JPS6125240B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a high-density mounting structure that saves plane space when mounting circuit elements such as ICs on a printed circuit board and minimizes the wiring distance between circuit components. Conventionally, when mounting circuit components such as ICs on a printed circuit board, the circuit components are placed flat on the surface of the printed circuit board. However, with this mounting structure, there is a limit to the saving of the flat space required for mounting. ,
If planar space is limited, an alternative high-density mounting structure is desired. Furthermore, when the chips are arranged on a plane, the wiring between the chips becomes long, which results in the inability to satisfy the demand for higher speed systems. The present invention is intended to fulfill this need, and aims to provide a high-density packaging structure that can significantly save planar space and minimize the wiring length between chips. Embodiments of the invention will now be described with reference to the drawings. The present invention exposes a circuit component connection terminal section on each peripheral surface under a printed circuit board that has a circuit component connection terminal section on the top surface and has an internal wiring pattern formed thereon, and connects a large number of facing printed circuit boards. By stacking, each printed circuit board is formed into a prismatic base to which three-dimensional wiring is connected, and a terminal portion for signal and power connection is formed on the bottom surface of the base for conduction through the patterns formed on each printed circuit board. However, circuit components can be mounted on the upper surface and each peripheral surface of the base. Next, the structure and manufacturing method will be explained in detail. FIG. 1 is an exploded perspective view showing the outline of the base body 1, which includes a large number of printed circuit boards 2 ₁ , 2 ₂ , 2 ₃ , . . .
..., 2 _o are stacked on top of each other. A terminal portion 3 for connecting circuit component terminals is provided on the upper surface of the printed circuit board ₂₁ . Further, the printed circuit boards 2 ₂ , 2 ₃ , . . . 2 _o are each provided with circuit component terminal connection terminal portions 4 exposed on their respective peripheral surfaces in a predetermined arrangement. These terminal portions 4 can be formed by a method such as forming a pattern on the end face using a conventional green sheet manufacturing method, baking and polishing the green sheet to form a pad using a thin film or screen printing. The lower surface of the printed circuit board _2o is provided with a plurality of signal and power connection terminals (not shown in detail), and the terminals are connected to each terminal section 3 and 4 through the patterns formed on each printed circuit board. Conductive. Since the terminal parts 3 and 4 are formed on the top surface and each peripheral surface of the base 1 in this way, the circuit components 5 are formed on the top surface and each peripheral surface of the base 1 as shown in FIG.
can be mounted by connecting each terminal portion 6 to the terminal portions 3 and 4. FIG. 3 shows another method for mounting circuit components on the base 1. As shown in FIG. In this example, the circuit component 5 is mounted on the top surface of the base 1 as in the case of FIG.
A printed circuit board 7 on which circuit components 5' are mounted is attached to each peripheral surface of the base 1. A terminal portion 4' is exposed on the opposite side of the printed circuit board 7 from the side on which the circuit component 5' is mounted, and the printed circuit board 7 is mounted by connecting this terminal portion to the terminal portion 4 on the peripheral surface of the base body 1. FIG. 4 shows a state in which the circuit components 5 and the printed circuit board 7 have been completely installed. A comparison of the planar space when such a mounting structure is adopted and when circuit components are mounted two-dimensionally on a printed circuit board as in the past is as follows. Assuming that the dimensions of the circuit components are S x S and the mounting pitch is 2S, the planar space required to arrange four circuit components side by side in the conventional method is shown by the chain line in Figure 5a. The area of the enclosed area is 4S x 4S = 16S ² . 5'' in the figure is a circuit component.On the other hand, the planar space required to arrange the circuit components 5 at the same pitch on each substrate surface according to the method of the present invention is within the range shown by the chain line in FIG.
The area is, for example, 5S x 5S = 25S ² . Here
5S is the standard pitch required for arranging substrates with circuit components mounted on them. In the former case, four circuit components 5" are mounted in 16S ² , so the planar space per one is 16S ² /
4 = 4S ² , and in the latter case, 4×5=20 circuit components 5 are mounted in 25S ² , so the planar space for each component is 25S ² /20=5/4S ² . In other words, in the case of the method of the present invention, the plane space is

It is possible to make [Formula]. In Figures 1 to 5, two stages of circuit components are arranged in that direction by stacking Z _o circuit boards, but in other application examples, two or more stages can be mounted with the same number of stacks _Zo . It becomes possible. An example of three stages is shown in FIGS. 6a and 6b. 6th
Figure a is a perspective view of the completed state, and Figure 6b is a perspective view showing how to stack the printed circuit boards. In this case, the mounting density is 4 x 6 + 4 in the area of 5S x 5S, since the occupied area does not change on a plane.
=28Y circuit components will be installed. The ratio with flat mounting is

[Formula] becomes. As described above, according to the present invention, it is possible to significantly save the planar space required for mounting circuit components, and it is particularly effective when there is no height restriction and it is desired to save the planar space. Further, according to the present invention, since the wiring between chips is performed within a three-dimensional base, the wiring length can be kept to a minimum.

[Brief explanation of the drawing]

The drawings show an embodiment of the high-density mounting structure according to the present invention. Fig. 1 is an exploded perspective view of the base, Fig. 2 is a perspective view showing the procedure for mounting circuit components, and Fig. 3 is an example of mounting other circuit components. FIG. 4 is a perspective view showing the completed assembly state; FIGS. 5 a and b are comparative illustrations of the required mounting plane space between the conventional method and the method of the present invention; FIGS. 6 a and b are diagrams showing the required mounting plane space. This is a perspective view showing another application example, in which 1 is a base, 2 ₁ , 2 ₂ ,
. . . , 2 _{o and} 7 are printed circuit boards, 3 and 4 are terminals for connecting circuit components, 5, 5', 5'' and 5 are circuit components, and 6 is a terminal section.

Claims (1)

[Claims] 1 Underneath the printed circuit board that has a terminal section for connecting circuit components on the top surface and has an internal wiring pattern formed thereon, terminal sections for connecting circuit components are exposed on each peripheral surface, and a number of printed circuit boards facing each other are stacked. forming a prismatic base body to which three-dimensional wiring connections are made between the respective printed circuit boards, and forming terminal portions for signal and power supply connection on the lower surface of the base body for conduction through the patterns formed on the respective printed circuit boards; A high-density mounting structure characterized in that circuit components can be mounted on the upper surface and each peripheral surface of the base.