JPH072198Y2 - Printing pressure measuring device of screen printing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an improvement of a device for measuring a printing pressure (hereinafter referred to as printing pressure) with which a squeegee of a screen printing machine presses a screen against a printing substrate. .

[Prior Art] A screen printing method is the most common method for thick film printing, and this apparatus is called a screen printing machine.

There are various factors to make the thickness of printed thick film uniform and good reproducibility. Among them, the main factors related to screen printing machines are printing pressure and squeegee movement speed (squeegee speed). , The distance between the screen frame of the screen and the printed board (snap-off distance), the parallelism between the printed board and the screen, and the inclination angle of the squeegee (attack angle).

Of these, the definition of printing pressure may be unclear,
Quantitative management is not easy with existing measurement methods.

The reason will be described below.

FIG. 3 is a block diagram of an example of a conventional printing pressure measuring device of a screen printing machine.

In the figure, 1 is a printing stage, 2 is a substrate placed on the printing stage 1 for screen printing, 3 is a displaceable mesh screen stretched on a plate frame 4,
5 is ink 6 with the screen 3 pressed against the substrate 2.
Is a squeegee that rubs against the screen to transfer the ink that has passed through the screen to the substrate 2, and 7 is a hydraulic cylinder that moves the squeegee up and down.

With this device, the hydraulic pressure in the cylinder is P ₁ = P ₂ , so if P ₂ is measured and the attack angle is θ, then P ₂ = Fsin θ
The printing pressure F is obtained from

[Problems to be Solved by the Invention] However, this device has a drawback that the actual printing pressure F is different even if the measured hydraulic pressure P ₂ is constant in the following cases.

When the attack angle θ is changed.

When changing the hardness of the squeegee.

When the screen tension changes.

When changing the length or height of the squeegee.

When the tip of the squeegee is worn.

These drawbacks occur because the deformation of the squeegee cannot be taken into consideration.

The present invention has been made to solve such a drawback, and an object thereof is to realize a printing pressure measuring device which is not affected by an error factor due to deformation of a squeegee.

[Means for Solving Problems] In the present invention, a squeegee is used to press a screen against the surface of a substrate placed on a printing stage, and in this state, the squeegee is moved to rub the ink on the screen, and the eyes of the screen are rubbed. In a screen printing machine that transfers the passed ink onto the substrate, the substrate is placed on the printing stage, the measurement plate is movably supported in the vertical direction, and the shaft is fixed; A printing pressure measuring device for a screen printing machine, comprising a force detecting means for supporting a shaft and detecting a force applied to a measuring plate.

[Embodiment] The present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a printing pressure measuring device according to the present invention. In FIG. 1, the same parts as those in FIG. 3 are designated by the same reference numerals.

In the figure, 10 is a measurement plate on which the substrate 2 is placed. A shaft 11 is fixed to the center of the measuring plate 10 and is supported by the shaft. The measuring plate 10 and the shaft 11 are made of a rigid body.

Reference numeral 12 is a printing stage, and the measurement plate 10 is provided in the dug portion 13.
Is stored. There is a shaft in the hole 14 provided in the dug portion 13.
11 are inserted, and a bearing 15 is arranged between them. As a result, the measuring plate 10 is moved to the printing stage.
It is supported by 11 so as to be movable in the vertical direction (a'a 'direction). The bearing 15 is provided to reduce the moving friction of the measuring plate 10 in the vertical direction.

Reference numeral 16 is a force detecting means which is attached to the printing stage 12 by an attaching member 17 and which supports the shaft 11 with a force receiving portion. As the force detecting means 16, for example, a compression type load cell is used. With this configuration, the force applied to the substrate 2 is transmitted to the load cell 16 via the rigid measuring plate 10 and the shaft 11.

Next, the procedure for setting the printing pressure of such an apparatus will be described.

First, the substrate 2 is placed on the measurement plate 10.

Next, a thick film paste of ink is placed on the screen. As a result, the deformation of the squeegee becomes the same as when printing.

The drop amount of the squeegee is adjusted so that the load applied to the load cell 16 becomes the required printing pressure. At this time,
Since the load applied to the substrate 2 is transmitted to the load cell 16 via the rigid measuring plate 10 and the shaft 11, (load measured by the load cell 16) = (printing pressure of the substrate 2). As a result, the printing pressure is detected.

When printing, set the drop amount obtained by squeegee adjustment.

FIG. 2 is a block diagram of another embodiment of the printing pressure measuring device according to the present invention.

In the embodiment of FIG. 1, the load transmission shaft and the plate holding shaft are shared, but in the embodiment of FIG. 2, the respective shafts are separated.

In FIG. 3, the measuring plate 10 has a load transmission shaft 18 at the center thereof.
And the plate holding shaft 19 is fixed near the end. The load transmission shaft 18 is fitted in the hole 14 and is supported by the force receiving portion of the load cell 16. Plate holding shaft
19 is inserted in the hole 20 of the printing stage 12, and a bearing 21 is arranged between these shafts and holes.

In the embodiment shown in FIG. 1, when the measuring plate 10 has a disk shape, the plate is rotated and the printing position of the substrate is displaced, and when the squeegee is placed near the edge of the substrate, the measuring plate 10
Has a drawback that the frictional force applied to the shaft 11 increases and the printing pressure apparently decreases, but these drawbacks are eliminated in the embodiment of FIG. In addition, printing pressure can be measured while the squeegee is moving.

[Effect] According to the present invention, the printing pressure is applied to the force detecting means 16 via the rigid measuring plate 10 and the shaft 11, and the printing pressure is detected by this force detecting means, so that an error factor due to deformation of the squeegee. Not affected by. In the conventional example shown in FIG. 3, the printing pressure may not be sufficiently transmitted due to the compressibility of the oil in the hydraulic cylinder 7 or the deformation of the squeegee, resulting in poor resolution and hysteresis. In the invention, since the printing pressure is transmitted by the rigid body, the resolution is good and the hysteresis is extremely small.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a printing pressure measuring device of a screen printing machine according to the present invention, FIG. 2 is a block diagram of another embodiment of the device according to the present invention, and FIG. 3 is a conventional screen printing. It is a diagram showing a configuration example of a printing pressure measuring device of the machine. 2 ... Substrate, 3 ... Screen, 5 ... Squeegee, 6 ...
… Ink, 10 …… Measuring plate, 11,18,19 …… Fixed shaft,
12 …… Printing stage, 14,20 …… Hole, 15,21 …… Bearing.

Claims (1)

[Scope of utility model registration request] 1. A squeegee presses a screen against the surface of a substrate placed on a printing stage, and in this state the squeegee is moved to rub the ink on the screen, and the ink passing through the eyes of the screen is transferred onto the substrate. In the screen printing machine, a measurement plate, on which the substrate is placed, is movably supported in the vertical direction on the printing stage, and a shaft is fixed; A printing pressure measuring device for a screen printing machine, comprising a force detecting means for detecting force.