 11 by the same repeatable distance. Once the workpiece W is fully received in the open hole 17 (see Figure 3N), the reference surface 18 is moved in the direction HR to close the hole 17, as shown in Figures 3O and 3P. As previously stated, this serves to horizontally reference the workpiece W. With the workpiece W now both vertically and horizontally referenced, they can undergo the printing operation.

[0033] Figure 3Q -3S shows the apparatus after the printing operation. (Example) Figure 3Q As shown in Figure 3R, after printing, the reference surface 18 moves to open the hole 17. As shown in Figure 3S, the tool 2 can be lowered by the movement of the lifting platform, and the printed workpiece W can be returned to the carrier.

[0034] The above embodiments are merely exemplary, and other possibilities and substitutions within the scope of this invention will be apparent to those skilled in the art. For example, although the vertical reference precedes the horizontal reference as described above, this is not absolutely necessary if the tower is equipped with means to lock the support surface in the reference horizontal position.

Claims

1. A tool for supporting multiple cut single-piece workpieces during a printing operation, the tool comprising multiple towers, wherein, Each tower extends along an axis and is configured to support a corresponding workpiece among the plurality of workpieces in a horizontal orientation, each tower comprising: main body; A head having a support surface disposed at the distal end of the head and configured to support the corresponding workpiece thereon, the support surface being displaceable relative to the body in a plane perpendicular to the axis; and The main body includes a pneumatic input to receive pressurized air and to provide a lifting force to the head to move it relative to the main body along the axis; and Each tower includes a locking mechanism for selectively locking the head relative to the body.

2. The tool according to claim 1, wherein, The head includes an elongated rod extending along the axis, and the body includes a sleeve having a central hole sized to slidably receive the rod therein along the axis.

3. The tool according to claim 2, wherein, The locking mechanism includes an air bearing disposed adjacent to the rod in the hole, such that when an air source is supplied to the air bearing, the rod can slide relative to the air bearing parallel to the axis, and when the air source is not supplied to the air bearing, the rod is locked relative to the air bearing.

4. A printer for printing printing media onto a plurality of cut single workpieces during a printing operation, comprising the tool according to claim 1.

5. The printer of claim 4, comprising a reference plate having a plurality of reference surfaces movable in a horizontal plane, each reference surface being arranged to movably contact one of the plurality of cut-out workpieces to align the cut-out workpiece in the horizontal plane during a horizontal reference operation.

6. The printer according to claim 5, wherein, The reference plate has a lower side that can contact the cut workpiece during vertical reference operation.

7. The printer according to claim 6, wherein, The reference surface is movable in the horizontal plane between an open configuration and a closed configuration, in which the cut workpiece supported by the corresponding support surface can enter a corresponding hole provided in the reference plate, and in the closed configuration, the hole is at least partially closed by the reference surface.

8. The printer according to claim 7, wherein, The lower side of the reference plate may contact the cut workpiece during the vertical reference operation only when the reference surface is in the closed configuration.

9. A method for referencing a plurality of cut-up workpieces within a printer prior to performing a printing operation, the printer comprising a tool for supporting a plurality of cut-up workpieces during a printing operation as claimed in claim 1 and a reference plate having a plurality of reference surfaces movable in a horizontal plane, the method comprising the steps of: i) Support the workpiece on the tool in a horizontal orientation; as well as ii) Perform vertical and horizontal reference operations in any order; The vertical reference operation includes lifting the supported workpiece to contact the lower side of the reference plate, and then locking the tool to hold the supported workpiece at a locked vertical distance from the base of the tool. as well as The horizontal reference operation includes lifting the supported workpiece into a corresponding hole provided in the reference plate, and moving the reference surface in the horizontal plane to contact the corresponding supported workpiece.

10. The method according to claim 9, wherein, The reference surface is movable in the horizontal plane between an open configuration and a closed configuration, in which the supported workpiece can enter the corresponding hole, and in the closed configuration, the hole is at least partially closed by the reference surface.

11. The method according to claim 10, wherein, The vertical reference operation includes moving the reference surface to the closed configuration before raising the supported workpiece to contact the lower side of the reference plate.

12. The method according to claim 10, wherein, The horizontal reference operation includes moving the reference surface to the open configuration before lifting the supported workpiece into the corresponding hole.

13. The method according to claim 9, wherein, The vertical reference operation includes sequentially lifting the supported workpiece to contact the lower side of the reference plate.

14. The method of claim 9, further comprising the step of lowering the tool after the vertical reference operation to move the supported workpiece away from the reference plate.

Images