JPS5880184A - Magnetic bubble memory device - Google Patents

Abstract

PURPOSE:To realize a high-speed working of a magnetic bubble memory device, by generating a magnetic field due to a reflection effect and by using the surface or entire part of a memory chip holding substrate as a conductor and then shielding the magnetic field by covering a driving coil set at the opposite side to the memory chip holding surface with the conductor. CONSTITUTION:A metallic conductor layer is provided on the surface of a substrate 3, and a memory chip is mounted on the substrate 3. Then an X-direction coil 9 and a Y-direction coil 8 are attached to the memory chip holding surface in order to generate a magnetic field in a metallic plate 10. Thus the bubble is driven. Furthermore a driving coil set at the opposite side to the memory chip holding surface is covered with a conductor 15. Thus the magnetic field of the opposite side is shielded. In such way, a high-speed working is possible without increasing the voltage to be applied to the driving coil.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a magnetic pull memory device that enables high-speed driving of an exhaust bubble.

(2) Prior art and problems A magnetic bubble memory chip (hereinafter referred to as a memory chip) that functions as a memory element in a magnetic bubble memory device is mounted on a printed wiring board, and a drive coil is attached and wound around it to provide a drive magnetic field. It is composed of ゛.

FIG. 1 is a front view of the board, and FIG. 2 is a perspective view of the board with the printed wiring pattern omitted.

The memory chip 1 is fixed to the center part 4 of the substrate 3 having a deep notch 2 using adhesive.
The first terminal is bonded to a printed wiring 5 provided on the substrate 3 at a bonding pad 6.

Here, the conventional substrate 3 is made of an inorganic material such as alumina porcelain or a polymeric material such as glass epoxy or polyimide, and a single-layer or multi-layer paulownia coating is applied thereon. The forest 5 has a structure in which it is welded to a lead terminal of a package (not shown) at the terminal s7 on the end surface of the board. This is for inserting a coil in the X direction to provide a driving magnetic field. ◎ Figures 3 and 4 show the process of installing the driving coil on the board 3. Figure 3 shows the coil that has been wound in advance. Figure 4 shows a Y-direction coil 8 attached to the center of the heavy plate 3 on which the memory chip l is mounted. Place the X-direction coil 9 on top of the direction coil 8 to form a round shape II
This is a w diagram.

Now, the Y-direction coil 8 and the X-direction coil 9Fi are installed perpendicularly in this way and are connected to the external coil driver Ig1kI through the package layered lead terminal to form a rotating magnetic field that moves the magnetic bubble. It is configured as follows.

Here, the operating frequency conventionally given to the drive coil is 1.
00KHz, but in order to drive the magnetic bubble (hereinafter referred to as bubble) at high speed, the operating frequency is set to -200KH, for example.
When the trench increases to more than g, the drive coil actance increases and becomes K when driven at 100KHz.

So, in order to obtain the required voltage with the conventional voltage value (
This is good for making the coil smaller, but it is impossible to do this unless you use an existing board, and the winding of the coil is too small! In order to equalize the numbers, it is necessary to increase the current value to obtain the necessary magnetic field, which is restricted in terms of heat generation, and neither method can be said to be practical.

(3) Purpose of the Invention The present invention enables high-frequency operation (t-TI) without changing the voltage value using a conventional drive coil, and thereby increases the speed of a server-pull memory device. It is something that can be achieved.

(4) Structure of the Invention The present invention generates a magnetic field due to the reflection effect by making the surface or the entire surface of the memory chip mounting board a conductor, and uses this to obtain the required magnetic field and improve the memory chip mounting surface. By wrapping the drive coil on the opposite side with a conductor, the serial actance is reduced by approximately half.

The refraction effect used in the present invention can be achieved by, for example, providing a conductor layer made of gold (i) on the surface of the substrate 30 in FIG. If you want to create an obtuse image of the directional coil 8 (the magnetic field produced by this), it is necessary to mount the memory chip on a substrate with a conductive layer instead of the conventional insulating substrate. be.

Figures 5 and 6 are cross-sectional views of examples of bubble memory devices using such substrates. The substrate used in the example of Figure 5 is a metal plate made of aluminum or copper. The surface of 100 is coated with heat-resistant resin 11 such as polyimide or polysiloxane, and printed wiring is printed on this to form a substrate.A mesori chip is mounted on the center of this substrate, and the rest is carried out in the same manner as before. The Y-direction coil 8 and the X-direction coil 9 are inserted in a similar manner to form an element having an appearance similar to that shown in FIG.

In this embodiment having the structure shown in FIG.
In this embodiment, the Y-direction coil 8 and the X-direction coil 9 on this surface Jj) are the reflection surface, and an image is generated in the metal plate 10, and these magnetic fields are reflected in the memory chip 1. Join us to drive the puzzles in this.

Next, in the case of Fig. 6, the substrate 12 is made of alumina, which is the same as before.
Although it is made of an insulating material such as polyimide, there is a conductive layer 13 made of a conductive film such as copper or silver on the upper layer, and an insulating layer 14 is formed on top of this using the same material as the substrate to form a printed wiring board. It consists of

In this embodiment, the upper surface of the conductor layer 13 is a reflection surface, and the crane images of the X-direction coil and the Y-direction coil are formed in the substrate 12 made of an insulating material.

Now, the direction of the magnetic field generated by the reflection effect is symmetrical to the direction caused by the original coil, and in order to be added to the memory nap mounted on the board, it is Contribution by coil and #1
It feels so hometown.

Next, in order to reduce the increase in flux actance when used at high frequencies, it is sufficient to shield the magnetic field on the back side of the substrate, and this can be done by covering the back side of the substrate with a conductor.

In the embodiments of FIGS. 5 and 6, copper foil 15 is used to wrap coils 8.9 on the bottom surfaces of substrates 10, 12.

By adopting this method, the magnetic field due to the coils 8 and 9 on the lower surface is shielded, and the reactance can be reduced to 1/2.

It should be noted that the shielding conductor may be provided electrically floating as in this embodiment, but it is advantageous in terms of noise countermeasures if it is connected to the substrate flexion conductor.

(5) Effects of the Invention The present invention provides that when a bubble memory device conventionally used at an operating frequency of 100 KHz is operated at a higher speed, the reactance of the drive coil increases. Although it is necessary to increase the voltage value applied to the drive coil, it is necessary to increase the voltage value applied to the drive coil by implementing the present invention, which uses the reflection effect to shield the magnetic field on the side opposite to the memory chip. We were able to achieve a speed increase of 200KHz without any problems.

[Brief explanation of drawings]

Figure 1 is a front view of the board on which the magnetic bubble memory chip is mounted, and Figure 2 is the f! Figure 43 shows the state in which the Y-direction coil is attached to the board, and Figure 41 shows the state in which the X-direction coil is attached to it. 1I7T er 1 structure. In the figure, l is a magnetic memory chip, 3-stroke board, 8 is a Y-direction coil,
9 pieces of X direction coil, 1o is gold b&, 11 is heat resistant resin,
12 is a thin board, 13 is a conductive layer, 14 is an insulating layer, and 15 is a single foil. Fig. 1 Fig. 5 Fig. 12 Fig. 4 Fig. 6 Fig. h

Claims (1)

[Claims] (1) A magnetic bubble formed by mounting and mounting a magnetic bubble memory chip in the center of a printed wiring board, and then attaching an X-direction coil and a Y-direction coil around the chip to form a magnetic bubble drive coil. A magnetic bubble memory device characterized in that a conductor layer is provided on the substrate on which the chip is mounted, and a drive coil (shielded using a conductor) on the back side of the substrate.