JPS63209895A - Structure of memory card - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to the structure of a memory card, in which a metal plate is used for the outer case, and in particular, the electrodes of an electronic circuit and the metal plate are electrically connected to The present invention relates to a memory card structure that reduces circuit ff power line impedance and improves the shielding effect against external noise to the card.

[Prior Art] In the conventional structure of a memory card, an electronic circuit is formed on a printed circuit board, and one or both sides of the electronic circuit are sealed with resin using a plastic plate. In addition, recently, there has been a market need for high-capacity, thin cards, so conventional cards have thinner substrates on which electronic circuits are formed, and it is necessary to pattern many signal lines on a limited substrate size. For this reason, the power supply lines of electronic circuits are sacrificed to the signal lines, and a sufficient power line pattern width cannot be secured, resulting in the power supply patterns becoming thinner.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, the power source impedance increases due to the insufficient power supply pattern of the electronic circuit, resulting in malfunction due to noise etc. and lack of margin in AC characteristics for high-speed operation. It also has the problem of being vulnerable to external noise. Therefore, the present invention is intended to solve these problems, and its purpose is to use a metal plate instead of a plastic plate to
The object of the present invention is to provide a means for electrically connecting at least one electrode with the metal plate at at least one point or more, thereby reducing power source impedance and cutting external noise through the shielding effect of the metal plate.

[Means for Solving the Problems] The structure of the memory card of the present invention is such that in a memory card in which an electronic circuit is formed between a pair of metal plates or an electronic circuit is formed on only one metal plate, Insert an insulating plate between the and the electronic circuit.

Among the electrodes of the electronic circuit, at least one electrode is electrically connected to the metal plate at at least one location.
Features PG.

Although it is desirable that the metal plate used in the present invention has particularly low sheet resistance per unit area, it is not limited to a specific metal plate.

[Function] According to the above configuration of the present invention, the impedance of the power supply line is reduced by connecting the power supply line of the electronic circuit with the metal plate of the exterior at least one point, and the electric potential of the metal plate is It has the same potential as the circuit electrode, increasing the shielding effect.

[Example] Figure 181 is a cross-sectional view of an example of the present invention, and 3
is the electronic circuit board, 4 is the signal line of the board, 5 is the power line of the board, 7 is the electronic parts such as ICs, capacitors, and resistors mounted on the board, and the electronic circuit is formed by 3°4.5.7. ing. The embodiment of FIG. 1 shows a case where seven electronic components are mounted on one side. in this case,
7 electronic components use surface mount technology (
It is mounted using SMT), and the height of the parts is also low.

The electronic component 7 makes a hole in the insulating plate 2 which is insulated from the metal plate 1, and the metal spring 6 connects the metal plate 1 to the power line of the board 5. Also, on the side 7 where no electronic components are provided, the power line of the board 5 and the metal plate 1 are made electrically conductive using the same method as above. Also, use the pie 7 holes of 8 on the electronic circuit board of 3, and connect both of the metal plates of 1 to 6.
Use a metal spring to create continuity.

[Effects of the Invention] As described above, according to the present invention, by using a metal plate for the exterior of the memory card, at least one electrode of the metal plate of the exterior and the electrode of the electronic circuit can be connected to the metal plate. By making at least one point electrically conductive,
It can reduce the power supply impedance of electronic circuits,
For high-speed operation, malfunctions due to noise etc. are eliminated, and A
This has the effect of considerably improving the margin of C characteristics.

Furthermore, since the exterior is made of a metal plate and is electrically connected to the electrodes of the electronic circuit, the shielding effect is increased and external noise from the card is cut.

[Other Usage Methods and Other Applications] In the WS1 diagram, an example has been described in which the electronic component 7 is mounted on one side, but in an electronic circuit consisting of 3, 4, and 5. The components may be mounted on both sides of the substrate, which is 3°4.5.

Further, in FIG. flS1, an embodiment is shown in which the metal plates l are a pair and are located on both sides, but of course they may be located only on one side.

On the other hand, in the cross-sectional view of the embodiment shown in Figure ff11, both of the pair of insulating plates l have the same potential as one electrode of the electronic circuit, but the upper side of the metal plate l has the same potential as the positive electrode of the electronic circuit. The lower side may be electrically connected to the negative electrode.

Also, in the pR1 diagram, the power line of the board 5 is connected to 3.
If this is not possible on the electronic circuit board consisting of 4.5, power may be supplied from the metal plate 1 through the metal spring 6.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. ff11 is a sectional view showing an embodiment of the memory card of the present invention. 1...Metal plate 2...Insulating plate 3...Electronic circuit board 4...Signal line of the board 5...Power line of the board 6...Metal spring 7...Electronic component 8...Via hole or above Applicant: Seiko Epson Co., Ltd. Representative Patent Attorney Tsutomu Mogami and 1 other person'1. -1・′ Figure 1

Claims (1)

[Claims] In a memory card in which an electronic circuit is formed between a pair of metal plates, or an electronic circuit is formed on only one metal plate,
A memory characterized in that an insulating plate is inserted between the metal plate and the electronic circuit, and at least one electrode of the electrodes of the electronic circuit is electrically connected to the metal plate at at least one location. Card structure.