JPH08148799A - Surface mounting part - Google Patents

Abstract

PURPOSE: To decrease inferior soldering such as Manhattan phenomenon by spread an insulating material on at least the upper side of an electrode. CONSTITUTION: An insulating material 1b of poor soldering wettability is spread on the upper side including an electrode. This makes it possible to accomplish the following: when a chip part 1 is soldered to an electrode 2a of a substrate 2, due to a melting time difference of a solder, for example, a solder cream which has first melted form a solder fillet 3a on the electrode 2a side first, and this hand fillet 3a further tries to move upward, but the insulating material 1b on the upper side of the chip part 1 prevents it so that the solder fillet 3a cannot reach the upper side of the electrode, thus weakening a difference of surface tension between the two electrodes and reducing occurrences of the Manhattan phenomenon such as the chip part 1 floating up.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount component such as a chip component which is surface-mounted on a circuit board.
The present invention relates to a surface mount component having a plurality of soldering terminals such as a chip capacitor and a chip resistor.

[0002]

2. Description of the Related Art As shown in a perspective view of FIG. 4, a conventional chip part 11 is formed into a substantially rectangular parallelepiped, and electrodes 11a are provided around both ends thereof. The mounting state of this chip component 11 is shown in FIG.
As described above, the chip component 11 is placed on the circuit board 12 with one surface thereof facing down, the solder cream 13 is applied to the board-side soldering terminals 12a, and the electrodes 11a are placed for reflow soldering. However, according to such a chip component, when reflow soldering causes a difference in the way heat escapes to the surroundings due to the shape of the board-side soldering terminal 12a (heat conduction difference), both ends are melted due to a difference in melting time. A difference occurs in the surface tension of the molten solder that acts on the electrodes.

Therefore, as shown in FIG. 6, the previously melted solder cream has a solder fillet 13a formed first on one side of the electrode 11a, and the solder fillet 13a further rises upward to form the solder fillet 13a. Electrode 1
When the surface tension acting on the end face of 1a is larger than that of the other electrode, there is a problem that a Manhattan phenomenon such as floating (rising) occurs and soldering failure occurs.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a surface mount component capable of reducing soldering defects such as the Manhattan phenomenon.

[0005]

In order to solve the above-mentioned problems, the present invention is characterized in that, in a surface mount component in which electrodes are provided at both ends, an insulator is applied to at least an upper side surface of the electrodes. To do. Further, the insulator is coated on the entire upper surface of the surface mount component. Further, the insulator is made of glass paste in which glass powder is mixed in flux. Alternatively, it is characterized in that the insulator is made of an aluminum paste in which a flux is mixed with aluminum powder.

[0006]

With the above-described structure, since the insulator is applied to the upper side surface of the chip component, the solder fillet is formed on the lower surface and the side surface of the electrode, but the solder fillet is not formed on the lower surface of the electrode. The surface tension is weakened and the chip parts are hard to float (stand up).

[0007]

Embodiments of the present invention will be described in detail below with reference to FIG. Reference numeral 1 is a chip component having electrodes 1a at both ends. 1b is a glass paste coated on the upper side surface including the electrode 1a, for example, a mixture of a large amount of fine glass powder in a flux containing resin as a main material and isopropyl alcohol as an auxiliary material, or The insulator 1b is made of an aluminum paste in which a fine powder of aluminum is mixed in the flux (poor solder wettability). The chip component 1 is connected to the circuit board 2 as shown in FIG.
When placed on the surface and heated to the temperature at which the solder melts, the solder fillet 3a is formed on the electrode 1a as usual, and the chip component 1 is soldered to the electrode 2a on the substrate 2. At this time, due to the difference in the melting time of the solder, for example, the solder cream that has melted first forms the solder fillet 3a first on the electrode 2a side, and the solder fillet 3a tries to rise further upward. 1 Insulator 1 on the upper side
b prevents this, the Doda fillet 3a cannot reach the upper side surface of the electrode 1a, the difference in surface tension between both electrodes is weakened, and the Manhattan phenomenon such as floating (rising) of the chip component 1 is reduced. become.

Next, the perspective view of FIG. 3 shows a second embodiment. As shown in the figure, the insulator 1b is applied to the entire upper part of the chip component 1. Chip component 1 of this embodiment
Can reduce the Manhattan phenomenon. Further, compared to the first embodiment, the workability is improved because the trouble of selecting and applying the insulator 1b only on the electrode is eliminated.

[0009]

As described above, according to the present invention, since the insulating material is applied to one side of the chip component, a large amount of solder is deposited on any terminal side in the soldering process. Even in such a case, the solder does not rise to the upper surface of the soldered terminal, the Manhattan phenomenon of the chip component can be prevented, and the solder bridge can be prevented at the same time.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of a surface mount component according to the present invention.

FIG. 2 is a perspective view showing a mounting state of the first embodiment of the surface mount component according to the present invention.

FIG. 3 is a perspective view showing a mounted state of a second embodiment of the surface mount component according to the present invention.

FIG. 4 is a perspective view of a conventional surface mount component.

FIG. 5 is a perspective view showing a mounting state of a conventional surface mount component.

FIG. 6 is a perspective view illustrating a Manhattan phenomenon of a conventional surface mount component.

[Explanation of symbols]

 1 Chip component 1a Electrode 1b Insulator

Claims (4)

[Claims] 1. A surface mount component having electrodes at both ends thereof, wherein an insulator is applied to at least an upper portion of a side surface of the electrode. 2. The surface mount component according to claim 1, wherein the insulator is coated on the entire upper surface of the surface mount component. 3. The surface mount component according to claim 1, wherein the insulator is made of glass paste in which glass powder is mixed in flux. 4. The surface mount component according to claim 1, wherein the insulator is made of an aluminum paste in which flux is mixed with aluminum powder.