JP2024022316A - Printer and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To retain a printing quality while suppressing damages on a surface of a matter to be printed in printing using two squeegees.

SOLUTION: A printer includes a printing part, a measurement part and a control part. The printing part prints paste on a matter to be printed via an opening of a printing mask by sequentially moving two squeegees on the printing mask. The measurement part measures a film thickness of printed paste. The control part controls each of the parts. The control part controls printing pressure of the one squeegee which moves last in the two squeegees based on a measurement result of a film thickness by the measurement part.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a printing device and a printing method.

2. Description of the Related Art Conventionally, there are printing devices that perform printing using a screen printing method. In such a printing device, a printing mask is placed on a printing material, and a squeegee is moved over the printing mask to print paste onto the printing material through an opening in the printing mask.

Here, the wear and tear of the squeegee that moves over the print mask affects print quality. The thickness of the paste printed on the printing material tends to increase as the squeegee wears out. For this reason, various methods have been proposed for controlling the film thickness of the paste. For example, a technique is known in which the film thickness of the paste is measured after printing a paste using a squeegee, and the printing pressure of the squeegee is controlled based on the measurement result of the film thickness.

Japanese Patent Application Publication No. 5-13926

By the way, some recent printing apparatuses perform printing using two squeegees. In such a printing device, two squeegees are sequentially moved over a printing mask to print paste onto a substrate through an opening in the printing mask. At this time, the first squeegee (hereinafter referred to as the "first squeegee") that moves among the two squeegees forces the paste out of the opening of the printing mask and applies it relatively thinly to the printing material. On the other hand, the last of the two squeegees (hereinafter referred to as the "second squeegee") pushes the paste out of the opening of the printing mask and further applies it to the printing material, so that the thickness of the paste reaches the desired thickness. The thickness is adjusted.

If the printing pressures of these two squeegees are uniformly controlled based on the above-mentioned paste film thickness measurement results, there is a risk that the surface of the printing material will be damaged. That is, in printing using two squeegees, as the film thickness of the paste increases, the printing pressure of the first squeegee increases together with the printing pressure of the second squeegee. When the printing pressure of the first squeegee increases, the tip of the first squeegee passes through the opening of the printing mask and comes into contact with the surface of the printing material to which paste has not yet been applied. As a result, the surface of the printing material may be scratched by the tip of the first squeegee, and damage may be caused to the surface of the printing material.

The disclosed technology has been made in view of the above, and provides a printing device and a printing method that can maintain printing quality while suppressing damage to the surface of a printing medium in printing using two squeegees. The purpose is to

In one embodiment, the printing device disclosed in the present application includes a printing section, a measuring section, and a control section. The printing unit prints the paste onto the printing material through the opening of the printing mask by sequentially moving two squeegees over the printing mask. The measurement unit measures the film thickness of the printed paste. The control section controls each section. The control unit controls the printing pressure of one of the two squeegees that moves last, based on the measurement result of the film thickness by the measurement unit.

According to one aspect of the printing apparatus disclosed in the present application, in printing using two squeegees, it is possible to maintain print quality while suppressing damage to the surface of the printing material.

FIG. 1 is a left side view showing a configuration example of a printing apparatus according to an embodiment. FIG. 2 is a side view of the printing unit according to the embodiment viewed from the positive direction of the X-axis. FIG. 3 is a diagram showing an example of a printing pressure control amount table according to the embodiment. FIG. 4 is a flowchart illustrating an example of processing operations of the printing apparatus according to the embodiment.

DESCRIPTION OF EMBODIMENTS Below, embodiments of a printing apparatus and a printing method disclosed in the present application will be described in detail based on the drawings. Note that the disclosed technology is not limited to this embodiment.

In each of the drawings referred to below, an orthogonal coordinate system is shown in which an X-axis direction, a Y-axis direction, and a Z-axis direction that are perpendicular to each other are defined, and the positive Z-axis direction is a vertically upward direction, in order to make the explanation easier to understand.

In addition, here, a front-rear direction is defined where the negative direction of the X-axis is the front, a positive direction of the X-axis is the rear, and a left-right direction is defined where the positive direction of the Y-axis is the right and the negative direction of the Y-axis is the left. . Further, a vertical direction is defined in which the positive direction of the Z-axis is the upper direction and the negative direction of the Z-axis is the lower direction.

The configuration of a printing apparatus 1 according to an embodiment will be described with reference to FIG. 1. FIG. 1 is a left side view showing a configuration example of a printing apparatus 1 according to an embodiment. A printing apparatus 1 shown in FIG. 1 prints a paste P on a substrate W, which is a printing target, using a screen printing method. As the paste P, for example, flux, solder paste, etc. are used. The printing device 1 includes a printing section 2, a conveying section 3, and a measuring section 4.

FIG. 2 is a side view of the printing unit 2 according to the embodiment viewed from the positive direction of the X-axis. As shown in FIG. 2, the printing unit 2 includes a holding table 21, a printing mask 22, a first squeegee 23_1, a second squeegee 23_2, a first elevating mechanism 24_1, a second elevating mechanism 24_2, and a moving plate. 25. Note that hereinafter, the first squeegee 23_1 and the second squeegee 23_2 may be collectively referred to as "squeegee 23." Further, the first elevating mechanism 24_1 and the second elevating mechanism 24_2 may be collectively referred to as the "elevating mechanism 24."

The holding table 21 holds the substrate W horizontally.

The printing mask 22 is, for example, a plate-shaped member made of metal. Print mask 22 is also called a screen plate. The print mask 22 is formed with openings (not shown) having a predetermined pattern. The printing mask 22 is configured to be movable between a printing position where it contacts the substrate W and a retracted position located above the printing position.

The two squeegees 23 are elastic members made of, for example, resin rubber. The two squeegees 23 are arranged side by side along the left-right direction. The two squeegees 23 are respectively attached to two lifting mechanisms 24 that raise and lower the two squeegees 23. Specifically, the first squeegee 23_1 is attached to the first elevating mechanism 24_1, and can be moved up and down in the vertical direction by the first elevating mechanism 24_1. Further, the second squeegee 23_2 is attached to the second elevating mechanism 24_2, and can be raised and lowered in the vertical direction by the second elevating mechanism 24_2.

The two lifting mechanisms 24 are attached to the moving plate 25. A squeegee 23 is attached to the lower end of the lifting mechanism 24. The elevating mechanism 24 supports the squeegee 23 rotatably around an axis parallel to the front-rear direction. The elevating mechanism 24 raises and lowers the squeegee 23. Specifically, the elevating mechanism 24 includes an actuator, and uses the driving force of the actuator to expand and contract the rod 24a to move the squeegee 23 up and down. The elevating mechanism 24 can change the pressing force (that is, printing pressure) of the squeegee 23 against the printing mask 22 by raising and lowering the squeegee 23. Specifically, the lifting mechanism 24 can increase the printing pressure of the squeegee 23 by extending the rod 24a and lowering the squeegee 23, and by retracting the rod 24a and raising the squeegee 23, The printing pressure of the squeegee 23 can be reduced. Note that the elevating mechanism 24 may be any mechanism as long as it obtains the driving force to extend and contract the rod 24a, for example, it may be a mechanism that obtains the driving force to extend and contract the rod 24a by pneumatic pressure, hydraulic pressure, etc. good.

The moving plate 25 is attached to a guide rail (not shown) extending in the left-right direction, and is movable in the left-right direction along the guide rail by a drive unit such as a linear motor.

The printing unit 2 prints the paste P onto the substrate W through the opening of the printing mask 22 by sequentially moving the two squeegees 23 over the printing mask 22.

That is, when the printing section 2 holds the substrate W carried into the printing section 2 on the holding table 21, the printing section 2 moves the printing mask 22 from the retracted position to the printing position and brings the printing mask 22 into contact with the substrate W. Paste P is placed on the print mask 22 in advance. Subsequently, the printing unit 2 presses the first squeegee 23_1 against the printing mask 22 by lowering the first squeegee 23_1 of the two squeegees 23 using the first elevating mechanism 24_1. Subsequently, the printing unit 2 moves the first squeegee 23_1 to the right over the printing mask 22 together with the first elevating mechanism 24_1 by moving the moving plate 25 to the right. As a result, the paste P placed on the print mask 22 is pushed out from the opening of the print mask 22 and applied to the substrate W. After finishing the movement of the first squeegee 23_1, the printing unit 2 raises the first squeegee 23_1 using the first elevating mechanism 24_1. Subsequently, the printing unit 2 presses the second squeegee 23_2 against the printing mask 22 by lowering the second squeegee 23_2 using the second elevating mechanism 24_2. Subsequently, the printing unit 2 moves the moving plate 25 to the left, thereby moving the second squeegee 23_2 to the left over the printing mask 22 together with the second elevating mechanism 24_2. As a result, the paste P placed on the print mask 22 is pushed out from the opening of the print mask 22 and applied to the substrate W. After finishing the movement of the second squeegee 23_2, the printing unit 2 raises the second squeegee 23_2 using the second elevating mechanism 24_2. Subsequently, the printing unit 2 moves the printing mask 22 from the printing position to the retreat position, and completes printing of the paste P on one substrate W.

Returning to the explanation of FIG. The transport section 3 is provided between the printing section 2 and the measuring section 4, and has a substrate transport device 31 therein. The substrate transport device 31 has a substrate holding mechanism that holds the substrate W. Further, the substrate transport device 31 is movable in the longitudinal direction and the vertical direction, and transports the substrate W between the printing section 2 and the measuring section 4 using a substrate holding mechanism.

The measuring unit 4 measures the film thickness of the paste P printed on the substrate W. The measurement unit 4 includes a holding table 41 and a film thickness sensor 42. The holding table 41 holds the substrate W horizontally.

The film thickness sensor 42 measures the film thickness of the paste P printed on the substrate W in a non-contact manner. As the film thickness sensor 42, for example, a spectral interference type film thickness sensor that irradiates the substrate W with laser light and measures the film thickness from the interference state of the light reflected from the front and back surfaces of the paste P can be used.

When the substrate W on which the paste P is printed by the printing section 2 is conveyed to the measuring section 4 by the conveying section 3, the measuring section 4 holds the substrate W on a holding table 41 and uses a film thickness sensor 42 to measure the substrate W. Measure the film thickness of paste P.

The printing device 1 also includes a control device 5 . The control device 5 is, for example, a computer, and includes a control section 51 and a storage section 52. The storage unit 52 stores programs that control various processes executed in the printing apparatus 1. The control unit 51 controls the operation of the printing apparatus 1 by reading and executing a program stored in the storage unit 52 .

Note that this program may be one that has been recorded on a computer-readable storage medium, and may be one that is installed in the storage unit 52 of the control device 5 from the storage medium. Examples of computer-readable storage media include hard disks (HD), flexible disks (FD), compact disks (CD), magnetic optical disks (MO), and memory cards.

By the way, in the printing apparatus 1, when printing is sequentially performed on a plurality of substrates W, the squeegee 23 in the printing section 2 gradually wears out, and the film thickness of the paste P printed on the substrates W varies. That is, the thickness of the paste P printed on the substrate W tends to increase as the squeegee 23 wears more.

On the other hand, as a technique for managing the film thickness of the paste P, it is possible to measure the film thickness of the paste P and control the printing pressure of the two squeegees 23 based on the measurement result of the film thickness. For example, it is conceivable to uniformly increase the printing pressure of the two squeegees 23 as the film thickness of the paste P increases.

However, in the technique of uniformly increasing the printing pressure of the two squeegees 23 as the film thickness of the paste P increases, the tip of the first squeegee 23_1, which moves first of the two squeegees 23, touches the opening of the printing mask 22. It comes into contact with the surface of the substrate W on which the paste P has not yet been applied. As a result, the surface of the substrate W may be scratched by the tip of the first squeegee 23_1, and the surface of the substrate W may be damaged.

Therefore, in the printing apparatus 1 according to the embodiment, the control unit 51 moves the squeegee to the last of the two squeegees 23 by controlling the second lifting mechanism 24_2 based on the measurement result of the thickness of the printed paste P. The printing pressure of the second squeegee 23_2 is controlled. As a result, after the paste P is applied to the substrate W with a certain thickness by the first squeegee 23_1, the paste P is applied to the desired thickness by the second squeegee 23_2 while the surface of the substrate W is covered with the paste P. Adjusted to film thickness. At this time, even if the tip of the second squeegee 23_2 passes through the opening of the printing mask 22, the surface of the substrate W is protected by the paste P that has already been applied. The surface is not easily scratched. As a result, in printing using the two squeegees 23, it is possible to maintain print quality while suppressing damage to the surface of the substrate W.

Further, the control unit 51 refers to the printing pressure control amount table shown in FIG. Control. FIG. 3 is a diagram showing an example of a printing pressure control amount table according to the embodiment. The printing pressure control amount table shown in FIG. 3 stores the printing pressure control amount ΔP (MPa) of the second squeegee 23_2 in association with each difference α (μm) of the film thickness of the paste P from a predetermined target value β. This table is created in advance by simulation or the like and is stored in the storage unit 52. The difference α is a value calculated according to the following equation (1).
α = (Thickness of paste P) - β ... (1)
Here, equation (1) indicates that when the difference α is a positive value, the film thickness of the paste P is larger than the target value β, and when the difference α is a negative value, the film thickness of the paste P is is smaller than the target value β.

The control unit 51 refers to the printing pressure control amount table, determines the printing pressure control amount ΔP corresponding to the difference α between the film thickness measured by the measurement unit 4 and the predetermined target value β, and sets the printing pressure control amount ΔP to the first value. The printing pressure of the second squeegee 23_2 is controlled by controlling the second lifting mechanism 24_2. For example, when the difference α is 1.5 (μm), the control unit 51 increases the printing pressure of the second squeegee 23_2 by 0.02 (MPa). Further, for example, when the difference α is −2.5 (μm), the control unit 51 reduces the printing pressure of the second squeegee 23_2 by 0.03 (MPa).

As the control unit 51 increases or decreases the printing pressure of the second squeegee 23_2 according to the difference α, the value of the film thickness of the paste P measured by the measurement unit 4 approaches the target value β. That is, when the difference α becomes a positive value, that is, when the film thickness of the paste P is larger than the target value β, by increasing the printing pressure of the second squeegee 23_2, the film thickness of the paste P becomes the target value β. can be reduced towards. Further, when the difference α becomes a negative value, that is, when the film thickness of the paste P is smaller than the target value β, the film thickness of the paste P is reduced to the target value β by decreasing the printing pressure of the second squeegee 23_2. can be increased towards.

In this way, the control unit 51 refers to the printing pressure control amount table and controls the second squeegee 23_2 with the printing pressure control amount ΔP determined from the film thickness measured by the measurement unit 4, without performing complicated calculations. The thickness of the paste P can be quickly brought close to the target value β.

By the way, if the printing pressure of the second squeegee 23_2 increases or decreases too much and deviates from the allowable range, various problems may occur. For example, if the printing pressure of the second squeegee 23_2 exceeds a predetermined upper limit, the load applied from the second squeegee 23_2 to the print mask 22 increases, and there is a risk that the print mask 22 may be damaged. Further, for example, when the printing pressure of the second squeegee 23_2 is lower than a predetermined lower limit value, the second squeegee 23_2 separates from the printing mask 22, and the paste P placed on the printing mask 22 spreads through the openings of the printing mask 22. There is a risk that printing defects may occur due to the printer not being extruded.

Therefore, the control unit 51 adds the printing pressure control amount ΔP corresponding to the difference α between the film thickness measured by the measurement unit 4 and the predetermined target value β to the current value of the printing pressure of the second squeegee 23_2 to generate an additional printing pressure. may be calculated, and an alert may be notified if the additional printing pressure exceeds the upper limit or falls below the lower limit. The alert may be notified by any method as long as it can notify the administrator of the printing device 1 of an abnormality. For example, the control unit 51 may display a message notifying the abnormality on a user interface (not shown) such as a display device included in the printing apparatus 1.

Thereby, the printing apparatus 1 according to the embodiment can notify in advance of a malfunction of the printing apparatus 1 due to the printing pressure of the second squeegee 23_2 deviating from the allowable range.

Next, processing operations of the printing apparatus 1 according to the embodiment will be described with reference to FIG. 4. FIG. 4 is a flowchart illustrating an example of the processing operation of the printing apparatus 1 according to the embodiment. Each process shown in FIG. 4 is executed under control by the control unit 51. Further, the processing operation shown in FIG. 4 is started at a predetermined timing, for example, at the timing when the substrate W is held on the holding table 21 of the printing section 2.

First, the control unit 51 controls the printing unit 2 to sequentially move the two squeegees 23 on the printing mask 22 to print the paste P on the substrate W through the opening of the printing mask 22 (step S101). Specifically, the control unit 51 prints the paste P on the substrate W by moving the first squeegee 23_1 and the second squeegee 23_2 over the printing mask in this order. When printing of the paste P on the substrate W is finished, the control section 51 controls the transport section 3 to transport the substrate W from the holding table 21 of the printing section 2 to the holding table 41 of the measuring section 4 .

Next, the control unit 51 controls the measurement unit 4 to measure the film thickness of the paste P printed on the substrate W (step S102).

Next, the control unit 51 refers to the printing pressure control amount table using the film thickness measured by the measurement unit 4, and controls the printing pressure corresponding to the difference α between the film thickness measured by the measurement unit 4 and the predetermined target value β. The amount ΔP is determined (step S103). Then, the control unit 51 calculates an additional printing pressure by adding the determined printing pressure control amount ΔP to the current value of the printing pressure of the second squeegee 23_2 (step S104).

Next, the control unit 51 determines whether the added printing pressure exceeds a predetermined upper limit value (step S105). If the added printing pressure does not exceed the predetermined upper limit (step S105; No), the control unit 51 determines whether the added printing pressure is less than the predetermined lower limit (step S106).

If the additional printing pressure does not fall below the predetermined lower limit value (step S106; No), the control unit 51 controls the second elevating mechanism 24_2 with the printing pressure control amount ΔP determined in step S103, thereby increasing the second squeegee 23_2. The printing pressure is controlled (step S107).

On the other hand, if the additional printing pressure exceeds the predetermined upper limit (step S105; Yes) or falls below the predetermined lower limit (step S106; Yes), the control unit 51 notifies an alert (step S108).

When the processes in steps S107 and S108 are completed, the control unit 51 controls the transport unit (not shown) to carry out the substrate W from the holding table 41 of the measurement unit 4 to the outside of the printing apparatus 1 (step S109), and carries out the process. complete.

Note that while performing the processing operation shown in FIG. 4, the control unit 51 controls the first lifting mechanism 24_1 so that the printing pressure of the first squeegee 23_1 of the two squeegees 23 is higher than the printing pressure of the second squeegee 23_2. The printing pressure of the first squeegee 23_1 may be controlled to a low constant value.

(Other variations)
In the embodiment described above, the case where the printing pressure of the second squeegee 23_2 is controlled based on the measurement result of the film thickness by the measurement unit 4 has been described as an example, but other printing parameters other than the printing pressure may be controlled. For example, the control unit 51 may control the moving speed or angle of the second squeegee 23_2 based on the measurement result of the film thickness by the measurement unit 4. Further, for example, the control unit 51 may control at least one of the printing pressure, moving speed, and angle of the second squeegee 23_2 based on the measurement result of the film thickness by the measurement unit 4.

As described above, the printing device (for example, the printing device 1) according to the embodiment includes a printing section (for example, the printing section 2), a measuring section (for example, the measuring section 4), and a control section (for example, the control section 51). ). The printing section sequentially moves two squeegees (for example, the first squeegee 23_1 and the second squeegee 23_2) over the printing mask (for example, the printing mask 22), thereby applying the printing material (for example, , print the paste on the substrate W). The measurement unit measures the film thickness of the printed paste. The control section controls each section. The control unit controls the printing pressure of one of the two squeegees that moves last (for example, the second squeegee 23_2) based on the measurement result of the film thickness by the measurement unit. Thereby, according to the printing apparatus according to the embodiment, in printing using two squeegees, it is possible to maintain print quality while suppressing damage to the surface of the printing material.

Further, the printing apparatus according to the embodiment calculates a printing pressure control amount (for example, printing pressure control amount ΔP) for each difference (for example, difference α) from a predetermined target value (for example, target value β) of the film thickness. It may further include a storage section (for example, the storage section 52) that stores a control amount table (for example, a printing pressure control amount table) that is stored in association with each other. The control section may refer to the control amount table and control the printing pressure of one of the squeegees with a control amount corresponding to the difference between the film thickness measured by the measurement section and the target value. Thereby, according to the printing apparatus according to the embodiment, the film thickness of the paste can be quickly brought close to the target value without performing complicated calculations.

In addition, the control unit calculates an additional printing pressure by adding a control amount corresponding to the difference between the film thickness measured by the measurement unit and the target value to the current printing pressure of one of the squeegee, and calculates the additional printing pressure until the added printing pressure reaches a predetermined value. An alert may be notified if the value exceeds the upper limit or falls below a predetermined lower limit. Thereby, according to the printing apparatus according to the embodiment, it is possible to notify in advance of a malfunction of the printing apparatus due to the printing pressure of one squeegee deviating from the allowable range.

The control unit also controls the marking of the other squeegee so that the printing pressure of the other squeegee that moves first (for example, the first squeegee 23_1) is a constant value lower than the printing pressure of one squeegee. The pressure may also be controlled. Thereby, according to the printing apparatus according to the embodiment, in printing using two squeegees, it is possible to maintain print quality while suppressing damage to the surface of the printing material.

1 Printing device 2 Printing section 3 Transport section 4 Measuring section 5 Control device 21 Holding table 22 Printing mask 23_1 First squeegee 23_2 Second squeegee 23 Squeegee 24_1 First elevating mechanism 24_2 Second elevating mechanism 24 Elevating mechanism 24a Rod 25 Moving plate 31 Substrate transport device 41 Holding table 42 Film thickness sensor 51 Control section 52 Storage section W Substrate

Claims (5)

a printing unit that prints paste onto a substrate through an opening in the printing mask by sequentially moving two squeegees over the printing mask;
a measuring unit that measures the film thickness of the printed paste;
It has a control unit that controls each part, and
The control unit includes:
and a control section that controls the printing pressure of one of the two squeegees that moves last based on the measurement result of the film thickness by the measurement section. further comprising a storage unit that stores a control amount table that stores a control amount of the printing pressure in association with each difference from a predetermined target value of the film thickness;
The control unit includes:
The printing pressure of the one squeegee is controlled by the control amount corresponding to the difference between the film thickness measured by the measurement unit and the target value with reference to the control amount table. 1. The printing device according to 1. The control unit includes:
An additional printing pressure is calculated by adding the control amount corresponding to the difference between the film thickness measured by the measurement unit and the target value to the current printing pressure of one of the squeegee, and the added printing pressure is set to a predetermined value. The printing apparatus according to claim 2, wherein an alert is notified when the value exceeds an upper limit value or falls below a predetermined lower limit value. The control unit includes:
A claim characterized in that the printing pressure of the other squeegee is controlled so that the printing pressure of the other squeegee that moves first among the two squeegees is a constant value lower than the printing pressure of the one squeegee. 1. The printing device according to 1. printing paste onto the substrate through the openings in the printing mask by sequentially moving two squeegees over the printing mask;
Measuring the film thickness of the printed paste,
A printing method comprising the step of controlling the printing pressure of one of the two squeegees that moves last based on the film thickness measurement result.

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