JP3243371B2 - Screen printing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing apparatus for mounting a solder paste at a predetermined position by screen printing before an electronic component is mounted on an electronic circuit board.

[0002]

2. Description of the Related Art In recent years, as the definition of conductor lines has been increased, finer control of operation of screen printing on electronic circuit boards has been required. However, conventionally, it can be said that there has been no method that can be called control in a strict sense, since a mechatronic switch is used at the start and end of the printing operation. In particular, there has been no type in which a printing result is determined and fed back to printing conditions.

[0003] The plate results in good quality in order to obtain stable, to determine the print result, automatically changing the parameters of the conditions including the printing operation to be adjusted is first requested and foremost. In particular, when performing test printing for optimizing printing conditions, a printing test using a combination of a printed circuit board (hereinafter abbreviated as a P-plate) and a test screen as a test print is provided for practical use. P-plate (hereinafter, referred to as
There is a need for a mechanism that can arbitrarily select any of the printing tests based on a combination of a screen plate (hereinafter, abbreviated as an actual screen) corresponding to an image pattern used in an actual electronic circuit. . And finally, on
It is hoped that a system that solves each of the above problems will be realized.
That's it. Therefore, the applicant should respond to these requests.
Screen printing method (described later) was developed.

[0004]

In the above-mentioned screen printing system, a gap is provided between the screen and the upper surface of the P-plate.
In the gap type with a gap, the squeegee is displayed on the screen
In the vicinity immediately below the surface that slides through the surface, the lower surface of the screen and P
-The upper surface of the plate has a squeegee blade portion along the printing direction.
Touches over the width and screens as squeegee moves
The lower surface of the screen is P
-The process of moving away from the on-board surface is important. why
Means separation of the screen plate from the upper surface of the P-plate.
In the case of a plate separation (hereinafter simply referred to as a plate separation),
-The lower surface of the screen and the upper surface of the P-plate accompanying the movement of the
Of the contact angle (hereinafter simply referred to as contact angle)
The speed of plate separation changes, resulting in uneven printing.
Or limit the high definition of the pattern to be printed.
Was a factor.

[0005]

[0006] Further, through the opening of the screen, P-
It is also desired to finely adjust the amount of printing material to be placed on a plate.

Therefore, the present invention relates to the screen printing method
Provide a screen printing device used for

[0008]

In order to solve the above problems SUMMARY OF THE INVENTION In the first the screen printing method, adopted is housing structure as a squeegee device which is a main portion of the printing apparatus, essential to the screen printed together various The apparatus includes a print result determination device that determines the print result of the P-plate and a central signal processing device (hereinafter, abbreviated as CPU) that performs signal processing for controlling the entire printing operation based on a signal from the determination device. And performs feedback-type control using the determination signal as a main feedback signal in a printing process.
Further, it is necessary for display, recording, and input / output, especially for the CPU
It has various terminal devices. In addition, a device for displaying and recording a print result is provided.

(Delete)

Therefore, the screen printing apparatus of the present invention,
A printing base that can supply a printed circuit board as a printing medium
A board supply device and a printing material placed on the upper surface of the printed circuit board.
Squeegee having a housing structure that can be printed on
A printing device comprising a printing device;
Print result judgment that can judge the print result of printed circuit board
Device and a determination signal output from the determination device.
The operation of the printed board supply device and the printing device is controlled.
Central signal processing device capable of outputting control signals for controlling
(CPU) in the screen printing apparatus.
Of the screen plate before and after the squeegee device advances
So that the angle is maintained at approximately the same angle
A cam that operates based on a judgment signal output from a judgment device
Screen holding frame or print base on the printing start side
Lifting the plate in conjunction with the movement of the squeegee device
Table on the printed circuit board with respect to the screen plate surface
Characterized in that the inclination angle of the surface is variable.
You.

[0011]

The screen printing apparatus of the present invention controls the above-mentioned separation speed by using the printing result determination apparatus.
Via a cam that operates based on the judgment signal
Lift the screen holding frame or printed circuit board on the printing start side
Printing on the upper surface of the screen plate
The configuration was such that the inclination angle of the upper surface of the substrate was variable .

[0013]

(Delete)

Incidentally, among the terms of the present invention used so far and also used below, a housing structure, a squeegee device,
The concept, meaning, and configuration of the blades and the like constituting the squeegee blade portion, the auxiliary side wall, and the squeegee blade portion as a set of two before and after the squeegee blade portion are found in the literature (Japanese Patent Application No. 5-39222). The same or equivalent.

[0016]

In the screen printing apparatus according to the present invention, a squeegee apparatus, which is a main part of the printing apparatus , has a housing structure which does not directly contact the outside air, and a printing result determination apparatus, a CPU and a P-plate supply apparatus. more location, from the determination result of the printing plate, the printing conditions can print control feedback type which can be variously controlled. In addition, printing the results display equipment
Can visualize more print results, can determine the direct printing results by the human eye, more and more print result recording equipment,
The determination of the printing result based on the abundant determination data is extended, so that finer print control can be performed.

(Delete)

[0018]

[0019]

[0020] Then, in the screen printing apparatus according to the invention, as plate separation speed control means, cleans and P-
The plate separation speed is controlled based on a signal from the printing result determination device by adopting a configuration in which the relative positional relationship between the respective holding devices of the plate is changed relative to the relative inclination angles of the respective upper surfaces. Can be.

[0021]

[0022] Still further, in this onset bright, and device information and data of the display and the recording and input regarding the printing operation, CPU capable of outputting a control signal for printing operation based on a signal from the input device about the plate release speed Means for calculating and correcting data, and even creating a management file and recording the file data in the recording device or reading the data from the device in reverse, and a means for issuing a control command based on the corrected data are also provided. With the provision , various printing operations in the printing process in the screen printing method can be controlled.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The gist of the present invention will be described below based on embodiments with reference to the drawings. FIG. 1 shows the basics of the present invention.
In block diagram for explaining the mechanism of consisting screen printing method, 1 P- plate feeder, 2 a printing apparatus whose main unit a squeegee device housing structure which has been described up to above, 3 the printing A print result determination device for determining the result of the P-plate printed by the device 2; a CPU 4 for performing various signal processing based on a determination signal from the determination device and for sending a feedback signal to the first and the second;
In Ru Oh. Similarly, print results by adding the print result display unit 5 for visualization that reflect, for example, in a cathode ray tube, also print the result to the example recording on various disk optionally above 3
Ru-added to <br/> feed may print result recording unit 6 as determined article. Incidentally, 7 Ru der thing needful in the actual printing process or work site in P- plate storage device. The solid lines with arrows connecting the blocks in FIG. 1 indicate the flow of electric signals and the flow of functions between the blocks. In short, the most important thing in FIG. 1 is that the printing result is issued from the determination device 3 and the CPU
4 is fed back to the printing device 2 and the P-plate supply device 1 via the printer 4.

FIG. 2 is a block diagram for explaining an additional mechanism of the above-mentioned screen printing method, where T indicates a test version and R indicates a practical version. Similarly, S means a screen plate, B means a P-plate, and C means "plate matching" in which the screen plate and the upper surface of the P-plate are in contact with each other for printing. Reference numerals 8 and 9 respectively denote a first selecting means for selecting a test version or a practical version as a P-plate and a second selecting means for selecting the same as a screen.
That is, the subscripts I and II correspond to the first and second means names. In order to optimize the printing conditions, a printing test is always performed without fail. However, a first printing test procedure using a combination of an actual substrate (practical P-plate) and an actual screen and a test substrate (test P-plate) are performed. The CPU 4 allows the user to arbitrarily select the procedure of the second print test in combination with the test screen.
2 is shown in FIG. 2, the solid line with an arrow indicates the flow of electric signals, and the one-dot chain line indicates that the above two types of screens are prepared.
Double-headed arrow with a thick solid line is you taste mind the above-mentioned version alignment, respectively.
3-5 is for more detailed explanation of the examples of the test print, and utility FIG. 3 in the above printing method
6 is a flowchart of a general print test regardless of non-practical use. However, actual printing is a combination of an actual substrate and an actual screen, and printing for practical use, not for testing. FIG. 4 shows only an example of the test screen plate, and the shape and pitch of the pattern are originally arbitrary.
FIG. 5 shows that the first to fourth tests are performed in the second print test procedure, and the fifth to seventh tests are performed following the test in the first print test procedure. This is a flow chart of performing the actual printing based on the result.

FIG. 6 shows that a required amount of printing material is supplied for each printing process into a squeegee device having a housing structure (hereinafter simply referred to as a squeegee device) which is a main part of the screen printing device according to the present invention. FIG. 4 is a cross-sectional view of a main part of a printing material supply device provided outside the squeegee device as printing material supply means. The solid shaded portion 10 is the main body of the apparatus, 11 is a pipe from which the printing material is discharged from the main body, 12 is a piston head for extruding the material, and 13 is the interior of the container which is pushed by the head. A moving plate (for example, a disk), and a threaded rod 14 directly connected to the head means a rotating shaft for propelling the head. Reference numeral 15 denotes a support that supports the rod serving as the rotation shaft and the main body. Reference numerals 16 (1) and 16 (2) both denote gears. 17 (1), 18 (2)
Is a spacer inserted before and after 16 (1) along the length direction of 14. The motor 17 is rotated based on the command signal from the CPU, and the printing material stored inside the main body 10 indicated by the solid hatching is discharged along with the discharge pipe 1.
1 and into the squeegee device.

FIG. 7 is a cross-sectional view of a main part of the squeegee device cited above. Reference numeral 19 conceptually denotes a squeegee device, specifically, an inner wall thereof. Reference numeral 20 denotes a squeegee blade at the bottom of the apparatus and in contact with the screen, and also indicates the presence of an auxiliary side wall for preventing printing material from escaping from the structure having the housing structure. 21 (1) and 21 (2) are squeegee blades, whereas 21 (1) provided forward along the printing direction (P) is almost fixed, whereas 21 (2) is fixed.
Is moved back and forth in the above-mentioned direction in accordance with the start and end of printing by a movable wall 22 attached to 20, and opens and closes toward the upper surface of the screen. Reference numerals 23 and 24 denote rollers for feeding the printing material to the squeegee blade portion, and at the same time, cooperate with a partition plate 25 shown by a thick solid line to rotate each direction of rotation, for example, 23 to rotate counterclockwise, and to rotate 24. It can be used as a means for adjusting the viscosity of the material by selecting clockwise or the like . In FIG. 7, reference numeral 26 denotes a material supply port for introducing the printing material (M) from the supply device into the squeegee device, and reference numeral 27 denotes an inert gas such as nitrogen gas for preventing oxidation of solder of the material base. (G) means the gas supply ports for supplying the gas into the apparatus. However, the gas supply device may be a normal gas cylinder as long as the valve is electrically operated, and is not shown. Ultimately, the gist of FIG. 7 is that each means operates based on the determination signal from the print result determination device.

FIGS. 8 and 9 are based on the intent that the most efficient use of the printing material at the optimum temperature is to adjust the temperature of the printing material at the plate matching stage. Reference numerals 28 and 29 denote screens and their holding frames, respectively, and reference numerals 31 and 32 in FIG. 9 denote P-plates and their holding tables, respectively, which are common to both figures.
33 (1), 33 (2) to each former two are metallic holding frame 29 represents a heat <br/> Den conductors such as metal is a good conductor of heat, the latter two are also held in the metal This means that the temperature of the screen or the P-plate is adjusted by directly connecting the heat conductor to a heat exchanger or a heat sink provided on the table 32 to indirectly adjust the temperature of the material during printing. That is, as in the case of FIGS.
And based on the determination signal of the print result to control the operation of the heat exchanger or heat sink, but to achieve the temperature adjustment of the printing material through the thermal conductor.

FIG. 10 is a sectional view of a main part of the screen printing apparatus according to the present invention, which relates to a main operation, that is, a printing operation, for explaining the concept of separation and speed of printing. Reference numerals 19, 20, 21, 28, 29, 31, 32
Has the same meaning as described above, 34 is a device for suspending the squeegee device, 35 is a guide rail that directly supports the suspension device and guides it along the printing direction, and 36 is the 34
Represents a motor for moving the printhead along the rail, and reference numerals a and b denote a start point and an end point of printing. That is, the figure shows the starting point (a) of the gap type streen printing.
Screen pressed by the squeegee blade part and auxiliary side wall so that the upper surface of the P-plate and the lower surface are in contact with each other
This shows that the angle (θ) between the upper surface and the contact surface becomes considerably small at the end point (b) of printing, and therefore, immediately after the squeegee blade slides on the screen upper surface, immediately after the blade. The speed at which the upper surface of the screen moves obliquely upward away from the P-plate changes with the movement of the squeegee device along with the angle, and there is a considerable difference between the initial stage and the final stage of printing, as shown in FIG. As long as the screen frame and thus the entire screen surface is maintained at the same height (gap) with respect to the P-plate upper surface, printing unevenness is more likely to occur in the former than in the latter. Therefore, if outputs a determination signal of the scan screen printing method in the printing result determining apparatus print unevenness occurs, as it a feedback signal, the plate separating capable of controlling the speed so as not to cause unevenness in the detaching speed Although a speed control means is provided, a method for finding the above control conditions will be described first.

First, as shown in FIG. 11, the test P-plate and the test streen are divided into a plurality of sections along the printing direction. 37 is one of the sections, and the other symbols have the same meanings as described above (the same applies to the following examples, and description thereof will be omitted). P below the screen version
The illustration of the plates is omitted; Next, as shown in FIG. 10, the initial speed (hereinafter, abbreviated as initial speed) of the speed at which the squeegee device 19 slides on the screen 8 along the printing direction by the motor 36 is set. Regarding the speed of the movement, the speed of finishing printing and returning from the screen to the starting point is not particularly important. Therefore, speaking of the squeegee speed, the squeegee moves by sliding along the printing surface along the printing direction during printing. Refers to speed. The squeegee speed is changed as appropriate for each of the divided sections. At this time, as is clear from FIG. 10, even if the squeegee moves with the initial speed being a constant speed, the angle and the magnitude, that is, the speed change, as shown in FIG.
By changing the squeegee speed, the fine adjustment can be further performed.

As described above, since the change in the plate separation speed is related to the occurrence of printing unevenness, the plate (printing) result for each section can be corrected while monitoring the result. Conversely, based on the plate separation speed calculated and obtained from the test results for the one where a good plate result was obtained in the divided section,
The optimum squeegee speed for each section can be determined. These are C
What is necessary is just to input to PU and to perform a control command. FIG. 12 shows an example of an input format for this purpose.
Is a kind of scale that can also be displayed on the test P-plate or the upper end of the actual substrate, and shows a numerical value when, for example, the entire section of the printing surface on the P-plate having a length of 200 mm is divided into five.

Another specific example of the plate separation speed control means described above is shown below. FIG. 13 shows the fixed P-
A main part for showing a mechanism for changing the gap between the lower surface of the screen and the upper surface of the plate by inclining the squeegee along the printing direction in accordance with the movement of the squeegee, thereby maintaining the plate separation speed relatively constant. In the structural sectional view, the screen holding frame on the printing start side is raised from the position of the printing start point shown by the solid line to the printing end point shown by the dotted line by the 39 (39 ') cam, and the screen is relatively inclined with respect to the P-plate upper surface. It changes the corner. FIG. 14 shows the relationship between the two at this time in a more easily understood manner. This figure shows that the starting point side screen frame is relatively lowered at the beginning of printing, and the frame is made the same height as the end point side as the printing end time approaches. Of course, this does not contradict the description of FIG. Therefore, if such a control means is employed, the separation angle (θ1) at the printing start point can be made substantially equal to that at the end point (θ2), and the squeegee speed is determined in the entire printing section of the P-plate. Even when the printing speed is high, the printing plate separation speed can be made substantially constant in the entire section, and as a result, printing unevenness of the entire printing plate can be prevented.

FIG. 15 shows another specific example of the plate separation speed control means. 14, the angle formed by the upper surface of the P-plate with respect to the lower surface of the screen plate is fixed by the cam 40 (40 '), opposite to the case of FIG.
By changing from 2) to the dotted line position (32 '), the surface on the screen also changes from the solid printing start point position (28) to the dotted line position (28'), but the separation angle described above is θ1.
It can be seen that, just from θ ′ to θ2 ′, there is almost no change as in the case of FIG. 14, so that control can be performed so as not to significantly change the plate separation speed as in the case of the previous figure.

Next, FIG. 16 shows a cross section of a main part of a mechanism for adjusting the blade length as a printing pressure adjusting means of the squeegee blade, which can be another factor of the occurrence of printing unevenness.
Reference numeral 20 denotes an auxiliary side wall of the squeegee device, 41 denotes an actuator provided near the side wall, such as a motor or a piezoelectric element, and 42 transmits the force of the driving body 41 to the squeegee blade portion to face the upper surface of the screen. In order to change the length. FIG. 16 is a kind of concept drawing, and the magnitude relationship between the elements is not limited by the drawing. Also in this case, the printing pressure of the squeegee blade can be adjusted by adjusting the squeegee blade length based on the determination signal of the printing result as in the previous examples.

FIG. 17 is a block diagram of a main part of an example in which the gist of the present invention is embodied as an actual system.
(For example, a keyboard) for inputting various information and data to the CPU, an output device (for example, a printer) for outputting processed information and data from the CPU, and printing on a P-board Each represents an image recognition device that is a direct device for determining the result. Solid lines and dotted lines connecting the devices represent the flow of each function of an electric signal or a printing operation. The part drawn by the dotted line means that it is stored in the housing or a larger device. Overall, FIG.
Is a phase equivalent to <br/> shall to that embodied by the addition of the aforementioned input-output device and an image recognition apparatus to an abbreviation only P- plate storage device in.

In addition to the above embodiments, various configurations and structures are allowed as long as they do not depart from the gist of the present invention. In particular, the present invention is not limited to the drawings of the above embodiments. Absent.

[0035]

As will be understood from the above description, the present invention has the following effects in screen printing.

A squeegee device having a housing structure is adopted as a squeegee device which is a main part of the printing device, a device for determining a printing result and a means for displaying and recording the result are provided, and the entire system is controlled by a CPU. Ki out to perform not been new feedback type control, the to contribute greatly to the industrial development of the screen printing field
The following effects are significant in the screen printing method
It is .

(Delete)

[0038]

[0039]

[0040] In the case of formic cap type screen printing, since the plate release speed can finely and automatically adjusted, it is possible to wipe the print irregularity.

[0041]

[0042] and subsequently, the with screen printing system embodying the method to have various additional functions to the CPU, a be achieved by caulking comprising the input and apparatus to the CPU, the printing operation information data And the industrial value to bring about a great development that the control of the entire process can be achieved through sufficient labor saving.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of a printing method.

FIG. 2 is a block diagram of a printing test procedure selection embodiment;

FIG. 3 is a flowchart of general test printing.

FIG. 4 is a top view of the test screen plate.

FIG. 5 is a flowchart illustrating an example of test printing.

FIG. 6 is a sectional view of a main part configuration showing an embodiment of a printing material supply apparatus.

FIG. 7 is a sectional view of a main part configuration showing an embodiment of a squeegee device.

FIG. 8 is a cross-sectional view of a main part showing an embodiment of a screen holding device.

FIG. 9 is a sectional view of a main part configuration showing an embodiment of a printed circuit board holding device.

FIG. 10 is a cross-sectional view of a main part configuration for explaining a change in a plate separation speed.

FIG. 11 is a top view showing an embodiment of division of a screen plate.

FIG. 12 is a diagram of an embodiment of a format for controlling a plate separation speed.

FIG. 13 is a cross-sectional view of a main part configuration showing an embodiment of a plate separation speed control unit.

FIG. 14 is a sectional view of a main part configuration showing an embodiment of a plate separation speed control mechanism.

FIG. 15 is a cross-sectional view of a main part configuration showing an embodiment of a plate separating speed control unit and a mechanism.

FIG. 16 is a cross-sectional view of a main part configuration showing an embodiment of a squeegee blade length adjusting mechanism.

FIG. 17 is a main part configuration diagram showing an embodiment of a printing operation control system.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 P-plate supply device 2 printing device 3 print result determination device 4, 4 ′ CPU 5 print result display device 6, 6 ′ print result recording device 7 P-plate storage device 8, 9 adopting means 10 printing material supply device 11 discharge Pipe 12 Piston head 13 Moving plate 14 Rotary shaft (rod) 15 Support 16 (1), 16 (2) Gear 17, 36, 41 Motor (actuator) 18 (1), 18 (2) Spacer 19 Squeegee device (inner wall) 20) Squeegee blade portion (auxiliary side wall) 21 (1), 21 (2) Squeegee blade 22 Movable wall 23, 24 Roller 25 Partition plate 26 Printing material supply port 27 Inert gas supply port 28, 28 'Screen 29, 29' Screen holding frame 30 (1), 30 (2), 33 (1), 33 (2) Thermal conductor 31, 31 'P-plate 32P- Holding device 34 Suspension device 35 Guide rail 37 Section (section) 38 Scale 39, 39 ', 40, 40' Cam 42 Linked body 43 Input device (keyboard) 44 Output device (printer) 45 Image recognition device T Test board printing R Actual Substrate printing S Screen plate B P-plate C Plate matching (printing) M Printing material G Inert gas P Printing direction θ Angle a Printing start point

Claims (1)

(57) [Claims] 1. A printing apparatus comprising: a printed circuit board supply device capable of supplying a printed circuit board as an object to be printed; and a squeegee apparatus having a housing structure capable of mounting a printing material on the upper surface of the printed circuit board and performing printing. An apparatus, a printing result determining apparatus capable of determining a printing result of a printed circuit board printed by the printing apparatus, and controlling operations of the printed circuit board supply apparatus and the printing apparatus based on a determination signal output from the determining apparatus. And a central signal processing device (CPU) capable of outputting a control signal for controlling the squeegee device so that the inclination angle of the screen plate before and after advancement of the squeegee device is maintained at substantially the same angle.
The screen holding frame or the printed circuit board at the printing start side is lifted in conjunction with the movement of the squeegee device via a cam that operates based on a determination signal output from the printing result determination device, so that the screen squeegee device is lifted from the upper surface. A screen printing apparatus characterized in that the inclination angle of the upper surface of the printed circuit board is variable.