JPH0347339Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a device that automatically displays the position of a terminal (through-hole) in which a defect such as a break or a short is present on a printed circuit board. It is concerned with things that can be quickly and accurately confirmed and provide benefits for subsequent revisions.

There is an automatic wiring inspection machine to inspect each conductor pattern of a printed circuit for defects (breaks and shorts). This is done by inserting needle electrodes created corresponding to the positions of each terminal (through hole) of the conductor pattern on the printed circuit board into the through holes of the printed circuit board, and checking the conduction status between each terminal (through hole). This tests the insulation condition all at once.

Defects recognized by this inspection machine are output and displayed as (1) X048, Y050, SHORT X'250, Y'122, for example. This is the through hole point A (048, 050) at coordinates (X, Y)
This means that there is a short circuit between the and through-hole point B (250, 122), which is a defect.

In addition, if there is a defect where through-hole point A and through-hole point B are insulated when they should be in a conductive state, the output will be as follows: (2) X048, Y050 OPEN X'250, Y'122 Is displayed.

Although the explanation has been mixed, the center of a through hole in a printed circuit board is determined to be located on either the X or Y plane coordinates with a pitch of, for example, 2.54 mm, and it is possible to indicate defects such as the above. It is.

Naturally, the defect position is known and corrected based on the defect information output by the wiring inspection machine, but conventionally, the first means of knowing the defect position is
As shown in the figure, the transparent synthetic resin film 1 has X,
The inspection sheet 3 with the Y coordinate line 2 is placed on top of the printed circuit board 4 that is the object to be inspected, and the through-hole points A and B corresponding to the position information from the wiring inspection machine are visually determined. After that, the inspection sheet 3 was peeled off, and arrow-shaped colored tape 5 was pasted to mark points A and B of the through holes.

However, it is clear that such work requires time and effort, and it is difficult to handle when there are many defective parts or when printed circuits are becoming larger and more precise as they are today. I often misjudged where I should have been. In the subsequent correction process when a mark was placed on a through-hole in an incorrect position, a complicated conduction pattern had to be examined one by one, resulting in a great loss of labor.

The present invention is a display device for quickly knowing the position of a defective through hole in a printed circuit board, and will be explained in detail based on FIG. 2 showing an embodiment. 7, a large number of point light emitting elements 8 are arranged in an X-Y matrix, and the arrangement pitch of each point light emitting element 8 is as follows.
As mentioned earlier, the pitch intervals at which the terminal through-holes of the printed circuit board are to be arranged are made to correspond in the same manner. For example, the centers of the light emitting elements are positioned at a pitch of 2.54 mm in the X and Y directions. This naturally matches the arrangement pitch of the through holes in the printed circuit board of the object to be inspected. (Of course, not all points have through holes).

Further, the input area 9 is provided with functions for inputting defect messages from the above-mentioned wiring inspection machine and for various operations.

Since X and Y are a set of two points, X, X' and Y,
It is better to have Y′. Furthermore, in addition to manually inputting position information by hitting the keyboard 10, it is also possible to automate the input by providing a tape reader 11 or a card reader 12.

As the point-emitting element 8, dot display using a light emitting diode or fluorescent display, XY dot display using a plasma display, or display using a CRT (cathode ray tube) is also possible. In short, it is sufficient to be able to display lights in an XY matrix.

The display device shown in FIG. 2 has protrusions 13 and 14 for alignment so that the printed circuit board can be aligned when it is placed.

The method of using the display device of the present invention is to place the printed circuit board to be inspected so that its through-hole and point-emitting element 8 match in the coordinate system, and then input defect information. This is done by lighting up a point light emitting element at a position corresponding to the defect. In this way, the lighting light can be visually recognized through the through-holes (holes are open from top to bottom) of the printed circuit board, so it is only necessary to mark the through-holes where the lighting light is leaking.

According to the device of the present invention, the actual location of the defect on the printed circuit board can be determined semi-automatically from the defect information from the wiring inspection machine, and the operator can simply identify the defective position of the printed circuit board. All you have to do is mark the through holes, which not only speeds up the work, but also eliminates any mistakes. If such a device is used, unnecessary labor will not be wasted in the subsequent correction process, and the advantages of the present invention are extremely high.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a conventional method for determining the location of a defect in a printed circuit board, and FIG. 2 is a perspective view showing an embodiment of the defect location display device for a printed circuit board according to the present invention. 3...Inspection sheet, 4...Printed circuit board, 5...
Color tape, 6...Display device, 7...Display area section, 8...Point light emitting element, 9...Input area section, 1
0...keyboard, 11...tape reader, 1
2...Card reader, 13, 14...Protrusions for positioning.

Claims (1)

[Scope of utility model registration request] A display area section comprising a large number of point light emitting elements arranged in an X-Y matrix in accordance with the specified pitch of through holes drilled in the printed circuit board, and a set of at least two of the many point light emitting elements. A defect in a printed circuit board comprising an input area section for inputting information for lighting the board, and a positioning protrusion for coordinating a through hole of the printed circuit board and a point light emitting element of the display area section in terms of coordinates. Position display device.