Solder paste dispensing transfer system and method for stencil printer

Abstract

A solder paste dispensing and transfer system for a stencil printer is configured to print assembly material on an electronic substrate. The transfer system includes a solder paste cassette mechanism coupled to a printhead assembly of the stencil printer, and a rotary indexing mechanism coupled to a frame of the stencil printer. The solder paste dispensing and transfer system is configured to transfer used solder paste cassettes from the printhead assembly to the rotary indexing mechanism supported by the frame, and to transfer new solder paste cassettes from the rotary indexing mechanism to the printhead assembly.

Description

[0001] This application is a divisional application of the invention patent application filed on June 12, 2020, with international application number PCT / US2020 / 037362, national application number 202080056627.2, and entitled "Solder Paste Dispensing and Transfer System and Method for Stencil Printing Machine".

[0002] Cross-reference to related applications

[0003] This application claims the benefit of co-pending U.S. Provisional Patent Application No. 62 / 931,496, filed November 6, 2019, entitled "MULTI-FUNCTIONAL PRINT HEAD FOR ASTENCIL PRINTER," and U.S. Provisional Patent Application No. 62 / 861,025, filed June 13, 2019, entitled "METHOD AND SYSTEM FOR AUTOMATED CHANGEOVER AND REPLACEMENT WITHIN ASTENCIL PRINTER," which are incorporated herein by reference in their entirety for all purposes. Background of the Invention 1. Technical Field

[0005] This application generally relates to stencil printing machines and related methods for printing adhesive materials (e.g., solder paste) on electronic substrates (e.g., printed circuit boards (PCBs)), and more specifically, to systems and methods for fully automating such stencil printing machines and methods. 2. Background Technology

[0007] When manufacturing surface mount printed circuit boards (PCBs), a stencil printer is used to print solder paste onto the PCB. Typically, a PCB with solder paste deposited on it, featuring a pad pattern or other conductive surface, is automatically fed into the stencil printer; and one or more holes or marks (called "reference points") on the PCB are used to properly align the PCB with the stencil printer's template or screen before the solder paste is printed onto it. In some systems, an optical alignment system implemented as a vision system is used to align the PCB with the template.

[0008] Once the circuit board is correctly aligned with the stencil in the printing press, the board is raised onto the stencil, solder paste is dispensed onto the stencil, and a squeegee blade (or scraper) traverses the stencil to force the solder paste through the orifices in the stencil onto the circuit board. As the scraper moves across the stencil, the solder paste tends to roll in front of the blade, which as needed mixes and trims the solder paste to achieve the desired viscosity to facilitate filling the orifices in the screen or stencil. The solder paste is typically dispensed from a standard cassette onto the stencil. The stencil is then separated from the circuit board, and the adhesion between the board and the solder paste leaves most of the material on the board. The material remaining on the stencil's surface is removed during a cleaning process before printing another circuit board.

[0009] Another process in circuit board printing involves inspecting the board after solder paste has been deposited on its surface. Inspecting the board is crucial to determining if clean electrical connections can be manufactured. Too much solder paste can cause short circuits, while too little in the appropriate locations can prevent electrical contact. Typically, a visual inspection system is further employed to provide two-dimensional or three-dimensional inspection of the solder paste on the board.

[0010] Modern stencil printers require manual intervention to perform routine operations. For example, during changeovers, operators must perform numerous manual tasks, such as changing stencils, replacing solder paste cartridges, changing squeegee blades, and replacing support tools. Each of these tasks requires manual operation. For instance, in most stencil printers, the operator must unlock the stencil, remove it, correctly insert the replacement stencil, and lock it in place. Changeover operations can take up to 30 minutes, during which time the stencil printer is not in operation, potentially causing PCB production line downtime.

[0011] Stencil printing presses also require manual intervention to perform replacement and / or replenishment operations. For example, solder paste cartridges that supply temperature-controlled solder paste to the stencil printing press need to be replaced over time (e.g., within four hours or less). Items subjected to normal wear and tear, such as squeegee blades and stencils, may need to be replaced periodically when damaged. Summary of the Invention

[0012] One aspect of this disclosure relates to a stencil printing machine for printing assembly material on an electronic substrate. In one embodiment, the stencil printing machine includes: a frame; a stencil coupled to the frame, the stencil having orifices formed therein; and a support assembly coupled to the frame, the support assembly including a tool configured to support the electronic substrate at a printing position below the stencil. The stencil printing machine further includes a printhead assembly coupled to the frame in such a way that the printhead assembly is configured to traverse the stencil during a printing stroke. The printhead assembly includes a doctor blade assembly and at least one solder paste cassette for depositing assembly material onto the stencil. The stencil printing machine further includes a solder paste dispensing and transfer system including a solder paste cassette mechanism coupled to the printhead assembly and a rotary indexing mechanism coupled to the frame. The solder paste dispensing and transfer system is configured to transfer used solder paste cassettes from the printhead assembly to the rotary indexing mechanism supported by the frame, and to transfer new solder paste cassettes from the rotary indexing mechanism to the printhead assembly.

[0013] Embodiments of the stencil printing machine may further include a rotary indexing mechanism configured to have: a rotary bearing configured to rotate, and a solder paste cartridge holder mounted on the top surface of the rotary bearing. The holder may include a half-wall configured to provide lateral support to the solder paste cartridge to maintain it in an upright position. The rotary indexing mechanism may further include a plurality of partitions provided to separate the solder paste cartridges supported by the rotary indexing mechanism from each other. The rotary indexing mechanism may be configured to rotate to present an open opening defined between two adjacent partitions to receive a used solder paste cartridge. The rotary indexing mechanism may be configured to rotate to present a new solder paste cartridge for transfer to the printhead assembly. The rotary indexing mechanism may further include a mounting bracket configured to secure the rotary indexing mechanism to a support member of the frame. The rotary indexing mechanism may further include a motor and bearing housing, and a shaft. The motor and bearing housing are fixed to the bottom of a mounting bracket to secure the motor and gearbox assembly. The shaft is connected to the motor bearing housing and a rotary bearing to drive the rotation of the rotary bearing. The solder paste cartridge mechanism may include a support bracket and an actuator. The support bracket is mounted on a support member of the printhead assembly, and the actuator is fixed to the support bracket to move the support bracket along the z-axis. The support bracket may include an end actuation device having a base with a receiving feature designed to receive the bottom portion of the nozzle of the solder paste cartridge. The end actuation device is configured to selectively engage and secure the nozzle of the solder paste cartridge and maintain the solder paste cartridge in a vertical, upright position. The support bracket may be fixed to the support member of the printhead assembly via at least one linear bearing so that the support bracket, actuator, and end actuation device are movable along the x-axis and driven by a timing belt. The actuator can be configured to move the solder paste cartridge upwards such that the open end of the solder paste cartridge is sealed by the cartridge sealing feature of the printhead assembly. The end actuation device may include a receiving feature having two spaced-apart protrusions sized to surround a narrow cylindrical portion of the nozzle of the solder paste cartridge so that the end actuation device can support the solder paste cartridge in a vertical, upright position.

[0014] Another aspect of this disclosure relates to a method for fully automating a replacement and / or changeover process within a stencil printing press. In one embodiment, the method includes: identifying a used solder paste cartridge within the stencil printing press that is scheduled for replacement; transferring the used solder paste cartridge from a printhead assembly with a solder paste cartridge mechanism to a rotary indexing mechanism; transferring a new solder paste cartridge from the rotary indexing mechanism to the solder paste cartridge mechanism; and installing the new solder paste cartridge within the printhead assembly.

[0015] Embodiments of the method may further include: transferring a used solder paste cartridge by presenting the open opening of a rotary indexing mechanism and moving the used solder paste cartridge to the open opening. Transferring a new solder paste cartridge may include: presenting the new solder paste cartridge to a solder paste cartridge mechanism and moving the new solder paste cartridge to the solder paste cartridge mechanism. Installing a new solder paste cartridge may include: moving the new solder paste cartridge along the z-axis to seal the open end of the solder paste cartridge.

[0016] Another aspect of this disclosure relates to a solder paste dispensing and transfer system for a stencil printer configured to print assembly material on an electronic substrate. In one embodiment, the transfer system includes a solder paste cassette mechanism coupled to a printhead assembly of the stencil printer, and a rotary indexing mechanism coupled to a frame of the stencil printer. The solder paste dispensing and transfer system is configured to transfer used solder paste cassettes from the printhead assembly to the rotary indexing mechanism supported by the frame, and to transfer new solder paste cassettes from the rotary indexing mechanism to the printhead assembly.

[0017] Embodiments of the transfer assembly may further include a rotary indexing mechanism configured to have: a rotary bearing configured to rotate, and a solder paste cartridge holder mounted on the top surface of the rotary bearing. The holder may include a half-wall configured to provide lateral support to the solder paste cartridge to maintain it in an upright position. The rotary indexing mechanism may further include a plurality of partitions provided to separate the solder paste cartridges supported by the rotary indexing mechanism from each other. The rotary indexing mechanism may be configured to rotate to present an open cavity defined between two adjacent partitions to receive a used solder paste cartridge. The rotary indexing mechanism may be configured to rotate to present a new solder paste cartridge for transfer to the printhead assembly. The rotary indexing mechanism may further include a mounting bracket configured to secure the rotary indexing mechanism to a support member of the frame. The rotary indexing mechanism may further include a motor and bearing housing, and a shaft. The motor and bearing housing are fixed to the bottom of a mounting bracket to secure the motor and gearbox assembly. The shaft is connected to the motor bearing housing and a rotary bearing to drive the rotation of the rotary bearing. The solder paste cartridge mechanism may include a support bracket and an actuator. The support bracket is mounted on a support member of the printhead assembly, and the actuator is fixed to the support bracket to move the support bracket along the z-axis. The support bracket may include an end actuation device having a base with a receiving feature designed to receive the bottom portion of the nozzle of the solder paste cartridge. The end actuation device is configured to selectively engage and secure the nozzle of the solder paste cartridge and maintain the solder paste cartridge in a vertical, upright position. The support bracket may be fixed to the support member of the printhead assembly via at least one linear bearing so that the support bracket, actuator, and end actuation device are movable along the x-axis and driven by a timing belt. The actuator can be configured to move the solder paste cartridge upwards such that the open end of the solder paste cartridge is sealed by the cartridge sealing feature of the printhead assembly. The end actuation device may include a receiving feature having two spaced-apart protrusions sized to surround a narrow cylindrical portion of the nozzle of the solder paste cartridge so that the end actuation device can support the solder paste cartridge in a vertical, upright position. Attached Figure Description

[0018] The accompanying drawings are not intended to be drawn to scale. In the drawings, every identical or nearly identical component shown in each drawing is indicated by the same reference numerals. For clarity, not every component may be labeled in each drawing. In the drawings:

[0019] Figure 1 This is a front view of a template printing press;

[0020] Figure 2 This is a front-view perspective view of a template printing machine;

[0021] Figure 3 yes Figure 2 The image shows a top view of a stencil printing press, with some parts removed.

[0022] Figure 4 This is a perspective view of a movable trolley according to an embodiment of the present disclosure, wherein the outer shell is removed to expose the internal structure of the movable trolley;

[0023] Figure 5A This is a perspective view of a tool tray according to an embodiment of the present disclosure;

[0024] Figure 5B It is a three-dimensional view of the tool tray supporting the tools and scraper blade assembly;

[0025] Figure 6 This is a perspective view of a tool tray according to another embodiment of the present disclosure;

[0026] Figure 7A and Figure 7B Cross-sectional views of a portion of the end actuation device of the printhead assembly and a portion of the doctor blade holder of the doctor blade assembly in the disengaged and engaged positions, respectively.

[0027] Figure 7C This is a cross-sectional view of the end control device and scraper blade holder in the engaged position;

[0028] Figure 8A and Figure 8B It is a cross-sectional view of a release mechanism configured to release the end actuation device from the scraper blade holder;

[0029] Figure 9A and Figure 9B It is a perspective view of a container configured to support the solder paste cartridge in both the retracted and extended positions.

[0030] Figure 10 It is a 3D view of the solder paste box;

[0031] Figures 11A to 11C It shows the process diagram of installing the solder paste box onto the printhead assembly;

[0032] Figure 12 It is a three-dimensional view of the solder paste box set in the solder paste box mechanism;

[0033] Figures 13A to 13C It is a perspective view of a printhead assembly configured to remove tools from the tool tray;

[0034] Figure 14 This is a perspective view of a solder paste dispensing and transfer system according to an embodiment of the present disclosure;

[0035] Figure 15AThis is an enlarged 3D view of the rotary indexing mechanism of the solder paste dispensing and transfer system;

[0036] Figure 15B This is an enlarged perspective view of the rotary indexing mechanism of the solder paste dispensing and transfer system, showing the details of the rotary indexing mechanism;

[0037] Figure 16A This is an enlarged perspective view of the end control device of the solder paste dispensing and transfer system, which has a solder paste box mechanism.

[0038] Figure 16B This is another enlarged perspective view of the end control device with a solder paste box mechanism;

[0039] Figure 17A and Figure 17B This is a perspective view showing the interaction between the rotary indexing mechanism of the solder paste dispensing and transfer system and the end actuation device with a solder paste cassette mechanism; and

[0040] Figure 18 This is an enlarged perspective view of the end control device with a solder paste box mechanism. Detailed Implementation

[0041] This disclosure generally relates to material application machines (referred to herein as “stencil printers,” “screen printers,” “printing machines,” or “printers”) and other equipment used in surface mount technology (SMT) production lines and configured to apply assembly materials (e.g., solder paste, conductive ink, or encapsulation materials) onto a substrate (e.g., a printed circuit board, referred herein as an “electronic substrate,” “circuit board,” “board,” “PCB,” “PCB substrate,” “substrate,” or “PCB board”) or to perform other operations such as inspection, rework, or arranging electronic components on the substrate. Specifically, embodiments of this disclosure are described below with reference to stencil printers used to produce printed circuit boards.

[0042] This disclosure will now be described in detail with reference to the accompanying drawings for illustrative purposes only and not for limiting its generality. This disclosure is not intended to limit its application to the details of the construction and arrangement of the components set forth in the following description or shown in the accompanying drawings. The principles set forth in this disclosure can be used in other embodiments and can be practiced or performed in various ways. Similarly, the wording and terminology used herein are for descriptive purposes and should not be considered limiting. Any reference to examples, embodiments, components, elements, or actions of systems and methods mentioned herein in the singular may also cover embodiments including the plural, and any reference to any embodiment, component, element, or action mentioned herein in the plural may also cover embodiments including only the singular. References in the singular or plural form are not intended to limit the systems or methods currently disclosed, their components, actions, or elements. The use of “comprising,” “including,” “having,” “containing,” “involving,” and variations thereof herein is intended to cover the items listed thereafter and their equivalents, as well as other items. References to “or” can be interpreted as inclusive, and thus any item described using “or” may indicate a single item, multiple items, or any of all items described. Furthermore, in the event of any inconsistency between the terminology used in this document and the documents incorporated herein by reference, the terminology used in the incorporated reference shall supplement the terminology used in this document; in the case of any inconsistency that cannot be reconciled, the terminology used in this document shall prevail.

[0043] For illustrative purposes, embodiments of this disclosure will now be described with reference to a stencil printer for printing assembly materials (such as solder paste) onto a circuit board. However, those skilled in the art will understand that embodiments of this disclosure are not limited to stencil printers for printing solder paste onto circuit boards, but can be used for other applications requiring the dispensing of other viscous assembly materials such as adhesives and sealants. For example, the apparatus can be used to print epoxy resin used as an underfill for chip-scale packages. Furthermore, the stencil printers according to embodiments of this disclosure are not limited to those printers for printing assembly materials on circuit boards, but include those printers for printing other materials on various substrates such as semiconductor wafers. Additionally, the terms screen and stencil are used interchangeably herein to describe means in a printer for defining a pattern to be printed onto a substrate. In some embodiments, the stencil printer may include one supplied by ITW Electronic Assembly Equipment, Hopkinton, Massachusetts. Or Edison TM Series of template printing machine platforms. Exemplary template printing machines are generally used... Figure 1 Reference numeral 5 indicates the type of printing press 5. In this embodiment, the stencil printer 5 is supplied by ITW Electronic Assembly Equipment, Inc., Hopkinton, Massachusetts. Series of template printing machine platforms.

[0044] refer to Figure 2 The stencil printer of the present disclosure is generally indicated by reference numeral 10. As shown, the stencil printer 10 includes a frame 12 that supports the components of the stencil printer. The components of the stencil printer may partially include a controller 14, a display 16, a stencil 18, and a printhead or printhead assembly, generally indicated by reference numeral 20, which is configured to apply solder paste in a manner described in more detail below.

[0045] like Figure 2 As shown and described below, the template and printhead assembly can be suitably coupled or otherwise connected to the frame 12. In one embodiment, the printhead assembly 20 can be mounted on a printhead assembly gantry 22, which is mounted on the frame 12. The printhead assembly gantry 22 enables the printhead assembly 20 to move along the y-axis under the control of the controller 14 and to apply pressure to the printhead assembly when it engages the template 18. In one embodiment, the printhead assembly 20 can be positioned above the template 18 and can be lowered in the z-axis direction to contact and seal the template.

[0046] The stencil printing press 10 may also include a conveyor system with tracks (not shown) for transporting printed circuit boards (sometimes referred to herein as “printed wiring boards,” “substrates,” or “electronic substrates”) to printing positions within the stencil printing press. The tracks, sometimes referred to herein as “traction feed mechanisms,” are configured to feed, load, or otherwise deliver the circuit boards to the working area of ​​the stencil printing press (which may be referred to herein as “printing nests”) and unload the circuit boards from the printing nests.

[0047] For further reference Figure 3 The stencil printing machine 10 has a support assembly 28 for supporting a circuit board 29 (shown in dashed lines). This support assembly raises and secures the circuit board, ensuring its stability during printing operations. In some embodiments, the substrate support assembly 28 may also include a specific substrate support system, such as a robust support member, multiple pins, or flexible tools, positioned below the circuit board when it is in the printing position. The substrate support system may be used in part to support internal areas of the circuit board to prevent it from flexing or warping during printing operations.

[0048] In one embodiment, the printhead assembly 20 may be configured to receive solder paste from a source (such as a dispenser, e.g., a solder paste cassette) that supplies solder paste to the printhead assembly during the printing operation. Instead of a solder paste cassette, other methods of supplying solder paste may be employed. For example, solder paste may be manually deposited between the blades or deposited from an external source. Additionally, in one embodiment, the controller 14 may be configured to use a system with an operating system suitable for Microsoft (such as Microsoft Corporation's Microsoft...). A personal computer with an operating system, having software specifically designed for applications to control the operation of the stencil printing machine 10. The controller 14 can be networked with a main controller used to control the production line for manufacturing circuit boards.

[0049] In one configuration, the stencil printer 10 operates as follows: A circuit board 29 is loaded into the stencil printer 10 using a conveyor track. A support assembly 28 raises and secures the circuit board 29 in the printing position. The print head assembly 20 is then lowered in the z-axis direction until the blades of the print head assembly contact the stencil 18 with the desired pressure. The print head assembly 20 is then moved through the stencil 18 in the y-axis direction via the print head assembly gantry 22. The print head assembly 20 deposits solder paste onto the circuit board 29 through orifices in the stencil 18. Once the print head assembly has completely traversed the stencil 18 across these orifices, the print head assembly is raised off the stencil and the circuit board 29 is lowered back onto the conveyor track. The circuit board 29 is released from the stencil printer 10 and transported so that a second circuit board can be loaded into the stencil printer. For printing on the second circuit board 29, the print head assembly is lowered in the z-axis direction to contact the stencil and moved through the stencil 18 in the opposite direction to that used for the first circuit board.

[0050] An imaging system 30 may be provided for aligning the stencil 18 with the circuit board 29 before printing and for inspecting the circuit board after printing. In one embodiment, the imaging system 30 may be positioned between the stencil 18 and a support assembly 28 on which the circuit board is supported. The imaging system 30 is coupled to an imaging gantry 32 to move the imaging system. In one embodiment, the imaging gantry 32 may be coupled to a frame 12 and include a beam extending between side rails of the frame 12 to provide reciprocating movement of the imaging system 30 on the circuit board 29 along the y-axis. The imaging gantry 32 may also include a carriage arrangement that accommodates the imaging system 30 and is configured to move along the length of the beam in the x-axis direction. The construction of the imaging gantry 32 for moving the imaging system 30 is well known in the solder paste printing industry. This arrangement allows the imaging system 30 to be positioned anywhere below the stencil 18 and above the circuit board 29 to capture images of predefined areas of the circuit board or the stencil, respectively.

[0051] After one or more applications of solder paste to the circuit board, excess solder paste may accumulate at the bottom of stencil 18, and the stencil wiper assembly (generally indicated by reference numeral 34) may move below the stencil to remove the excess solder paste. In other embodiments, stencil 18 may move above the stencil wiper assembly.

[0052] As mentioned earlier, stencil printing machines require manual intervention to perform certain parts replacement and / or replenishment operations. For example, a typical stencil needs to be replaced after a certain period of time (e.g., four hours). Furthermore, the stencil needs to be replaced for different production cycles. Additionally, the solder paste cassette that supplies temperature-controlled solder paste to the stencil printing machine needs to be replaced over time (e.g., within four hours or less). Different production cycles may require different solder paste materials. Another item that needs periodic replacement is the doctor blade, which wears down during use. And finally, the tools used to support the substrate in the printing position need to be replaced when changing from one production product to another.

[0053] A system and method for replacing tools used to support a substrate in a printing position includes: either for a new production round or because a defect in an existing tool is detected, retrieving a new tool from a tool warehouse and conveying it to one of several stencil printing machines. On the production line, the used tool is removed from the stencil printing machine, and a new tool is inserted into the stencil printing machine and secured for use. The used tool is conveyed to a station where it is inspected and, if usable, cleaned for reuse. If defective, the tool is scrapped responsibly. Once cleaned, the tool is conveyed back to the tool warehouse, where it is ready for use during the same or different production rounds.

[0054] Systems and methods for replacing a doctor blade or a pair of doctor blades include: either for a new production round or because a defect in an existing doctor blade assembly is detected, retrieving a new doctor blade assembly from a doctor blade assembly warehouse and conveying the new doctor blade to one of several stencil printing machines. On the production line, used doctor blades are removed from the stencil printing machines, and new doctor blades are inserted into the stencil printing machines and secured for use. Used doctor blades are conveyed to a station where they are inspected and, if usable, cleaned for reuse. Defective doctor blades are discarded responsibly. Once cleaned, the doctor blades are conveyed back to the doctor blade warehouse, where they are ready for use during the same or different production rounds.

[0055] Systems and methods for replacing solder paste cartridges include: either for a new production cycle or because existing solder paste cartridges are depleted, retrieving new solder paste cartridges from a solder paste cartridge warehouse and conveying them to one of several stencil printing machines. The stencil printing machines may be part of a single production line for manufacturing printed circuit boards or part of several production lines. The number of stencil printing machines may vary. Storage of solder paste cartridges in the warehouse and conveying of the cartridges should be carried out in a temperature- and / or climate-controlled environment suitable for preserving the solder paste contained within the cartridges. On the production line, “depleted” or used solder paste cartridges are removed from the stencil printing machine, and “full” or new solder paste cartridges are inserted into the stencil printing machine and secured for use. Depleted solder paste cartridges are conveyed to a station where they are preserved (because they were not fully used) or for recycling. Once preserved or recycled, the solder paste cartridges are conveyed back to the solder paste cartridge warehouse, where they are ready for reuse during the same or different production cycles.

[0056] Embodiments of this disclosure relate to a delivery system configured to automate the replacement process of a stencil printer and implement one or more of the systems and methods described herein. In one embodiment, the delivery system includes a mobile trolley configured to engage the stencil printer to supply and receive replacement and replenishment parts and materials. For example, the stencil printer may include a docking station configured to receive the mobile trolley. The docking station may include an interface enabling the mobile trolley to communicate with the stencil printer. The single-item mobile trolley may be configured to include a replacement support tool, a replacement doctor blade, a replenishment doctor blade, a replacement solder paste cassette, and a replenishment solder paste cassette. During replacement, for example, the stencil printer must be reconfigured to produce different articles. Therefore, new support tools adapted to different substrates, new blades of different lengths, and different types of solder paste can be employed within the stencil printer to produce different products.

[0057] The replacement process described herein can be implemented using a single-item mobile cart configured to replace and / or replenish each item. In other embodiments, more than one mobile cart may be provided.

[0058] The movable trolley or another movable trolley is configured to support a predetermined number of tools used to support printed circuit boards in the printing position. These tools are selected for a specific production cycle expected on a particular day or during a specific time period. The movable trolley and / or stencil printer can be configured to identify support tools, store support tools, transport support tools to and from the stencil printer, inspect support tools, and interface with the stencil printer. The movable trolley can also be configured to remove used parts, such as support tools, from the stencil printer.

[0059] The movable trolley or another movable trolley is configured to support a predetermined number of doctor blades, selected for a specific production cycle on a particular day or during a specific time period. The movable trolley and / or stencil printing machine can be configured to identify doctor blades, store doctor blades, transport doctor blades to and from the stencil printing machine, inspect doctor blades, and interface with the stencil printing machine. The movable trolley can also be configured to remove used parts, such as doctor blades, from the stencil printing machine.

[0060] The movable trolley or another movable trolley is configured to support a predetermined number of solder paste cartridges selected for a specific production cycle on a particular day or during a specific time period. The movable trolley and / or stencil printer can be configured to identify solder paste cartridges, store them in a suitable environment, transport them to and from the stencil printer, inspect them, and interface with the stencil printer. The movable trolley can also be configured to remove used parts, such as solder paste cartridges, from the stencil printer. Additionally, the movable trolley can be configured for long-term storage of solder paste cartridges. In one embodiment, long-term storage of solder paste can be achieved by refrigeration at 0 to 10°C (32°F to 50°F). The solder paste cartridges can be stored in a location within the movable trolley to maintain this temperature range. In another embodiment, the movable trolley can be configured to preheat the solder paste cartridges before use to prepare them for use in the stencil printer.

[0061] refer to Figure 4 In one embodiment, the movable trolley, generally indicated by reference numeral 40, includes a frame or housing 42 configured to support items for replacement and / or replenishment. As shown, the frame 42 is generally rectangular and supported on wheels or casters (not shown). In one embodiment, the movable trolley 40 is configured to be manually moved by an operator by pushing the frame 42 of the trolley. In this embodiment, the movable trolley 40 may be configured with a push rod or handle. In another embodiment, the movable trolley 40 is configured to be moved automatically, either by remote control or by an automation control device associated with the movable trolley, the stencil printing machine 10, the production line, and / or some other dedicated control device. In this embodiment, the movable trolley 40 may include wheels driven by a suitable motor and drivetrain, and the control device associated with the movable trolley, the stencil printing machine 10, the production line, and / or some other dedicated control device is configured to control the movable trolley. The mobile cart 40 may also include one or more sensors and / or vision systems, such as cameras, to guide the mobile cart from, for example, a warehouse to a template printing machine.

[0062] The movable cart 40 includes a translatable bracket (generally indicated by reference numeral 44) that can be configured to support one or more items, such as replacement user templates, replacement support tools, replacement and / or replenishment scraper blades, and replacement and / or replenishment solder paste boxes. The translatable bracket 44 includes a rectangular structure 46 having a top 48, a bottom 50, opposite sides 52, 54, an open front, and an open rear. The sides 52, 54 of structure 46 may include slots, each indicated by reference numeral 56, each slot configured to receive and support the opposite two edges of a flat item (such as template 18, and in the illustrated embodiment, a tool tray (generally indicated by reference numeral 60)). Structure 46 can be configured to receive a number of items, such as ten or more items. The spacing between the slots 56 can be determined to receive a standard template frame therein.

[0063] The movable bracket 44 further includes four vertically oriented rods, each indicated by reference numeral 62, positioned at the four corners of the structure 46. As shown, the top of the structure 46 includes two rod members 64, 66, one rod member 64 fixed to the top 48 of the structure near the open front portion, and the other rod member 66 fixed to the top near the open rear portion. Similarly, the bottom of the structure 46 includes two rod members 64a, 66a, one rod member 64a fixed to the bottom 50 of the structure near the open front portion, and the other rod member 66a fixed to the bottom near the open rear portion. Each rod member 64, 64a and 66, 66a includes two openings formed at opposite ends of the rod, positioned to receive the corresponding rod. This arrangement allows the structure 46 to move vertically relative to the rods 62 to raise and lower the structure. Suitable mechanisms can be provided to raise and lower the structure 46 under the control of a controller. For example, a ball screw drive assembly may be provided to move structure 46 to position the "shelf" defined by slit 56 adjacent to the stencil printing machine 10. These "shelves" may be specifically designed to support tool trays 60, which may be configured to support items, including but not limited to new and used support tools, new and used scraper blades, and new and depleted / used solder paste boxes. Some shelves may include tool trays 60, which are designated as "clean shelves" to support clean or new items ready for use within the stencil printing machine 10. Some shelves may include tool trays 60, which are designated as "dirty shelves" to support used items to be removed from the stencil printing machine 10. As mentioned earlier, the spacing between slits 56 may be spaced apart by a specific distance to receive various items. For example, these shelves may be spaced 3 / 8 inch to 1 inch apart. 1 / 2 inches to accommodate the thickness of the template frame and tool tray.

[0064] The movable trolley 40 may be configured with one or more means for conveying items from the movable trolley to the stencil printing machine 10 and from the stencil printing machine to the movable trolley. For example, the means may include a conveyor arm 68 configured to push the stencil 18 and the tool tray 60 onto and remove them from the movable trolley 40, respectively. Figure 4 As shown, the conveyor arm 68 is pushing the tool tray 60 away from the movable trolley 40, where the tool tray is positioned to be received by the stencil printing machine. Any suitable mechanism can be provided to move the conveyor arm, such as a ball screw drive assembly.

[0065] See Figure 5A and Figure 5B The tool tray 60 includes a rectangular or square frame 70 and a flat body 72. The size of the frame 70 can be determined to be similar to the size of the frame of the template 18. In one embodiment, the tool tray 60 can be made of a lightweight but strong material, such as aluminum alloy. Figure 5A As shown, the body 72 of the tool tray 60 may include several cuts (each cut indicated by reference numeral 74) and several recesses (each recess indicated by reference numeral 76) to receive and support tools and scraper blade assemblies, respectively. Figure 5B As shown, these cutouts 74 are configured to receive and secure support tools (each support tool is indicated by reference numeral 78) provided for supporting the electronic substrate 29 during stencil printing operations. Recesses 76 are configured to receive and secure squeegee blade assemblies (each squeegee blade assembly is indicated by reference numeral 80) used by the printhead assembly 20 for stencil printing operations.

[0066] As described above, the tool tray 60 is substantially the same as the template in terms of form factor to allow for handling and storage / retrieval of the tool tray in substantially the same manner as the template. The movable trolley 40 and the tool tray 60 are particularly well-suited for handling the template and tool tray in a universal manner. The movable trolley 40 is configured to partially deliver the tool tray 60 from the movable trolley to the template printing machine 10, and the template printing machine is configured to subsequently receive the tool tray. For example, a conveyor arm 68 can be used to push the tool tray 60 away from the carrier 44 and to remove the work tray from the carrier.

[0067] In some embodiments, the tool tray 60 may include reference points that can be viewed by the imaging system 30 of the stencil printing press 10 to establish alignment with parts and positions on the tool tray. Alignment methods with the tool tray 60 can be employed by capturing and analyzing the positions of these reference points.

[0068] See Figure 6 The printhead assembly 20 of the stencil printing machine 10 includes an end-effector 82 configured to pick up and release items from the tool tray 60. As previously described, the printhead assembly 20 is mounted on a printhead assembly gantry 22, which moves the printhead assembly along the y-axis under the control of the controller 14. The printhead assembly 22 is configured to move along the z-axis, as described above.

[0069] In one embodiment, the end actuation device 82 can be configured to pick up and release the doctor blade assembly 80. The end actuation device 82 is configured to engage and disengage with the doctor blade assembly 80 without the aid of tools to attach the doctor blade assembly to the printhead assembly 20 and to remove the doctor blade assembly from the printhead assembly. As shown, the tool tray 60 is configured with a spring-loaded locking mechanism to secure the doctor blade holder of the doctor blade assembly 80 to the end actuation device 82 of the printhead assembly 20. The passive picking up and dropping of the doctor blade assembly 80 can be performed via the end actuation device 82 without the need for additional shafts or actuators.

[0070] See Figures 7A to 7C The end-operated device 82 includes a rectangular body 84, which is secured to the printhead assembly 20 by a pair of connecting rods (each connecting rod is indicated by reference numeral 86). The end-operated device 82 further includes a pair of downwardly extending pins. Figure 7C (Each pin is indicated by reference numeral 88), wherein each pin has a notch 90, the purpose of which will be described when the mechanism is described. The scraper blade assembly 80 includes a retainer 92 in which an L-shaped recess 94 is formed. The recess 94 includes a vertical portion 94a and a horizontal portion 94b. The mechanism includes a spring-loaded pin 96 received within the horizontal portion 94b of the recess 94, the spring-loaded pin being biased toward the vertical portion 94a of the recess by a spring 98.

[0071] Figure 7A and Figure 7B The pin 88 of the end actuation device 82 is shown entering the vertical portion 94a of the recess 94. As the pin 88 enters the vertical portion 94a of the recess 94, the inclined portion of the pin engages the corresponding inclined portion of the spring-loaded pin 96. The downward movement of the pin 88 causes the spring-loaded pin 96 to move against the bias of the spring 98 until the notch 90 of the pin receives the engagement element 100 of the spring-loaded pin, thereby engaging and securing the retainer 92 of the scraper blade assembly 80 to the end actuation device 82. Figure 7C The image shows two pins 88 secured by their respective spring-loaded pins 96 to hold the doctor blade assembly 80 in place by a retainer 92. In this position, the end actuation device 82 secures the doctor blade assembly 80, which can be used to perform stencil printing operations.

[0072] Figure 8A and Figure 8B The pin 88 of the end actuation device 82 is shown retracting from the vertical portion 94a of the recess 94. An upwardly extending element 102 is provided on the tool tray 60 to retract the spring-loaded pin 96 from... Figure 7B and Figure 7C The indicated engagement position is moved to Figure 7A The disengagement position is shown. See also... Figure 8A The inclined portion of element 102 engages with a corresponding inclined portion formed on the spring-loaded pin 96. Downward movement of the end actuation device 82 toward element 102 causes the spring-loaded pin 96 to move against the bias of the spring 98 until the engaging element 100 of the spring-loaded pin is removed from the notch 90 of the pin 88, thereby releasing the scraper blade assembly 80 from the end actuation device 82. Figure 8B As shown. Component 102 holds the spring-loaded pin 96 in the disengaged position, thereby releasing the retainer 92 of the scraper blade assembly 80.

[0073] In some embodiments, the end actuation device 82 may employ a magnet to engage a magnetic material associated with the doctor blade assembly 80 to secure the doctor blade assembly to the printhead assembly 20 and to release the doctor blade assembly from the printhead assembly.

[0074] See back Figure 4 The movable trolley 40 includes replacement solder paste cartridges, each denoted by reference numeral 110. As shown, the solder paste cartridges 110 are supported on the solder paste cartridge storage area (or "on-deck-circle") of the movable trolley 40 to allow the stencil printing press 10 to continuously supply solder paste for uninterrupted operation. See also Figure 9A and Figure 9B The frame 12 of the stencil printing machine 10 includes blocks 114 with recesses configured to support solder paste cartridges 110 in an upright position when receiving solder paste cartridges from a movable trolley 40. Blocks 114 are attached to a movable support arm 116, which is coupled to the frame 12 of the stencil printing machine 10 and configured to move from a retracted position to an extended position. Each solder paste cartridge 110 is supported by a cylindrical half-wall 118 to provide lateral support, thereby assisting in maintaining the solder paste cartridge in an upright position. Figure 9A and Figure 9B The block 114 shown is configured to support two solder paste boxes 110, but the block can be configured to support any number of solder paste boxes.

[0075] Figure 9A The block 114 and movable support arm 116 are shown in the retracted position, when the stencil printer 10 stores the solder paste box 110. Figure 9B The block 114 and movable support arm 116 are shown in the extended position, in which solder paste container 110 can be transferred from movable trolley 40 to the block. Any suitable mechanism can be provided to move the movable support arm 116, such as a ball screw drive assembly.

[0076] In some embodiments, the solder paste box 110 can be manually mounted onto block 114 of the stencil printing machine 10 without the need for a movable trolley.

[0077] See Figure 10 Multiple solder paste boxes 110 can be set in the storage box 112 containing "N" solder paste boxes to allow operation of the stencil printer 10 (including solder paste replacement) even when the movable trolley 40 is not present. The number of solder paste boxes 110 provided by the storage box 112 can be determined by the logistical requirements of the stencil printer 10 and the specific application.

[0078] See Figures 11A to 11C The process of mounting the solder paste cartridge 110 onto the printhead assembly 20 is illustrated sequentially. The printhead assembly 20 includes a solder paste cartridge mechanism comprising a support bracket 120 configured to receive, place, seal, and press the solder paste cartridge 110 onto the printhead assembly 20. As shown, the support bracket 120 includes a base 122 having a receiving feature 124 designed to receive the bottom portion of the solder paste cartridge 110. In the example shown, the receiving feature 124 includes two spaced-apart protrusions sized to surround a narrow cylindrical portion of the solder paste cartridge 110. This narrow cylindrical portion is positioned between the two wider cylindrical portions to capture the protrusions therebetween. The printhead assembly 20 is configured to move the printhead assembly gantry 22 to the solder paste cartridge 110 to secure the solder paste cartridge to the support bracket 120 of the solder paste cartridge mechanism.

[0079] The support bracket 120 of the solder paste container mechanism further includes an upright member 126 configured to secure, seal, and press against the upper portion of the solder paste container 110. The upright member 126 includes a sealing portion 128 designed to seal the upper portion of the solder paste container 110. Once the solder paste container 110 is positioned in the receiving feature 124 of the base 122, the base is configured to... Figure 11B and Figure 11CThe solder paste cartridge 110 is moved upwards as shown to seal the pneumatic connection between the sealing portion 128 and the solder paste container 110. Once pressurized, the solder paste cartridge 110 is ready to perform a dispensing operation. Any suitable mechanism can be used to move the base 122 in the upward and downward directions to engage and disengage the solder paste cartridge 110 from the sealing portion 128, respectively. For example, a pneumatic assembly 130 can be provided to move the base 122. Another pneumatic cylinder 132 can be used to lower the entire cylinder assembly during the dispensing operation. In one embodiment, the pneumatic cylinder 132 moves the printhead assembly 20 up and down along the z-axis. After the solder paste cartridge 110 is raised to seal against the sealing portion 128, the solder paste cartridge can be pressurized when solder paste needs to be dispensed. The connection of this assembly is achieved through the upright member 126 and the sealing portion 128.

[0080] Figure 12 A solder paste container 110, secured and sealed by a solder paste container mechanism, is shown. Therefore, the solder paste container mechanism is capable of housing and sealing the solder paste container 110. The solder paste container mechanism can be configured to receive solder paste containers or solder paste jars of different sizes.

[0081] In some embodiments, each solder paste box 110 includes a one-dimensional barcode label that is wrapped around the solder paste box from beginning to end, thereby allowing the barcode to be read from any orientation relative to the tube.

[0082] See Figures 13A to 13C The support tool moving mechanism, generally indicated by reference numeral 140, is configured to move the support tool 78 from the tool tray 60 to the stencil printing press 10. As shown, the support tool moving mechanism 140 includes a plate 142 mounted on the printhead assembly 20. The plate 142 has four linear bearings, each linear axis indicated by reference numeral 144, wherein a first set of linear bearings is positioned one on one side of the plate above the other, while a second set of linear bearings is positioned one on the other on the other side of the plate. Each set of linear bearings 144 has a tool member 146 configured to move laterally on the linear bearing. Any suitable mechanism can be used to move the tool member 146. For example, a ball screw drive assembly can be provided to move the tool member 146 along the linear bearing. In one embodiment, the mechanism can be powered by a drive assembly that moves the printhead assembly 20 up and down along the z-axis. Each tool component 146 includes a downwardly extending pin 148 having a head configured to be received within a receiving feature 150 associated with a support tool 78.

[0083] Figure 13AThe tool components 146 are shown to have pins 148 received in corresponding mating features 150 of a support tool 78. These tool components 146 may extend to a width wider than the support tool 78 and move toward each other to capture the support tool 78 between the pins via the receiving features 150. A tool tray 60 may include recesses formed therein, positioned adjacent to the support tool 78 such that the pins 148 can be arranged laterally adjacent to the receiving features 150 of the support tool 78. Figure 13B The printhead assembly 20 is shown rising along the z-axis to pick up a support tool 78. Mechanisms for picking up and lowering the support tool 78 can be configured to engage and secure the support tool, and may include magnets to facilitate attachment and detachment of the support tool from the tool assembly. As shown, an opening (e.g., a cutout 74) is provided in the tool tray 60 to facilitate access to the support tool in the stencil printing press from the printhead assembly 20 when the tool tray is in the stencil printing press 10.

[0084] This arrangement allows the movable trolley 40 to be configured to support a predetermined number of support tools 78 for supporting the printed circuit board 29 in the printing position. The movable trolley 40 and the stencil printer 10 operate on each other to identify the support tools 78, store the support tools, transport the support tools to and from the stencil printer, inspect the support tools, and interface with the stencil printer. The movable trolley 40 and the stencil printer 10 also operate on each other to remove used parts, such as the support tools 78, from the stencil printer.

[0085] In some embodiments, multiple motion axes in the movable cart 40 can minimize the cost and complexity of the drive system. These drives can be located on the movable cart 40 or the stencil printing machine 10.

[0086] In some embodiments, the printhead assembly 20 is capable of picking up and placing the support tool 78. The same printhead assembly 20 is also capable of picking up and placing the scraper blade assembly 80.

[0087] In some embodiments, instead of the printhead assembly gantry 22, a mechanism for managing the support tool or plate 78, the scraper blade assembly 80, and the solder paste box 110 may be provided on other gantry (e.g., imaging system gantry 32 or stencil wiper assembly gantry).

[0088] The movable trolley 40 may be configured with an interface designed to dock within a docking station provided on the stencil printing machine 10. In one embodiment, the interface of the movable trolley is configured to dock within the docking station of the stencil printing machine 10 from both a mechanical interface and an electronic communication interface. In a particular embodiment, the movable trolley may be configured with a unique mechanical interface that mates with a unique mechanical interface of the stencil printing machine 10. The unique mechanical interface may include geometric features. In another embodiment, the movable trolley may be configured with a pin received within a guide associated with the stencil printing machine 10 to align the movable trolley with the stencil printing machine before full docking. The pin and guide may be reversed, with the pin disposed on the stencil printing machine 10 and the guide disposed in the movable trolley. Other types of guides may be used, such as electro / magnetic guides, visual guides, sensors, latches, etc. When docked within the docking station of the stencil printing machine 10, the movable trolley may physically engage with or be separated from the stencil printing machine.

[0089] In some embodiments, the movable trolley can be configured to clean the scraper blades by removing or otherwise removing used solder paste from the scraper blades.

[0090] In some embodiments, the movable trolley can be configured to replace used doctor blades by releasing the doctor blade from the printhead 20 and positioning the used doctor blade on an outwardly opening shelf of the movable trolley. A new doctor blade is then retrieved from the movable trolley and mounted on the printhead 20 of the stencil printing machine 10.

[0091] In some embodiments, the mobile cart includes a controller adapted to control the operation of the mobile cart based on operating parameters obtained by the controller. The controller may be configured to communicate with the controller 14 of the stencil printing machine 10 and / or with a controller associated with the production line. In one embodiment having multiple mobile carts, the controller may be implemented as multiple controllers disposed in each mobile cart, the multiple controllers communicating with each other via a controller area network (CAN) bus or other type of network. In other embodiments, a master controller may be provided to control the operation of the controller of the mobile cart 80. Each mobile cart may be provided with a display operatively coupled to the controller. The display is adapted to display operating parameters of the mobile cart, such as, but not limited to, the number of clean and used stencils, the number of full and empty / used solder paste boxes, the number of new and used scraper blades, and / or the number of new and used tools. A suitable monitor may be provided to obtain this information. Alternatively, or in addition to the foregoing embodiments, the operating parameters may be displayed on a display 16 disposed within the stencil printing machine 10 and / or on a display associated with the production line.

[0092] In other embodiments, the movable trolley may be controlled by the controller 14 of the stencil printing machine 10 and / or a controller associated with the production line. The controller may be a controller dedicated to one or more movable trolleys.

[0093] In some embodiments, material identification for items on a mobile cart may include means for manipulating the items and a scanner for scanning and identifying the items. For example, for solder paste cartridges, the mobile cart may be configured to include clamping wheels to rotate the solder paste cartridges to align a code or predetermined identification mark set on the solder paste cartridges with a scanner set on the mobile cart. The system is configured to associate the material identification associated with the solder paste cartridges with the formulation, production time, etc., for the stencil printer 10. In one embodiment, a barcode for identifying the items may be implemented. For example, the barcode may include a 1D scanner for UPC codes, a 2D scanner for QRC codes, a printed mark applied to the item, or a laser-etched mark etched onto the item. In another embodiment, an RFID system for identifying the items may be implemented. For example, the RFID system may include an RFID tag applied to the item and an RFID reader associated with the mobile cart 40 or the stencil printer 10. In the RFID system, a line-of-sight between the reader and the item is not required. Furthermore, scanning is not required to identify all items within the mobile cart. In another embodiment, an imaging or vision system for identifying items can be implemented. The vision system may be an imaging system similar to the imaging system 30 associated with the stencil printer 10, and may be connected to the stencil printer, outside the stencil printer, or connected to a movable trolley.

[0094] In some embodiments, a database is provided to track items stored on a mobile cart. In one embodiment, the database may include an open application (App) architecture and be configured to push data to the stencil printer 10. The mobile cart 40 may be configured to communicate with the stencil printer 10 to push / pull data to the stencil printer and / or the production line, or may be configured to communicate directly with the production line. The database may include job information or material information. The database may also communicate with a manufacturing execution system (MES) associated with the production line, the stencil printer 10, or both. The MES system may be configured to know which materials are needed for a given production cycle. The mobile cart may be configured to communicate with the MES system to adjust the delivery of items to the stencil printer 10.

[0095] The database can also be configured to retrieve information about items based on identifiers (e.g., barcode numbers). In one embodiment, a central management system may be provided, wherein the stencil printer 10 and / or the mobile cart 40 are programmed to accept materials from the mobile cart. The mobile cart 40 is programmed to update the database to identify the materials on the mobile cart, load information from the network into the database associated with the mobile cart and / or the stencil printer 10, and bind this information back to the MES system.

[0096] The database can also be configured to store additional information, such as usage and consumption. The database can be configured to store information locally or remotely, and can be configured to store data associated with one or more production cycles. For example, the database can be configured to acquire and store data including, but not limited to, traceability of templates, solder paste containers, scraper blades and tools, solder paste usage, cycles, etc.

[0097] The database can be configured to share predictive data when replacement / replenishment is required. For example, in terms of storing information related to solder paste cartridges, the database can be configured to perform one or more of the following: store information about when solder paste cartridges need replenishment; perform a function when solder paste cartridges are low; trigger alarms and / or reports for low solder paste cartridge levels; signal to the inventory control system associated with the stencil printer 10 and / or the production line; analyze consumable usage based on operating parameters and actual usage, as well as upstream / downstream equipment activity; predict (for the stencil printer and / or the mobile cart 80) replacement or maintenance; and correlate multiple points to predict when to replace solder paste cartridges. The database can also be configured to share predictive data for other modifiable / consumable items, such as stencils, solder paste cartridges, scraper blades, and tools.

[0098] The database can be configured to store data associated with batch traceability. Additionally, RFID or mechanical key connections to the template plate or template rack ensure correct alignment / orientation / direction / front / back / up / down position when these items are inserted into the template printing machine 10. This information can be used to verify correct alignment and / or assembly before items are transported from the warehouse and / or before they are installed in the template printing machine 10. Low-cost readers can perform this function.

[0099] In some embodiments, the mobile cart can be configured to store materials. The mobile cart can be configured to flexibly adapt to the location from which materials come and go. Additionally, the mobile cart can be configured to identify the location of specific materials on the mobile cart. In some embodiments, whether delivered automatically or manually, the location is a remote location, a local location, on the mobile cart, and / or on the stencil printing machine 10. As described above, the mobile cart can be configured to control environmental parameters. For example, the mobile cart can be configured to control the temperature of the solder paste contained in the solder paste boxes by cooling stored solder paste boxes, heating solder paste boxes ready for use, and cooling solder paste boxes that have been used but still retain solder paste. The mobile cart can also be configured to predict when to begin heating / cooling the solder paste boxes based on upcoming production, track shelf-life times, and individually control each solder paste box to the appropriate temperature at the correct time. In other embodiments, the mobile cart may include a box ejector to move the solder paste boxes. The mobile cart can also be configured to control humidity to avoid condensation. The mobile cart can also be configured to operate in a clean environment, such as a Standard Mechanical Interface (SMIF) environment.

[0100] In some embodiments, the mobile cart can be configured to perform inventory control. Specifically, the mobile cart can be configured to identify where materials are located, how much material is used, how materials are used, when materials are used, link materials and information about materials to a customer's inventory control system, and track the type of material consumed per board or multiple batches of boards.

[0101] In some embodiments, a mobile trolley can be configured to organize items stored on the trolley. As previously described, in one embodiment, a mobile trolley can be provided to store, transport, and deliver multiple resources, including but not limited to stencils, solder paste boxes, squeegee blades, and tools. In another embodiment, a mobile trolley can be configured to store a single resource or item, transport it, and deliver it to the stencil printing machine 10. For example, a mobile trolley can be configured to store multiple stencils. A mobile trolley can be configured to serve multiple production lines. In another embodiment, a mobile trolley can be configured to serve a single stencil printing machine 10.

[0102] In some embodiments, the mobile cart can be configured to transport items from the mobile cart to the stencil printing machine 10 and from the stencil printing machine to the mobile cart, taking into account the height difference between the mobile cart and the stencil printing machine. The transport can be automated or manual. In one embodiment, the mobile cart can be moved or remotely controlled via Automated Guided Vehicle (AVG) technology associated with the mobile cart. In another embodiment, the mobile cart can be configured to move autonomously. In yet another embodiment, the mobile cart can be configured to move manually. In still another embodiment, the mobile cart can be configured to move items stored on the mobile cart automatically and / or manually. For example, the mobile cart can be configured to move items automatically and can provide for interruptions to pre-planned activities during which items are moved manually.

[0103] In some embodiments, the time associated with performing the conveying function of the mobile cart can be programmed to take into account shift changes (e.g., staff rotation), scheduled maintenance, on-demand activities (e.g., formula changes), and predicted events (timely replacement). The time can be programmed to meet the balance control requirements of multiple production lines with one or more mobile carts, as well as to meet the real-time on-demand material supply needs on the production line.

[0104] In some embodiments, the mobile cart is configured to perform inspections. For example, the mobile cart can inspect items on and off the cart, including templates, solder paste containers, scraper blades, and tools. In one embodiment, a vision system associated with the mobile cart can be configured to acquire images of the items. The vision system, combined with a controller, can be configured to inspect cleanliness, damage, wear, and label reliability, such as worn, soiled, or torn barcode labels. The vision system can be implemented as any type of 2D, 3D, or color camera.

[0105] In some embodiments, the interface and docking station may be configured with a clamping system to hold the movable trolley in place relative to the stencil printing machine 10. For example, a magnetic clamping system may be employed.

[0106] In some embodiments, the stencil printing machine 10 may be configured with multiple docking stations, for example, five docking stations. The docking stations may be located in front of or behind the stencil printing machine 10.

[0107] The mobile cart and / or stencil printing machine 10 can be configured to verify whether the mobile cart can dock and interface with the stencil printing machine. In one embodiment, verification can be provided to confirm that the mobile cart is in the correct position and ready to interface with the stencil printing machine 10. This verification process can also determine whether the correct material is on the mobile cart and whether the material information of the mobile cart can be received from the MES system or identified locally. If incorrect, the mobile cart 40 can be configured to activate alarms and / or warn the operator in the event of incorrect or damaged material on the mobile cart.

[0108] In some embodiments, the movable cart may be configured with an actuation device or actuator to move items onto and remove them from the movable cart once it is engaged with the stencil printing machine 10. Embodiments of the actuator may be implemented on the movable cart, the stencil printing machine 10, or both. In another embodiment, items may be manually loaded and unloaded from the movable cart.

[0109] In some embodiments, the movable trolley can be configured to connect to the production line interface. In this embodiment, the production line operator can confirm the correct position and respond upon receiving the movable trolley on the stencil printing machine 10.

[0110] In some embodiments, the mobile cart can be configured to communicate with the stencil printing machine 10, the production line, and / or select machines within the production line via an open platform. The communication system may include wired systems, wireless systems (via public networks, mesh networks, Bluetooth, Wi-Fi, Zigbee, WAN, nodes, Li-Fi, etc.), combinations of wired and wireless systems, and infrared (IR) systems.

[0111] In some embodiments, the mobile cart may be configured with a dedicated power supply. In one embodiment, the mobile cart includes a battery configured to power automated components disposed within the mobile cart, such as mechanisms for moving stencils in and out of the mobile cart, structures for moving solder paste boxes in and out of the mobile cart, mechanisms for moving scraper blades in and out of the mobile cart, and mechanisms for moving tools in and out of the mobile cart. In other embodiments, the mobile cart may be configured with an uninterrupted power supply. The power supply may be configured to support actuation during "docking" (a high voltage from the stencil printer during docking, and a low voltage otherwise when not docked). The power supply may be configured to recharge for autonomous operation, for example, by recharging the battery with power supplied by the stencil printer 10.

[0112] In some embodiments, the mobile cart can be configured to function in conjunction with the template printer 10. For example, the mobile cart can be configured to provide a handshake function with the template printer 10 before the item is delivered, such as “Please give me template #1234”. The mobile cart and the template printer 10 can be configured with a communication protocol and / or a library reference about what is available for consumption. The mobile cart can be configured to determine whether the mobile cart has the correct item. The handshake function can be configured to ensure the correct delivery of the item, such as “This is template #1234”, and / or subsequent delivery of the item, such as “I now have template #1234”. In one embodiment, the mobile device can be configured to scan and identify items in the mobile cart and determine, for example, whether the item is ready for use, needs cleaning, etc.

[0113] In some embodiments, the mobile cart can be configured to resolve errors associated with handling and restoring items in the mobile cart. For example, the mobile cart can be configured to detect incomplete actions by one party, incomplete transfer of items (e.g., stuck or blocked items), dropped transfers (e.g., “I sent you template #1234, didn’t you receive it?”), and human intervention or takeover (e.g., “Here, let me help you”). In one embodiment, a controller associated with the mobile cart can be configured to perform static discharge, data recovery, and / or security.

[0114] In some embodiments, the mobile trolley can be configured with a higher level of capability. In addition to repositioning all the equipment to the correct height, the mobile trolley will need to pull in / out all the equipment attached to the stencil printing machine.

[0115] In some embodiments, the existing stencil printing machine gantry, track, and printhead of the stencil printing machine 10 can be configured to allow items to move back and forth in and out.

[0116] In some embodiments, the print head 20 of the stencil printing machine 10 can be configured to lift and reciprocate the tool plate.

[0117] In some embodiments, the movable trolley may be equipped with a solder paste cartridge shifter at the top of the movable trolley for loading / unloading solder paste cartridges.

[0118] In some embodiments, the mobile cart can be configured to communicate with the stencil printing machine 10, the production line, and the warehouse associated with the production line.

[0119] In some embodiments, the mobile cart may be configured with an electric / pneumatic interface.

[0120] In some embodiments, the mobile cart can be configured to track new and used consumables on the mobile cart, such as solder paste cartridges, including their location, temperature, and other data.

[0121] In some embodiments, the mobile cart can be configured to store and supply templates over the duration of a production cycle.

[0122] In some embodiments, the movable trolley can be configured to verify and ensure that the scraper blade is associated with the template to ensure part compatibility during replacement.

[0123] In some embodiments, the scraper blade may include disposable blades, which are plastic-molded blades.

[0124] In some embodiments, the mobile cart can be configured to scan all consumables using a suitable scanning device, such as a barcode reader or an RFID reader.

[0125] In some embodiments, the movable trolley may be configured with a shifting mechanism to properly position consumables.

[0126] In some embodiments, the mobile cart may be configured with a bypass switch to disconnect the mobile cart from the stencil printing machine 10 in case of a problem with the mobile cart.

[0127] In some embodiments, the mobile cart can be configured to move manually or by means of an automated guided vehicle (AGV).

[0128] In some embodiments, the movable trolley can be configured to dock and interface with the template printing machine 10.

[0129] In some embodiments, the mobile cart can be configured to serve multiple template printing machines 10.

[0130] In some embodiments, the mobile cart can be configured to be dedicated to a single consumable item, such as a template, or multiple consumable / replaceable items.

[0131] In some embodiments, the mobile cart can be configured to deliver and present consumables to be cleaned at a remote station.

[0132] In some embodiments, the mobile cart can be configured to reload materials at a warehouse associated with the warehouse.

[0133] In some embodiments, the mobile cart can be configured to be actively or passively controlled by the climate.

[0134] In some embodiments, the mobile cart can be configured to be controlled by an application (App) that is integrated with a smartphone.

[0135] As used in this article, "automated" or "fully automated" replacement describes the replacement or replenishment of items without human intervention.

[0136] As used in this article, "partially automated" replacement describes the replacement or replenishment of items with some or limited human intervention.

[0137] As used in this article, “transporting,” “transporting,” “transferring,” or “transferring” describes the manual or mechanical movement of items from one location to another.

[0138] As used in this article, "installing" or "installing" describes the process of placing an item in a ready-to-use location.

[0139] As described above, the movable trolley 80 and the robotic arm 140 can be used to replace other items within the stencil printing machine 10. For example, the stencil wiper assembly 34 includes consumables, such as paper and solvents, that can be automatically replaced by the movable trolley 80 and the robotic arm 140.

[0140] The concepts disclosed herein can be used in other types of equipment used to manufacture electronic substrates, including dispensers, pick-and-place machines, reflow ovens, wave soldering machines, selective soldering machines, inspection stations, and cleaning stations. For example, the concept of replacing solder paste cartridges can be used in dispensers for dispensing viscous materials. In another example, the concept of replacing tools can be utilized in dispensers and pick-and-place machines for mounting electronic components onto electronic substrates. In yet another example, the concept of replacing items can be used to replace solder in wave soldering machines and selective soldering machines, and to clean products in cleaning stations.

[0141] Solder paste distribution and transfer system and method

[0142] In one embodiment, the stencil printing machine includes a solder paste dispensing and transfer system configured to remove used or depleted solder paste cartridges from the printhead assembly and install new solder paste cartridges in the printhead assembly. The solder paste dispensing and transfer system may be configured to include a rotary indexing mechanism designed to receive used solder paste cartridges from the printhead assembly of the stencil printing machine and deliver new solder paste cartridges to the printhead assembly of the stencil printing machine. The rotary indexing mechanism may be positioned on the frame of the stencil printing machine. The solder paste dispensing and transfer system may be further configured to include a solder paste cartridge mechanism with end-operated means configured to deliver used solder paste cartridges to the rotary indexing mechanism and receive new solder paste cartridges from the rotary indexing mechanism. The solder paste cartridge mechanism may be positioned on the printhead assembly of the stencil printing machine.

[0143] In some embodiments, solder paste cartridges can be manually mounted onto the rotary indexing mechanism of the solder paste dispensing and transfer system of a stencil printing press. The number of solder paste cartridges stored in the rotary indexing mechanism of the solder paste dispensing and transfer system can be determined by the logistical requirements of the stencil printing press and the specific application. The process of mounting the solder paste cartridges onto the printhead assembly includes receiving, placing, sealing, and pressing the cartridges onto the printhead assembly. The rotary indexing mechanism cooperates with a solder paste cartridge mechanism having end-operated manipulation devices to achieve this process.

[0144] In some embodiments, the solder paste dispensing and transfer system is configured such that the solder paste cartridge mechanism interfaces with a rotary indexing mechanism. The solder paste cartridge mechanism is configured to include a support bracket, an actuator, and an end actuation device configured to receive, place, seal, and press the solder paste cartridge onto a material dispenser assembly mounted on a printhead assembly. The support bracket may include a base having a receiving feature designed to receive the bottom portion of the paste cartridge / material box. The receiving feature may include two spaced-apart prongs sized to surround a narrow cylindrical portion of the nozzle of the solder paste cartridge, wherein the narrow cylindrical portion is arranged between two wider cylindrical portions to capture the prongs therebetween. The support bracket of the solder paste cartridge mechanism may further include an upright member having a sealing portion configured to secure and seal the upper portion of the solder paste cartridge / material box and deliver pressurized air to the solder paste cartridge to dispense solder paste or other dispensable materials without user intervention or interaction.

[0145] See the attached figures, especially see Figure 14 The solder paste dispensing and transfer system of this disclosure includes a rotary indexing mechanism (generally indicated by reference numeral 200) and a solder paste cassette mechanism (generally indicated by reference numeral 202). As shown, the rotary indexing mechanism 200 is fixed to the support member 204 of the frame 12 and located at the front of the stencil printing machine 10. In other embodiments, the rotary indexing mechanism 200 may be positioned at the rear of the stencil printing machine 10. The solder paste cassette mechanism 200 is mounted on the support member 206 of the printhead assembly 20 and moves with the printhead assembly via the printhead assembly gantry 22. Figure 14 As shown, the printhead assembly 20 and the solder paste cartridge mechanism 202 can be moved along the y-axis towards the front of the stencil printing machine 10 via the printhead assembly gantry 22 to the vicinity of the rotary indexing mechanism 200. In this position, the solder paste cartridge mechanism 202 can transfer exhausted or used solder paste cartridges (such as solder paste cartridge 110) to the rotary indexing mechanism 200 and receive new solder paste cartridges from the rotary indexing mechanism.

[0146] See Figure 15A and Figure 15BThe rotary indexing mechanism 200 includes a mounting bracket 210 configured to secure the rotary indexing mechanism to a support member 204 of the frame 12. A motor and bearing housing 212 is fixed to the bottom of the mounting bracket 210 to secure a motor and gearbox assembly 214, which is provided to drive rotation of the shaft 216 of the rotary indexing mechanism 200. In one embodiment, the operation of the motor and gearbox assembly 214 of the rotary indexing mechanism 200 is controlled by a controller 14 of the stencil printing machine 10.

[0147] The rotary indexing mechanism 200 further includes a rotary bearing 220, which, in the illustrated embodiment, is a circular disc mounted on a shaft 216. Therefore, the rotary bearing 220 is configured to rotate clockwise or counterclockwise via the operation of a motor and gearbox assembly 214. A solder paste cartridge holder 222 is mounted on the top surface of the rotary bearing 220. In one embodiment, the holder 222 is implemented as a half-wall configured to provide lateral support to the solder paste cartridge 110 to help maintain it in a vertical, upright position. The rotary indexing mechanism 200 further includes a plurality of partitions, each indicated by reference numeral 224, provided to separate the solder paste cartridges 110 supported by the rotary indexing mechanism from each other. In the illustrated embodiment, three partitions 224 are present; however, any number of partitions can be provided, depending on the number of solder paste cartridges 110 supported by the rotary indexing mechanism 200.

[0148] The top surface of the rotary indexing mechanism 200's rotary bearing 220 is configured to support the nozzle 111 of the solder paste cartridge 110, placing the solder paste cartridge in an upright position. The rotary indexing mechanism 200 can rotate to present an open cavity defined between two adjacent separators 224 to the solder paste cartridge mechanism 202, thereby receiving a used or exhausted solder paste cartridge 110 from the solder paste cartridge mechanism. In this position, the solder paste cartridge mechanism 202 can transfer the used solder paste cartridge 110 to the open cavity of the rotary indexing mechanism 200. The rotary indexing mechanism 200 can further rotate to present a new solder paste cartridge 110 for transfer to the solder paste cartridge mechanism. In this position, the solder paste cartridge mechanism 202 can receive the new solder paste cartridge 110 and mount it within the printhead assembly 20 for operation.

[0149] See Figure 16A and Figure 16BThe solder paste cartridge mechanism 202 includes a support bracket 230 mounted on a support member 206 of the printhead assembly 20, and an actuator 232 fixed to the support bracket. In one embodiment, the actuator 232 is a linear actuator configured to move vertically along the z-axis. The support bracket 230 may include an end actuation device 234 having a base with a receiving feature designed to receive the bottom portion of the nozzle 111 of the solder paste cartridge 110. The end actuation device 234 is configured to selectively engage and secure the nozzle 111 of the solder paste cartridge 110 and maintain the solder paste cartridge in a vertical, upright position. This arrangement allows the end actuation device 234 of the printhead assembly 202 to be actuated to engage and secure the nozzle 111 of the solder paste cartridge 110 to support the solder paste cartridge in a vertical, upright position and to move the solder paste cartridge to an operating position within the printhead assembly 20.

[0150] The actuator 232 of the solder paste cartridge mechanism 202 is fixed to the support member 206 of the printhead assembly 20 via a support bracket 230 and is configured to move along the y-axis direction via movement provided by the printhead assembly gantry 22. The support bracket 230 can be fixed to the support member 206 of the printhead assembly 20 via a linear bearing so that the support bracket, actuator 232, and end effector 234 can move along the x-axis direction. In one embodiment, as... Figure 14 As most clearly shown, the support bracket 230 is mounted to the support member 206 of the printhead assembly 20 via two linear rod supports (each denoted by reference numeral 236) and is driven by a timing belt 238 connected to a motor. This allows the end actuator 234 to move laterally to the rotary indexing mechanism 200. Other drives, such as a motor and ball screw assembly, can be used to drive the movement of the support bracket 230 and thus the movement of the end actuator 234. The printhead assembly 20 is configured to move laterally along the x-axis to deposit solder paste (or another suitable assembly material) at a desired location across the width of the stencil 18.

[0151] See Figure 17A and Figure 17B The actuator 232 is configured to move the end actuation device 234 of the solder paste cartridge mechanism 202 by moving it up and down along the z-axis. This arrangement causes the end actuation device 234 to move laterally toward the nozzle 111 of the solder paste cartridge 110 located in the rotary indexing machine 200 to fix the nozzle of the solder paste cartridge. Figure 17AThis arrangement is illustrated. Once secured by the end-operated device 234, the actuator 232 moves the solder paste cartridge 110 upwards, such that the open end of the solder paste cartridge is sealed by the solder paste cartridge sealing feature 240 of the printhead assembly 20. After the solder paste cartridge 110 is raised to be sealed against the sealing feature 240, the solder paste cartridge can be pressurized when solder paste needs to be dispensed. After being sealed, the solder paste cartridge 110 can be moved away from the rotary indexing mechanism 200. In one embodiment, the operation of the actuator 232 of the solder paste cartridge mechanism 202 is controlled by the controller 14 of the stencil printing machine 10.

[0152] See Figure 18 In one embodiment, the end-operated device 234 includes a receiving feature 250 that may include two spaced-apart forks sized to surround a narrow cylindrical portion of the nozzle 111 of the solder paste container 110, wherein the narrow cylindrical portion is arranged between two wider cylindrical portions to capture the forks therebetween. This arrangement allows the forks of the receiving feature 250 to be captured between the two wider cylindrical portions of the nozzle 111, enabling the end-operated device 234 to support the solder paste container 110 in an upright position. Other end-operated device configurations may be used in conjunction with complementary features of the nozzle to secure the nozzle 111 of the solder paste container 110 to the end-operated device.

[0153] In some embodiments, the rotary indexing mechanism 200 and the solder paste container mechanism 202 may be configured to receive solder paste containers or solder paste jars of different sizes.

[0154] In some embodiments, the solder paste container 110 is configured to contain assembly materials, including but not limited to solder paste, conductive ink, or encapsulation materials.

[0155] In some embodiments, each solder paste box 110 includes a one-dimensional barcode label that is wrapped around the solder paste box from beginning to end, thereby allowing the barcode to be read from any orientation relative to the tube.

[0156] Therefore, having described several aspects of at least one embodiment, it will be understood that various changes, modifications, and improvements will readily occur to those skilled in the art. Such changes, modifications, and improvements are intended to be part of and fall within the scope of this disclosure. Thus, the preceding description and figures are merely examples.

Claims

1. A stencil printing machine for printing assembly materials on an electronic substrate, the stencil printing machine comprising: frame; A template connected to the frame, the template having openings formed therein; A support assembly connected to the frame, the support assembly being configured to support the electronic substrate at a printing position below the template; A printhead assembly coupled to the frame such that the printhead assembly is configured to traverse the stencil during the printing stroke, the printhead assembly including a doctor blade assembly and at least one solder paste hopper to deposit assembly material onto the stencil; as well as Solder paste dispensing and transfer system, the solder paste dispensing and transfer system comprising: A rotary indexing mechanism connected to the frame. The solder paste dispensing and transfer system is configured to transfer used solder paste cartridges from the printhead assembly to the rotary indexing mechanism supported by the frame, and to transfer new solder paste cartridges from the rotary indexing mechanism to the printhead assembly. The rotary indexing mechanism includes: a turntable bearing configured to rotate, a solder paste cartridge holder mounted on the top surface of the turntable bearing, and a plurality of separators provided to separate the solder paste cartridges supported by the rotary indexing mechanism from one another.

2. The stencil printer of claim 1, wherein, The tube holder includes a half-wall configured to provide lateral support to one of a new solder paste container and a used solder paste container to maintain the solder paste container in a vertical, upright position.

3. The template printing machine as described in claim 1, wherein, The rotary transposition mechanism is configured to be rotated to present an open cavity defined between two adjacent separators to receive the used solder paste cartridge, and to be rotated to present the new solder paste cartridge for transfer to the printhead assembly.

4. The template printing machine as described in claim 1, wherein, The rotary indexing mechanism further includes a mounting bracket configured to secure the rotary indexing mechanism to a support member of the frame.

5. The template printing machine as described in claim 4, wherein, The rotary indexing mechanism further includes a motor and bearing housing, and a shaft. The motor and bearing housing are fixed to the bottom of the mounting bracket to fix the motor and gearbox assembly. The shaft is connected to the motor and bearing housing and the turntable bearing to drive the rotation of the turntable bearing.

6. A method for fully automating the replenishment and / or replacement process within a stencil printing press, the method comprising: Identify the used solder paste boxes within the template printing machine that are scheduled for replacement; The used solder paste box is transferred from the printhead assembly to the rotary indexing mechanism; The new solder paste cartridge is transferred from the rotary indexing mechanism to the printhead assembly; as well as The new solder paste box is installed inside the printhead assembly. The rotary indexing mechanism includes a turntable bearing configured to rotate, a solder paste cartridge holder mounted on the top surface of the turntable bearing, and a plurality of partitions provided to separate the solder paste cartridges supported by the rotary indexing mechanism from one another, the plurality of partitions defining a plurality of open openings.

7. The method of claim 6, wherein, Transferring the used solder paste container includes: presenting one of the plurality of open openings of the rotary indexing mechanism, and moving the used solder paste container to the open opening.

8. The method of claim 6, wherein, Transferring the new solder paste cassette includes presenting the new solder paste cassette to the solder paste cassette mechanism of the printhead assembly and moving the new solder paste cassette to the solder paste cassette mechanism.

9. The method of claim 6, wherein, Installing the new solder paste box includes moving the new solder paste box along the z-axis to seal the open end of the solder paste box.

10. A solder paste dispensing and transfer system for a stencil printer configured to print assembly material on an electronic substrate, the solder paste dispensing and transfer system comprising: A rotary indexing mechanism connected to the frame of the template printing machine; The print head assembly of the stencil printing machine is configured to transfer used solder paste cartridges to the rotary indexing mechanism supported by the frame, and to transfer new solder paste cartridges from the rotary indexing mechanism to the print head assembly. The rotary indexing mechanism includes: a turntable bearing configured to rotate, a solder paste cartridge holder mounted on the top surface of the turntable bearing, and a plurality of separators provided to separate the solder paste cartridges supported by the rotary indexing mechanism from one another.

11. The solder paste dispensing and transfer system of claim 10, wherein, The tube holder includes a half-wall configured to provide lateral support to one of a new solder paste container and a used solder paste container to maintain the solder paste container in a vertical, upright position.

12. The solder paste dispensing and transfer system of claim 10, wherein, The rotary transposition mechanism is configured to be rotated to present an open cavity defined between two adjacent separators to receive the used solder paste cartridge, and to be rotated to present the new solder paste cartridge for transfer to the printhead assembly.

13. The solder paste dispensing and transfer system as claimed in claim 10, wherein, The rotary indexing mechanism further includes a mounting bracket configured to secure the rotary indexing mechanism to a support member of the frame.

14. The solder paste dispensing and transfer system as claimed in claim 13, wherein, The rotary indexing mechanism further includes a motor and bearing housing, and a shaft. The motor and bearing housing are fixed to the bottom of the mounting bracket to fix the motor and gearbox assembly. The shaft is connected to the motor and bearing housing and the turntable bearing to drive the rotation of the turntable bearing.

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