JPH0482252A - Mounting structure of semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To realize a high-density mounting operation by a method wherein a ground interconnection layer protrudes over the whole outer-circumferential side face of a package substrate and this protruding part is connected electrically to a surface pad of a ground layer on a printed-circuit board. CONSTITUTION:A ground interconnection layer 1 is set in a buried state nearly over the whole face inside an insulating package substrate 3. The ground interconnection layer 1 is buried and attached so as to protrude nearly uniformly over the whole side face (four side faces in the case of a square substrate) of the package substrate 3. Said protruding part of the ground interconnection layer 1 is connected electrically, by using a grounding connection member 2, to a ground surface pad 8 of a ground interconnection layer 12 on a printed- circuit board 9.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a semiconductor integrated circuit mounting structure, and more particularly to a mounting structure including a package for housing a multi-pin semiconductor integrated circuit.

Prior Art In the conventional mounting structure of this type of package, the ground terminal, which serves as the reference for the signal potential, has the same shape as the signal terminal. are connected by soldering etc.

FIG. 4 shows a partial longitudinal sectional view of such a package mounting structure. Semiconductor integrated circuit chip (hereinafter referred to as 1c chip)
5 is mounted on the main surface of the insulating package substrate 3.

Input/output pins 51 of this IC chip 5 are connected to the package internal conductor wiring pattern 4 via connection lines 6.

This wiring pattern 4 is attached to the package substrate 3 in a protruding manner and is connected to the one-tone wire ]0.

This lead wire 10 is connected to a surface pad 7 on a printed circuit board 9 by soldering. This printed circuit board 9 is provided with wiring patterns 11 and 12 having a multilayer structure.
A surface pad 7 is printed and arranged on the surface of this printed circuit board 9.

In such a conventional IC package mounting structure, when the number of signal terminals of the IC chip 5 to be housed and mounted increases and the configuration becomes a multi-pin configuration, it is necessary to suppress the operation noise of the ground terminal, which is the reference of the signal potential. , a large number of ground terminals are required in proportion to the number of signal terminals. Therefore, I.C.
The disadvantage is that the package becomes larger, which impedes high-density mounting on printed wiring boards.

Furthermore, if only the number of signal terminals is increased without increasing the number of ground terminals in order to prevent the package from becoming larger, the electrical operation of the signal terminals will cause operational noise to be superimposed on the ground terminal, reducing the reliability of circuit operation. There is a drawback that it does. In particular, when the circuit is operated at high speed, there is a disadvantage that the reliability decreases significantly.

OBJECTS OF THE INVENTION An object of the present invention is to provide a semiconductor integrated circuit mounting structure in which the number of ground terminals is substantially increased, which would otherwise lead to an increase in the size of the package, thereby improving the reliability of the circuit.

Structure of the Invention According to the present invention, there is provided an insulating package substrate on which a semiconductor integrated circuit chip is mounted, a lead wire attached to the package substrate in a protruding manner and connected to an input/output bin of the chip, and a lead wire connected to the lead wire. A semiconductor integrated circuit mounting structure comprising: a printed circuit board having a surface pad;
a ground layer made of a conductor embedded in the insulating package substrate and protruding substantially uniformly from a side surface of the package substrate; and between the protrusion of the ground layer and the ground butt of the surface butt of the printed circuit board. and a ground connection member electrically connected to the ground connection member.

Example The present invention will be described in detail below using the drawings.

FIGS. 1 and 2 are partial vertical cross-sectional views of an embodiment of the present invention, with different cross-sections.

In both figures, parts equivalent to those in FIG. 4 are indicated by the same reference numerals.

Regarding the difference from the conventional example shown in FIG. 4, the ground wiring layer 1 is buried almost entirely within the insulating package substrate 3. It is assumed that the ground wiring layer 1 is embedded and attached so as to protrude substantially uniformly from all sides of the package substrate 3 (four side surfaces in the case of a rectangular substrate).

The protruding portion of the ground wiring layer 1 and the ground surface pad 8 of the ground wiring layer 12 of the printed circuit board 9 are electrically connected by a ground connecting member 2 .

FIG. 3 shows a state in which this ground connection member 2 is separated from the mounting structure shown in FIGS. It is fixed by soldering to 8.

Note that the other structures are the same as the conventional example shown in FIG. 4, and their explanation will be omitted.

Effects of the Invention In this way, the ground wiring layer 1 is made to protrude over the entire outer peripheral side surface of the package substrate 3, and this protrusion and the printed circuit board 9
The ground layer] 2 is connected to the surface pad 8 by soldering, etc., so even if the number of signal terminals increases, there is no need to increase the number of ground terminals accordingly, making high-density mounting possible. .

At the same time, the connection area with the ground increases, and all signal pins come close to the ground, so the IC
Less susceptible to chip operation noise.

[Brief explanation of drawings]

1 and 2 are longitudinal cross-sectional views of an embodiment of the present invention, FIG. 3 is a vertical cross-sectional view of the clamp member shown in FIGS. 1 and 2, cut away, and FIG. 4 is a conventional IC chip. FIG. 3 is a vertical cross-sectional view showing the mounting structure. Explanation of symbols of main parts 1,] 2...Ground wiring layer 2...Ground connection member 3...Package board 5...IC chip 6... ... Connection wire 7.8 ... Surface pad 10 ... Lead wire 51 ... IC pin Applicant: NEC Corporation (1 other person)

Claims (1)

[Claims] (1) A printed circuit board having an insulating package substrate on which a semiconductor integrated circuit chip is mounted, a lead wire attached to the package substrate in a protruding manner and connected to the input/output pin of the chip, and a surface pad connected to the lead wire. a semiconductor integrated circuit mounting structure including a substrate, a ground layer made of a conductor embedded in the insulating package substrate and protruding substantially uniformly from a side surface of the package substrate; and a protruding portion of the ground layer. and a ground connection member that electrically connects the ground pad of the surface pad of the printed circuit board.