JPH04217384A - Printed board - Google Patents

Abstract

PURPOSE:To inhibit remaining soldering balls from creeping into the clearance between equipment and equipment, and hence prevent the generation of resultant serious troubles by installing an island-like land around a land to which a component is mounted and absorbing dispersed soldering balls into the island-like land and removing the soldering balls. CONSTITUTION:An island-like land 1b is laid out around a land to which a component is mounted, especially in the direction where soldering balls are dispersed, which forces the dispersed soldering balls to be absorbed into the island-like land 1b. Therefore, high quality soldering is available. It is also possible to adsorb the dispersed soldering balls in every direction.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure around a solder bonding land of a printed circuit board.

0002

2. Description of the Related Art In recent years, with the spread of surface mount devices (SMD), soldering using cream solder has rapidly increased.

An example of the above-mentioned conventional printed circuit board will be explained below with reference to the drawings.

FIG. 3 shows a plan view of a conventional printed circuit board. In FIG. 3, 1 is a printed circuit board. 1a is a land to which a component is to be soldered, 2 is cream solder, and 3 is a chip component.

[0005]

[Problems to be Solved by the Invention] However, with the above configuration, defects such as bridges may occur due to scattered solder balls, and remaining solder balls may sneak into gaps in the equipment, causing serious equipment failure. There was a problem.

In view of the above problems, the present invention provides a printed circuit board that absorbs and removes solder balls and solves the above problems.

The soldering process for the printed circuit board constructed as described above will be explained below.

[0008] When the solder is heated by means such as an electric furnace or infrared ray irradiation to melt it, the solvent in the flux component of the cream solder or the water absorbed by the cream solder bumps and the solder becomes a ball and scatters. .

[0009]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the printed circuit board of the present invention is characterized in that it has island-shaped lands around lands on which components are mounted.

0010

[Operation] The printed circuit board of the present invention has the above-described structure so that the scattered solder balls are absorbed into the island-shaped lands and removed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A printed circuit board according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a plan view of a printed circuit board in a first embodiment of the present invention. In Figure 1, 1
is a printed circuit board. 1a is a land, 1b is an island land, 2 is cream solder, and 3 is a chip component.

The operation of the printed circuit board configured as described above will be explained below using FIG. 1.

As shown in FIG. 1, island-shaped lands are provided around the lands on which components are mounted, so that the solder that splatters is absorbed by the lands.

As described above, according to this embodiment, high-quality soldering can be achieved by arranging island-shaped lands in two directions around the lands on which components are mounted, where solder is particularly likely to scatter.

A second embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a plan view of a printed circuit board showing a second embodiment of the present invention. In FIG. 2, 1 is a printed circuit board. 1a is a land, 1b is an island land, 2 is cream solder, and 3 is a chip component. The above configuration is similar to the configuration shown in FIG.

The difference from the configuration shown in FIG. 1 is that an island-shaped land is provided in an annular manner around the land on which components are mounted.

The operation of the printed circuit board configured as described above will be explained below. As shown in FIG. 2, since island-shaped lands are arranged around the lands on which components are mounted, the scattered solder is absorbed into the lands.

According to this embodiment, solder balls scattered in all directions can be absorbed by arranging the island-shaped lands in an annular manner.

[0020]

As described above, the present invention provides island-shaped lands around lands on which components are mounted, thereby eliminating solder balls and enabling high-quality soldering. Furthermore, cleaning to remove solder balls is no longer necessary, making this technique particularly useful when trying to eliminate cleaning by using no-clean flux.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a printed circuit board in a first embodiment of the present invention.

FIG. 2 is a plan view of a printed circuit board in a second embodiment of the present invention.

[Figure 3] Plan view of a conventional printed circuit board

[Explanation of symbols]

1 Printed circuit board 1a land 1b Island land 2 Cream solder 3 Chip parts

Claims (2)

[Claims] 1. A printed circuit board having an island-like land around a solder bonding land on which a component is mounted. 2. A printed circuit board characterized in that an island-shaped land provided around a solder bonding land on which a component is mounted surrounds the component in an annular shape.