JPH0458197B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for detecting the relative position of overlapping marks, particularly when performing multilayer printing.
The present invention relates to a device suitable for detecting printing misalignment for each layer.

[Prior Art] Conventionally, when printing a multilayer printed wiring board, a method for detecting relative printing misalignment for each layer is to read a reference pattern and marks on the printed wiring board with an image input device, and perform image processing. The device counts the number of pixels to understand the positional deviation, and based on that,
If necessary, the position of the print mask that caused the misalignment was manually corrected.

As the reference pattern, use points with an area that allows the number of pixels to be counted, and either input them into the image processing device in advance as reference data, or simultaneously input marks on the printed wiring board that will be the specimen. A comparison was being made. Incidentally, related devices of this type include, for example, Japanese Patent Application Laid-Open No. 61-5385.

[Problem to be solved by the invention]

In the above conventional technology, a reference pattern is required, and it takes time to compare the reference pattern with the printed wiring board to be tested, which does not match the takt time of the printing machine, so the printed wiring board is not printed on the printing line. It is not possible to check the total number. However, in reality, visual inspection is performed because it is only necessary to know the relative misalignment of printing for each printing layer, but even so, there is a limit to the reduction of processing time, and it does not match the takt time of the printing machine. .

An object of the present invention is to automatically correct the relative positional deviation between the lower layer and the upper layer for each printed layer in a printed wiring board that prints two or more layers in a processing time that matches the takt time of the printing machine. An object of the present invention is to provide a device for checking the relative deviation amount during printing.

[Means to solve the problem]

In order to achieve the above object, the configuration of a device for detecting the relative position of overlapping marks according to the present invention is a device for detecting misalignment of each layer of a printed wiring board that prints two or more layers. an input device that reads a lower layer mark and an upper layer mark that are printed on top of each other, and a device that identifies the lower layer mark and the upper layer mark based on either the difference in color or the shade of color of the read image. , consisting of a processing device that calculates the relative deviation between the identified lower layer mark and the upper layer mark, an output device that displays the calculation result of the processing device, and a device that controls each of the above devices in relation to each other. It is.

[Effect]

On the printed wiring board to be tested, for example, two or more cross shapes (see Figure 2 a) in a circle with a diameter of 3 to 4 mm for each printed layer are placed on the edge of the printed wiring board and used as marks. It is being said. This mark is left on the copper foil in the lower layer, and is printed at the same time as the resist ink is printed in the upper layer. Since the color of the mark on the lower layer is different from the color of the mark on the upper layer, or there is a difference in shading, this mark is read in with an input device, and the read image is first extracted using a known color extraction device. The center or centroid position of the image is extracted and the position of the center or centroid of the image is processed by the image processing device, and then, upon receiving the calculation end signal, the processing is switched to extraction of only the upper layer marks and the position of the center or centroid of the image is calculated by the processing device. Process.

The position of the mark on the lower layer and the position of the mark on the upper layer are further compared and calculated within the processing device, and the amount of relative positional deviation is displayed on, for example, a display unit of the image output device.

Since marks on both the upper and lower layers can be read and relative positional deviations can be detected relatively quickly, positional deviations can be detected in accordance with the takt time of the printing press.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 is a block diagram including a partial perspective view showing the configuration of an inspection device according to an embodiment of the present invention, FIG. 2 is a plan view showing marks on printed matter, and FIG.
7 is a flowchart showing a procedure for inspecting mark positional deviation.

As shown in FIG. 1, the printed wiring board 7 is carried by a conveyance device 1 to a positioning device 2 which is disposed below the image input device 3 and which fixes the printed wiring board 7 in a predetermined position with a predetermined precision. Fixed.

On the upper surface of the printed wiring board 7, marks 8 on the upper layer of printed matter (hereinafter referred to as upper layer marks) are placed at positions where marks 8 on the upper layer of printed matter overlap on at least two marks 9 on the lower layer of printed matter (hereinafter referred to as lower layer marks) as shown in FIG. 2a. The lower layer mark 9 and the upper layer mark 8 have different colors. For example, the color of the lower layer mark 9 is the color of the copper foil, and the color of the upper layer mark 8 is the color of the registration mark.

The number of image input devices 3 corresponds to the number of marks, reads the upper and lower layer marks 8 and 9 of the printed wiring board 7 on the positioning device 2, and inputs the read image data to the color extraction device 10 as an electronic signal. .

The control device 6 initially gives a command to the color extraction device 10 to extract only the color of the lower layer mark 9 from the input image data, and causes the image processing device 4 to perform arithmetic processing on the image data of the lower layer mark 9.

When the arithmetic processing of the lower layer mark 9 is completed, the image processing device 4 sends an end signal to the control device 6, simultaneously records the arithmetic data in an internal memory section, and waits for the next signal issued from the control device 6. be in a state of doing so.

When the control device 6 receives the end signal regarding the lower layer mark 9, it then sends an arithmetic processing command for the image data of the upper layer mark 8 to the image processing device 4, and the same processing as described above is performed and the arithmetic data is processed. recorded. The same scanning, processing, and recording are repeated for each mark, and when the above operations are completed, a command to execute a comparison calculation regarding the relative positions of the lower layer mark 9 and the upper layer mark 8 is sent from the control device 6 to the image processing device 4. executed. The flowchart in FIG. 3 shows a procedure for inspecting such a mark misalignment to prevent printing misalignment.

The results of this comparison calculation are displayed on the image output device 5, and when the amount of positional deviation between the lower layer mark 9 and the upper layer mark 8 exceeds the allowable value, a lamp display or an alarm sound is displayed on the alarm unit 6', and the amount of positional deviation is alerts you that the printing press needs adjustment. In response to this alarm, the operator should correct the position of the printing mask,
To ensure that the misalignment of printing on a subsequent printed wiring board is within an allowable value.

When the printing misalignment amount is within the allowable value, the positioning device 2 is unfixed and the printed wiring board 7 is carried out by the conveying device 1.

As a position mark, as shown in Fig. 2b,
The same effect can be obtained by using the land 9' in the lower layer and the peripheral edge 8' of the circular hole in the resist in the upper layer.

As described above, according to this embodiment, there is no need for a reference pattern, and the marks on the lower layer and the upper layer that are provided overlapping each other are identified and the relative positions are calculated, so the processing speed is fast. Therefore, it is possible to perform a complete inspection of printed wiring boards in accordance with the processing speed of the printing machine, and reliability can be improved.

In addition to being integrated into the printing line and automatically inspecting it, if the printing misalignment exceeds the allowable value, an alarm can be issued and the printing press can be adjusted immediately, minimizing the occurrence of defective products and improving economic efficiency. .

〔Effect of the invention〕

As explained in detail above, according to the present invention,
To provide a device that automatically checks the relative positional deviation between a lower layer and an upper layer for each printing layer in a processing time that matches the tact time of a printing machine and grasps the relative deviation amount during printing. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a block diagram including a partial perspective view showing the configuration of an inspection device according to an embodiment of the present invention, FIG. 2 is a plan view showing marks on printed matter, and FIG.
7 is a flowchart showing a procedure for inspecting mark positional deviation. 1... Conveyance device, 2... Positioning device, 3...
Image input device, 4... Image processing device, 5... Image output device, 6... Control device, 7... Printed wiring board,
8... Upper layer mark, 9... Lower layer mark, 10...
Color extraction device, 6'...alarm unit.

Claims (1)

[Claims] 1. A device for detecting misalignment of each layer of a printed wiring board that prints two or more layers, which reads lower layer marks and upper layer marks that are printed overlappingly on the printed wiring board. An input device, a device that identifies the lower layer mark and the upper layer mark based on either the difference in color or the shade of the color of the read image, and the device that calculates the relative deviation between the identified lower layer mark and the upper layer mark. 1. A device for detecting relative positions of overlapping marks, comprising: a processing device that performs the following operations; an output device that displays the calculation results of the processing device; and a device that controls each of the above devices in relation to each other.