Wiping device for stencil printers

Abstract

The present disclosure provides a squeegee device 700 for a stencil printer, comprising a squeegee holder 710, a squeegee 720 having a movement path for squeegeeing a material discharged onto a stencil 130, the squeegee 720 being disposed obliquely with respect to the stencil 130 and rearward of the movement path, and a mounting assembly 730 configured to attach the squeegee 720 to the squeegee holder 710. The mounting assembly 730 is further configured to adjust an inclination angle of the squeegee 720 with respect to the stencil 130 and maintain the squeegee 720 at the adjusted angular position.

Description

Technical Field

[0001] The present disclosure relates generally to a squeegee assembly in a stencil printer for printing a viscous material such as solder paste onto a substrate such as a printed circuit board.

Background Art

[0002] In a typical circuit board manufacturing process, a stencil printer is used to print solder paste onto a printed circuit board. A circuit board, also referred to broadly as an electronic substrate, has a pattern of solder pads or some other conductive surfaces onto which solder paste can be deposited, and the circuit board is automatically fed into the stencil printer. Before printing solder paste onto the circuit board, a particular hole or marking on the circuit board, referred to as a fiducial point, is used to align the circuit board with the stencil or mesh board of the stencil printer. The fiducial point is used as a reference point for aligning the circuit board with the stencil. When the circuit board is aligned with the printer's stencil, the circuit board is raised up to the stencil by a substrate support and fixed relative to the stencil. The stencil support may be, for example, a platform having pins or other article supports. Thereafter, by moving a squeegee or a squeezer across the stencil, solder paste is ejected, whereby the solder paste lands on the circuit board through the holes of the stencil. The solder paste is typically ejected onto the stencil from a standard solder paste supply cartridge. When the printing operation is completed, the circuit board is released, lowered, and after being detemplated from the template, it is conveyed to another location within the printed circuit board manufacturing line. As the squeegee moves across the stencil, the solder paste spreads in front of the squeegee, thereby helping the solder paste to be mixed as needed to reach a desired viscosity and fill the holes of the mesh board or stencil.

Summary of the Invention

[0003] According to a first aspect of the present disclosure, the present disclosure provides a scraping device for a stencil printer, comprising a scraper holder, a scraper having a path for scraping off material discharged onto a stencil, the scraper being positioned obliquely to the stencil and obliquely to the rear of the path, and a mounting assembly configured to attach the scraper to the scraper holder. The mounting assembly is configured to adjust the inclination angle of the scraper with respect to the stencil and to maintain the scraper in the adjusted angular position.

[0004] According to the scraping device described above, the mounting assembly comprises a support column having a pivot axis, which is connected to a scraper holder. The scraper is connected to the support column and has a longitudinal direction laterally to the movement path, and the longitudinal direction of the scraper coincides with the direction of the pivot axis. The inclination angle of the scraper relative to the stencil is adjusted by rotating the support column about its pivot axis.

[0005] According to the scraping device described above, the mounting assembly further comprises a pair of connecting blocks that connect the two axial ends of the support column to the scraper holder, respectively. The connecting blocks have a locked state and an unlocked state. When the connecting blocks are in the unlocked state, the support column can adjust the tilt angle of the scraper relative to the stencil by rotating about its axis of rotation. When the connecting blocks are in the locked state, the connecting blocks restrict the support column from rotating about its axis of rotation so as to maintain the scraper in the adjusted angular position.

[0006] According to the scraping device described above, the connecting block comprises a hole and an opening communicating with the hole. The opening is located on one side of the hole. The hole is used to receive the axial end of the support column, and the opening divides the connecting block into a first part and a second part, the first part and the second part being able to open and close relative to each other to increase or decrease the size of the hole. The mounting assembly further comprises fasteners for detachably fastening the first part and the second part at the opening, such that the connecting block has a locked state and an unlocked state.

[0007] According to the scraping device described above, the scraping device further comprises an angle indicator device. The angle indicator device is fixedly connected to a support column and is configured to indicate the inclination angle of the scraper relative to the stencil based on its relative position to the connecting block.

[0008] According to the scraping device described above, the angle indicator is a marker plate. The marker plate is connected to one axial end of the support column and is configured to rotate together with the support column.

[0009] According to the scraping device described above, the indicator plate has a reference edge. The reference edge is positioned parallel to the scraper. An angle scale is provided on the connecting block, and the scale pointed to by the reference edge represents the angle of inclination of the scraper relative to the stencil.

[0010] According to the scraping device described above, the indicator plate is located on the opposite side of the scraper in the connecting block.

[0011] According to the scraping device described above, a limiting groove is provided in the indicator plate. The limiting groove extends circumferentially and receives limiting pins located in the connecting block.

[0012] According to the scraping device described above, the support column has a generally flat support surface located on its first side.

[0013] According to the scraping device described above, the mounting assembly further comprises a support plate. The support plate is clamped between the support surface of the support column and the scraper. The scraper can flex around the bottom edge of the support plate.

[0014] According to a second aspect of this disclosure, the disclosure provides a stencil printer equipped with a scraping device according to the first aspect described above. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view of a stencil printer as an example of the disclosure. [Figure 2A] This is a perspective view of one viewpoint of a scraping device as an example of the present disclosure. [Figure 2B] This is a perspective view of the scraping device shown in Figure 2A from a different viewpoint. [Figure 3A] Figure 2A is an exploded view of the scraping device shown. [Figure 3B] Figure 2A is an exploded view of some of the components of the scraping device shown. [Figure 4A] Figure 2A is a perspective view of the connection block in the scraping device shown. [Figure 4B] Figure 2A is a side view of the connection block in the scraping device. [Figure 5] Figure 2A is a perspective view of the support column in the scraping device shown. [Figure 6A] This is a side view of the scraper of the scraping device shown in Figure 2A relative to the stencil, at the first inclined angle position. [Figure 6B] This is a side view of the scraper of the scraping device shown in Figure 2A relative to the stencil, at the second inclined angle position. [Figure 7A] This is a perspective view of one viewpoint of a scraping device, as an example of another example of this disclosure. [Figure 7B] This is a perspective view of the scraping device shown in Figure 7A from a different viewpoint. [Figure 8A] Figure 7A is a partially exploded view of the scraping device. [Figure 8B]Another exploded view of the scraping device of FIG. 7A. [Figure 9A] Side view of the scraper of the scraping device shown in FIG. 7A with respect to the stencil at the first tilt angle position. [Figure 9B] Side view of the scraper of the scraping device shown in FIG. 7A with respect to the stencil at the second tilt angle position.

Embodiments for Carrying Out the Invention

[0016] Various specific embodiments of the present disclosure will be described below with reference to the accompanying drawings forming part of this specification. Terms indicating directions such as "front", "rear", "upper", "lower", "left", "right", "top", "bottom", etc. are used in this disclosure to describe various exemplary structural components and elements of the present disclosure. However, it should be understood that these terms are used herein merely for the convenience of illustration and are determined based on the exemplary directions shown in the accompanying drawings. Since the examples disclosed in the present disclosure can be arranged in different orientations, these terms indicating directions are for the purpose of illustration only and should not be regarded as limiting.

[0017] FIG. 1 is a perspective view of a stencil printer 100 according to an example of the present disclosure. As shown in FIG. 1, the stencil printer 100 includes a rack 110 that supports various components of the stencil printer. The components of the stencil printer 100 include a controller 120, a display 125, a stencil 130, and a print head assembly or print head 140 for applying a dispensed material (e.g., solder paste). The stencil 130 and the print head 140 can be preferably combined with or connected to the rack 110. In one example, the print head 140 can be attached to a print head bracket 150, and the print head bracket 150 can be attached to the rack 110. Under the control of the controller 140, the bracket 150 can move the print head 140 in a Y-axis direction perpendicular to the X-axis and Z-axis. The print head 140 can be disposed above the stencil 130, and the front scraper or rear scraper of the print head 140 can be lowered in the Z-axis direction to contact the stencil 130. Thereafter, via the bracket 150, the scraper of the print head 140 can move through the stencil 130 to enable the solder paste to be printed onto the circuit board.

[0018] The stencil printer 100 can also include a transport system that includes a track 160 used to transfer a printed circuit board (sometimes referred to as a "printed wiring board", "substrate", or "electronic substrate") to a printing position inside the stencil printer 100. The track 160, also referred to herein as a "feeding mechanism", is configured to provide, load, or transfer a circuit board to the working area of the stencil printer 100 and to remove the circuit board from the working area. The stencil printer 100 has a support assembly 170 for supporting the circuit board.

[0019] In some examples, the print head 140 may be configured to obtain solder material from a supply source such as a dispenser (e.g., a solder paste cartridge) that provides solder paste to the print head during printing. Other methods of supplying solder paste may be used instead of a solder paste cartridge. For example, the solder paste may be manually deposited between scrapers, or the solder paste may be supplied from an external source. Furthermore, in some examples, the controller 120 may be configured to control the operation of the stencil printer 100 using a personal computer with a Microsoft DOS or Windows® XP operating system and application-specific software. The controller 120 may be networked with a host controller used to control a production line for manufacturing circuit boards.

[0020] In some examples, the stencil printer 100 operates as follows: The circuit board is fed into the stencil printer 100 in the X-axis direction by the transport track 160. The support assembly 170 raises the circuit board and secures it in the printing position. The print head 140 then lowers the desired print head scraper in the Z-axis direction until the print head scraper contacts the stencil 130 with the desired pressure. The print head 140 then moves in the Y-axis direction through the stencil 130 by the print head bracket 150. The print head 140 deposits solder paste so that it falls onto the circuit board through the holes in the stencil 130. Once the print head 140 has completely crossed the stencil 130, the scraper rises away from the stencil 130 and the circuit board descends back to the transport track 160. The circuit board is then released and ejected from the stencil printer 100, allowing a second circuit board to be loaded into the stencil printer 100. To print on the second circuit board, another scraper makes contact with the stencil along the Z-axis, and the print head 140 moves across the stencil 130 in the opposite direction to the direction used for the first circuit board.

[0021] Referring further to Figure 1, an imaging system 180 can be provided to align the stencil 130 with the circuit board before printing and to inspect the circuit board after printing. In one example, the imaging system 180 can be positioned between the stencil 130 and a support assembly 170 that supports the circuit board. The imaging system 180 is connected to an imaging bracket 185 that moves the imaging system. In the scraper assembly, the imaging bracket 185 can be connected to a rack 110, and the imaging bracket 185 has a beam extending between the side rails of the rack 110 so that the imaging system 180 can move back and forth in the Y-axis direction above the circuit board. The imaging bracket 185 may also have a transport device that surrounds the imaging system 180 from the outside and is positioned to move in the X-axis direction along the length of the beam. The structure of the imaging bracket 185 for moving the imaging system 180 is well known in the art of solder paste printing. The method is as follows: To obtain images of a predetermined area of ​​the circuit board or stencil, the imaging system 180 can be positioned at any location above the circuit board and below the stencil 130.

[0022] In the scraper assembly, the print head 140 includes a frame member 145 that forms part of the bracket 150. The frame member 145 is configured to move along the printing direction, such as the Y-axis direction. In particular, the frame member 145 is configured to slide at both ends along the straight track (not shown in Figure 1) of the rack 110 of the stencil printer 100. This structure allows the print head bracket 150 to move along the Y-axis direction. In the scraper assembly, the frame member 145 supports a scraping device having a front scraper and a rear scraper, and a moving mechanism configured to move the scrapers independently. Under the control of each moving mechanism, each scraper is configured to move along the Z-axis direction from a high position a certain distance from the stencil 130 to a low position that engages with the stencil 130 and applies pressure to the stencil 130.

[0023] Figures 2A and 2B show the overall structure of a scraping device 200 with a scraper assembly according to the present disclosure, where Figure 2A is a perspective view of the scraping device 200 from one viewpoint, and Figure 2B is a perspective view of the scraping device 200 of Figure 2A from another viewpoint. As shown in Figures 2A and 2B, the scraping device 200 comprises a scraper holder 210, a scraper 220, and a mounting assembly 230 for attaching the scraper 220 to the scraper holder 210. The scraper holder 210 is connected to a scraper movement mechanism (not shown in the figures). The scraper 220 is, for example, a front scraper, and for ease of illustration, in the scraping device 200 shown in Figures 2A to 2C, only the front scraper and its mounting elements are shown, and the rear scraper and its mounting elements are omitted. Furthermore, the scraping device 200 may also comprise other components not shown in the figures.

[0024] The scraper 220 has a path for scraping off material (solder paste) extruded onto the stencil 130, and this path extends along the Y-axis. The scraper 220 is generally rectangular, having a long side 221 and a short side 223. The longitudinal direction of the scraper 220 coincides with the X-axis and is perpendicular to the path. The scraper 220 is positioned obliquely to the stencil 130 and obliquely to the rear of the path so that it applies pressure to the material extruded onto the stencil 130 through the scraper 220, causing the extruded material to fall through the holes in the stencil 130 onto the electronic substrate below the stencil 130. In addition to allowing the scraper 220 to be mounted on the scraper holder 210, the mounting assembly 230 allows adjustment of the inclination angle of the scraper 220 relative to the stencil 130. Furthermore, the mounting assembly 230 can maintain the scraper 220 in a adjusted angular position so that the scraper 220 can perform the scraping operation at the adjusted inclination angle.

[0025] Figures 3A and 3B show specific components of the mounting assembly 230. Figure 3A is an exploded view of the scraping device 200, and Figure 3B is an exploded view of some components of the scraping device 200. As shown in Figures 3A and 3B, the mounting assembly 230 comprises a support column 310 for supporting and holding the scraper 220, and a pair of connecting blocks 320 for connecting the support column 310 to the scraper holder 210. The mounting assembly 230 further comprises a support plate 330 and a back plate 340 for better connection and holding the scraper 220 on the support column 310.

[0026] The support column 310 is generally cylindrical with a rotation axis X, and a pair of connecting blocks 320 each connect the two axial ends 312 of the support column 310 to the scraper holder 210. The longitudinal direction of the scraper 220 coincides with the direction of the rotation axis X, and the inclination angle of the scraper 220 relative to the stencil 130 is adjusted by rotating the support column 310 about its rotation axis X. The support column 310 has a generally flat support surface 315 located on its first side. The support surface 315 is formed, for example, by cutting off a portion of the support column 310 that extends along the rotation axis X beyond the long side 221 of the scraper 220. The support plate 330 is generally rectangular and is clamped between the support surface 315 and the scraper 220, and the support surface 315, the support plate 330 and the scraper 220 are generally parallel. The support plate 330 has a bottom edge 335, and the scraper 220 can bend towards the rear of its movement path around the bottom edge 335 of the support plate 330, thereby enabling better scraping. The support plate 330 increases the surface area that supports the scraper 220. Of course, depending on the scraper assembly, the support surface 315 on the support column 310 may be set to be large enough that the mounting assembly 230 does not have a support plate 330.

[0027] To connect the scraper 220, the support plate 330, and the support column 310, the scraper assembly of the present disclosure is provided with two sets of fasteners, namely a first set of fasteners 350 and a second set of fasteners 370, the first set of fasteners 350 first connects the scraper 220 as a subassembly to the support plate 330, and then the second set of fasteners 370 connects the subassembly of the scraper 220 and the support plate 330 to the support column 310. In particular, the first set of fasteners 350 connects the scraper 220 to the support plate 330 from the first side of the support column 310 (i.e., the side on which the support surface 315 is located), and the second set of fasteners 370 connects the support plate 330 to the support column 310 from the second side opposite to the first side of the support column 310. The first set of fasteners 350 includes a plurality of fasteners, such as bolts. The second set of fasteners 370 also includes a plurality of fasteners such as bolts. When the scraper 220 is connected to the support column 310, the rotational position of the support column 310 about its axis of rotation X can be adjusted, that is, the inclination angle of the scraper 220 relative to the stencil 130 can be adjusted.

[0028] A pair of connecting blocks 320 are each connected to the scraper holder 210 by multiple fasteners (e.g., bolts) 360.

[0029] Figures 4A and 4B show the specific structure of one of a pair of connecting blocks 320 of the mounting assembly 230, and the structure of the pair of connecting blocks 320 is identical. Figure 4A is a perspective view of the connecting block 320, and Figure 4B is a side view of the connecting block 320. As shown in Figures 4A and 4B, the connecting block 320 is generally square and connects to the scraper holder 210 at its top 425.

[0030] The connecting block 320 has a hole 421 that penetrates the first side 432 and the second side 434, which are opposite to each other, and an opening 423 that communicates with the hole 421, located at the bottom 427 of the connecting block 320 and similarly penetrating the first side 432 and the second side 434 of the connecting block 320. The opening 423 divides the connecting block 320 into a first portion 426 and a second portion 428 that can be deflected relative to each other. The first portion 426 and the second portion 328 are connected at the top 425 of the connecting block 320 and separated at the bottom 427 of the connecting block 320 by the opening 423, so that the first portion 426 and the second portion 428 can be opened and closed relative to each other. The hole 421 is formed by joining the inner walls of the first portion 426 and the second portion 428, thereby increasing and decreasing the radial dimension (e.g., cross-section) of the hole 421 by opening and contracting the first portion 426 and the second portion 428 relative to each other. The hole 421 is used to receive the axial end 312 of the support column 310, which can be tightened by the connecting block 320 when the radial dimension of the hole 421 is reduced, and can be disengaged by the connecting block 320 when the radial dimension of the hole 421 is increased.

[0031] The mounting assembly 230 further comprises a fastener 390 that detachably fastens the first portion 426 and the second portion 428 to each other by passing through an opening 423. The fastener 390 allows the connecting block 320 to have a locked state and an unlocked state. When the fastener 390 is loosened so that the first portion 426 and the second portion 328 of the connecting block 320 are released from each other, the connecting block 320 becomes unlocked, and the axial end 312 of the support column 310 is disengaged by the connecting block 320. Thus, the support column 310 can adjust the inclination angle of the scraper 220 relative to the stencil 130 by rotating about its axis of rotation X. When the fastener 390 is fastened so that the first part 426 and the second part 328 of the connecting block 320 cannot be opened relative to each other, the connecting block 320 is locked, and the axial end 312 of the support column 310 is tightened by the connecting block 320. Thus, the connecting block 320 restricts the rotation of the support column 310 about its axis of rotation X, thereby maintaining the scraper 220 in the adjusted angular position.

[0032] Slots 429 are provided in both the first portion 426 and the second portion 428 of the connecting block 320, and the slots 429 also penetrate the first side surface 432 and the second side surface 434 of the connecting block 320, but the slots 429 do not communicate with the holes 421. The slots 429 divide the first portion 426 / second portion 428 of the connecting block 320 into two connected sections, making the connection very thin, thereby improving the deformability (i.e., reducing the rigidity) of the first portion 426 and the second portion 428, and allowing the first portion 426 and the second portion 328 to open and close more easily relative to each other.

[0033] Figure 5 shows the specific structure of the support column 310 in the mounting assembly 230. As shown in Figure 5, the axial end 312 of the support column 310 is still cylindrical, and the support surface 315 is located between the axial end 312.

[0034] Figures 6A and 6B show side views of the scraper 220 relative to the stencil 130 at a first and second inclination angle position, respectively. In Figure 6A, the internal angle between the scraper 220 and the stencil 130 is θ1, and in Figure 6B, the internal angle between the scraper 220 and the stencil 130 is θ2, with θ1 being greater than θ2. The internal angle between the scraper 220 and the stencil 130 (i.e., the inclination angle of the scraper 220 relative to the stencil 130) is achieved by rotating the support column 310 around its axis of rotation X. The rotation of the support column 310 causes the connected scraper 220 to rotate along with it, thereby adjusting the inclination angle of the scraper 220 relative to the stencil 130. If it is necessary to adjust the inclination angle of the scraper 220 relative to the stencil 130, the connecting block 320 can be released from a locked state by loosening the fastener 390 (Figure 3A), that is, by rotating the support column 310 around its axis of rotation X. Once the inclination angle of the scraper 220 relative to the stencil 130 is adjusted to the desired angle, the connecting block 320 can be locked from a released state by tightening the fastener 390 (Figure 3A), that is, by restricting the rotation of the support column 310 around its axis of rotation X, thereby maintaining the scraper 220 in the adjusted angular position.

[0035] Figures 7A and 7B show a scraping device 700 with another scraper assembly of the present disclosure, where Figure 7A is a perspective view of the scraping device 700 from one viewpoint and Figure 7B is a perspective view of the scraping device 700 from another viewpoint. The scraping device 700 shown in Figures 7A and 7B is similar to the scraping device 200 shown in Figures 2A and 2B, and similarly comprises a scraper holder 710, a scraper 720, and a mounting assembly 730 for attaching the scraper 720 to the scraper holder 710, the mounting assembly 730 being able to adjust the inclination angle of the scraper 720 with respect to the stencil 130. The scraping device 700 differs from the scraping device 200 in that it further comprises an angle indicator device for indicating the inclination angle of the scraper 720 with respect to the stencil 130. Furthermore, the scraping device 700 further comprises a pair of vertically movable baffles 780 positioned on both sides of the movement path of the scraper 720, and a pair of elastic plates 790 for resetting each of the baffles 780.

[0036] Figures 8A and 8B show the specific structure of the scraping device 700, where Figure 8A is a partially exploded view of the scraping device 700, Figure 8B is another partially exploded view of the scraping device 700, and Figure 8B shows a rear view of Figure 8A. As shown in Figures 8A and 8B, the mounting assembly 730 comprises a support column 810 and a pair of connecting blocks 820, the support column 810 and the pair of connecting blocks 820, respectively, connected to the scraper holder 710 by a plurality of fasteners (e.g., bolts) 860. The mounting assembly 730 further comprises a support plate 830 and a backing plate 840 for better connection and holding of the scraper 720 on the support column 810. The support column 810, support plate 830 and backing plate 840 have the same structure as the support column 310, support plate 330 and backing plate 340 of the scraping device 200, respectively, and therefore will not be described herein. The connecting block 820 is structurally similar to the connecting block 320 of the scraping device 200, but differs in that the connecting block 320 has a slot 429, while the connecting block 820 does not. The connecting block 820 includes a hole 821 and an opening 823 located on one side of the hole 821 and communicating with the hole 821. The opening 823 divides the connecting block 820 into a first portion 826 and a second portion 828, which can open and close relative to each other to increase or decrease the size of the hole 821. The first portion 826 and the second portion 828 are detachably fastened at the opening 823 by fasteners 890 so that the connecting block 820 has a locked state and an unlocked state. When the connecting block 820 is in the unlocked state, the support column 310 can be rotated to adjust the inclination angle of the scraper 720 relative to the stencil 130. When the connecting block 820 is locked, the support column 310 cannot rotate, thereby maintaining the scraper 720 in the adjusted angular position.

[0037] Unlike the scraping device 200, which connects the support column 310, support plate 330, scraper 220, and backing plate 340 with two sets of fasteners, the scraping device 700 connects the support column 810, support plate 830, scraper 720, and backing plate 840 with a positioning pin 817 located on the support column 810 and a set of fasteners 850. Specifically, the support plate 830 is first positioned relative to the support column 810 by the positioning pin 817, and then the support plate 830, scraper 720, and backing plate 840 are fastened to the support column 810 by the fastener assembly 850. In this way, the scraper 720 is clamped between the support plate 830 and the backing plate 840 and can flex around the bottom edge 835 of the support plate 830. The support plate 830 is in contact with the support surface 815 of the support column 310. The rotational position of the support column 810 about its axis of rotation X can be adjusted, that is, the inclination angle of the scraper 720 relative to the stencil 130 can be adjusted.

[0038] Furthermore, as shown in Figures 8A and 8B, the scraper assembly 700 further comprises an angle indicator device fixedly connected to the support column 810. The position of the angle indicator device relative to the connecting block 820 can indicate the inclination angle of the scraper 720 relative to the stencil 130. The angle indicator device is, for example, an indicator plate 750 fastened to one axial end of the support column 810 with a fastener 756 and configured to rotate with the support column 810. The indicator plate 750 is positioned on the opposite side of the connecting block 820 from the support column 810. As can be seen from Figures 8A and 8B, the support column 810 is positioned inside the connecting block 820, while the indicator plate 750 is positioned outside the connecting block 820. The indicator plate 750 is generally fan-shaped and has a reference edge 752 positioned parallel to the scraper 720 (see Figures 9A and 9B). The connecting block 820 is provided with an angle scale 822, and the scale pointed to by the reference edge 752 represents the inclination angle of the scraper 720 relative to the stencil 130.

[0039] In addition, the indicator plate 750 is also provided with a limiting groove 753, which extends in the circumferential direction. A limiting pin 757 is provided on the connecting block 820, which is received in the limiting groove 753 and can move along the limiting groove 753 as the indicator plate 750 rotates. The limiting groove 753 engages with the limiting pin 757 to limit the range of rotation of the indicator plate 750 in order to facilitate angle adjustment of the scraper 720.

[0040] Furthermore, as shown in Figures 8A and 8B, a pair of baffles 780 of the scraper assembly 700 are used to hold solder paste in the path of the scraper 720 during squeegeeing of the material to be applied (solder paste) by the scraper 720. The baffles 780 are connected to the connecting block 820 so as to be vertically movable by fasteners 783. The baffles 780 are positioned on the side of the connecting block 820 that is connected to the support column 810. The baffles 780 are generally U-shaped and therefore have space to avoid the support column 810 so that the baffles 780 do not interfere with the support column 810 during vertical movement. A pair of chutes 785 are provided on the baffles 780, and the fasteners 783 positioned on the connecting block 820 are received by the chutes 785 and can move along the chutes 785, thereby enabling the movement of the baffles 780 relative to the connecting block 820.

[0041] When the scraper 720 is used to squeegee the solder paste, a certain amount of pressure must be applied to the stencil 130. Therefore, the scraper assembly 700 moves downward relative to the stencil 130, deforming the scraper 720 to apply pressure. In order to retain the solder paste in the path of the scraper 720, the lowest ends of the pair of baffles 780 and the lowest end of the scraper 720 must all be in contact with the stencil 130 when in operation. Therefore, in order to retain the solder paste in the path of the scraper 720 without affecting the operation of the scraper 720, the baffles 780 must be able to move up and down relative to the connecting block 820 and the scraper holder 710. That is, the baffles 780 need to move upward when pressure is applied to the stencil by the scraper 720 and the stencil is deformed, and the baffles 780 need to move downward when pressure is no longer applied to the stencil by the scraper 729 or when the pressure applied decreases in order to return the stencil to its original shape. Thus, the lowest end of the baffle 780 is always coplanar with the lowest end of the scraper 720 (i.e., both are in contact with the stencil 130), and the baffle 780 always holds solder paste in the path of the scraper 720 without affecting the operation of the scraper 720. To allow the baffle 780 to move up and down relative to the mounting block 820 with deformation of the scraper 720, the scraper assembly 700 further comprises a pair of elastic plates 790 connected to the scraper holder 710, each extending to a position above the pair of baffles 780. Furthermore, the pair of elastic plates 790 are configured to elastically deform due to the thrust of the baffles 780 when the pair of baffles 780 moves upward, and to allow the pair of baffles 780 to move downward due to the restoring force.

[0042] Figures 9A and 9B are side views of the scraper 720 in the scraping device 700 for the stencil 130 at a first and second inclination angle position, respectively, and the baffle 780 is not shown in order to clearly show the scraper 720. In Figure 9A, the internal angle between the scraper 720 and the stencil 130 is θ3, and in Figure 9B, the internal angle between the scraper 220 and the stencil 130 is θ4. As shown in Figure 9A, the reference edge 752 of the marking plate 750 is aligned to a 65-degree angle scale, which indicates that the internal angle θ3 between the scraper 720 and the stencil 130 is 65 degrees. As shown in Figure 9B, the reference edge 752 of the marking plate 750 is aligned to a 40-degree angle scale, which indicates that the internal angle θ4 between the scraper 720 and the stencil 130 is 40 degrees. Through the angle indicated by the reference edge 752 of the marker plate 750, the operator can easily identify and adjust the inclination angle of the scraper 720 relative to the stencil.

[0043] Through long-term observation, the inventors of this disclosure have found that the inclination angle of the scraper relative to the stencil in existing stencil printers is not adjustable; that is, the inclination angle of the scraper relative to the stencil is the same regardless of the viscosity of the material being extruded, the size of the holes in the stencil, etc., and therefore the same pressure is always applied to the stencil by the scraper, which often prevents the material being extruded by the stencil printer from falling from the stencil onto the electronic substrate below the stencil at the desired speed. To this end, this disclosure provides a scraper assembly and a stencil printer using the scraper assembly, the scraper assembly of this disclosure having a mounting assembly arranged so that the angle of the scraper relative to the stencil can be adjusted as required and the stencil can be maintained at the adjusted angle position. More specifically, when used in the field, various influencing factors such as the viscosity of the material being extruded and the size of the holes in the stencil can also be taken into consideration in order to adjust the angle of the scraper relative to the stencil so that the material being extruded, squeegeeed by the scraper, falls from the holes in the stencil onto the electronic substrate below the stencil at the desired speed. Furthermore, the mounting assembly of the scraper assembly of this disclosure, for adjusting the angle of the scraper relative to the stencil, is not only simple in structure but also easy to operate, thereby allowing the field operator to easily adjust the angle of the scraper relative to the stencil.

[0044] While this disclosure has been described in conjunction with the example of scraper assembly outlined above, various alternative forms, modifications, changes, improvements, and / or substantial equivalents may be apparent to those skilled in the art, whether currently known or foreseeable in the near future. In addition, the technical effects and / or technical problems described herein are illustrative and not limiting, and therefore the disclosure may be used to solve other technical problems, may have other technical effects, and / or may solve other technical problems. Accordingly, the example of scraper assembly in this disclosure described above is illustrative and not intended to limit. Various modifications can be made without departing from the spirit or scope of this disclosure. Accordingly, this disclosure is intended to include all known or previously developed alternative forms, modifications, changes, improvements, and / or substantial equivalents. [Configuration 1] A scraping device (200, 700) for a stencil printer, Scraper holder (210, 710), A scraper (220, 720) having a path for squeezing material discharged onto a stencil (130), wherein the scraper (220, 720) is positioned diagonally to the stencil (130) and diagonally to the rear of the path, A mounting assembly (230, 730) is configured to attach the scraper (220, 720) to the scraper holder (210, 710), Equipped with, The mounting assembly (230, 730) is configured to allow adjustment of the inclination angle of the scraper (220, 720) relative to the stencil (130) and to maintain the scraper (220, 720) in the adjusted angular position. Scraping device (200, 700). [Configuration 2] The aforementioned mounting assembly (230, 730) A support column (310, 810) having a rotation axis X, which is connected to the scraper holder (210, 710), Equipped with, The scrapers (220, 720) are connected to the support columns (310, 810), and the scrapers (220, 720) have a longitudinal direction laterally with respect to the movement path, and the longitudinal direction of the scrapers (220, 720) coincides with the direction of the rotation axis X. The inclination angle of the scraper (220, 720) relative to the stencil (130) is adjusted by rotating the support column (310, 810) about its rotation axis X. Scraping device (200, 700) as described in Configuration 1. [Configuration 3] The aforementioned mounting assembly (230, 730) A pair of connecting blocks (320, 820) connect the two axial ends of the support columns (310, 810) to the scraper holders (210, 710), respectively. Furthermore, The connecting block (320, 820) has a locked state and an unlocked state, and when the connecting block (320, 820) is in the unlocked state, the support column (310, 810) can adjust the inclination angle of the scraper (220, 720) relative to the stencil (130) by rotating about its rotation axis X, and when the connecting block (320, 820) is in the locked state, the connecting block (320, 820) restricts the rotation of the support column (310, 810) about its rotation axis X in order to maintain the scraper (220, 720) in the adjusted angular position. Scraping device (200, 700) as described in configuration 2. [Structure 4] The connecting block (320, 820) comprises holes (421, 821) and openings (423, 823) communicating with the holes (421, 821), the openings (423, 823) being positioned on one side of the holes (421, 821) to receive the axial ends of the support columns (310, 810), the openings (423, 823) dividing the connecting block (320, 820) into a first part (426, 826) and a second part (428, 828), the first part (426, 826) and the second part (428, 828) being able to open and close relative to each other to increase or decrease the size of the holes (421, 821), The mounting assembly (230, 820) further comprises fasteners (390, 890) which detachably fasten the first portion (426, 826) and the second portion (428, 828) in the opening (423, 823) such that the connecting block (320, 820) has a locked state and an unlocked state. Scraping device (200, 700) as described in configuration 3. [Composition 5] Furthermore, An angle indicator device fixedly connected to the support column (810), configured to indicate the inclination angle of the scraper (720) relative to the stencil (130) based on its relative position to the connecting block (820), The scraping device (700) described in configuration 3, comprising: [Composition 6] The scraping device (700) according to configuration 5 is an angle indicator device which is an indicator plate (750) connected to one axial end of the support column (810) and configured to rotate together with the support column (810). [Composition 7] The sign plate (750) has a reference edge (752) that is arranged parallel to the scraper (720), The scraping device (700) according to configuration 6, wherein the connecting block (820) is provided with an angle scale, and the scale pointing to the reference edge (752) represents the inclination angle of the scraper (720) relative to the stencil (130). [Structure 8] The scraping device (700) according to configuration 6 is located on the opposite side of the scraper (720) in the connecting block (820). [Composition 9] The scraping device (700) according to configuration 6, wherein the indicator plate (750) is provided with a limiting groove (753), the limiting groove (753) extends in the circumferential direction and receives a limiting pin (757) arranged on the connecting block (320). [Configuration 10] The scraping device (200, 700) according to configuration 2, wherein the support columns (310, 810) are provided with generally flat support surfaces (315, 815) positioned on their first sides. [Composition 11] The aforementioned mounting assembly (230, 730) A support plate (330, 830) is tightened between the support surface (315, 815) of the support column (310, 810) and the scraper (220, 720), Furthermore, The scraping device (200, 700) according to configuration 10, wherein the scraper (220, 720) can bend around the bottom edge (335, 835) of the support plate (330, 830). [Composition 12] A stencil printer equipped with a scraping device (200, 700) as described in any one of configurations 1 to 11.

Claims

1. A scraping device (200, 700) for a stencil printer, Scraper holder (210, 710), A scraper (220, 720) having a movement path for squeezing material discharged onto a stencil (130), wherein the scraper (220, 720) is positioned diagonally to the stencil (130) and diagonally to the rear of the movement path, A mounting assembly (230, 730) is configured to attach the scraper (220, 720) to the scraper holder (210, 710), Equipped with, The mounting assembly (230, 730) is configured to allow adjustment of the inclination angle of the scraper (220, 720) relative to the stencil (130), and to maintain the scraper (220, 720) in the adjusted angular position. The aforementioned mounting assembly (230, 730) A support column (310, 810) having a rotation axis X, which is connected to the scraper holder (210, 710), Equipped with, The scrapers (220, 720) are connected to the support columns (310, 810), and the scrapers (220, 720) have a longitudinal direction laterally with respect to the movement path, and the longitudinal direction of the scrapers (220, 720) coincides with the direction of the rotation axis X. The inclination angle of the scraper (220, 720) relative to the stencil (130) is adjusted by rotating the support column (310, 810) about its rotation axis X. The support columns (310, 810) are provided with generally flat support surfaces (315, 815) positioned on their first side, The aforementioned mounting assembly (230, 730) A support plate (330, 830) is tightened between the support surface (315, 815) of the support column (310, 810) and the scraper (220, 720). Furthermore, The scraper (220, 720) can bend around the bottom edge (335, 835) of the support plate (330, 830). Scraping device (200, 700).

2. The aforementioned mounting assembly (230, 730) A pair of connecting blocks (320, 820) connect the two axial ends of the support columns (310, 810) to the scraper holders (210, 710), respectively. Furthermore, The connecting blocks (320, 820) have a locked state and an unlocked state, and when the connecting blocks (320, 820) are in the unlocked state, the support columns (310, 810) can adjust the inclination angle of the scraper (220, 720) relative to the stencil (130) by rotating about their rotation axis X, and when the connecting blocks (320, 820) are in the locked state, the connecting blocks (320, 820) restrict the rotation of the support columns (310, 810) about their rotation axis X in order to maintain the scraper (220, 720) in the adjusted angular position. The scraping device (200, 700) according to claim 1.

3. The connecting block (320, 820) comprises holes (421, 821) and openings (423, 823) communicating with the holes (421, 821), the openings (423, 823) being positioned on one side of the holes (421, 821) to receive the axial ends of the support columns (310, 810), the openings (423, 823) dividing the connecting block (320, 820) into a first portion (426, 826) and a second portion (428, 828), the first portion (426, 826) and the second portion (428, 828) being able to open and close relative to each other to increase or decrease the size of the holes (421, 821), The mounting assembly (230, 820) further comprises fasteners (390, 890) which detachably fasten the first portion (426, 826) and the second portion (428, 828) in the opening (423, 823) such that the connecting block (320, 820) has a locked state and an unlocked state. The scraping device (200, 700) according to claim 2.

4. Furthermore, An angle indicator device fixedly connected to the support column (810), configured to indicate the inclination angle of the scraper (720) relative to the stencil (130) based on its relative position to the connecting block (820), The scraping device (700) according to claim 2, comprising:

5. The scraping device (700) according to claim 4, wherein the angle indicator device is an indicator plate (750) connected to one axial end of the support column (810), and the indicator plate (750) is configured to rotate together with the support column (810).

6. The sign plate (750) has a reference edge (752) that is arranged parallel to the scraper (720), The scraping device (700) according to claim 5, wherein the connecting block (820) is provided with an angle scale, and the scale pointing to the reference edge (752) represents the inclination angle of the scraper (720) relative to the stencil (130).

7. The scraping device (700) according to claim 5, wherein the indicator plate (750) is located on the opposite side of the scraper (720) in the connecting block (820).

8. The scraping device (700) according to claim 5, wherein the indicator plate (750) is provided with a limiting groove (753), the limiting groove (753) extends in the circumferential direction and receives a limiting pin (757) arranged on the connecting block (320).

9. A stencil printer comprising a scraping device (200, 700) according to any one of claims 1 to 8.

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