JPH0976454A - Electronic component mounting method - Google Patents

Abstract

(57) Abstract: A conventional method of recognizing a recognition mark provided on a printed circuit board and a printing mask and matching the positional relationship between the two is a positional deviation between the both, especially in a narrow pitch portion of a leaded electronic component. There is a tendency that the positional deviation becomes large, and therefore, the printing deviation occurs, the positional deviation occurs even when the electronic component is mounted, and the soldering failure occurs after the reflow soldering. SOLUTION: An identification mark 2a provided on a printed circuit board 1
And the recognition mark 2b provided on the printing mask 5 is detected by the recognition device 4 including the photographing device 3 and the image recognition means, and stored as position data, respectively. In the state where the relative position with respect to the substrate 1 is corrected and aligned, the displacement amount between the narrow pitch electrode pattern 7 of the printed substrate 1 and the corresponding mask pattern opening 6 of the printing mask 5 is directly recognized. Then, based on this, before applying the cream solder, the electrode pattern 7 and the mask pattern opening 6 are aligned with each other, and then the cream solder printing is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting method for electronic parts,
In particular, it relates to a method of mounting an electronic component having a large number of leads at a narrow pitch on an electrode on a printed board.

[0002]

2. Description of the Related Art Conventionally, when a leaded electronic component is mounted on a substrate on which electrodes corresponding to the leads are mounted, a recognition mark for positioning is provided in advance at a position where a printing mask and a printed circuit board face each other, and printing is performed. The recognition mark position on the substrate is recognized by the image recognition means, the recognition mark position of the printing mask is similarly recognized, each image processing is performed, and the deviation is calculated, and the printing is performed according to the deviation amount. Correct the relative position between the mask for the printed circuit board and the printed circuit board, align the position, then print the cream solder on the electrode pattern on the printed circuit board, mount the electronic component on the electrode pattern, and reflow solder the electronic component. Was.

The method of mounting the electronic component with leads will be described in more detail below with reference to the drawings. FIG.
(a), (b) is an explanatory view showing a mounting method of the electronic component with a lead, in the figure, 21 is a printed circuit board, 22a, 22b is a recognition mark, 23 is a photographing device such as a television camera, 24 is an image A position recognizing device composed of recognizing means and the like, and 25 is a printing mask. When mounting the electronic parts, first, the printed circuit board 21 is arranged by the lighting device (not shown), the photographing device 23 such as a television camera, and the position recognition device 24 connected to the photographing device 23 according to the arrangement shown in FIG. After recognizing the above recognition mark 22a,
By the arrangement shown in the figure (b), the recognition mark 22b of the printing mask 25 is recognized, image processing is performed on each, and the positional displacement amount between the two is obtained, and the relative position is corrected according to this displacement amount, Align and print cream solder. Next, in the mounting process of the electronic component, the printing mask 25 is removed from the arrangement shown in FIG. 6B, the recognition mark 22a on the printed board 21 is recognized again, and the mounting position is corrected,
The electronic parts were mounted and soldered by reflow soldering.

[0004]

However, in the method of recognizing and correcting the recognition mark of the printed circuit board or the printing mask as described above, the wiring pattern on the printed circuit board and the pattern position of the printing mask are not When dimensional accuracy variation or lot-to-lot variation occurs, there is a tendency for misalignment to become large, especially in the part where the leads of electronic components with leads are arranged at a narrow pitch, which causes printing misalignment and mounting of electronic components. Even at times, misalignment occurred, and soldering failure occurred after reflow soldering.

The present invention solves the above-mentioned problems of the prior art. The positioning recognition marks of the printed circuit board and the printing mask are detected as position data by the image recognition means to correct the position, and further before the cream solder printing, By directly recognizing the narrow-pitch electrode pattern and the corresponding mask pattern and performing more accurate position correction, the printing accuracy of cream solder is improved, pattern misalignment during printing is eliminated, and adjacent patterns It is an object of the present invention to provide an electronic component mounting method which prevents the occurrence of a solder bridge and secures a highly reliable solder joint even in a narrow pitch.

[0006]

In order to solve the above-mentioned problems, the present invention provides a television camera with an identification mark provided on a printed board and an identification mark provided on a printing mask in a step of printing cream solder on a printed board. After being detected by a recognition device composed of image capturing means and image recognition means, the coordinate values of the respective recognition marks are stored as respective position data, and a printing mask is used according to the amount of deviation between the two position data. Directly recognizing the amount of deviation between the narrow pitch electrode pattern on the printed circuit board and the corresponding mask pattern opening of the printing mask in the state of alignment by correcting the relative position with the printed circuit board, Based on this, after applying the cream solder, the electrode pattern is aligned with the mask pattern opening of the printing mask, and then the It is designed to perform solder solder printing, and then mount an electronic component having leads and solder it. Also, a positioning mark is printed at the time of cream solder printing on a printed circuit board, so that the electronic component In the mounting step, the position of the positioning mark is detected by the image recognition means, the mounting position of the electronic component is aligned with the cream solder pattern based on this, and soldering is performed in a low oxygen concentration atmosphere. It was done.

[0007]

Operation: With the printed circuit board and the printing mask positioned on the basis of the positioning recognition marks of the printed circuit board and the cream solder printing mask, an electrode pattern of a narrow pitch on the printed circuit board and a mask of the printing mask corresponding to the electrode pattern. By directly recognizing the deviation amount of the pattern opening and aligning the electrode pattern and the mask pattern opening according to the deviation amount, the printing accuracy is improved, the printing deviation is eliminated, and after the electronic component is mounted, Also in the reflow process, it is possible to prevent the occurrence of solder bridges between adjacent electrodes. In addition, the positioning mark is printed in the printing process, this is recognized in the electronic component mounting process, the position is corrected, and then the electronic component is mounted so that the printed solder paste and the mounting position of the electronic component are relative to each other. It is possible to correct various positional deviations, and the same operation as described above is achieved in the narrow pitch portion of each pattern.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 (a), (b), (c) and FIGS. 2 (a), (b) are explanatory views showing a method for mounting electronic components with leads, in which 1 is a printed circuit board, 2a, 2b. Is a recognition mark, 3 is a photographing device such as a television camera, 4 is a position recognition device including image recognition means, 5 is a printing mask, 6 is a mask pattern opening provided in the printing mask 5, and 7 is a mask pattern opening. Is an electrode pattern provided on the printed circuit board 1 looking through the mask pattern opening 6, 8 is a positioning mark printed on the printed circuit board 1, 9 is a solder paste printing pattern, and 10 is an electronic component , 11 are leads of the electronic component 10.

To explain the mounting method, first, referring to FIG.
As shown in (a), a plurality of recognition marks 2a on the printed circuit board 1 are detected by a recognition device 4 including a photographing device 3 such as a television camera and an image recognition means, and the coordinate value of each recognition mark is used as position data. After storing, print mask 5
The recognition mark 2b is detected by the recognition device 4 by the same method as the above means as shown in FIG. 9B, and the coordinate value of each recognition mark is stored as position data. The positional shift data between the print mask 5 and the printed circuit board 1 is obtained from the positional shift amount, and the stage on which the printed circuit board 1 is mounted is moved and corrected according to this positional shift to align the two. .

Further, as shown in FIG. 1C, the portion of the electrode pattern 7 having a narrow pitch on the printed board 1 and the mask pattern opening 6 of the corresponding printing mask are formed by the image recognition means. By directly recognizing and aligning with the same means as described above, the electrode pattern 7 and the pattern 6 of the printing mask are aligned in an accurate positional relationship. Further, as shown in FIG. 2, when the cream solder is printed, the positioning mark 8 is simultaneously printed on the printed board 1, and the positioning mark 8 is detected by the image recognizing means in the component mounting step, and the actual printing is performed. After the lead 11 of the electronic component 10 is aligned with the printed pattern 9 of the solder paste, the electronic component 10 is mounted, and the low oxygen concentration atmosphere (for example, nitrogen gas is filled and the oxygen concentration is several hundreds). ppm
By reflow soldering in an atmosphere such as), the solder wets and spreads on the leads due to the self-alignment effect, so that the solder is surely soldered.

As described above, in the present embodiment, the position correction is performed by directly recognizing each pattern having a narrow pitch before the cream solder printing, so that the cream solder printing accuracy can be further improved. Also, in the printing process, by printing the positioning mark on the printed circuit board,
When mounting the electronic component, the positioning mark is directly recognized to align the mounting position of the electronic component on the printed circuit board, so that highly reliable solder bonding between the electronic component and the printed circuit board can be performed.

[0012]

As described above, according to the present invention, the positioning recognition marks of the printed circuit board and the printing mask are detected as position data by the image recognition means to correct the position, and further, before the cream solder printing, the narrowing is performed. By directly recognizing the pitch electrode pattern and mask pattern and performing more accurate position correction, the printing accuracy of cream solder is improved, pattern deviation during printing is eliminated, and solder bridges between adjacent patterns occur. It is possible to prevent soldering and secure a highly reliable solder joint even at a narrow pitch. Further, by printing the positioning mark on the printed circuit board in the printing process, the position of the positioning mark is detected by the image recognition means in the mounting process of the electronic component, and based on this, the printed pattern of the cream solder is printed. By matching the mounting positions of the electronic components and soldering in an atmosphere of low oxygen concentration, the reliability of solder joint is improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a mounting method of an electronic component of the present invention, (a) is a perspective view showing a recognition state of recognition marks on a printed circuit board, and (b) is a recognition of a printing mask. FIG. 3C is a perspective view showing a mark recognition state, and FIG. 3C is a partially enlarged plan view showing an overlap between the pattern on the substrate and the printing mask.

FIG. 2 is an explanatory diagram of an electronic component mounting step in one embodiment of an electronic component mounting method of the present invention, in which (a) is a perspective view showing a recognition state of a positioning mark on a printed circuit board;
(b) is a partially enlarged plan view showing a mounting state of electronic components.

3A and 3B are explanatory views showing an example of a conventional electronic component mounting method, in which FIG. 3A is a perspective view showing a recognition state of a recognition mark of a printed circuit board, and FIG. 3B is a recognition state of a recognition mark of a printing mask. FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Printed circuit board, 2a ... Printed circuit board recognition mark, 2b ... Printing mask recognition mark, 3 ... Imaging device, 4 ... Recognition device, 5 ... Printing mask, 6 ... Mask pattern opening part, 7 ... Electrode pattern, 8 ... Positioning mark, 9 ... Cream solder print pattern,
10… electronic components, 11… leads.

Claims (2)

[Claims] 1. In a step of printing cream solder on a printed circuit board, the recognition mark provided on the printed circuit board and the recognition mark provided on the printing mask are detected by a recognition device including a photographing means such as a television camera and an image recognition means. Then, after storing the coordinate values of the respective recognition marks as the respective position data, according to the amount of deviation between the position data of the two,
While aligning by correcting the relative position between the printing mask and the printed circuit board, the deviation amount of the narrow pitch electrode pattern on the printed circuit board and the corresponding mask pattern opening of the printing mask is directly measured. Recognize, based on this, after performing alignment of the electrode pattern and the mask pattern opening of the printing mask before applying cream solder, cream solder printing is performed, and then electronic components having leads are mounted, A method of mounting an electronic component, which is characterized by soldering. 2. A positioning mark is printed at the time of cream solder printing on a printed circuit board, and the position of this positioning mark is detected by an image recognizing means in the electronic component mounting step, and printing is performed based on this. 2. The electronic component mounting method according to claim 1, wherein the mounting position of the electronic component is aligned with the cream solder pattern and soldering is performed in a low oxygen concentration atmosphere.