JPH0453022Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Summary] Regarding the structure of a printed circuit board for surface mounting, the purpose of this is to prevent new wiring from interfering with probing tests when modifying a printed circuit board. This is a surface mounting printed circuit board in which via holes, dedicated pads, and electrical component terminals 7 (hereinafter referred to as via holes, etc.) are arranged substantially on the same plane as the surface of the board, and the via holes, etc. Among them, identification marks that are visible from the substrate surface are attached to the parts that are to be contacted by the pins of the tester during the probing test.

[Industrial application field]

The present invention relates to the structure of a printed circuit board for a computer or the like, and more particularly, to the identification of the positions of via holes and component terminals in a printed circuit board for surface mounting.

[Conventional technology]

After components are mounted on a printed circuit board used in a computer, etc., a probing test is performed on the component terminals mounted and placed at a predetermined location to check performance, and the waveform of the signal at this location is checked. . This probing test is automatically performed by bringing a large number of test pins provided for the test into contact with these terminals all at once.

In most conventional printed circuit boards, when mounting an electrical component 3, the lead 1 is inserted into a mounting hole arranged on the surface of the board 2, and the tip 1a is slightly extended from the surface, as shown in FIG. A terminal is formed and fixed in a protruding state. Therefore, the above-mentioned probing test was also conducted by touching the tip of the protruding lead 1a from the back side with the test pin 4 having a flat head. In such a conventional board, even when new conductive wires are manually wired on the printed circuit board in order to modify the printed circuit board, the modification wiring 5 is installed no matter where it is placed. , is located at a lower position than the tip 1a of the protruding lead, so that it did not interfere with the probing test described above.

However, due to the recent trend of making printed circuit boards lighter, thinner, shorter, and smaller, there is a shift toward surface mounting of components. As shown in Fig. 3, according to this method, the lead 1 of the component does not protrude to the back side.
A flat terminal 7 is provided on the surface side on the inner surface which is substantially the same as this.
The terminals 7 and the printed circuits are arranged in such a manner that the probing test is performed on predetermined ones out of a large number of via holes 8 that connect these terminals 7 and printed circuits. Also, a short part 6 dedicated to probing tests is also provided on the front side.

[Problem that the invention attempts to solve]

When wiring for modification is applied to the above-mentioned surface mount type printed circuit board, as shown in FIG. There is a possibility that the wiring may be routed over the component terminal 7 for testing, the dedicated pad 6, and the via hole 8. In such a case,
During the probing test, the test pin 4 is obstructed by this wiring 5 and cannot access the terminal etc.
There was a drawback that the desired test could not be carried out.

The present invention aims to solve the problems of the prior art, and provides a substrate structure that allows probing tests to be carried out smoothly even when modified wiring is applied.

[Means for solving problems]

The present invention is a printed circuit board for surface mounting, in which a large number of via holes, special parts, and terminals of electrical components (hereinafter referred to as via holes, etc.) are arranged substantially on the same plane as the surface of the board. This is a structure of a printed circuit board characterized in that an identification mark that is visible from the surface of the circuit board is attached to a via hole or the like at a location where a pin of a tester should come into contact during a probing test.

Hereinafter, the present invention will be explained in more detail based on preferred embodiments shown in the drawings.

FIG. 1 shows a part of a plan view of a surface mounting printed circuit board to which the present invention is applied. As is well known, a large number of via holes 8 are arranged throughout the surface of the board 2 for connecting printed wirings, and
An electrical component 3 is mounted with its lead 1 fixed to a terminal 7 on the surface of the board. Furthermore, a special part 6 for probing test is also provided. As described above, these via holes, terminals, and pads (hereinafter referred to as via holes, etc.) are arranged substantially in the same plane as the surface of the substrate, that is, in a state in which they hardly protrude from the surface.

In the present invention, when modifying the board 2, an identification mark 10 is provided to draw the operator's attention so that the new wiring 5 is placed in a position where it will not interfere with via holes etc. required for probing tests. This is attached to the via hole 8, pad 6, and terminal 7. The mark 10 needs to be clearly visible from the surface of the substrate 2, and for example, signals such as ◯, △, □, or color coding such as red and blue are used.

When installing wiring for modification, the operator should check this sign 10 and perform wiring while being careful not to run the wiring over via holes or the like marked with this sign.

Printed circuit board 2 wired with this in mind
Since the modification wiring 5 is not provided at the location necessary for the probing test, the pins of the tester can access predetermined via holes etc. without being obstructed.

[Effect of idea]

According to the present invention, the positions of via holes, etc. necessary for probing tests are distinguished from others at a glance by identification marks, so that workers can avoid this and carry out modified wiring. . This prevents interference with probing tests caused by modified wiring, which has often occurred in the past, and allows smooth testing.

[Brief explanation of drawings]

Fig. 1 is a partial plan view of a printed circuit board according to the present invention, Fig. 2 is a side view showing a conventional probing test method, and Fig. 3 is a probing test using modified wiring for a conventional surface mount printed circuit board. FIG. 3 is a side view showing a disturbance situation. 1... Lead, 2... Printed circuit board, 3... Electrical parts, 4... Test pin, 5... Wiring for modification,
6... Dedicated parts, 7... Terminals, 8... Via holes, 10... Identification signs.

Claims (1)

[Scope of utility model registration request] A large number of via holes 8, dedicated pads 6, and terminals 7 of electrical components 3 (hereinafter referred to as via holes, etc.)
is a surface mount printed circuit board that is arranged substantially on the same plane as the surface of the board 2, and the portions of the via holes 8, 6, and 7 that are to be contacted by the pins of the tester during the probing test. A printed circuit board structure characterized in that an identification mark 10 that is visible from the surface of the board 2 is attached to the printed circuit board.