JPH04205991A - Portable storage device - Google Patents

Abstract

PURPOSE:To improve the noise resistant amt. by changing an external metal panel and impedance for a GND pattern of an interior wiring substrate in exchanging panel GND connecting holders. CONSTITUTION:The wiring substrate 3 packaged with a connector 2 to be electrically connected to an external device and a semiconductor storage element 1 is fixed to a resin molded frame, and the panel GND connecting holder 7 for electrically connecting the metal panel 5 fixedly connected with this frame and prescribed wiring of the wiring substrate 3 is freely attachably and detachably mounted to the frame 4. Consequently, the panel GND connecting holder 7 fitted with a panel GND short-circuited electrode 8 or the panel GND connecting holder 7 without being fitted with the panel GND short-circuited electrode, etc., can be used by change, and the wiring of the wiring substrate 3 and impedance of the metal panel 5 can easily be changed over. By this method, a system having a high resistant amt. can be obtained at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a portable storage device incorporating a semiconductor storage element with improved resistance to external noise.

[Conventional technology]

FIG. 4 shows a conventional portable storage device of this kind. In the figure, 1 is a semiconductor memory element, 2 is a connector, 3 is a wiring board on which the semiconductor memory element 1 and connector 2 are mounted, and 4 is a wiring board. A resin molded frame for fixing 3.
5 is a metal panel adhesively fixed to the resin molded frame 4;
Reference numeral 6 denotes a panel-GND conduction spring for electrically connecting the GND (ground) pattern of the wiring board 3 and the metal panel 5.

When this conventional portable storage device is connected to an external device (not shown) and a statically charged human body pulls out the portable storage device from the external device, static electricity is applied to the metal panel 5 as external noise, causing electrostatic discharge. Occur. The static electricity applied to the metal panel 5 flows through the GND pattern of the wiring board 3 via the panel/GND conduction spring 6, through the GND terminal of the connector 2, and into the GND terminal of the external device. At this time, the impedance of the GND pattern on the external device side may not be low enough, and the GND level of the external device may fluctuate due to electrostatic discharge current, causing malfunction of the external device.
In some cases, the electrostatic discharge resistance may be increased.

[Problem to be solved by the invention]

As described above, in the conventional portable storage device, the necessity of the panel/GND continuity spring 6 was determined after a combination test with external equipment. Since the device is built into a resin molded frame 4 constituting the device and sealed with a metal panel 5, it is impossible to attach or detach it from the outside, which poses problems such as the possibility that it cannot be used in common with different external devices.

This invention was made to solve such problems, and an object of the present invention is to obtain a portable storage device in which the connection between the metal panel 5 and the wiring board 3 to GND can be easily switched from the outside. .

[Means to solve the problem]

In the portable storage device according to the present invention, a connector electrically connected to an external device and a wiring board on which a semiconductor memory element is mounted are fixed to a frame, and a metal panel provided on the frame and a predetermined part of the wiring board are fixed to the frame. A connection holder that electrically connects to the wiring is detachably attached to the frame.

[Effect]

The connection holder in this invention connects the metal panel and the predetermined wiring of the wiring board, and is configured to be detachably attached to the frame, so that it is possible to improve the electrical connection and impedance between the wiring of the wiring board and the metal panel. can be easily switched, and a system with high noise tolerance can be realized at low cost.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

That is, in FIG. 1, 7 is a removable panel/GND connection holder that is assembled and fixed in the resin molded frame 4;
is attached to the inside of the panel/GND connection connection holder, and is used to electrically short-circuit the GND pattern of the metal panel 5 and the wiring board 3 when the holder 7 is connected to the resin molded frame 4. It is an electrode. The rest of the configuration is the same as the conventional one shown in FIG. 4, so the explanation will be omitted.

With this configuration, static electricity applied to the exterior metal panel of the portable storage device while connected to an external device (not shown) is removed through the wiring through the panel, the panel attached to the GND connection holder, and the GND shorting electrode. It flows into the GND pattern on the board, and flows into the GND pattern of the external device via the GND terminal of the connector. Depending on the external device, the impedance of the GND pattern is high, so a slight electrostatic discharge current may cause the GND potential to fluctuate, causing the external device to malfunction.
In some cases, the static electricity resistance may be improved without the GND shorting electrode. In such a case, the electrostatic resistance can be improved by replacing the panel with a panel without a GND connection electrode or a GND connection holder as shown in FIG.

In this embodiment, only the case where the GND patterns of the exterior metal panel 5 and the internal wiring board 3 are short-circuited or opened by replacing the panel/GND connection connection holder internally has been described. Panel GN as shown
By using a holder in which an electrode 8 to which a resistor 9 and a capacitor 10 are connected in parallel is attached inside the D-connection holder, a system with higher noise tolerance can be realized.

〔Effect of the invention〕

As described above, in the portable storage device according to the present invention, the impedance for the GND pattern of the exterior metal panel and the internal wiring board can be easily switched by replacing the panel GND connection holder, and the portable storage device is connected. By determining the optimal panel-to-GND IFimpedance according to the external equipment, a system with higher noise tolerance can be realized at a lower cost.

[Brief explanation of the drawing]

FIG. 1 is a perspective view and a sectional view of a main part showing one embodiment of the present invention, FIGS. 2 and 3 are a sectional view of a main part showing another embodiment of the invention, and FIG. 4 is a conventional 1 is a perspective view of this type of portable storage device and a cross-sectional view of a main part thereof; FIG. In the figure, 1 is a semiconductor memory element, 2 is a connector, 3 is a wiring board, 4 is a resin molded frame, 5 is a metal panel, and 7 is a panel/GND connection holder. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] A wiring board on which a connector electrically connected to an external device and a semiconductor memory element are mounted, a frame that fixes this wiring board, a metal panel that is fixed to this frame, and a predetermined wiring of this metal panel and the wiring board. A portable storage device with a removable connection holder for electrical connection.