JPH03217100A - Coating method for adhesive - 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 the Invention The present invention relates to an adhesive application method used when applying an adhesive to a circuit board for temporarily fixing mounted electronic components.

Conventional TechnologyIn the process of mounting electronic components on a circuit board, prior to mounting the electronic components on the circuit board, an adhesive is applied to the circuit board to temporarily fix the electronic components until they are permanently fixed with solder, etc. There is a process of applying it.

Normally, when applying this adhesive, an adhesive applicator is used that is configured to introduce high-pressure gas into the upper space of the application nozzle containing the adhesive and discharge the adhesive. A predetermined amount of adhesive is applied onto the substrate by discharging it from a coating nozzle.

By the way, the reliability of adhesion is greatly influenced by the amount of adhesive applied. In other words, if the amount of adhesive applied is too small, it will not be possible to bond reliably, and if it is too much, the electronic components may move when installed, or the adhesive may flow onto the electrodes of the circuit board, resulting in poor bonding. will occur.

Conventionally, when starting up an adhesive applicator, adhesive is test applied onto a test substrate, and the pressure of high-pressure gas (hereinafter referred to as discharge pressure) introduced into the applicator nozzle is applied to ensure proper application. ) was being adjusted.

Problem to be Solved by the Invention However, in the above method, while applying adhesive to each circuit board on which electronic components are to be mounted, hardened adhesive adheres to the application nozzle and causes clogging. There is a problem in that a proper coating state may not be obtained due to a change in the surrounding temperature condition or a problem in that highly reliable coating cannot be achieved.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide an adhesive coating method that enables coating with high reliability.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention applies a test adhesive to each substrate prior to the actual adhesive application process to three substrates, and calculates the area of the application point. The method is characterized in that the test coating is repeated by correcting the coating conditions until the area falls within a predetermined tolerance range or reaches a predetermined number of times, and when the area falls within the tolerance range, the main coating step is started.

The product of the area and height of the coating point may be used instead of the area of the coating point.

Furthermore, if one adhesive part has multiple application points, the total area of the multiple application points or the total product of the area and height must be within the allowable range, and the area or area and height of each application point must be within the allowable range. When the product of is equal to or greater than the minimum target value, the main coating process is started.

According to the above structure of the present invention, test coating is performed on each board prior to the wood coating process, the shape of the coating point is recognized, the area is calculated, and the coating conditions are corrected until a predetermined tolerance is reached. After repeating test coating, the main coating process is started, so that the amount of adhesive applied is stable in the main coating process, and highly reliable adhesive coating can be performed on each board.

Furthermore, if the height of the coating point is also recognized and the coating amount is detected as the product of the area and the height, it is possible to prevent variations in the coating amount due to variations in the coating height due to changes in viscosity.

Furthermore, when a single adhesive part has multiple application points, it is possible to ensure adhesion at all application points by not only determining the total amount of application but also whether the application amount at each application point is greater than or equal to the minimum target value. It is possible to obtain a stable adhesive state.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 and 3.

First, the general structure of the adhesive applicator will be explained with reference to FIG. 3. 1 is a main body, and an - It is configured to fix the circuit board 3 at a predetermined position on the Y table 2. Above the X-Y table 2, there is a coating nozzle 5, a television camera 6 for visually recognizing the shape of the coating point, and a height control system consisting of a laser displacement meter and an ultrasonic displacement meter for detecting the height of the coating point. A coating head 4 is provided in which a detection means 7 and a coating head 4 are arranged side by side in the X direction. The coating head 4 is configured to be movable in the direction in which the coating nozzle 5, television camera 6, and height detection means 7 are arranged, that is, in the X direction.

Next, the process of applying adhesive to the circuit board 3 will be explained with reference to FIG.

When the circuit board 3 is carried onto the X-Y table 2 by an appropriate conveyance means and fixed at a predetermined position, a test coating area set at an appropriate location on the circuit board 3 is located directly below the coating nozzle 5. is positioned so that From this state,
It is determined whether test coating has already been performed a specified number of times with steno knob #1, and if the specified number of times has not been reached, a test application process is started. In step #2, test coating is performed using the coating nozzle 5 under predetermined coating conditions set in advance.

Next, in step #3, the coating head 4 is moved in the X direction, the television camera 6 is positioned above the coating point to recognize the shape of the coating point, and the height detection means 7 is positioned opposite to the coating point. Step #4 recognizes the height of the application point, then image-processes the recognized image in Step #4 to calculate the area of the application point, and calculates the product of the area and height.

Then, in step #5, it is determined whether the product of the area and the height of the coating point is within an allowable range preset as an appropriate coating state. If it is not within the allowable range, in step #6, the application amount is corrected by correcting the adhesive discharge time from the application nozzle 5. That is, if the product of the area and height of the application point is too large, the ejection time is shortened, and if it is too small, the ejection time is lengthened. Note that instead of correcting the ejection time, the application amount may be corrected by correcting the ejection pressure or by correcting the adhesive temperature and changing the viscosity.

After changing the discharge conditions in this manner, the process returns to step #1 and test coating is repeated in the same manner as above. When the test coating reaches the predetermined number of times, it is unlikely that a proper coating state will be obtained even if the test coating is repeated more than that, so the process moves to step #7 and stops due to an error.

On the other hand, if the product of area 7 and height of the application point is within the allowable range in step #5, step #5
8, the amount of correction of the coating conditions obtained by the test coating is added to the coating conditions in the main coating process, and then the process moves to the main coating process of step #9. In the main coating process,
A predetermined adhesive application position on the circuit board 3 is sequentially positioned directly below the application nozzle 5 on the X-Y table 2, and the adhesive is discharged under the above-mentioned discharge conditions to apply the adhesive in an appropriate application state. . When the application of the adhesive to each position on the circuit board 3 is completed, the circuit board 3 is carried out by a transport means as appropriate, the next circuit board 3 is carried in, and the above operation is repeated.

In the above embodiment, the product of the area and height of the application point was used to detect the amount of adhesive applied, but the height detection stage 7 was omitted and the application amount was detected only by the area of the application point. You may also do so. However, by including the height, it is possible to prevent variations in the coating amount due to variations in the coating height when the viscosity of the adhesive changes.

Next, an embodiment of the coating process in which a plurality of coating points are provided on one bonding part will be described with reference to FIG. 2. In Figure 2, stamps #11-13, 16-
Reference numerals 19 correspond to steps #1 to #3 and #6 to #9 in FIG. 1, respectively, and a description thereof will be omitted.

In this embodiment, only the shape of the application point is recognized in step #13, and the area of each of the plurality of application points and the total area are calculated in step #14. And step #15a
In step #16, it is determined whether the total area of the application points is within the permissible range, and if it is not within the permissible range, the process proceeds to step #16, where the test application is repeated by correcting the discharge time, discharge pressure, or adhesive temperature.

When the total area of application points is within the allowable range, step #15
The process moves to step #b, and it is determined whether the area of each coating point is equal to or larger than the minimum target value. If there is a coating point whose area is less than the minimum target value, the process moves to step #16 and each coating point is After correcting the ejection conditions, the process returns to step 1, repeats the above coating test, and when the total area of the coating points is within the allowable range and the area of each coating point is all greater than or equal to the minimum target value, the main coating process is started. According to this embodiment, it is possible to reliably adhere at all application points and to obtain a stable adhesion state.

In the embodiment shown in Fig. 2, only the shape of the coating point is recognized and the coating amount is detected based on its area, but this embodiment also recognizes the height of the coating point and calculates the area and height. It goes without saying that the coating amount may be detected by the product of .

Effects of the Invention According to the present invention, test coating is performed on each substrate prior to the main coating process, the shape of the coating spot is recognized, the area is calculated, and the coating conditions are corrected until a predetermined tolerance is achieved. After repeating test coating, the main coating process is started, so that the amount of adhesive applied is stable in the main coating process, and highly reliable adhesive coating can be performed on each board.

Furthermore, if the height of the coating point is also recognized and the coating amount is detected as the product of the area and the height, it is possible to prevent variations in the coating amount due to variations in the coating height due to changes in viscosity.

Furthermore, when a single adhesive part has multiple application points, it is possible to ensure adhesion at all application points by not only determining the total amount of application but also whether the application amount at each application point is greater than or equal to the minimum target value. It is possible to obtain a stable adhesive state.

[Brief explanation of drawings]

FIG. 1 is a flowchart of an adhesive application method according to an embodiment of the present invention, FIG. 2 is a flowchart of an adhesive application method according to another embodiment of the invention, and FIG. 3 shows a schematic configuration of an adhesive application device. FIG. 3----------Circuit board 5--1--1 coating nozzle 6--Television camera 7--Height detection means.

Claims (3)

[Claims] (1) Prior to the main adhesive application process for each board, test apply the adhesive, calculate the area of the application point, and until the area falls within a predetermined tolerance or reaches a predetermined number of times. Correct the application conditions and repeat the test application.
An adhesive application method characterized by moving to a main application step when the area falls within an allowable range. (2) The adhesive coating method according to claim 1, characterized in that the product of the area and height of the coating point is used instead of the area of the coating point. (3) If one adhesive part has multiple application points, the total area of the multiple application points or the sum of the product of area and height is within the allowable range, and the area or area and height of each application point 3. The adhesive coating method according to claim 1, wherein the main coating step is performed when the product of .