JPH05243779A - Electronic device - Google Patents

Abstract

PURPOSE:To improve workability of an electronic device which uses a leadless type coaxial capacitor. CONSTITUTION:In an electronic device where a leadless type coaxial capacitor 4 is soldered to a metal case 5 or a metal plate and then is inserted into a resin case with a terminal 7, the coaxial capacitor 4 is soldered to the terminal 7, and further a circuit board 1 is soldered to the terminal 7, spacing between the coaxial capacitor 4 and the circuit board 1 is set to 2mm or less, thus preventing solder from flowing to the terminal 7 and short-circuiting between the metal case 5 or the metal plate and the terminal 7 due to overheating or excessive amount of solder supply when soldering the terminal 7 and the circuit board 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an electronic device,
The present invention relates to a structure that reduces the influence of electromagnetic interference.

[0002]

2. Description of the Related Art FIG. 4 shows, for example, Japanese Patent Laid-Open No. 62-266429.
FIG. 2 is a cross-sectional view showing a pressure sensor disclosed in Japanese Patent Publication No. JP-A-2003-163, in which 1 is a pressure sensor unit 2 and a hybrid IC.
It is a circuit board with 3 assembled. Reference numeral 4 is a leadless type feedthrough capacitor, which is soldered to the metal case 5 and, after the metal case 5 is inserted into the resin case 6, is soldered to the terminal 7. Further Terminal 7
The circuit board 1 is also soldered to.

Next, the operation will be described. By arranging the feedthrough capacitor 4 through the terminal 7 of the resin case 6 as described above, electromagnetic noise that gets on the input / output line and enters the electronic device can be bypassed, and electromagnetic interference can be reduced. By saving the space for installing the feedthrough capacitor 4 on the circuit board 1, the electronic device can be downsized.

[0004]

Since the conventional electronic device is constructed as described above, when the soldering conditions when soldering the terminal and the circuit board are not appropriate,
For example, if it is overheated, solder 8 on the terminal.
When the amount of solder further increases, as shown in FIG. 5, the resist on the upper surface of the through capacitor initially stays on the through capacitor as shown in FIG. 5, but when the amount of solder increases further, as shown in FIG. Finally, there was a problem that the terminal flowed out due to its own weight and the terminal and the metal case were short-circuited.

The present invention has been made in order to solve the above problems, and when a circuit board is assembled in a resin case, a short circuit due to a solder flow occurs even when the soldering working conditions of the terminal and the circuit board are not appropriate. The purpose is to obtain an electronic device that can prevent

[0006]

The electronic device according to the present invention has a clearance of 2 mm between the feedthrough capacitor and the circuit board.
It is arranged as follows.

Further, the solder for soldering the feedthrough capacitor and the terminal is one having a higher melting point than the solder for soldering the circuit board and the terminal.

[0008]

In the electronic device according to the present invention, the amount of molten solder accumulated between the feedthrough capacitor and the circuit board can be reduced to prevent the solder from flowing. And prevent the terminal from short-circuiting.

[0009]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the same parts as those in the prior art are designated by the same reference numerals. The clearance g between the feedthrough capacitor 4 and the circuit board 1 should be 2 mm or less. Also, feedthrough capacitor 4 and terminal 7
As the solder for soldering, the one having a higher melting point than the solder for soldering the circuit board 1 and the terminal 7 is used.

Next, the operation will be described. If the soldering conditions of the circuit board 1 and the terminal 7 are improper, for example, if they are overheated, the solder flows over the terminals 7, and even if the amount of solder increases, the clearance between the feedthrough capacitor 4 and the circuit board 1 will be Since it is narrow, it is possible to limit the amount of solder that remains during this period, as shown in FIG. 2, and it is possible to prevent the solder from flowing down due to the surface tension of the resist and the solder applied to the upper surface of the feedthrough capacitor 4. Also,
The solder that joins the feedthrough capacitor 4 and the terminal 7 is less likely to melt due to the heat sink effect of the metal plate 5 on which the feedthrough capacitor is mounted and due to the use of high melting point solder. FIG. 3 shows the test results when solder is excessively supplied and soldered with 10 samples each having a different clearance g between the circuit board and the feedthrough capacitor. When the clearance g was 3 mm, all were short, but 2
In mm, the result was that there was no short circuit. Figure 3
In the table, “OK” indicates the result of the experiment in which the terminal and the metal case are not short-circuited, and “NG” indicates the result of the short-circuit.

[0011]

As described above, according to the present invention, since the clearance between the feedthrough capacitor and the circuit board is configured to be 2 mm or less, the amount of solder remaining between the feedthrough capacitor and the circuit board can be reduced. It is possible to prevent the metal case and the terminal from being short-circuited.

[Brief description of drawings]

FIG. 1 is a sectional side view showing an electronic device according to an embodiment of the present invention.

FIG. 2 is an enlarged side view showing a terminal / feedthrough capacitor solder portion according to an embodiment of the present invention.

FIG. 3 is a graph showing test results in the present invention.

FIG. 4 is a sectional side view showing a conventional electronic device.

FIG. 5 is an enlarged side view showing a terminal / through capacitor solder portion of a conventional electronic device.

FIG. 6 is an operation explanatory diagram from the state of FIG. 5;

[Explanation of symbols]

 1 Circuit board 4 Feedthrough capacitor 5 Metal case 7 Terminal 8 Solder

Claims (2)

[Claims] 1. A circuit in which a feedthrough capacitor soldered to a metal case, a terminal soldered to the feedthrough capacitor, and an electronic component mounted on the feedthrough capacitor and having the terminal soldered thereto are mounted. An electronic device comprising a board, wherein the gap between the feedthrough capacitor and the circuit board is set to 2 mm or less. 2. The electronic device according to claim 1, wherein a solder for soldering the feedthrough capacitor and the terminal has a higher melting point than a solder for soldering the circuit board and the terminal.