JPS5852695Y2 - printed wiring board - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of printed wiring boards on which chip-shaped electronic components without lead wires are mounted. When installing a chip-shaped electronic component on the copper foil end on which the chip-shaped electronic component is mounted, mark a mark that serves as a reference point to check whether the chip-shaped electronic component is mounted in the correct position determined by the numerical control data. By providing a
The object of this invention is to easily measure the degree of deviation from the normal position when the mounting is misaligned, and to make it possible to correct the deviation.

A conventional printed wiring board of this kind is as shown in FIG. Since both electrode parts 4, 4' of the chip-shaped electronic component 3 were placed and connected, both electrode parts 4, 4' of the chip-shaped electronic component 3 were correctly placed and connected on the chip-shaped electronic component mounting copper foil ends 2, 2'. It was difficult to measure whether the position was correct and how much it had deviated from the correct position.

This invention is an improvement to eliminate these conventional drawbacks, and the embodiments shown in FIG. 2 and subsequent figures will be described in detail with the same reference numerals used for the same parts as in the conventional example shown in FIG. 1.

That is, in the embodiment of this invention shown in FIG.
Both electrodes 4, 4' of the chip-shaped electronic component 3 are placed on the copper foil ends 2, 2' for mounting the chip-shaped electronic component printed wiring on the printed circuit board 1 using, for example, an automatic chip-shaped electronic component mounting machine.
A mark 5.5' is provided as a reference point for checking whether the cable is connected to the correct position predetermined by the numerical control device.

In this embodiment, the marks 5, 5' are round holes with a diameter of about 0.8 mm drilled in the copper foil ends 2, 2' for mounting the chip-shaped electronic components.

This round hole is provided at the same time as the printed wiring.

The center of the round hole is the longitudinal center line Both electrode parts 4, 4 when aligned in the middle of parts 2, 2'
It is set at the point where the respective ends 4a and 4a' intersect.

Here, assume that the horizontal length of the chip-shaped electronic component 3 in the figure is approximately 3.2 mm and the vertical length of the chip-shaped electronic component 3 is approximately 1.6 mm, and for the correct mounting position of the chip-shaped electronic component 3 shown in FIG. Third
As shown in A in the figure, the chip-shaped electronic component 3 is moved to the left by about 9
．． If it is shifted by 4 mm, the mark 5 provided on the copper foil end 2 for mounting the chip-shaped electronic component on the left side will be completely hidden by the electrode section 4 of the chip-shaped electronic component 3 and will become invisible.
The mark 5' on the right side becomes visible, and the chip-shaped electronic component 3 is moved 0.4m to the right side as shown in FIG. 3B.
If the mark 5' is shifted by m, the mark 5' on the right side is completely hidden by the electrode section 4' of the chip-shaped electronic component 3 and becomes invisible, whereas the mark 5 on the left side becomes visible.

Therefore, the deviation in mounting of the chip-shaped electronic component 3 in the left-right direction becomes clear.

Next, as shown in C of FIG. 3, if the chip-shaped electronic component 3 is shifted downward by about Q, 4 mm in the figure, then the upper end 3a of the chip-shaped electronic component 3 is at the circumference of both marks 5° 5'. touch the top.

On the other hand, if the chip-shaped electronic component 3 is shifted upward by about 0.4 mm as shown in D in FIG. touch the top.

Therefore, even when there is a mounting misalignment in the vertical direction of the chip-shaped electronic component 3, the mounting misalignment is checked using the marks 5, 5' as a reference, so that the mounting misalignment becomes clear.

The above explanation is based on the case where the chip-shaped electronic component 3 is shifted by about 0.4 mm vertically and horizontally, but in the case where the chip-shaped electronic component 3 is shifted by 9.4 mm or more in the horizontal direction, only one mark is completely shifted. By being clearly visible,
In the case of a displacement of about 0.4 mm or more in the vertical direction, more than half of the circumferences of both marks are clearly visible even by visual inspection, so that the mounting displacement of the chip-shaped electronic component 3 becomes clear.

Further, the degree of mounting misalignment of the chip-shaped electronic component 3 can also be determined by the degree of overlap between the electrode portions 4, 4' and the marks 5, 5'.

If there is a large visual error in the installation of chip-shaped electronic components, and if installation accuracy is required, measure by enlarging it with a TV camera, etc., and attach a scale to the screen that is reflected by the TV camera. If you leave it there, you can easily measure the degree of deviation.

Also, if you enlarge it with a TV camera, it will be about 0.4m.
It is possible to measure deviations of less than m.

In addition, when a chip-shaped electronic component shifts in the left-right direction, the circumference of one mark always appears larger than the circumference of the other mark, and when it shifts in the vertical direction by about 2.2 mm or more, Since more than half of the circumference of both marks is visible, by measuring the deviation between the circumference of those marks and the edge of the chip-shaped electronic component, it is possible to clearly see how much the chip-shaped electronic component has shifted vertically and horizontally. Become.

In this embodiment, the marks 5 and 5' are circular holes, but they are not limited to circular shapes, and substantially the same effect can be obtained by making them triangular, square, or polygonal, for example.

Further, the marks 5, 5' are not limited to holes, and may be printed in the shape described above, for example.

As described above, this invention is for checking whether the electrode part of a chip-shaped electronic component is attached to the correct predetermined position when it is attached to the end of the metal foil for mounting the chip-shaped electronic component on a printed wiring board. We have provided a printed wiring board with a mark that serves as a reference point on the edge of the metal foil for mounting chip-shaped electronic components. I was unable to clearly confirm whether the installation was misaligned, but
By using this invention, the correct mounting position of the chip-shaped electronic component indicated by the above marks can be clearly confirmed, and it is possible to see how much the chip-shaped electronic component is deviated from that position in either the vertical or horizontal direction. It is now easy to measure, and if there is a deviation, it can be easily corrected.

Recent numerically controlled automatic chip mounting machines are equipped with a data correction function, so if the corrected value of the numerically controlled data can be visually measured by using a printed wiring board like this invention, then the numerically controlled Data can be corrected instantly, improving the operating rate of the automatic chip mount machine.
Since the quality of installation is also improved, the industrial value is immeasurable.

On the other hand, when using a conventional printed wiring board to move a chip-shaped electronic component whose mounting position deviates from the standard value, manually move it to the correct position using a tapered tool such as tweezers. This resulted in a large loss of man-hours.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing a conventional printed wiring board, Fig. 2 is a plan view showing a printed wiring board of this invention, and Fig. 3 is an explanation of mounting misalignment of chip-shaped electronic components connected to this printed wiring board. be. 1... Printed circuit board, 2, 2'... End of copper foil for mounting chip-shaped electronic components, 3... Chip-shaped electronic components, 3a, 3a'...・Top, bottom edge, 4.4
'... Electrode, 4a, 4a'... End, 5
．． 5'...Mark, X...Longitudinal center line, O...Center of chip-shaped electronic component.

Claims (1)

[Scope of utility model registration request] When attaching the electrode part of the chip-shaped electronic component to the end of the metal foil for mounting the chip-shaped electronic component on the printed wiring board, a mark is placed as a reference point to check whether it is installed in the correct predetermined position. A printed wiring board characterized in that the chip-shaped electronic component is mounted on the edge of the metal foil.