JPS60130894A - Method of mounting electronic part - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electronic component mounting method for simultaneously mounting electronic components on both sides of a printed circuit board by soldering.

[Prior art]

Conventionally, there is a method shown in FIG. 1 for attaching electronic components such as resistors, capacitors, and semiconductor chips to both sides of a printed circuit board by soldering. In this figure, 1 is a printed circuit board on which electronic components are attached to both sides, 2 is an electronic component that is attached to the top surface of the printed circuit board 1, and 3 is an electronic component that can be attached to the bottom surface of the printed circuit board 1, which in this case is a chip component. . 4 is a solder oval, and 5 is molten solder within the solder top 4.

Next, the effect will be explained. The chip component 3 is immersed in the molten solder 5 of the solder head 4 and moved in the direction of the arrow X, thereby simultaneously soldering 20 electronic components on the upper surface of the chip component 3. However, in this method, a semiconductor chip component such as a flat package that is mounted on the same surface as the chip component 3 is directly soldered with high-temperature molten solder 5.
The reliability of the parts is improved because it is attached by immersing it in water.
do not have. In particular, the functions of semiconductor chip components.

From a structural standpoint, it is better to avoid touching the high-temperature molten solder 5 as much as possible. In addition, since a part of the molten solder 5 moves horizontally within the J molten solder 5, it rises on the top surface of the printed circuit board 1, which leaves a negative impact on the electronic components 2 on the top surface.
＃ヲwas extending.

Other mounting methods include first mounting the electronic components on one side and then mounting the electronic components on the other side, but this requires manual soldering, which requires additional processing time. (5. It is unfavorable from both quality and economical points of view.

[Summary of the invention]

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional circuit board, and the electronic components on both sides of the printed circuit board are immersed in molten solder by dipping only the electronic components on one side of the printed circuit board into melted solder. The purpose is to solder at the same time.

[Example of 31s] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic diagram for explaining one embodiment of the present invention, in which it is preferable for quality reasons to avoid immersing the upper surface of the printed circuit board 1 in high-temperature molten solder. The leads of the semiconductor chip component 2a such as the above are temporarily fixed in position by the mounting hole 1a provided in the printed circuit board 1 as shown in FIG. 3(a)K, and the semiconductor chip component 2a is temporarily fixed in position as shown in FIG. As shown in the figure, a sufficient amount of preliminary solder 1c is applied to the part to be soldered in advance to the outer layer conductor 1b't? Solder is applied through it.

In addition, other chip components are placed on the bottom surface of the printed circuit board 1.
In other words, 5Kj of molten solder? The electronic component 3a, which does not have much adverse effect even if crushed, is temporarily fixed in place.

When the printed circuit board 1 is gently dipped vertically into the molten solder 5 in the solder tank 4, that is, in the direction of the arrow Y in FIG. 1c is melted and soldered as shown in FIG. 3(C), and the electronic component 3 on the bottom surface is
A is directly soldered using TM welding solder 5, and necessary electronic components can be attached to both sides of the printed circuit board 1 at the same time.

By the way, in the past, soldering was performed by moving horizontally in the direction of the arrow X in FIG. The object is moved in the vertical direction, that is, in the directions of arrows Y and Y'. This method is also advantageous in terms of space.

It should be noted that in the above embodiment, the explanation focused on chip parts.
It is easy to think of attaching electronic components such as switches and volume controllers to the upper surface of the printed circuit board 1.

[Young fruit of invention]

As explained above, this 31-year-old has electronic components on the top surface of the printed circuit board that should not be immersed in high-temperature molten solder, and electronic components on the bottom surface that can be immersed in molten solder without any negative effects. The components were temporarily attached, and the electronic components on the top surface were pre-soldered, so that when the electronic components on the bottom surface were dipped into the molten solder, the electronic components on the top surface were also soldered at the same time. Electronic components that require reliability do not need to be immersed in molten solder, which has the effect of realizing economical and surface-quality soldering.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a conventional electronic component mounting method, Fig. 2 is a diagram showing a tightening method for electronic component mounting according to an embodiment of the present invention, and Fig. 3 (a), (b), (c). 1 is an enlarged sectional view of the sleeve showing the processing steps of the electronic component mounting method of the present invention. In the figure, 1 is a printed circuit board to which double-sided Km child components are attached, 2 is a semiconductor chip component that is attached to the top surface of a ft printed circuit board, 3a is an electronic component that is also attached downward, 4 is a solder oval, and 5 is a molten solder. be. Note that the same reference numerals in Figure 1 indicate the same or corresponding parts. Agent Masuo Oiwa (2 others)

Claims (1)

[Claims] In an electronic component mounting method in which electronic components on both sides of a printed circuit board are soldered using molten solder in a solder bath, an appropriate amount of spare material is placed on the top surface of the Relint board before soldering electronic components that cannot be immersed in the molten solder. After applying solder and temporarily fixing, and temporarily fixing an electronic component that can be dipped into the molten solder on the lower surface, only the electronic component on the lower surface is immersed in the molten solder, and both electronic components are attached to both sides of the printed circuit board. The electronic component installation method is characterized by simultaneous installation.