JPS6366991A - Method of attaching chip parts - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for mounting chip components such as capacitors, resistors, varistors, and thermistors.

(Prior Art) As shown in FIG. 5, a commonly used method for mounting chip components on a circuit board is to mount a chip component 13 on a board electrode 12 attached to a circuit board 11, and then attach the chip component 13 to a circuit board 11. This is a method in which the electrode 14 of the chip component 13 and the substrate electrode 12 are attached with solder 15.

However, in the above method, due to the difference in thermal expansion coefficient between the chip component 13 and the circuit board 11, the solder 15 has a defect in which the solder 15 cracks due to the thermal history of the circuit board 11 and the chip component 13. Since the sum of the thicknesses is the total thickness, there is a problem that it is unsuitable for use in electronic sounders that require a thin design.

Therefore, as a means to solve the above problem,
Some of these are disclosed in Japanese Patent Application Laid-Open No. 55-27664.

What is disclosed in both publications is a circuit board 16 in which a through hole 18 of a size into which a chip component 17 is fitted is formed in a circuit board 16, as shown in FIG. 6, and is provided on one side of the circuit board 16. A part of the electrode 19 is made to protrude into the through hole 18, and the chip component 17 is inserted into the through hole 18, and the substrate electrode 19 is inserted into the through hole 18.
The electrode 20 of the chip component 17 and the substrate electrode 19 are soldered 21 to each other, and the total thickness is made as thin as possible, making it suitable for electronic equipment that requires a thin design. It is attracting attention as a mounting method for chip parts that can greatly contribute to the use of

However, even with the above method, due to the difference in thermal expansion coefficient that exists between the circuit board 16 and the chip component 17, it is not possible to eliminate defects in which the solder 21 cracks due to the thermal history of the solder 21. There were problems in terms of gender and practical issues that needed to be solved.

(Problems to be Solved by the Invention) The present invention solves the problems of the above-mentioned conventional methods, is suitable for use in electronic equipment that requires thinness, and is reliable when attached to a circuit board. It is an object of the present invention to provide a method for attaching chip components that is rich in practical value.

[Structure of the Invention (Means for Solving the Problems)] The chip component mounting method of the present invention is based on a circuit board having a transparent conductor large enough to accommodate the chip component having a conductive layer formed on the opposite side of the inner wall that is conductive to the board electrode. A hole is provided, and a chip component in which a metal piece with a U-shaped cross section and a spring action is attached to the 'Fi electrode is inserted into the through hole, and the metal piece is connected directly to the conductive layer or via solder. It is characterized by the fact that it can be connected by

(Function) According to the above configuration, the chip components are assembled into the circuit board without soldering, so the soldering described in the conventional method is a problem that occurs when the circuit board and chip components are connected. There is absolutely no cause for cracks to occur in the solder due to differences in thermal expansion coefficients, and even if a metal piece with a U-shaped cross section and a conductive layer formed on a circuit board are soldered, there will be no cracks between the electrode of the chip component and the conductive layer. The metal piece with a U-shaped cross section interposed therein acts as a spring to absorb the difference in thermal expansion coefficient between the chip component and the circuit board, and there is no occurrence of cranking of the solder.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

That is, as shown in FIG. 1, a through hole 2 is formed in a circuit board 1, a conductive layer 4 that is electrically connected to a substrate electrode 3 is formed on the opposite side of the inner wall of the through hole 2, and then a second conductive layer 4 is formed in the through hole 2. As shown in the figure, a chip component 7 is attached to the electrode 5 by welding or soldering a metal piece 6 having a spring action and a U-shaped cross section as shown in FIG. 4, and insert the metal piece 6 into the conductive layer 4.
It is designed so that it can be directly connected to the . In addition, the fourth
The figure shows a plan view of a circuit board 1 used in the present invention.

According to the method for attaching chip components configured as described above, soldering is possible even if the circuit board 1 and the chip component 7, which have different thermal expansion coefficients from each other, expand thermally during the thermal history process, the circuit board 1 and the chip component 7 between the chip component 7
There is only a metal piece 6 with a U-shaped cross section that has a spring action and is attached to the electrode 5 of the circuit board 1, and there is no soldering to connect it to the circuit board 1, so there is no cause for the occurrence of solder cracks. , has the excellent advantage of ensuring a highly reliable connection to the circuit board 1 over a long period of time.

In the above embodiment, the method of connecting the metal piece 6 with a U-shaped cross section by directly contacting the conductive layer 4 of the circuit board 1 was explained as an example, but the metal piece 6 with a U-shaped cross section and the circuit board Even if the conductive layers 4 of 1 are connected by soldering, the difference in coefficient of thermal expansion is absorbed by the spring action of the metal piece 6 with a U-shaped cross section, so the metal piece 6 with a U-shaped cross section and the circuit board Cracks do not occur in the solder connecting the conductive layers 4 of 1, and the reliability of the connection to the circuit board 1 is further improved. In addition, in the above embodiment, a metal piece having a U-shaped cross section was used as an example, but it is of course applicable to metal pieces with other shapes. Although the explanation has been given by exemplifying a rectangular plate-shaped one, it goes without saying that it can also be applied to a cylindrical Melf-type one.

[Effects of the Invention] According to the present invention, by attaching a metal piece having a U-shaped cross section and having a spring action to an electrode and inserting a chip component into a through hole provided in a circuit board, a metal piece having a U-shaped cross section can be formed. To provide a method for attaching chip components that does not cause cracks in the solder and ensures a highly reliable connection over a long period of time, even when the chip is directly connected to a conductive layer of a circuit board, or even when connected through solder. be able to.

[Brief explanation of the drawing]

Figures 1 to 4 relate to one embodiment of the present invention;
The figure is a cross-sectional view showing how to attach the chip parts, and the second figure is the first one.
3 is a perspective view showing the chip components that make up the figure, FIG. 3 is a perspective view that does not show the metal pieces that make up the figure 1, FIG. FIG. 6 is a cross-sectional view showing each method of attaching a chip component according to a conventional reference example. 1... Circuit board 2... Through hole 3... Substrate electrode 4...
Conductive layer 5... Electrode of chip component 6...
...Metal piece 7... Chip component patent application Marukon Electronics Co., Ltd. Figure 1 Perspective view of chip component Figure 2 Figure 4 Figure 5 ' Figure 6

Claims (2)

[Claims] (1) A through hole large enough to accommodate a chip component is provided in the circuit board, a conductive layer that is electrically connected to the board electrode is provided on the opposite side of the inner wall of the through hole, and the electrode of the chip component has a U-shaped cross section with a spring action. A method for attaching a chip component, comprising: attaching a metal piece, inserting the chip component into the through hole, and connecting the metal piece to the conductive layer. (2) A method for attaching a chip component according to claim (1), characterized in that the metal piece and the conductive layer are connected by soldering.