JPS6022433B2 - Shield package for magnetic bubble device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shield package for a magnetic bubble device, and aims to improve the magnetic shielding effect and reduce crosstalk noise between terminals of each system.

FIG. 1 is a perspective view of a secondary dual line (dM1inli ship) type magnetic bubble device package;
Figure A is a perspective view of the magnetic shielding case used in the same package, in an exploded state and in an assembled state. 1
, 2 are upper and lower magnetic shield cases, which are formed by bending magnetic plates into a U-shape.

When used, they are assembled so as to face each other as shown in Figure 2, so that both side plates 11 and 21 and 12 and 22 overlap each other, and the unit 3 of the magnetic bubble device is housed therein. The unit 3 consists of a plane on which a magnetic bubble chip is mounted, a permanent magnet for generating a bias magnetic field, and a coil for generating a rotating magnetic field. Terminals 4 connected to the plane are drawn out in a dual line form from the side of the shield case where there is no side plate. Such a shield case provides magnetic shielding between the magnetic bubble device and the outside, but in order to enhance the shielding effect, it is necessary to couple the cases 1 and 2 so that the magnetic resistance is small.

Therefore, countermeasures have been taken, such as increasing the plate thickness of the shield case, but because there are gaps between the side plates 11 and 21 and between 12 and 22, sufficient effects cannot be obtained. In addition, since the lead terminals are arranged in two consecutive rows, the sense terminal in particular picks up noise from adjacent coil drive terminals and gate terminals, reducing the S/N ratio of the output signal. There are negative effects of doing so. The present invention solves these problems all at once, improves the magnetic shielding effect between the inside and outside of the magnetic bubble diaphragm unit, and reduces crosstalk noise between the sense system, gate system, and coil drive circuits. It is.

For this reason, the present invention provides overlapping parts of side plates on sides where conventional side plates did not exist, but explores a configuration in which window holes for terminals are formed on both sides of the side plate as a boundary, and mutually Terminals that are susceptible to interference are pulled out with the side panel as the boundary. FIG. 3 is a perspective view of the assembled magnetic shield case according to the present invention.

In the case of the present invention, the upper and lower cases 1 and 2 have side plates 11 and 12,
Side plates 13, 14, 23, and 24, which overlap each other when assembled, are also formed by bending on two other sides of the sides 21 and 22. A window hole for drawing out the lead terminal is required, but this window hole can be made by partially arranging the side plates 13, 23, 14, and 24 in the middle of the sides, so that window holes A and B are formed on both sides of the side plates 13, 23, 14, and 24.
, a, and b. When a magnetic bubble device unit is housed in a shield case and the terminals are pulled out, the terminals that need to avoid crosstalk noise between them should be
Pull out through separate window holes.

FIGS. 4 and 5 are plan views illustrating terminal distribution to each window hole A, B, a, and b. In FIG. 4, sense terminals 5, 5' and gate terminals 6, 6' are arranged in windows B, b, and drive coils 7, 7' are arranged in other windows A, a. Normally, the current flowing through the drive coil for generating the rotating magnetic field is large and becomes a source of noise in the sense system and gate drive system.
7' only, sense terminals 5, 5' and gate terminals 6, 6'
It is best to pull it out from a separate window A, a. That is, since there are side plates 13, 23, 14, 24 of the shield case between the coil terminals 7, 7' and other terminals, crosstalk between the coil terminals and other terminals is blocked. Ru. In addition, if the sense system is also subject to noise interference from the gate system, use windows B and b as shown in Figure 5.
It is preferable to arrange only the sense terminals 5, 5' independently, and to draw out the gate terminals 6, 6' and the coil terminals 7, 7' from the same windows A, a.

In this way, the side plates 13, 23, 14 of the shield case,
24 is partially formed in the middle of the side, and terminal draw-out windows are provided separately on both sides, thereby reducing crosstalk noise between circuits having different functions.

At the same time, the side plates 13 and 23, 14 and 24 make the magnetic coupling between the upper and lower shield cases 1 and 2 closer and reduce magnetic resistance, thereby improving the shielding effect between the inside and outside. In particular, the side plates 13, 23, 14, 2 also serve as window hole divisions.
4 in the middle of the sides, the distance d from the center of the bubble chip to these side plates is smaller than the distance D from other conventional side plates 11, 21, 12, and 22. Therefore, a disturbance magnetic field that attempts to act on the center of the built-in chip flows through the side plates 13, 23, 14, and 24 at the shortest position and is shielded. This significantly improves the magnetic shielding effect between the inside and outside of the magnetic bubble bag, and is particularly effective in a single-chip magnetic bubble device with a small number of terminals. Although the illustrated example is an example implemented in a dual in-line type package, a package having terminals on four sides is also applicable. In this case, it is preferable that the side plates on the two shorter sides are also provided in the middle of the sides.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a conventional dual-in-line magnetic bubble device package, and Figure 2 (A) is a perspective view of the magnetic shielding case used in the package in an exploded state and a roughly assembled state. It is. FIG. 3 is a perspective view of a state in which the magnetic shield case according to the present invention is combined, and FIGS. 4 and 5 are plan views illustrating terminal distribution to each terminal extraction window hole. In the figure, 1, 2
is the shield case, 11...14, 21...24 is the side plate, A
, B, a, b are terminal extraction window holes, 5, 5' are sense terminals, 6, 6' are gate terminals, and 7, 7' are drive coil terminals. Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. In a magnetic shield case assembled so that the openings of two shield cases having a U-shaped cross section face each other and the side plates of each shield case overlap each other, the overlapping portions are formed on four sides, and the lead terminals are pulled out. A magnetic bubble characterized in that one side of the window hole for the magnetic bubble is divided into a plurality of parts by the overlapping portion, and lead terminals to be prevented from interfering with each other are drawn out from the separate window holes. Device.