JPH034600A - Electronic component mounting device - Google Patents

Abstract

PURPOSE:To mount a component on a printed board with an optimal pressure so as to prevent a solder bridge by a method wherein a displacement sensor is provided under the printed board to measure the warpage of the board, and the distance that a mounting device is made to descend is corrected corresponding to the warpage of the board. CONSTITUTION:A sensor 8 is provided under a printed board 6, and the degree of warpage epsilon of the board 6 is measured as a vertical displacement. A control section receives a measured value and corrects the descent set distance of a suction nozzle 5A of a component mounting device basing on the measured value, and the mounting device mounts a component 1 pressing its leads 1A against a cream solder 7 on the board 6 with an optimal pressure. Even if the board 1 warps vertically, the descent distance of the nozzle 5A is corrected to an optimal value and then the component 1 can be mounted on the board 6. By this constitution, an electronic component can be mounted under optimal conditions with no solder bridge.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electronic component mounting machine, and more specifically, to preventing adjacent solder cream from flowing and merging when soldering leads of electronic components. This article relates to an electronic component mounting machine that can.

(Prior Art) First, the overall configuration of a conventional electronic component mounting machine will be explained with reference to Fig. 2.The conventional electronic component mounting machine supplies electronic components (1) as shown in Fig. 3. parts supply section (2
), a component supply device (4) that sucks the electronic component (1) from the component supply section (2) and supplies it to the positioning device (3) for the electronic component (1); The electronic components (1) that have been supplied and positioned are sucked into the suction nozzle (5).
A), the suction nozzle (5A) is lowered from a predetermined height at a predetermined position of the printed circuit board (6), and the lead (IA) of the electronic component (1) is attached to the printed circuit board as shown in FIG. (6) A component mounting device (5) that lightly presses and mounts the component onto the cream solder (7) above, and the component mounting device (
5), and a support body (8) that supports the printed circuit board (6) when the electronic component (1) is mounted.

If the printed circuit board (6) has cream solder (7) in advance as shown in FIG. 5, and the printed circuit board (6) is not warped as shown by the imaginary line in FIG. By lowering the suction nozzle (5^) of (5) from a preset height, the lead (IA) of electronic component (1) can be attached with an appropriate pressing force as shown in Figure 5. can.

[Problem to be solved by the invention]

However, the conventional electronic component mounting machine always lowers the suction nozzle (5A) from a preset height to mount the electronic component (1), regardless of the state of the printed circuit board (6). There is. Therefore, if the suction nozzle (5A) is lowered while the printed circuit board (6) is still warped upward as shown in Fig. 3, the printed circuit board (6) will receive an extra electron beam by the amount of warp (ε). The part (11) will be pressed, and as shown in Figure 6, apply cream solder (
When the lead (IA) is deeply inserted into 7), the cream solder (7) protrudes and expands to the surrounding area, which may cause adjacent cream solder (7) and (7) to coalesce and create a solder bridge. If the electronic component (1) is pressed too much against the printed circuit board (6), it will slip between the electronic component (1) and the mounting nozzle (5^) and shift laterally, resulting in a solder bridge as shown in FIG. In particular, printed circuit boards for electronic components (1) (
6), the mounting pressure per lead (IA), that is, the pressure applied to the cream solder (7), must be adequately controlled, and the printed circuit board (6)
The slight amount of warpage (ε) in the electronic component (1) has a great influence on the quality of the mounting of the electronic component (1). cannot be corrected, and the product is likely to be defective. Also, these things are true for electronic parts (1) leads (1^), (]^
) The smaller the pitch, the more noticeable it is.

The present invention has been made to solve the above problems, and is an electronic component mounting machine that mounts electronic components on a printed circuit board with an optimal pressing force without being affected by the warpage of the printed circuit board, and that does not cause solder bridges. It provides:

(Means for Solving the Problems) The electronic component mounting machine of the present invention is provided with a displacement measurement sensor below the printed circuit board that measures the amount of warpage of the printed circuit board as an amount of displacement in the vertical direction. The electronic component is mounted by correcting the downward movement distance of the component mounting device based on the measured value.

[Effect]

In the electronic component mounting machine of the present invention, when the displacement measurement sensor measures the amount of warpage of the printed circuit board, the distance that the component mounting device should descend is corrected in accordance with the measured amount of warpage, and the optimum pressing force is applied. Attach electronic components to a printed circuit board.

〔Example〕

Hereinafter, based on the embodiment shown in FIG. 1, parts that are the same as or equivalent to the conventional ones will be given the same reference numerals, and the description thereof will be omitted, and the features of the present invention will be mainly described.

As shown in FIG.
) is provided with a displacement measurement sensor (8) that measures the amount of warpage (ε) of the printed circuit board (6) as the amount of displacement in the vertical direction. The displacement measurement sensor (8) optically measures the amount of warpage (ε) of the printed circuit board (6), and when the amount of warpage (ε) is measured, the measured value is sent to the control section of the device of this embodiment (see Fig. (not shown). Upon receiving the measurement value, the control unit causes the suction nozzle (5) of the component mounting device (5) to
The preset distance for descending of the suction nozzle (5) is corrected based on the measured value, and the suction nozzle (5) is moved by the corrected distance.
A).

According to the device of this embodiment, even if the printed circuit board (6) is warped upward by the amount of warpage (ε), the displacement measurement sensor (8) measures the amount of warpage (ε), and based on the measured value, Correct the distance that the suction nozzle (5^) should descend and attach the lead (IA) of the electronic component (1) to the printed circuit board (
6) to mount the electronic component (1) on the printed circuit board (6) in a proper state as shown in FIG. 5 by pressing it onto the cream solder (7).

In this example, as is clear from the measurement method of the displacement measurement sensor (8), even if the printed circuit board (6) is warped in either the vertical or the vertical direction, the descending distance of the suction nozzle (5^) is optimized. After correcting the values, the electronic component (1) can be mounted on the printed circuit board (6).

(Effects of the Invention) According to the present invention, an electronic component mounting machine is provided that mounts electronic components on a printed circuit board with an optimal pressing force without being affected by warpage of the printed circuit board, and does not cause solder bridging. can do.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram for explaining the concept of the essential parts of an embodiment of the electronic component mounting machine of the present invention, FIG. 2 is a perspective view showing the overall configuration of the electronic component mounting machine, and FIG. 3 is a conventional Figure 1 is a diagram equivalent to the electronic component mounting machine shown in Figure 4. Figure 4 is an enlarged sectional view of a printed circuit board before electronic components are mounted on it, and Figure 5 is a printed circuit board with electronic components mounted in a normal state. FIG. 6 is a cross-sectional view showing an enlarged view of the board, FIG. 6 is a view equivalent to FIG. 5 showing a state in which electronic components are firmly attached and a solder bridge is formed, and FIG. 5 is a view corresponding to FIG. 5 showing a state in which a solder bridge is formed; FIG. In each figure, (1) is an electronic component, (5) is a component mounting device, (5^) is a suction nozzle, (6) is a printed circuit board, (
8) is a displacement measurement sensor, and (ε) is the amount of warpage. In each figure, the same reference numerals indicate the same or corresponding parts. Fig. 11 Fig.

Claims (1)

[Claims] In an electronic component mounting machine that lowers a component mounting device from a predetermined distance above a printed circuit board to mount electronic components on the printed circuit board, an amount of warpage of the printed circuit board is measured as an amount of vertical displacement below the printed circuit board. An electronic component mounting machine characterized in that a displacement measuring sensor is provided, and the electronic component is mounted by correcting the distance based on the measured value of the displacement measuring sensor.