JPH1168301A - Mounting method for chip component and chip component used for the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve quality and to reduce mounting man-hour by working the surface area of the lead electrode of a chip component to be enlarged and supplying the appropriate amount of solder to the lead electrode beforehand. SOLUTION: This method is composed of a process for forming a notch 5 passed through an electrode connection part 3 at the electrode connection part 3 of the lead electrode 2 of this chip component 1 and working the surface area to be enlarged, the process for supplying solder plating 6 to the lead electrode 2 whose surface area is enlarged, the process for loading the chip component 1 supplied with the solder plating 6 onto a printed board 10 and the process for fusing the solder plating 6 of the chip component 1 loaded on the printed board 10 and joining the electrode connection part 3 of the lead electrode 2 to the pad 4 of the printed board 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a chip component mounted on a printed circuit board and mounting by soldering, and a chip component used in this method.
A chip component mounting method capable of increasing the surface area of a lead electrode of a chip component and supplying an appropriate amount of solder to the lead electrode in advance to improve quality and reduce the number of mounting steps, and used in this method. Related to chip components.

[0002]

2. Description of the Related Art Conventionally, a surface mounting chip component disclosed in Japanese Utility Model Application Laid-Open No. 2-38721 has been proposed to improve the quality of soldering at the lead electrode portion of the chip component. The chip component for surface mounting described in Japanese Utility Model Application Laid-Open No. 2-38721 is such that a concave notch is formed in a lead electrode of the chip component to increase the surface area of the lead electrode.

When the concave notch is formed in the lead electrode as described above, the surface area of the lead electrode is increased, a large amount of solder can be supplied to one lead electrode, and the electrode is reliably placed on the printed circuit board. Can be connected. In addition, in the lead electrode having the notch formed in this way, even when the amount of supplied solder is too large, the solder is absorbed into the concave notch, so that there is no protrusion of the solder and the like, and the soldering quality is improved. It becomes possible.

At present, a reflow method is generally used as a method for mounting chip components on a printed circuit board. In this reflow method, cream solder is printed in advance on the electrodes (hereinafter referred to as "pads") on the printed circuit board, the lead electrodes are positioned on top of them, and the chip components are mounted. By doing so, the cream solder on the pad is melted, and the pad and the lead electrode of the chip component are joined by soldering. Japanese Utility Model Application Laid-open No. 2-3872
The surface mount chip component of Japanese Patent Publication No. 1 is also mounted on a printed circuit board by this reflow method.

[0005]

However, in such a method of mounting chip parts by the conventional reflow method, in the step of printing cream solder on a substrate,
Depending on the conditions such as the viscosity of the solder and the printing screen, there is a problem that shortage or excessive supply of the solder is likely to occur, or dirt is likely to occur, resulting in poor soldering such as disconnection or short circuit of the chip component with the lead electrode. .

Further, in such a reflow process, an appropriate amount of solder cannot be supplied according to the shape and size of each chip component. Normally, chip components mounted on printed circuit boards have different shapes and sizes, and the shape and size of lead electrodes also differ for each chip component, and the appropriate amount of solder differs for each chip component. Come.

However, in the conventional reflow method, cream solder is uniformly supplied to the pads of the printed circuit board in advance by printing regardless of such differences in chip components, so that the amount of solder for each chip component must be adjusted. It was difficult. For this reason, depending on the size and shape of the chip component, shortage or excessive supply of solder may occur, and there is a possibility that soldering failure or overrun may occur due to excessive solder.

As described above, the conventional mounting method in which chip components of various shapes are collectively soldered by the reflow method has a problem that soldering defects are likely to occur.

In the above-mentioned surface mounting chip component disclosed in Japanese Utility Model Application Laid-Open No. 2-38721, when the amount of supplied solder is large, the excess solder can be absorbed by the recess formed in the lead electrode. In this respect, it was possible to solve the problem of the conventional reflow method.

[0010] However, when the amount of supplied solder is small, the solder is absorbed into the concave notch of the lead electrode, so that the amount of solder necessary for bonding is rather insufficient. In addition, this actual practice 2-387
In the surface mount chip components of No. 21, the supply of solder is
The conventional reflow method of printing cream solder on the printed circuit board at once was adopted.

[0011] Therefore, in the chip component disclosed in Japanese Utility Model Application Laid-Open No. 2-38721, when the amount of supplied solder is small, there is a problem that soldering failure is more likely to occur, and the soldering accompanied with the solder printing on the printed circuit board side. There is still a possibility that printing drooling and bleeding may still occur, and the problem of the conventional reflow method has not been sufficiently solved.

The present invention has been proposed in order to solve the problems of the prior art. The present invention enlarges the surface area of a lead electrode of a chip component and applies an appropriate amount of solder to the lead electrode in advance. By supplying, it solves the problems of the conventional reflow method, enables appropriate solder supply according to each chip component, improves quality and reduces the number of mounting steps, and improves soldering reliability and reliability. The present invention relates to a chip component mounting method capable of achieving an improvement in productivity and a chip component used in this method.

[0013]

According to a first aspect of the present invention, there is provided a method of mounting a chip component, comprising the steps of: expanding a surface area of a lead electrode of the chip component; Supplying solder to the lead electrodes of the component, mounting the chip component supplied with the solder on a printed circuit board, melting the solder of the chip component mounted on the printed circuit board, and forming the lead on the printed circuit board. Bonding the electrodes.

According to the chip component mounting method of the present invention comprising the above steps, the surface area of the lead electrode of the chip component is enlarged so that a larger amount of solder plating can be easily performed on the electrode portion than usual. Becomes possible. Thereby, the amount of cream solder supplied to the printed circuit board side can be reduced or made unnecessary.

Further, by supplying solder to the lead electrodes of the chip components in advance, it becomes possible to supply an appropriate amount of solder corresponding to the shape and size of the lead electrodes of each chip component. Insufficient, excessive, or protruding amount of solder such as solder supply by printing is eliminated, and the quality can be improved and the number of mounting steps can be reduced.

According to a second aspect of the present invention, the step of enlarging the surface area of the lead electrode of the chip component is a step of forming a cutout in the lead through the lead electrode. In the third aspect, the step of enlarging the surface area of the lead electrode of the chip component is a step of forming the lead electrode into a waveform.

According to the chip component mounting method of the present invention comprising the above steps, a notch formed of a through hole or a comb-like slit is formed in the lead electrode, or the shape of the lead electrode itself is formed into a waveform. Accordingly, the solder supply area can be increased, and a large amount and appropriate amount of solder can be supplied to the electrode portion.

A chip component according to a fourth aspect is a chip component having one or more lead electrodes used in the chip component mounting method according to the first, second, or third aspect, wherein at least one of the lead electrodes is provided. One is provided with a notch penetrating the lead electrode, and solder is supplied to the lead electrode provided with the notch. According to claim 5, the notch is formed by one or more through holes. In claim 6, a plurality of slits are formed in a comb shape. Further, according to claim 7, the lead electrode is formed in a wave shape, and the solder is supplied to the lead electrode.

According to the chip component of the present invention having such a configuration, the surface area is increased by forming a through hole or a comb-shaped notch in the lead electrode of the chip component, or by forming the lead electrode itself in a waveform. Therefore, a large amount of solder can be supplied to the lead electrode, and the amount of cream solder supplied to the printed circuit board side can be eliminated or reduced.

Further, since the solder is supplied to the lead electrodes of the chip components in advance, it is possible to supply an appropriate amount of solder corresponding to the shape and size of the lead electrodes of each chip component, as in the conventional reflow method. Insufficient, excessive, or protruding amount of solder is eliminated.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a chip component mounting method of the present invention and a chip component used in this method will be described with reference to the drawings. First Embodiment First, a first embodiment of a chip component mounting method of the present invention and a chip component used in this method will be described. FIG. 1A is a plan view showing a state in which a chip component used in the chip component mounting method according to the first embodiment of the present invention is mounted on a printed circuit board, and FIG.
FIG.

As shown in FIG. 1, the chip component according to the present embodiment is a chip component mounted and mounted on a printed circuit board 10 and includes a component body 1 and a lead electrode 2. A plurality of lead electrodes 2 extend to the outside from both side surfaces. The lead electrode 2 is bent toward the printed circuit board 10 and
The electrode connection part 3 to be mounted and contacted is formed.

The electrode connection part 3 is mounted in a position aligned with the pad 4 on the printed circuit board 10, and is joined by soldering. The pads 4 of the printed circuit board 10 are connected to the printed circuit board 10 in advance by copper wiring.
It is formed in the upper predetermined position.

Here, details of the lead electrode 2 according to the present embodiment are shown in FIGS. 2A and 2B are enlarged views showing a state before the solder is supplied to the lead electrode 2 of the present embodiment. FIG. 2A is a partial cross-sectional side view of a main part, and FIG. 2B is a plan view of the main part. 3A and 3B are enlarged views showing a state in which solder is supplied to the lead electrode 2 shown in FIG. 2, wherein FIG. 3A is a partial cross-sectional side view of a main part, and FIG. 3B is a plan view of a main part.

As shown in these figures, in the present embodiment, a notch 5 made of a circular through hole is formed in the electrode connection portion 3 of the lead electrode 2. One cutout 5 formed of this through hole is formed substantially at the center of the electrode connection portion 3 and penetrates the electrode connection portion 3 in the vertical direction.

The notch 5 increases the surface area of the lead electrode 2 by an amount corresponding to the inner wall surface of the notch 5, and also provides a solder supply space in the hollow portion of the through hole formed by the notch 5, so that a large amount of solder is provided. Supply becomes possible.

The electrode connecting portion 3 having the cutout 5 is covered with a solder plating 6 as shown in FIG. The solder plating 6 is formed by immersing the electrode connection portion 3 in a previously melted solder.

Here, as a method of supplying the solder to the electrode connecting portion 3, in addition to the method of immersing the lead electrode 2 in the molten solder to form the solder plating 6, the solder is supplied to the lead electrode by electrolytic plating. There are methods.

However, the method of supplying solder by electrolytic plating is not necessarily suitable for mass production because of the long growth time and the necessity of controlling the plating current, electrolytic solution and the like. Therefore, in the present invention, a method of immersing the lead electrode 2 in molten solder is desirable, and this method is also employed in the present embodiment.

Next, the steps of the method for mounting a chip component according to the present embodiment having such a configuration will be described with reference to FIG. FIG. 4 is a schematic explanatory view showing the steps of the chip component mounting method of the present embodiment.

First, the surface area of the lead electrode 2 of the chip component is enlarged (the state shown in FIG. 4A). In the step of enlarging the surface area of the lead electrode 2, in the present embodiment, the notch 5 is formed in the electrode contact portion 3 of the lead electrode 2 by a circular through-hole vertically penetrating the electrode contact portion 3. Performed by As the formation of the notch 5,
It can be performed by means such as punching, cutting, and integral molding.

Next, solder is supplied to the lead electrode 2 of the chip component whose surface area has been enlarged (the state shown in FIG. 4B). As described above, the method of supplying the solder to the lead electrode 2 is performed by immersing the lead electrode in the molten solder to form the solder plating 6.

Next, the chip component on which the solder plating 6 has been applied is mounted on the printed circuit board 10 while the lead electrodes 2 are aligned with the pads 4 (the state shown in FIG. 4C). Finally, the printed circuit board 10 on which the chip components are mounted
Is heated to melt the solder plating 6 supplied to the lead electrode 2 of the chip component. As a result, the molten solder is connected to the lead electrode 2 of the chip component and the printed circuit board 1.
The pads 4 of 0 are connected to complete the mounting (the state shown in FIG. 4D).

As described above, according to the chip component mounting method of the present embodiment and the chip component used in this method, since the surface area of the lead electrode 2 of the chip component is increased, a larger amount of solder The plating 6 can be easily performed. Thereby, the amount of cream solder supplied to the printed circuit board 10 can be made unnecessary.

Further, since solder is supplied to the electrode portion in advance, the shape of the lead electrode 2 of each chip component,
An appropriate amount of solder corresponding to the size can be supplied, and the shortage, excessive amount, protrusion, and the like of the solder amount are eliminated, and the quality can be improved and the number of mounting steps can be reduced.

Thus, according to the chip component mounting method of the present embodiment, in addition to the case where no solder printing is performed on the printed circuit board 10 side as described above, it is possible to adjust a component having an appropriate amount of solder to a small amount. Even when a small amount of solder is supplied to the printed circuit board 10 by printing, a sufficient amount of solder is supplied in advance to the chip component side. The amount can be adjusted and supplied.

For example, a sufficient amount of solder can be secured even if the amount of solder supplied to the printed circuit board by batch printing is reduced in accordance with minute components such as semiconductors having a small amount of appropriate solder. Soldering can be performed.

Further, by eliminating the need to supply the solder by batch printing to the printed circuit board 10 side (or to reduce the amount of supplied solder), it is possible to eliminate defects caused by solder printing. In particular, the solder printing process on the printed circuit board side in the reflow process is a process in which solder printing, blurring, and the like are likely to occur and defects are likely to occur. The method is extremely advantageous in improving the quality, and also eliminates the need for an adjustment operation or the like when a solder defect occurs, leading to an improvement in productivity by reducing the number of steps.

In this embodiment, in order to increase the surface area of the lead electrode 2, a notch 5 having a circular through-hole shape is formed in the connection part 3. The invention is not limited to the embodiment, and various things can be adopted. For example, as shown in FIG. 5A, the through hole forming the notch 5 has a truncated conical shape, or as shown in FIG. 5B, a plurality of through holes having different diameters of a large diameter and a small diameter. May be combined.

Although not particularly shown, a plurality of notches 5 can be provided, and the shape is not limited to a circular through hole, but can be a square, an ellipse, or the like, and the surface area of the lead electrode 2 is increased. Any shape and size may be used as long as the shape and size can be adjusted.

Further, as a method of increasing the surface area of the lead electrode 2, in addition to the method of forming the notch 5 in the connection portion 3 shown in the present embodiment, for example, as shown in FIG. The shape of the second electrode connection part 3 itself can also be formed in a wave shape.

The various shapes of the cutouts 5 and the formation of the electrode connection portions 3 in a corrugated form can be used in an appropriate combination, and the surface area of the lead electrodes of the chip component can be increased. It is also possible to include a normal lead electrode that is not allowed.

[Second Embodiment] Next, a second embodiment of the chip component of the present invention will be described with reference to FIGS. 6A and 6B are enlarged views showing a state before solder is supplied to the lead electrodes 2 in the chip component according to the second embodiment of the present invention, wherein FIG. 6A is a plan view of a main part, and FIG. It is a front view. 7A and 7B are enlarged views showing a state in which solder is supplied to the lead electrode 2 shown in FIG. 6, wherein FIG. 7A is a plan view of a main part and FIG. 7B is a front view of a main part.

As shown in these figures, the chip component of this embodiment has substantially the same configuration as that of the above-described first embodiment, and the shape of the notch 5 provided in the electrode connection portion 3 is changed. It was done.

That is, in this embodiment, the electrode connecting portion 3
In addition, a plurality of slits are formed in a comb shape, and the comb-shaped slits constitute the notch 5. By providing the notch 5 in a comb shape in the electrode connection portion 3 as described above,
The surface area of the lead electrode 2 is increased. Then, solder plating 6 is applied to the electrode connecting portion 3 as in the case of the first embodiment described above.

According to the chip component of the present invention having such a structure, the surface area is increased by forming a comb-shaped notch in the lead electrode 2 of the chip component. It is possible to supply the solder, and it becomes unnecessary to supply the solder to the printed circuit board 10 side.
In particular, in this embodiment, since the notch 5 is formed by a plurality of slits, the surface area of the lead electrode 2 is further increased, and a larger amount of solder plating 6 can be supplied.

Also, since the solder plating 6 is supplied to the lead electrodes 2 of the chip components in advance, an appropriate amount of solder corresponding to the shape and size of the lead electrodes 2 of each chip component is provided as in the first embodiment. Supply becomes possible, and shortage, excess, protrusion, etc. of the amount of solder are eliminated.

[0048]

As described above, according to the chip component mounting method of the present invention and the chip component used in this method,
By increasing the surface area of the lead electrodes of chip components and supplying the appropriate amount of solder to the lead electrodes in advance, the problems of the reflow method can be eliminated, and the appropriate amount of solder supply required for soldering chip components can be reduced. By being adjustable, the reliability of soldering and the productivity can be improved, and the quality can be improved and the number of mounting steps can be reduced.

[Brief description of the drawings]

FIG. 1A is a plan view showing a state in which a chip component used in a method for mounting a chip component according to a first embodiment of the present invention is mounted on a printed circuit board, and FIG. It is.

FIGS. 2A and 2B are enlarged views showing a state before solder is supplied to a lead electrode of the chip component according to the first embodiment of the present invention, wherein FIG. FIG. 3 is a plan view of a main part.

FIG. 3 is an enlarged view showing a state where solder is supplied to the lead electrode shown in FIG. 2, and FIG.
(B) is a main part plan view.

FIG. 4 is a schematic explanatory view showing steps of a method for mounting a chip component according to the first embodiment of the present invention.

FIG. 5 is a main part side view showing a modified embodiment of the lead electrode of the chip component according to the first embodiment of the present invention, showing the lead electrode in a state before solder is supplied;

FIGS. 6A and 6B are enlarged views showing a state before supplying solder for lead electrodes in the chip component according to the second embodiment of the present invention, wherein FIG. 6A is a plan view of a main part, and FIG. It is a front view.

7A and 7B are enlarged views showing a state in which solder is supplied to the lead electrodes shown in FIG. 6, wherein FIG. 7A is a plan view of a main part and FIG. 7B is a front view of a main part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Component main body 2 Lead electrode 3 Electrode connection part 4 Pad 5 Notch 6 Solder plating 10 Printed circuit board

Claims (7)

[Claims] A step of enlarging the surface area of the lead electrode of the chip component; a step of supplying solder to the lead electrode of the chip component having the increased surface area; and mounting the chip component supplied with the solder on a printed circuit board. And melting the solder of the chip component mounted on the printed circuit board and joining the lead electrode to the printed circuit board. 2. The step of enlarging the surface area of the lead electrode of the chip component comprises the step of forming a cutout in the lead electrode, the cutout penetrating the lead electrode.
The mounting method of the described chip component. 3. The method according to claim 1, wherein the step of enlarging the surface area of the lead electrode of the chip component comprises the step of forming the lead electrode into a waveform. 4. A chip component having one or more lead electrodes used in the chip component mounting method according to claim 1, 2, or 3, wherein at least one of the lead electrodes penetrates the lead electrode. A chip component comprising a notch, and solder being supplied to a lead electrode provided with the notch. 5. The chip component according to claim 4, wherein the notch comprises one or more through holes. 6. The chip component according to claim 4, wherein the notch has a plurality of slits formed in a comb shape. 7. A chip component comprising at least one lead electrode used in the chip component mounting method according to claim 1, 2 or 3, wherein at least one of the lead electrodes has a wavy shape. A chip component wherein solder is supplied to a corrugated lead electrode.