Screen printing machine

Abstract

To provide a screen printing machine capable of solving such problems that conventional methods of printing circuits while conveying a single strip-shaped tape are inefficient, although conveying two or more strip-shaped tapes with respect to a single screen mask enables approximately double to several times of printing, since the several strip-shaped tapes have slight elasticity, minute misalignments in printing positions occur.SOLUTION: A screen printing machine comprises: a conveying device 3 having a suction table that conveys two rows of strip-shaped tapes 1; a screen mask 2 that can be driven in an X direction, a Y direction, a θ direction, and upward and downward directions; a printing squeegee 6 that is driven, stopped, and vertically moved in two stages; two CCD cameras that move in two stages corresponding to the first-row and second-row strip-shaped tapes 1; and a control device that performs synchronous control with the screen mask 2 and alignment marks 5 provided on the two rows of strip-shaped tapes 1 being printed matters.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a screen printing machine that uses a strip-shaped film tape to print circuit boards on which semiconductor components are mounted and assembled. [Background technology]

[0002] Conventionally, screen printers have been used to form patterns on COFs and FPCs, which use strip-shaped flexible film tape to serve as circuit boards for mounting and assembling semiconductor components. In screen printers that print with SR ink (photosensitive ink), for example, a reel method is used to print while feeding one strip of tape (see FIG. 11) onto one screen mask. However, the conventional method of printing while feeding one strip of tape has been problematic in terms of efficiency. Therefore, the present invention simultaneously feeds and feeds, for example, two strips of tape (see FIG. 1) onto one screen mask, enabling approximately twice the printing volume compared to previous printing methods. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-78464 A (see the claims, detailed description of the invention, and Figures 1 and 2) Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, with the increasing density of electronic components, the pitch of electrode pads on substrates has become finer and smaller, which poses various problems that must be solved when performing screen printing. Conventionally, printing circuits by feeding a single strip of tape is inefficient. However, by feeding two or more strips of tape per screen mask, printing can be performed approximately twice to several times more efficiently. However, because these several strips of tape have a slight elasticity, slight misalignment of the printing position occurs. The object of the present invention is to provide a screen printing machine that can solve this problem. [Means for solving the problem]

[0005] A first aspect of the present invention that can achieve the above object is a screen printing machine as set forth in claim 1, which is as follows. The system is configured to be synchronized and controlled by a control device using a conveying device with a suction table that conveys two rows of strip tape, a screen mask that can be driven in the X, Y, and θ directions and up and down, a printing squeegee that can be driven, stopped, and moved up and down in two stages, two CCD cameras that move in two stages to match the first and second rows of strip tape, and alignment marks on the screen mask and the two rows of strip tape that are the printed material.

[0006] A second aspect of the present invention that can achieve the above object is a screen printing machine as set forth in claim 2, which is as follows. The system is configured to be synchronized and controlled by a control device using a conveying device with a suction table that conveys three or more rows of strip tape, a screen mask that can be driven in the X direction, Y direction, θ direction, and up and down directions, a printing squeegee that drives, stops, and moves up and down in three or more stages, two CCD cameras that move in three or more stages to match the first, second, third or more, or multiple rows of strip tape, and alignment marks provided on the screen mask and the three or more rows of strip tape that is the printed material. [Effects of the Invention]

[0007] The screen printing machine according to the present invention has the above-described configuration and thereby provides the following effects. (1) By simultaneously feeding and supplying two rows of strip tape onto one screen mask, it is possible to print approximately twice as much. This is because the first and second rows are not always fed with precision, and slight misalignment occurs. The screen printing machine of the present invention is a screen printing machine that can repeatedly supply tape with high precision, for example, within an error of 20 μm, when the finished product is produced. (2) By simultaneously feeding and supplying three or more rows of tape for one screen mask, printing can be performed approximately three times or more. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram showing an embodiment of a screen printing machine of the present invention. [Figure 2] This is a schematic diagram showing an embodiment of a screen printing machine that includes a conveying device consisting of a suction table that simultaneously supplies two strip-shaped tapes, and three motors (e.g., servo motors) that drive a screen mask required for positioning in the X, Y, and θ directions above the conveying device. [Figure 3] This is a schematic diagram showing the structure in which a CCD camera showing one embodiment of the present invention aligns (adjusts) to the alignment mark on the first row of strip tape, checks the forward stop marker, feeds back the positional deviation to a PC, moves the screen mask, and aligns the marker on the strip tape with the marker on the screen mask. [Figure 4] In one embodiment of the present invention, after the alignment of the first row of strip-shaped tape is completed, the CCD camera is moved to the position of the alignment marker on the second row of strip-shaped tape, and any positional deviation of the markers is recognized and stored in the PC in the same manner as in Figure 3, and the markers on the strip-shaped tape are aligned with the markers on the screen mask. However, at this time, the screen mask is not yet driven, and the CCD camera returns to its original position. This is a schematic diagram showing the structure. [Figure 5] 10 is a schematic diagram showing a state in which the CCD camera of one embodiment of the present invention has returned to its original position, the screen mask has descended to the printing position, and the printing squeegee has also descended. FIG. [Figure 6] FIG. 1 is a schematic diagram showing a state in which the printing squeegee of the present invention is temporarily stopped at point A, and printing of the first row of strip tape has been completed. [Figure 7] After the printing squeegee stops at point A, it rises and the printing table, which is the conveying device for the first row, descends. At this point, the values ​​stored in the PC, such as the positional deviation of the alignment markers on the strip tape for the second row in Figure 4, are used to drive the screen mask in the X, Y, and θ directions at this timing to align the second row. This is a schematic diagram showing the state in which the printing squeegee stops at point A and the printing table, which is the conveying device for the first row, descends. [Figure 8] FIG. 10 is a schematic diagram showing the state in which the squeegee is lowered to the printing position again after the alignment of the screen mask is completed. [Figure 9] FIG. 1 is a schematic diagram showing the squeegee moving from point A to point B. [Figure 10] 10 is a schematic diagram showing the state in which the squeegee rises at point B and the printing table descends as shown by the arrow. [Figure 11] In order to accurately recognize the printing position on the strip tape of a conventional screen printer, alignment marks are generally provided at any desired locations within a single printing area as needed. This is a schematic diagram showing how the alignment marks are normally aligned (adjusted) using two CCD cameras. DETAILED DESCRIPTION OF THE INVENTION

[0009] This screen printing machine is synchronously controlled by a control device using a conveying device with a suction table that conveys two rows of strip tape, a screen mask that can be driven in the X, Y, and θ directions and up and down, a printing squeegee that can be driven, stopped, and moved up and down in two stages, two CCD cameras that move in two stages to match the first and second rows of strip tape, and alignment marks on the screen mask and the two rows of strip tape that are the printed material. [Example]

[0010] An embodiment of the screen printing machine of the present invention will be described below with reference to the drawings. An embodiment of the screen printing machine of the present invention will be described with reference to FIGS. First, in order to explain the difference between the present invention and the conventional example, the conventional example will be described with reference to FIG. In order to accurately recognize the printing position, multiple alignment marks are generally placed on the strip tape at any desired location within the printing area as needed. These alignment marks are usually viewed using two CCD cameras, one on the left and one on the right, to perform fine position adjustments for alignment. The screen printing machine of the present invention comprises a roll means for winding up a strip-shaped film tape, a conveying device having a suction table for conveying the strip-shaped film tape, an ink supplying means for supplying ink to a screen mask, a motor for moving the screen mask in the X, Y, and θ directions, a CCD camera, and a squeegee.

[0011] The present invention will now be described in further detail. When printing on long substrates such as strip-shaped film sheets or film tapes, the film tape may become slightly twisted, causing misalignment between the two strips of film tape. To improve this, the screen printing machine of the present invention has discovered that moving the film tape to adjust it can gradually increase the misalignment, and has solved this drawback by fine-tuning the screen mask in the X-axis, Y-axis, and θ-axis (theta-axis) directions.

[0012] The structure and function of the present invention will be described with reference to FIGS. The screen printing machine shown in Figure 1 is a machine in which two strips of tape 1 are fed onto one screen mask 2 by a conveying device 3, and both strips (two rows) can then be positioned with an error of less than 20 μm. The operation procedure of the screen printing machine of the present invention will be described below with reference to FIGS. In Figure 2, two strips of tape 1 are supplied at the same time, and the tape 1 is conveyed while being fixed in place by a conveying device 3 with a suction table, with conveying accuracy within a range of about 1 mm. Furthermore, to fine-tune the movement of the screen mask 2, three motors (e.g., servo motors) are required to drive the screen mask in the necessary X, Y, and θ directions. Next, in Figure 3, the CCD camera 4 uses the alignment marks 5 on the first row of strip tape 1 to move forward and stop for alignment (adjustment), check the alignment marks 5, and feed back any positional deviation to a PC (not shown) to move the screen mask 2 and align the marks on the strip tape 1 with the marks on the screen mask 2. Next, in Figure 4, after the alignment of the first row of strip tape 1 is completed, the CCD camera 4 moves to the position of the alignment mark 5 of the second row of strip tape 1, and recognizes any positional deviation of the alignment mark 5, etc., as explained in Figure 3, and stores the information in the PC. Here, the difference from what has been explained in FIG. 3 is that the screen mask 2 is not yet driven and the CCD camera 4 returns to its original position. In FIG. 5, the CCD camera 4 returns, the screen mask 2 descends to the printing position, and at the same time the printing squeegee 6 descends. Next, as shown in FIG. 6, the printing squeegee 6 stops temporarily at point A, where printing on the first row of the strip of tape 1 is completed. In Figure 7, the printing squeegee 6 stops at point A and then rises, and the printing table 7 of the transport device 3 having the first row of suction tables descends. However, in some cases the printing table 7 does not need to descend, and in this case the rising position of the printing squeegee 6 can be any position. At this timing, the screen mask is driven in the X, Y, and θ directions, taking into consideration the positional deviation of the alignment marks 5 on the second row of tape strip 1, etc., stored in the PC in Figure 4, to align the second row of tape strip 1. In other words, it is not possible to align different values ​​for the first and second rows of tape strip 1 simultaneously in one go. In FIG. 8, after the alignment of the screen mask 2 is completed, the printing squeegee 6 is lowered again to the printing position. Next, as shown in Fig. 9, the printing squeegee 6 moves from point A to point B. Then, as shown in Fig. 10, at point B, the printing squeegee 6 rises and the printing table 7 of the transport device 3 having the suction table descends. In the above-described work process, the control of the movement of the screen mask 2 in the X, Y, and θ directions, the control of the vertical movement of the conveying device 3 with the suction table, the control of the movement of the two CCD cameras 4 in the left and right directions including temporary stops, and the control of the conveying of the strip tape 1 are all synchronized, and conventional control means are adopted. [Industrial Applicability]

[0013] The present invention can be applied to various types of printing presses, in which printing materials are transported in multiple rows, as opposed to a single row in order to increase the throughput. [Explanation of symbols]

[0014] 1. Strip tape 2. Screen Mask 3. Conveyor device 4. CCD camera 5 Alignment mark 6. Printing squeegee 7. Printing table

Claims

1. A screen printing machine characterized by a conveying device having a suction table for conveying two rows of strip-shaped tape, a screen mask that can be driven in the X direction, Y direction, θ direction, and up and down directions, a printing squeegee that can be driven, stopped, and moved up and down in two stages, two CCD cameras that can move in two stages in accordance with the first and second rows of strip-shaped tape, and a control device that synchronously controls the screen mask and the two rows of strip-shaped tape that are the printed matter.

2. A screen printing machine characterized by comprising: a conveying device having a suction table for conveying three or more rows of strip-shaped tape; a screen mask that can be driven in the X direction, Y direction, θ direction, and upward and downward directions; a printing squeegee that can be driven, stopped, and moved up and down in three or more stages; two CCD cameras that can be moved in three or more stages in accordance with the first, second, third or more, or multiple rows of strip-shaped tape; and a control device that controls the screen mask and the three or more rows of strip-shaped tape in synchronization with each other using alignment marks provided on the screen mask and the three or more rows of strip-shaped tape that is the printed material.

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