JPH0265295A - Printed board - Google Patents

Abstract

PURPOSE:To prevent cream solder applied onto a chip land from flowing sidewards and to eliminate a short circuit failure so as to improve soldering in quality by a method wherein a resist is provided to overlap both adjacent chip lands. CONSTITUTION:A resist section 2B is provided overlapping both adjacent chip component lands 3A and 3B. Therefore, a cream solder 4 applied onto the chip lands 3A and 3B can be prevented from flowing sidewards by the thickness of the resist 2B overlapped with the chip lands 3A and 3B. And, the thickness of the overlapped resist 2B is equal to or less than that of the applied cream solder.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a method for forming a chip land around a chip land in order to prevent a solder connection between a land for a chip component that can be used in an electronic circuit mounting board and a land of an adjacent chip component. This invention relates to a printed circuit board using a printing resist.

BACKGROUND OF THE INVENTION In recent years, printed circuit boards have been packaged with high density, mounted components have been miniaturized, and the distance between the leads of integrated circuits has become smaller, and it is desired that the quality of soldering during mounting be improved. Hereinafter, an example of the conventional printed circuit board mentioned above will be described with reference to the drawings.

FIG. 3 shows a conventional resist for preventing solder connection between a chip component mounting land of a printed circuit board and an adjacent land of the chip component. In FIG. 3, a chip component land 3 and a chip land connection pattern are formed on a substrate 1''2, and a resist 2 is provided at locations where soldering is not required, such as between the chip land 3 and adjacent lands and on the connection pattern. ing.

In the conventional printed circuit board configured as described above, the fourth
As shown in the figure, soldering of electronic components is sometimes done by applying cream solder 4 on the chip component land 3, placing the chip component 6 on the solder 4, and then melting and solidifying the solder 4. There is a method of electrically connecting the electrode 6 of the component 6 and the land 3 (Japanese Patent Laid-Open No. 129968/1983).

Problems to be Solved by the Invention However, in the above configuration, since the register 2A3/.7 is located between the adjacent lands 3 of the chip component 6, there is a The applied cream solder 4 is directed towards the adjacent land (X direction)
When the solder melts, the chip lands 3 are soldered to each other. Furthermore, when the chip component 6 is placed after applying the cream solder, the cream solder 4 flows out in the direction of the adjacent land (X direction), resulting in a similar solder connection.

In view of the above problems, the present invention provides a printed circuit board that prevents the occurrence of defective solder connections between adjacent lands by preventing the leakage of cream solder applied to adjacent chip lands.

Means for Solving the Problems In order to solve the above problems, the printed circuit board of the present invention is provided with a resist portion superimposed on both adjacent chip lands.

According to the above-described structure, the cream solder on the chip land is prevented from flowing sideways due to the thickness of the resist portion of the land, and it is possible to eliminate defects such as solder connections between adjacent lands.

EXAMPLE Hereinafter, a printed circuit board according to an example of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of one embodiment of the present invention, and FIG. 2 is a cross-sectional view when chip components are connected. In this embodiment, adjacent chip component lands 3A, 3
A resist portion 2B is provided which overlaps both of the resist portions B and B.

Regarding the printed circuit board configured as above, the following is the first part.
The operation will be explained using FIG. The cream solder 4 applied on the chip lands 3A and 3B can be prevented from flowing horizontally due to the thickness of the register 7) 2B superimposed on the lands 3 and 3B. Here, the overlapping thickness of Regime) 2B is to prevent the cream solder from flowing in, and may be equal to or less than the thickness of the cream solder applied.

As described above, according to this embodiment, the adjacent chip lands 3
By providing superimposed resists on A and 3B, solder connections can be eliminated and solder quality can be improved. In the above embodiments, it is effective to use a semiconductor IC as the chip component and a lead as the electrode.

Effects of the Invention As described above, in the present invention, by providing a resist that overlaps both adjacent chip lands, it is possible to prevent the cream solder applied on the chip lands from flowing sideways, and to prevent the chips from flowing when the cream solder melts. It is possible to eliminate short-circuit defects caused by solder connections between lands and improve solder quality.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a printed circuit board according to an embodiment of the present invention, Fig. 2 is a sectional view when chip components are connected, Fig. 3 is a plan view of a conventional printed circuit board, and Fig. 4 is a plan view of a conventional printed circuit board. It is a sectional view when connected. 1...Substrate, 2...Resist, 3...
...Land for chip parts, 4...Solder, 5.
...Chip component electrode.

Claims (1)

[Claims] A printed circuit board comprising adjacent lands for chip components and a resist portion disposed so as to overlap both the adjacent chip lands.