JPS5874065A - Mounting structure for semiconductor device - Google Patents

Abstract

PURPOSE:To perform a high density mounting, by connecting the signal wire of each semiconductor device to the signal wire which corresponds to adjacent other device and connecting the signal wire for chip selection to the pattern for chip selection of a substrate. CONSTITUTION:A package 12 is contacted on the printed substrate 11 at the minimum surface part of a hexahedron, and the external lead wire of the package is soldered to chip selector terminals 13 on the substrate. The signal wire led out from a chip is connected to a conductive layer 14 on the package surface only by the wire of the same potential, common conductive layers are collected to a bakelite terminal plate 15, and common chip selector terminals are collected to a bakelite terminal plate 17 on the mounting end part for a package. When package end parts are fixed by terminal plates 15 and 17, a mounting can be securely performed. When insulating heat radiation plates 18 are respectively interposed among packages, the thermal radiation of the device becomes good, and the characteristic of device is stabilized resulting in the improvement of the reliability. Besides, stacks in multi stages via insulators are also available.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure for mounting semiconductor devices such as Lll on a printed circuit board at high density.

FIG. 1 shows a conventional mounting structure in which a large number of semiconductor devices such as LSIs are combined and mounted on a printed circuit board to form an electronic circuit or the like.

As shown in the figure, external lead wires 2 led out from an in-line seven-channel package with a semiconductor chip mounted are connected to a pattern 4 of a conductive layer such as solder in a predetermined pattern formed on a printed circuit board 8. It is installed in the substrate through matching through holes (not shown). However, if the packages are placed one by one on the printed circuit board 8 so that the widest part of the hexahedron of the rectangular parallelepiped is in contact with the printed circuit board, the number of packages that can be mounted on the printed circuit board will be reduced. .

Furthermore, the external lead wires coming out from the side of the package are formed into a predetermined pattern by terminals provided on the printed circuit board, that is, conductor layers, and are used as chip terminals for selecting the semiconductor chips in the package. It is connected to the power supply terminal for driving the semiconductor chip or to each terminal that connects to the signal line led out from the semiconductor chip, but it is better to connect the common conductors together for higher packaging density. To increase.

In the present invention, the package is installed on the printed circuit board so that the rectangular-shaped surface with the smallest area of the hexahedral pot shape that forms the package is in contact with the printed circuit board, and the common signal line is connected to the common terminal. It is an object of the present invention to provide a mounting structure for semiconductor devices in which semiconductor devices are mounted at high density on a printed circuit board in a manner such that they are connected to each other.

The mounting structure of the semiconductor device to achieve this purpose is as follows:
A semiconductor device is formed by accommodating a semiconductor chip in a cage, and mounting a plurality of semiconductor devices adjacent to each other on a substrate, each having a signal line led out from the chip on the surface, and each signal line is connected to another adjacent semiconductor device. Connected directly to the corresponding signal line of the semiconductor device,
It is characterized in that at least the signal lines for chip selection among the signal lines are respectively connected to the chip selection patterns provided on the substrate. An embodiment of the present invention will be described in detail below with reference to the drawings.

Figures 1 through 4 are perspective views showing one embodiment of the mounting structure of the semiconductor device of the present invention. A package 12 having a hexahedral structure is placed so that the surfaces of the hexahedron with the smallest surface area are in contact with each other. Chip select terminals 13 are soldered to the printed circuit board in a predetermined pattern to select the semiconductor chips in the package and write/read only those chips, and the external lead wires of the package come into contact with these terminals. Let's do it like this. As for the signal lines for deriving the signals obtained from the chip, only the signal lines of the same potential are connected from the terminal of the chip f signal line to the conductor layer 14 provided on the package surface by metallization in a predetermined pattern. The common conductor layers are then assembled into a terminal board 15 formed by, for example, paklyshi as shown in FIG. Here, reference numeral 16 in FIG. 8 is a collection of common chip select terminals and is formed on a bakelite terminal member 17 provided at the end of the package where it is mounted.

': By fixing the ends of the package mounted with the terminal board 15 and the terminal member 17 in this way, the mounting becomes more reliable.

As shown in FIG. 4, if an insulating heat dissipation plate 18 such as ceramic is sandwiched between the packages to be mounted, heat dissipation from the semiconductor device will be improved and the characteristics of the semiconductor device will be improved. A highly reliable mounting structure is formed.

Further, in spite of the above embodiments, it is also possible to stack packages in multiple stages and laminate them with insulating plates such as ceramics interposed therebetween.

Furthermore, although the above embodiments have been described using a ceramic package as an example, it is also possible to use a chip inner layer formed of an insulating substrate such as a ceramic vine.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the mounting structure of a conventional semiconductor device, and from the first intention up to FIG. 4 are diagrams showing the mounting structure of the semiconductor device of the present invention. In the cabinet, 1.12 is a package, 2 is an external Lee F18
indicates an insulating plate.

Claims (1)

[Claims] A semiconductor chip is housed in a package, and several semiconductor devices are mounted adjacently on a substrate, each having a signal line leading from the chip on the surface, and each signal line is
directly connected to the corresponding signal line of other semiconductor devices
A mounting structure for a semiconductor device, wherein at least a chip selection signal line among the signal lines is connected to a chip selection pattern provided on the substrate.