WO2020125187A1

WO2020125187A1 - Pcb printing apparatus and control method therefor

Info

Publication number: WO2020125187A1
Application number: PCT/CN2019/112502
Authority: WO
Inventors: 邱国良; 宋先玖
Original assignee: 东莞市凯格精密机械有限公司
Priority date: 2018-12-17
Filing date: 2019-10-22
Publication date: 2020-06-25
Also published as: CN109413889A

Abstract

A PCT printing apparatus, comprising a steel mesh and a scraping blade, and further comprising a scraping blade pressure adjustment mechanism, the pressure adjustment mechanism comprising a controller (10), an electric proportional valve (20), a scraping blade cylinder (30) and a solenoid valve (40); the controller (10) being connected to the electric proportional valve (20); an air outlet opening of the solenoid valve (40) being in communication with an air inlet opening of the electric proportional valve (20) by means of an air tube, an air inlet opening of the scraping blade cylinder (30) being in communication with an air outlet opening of the electric proportional valve (20) by means of an air tube, and an air outlet opening of the scraping blade cylinder (30) being in communication with an air exhaust opening of the solenoid valve (40) by means of an air tube; a push rod of the scraping blade cylinder (30) being fixedly connected to the scraping blade, so as to drive the scraping blade to rise and lower. Maintaining a pre-determined initial pressure by means of controlling contact pressure between a scraping blade and a steel mesh solves the problem of non-uniform solder paste thickness which easily arises when printing, improving PCT printing quality and strengthening overall PCB functionality.

Description

Device for printing PCB board and control method thereof

This application requires the priority of the Chinese patent application submitted to the Chinese Patent Office on December 17, 2018, with the application number 201811543519.9 and the invention titled "A PCB printing device and its control method", the entire contents of which are incorporated by reference In this application.

Technical field

The invention relates to the technical field of printing, in particular to a PCB board printing device and a control method thereof.

Background technique

In the process of PCB board production, printing is a relatively important process, and the printing quality largely determines the overall working performance of the PCB board. At present, the problem of uneven thickness of solder paste is likely to occur during printing, which affects the overall performance of the PCB board. Therefore, how to ensure the uniform thickness of the solder paste has become an urgent technical problem to be solved.

Summary of the invention

The object of the present invention is to provide a device for PCB board printing and a control method thereof to solve the problem of uneven thickness of solder paste.

To achieve this goal, the present invention uses the following technical solutions:

A PCB printing device includes a steel mesh, a scraper, and a scraper pressure adjustment mechanism. The pressure adjustment mechanism includes a controller, an electric proportional valve, a scraper cylinder, and a solenoid valve;

The controller is connected to the electric proportional valve; the air outlet of the solenoid valve is connected to the air inlet of the electric proportional valve through the trachea, the air inlet of the scraper cylinder is connected to the air outlet of the electric proportional valve through the trachea, and the air outlet of the scraper cylinder is connected to the solenoid valve through the air pipe Exhaust port; the jack of the scraper cylinder is fixedly connected to the scraper to drive the scraper up and down;

The controller compares the voltage value output by the electric proportional valve to determine the current pressure value acting on the steel mesh in real time, and increases the compressed air in the scraper cylinder when the current pressure value of the scraper cylinder is less than the preset pressure value, or When the current pressure value of the cylinder is greater than the preset pressure value, the compressed air in the scraper cylinder is reduced.

A control method for PCB board printing, including: using a scraper cylinder to drive a scraper to perform a solder paste scraping step,

In the step of using the scraper cylinder to drive the scraper to perform the solder paste scraping operation, the current pressure value of the scraper acting on the steel mesh is detected in real time;

If the current pressure value is less than the preset pressure value, increase the compressed air in the cylinder until the current pressure value is adjusted to the preset pressure value;

If the current pressure value is greater than the preset pressure, the compressed air in the cylinder is reduced until the current pressure value is adjusted to the preset pressure value.

Optionally, the step: before using the scraper cylinder to drive the scraper to perform the solder paste scraping operation, further includes:

The conveyor belt transports the PCB board to the printing platform;

CCD stop plate cylinder for rough positioning of PCB board;

The printing platform rises from the initial position of the printing platform to the imaging position of the printing platform, and the clamping plate clamps the PCB board;

The CCD moves from the initial position of the CCD to the imaging position of the CCD, performs rough stop positioning and imaging on the PCB board, and outputs the image processing result;

According to the CCD image processing results, the PCB board is precisely positioned;

The CCD returns to the initial position of the CCD, and the printing platform rises to the printing position of the printing platform so that the PCB board contacts the steel mesh.

Optionally, the step: after the step of using the scraper cylinder to drive the scraper to perform the solder paste scraping operation, further includes:

After printing is completed, the scraper cylinder drives the scraper to rise back to the alternate position of the scraper, and then the scraper rises from the alternate position of the scraper to the initial position of the scraper.

Optionally, the step: after printing is completed, the scraper cylinder drives the scraper to rise back to the alternate position of the scraper, and then the scraper rises from the alternate position of the scraper to the initial position of the scraper, further including:

Steel mesh release;

The printing platform descends from the printing position of the printing platform to the initial position of the printing platform;

The conveyor belt transports the PCB board out.

Optionally, the step: the CCD is moved from the initial position of the CCD to the image capturing position of the CCD, the image is captured on the PCB board and the image processing result is output, which specifically includes:

After the CCD is moved to the CCD imaging position, the stop plate cylinder on the CCD is extended to stop the PCB board. Then the camera on the CCD moves to capture the image information of at least two mark points on the PCB board, and the CCD image the image information Processing, analyze the position of each mark point, and output the image processing result.

Optionally, the step: precisely positioning the PCB according to the image processing result of the CCD, specifically including:

The position of each mark point on the PCB board output according to the image processing result of the CCD is adjusted to correspond to the mark point on the steel mesh one by one, and the PCB board is precisely positioned.

Optionally, the step: before the transport belt transports the PCB board to the printing platform, further includes:

After receiving the feed signal from the feed sensor, the baffle cylinder acts and extends the baffle.

Optionally, the step: after the transport belt transports the PCB board to the printing platform, further includes:

After receiving the incoming signal from the incoming sensor, the conveyor belt stops.

Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

The invention maintains the preset initial pressure by controlling the pressure of the contact between the scraper and the steel mesh, solves the problem of uneven thickness of solder paste during printing, improves the quality of PCB board printing, and enhances the overall performance of the PCB board.

BRIEF DESCRIPTION

In order to more clearly explain the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, without paying any creative labor, other drawings can be obtained based on these drawings.

1 is a flowchart of a method for controlling PCB board printing provided by an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a scraper pressure adjustment mechanism for PCB board printing provided by an embodiment of the present invention;

FIG. 3 is a flowchart of a method for maintaining a constant voltage for PCB board printing according to an embodiment of the present invention.

In the picture:

10. Controller; 20. Electric proportional valve; 30. Scraper cylinder; 40. Solenoid valve; 51. Intake speed adjustment valve; 52. Outlet speed adjustment valve; 60. Industrial control machine.

detailed description

In order to make the purpose, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the drawings in the embodiments of the present invention. Obviously, the following The described embodiments are only a part of the embodiments of the present invention, but not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the drawings The orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as limiting the present invention.

It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to another component or there may be a centrally located component at the same time. When a component is considered to be "set on" another component, it may be set directly on another component or there may be a center-set component at the same time.

The technical solutions of the present invention will be further described below with reference to the drawings and through specific implementations.

Please refer to Figure 1, a control method for PCB printing, including the following steps:

Step S101: After receiving the feed signal from the feed sensor, the transport motor rotates, the baffle cylinder moves, and the baffle is extended; wherein, when the PCB board is placed on the transport belt, the feed sensor acts and launches料信号。 Material signals.

Step S102: The conveyor belt transports the PCB board to the printing platform. When the PCB board is transported to the baffle, it will be blocked by the baffle.

Step S103: After receiving the material arrival signal from the material arrival sensor, the conveyor belt stops; at this time, the PCB board is located on the printing platform, and at this time, the printing platform is located at the initial position of the printing platform.

Step S104: the CCD stop plate cylinder coarsely positions the PCB board to ensure accurate position during printing, thereby improving printing quality.

Step S105: the baffle cylinder operates, and the baffle is retracted.

Step S106: the printing platform rises from the initial position of the printing platform to the image capturing position of the printing platform, and the clamping plate clamps the PCB board.

Step S107: the CCD is moved from the initial position of the CCD to the CCD imaging position to perform rough stop positioning and imaging on the PCB board and output image processing results; after the CCD imaging, image processing is performed on the acquired image and corresponding image processing is output result.

Specifically, after the CCD is moved to the CCD imaging position, the stop plate cylinder on the CCD is extended to stop the PCB board, and then the camera on the CCD moves to capture the image information of at least two mark points on the PCB board. The information is image processed, the position of each mark point is analyzed, and the image processing result is output.

Step S108: accurately positioning the PCB board according to the image processing result of the CCD; specifically, the position of each mark point on the PCB board output according to the image processing result of the CCD is adjusted to correspond one-to-one with the mark points on the steel mesh , Precise positioning of the PCB board.

Step S109: The CCD returns to the initial position of the CCD, and the printing platform rises to the printing position of the printing platform, so that the PCB board and the steel mesh are in full contact.

Step S110: a step of using a scraper cylinder to drive the scraper to perform the solder paste scraping operation; in a step of using the scraper cylinder to drive the scraper to perform solder paste scraping operation, the current pressure value of the scraper acting on the steel mesh is detected in real time;

Specifically, after step S110, it further includes: after printing is completed, the scraper cylinder 30 drives the scraper to rise back to the alternate position of the scraper, and then the scraper rises from the alternate position of the scraper to the initial position of the scraper.

Step S111: The steel mesh is demolded.

Step S112: The printing platform is lowered from the printing position of the printing platform to the initial position of the printing platform.

Step S113: The conveyor belt transports the PCB board out to complete the printing of the PCB board.

A PCB board printing device includes a steel mesh, a scraper, and a scraper pressure adjustment mechanism.

Referring to FIG. 2, the scraper pressure adjustment mechanism includes a controller 10, an electric proportional valve 20, a scraper cylinder 30, a solenoid valve 40, an intake speed adjustment valve 51, an exhaust speed adjustment valve 52, and an industrial control machine 60; the controller 10 is connected to the electrical Proportional valve 20, solenoid valve 40 and industrial control machine 60; the air inlet of the scraper cylinder 30 communicates with the electric proportional valve 20 through the trachea, and the air outlet of the scraper cylinder 30 communicates with the solenoid valve 40 through the trachea; the ejector of the scraper cylinder 30 is fixedly connected to the scraper , So that the scraper cylinder 30 drives the scraper up and down; the intake speed adjustment valve 51 is provided between the intake port of the scraper cylinder 30 and the electric proportional valve 20 for adjusting the speed of compressed air intake, and the exhaust speed adjustment valve 52 is provided on the scraper Between the air outlet of the cylinder 30 and the solenoid valve 40, it is used to adjust the speed of the exhaust when the ejector of the scraper cylinder 30 is retracted.

The controller 10 compares the voltage value output by the electric proportional valve 20 to determine the current pressure value acting on the steel mesh in real time, and increases the compression in the blade cylinder 30 when the current pressure value of the blade cylinder 30 is less than the preset pressure value Air, or reduce the compressed air in the scraper cylinder 30 when the current pressure value of the scraper cylinder 30 is greater than the preset pressure value.

Please refer to FIG. 3, step S110 specifically includes the following steps:

Step S1101: the controller 10 controls the blade to be lowered from the initial position of the blade to the alternate position of the blade;

Step S1102: the controller 10 controls the solenoid valve 40 to turn on, and compressed air flows from the solenoid valve 40 to the electric proportional valve 20;

Step S1103: The controller 10 outputs a preset voltage value to the electric proportional valve 20. After receiving the voltage value output by the controller 10, the electric proportional valve 20 converts the electric proportional valve 20 to output the corresponding proportion of compressed air to the scraper cylinder 30. , Excess compressed air will be discharged from the exhaust port of the electric proportional valve 20.

Under the action of compressed air, the scraper cylinder 30 drives the scraper down to make full contact with the steel mesh. At this time, the pressure between the scraper and the steel mesh is defined as a preset pressure value.

The electric proportional valve 20 feeds back the current voltage value to the controller 10 in real time, and reflects the actual compressed air ratio of the current electric proportional valve 20 to the controller 10. The controller 10 converts the current voltage value according to the current voltage value to obtain the current pressure value acting on the steel mesh.

Step S1104: The controller 10 controls the scraper to scrape the solder paste. During the scraper scraping process, due to the error of the flatness of the steel mesh and the PCB board, the distance of the cylinder extension will change, so that the cylinder gas storage volume changes, so that The pressure between the scraper and the steel mesh changes.

Step S1105: determine whether the current pressure value between the scraper and the steel mesh is less than or greater than the preset pressure value.

Step S1106: If the current pressure value between the blade and the steel mesh is less than the preset pressure value, the controller 10 controls the electric proportional valve 20 to deliver compressed air to the blade cylinder 30, thereby increasing the air pressure in the blade cylinder 30 until the current pressure The value is adjusted to a preset pressure value, so that the scraper cylinder 30 maintains a stable pressure output, and finally the pressure at which the scraper contacts the steel mesh is controlled to maintain the preset pressure value.

Step S1107: If the current pressure value between the blade and the steel mesh is greater than the preset pressure value, the controller 10 controls the electric proportional valve 20 to discharge excess compressed air through the exhaust port until the current pressure value is adjusted to the preset pressure value , So that the scraper cylinder 30 maintains a stable pressure output, and finally controls the pressure at which the scraper contacts the steel mesh to maintain a preset pressure value.

After step S1107, it also includes: after the printing is completed, the controller 10 controls the cylinder rod to retract, and drives the scraper to rise away from the stencil. When the cylinder drives the scraper to the alternate position of the scraper, the controller 10 continues to control the scraper to rise until the scraper returns The initial position of the scraper.

This embodiment provides a control method for PCB board printing. By controlling the pressure of the contact between the scraper and the steel mesh to maintain the preset initial pressure, the problem of uneven thickness of solder paste during printing is solved, and PCB board printing is improved. The quality enhances the overall performance of the PCB board.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still The technical solutions described in the embodiments are modified, or some of the technical features are equivalently replaced; and these modifications or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

A PCB board printing device includes a steel mesh and a scraper, and is characterized in that it further includes a scraper pressure adjustment mechanism, and the pressure adjustment mechanism includes a controller, an electric proportional valve, a scraper cylinder, and a solenoid valve;

The controller is connected to the electric proportional valve; the air outlet of the solenoid valve is connected to the air inlet of the electric proportional valve through the trachea, the air inlet of the scraper cylinder is connected to the air outlet of the electric proportional valve through the trachea, and the air outlet of the scraper cylinder is connected to the solenoid valve through the air pipe Exhaust port; the jack of the scraper cylinder is fixedly connected to the scraper to drive the scraper up and down;

The controller compares the voltage value output by the electric proportional valve to determine the current pressure value acting on the steel mesh in real time, and increases the compressed air in the scraper cylinder when the current pressure value of the scraper cylinder is less than the preset pressure value, or When the current pressure value of the cylinder is greater than the preset pressure value, the compressed air in the scraper cylinder is reduced.
A control method of PCB board printing, which is characterized by comprising: a step of driving a scraper by a scraper cylinder to perform a solder paste scraping operation;

In the step of using the scraper cylinder to drive the scraper to perform the solder paste scraping operation, the current pressure value of the scraper acting on the steel mesh is detected in real time;

If the current pressure value is less than the preset pressure value, increase the compressed air in the cylinder until the current pressure value is adjusted to the preset pressure value;

If the current pressure value is greater than the preset pressure, the compressed air in the cylinder is reduced until the current pressure value is adjusted to the preset pressure value.
The method for controlling PCB board printing according to claim 2, wherein the step: before the step of performing scraping solder paste operation by using a scraper cylinder to drive the scraper, further comprising:

The conveyor belt transports the PCB board to the printing platform;

CCD stop plate cylinder for rough positioning of PCB board;

The printing platform rises from the initial position of the printing platform to the imaging position of the printing platform, and the clamping plate clamps the PCB board;

The CCD moves from the initial position of the CCD to the imaging position of the CCD, performs rough stop positioning and imaging on the PCB board, and outputs the image processing result;

According to the CCD image processing results, the PCB board is precisely positioned;

The CCD returns to the initial position of the CCD, and the printing platform rises to the printing position of the printing platform so that the PCB board contacts the steel mesh.
The control method for PCB board printing according to claim 2, wherein the step: after the step of performing the operation of scraping the solder paste by using a scraper cylinder to drive the scraper, further comprising:

After printing is completed, the scraper cylinder drives the scraper to rise back to the alternate position of the scraper, and then the scraper rises from the alternate position of the scraper to the initial position of the scraper.
The control method of PCB printing according to claim 4, wherein in the step: after printing, the scraper cylinder drives the scraper to rise back to the alternate position of the scraper, and then the scraper rises from the alternate position of the scraper to the position of the scraper After the initial position, it also includes:

Steel mesh release;

The printing platform descends from the printing position of the printing platform to the initial position of the printing platform;

The conveyor belt transports the PCB board out.
The control method of PCB printing according to claim 3, characterized in that, in the step: the CCD is moved from the initial position of the CCD to the imaging position of the CCD, the PCB is imaged and the image processing result is output, specifically including :

After the CCD is moved to the CCD imaging position, the stop plate cylinder on the CCD is extended to stop the PCB board. Then the camera on the CCD moves to capture the image information of at least two mark points on the PCB board, and the CCD image the image information Processing, analyze the position of each mark point, and output the image processing result.
The control method for PCB board printing according to claim 3, characterized in that, the step: performing precise positioning on the PCB board according to the image processing result of the CCD, specifically including:

The position of each mark point on the PCB board output according to the image processing result of the CCD is adjusted to correspond to the mark point on the steel mesh one by one, and the PCB board is precisely positioned.
The method for controlling PCB board printing according to claim 3, characterized in that, the step: before the transport belt transports the PCB board to the printing platform, further comprising:

After receiving the feed signal from the feed sensor, the baffle cylinder acts and extends the baffle.
The method for controlling PCB board printing according to claim 3, characterized in that, after the step of transporting the PCB board to the printing platform by a conveyor belt, the method further comprises:

After receiving the incoming signal from the incoming sensor, the conveyor belt stops.