JPH0828567B2 - Printer - Google Patents

Description

The present invention relates to a printing machine for supplying a paste to a fine-pitch printed circuit board, and more particularly to a printing machine suitable for precise paste reciprocal printing.

[Conventional technology]

In a conventional printing machine, various proposals have been made for the purpose of improving printability and speeding up printing speed when performing paste printing on a printed circuit board.

For example, in the method disclosed in Japanese Patent Laid-Open No. 60-137683, the squeegee printing speed is changed during the paste rolling adjustment and during printing in order to speed up the paste printing. That is, as shown in FIG. 2, in the paste rolling area 36, the print speed of the squeegee indicated by the arrow 33a is changed from a low speed (speed at which the paste 34 is rolling) to a high speed, and the print area 35 is changed. Then, arrow 33b
The squeegee printing speed indicated by is set to high speed and constant. Incidentally, 31 is a mask, 32 is a squeegee, and 37 is a rolling direction of the paste 34.

Further, in this method, the squeegee is not inclined with respect to the moving direction and is always orthogonal. Therefore, no mechanism for shifting the squeegee depending on the moving direction is provided.

[Problems to be Solved by the Invention]

In the above-mentioned conventional technique, for parts having two kinds of pad directions such as a QFP (quad flat package) in which the lead interval is reduced to 0.5 mm or less, when the mask hole size is the same, the printing solder amount is the same. There is no consideration about the point of changing the mask hole size (hole width direction),
I had to get the same amount.

In other words, the printing speed of the squeegee is constant, so if the hole is short in the squeegee movement direction, the contact length between the squeegee and the hole is long, and even if the contact time is short, the total amount of paste entering the hole is large. Become. Also, in the case of a hole that is long in the squeegee moving direction, the total amount of paste that enters the hole is small for the completely opposite reason.

An object of the present invention is to improve such problems, and if the mask hole shape and size are the same, it is possible to print the same amount of paste even on pads in different directions, Another object of the present invention is to provide a printing machine capable of reciprocal printing.

[Means for solving the problem]

To achieve the above object, the printing machine of the present invention comprises means for shifting the squeegee position (see FIG. 7) and means for switching the tilt angle of the squeegee with respect to the printing table surface depending on the squeegee movement direction during reciprocal printing. (See Fig. 6)
It is equipped with, and the squeegee is attached by inclining it up to 45 degrees to the moving direction of the squeegee, and it is also attached to the side of the rectangular hole on the mask.
The squeegee is set to intersect with each other at the same time, and the squeegee position is shifted so that the residual paste at the time of forward printing is collected and supplied at the time of reprinting, and printing is continued while collecting the residual paste. is there.

[Action]

In the present invention, the squeegee is moved in advance in the moving direction.
Tilt at 45 ° and set.

As a result, as long as the holes have the same shape, the change in the contact length between the squeegee and the hole in the squeegee movement direction is the same over time, and the contact time is the same. The impact is the same. Therefore, the squeegee can print exactly the same amount of paste whether it is a long hole or a short hole in the moving direction.

Further, since the squeegee angle switching mechanism causes the squeegee to rotate at the same angle around the upper portion of the mounting portion, reciprocal printing is possible.

Furthermore, the squeegee position moving mechanism shifts the squeegee position during reciprocation (forward and reverse directions), so that during printing in the forward direction, the paste that moves along the squeegee surface and flows out and remains on the mask does not move in the reverse direction. The paste is smoothly supplied to the squeegee because it is rewound in the squeegee during printing.

This eliminates the need for a paste supply mechanism, and since the overlapping print width in reciprocal printing can be made large, the actual print width can be made large.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a printing machine according to an embodiment of the present invention,
FIG. 3 is an assembly drawing of a squeegee according to an embodiment of the present invention,
FIG. 4 is an explanatory view of the movement of the squeegee in one embodiment of the present invention, FIG. 5 is an explanatory view of the time when the squeegee crosses the hole of the mask in one embodiment of the present invention, and FIG. 6 is one embodiment of the present invention. FIG. 7 is a block diagram of a squeegee angle switching mechanism in an example, and FIG. 7 is a block diagram of a squeegee position moving mechanism in an embodiment of the present invention.

In FIG. 1, 1 is a squeegee for printing a paste, 2 is a squeegee moving mechanism, 3 is a printing table, 4 is a printed circuit board, 5 is a mask, 6 and 7 are printed circuit board fixing blocks, and 8 and 9 are masks. A fixed handle, 10 is an alignment mechanism, 11 is a table up / down mechanism, and 12 is a squeegee up / down mechanism.

In this embodiment, at the time of initializing, the squeegee 1 is at the right end and in a raised position, the printing table 3 is in a lowered position, and the printed circuit board 4 and the mask 5 are in a removed state. In addition, the squeegee 1 has a 45
It is installed so that it is at an angle of °.

Further, the squeegee moving mechanism 2 is used for printing when printing.
Is to move left and right, and the alignment mechanism 10
The printed circuit board 4 fixed on the print table 3 and the mask 5 are aligned with each other.

Further, the table raising / lowering mechanism 11 raises and lowers the printing table 3 to provide a printing / printing board 4 setting / resetting position. That is, it is at the time of printing and at the time of setting / resetting the printed circuit board 4.

Further, the squeegee up / down mechanism 12 raises and lowers the squeegee 1 to provide a position for printing and setting / resetting the mask 5. In other words, when printing
It is on reset.

If the stroke of the squeegee up / down mechanism 12 is sufficient and the printed circuit board 4 can be set / reset and fixed, the table up / down mechanism 11 may be omitted. Further, the squeegee up / down mechanism 12 may be moved up and down only around the squeegee 1, and the squeegee moving mechanism 2 may not be moved up and down.

 Here, the assembly of the squeegee portion will be described.

In FIG. 3, (a) is a top view of the squeegee 1 in a set state, and (b) is a front view.

In this embodiment, the squeegee 1 is held in the squeegee holder 13 and is set so as to be inclined with respect to the printed circuit board 4. If the squeegee 1 is a sword squeegee, it is set upright on the printed circuit board 4.

Next, the execution print width when the squeegee 1 is moved in the reciprocating print direction will be described.

In FIG. 4, (a) is a view of the squeegee 1 seen from above when the squeegee 1 is moved in the left-right direction, and (b) is a front view of the squeegee 1 in the case of (a). A is the print width when the squeegee 1 is moved to the right, B is the print width when the squeegee 1 is moved to the left, and C is the effective print width.

In this embodiment, the squeegee 1 is set at an angle of 45 ° with respect to the moving direction. Further, in order to continue printing while collecting the paste, the position is slightly shifted during the reciprocation, and the printing is executed. As a result, the effective print width C is where the print width A and the print width B overlap.

Next, the time during which the squeegee 1 contacts the holes on the mask 5 in this embodiment will be described.

In FIG. 5, 24 and 25 are holes of the same shape and size, which are installed on the mask 5 by rotating 90 °, and ˜ indicate squeegee movement positions per unit time. Also, (a) is a hole
Shows the contact time when the long side of 26 and the short side of hole 24 are orthogonal to the squeegee movement direction, and (b) shows the case where each side of holes 24 and 25 intersects the squeegee movement direction at 45 °. The contact time is shown.

In the case of (a), the contact is 5 units time in the hole 24 and 2 units time in the hole 25, which are very different. Therefore, the printed amount of the paste is different between the holes 24 and 25. on the other hand,
In the case of (b), both the holes 24 and the holes 25 are in contact with each other for 7 units of time, and the printing amount of the paste is the same. As a result, in this embodiment, the squeegee 1 is set so as to be inclined by 45 ° with respect to the moving direction.

Even if the squeegee 1 and the holes 24 and 25 do not come into contact with each other at exactly 45 °, it is sufficient that there is no significant difference in the printing amount.

Next, the squeegee angle switching mechanism of this embodiment will be described.

In FIG. 6, 1 is a squeegee, 13 is a squeegee holder, 14 is a squeegee bracket, 15 is a squeegee angle switching shaft, 16 is a squeegee angle switching rod, 17 is a stopper A, 18
Is a stopper B, 19 is a squeegee angle switching mechanism bracket,
Reference numeral 20 is a moving shaft of a squeegee angle switching mechanism.
It is included in the printing machine shown in the figure.

In this embodiment, the squeegee holder 13 is fixed to the squeegee bracket 14, and the squeegee bracket 14 rotates about the squeegee angle switching shaft 15 by the squeegee angle switching rod 16 up to the stopper A17 and the stopper B18. As a result, the inclination of the squeegee 1 with respect to the printed circuit board 4 is reversed during reciprocation.

Next, the squeegee position moving mechanism of this embodiment will be described.

In FIG. 7, 1 is a squeegee, 13 is a squeegee holder, 14 is a squeegee bracket, 15 is a squeegee angle switching shaft, 16 is a squeegee angle switching rod, 20 is a squeegee angle switching mechanism moving shaft, 21 is a squeegee position changing drive shaft, Reference numeral 22 is a squeegee position changing rod, and 23 is a squeegee angle switching mechanism moving rod, which are included in the printing machine shown in FIG.

In this embodiment, the squeegee angle switching mechanism including the squeegee bracket 14 is integrally moved by the squeegee position changing drive shaft 21 along the squeegee angle switching shaft 15 and the squeegee angle switching mechanism moving shaft 20, respectively. As a result, when performing reciprocal printing, the squeegee position is moved so as to increase the effective printing width.

In this embodiment, the squeegee angle switching mechanism (6th
(Fig.) And a squeegee position moving mechanism (Fig. 7) are provided. Instead of these, two squeegees 1 are prepared so that their inclinations with respect to the printed circuit board 4 are opposite to each other (c-shaped) and the printing direction is By providing a mechanism for selecting the squeegee to be used, the same effect can be obtained.

Next, the procedure of paste printing will be described with reference to FIGS. 1 and 6 to 8.

FIG. 8 is a control flow chart at the time of paste printing in one embodiment of the present invention.

In this embodiment, first, the mask 5 is set and fixed by the left and right mask fixing handles 8 and 9 (801).

Next, the printed circuit board 4 is set on the printing table 3 and then fixed by the left and right printed circuit board fixing blocks 6 and 7 (802, 803).

Next, after the printing table 3 is raised by the table up-and-down mechanism 11, the alignment of the printed board 4 and the mask 5 is performed by the alignment mechanism 10 (804, 805).

Next, after the paste is supplied onto the mask 5, the squeegee 1 is lowered by the squeegee up / down mechanism 12 and then moved by the squeegee moving mechanism 2 to perform reciprocal printing (806 to 8).
08). Then, when the movement is completed, the squeegee lifting mechanism 12
To raise squeegee 1 (809).

Next, the printing table 3 is lowered by the table up-and-down mechanism 11, the fixation of the printed board 4 is released by the left and right printed board fixing blocks 6, 7, etc., and then the printed board 4 is removed (810 to 812).

Then, if the same printed circuit board 4 is printed next time (813), the inclination of the squeegee 1 with respect to the printing table 3 is set reversely by the squeegee angle switching mechanism shown in FIG. 6 (814). Further, the squeegee position moving mechanism shown in FIG. 7 shifts the squeegee 1 obliquely with respect to the squeegee moving direction (815). Then, the process returns to step 802 to repeat these controls.

In step 813, the same printed circuit board 4
If not, put the mask 5 on the left and right mask fixing handles.
Loosen and remove 8,9 and collect the paste (816,81
7). If there is another print creation (818), step
Returning to step 801, the processing ends if there is no.

〔The invention's effect〕

According to the present invention, if the mask has the same hole shape and size, it is possible to print the same amount of paste even with holes arranged by rotating 90 ° with respect to the squeegee movement direction, and to secure an effective print width. And reciprocal printing is also possible.

Therefore, in order to print the same amount of paste, it is not necessary to change the shape and size of the hole rotated by 90 °, so that not only the know-how of mask hole design becomes unnecessary, but also the design man-hour can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a printing machine according to an embodiment of the present invention, FIG. 2 is an explanatory view of a conventional paste printing method using a squeegee, and FIG. 3 is an assembly view of a squeegee according to an embodiment of the present invention. FIG. 4 is an explanatory view of the movement of the squeegee in one embodiment of the present invention, FIG. 5 is an explanatory view of the time when the squeegee crosses the hole of the mask in one embodiment of the present invention, and FIG. 6 is an embodiment of the present invention. Schematic diagram of the squeegee angle switching mechanism in
FIG. 7 is a configuration diagram of a squeegee position moving mechanism in one embodiment of the present invention, and FIG. 8 is a control flowchart at the time of paste printing in one embodiment of the present invention. 1: Squeegee, 2: Squeegee moving mechanism, 3: Printing table, 4: Printed circuit board, 5: Mask, 6, 7: Printed circuit board fixed block,
8, 9: Mask fixing handle, 10: Positioning mechanism, 11: Table up / down mechanism, 12: Squeegee up / down mechanism, 13: Squeegee holder, 1
4: Squeegee bracket, 15: Squeegee angle switching shaft, 16: Squeegee angle switching rod, 17: Stopper A, 18: Stopper B, 19: Squeegee angle switching mechanism bracket, 20: Squeegee angle switching mechanism moving shaft, 21: Squeegee position Changing drive shaft, 22: Squeegee position changing rod, 23: Squeegee angle switching mechanism moving rod, 24, 2
5: Hole on the mask 5, 31: Mask, 32: Squeegee, 33a, 33b: Squeegee printing speed arrow, 34: Paste, 35: Printing area, 36: Paste rolling area, 37: Paste 34 Rolling direction, ~: Squeegee movement position per unit time, A
~ C: Print width.

Claims (1)

[Claims] 1. A squeegee, a means for moving the squeegee on a printing table, a printing table for setting a printed board, a means for fixing the printed board on the printing table, and a mask on the printed board. Attaching means, means for aligning the position of the printed circuit board and the mask,
In a printing machine equipped with means for moving the printing table up and down and means for moving the squeegee up and down, means for shifting the squeegee position depending on the direction of squeegee movement during reciprocal printing, and angle of inclination of the squeegee with respect to the printing table surface. And a means for switching the squeegee, the squeegee is attached at an angle of up to 45 ° with respect to the squeegee moving direction, and the squeegee position is shifted so that the residual paste during forward printing is collected and supplied during reprinting. Printer.