JPH0955565A - Printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance workability in the removing work of surface mounted device by forming lands for removing the surface mounted device, while coupling each other, in the vicinity of lands for wiring the surface mounted device. SOLUTION: When a surface mounted device is removed, the head of a soldering iron 9 is applied to a part between lands 5, 6 thus heating the lands 5, 6 simultaneously. Consequently, the solder stored previously at the lands 5, 6 at the time of reflow is thermally fused to increase the contact area with soldering iron 9 thus promoting transmission of heat. Heat from the soldering iron 9 is transmitted to wiring patterns 7, 8 and the solder stored at the lands 3, 4 is heated along with the electrodes 2a, 2b of a chip device 2. When the solder stored at the lands 3, 4 is fused and the chip device 2 is heated sufficiently, the chip device 2 can be moved easily thus facilitating the removing work. This method enhances workability in the removing work of surface mounted device.

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, and more particularly to a printed wiring board with improved work for removing surface mount components.

[0002]

2. Description of the Related Art Conventionally, as a method for removing a surface mounting component, for example, a chip component 2 soldered to lands 3 and 4 formed on a surface of a printed wiring board 1 on which electronic components such as surface mounting components are mounted, As shown in FIG. 3 (A), a method of simultaneously applying soldering tips to the two electrodes 2a and 2b of the chip component 2 by using two soldering irons 9 and 10 to melt and remove the solder on the lands 3 and 4, and
As shown in FIG. 3B, the kneading solder 11 is melted with only one soldering iron 9 and a large amount of solder 12 is poured so as to extend over both the electrodes 2a and 2b of the chip component 2,
There has been a method in which the electrodes 2a and 2b are simultaneously heated and removed.

[0003]

However, these methods have a problem that the former requires two soldering irons and the latter requires kneading solder to be melted in, and both of them have poor workability. It was An object of the present invention is to provide a printed wiring board that solves the above-mentioned conventional problems and can improve the workability of removing surface mount components.

[0004]

A printed wiring board according to the present invention has a wiring pattern of the printed wiring board,
It is formed by connecting a land for surface mount component removal in the vicinity of the land for surface mount component wiring. Further, the surface mounting component wiring lands and the surface mounting component removing lands are formed in the number corresponding to the number of electrodes of the surface mounting component. Further, the intervals of the surface mounting component removing lands are as close as possible. Further, the surface mount component is a chip component.

[0005]

The surface mounting component removing land is connected and formed in the vicinity of the surface mounting component wiring land of the printed wiring board. When removing the surface mount component, if you apply a soldering iron to the surface mount component removal land and heat it, the land for wiring the surface mount component will be heated via the connection pattern and the solder on the land will melt and the surface mount component will be easy. Removed.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a printed wiring board according to the present invention will be described below with reference to the schematic view of FIG. The present invention, when designing the wiring pattern of the printed wiring board 1,
A feature is that a land for removing surface-mounted components is provided. That is, in the printed wiring board 1, wiring lands 3 and 4 to which electrodes 2a and 2b of a chip component (chip resistor, etc.) 2 are solder-connected are formed on the surface of a substrate to which electronic components such as surface mount components are attached. There is. The wiring lands 3 and 4 are connected to other electronic components by a printed wiring pattern on the back surface of the substrate 1. Lands 5 and 6 for applying a soldering iron 9 at the time of removing the surface-mounting component are formed by connecting with patterns 7 and 8 in a space portion near the lands 3 and 4 and not interfering with other surface-mounting components. The lands 5 and 6 are formed to be large enough so that the soldering iron 9 can be applied thereto, so that the solder can be accumulated on the lands during reflow. The distance between the lands 5 and 6 should be as narrow as possible so that solder bridging between lands does not occur during reflow.

A description will be given of how to apply the soldering iron 9 for removing the surface-mounted component in the above-mentioned structure for repair, replacement and the like. First, the tip of the soldering iron 9 is placed near the land 5 and the land 6 to heat the lands 5 and 6 at the same time. The solder that had been accumulated in the lands 5 and 6 during reflow was melted by heating, and the contact with the soldering iron 9 increased,
Heat can be easily transmitted. The heat transferred from the soldering iron 9 is the wiring patterns 7 and 8
The solder accumulated in the lands 3 and 4 and the electrodes 2a and 2b of the chip component 2 are heated. The solder accumulated in the lands 3 and 4 is melted, and the sufficiently heated chip component 2 can be easily moved by moving the soldering iron 7, and the detaching work becomes easy. As described above, if the land portion for removing the surface mount component is heated with the soldering iron, the surface mount component can be easily removed, and the workability of removing the surface mount component is improved.

[0008]

[Embodiment] In the above embodiment, the case of the surface mount component having two electrodes has been described.
It can be implemented even with surface-mounted components having electrodes of more than a certain number if the wiring pattern is properly designed. For example, as shown in FIG. 2, surface mounting components (transistor,
Each electrode 20a, 20b, 20c of the diode 20)
Are the wiring lands 2 of the printed wiring board 1, respectively.
Soldered to 1, 22, and 23. The wiring lands 21, 22, and 23 are connected to other electronic components by a printed wiring pattern on the back surface of the substrate 1. Each wiring land 21,
Lands 24, 25, 26 for removing surface-mounted components are formed in the vicinity of 22, 23, and wiring patterns 27, 2 are formed.
It is connected by 8 and 29. The distance between the surface mounting component removing lands 24, 25, 26 is made as narrow as possible so that solder bridging does not occur during reflow. In the above structure, the surface mounting component 20 can be easily removed by simultaneously applying the soldering iron to the lands 24, 25 and 26 in the same manner as described with reference to FIG.

[0009]

According to the present invention, the workability of removing surface-mounted components is improved, and defects (pattern peeling) that occur during removal are reduced. In addition, there is almost no increase in cost.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment of a printed wiring board according to the present invention.

FIG. 2 is a schematic view of another embodiment of the printed wiring board according to the present invention.

FIG. 3 is a schematic diagram showing an example of a conventional method for removing surface-mounted components from a printed wiring board.

[Explanation of symbols]

 1 Printed wiring board 2 Chip parts 3,4 Wiring lands 5,6 Surface mounting component removal lands 7,8 Wiring pattern 9 Soldering iron

Claims (4)

[Claims] 1. A printed wiring board formed by connecting surface mounting component removing lands in the vicinity of the surface mounting component wiring lands. 2. The printed wiring board according to claim 1, wherein surface mounting component wiring lands and surface mounting component removing lands are formed in a number corresponding to the number of electrodes of the surface mounting component. 3. The printed wiring board according to claim 2, wherein the surface mounting component removing lands are as close as possible to each other. 4. The printed wiring board according to claim 2, wherein the surface mount component is a chip component.