JPH01238189A - Double printing of flexible substrate - Google Patents

Abstract

PURPOSE:To rapidly and accurately lap print by plating a flexible board printed with a picture pattern on a screen printing base, then further lap printing a picture pattern on a printed board by a next aligned screen printing plate. CONSTITUTION:Positioning holes are formed at two points on the diagonal lines of boards in which first printing is finished, one of which is used as a dummy. Then, a second screen printing plate 2 is suitably set in a screen printer 20, and a dummy board 5 is adhered with a tape 3 while observing the picture pattern of the plate 2 inside the plate 2. Then, the tape 2 which adheres the board 5 is peeled, and the board 5 is removed from the plate 2. Thereafter, the positioning hole of the board desired to be lap printed is aligned to a marker 7 on a printing base 1 with bare eyes, the board is secured on the base 1, and lap printed. Thus, even if the profile dimensional accuracy of the board is wrong, its alignment accuracy does not become irregular.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention places a flexible substrate on which a predetermined pattern is printed on a screen printing table, and then uses an aligned screen printing plate to The present invention relates to a method of further overprinting the above-mentioned predetermined pattern on the flexible substrate printed with the predetermined pattern.

[Prior Art] What is important when performing overprinting is the positional relationship between the already printed pattern and the pattern to be overprinted. In the manufacture of printed circuit boards, the following 41 types of alignment methods have conventionally been adopted in order to minimize misalignment.

The first example is what is called the hit printing method. An outline of this method is shown in FIGS. 2A, 2B, and 2C.

In FIG. 2A, 20 is a screen printing machine, 1
is a screen printing stand, and 2 is a screen printing plate.

First, for printing position alignment, one of the substrates that has been printed for the first time is prepared as a dummy substrate. Next, referring to FIG. 2A, two
Set the screen printing plate 2 at an appropriate position.

Next, the dummy substrate 5 is placed on the screen printing stand 1.

Next, referring to FIG. 2B, the motor (not shown) attached to the screen printing machine 20 is rotated to suck air (air is sucked in the direction shown by arrow 8), and slowly The screen printing plate 2 is lowered onto the screen printing table 1. Then, the positional relationship between the dummy substrate 5 and the screen printing plate 2 is examined with the naked eye from directly above, and the position adjustment knob (not shown) installed between the screen printing plate 2 and the screen printing table 1 is checked. ) to the left or right little by little to finely adjust the position of the screen printing plate 2 in the vertical and horizontal directions. When the fine adjustment is completed, stop the air suction and place the screen printing plate 2 on the screen printing table 1.
Raise it from

Next, prepare two thin plates, such as unclad (meaning that no copper foil is pasted) plate 9, having the same thickness as the dummy board 5 or slightly thinner, cut into rectangles of 9 x 50 mm. Apply double-sided tape to one side of each. Then, referring to FIG. 2C, while firmly holding the dummy board 5 with one hand so that it does not move, use the other hand to place the board 9 on which the double-sided tape is pasted on the four corners of the dummy board 5. Stick it tightly to one corner (usually the lower left corner) and paste it on the screen printing table 1 in a square shape. Then, the dummy board 5 is placed on the screen printing table 1.
When removed, the thin plate 9 stuck in a V-shape remains on the screen printing table 1 as a frame. In this way, a certain positional relationship is established between the screen printing plate 2 and the T-shaped frame formed by the thin plate 9. After that, when performing the actual printing, place one corner of the four corners (usually the lower left corner) of the board on which you want overprinting to the corner of the square frame and print. can do. Note that if the thin plate 9 forming the frame is thicker than the thickness of the substrate on which overprinting is desired, it cannot be used because the printing operation will be difficult.

A second method for overprinting is to use pins. Figures 3A, 3B, 3C and 3D schematically illustrate this method.

Referring to FIG. 3A, when printing the substrate 5 for the first time, 0.9
Print a circle 4 of ~1.0φ. Thereafter, a hole having the same diameter as the circle 4 is drilled in the circle 4 using a punch or a drill. The figure shows a case where holes are made at two diagonal corners.

Next, referring to FIG. 3B, the second
The screen printing plate 2 for the second printing is set at an appropriate position. Next, one of the substrates 5 that has finished the first printing
The sheet is placed on the screen printing stand 1 as a dummy. In the figure, 5 is a dummy substrate. Next, a motor (not shown) attached to the screen printing machine 20 is rotated,
The air is suctioned (air is pulled in the direction of arrow 8 in the figure), and the screen printing plate 2 is slowly lowered onto the screen printing table 1. Then, the positional relationship between the dummy substrate 5 and the screen printing plate 2 is examined with the naked eye from directly above, and the position adjustment knob (not shown) installed between the screen printing plate 2 and the screen printing table 1 is checked. ) to the left or right little by little to finely adjust the position of the screen printing plate 2 in the vertical and horizontal directions.

Next, referring to FIG. 3C, after the fine adjustment is completed, the suction of air is stopped and the screen printing plate 2 is raised from the screen printing table 1.

Next, prepare 4 or 2 pins. The diameter of this pin shall be 0.1 mm smaller than the diameter of the holes drilled at the four or two corners of the dummy board 4, and the length of the pin shall be the same thickness as the dummy board 5 or longer. 0.1mm
The length shall be short.

Referring to FIGS. 3C and 3D, apply adhesive to the bottom surface of this pin 10, and firmly press the dummy substrate 5 on the screen printing table 1 with one hand so that it does not move.
With your other hand, press the four corners or two corners provided on the dummy board 5.
Place the pin coated with the above adhesive into the hole in the corner, with the bottom facing down.

Next, after the adhesive has dried, screen printing table 1 and pin 1
0 is fixed, the dummy substrate 5 is slowly raised directly above and removed from the screen printing table 1. In this way, the screen printing plate 2 and the pin 1 on the screen printing table 1 are
0, a certain positional relationship is created. After that, in the actual printing, if you fit the pins 10 into the holes at the four corners or two diagonal corners of the board on which you want overprinting, set the board 5, and then start printing, you can perform overprinting. Can be done.

Note that if the length of the pin to be used is longer than the thickness of the substrate, a hole will be made in the screen printing plate 2, so care must be taken.

A third method for overprinting is to use print alignment marks. FIG. 4 is a diagram for explaining this method.

In the figure, 11 is an alignment mark printed on the board 5;
Reference numeral 1' corresponds to the alignment mark 11 described above, and is an alignment mark provided on the screen printing plate 2. Next, the operation will be explained. screen printing machine 20
The second screen printing plate 2 is set appropriately, the substrate 5 that has been printed for the first time is placed on the screen printing stand 2, and then the motor attached to the screen printing machine 20 (not shown) is placed on the screen printing table 2. ) to suction air (pull air in the direction shown by arrow 8), and slowly lower screen printing plate 2 onto screen printing table 1. Next, the positional relationship between the alignment mark 11 printed on the substrate 5 and the alignment mark 11' provided on the screen printing plate 2 is examined with the naked eye from directly above, and the positional relationship between the alignment mark 11 printed on the substrate 5 and the alignment mark 11' provided on the screen printing plate 2 is checked. By turning a position adjustment knob (not shown) installed between screen printing plate 1 and screen printing plate 2 little by little to the left or right, the screen printing plate 2 can be moved vertically and horizontally.
After finely adjusting the position and aligning the two alignment marks 11 and 11' accurately, the second printing is performed.

The fourth example of the overprinting method is the simplest method,
This is a method of aligning the first printed pattern with the second screen printing pattern for each board to be printed. First, the second screen printing plate is appropriately set in the screen printing machine. Next, the substrate that has been printed for the first time is placed on a screen printing table. Next, the motor attached to the screen printing machine is rotated to suction air, and the screen printing plate is slowly lowered onto the screen printing table. Then, check the positional relationship between the board and the screen printing plate with the naked eye from directly above, and move the position adjustment knob installed between the screen printing plate and the screen printing stand to the left or right, based on the position of the design. Finely adjust the position of the screen printing plate vertically and horizontally by turning it little by little to the right. After that, a second printing is performed.

[Problems to be Solved by the Invention] The conventional alignment method is configured as described above. However, both methods have the following problems.

In the first conventional per printing method, when this method is applied to a flexible substrate having a thickness of only 50 to 100 μm, it becomes difficult to fix the substrate on which overprinting is desired in that position.

This is because, in this per-printing method, when the above-mentioned flexible substrate is used as the substrate 5, the thickness of the thin plate 9 forming the frame is the same as or less than the thickness of the flexible substrate, as shown in FIG. 2C. It needs to be thinner than
This is because if the thin plate 9 is made thinner than 50 to 100 μm, it will no longer be possible to fix the substrate. Furthermore, since this method performs alignment based on the thin plate 9 forming the frame, there is a problem in that if the external dimensions of the board 5 vary, the accuracy of pattern alignment also varies accordingly. was.

Next, regarding the method using the second bottle, referring to Figure 3D, it is difficult to apply this method to a flexible substrate with a thickness of 50 to 100 μm (although this method (This is effective for thick boards)
. This is because in this method, in order to prevent the bottle 10 from tearing the screen printing plate 2, the length of the bottle 10 must be made shorter than the thickness of the flexible substrate 5;
This is because if the length of the bottle 10 is shortened in this way, the bottle 10 will not be able to fix the substrate 4 in an appropriate position.

The third method using printed alignment marks can also be applied to thin flexible substrates. However, the fourth
Referring to the figure, this method requires alignment for each board to be printed, so it takes too much time and the positioning accuracy varies from board to board. Not suitable for what is required.

Similar to the third method, problems with the fourth method include that it takes too much time and that positional accuracy varies because alignment must be performed for each substrate to be printed.

This invention was made to solve the above-mentioned problems, and it is an object of the present invention to provide a method for overprinting flexible substrates, which can perform overprinting quickly and accurately.

[Means for Solving the Problems] The present invention places a flexible substrate on which a predetermined pattern is printed on a screen printing table, and then prints the predetermined pattern using an aligned screen printing plate. This relates to a method of further overprinting on a printed flexible substrate.

It includes the following steps.

(1) A step of drilling positioning holes in at least two locations on the flexible substrate. The positioning holes are drilled based on the marks printed together with the patterns printed during the first printing.

(2) A step of fixing drafting marks at at least two locations on the screen printing table.

The positional relationship of each of the above drafting marks is as follows when the above flexible substrate is placed on the above screen printing table.
The positioning holes bored in the flexible substrate are selected so as to overlap the drafting marks.

(3) Aligning the positioning holes drilled in the flexible substrate with the drafting marks fixed on the screen printing table, and then placing the flexible substrate on the screen printing table.

(4) Next, a step of overprinting on the flexible substrate using the aligned screen printing plate.

[Operation] Align the positioning holes drilled in the flexible substrate with the drafting marks fixed on the screen printing table, then place the flexible substrate on the screen printing table, and then perform the alignment. Since the process of overprinting onto a flexible substrate using a screen printing plate that has been completed is adopted, the alignment work is simplified and its accuracy is also high.

[Example code] An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1A, 1B, and 1C show an embodiment of the present invention.

First, a plurality of substrates that have been printed for the first time are prepared. Then, positioning holes are made at two diagonal points on each board using a poza or a drill.

This positioning hole is drilled based on a mark printed at a predetermined position at the same time during the first printing. QH one of the boards with the positioning hole made as a dummy.

Referring to FIG. 1A, the second screen printing plate 2 is appropriately set on the screen printing machine 20.

Next, the dummy substrate 5 is pasted on the inside of the screen printing plate 2 (the side coated with emulsion) using commercially available tape 3 (for example, Sellotape) in the correct position while observing the design of the screen printing plate 2. .

Next, place two drafting marks, such as circular markers, for printing.
Prepare one. This circular marker is selected to have a diameter equal to the diameter of the positioning hole 4 made in the substrate 5.

The suitable diameter of this positioning hole is 2 to 3 φ for the best workability. Next, prepare two pieces of transparent polyester film cut into 10 mm squares, and paste the above-mentioned drafting mask on them (hereinafter, this integrated piece will be referred to as
It is abbreviated as marker 7. ). Next, double-sided tapes 6 and 6' are applied to both sides of the marker 7, respectively. Then, one side of the double-sided tape 6 is peeled off and pasted so as to fill the positioning hole 4 of the dummy substrate 5 attached to the inside of the screen printing plate 2. When this pasting is completed, one side of the other double-sided tape 6' is also peeled off.

Next, referring to FIG. 1B, the motor (not shown) attached to the screen printing machine 20 is turned to a suction state (air is drawn in the direction shown by arrow 8 in the figure). Then, the screen printing plate 2 is lowered into a printing state. At this time, one side of the other double-sided tape 6' is attached onto the screen printing table 1. Next, referring to FIG. 1C, when the suction is stopped and the screen printing plate 2 is raised again, the marker 7 remains on the screen printing table 1, adhered by the other double-sided tape 6'. At this time, one double-sided tape 6 may also adhere to the marker 7 and remain on the screen printing plate 2 side, but in this case, the one double-sided tape 6 may be removed.

Next, the cellophane tape 3 fixing the dummy substrate 5 is peeled off, and the dummy substrate 5 is removed from the screen printing plate 2. Thereafter, the positioning holes of the substrate desired for overprinting are aligned with the marker 7 on the screen printing table 1 with the naked eye, and then the substrate is fixed on the screen printing table 1 and overprinting is performed. After printing is completed, the next substrate is replaced with the same operation as described above, that is, the positioning hole 4 of the substrate is aligned with the marker 7. By repeating such operations, it is possible to perform overlapping printing one after another. This alignment operation is a simple operation, and the alignment accuracy is extremely high.

Therefore, flexible substrates can be overprinted quickly and accurately. This is true even if the flexible substrate is opaque.

Furthermore, with this method, even if the external dimensions of the substrate have poor accuracy and vary, the alignment accuracy does not vary. This is because the alignment reference is based on the positioning holes 4 (see FIG. 1C) that are drilled based on marks printed at predetermined positions at the same time during the first printing. Therefore, the problem that occurred in the case of the first conventional example, that is, the accuracy of printing positioning varies due to variations in external dimensions, is solved.

In addition, in the second prior art, as shown in FIG. In some cases, there was a problem that the substrate was not fixed sufficiently. However, with the method according to the invention, such problems do not arise.

Further, according to the present invention, the problems encountered in the third conventional technique and the fourth conventional technique are also solved. That is, the trouble of having to align the screen printing plates for each print is eliminated, and the problem of positional accuracy varying from print to print is also solved.

As described above, the present invention eliminates all the problems of the conventional method and allows quick and accurate overprinting, making it suitable for mass production.

Further, the present invention can be applied not only to transparent flexible substrates but also to opaque flexible substrates.

This invention has been described above with reference to specific examples, but
The invention may be embodied in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments described above are in all respects merely illustrative;
It should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted in any way by the main text of the specification. Furthermore, all modifications and changes that come within the scope of equivalents of the claims are intended to be within the scope of the present invention.

[Effects of the Invention] Since the method for overprinting flexible substrates according to the present invention is configured as described above, alignment becomes easy, and
Also, the accuracy becomes higher. As a result, you can quickly and accurately
This has the effect that flexible substrates can be printed in layers.

[Brief explanation of the drawing]

FIGS. 1A, 1B, and 1C are process diagrams of an embodiment of the present invention. FIG. 2A, FIG. 2B, and FIG. 2C are process diagrams of a first conventional example called the hit printing method. 3A, 3B, 3C, and 3D are process diagrams showing a second conventional method using pins. FIG. 4 is a third conventional example, and is a diagram showing a method using printed alignment marks. In the figure, 1 is a screen printing stand, 2 is a screen printing plate, 4 is a positioning hole, 5 is a flexible substrate, 6 is a double-sided tape, 7 is a marker, and 20 is a screen printing machine. In each figure, the same reference numerals indicate the same or corresponding parts. Figure 1B Figure 10\ False

Claims (1)

[Claims] A flexible substrate with a predetermined design printed on it is placed on a screen printing table, and then a screen printing plate that has been aligned is used to place the flexible substrate with the predetermined design printed on it. A method of further overprinting the flexible substrate, wherein positioning holes are bored in at least two places on the flexible substrate, and the positioning holes are bored based on a mark printed at a predetermined position along with the predetermined pattern. Drafting marks are fixed at at least two locations on the screen printing table, and the positional relationship of each of the drafting marks is such that when the flexible substrate is placed on the screen printing table,
The positioning holes drilled in the flexible substrate are selected so as to overlap the drafting marks, and when performing overprinting, the drafting marks fixed on the screen printing table are Align the positioning holes drilled in the flexible substrate, then place the flexible substrate on the screen printing stand, and then use the aligned screen printing plate to print on the flexible substrate. A method for overprinting flexible substrates.