JPH0260748A - Detection of defect for screen printing - Google Patents

Abstract

PURPOSE:To enable a board within an allowable range of printing staining precision to be effectively produced by a method wherein when the printing staining precision of a screen plate is outside the allowable range, stains are wiped off by cleaning a screen and besides, the printed substrate is recognized. CONSTITUTION:Screen printing is performed by establishing an allowable range of printing staining of a screen plate 3. After ending printing operation of a board, a staining length of a part wherein printing staining on a contact surface to the strate of the screen plate 3 is generated, is measured. When the printing staining length is outside the allowable range by judgement by comparison with an established value, cleaning is performed. The printing staining length generated on the printed board 10 is measured and is compared with the established value to be judged. When the printing staining length is outside the allowable range, cleaning is performed, and an established value of a staining allowable range of the screen plate is altered to be made to be within a printing precision allowance of the board. Whether the number of produced boards is the prearranged number of the substrates to be produced or not is judged, and when it is the prearranged number of the boards to be produced, the boards is ended to be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a screen printing defect detection method for determining the bleeding accuracy of screen printing and the bleeding accuracy of a printed substrate.

Conventional technology Conventionally, when a screen printing machine prints several times, the screen gets dirty with cream solder. By wiping off the stains caused by the cream solder, the cream solder printed on the board was prevented from coming into contact with each other. To explain the screen printing operation with reference to FIG. Cream solder 2a comes out from the pattern hole portion and is printed on the substrate 7 as shown in 2b.

In the cleaning operation, as shown in FIG. The cream solder 2C remaining on the screen plate 3 is wiped off with the paper 8 by moving the screen plate 3 while pressing it. After cleaning once, the cleaner squeegee 5 separates from the screen plate 3 in preparation for the next cleaning operation, winds up the dirty portion of the paper 8 with the take-up roller Lv6, and the paper feed roller JV4 removes the paper during the winding process. It works to apply tension to the paper 8 so that it does not bend.

This manual wiping work has also been automated and is now more streamlined than manual wiping, but the number of print settings for cleaning (how many times to perform the printing operation before cleaning) is up to the operator. was determined empirically.

Problems to be Solved by the Invention However, with the above configuration, it is possible to suppress the bleeding that occurs on the board by reducing the number of times of printing for one cleaning operation, but how to set the number of times of printing. Therefore, if the number of times set is too low, the cleaning operation may be performed even though the screen is not dirty, and if the number of times set is too high, the cleaning operation may not be performed even if the screen is dirty, and the cleaning operation may not be performed when required. This caused problems such as printing smearing.

In view of the above problems, the present invention aims to rationalize the cleaning operation by recognizing the screen plate and performing the cleaning operation only when necessary.It also recognizes the printed substrate to prevent printing smearing. The point is to check whether there is.

Means for Solving the Problems The present invention comprises a first step of setting an allowable range for printing blur on a screen plate, a second step of performing screen printing, a third step of checking the state of the screen plate, and a third step of checking the condition of the screen plate. The fourth step is to measure the printing bleed, the sixth step is to determine whether the printing bleed on the screen plate is within an acceptable range, and the sixth step is to perform a cleaning operation if the printing bleed on the screen plate is outside the allowable range. 6th step, 7th step of looking at the screen printed board, 8th step of measuring the printing bleed of the screen printed board, and 8th step of determining whether the printing smear of the board is within the allowable range. 9 steps, and a 10th step of performing a cleaning operation when the printing bleed on the screen-printed board is outside the allowable range;
The method is characterized by comprising an eleventh step of changing the allowable range setting value of the screen plate.

Function: With the above-described configuration, the present invention recognizes the screen, and when the printing bleed accuracy of the screen plate is outside the permissible range, the screen is cleaned to wipe off the dirt, and the printed board is also recognized. This will enable efficient production of substrates within the print smear tolerance.

EXAMPLE An example of the present invention will be described below. FIG. 1 is an explanatory diagram showing the configuration of an embodiment of an apparatus to which the screen printed board defect detection method of the present invention is applied. FIG. 2 shows the flowchart.

Reference numeral 1 denotes a squeegee. This squeegee 1 performs null-clean printing and moves in the direction of the arrow X. Cream solder 2 forms a substance to be printed on the substrate, and a screen plate 3 forms a pattern on the substrate 1o. TV left camera is screen version 3
It is configured so that the state of the screen version 3 can be viewed from the bottom side of the screen,
The cleaner squeegee 6 moves in the direction of the arrow Y and wipes away the dirt caused by the cream solder 2 on the contact surface of the screen plate 3 with the substrate 10 with the paper 7 wrapped in a row/L/4. It is configured to look at the substrate 1o.

The stain caused by the cream solder on the contact surface of the screen plate 3 with the substrate 10, that is, the cream solder portion that has occurred around the pattern of the screen plate 3 in FIG. 4, will be described as a print bleed based on the flowchart of FIG. 2. 11 is a step for setting the permissible range of printing blur on the screen plate 3, and in FIG. 4, the distance d1. When the sum of d2 is called the bleed length, the permissible range of print bleed is determined by subtracting the bleed length from the distance between lands, and the first set value is set to 0.2-. 1
2 is a step of performing screen printing, 13 is a step of checking the contact surface of the screen plate 3 with the substrate after the printing operation of one board is completed, 14 is a step of measuring the length of the bleeding in the area where the printing blur has occurred, 15 16 is a step in which cleaning is performed when the printing bleed length is outside the allowable range in step 15, and 17 is a step in which the printed substrate 1o is viewed. 1
8 is a step of measuring the print blur length that has occurred on the substrate 10; 19 is a step of making a comparison judgment with a set value; 20
19 is the step of cleaning when the printing bleed length is outside the allowable range in Nutep; 21 is the step of changing the set value of the bleed permissible range of the screen plate to bring the printing accuracy of the board within the allowable range; 22 is a step for determining whether the number of boards to be produced is the planned number of boards to be produced; if the number of boards to be produced is the number to be produced, the board production is finished; if the number of boards to be produced has not been reached, the process returns to step 12.

Effects of the Invention The present invention recognizes the screen plate and the board, and performs a cleaning operation when the print bleed length is outside the allowable range, thereby preventing conduction between lands due to print bleed on the board. That is.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a screen printing defect detection device according to an embodiment of the present invention, FIG. 2 is a flowchart, and FIG.
FIG. 4b is a front view of a conventional screen printing machine equipped with a cleaning device, and FIG. 4 is a diagram showing a printing bleed state caused by cream solder that occurs between lands on a screen plate or a substrate. 1...Squeegee, 2a, 2b, 2c...
...Cream solder, 3...Screen version, 4
... Paper supply roll, 5 ... Cleaner squeegee, 6 ... Winding roll, 7 ...
...Paper, 8...Camera for screen recognition, 9.
...Camera for board recognition, 1o... Board. Name of agent: Patent attorney Shigetaka Awano and 1 other person 2nd
Diagram Ease~ji

Claims (1)

[Claims] Step 1: Set the tolerance range for printing smear on the screen version.
The second step is to perform screen printing, the third step is to check the condition of the screen plate, the fourth step is to measure the printing bleed on the screen plate, and whether the printing bleed on the screen plate is within the allowable range. A sixth step of making a judgment, a sixth step of performing a cleaning operation if the print bleed on the screen plate is outside the tolerance, a seventh step of checking the screen printed board, and a seventh step of checking the screen printed board's print bleed. The eighth step is to measure the print bleed on the board, the ninth step is to determine whether the print bleed on the board is within the allowable range, and the cleaning operation is performed if the print bleed on the screen-printed board is outside the allowable range. A method for detecting defects in screen printing, comprising a tenth step in which the screen printing defect is detected, and an eleventh step in which the allowable range setting value of the screen plate is changed.