JPH10329304A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong the service life of a squeegee by preventing uneven abrasion thereof. SOLUTION: The printer 10 for printing a print material onto a matter 16 to be printed using a squeegee 13a movable while touching a screen 12a having an opening comprises a squeegee moving mechanism 14, and a controller 15 for controlling driving of the squeegee moving mechanism 14 wherein the controller 15 controls driving of the squeegee moving mechanism 14 according to the pattern data of the opening.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus for printing various printing materials such as cream solder and conductor / insulator paste on a substrate such as a printed circuit board.

[0002]

2. Description of the Related Art In a surface mounting technique for mounting an electronic component such as a chip component on a printed circuit board, cream solder is printed on a conductive pattern formed in advance on the surface of the printed circuit board to mount the electronic component. Thereafter, a method is used in which the cream solder is heated and melted to solder the electronic component onto a printed circuit board. When printing cream solder on the above-described conductive pattern on a printed circuit board, for example, a cream solder printing apparatus as shown in FIG. 11 is used.

The cream solder printing apparatus 1 includes a screen 2, a squeegee 3, and a squeegee moving mechanism 4. The screen 2 is made of, for example, an extremely thin metal plate having an opening 2a corresponding to a printing location of cream solder in a conductive pattern on a printed circuit board, and has a peripheral edge attached to a frame 2b. The squeegee moving mechanism 4 includes a motor 4b for rotating and driving a ball screw 4a whose axis is arranged in the direction indicated by the arrow X, a movable portion 4c screwed to the ball screw 4a, and a driving direction in the direction indicated by the arrow Z. An air cylinder 4d is provided on the movable portion 4c and has a squeegee 3 made of, for example, hard rubber. The air cylinder 4d is provided above the screen 2.

When printing cream solder on a conductive pattern of a printed board using the cream solder printing apparatus 1 having such a configuration, first, the printed board is placed on a table provided below the screen 2. And the screen 2 is overlaid on the aligned printed circuit board. Next, an appropriate amount of cream solder 5 is placed near the frame 2b on the screen 2, and the motor 4b is driven to rotate the ball screw 4a. The squeegee 3 is positioned above the frame 2b and the cream solder 5. The squeegee 3 is moved in the direction of the arrow X1 in FIG.

Then, the squeegee 3 is lowered in the direction indicated by arrow Z1 in FIG.
Of the squeegee 3 is brought into contact with the surface of the squeegee 3 with a predetermined pressing force (printing pressure). In this state, the motor 4b is driven in the direction opposite to the previous direction to rotate the ball screw 4a, and the squeegee 3
Is moved in the illustrated arrow X2 direction (printing direction). As a result, the cream solder 5 moves on the screen 2 by being pushed by the squeegee 3, and is pushed into the opening 2 a of the screen 2. Then, the cream solder 5 pressed into the opening 2a of the screen 2 is cut off at the edge of the opening 2a of the screen 2 and simultaneously printed on the conductive pattern of the printed circuit board.

[0006]

In the cream solder printing apparatus 1, usually, a large number of printed circuit boards having the same conductive pattern are repeatedly printed. In the early stage of printing, as shown in FIG. 12A, the portion of the squeegee 3 that comes into contact with the edge of the opening 2a of the screen 2 is flat. The portion is neatly cut and printed on the conductive pattern of the printed circuit board 6 neatly.

However, when the same printing is repeated, especially when the openings 2a of the screen 2 overlap a lot in the printing direction, the portion of the squeegee 3 which comes into contact with the edges thereof wears more than the other portions. If the openings 2a of the screen 2 do not overlap much in the printing direction, the portions of the squeegee 3 that come into contact with their edges will have less wear than the other portions and the edges of the openings 2a of the screen 2 The portion of the squeegee 3 that does not come into contact with the portion at all does not wear out, so that the wear of one squeegee 3 varies.

[0008] Then, the cream solder 5 enters the worn portion of the squeegee 3, and the cream solder 5 swells at the edge of the opening 2 a of the screen 2 as shown by reference numeral 5 a in FIG. The thickness of the cream solder 5 printed on the conductive pattern is not constant. When the wear further proceeds, as shown by reference numeral 5b in FIG.
As shown in FIG. 3A, the cream solder 5 printed on the conductive pattern of the printed circuit board 6 has an uneven thickness. Then, when the cream solder 5 is melted, there is a problem that a solder bridge is formed between adjacent conductive patterns or connection terminals of adjacent electronic components.

For this reason, in the conventional cream solder printing apparatus 1, when the operator manages the wear state of the squeegee 3 and the squeegee 3 becomes incapable of printing,
The squeegee 3 is replaced with a new squeegee 3 or the worn portion of the squeegee 3 is polished again. Therefore, at this time, printing is interrupted, and there is a problem that work efficiency is reduced.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a printing apparatus capable of preventing uneven wear of a squeegee and extending the life of the squeegee.

[0011]

According to the present invention, there is provided a printing apparatus for printing a printing material on a printing material by a squeegee moving in contact with a screen having an opening. A squeegee moving mechanism to be moved and a control device for controlling the driving of the squeegee moving mechanism are provided, and the control device controls the driving of the squeegee moving mechanism according to the pattern data of the opening.

According to the above configuration, the squeegee can be shifted in accordance with the pattern data of the opening of the screen, so that the portion of the squeegee that contacts the edge of the opening of the screen can be changed, and the wear of the squeegee can be reduced uniformly. Can be

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The embodiments described below are preferred specific examples of the present invention,
Although various technically preferred limits are given, the scope of the present invention is not limited to these embodiments unless otherwise specified in the following description.

FIG. 1 is a schematic configuration diagram showing an example of a cream solder printing apparatus as an embodiment of the printing apparatus according to the present invention, and FIG. 2 is a perspective view of a main part thereof. The cream solder printing apparatus 10 includes a substrate holding unit 11, a screen unit 12, a squeegee unit 13, a squeegee moving mechanism 14, and a control device 15. The substrate holding unit 11 includes a clamp unit 11 that holds a printed circuit board 16 that is a printing object.
a, Suction unit 11b that sucks and holds printed circuit board 16
And a backup mechanism 11c for moving the printed circuit board 16 in the direction of the arrow Z in the figure.

The screen section 12 includes a screen 12a and a frame 12 on which the periphery of the screen 12a is mounted.
b, and is disposed above the substrate holding unit 11. Screen 12
a is made of, for example, an extremely thin metal plate having openings formed in the conductive patterns of the printed circuit board 16 corresponding to the printed portions of the cream solder. The squeegee portion 13 includes a squeegee 13a made of, for example, hard rubber and a holder 13b for holding the squeegee 13a.

The axis of the squeegee moving mechanism 14 is indicated by an arrow X in the figure.
A motor 14b that rotationally drives a ball screw 14a disposed so as to be oriented in the same direction, an X movable portion 14c screwed into the ball screw 14a, and an axis disposed in the illustrated Y direction and supported by the X movable portion 14c. Motor 14e for rotating and driving the ball screw 14d, Y screwed to the ball screw 14d
It comprises a movable section 14f and an air cylinder 14g to which the squeegee section 13 is attached, which is disposed on the Y movable section 14f so that the driving direction is in the direction of the arrow Z in the drawing,
It is arranged above the screen section 12.

The control unit 15 controls the clamp unit 11a, the suction unit 11b, the backup mechanism 11c of the board holding unit 11, the motors 14b and 14e of the squeegee moving mechanism 14, and the air cylinder 14g, thereby controlling the printed board 1
6 and move the squeegee unit 13 in the illustrated arrow X direction, the illustrated arrow Y direction, and the illustrated arrow Z direction.
In this case, as shown in FIG. 3, the control device 15 stores, for example, the number of substrates of the printed circuit board 16, the size of the substrate, and the pattern of the opening formed by coordinate data in the rectangular coordinate system (xy coordinate system) defined on the screen 12a. Is input in advance, and based on these data, the position of the printed board 16 and the printing direction of the squeegee unit 13 (arrow X in the figure)
(1 direction) movement amount x, slide direction (arrow Y direction in the figure)
, The movement timing y, the number of movements n, and the like are determined.

When printing cream solder on the conductive pattern of the printed circuit board 16 using the cream solder printing apparatus 10 having such a configuration, first, the control device 15 drives the clamp section 11a of the board holding section 11 to drive. The printed circuit board 16 placed on the suction section 11b of the board holding section 11
After the peripheral edge of the suction portion 11b is
Is driven to suck and hold the printed board 16. Then, the control device 15 drives the backup mechanism 11c of the board holding unit 11, and the printed circuit board 1 in the above-described state.
6, the upper surface of the printed circuit board 16 is brought into close contact with the lower surface of the screen 12a (see FIG. 4). Here, the screens 12a are, for example, as shown in FIG. 5, three screens arranged along the printing direction (the arrow X1 direction in the drawing).
It is assumed that two openings A, B, and C are provided.

Next, the controller 15 drives the motors 14b and 14e of the squeegee moving mechanism 14 to drive the ball screw 14
a and 14d are driven to rotate, and one end of the squeegee 13a of the squeegee unit 13 is positioned above the appropriate amount of the cream solder 18 placed near the clamp unit 12c on one side of the screen 12a and the clamp unit 12c. While moving the X movable portion 14c in the direction of the arrow X shown in the drawing,
The Y movable section 14f is moved in the direction indicated by the arrow Y in the figure. Then, the control device 15 operates the air cylinder 14g to lower the squeegee 13a in the direction of the arrow Z1 in the drawing, and causes the squeegee 13a to contact the surface of the screen 12a with a predetermined pressing force (printing pressure) (see FIG. 5).

In this state, the control device 15
B is driven to rotate the ball screw 14a to move the squeegee 13a in the direction of the arrow X1 in the figure. Thus, the cream solder 18 is moved by being pushed by the squeegee 13a, and is pushed into the opening A of the screen 12a. Then, the cream solder 18 pushed into the opening A is cut at the edge of the opening A and simultaneously printed on the conductive pattern of the printed circuit board 16 (FIG. 6).
reference). When the squeegee 13a has passed the opening A, the control device 15 stops driving the motor 14b, drives the motor 14e to rotate the ball screw 14d, and moves the squeegee 13a in the illustrated arrow Y1 direction by a predetermined amount. By the way, the driving of the motor 14e is stopped (see FIG. 7).

In this state, the control device 15
B is driven to rotate the ball screw 14a to move the squeegee 13a in the direction of the arrow X1 in the figure. Thereby, the cream solder 18 is moved by being pushed by the squeegee 13a, and is pushed into the opening B of the screen 12a. The cream solder 18 pushed into the opening B is cut on the edge of the opening B and printed on the conductive pattern of the printed circuit board 16 (FIG. 8).
reference). When the squeegee 13a has passed the opening B, the control device 15 stops driving the motor 14b, drives the motor 14e to rotate the ball screw 14d, and moves the squeegee 13a by a predetermined amount in the direction indicated by the arrow Y1. By the way, the driving of the motor 14e is stopped (see FIG. 9).

In this state, the control device 15
B is driven to rotate the ball screw 14a to move the squeegee 13a in the direction of the arrow X1 in the figure. Thereby, the cream solder 18 is moved by being pushed by the squeegee 13a, and is pushed into the opening C of the screen 12a. Then, the cream solder 18 pushed into the inside of the opening C is cut at the edge of the opening C and printed on the conductive pattern of the printed circuit board 16 (FIG. 1).
0).

Then, the controller 15 controls the squeegee 13a
When the motor reaches the vicinity of the clamp portion 12c on the other side, the motor 14
The drive of b is stopped, the air cylinder 14g is operated to raise the squeegee 13a in the direction indicated by the arrow Z2, and the squeegee 13a is retracted from the surface of the screen 12a. The control device 15 drives the motor 14b in the opposite direction to rotate the ball screw 14a, and moves the squeegee 13a in the direction indicated by the arrow X2 to return to the initial state. By repeating the above operation, cream solder can be continuously printed on the plurality of printed circuit boards 16.

By performing the printing control as described above,
The squeegee 13a has openings A of the screen 12a,
The squeegee 13a is shifted in the area between B and C.
Does not come into contact with the edges of the openings A, B, and C, and the wear of the squeegee 13a is made uniform. Accordingly, the thickness of the cream solder 18 to be printed becomes uniform, and the formation of a solder bridge between the conductive patterns of the printed circuit board 16 or the connection terminals of the mounted electronic components due to the melting of the cream solder 18 is reliably eliminated. Can be.

Furthermore, since the wear of the squeegee 13a is uniform, it is not necessary to replace or regrind the squeegee 13a due to uneven wear, so that the life of the squeegee 13a is prolonged and printing interruption is reduced. Therefore, the work efficiency can be improved, and the deterioration of the print quality in the continuous printing can be reduced. In addition, squeegee 13a
May be shifted, for example, once or after a predetermined number of printing steps, or simultaneously with the movement in the direction of the arrow X1 in the figure.

[0026]

As described above, according to the present invention,
It is possible to prevent uneven wear of the squeegee and extend the life of the squeegee.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of a cream solder printing apparatus which is an embodiment of a printing apparatus according to the present invention.

FIG. 2 is an enlarged perspective view showing a squeegee unit and a squeegee moving mechanism in the cream solder printing apparatus of FIG.

FIG. 3 is a view showing an example of data of a control device in the cream solder printing apparatus of FIG. 1;

FIG. 4 is a schematic side view showing a state during cream solder printing in the cream solder printing apparatus of FIG. 1;

FIG. 5 is a partial plan view showing a first stage of a cream solder printing process by the cream solder printing apparatus of FIG. 1;

FIG. 6 is a partial plan view showing a second stage of the cream solder printing process by the cream solder printing apparatus of FIG. 1;

FIG. 7 is a partial plan view showing a third stage of the cream solder printing process by the cream solder printing apparatus of FIG. 1;

FIG. 8 is a partial plan view showing a fourth stage of the cream solder printing process by the cream solder printing apparatus of FIG. 1;

FIG. 9 is a partial plan view showing a fifth stage of the cream solder printing process by the cream solder printing apparatus of FIG. 1;

FIG. 10 is a partial plan view showing a sixth step of the cream solder printing process by the cream solder printing apparatus of FIG. 1;

FIG. 11 is a schematic perspective view showing an example of a conventional cream solder printing apparatus.

FIG. 12 is an enlarged cross-sectional view of the cream solder printing apparatus of FIG. 11 in a state where the squeegee is not worn, in a worn state, and in a state where the squeegee is further worn.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Cream solder printing apparatus, 11 ... Substrate holding part, 12 ... Screen part, 12a ... Screen, 13 ... Squeegee part, 13a ... Squeegee, 1
4 ... Squeegee moving mechanism, 15 ... Control device, 16
... Printed circuit board, 18 ... Cream solder

Claims (3)

[Claims] 1. A printing apparatus for printing a printing material on a printing material by a squeegee moving in contact with a screen having an opening, comprising: a squeegee moving mechanism for moving the squeegee; and a drive for driving the squeegee moving mechanism. And a control device for controlling the driving of the squeegee moving mechanism according to the pattern data of the opening. 2. The printing apparatus according to claim 1, wherein the pattern data is coordinate data of the opening in a rectangular coordinate system defined on the screen. 3. The printing apparatus according to claim 1, wherein the control device controls the driving of the squeegee moving mechanism so that the squeegee uniformly contacts the edge of the opening within the screen contact area. .