JPH0794857A - Printed wiring board - Google Patents

Abstract

PURPOSE:To prevent solder short-circuit in the case of soldering of an integrated circuit parts wherein intervals between lead terminals are small, by arranging soldering parts in a zigzag type so as to be shifted in the direction intersecting the arragnement direction of parts fixing holes. CONSTITUTION:A printed wiring board 1 has a conducting pattern surface 2 wherein a conducting pattern of copper or the like is formed. In the parts fixing land 3 on the conducting pattern surface 2, parts fixing holes 4 into which the lead terminals of integrated circuit parts or elements are inserted are formed so as to correspond with the number and the interval of lead terminals. On the conducting pattern surface 2, resist is spread on the region except soldering portions 5 around the parts fixing holes 4. When the resist is spread, each of the soldering portions 5 is shifted in the direction intersecting the arrangement direction of parts fixing holes 4, and the soldering portions are exposed and arranged in a zigzag type. Hence the overlapping part on a line in the soldering part is small, so that bridging of whiskers generated in the parts fixing land 3 does not occur.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board used in electronic equipment and the like, and more particularly to a mounting portion for an integrated circuit component.

[0002]

2. Description of the Related Art Conventionally, a printed wiring board used in electronic equipment or the like has a soldering portion around the component mounting holes of component mounting lands adjacent to each other, and a resist is applied to the periphery of the soldering portion. is there. Note that the resist prevents the solder from getting wet to unnecessary portions during soldering. Hereinafter, such a conventional printed wiring board will be described with reference to the drawings. FIG. 8 is a top view showing a main part of a conventional printed wiring board.

In FIG. 8, a printed wiring board 1 has a conductive pattern surface 2 having a conductive pattern formed of copper or the like. The plurality of component mounting lands 3 on the conductive pattern surface 2 are provided with component mounting holes 4 into which lead terminals of integrated circuit components and elements are inserted, corresponding to the number and intervals of the lead terminals. Further, on the conductive pattern surface 2, the resist shown by the right diagonal line is applied to the portion other than the soldering portion 5 around the component mounting hole 4. When applying the resist, the soldering portions 5 are exposed and arranged in a straight line.

In recent years, as integrated circuits have come to be used more and more due to downsizing of electronic equipment and progress of electronic parts technology,
The distance between adjacent lead terminals is gradually reduced, and when soldering an integrated circuit component having a lead terminal interval of 1.78 mm, the lead terminals arranged in a straight line are arranged in correspondence with each other. The gap between the mounting lands is 0.5 mm or less, and the width of the resist applied to each soldering part is also
It becomes 0.5 mm or less.

[0005]

In the conventional printed wiring board, when soldering an integrated circuit component having a small gap between the lead terminals by the jet soldering method,
Since the gap between adjacent component mounting lands becomes smaller,
There was a problem that "beard" generated on the adjacent component mounting land crossed over the resist and was bridged, resulting in a solder short.

An object of the present invention is to provide a printed wiring board which prevents a solder short circuit when soldering an integrated circuit component having a small space between lead terminals.

[0007]

In order to solve the above-mentioned problems, in the printed wiring board of the present invention, the soldering portions are arranged in a zigzag pattern by shifting them in a direction intersecting the arrangement direction of the component mounting holes. did.

[0008]

When the soldering portion of the printed wiring board constructed as described above is soldered by the jet soldering method, the adjacent soldering portions are displaced in a zigzag pattern, and therefore, the soldering portion is directly connected. Since there are few overlapping parts on the line, there is no "beard" bridging that occurs in the component mounting land.

Therefore, according to the present invention, it is possible to prevent a solder short circuit when soldering an integrated circuit component having a small gap between the lead terminals.

[0010]

Embodiments of the present invention will be described with reference to the drawings. The elements common to the drawings are given the same reference numerals. FIG. 1 is a top view showing a first embodiment of the present invention. The present embodiment differs from the conventional technique in that the soldering portions are arranged in a staggered pattern. In FIG. 1, a printed wiring board 1 has a conductive pattern surface 2 having a conductive pattern formed of copper or the like. The component mounting lands 3 on the conductive pattern surface 2 are provided with component mounting holes 4 into which lead terminals of integrated circuit components and elements are inserted, in correspondence with the number and intervals of the lead terminals.

Further, on the conductive pattern surface 2, a portion shown around the component mounting hole 4 other than the soldering portion 5 is coated with a right-hatched line. When applying the resist, the soldering portions 5 are arranged in a zigzag exposed manner by shifting the soldering portions 5 in a direction intersecting the arrangement direction of the component mounting holes 4.

When the printed wiring board 1 having the above-mentioned structure is soldered, since the adjacent soldering portions are staggered, there are few overlapping portions on the straight line of the soldering portions, so that they are generated on the component mounting land. The "beard" bridge does not occur.

Next, a second embodiment of the present invention will be described with reference to the drawings. 2 is a top view showing a second embodiment of the present invention, and FIG. 3 is a sectional view taken along the line AA of FIG. The second embodiment differs from the first embodiment in that silk ink is applied between the component mounting lands.

In FIG. 2, the printed wiring board 1 has a conductive pattern surface 2 having a conductive pattern formed of copper or the like. The plurality of component mounting lands 3 on the conductive pattern surface 2 are provided with component mounting holes 4 into which lead terminals of integrated circuit components and elements are inserted, corresponding to the number and intervals of the lead terminals. Further, on the conductive pattern surface 2, a resist shown by a right diagonal line is applied to a portion other than the soldering portion 5 around the component mounting hole 4 and the silk ink coating portion 11 which is a gap between the component mounting lands 3. .

When applying the resist, each soldering portion 5
Are shifted in a direction intersecting with the arrangement direction of the component mounting holes 4 and are exposed and arranged in a zigzag pattern. Further, the silk ink application portion 11 between the component mounting lands 3 is applied with the silk ink indicated by the left diagonal line. In addition, as shown in FIG.
The component mounting land 3 made of copper foil has a thickness of about 40 μm, whereas the silk ink has a thickness of about 35 μm and the resist has a thickness of about 10 μm.

When the printed wiring board 1 having the above-described structure is soldered, since the adjacent soldering portions are staggered, there are few overlapping portions on the straight line of the soldering portions, so that they are generated in the component mounting land. The "beard" bridge does not occur. Further, as shown in FIG. 3, the thickness of the component mounting land 3 is about 40 μm, whereas the thickness of the resist is only about 10 μm, but the thickness of the silk ink is about 35 μm. When the ink is applied, contact between adjacent solders is less likely to occur.

Next, a third embodiment of the present invention will be described with reference to the drawings. 4 is a top view showing a third embodiment of the present invention, and FIG. 5 is a sectional view taken along the line AA of FIG. The third embodiment differs from the first and second embodiments in that only the silk ink is applied around the soldered portion and the resist is applied around it.

In FIG. 4, the printed wiring board 1 has a conductive pattern surface 2 having a conductive pattern formed of copper or the like. The component mounting lands 3 on the conductive pattern surface 2 have component mounting holes 4 into which lead terminals of integrated circuit components and elements are inserted.
Are provided in correspondence with the number and intervals of the lead terminals.
Further, on the conductive pattern surface 2, several component mounting lands 3
A resist, which is indicated by a right diagonal line, is applied to a portion other than the silk ink applying portion 11 which forms a group.

In the silk ink application section 11, the silk ink shown by the left diagonal line is applied to the portion other than the soldering section 5 around the component mounting hole 4. When applying the silk ink, the soldering portions 5 are arranged in a zigzag exposed manner by shifting in a direction intersecting the arrangement direction of the component mounting holes 4.
As shown in FIG. 5, the thickness of the component mounting land 3 made of copper foil is about 40 μm as in the second embodiment, whereas the thickness of the silk ink is about 35 μm and the thickness of the resist is about 10 μm. Is.

When the printed wiring board 1 having the above-described structure is soldered, since the adjacent soldering portions are staggered, there are few overlapping portions on the straight lines of the soldering portions. The "beard" bridge does not occur. Further, as shown in FIG. 5, the thickness of the component mounting land 3 is about 40 μm, whereas the thickness of the resist is only about 10 μm, but the thickness of the silk ink is about 35 μm. When the ink is applied, the contact between adjacent solders is less likely to occur as in the second embodiment.

Next, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a top view showing a fourth embodiment of the present invention, and FIG. 7 is a top view showing a modification of the fourth embodiment. The fourth embodiment differs from the first embodiment in that the shape of the soldering portion is different.

In FIG. 6, the printed wiring board 1 has a conductive pattern surface 2 having a conductive pattern formed of copper or the like. The component mounting lands 3 on the conductive pattern surface 2 have component mounting holes 4 into which lead terminals of integrated circuit components and elements are inserted.
Are provided in correspondence with the number and intervals of the lead terminals.

Further, on the conductive pattern surface 2, a portion shown around the component mounting hole 4 other than the soldering portion 21 is coated with a right-hatched line. When applying the resist, each soldering portion 5 is staggered in a direction intersecting the arrangement direction of the component mounting holes 4, and the shape is exposed in a substantially diamond shape having a long diagonal line in the intersecting direction. To arrange.

Interval L2 between the soldering portions 21 of the fourth embodiment
Is the distance L1 between the soldering portions 5 of the first embodiment shown in FIG.
It is longer than that. Therefore, when soldering
Bridging of "beard" that tends to occur in the direction parallel to the movement of the printed wiring board 1 is further less likely to occur.

In the fourth embodiment, the soldering portion 21 has a substantially diamond shape, but it may be a teardrop-shaped soldering portion 22 as shown in FIG. 6 (a). Further, the periphery of the component mounting hole 4 as shown in (b) is substantially circular, and the soldering portion 23 having the same width as it is separated from the component mounting hole 4, and the periphery of the component mounting hole 4 as shown in (c) is substantially circular. The soldering portion 24 may be circular and taper as it goes away from the component mounting hole 4 and has a wider width as it goes further away.

[0026]

Since the present invention is configured as described above, it has the following effects.

That is, when the soldering portions are arranged in a zigzag pattern while being displaced in a direction intersecting with the arrangement direction of the component mounting holes, when soldering an integrated circuit component having a small space between the lead terminals. In addition, solder short circuit can be prevented.

[Brief description of drawings]

FIG. 1 is a top view showing a first embodiment of the present invention.

FIG. 2 is a top view showing a second embodiment of the present invention.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a top view showing a third embodiment of the present invention.

5 is a cross-sectional view taken along the line AA of FIG.

FIG. 6 is a top view showing a fourth embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a modified example of the fourth embodiment.

FIG. 8 is a top view showing a main part of a conventional printed wiring board.

[Explanation of symbols]

 1 Printed wiring board 3 Component mounting land 4 Component mounting hole 5 Soldering part

Claims (6)

[Claims] 1. A printed wiring board having a soldering portion formed by exposing a periphery of a component mounting hole of a component mounting land adjacent to each other to form a soldering portion, and the soldering portion is arranged in the arrangement of the component mounting holes. A printed wiring board, which is arranged in a zigzag pattern by shifting in a direction intersecting the direction. 2. The printed wiring board according to claim 1, wherein silk ink is applied between the component mounting lands. 3. A printed wiring board in which the soldering portions are formed by exposing the periphery of the component mounting holes of the component mounting lands that are adjacent to each other and applying a resist, wherein the soldering portions are arranged in the arrangement direction of the component mounting holes. Be staggered in a direction intersecting with each other, apply only silk ink to the area including the component mounting land and around the soldering area, and apply the resist outside this area. A printed wiring board characterized by. 4. The soldering part has a substantially elliptical shape having a major axis in the intersecting direction, or claim 3.
Printed wiring board described. 5. The printed wiring board according to claim 1, wherein the soldering portion is tapered in the intersecting direction. 6. The printed wiring board according to claim 5, wherein the soldering portion has a substantially diamond shape having a long diagonal line in the intersecting direction.