JPH07282218A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To reinforce a GND line and to eliminate the need for the GND layer of a printed wiring board by electrically connecting the GND pin of an LSI package mounted on the printed wiring board to a housing through a conductive member. CONSTITUTION:The printed wiring board 3 mounted with the LSI package 2 is stored in the housing consisting of a metallic plate 6 such as an Al thin plate and a core 7. The metallic plate 6 is adhered to the core 7 through, for example, a heat-pressing bonding sheet. This memory card 1a is constituted by bending the GND pin among pin (lead) constituting the external terminals of the LSI package 2 mounted on the printed wiring board 3 toward the metallic plate 6 and directly connecting its tip to the reverse surface of the metallic plate 6. In this case, the GND pin and the reverse surface of the metallic pin 6 are coated with solder paste in advance, and the temperature of the heat- pressing bonding of the metallic plate 6 to the core 7 is set to the fusion temperature of solder, thereby soldering the pin to the reverse surface of the metallic plate 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit device, and is particularly effective when applied to a thin semiconductor integrated circuit device such as a memory card in which a printed wiring board on which an LSI package is mounted is housed in a thin housing. It is about technology.

[0002]

2. Description of the Related Art In thin electronic devices such as notebook type personal computers and electronic notebooks, a memory card (sold separately) is used as a means for increasing the memory of the main body.

A memory card has a structure in which a printed wiring board on which an LSI package such as DRAM or SRAM is mounted is housed in a thin casing, and this memory card is used as a main body of a notebook type personal computer when a memory is added. Implement and use. Note that the technology for mounting notebook computers and electronic notebooks is described in "Electronic Materials (September 1992)" p37-p51 issued by the Industrial Research Committee.

In order to prevent the electrostatic discharge damage of the LSI package mounted on the printed wiring board, the memory card usually has a case in which a part of the housing is made of metal, and a ground potential line or the like provided on the printed wiring board. Reference potential line (hereinafter referred to as GND
One end (referred to as a line) (GND pad) and the housing are electrically connected via a metal spring member or the like.

[0005]

However, the printed wiring board used in the above-mentioned memory card has a signal layer,
Since it has a multilayer wiring structure including a power supply layer and a GND layer, there is a problem that the manufacturing cost is high and the memory card is expensive.

Further, as the capacity of the RAM mounted on the memory card increases, the wiring density of the printed wiring board increases, and when the signal wiring and the GND wiring are arranged close to each other, noise is generated in the signal wiring. Occurs and the operation reliability of the memory card deteriorates.

An object of the present invention is to provide a technique capable of reducing the manufacturing cost of a thin semiconductor integrated circuit device such as a memory card.

Another object of the present invention is to provide a technique capable of improving the operational reliability of a thin semiconductor integrated circuit device such as a memory card.

Another object of the present invention is to provide a technique capable of easily realizing an electrostatic breakdown preventing structure for a thin semiconductor integrated circuit device such as a memory card.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0011]

The typical ones of the inventions disclosed in the present application will be outlined below.

In the semiconductor integrated circuit device of the present invention, the printed wiring board on which the LSI package is mounted is housed in a conductive casing, and the GND pin of the LSI package mounted on the printed wiring board and the casing are connected via a conductive member. Electrical connection.

Further, the semiconductor integrated circuit device of the present invention is L
An LSI in which a printed wiring board mounted with an SI package is housed in a conductive housing and mounted on the printed wiring board.
The GND pin of the package and the housing are directly connected.

[0014]

According to the above-mentioned means, the GND line is reinforced by utilizing the housing for accommodating the printed wiring board as the GND plate, and the GND layer of the printed wiring board becomes unnecessary.

As a result, the number of wiring layers of the printed wiring board can be reduced and the manufacturing cost can be reduced. Also,
It is possible to prevent noise from being generated in the signal wiring.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view of a memory card according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a main part of FIG.

As shown in FIG. 1, the memory card 1a of this embodiment has a printed wiring board 3 having a plurality of LSI packages 2 mounted on both sides. The printed wiring board 3 has a multilayer wiring structure in which a signal layer and a power supply layer are provided on a synthetic resin substrate such as polyimide, and is connected to a connector 5 via a connection pin 4 provided at one end thereof.

The LSI package 2 is, for example, TSO.
P (Thin Small Outline Package), in which a semiconductor chip forming a memory LSI such as DRAM or SRAM is sealed.

The printed wiring board 3 on which the LSI package 2 is mounted is housed inside a casing composed of a metal plate 6 such as an Al thin plate and a core 7. The metal plate 6 is bonded to the core 7 via, for example, a thermocompression bonding sheet.

As shown in the enlarged view of FIG. 2, the memory card 1a according to the first embodiment has the GND pin among the pins (leads) 8 constituting the external terminals of the LSI package 2 mounted on the printed wiring board 3. 8 (GND) is bent to the metal plate 6 side, and the tip thereof is directly connected to the back surface of the metal plate 6.

To assemble this memory card 1a,
First, the LSI package 2 in which the GND pin 8 (GND) is previously bent in the opposite direction is surface-mounted on the printed wiring board 3, then the printed wiring board 3 is connected to the connector 5, and then inserted into the core 7, and finally. , Metal plate 6
Is thermocompression bonded to the core 7. At this time, a solder paste is previously applied to the GND pin 8 (GND) and the back surface of the metal plate 6, and the temperature at which the metal plate 6 is thermocompression bonded to the core 7 is set to the melting temperature of the solder (about 200 ° C.). ) To G
The ND pin 8 (GND) is soldered to the back surface of the metal plate 6.

As described above, the memory card 1 of the first embodiment
According to a, the GND pin 8 (GN
By directly connecting D) to the back surface of the metal plate 6, an electrostatic breakdown preventing structure can be easily realized.

Further, by using the metal plate 6 which is a part of the housing as a GND plate, the GND line is reinforced, and the GND layer of the printed wiring board 3 becomes unnecessary.
This reduces the number of wiring layers of the printed wiring board 3,
Since the manufacturing cost can be reduced, the memory card 1a can be provided at low cost.

Further, since the printed wiring board 3 can be thinned by reducing the number of wiring layers of the printed wiring board 3, the thinning of the memory card 1a can be promoted.

Further, since the GND layer of the printed wiring board 3 can be omitted, noise is not generated in the signal wiring even if the wiring density of the printed wiring board 3 is improved, so that the memory card 1a can be made highly reliable and high performance. Can be realized.

(Embodiment 2) FIG. 3 is a sectional view of a memory card according to an embodiment of the present invention, and FIG. 4 is an enlarged sectional view of a main part of FIG.

The memory card 1b of the second embodiment shown in FIG.
Is a GND pin 8 (GND pin) of the LSI package 2 mounted on the printed wiring board 3, as shown in FIG.
D) Solder one end of the metal spring 9 to the spring 9
By contacting the other end of the metal plate 6 with the back surface of the metal plate 6, the GND pin 8 (GND) and the metal plate 6 are electrically connected.

The spring 9 is not limited to the U-shape as shown in FIG. 4, but any shape can be used.

According to the memory card 1b of the second embodiment,
The same effect as that of the first embodiment can be obtained.

(Embodiment 3) FIG. 5 is a sectional view of a memory card according to an embodiment of the present invention, and FIG. 6 is an enlarged sectional view of an essential part of FIG.

A memory card 1c of the third embodiment shown in FIG.
Is a GND pin 8 (GND pin) of the LSI package 2 mounted on the printed wiring board 3, as shown in FIG.
A conductive rubber-like elastic body 10 is adhered to D), and the GND pin 8 (GND) and the metal plate 6 are electrically connected via the rubber-like elastic body 10.

The rubber-like elastic body 10 is not limited to the elliptical shape as shown in FIG. 4, and various shapes can be used.

According to the memory card 1c of the third embodiment,
The same effects as those of the first and second embodiments can be obtained.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

The means for electrically connecting the GND pin of the LSI package to the metal plate is not limited to the spring (Example 2) or the rubber-like elastic body (Example 3), but various conductive members such as flexible wiring. Is available.

The present invention is not limited to a memory card, but can be widely applied to various semiconductor integrated circuit devices in which a printed wiring board on which an LSI package is mounted is housed in a thin casing.

[0038]

The effects obtained by the typical ones of the inventions disclosed in this application will be briefly described as follows.
It is as follows.

According to the present invention, it is possible to easily realize an electrostatic breakdown preventing structure for a thin semiconductor integrated circuit device.

According to the present invention, the GND line of the thin semiconductor integrated circuit device can be strengthened.

According to the present invention, a thin semiconductor integrated circuit device can be provided at low cost.

According to the present invention, thinning of a thin semiconductor integrated circuit device can be promoted.

According to the present invention, high reliability and high performance of a thin semiconductor integrated circuit device can be realized.

[Brief description of drawings]

FIG. 1 is a sectional view of a memory card according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the memory card shown in FIG.

FIG. 3 is a sectional view of a memory card according to another embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view of a main part of the memory card shown in FIG.

FIG. 5 is a sectional view of a memory card according to another embodiment of the present invention.

6 is an enlarged cross-sectional view of a main part of the memory card shown in FIG.

[Explanation of symbols]

 1a to 1c Memory card 2 LSI package 3 Printed wiring board 4 Connection pin 5 Connector 6 Metal plate 7 Core 8 Pin (lead) 8 (GND) GND pin 9 Spring 10 Rubber-like elastic body

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 25/10 25/11 25/18

Claims (5)

[Claims] 1. A semiconductor integrated circuit device in which a printed wiring board on which an LSI package is mounted is housed in a thin housing, wherein at least a part of the housing is made of a conductive material, and the printed wiring board is mounted on the printed wiring board. A semiconductor integrated circuit device characterized in that a GND pin of a mounted LSI package and the case are electrically connected via a conductive member. 2. The semiconductor integrated circuit device according to claim 1, wherein the conductive member is made of a rubber-like elastic body. 3. The semiconductor integrated circuit device according to claim 1, wherein the conductive member is a spring. 4. A semiconductor integrated circuit device in which a printed wiring board on which an LSI package is mounted is housed in a thin housing, wherein at least a part of the housing is made of a conductive material, and the printed wiring board is mounted on the printed wiring board. A semiconductor integrated circuit device characterized in that a GND pin of a mounted LSI package is directly connected to the casing. 5. The semiconductor integrated circuit device according to claim 1, which is a memory card.