JPH0766524A - Printed board - Google Patents

Abstract

PURPOSE:To provide a printed board in the increased package density in the long direction by shortening the chip component interval keeping in-series arrangement state of chip components furthermore enhancing the solderability of the chip components onto a common land. CONSTITUTION:Within the printed substrate comprising two each of chip type circuit components arranged in-series, the two each of chip type circuit components are provided in almost contact state on a common land 20a capable of holding the electrical connection to the two each of chip type circuit parts in common. At this time, the common land 20a is provided to be protruded from both sides of respective two each of chip components 11a, 11b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board applied to various electronic devices, and more particularly to a printed circuit board in which chip-shaped circuit components are arranged in series.

[0002]

2. Description of the Related Art When a wiring pattern is formed on a substrate by using chip-shaped circuit components such as resistors and capacitors (hereinafter referred to as chip components), the higher the chip component mounting density, that is, the narrower the chip component spacing, Many chip components can be mounted on one board, and the board can be miniaturized. Figure 5 shows a small rectangular chip capacitor (chip component).
FIG. One of such rectangular chip capacitors
Two types of 2125 type chip capacitors 1
Is formed according to the standard shown in FIG. 5 having a length (L) of about 2 mm, a width (W) of about 1.25 mm and a thickness (t) of about 0.6 mm.

FIG. 6 shows a configuration in which chip components such as the capacitor 1 are arranged in series in the longitudinal direction. In particular, FIG. 6 (a)
Shows a plan view, and FIG. 6B is a sectional view taken along line XX ′ in FIG. In FIG. 6A, the solder (4 in FIG. 6B) is omitted in order to make the land arrangement particularly easy to understand. As shown in FIGS. 6A and 6B, the chip component 1a and the chip component 1b are provided on the lands 3a and 3b and the lands 3c and 3d, respectively, which are arranged on the printed circuit board 2.
The two chip components are soldered (solder: 4) and connected in series. In such a serial arrangement of the chip components 1a and 1b, when the above-mentioned 2125 type chip components are used, the distance between the center lines of the lands associated with the respective chip components (and thus the center lines between the respective chip components) is 3. For a chip component having a length of 5 mm and a length of 2 mm, the distance between the components is 1.5 mm.

[0004]

Each of the above chip parts 1
The spacing between a and 1b has conventionally been limited due to various restrictions due to board design accuracy including land pattern design component placement for optimizing the amount of solder, mounting accuracy of a mounting machine for mounting chip components on a substrate, and the like. It could not be made shorter than about 1.5 mm described above. Therefore, it is difficult to improve the mounting density in the conventional serial arrangement configuration of the chip components 1a and 1b as shown in FIG.

Further, as a matter of course, the soldering mounting of the chip component on the printed board is required to be solderable to the land on the printed board.

The present invention provides a printed circuit board in which chip components are arranged in series in the longitudinal direction to reduce the interval between the chip components to improve the mounting density and to improve the solderability of the chip components to the land. With the goal.

[0007]

A printed circuit board according to a first aspect of the present invention is a printed circuit board in which two chip-shaped circuit components are arranged in series. The two chip-shaped circuit components are provided in contact with each other on a common land capable of sharing electrical connection with each other, and when the two chip components are arranged on the common land, A common land is provided so as to project on both sides of each of the two chip components.

According to a second aspect of the present invention, in a printed circuit board according to the present invention, two chip-shaped circuit components which are in contact with each other on the common land are arranged in the entire length in the longitudinal direction, and predetermined soldering margins are provided on both sides in the longitudinal direction. It is characterized in that a length obtained by adding the lengths is set as a serial arrangement mounting length of the two chip-shaped circuit components.

[0009]

According to the printed circuit board of the present invention, the two chip-shaped circuit components are provided in contact with each other on a common land capable of sharing electrical connection with the two chip-shaped circuit components. Therefore, it is possible to suppress the component interval of the chip-shaped circuit components to almost zero, and the packaging density can be improved. Moreover, according to the present printed circuit board, when the two chip components are arranged on the common land, the common land is provided so as to project to both sides of the two chip components. The portion can be effectively applied to soldering, and the solderability on the side surface of the chip component can be improved.

According to the printed circuit board of claim 2, a predetermined soldering margin length is added to both sides in the longitudinal direction of the total length in the longitudinal direction of the two chip-shaped circuit components in contact with each other on the common land in series. Since the length is set to the mounting length of the two chip-shaped circuit components arranged in series, it is possible to suppress the component interval of the chip-shaped circuit components to almost 0, and further, to improve the solderability of the chip components arranged in series. It is possible to improve the mounting density in an improved state.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view for explaining a printed circuit board having a chip component serial arrangement according to the present invention. In particular, FIG. 1A shows two printed circuit boards arranged in series and mounted on paste-like solder. The high-density mounting state of the chip parts of
FIG. 1B shows a high-density mounting printed circuit board according to the present invention after soldering by a reflow method from the high-density mounting state of FIG. 1A. 2 is a sectional view taken along the line YY 'of FIG. 1 (b), and FIG. 3 is a sectional view taken along the line ZZ' of FIG. 1 (b).

First, as shown in FIG. 1A, a rectangular land 13a, a common land 20a, and a land 13b are provided on the printed circuit board 12 as pattern conductors, and the common land 20a has a length L1. A rectangular chip part 11a having a width W1 and a rectangular chip part 11b having a length L2 and a width W2 have one end at a common land 20a.
It is mounted via the solder paste 15 so as to be shared. On the other hand, the solder paste 15 is applied to the lands 13a and 13b at the other ends of the chip components 11a and 11b, respectively.
Is installed through. Width W3 of common land 20a
Is larger than the width W1 of the chip part 11a and the width W2 of the chip part 11b in order to improve the solderability on the side surface. In this embodiment, the common land 20a is slightly wider on one side than the chip parts 11a and 11b.
In the embodiment, the widths of the lands 13a and 13b are also equal to the width W3 of the common land 20a.

The chip components 11a and 11b are, for example, chip capacitors, and the distance W5 between the chip components 11a and 11b is the minimum distance for mounting the chip components on the paste-like solder. By using the common land 20a in this manner, a component interval of about 1/3 of the conventional one can be obtained by arranging two chip components in series.

Chip components are mounted in the serial arrangement shown in FIG. 1A, the printed circuit board is soldered by a normal reflow method, and higher density mounting is performed as shown in FIGS. 1B and 2. obtain. As shown in FIGS. 1B and 2, after the reflow soldering, the chip components are attracted by the surface tension of the melted solder during the reflow, and the chip components 11a
The chip component 11b and the chip component 11b are substantially in contact with each other at substantially the center of the common land 20a. In FIG. 1B, there is no gap between the chip components 11a and 11b, and the solder does not enter between the chips, and it is drawn as if the soldering becomes unstable. Since the portion where 11b contacts has fine irregularities, melted solder enters during reflow due to the capillary phenomenon, and there is no problem in solderability. Therefore, the chip component 1 shown in FIG.
Length L1 from the left end of 1a to the right end of chip component 11b
0 is a length that is a combination of the component lengths L1 and L2. Since the chip components 11a and 11b are in contact with each other substantially at the center in this manner, the length between the left end of the chip component 11a and the left end of the land 13a in FIG.
1. On the other hand, if the length between the right end of the chip component 11b and the right end of the land 13b is P2, the lengths P1 'and P2 corresponding to P1 and P2 in FIG. 'Is the chip component 11a and the chip component 11
It is longer than P1 and P2 by the distance W1 from b. P
If the total length of 1 ', L10 and P2' is L12, it is necessary to minimize L12 as much as possible in order to increase the mounting density of the series arrangement of the chip components 11a and 11b. L1
Since L2 and L2 are fixed, P1 'and P2' are minimized. To do this, set the lengths of P1 and P2 to 0, and set W1
Is the minimum value of the component mounting machine accuracy, for example, 0.5 mm in the case of the above 2125 type, so P1 'is 0.25 mm, P
2'is set to 0.25 mm.

The 0.25 mm portion of this land is shown in FIG.
As shown in FIG.
It serves as a soldering margin necessary for fixing 1a and 11b.
This soldering length can be selected as a predetermined length depending on the size of the chip component, the amount of solder, and the like. Further, the solder 14 rises from below and enters the gap between the contact parts of the chip components 11a and 11b. Therefore, the chip components 11a and 11
Although the contact state of the contact portion of b slightly changes depending on the surface state of the side surfaces of the chip components 11a and 11b, the chip components come close to each other and are almost in contact with each other by soldering such as ordinary reflow soldering.

In this way, the land 13a, the common land 20a, and the land 13b are arranged on the printed circuit board 12 so that L12 becomes L1 + L2 + W5.
By mounting 1a and 11b, it was possible to improve the high-density mounting of chip components arranged in series to an almost ideal level.

FIG. 3 is a sectional view taken along the line ZZ 'of FIG. As shown in FIG. 1B and FIG.
The side surfaces of the a and 11b are soldered (solder 14) by utilizing the regions expanded on both sides of the common land 20a, and the soldering of the chip components 11a and 11b to the common land 20a is made firmer. In this embodiment, the land 13a,
Similarly to the common land 20a, the width of 13b is also increased to improve the solderability of the chip component in the width direction as compared with the solderability of the chip component side surface in the length direction described above.

2 on common land after reflow soldering
The contact of the individual chip parts is performed approximately at the center of the common land as described above. Therefore, it is necessary to solder at least the contact portion and the side surface in the vicinity thereof particularly firmly.
FIG. 4 is a diagram for explaining common lands of various shapes according to the present invention, and in particular, FIG. 4 (a1), (b1), (c)
1) is a plan view, and FIG. 4 (a2), (b2), (c)
2) is a sectional view taken along the line AA ′ of FIG.
It is a BB 'sectional view of (b1), and CC' sectional view of FIG.4 (c1).

The common land 20b shown in FIG. 4 (a1) has its side portions outside the chip parts 11a and 11b (both sides).
In the common land 20b region protruding in a curved shape, the soldering (solder 14) is firmly performed (FIG. 4 (a2)). Similarly, FIG. 4 (b1)
In this case, a common land 20c having side portions projecting outward in a triangular shape from the chip parts 11a and 11b is provided, and soldering is firmly performed in the projecting region (see FIG.
2)), and in FIG. 4 (c1), the chip components 11a and 11b.
Common land 20 protruding from the outside in a symmetrical stepwise manner
d is provided, and soldering is firmly made in the protruding region (FIG. 4 (c2)).

As described above, in order to improve solderability, FIG. 1 (b), FIG. 4 (a1), FIG. 4 (b1), FIG.
Although the common land having the shape shown in (c1) is used, the shape is not limited to these shapes and any other shape having a similar function can be used. In this case, the protruding length on one side is selected according to the shape of the chip component, the size of the electrode portion, and the like.

[0022]

As described above, according to the present invention, 2
Since the individual chip components are arranged in series so that they are almost in contact with each other, the mounting density of the chip components arranged in series can be further improved, and a printed circuit board with improved solderability can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view for explaining a printed circuit board in which chip components are arranged in series according to the present invention.

FIG. 2 is a sectional view taken along line YY ′ of FIG.

FIG. 3 is a sectional view taken along line ZZ ′ of FIG.

FIG. 4 is a diagram for explaining various common lands according to the present invention.

FIG. 5 is a perspective view for explaining the shape of a chip capacitor.

FIG. 6 is a diagram showing a printed circuit board in which chip components are arranged in series by a conventional mounting method.

[Explanation of symbols]

 1a, 1b, 11a, 11b Chip parts 2, 12 Printed circuit boards 3a, 3b, 3c, 3d, 13a, 13b Land 14 Solder 15 Solder paste 20a, 20b, 20c, 20d Common land

Claims (2)

[Claims] 1. A printed circuit board in which two chip-shaped circuit components are arranged in series, wherein the two chips are mounted on a common land that can share electrical connection with the two chip-shaped circuit components. Circuit components are provided in a state of being in close contact with each other, and when the two chip components are arranged on the common land, the common land projects on both sides of each of the two chip components. A printed circuit board characterized by being provided. 2. A length obtained by adding a predetermined soldering allowance length on both sides in the longitudinal direction to the total length in the longitudinal direction of the serial arrangement of the two chip-shaped circuit components in contact with each other on the common land. The printed circuit board according to claim 1, wherein the chip-shaped circuit components are arranged in series and mounted.