JPH07254766A - Printed wiring board - Google Patents

Abstract

PURPOSE:To increase the packaging density by a method wherein the first surface packaging part is packaged on an inner layer wiring pattern exposed by a notch while the second surface packaging part is packaged on the surface of the wiring pattern so as to cover the first surface packaging part so as to laminatedly package the first second packaging parts. CONSTITUTION:A notch 12 is partly made on a board 2 having a wiring pattern exceeding two layers thereon so as to expose an inner layer wiring pattern 13 so that the first surface packaging part 19 may be packaged on this exposed inner layer wiring pattern 13 as well as to package the second surface packaging part 20 is to be packaged on the surface of the wiring patterns 7, 8 so as to cover the first surface packaging part 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board having a wiring pattern of two or more layers (multilayer wiring pattern).

[0002]

2. Description of the Related Art Generally, a printed wiring board having a multilayer wiring pattern shown in FIG. 2 is known. Figure 2
In FIG. 1, reference numeral 1 is a printed wiring board, which is composed of three stacked substrates 2, 3, and 4. The wiring pattern 5 on the substrate 2
6, 7, and 8 are provided, and wiring patterns (not shown) are also provided on the substrates 3 and 4. The lead type component 9 is soldered to the wiring patterns 5 and 6, and the wiring patterns 7 and 8
The surface mount component 10 is mounted on the board with the cream solder 11. The wiring patterns 6, 7 and 8 described above are connected to the wiring patterns of the substrate 2 or 3 by through holes.

[0003]

As described above, in the conventional printed wiring board having the multilayer wiring pattern, the components 9, 10 can be mounted only on the wiring patterns 5, 6, 7, 8 on the surface. However, the components cannot be stacked and mounted, and therefore the mounting density cannot be increased sufficiently. The present invention aims to eliminate the above-mentioned drawbacks.

[0004]

In order to achieve the above object, the printed wiring board of the present invention is a printed wiring board having a wiring pattern of two or more layers, in which the substrate provided with the wiring pattern on the surface is partially formed. Are cut out to expose the inner layer wiring pattern, the first surface mounting component is mounted on the exposed inner layer wiring pattern, and the second surface mounting component is provided on the surface so as to cover the first surface mounting component. It is characterized by being mounted on the wiring pattern.

[0005]

By mounting the first surface mounting component on the exposed inner layer wiring pattern and mounting the second surface mounting component on the surface wiring pattern so as to cover the first surface mounting component, Since the first surface mounting component and the second surface mounting component can be stacked and mounted, the mounting density can be increased.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a schematic sectional view showing a printed wiring board. In this figure, the same symbols as those in FIG. 2 have the same effect. Reference numeral 12 denotes a cutout, which partially cuts out the substrate 2 on which the surface wiring patterns 7 and 8 are provided. The inner layer wiring patterns 13 and 14 provided on the substrate 3 are exposed from the notches 12. Reference numeral 19 is a first surface mounting component, and 20 is a second surface mounting component. The first surface mounting component 19 is mounted on the inner layer wiring patterns 13 and 14 exposed by the cutouts 12 and the first surface mounting component 19 is mounted. A second surface mount component 20 is mounted on the surface wiring patterns 7 and 8 so as to cover the surface mount component 19. Reference numeral 16 denotes cream solder.

In the above-described embodiment, the cutout 12 is provided with the opening in the substrate 2, but the cutout 12 may be a cutout near the edge of the substrate 2. Further, the cutout 12 may be provided in the substrates 2 and 3.

[0008]

Since the present invention is configured as described above, the first surface mounting component is mounted on the exposed inner layer wiring pattern, and the second surface mounting component is covered with the second surface mounting component. By mounting the surface mounting component of (1) on the wiring pattern on the surface, the first surface mounting component and the second surface mounting component can be stacked and mounted, so that the mounting density can be increased.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a printed wiring board showing an embodiment of the present invention.

FIG. 2 is a perspective view illustrating a conventional printed wiring board.

[Explanation of symbols]

 2, 3 Substrate 7, 8 Surface wiring pattern 12 Notch 13, 14 Inner layer wiring pattern 16 Cream solder 19 First surface mounting component 20 Second surface mounting component

Claims (1)

[Claims] 1. In a printed wiring board having a wiring pattern of two or more layers, the substrate on the surface of which the wiring pattern is provided is partially cut out to expose the inner layer wiring pattern,
The first surface mounting component is mounted on the exposed inner layer wiring pattern, and the second surface mounting component is mounted on the wiring pattern on the surface so as to cover the first surface mounting component. Wiring board.