JPH10757A - Screen printing apparatus for cream solder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically set an optimum starting point for an approach attended with an angle of attack of a squeegee. SOLUTION: A squeegee 12 is slid along a carrying screw 3 on a screen mask 2 laminated on a base sheet 1 to print a cream solder on the base sheet 1. When an angle of attack of the squeegee 12 is changed from θ1 to θ2 attended with changing the kind of the cream solder 16, the squeegee 12 is rotated around a hinge 10 by driving a motor 20 and the angle is detected by means of a potentiometer 21. In addition, deviation of the lower end part of the squeegee 12 accompanied with changing the angle of attack is calculated by a control part 22 and based on this result of calculation, the carrying screw 3 is rotated by driving the motor to move the squeegee 3 to an optimum starting point (a) for an approach.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cream solder screen printing apparatus for printing cream solder on a substrate for soldering electronic components.

[0002]

2. Description of the Related Art A screen printing apparatus for cream solder is
By placing a screen mask on the substrate and sliding a squeegee on the screen mask, cream solder is printed on the electrodes of the circuit pattern on the substrate through the pattern holes opened in the screen mask. .

FIG. 4 is a partial side view of a conventional cream solder screen printing apparatus. On the substrate 1, a screen mask 2 is arranged. A feed screw 3 is disposed above the screen mask 2 in a horizontal posture. A nut 4 is screwed to the feed screw 3, and a block 5 is coupled to a lower portion of the nut 4.

The cylinders 6, 7 are held inside the block 5, and the rods 8, 9 of the cylinders 6, 7 project downward. At the lower end of the rods 8 and 9, hinges 10
The squeegees 12 and 13 are held via 11. When the rods 8, 9 of the cylinders 6, 7 protrude and retract, the squeegee 1
2 and 13 move up and down, and either one of the squeegees 12 and 13
Is grounded on the screen mask 2. In this state, when the motor 14 is driven to rotate the feed screw 3, the nut 4 moves along the feed screw 3, and the squeegees 12 and 13 slide on the screen mask 2 and are opened in the screen mask 2. The cream solder 16 is printed on the electrodes of the substrate 1 through the pattern holes (not shown). Reference numeral 15 denotes a frame for holding the feed screw 3.

As shown in the figure, the squeegees 12 and 13 are held by the hinge portions 10 and 11 in an inclined posture, and slide on the screen mask 2 in an inclined posture while contacting the ground. Is referred to as an attack angle. The operator changes the attack angle θ according to the type of the cream solder 16 based on experience or the like. Conventionally, this attack angle θ
Means that the operator connects the squeegees 12 and 13 with the hinges 10 and 1
It was changed by manually rotating around the center 1.

[0006]

The point at which the squeegees 12, 13 start sliding on the screen mask 2 is referred to as a starting point, and the distance from the starting point to the substrate 1 is referred to as a starting distance. In FIG. 4, the approach start point of the squeegee 12 indicated by a solid line is a, and the approach distance is L1. Further, the squeegee 12 is rotated to the position indicated by the dashed line to change the attack angle, and the squeegee 12 is lowered so that the screen mask 2
, The approaching start point is b, and the approaching distance is L2.

When the squeegee 12 runs on the screen mask 2 toward the substrate 1, the cream solder 16 on the screen mask 2 is rolled in the direction of the arrow and kneaded. Here, if the approach distance is too long, the approach time will be long, and the workability will be reduced. On the other hand, if the approach distance is too short, the rolling will be insufficient (insufficient kneading of the cream solder 16), and the cream solder 16 will be
Cannot be sufficiently filled in the pattern holes, resulting in poor printing. Therefore, in this type of cream solder screen printing apparatus, it is desirable to appropriately set the optimal approach start point, that is, the optimal approach distance.

However, conventionally, every time the attack angle is changed, the approach starting point is corrected by the operator based on experience or the like, so that it is unavoidable that an individual error of the operator occurs, and a correct optimal approach starting point is required. There was a problem that it was difficult to set.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned conventional problems and to provide a cream solder screen printing apparatus capable of automatically setting an optimum approach start point in response to a change in an attack angle.

[0010]

A screen printing apparatus for cream solder according to the present invention comprises a screen mask disposed on a substrate, a squeegee sliding on the screen mask, and a sliding means for sliding the squeegee. Vertical movement means for vertically moving the squeegee, and an optimum approach start position of the squeegee according to the magnitude of the attack angle of the squeegee, and the sliding means is driven based on the calculation result to drive the squeegee. And a control unit for sliding to an optimum approach start position.

[0011]

According to the present invention, the squeegee can be automatically moved to the optimum approach start point by adjusting the position of the squeegee by sliding the squeegee in accordance with a change in the attack angle of the squeegee. it can.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a cream solder screen printing apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram of the control system, and FIG. 3 is a partial side view of the same. In each figure, the same elements as those of the conventional example shown in FIG. 4 are denoted by the same reference numerals, and the description thereof will be omitted. Only the configuration different from the conventional example of FIG.

In FIG. 2, the hinges 10 and 11 incorporate a motor 20 as rotating means for rotating the squeegees 12 and 13 about the hinges 10 and 11, and a potentiometer 21 as attack angle detecting means. . In FIG. 3, reference numeral 22 denotes a control unit,
Drive circuit 25 for driving the motor, potentiometer 21
Etc. are connected. The control unit 22 includes a memory 23 for storing data. Reference numeral 24 denotes an input unit such as a keyboard and a mouse for inputting necessary data. Also 26
Numeral denotes a positioning portion for clamping and positioning the substrate 1.

[0014] The cream solder printing operation of this cream solder screen printing apparatus is the same as that of the conventional example, and a description thereof will be omitted. Next, how to change the attack angle and squeegee 1
A method for setting the optimum approach start points 2 and 13 will be described. In FIG. 2, the attack angle of the squeegee 12 is changed from θ1 to θ2. Data such as the size of the attack angle θ 1, the size of the substrate 1, the type of the cream solder 16, the current position of the optimum starting point a, and the optimum running distance L are registered in the memory 23.

Now, with the change of the type of the cream solder 16, it is input to the input section 24 that the attack angle is changed from θ1 to θ2, and that the position of the optimum approach start point is the point a (note that the cream solder is changed). It is assumed that the optimum attack angle for each type is determined in advance by performing a test or the like, and the position of the optimum approach start point differs depending on the type of cream solder. Then, the motor 20 is driven, the squeegee 12 is rotated about the hinge 10, and when the potentiometer 21 detects that the attack angle has become θ2, the driving of the motor 20 is stopped. In FIG. 2, the squeegee 12 indicated by a broken line is after the attack angle has been changed, and the attack angle of the squeegee 12 has been changed from θ1 to θ2. The distance ΔL is shifted. Therefore, the control unit 22 calculates the distance ΔL. Then, the motor 14 is driven to slide the squeegee 12 rightward by the distance ΔL (see the squeegee 12 indicated by a chain line). Next, cylinder 6
If the squeegee 12 is lowered by projecting the rod 8 of
The squeegee 12 lands at the optimum approach start point a. Then, the operation of printing the cream solder 16 on the substrate 1 is restarted.

[0016]

According to the present invention, the position of the squeegee is adjusted in accordance with the change of the attack angle of the squeegee, whereby the squeegee can be automatically moved to the optimum approach start point.

[Brief description of the drawings]

FIG. 1 is a side view of a cream solder screen printing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a control system of the cream solder screen printing apparatus according to one embodiment of the present invention.

FIG. 3 is a partial side view of a cream solder screen printing apparatus according to an embodiment of the present invention.

FIG. 4 is a partial side view of a conventional cream solder screen printing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Screen mask 3 Feed screw 4 Nut 6,7 Cylinder 10,11 Hinge 12,13 Squeegee 14 Motor 16 Cream solder 20 Motor 21 Potentiometer 22 Control part

Claims (1)

[Claims] 1. A screen mask disposed on a substrate,
A squeegee that slides on the screen mask, a sliding unit that slides the squeegee, a vertical movement unit that moves the squeegee up and down, and an optimum approach start position of the squeegee according to the attack angle of the squeegee And a controller for driving the sliding means based on the calculation result to slide the squeegee to the optimum approach start position.