JPH02209242A - Positional alignment of matter to be printed in screen printing and its apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method and apparatus for aligning the position of a printing medium in screen printing.

"Prior Art and Problems to be Solved by the Present Invention" Conventionally, in screen printing, various types of alignment have been considered for alignment related to the printing position of a printing medium.

If simplicity and speed are important, it is possible to perform position alignment at the print station and immediately print after position alignment.Also, when consideration is given to printing accuracy and versatility, In many cases, a method is adopted in which the alignment area and printing station are separated. The present invention is based on the latter case, and aims to more easily and quickly align a predetermined printing position with respect to a printing medium on an alignment table.

Various methods have been proposed for aligning the printing material at a location distant from the printing station, but among them, the method is relatively advantageous in terms of accuracy and speed.
Alignment methods that use both a solid-state image pickup device, typified by a CCD camera, and a computer system are becoming widely adopted.

When using this type of alignment method, it is necessary to match the printing origin, which stores the basic positional relationship for printing processing, with a reference mark at a predetermined position on the printing medium, but this matching process is difficult. In many cases, it is necessary to calculate and determine the positional relationship that should be the opposition each time the lot changes, using a predetermined learning method from the beginning, and the size and shape of the printing material to be processed remains almost constant. Regardless of whether you look at it on a lot basis, it is important to be quick in production processes that involve high-scale, low-volume production, such as the printed circuit board production process, where printing is often performed continuously on lofts with different numbers of blocks. This is a problem because of its shortcomings. In other words, the trouble of having to determine the positional relationship that should be an opposition from the beginning by calculation according to a certain learning method for each lot may not be able to cope with continuous automatic printing processing at the printing station. It means that there is.

"Means for solving problems" The present invention is based on the patent application No. 59-114664 filed by the applicant.
This method basically adopts the alignment method at the printing station disclosed in the above issue as a means of specifying the printing origin, and attempts to solve the problems seen in the prior art described above. A printing origin is set in the computer in which the positional relationships on the χ, y, and θ axes, which should be the basic opposition for printing processing, are stored in advance based on the specific point, and this origin is recognized. The reference point of the CCD camera automatically approaches the printing material, which is located on a specific point on the alignment table and has a reference mark attached at a certain distance from this specific point, and It will automatically search until it roughly matches, and after searching, it will stop and be fixed at that position, and the adjustment for accurate matching with the reference mark of the printed material to be carried in will be made at the reference point of the CCD camera. The solution to this problem is to move the matching table.

"Operation" According to the present invention, a printing origin is set in the computer, which stores the positional relationship that should be the basic opposition for printing processing from a specific point in the matching table, and
The reference point of the CD camera is movably arranged, and a reference mark is added to the printing material at a point that is in a certain positional relationship from a specific point on the alignment table, so that the printing origin that should be the basic collision point is recognized. The CCD camera is configured to automatically search for the reference mark until the reference point of the CCD camera roughly matches the reference mark on the printing material, and then automatically stops and fixes after the search. If the printing material is located at a specific point on the matching table, the reference mark will be in the area of the reference point of the CCD camera, even if it is not only in a lot but also in different lofts with different sizes and shapes. Accurate alignment between the reference point of the CCD camera and the reference mark on the printing material can be easily adjusted by moving the alignment table relative to the fixed reference point of the CCD camera. Realize.

Therefore, although there is a restriction that the reference point of the CCD camera can be moved within a preset range, it is possible to quickly respond to items within a lot with different sizes and shapes within a considerable range. This eliminates the inconvenience of having to perform a process of specifying the positional relationship that should be the basic opposition for printing processing from the beginning every time the printing process changes.

"Example" Examples of the present invention will be described below based on an apparatus for carrying out the present invention.

The printing origin X, which should be the basic opposition for the printing process at the printing station, is determined by the relationship between this specific point P and the specific part 2a' of the CCD camera 2a, with the center point of the alignment table l as the specific point P. The positional relationship on the χ axis, y axis, and θ axis, that is, the respective coordinate systems are comprehensively stored and set in the computer P, and the position is located on the specific point P of the matching table 1. Then, for a printing material M that has a reference mark B attached to a part that is in a certain positional relationship from the specific point P, the desired position of this printing material M on the matching table l is specified. This is the basic opposition for

The printing origin X, which stores the positional relationship that should be the basic opposition, is set at the reference point A of the CCD camera 2a mounted on the CCD camera unit 2, which is movable on the alignment table 1 in the chi-axis and y-axis directions. Recognized. Therefore, the reference point A of this CCD camera is the specific point P of the matching table 1.
automatically approaches the printing medium M located above, and
The reference mark B is automatically searched. In this exploration process, in consideration of simplicity, the present invention adds a reference mark B of the printing material M near the side edge 3 of the printing material M and at a position facing the reference point A of the CCD camera. It is. As mentioned earlier, the reference marks B are 11 marked at certain positions with reference to the specific point P of the matching table 1.

The reference point A of the CCD camera is moved in the direction of a specific point P of the alignment table l until the CCD camera unit 2 captures the side edge 3 of the printing medium M by the operation of the pulse motor PM and the ball screw 4, and then moves to the side. The reference mark B attached near the edge 3 is captured while being moved slightly in the chi-axis and y-axis directions.

In this way, the reference point A of the CCD camera can be moved along with the movement of the CCD camera unit 2, and the movement is achieved by using the pulse motors PM, PM2 provided in the CCD camera unit 2 as a driving source. ing.

Further, the reference point A of the CCD camera is arranged to face the two side edges 3 of the printing medium M, which means that the reference mark B of the printing medium M is located at the two side edges 3. This is because the pulse motor, which is the driving source of the camera unit 2 equipped with the CCD camera 2a, must be provided in the pulse motor 3.
P M t and P M 2 are also provided in each CCD camera unit 2 for the χ-axis direction and the y-axis direction.

In this way, setting the reference mark B of the printing medium M on the alignment table 1 near the two 111 overhang parts 3 is as follows:
This is because it is necessary as a center point when moving the alignment table 1 in the θ-axis direction in order to realize accurate matching between the reference mark B of the printing medium M and the reference point A of the CCD camera.

The position of the printing medium M carried onto the matching table l is regulated so that it is always located on a specific point P on the matching table l.

The printing medium M only needs to be positioned on a specific point P of the alignment table l, but this means that the basic opposition that determines the predetermined positional relationship to be printed is the specific point Plt.
This is because it has been determined as a standard, and this basic technique is to set the printing origin X to L! This is because the reference point A of the CCD camera that is aware of the specific point P automatically searches the reference mark B on the printing medium M that is attached as a reference, and as a result, the positional relationship to be printed is determined. Although there is a restriction that the CCD camera that recognizes the printing origin X as a basic city that defines if,
It is possible to quickly respond to different lots of printing materials M having different sizes and shapes without disturbing the continuity of the printing process.

When the reference point A of the CCD camera captures the side edge 3 of the printing medium M and then captures the reference mark B within that area, the CCD camera unit 2 is automatically stopped by the operation of the automatic brake mechanism 5. , at that position the matching table l
The important thing here is that C
The CCD camera unit 2 itself is equipped with a sensor that detects that the reference point A of the CD camera has captured the reference mark B of the printing medium M, and an automatic brake mechanism 5 that is operated via a computer in response to a command from this sensor. This is what is happening.

The automatic brake mechanism 5 stops the print material M at a predetermined position, and the reference mark B of the printing material M carried onto the alignment table 1 accurately matches the reference point A of the fixed CCD camera. As mentioned above, the matching table 1 is determined based on the preset computer calculation based on the detection signal from the CCD camera 2. , by moving in the y-axis or θ-axis direction.

As described above, the reference point A of the CCD camera is automatically fixed at a predetermined position by the automatic braking mechanism 5 that operates in conjunction with the sensor. It is clear that this method is more advantageous in terms of speed compared to the conventional specification in which it is fixed in position using appropriate means.

In the present invention, a reference point A of the CCD camera, which can be equated with a basic positional relationship that determines the positional relationship to be printed, with a specific point P of the matching table 1 as a reference, and a target point on the specific point P. The matching of the printed material M with the reference mark B is achieved through the interlocking action of sensors including a CCD camera 2 that detect various conditions and the calculation activities of a computer that operates in response to signals from these sensors. Of course there is.

FIGS. 1 and 2 are schematic diagrams of devices for implementing the method of the present invention, including a CCD camera 2 and a pulse motor PM.

PM2. Two CCD camera units 2 equipped with an automatic brake mechanism 5 and the like are arranged above the alignment table l and facing a specific point P on the table, near two side edges 3 of the printing medium M. The reference mark B attached to the CCD
The reference point A of the camera is automatically searched in the y-axis direction, that is, the alignment table l
First, move the side edge 3 of the printing medium M in the direction of the origin P.
Then, move the χ wheel in the y-axis direction to reach the reference mark B.
(See Figures 3(a) and 3(b)).

As mentioned earlier, PM in the figure is a pulse motor as a drive source for the CCD camera unit 2 in the y-axis direction, and P
M2 is a pulse motor for movement in the χ axis direction, and PM.

PM4 is a pulse motor for moving the alignment table l in the y-axis direction; PM4 is a pulse motor for moving in the .chi.-axis direction; and PM5 is a pulse motor for moving in the .theta.-axis direction.

As described above, the apparatus for carrying out the method of the present invention includes:
A CCD camera unit 2 is movably disposed on an alignment table 1, and the alignment table 1 is arranged in the χ axis direction, y
Pulse motor is the drive source in the axial direction and θ-axis direction
P M 3+ P M 4. In a 3N structure consisting of three stages each equipped with P M s,
Of course, the structure is not limited to this, but in short, it is a standard for a CCD camera that recognizes the printing origin X, which is the basic area for printing processing, based on the specific point P of the matching table l. The reference mark B is automatically searched so that the point A matches the reference mark B of the printing medium M located on the specific point P of the alignment table 1, at least generally, and after the search, it is automatically stopped and fixed. Then, any structure may be used as long as the alignment table 1 can be moved to accurately match the reference mark B of the printing material M that is subsequently carried in.

r Effects of the Present Invention Since the present invention has the above-described configuration, the positional relationship of the printing material to be printed is such that the printing material is located on a specific point of the alignment table and the reference mark is located on the CC.
D As long as the reference point of the camera is marked within the movable range, the positional relationship to be printed can be determined for each loft even if the printing materials are in different lofts with different sizes and shapes. The learning method eliminates the need to recalculate and specify from the beginning, and is expected to provide faster processing compared to conventional position matching methods.

In particular, in a printing process for producing a wide variety of products in small quantities, such as printed circuit boards, highly accurate position alignment can be performed more quickly and easily without impairing the continuous and automatic printing process.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of an apparatus for carrying out the method of the present invention, FIG. 2 is a schematic top view of FIG. 1, and FIGS. 3(a) and 3(b) are reference points of a CCD camera. FIG. 4 is a schematic explanatory diagram of a matching process between the reference mark and the reference mark on the printing medium. DESCRIPTION OF SYMBOLS 1... Alignment table, 2... CCD camera unit, 2a... CCD camera, 2a... Specific part of CCD camera, 3... ms part of printing material, 5... Automatic brake mechanism , A... Reference point of CCD camera, B... Reference mark of printing material, M... Printing material, P... Specific point, PM, ~PM5
...Pulse motor-X...Printing origin.

Claims (3)

[Claims] (1) In screen printing, in which a printing medium whose position has been aligned on an alignment table is transferred to a printing station for printing, the center point of the alignment table is set as a specific point, and the arrangement is movable between this specific point and the alignment table. The printing origin X, which is stored in advance in the positional relationship on the x-axis, y-axis, and θ-axis, which should be the basic opposition for printing processing in relation to the specific part of the CCD camera that has been used, is set in the computer, and this origin The reference point A of the CCD camera that has recognized this is located on a specific point on the matching table, and automatically approaches the printing material on which the reference mark B is attached at a point that is in a certain positional relationship from this specific point. The system automatically searches until the reference mark B roughly coincides with the reference mark B, and then stops and fixes the reference mark B at that position. A method for aligning the position of a printing material in screen printing, characterized in that adjustment for alignment is performed by moving an alignment table with respect to a reference point A of a CCD camera. (2) Add the reference mark B of the printing material near the side edge of the printing material opposite to the reference point A of the CCD camera, so that the reference point A of the CCD camera is first placed on the side of the printing material on the alignment table. Screen printing according to item 1, characterized in that the screen printing device captures the edge and then automatically searches until it roughly matches the reference mark B, and after the search, it is stopped by an automatic brake mechanism and becomes immovable. A method for aligning printing substrates in (3) The printing origin X, which stores in advance the positional relationship on the x-axis, y-axis, and θ-axis that should be the basic opposition for printing processing in the relationship between the specific point of the matching table and the specific part of the CCD camera, A CC that is set in a computer and equipped with a reference point A of a CCD camera that recognizes the origin X, a drive source for movement in the x-axis and y-axis directions, and an automatic brake mechanism.
A D camera unit is placed on the matching table, and the reference point A of the CCD camera is located on a specific point on the matching table,
Reference mark B is placed at a point in a certain positional relationship from this specific point.
It automatically approaches the printing material with the reference mark B and automatically searches until it roughly coincides with the reference mark B, and after the search, it automatically stops and fixes at that position, and the printing material to be carried in. The alignment table that describes the body is set on the x-axis, y-axis, and θ.
A device for aligning a printing material in screen printing, characterized in that it is movable in the axial direction.