TW201309486A - Stepping screen printer and a method of processing protective layer thereby - Google Patents

Abstract

The present invention relates to a stepping screen printer and a method of processing a protective layer by using a stepping screen printer. The stepping screen printer comprises a locating stage, an alignment corrector, a control unit, and an execution unit. The execution unit receives machine instructions from the control unit and performs the stepping screen printing. The method of processing the protective layer provided by the present disclosure is to utilize the stepping screen printing for printing an etching paste or a peeling glue on surface of the protective layer so as to form a pattern on the protective layer. The present invention is able to overcome the defects of low consistency of coating etching paste etc. The present disclosure adopts a method of step by step screen coating for coating the etching paste or the peeling glue to resolve the surface processing problem of big-size products.

Description

Stepping screen printing method and printing device thereof

The present invention relates to a screen printing method and a printing apparatus thereof, and in particular to a screen printing method for processing a surface of an object and a printing apparatus therefor.

In recent years, with the continuous development of touch technology, touch panels and display panels combine to form a touch display device and are widely used in applications such as mobile phones, personal digital assistants (PDAs), game console input interfaces, computer touch screens, and the like. Among various electronic products. The touch panel includes a transparent substrate, a conductive layer disposed on the transparent substrate, and a protective layer. The conductive layer is connected to an external control circuit through a peripheral conductive line. The protective layer is applied to the entire conductive layer and the peripheral conductive line. In order to electrically connect the conductive layer to the external control circuit, it is necessary to peel off the protective layer applied to the interface between the peripheral conductive line and the external control circuit.

There are two methods for performing stripping: photolithography and screen printing. Photoetching lithography, or lithography, is a precision surface processing technique that combines pattern copying and chemical etching to etch a geometric pattern corresponding to a mask over a cerium oxide or metal film. Lithography is a complex process in which a specific portion of a surface film is removed through a series of production steps to form a predetermined pattern. Generally, the processes of cleaning, coating a photoresist layer, exposing, developing, drying, etching, and stripping are included. Therefore, the production process is complicated and the working time is long, and the investment cost required for the equipment and the chemical materials is large, resulting in high production cost. In particular, for large-sized touch panels, these problems are more serious, and the complicated production process tends to cause a drop in production yield.

Screen printing is one of the main printing methods for stencil printing. Please refer to FIG. 1 , which is a schematic structural view of a conventional screen printing apparatus, including a screen 1 , a doctor blade 5 , an etching paste 4 , and a table 6 for carrying the substrate 8 . A general screen 1 comprises a solid body 2 and a through hole 3, wherein the through hole 3 constitutes a pattern to be etched, as shown in the figure A. At the time of printing, the etching paste 4 is placed on the preset screen 1, and the etching paste 4 is printed on the substrate 8 from the through hole 3 of the screen 1 under the pressing of the doctor blade 5 to form the pattern 7. It can be seen that screen printing is relatively simple in process technology compared to lithography. However, in the case of a medium-sized and large-sized touch panel, when the area of the protective layer printed is large, the size of the screen used is relatively large, and it is difficult to apply a large-size screen at a time. Controlling the consistency of tension and shape of the entire large-size screen, and thus it is difficult to ensure the consistency of the etching paste dose printed on the substrate, resulting in inconsistent printing area on the substrate, and being applied in the touch panel. The peeling of the protective layer on the touch panel may not meet the requirements, and even affect the conduction performance with the external circuit.

In view of the above, an object of the present invention is to provide a stepping screen printing method and a printing apparatus thereof, which use a small-sized screen to replace a large-sized screen, and a step-by-step screen printing method for a medium-sized workpiece surface. The printing process is carried out to achieve a good effect of uniform coating of the printing dose.

The technical solution adopted by the present invention is: a stepping screen printing method, the method comprising the steps of: sequentially moving a screen to a plurality of positions of a workpiece to be printed area, wherein the screen comprises a preset pattern, And the area of the area to be printed is larger than the coated area of the screen; and the screen printing process is performed to form the preset pattern at a plurality of positions of the area to be printed.

The stepping screen printing method may further include the steps of: locating a starting position of the area to be printed; and moving the screen to the starting position.

The initial position of the positioning area to be printed is determined by photographing the positioning mark of the area to be printed.

The screen printing process prints an etching paste or a peelable paste on the area to be printed.

The etching paste may be ammonium hydrogen fluoride (NH ₄ HF ₂ ), and the area to be printed is a predetermined region on the surface layer of the workpiece formed by cerium oxide. After the etching paste is printed on a predetermined region on the surface layer of the workpiece formed by the cerium oxide, cleaning may be performed to remove the cerium oxide material in the region where the etching paste and the etching paste are located.

The peelable glue is mainly composed of a vinyl resin and an ester plasticizer (ester-based plasticizer), and the area to be printed is a predetermined region on the surface of the workpiece. A conductive layer is coated on the surface of the workpiece. After the peelable glue is printed on a predetermined area of the surface layer of the workpiece, the workpiece that has been subjected to the peelable printing is baked; and a protective layer is coated on the workpiece; and the peelable glue on the workpiece is peeled off, That is, a predetermined pattern is formed in the predetermined area. After peeling off the peelable glue, it can also be cleaned to completely remove the peelable glue remaining on the workpiece.

A stepping screen printing apparatus according to the present invention comprises a screen comprising a predetermined pattern; a workpiece comprising a region to be printed, wherein an area of the area to be printed is larger than a coated area of the screen; An execution unit sequentially moves the screen to a plurality of positions of the to-be-printed area of the workpiece to perform a screen printing process, thereby forming a preset pattern at a plurality of positions of the area to be printed.

The stepping screen printing apparatus may further include a control unit and an alignment corrector, the execution unit being electrically connected to the control unit and the alignment corrector, wherein the alignment corrector, Sensing and capturing a position signal of the screen and the area to be printed for positioning a starting position of the area to be printed and feeding back a positional relationship between the screen and the area to be printed; the control unit receiving the alignment corrector a sensed and captured position signal, and outputting an instruction signal to the execution unit to control and adjust a motion direction and speed of the execution unit; and the execution unit receiving an instruction signal of the control unit and pressing the The received command signal drives the screen and the squeegee to perform a screen printing process.

The control unit comprises: a computer, accepting a position signal sensed and captured by the alignment corrector and forming a machine instruction; the computer can also be used for human-computer interaction, and the operator inputs a desired processing pattern and basis through a computer Machine instructions of the computer control the direction and speed of movement of the execution unit; and a controller coupled to the computer and receiving the machine instructions to control the direction and speed of movement of the execution unit in accordance with machine instructions of the computer.

The alignment corrector includes a displacement sensor and a camera, wherein the camera is coupled to the control unit to detect a position of the positioning mark, determine a position of the area to be printed and a screen, and The position signal is transmitted to the control unit; the displacement sensor is configured to detect a position when the execution unit performs a screen printing process. The camera is a charge coupled device camera.

The execution unit includes a driving motor and a robot arm, wherein the driving motor is connected to the control unit, and after receiving an instruction from the control unit, outputting power to drive the mechanical arm and the squeegee mechanism; Under the driving of the driving motor, the screen and the squeegee mechanism are moved to perform a screen printing operation.

The drive motor may be an X-Y-Z three-axis drive motor, which is composed of a linear guide and a ball screw, and is driven by the X-Y-Z three-axis drive motor.

The screen is provided with an etching paste or a peelable glue, and the squeegee mechanism prints the etching paste or strippable glue on the area to be printed.

The screen is a silk screen or a steel screen.

The stepping screen printing apparatus further includes a working platform connected to the execution unit for carrying and fixing a workpiece, the workpiece surface is the area to be printed, and the working platform is at the execution unit The workpiece is loaded and moved under driving.

The stepping screen printing method and the printing device provided by the invention can effectively overcome the disadvantages of easy deformation and poor printing dose consistency when using a large size screen. Compared with large-size screens, small-size screens are not easily deformed, which can effectively extend the life of the screen and reduce production costs. At the same time, the tension and shape of the small-sized screen are more easily consistent when coating, thereby ensuring the consistency of the printed dose. Therefore, the present invention can effectively solve the protective layer of the medium and large size touch panels by replacing the large size screen with a small size screen and printing the program on the surface of the medium and large workpieces by the stepwise screen printing method. Dealing with the problem.

The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

As shown in FIG. 2 , a touch panel includes a glass substrate 51 , a conductive layer 52 and a protective layer 53 , wherein the conductive layer 52 can be made of indium tin oxide (ITO) or other materials having similar functions, and is disposed on the surface of the glass substrate 51 . The protective layer 53 may be a ceria layer and is coated on the conductive layer 52. The electrode of the conductive layer 52 is connected to the external control circuit through the peripheral conductive line 521. In order to be electrically connected to an external control circuit (not shown), the touch panel needs to be disposed at the interface between the peripheral conductive line 521 and the external control circuit. The protective layer 53 is etched through an interface 531 to establish good electrical contact between the external control circuitry and the conductive layer 52.

According to the invention, the etching paste or the strippable glue is printed on the touch panel by step-by-step screen printing, and the corresponding protective layer material on the peripheral conductive line 521 is removed, so that the protective layer 53 is formed. A preset pattern.

3 and FIG. 4 are schematic diagrams showing the operation of the stepper screen printing of the present invention, wherein the workpiece 810 is located on a working platform 40 and includes a to-be-printed area 9 on which the screen 801 is sequentially moved for printing. The upper left corner of the figure is an enlarged schematic view of a single print, the substrate 808 is a part of the body of the workpiece 810 and its area is a part of the area to be printed 9, and when the screen 801 is moved over the substrate 808 for printing, The etching paste 805 is placed on the preset screen 801, and the etching paste 805 is printed on the surface of the substrate 808 from the through hole 802 of the screen 801 by the squeegee 804 to form a pattern 807, as shown in the figure A. A single print area 806 is formed, which is the coated area of the screen 801. Since the area of the area to be printed 9 is larger than the area of the single printing area 806 of the screen 801, the present invention moves the screen 801 to different positions of the area to be printed 9 for printing, and the moving manner can be step by step. As shown in FIG. 4, on the area to be printed 9 of the workpiece 810, The direction of the screen printing is completed step by step, and the single printing area 806 is completed step by step; after the printing is completed at different positions on all the areas 9 to be printed, the printing of the entire workpiece 810 is completed. If it is shown on the printing of the protective layer 53 of FIG. 2, the etching paste 805 can be printed on the protective layer 53 corresponding to the peripheral position where the peripheral conductive line 521 is located.

5 is a schematic flow chart of a stepping screen printing method according to the present invention. The printing etching paste is used to remove the protective layer 53 material, and the following steps are included: S1: forming a protective layer on the workpiece, and the workpiece is provided with a conductive layer. The protective layer is formed on the conductive layer; S2: the etching paste is printed on the surface of the protective layer by step-screen printing to form a pattern required for the protective layer (ie, the aforementioned predetermined pattern). The stepping screen printing is to print the etching paste by a stepping screen printing device. The step of the stepping screen printing is: S201, using a Charge Coupled Device (CCD) camera, Calling a CCD camera to locate the starting position of the workpiece; S202, moving the robot arm to move the carried screen to the starting position; S203, printing the etching paste on the surface of the protective layer by screen printing S204, the mobile robot arm moves the screen to different positions and repeats S203; S205, when all the regions are completed, the entire workpiece is printed and the printing is completed.

Wherein, the protective layer is made of cerium oxide, and the etching paste is printed on the protective layer by using a stepping screen printing device using ammonium hydrogen fluoride (NH ₄ HF ₂ ), and a chemical reaction occurs, and the chemical equation of the reaction is performed. for:

SiO ₂ +6NH ₄ HF ₂ →H ₂ (SiF ₆ )+6NH ₄ F+2H ₂ O

After the etching paste is applied on the surface of the protective layer, the protective layer processing method further comprises the step S3: cleaning, removing the protective layer material in the region where the etching paste and the etching paste are located, and after the chemical reaction is completed, the fluorine in the coating region of the etching paste is applied. Removal of materials such as ammonium (NH ₄ F).

6 is another schematic flow chart of the stepping screen printing method of the present invention, which uses printing peelable glue to remove the protective layer 53 material, and includes the following steps: T1, stepping screen printing on a workpiece will be peelable Printing the glue on the surface of the workpiece, the peelable glue forming a pattern corresponding to the preset pattern of the screen on the surface of the workpiece; T2, baking the workpiece; T3, coating a protective layer on the workpiece And T4, peeling off the peelable glue on the workpiece to form a pattern required for the protective layer (ie, the aforementioned predetermined pattern).

Wherein the stepping screen printing is to print the peelable glue by using a stepping screen printing device, and the step of stepping screen printing is: T101, using a charge coupled device camera to position the workpiece. a starting position; T102, moving the robot arm to move the carried screen to the starting position; T103, printing the peelable glue on the surface of the protective layer by screen printing; T104, moving the robot arm to move the screen to In the next area, repeat T103; T105 to complete the printing. The peelable glue is mainly a vinyl resin and an ester plasticizer (ester-based plasticizer).

After peeling off the peelable glue on the workpiece, a cleaning step T5 is further included to remove the peelable glue remaining on the workpiece.

Figure 7 is a block diagram of a stepping screen printing apparatus of the present invention, a stepping screen printing apparatus comprising a screen (not shown) including a predetermined pattern; a workpiece 100 comprising a region to be printed, wherein The area to be printed is larger than the coated area of the screen; and an execution unit 30 is connected to the screen to sequentially move the screen to different positions of the area to be printed of the workpiece 100. A screen printing process is performed whereby a predetermined pattern is formed at different locations of the area to be printed.

The stepping screen printing apparatus further includes a control unit 10 and an alignment corrector 20, and the execution unit 30 is connected to the control unit 10 and the alignment corrector 20, wherein the alignment corrector 20 Sensing and capturing a position signal of the screen and the area to be printed, for positioning a starting position of the area to be printed and feeding back a positional relationship between the screen and the area to be printed; the control unit 10 receiving the alignment correction a position signal sensed and captured by the device 20, and outputting an instruction signal to the execution unit 30 to control and adjust the direction and speed of movement of the execution unit 30; the execution unit 30 receives an instruction of the control unit 10 The signal is pressed according to the received command signal, and the screen and the squeegee mechanism are moved to perform the screen printing process.

The control unit 10 includes a controller 101 and a computer (i.e., PC) 102. The computer 102 receives and processes the position signals sensed by the alignment corrector 20 and forms machine instructions. The controller 101 is coupled to the computer 102 and receives the signals. The machine commands to adjust and control the direction and speed of movement of the execution unit 30; the computer 102 is used for human-computer interaction to monitor the motion data of the execution unit 30, and the controller 101 is set, and the operator inputs through the computer 102. The pattern and program to be processed, the computer 102 converts the pattern and program into machine instructions and transmits the machine instructions to the controller 101.

The alignment corrector 20 includes a camera 201 and a displacement sensor 202. The camera 201 is coupled to the computer 102 of the control unit 10 to sense and position the workpiece 100 by sensing the position of the positioning mark on the workpiece 100. The position of the area to be printed and the position of the screen, the camera 201 transmits the captured position information of the workpiece 100 to the computer 102 of the control unit 10 for processing. The camera 201 is a Charge Coupled Device camera, and the position of the workpiece 100 is determined by off-axis alignment. The displacement sensor 202 is used to monitor the position of the execution unit 30 when performing the screen printing process. For example, the displacement sensor 202 can detect the position signal of the robot arm 302 to determine the position of the robot arm 302 and feed it back to the controller 101 for processing.

The executing unit 30 includes a driving motor 301 and a mechanical arm 302. The driving motor 301 is connected to the control unit 10, and receives the command signal of the control unit 10 and performs step-by-step screen printing according to the received command signal to output power. For driving the robot arm 302 and the working platform 40; the robot arm 302 is used for loading the screen and the squeegee mechanism (not shown), and the robot arm 302 drives the screen and the squeegee to move the screen printing under the driving of the driving motor 301. action. The squeegee mechanism includes a scraper and a driving device for swaying the scraper to the right and left, a scraper clutch press device and a scraper lifting device. The robot arm 302 performs a screen printing operation step by step, and moves the screen in different areas according to the command signal, and prints the screen pattern on the surface of the workpiece 100 on each area. The driving motor 301 includes an X-Y-Z three-axis driving motor, and the robot arm 302 is composed of a linear guide rail and a ball screw, and is driven by the X-Y-Z three-axis driving motor.

The positioning workpiece table 40 is used to carry and fix the workpiece 100 to be processed. The workpiece 100 is marked with a plurality of positioning marks to facilitate the detection and positioning of the charge coupled device camera.

The stepping screen printing device can adopt the method of moving the screen plate and the squeegee mechanism when moving stepwise; the stepping displacement can also be performed by using the mobile working platform.

The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalents, improvements, etc., which are made within the spirit and principles of the present invention, should be included in the present invention. Within the scope of protection.

1. . . Web version

2. . . entity

3,802. . . Through hole

4,805. . . Etching paste

5,804. . . scraper

6. . . Workbench

7,807. . . pattern

8. . . Carrying substrate

51. . . glass substrate

52. . . Conductive layer

53. . . The protective layer

521. . . Peripheral conductive line

531. . . interface

40. . . Work platform

801. . . Web version

806. . . Single print area

808. . . Substrate

810,100. . . Workpiece

9. . . Area to be printed

10. . . control unit

20. . . Alignment corrector

30. . . Execution unit

101. . . Controller

102. . . computer

201. . . Camera

202. . . Motion detector

301. . . motor

302. . . Mechanical arm

S1-S3, S201-S205, T1-T5, T101-T105. . . The process of stepping screen printing method

1 is a schematic structural view of a conventional screen printing apparatus;

2 is a schematic structural view of a touch panel of the present invention;

Figure 3 is a schematic view showing the operation of the stepping screen printing of the present invention;

Figure 4 is a schematic view showing the operation of the stepping screen printing of the present invention;

Figure 5 is a flow chart of the stepping screen printing method of the present invention;

Figure 6 is a flow chart of another stepping screen printing method of the present invention;

Figure 7 is a block diagram showing the stepping screen printing apparatus of the present invention.

S1-S3, S201-S205. . . The process of stepping screen printing method

Claims (20)

A stepping screen printing method comprises: sequentially moving a screen to a plurality of positions of a workpiece to be printed area, wherein the screen comprises a predetermined pattern, and the area of the area to be printed is larger than the coating of the screen An area; and a screen printing process to form the predetermined pattern at the locations of the area to be printed. The stepping screen printing method according to claim 1, further comprising the steps of: positioning a starting position of the area to be printed; and moving the screen to the starting position. The stepping screen printing method according to claim 2, wherein the starting position of the area to be printed is determined by photographing at least one positioning mark of the area to be printed. The stepping screen printing method according to claim 1, wherein the screen printing process prints an etching paste or a peelable paste on the area to be printed. The stepping screen printing method according to claim 4, wherein the etching paste is ammonium hydrogen fluoride, and the area to be printed is a predetermined region on the surface layer of the workpiece formed by cerium oxide. The stepping screen printing method according to claim 5, further comprising: a cleaning step of removing the cerium oxide material in the region where the etching paste and the etching paste are located. The stepping screen printing method according to claim 4, wherein the peelable glue is mainly composed of a vinyl resin and an ester plasticizer, and the area to be printed is a predetermined area on the surface of the workpiece. The stepping screen printing method according to claim 7, wherein the surface of the workpiece is coated with a conductive layer. The stepping screen printing method according to claim 7, further comprising the steps of: baking the workpiece that has been subjected to peelable printing; coating a protective layer on the surface of the workpiece; and peeling off The strippable glue on the workpiece to form the predetermined pattern in the predetermined area. The stepping screen printing method according to claim 9, further comprising: a cleaning step of removing the peelable glue remaining on the workpiece. A stepper screen printing apparatus comprising: a screen comprising a predetermined pattern; a workpiece comprising a region to be printed, wherein an area of the area to be printed is larger than a coated area of the screen; and an execution unit, sequential The screen is moved to a plurality of positions of the to-be-printed area of the workpiece to perform a screen printing process, whereby the predetermined pattern is formed at the positions of the area to be printed. The stepping screen printing apparatus according to claim 11, further comprising: an alignment corrector electrically connected to the execution unit to sense and capture at least one position signal of the screen and the area to be printed a positioning position of the area to be printed and a positional relationship between the screen and the area to be printed; and a control unit electrically connected to the execution unit to receive and sense the alignment corrector The position signal, and outputting a command signal to the execution unit, thereby controlling and adjusting the moving direction and speed of the executing unit, the executing unit further receiving the command signal of the control unit and driving the command signal according to the received command signal The screen printing process is performed by a screen and a squeegee mechanism. The stepping screen printing apparatus of claim 12, wherein the control unit comprises: a computer that receives the position signal sensed and captured by the alignment corrector and forms a machine command, wherein the computer For human-computer interaction, an operator inputs a pattern and a program to be processed through the computer, the computer converts the pattern and the program into the machine instruction; and a controller connected to the computer and receives the machine instruction, according to The machine instructions of the computer control the direction and speed of movement of the execution unit. The stepper printing apparatus according to claim 12, wherein the alignment corrector comprises: a camera connected to the control unit for detecting a position of the at least one positioning mark, determining the area to be printed And the position of the screen and transmitting the corresponding position signal to the control unit; and a displacement sensor for detecting the position of the execution unit when performing the screen printing process. The stepping screen printing apparatus according to claim 14, wherein the camera is a charge coupled device camera. The stepping screen printing apparatus according to claim 12, wherein the execution unit comprises: a driving motor connected to the control unit; and a mechanical arm connected to the driving motor; wherein the driving motor receives the After the command from the control unit, the power is output to drive the robot arm and the squeegee mechanism; the robot arm drives the screen and the squeegee to move to perform the screen printing operation under the driving of the driving motor. The stepping screen printing apparatus according to claim 16, wherein the driving motor is an XYZ three-axis driving motor, and the robot arm is composed of a linear guide rail and a ball screw, and is configured by the XYZ three-axis direction. Drive motor drive. The stepping screen printing apparatus according to claim 12, wherein the screen is provided with an etching paste or a peelable glue, and the squeegee mechanism prints an etching paste or a peelable glue on the area to be printed. The stepping screen printing apparatus according to claim 11, wherein the screen is a silk screen or a steel screen. The stepping screen printing apparatus of claim 11, further comprising: a working platform connected to the execution unit for carrying and fixing the workpiece, the surface of the workpiece being the area to be printed, the work The platform loads and moves the workpiece under the driving of the execution unit.