JPH066021A - Pattern configuration for soldering land - Google Patents

Abstract

PURPOSE:To conduct a reliable soldering operation without generation of a phenomenon which develops to an obstacle in a printed wiring board and the like, and to obtain the pattern configuration for the soldered land formed into suitable shape for the chip type electronic part especially for surface mounting. CONSTITUTION:The title pattern configuration of soldering land contains a printed circuit board used to mount on the same surface the surface mounting part, such as multipin-formed and narrow-pitch lead-wired QFP and the like, and a surface mounting cylindrical chip part 4, a soldering land 2 of desired shape to be used for the chip part 4 provided on the appropriate part on the printed circuit board, and a cream solder printing region having the prescribed area and containing the soldering land 2. The desired shape of the soldering land 2 is the shape in which the fused cream solder 3 is collected in the center of the land.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention enables a reliable soldering work in a printed wiring board without causing an obstacle, and is particularly suitable for a chip type electronic component for surface mounting. The present invention relates to a pattern shape of a soldering land, which has a preferable shape.

[0002]

2. Description of the Related Art As a chip type electronic component for surface mounting, a square type or a cylindrical type has been conventionally used, and a pattern of a soldering land for that purpose is as shown in FIG. Has been used. First, in FIG. 5A, a pair of conductive patterns 1
Square soldering lands 2 are provided on the opposite tip portions of the above, and a required solder resist 6 is applied except for the (adhesion) region 2A including the soldering lands 2. Next, in FIG. 5B, after printing an appropriate amount of cream solder 3 on the rectangular soldering land 2, the necessary chip type electronic component 4 (in this conventional example, a cylindrical type) is obtained. , But at this time the electrodes 4 on both ends
A is placed on the soldering land 2 at an appropriate position. Then, FIG. 5C shows a conventional example after the reflow process is performed. As can be seen here, the chip-type electronic component 4 is connected by the solder 5 made of an appropriate material and placed on the soldering land 2. Although the soldering land 2 is rectangular in this conventional example, for example, according to Japanese Utility Model Publication No. 3-51989, the mounted chip has a shape and an arrangement of a pair of effective soldering lands. The longitudinal direction of the electronic component is slanted with respect to the mounting position of the electronic component so that the positional deviation of the electronic component can be absorbed, and the reliability of soldering is improved accordingly.

By the way, in the case of the conventional example as shown in FIG. 5, in order to absorb the positional deviation of the mounted chip type electronic component and to increase the solder leak surface to the electrode of the component, the soldering land is used. Is larger than the size of the electrode portion. However, when the chip-type electronic component is of a cylindrical type, there is a gap on the lower side of this component, so that the amount of solder used from the solder entering there is large, and the shape of the component itself is Therefore, the connection area with the soldering land is reduced, and the reliability of the connection becomes uncertain. Further, in the case of the above-mentioned publication, when the adhesive for temporarily fixing the component cannot be used, it becomes impossible to absorb the positional deviation when the component is mounted. In addition, since the self-alignment effect at the time of reflow work for soldering cannot be expected, it is easy for displacement to occur due to the vibration generated at the time of this reflow work, and a so-called chip standing phenomenon (tombstone phenomenon) occurs. It becomes easier to get up.

Recently, due to the increase in the number of QFP pins, the narrower pitch of lead wires, the increase in the number of mounted parts, and the like, the number of electronic devices in which various electronic parts are mounted in high density has increased. In such a case, QFP, SOP, various chip parts, etc. are mounted on the same printed wiring board. Further, in the printing of cream solder which is usually used, in order to prevent the bridging of the QFP described above, the printing is performed by adjusting the application amount of the cream solder to the QFP, and from this fact, it is possible to connect the chip components. Therefore, the amount of solder used is reduced. In addition, for high density as described above,
The area of the soldering land used tends to be small, and the amount of solder for connection is reduced accordingly, which causes concern about the reliability of connection of components to the board.

[0005]

As described above, in the above-mentioned prior art, in order to absorb the positional deviation of the mounted chip type electronic component and to increase the solder leak surface for the electrode of the component. The area of the soldering land is made larger than the area of the electrode part, but when the electronic part is a cylindrical type, it is used for the solder to enter the gap under the part. As the amount of solder to be applied increases, the connection area with the soldering land decreases due to the shape of the component itself, and there is concern about the reliability of the connection. Further, in the above-mentioned publication, if the adhesive for temporarily fixing the component cannot be used, it becomes impossible to absorb the positional deviation when the component is mounted. Furthermore, since the self-alignment effect at the time of reflow work for soldering cannot be expected, the positional deviation easily occurs due to the vibration generated at this time, and so-called chip standing phenomenon (tombstone phenomenon) easily occurs. There were some problems.

The present invention has been made to solve the above-mentioned problems, and in a printed wiring board,
It is possible to provide a reliable soldering work without causing an obstacle, and to provide a pattern of a soldering land which has a shape suitable for a chip-type electronic component for surface mounting. That is the purpose.

[0007]

The pattern shape of the soldering land according to the present invention includes: a surface mounting component such as QFP having a large number of pins and a narrow lead pitch, and a cylindrical chip component for surface mounting. A printed circuit board for mounting on the same surface; a soldering land of a desired shape for the chip component, which is provided in a proper place on the printed circuit board; and a cream solder of a required area including a portion of the soldering land. A pattern shape of a soldering land including a print region; wherein the desired shape of the soldering land is a shape in which the melted cream solder gathers in the center of the land.

[0008]

In the pattern of the soldering land according to the present invention, the land for the surface mounting component such as QFP is provided by providing the cream solder printing area having a required area including the soldering land for the chip component. Compared to
A large amount of cream solder can be applied on and around the soldering land for the chip component. Moreover, since the soldering land for the chip component has a shape in which the melted cream solder gathers in the center of the land, according to the pattern shape of the soldering land according to the present invention,
It is possible to mount a surface mounting component such as QFP having a large number of pins and a narrow lead wire pitch and a surface mounting cylindrical chip component on the same surface of the printed circuit board. And, for this reason, it is possible to enable a reliable soldering work without causing an obstacle.
In particular, there is an advantage that the shape is suitable for a chip-type electronic component for surface mounting.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic explanatory view of an embodiment of a pattern shape of a soldering land according to the present invention. First, in FIG. 1 (A), substantially triangular soldering lands 2 (provided that the tips of the arrows face each other) are provided at the opposing tips of the pair of conductive patterns 1. The required solder resist 6 is applied except for the substantially rectangular region 2A that includes it. Next, in FIG. 1B, after the cream solder 3 is printed on the substantially triangular soldering land 2, a pair of electrodes 4A of a necessary chip type electronic component 4 (here, a cylindrical type) is formed. Are mounted so as to face the soldering lands 2.

FIG. 2 is another schematic illustration of the pattern shape of the soldering land according to the above embodiment. First, Figure 2
In (A), a substantially triangular soldering land 2 is provided at the end portions of the pair of conductive patterns 1 facing each other (so that the tips of the arrows face each other). The required solder resist 6 is applied except for the shape region 2A. Next, in FIG. 2B, substantially triangular soldering lands 2 are provided (opposite triangular bases face each other) at the opposing tips of the pair of conductive patterns 1. The required solder resist 6 is applied except for the substantially rectangular region 2A including the.

FIG. 3 is another schematic illustration of the pattern shape of the soldering land according to the above embodiment. First, Fig. 3
In (A), a pair of conductive patterns 1 are provided with substantially triangular soldering lands 2 at their opposite ends (so that the bases of the triangles face each other). The required solder resist 6 is applied except the region 2A having the shape. Next in FIG.
In (B) of FIG.
After the cream solder 3 is printed on top, a pair of electrodes 4A of the necessary chip-type electronic component 4 (here, cylindrical type)
Are mounted so as to face the soldering lands 2.

FIG. 4 is still another schematic illustration of the pattern shape of the soldering land according to the above embodiment. First, in FIG. 4A, substantially circular (or elliptical) soldering lands 2 are provided at the opposing tips of the pair of conductive patterns 1, and a substantially rectangular region including the soldering lands 2 is provided. The required solder resist 6 is applied so that 2A is formed. Next, in FIG. 4B, substantially circular (or elliptical) soldering lands 2 are provided at the opposing tips of the pair of conductive patterns 1, and a similar shape including the soldering lands 2 is provided. Area 2A
The required solder resist 6 is applied so that In the subsequent FIG. 4C, the cream solder 3 is printed on the substantially circular (or elliptical) soldering land 2 for the shape shown in FIG. 4B. , The pair of electrodes 4A of the necessary chip-type electronic component 4 (here, a cylindrical type) is the soldering land 2
It is mounted so as to face. Also, FIG. 4 (D)
4 shows a modified example in the case of FIG. 4 (B). That is, an appropriate number (four in this case) of the convex portions 2B are provided on the substantially circular (or elliptical) soldering land 2, and the solder used for adhering the components is the soldering land 2. It is made easy to gather in the central portion of the region 2A having a similar shape including the region. Further, FIG. 4E also shows a modification of the case of FIG. 4B. That is, an appropriate number (here, three) of cusps 2 are provided on the substantially circular (or oval) soldering land 2.
C is provided, and the solder used for bonding the parts is a region 2A having a similar shape including the soldering land 2.
It is designed to be easy to gather in the central part of the.

[0013]

As described in detail above, the pattern shape of the soldering land according to the present invention is: surface mounting parts such as QFP in which the number of pins is increased and lead wires are narrowed in pitch, and surface mounting parts. A printed circuit board for mounting a cylindrical chip component on the same surface; a soldering land of a desired shape for the chip component, which is provided at a proper position on the printed circuit board; and a portion of the soldering land. A pattern shape of a soldering land including a cream solder printing area of a required area; wherein the desired shape of the soldering land is a shape in which molten cream solder gathers in the center of the land. It is a thing. Further, since it has such a configuration, it is possible to enable reliable soldering work without causing various obstacles, which is particularly suitable for chip-type electronic components for surface mounting. It has a unique shape, which has advantageous results.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an embodiment of a pattern shape of a soldering land according to the present invention.

FIG. 2 is another schematic illustration of the pattern shape of the soldering land according to the above-mentioned embodiment.

FIG. 3 is another schematic illustration of the pattern shape of the soldering land according to the above embodiment.

FIG. 4 is still another schematic exemplification of the pattern shape of the soldering land according to the embodiment.

FIG. 5 is an exemplary view of a pattern shape of a conventional soldering land for a printed wiring board.

[Explanation of symbols]

 1: Conductive pattern; 2: Soldering land; 2A: (Adhesive) area; 3: Cream solder; 4: (Chip type) electronic component; 4A: Electrode; 5: Solder; 6: Solder resist;

Claims (1)

[Claims] 1. A Q having a large number of pins and a narrow lead wire pitch.
A printed circuit board for mounting a surface-mounting component such as FP and a surface-mounting cylindrical chip component on the same surface; a soldering land having a desired shape for the chip component provided in an appropriate place on the printed circuit board. And a pattern shape of a soldering land including a required area of the solder paste printing area including the portion of the soldering land; wherein the desired shape of the soldering land is the melted cream solder. Pattern shape of the soldering land, characterized in that