JP2002246741A - Printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed circuit board that can electrically and simply detect a non-soldered portion between a component having leads that is packaged onto the printed circuit board and a conductive pattern land of the printed circuit board, can improve reliability in inspection, and can reduce man-hours. SOLUTION: Points 4 for inspection comprising plural lands 2 and 3 for inspection are provided on a conductive pattern surface 5 on the printed circuit board 1, and the plural lands 2 and 3 for inspection are formed at specified intervals A. The specified interval A is set to distance, where the lands 2 and 3 for inspection can be connected by solder, when the conducive pattern surface 5 of the printed circuit board 1 is subjected to dip soldering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board used for electronic equipment, and more particularly to a technique for detecting an unsoldered portion of dip solder on a printed circuit board conductor pattern surface.

[0002]

2. Description of the Related Art Conventionally, in general, when mounting a component with a lead at a predetermined position on a printed circuit board, the lead is inserted into a hole (including a through hole) provided on the printed circuit board, and the lead is mounted on the component mounting surface. This is achieved by connecting a portion protruding from the conductor pattern surface on the opposite side to the conductor pattern land provided around the perforation on the conductor pattern surface by dip soldering.

[0003] Then, it is necessary to inspect whether or not the components with leads to be mounted and the conductor pattern lands of the printed circuit board are connected well by soldering. In this inspection, an unsoldered portion is visually detected. Inspections are performed, and further inspections are performed on the printed circuit board circuits for continuity, non-conduction, presence / absence of defective parts, and the like by an in-circuit tester.

[0004]

However, the conventional inspection for visually detecting an unsoldered portion is inferior in reliability and requires many man-hours.

In recent years, as electronic devices have become smaller and thinner, the shape of a printed circuit board used for the main body and operation section of the electronic device has tended to be substantially elongated and rectangular. Warping tends to occur in the longitudinal direction (especially in the soldering process line), and therefore, there is a problem that an unsoldered portion tends to occur particularly at the end of the printed circuit board.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and it is possible to electrically and easily detect an unsoldered portion between a mounted leaded component and a conductor pattern land on a printed circuit board. Another object of the present invention is to provide a printed circuit board that can improve the reliability of inspection and reduce the number of steps.

[0007]

In order to solve the above-mentioned problems, a printed circuit board according to the present invention employs the following means.

According to a first aspect of the present invention, an inspection point including a plurality of inspection lands is provided on a conductor pattern surface of a printed circuit board, and the plurality of inspection lands are formed at predetermined intervals, and the predetermined intervals are equal to each other. Also, the present invention relates to a printed circuit board, characterized in that when the conductor pattern surface of the printed circuit board is subjected to dip soldering, the distance between respective inspection lands is a distance connectable by soldering.

According to a first aspect of the present invention, when a conductor pattern surface of a printed circuit board is dip-soldered, if the dip-soldering is performed normally, a plurality of inspection lands at inspection points are soldered. In the case where the test lands are electrically connected to each other, and if the dip soldering is not performed normally, the multiple test lands at the test points are not connected by solder, and The land is not electrically connected. Thus, unsolder at the inspection point can be electrically detected.

A second aspect of the present invention relates to a printed circuit board according to the first aspect, wherein the inspection point is provided at an end of the printed circuit board.

According to a second aspect of the present invention, when a conductor pattern surface of a printed circuit board is subjected to dip soldering, a plurality of inspection points are inspected at an end of the printed circuit board (particularly, at a corner of the printed circuit board). The lands are electrically connected or not connected by the solder. Thus, unsolder at the end of the printed circuit board can be electrically detected.

A third gist of the present invention is characterized in that the plurality of inspection lands are provided so as to be opposed to each other in the soldering direction in dip soldering the conductor pattern surface of the printed circuit board. Alternatively, the present invention relates to a printed board according to the second aspect.

According to the third aspect of the present invention, when the conductor pattern surface of the printed circuit board is subjected to dip soldering, the inspection points of the inspection points provided opposite to the soldering direction (longitudinal direction of the printed circuit board). The plurality of inspection lands are electrically connected or not electrically connected by the solder.
This makes it possible to electrically detect the unsoldered state at the inspection point in the soldering direction of the dip solder.

A fourth gist of the present invention is that a predetermined interval between the plurality of inspection lands is set such that when the conductor pattern surface of the printed circuit board is subjected to dip soldering, when the warpage of the printed circuit board is small, each of the inspection lands is provided. The present invention relates to a printed circuit board according to any one of the first to third aspects, wherein when the printed wiring boards are connected to each other by solder and the warped state of the printed wiring boards is large, the distance between the inspection lands is not connected by soldering.

According to a fourth aspect of the present invention, when dip soldering a conductor pattern surface of a printed circuit board, when the warped state of the printed circuit board is small, the plurality of test lands at the test points are soldered. When the printed circuit board is connected and electrically conducted and the warped state of the printed circuit board is large, the plurality of inspection lands at the inspection points are not connected by solder and are not electrically conducted. This makes it possible to electrically detect the unsoldered state at the inspection point based on the degree of warpage of the printed circuit board.

According to a fifth aspect of the present invention, the plurality of inspection lands include a first inspection land, a second inspection land, and a conductor pattern connecting the first inspection land and the second inspection land. Wherein the first inspection lands are formed at predetermined intervals, and the second inspection lands are formed outside the first inspection land regions by conductor patterns. Related to a printed circuit board.

According to the fifth aspect of the present invention, since the second inspection lands connected by the conductor pattern from the first inspection lands are formed outside the first inspection land regions, the respective first lands are formed. The conduction or non-conduction between the inspection lands can be detected by the second inspection lands.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a printed circuit board according to an embodiment of the present invention.

FIGS. 1 and 2 show an embodiment (1) of a printed circuit board according to the present invention.

The printed circuit board 1 has a plate shape and is formed in a substantially rectangular shape. As a material, a copper-clad laminate made of an electrically insulating substrate and a conductive material is used. The back side is a component mounting surface (not shown). For example, components with leads are mounted by inserting leads into perforations (including through holes) provided in the printed circuit board 1. The front surface side is the conductor pattern surface 5, and a conductor pattern (electric circuit) is formed by, for example, etching a copper foil of a copper-clad laminate. A conductor pattern land 6 for dip soldering is formed around the perforations on the conductor pattern surface 5. An inspection point 4 for detecting unsoldered dip solder is provided at an end of the conductive pattern surface 5 (a corner of the printed board 1).
Are provided. In addition, this inspection point 4
Is formed, for example, by etching a copper foil of a copper-clad laminate like a conductor pattern.

The inspection point 4 includes a plurality of inspection lands 2 and 3 and is formed at a predetermined interval A. The plurality of inspection lands 2 and 3 are arranged so as to face the soldering direction B of the dip solder (the longitudinal direction of the printed circuit board 1). As the shape of the inspection lands 2 and 3, for example, the inspection land 2 on the front side in the soldering traveling direction B is circular, and the inspection land 3 on the rear side in the soldering traveling direction B is in the soldering traveling direction. It is formed in a rectangle whose long side faces B.

Next, the predetermined interval A will be described. Table 1
Represents the distance A (distance) between the inspection lands 2 and 3 when the conductor pattern surface 5 of the printed circuit board 1 is dip-soldered in a state where the printed circuit board 1 is not warped, and the solder state at the distance A. It is. In the table, ○ indicates that the inspection lands 2 and 3 are connected by solder, Δ indicates that the inspection lands 2 and 3 may not be connected by solder, and x indicates that the inspection lands 2 and 3 are not connected. This indicates that the three are not connected by solder.

[0023]

[Table 1]

In the case of Table 1, the inspection lands 2
The interval A of 3 is 0.35 mm or less. The reason for this is that, as shown in Table 1, when the soldering state of the space A between the inspection lands 2 and 3 was investigated by changing the space A between the inspection lands 2 and 3, A is 0.35
When the distance A between the test lands 2 and 3 is 0.4 mm or more, the test lands 2 and 3 are connected by solder. This is because they are not electrically conducted.

Table 2 shows inspection lands when the conductor pattern surface 5 of the printed circuit board 1 is subjected to dip soldering when the printed circuit board 1 is warped when the warp of the printed circuit board 1 is large or small. It shows a few intervals A (distance) and the solder state in the interval A. In the table, ○ indicates that the inspection lands 2 and 3 are connected by solder, and △ indicates that the inspection lands 2 and 3 may not be connected by solder.

[0026]

[Table 2]

In the case of Table 2, the inspection lands 2, 3
When the distance A between the lands 2 and 3 is not less than 0.35 mm and the warpage of the printed circuit board 1 is large, the lands 2 and 3 for inspection are not connected by solder and are not electrically connected. Is less than 0.35 mm, and when the warpage of the printed circuit board 1 is small, the space A between the inspection lands 2 and 3 is connected by solder and electrically connected regardless of the warped state of the printed circuit board 1. State.

Next, detection of an unsoldered portion of the printed circuit board 1 configured as described above will be described. Inspection of the continuity, non-conduction and presence / absence of a defective component of the printed circuit board is performed by an in-circuit tester (in-circuit inspection process). Therefore, unsoldering at the inspection point 4 is detected using this in-circuit tester. Specifically, a test pin (contact probe) of an in-circuit tester is brought into contact with the test lands 2 and 3 at the test point 4 to check the continuity and non-conduction between the test lands 2 and 3.
If the test lands 2 and 3 are in a conductive state, the test lands 2 and 3 are connected by solder and the test result is passed. If the test lands 2 and 3 are in a non-conductive state, the test is performed. The solder lands 2 and 3 are not connected by solder and unsolder is detected, and the inspection result is rejected. In addition, the printed circuit board 1 which has failed the inspection is shifted to the detailed confirmation and correction process.

As described above, according to this embodiment (1), the inspection points 4 composed of a plurality of inspection lands 2 and 3 are provided on the conductor pattern surface 6 of the printed board 1, and the inspection lands 2 and 3 Because it is formed with an interval A,
When the conductor lands 2 and 3 are connected by soldering when the conductor pattern surface 5 of the printed circuit board 1 is dip-soldered, conduction is detected by the in-circuit tester, and it is detected that the inspection point 4 is not unsoldered. If the test lands 2 and 3 are not connected by solder, the non-conductivity is detected by the in-circuit tester.
Can be detected as not soldered. This makes it possible to easily and electrically detect that there is an unsoldered portion after dip soldering the conductor pattern surface 6 of the printed circuit board 1.

The inspection point 4 is connected to the printed circuit board 1.
, It is possible to detect an unsoldered portion which is likely to be generated particularly at the end of the printed circuit board 1.

Further, by providing the plurality of inspection lands 2 and 3 in the soldering traveling direction B when the conductor pattern surface 5 of the printed circuit board 1 is subjected to the dip soldering, the unsoldering with respect to the soldering traveling direction B Parts can be detected.

Further, when the conductor pattern surface 5 of the printed circuit board 1 is subjected to dip soldering when the warpage of the printed circuit board 1 is small, the distance between the test lands 2 and 3 is set to a predetermined distance A between the plurality of test lands 2 and 3. When the printed circuit board 1 is connected by solder and the warpage of the printed circuit board 1 is large,
By setting the distance not to be connected by solder, it is possible to detect an unsoldered part when the warpage of the printed circuit board 1 is large.

Next, an embodiment (2) of the present invention will be described. 3 and 4 show a printed circuit board according to an embodiment (2) of the present invention. In the description similar to that of the embodiment (1), the same reference numerals are given and the details are omitted.

The printed circuit board 10 of the embodiment (2)
Is a modification of the shape of the inspection land at the inspection point in the embodiment (1). The inspection lands of the printed circuit board 10 are composed of a plurality of inspection lands 20, 30, and the respective inspection lands 20, 30 are first inspection lands 21, 31, second inspection lands 22, 32, and second inspection lands 22, 32. The first inspection lands 21, 31 and the second inspection lands 22,
32 and a conductor pattern that connects them to each other.
Each of the first inspection lands 21 and 22 is formed at a predetermined interval (for example, 0.3 mm), and the second inspection lands 22 and 32 are formed of the first inspection lands 21 and 31 adjacent to each other by a conductor pattern. It is formed outside the inspection land area. For example, the inspection land 20 is formed to face the soldering traveling direction B when the conductor pattern surface 5 of the printed circuit board 10 is subjected to dip soldering, and the inspection land 3 is formed.
0 is formed in a direction parallel to or different from the soldering proceeding direction B.

In this embodiment (2), when the conductor pattern surface 5 of the printed circuit board 10 is subjected to dip soldering, the first inspection lands 21 and 31 can be connected to each other by soldering. If the lands 21 and 31 are connected by solder, conduction is detected by the in-circuit tester, and it can be detected that the inspection point is not unsoldered. If the first inspection lands 21 and 31 are not connected by solder, the Non-conduction is detected by the circuit tester, and it is detected that the inspection point is not soldered.

Here, since the second inspection lands 22 and 32 are formed outside the adjacent first inspection land regions by the conductor patterns, the continuity inspection of the first inspection lands 21 and 31 requires in-circuit The test pins of the tester can be brought into contact with the second inspection lands having a sufficient space.

[0037]

As described above, according to the first aspect of the present invention, an inspection point including a plurality of inspection lands is provided on a conductor pattern surface of a printed circuit board, and a plurality of inspection lands are provided at predetermined intervals. When dip soldering the conductor pattern surface of the printed circuit board, if multiple test lands are connected by solder, it is detected that they are electrically conductive and the test points are not unsoldered. If the plurality of inspection lands are not connected by soldering, it can be detected as electrically non-conductive, and it can be detected that the inspection point is not soldered. This makes it possible to easily and electrically detect the presence of an unsoldered portion after dip soldering the conductor pattern surface of the printed circuit board, thereby improving the reliability of dip soldering inspection of the printed circuit board conductor pattern surface and reducing man-hours. There is an effect that can be done.

According to a second aspect of the present invention, in the printed circuit board according to the first aspect, the inspection point is provided at an end of the printed circuit board, so that an unsoldered portion particularly easily generated at the end of the printed circuit board is provided. There is an effect that can be detected.

According to the third aspect of the present invention, in the printed circuit board according to the first or second aspect, a plurality of inspection lands are opposed to each other in a soldering advancing direction when dip soldering the conductor pattern surface of the printed board. With such a configuration, there is an effect that an unsoldered portion in the soldering traveling direction can be detected.

According to the fourth aspect of the present invention, in the printed circuit board according to any one of the first to third aspects, a predetermined interval between the plurality of inspection lands is adjusted by dip soldering the conductor pattern surface of the printed circuit board. When the warpage of the printed circuit board is small, the inspection lands are connected by solder, and when the warpage of the printed circuit board is large, the inspection lands are not connected by solder. There is an effect that can be detected.

According to the fifth aspect of the present invention, in the printed circuit board according to any one of the first to fourth aspects, the second inspection land is formed outside the adjacent first inspection land region by the conductor pattern. Therefore, there is an effect that the continuity inspection of the first inspection land can be performed on the second inspection land having a sufficient space.

[Brief description of the drawings]

FIG. 1 is an embodiment (1) of a printed circuit board according to the present invention.
FIG.

FIG. 2 is an enlarged view of the printed circuit board of FIG.

FIG. 3 is an embodiment (2) of a printed circuit board according to the present invention;
FIG.

FIG. 4 is an enlarged view of the printed circuit board of FIG. 3;

[Explanation of symbols]

 1, 10 Printed base material 2, 3, 20, 30 Inspection land 21, 31 First inspection land 22, 32 Second inspection land 4 Inspection point 5 Conductor pattern surface 6 Conductor pattern land A Spacing B Soldering progress direction

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mamoru Morikawa 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka F-term (reference) 5E319 AC01 AC11 CC23 CD52

Claims (5)

[Claims] An inspection point including a plurality of inspection lands is provided on a conductor pattern surface of a printed board, and the plurality of inspection lands are formed at predetermined intervals, respectively.
The printed board is characterized in that the predetermined interval is a distance that can be connected between the respective inspection lands by soldering when the conductor pattern surface of the printed board is subjected to dip soldering. 2. The printed circuit board according to claim 1, wherein the inspection point is provided at an end of the printed circuit board. 3. The method according to claim 1, wherein the plurality of inspection lands are provided so as to be opposed to each other in a soldering direction when the conductor pattern surface of the printed circuit board is subjected to dip soldering.
Or the printed circuit board according to 2. 4. The method according to claim 1, wherein the predetermined spacing between the plurality of inspection lands is such that when the conductor pattern surface of the printed circuit board is dip-soldered, when the warpage of the printed circuit board is small, the respective inspection lands are connected by soldering. The printed board according to any one of claims 1 to 3, wherein when the warped state of the printed board is large, the distance between the respective inspection lands is not connected by solder. 5. The first inspection land includes a first inspection land, a second inspection land, and a conductor pattern connecting the first inspection land and the second inspection land. 5. The printed circuit board according to claim 1, wherein the lands are formed at predetermined intervals, and the second inspection lands are formed outside the first inspection lands by a conductor pattern. 6. .